333 research outputs found
Antimüllerian hormone in relation to tobacco and marijuana use and sources of indoor heating/cooking
To evaluate exposure to tobacco, marijuana and indoor heating/cooking sources in relation to anti-Müllerian hormone (AMH) levels
The effect of finasteride on the prostate gland in men with elevated serum prostate-specific antigen levels.
Prostate cancer is a disease associated with androgens. It has been hypothesized that reducing the conversion of testosterone (T) to dihydrotestosterone (DHT) in the prostate by the use of the drug finasteride, a 5alpha-reductase inhibitor, will reduce the incidence of prostate cancer. We investigated the chemopreventive potential of finasteride by evaluating its effect on the prostate gland of men with elevated serum prostate-specific antigen (PSA). Fifty-two men with elevated PSA and prostate sextant biopsies negative for cancer were randomized to receive finasteride 5 mg day(-1) (27 patients) or no medication (25 patients) for 12 months and were rebiopsied at 12 months. The biopsies were evaluated for the presence of cancer, the proportion of glandular and hyperplastic tissue, and the presence of high-grade prostatic intraepithelial neoplasia (PIN). Epithelial proliferation was assessed in the prestudy and 12-month biopsies by immunohistochemistry using antibody to proliferating cell nuclear antigen (PCNA). Serum blood samples were drawn at baseline and after 1, 3, 6 and 12 months of study. In the control group, serum levels of PSA and T were unchanged throughout the 12 months. In the finasteride group, PSA decreased 48% (P < 0.001), DHT decreased 67% (P < 0.001) and T increased 21% (P < 0.001). Histological evaluation of prestudy and 12-month biopsy specimens revealed that the finasteride group had a 30% reduction in the percentage of hyperplastic epithelial tissue (P = 0.002), although this decrease was not statistically significantly different between the finasteride and control groups (P = 0.11). In patients with PIN on prestudy biopsy, no change occurred in the PIN lesions with finasteride treatment. Finasteride also had no effect on the proliferation index of prostatic epithelial cells. Of the 27 patients treated with finasteride, eight (30%) had adenocarcinoma of the prostate detected on the 12-month biopsy, compared with one (4%) of the control patients (P = 0.025). In the treatment group, six cancers occurred in the eight patients with PIN on the prestudy biopsy; in the observation group no cancers were detected in the five patients with PIN on the prestudy biopsy (P = 0.021). Two cancers occurred in the 19 men in the treatment group with no evidence of PIN on the prestudy biopsy, compared with one cancer in the 20 men in the observation group with no evidence of PIN on the prestudy biopsy (P = 0.60). This study, using a novel model for evaluating short-term efficacy of chemopreventive or therapeutic agents in men at high risk of prostate cancer, provides little evidence that finasteride is an effective chemopreventive agent for prostate cancer in men with elevated PSA
MiR-155 has a protective role in the development of non-alcoholic hepatosteatosis in mice
Hepatic steatosis is a global epidemic that is thought to contribute to the pathogenesis of type 2 diabetes. MicroRNAs (miRs) are regulators that can functionally integrate a range of metabolic and inflammatory pathways in liver. We aimed to investigate the functional role of miR-155 in hepatic steatosis. Male C57BL/6 wild-type (WT) and miR-155−/− mice were fed either normal chow or high fat diet (HFD) for 6 months then lipid levels, metabolic and inflammatory parameters were assessed in livers and serum of the mice. Mice lacking endogenous miR-155 that were fed HFD for 6 months developed increased hepatic steatosis compared to WT controls. This was associated with increased liver weight and serum VLDL/LDL cholesterol and alanine transaminase (ALT) levels, as well as increased hepatic expression of genes involved in glucose regulation (Pck1, Cebpa), fatty acid uptake (Cd36) and lipid metabolism (Fasn, Fabp4, Lpl, Abcd2, Pla2g7). Using miRNA target prediction algorithms and the microarray transcriptomic profile of miR-155−/− livers, we identified and validated that Nr1h3 (LXRα) as a direct miR-155 target gene that is potentially responsible for the liver phenotype of miR-155−/− mice. Together these data indicate that miR-155 plays a pivotal role regulating lipid metabolism in liver and that its deregulation may lead to hepatic steatosis in patients with diabetes
IGF1 genotype, mean plasma level and breast cancer risk in the Hawaii/Los Angeles multiethnic cohort
The insulin-like growth factor 1 gene (IGF1) is a strong candidate gene for a breast cancer susceptibility model. We investigated a dinucleotide repeat 969 bp upstream from the transcription start site of the IGF1 gene for possible associations with plasma IGF1 levels and breast cancer risk in a multiethnic group of postmenopausal women. Furthermore, we investigated the relation between race/ethnicity, mean plasma IGF1 levels and breast cancer rates in the Hawaii/Los Angeles Multiethnic Cohort. The mean age-adjusted IGF1 level among Latino-American women, 116 ng ml(-1), was statistically significantly lower than the mean age-adjusted IGF1 levels for each of the three other racial/ethnic groups, African-American, Japanese-American and Non-Latino White women (146, 144 and 145 ng ml(-1), respectively) (P<0.0001). Latino-American women have the lowest breast cancer rates of any racial/ethnic group in the cohort. These results support the investigation of an expansion of the hypothesis for an important role of IGF1 in breast cancer tumorigenesis to different racial/ethnic groups and to postmenopausal women. It is unlikely that any involvement of IGF1 in breast cancer aetiology is mediated by the IGF1 dinucleotide repeat polymorphism, which was not significantly associated with circulating IGF1 levels nor breast cancer risk in this study. Research into relevant determinants of IGF1 levels in the blood must continue
Immunopathogenesis of rheumatoid arthritis
Rheumatoid arthritis (RA) is the most common inflammatory arthropathy. The majority of evidence, derived from genetics, tissue analyses, models, and clinical studies, points to an immune-mediated etiology associated with stromal tissue dysregulation that together propogate chronic inflammation and articular destruction. A pre-RA phase lasting months to years may be characterized by the presence of circulating autoantibodies, increasing concentration and range of inflammatory cytokines and chemokines, and altered metabolism. Clinical disease onset comprises synovitis and systemic comorbidities affecting the vasculature, metabolism, and bone. Targeted immune therapeutics and aggressive treatment strategies have substantially improved clinical outcomes and informed pathogenetic understanding, but no cure as yet exists. Herein we review recent data that support intriguing models of disease pathogenesis. They allude to the possibility of restoration of immunologic homeostasis and thus a state of tolerance associated with drug-free remission. This target represents a bold vision for the future of RA therapeutics
Anti-Mullerian Hormone Concentrations in Premenopausal Women and Breast Cancer Risk
Laboratory models support an inverse association between anti-Müllerian hormone (AMH) and breast tumor development. Human studies are lacking; one study (N=105 cases, 204 controls) with prospectively-collected serum reported the opposite—an approximate 10-fold increase in breast cancer risk comparing 4th to 1st quartile AMH levels. We investigated the relation between serum AMH levels and breast cancer risk in a case-control (N=452 cases, 902 controls) study nested within the prospective Sister Study cohort of 50,884 women. At enrollment, participants were ages 35-54, premenopausal, and completed questionnaires on medical and family history, lifestyle factors, and demographics. AMH (ng/ml) was measured by ultrasensitive ELISA in serum collected at enrollment and log-transformed for analysis. Multivariate conditional logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI) to account for matching on age and enrollment year. Mean age at enrollment was 46.8 years with an average 2.9 years from blood draw to breast cancer diagnosis (SD=1.9). AMH concentrations were below the limit of detection (0.003 ng/ml) for ~25% of samples. Compared with samples below the LOD, women with AMH >2.84 ng/ml (90th percentile among controls) had a two-fold increase in breast cancer odds (OR=2.25; 95% CI: 1.26-4.02). For each 1-unit increase in lnAMH, overall breast cancer odds increased by 8% (OR=1.08; 95% CI: 1.02-1.15) and odds of ER-positive, invasive disease increased by 15% (OR=1.15; 95% CI: 1.05-1.25). Our findings demonstrate an overall positive relation between AMH and breast cancer
Circulating and intraprostatic sex steroid hormonal profiles in relation to male pattern baldness and chest hair density among men diagnosed with localized prostate cancers
Background: Prospective cohort studies of circulating sex steroid hormones and prostate cancer risk have not provided a consistent association, despite evidence from animal and clinical studies. However, studies using male pattern baldness as a proxy of early-life or cumulative androgen exposure have reported significant associations with aggressive and fatal prostate cancer risk. Given that androgens underlie the development of patterned hair loss and chest hair, we assessed whether these two dermatological characteristics were associated with circulating and intraprostatic concentrations of sex steroid hormones among men diagnosed with localized prostate cancer.
Methods:We included 248 prostate cancer patients from the NCI Prostate Tissue Study, who answered surveys and provided a pre-treatment blood sample as well as fresh frozen adjacent normal prostate tissue. Male pattern baldness and chest hair density were assessed by trained nurses before surgery. General linear models estimated geometric means and 95% confidence intervals (95%CIs) of each hormone variable by dermatological phenotype with adjustment for potential confounding variables. Subgroup analyses were performed by Gleason score (\u3c7 vs ≥7) and race (European American vs. African American).
Results: We found strong positive associations of balding status with serum testosterone, dihydrotestosterone (DHT), estradiol, and sex hormone-binding globulin (SHBG), and a weak association with elevated intraprostatic testosterone. Conversely, neither circulating nor intraprostatic sex hormones were statistically significantly associated with chest hair density. Age-adjusted correlation between binary balding status and three-level chest hair density was weak (r = 0.05). There was little evidence to suggest that Gleason score or race modified these associations.
Conclusions: This study provides evidence that balding status assessed at a mean age of 60 years may serve as a clinical marker for circulating sex hormone concentrations. The weak-to-null associations between balding status and intraprostatic sex hormones reaffirm differences in organ-specific sex hormone metabolism, implying that other sex steroid hormone-related factors (eg, androgen receptor) play important roles in organ-specific androgenic actions, and that other overlapping pathways may be involved in associations between the two complex conditions
Long Sun-Exposures Influencing High Sub-Cutaneous Synthesis of Vitamin-D3 may be Associated with Exacerbation of Symptoms in Allergic-Asthma.
Does excessive sun-exposure, non-use of sunscreen and/or high doses of vitamin-D3 supplements provoke exacerbation of asthma? Clinical examinations, retrospective records-access and questionnaire surveys were distributed to a convenience sample of allergic-asthma patient (n=183). Patients (19-89 years) attending the outpatient respiratory clinics at Maidstone Hospital were enrolled. 90.3% of patients (total IgE levels ≥75 kU/L ; n=103) exposed to direct sunlight of ≥ 15 minutes per day continuously for 6-7 days presented with wheeze (χ2(1) = 7.46; p< 0.05) compared to only 9.7% patients of similar atopy-status, presenting with wheeze if exposed to sunlight of < 15 minutes per day for 6-7 days. 68.9% patients (with IgE levels ≥ 75 kU/L ; n=103), non-users of sunscreen (SPF 30 and above), exposed to direct sunlight of ≥ 15 minutes per day continuously for 6-7 days developed a wheeze, compared to fewer users of sunscreen (9.7%, n=103), exposed to the same duration of sunlight who developed asthma symptoms (p< 0.05). Vitamin-D3 supplementation in asthma-patients with clinical signs of hypovitaminosis-D (n=21), produced symptoms of morning chest-tightness (76.2%), allergic rhinitis (61.9%) and wheeze (100%), 2 weeks after initiation of treatment. Our results advocate direct sunlight exposure < 15 minutes per day and use of sunscreen as a novel approach to preventing atopic-asthma symptoms in allergic-asthma patients.. Activated vitamin-D3 is well-recognised to shift the immune-balance towards Th2 predominance, favouring allergic asthma. These results suggest that limiting subcutaneous synthesis of vitamin-D3 in asthma patients and re-addressing dosage of vitamin-D3 supplementation is necessary may contribute to prevent exacerbation of symptoms
Prospective case-control study of premenopausal serum estradiol and testosterone levels and breast cancer risk
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