Search

Purpose: Patients with tumor-induced osteomalacia (TIO) often suffer from irreversible height loss due to vertebral deformity. However, the prevalence of vertebral deformity in TIO patients varies among limited studies. In addition, the distribution and type of vertebral deformity, as well as its risk factors, remain unknown. This study aimed to identify the prevalence, distribution, type and risk factors for vertebral deformity in a large cohort of TIO patients., Methods: A total of 164 TIO patients were enrolled in this retrospective study. Deformity in vertebrae T4-L4 by lateral thoracolumbar spine radiographs was evaluated according to the semiquantitative method of Genant. Bone microstructure was evaluated by trabecular bone score (TBS) and high-resolution peripheral QCT (HR-pQCT)., Results: Ninety-nine (99/164, 60.4%) patients had 517 deformed vertebrae with a bimodal pattern of distribution (T7-9 and T11-L1), and biconcave deformity was the most common type (267/517, 51.6%). Compared with patients without vertebral deformity, those with vertebral deformity had a higher male/female ratio, longer disease duration, more height loss, lower serum phosphate, higher bone turnover markers, lower TBS, lower areal bone mineral density (aBMD), lower peripheral volumetric BMD (vBMD) and worse microstructure. Lower trabecular vBMD and worse trabecular microstructure in the peripheral bone and lower spine TBS were associated with an increased risk of vertebral deformity independently of aBMD. After adjusting for the number of deformed vertebrae, we found little difference in clinical indexes among the patients with different types of vertebral deformity. However, we found significant correlations of clinical indexes with the number of deformed vertebrae and the spinal deformity index., Conclusion: We reported a high prevalence of vertebral deformity in the largest cohort of TIO patients and described the vertebral deformity in detail for the first time. Risk factors for vertebral deformity included male sex, long disease duration, height loss, abnormal biochemical indexes and bone impairment. Clinical manifestation, biochemical indexes and bone impairment were correlated with the number of deformed vertebrae and degree of deformity, but not the type of deformity., (© 2022. The Author(s), under exclusive licence to Italian Society of Endocrinology (SIE).)

Objective: To evaluate the ability of 68 Ga-Pentixafor (nuclide ligand imaging agents for chemokine receptor 4) PET/CT to differentiate between aldosterone-producing adenoma (APA) and adrenal nonfunctional adenoma (NFA), and to assess how well this imaging method correlates with clinical features and postoperative outcomes. Methods: This was a cross-sectional study involving 73 APA and 12 NFA patients who received 68 Ga-Pentixafor PET/CT imaging at Peking Union Medical College Hospital from August 2018 to October 2021. The receiver operating characteristic (ROC) curve was used to evaluate the differential value of visual analysis and the maximum standard uptake value (SUV max ) of the focus on APA and NFA. The related factors of SUV max , and its predictive effect on postoperative outcomes were analyzed using Pearson or Spearman analysis and χ 2 text. Results: 68 Ga-Pentixafor PET/CT imaging was positive in 64 APA patients (sensitivity=87.7%) and negative in all 12 NFA patients (specificity=100%). The area under the ROC curve with SUV max differentiating APA and NFA was 0.932 ( P <0.001). When the SUV max cut-off point was 6.23, the sensitivity was 80.8% and the specificity was 100%. The SUV max correlated positively with lesion size ( r =0.598) and aldosterone/renin activity ratio ( r =0.313) and correlated negatively with potassium level ( r =-0.286), renin activity ( r =-0.240) and age of diagnosis ( r =-0.273) (all P <0.05). Of the patients who underwent adrenalectomy and received more than 6 months of post-surgical follow-up, the clinical complete remission rate was higher for 68 Ga-Pentixafor PET/CT imaging-positive patients than imaging-negative patients (24/39 vs. 0/4, P =0.031). Conclusions: 68 Ga-Pentixafor PET/CT is effective at differentiating between APA and NFA. The SUV max of 68 Ga-Pentixafor PET/CT correlates with age at onset, lesion size, and the severity of clinical manifestations, and is able to predict postoperative outcomes.

Pancreatic neuroendocrine neoplasms (pNENs) are highly heterogeneous, and the management of pNENs patients can be intractable. To address this challenge, an expert committee was established on behalf of the Group of Pancreatic Surgery, Chinese Society of Surgery, Chinese Medical Association, which consisted of surgical oncologists, gastroenterologists, medical oncologists, endocrinologists, radiologists, pathologists, and nuclear medicine specialists. By reviewing the important issues regarding the diagnosis and treatment of pNENs, the committee concluded evidence-based statements and recommendations in this article, in order to further improve the management of pNENs patients in China.

Objective: To investigate the effect of microRNA-26a-5p on osteogenic differentiation of human periodontal ligament stem cells (hPDLSC) and its related mechanisms. Methods: hPDLSC in periodontal tissues from healthy adults and hPDLSC from periodontitis patients (PPDLSC) were isolated and cultured in vitro , respectively. The PPDLSC were divided into Ⅰ, Ⅱ, Ⅲ, Ⅳ and Ⅴ groups. Group Ⅰ is control group, and the other four groups were transiently transfected with miR-NC, miR-26a-5p, antimiR-NC and antimiR-26a-5p lentiviral vectors, respectively. The osteogenic differentiation abilities of the cells in vitro were determined by alizarin red staining, alkaline phosphatase (ALP) activity assay and real-time quantitative PCR (qPCR). Totally 40 male mice (6-weeks) were equally divided into five groups with 8 mice in each group. The PPDLSCs cells (1×10(7)/ml) in Ⅰ, Ⅱ, Ⅲ, Ⅳ and Ⅴ groups, which adhered to hydroxyapatine-tricalcium phosphate (HA-TCP), were implanted into the nude mice subcutaneously and the animal models were constructed to analyze the effect of miR-26a-5p on the osteogenic differentiation of PPDLSCs in vivo . PPDLSCs were divided into A, B, C, D groups, and transfected with miR-26a-5p+Wnt5a-Wt, miR-NC+Wnt5a-Wt, miR-26a-5p+Wnt5a-Mut and miR-NC+Wnt5a-Mut in each of the above mentioned 5 groups, respectively. The luciferase activity assay was used to detect the relative luciferase in A, B, C and D groups to analyze the targeting relationship between miR-26a-5p and Wnt5a. Osteogenic differentiation related proteins expression were analyzed by western blotting. Results: hPDLSC and PPDLSC were observed consistent with the characteristics of mesenchymal stem cells and had osteogenic differentiation ability in vitro . Compared with hPDLSC [(89.87±8.12)%], the osteogenic capacity of PPDLSC [(31.46±6.56)%] was significantly lower ( P< 0.05). The ALP activity (1.88±0.59), calcified nodules (79.88±5.92), the expression of the osteogenic differentiation markers Runt-related transcription factor 2 (Runx2) (2.40±0.70), ALP (2.10±0.60) and osteocalcin (3.00±0.90) mRNA in the PPDLSC from Group Ⅲ were significantly higher in comparison with the control group [(0.88±0.34), (29.69±2.65), (1.30±0.30), (0.09±0.25), (1.71±0.50)], while those from Group Ⅴ[(0.44±0.07), (14.83±3.05), (0.50±0.11), (0.30±0.08) and (0.80±0.17)] were significantly lower ( P< 0.05). In vivo studies in nude mice showed that the proportion of the osteogenic region [(34.96±5.65)%] in the miR-26a-5p group was significantly increased in comparison with the control group [(23.28±3.03)%], while in the antimiR-26a-5p group [(8.02±2.27)%] was significantly lower ( P< 0.05). The luciferase activity of the Group A (0.46±0.06) was significantly lower than Group B (3.46±0.45) ( P< 0.05). Compared with the control group, the expression levels of Wnt5a protein, calmodulin kinase Ⅱ and protein kinase C proteins in the Group Ⅲ were significantly decreased, while those in the GroupⅤ were significantly increased ( P< 0.05). Conclusions: MicroRNA-26a-5p could promote osteogenic differentiation of PPDLSC in vivo and in vitr o, and its mechanism might be inhibiting the activation of Wnt/Ca(2+) signaling pathway by targeting Wnt5a.

Aim: To determine the optimal cut-points of visceral adipose tissue (VAT) areas at different anatomic levels to discriminate participants with cardiometabolic risk factors in a Chinese middle-aged population., Methods: A total of 1744 individuals who underwent regular health checks in Nanjing BENQ Medical Center from January 2013 to December 2016 were included in this cross-sectional study. VAT areas were measured by abdominal quantitative computed tomography at the L2/3 intervertebral disk and umbilicus levels. Cardiometabolic risk factors including serum triglycerides, HDL cholesterol levels, plasma glucose and blood pressure were defined using IDF 2005 criteria for metabolic syndrome., Results: The cut-points for VAT area at the umbilicus level were 111 cm 2 for men and 96 cm 2 for women to identify people with one or more cardiometabolic risk factors. For VAT area at the L2/3 level, the optimal cut-points were 142 cm 2 for men and 115 cm 2 for women. A VAT area at the L2/3 level of ≥ 142 cm 2 for men or 115 cm 2 for women significantly increased the prevalence of hyperglycaemia [odds ratio (OR) 3.18, 95% confidence interval (CI) 2.45-4.13], hypertension (OR 2.81, 95% CI 2.27-3.49) and dyslipidaemia (OR 4.37, 95% CI 3.50-5.45) after adjusting age., Conclusions: The optimal cut-points for VAT area at the umbilicus level and L2/3 level were 111 cm 2 and 142 cm 2 for men and 96 cm 2 and 115 cm 2 for women to identify participants with one or more cardiometabolic risk factors., (© 2019 Diabetes UK.)

We have introduced an effective treatment for mandibular condylar osteochondroma with a digital cutting guide and endoscopically-assisted vertical ramus osteotomy (VRO). Eleven patients with unilateral condylar osteochondroma, who did not require orthognathic surgery or had less than 3mm deviation of the chin and a stable occlusion, were treated during the period April 2013-January 2017 with a digital cutting guide and endoscopically-assisted VRO. Clinical data collected included the occlusion, facial contour, and maximum mouth opening (MMO). Computed tomographic (CT) scans were taken before and after operation. Two patients also had additional shaping of the mandibular contour. The pathological diagnosis was confirmed to be osteochondroma in all cases. A mean (range) 19 (12-40) months of follow-up for all 11 cases showed stable postoperative occlusion and facial aesthetics. There were no functional disturbances, recurrence, or condylar absorption. VRO is an alternative to orthognathic surgery for patients with osteochondroma who do not have severe malocclusions. The digital cutting guide and endoscopically-assisted VRO make it possible to achieve precise resection of the tumour and maintain the occlusion with minimal invasion., (Copyright © 2018 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Background: Fas-associated protein with death domain (FADD) is a classic adaptor protein in apoptosis. Increasing evidence has shown that FADD is also implicated in T-cell development, activation and proliferation. The role of FADD in inflammatory disorders remains largely unexplored., Aim: To assess the role of FADD in inflammatory disorders., Methods: We established an experimental model of contact hypersensitivity (CHS) by using 2,4,6-trinitrochlorobenzene (TNCB) on transgenic mice expressing a dominant negative mutant of FADD (FADD-DN), RESULTS: CHS responses were clearly attenuated in FADD-DN mice compared with control mice. In the retroauricular lymph nodes, the ratio of CD8+ T cells was also decreased., Conclusion: FADD-DN appears to play a protective role in TNCB-induced CHS reactions., (© 2017 British Association of Dermatologists.)

Aims: To examine whether the age profile of people with Type 1 diabetes differs from that of the general population and in what manner, and to study the clinical characteristics related to metabolic disorders among people with Type 1 diabetes in China., Methods: We sequentially enrolled 849 people with Type 1 diabetes from hospital records review, inpatient wards and outpatient clinics. Data were collected via face-to-face interviews, medical records and venous blood samples. Beijing census data for 2011 were used to provide the general population statistics. Descriptive analysis of the results and tests for differences were performed., Results: The median (interquartile range) age at diagnosis of diabetes was 16 (9-28) years and the duration of diabetes was 4 (1-8) years. The mean ± sd HbA 1c concentration was 76±28 mmol/mol (9.1±2.5%). Compared with the general population, the population with Type 1 diabetes comprised more young individuals and fewer elderly individuals. The overall prevalence of metabolic syndrome among those with Type 1 diabetes was 10.1% (95% CI 7.9-12.2). People with metabolic syndrome were older and were diagnosed with diabetes at an older age. Hypertension and dyslipidaemia were more common in obese individuals with Type 1 diabetes than in their non-obese counterparts., Conclusions: Compared with the general population, people with Type 1 diabetes comprised more young and fewer elderly individuals. The prevalence of metabolic syndrome in the Type 1 diabetes population was 10.1%. Hypertension and dyslipidaemia were more prevalent in obese than non-obese individuals., (© 2018 Diabetes UK.)

Objective: To investigate the prognostic value of dynamic monitoring of RUNX1-RUNX1T1 transcript in pediatric patients with t (8;21) acute myeloid leukemia (AML) . Methods: The clinical features and RUNX1-RUNX1T1 transcript levels of 55 pediatric t (8;21) AML patients, newly diagnosed from Jan. 2010 to Apr. 2016, were analyzed retrospectively. The relationship between the minimal residual disease (MRD) and prognosis was analysed by dynamic monitoring of RUNX1-RUNX1T1 transcript levels using real-time quantitative PCR (RQ-PCR) technology. Results: The RUNX1-RUNX1T1 transcript levels in bone marrow cells at diagnosis was not related to relapse. After one course of induction therapy, patients with a more than 2 Log reduction of RUNX1-RUNX1T1 transcript levels (>2 Log) had lower 5 years cumulative incidence of relapse (CIR) [ (24.3±8.4) % vs (52.6±9.7) %, χ (2)=9.046, P =0.003], relapse-free survival (RFS) [ (71.6±12.7) % vs (48.1±13.2) %, χ (2)=5.814, P =0.016], and better overall survival (OS) [ (76.9±12.5) % vs (48.9±14.7) %, χ (2)=6.346, P =0.012], compared to patients with a less than 2 Log reduction (a<2 Log) . Multivariate Cox survival analysis suggested that a>2 Log reduction in RUNX1-RUNX1T1 transcript levels after a course of induction therapy was an independent prognostic factor for RFS ( HR =0.263, 95% CI 0.081-0.851, P =0.026) and OS ( HR =0.214, 95% CI 0.057-0.808, P =0.023) . During consolidation therapy and follow-up period, molecular relapse of 16 cases and hematologic relapse of 13 cases were identified by continuous dynamic monitoring of RUNX1-RUNX1T1 transcript levels, with a median interval of 4.0 (1.5-5.8) months from the molecular relapse to hematologic relapse. 2 cases of molecular relapse who received timely allogeneic hematopoietic stem cell transplantation did not experience hematologic relapse. Conclusion: Dynamic monitoring RUNX1-RUNX1T1 transcript levels by RQ-PCR technique can subdivide patients into relatively low and high risk group, early screen patients at high risk of relapse and provide a scientific basis for precision stratification and risk-adapted therapy for pediatric t (8;21) AML children.

Objective: To explore the application value of pedicled thoracodorsal artery perforator flap in immediate partial breast reconstruction for breast cancer. Methods: This study is a prospective case series studies. Totally 128 cases of primary breast cancer patients who prepared to receive the breast-conserving surgery combine with immediate partial breast reconstruction of pedicled thoracodorsalartery perforator flap were enrolled in Breast Cancer Prevention and Treatment Center of Peking University Cancer Hospital from June 2013 to March 2016. Finally, the operations had been completed successfully in 33 eligible cases. All patients were female with a median age of 40 years (ranging from 22 to 52 years). The perforator vessel location, the donor area design, the post-operative complications, the influence of radiation and chemotherapy had been evaluated. Results: The average diameter of thoracic dorsal artery perforators measured by Doppler ultrasound before the operation was (1.5±0.4) mm (ranging from 0.6 to 2.7 mm). The average size of flaps was 15 cm×6 cm. The average time of operations was (271±72) minutes (ranging from 120 to 245 minutes). Drainage tube removed on (4.7±2.1) days after operation (ranging from 3 to 12 days). All patients received follow-up, and there was no local recurrence and distant metastasis during a median follow-up of 17(12) months ( M ( Q(R) )) (ranging from 5 to 38 months). All TDAP flaps were survival, the wound complication rates was 6% (2/33). Conclusions: The breast reconstruction of pedicled thoracodorsal artery perforator flap is a good choice of repairing local breast defect of breast conserving surgery.Its advantages are no-influence of latissimus dorsi function and little complications in donor area.

Objective: To establish SD rat posterior capsular opacification (posterior capsular opacification- PCO) animal model, and to detect the expression of Akt/NF-kb signaling pathway in the PCO model., Methods: 30 healthy SD rats were randomly divided into control group (0d) and the experimental groups (7d and 14 d), there were 10 rats at all time points. All rats (right eye) were treated with the lens capsule, and the inflammatory reaction of the anterior segment of the eye and the occurrence of PCO at different time points were observed under the microscope. The TGF-β concentration of humor aquosus was measured at the different time points by ELISA method. Eyeballs were removed after the rats were killed. RT-PCR method was used to detect the gene expression levels of Akt and NF-κb and Westen Blot method to detect the protein expression of Akt, p-Akt, NF-κb and p-NF-κb., Results: TGF-β concentration, Akt and NF-κb gene expression, and Akt, p-Akt, NF-κb and p-NF-κb protein expression in humor aquosus, increased with the time and the time-dependence was significant., Conclusion: Akt/NF-κb signaling pathway may be closely related to the occurrence and development of PCO, which may be related to the role of protein phosphorylation (Fig. 5, Ref. 20).

Aim: To investigate the ability of combined 2-[ 18 F]-fluoro-2-deoxy-d-glucose ( 18 F-FDG) positron-emission tomography (PET)/computed tomography (CT) to determine potential causes of secondary haemophagocytic lymphohistiocytosis (sHLH) and to predict prognosis., Material and Methods: Forty-three patients (male/female 20/23, median age 48.5 years), who were diagnosed with sHLH and underwent FDG-PET/CT before treatment, were retrospectively reviewed. The clinical characteristics were compared to identify the predictors of high-yield FDG-PET/CT. Univariate and multivariate analyses were conducted to identify factors associated with survival. Statistical analysis was performed using SPSS version 19.0., Results: PET results were helpful in 65.1% (28/43), whilst non-contributory in 34.9% (15/43) of patients with regard to the final diagnosis. Lymphoma was the most common (25/43) reason for sHLH, and patients with focal FDG uptake were more likely to be diagnosed with underlying diseases. C-reactive protein (CRP) was found to be a good indicator for the usefulness of PET/CT in HLH patients. Multivariate analysis showed that therapy regimen (hazard ratio [HR]=4.99, p=0.026), fibrinogen (FBG) <1.5 g/l (HR=3.87, p=0.049) and spleen:mediastinum ratio (SP/M) (HR=7.44, p=0.006) were independent prognostic factors for survival., Conclusion: FDG-PET/CT could be a useful technique for detecting underlying diseases causing sHLH. CRP was a useful predictor of FDG-PET/CT effectiveness. Therapy regimen, FBG level, and SP/M were independent prognostic factors for HLH survival., (Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Background: Guidelines for the use of chemotherapy and endocrine therapy recently recommended that estrogen receptor (ER) status be considered positive if ≥1% of tumor cells demonstrate positive nuclear staining by immunohistochemistry. In clinical practice, a range of thresholds are used; a common one is 10% positivity. Data addressing the optimal threshold with regard to the efficacy of endocrine therapy are lacking. In this study, we compared patient, tumor, treatment and survival differences among breast cancer patients using ER-positivity thresholds of 1% and 10%., Methods: The study population consisted of patients with primary breast carcinoma treated at our center from January 1990 to December 2011 and whose records included complete data on ER status. Patients were separated into three groups: ≥10% positive staining for ER (ER-positive ≥10%), 1%-9% positive staining for ER (ER-positive 1%-9%) and <1% positive staining (ER-negative)., Results: Of 9639 patients included, 80.5% had tumors that were ER-positive ≥10%, 2.6% had tumors that were ER-positive 1%-9% and 16.9% had tumors that were ER-negative. Patients with ER-positive 1%-9% tumors were younger with more advanced disease compared with patients with ER-positive ≥10% tumors. At a median follow-up of 5.1 years, patients with ER-positive 1%-9% tumors had worse survival rates than did patients with ER-positive ≥10% tumors, with and without adjustment for clinical stage and grade. Survival rates did not differ significantly between patients with ER-positive 1%-9% and ER-negative tumors., Conclusions: Patients with tumors that are ER-positive 1%-9% have clinical and pathologic characteristics different from those with tumors that are ER-positive ≥10%. Similar to patients with ER-negative tumors, those with ER-positive 1%-9% disease do not appear to benefit from endocrine therapy; further study of its clinical benefit in this group is warranted. Also, there is a need to better define which patients of this group belong to basal or luminal subtypes.

The magnetization behaviors and spin configurations of the classical Ising model on a Shastry-Sutherland lattice are investigated using Monte Carlo simulations, in order to understand the fascinating magnetization plateaus observed in TmB(4) and other rare-earth tetraborides. The simulations reproduce the 1/2 magnetization plateau by taking into account the dipole-dipole interaction. In addition, a narrow 2/3 magnetization step at low temperature is predicted in our simulation. The multi-step magnetization can be understood as the consequence of the competitions among the spin-exchange interaction, the dipole-dipole interaction, and the static magnetic energy.

STAR's measurements of directed flow (v1) around midrapidity for π±, K±, KS0, p, and p[over ¯] in Au+Au collisions at √[sNN]=200  GeV are presented. A negative v1(y) slope is observed for most of produced particles (π±, K±, KS0, and p[over ¯]). In 5%-30% central collisions, a sizable difference is present between the v1(y) slope of protons and antiprotons, with the former being consistent with zero within errors. The v1 excitation function is presented. Comparisons to model calculations (RQMD, UrQMD, AMPT, QGSM with parton recombination, and a hydrodynamics model with a tilted source) are made. For those models which have calculations of v1 for both pions and protons, none of them can describe v1(y) for pions and protons simultaneously. The hydrodynamics model with a tilted source as currently implemented cannot explain the centrality dependence of the difference between the v1(y) slopes of protons and antiprotons.

We report new STAR measurements of midrapidity yields for the Λ, Λ[over ¯], K(S)(0), Ξ(-), Ξ[over ¯](+), Ω(-), Ω[over ¯](+) particles in Cu+Cu collisions at √S(NN)==200  GeV, and midrapidity yields for the Λ, Λ[over ¯], K(S)(0) particles in Au+Au at √S(NN)==200  GeV. We show that, at a given number of participating nucleons, the production of strange hadrons is higher in Cu+Cu collisions than in Au+Au collisions at the same center-of-mass energy. We find that aspects of the enhancement factors for all particles can be described by a parametrization based on the fraction of participants that undergo multiple collisions.

We report transverse momentum (p(T)≤15  GeV/c) spectra of π(±), K(±), p, p[over ¯], K(S)(0), and ρ(0) at midrapidity in p+p and Au+Au collisions at √S(NN)=200  GeV. Perturbative QCD calculations are consistent with π(±) spectra in p+p collisions but do not reproduce K and p(p[over ¯]) spectra. The observed decreasing antiparticle-to-particle ratios with increasing p(T) provide experimental evidence for varying quark and gluon jet contributions to high-p(T) hadron yields. The relative hadron abundances in Au+Au at p(T)≳8  GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.

Metaplastic sarcomatoid carcinoma (MSC) of the breast is usually triple receptor (ER, PR, and HER2) negative and is not currently recognized as being more aggressive than other triple receptor-negative breast cancers. We reviewed archival tissue sections from surgical resection specimens of 47 patients with MSC of the breast and evaluated the association between various clinicopathologic features and patient survival. We also evaluated the clinical outcome of MSC patients compared to a control group of patients with triple receptor-negative invasive breast carcinoma matched for patient age, clinical stage, tumor grade, treatment with chemotherapy, and treatment with radiation therapy. Factors independently associated with decreased disease-free survival among patients with stage I-III MSC of the breast were patient age > 50 years (P = 0.029) and the presence of nodal macrometastases (P = 0.003). In early-stage (stage I-II) MSC, decreased disease-free survival was observed for patients with a sarcomatoid component comprising ≥ 95% of the tumor (P = 0.032), but tumor size was the only independent adverse prognostic factor in early-stage patients (P = 0.043). Compared to a control group of triple receptor-negative patients, patients with stage I-III MSC had decreased disease-free survival (two-sided log rank, P = 0.018). Five-year disease-free survival was 44 ± 8% versus 74 ± 7% for patients with MSC versus triple receptor-negative breast cancer, respectively. We conclude that MSC of the breast appears more aggressive than other triple receptor-negative breast cancers.

We report the first measurement of the parity-violating single-spin asymmetries for midrapidity decay positrons and electrons from W+ and W- boson production in longitudinally polarized proton-proton collisions at sqrt[s] = 500 GeV by the STAR experiment at RHIC. The measured asymmetries, A(L)(W+) = -0.27 ± 0.10(stat.) ± 0.02(syst.) ± 0.03(norm.) and A(L)(W-) = 0.14 ± 0.19(stat.) ± 0.02(syst.) ± 0.01(norm.), are consistent with theory predictions, which are large and of opposite sign. These predictions are based on polarized quark and antiquark distribution functions constrained by polarized deep-inelastic scattering measurements.

The contribution of B meson decays to nonphotonic electrons, which are mainly produced by the semileptonic decays of heavy-flavor mesons, in p + p collisions at √s=200  GeV has been measured using azimuthal correlations between nonphotonic electrons and hadrons. The extracted B decay contribution is approximately 50% at a transverse momentum of pT≥5  GeV/c. These measurements constrain the nuclear modification factor for electrons from B and D meson decays. The result indicates that B meson production in heavy ion collisions is also suppressed at high pT.

We report the first measurements of the kurtosis (κ), skewness (S), and variance (σ2) of net-proton multiplicity (Np-Np) distributions at midrapidity for Au+Au collisions at square root of s(NN)=19.6, 62.4, and 200 GeV corresponding to baryon chemical potentials (μB) between 200 and 20 MeV. Our measurements of the products κσ2 and Sσ, which can be related to theoretical calculations sensitive to baryon number susceptibilities and long-range correlations, are constant as functions of collision centrality. We compare these products with results from lattice QCD and various models without a critical point and study the square root of s(NN) dependence of κσ2. From the measurements at the three beam energies, we find no evidence for a critical point in the QCD phase diagram for μB below 200 MeV.

We report the first three-particle coincidence measurement in pseudorapidity (Δη) between a high transverse momentum (p⊥) trigger particle and two lower p⊥ associated particles within azimuth |Δϕ|<0.7 in square root of s(NN)=200 GeV d+Au and Au+Au collisions. Charge ordering properties are exploited to separate the jetlike component and the ridge (long range Δη correlation). The results indicate that the correlation of ridge particles are uniform not only with respect to the trigger particle but also between themselves event by event in our measured Δη. In addition, the production of the ridge appears to be uncorrelated to the presence of the narrow jetlike component.

Nuclear collisions recreate conditions in the universe microseconds after the Big Bang. Only a very small fraction of the emitted fragments are light nuclei, but these states are of fundamental interest. We report the observation of antihypertritons--comprising an antiproton, an antineutron, and an antilambda hyperon--produced by colliding gold nuclei at high energy. Our analysis yields 70 +/- 17 antihypertritons ((Lambda)(3)-H) and 157 +/- 30 hypertritons (Lambda3H). The measured yields of Lambda3H ((Lambda)(3)-H) and 3He (3He) are similar, suggesting an equilibrium in coordinate and momentum space populations of up, down, and strange quarks and antiquarks, unlike the pattern observed at lower collision energies. The production and properties of antinuclei, and of nuclei containing strange quarks, have implications spanning nuclear and particle physics, astrophysics, and cosmology.

Parity-odd domains, corresponding to nontrivial topological solutions of the QCD vacuum, might be created during relativistic heavy-ion collisions. These domains are predicted to lead to charge separation of quarks along the system's orbital momentum axis. We investigate a three-particle azimuthal correlator which is a P even observable, but directly sensitive to the charge separation effect. We report measurements of charged hadrons near center-of-mass rapidity with this observable in Au + Au and Cu + Cu collisions at square root of s(NN) = 200 GeV using the STAR detector. A signal consistent with several expectations from the theory is detected. We discuss possible contributions from other effects that are not related to parity violation.

Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au + Au and p + p collisions at square root of s(NN) = 200 GeV. Strong short- and long-range correlations (LRC) are seen in central Au + Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short-range correlations are observed in peripheral Au + Au collisions. Both the dual parton model (DPM) and the color glass condensate (CGC) predict the existence of the long-range correlations. In the DPM, the fluctuation in the number of elementary (parton) inelastic collisions produces the LRC. In the CGC, longitudinal color flux tubes generate the LRC. The data are in qualitative agreement with the predictions of the DPM and indicate the presence of multiple parton interactions.

We report K/pi fluctuations from Au + Au collisions at sqrt[s(NN)]= 19.6, 62.4, 130, and 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider. K/pi fluctuations in central collisions show little dependence on incident energy and are on the same order as those from NA49 at the Super Proton Synchrotron in central Pb + Pb collisions at sqrt[s(NN)]=12.3 and 17.3 GeV. We report results for the collision centrality dependence of K/pi fluctuations and results for charge-separated fluctuations. We observe that the K/pi fluctuations scale with the charged particle multiplicity density.

Seven-in-absentia homologue 1 (Siah1) is an E3 ubiquitin ligase that regulates the ubiquitination and proteasome-dependent degradation of a number of proteins. Here we report that Siah1 modulates multidrug resistance 1 (MDR1)/P-glycoprotein-mediated drug resistance in the cancer cell lines examined. Siah1, but not its ligase-dead mutant, down-regulates MDR1/P-glycoprotein and sensitizes the multidrug-resistant cells to chemotherapeutic agents. Mechanistically, Siah1 does not promote P-glycoprotein degradation but decreases its expression transcriptionally by promoting c-Jun transcription factor binding to the activator protein 1 (AP1) site in the MDR1 promoter. Moreover, Siah1 triggers c-Jun NH2-terminal kinase (JNK) activation, leading to enhanced phosphorylation of c-Jun, and the JNK/c-Jun signalling axis is critical for Siah1 to down-regulate MDR1/P-glycoprotein expression. These findings demonstrate a previously unidentified role for Siah1 in regulating MDR1/P-glycoprotein expression through the JNK/c-Jun pathway.

Atrial natriuretic peptide (ANP) as well as its receptors is found in mammalian ovary and follicular cells and its function in oocyte meiotic maturation has also been reported in Xenopus, hamster and rat. But the results are controversial and the physiological mechanism of ANP on oocyte maturation is not clear, especially the relationship between gonadotrophin and ANP as well as the signal transduction, and these need further study. The present study conducted experiments to examine these questions by using drug treatment and Western blot analysis and focused on pig oocyte meiotic maturation and cumulus expansion in vitro. The results revealed that ANP could inhibited FSH-induced pig oocyte maturation and cumulus expansion and prevent the full phosphorylation of mitogen-activated protein kinase in both oocytes and cumulus cells, and that these inhibitory effects could be mimicked by 8-Br-cyclic guanosine 5'-monophosphate (8-Br-cGMP), but blocked by a protein kinase G (PKG) inhibitor KT5823. Zaprinast, a cGMP-specific phosphodiesterase inhibitor, could enhance the inhibitory effect of ANP on oocyte maturation. A specific analogue of ANP, C-ANP-(4-23), which binds to the natriuretic peptide receptor-C (NPRC), had no effect in either FSH-induced or spontaneous oocyte maturation. Treatment with forskolin, a stimulator of adenylate cyclase, had a biphasic effect; 44 h treatment induced cumulus expansion but inhibited oocyte maturation while 2 h treatment induced maturation of cumulus-enclosed oocytes (CEOs). Both ANP and C-ANP-(4-23) could inhibit the effect of forskolin on CEO maturation, and these inhibitory effects of ANP/C-ANP-(4-23) could be blocked by preincubation with pertussis toxin (PT), consistent with mediation by a Gi protein(s) in the cumulus cells. All these results suggest that ANP is a multifunctional regulator of FSH and forskolin on pig CEO maturation by two signalling mechanisms: one is via a cGMP/PKG pathway, the other is via NPRC receptors in cumulus cells and the activation of the PT-sensitive Gi protein(s).

Aims: Invasive micropapillary carcinoma (IMPC) is a rare variant of ductal carcinoma of the breast and is characterized by high metastatic potential and an aggressive clinical course. This tumour is hence ideal for studying the mechanism underlying tumour biological behaviour, especially metastasis. Cell adhesion molecules, such as CD44 and E-cadherin (Ecad), and angiogenesis are considered important in the invasion and metastasis of tumours., Methods and Results: We immunohistochemically analysed 23 IMPCs for expression of a standard form of CD44 (CD44s), Ecad, and CD34 to measure microvessel density (MVD). Results are compared with the changes observed in 23 tubular carcinomas (TCs), another variant of ductal carcinoma that rarely metastasizes. Evaluation of haematoxylin and eosin (H&E) sections showed a higher prevalence of lymph-vascular invasion (19/23, 83%) and regional lymph node involvement (12/15, 80%) in IMPCs; whereas no lymph-vascular invasion or lymph node metastasis was identified in TCs. Loss or reduction of CD44s immunoreactivity was significantly frequent in IMPC (39%) compared with TC (4%) (P = 0.0098), and was associated with positive axillary lymph nodes and lymph-vascular invasion. All cases of IMPC and TC strongly expressed Ecad. MVD (in five 200x fields) was significantly higher in IMPC (88 +/- 37) than in TC (57 +/- 16) (P = 0.001). In the IMPC group, MDV was higher in cases with positive lymph node(s) (P = 0.048), and cases with loss or reduction of CD44s expression (P = 0.011). The same trend was also demonstrated in cases with lymph-vascular invasion (P = 0.077). Moreover, the vessels in IMPC had much smaller calibres with thinner walls than those in TC., Conclusions: Loss of the CD44 adhesion molecule and high MVD may play a significant role in the high incidence of lymph-vascular permeation and metastasis in IMPC.

The yield for the multistrange Xi(-) hyperon has been measured in 6A GeV Au+Au collisions via reconstruction of its decay products pi(-) and Lambda, the latter also being reconstructed from its daughter tracks of pi(-) and p. The measurement is rather close to the threshold for Xi(-) production and therefore provides an important test of model predictions. The measured yield for Xi(-) and Lambda are compared for several centralities. In central collisions the Xi(-) yield is found to be in excellent agreement with statistical and transport model predictions, suggesting that multistrange hadron production approaches chemical equilibrium in high baryon density nuclear matter.

Source images are extracted from two-particle correlations constructed from strange and nonstrange hadrons produced in 6A GeV Au+Au collisions. Very different source images result from pp vs p Lambda vs pi(-)pi(-) correlations. Scaling by transverse mass can describe the apparent source size ratio for p/pi(-) but not for Lambda/pi(-) or Lambda/p. These observations suggest important differences in the space-time emission histories for protons, pions, and neutral strange baryons produced in the same events.

Purpose: We have shown previously that when monolayer cultures of Chinese hamster ovary (CHO) cells are exposed to very low fluences of alpha-particles, HPRT mutations are induced in non-irradiated 'bystander' cells in the population. The present investigation was designed to examine the role of DNA repair in this process., Materials and Methods: The DNA double-strand repair-deficient mutant cell line xrs-5 was exposed to mean doses of alpha-particles as low as 0.04 cGy whereby less than 1% of the nuclei were traversed by an alpha track and thus received any radiation exposure., Results: With this very low alpha-particle fluence, most of the cells in the xrs-5 population appeared to be at risk for the induction of mutations, indicating a much larger bystander effect than observed with wild-type CHO cells. Molecular structural analyses showed that xrs-5 mutants primarily involved partial and total gene deletions as opposed to wild-type cells where point mutations predominated in bystander cells., Conclusions: These results indicate a very large bystander effect in xrs-5 cells. They support the hypothesis that unrepaired or misrepaired double-strand breaks (DSB), arising from opposed DNA lesions, enhance the sensitivity of bystander cells in xrs-5 cultures to the induction of mutations.

Rapidity distributions of protons from central 197Au+197Au collisions measured by the E895 Collaboration in the energy range from (2-8)A GeV at the Brookhaven AGS are presented. Longitudinal flow parameters derived using a thermal model including collective longitudinal expansion are extracted from these distributions. The results show an approximately linear increase in the longitudinal flow velocity, (L), as a function of the logarithm of beam energy.

We have shown previously that damage signals may be transmitted from irradiated cells to nonirradiated cells in monolayer cultures, leading to changes in gene expression and an enhanced frequency of mutations in these "bystander" cells. The present study was designed to test the hypothesis that mutations occurring in bystander cells result from a different mechanism than those occurring in irradiated cells, and thus show differences in molecular structure. Structural changes in the HPRT gene of Chinese hamster ovary (CHO) cells were determined by multiplex PCR analysis. A total of 790 mutant clones derived from monolayer cultures exposed to mean doses of 0, 0.5 or 10 cGy of alpha-particle radiation (0, 3% or 44%, respectively, of nuclei traversed by one or more alpha particles) were examined. Whereas mutations induced by 10 cGy included a high frequency of deletions, nearly all mutations occurring in bystander cells in cultures irradiated with 0.5 cGy involved point mutations, confirming our hypothesis that they are induced by a different mechanism.

We report a particle source imaging analysis based on two-pion correlations in high multiplicity Au+Au collisions at beam energies between 2A and 8A GeV. We apply the imaging technique introduced by Brown and Danielewicz, which allows a model-independent extraction of source functions with useful accuracy out to relative pion separations of about 20 fm. The extracted source functions have Gaussian shapes. Values of source functions at zero separation are almost constant across the energy range under study. Imaging results are found to be consistent with conventional source parameters obtained from a multidimensional Hanburg-Brown-Twiss analysis.

Copper phthalocyanine-Fe2O3 nanoparticles alternating thin films were fabricated by Langmuir-Blodgett technique. Molecular orientation of [4-(4'-benzyloxy phenyl sulfonyl)phenoxy]-tris-4-(2,4-di-t-phenoxy) phthalocyanine copper (II) in its alternating LB films, deposited at different conditions, was studied by polarized UV-Vis spectra. The tilt extent of the copper phthalocyanine molecule on its LB films increases with the surface pressure of the subphase increasing on the same subphase, or with Fe2O3 concentration decreasing at the same pressure. The orientation of the copper phthalocyanine derivative is important for the gas-sensing properties. The bigger the tilt extent of the phthalocyanine molecule is, the greater the sensitivity of the film is.

Directed flow measurements for Lambda hyperons are presented and compared to those for protons produced in the same Au+Au collisions (2A, 4A, and 6A GeV; b<5-6 fm). The measurements indicate that Lambda hyperons flow consistently in the same direction but with smaller magnitudes. A strong positive flow [for Lambdas] has been predicted in calculations which include the influence of the Lambda-nucleon potential. The experimental flow ratio Lambda/p is in qualitative agreement with expectations (approximately 2/3) from the quark counting rule at 2A GeV but is found to decrease with increasing beam energy.

In vitro studies have implicated nuclear respiratory factor 1 (NRF-1) in the transcriptional expression of nuclear genes required for mitochondrial respiratory function, as well as for other fundamental cellular activities. We investigated here the in vivo function of NRF-1 in mammals by disrupting the gene in mice. A portion of the NRF-1 gene that encodes the nuclear localization signal and the DNA-binding and dimerization domains was replaced through homologous recombination by a beta-galactosidase-neomycin cassette. In the mutant allele, beta-galactosidase expression is under the control of the NRF-1 promoter. Embryos homozygous for NRF-1 disruption die between embryonic days 3.5 and 6.5. beta-Galactosidase staining was observed in growing oocytes and in 2. 5- and 3.5-day-old embryos, demonstrating that the NRF-1 gene is expressed during oogenesis and during early stages of embryogenesis. Moreover, the embryonic expression of NRF-1 did not result from maternal carryover. While most isolated wild-type and NRF-1(+/-) blastocysts can develop further in vitro, the NRF-1(-/-) blastocysts lack this ability despite their normal morphology. Interestingly, a fraction of the blastocysts from heterozygous matings had reduced staining intensity with rhodamine 123 and NRF-1(-/-) blastocysts had markedly reduced levels of mitochondrial DNA (mtDNA). The depletion of mtDNA did not coincide with nuclear DNA fragmentation, indicating that mtDNA loss was not associated with increased apoptosis. These results are consistent with a specific requirement for NRF-1 in the maintenance of mtDNA and respiratory chain function during early embryogenesis.

Objective: To establish a rather ideal experimental brain injury model in rats, in which diffuse axonal injury(DAI) and focal brain contusion were made concurrently., Methods: The pathophysiological changes were monitored, and the histological changes were observed under naked eye, microscope and electric microscope., Results: 1. The mortality in the group suffering from DAI with focal contusion(Group A) was much higher than that in DAI(Group B) and sham group(Group C); 2. The time of post-injury primary coma in Group A [(5.19 +/- 0.49) h] was longer than that in Group B [(2.75 +/- 0.16) h] and Group C [(2.77 +/- 0.20) h] significantly(P < 0.01); 3. Immunohistological examination showed that the diffuse axonal injury could be seen in several parts of the brain(subcortical, corpus callosum and brainstem) in Group A; 4. We observed in Group A under electric microscope that the axons were swollen and degenerated fragmently, neurofilaments ranged disorderly and there was vacuolation., Conclusion: The model is cheap, simple and can be easily repeated. Furthermore it can be used to research the changes of pathophysiology, histology and moleculobiochemistry of head injury in human beings.

In this paper, we report the optical properties of SnO2 semiconductor nanoparticles in hydrosols and those of SnO2 semiconductor nanoparticles in organosols in which the surfaces of the particles are coated by a layer of organic surfactant molecules. The photoluminescence spectra of SnO2 semiconductor nanoparticles in the hydrosols and organosols in different conditions were measured and discussed. We conclude that the surface structure of the SnO2 semiconductor nanoparticles affects their optical properties strongly. The oxygen deficiencies on the surface of SnO2 semiconductor nanoparticles play an important role in the optical properties. The surface modification of the particles effectively removes the surface defects of the particles and enhances the intensity of luminescence.

Nuclear respiratory factor 1 (NRF-1) is a nuclear transcription factor that has been implicated in the nuclear control of respiratory chain expression in mammalian cells. Here, we demonstrate that a complex pattern of alternative splicing contributes to sequence heterogeneity within the human NRF-1 5'-untranslated region (UTR). At least six different 5'-UTR exons (UTRs 1-6) were detected in NRF-1 transcripts. These exons were mapped to human NRF-1 genomic clones and their sequences, including donor and acceptor splice junctions, determined. Two of the human UTR exons were derived from insertions of Alu-sq family members into the NRF-1 locus. The distance between the transcription initiation sites in UTR1 and the first protein coding exon is approx. 47kb, bringing the total length of the human NRF-1 gene to approx. 104kb. In contrast to human, only two UTR exons were found in mouse. The mouse UTR1 sequence obtained is identical to human UTR1, but mouse UTR2 bears no resemblance to any of the human exons. Mutations within human UTR1 modulate NRF-1 expression by interfering with mRNA translational efficiency in transfected cells and in an in vitro translation system. The effects of the mutations are proportional to their ability to disrupt predicted mRNA secondary structures within UTR1. Thus, the unusually high sequence conservation within UTR1 in part reflects selective constraints on translational expression.

Objective: Survival motor neuron gene(SMN) and neuronal apoptosis inhibitory protein gene (NAIP) have been identified as the candidates of progressive spinal muscular atrophy (SMA)-determining genes. The aims of this study were to investigate the absence of SMN gene exon 7 in Chinese SMA patients, to confirm the relationship between the deletion of the SMN and SMA further, and to establish methods for gene diagnosis and prenatal diagnosis of SMA., Methods: PCR-SSCP with silver staining method was used to detect the genomic DNA of 37 SMA patients and 30 normal individuals for deletions of SMN exon 7., Results: Homozygous deletion of the SMN exon 7 was identified in 86.7%(13/15) of type I SMA patients and 86.4%(19/22) of type II patients. In the 88 controls (including parents of patients and normal individuals), homozygous absence of SMA exon 7 was only found in a mother of a patient., Conclusion: The data support that homozygous absence of SMN exon 7 is strongly associated with SMA. The percentage of homozygous deletions in this study is almost as high as that reported by other researchers. This method is useful, reliable and effective for gene diagnosis and prenatal diagnosis of SMA.

67 adult women with a history of recurrent lower urinary tract infection (UTI) were randomized for acupuncture treatment, sham acupuncture, or no treatment. The incidence rate of UTI over the following six months was noted. In the acupuncture group a total of 85% was free of cystitis during the six-month observational period, as compared to 58% in the sham group (p < 0.05), and 36% in the control group (p < 0.01). Compared to the acupuncture group, twice as many incidents of cytitis occurred in the sham group, and three times as many in the control group (p < 0.05). Acupuncture seems a worthwhile alternative in the prevention of frequently recurring cystitis in women.

Cross-linking CD40 mediates B lymphocyte growth and differentiation and regulates cell death pathways by an unknown mechanism. Previous reports have suggested that protein tyrosine kinase activity is critical for CD40-mediated biologic responses. We show here that CD40 engagement on murine B cells results in the rapid tyrosine phosphorylation of the STAT6 transcription factor and the transactivation of a reporter gene containing an IFN-regulatory factor-1 STAT-binding site. In earlier studies, surface Ig engagement was found to produce rapid activation of STAT6 accompanied by later induction of STAT1, which is not observed after CD40 ligation. Thus, these results define mitogenic receptor-specific induction of STAT proteins in B cells and identify a novel and direct signal transduction pathway from the cell surface to the nucleus activated in B cells stimulated through CD40 that regulates a gene previously shown to be involved in oncogenesis and programmed cell death.

Cytokine and growth factor receptor engagement leads to the rapid phosphorylation and activation of latent, cytosolic signal transducers and activators of transcription (STAT) proteins, which then translocate to the nucleus where they regulate transcriptional events from specific promoter sequences. STAT3 expression in particular has been associated with Abl, Src, and HTLV-1 transformation of normal cells. B-1 lymphocytes are self-renewing, CD5+ B cells that display a propensity for malignant transformation and are the normal counterpart to human chronic lymphocytic leukemias. Further, B-1 cells are characterized by aberrant intracellular signaling, including hyperresponsiveness to phorbol ester PKC agonists. Here we demonstrate that B-1 lymphocytes constitutively express nuclear activated STAT3, which is not expressed by unmanipulated conventional (B-2) lymphocytes. In contrast, STAT3 activation is induced in B-2 cells after antigen receptor engagement in a delayed fashion (after 3 h). Induction of STAT3 is inhibited by both the serine/threonine protein kinase inhibitor H-7 and the immunosuppressive drug rapamycin and requires de novo protein synthesis, demonstrating novel coupling between sIg and STAT proteins that differs from the classical paradigm for STAT induction by cytokine receptors. The inability of prolonged stimulation of conventional B-2 cells with anti-Ig, a treatment sufficient to induce CD5 expression, to result in sustained STAT3 activation suggests that STAT3 is a specific nuclear marker for B-1 cells. Thus, STAT3 may play a role in B cell antigen-specific signaling responses, and its constitutive activation is associated with a normal cell population exhibiting intrinsic proliferative behavior.

The murine fra-1 gene, encoding Fos-related Ag 1, was isolated from a splenic cDNA library and sequenced. Murine fra-1 was highly homologous to rat and human fra-1. Oligonucleotide primers based on the murine sequence were used to construct a quantitative reverse transcription-PCR assay for gene expression. B lymphocyte stimulation via both CD40 and surface Ig (sIg) receptors substantially induced fra-1 expression, and for both receptors, induction was protein kinase C (PKC) dependent. This contrasts with induction of c-fos by both CD40 and sIg, which is PKC independent and indicates that CD40 is capable of signaling through PKC or a closely related kinase. Induction of fra-1 following engagement of CD40 did not require protein synthesis, suggesting that the PKC-dependent linkage between CD40 and fra-1 is direct. CD40-mediated fra-1 induction did require tyrosine kinase activity. These results demonstrate that CD40, like sIg, may employ PKC in producing select outcomes, that individual B cell receptors may signal downstream events via both PKC-dependent and PKC-independent pathways, and that multiple signal transduction pathways may be used to activate the expression of closely related genes.

The regulation of the STAT1 alpha transcription factor was assessed during B cell activation induced by cross-linking the surface IgM Ag receptor. Surface Ig ligation or pharmacologic stimulation with PMA and ionomycin resulted in the delayed (2-3 h after stimulation) nuclear appearance of tyrosine-phosphorylated STAT1 alpha, in contrast to the rapid induction that follows cytokine treatment. Nuclear expression of phosphorylated STAT1 alpha was abrogated by co-incubation of anti-Ig-treated B cells with the protein synthesis inhibitor cycloheximide (CHX), with the protein kinase inhibitor H-7, or with the immunosuppressive drug rapamycin. Tyrosine-phosphorylated STAT1 alpha was found to be recruited to the STAT binding site of the IFN regulatory factor-1 (IRF-1) gene promoter only after 2 to 3 h, and this association was also inhibitable by CHX and rapamycin. The arrival of STAT1 alpha coincided with attenuation of anti-Ig-induced STAT-binding activity specific for the IRF-1 promoter site, and both rapamycin and CHX treatment counteracted the loss of this activity. Furthermore, basal transcription of the endogenous IRF-1 gene was decreased as a result of anti-Ig treatment, and this effect of anti-Ig was blocked by co-incubation with rapamycin. Thus, STAT1 alpha plays a dynamic role in the composition of IRF-1 promoter-specific DNA binding complexes stimulated by B cell Ag receptor ligation, and nuclear expression of phosphorylated STAT1 alpha is regulated in a unique fashion by Ag receptor engagement. In addition, surface Ig cross-linking imparts negative regulatory control of IRF-1 gene expression, possibly through activation of STAT1 alpha.