586 results on '"Zhou, HX"'
Search Results
2. Deposition behavior and bonding mechanism during cold spraying of Ti6Al4V on different substrates
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Zhou, HX, Jiang, SW, Li, XT, and Li, CX
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- 2022
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3. By Increasing the Expression and Activation of STAT3, Sustained C5a Stimulation Increases the Proliferation, Migration, and Invasion of RCC Cells and Promotes the Growth of Transgrafted Tumors
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Zheng JM, Zhou HX, Yu HY, Xia YH, Yu QX, Qu HS, and Bao JQ
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c5a ,c5ar1 ,renal cell carcinoma ,stat3 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
Jing-Min Zheng,1,* Han-Xi Zhou,1,* Hong-Yuan Yu,1,* Yu-Hui Xia,2 Qing-Xin Yu,2 Hang-Shuai Qu,1 Jia-Qian Bao1 1Department of Urology, Taizhou Hospital, Wenzhou Medical University, Linhai, Zhejiang, People’s Republic of China; 2Department of Pathology, Taizhou Hospital, Wenzhou Medical University, Linhai, Zhejiang, People’s Republic of China*These authors contributed equally to this work.Correspondence: Jing-Min ZhengDepartment of Urology, Taizhou Hospital, Wenzhou Medical University, 150 Ximen Road, Linhai, Zhejiang, 317000, People’s Republic of ChinaTel +86-576-85133065Fax +86-576-85199800Email zhengjingmin@enzemed.comBackground: Contradictive results about the direct role of C5a/C5aR1 axis in different cancer cells have been reported. The direct effect of C5a on human renal cell carcinoma (RCC) cells and the underlying mechanism are not clear. The aim of this study is to investigate the role of C5a/C5aR1 axis in RCC cells and its working mechanism.Methods: RCC cells were infected with lentivirus Lenti-C5a, which was designed to over-express secretory C5a in the cells, or directly treated with recombinant C5a, the influence of these treatments in the cells and the underlying mechanism were explored.Results: Transfection of RCC cells with Lenti-C5a markedly increased the production of C5a and significantly increased the proliferation, migration, and invasion of RCC cells, but direct addition of C5a to the cell culture medium had no such effects though it indeed induced a transient intracellular calcium rise. RCC cells were found to express carboxypeptidase D and M, which reportedly to inactivate C5a. Also, the RCC cells stably transfected with Lenti-C5a produced larger transgrafted tumors in nude mice compared with the non-transfected or control virus transfected cells. In addition, over-expression of C5a significantly increased the expression and phosphorylation of STAT3 as well as the phosphorylated JNK level. Furthermore, the effect of C5a over-expression on RCC cells’ proliferation, migration, and invasion could be blocked by Stattic, a STAT3-specific inhibitor.Conclusion: Chronic over-activation of C5a/C5aR1 axis could directly increase RCC cells’ proliferation, migration, and invasion and thus contribute directly to the progression of the disease. Over-activation of STAT3 pathway is among the underlying mechanism.Keywords: C5a, C5aR1, renal cell carcinoma, STAT3
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- 2021
4. Reduced Vitamin D Levels are Associated with Stroke-Associated Pneumonia in Patients with Acute Ischemic Stroke
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Huang GQ, Cheng HR, Wu YM, Cheng QQ, Wang YM, Fu JL, Zhou HX, and Wang Z
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acute ischemic stroke ,stroke-associated pneumonia ,vitamin d. ,Geriatrics ,RC952-954.6 - Abstract
Gui-Qian Huang,1,* Hao-Ran Cheng,1,* Yue-Min Wu,1 Qian-Qian Cheng,2 Yu-Min Wang,3 Jia-Li Fu,3 Hui-Xin Zhou,3 Zhen Wang1 1Department of Neurology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang, People’s Republic of China; 2School of Mental Health, Wenzhou Medical University, Wenzhou 325000, Zhejiang, People’s Republic of China; 3Department of Laboratory Medicine, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang, People’s Republic of China*These authors contributed equally to this workCorrespondence: Zhen WangDepartment of Neurology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou 325000, Zhejiang, People’s Republic of ChinaTel +86 577-555780166Fax +86 577-55578033Email wangzhen_wenzhou@163.comBackground and aim: Stroke-associated pneumonia (SAP) is a common complication in patients with acute ischemic stroke (AIS). This study explored the potential relationship between serum vitamin D levels and SAP.Methods: This study recruited 863 consecutive AIS patients. In-hospital SAP was defined as a complication that occurred after stroke, during hospitalization, that was confirmed radiographically. Serum vitamin D levels were measured within 24 hrs of admission and the patients were divided into vitamin D sufficient (>50 nmol/L), insufficient (25–50 nmol/L), and deficient (Results: In this study, 102 (11.8%) patients were diagnosed with SAP. Compared to the patients without SAP, patients with SAP had significantly lower vitamin D levels (P = 0.023). The incidence of SAP was significantly higher in patients with vitamin D deficiency than in those with vitamin D insufficiency or sufficiency (21.2% vs 16.2% & 9.5%, P = 0.006). After adjusting for confounders, vitamin D deficiency and insufficiency were independently associated with SAP (OR = 3.034, 95% CI = 1.207–7.625, P = 0.018; OR = 1.921, 95% CI = 1.204–3.066, P = 0.006, respectively). In multiple-adjusted spline regression, vitamin D levels showed a linear association with the risk of SAP (P < 0.001 for linearity).Conclusion: Reduced vitamin D is a potential risk factor of in-hospital SAP, which can help clinicians identify high-risk SAP patients.Keywords: acute ischemic stroke, stroke-associated pneumonia, vitamin D
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- 2019
5. Effect of gas temperature on the interfacial bonding of cold-spray additive-manufactured Ti6Al4V
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Zhou, HX, primary, Li, ZJ, additional, and Jiang, SW, additional
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- 2023
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6. Epidemiology of worldwide spinal cord injury: a literature review
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Kang Y, Ding H, Zhou HX, Wei ZJ, Liu L, Pan DY, and Feng SQ
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spinal cord injury ,etiology ,incidence ,patients demographics ,complications ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Yi Kang,1,2,* Han Ding,1,2,* Hengxing Zhou,1,2 Zhijian Wei,1,2 Lu Liu,1,2 Dayu Pan,1,2 Shiqing Feng1,2 1Department of Orthopaedics, Tianjin Medical University General Hospital, 2Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, People’s Republic of China *These authors contributed equally to this work Study design: A literature review of worldwide epidemiology of spinal cord injury (SCI). Objectives: To review the epidemiological indicators of SCI, such as incidence, prevalence, demographic characteristics, etiology, level and severity of injury, complications and mortality. Setting: The Department of Orthopaedics, Tianjin Medical University General Hospital, Heping District, Tianjin, People’s Republic of China. Methods: We searched articles published in PubMed, Medline, EMBASE and the Web of Science between January 1993 and June 2017 using the key words “spinal cord injury”, “traumatic spinal cord injury”, “non-traumatic spinal cord injury” and “epidemiology”. The incidence, etiology, prevalence, patient demographics, level and severity of injury, complications and mortality were reviewed from the articles. Results: The epidemiology of SCI has changed. Motor vehicle accidents and falls have become the most common reasons of injury gradually. Incidence of SCI varies by regions or countries, and it has gradually increased with the expansion of human activities. The number of male patients were significantly more than female, the average age of patients with SCI had a tendency to increase gradually. The cervical level of spine was the most common part of injury; there were more number of patients with tetraplegia than patients with paraplegia. Electrolyte disturbances, pulmonary infections, urinary tract infections and bedsores were the four most common complications. Conclusion: We must have a greater understanding of epidemiology to implement more preventative measures. The epidemiology in different regions is of significant difference, which may be resulted from economic, science and technology, medical, geographical and even social conditions. Therefore, we must establish appropriate intervention measures according to the particularity of population. Keywords: spinal cord injury, etiology, incidence, patient demographics, complications
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- 2017
7. A rapid and highly sensitive protocol for the detection of Escherichia coli O157:H7 based on immunochromatography assay combined with the enrichment technique of immunomagnetic nanoparticles
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Qi H, Zhong Z, Zhou HX, Deng CY, Zhu H, Li JF, Wang XL, and Li FR
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Medicine (General) ,R5-920 - Abstract
Hui Qi1, Zhen Zhong1, Han-Xin Zhou1, Chun-Yan Deng1, Hai Zhu2, Jin-Feng Li2, Xi-Li Wang2, Fu-Rong Li1,31Clinical Medical Research Center, The Second Clinical Medical College (Shenzhen People's Hospital), Jinan University, 2Shenzhen Bioeasy Biotechnologies Co, Ltd, 3Shenzhen Institute of Gerontology, Shenzhen, People's Republic of ChinaBackground: Escherichia coli O157:H7 (E. coli O157:H7) is an important pathogenic bacterium that threatens human health. A rapid, simple, highly sensitive, and specific method for the detection of E. coli O157:H7 is necessary.Methods: In the present study, immunomagnetic nanoparticles (IMPs) were prepared with nanopure iron as the core, coated with E. coli O157:H7 polyclonal antibodies. These IMPs were used in combination with immunochromatographic assay (ICA) and used to establish highly sensitive and rapid kits (IMPs+ICA) to detect E. coli O157:H7. The kits were then used to detect E. coli O157:H7 in 150 food samples and were compared with conventional ICA to evaluate their efficacy.Results: The average diameter of IMPs was 56 nm and the amount of adsorbed antibodies was 106.0 µg/mg. The sensitivity of ICA and IMPs+ICA was 105 colony-forming units/mL and 103 CFUs/mL, respectively, for purified E. coli O157:H7 solution. The sensitivity of IMPs+ICA was increased by two orders, and its specificity was similar to ICA.Conclusion: The kits have the potential to offer important social and economic benefits in the screening, monitoring, and control of food safety.Keywords: colloidal gold, immunomagnetic nanoparticles, Escherichia coli O157:H7, immunochromatographic assay
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- 2011
8. Detection of micrometastases in peripheral blood of non-small cell lung cancer with a refined immunomagnetic nanoparticle enrichment assay
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Li Q, Qi H, Zhou HX, Deng CY, Zhu H, Li JF, Wang XL, and Li FR
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Medicine (General) ,R5-920 - Abstract
Qing Li1, Hui Qi1, Han-Xin Zhou1, Chun-Yan Deng1, Hai Zhu3, Jin-Feng Li3, Xi-Li Wang3, Fu-Rong Li1,21Clinical Medical Research Center, The Second Clinical Medical College (Shenzhen People's Hospital), Jinan University, Shenzhen, People's Republic of China; 2Shenzhen Institute of Gerontology, Shenzhen, People's Republic of China; 3Shenzhen Bioeasy Biotechnologies Co Ltd, Shenzhen, People's Republic of ChinaAbstract: Fe3O4 particles are currently used as the core of immunomagnetic microspheres in the immunomagnetic enrichment assay of circulating tumor cells (CTCs). It is difficult to further improve the sensitivity of CTC detection or to improve tumor cell-type identification and characterization. In the present study, we prepared immunomagnetic nanoparticles with nanopure iron as the core, coated with anti-cytokeratin 7/8 (CK7/8) monoclonal antibody. These immunomagnetic nanoparticles (IMPs) were used in conjunction with immunocytochemistry (ICC) to establish a refined immunomagnetic nanoparticle enrichment assay for CTC detection in non-small cell lung cancer (NSCLC). The assay was compared with nested reverse transcription polymerase chain reaction (RT-PCR) to detect CK19 mRNA and lung specific X protein (LUNX) mRNA. Human lung adenocarcinoma cell line A549 was used for sensitivity and specificity evaluation. Peripheral blood samples were collected from each group for CTC detection. The average diameter of the immunomagnetic nanoparticles was 51 nm, and the amount of adsorbed antibodies was 111.2 µg/mg. We could detect down to one tumor cell in 5 × 107 peripheral blood mononuclear cells. The sensitivity was consistent with that of nested RT-PCR; however, the false positive rate was significantly reduced. The modified assay combined with ICC did not differ from nested RT-PCR in sensitivity, but it had significantly increased specificity. This approach could, therefore, contribute to identification of micrometastases, re-defining clinical staging, and guiding individual postoperative treatments. The technique shows considerable potential clinical value and further clinical trials are warranted.Keywords: NSCLC, circulating tumor cells, nested RT-PCR, immunomagnetic nanoparticles, immunocytochemistry
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- 2011
9. Suppression of EGFR expression by antisense or small interference RNA inhibits U251 glioma cell growth in vitro and in vivo
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Zhou Hx, Mingzhe Qiu, Zhi-yong Zhang, Peiyu Pu, Jiang H, Guang-xiu Wang, Zhifan Jia, Chunsheng Kang, Jin Chang, and Shizhu Yu
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Cancer Research ,Genetic enhancement ,Genetic Vectors ,Gene Expression ,Mice ,chemistry.chemical_compound ,RNA interference ,Catalytic Domain ,Glioma ,Tumor Cells, Cultured ,medicine ,Animals ,Humans ,RNA, Antisense ,Epidermal growth factor receptor ,RNA, Small Interfering ,Molecular Biology ,Matrigel ,biology ,Brain Neoplasms ,Cell growth ,RNA ,Genetic Therapy ,medicine.disease ,Xenograft Model Antitumor Assays ,Molecular biology ,ErbB Receptors ,chemistry ,biology.protein ,Molecular Medicine ,RNA Interference ,Growth inhibition ,Plasmids - Abstract
Epidermal growth factor receptor (EGFR) had been reported as one of the major responsible genes for malignant progression and phenotype reversion of gliomas, and has been used as one of the most important therapeutic targets. In the present study, small interference RNA (siRNA) and antisense EGFR expression constructs, which target sequences of human EGFR catalytic domain (2400-2420) and the 3'-coding region, respectively, were used to examine the growth inhibition effects on U251 glioma cells. Cell growth was significantly inhibited and G2/M arrest was observed in antisense- and siRNA-treated groups. Matrigel matrix demonstrated spotted cell clustering pattern in antisense- and siRNA-transfected U251 cells, indicating poor cell growth activities. In addition, the tumor volumes in U251 subcutaneous mice model treated with antisense and siRNA were significantly smaller than those treated with control siRNA and phosphate-buffered saline. Also, glial fibrillary acidic protein expression was upregulated in antisense- and siRNA-treated groups than the control groups. Our results demonstrated that antisense- or siRNA-targeting intracellular region of EGFR can inhibit EGFR expression, exerted growth inhibition effect on U251 glioma cells in vitro and in vivo. Consequently, siRNA expression plasmid-mediated gene therapy would be a new strategy in treatment of gliomas.
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- 2006
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10. Data-driven docking: HADDOCK's adventures in CAPRI
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van Dijk, Aalt-Jan, de Vries, SJ, Dominguez, C, Chen, H, Zhou, HX, Bonvin, AMJJ, van Dijk, Aalt-Jan, de Vries, SJ, Dominguez, C, Chen, H, Zhou, HX, and Bonvin, AMJJ
- Abstract
We have shown previously that given high-resolution structures of the unbound molecules, structure determination of protein complexes is possible by including biochemical and/or biophysical data as highly ambiguous distance restraints in a docking approach. We applied this method, implemented in the HADDOCK (High Ambiguity Driven DOCKing) package (Dominguez et al., J Am Chem Soc 2003; 125:1731-1737), to the targets in the fourth and fifth rounds of CAPRI. Here we describe our results and analyze them in detail. Special attention is given to the role of flexibility in our docking method and the way in which this improves the docking results. We describe extensions to our approach that were developed as a direct result of our participation in CAPRI. In addition to experimental information, we also included interface residue predictions from PPISP (Protein-Protein Interaction Site Predictor; Zhou and Shan, Proteins 2001;44:336 -343), a neural network method. Using HADDOCK we were able to generate acceptable structures for 6 of the 8 targets, and to submit at least 1 acceptable structure for 5 of them. Of these 5 submissions, 3 were of medium quality (Targets 10, 11, and 15) and 2 of high quality (Targets 13 and 14). In all cases, predictions were obtained containing at least 40% of the correct epitope at the interface for both ligand and receptor simultaneously. (c) 2005 Wiley-Liss, Inc.
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- 2005
11. Data-driven docking: HADDOCK's adventures in CAPRI
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NMR Spectroscopy 1, Sub Analysis begr. 01-01-2014, NMR-spectroscopie, van Dijk, Aalt-Jan, de Vries, SJ, Dominguez, C, Chen, H, Zhou, HX, Bonvin, AMJJ, NMR Spectroscopy 1, Sub Analysis begr. 01-01-2014, NMR-spectroscopie, van Dijk, Aalt-Jan, de Vries, SJ, Dominguez, C, Chen, H, Zhou, HX, and Bonvin, AMJJ
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- 2005
12. Clinical Value of Tumour Specific Growth Factor (TSGF) and Carbohydrate Antigen-125 (CA-125) in Carcinoma of the Endometrium
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Yu, B, primary, Xu, PZ, additional, Wang, QW, additional, Zhou, H, additional, and Zhou, HX, additional
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- 2009
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13. Effect of experimental acute hypertension of the biliary tract on hemodynamics and activity of the major splanchnic nerve in rabbits
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Liu Sb, Li Zw, Zhou Hx, Wang Dx, Xiong St, Ye Jy, Zheng Qc, Y Hu, and Zhang Sx
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business.industry ,Biliary Tract Diseases ,Hemodynamics ,Splanchnic Nerves ,Simple type ,Splanchnic nerves ,Catheter ,medicine.anatomical_structure ,Blood pressure ,Biliary tract ,Management of Technology and Innovation ,High pressure ,Anesthesia ,medicine ,Duodenum ,Animals ,Humans ,Rabbits ,Hypotension ,business - Abstract
An experimental study of the effect of acute biliary hypertension on hemodynamics and activity of the major splanchnic nerve was conducted in Japanese big ear white rabbits. A catheter with an inflatable rubber bag fixed to its anterior end was inserted into the extrahepatic biliary duct via the duodenum, and a biliary high pressure of 20 kFa (150 mmHg) was created and maintained for 2 h by inflating the bag with water. The right major splanchnic nerve was isolated and the impulse frequencies of the nerve were recorded during the study. Arterial blood pressure was also dynamically monitored. A significant fall of the arterial blood pressure (P less than 0.01) and an increase in impulse frequency of the nerve (P less than 0.01) were found in this "simple type" acute biliary high pressure without infection. Biliary decompression immediately eliminated these abnormalities (P less than 0.01). The drop in blood pressure was much less prominent if the right splanchnic nerve was blocked prior to biliary high pressure.
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- 1991
14. Comparison of three Brownian-dynamics algorithms for calculating rate constants of diffusion-influenced reactions
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Zhou, HX and Zhou, HX
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A new algorithm for calculating the rate constants of diffusion-influenced reactions from Brownian-dynamics simulations is introduced and compared with two previous algorithms. It is based on the mean residence time of the pair of reactant molecules in the reactive region after the molecules are started from that region. Of the previous algorithms, one is based on the capture probability of one reactant molecule started on a spherical surface enclosing the other reactant molecule [Northrup et al., J. Chem. Phys. 80, 1517 (1984)]; the other is based on the survival probability of the pair of reactant molecules started in the reactive region [Zhou, J. Phys. Chem. 94, 8794 (1990)]. In the implementation of the residence-time based algorithm, analogy can be drawn between diffusion-influenced bimolecular reactions and diffusive energy-barrier crossing processes. When the reactive region is small, the pair of reactant molecules will be near the reactive region even after many multiples of the mean residence time have elapsed. Hence the residence time in the reactive region will not be significantly affected by the presence of an interaction potential U if the potential is smooth around the reactive region. This rationalizes an earlier analytic result k = k(0)[exp(-U/k(B)T)], where k and k(0) are the rate constants in the presence and absence of the potential. The three simulation algorithms are applied to the binding of a pointlike ligand to an immobile sphere with a reactive patch in the presence and absence of a Coulomb potential. The survival-probability based algorithm is always the most accurate and efficient one. (C) 1998 American Institute of Physics.
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- 1998
15. Conformation gating as a mechanism for enzyme specificity
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Zhou, HX, Wlodek, ST, McCammon, JA, Zhou, HX, Wlodek, ST, and McCammon, JA
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Acetylcholinesterase, with an active site located at the bottom of a narrow and deep gorge, provides a striking example of enzymes with buried active sites. Recent molecular dynamics simulations showed that reorientation of five aromatic rings leads to rapid opening and closing of the gate to the active site. Hn the present study the molecular dynamics trajectory is used to quantitatively analyze the effect of the gate on the substrate binding rate constant. For a 2.4-Angstrom probe modeling acetylcholine, the gate is open only 2.4\% of the time, but the quantitative analysis reveals that the substrate binding rate is slowed by merely a factor of 2, We rationalize this result by noting that the substrate, by virtue of Brownian motion, will make repeated attempts to enter the gate each time it is near the gate. Hf the gate is rapidly switching between the open and closed states, one of these attempts will coincide with an open state, and then the substrate succeeds in entering the gate. However, there is a limit on the extent to which rapid gating dynamics can compensate for the small equilibrium probability of the open state. Thus the crate is effective in reducing the binding rate for a ligand 0.4 Angstrom bulkier by three orders of magnitude. This relationship suggests a mechanism for achieving enzyme specificity without sacrificing efficiency.
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- 1998
16. Theory of the diffusion-influenced substrate binding rate to a buried and gated active site
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Zhou, HX and Zhou, HX
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The effects of stochastic gating on the diffusion-influenced substrate binding rate to a buried active site are studied. An approximation introduced by Samson and Deutch [J. Chem. Phys. 68, 285 (1978)] is shown to be equivalent to making the constant-flux approximation on the entrance to the active site. The constant-flux approximation is then extended to the case where the entrance to the active site is stochastically gated because of conformational fluctuations of the enzyme. The stochastically gated rate constant, k(sg), is found to be given by the relation 1/k(sg) = 1/k + w(o)/w(c)(w(o) + w(c))(h) over cap(w(o) + w(c)), where k is the rate constant in the absence of gating, (h) over cap(s) is the Laplace transform of the total flux across the entrance after the substrate is started from an equilibrium distribution outside the entrance, and w(o) and w(c) are the transition rates between the open and closed gating states. This relation reduces to an approximate relation derived earlier for a more restrictive situation, where the reactivity within the active site is gated. The leading term in the expansion of s (h) over cap(s) for large s is DA[exp(-beta U)](s/D)(1/2)/2, where D is the diffusion coefficient of the substrate, A is the total area of the entrance, and [exp(-beta U)] is the average Boltzmann factor on the entrance. The time scale of conformational fluctuations, similar to a few picoseconds, is much shorter than the time scale of diffusion, so this leading term is useful for estimating (w(o) + w(c))(h) over cap(w(o) + w(c)). A further consequence of the disparity in time scales is that the value of (w(o) + w(c))(h) over cap(w(o) + w(c)) is much larger than k. As a result the decrease of the rate constant due to gating is relatively small (unless the entrance to the active site is closed nearly all the time). This suggests that a buried and gated active site may play the important role of controlling enzyme specificity without sacrificing efficiency. (C)
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- 1998
17. Enhancement of protein-protein association rate by interaction potential: Accuracy of prediction based on local Boltzmann factor
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Zhou, HX and Zhou, HX
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Electrostatic interactions are known experimentally to enhance the rate of protein-protein association by three to four orders of magnitude. However, theoretical efforts to quantitatively account for such rate enhancement have been hampered by the need to consider a large number of relative configurations of two associating proteins sampled during their diffusional encounter. Our recent work indicates that a good estimate of the rate enhancement is given by the average Boltzmann factor in the region of configurational space where association can effectively take place. This estimate is tested on a model system consisting of two spherical proteins, each with a `'reactive patch.'' Three different forms of interaction potential are considered. Comparison with exact results for the association rate constant demonstrates that predictions based on the local Boltzmann factor are accurate to within similar to 50\% for realistic sizes of the reactive region and amplitudes of the interaction potential.
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- 1997
18. Theory and simulation of the influence of diffusion in enzyme-catalyzed reactions
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Zhou, HX and Zhou, HX
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The Michaelis-Menten equation for the kinetics of a simple enzyme-catalyzed reaction is based on the assumption that the two steps of the reaction, (i) reversible formation of the enzyme-substrate complex (ES) by diffusional encounter and (ii) irreversible conversion of the substrate in ES to product, are both described by ordinary rate equations. It is well-known that the rate coefficient, k(t), for enzyme-substrate binding is time dependent due to the influence of diffusion. Will the influence of diffusion lead to non-Michaelis-Menten kinetics? To address this question, three theoretical approaches to account for the influence of diffusion on the kinetics of enzyme-catalyzed reactions are discussed and tested on a model system. It is found that the restriction on the site for enzyme-substrate binding makes the time dependence of k(t) sufficiently weak so that deviation from the Michaelis-Menten equation is unlikely to be observed. Within the range of parameters that is of practical interest, the three theories all predict that the effective rate constant for substrate association is given by k(infinity) and the effective rate constant for substrate dissociation is given by k(d)k(infinity)/k(0), where k(d) is the rate constant for ES to form a geminate pair. Previous work has shown that k(infinity)/k(0) depends only weakly on interaction potential, hence favorable electrostatic interactions between enzyme and substrate, while enhancing the association rate constant k(infinity) significantly, will suppress the effective dissociation rate constant only marginally. By analogy, the release of product is also expected to be marginally affected by electrostatic interactions. Enzymes are thus found to enjoy all the benefits of electrostatic interactions but suffer very little from their side effects.
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- 1997
19. Design of fast enzymes by optimizing interaction potential in active site
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Zhou, HX, Wong, KY, Vijayakumar, M., Zhou, HX, Wong, KY, and Vijayakumar, M.
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The diffusional encounter between substrate and enzyme, and hence catalytic efficiency, can be enhanced by mutating charged residues on the surface of the enzyme. In this paper we present a simple method for screening such mutations. This is based on our earlier result that electrostatic enhancement of the enzyme-substrate binding rate constant can be accounted for just by the interaction potential within the active site, Assuming that catalytic and structural integrity is maintained, the catalytic efficiency can be optimized by surface charge mutations which lead to stronger interaction potential within the active site, Application of the screening method on superoxide dismutase shows that only charge mutations close to the active site will have practical effect on the catalytic efficiency, This rationalizes a large number of findings obtained in previous simulation and experimental studies.
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- 1997
20. Modeling of protein conformational fluctuations in pK(a) predictions
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Zhou, HX, Vijayakumar, M., Zhou, HX, and Vijayakumar, M.
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A method is presented to account for conformational fluctuations of a protein in predicting the pK(a) values of its titrating groups. Conformations of the protein are generated by conventional molecular dynamics or Monte Carlo simulations, in which the protonations of the titrating groups are fixed. For each protein conformation, the electrostatic free energies required to add a proton charge to a titrating group while other groups are either unprotonated or protonated are calculated within a dielectric continuum model. These are used to determine the mean protonations of the titrating groups in the conformation at a series of pH values. The mean protonations are then used to determine the relative weight of the particular conformation with the titrating groups having all possible protonations. A conformationally averaged mean protonation for each titrating group is finally obtained by the weighted sum of the group's mean protonations in all the conformations. This method is applied to yeast iso-1-ferricytochrome c. The predicted pK(a) values are in general agreement with experimental results. (C) 1997 Academic Press Limited.
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- 1997
21. Dielectric continuum model for calculating reorganization free energies of electron transfer in proteins
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Zhou, HX and Zhou, HX
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A dielectric continuum model is developed for calculating polarization reorganization energies of electron transfer reactions that occur in proteins. The model is based on an earlier microscopic formulation of the Marcus electron transfer theory. The classical Marcus result, lambda=Delta G(1-0)(op)-Delta G(1-0), for the free energy of polarization reorganization is derived from the microscopic theory. Both Delta G(1-0)(op) and Delta G(1-0) denote the electrostatic free energy due to a positive unit charge (+e) distributed in the region representing the electron donor and a negative unit charge (-e) distributed in the region representing the electron acceptor. In calculating Delta G(1-0)(op), the donor and acceptor as well as the environment surrounding them take the optical dielectric constant epsilon(op). In calculating Delta G(1-0), the donor and acceptor keep the optical dielectric constant but the environment takes the static dielectric constant epsilon. The environment consists of the protein matrix (where epsilon(op)=epsilon(op) and epsilon=epsilon(p)) and the solvent (where epsilon(op)=epsilon(s)(op) and epsilon=epsilon(s)). The polarization reorganization free energy can be approximated as the sum of two components lambda(1) and lambda(2). In calculating lambda(1), the protein region is extended outward to infinity. For the case where the donor and acceptor are modeled as spheres (with both radii equal to a and center-center distance at r) and the electron charge is put at either center, a Marcus result, lambda(1)=[(1/epsilon(p)(op))-(1/epsilon(p))][(1/a)-(1/r)]e(2), is found to be highly accurate (maximum error 4\%). In calculating lambda(2), the protein region is extended inward to fill the donor and acceptor. The magnitude of lambda(2) is usually much smaller than lambda(1). A toy electron-transfer protein is studied both by the dielectric continuum model and by implementing the microscopic formulation through computer simulations. Agreement of the result
- Published
- 1996
22. Effect of interaction potentials in diffusion-influenced reactions with small reactive regions
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Zhou, HX and Zhou, HX
- Abstract
The effect of interaction potentials on the rate coefficients of irreversible diffusion-influenced bimolecular reactions is studied, If the region of configurational space where reaction can occur is small, the rate coefficient k in the presence of an interaction potential U is shown to be simply given by k(0), the rate coefficient in the absence of the interaction potential, scaled by (exp(-beta U)), the average Boltzmann factor in the reaction region. For a finite size of the reactive region, this relation is generally more accurate for potentials with smaller values of (exp(-beta U)) and, at a given value of (exp(-beta U)),more accurate for potentials that vary less significantly around the reactive region. (C) 1996 American Institute of Physics.
- Published
- 1996
23. Theory and simulation of the time-dependent rate coefficients of diffusion-influenced reactions
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Zhou, HX, Szabo, A., Zhou, HX, and Szabo, A.
- Abstract
A general formalism is developed for calculating the time-dependent rate coefficient k(t) of an irreversible diffusion-influenced reaction. This formalism allows one to treat most factors that affect k(t), including rotational Brownian motion and conformational gating of reactant molecules and orientation constraint for product formation. At long times k(t) is shown to have the asymptotic expansion k(infinity)[1 + k(infinity)(pi Dt)(-1/2)/4 pi D + ...] where D is the relative translational diffusion constant. An approximate analytical method for calculating k(t) is presented. This is based on the approximation that the probability density of the reactant pair in the reactive region keeps the equilibrium distribution but with a decreasing amplitude. The rate coefficient then is determined by the Green function in the absence of chemical reaction, Within the framework of this approximation, two general relations are obtained. The first relation allows the rate coefficient for an arbitrary amplitude of the reactivity to be found if the rate coefficient for one amplitude of the reactivity is is known. The second relation allows the rate coefficient in the presence of conformational gating to be found from that in the absence of conformational gating. The ratio k(t)/k(0) is shown to be the survival probability of the reactant pair at time t starting from an initial distribution that is localized in the reactive region. This relation forms the basis of the calculation of k(t) through Brownian dynamic's simulations. Two simulation procedures involving the propagation of nonreactive trajectories initiated only from the reactive region are described and illustrated on a model system. Both analytical and simulation results demonstrate the accuracy of the equilibrium-distribution approximation method.
- Published
- 1996
24. Time-dependent rate coefficients from Brownian dynamics simulations
- Author
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Potter, MJ, Luty, B., Zhou, HX, McCammon, JA, Potter, MJ, Luty, B., Zhou, HX, and McCammon, JA
- Abstract
The kinetics of a diffusion-influenced reaction is described by a time-dependent rate coefficient k(t). In this paper, we implement an algorithm for calculating k(t), introduced by one of us, in the UHBD software package. In the implementation, the electrostatic force exerted on a diffusing substrate by an enzyme is obtained from a finite-difference solution of the Poisson equation. The rate coefficient is obtained by starting the substrate in the active site and monitoring its survival probability using Brownian dynamics simulations. The technique is applied to the binding of superoxide to Cu/Zn superoxide dismutase. The long-time limit of k(t) is found to be in agreement with both the experimental value and that calculated using an algorithm designed specifically for finding k(infinity).
- Published
- 1996
25. Theory and simulation of stochastically-gated diffusion-influenced reactions
- Author
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Zhou, HX, Szabo, A., Zhou, HX, and Szabo, A.
- Abstract
The kinetics of the irreversible diffusion-influenced reaction between a protein (P) and a ligand (L) is studied when [L] much greater than [P] and the reactivity is stochastically gated due to conformational fluctuations of one of the species. If gating is due to the ligand, we show that the Smoluchowski rate equation, d[P(t)]/dt = -k(t)[L][P(t)], can be generalized by simply using a stochastically-gated time-dependent rate coefficient, k(sg)(t). However, if gating is due to the protein, this is no longer true, except when the gating dynamics is sufficiently fast or the Ligand concentration is very low. The dynamics of ail the ligands around a protein become correlated even when they diffuse independently. An approximate theory for the kinetics of protein-gated reactions that is exact in both the fast and slow gating limits is developed. In order to test this theory, a Brownian dynamics simulation algorithm based on a path-integral formulation is introduced to calculate both k(sg)(t) and the time dependence of the protein concentration. Illustrative simulations using a simple model are carried out for a variety of gating rates. The results are in good agreement with the approximate theory.
- Published
- 1996
26. A 240-fold electrostatic rate-enhancement for acetylcholinesterase-substrate binding can be predicted by the potential within the active site
- Author
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Zhou, HX, Briggs, JM, McCammon, JA, Zhou, HX, Briggs, JM, and McCammon, JA
- Published
- 1996
27. Dihydroartemisinin inhibits angiogenesis in pancreatic cancer by targeting the NF-κB pathway.
- Author
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Wang SJ, Sun B, Cheng ZX, Zhou HX, Gao Y, Kong R, Chen H, Jiang HC, Pan SH, Xue DB, Bai XW, Wang, Shuang-Jia, Sun, Bei, Cheng, Zhuo-Xin, Zhou, Hao-Xin, Gao, Yue, Kong, Rui, Chen, Hua, Jiang, Hong-Chi, and Pan, Shang-Ha
- Abstract
Purpose: Dihydroartemisinin (DHA) has recently shown antitumor activity in human pancreatic cancer cells. However, its effect on antiangiogenic activity in pancreatic cancer is unknown, and the mechanism is unclear. This study was aimed to investigate whether DHA would inhibit angiogenesis in human pancreatic cancer.Methods: Cell viability and proliferation, tube formation of human umbilical vein endothelial cells (HUVECs), nuclear factor (NF)-κB DNA-binding activity, expressions of vascular endothelial growth factor (VEGF), interleukin (IL)-8, cyclooxygenase (COX)-2, and matrix metalloproteinase (MMP)-9 were examined in vitro. The effect of DHA on antiangiogenic activity in pancreatic cancer was also assessed using BxPC-3 xenografts subcutaneously established in BALB/c nude mice.Results: DHA inhibited cell proliferation and tube formation of HUVECs in a time- and dose-dependent manner and also reduced cell viability in pancreatic cancer cells. DHA significantly inhibited NF-κB DNA-binding activity, so as to tremendously decrease the expression of NF-κB-targeted proangiogenic gene products: VEGF, IL-8, COX-2, and MMP-9 in vitro. In vivo studies, DHA remarkably reduced tumor volume, decreased microvessel density, and down-regulated the expression of NF-κB-related proangiogenic gene products.Conclusions: Inhibition of NF-κB activation is one of the mechanisms that DHA inhibits angiogenesis in human pancreatic cancer. We also suggest that DHA could be developed as a novel agent against pancreatic cancer. [ABSTRACT FROM AUTHOR]- Published
- 2011
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28. Association between autistic features and empathy in Chinese patients with chronic schizophrenia.
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Ma Z, Chang ZH, Zhou HX, Wang DM, and Zhang XY
- Subjects
- Humans, Female, Male, Adult, Chronic Disease, Autistic Disorder psychology, Schizophrenic Psychology, Middle Aged, China, Psychiatric Status Rating Scales, Severity of Illness Index, Young Adult, Neuropsychological Tests, East Asian People, Empathy physiology, Schizophrenia physiopathology, Schizophrenia complications
- Abstract
Objectives: It is common for patients with schizophrenia to exhibit symptoms of autism. Both autism spectrum disorders and schizophrenia share similar patterns of empathy deficits. This study purposed to explore the association between autistic features and empathy in Chinese patients with chronic schizophrenia., Methods: We enrolled 857 patients with chronic schizophrenia. The Positive and Negative Syndrome Scale (PANSS), Repeatable Battery for the Assessment of Neuropsychological 7 Status (RBANS), and Interpersonal Reactivity Index (IRI) were employed to assess the participants' clinical symptoms, neurocognition, and empathy, respectively. The severity of autistic symptoms was assessed with the PANSS Autism Severity Scale (PAUSS), with PAUSS scores ≥ 30 were considered to have significant autistic features., Results: 114 schizophrenia patients (13.3%) had autistic features. Compared to schizophrenia patients without autistic features, those with autistic features had more severe clinical symptoms, and poorer neurocognition and empathic abilities. Female sex and empathic concerns were independently associated with autistic features in patients with chronic schizophrenia., Conclusions: Our results suggest that autistic features tend to manifest quite commonly among patients with chronic schizophrenia. Empathy deficits are strongly associated with autistic features in patients with chronic schizophrenia, strengthening the view that autistic features may characterize a subgroup of schizophrenia patients., Competing Interests: Declarations. Conflict of interest: No conflict of interest was disclosed for each author. Ethical Statement: This study was approved by the Ethics Committee of the First Affiliated Hospital of Shanxi Medical University. The authors asset that all procedures contributing to this work comply with the ethical standards of the relevant national and institutional committees on human experimentation and with the Helsinki Declaration of 1975, as revised in 2008. Each patient signed a written informed consent form before participating in the trial and after they had been provided with a detailed explanation of the study., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)
- Published
- 2025
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29. Membrane Association of Intrinsically Disordered Proteins.
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MacAinsh M, Muhammedkutty FNK, Prasad R, and Zhou HX
- Abstract
It is now clear that membrane association of intrinsically disordered proteins or intrinsically disordered regions regulates many cellular processes, such as membrane targeting of Src family kinases and ion channel gating. Residue-specific characterization by nuclear magnetic resonance spectroscopy, molecular dynamics simulations, and other techniques has shown that polybasic motifs and amphipathic helices are the main drivers of membrane association; sequence-based prediction of residue-specific membrane association propensity has become possible. Membrane association facilitates protein-protein interactions and protein aggregation-these effects are due to reduced dimensionality but are similar to those afforded by condensate formation via liquid-liquid phase separation (LLPS). LLPS at the membrane surface provides a powerful means for recruiting and clustering proteins, as well as for membrane remodeling.
- Published
- 2025
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30. [Emphasis the early diagnosis and treatment of plasma cell disease-related kidney disease].
- Author
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Zhou HX, Chen WM, and Gao W
- Subjects
- Humans, Paraproteinemias diagnosis, Paraproteinemias therapy, Early Diagnosis, Kidney Diseases diagnosis, Kidney Diseases etiology, Kidney Diseases therapy
- Abstract
Plasma cell disorders represent a spectrum of complex diseases, ranging from benign conditions to malignancies. The monoclonal immunoglobulins produced in these disorders can result in various renal pathologies, which may present as differing degrees of renal insufficiency. In severe instances, patients may necessitate dialysis or kidney transplantation. The recovery of kidney damage is relatively delayed after treatment. Some patients achieved hematological complete response, but kidney impairment may progressively worsen. Clinicians need to be more vigilant and pay more attention to PCD related kidney impairment. Early diagnosis and treatment are of great significance for reversing renal dysfunction and improving survival.
- Published
- 2025
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31. The Prospective Use of Avapritinib in Relapsed/Refractory (R/R) RUNX1-RUNX1T1-Positive AML Patients With KIT Mutation.
- Author
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Han SY, Xu XY, Zhou M, Su JW, Zhou HX, and Han Y
- Abstract
Competing Interests: Disclosure The authors declare no competing financial interests.
- Published
- 2025
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32. Mycobacterium tuberculosis CrgA Forms a Dimeric Structure with Its Transmembrane Domain Sandwiched between Cytoplasmic and Periplasmic β-Sheets, Enabling Multiple Interactions with Other Divisome Proteins.
- Author
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Shin Y, Prasad R, Das N, Taylor JA, Qin H, Hu W, Hu YY, Fu R, Zhang R, Zhou HX, and Cross TA
- Abstract
CrgA is a key transmembrane (TM) protein in the cell division process of Mycobacterium tuberculosis ( Mtb ), the pathogen responsible for tuberculosis. While many of the Mtb divisome proteins have been identified, their structures and interactions remain largely unknown. Previous studies of CrgA using oriented-sample solid-state NMR have defined the tilt and rotation of the TM helices, but the cytoplasmic and periplasmic domains and even the oligomeric state were uncharacterized. Here, combining oriented-sample and magic-angle spinning solid-state NMR spectra, we solved the full-length structure of CrgA. The structure features a dimer with a TM domain sandwiched between a cytoplasmic β-sheet and a periplasmic β-sheet. The β-sheets stabilize dimerization, which in turn increases CrgA's ability to participate in multiple protein interactions. Within the membrane, CrgA binds FtsQ, CwsA, PbpA, FtsI, and MmPL3 via its TM helices; in the cytoplasm, Lys23 and Lys25 project outward from the β-sheet to interact with acidic residues of FtsQ and FtsZ. The structural determination of CrgA thus provides significant insights into its roles in recruiting other divisome proteins and stabilizing their complexes for Mtb cell wall synthesis and polar growth.
- Published
- 2025
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33. [Impact of arsenic exposure on the hepatic metabolic molecular network in obese pregnant mice using metabolomics and proteomics].
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Cai LJ, Wang Y, Tan JF, Zhou HX, Liang SJ, Wu Y, and Zhang J
- Subjects
- Animals, Mice, Female, Pregnancy, Lipid Metabolism drug effects, Oxidative Stress, Arsenic toxicity, Proteomics, Liver metabolism, Liver drug effects, Obesity metabolism, Obesity chemically induced, Metabolomics
- Abstract
Arsenic is a ubiquitous environmental toxin that can affect normal physiological processes. Although the health impacts of arsenic have been investigated, its influence on hepatic metabolism in obese pregnant women and the underlying mechanisms remain unclear. Multi-omics analysis, including metabolomics and proteomics, can improve the understanding of arsenic-induced hepatotoxicity in obese pregnant women. This study aimed to investigate the adverse effects of gestational arsenic exposure on hepatic metabolism in high-fat-diet-induced obese pregnant mice. Following arsenic exposure during pregnancy, the liver tissue was evaluated comprehensively using metabolomics and proteomics techniques combined with pathological and biochemical analyses. Arsenic exposure not only significantly increased lipid accumulation in the livers of obese pregnant mice but also elevated inflammatory factors and oxidative stress markers. Specifically, histopathological examination revealed more steatosis, inflammatory cell infiltration, and hepatocyte ballooning in the livers of arsenic-exposed mice than in those of controls. These changes indicate that arsenic exposure exacerbates hepatic lipid accumulation and induces liver damage in the context of obesity. Metabolomic analysis provided further insight into the metabolic-level disruption caused by arsenic exposure. Significant changes were observed in lipid metabolism pathways, particularly the arachidonic acid metabolism pathway. As arachidonic acid and its metabolites play important roles in inflammation and oxidative stress, this pathway may be critical in arsenic-induced hepatotoxicity. Additionally, proteomic analysis showed differences in the expression levels of several key proteins involved in lipid synthesis, oxidative stress, and inflammatory response. Notably, oxidative-stress-related proteins, including glutathione peroxidase 4 (GPX4), were upregulated, suggesting an increased oxidative burden. In summary, there are complex interaction mechanisms among arsenic exposure, inflammatory response, and related lipid metabolism. The integration of metabolomics and proteomics aided in clarifying the molecular alterations induced by arsenic. The results show that arsenic exposure significantly affects hepatic lipid metabolism in obese pregnant mice through multiple metabolic pathways and protein regulatory mechanisms. In addition to providing new insights into the relationship between arsenic exposure and obesity as well as related metabolic diseases, this study can act as a reference for environmental health risk assessment and the formulation of public health policies. This enhanced understanding of the adverse effects of arsenic on hepatic metabolism will contribute to the development of strategies for mitigating the health risks associated with environmental toxins, particularly for vulnerable groups such as obese pregnant women.
- Published
- 2025
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34. Direct and indirect salt effects on homotypic phase separation.
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MacAinsh M, Dey S, and Zhou HX
- Subjects
- Heterogeneous Nuclear Ribonucleoprotein A1 chemistry, Heterogeneous Nuclear Ribonucleoprotein A1 metabolism, Intrinsically Disordered Proteins chemistry, Protein Conformation, Phase Separation, Molecular Dynamics Simulation, Sodium Chloride chemistry
- Abstract
The low-complexity domain of hnRNPA1 (A1-LCD) phase separates in a salt-dependent manner. Unlike many intrinsically disordered proteins (IDPs) whose phase separation is suppressed by increasing salt concentrations, the phase separation of A1-LCD is promoted by >100 mM NaCl. To investigate the atypical salt effect on A1-LCD phase separation, we carried out all-atom molecular dynamics simulations of systems comprising multiple A1-LCD chains at NaCl concentrations from 50 to 1000 mM NaCl. The ions occupy first shell as well as more distant sites around the IDP chains, with Arg sidechains and backbone carbonyls the favored partners of Cl
- and Na+ , respectively. They play two direct roles in driving A1-LCD condensation. The first is to neutralize the high net charge of the protein (+9) by an excess of bound Cl- over Na+ ; the second is to bridge between A1-LCD chains, thereby fortifying the intermolecular interaction networks in the dense phase. At high concentrations, NaCl also indirectly strengthens π-π, cation-π, and amino-π interactions, by drawing water away from the interaction partners. Therefore, at low salt, A1-LCD is prevented from phase separation by net charge repulsion; at intermediate concentrations, NaCl neutralizes enough of the net charge while also bridging IDP chains to drive phase separation. This drive becomes even stronger at high salt due to strengthened π-type interactions. Based on this understanding, four classes of salt dependence of IDP phase separation can be predicted from amino-acid composition., Competing Interests: MM, SD, HZ No competing interests declared, (© 2024, MacAinsh et al.)- Published
- 2024
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35. [Predictors of adverse outcomes in patients with chronic obstructive pulmonary disease and pulmonary embolism and the predictive value of the simplified pulmonary embolism severity index].
- Author
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Peng LG, Liu SM, Pu JQ, Zeng JX, Chen XQ, Yuan JL, Yi Q, and Zhou HX
- Subjects
- Humans, Male, Female, Aged, Retrospective Studies, Hospital Mortality, China, Prognosis, Predictive Value of Tests, Logistic Models, Intensive Care Units, Middle Aged, Risk Factors, Aged, 80 and over, ROC Curve, Pulmonary Disease, Chronic Obstructive complications, Pulmonary Embolism, Severity of Illness Index
- Abstract
Objective: To explore the relevant factors associated with poor prognosis in patients suffering from chronic obstructive pulmonary disease (COPD) combined with pulmonary embolism (PE), and investigate the predictive value of the simplified pulmonary embolism severity index (sPESI) score on adverse outcomes in these patients. Methods: A total of 168 patients with COPD and PE who were treated at West China Hospital of Sichuan University from January 1, 2018, to December 30, 2020 were retrospectively included. Patients were divided into adverse outcome group and control group based on the occurrence of adverse outcomes [any of the following events: in-hospital death, intensive care unit (ICU) admission, and endotracheal intubation]. Correlation factors for poor prognosis were explored using multivariate logistic regression analysis. Receiver operating characteristic (ROC) curve was employed to assess the predictive value of the sPESI score for adverse outcomes in COPD patients with PE. Results: A total of 168 patients were studied, with an age of (73.4±10.4) years and 119 male (70.8%). In the adverse outcome group, there were 18 cases (10.7%), including 12 in-hospital deaths, 6 ICU admission, and 1 endotracheal intubation. The control group comprised 150 cases (89.3%). Statistically significant differences were observed between two groups regarding the proportion of patients with diabetes, nephrotic syndrome, severe pneumonia, respiratory failure and lower extremity edema, and the pulse, diastolic blood pressure, pulse oxygen saturation, lactate dehydrogenase and cholesterol levels (all P <0.05). Multivariate logistic regression analysis revealed that severe pneumonia, respiratory failure, lower extremity edema, and diastolic blood pressure<60 mmHg (1 mmHg=0.133 kPa) are correlative factors of adverse outcomes in patients with COPD complicated by PE [ OR (95% CI ) were 7.363 (1.053-51.772), 4.077 (1.030-16.133), 4.490 (1.131-17.832), and 8.060 (1.209-53.918), respectively, all P <0.05]. The sPESI score in the adverse outcome group was higher than that in the control group [ M ( Q
1 , Q3 ), 2 (2, 2) vs 1 (1, 2) score, P =0.006]; the optimal cutoff value for sPESI score was 2 score, the sensitivity was 77.8%, the specificity was 54.0%, and the area under the curve (AUC) and 95% CI were 0.681 (0.554-0.809) based on the ROC curve analysis. Patients with sPESI≥2 score exhibited a 4.109-fold (95% CI : 1.292-13.063, P =0.017) increased risk of adverse prognosis compared to those with sPESI<2 score. Conclusions: Patients with COPD combined with PE have a higher incidence of adverse prognostic outcomes. Severe pneumonia, respiratory failure, lower limb edema, and diastolic pressure<60 mmHg are associated factors for poor prognosis. The sPESI score has some value in predicting adverse outcomes in COPD patients with PE.- Published
- 2024
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36. Tardigrade Dsup: Interactions with DNA and protection of cells from oxidative stress.
- Author
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Ni GS, Su H, Zhu Y, Dhiman A, Zhou HX, Lin W, and Hao N
- Abstract
The remarkable capability of Tardigrade to survive under extreme conditions has been partially attributed to Dsup, an intrinsically disordered, highly positively charged protein. Dsup has been shown to bind to DNA in vitro, a property that has been associated with the capability of Dsup to exhibit stress-protective effects when expressed in mammalian cells. However, DNA binding of Dsup has not been visualized in living cells and expression of Dsup in different cell types was associated with either protective or detrimental effects. In addition, the effect of Dsup expression has not been clearly demonstrated at the organism level. Here we combined molecular dynamics (MD) simulations and fluorescence lifetime imaging microscopy (FLIM)-Förster resonance energy transfer (FRET) to interrogate Dsup-DNA interactions and demonstrated Dsup binding to DNA in living mammalian cells. Furthermore, Dsup expression in both HEK293T cells and yeast enhanced cell survival in the presence of hydrogen peroxide, suggesting that the presence of Dsup allows both mammalian and yeast cells to better cope with oxidative stress conditions. This study provides a better understanding of the property and functional role of Dsup and lays a foundation to explore new approaches to enhance stress resistance., Competing Interests: Competing Interests The authors declare no competing interests.
- Published
- 2024
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37. Protamine-Mediated Tangles Produce Extreme Deoxyribonucleic Acid Compaction.
- Author
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Ahlawat V, Dhiman A, Mudiyanselage HE, and Zhou HX
- Subjects
- Hydrogen Bonding, Protamines chemistry, Protamines metabolism, DNA chemistry, Molecular Dynamics Simulation, Nucleic Acid Conformation
- Abstract
In sperm cells, protamine replaces histones to compact DNA 10-20 times more than in somatic cells. To characterize the extreme compaction, we employed confocal microscopy and optical tweezers to determine the conformations and stability of protamine-bound λ-DNA. Confocal images show increasing compaction of λ-DNA at increasing protamine concentration. In the presence of protamine, single λ-DNA molecules form tangles that withstand forces strong enough (∼55 pN) for strand separation and shorten the contour length by up to 40% even at high forces, as well as bends and loops that rupture at 10-40 pN forces. Strand separation nucleates tangles, implicating protamine interactions with DNA bases. Molecular dynamics simulations show that Arg sidechains of protamine each form hydrogen bonds with multiple bases, frequently in the form of a wedge between the two strands of DNA. Protamine may participate in both local and higher-order chromatin organization, leading to extreme compaction and global transcription silencing.
- Published
- 2024
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38. Predicting the sequence-dependent backbone dynamics of intrinsically disordered proteins.
- Author
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Qin S and Zhou HX
- Subjects
- Protein Conformation, Nuclear Magnetic Resonance, Biomolecular, Amino Acids chemistry, Computational Biology methods, Intrinsically Disordered Proteins chemistry
- Abstract
How the sequences of intrinsically disordered proteins (IDPs) code for functions is still an enigma. Dynamics, in particular residue-specific dynamics, holds crucial clues. Enormous efforts have been spent to characterize residue-specific dynamics of IDPs, mainly through NMR spin relaxation experiments. Here, we present a sequence-based method, SeqDYN, for predicting residue-specific backbone dynamics of IDPs. SeqDYN employs a mathematical model with 21 parameters: one is a correlation length and 20 are the contributions of the amino acids to slow dynamics. Training on a set of 45 IDPs reveals aromatic, Arg, and long-branched aliphatic amino acids as the most active in slow dynamics whereas Gly and short polar amino acids as the least active. SeqDYN predictions not only provide an accurate and insightful characterization of sequence-dependent IDP dynamics but may also serve as indicators in a host of biophysical processes, including the propensities of IDP sequences to undergo phase separation., Competing Interests: SQ, HZ No competing interests declared, (© 2023, Qin and Zhou.)
- Published
- 2024
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39. Amino acid-dependent phase equilibrium and material properties of tetrapeptide condensates.
- Author
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Zhang Y, Prasad R, Su S, Lee D, and Zhou HX
- Abstract
The rules of how amino acids dictate the physical properties of biomolecular condensates are still incomplete. Here, we study condensates formed by tetrapeptides of the form XXssXX. Eight peptides form four types of condensates at different concentrations and pHs: droplets (X = F, L, M, P, V, and A), amorphous dense liquids (X = L, M, P, V, and A), amorphous aggregates (X = W), and gels (X = I, V, and A). The peptides exhibit differences in phase equilibrium and material properties, including a 368-fold range in the threshold concentration for phase separation and a 3,856-fold range in viscosity. All-atom molecular dynamics simulations provide physical explanations of these results. The present work also reveals widespread critical behaviors-including critical slowing down manifested by amorphous dense liquids and critical scaling obeyed by fusion speed-with broad implications for condensate functions., Competing Interests: DECLARATION OF INTERESTS The authors declare that they have no competing interests.
- Published
- 2024
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40. [A multicenter study on effect of delayed chemotherapy on prognosis of Burkitt lymphoma in children].
- Author
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Song L, Jin L, Zhang YH, Yang XM, Duan YL, Zheng MC, Zhai XW, Liu Y, Liu W, Liu AS, Yuan XJ, Dai YP, Zhang LP, Wang J, Sun LR, Liu R, Zhang BX, Jiang L, Wei HX, Chen KL, Jin RM, Wang XG, Zhou HX, Wang HM, Zhuang SS, Zhou CJ, Gao ZF, Mu X, Zhang KH, and Li F
- Subjects
- Humans, Retrospective Studies, Child, Female, Male, Prognosis, Child, Preschool, Adolescent, Time-to-Treatment, China, Tumor Lysis Syndrome etiology, Survival Rate, Infant, Burkitt Lymphoma drug therapy, Antineoplastic Combined Chemotherapy Protocols therapeutic use
- Abstract
Objective: To analyze the factors affecting delayed chemotherapy in children with Burkitt lymphoma (BL) and their influence on prognosis. Methods: Retrospective cohort study. Clinical data of 591 children aged ≤18 years with BL from May 2017 to December 2022 in China Net Childhood Lymphoma (CNCL) was collected. The patients were treated according to the protocol CNCL-BL-2017. According to the clinical characteristics, therapeutic regimen was divided into group A, group B and group C .Based on whether the total chemotherapy time was delayed, patients were divided into two groups: the delayed chemotherapy group and the non-delayed chemotherapy group. Based on the total delayed time of chemotherapy, patients in group C were divided into non-delayed chemotherapy group, 1-7 days delayed group and more than 7 days delayed group. Relationships between delayed chemotherapy and gender, age, tumor lysis syndrome before chemotherapy, bone marrow involvement, disease group (B/C group), serum lactate dehydrogenase (LDH) > 4 times than normal, grade Ⅲ-Ⅳ myelosuppression after chemotherapy, minimal residual disease in the interim assessment, and severe infection (including severe pneumonia, sepsis, meningitis, chickenpox, etc.) were analyzed. Logistic analysis was used to identify the relevant factors. Kaplan-Meier method was used to analyze the patients' survival information. Log-Rank was used for comparison between groups. Results: Among 591 patients, 504 were males and 87 were females, the follow-up time was 34.8 (18.6,50.1) months. The 3-year overall survival (OS) rate was (92.5±1.1)%,and the 3-year event-free survival (EFS) rate was (90.5±1.2)%. Seventy-three (12.4%) patients were in delayed chemotherapy group and 518 (87.6%) patients were in non-delayed chemotherapy group. The reasons for chemotherapy delay included 72 cases (98.6%) of severe infection, 65 cases (89.0%) of bone marrow suppression, 35 cases (47.9%) of organ dysfunction, 22 cases (30.1%) of tumor lysis syndrome,etc. There were 7 cases of chemotherapy delay in group B, which were seen in COPADM (vincristine+cyclophosphamide+prednisone+daunorubicin+methotrexate+intrathecal injection,4 cases) and CYM (methotrexate+cytarabine+intrathecal injection,3 cases) stages. There were 66 cases of chemotherapy delay in group C, which were common in COPADM (28 cases) and CYVE 1 (low dose cytarabine+high dose cytarabine+etoposide+methotrexate, 12 cases) stages. Multinomial Logistic regression analysis showed that the age over 10 years old ( OR =0.54,95% CI 0.30-0.93), tumor lysis syndrome before chemotherapy ( OR =0.48,95% CI 0.27-0.84) and grade Ⅲ-Ⅳ myelosuppression after chemotherapy ( OR =0.55,95% CI 0.33-0.91)were independent risk factors for chemotherapy delay.The 3-year OS rate and the 3-year EFS rate of children with Burkitt lymphoma in the delayed chemotherapy group were lower than those in the non-delayed chemotherapy group ((79.4±4.9)% vs. (94.2±1.1)%, (80.2±4.8)% vs. (92.0±1.2)%,both P <0.05). The 3-year OS rate of the group C with chemotherapy delay >7 days (42 cases) was lower than that of the group with chemotherapy delay of 1-7 days (22 cases) and the non-delay group (399 cases) ((76.7±6.9)% vs. (81.8±8.2)% vs. (92.7±1.3)%, P =0.002).The 3-year OS rate of the chemotherapy delay group (9 cases) in the COP (vincristine+cyclophosphamide+prednisone) phase was lower than that of the non-chemotherapy delay group (454 cases) ((66.7±15.7)% vs. (91.3±1.4)%, P =0.005). Similarly, the 3-year OS rate of the chemotherapy delay group (11 cases) in the COPADM1 phase was lower than that of the non-chemotherapy delay group (452 cases) ((63.6±14.5)% vs. (91.5±1.3)%, P =0.001). Conclusions: The delayed chemotherapy was related to the age over 10 years old, tumor lysis syndrome before chemotherapy and grade Ⅲ-Ⅳ myelosuppression after chemotherapy in pediatric BL. There is a significant relationship between delayed chemotherapy and prognosis of BL in children.
- Published
- 2024
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41. Membrane-assisted Aβ40 aggregation pathways.
- Author
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Muhammedkutty FNK and Zhou HX
- Abstract
Alzheimer's disease (AD) is caused by the assembly of amyloid-beta (Aβ) peptides into oligomers and fibrils. Endogenous Aβ aggregation may be assisted by cell membranes, which can accelerate the nucleation step enormously, but knowledge of membrane-assisted aggregation is still very limited. Here we used extensive MD simulations to structurally and energetically characterize key intermediates along the membrane-assisted aggregation pathways of Aβ40. Reinforcing experimental observations, the simulations reveal unique roles of GM1 ganglioside and cholesterol in stabilizing membrane-embedded β-sheets and of Y10 and K28 in the ordered release of a small oligomeric seed into solution. The same seed leads to either an open-shaped or R-shaped fibril, with significant stabilization provided by inter- or intra-subunit interfaces between a straight β-sheet (residues Q15-D23) and a bent β-sheet (residues A30-V36). This work presents the first comprehensive picture of membrane-assisted aggregation of Aβ40, with broad implications for developing AD therapies and rationalizing disease-specific polymorphisms of amyloidogenic proteins.
- Published
- 2024
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42. Esophageal ulcer and multisystem inflammatory syndrome after COVID-19: A case report.
- Author
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Yang N, Liu Z, Jin T, Xin HW, Gu L, Zheng Y, Zhou HX, Li N, and Liu XJ
- Abstract
Background: Multisystem inflammatory syndrome in adults (MIS-A) is a rare but severe disease occurring several weeks after severe acute respiratory syndrome coronavirus 2 infection. It develops in adults with inflammation of different organs including the gastrointestinal tract, heart, kidneys, skin and hematopoietic system., Case Summary: We present a 58-year-old Chinese man diagnosed with MIS-A. His chief complaints were fever, generalized fatigue and anorexia, accompanied with rashes on his back. Further examination showed cardiac, renal and liver injury. He had melena and gastroscopy indicated esophageal ulcer and severe esophagitis. Repeated blood and sputum culture did not show growth of bacteria or fungi. Antibiotic treatment was stopped due to unsatisfactory performance. His condition improved after prednisone and other supportive treatment., Conclusion: Gastrointestinal involvement in MIS-A is not uncommon. Intestinal involvement predominates, and esophageal involvement is rarely reported. Esophageal ulcer with bleeding could also be a manifestation of MIS-A., Competing Interests: Conflict-of-interest statement: All authors declare that they have no competing interests., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)
- Published
- 2024
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43. [Analysis of the therapeutic effect of avatinib bridged allogeneic hematopoietic stem cell transplantation on 7 cases of recurrent/refractory RUNX1-RUNX1T1 positive acute myeloid leukemia with KIT mutations].
- Author
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Han SY, Zhou HX, Han Y, and Wu DP
- Subjects
- Humans, Male, Female, Adult, Middle Aged, Retrospective Studies, Adolescent, Young Adult, RUNX1 Translocation Partner 1 Protein genetics, Transplantation, Homologous, Oncogene Proteins, Fusion genetics, Hematopoietic Stem Cell Transplantation methods, Leukemia, Myeloid, Acute genetics, Leukemia, Myeloid, Acute therapy, Mutation, Core Binding Factor Alpha 2 Subunit genetics, Proto-Oncogene Proteins c-kit genetics
- Abstract
Objective: To evaluate the efficacy of avatinib plus allogeneic hematopoietic stem cell transplantation (allo-HSCT) for the treatment of recurrent/refractory RUNX1-RUNX1T1 positive acute myeloid leukemia (AML) with KIT mutations. Method: A retrospective study was conducted on the clinical data of seven relapsed/refractory AML patients containing the RUNX1-RUNX1T1 fusion gene and KIT mutation who received afatinib plus allo-HSCT treatment at the First Affiliated Hospital of Soochow University from June 2019 to June 2023. Results: The seven AML patients included one male and six females with a median age of 37 (18-56) years. All seven patients had KIT mutations (five positive for D816V and two positive for D816Y) . There were two refractory patients and five relapsed patients (all of whom had bone marrow recurrence) . All patients had to complete at least one course of treatment with afatinib before transplantation. Four patients achieved complete remission (CR) after treatment with afatinib, six patients had negative KIT gene mutations, and one had a decreased KIT gene mutational burden. There were three cases of unrelated identical transplantation and four cases of haploidentical transplantation. All patients received the modified Bu/Cy pretreatment regimen. After transplantation, all patients were successfully implanted and a bone marrow examination showed CR and minimal residual disease turned negative. Five patients exhibited negative fusion genes. Two patients died from infection following transplantation. Conclusion: Afatinib plus allo-HSCT may be an effective and safe new treatment strategy for RUNX1-RUNX1T1 positive AML patients with KIT-D816 mutation.
- Published
- 2024
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44. [Analysis of the prognostic factors in primary plasma cell leukemia in the era of novel agents].
- Author
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Deng JJ, Jin XY, Zhang ZY, Zhou HX, Yang GZ, Geng CY, Jian Y, Chen WM, and Gao W
- Subjects
- Humans, Middle Aged, Adult, Aged, Prognosis, Retrospective Studies, Hematopoietic Stem Cell Transplantation, Male, Female, Survival Rate, Remission Induction, Leukemia, Plasma Cell therapy, Leukemia, Plasma Cell diagnosis
- Abstract
Objective: To explore the prognostic factors of primary plasma cell leukemia (pPCL) in the era of novel agents. Methods: The clinical data of 66 patients with pPCL treated at the Department of Haematology, Beijing Chao-Yang Hospital, Capital Medical University from 2011 to 2022 were retrospectively collected to analyze their prognostic factors. Results: Among the 66 patients with pPCL, the median age was 59 (range: 29-79) years. The median overall survival (OS) duration was 19.0 (95% CI 10.4-27.6) months, and the median progression-free survival (PFS) duration was 11.0 (95% CI 6.5-15.6) months. The median OS and PFS were significantly longer in patients with the best post-treatment response of very good partial remission (VGPR) or better than in patients with a response of partial remission (PR) or worse (median OS: 33.0 months vs 6.0 months, P <0.001; median PFS: 16.0 months vs 3.0 months, P <0.001). OS was significantly longer in patients who underwent autologous hematopoietic stem cell transplantation than in those who did not undergo transplantation (49.0 months vs 6.0 months, P =0.002), and there was a trend toward a longer PFS in patients who underwent transplantation than in those who did not undergo transplantation (19.0 months vs 8.0 months, P =0.299). The median OS and PFS were significantly longer in patients who received maintenance therapy than in those who did not receive maintenance therapy (median OS: 56.0 months vs 4.0 months, P <0.001; median PFS: 20.0 months vs 2.0 months, P <0.001). Multivariate analysis showed that hypercalcemia was an independent risk factor ( HR =3.204, 95% CI 1.068-9.610, P =0.038) for patients with pPCL, while receiving maintenance therapy ( HR =0.075, 95% CI 0.022-0.253, P <0.001) and post-treatment response of VGPR or better ( HR =0.175, 95% CI 0.048-0.638, P =0.008) were independent protective factors for patients with pPCL. Conclusions: In the era of novel agents, hypercalcemia, receiving maintenance therapy, and post-treatment response of VGPR or better are independent prognostic factors for pPCL.
- Published
- 2024
- Full Text
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45. Fundamental Aspects of Phase-Separated Biomolecular Condensates.
- Author
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Zhou HX, Kota D, Qin S, and Prasad R
- Subjects
- Proteins chemistry, Proteins metabolism, Humans, Phase Transition, Biomolecular Condensates chemistry, Biomolecular Condensates metabolism
- Abstract
Biomolecular condensates, formed through phase separation, are upending our understanding in much of molecular, cell, and developmental biology. There is an urgent need to elucidate the physicochemical foundations of the behaviors and properties of biomolecular condensates. Here we aim to fill this need by writing a comprehensive, critical, and accessible review on the fundamental aspects of phase-separated biomolecular condensates. We introduce the relevant theoretical background, present the theoretical basis for the computation and experimental measurement of condensate properties, and give mechanistic interpretations of condensate behaviors and properties in terms of interactions at the molecular and residue levels.
- Published
- 2024
- Full Text
- View/download PDF
46. Calculating Structure Factors of Protein Solutions by Atomistic Modeling of Protein-Protein Interactions.
- Author
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Qin S and Zhou HX
- Abstract
We present a method, FMAPS(q), for calculating the structure factor, S ( q ) , of a protein solution, by extending our f ast Fourier transform-based m odeling of a tomistic p rotein-protein interactions (FMAP) approach. The interaction energy consists of steric, nonpolar attractive, and electrostatic terms that are additive among all pairs of atoms between two protein molecules. In the present version, we invoke the free-rotation approximation, such that the structure factor is given by the Fourier transform of the protein center-center distribution function g C ( R ) . At low protein concentrations, g C ( R ) can be approximated as e - β W ( R ) , where W ( R ) is the potential of mean force along the center-center distance R . We calculate W ( R ) using FMAPB2, a member of the FMAP class of methods that is specialized for the second virial coefficient [Qin and Zhou, J Phys Chem B 123 (2019) 8203-8215]. For higher protein concentrations, we obtain S ( q ) by a modified random-phase approximation, which is a perturbation around the steric-only energy function. Without adjusting any parameters, the calculated structure factors for lysozyme and bovine serum albumin at various ionic strengths, temperatures, and protein concentrations are all in reasonable agreement with those measured by small-angle X-ray or neutron scattering. This initial success motivates further developments, including removing approximations and parameterizing the interaction energy function.
- Published
- 2024
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47. Gestational Exposure to PM 2.5 and Specific Constituents, Meconium Metabolites, and Neonatal Neurobehavioral Development: A Cohort Study.
- Author
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Lu ZH, Liu C, Chen YJ, Chen YJ, Lei XN, Cai LJ, Zhou HX, Chang H, Zhu M, Wang YX, and Zhang J
- Subjects
- Humans, Female, Pregnancy, Cohort Studies, Infant, Newborn, Adult, Air Pollutants, Particulate Matter, Meconium chemistry, Maternal Exposure
- Abstract
Exposure to fine particulate matter (PM
2.5 ) during pregnancy has been inversely associated with neonatal neurological development. However, the associations of exposure to specific PM2.5 constituents with neonatal neurological development remain unclear. We investigated these associations and examined the mediating role of meconium metabolites in a Chinese birth cohort consisting of 294 mother-infant pairs. Our results revealed that exposure to PM2.5 and its specific constituents (i.e., organic matter, black carbon, sulfate, nitrate, and ammonium) in the second trimester, but not in the first or third trimester, was inversely associated with the total neonatal behavioral neurological assessment (NBNA) scores. The PM2.5 constituent mixture in the second trimester was also inversely associated with NBNA scores, and sulfate was identified as the largest contributor. Furthermore, meconium metabolome analysis identified four metabolites, namely, threonine, lysine, leucine, and saccharopine, that were associated with both PM2.5 constituents and NBNA scores. Threonine was identified as an important mediator, accounting for a considerable proportion (14.53-15.33%) of the observed inverse associations. Our findings suggest that maternal exposure to PM2.5 and specific constituents may adversely affect neonatal behavioral development, in which meconium metabolites may play a mediating role.- Published
- 2024
- Full Text
- View/download PDF
48. Metronomic chemotherapy in cancer treatment: new wine in an old bottle.
- Author
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Wu HL, Zhou HX, Chen LM, and Wang SS
- Subjects
- Humans, Angiogenesis Inhibitors administration & dosage, Angiogenesis Inhibitors therapeutic use, Antineoplastic Agents administration & dosage, Antineoplastic Agents therapeutic use, Animals, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Antineoplastic Combined Chemotherapy Protocols administration & dosage, Administration, Metronomic, Neoplasms drug therapy, Tumor Microenvironment drug effects
- Abstract
Over the past two decades, metronomic chemotherapy has gained considerable attention and has demonstrated remarkable success in the treatment of cancer. Through chronic administration and low-dose regimens, metronomic chemotherapy is associated with fewer adverse events but still effectively induces disease control. The identification of its antiangiogenic properties, direct impact on cancer cells, immunomodulatory effects on the tumour microenvironment, and metabolic reprogramming ability has established the intrinsic multitargeted nature of this therapeutic approach. Recently, the utilization of metronomic chemotherapy has evolved from salvage treatment for metastatic disease to adjuvant maintenance therapy for high-risk cancer patients, which has been prompted by the success of several substantial phase III trials. In this review, we delve into the mechanisms underlying the antitumour effects of metronomic chemotherapy and provide insights into potential combinations with other therapies for the treatment of various malignancies. Additionally, we discuss health-economic advantages and candidates for the utilization of this treatment option., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)
- Published
- 2024
- Full Text
- View/download PDF
49. Amino Acid-Dependent Material Properties of Tetrapeptide Condensates.
- Author
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Zhang Y, Prasad R, Su S, Lee D, and Zhou HX
- Abstract
Condensates formed by intrinsically disordered proteins mediate a myriad of cellular processes and are linked to pathological conditions including neurodegeneration. Rules of how different types of amino acids (e.g., π-π pairs) dictate the physical properties of biomolecular condensates are emerging, but our understanding of the roles of different amino acids is far from complete. Here we studied condensates formed by tetrapeptides of the form XXssXX, where X is an amino acid and ss represents a disulfide bond along the backbone. Eight peptides form four types of condensates at different concentrations and pH values: droplets (X = F, L, M, P, V, A); amorphous dense liquids (X = L, M, P, V, A); amorphous aggregates (X = W), and gels (X = I, V, A). The peptides exhibit enormous differences in phase equilibrium and material properties, including a 368-fold range in the threshold concentration for phase separation and a 3856-fold range in viscosity. All-atom molecular dynamics simulations provide physical explanations of these results. The present work also reveals widespread critical behaviors, including critical slowing down manifested by the formation of amorphous dense liquids and critical scaling obeyed by fusion speed, with broad implications for condensate function., Competing Interests: Competing interests: Authors declare that they have no competing interests.
- Published
- 2024
- Full Text
- View/download PDF
50. The global pattern of epiphytic liverwort disparity: insights from Frullania.
- Author
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Yu Y, Fan MY, Zhou HX, and Song YQ
- Subjects
- Biological Evolution, Biodiversity, Plant Dispersal, Hepatophyta genetics
- Abstract
The geographical and ecological patterns of morphological disparity are crucial to understand how species are assembled within communities in the context of the evolutionary history, morphological evolution and ecological interactions. However, with limited exceptions, rather few studies have been conducted on the global pattern of disparity, particularly in early land plants. Here we explored the spatial accumulation of disparity in a morphologically variable and species rich liverwort genus Frullania in order to test the hypothesis of latitude disparity gradient. We compiled a morphological data set consisting of eight continuous traits for 244 currently accepted species, and scored the species distribution into 19 floristic regions worldwide. By reconstructing the morphospace of all defined regions and comparisons, we identified a general Gondwana-Laurasia pattern of disparity in Frullania. This likely results from an increase of ecological opportunities and / or relaxed constraints towards low latitudes. The lowest disparity occurred in arid tropical regions, largely due to a high extinction rate as a consequence of paleoaridification. There was weak correlation between species diversity and disparity at different spatial scales. Furthermore, long-distance dispersal may have partially shaped the present-day distribution of Frullania disparity, given its frequency and the great contribution of widely distributed species to local morphospace. This study not only highlighted the crucial roles of paleoenvironmental changes, ecological opportunities, and efficient dispersal on the global pattern of plant disparity, but also implied its dependence on the ecological and physiological function of traits., (© 2024. The Author(s).)
- Published
- 2024
- Full Text
- View/download PDF
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