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Biomedical subjects

S Nader

Publications and source records attributed to S Nader.

At least 19 recordsLinked to original sources
PubMed2006

Polycystic ovary syndrome, oral contraceptives and metabolic issues: new perspectives and a unifying hypothesis.

In the chronic treatment of polycystic ovary syndrome (PCOS), oral contraceptive pills (OCPs) are commonly used to induce regular menses, protect the endometrium and ameliorate androgenic symptoms. However, the long-term safety of OCP use in PCOS has not been established, and the literature reveals conflicting data concerning the metabolic effects of OCPs in this patient population, with outcomes ranging from improvement of glucose tolerance to the development of frank diabetes. This article presents new perspectives and a unifying hypothesis concerning the effects of OCPs on carbohydrate metabolism in PCOS and attempts to explain the divergent findings in published reports.

Carbohydrate Metabolism↗
PubMed2003

Assessment of analysis by gender in the Cochrane reviews as related to treatment of cardiovascular disease.

BACKGROUND: Cardiovascular disease (CVD) is the leading killer of women in the United States, yet medical care is often based on evidence from clinical trials performed predominantly with men. Numerous studies show that CVD risk factors, clinical presentation, treatment, and treatment outcomes can vary between men and women. METHODS: The Cochrane Library maintains a large database of critically appraised evidence including meta-analyses of clinical trials, called Systematic Reviews. There were 30 Systematic Reviews pertaining to the treatment of CVD published collectively by the Cochrane Heart Group, Hypertension Group, and Peripheral Vascular Diseases Groups at the time of our study. We examined these 30 Systematic Reviews and the great majority of the clinical trials used for their meta-analyses for inclusion of women and gender-based data analyses. Women comprised only 27% of the pooled population of 258 clinical trials. RESULTS: Of those trials that included both men and women (n = 196), only 33% examined outcomes by gender. In trials that performed a gender-based analysis, 20% reported significant (p < 0.05) differences in cardiovascular-related outcomes by gender. CONCLUSIONS: We conclude that (1) there are not enough large-scale clinical trials or meta-analyses concerning CVD in women to determine if their medical treatment should differ from that of men, (2) all clinical trials relating to CVD treatment should have significantly more female participants, and gender-based analyses should be performed, as currently recommended for National Institutes of Health (NIH)-sponsored research by the NIH Revitalization Act of 1993, and (3) the Cochrane Library would be a more useful tool for the evidence-based healthcare of women if the Systematic Reviews used all available gender-specific information in their analyses.

Bibliometrics↗
PubMed2000

Elevated circulating levels of serum tumor necrosis factor-alpha in patients with hemodynamically significant pressure and volume overload.

OBJECTIVES: We sought to determine whether serum tumor necrosis factor-alpha (TNF-alpha) levels are elevated in patients with hemodynamically significant pressure and volume overload. BACKGROUND: It has been previously shown that TNF-alpha messenger ribonucleic acid (mRNA) and protein are rapidly expressed in the hearts of animal models subjected to abrupt hemodynamic overloading. The clinical significance of these experimental findings has not been tested in pathophysiologically relevant clinical models in human subjects. METHODS: We prospectively measured serum TNF-alpha levels and serum TNF receptor 1 and 2 levels in 21 patients with severe aortic stenosis (AS), in 26 patients with 3+ to 4+ mitral regurgitation (MR) and in normal age- and gender-matched control subjects. Patients with AS and MR were either in New York Heart Association (NYHA) functional class I or II and had no significant coronary disease. We compared the cytokine levels among the groups using analysis of variance. We related cytokine levels to the severity of AS using simple regression analysis. RESULTS: Serum TNF-alpha levels in patients with AS (2.1 +/- 1.6 pg/ml, n = 21) and MR (1.3 +/-0.7 pg/ml, n = 26) were significantly higher than those in the control subjects (0.7 +/-0.2 pg/ml, n = 28). Serum TNF receptor 1 and 2 levels were also higher in patients with AS and MR than in control subjects. Cytokine levels were higher in patients in NYHA class II than in those in class I. In patients with a normal ejection fraction (>50%, n = 16), there was a mild positive correlation (r = 0.56, p = 0.025) between serum TNF-alpha levels and the mean gradient across the aortic valve. CONCLUSIONS: This study demonstrates that serum TNF-alpha is elevated in patients with chronic hemodynamic overloading and early cardiac decompensation. Furthermore, these findings suggest not only that peripheral TNF-alpha levels correlate with the severity of the hemodynamic pressure overload, but also that peripheral TNF-alpha and TNF receptor levels increase in direct relation to deteriorating NYHA functional class.

Aged↗
PubMed2000

Improvement in right ventricular systolic function after surgical correction of isolated tricuspid regurgitation.

Chronic tricuspid regurgitation (TR) may lead to impairment in right ventricular (RV) function. Whether surgical correction results in restoration of normal RV geometry and function is unknown. The purpose of this study was to determine whether surgical correction of TR results in improved RV geometry and function. Measurements of RV areas were made from digitized 4-chamber echocardiographic views. Right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV), and ejection fraction (EF) were calculated with the single-plane subtraction method. There was a significant decrease in RVEDV (109.06 +/- 12.45 versus 71.63 +/- 6. 83; P =.005) and RVESV (76.2 +/- 9.83 versus 44.5 +/- 5.58; P =.002) and a significant increase in RVEF (0.30 +/- 0.05 versus 0.38 +/- 0. 05; P =.01) at a mean follow-up of 130 +/- 63 days after surgery. These results demonstrate significant remodeling of the right ventricle with reduction in size and improved EF after tricuspid valve surgery.

Adult↗
PubMed2000

Intractable nausea, vomiting and diarrhea in a Mexican woman with No recent travel history.

A 45-year-old Mexican woman with a history of noninsulin dependent diabetes mellitus (NIDDM), hypertension, and coronary artery disease presented to the hospital after 2 months of intractable nausea, vomiting and diarrhea-all made worse by eating and drinking. She reported fever, chills, anorexia and a documented 50-pound weight loss during this period. She denied the signs and symptoms of melena, hematochezia, steatorrhea or constipation. She also reported left leg pain and decreased sensation and strength of her left leg compared to the right leg. She had been hospitalized 2 weeks prior to admission with the same symptoms and a diagnosis of viral gastroenteritis. She was also treated for H. pylori, but subsequent biopsy results were negative by Steiner stain.

Adrenal Cortex Hormones↗
PubMed1999

Review: Ageing and hormones.

With ageing, there is a decline in hormone levels, including oestrogen, testosterone, dehydroepiandrosterone and growth hormone. Replacement of these hormones has been investigated and reviewed in this paper. There are still controversies regarding the benefits and risks of replacement therapy.

Aging↗
PubMed1998

Analysis of the persistence of humoral and cellular immunity in children and adults immunized with varicella vaccine.

The persistence of humoral and cellular immunity to varicella-zoster virus (VZV) was evaluated in 60 children and 18 adults immunized with live attenuated VZV vaccine. At a mean of 5 years after vaccination, 93% of children and 94% of adults had IgG antibodies to VZV as determined by ELISA. VZV antibody concentrations were significantly higher at 5 years than at 1 year after immunization in children and adults. Cell-mediated immunity to VZV was detected in 87% of children and 94% of adults at 5 years. The mean stimulation index was significantly higher at 5 years than at 1 year among children and adults. Cytokine responses to VZV, including interleukin-2, interferon-gamma, and interleukin-10 were equivalent between children and adults at 5 years. In summary, varicella immunization induced long-term humoral and cellular immunity, and initial differences between cell-mediated responses in children and adults diminished over time.

Adolescent↗
PubMed1997

Spinal cord surgery and galactorrhea: a case report.

We report the case of a 39-year-old nonpregnant woman with amenorrhea and galactorrhea after spinal cord surgery. Activation of the afferent neuroendocrine pathway is postulated to have occurred at surgery.

Adult↗
PubMed1997

Early reconstitution of immunity and decreased severity of herpes zoster in bone marrow transplant recipients immunized with inactivated varicella vaccine.

Varicella-zoster virus (VZV) causes herpes zoster after bone marrow transplantation (BMT). The immunogenicity of heat-inactivated varicella vaccine and effects on VZV pathogenesis were evaluated in 75 BMT patients randomized to receive vaccine or no intervention. Among 14 patients given a single dose at 1 month after transplantation, the mean (+/-SE) stimulation index (SI) was 12.20 +/- 3.13 compared with 4.83 +/- 2.74 (P = .036) in 14 unvaccinated patients, but clinical disease was not altered. Among 24 patients vaccinated at 1, 2, and 3 months, mean SI was 8.43 +/- 3.89 versus 2.00 +/- 0.33 (P = .014) in 23 unvaccinated patients at 4 months and 8.56 +/- 2.81 versus 5.30 +/- 2.47 (P = .043) at 5 months. Disease severity associated with VZV reactivation was decreased dramatically in vaccinees given three doses; severity scores were 6.4 +/- 1.0 versus 11.8 +/- 1.1 (P = .007). This experience with varicella vaccine in BMT patients is the first evidence that active immunization can reduce morbidity due to herpesvirus reactivation in high-risk populations.

Adolescent↗
PubMed1997

The effect of a desogestrel-containing oral contraceptive on glucose tolerance and leptin concentrations in hyperandrogenic women.

Ovarian hyperandrogenism can be associated with insulin resistance, hyperinsulinemia, glucose intolerance, and obesity. High levels of the lipostatic hormone, leptin, have also been reported in this condition. The purpose of the present study was to examine the effect of an oral contraceptive (OC) of low androgenicity containing desogestrel on glucose tolerance in hyperandrogenic women and the impact of changes in androgenic/estrogenic status on leptin concentrations. Sixteen nondiabetic hyperandrogenic women, aged 29 +/- 1 yr with a body mass index (BMI) of 36.8 +/- 1.8 kg/m2, underwent an oral glucose tolerance test before and after 6 months of therapy with the OC. Free testosterone decreased and sex hormone-binding globulin increased after therapy (P < 0.001). Glucose tolerance deteriorated significantly, and two women developed diabetes. Body weight, BMI, and leptin did not change significantly. Leptin correlated with BMI before (r = 0.56; P = 0.02) and after (r = 0.51; P = 0.04) treatment, but not with glucose, insulin, total and free testosterone, or sex hormone-binding globulin before or after treatment. In conclusion, 1) glucose tolerance should be monitored in hyperandrogenic women using OC, even those of low androgenicity; and 2) changes in androgenic/estrogenic status had no effect on the leptin concentration, suggesting that its sexual dimorphism is not related to sex steroids.

Adult↗
PubMed1996

Euthyroid sick syndrome in psychiatric inpatients.

Numerous disorders are associated with euthyroid sick syndrome (ESS). This retrospective study examines the incidence and circumstances of ESS among 3188 psychiatric inpatients. There were 324 patients (10.2%) who met strictly defined criteria for ESS. Of these, 95 were hyperthyroxinemic (HT), 6 were hypothyroxinemic, 179 had mildly elevated thyroid-stimulating hormone (HTSH), and 47 had suppressed TSH. All were classified by DSM-III-R discharge diagnoses, encompassing five categories. chi 2 tests of significance of the 95 HT and 179 HTSH subjects revealed the following: 1) no relationship with age or gender; 2) the frequencies of HT and HTSH differed significantly (p < .05 and p < .01, respectively) across the five psychiatric categories; 3) HT frequency was highest in mood disorders (HT in mood versus others p < .02); and 4) HTSH frequency was highest in substance abuse (HTSH in substance abuse versus others p < .02). In conclusion, ESS is common in psychiatric inpatients, especially HT and HTSH; pathophysiologic mechanisms may vary according to psychiatric diagnosis.

Adult↗
PubMed1996

Recurrent hyperthyroidism in consecutive pregnancies characterized by hyperemesis.

A 34-year-old Caucasian woman was seen and evaluated for hyperemesis and abnormal thyroid function tests, consistent with hyperthyroidism, during her second pregnancy. Her hyperemesis and hyperthyroidism both resolved during the second trimester of this pregnancy. She recounted very similar symptoms of similar duration in her first pregnancy. She was again monitored in a third pregnancy during which hyperemesis and hyperthyroidism were once more documented, resolving during the second trimester. The recurrence of hyperemesis in three consecutive singleton pregnancies, with documentation of transient hyperthyroidism in two of these pregnancies, is suggestive of human chorionic gonadotropin (hCG)-mediated hyperthyroidism. Either the trophoblasts synthesized hCG of high thyrotropic grade or, alternatively, hCG could be modified in the maternal tissues, resulting in molecules with greater thyrotropic activity. These potential mechanisms are discussed.

Adult↗
PubMed1995

Age-related differences in cell-mediated immunity to varicella-zoster virus among children and adults immunized with live attenuated varicella vaccine.

Live attenuated varicella vaccine elicits protection against varicella-zoster virus (VZV), but adults require two doses to achieve optimal seroconversion rates. To assess the potential role of cell-mediated immunity (CMI), T cell proliferation to VZV antigen was compared in children and adults. Mean stimulation indices (SI) in two cohorts of 39 children tested 6 weeks after vaccination were 28.6 +/- 6.21 and 22.1 +/- 3.84, whereas 20 adult vaccines had a mean SI of 9.1 +/- 0.99 (P = .04). Vaccinees had significant increases in CMI after a second dose of vaccine. At 1 year, VZV CMI was significantly lower in adults after two doses (10.0 +/- 1.13 vs. 15.6 +/- 1.77; P = .02), even though 82% of children received one dose. Limitations in the adult helper T cell response to VZV antigens may explain the need for booster doses to elicit effective immunity and the more frequent occurrence of varicella when adult vaccines are exposed to wild type virus.

Adolescent↗
PubMed1994

Effects of beta-blockade on neurohumoral responses and neurochemical markers in pacing-induced heart failure.

We investigated neurohumoral profiles and transmitter and neuroenzyme markers of cardiac autonomic innervation in control (unpaced) dogs and three groups of dogs with pacing-induced heart failure (paced, paced + beta-adrenergic blockade, and paced + cardiac denervation). Left ventricular ejection fraction decreased significantly and to a comparable extent in all paced groups. Pacing increased plasma norepinephrine (NE); increases in NE were not attenuated but instead tended to be exaggerated by treatment with propranolol or cardiac denervation. Atrial hypertrophy occurred in all paced groups compared with the control group. However, atrial and right ventricular hypertrophy were not as pronounced in the paced plus cardiac denervation group as in the paced and paced plus propranolol groups. Pacing also depleted neuropeptide Y and NE from all heart chambers; propranolol treatment did not modify these local tissue changes. Pacing caused selective depletion of neuroenzymes predominantly in the left ventricle; again, propranolol did little to modify these changes. In this study of paced animals with experimentally maintained cardiac dysfunction, failure to modify noradrenergic responses with intrapericardial cardiac denervation suggests that noncardiac sources contribute predominantly to high plasma NE. Failure to modify neurohumoral, neuropeptide, and neuroenzyme responses with beta-antagonist suggests this treatment has little practical direct influence on sympathetic vasomotor activity or neuronal function in heart failure.

Animals↗
PubMed1993

Serum androgens in hyperinsulinemic Pima Indian and obese Caucasian women and their response to short-term insulin infusion.

Insulin resistance and its attendant hyperinsulinemia has been linked with hyperandrogenism. Insulin resistance is characteristic of the Pima Indians of the Gila River Indian community in central Arizona. Serum androgens, testosterone and dehydroepiandrosterone sulfate (DHEA-S) were quantitated at baseline and in response to low- and high-dose insulin infusion in 11 obese, hyperinsulinemic Pima Indian and 10 obese, hyperinsulinemic Caucasian women and were compared with baseline androgens in 16 nonobese Caucasian women. While there was no significant testosterone or DHEA-S response to short-term insulin infusion in either Pimas or obese Caucasians, both these groups had higher baseline testosterone concentrations (67 +/- 6.5 ng/dl in the Pimas, 55 +/- 5.9 ng/dl in the obese Caucasians) as compared with the nonobese Caucasians (28 +/- 2 ng/dl; p < 0.001). Baseline DHEA-S concentrations were not significantly different in the three groups. Given the hyperinsulinemic status of both the Pimas and the obese Caucasians, the finding of higher testosterone concentrations in these subjects as compared with nonobese Caucasians supports a role for insulin in ovarian androgen production and demonstrates that hormonal interactions that may be operating in obese hyperinsulinemic Caucasian subjects also operate in obese, hyperinsulinemic Pima Indians.

Adipose Tissue↗