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Abstract Actin filament assembly and the regulation of its mechanical properties are fundamental processes essential for eukaryotic cell function. Residue E167 in vertebrate actins forms an inter-subunit salt bridge with residue K61 of the adjacent subunit. Saccharomyces cerevisiae actin filaments are more flexible than vertebrate filaments and have an alanine at this position (A167). Substitution of this alanine for a glutamic acid (A167E) confers Saccharomyces cerevisiae actin filaments with salt-dependent stiffness similar to vertebrate actins. We developed an optimized cryogenic electron microscopy workflow refining sample preparation and vitrification to obtain near-atomic resolution structures of wild-type and A167E mutant Saccharomyces cerevisiae actin filaments. The difference between these structures allowed us to pinpoint the potential binding site of a filament-associated cation that controls the stiffness of the filaments in vertebrate and A167E Saccharomyces cerevisiae actins. Through an analysis of previously published high-resolution reconstructions of vertebrate actin filaments, along with a newly determined high-resolution vertebrate actin structure in the absence of potassium, we identified a unique peak near residue 167 consistent with the binding of a magnesium ion. Our findings show how magnesium can contribute to filament stiffening by directly bridging actin subunits and allosterically affecting the orientation of the DNase-I binding loop of actin, which plays a regulatory role in modulating actin filament stiffness and interactions with regulatory proteins.

AIM: To report a one-year clinical outcomes of low-dose laser cycloplasty (LCP) among malignant glaucoma patients. METHODS: In this prospective, multicenter, non-comparative clinical study, participants with malignant glaucoma were recruited and underwent LCP at eight ophthalmic centers in China. Patients were followed up at 1wk, 1, 3, 6, and 12mo. Intraocular pressure (IOP), number of glaucoma medications, anterior chamber depth (ACD), and complications were recorded. Anatomical success was defined as the reformation of the anterior chamber based on slit-lamp biomicroscopy. Recurrence was defined by the presence of a shallow or ?at anterior chamber after initial recovery from treatment. RESULTS: A total of 34 eyes received LCP. Mean IOP and medications decreased from 36.1±11.5 mm Hg with 3.3±1.5 glaucoma medications pre-treatment to 20.9±9.8 mm Hg (P

Common challenges in cryogenic electron microscopy, such as orientation bias, conformational diversity, and 3D misclassification, complicate single particle analysis and lead to significant resource expenditure. We previously introduced an in silico method using the maximum Feret diameter distribution, the Feret signature, to characterize sample heterogeneity of disc-shaped samples. Here, we expanded the Feret signature methodology to identify preferred orientations of samples containing arbitrary shapes with only about 1000 particles required. This method enables real-time adjustments of data acquisition parameters for optimizing data collection strategies or aiding in decisions to discontinue ineffective imaging sessions. Beyond detecting preferred orientations, the Feret signature approach can serve as an early-warning system for inconsistencies in classification during initial image processing steps, a capability that allows for strategic adjustments in data processing. These features establish the Feret signature as a valuable auxiliary tool in the context of single particle analysis, significantly accelerating the structure determination process.

BackgroundDeep vein thrombosis (DVT) in lower extremities as a common complication of acute ischemic stroke (AIS) has long been studied. However, as the therapeutic options for AIS continue to advance, the pathogenic mechanisms behind DVT may change. Endovascular thrombectomy (EVT) has replaced intravenous thrombolysis and become the preferred treatment for AIS patients with large vessel occlusions. Therefore, it is important to update our understanding of DVT and its management. This study aimed to determine the prevalence and risk factors of DVT in AIS patients following EVT.MethodsIn this retrospective study, 245 AIS patients who had received EVT were recruited between January 2020 and December 2021. Within 10 days (median 4 days) of thrombectomy, DVT was diagnosed by ultrasonography. Demographic characteristics, clinical findings, and therapeutic procedures were compared between patients with and without DVT using univariate analysis. Cutoff points were defined for EVT time and plasma D-dimer concentration. Multivariable logistic regression was then used to determine the independent risk factors for DVT and evaluate their predictive power.ResultsThe prevalence of DVT in AIS patients after EVT was 27.3%. Multifactorial logistic regression analysis showed that age (OR 1.036, 95% CI 1.001–1.073; P = 0.045), female sex (OR 3.015, 95% CI 1.446–6.289; P = 0.003), lower limb muscle strength less than grade three (OR 7.015, 95% CI 1.887–26.080; P = 0.004), longer EVT time (OR 1.012, 95% CI 1.004–1.020; P = 0.003), and higher D-dimer levels (OR 1.350, 95% CI 1.150–1.585; P < 0.001) were independently associated with higher DVT risk in AIS patients following EVT. The cutoff points for operative time of EVT and plasma D-dimer were 65.5 min and 1.62 mg/L, respectively, above which the risk for DVT was dramatically increased with OR > 4 in AIS patients.ConclusionAIS patients are at increased risk of developing DVT following EVT particularly if they have undergone prolonged thrombectomy procedures and exhibit high plasma levels of D-dimers. However, the results of our study need to be validated by a multicenter prospective study with a larger population of stroke patients.

Temperature and food density are the most important factors influencing the population dynamics of rotifers. In the present study, the effects of temperature and food concentration on the developmental durations, egg ratio, and life-table demography in Brachionus angularis and Keratella valga were studied at four temperatures (15 °C, 20 °C, 25 °C and 30 °C) and four food levels (0.5 × 106, 1.0 × 106, 2.0 × 106 and 3.0 × 106 cells/mL Scenedesmus obliquus). The results showed significant effects of both temperature and food concentration, independently and interactively on the embryonic development (ED), juvenile period (JP), average lifespan (LS), generation time (T) and intrinsic rate of population increase (rm) in B. angularis, while the ED, life expectancy at hatching (e0), LS, T and rm in K. valga. In all conditions, the number of eggs per female and rm in B. angularis were higher than those in K. valga. These results suggested that B. angularis might be more suitable to mass culture in aquaculture than K. valga, and a potential prey for fish larvae in freshwater aquaculture.

PurposeThis study aimed to evaluate the efficacy and safety of predeposit autologous RBC apheresis (PARA) in patients undergoing multilevel spinal fusion surgery.MethodsA total of 112 patients from January 2020 to June 2022 were divided into two groups according to PARA: the PARA group (n = 51) and the control group (n = 61). The baseline characteristics of the patients, outcomes, transfusion cost, hospitalization cost, length of stay, complications, and changes in hemoglobin and hematocrit levels between the two groups were compared.ResultsThe baseline characteristics were similar in both groups. No significant differences were found in functional outcomes, including VAS score (p = 0.159), ODI score (p = 0.214), JOA score (p = 0.752), and SF-36 score (p = 0.188) between the PARA and control groups. The amount and rate of intraoperative and perioperative allogeneic RBC transfusion were significantly higher in the control group than in the PARA group (p < 0.001). The postoperative (9.04 ± 3.21 vs. 11.05 ± 3.84, p = 0.004) and total length of stay (15.78 ± 3.79 vs. 17.36 ± 4.08, p = 0.038) in the PARA group were significantly lower than those in the control group, respectively. Despite no difference in hospitalization cost (p = 0.737), the total blood transfusion cost in the PARA group was significantly lower, compared with the control group (p < 0.001). For safety evaluation, there were no significant differences in Hb and Hct levels between the two groups at admission, on postoperative day 1, and postoperative day 3, respectively (p > 0.05). Moreover, the number of postoperative infections in the PARA group was significantly lower than that in the control group (p = 0.038).ConclusionPARA was a novel, safe, and highly efficient technique for mass autologous blood preparation in a quite short preparation time. This method could significantly reduce the amount of allogeneic blood transfusion and length of stay, which could provide a theoretical basis for following clinical practice about the technique.

Argonaute (AGO) proteins are the core of the RNA-induced gene silencing complex which regulate a wide variety of processes in plants, from organ development to abiotic stress responses. They have been identified in many plants, but little is known in longan (Dimocarpus longan Lour.), and how AGO functions in the signaling pathways in plant embryos in response to changing environmental stimuli remains unclear. In the present research, a genome-wide analysis of the AGO gene family members and their roles in somatic embryogenesis (SE), zygotic embryogenesis (ZE), tissue developmental processes, and responses to hormones, light and abiotic stress in longan were conducted. Ten longan AGO genes were identified genome-wide and divided into four clades. They were distributed on chromosomes 1, 4, 8, 10, 12, 13, 14, and 15, and had 2–23 introns. The expression profiling implied that DIAGOs regulated early and middle embryogenesis, as well as developmental processes of seed, flower, and stem in longan. In addition, the transcript levels of DIAGOs in response to exogenous hormones, light and abiotic stress showed differences in expression patterns. These results provide the useful information for further elucidation of RNAi-mediated gene silencing in longan embryogenic callus (EC).

Plasmodium falciparum moves by an atypical process called gliding motility which comprises of atypical myosin A (PfMyoA) and filaments of the dynamic and divergent PfActin-1 (PfAct1). Here authors present the cryo-EM structure of PfMyoA bound to filamentous PfAct1 stabilized with jasplakinolide and provide insights into the interactions that are required for the parasite to produce the force and motion required for infectivity.

The baking industries and disinfection of tap water released a considerable amount of bromate into surface water, which has been reported as a carcinogenic compound to mammals. Rotifers play an important role in freshwater ecosystems and are model organisms to assess environmental contamination. In the present study, the effects of different concentrations (0.001, 0.01, 0.1, 1, 10, 100 and 200 mg/L) of bromate on the life-table and population growth parameters were investigated in the rotifer Brachionus calyciflorus. The results showed that the 24-h LC50 of bromate to B. calyciflorus was 365.29 mg/L (95%Cl: 290.37–480.24). Treatments with 0.01, 10 and 200 mg/L bromate shorten the reproductive period. High levels of bromate (100 and 200 mg/L) significantly decreased net reproductive rate, intrinsic rate of population increase, life span, mictic rate of B. calyciflorus. To investigate the underlying mechanisms, swimming speed and antioxidative biomarkers were compared between bromate treatments and the control. The results showed that glutathione (GSH) and malondialdehyde (MDA) contents, total superoxide dismutase (T-SOD) and peroxidase (POD) activities decreased significantly in response to bromate exposure and the reasons required further investigation. Treatments with 0.001–200 mg/L bromate all significantly reduced swimming linear speed to rotifer larvae and treatments with 100–200 mg/L bromate significantly suppressed the swimming linear speed of adult rotifer. These changes would reduce filtration of algal food and could explain the decreased survival and reproduction. Overall, bromate may not show acute toxicity to rotifers, but still have potential adverse effects on rotifer behavior, which may then influence the community structure in aquatic ecosystems.

Background & aimsHelicobacter pylori (H. pylori) infection remains high in China though the incidence of inflammatory bowel disease (IBD) has increased. Our aim was to investigate the relationship between the prevalence of H. pylori and inflammatory bowel disease.MethodsHospitalized IBD patients including Crohn's disease (CD) and ulcerative colitis (UC) who had tested H. pylori antibody were enrolled. Controls were chose from age- and sex- matched healthy physical examination people who had H. pylori antibody test in a 1:2 fashion (IBD patients:controls). IBD medical history was recorded. All patients were typed by the Montreal classification. Mayo Clinic score and the Harvey-Bradshaw Severity Index were used to evaluate their disease activity. Patients and controls that had H. pylori eradication therapy before were excluded.ResultsTwo hundred and sixty IBD patients including 213 CD patients and 47 UC patients, and 520 controls were involved in this study. The prevalence of H. pylori infection in IBD patients (9.6%, 25/260) and IBD newly diagnosed patients (12.1%, 8/66), as well as CD patients (8.9%, 19/213) including CD newly diagnosed patients (10.6%, 5/47) and UC patients (12.8%, 6/47) was significantly lower than controls (29.8%, 155/520) (p = 2.796*10-10, 0.007, 5.723*10-9, 0.016, 0.014), while there was no statistically difference between UC newly diagnosed patients and the controls, and IBD patients with different disease type, disease activity and treatment history.ConclusionsH. pylori infection had a negative association with IBD, especially CD.

Cell-cell and cell-matrix junctions transmit mechanical forces during tissue morphogenesis and homeostasis. α-Catenin links cell-cell adhesion complexes to the actin cytoskeleton, and mechanical load strengthens its binding to F-actin in a direction-sensitive manner. Specifically, optical trap experiments revealed that force promotes a transition between weak and strong actin-bound states. Here, we describe the cryo-electron microscopy structure of the F-actin-bound αE-catenin actin-binding domain, which in solution forms a five-helix bundle. In the actin-bound structure, the first helix of the bundle dissociates and the remaining four helices and connecting loops rearrange to form the interface with actin. Deletion of the first helix produces strong actin binding in the absence of force, suggesting that the actin-bound structure corresponds to the strong state. Our analysis explains how mechanical force applied to αE-catenin or its homolog vinculin favors the strongly bound state, and the dependence of catch bond strength on the direction of applied force.

Abstract At present, all cell strains derived from acute lymphoblastic leukemia (ALL) patients with the long arm of chromosome 11 aberration are accompanied with mixed lineage leukemia (MLL) gene rearrangement. In this study, we established a permanent ALL cell strain CHH-1 with the long arm of chromosome 11 aberration and without MLL rearrangement, hoping that it could be used for the research of ALL with such genetic abnormality. CHH-1 cell strain was certified through morphology, immunophenotype, genetics and immunoglobulin (Ig) gene rearrangement analysis. Cell characteristics including tumorigenic ability, semisolid colony forming ability, telomerase activity, autocrine and invasion were further detected. Cells were with an add(11)(q23) structural abnormality without MLL rearrangement, and were consistent with the genetic abnormality of the patient. In addition, these cells had features of tumor-forming ability, high colony forming capacity, unique cytokine autocrine mode, high telomerase activity, and high invasion ability. CHH-1 may prove to be a useful cell model for the research of human leukemia with genetic aberration in chromosome 11, and help explore the role of such genetic abnormality in the pathogenesis, progression and prognosis of ALL, and in developing new target drugs.

Using conventional imaging modalities, it is difficult to detect recurrent lesions in prostate cancer patients who have undergone biochemical relapse, especially in patients with low prostate-specific antigen (PSA) levels. We retrospectively reviewed the files of fifty patients with histopathologically confirmed prostate cancer who underwent 99mTc-labeled prostate-specific membrane antigen (PSMA) single-photon emission computed tomography (SPECT)/computed tomography (CT), magnetic resonance imaging (MRI), and bone scan within a 30-day period. PSMA-SPECT/CT indicated metastatic lesions in 39 patients and had a higher detection rate (78.0%) than bone scan (34.0%) or MRI (40.0%). The diagnostic efficiency of PSMA-SPECT/CT imaging for bone and lymph node metastases (50.0% and 42.0%) was better than bone scan (34.0% and 0.0%) or MRI (24.0% and 20.0%). PSMA-SPECT/CT provided a higher detection rate at serum PSA levels of ≤1 ng ml−1, 1-4 ng ml−1, 4-10 ng ml−1, and >10 ng ml−1. No correlation was found between Gleason score, PSA level, and the tracer tumor/background ratio of metastatic lesions. With the aid of PSMA-SPECT/CT imaging, the therapeutic strategy was changed for 31 patients, and this may have enhanced their clinical outcome. In conclusion, PSMA-SPECT/CT imaging could detect more metastatic lesions and achieve a higher detection rate than conventional imaging modalities at different serum PSA levels in prostate cancer patients who had undergone biochemical relapse.

Background and Objectives. The feasibility and safety of single-port laparoscopic surgery for left lateral liver lobectomy are largely unknown. This study is aimed at comparing the effectiveness and safety between single-port laparoscopic (SPL) and conventional multiport laparoscopic (CL) surgeries for hepatic left lateral sectionectomy. Methods. A total of 65 patients receiving laparoscopic hepatic left lateral sectionectomy between January 2008 and July 2015 were included and divided into the SPL group (n=40) and the CL group (n=25). Results. There was no significant difference in the operative time, estimated intraoperative blood loss, length of hospital stay, and incidences of postoperative complications (biliary leakage, hemorrhage, and contusion at incision) between groups (all P>0.05). However, the SPL group had a significantly lower VAS pain score (at 24 h but not 7 days postoperation) and higher cosmetic satisfaction scores (at both 2 months and 6 months postoperation) than the CL group (all P

Toxic effects of tribromomethane (TBM), a most used drinking water disinfection byproduct, on rotifers are unknown. we investigated the effects of TBM (0, 0.001, 15, 30, 45, 60, and 75 mg/L) on the life table demography of the freshwater rotifer, Brachionus calyciflorus, fed with three densities (1.0, 2.0, and 4.0 × 106 cells/mL) of Scenedesmus obliquus. It showed that the TBM exposure decreased survivorship and fecundity of the rotifer and significantly affected the developmental stages and life table demographic parameters of B. calyciflorus. Compared with the control, treatments with 30-75 mg/L TBM significantly prolonged the juvenile period of rotifer under different algal densities. Treatments with 0.001 and 15 mg/L TBM significantly decreased the net reproductive rate of rotifer under the algal density of 1.0 × 106 cells/mL, while increased and did not affect it under the algal density of 2.0 and 4.0 × 106 cells/mL, respectively. These results demonstrate that TBM is toxic to B. calyciflorus, and the increased algal density can reduce the toxic effects of TBM on rotifers. The current safety limit of TMB in natural water could affect the community structure of organisms in the aquatic system. [ABSTRACT FROM AUTHOR]