Computational explorations of the interaction between laccase and bisphenol A: influence of surfactant and different organic solvents.

Bisphenol A (BPA), as an environmental endocrine disruptor can cause damage to the reproductive, nervous and immune systems. Laccase can be used to degrade BPA. However, laccase is easily deactivated, especially in organic solvents, but the specific details are not clear. Molecular dynamics simulations were used to investigate the reasons for changes in laccase activity in acetonitrile (ACN) and dimethyl formamide (DMF) solutions. In addition, the effects of ACN and DMF on the activity of laccase and surfactant rhamnolipid (RL) on the degradation of BPA by laccase were investigated. Results showed that addition of ACN changed the structure of the laccase, not only decreasing the van der Waals interaction that promoted the binding of laccase with BPA, but also increasing the polar solvation free energy that hindered the binding of laccase with BPA, so it weakened the laccase activity. DMF greatly enhanced the van der Waals interaction between laccase and BPA, and played a positive role in their binding. The addition of surfactant RL alleviated the effect of organic solvent on the activity of laccase by changing the polar solvation energy. The mechanism of surfactant RL affecting laccase activity in ACN and DMF is described, providing support for understanding the effect of organic solvents on laccase.

[Effects of persistent Echinococcus multilocularis infections on hepatic fibrosis in mice].

OBJECTIVE: To investigate the effects of persistent Echinococcus multilocularis infections on hepatic fibrosis in mice, so as to provide insights into the understanding of liver fibrogenesis induced by E. multilocularis infections and the treatment of alveolar echinococcosis. METHODS: Hepatic stellate HSC-T6 and LX-2 cells were exposed to the sera (25, 50 and 100 µL) from Meriones unguiculatus infected with E. multilocularis, and E. multilocularis, germinal layer cells (GCs) and protoscoleces (PSCs) for 48 hours, respectively. The cell proliferation was measured using a CCK-8 assay, and the levels of collagen 1 (Col1) and α-smooth muscle actin (α-SMA) were measured in the culture supernatant of HSC-T6 cells using ELISA. In addition, the serum and liver samples were collected 1, 2, 4, 6, 8 months post-infection with E. multilocularis, respectively. The serum Col1 and α-SMA concentrations were measured using enzyme-linked immunosorbent assay (ELISA), and the deposition of collagen fibers was examined in mice livers using Sirius red staining. RESULTS: The sera of E. multilocularis-infected gerbils promoted the proliferation of HSC-T6 and LX-2 cells in vitro, and there were significant differences seen in the proliferative rate of HSC-T6 (FHSC-T6 = 126.50, P < 0.05) and LX-2 cells (FLX-2 = 201.50, P < 0.05) among different serum groups, with the highest proliferative rate of HSC-T6 (573.36% ± 206.34%) and LX-2 cells (940.38% ± 61.65%) found following exposure to 100 µL mouse sera. Exposure to serum from E. multilocularis-infected gerbils resulted in an increase in the Col1 and α-SMA levels in the culture supernatant of HSC-T6 cells, with the greatest Col1 (20.99 ng/mL ± 2.01 ng/mL) and α-SMA levels (305.52 pg/mL ± 16.67 pg/mL) measured following exposure to 100 µL sera. The metacestodes (142.65% ± 9.17% and 189.99% ± 7.75%), GCs (118.55% ± 8.96% and 122.54% ± 0.21%) and PSCs of E. multilocularis (156.34% ± 17.45% and 160.59% ± 31.41%) all promoted the proliferation of HSC-T6 and LX-2 cells in vitro, and there were significant differences in the proliferative rates of HSC-T6 (FHSC-T6 = 11.24, P < 0.05) and LX-2 cells among groups (FLX-2 = 47.72, P < 0.05). Exposure to E. multilocularis resulted in an increase in Col1 and α-SMA levels in the culture supernatant of HSC-T6 cells, and the highest Col1 (4.43 ng/mL ± 2.23 ng/mL) and α-SMA levels (285.20 pg/mL ± 90.67 pg/mL) were detected following treatment with E. multilocularis metacestodes. In addition, a persistent increase was seen in the deposition of collagen fibers in mice livers 1 to 8 months post-infection with E. multilocularis, with the greatest Col1 level (280.26 ng/mL ± 23.04 ng/mL) seen 6 months post-infection and the highest α-SMA level (33.68 ng/mL ± 4.45 ng/mL) detected 8 months post-infection, respectively. CONCLUSIONS: Persistent E. multilocularis infections promote hepatic stellate cell proliferation, induce an increase in mouse serum Col1 and α-SMA levels, and cause elevated deposition of collagen fibers in mice livers. The infective stage of E. multilocularis is a critical period for inducing hepatic fibrosis of alveolar echinococcosis.

Pathological changes in Sertoli cells and dysregulation of divalent metal transporter 1 with iron responsive element in the testes of idiopathic azoospermia patients.

Iron is essential for rapidly dividing spermatocytes during normal mammalian spermatogenesis. Decreased transferrin and transferrin receptor levels were observed in seminal plasma from idiopathic azoospermia (IA) patients, suggesting disturbed iron metabolism in IA testes. However, how Sertoli cells (SCs) contribute to the iron homoeostasis in IA is still unclear. In this study, we analysed 30 IA and 30 age-matched obstructive azoospermia (OA) patients undergoing testicular sperm aspiration (TESA). SCs hyperplasia was indicated by higher SC density and Ki-67 labelling index in the IA TESA specimens. The attenuated expression of superoxide dismutase (SOD) suggested an impaired antioxidative capacity in IA testes. We further detected increased levels of iron importer divalent metal transporter 1 with iron responsive element (DMT1 + IRE) in IA testes, whereas the increasing trend of iron exporter ferroportin 1 (FPN1) was not statistically significant. Next, we demonstrated that iron regulatory protein 1 (IRP1) and hypoxia-inducible factor-1α (HIF-1α), which can potentially bind to the IRE and hypoxia-responsive element in the DMT1 + IRE mRNA, were both up-regulated in IA testes. Unexpectedly, HIF-2α was down-regulated in IA testes. These results indicate that there is a dysregulation of DMT1 + IRE in IA testes, which might due to the up-regulation of IRP1 and HIF-1α.

A comparison of clinical efficacy and economic value in Basalin- and Lantus-treated patients with type 2 diabetes using continuous glucose monitoring system.

AIM: To determine the clinical non-inferiority of recombinant glargine-Basalin vs glargine-Lantus, in treatment of type 2 diabetes mellitus (T2DM) using continuous glucose monitoring system (CGMS). METHODS: One hundred patients with T2DM were recruited. They were either regularly taking Basalin (Basalin group) or Lantus (Lantus group) (n = 50 each). CGMS was employed to real-time monitor blood glucose profile for 4 days (from day 1 to day 5). To exclude the effect of patient background, the study design was to have a blinded crossover from glargine-Basalin to glargine-Lantus on day 3, and vice versa. 24-hour mean blood glucose (24hMBG), 24-hour standard deviation of blood glucose (24hSDBG), 24-hour mean amplitude of glycemic excursion (24hMAGE), and number of glycemic excursion (NGE) every 24 h (24hNGE) were calculated for each glargine from 100 patients. RESULTS: No significant difference of 24hMBG, 24hSDBG, 24hMAGE, and 24hNGE (p > 0.05 for all) was found between Basalin and Lantus treatments. The glucose area under the curve and time when blood glucose was below 3.9 mmol/L, between 3.9 and 10.0 mmol/L, or above 10.0 mmol/L were similar between Basalin and Lantus treatment. The frequency of hypoglycemic episodes was also similar. However, the mean cost of Basalin was only 72% of Lantus's in one treatment course. CONCLUSION: Glargine-Basalin is non-inferior in clinical efficacy compared to glargine-Lantus. In view of the large difference in the cost of glargine-Basalin, it would be much more cost-effective for our patients.

The effects of add-on exenatide to insulin on glycemic variability and hypoglycemia in patients with type 1 diabetes mellitus.

OBJECTIVE: To investigate the effect of add-on exenatide to insulin on glycemic excursion and the counter-regulatory hormone in response to hypoglycemia in patients with type 1 diabetes mellitus (T1DM). METHODS: 30 patients with T1DM were recruited and randomly assigned to exenatide + insulin-treated group (group 1, n = 15) or insulin-only-treated group (group 2, n = 15) for 4 weeks. All patients had continuous glucose monitor system (CGMS) applied at before (week-0) and after (week-4) treatment to evaluate the glycemic variability. All patients had an arginine-stimulated test at before and after treatment. Six patients from each group also had hypoglycemic clamp test to assess counter-regulatory hormone level. RESULTS: Patients in the exenatide group had significant reductions in body weight, body mass index (BMI), total insulin dose, bolus insulin dose, fructosamine, and glycemic excursion after 4 weeks' treatment. Compared with patients in group 2, the mean amplitude of glycemic excursion (MAGE) and coefficient of variation (CV) of exenatide group decreased significantly. Similarly, a significant decrease of glucagon (GLC) in the arginine-stimulated test was found in group 1. No significant changes of GLC, growth hormone (GH), cortisol (COR), epinephrine (E), and norepinephrine (NE) were found in both groups during hypoglycemia clamp test. However, patients who had residual islet function in group 1 showed an upward trend of basic C-peptide (C-P) and GLC during the hypoglycemia period. CONCLUSION: Although exenatide could inhibit glucagon secretion during euglycemia or hyperglycemia in patients with T1DM, it has no effect on GLC and counter-regulatory hormones during hypoglycemia clamp in patients with no functional residual islet test.

Hydroxytyrosol Attenuates LPS-Induced Acute Lung Injury in Mice by Regulating Autophagy and Sirtuin Expression.

BACKGROUND: Recently, the effects of hydroxytyrosol on autophagy during acute lung injury (ALI) have drawn increasing attention. OBJECTIVE: We explored the underlying molecular mechanisms by which hydroxytyrosol exerts its anti-inflammatory effects in a murine model of ALI by up-regulating autophagy. METHODS: Male BALB/c mice, challenged with intranasal instillations of LPS, were treated with or without hydroxytyrosol (HT, 100 mg/kg, intragastrically) 1 h prior to LPS exposure. Twenty-four hours later, lung and bronchoalveolar lavage (BAL) fluid samples were obtained for the determination of lung wet to dry weight (W/D) ratios, protein leakage levels, and differential counts of inflammatory cells in BAL fluid. LPS-induced cytokine activity, inflammatory factor levels, sirtuin (SIRT1/3/6) expression, mitogenactivated protein kinase (MAPK) activation, and autophagy marker expression in ALImice were examined by western blotting and staining methods. Molecular docking between HT and SIRT and MAPK was studied with a Sybyl/Surflex module. RESULTS: LPS-stimulated SIRT inhibition, MAPK phosphorylation, and autophagy suppression were all notably abolished by HT administration. HT treatment significantly attenuated pulmonary edema and inflammatory cell infiltration into lung tissues, accompanied by decreased lung W/D ratios, protein concentrations, and inflammatory cell levels in BAL fluid. LPS driven release of inflammatory mediators, including TNF-α, IL-1ß, IL-6, IL-10, and MCP-1, was strongly regulated by HT. CONCLUSIONS: The protective effect of HT on lung inflammation in ALI mice may be attributed to the promotion of autophagy, which is likely associated with the activation of the SIRT/MAPK signaling pathway. Importantly, this study provides new insight into the molecular mechanisms of HT and its therapeutic potential in the treatment of acute respiratory distress syndrome.

WITHDRAWN The clinical effectiveness of telemedicine for chronic heart failure: A systematic review and meta-analysis.

Ahead of Print article withdrawn by publisher

Chemotherapy plus estramustine for management of castration-resistant prostate cancer: meta-analysis of randomized controlled trials.

OBJECTIVE: Estramustine, an agent with both hormonal and non-hormonal effects in men, is supposed to be effective in treating castration-resistant prostate cancer. However, previous studies have reported conflicting results. We conducted this meta-analysis to evaluate the efficacy and toxicity of additional estramustine to chemotherapy. METHODS: Data sources including PubMed, Medline, EMBASE, and Cochrane Controlled Trials Register were searched to identify potentially relevant randomized controlled trials. Prostate specific antigen (PSA) response, overall survival, and grade 3 to 4 toxicity were analyzed. RESULTS: Seven randomized controlled trials, a total of 839 patients, were enrolled. The pooled odds ratio for PSA response was 3.02 (95% CI=1.69-5.39, P=.0002); the pooled hazard ratio for overall survival was .95 (95% CI=.80-1.14, P=.58); the pooled odds ratio for nausea/vomiting and cardiovascular toxicity were 3.90 (95% CI=1.05-14.45, P=.04) and 2.22 (95% CI=1.15-4.30, P=.02). No significant difference was detected for neutropenia, anemia, thrombocytopenia, diarrhea, fatigue, or neuropathy (P>.05). CONCLUSIONS: According to this meta-analysis, chemotherapy with additional estramustine increased the PSA response rate. However, it increased the risk of grade 3 or 4 adverse effects such as nausea/vomiting and cardiovascular events, and the overall survival was not improved for castration-resistant prostate cancer patients.

Vibro-acoustic analysis of a rectangular cavity bounded by a flexible panel with elastically restrained edges.

A coupled system consisting of an acoustic cavity and an elastic panel is a classical problem in structural acoustics and is typically analyzed using modal approaches based on in vacuo structural modes and the rigidly walled acoustic modes which are pre-determined based on separate component models. Such modeling techniques, however, tend to suffer the following drawbacks or limitations: (a) a panel is only subjected to ideal boundary conditions such as the simply supported, (b) the coupling between the cavity and panel is considered weak, and (c) the particle velocity cannot be correctly predicted from the pressure gradient on the contacting interface, to name a few. Motivated by removing these restrictions, this paper presents a general method for the vibro-acoustic analysis of a three-dimensional (3D) acoustic cavity bounded by a flexible panel with general elastically restrained boundary conditions. The displacement of the plate and the sound pressure in the cavity are constructed in the forms of standard two-dimensional and 3D Fourier cosine series supplemented by several terms introduced to ensure and accelerate the convergence of the series expansions. The unknown expansions coefficients are treated as the generalized coordinates and determined using the Rayleigh-Ritz procedure based on the energy expressions for the coupled structural acoustic system. The accuracy and effectiveness of the proposed method are demonstrated through numerical examples and comparisons with the results available in the literature.

Subunit vaccine candidate AMM down-regulated the regulatory T cells and enhanced the protective immunity of BCG on a suitable schedule.

Mycobacterium bovis bacillus Calmette-Guérin (BCG) priming and subunit vaccine boosting strategies are urgently needed to improve the protective efficacy of BCG in adult population. However, the schedule of subunit vaccine boosting is not well investigated, especially the optimal immune responses and vaccine immunization schedules are still not clear. We have constructed a novel subunit vaccine candidate consisting of fusion protein Ag85B-Mpt64 (190-198)-Mtb8.4 (AMM) in a complex adjuvant composed of dimo-thylidioctyl ammonium bromide (DDA) and BCG polysaccharide nucleic acid (BCG-PSN). In this study, we compared the effect of different boosting schedules of the subunit vaccine in the prime-boost strategies. C57BL/6 mice were primed with BCG first and then boosted with the AMM vaccine once at 10th week, twice at 8th, 10th week, or thrice at 6th, 8th, 10th week, respectively. The immune responses were evaluated at the 14th and 20th weeks, respectively. Twelve weeks after the last immunization, the mice were challenged with virulent Mycobacterium tuberculosis strain H37Rv, and the protective effect was evaluated. The results showed that BCG priming and the AMM vaccine boosting twice induced the strongest antigen-specific IFN-γ and IL-2 production, down-regulated CD4+ CD25+ FoxP3+ regulatory T cells (Tregs) and had the best protective effect among all groups, while boosting thrice induced the strongest IL-4 production and did not improve BCG-primed protection significantly. Boosting BCG with the AMM vaccine twice instead of once or thrice induced strong Th1-type immunity and down-regulated Tregs significantly, which correlated with the best protection against M. tuberculosis infection in mice.

Acoustic analysis of a rectangular cavity with general impedance boundary conditions.

A Fourier series method is proposed for the acoustic analysis of a rectangular cavity with impedance boundary conditions arbitrarily specified on any of the walls. The sound pressure is expressed as the combination of a three-dimensional Fourier cosine series and six supplementary two-dimensional expansions introduced to ensure (accelerate) the uniform and absolute convergence (rate) of the series representation in the cavity including the boundary surfaces. The expansion coefficients are determined using the Rayleigh-Ritz method. Since the pressure field is constructed adequately smooth throughout the entire solution domain, the Rayleigh-Ritz solution is mathematically equivalent to what is obtained from a strong formulation based on directly solving the governing equations and the boundary conditions. To unify the treatments of arbitrary nonuniform impedance boundary conditions, the impedance distribution function on each specified surface is invariantly expressed as a double Fourier series expansion so that all the relevant integrals can be calculated analytically. The modal parameters for the acoustic cavity can be simultaneously obtained from solving a standard matrix eigenvalue problem instead of iteratively solving a nonlinear transcendental equation as in the existing methods. Several numerical examples are presented to demonstrate the effectiveness and reliability of the current method for various impedance boundary conditions, including nonuniform impedance distributions.

Fungal endophytes from Acer ginnala Maxim: isolation, identification and their yield of gallic acid.

AIMS: The aim of the study was to isolate the endophytic fungi from Acer ginnala and screen isolates rich in gallic acid. METHODS AND RESULTS: After epiphytic sterilization, 145 fungal endophytes were isolated from the stem, annual twig and seed of Acer ginnala. The endophytes were grouped into ten different taxa, Phomopsis sp., Neurospora sp., Phoma sp., Epicoccum sp., Penicillium sp., Alternaria sp., Fusarium sp., Trichoderma sp., Cladosporium sp. and a species of Pleosporales Incertae Sedis, by their morphological traits and ITS-rDNA sequence analysis. The content and yield of gallic acid of 141 isolates were determined by HPLC. On average, the species of Pleosporales Incertae Sedis had the highest content and yield of gallic acid (13.28 mg g(-1) DW; 119.62 mg l(-1)), while Alternaria sp. had the lowest. CONCLUSIONS: Of 141 fungal endophytes from A. ginnala, Phomopsis sp. isolate SX10 showed both the highest content and the highest yield of gallic acid (29.25 mg g(-1) DW; 200.47 mg l(-1)). SIGNIFICANCE AND IMPACT OF THE STUDY: Endophytic fungi isolated from A. ginnala may be used as potential producers of gallic acid and other compounds with biological activities, or functioned as elicitors to produce natural compounds.

Products and bioenergy from the pyrolysis of rice straw via radio frequency plasma and its kinetics.

The radio frequency plasma pyrolysis technology, which can overcome the disadvantages of common pyrolysis methods such as less gas products while significant tar formation, was used for pyrolyzing the biomass waste of rice straw. The experiments were performed at various plateau temperatures of 740, 813, 843 and 880K with corresponding loading powers of 357, 482, 574 and 664W, respectively. The corresponding yields of gas products (excluding nitrogen) from rice straw are 30.7, 56.6, 62.5 and 66.5wt.% with respect to the original dried sample and the corresponding specific heating values gained from gas products are about 4548, 4284, 4469 and 4438kcalkg(-1), respectively, for the said cases. The corresponding combustible portions remained in the solid residues are about 64.7, 35, 28.2 and 23.5wt.% with specific heating values of 4106, 4438, 4328 and 4251kcalkg(-1) with respective to solid residues, while that in the original dried sample is 87.2wt.% with specific heating value of 4042kcalkg(-1). The results indicated that the amount of combustibles converted into gas products increases with increasing plateau temperature. The kinetic model employed to describe the pyrolytic conversion of rice straw at constant temperatures agrees well with the experimental data. The best curve fittings render the frequency factor of 5759.5s(-1), activation energy of 74.29kJ mol(-1) and reaction order of 0.5. Data and information obtained are useful for the future design and operation of pyrolysis of rice straw via radio frequency plasma.

Genetic diversity of the azuki bean (Vigna angularis (Willd.) Ohwi & Ohashi) gene pool as assessed by SSR markers.

To facilitate the wider use of genetic resources including newly collected cultivated and wild azuki bean germplasm, the genetic diversity of the azuki bean complex, based on 13 simple sequence repeat (SSR) primers, was evaluated and a core collection was developed using 616 accessions originating from 8 Asian countries. Wild germplasm from Japan was highly diverse and represented much of the allelic variation found in cultivated germplasm. The SSR results together with recent archaeobotanical evidence support the view that Japan is one center of domestication of azuki bean, at least for the northeast Asian azuki bean. Cultivated azuki beans from China, Korea, and Japan were the most diverse and were genetically distinct from each other, suggesting a long and relatively isolated history of cultivation in each country. Cultivated azuki beans from eastern Nepal and Bhutan were similar to each other and quite distinct from others. For two primers, most eastern Nepalese and Bhutanese cultivated accessions had null alleles. In addition, wild accessions from the Yangtze River region of China and the Himalayan region had a null allele for one or the other of these primers. Whether the distinct diversity of azuki bean in the Himalayan region is due to introgression or separate domestication events requires further study. In contrast, western Nepalese azuki beans showed an SSR profile similar to that of Chinese azuki beans. The genetic distinctness of cultivated azuki beans from Vietnam has been revealed for the first time. The specific alleles indicate that Vietnamese azuki beans have been cultivated in isolation from Chinese azuki beans for a long time. Wild germplasm from the Himalayan region showed the highest level of variation. Based on the results, Himalayan germplasm could be considered a novel gene source for azuki bean breeding. A comparison with mungbean SSR analysis revealed that the mean gene diversity of cultivated azuki bean (0.74) was much higher than that of cultivated mungbean (0.41). The reduction in gene diversity due to domestication, the domestication bottleneck, in azuki bean is not strong compared with that in mungbean.

Suppression of pro-metastasis phenotypes expression in malignant pleural mesothelioma by the PI3K inhibitor LY294002 or the MEK inhibitor UO126.

BACKGROUND: This study aimed to evaluate the impact of selective abrogation of either the MEK/ERK1/2 (UO126 or PD98059) or the PI3K/AKT (LY294002) signaling cascade on cell proliferation, motility and invasion and production of VEGF (collectively termed pro-metastasis phenotypes) in cultured malignant pleural mesothelioma (MPM) cells. MATERIALS AND METHODS: Treatment-induced cytotoxicity was evaluated by MTT or Annexin V assays. Cell motility was assessed by wound healing and Matrigel invasion assays. VEGF in conditioned media of cancer cells was measured by ELISA. RESULTS: LY294002 and UO126 significantly inhibited cell proliferation and clonogenicity of MPM cells in vitro. A substantial reduction of cell motility, Matrigel invasion as well as inhibition of basal or EGF-induced VEGF production were observed in drug-treated cells. CONCLUSION: The selective MEK or PI3K kinase inhibitors are equally effective in down-regulating the expression of pro-metastasis phenotypes, suggesting that MEK or PI3K are appropriate targets for the development of molecular therapeutics for malignant pleural mesothelioma.

Relationship of leptin and sex hormones to bone mineral density in men.

Sex hormones are strongly associated with bone mineral density (BMD) in adult humans. Leptin, a hormonal product of the OB gene, also appears to be associated with BMD, but results from previous studies are conflicting. Most of the studies in this area have been in women and apparently none have simultaneously analyzed the relationship of estradiol, testosterone, and leptin with BMD in healthy men. To address these issues, serum sex hormones, sex-hormone-binding globulin (SHBG), leptin, dehydroepiandrosterone sulfate (DHEAS), and insulin were measured in 50 apparently healthy men, 18-66 years of age. After controlling for age and body mass index (BMI), BMD correlated positively with estradiol ( p=0.007) and testosterone ( p=0.019), but negatively with leptin ( p=0.001). No significant correlations between BMD and SHBG, DHEAS, or insulin were observed. In multiple regression analysis with age, BMI, estradiol, testosterone, and leptin as the independent variables, only age ( p<0.05), BMI ( p<0.001), and leptin ( p=0.004) were significantly related to BMD. These findings suggest that in men, leptin may have an important negative relationship with BMD.

Association of hyperandrogenemia and hyperestrogenemia with type 2 diabetes in Hispanic postmenopausal women.

OBJECTIVE: Accumulating evidence suggests that hyperandrogenemia may be a risk factor for coronary heart disease (CHD) in women. The present study was carried out to test the hypothesis that hyperandrogenemia is associated with type 2 diabetes in women and thus may contribute to the increased risk of CHD in women with type 2 diabetes. RESEARCH DESIGN AND METHODS: Sex hormones, sex hormone-binding globulin (SHBG), and risk factors for CHD were measured in 20 postmenopausal women with type 2 diabetes and in 29 control subjects. All of the diabetic and control subjects were Hispanic women aged >55 years who were not taking hormone replacement therapy lipid-lowering drugs, or insulin and who were otherwise randomly chosen from a cohort of stroke-free subjects from the Northern Manhattan Stroke Study RESULTS: Mean age, BMI, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, blood pressure, and smoking were not significantly different between cases and control subjects, but waist-to-hip ratio (WHR) was significantly higher in the diabetic subjects (P = 0.01). The mean levels of free testosterone (FT) (P = 0.01), dehydroepiandrosterone sulfate (P<0.04), and estradiol (P = 0.01) (controlled for WHR) were significantly higher in the diabetic subjects; with the statistical outliers removed, the testosterone (P = 0.05) and androstenedione (P = 0.002) levels (controlled for WHR) were also significantly higher in the diabetic subjects. The mean levels of estrone, cortisol, and SHBG were not significantly different. The results were similar in the 10 diabetic subjects treated with diet only Significant positive correlations (controlled for age and BMI) were observed between FT or testosterone and cholesterol, LDL cholesterol, and blood pressure. CONCLUSIONS: Postmenopausal Hispanic women with type 2 diabetes had both hyperandrogenemia and hyperestrogenemia, and testosterone or FT correlated positively with risk factors for CHD. Hyperandrogenemia may be a link between diabetes and CHD in women.

Overexpression of ErbB2 blocks Taxol-induced apoptosis by upregulation of p21Cip1, which inhibits p34Cdc2 kinase.

Overexpression of the receptor tyrosine kinase p185ErbB2 confers Taxol resistance in breast cancers. Here, we investigated the underlying mechanisms and found that overexpression of p185ErbB2 inhibits Taxol-induced apoptosis. Taxol activates p34Cdc2 kinase in MDA-MB-435 breast cancer cells, leading to cell cycle arrest at the G2/M phase and, subsequently, apoptosis. A chemical inhibitor of p34Cdc2 and a dominant-negative mutant of p34Cdc2 blocked Taxol-induced apoptosis in these cells. Overexpression of p185ErbB2 in MDA-MB-435 cells by transfection transcriptionally upregulates p21Cip1, which associates with p34Cdc2, inhibits Taxol-mediated p34Cdc2 activation, delays cell entrance to G2/M phase, and thereby inhibits Taxol-induced apoptosis. In p21Cip1 antisense-transfected MDA-MB-435 cells or in p21-/- MEF cells, p185ErbB2 was unable to inhibit Taxol-induced apoptosis. Therefore, p21Cip1 participates in the regulation of a G2/M checkpoint that contributes to resistance to Taxol-induced apoptosis in p185ErbB2-overexpressing breast cancer cells.

Overexpression of both p185c-erbB2 and p170mdr-1 renders breast cancer cells highly resistant to taxol.

We recently found that overexpression of p185c-erbB2 in c-erbB2 transfected MDA-MB-435 breast cancer cells (435.eB transfectants) confers a 5-9-fold increase in Taxol resistance. To examine whether Taxol resistance is a common phenomenon in other c-erbB2 overexpressing breast cancer cell lines, we tested a panel of human breast cancer cell lines established from different patients and expressing pl85c-erbB2 at different levels for their sensitivity to Taxol and Taxotere, a synthetic taxoid. Higher expression of p185c-erbB2 in these breast cancer cell lines indeed correlated well with resistance to Taxol and Taxotere, and the degree of resistance was about 100-fold that in c-erbB2-overexpressing 435.eB transfectants, demonstrating that these breast cancer cells are highly resistant to Taxol. Since mdr-1-encoded p-glycoprotein (p170mdr-1) has been implicated in Taxol resistance, we next examined the p170mdr-1 levels in these breast cancer cell lines that are highly resistant to Taxol. Higher levels of p170mdr-1 expression were found in several breast cancer cell lines that are highly resistant to Taxol. Since these same breast cancer cell lines also expressed higher levels of p185c-erbB2, we sought to determine the relative contribution of p185c-erbB2 and p170mdr-1 overexpression to Taxol resistance. We first specifically down-regulated cell surface p185c-erbB2 using anti-p185c-erbB2 monoclonal antibodies and assayed sensitivity of these cells to Taxol. We next specifically inactivated p170mdr-1 function using p170mdr-1 blockers (thioridazine or verapamil) and again assayed Taxol sensitivity. Both p185c-erbB2 down-regulation and p170mdr-1 blockade significantly sensitized the breast cancer cell lines to Taxol. The results indicate that overexpression of either p185c-erbB2 or p170mdr-1 renders human breast cancer cells resistant to Taxol. Furthermore, p185c-erbB2 synergizes with p170mdr-1 conferring higher degrees of Taxol resistance. Finally, combination therapy (down-regulation of p185c-erbB2 plus blocking p170mdr-1 plus administration of Taxol) may be beneficial to breast cancer patients whose tumors express high levels of both p185c-erbB2 and p170mdr-1.

Serum sex hormone levels in postmenopausal women with hypertension.

In order to test the hypothesis that an alteration in the sex hormone milieu may underlie risk factors for myocardial infarction, fasting serum sex hormones, ie, estradiol, testosterone, free testosterone, and androstenedione, were measured in 24 hypertensive and in 19 healthy postmenopausal women. The mean serum free testosterone level (P=0.01) and the free-to-total testosterone ratio (P < 0.04) were increased in the women with hypertension. In a stepwise multiple regression analysis on the hypertensive and normotensive groups combined, with systolic blood pressure (SBP) as the dependent variable and body mass index, age, free testosterone, estradiol, insulin, and cholesterol levels as the independent variables, only free testosterone showed an independent relationship to SBP (P=0.009). The finding in the present study of an independent positive relationship of free testosterone with hypertension is consistent with a similar relationship of free testosterone with other risk factors for myocardial infarction in women found in previous studies and supports the hypothesis.