Search PubMed⌕ Search

Biomedical subjects

S Daya

Publications and source records attributed to S Daya.

At least 55 records · Page 3Linked to original sources
PubMed2000

Effects of alendronate and hormone replacement therapy, alone or in combination, on bone mass in postmenopausal women with osteoporosis: a prospective, randomized study.

The effectiveness of hormone replacement therapy (HRT) and alendronate, alone and in combination, was evaluated in 120 postmenopausal patients with osteoporosis with bone mineral density (BMD) measurements at least 2 SD below the mean value for young premenopausal subjects. They had no contra-indications to HRT or alendronate use and were randomized to three different treatment groups. Group I was treated with micronized 17 beta-oestradiol 2 mg and norethisterone acetate 1 mg/day per os, group II received alendronate 10 mg/day per os and group III received micronized 17 beta-oestradiol 2 mg, norethisterone acetate 1 mg/day per os and alendronate 10 mg/day per os for 1 year. Elementary calcium 1500 mg/day was supplied to patients in all three groups. Spinal and femoral neck BMD and markers of bone mineral metabolism were measured on each patient before treatment and 6 and 12 months after treatment in 95 patients. At the end of the 12th month, significant increases in spinal and femoral neck BMD were found in all groups. Increases in spinal BMD were significantly higher in patients treated with alendronate and alendronate with HRT when compared with patients treated with HRT only. No significant difference was found in femoral neck BMD changes between the groups. Significant decreases in bone resorption and markers of bone formation were observed in all groups. Alendronate was found to be more effective than HRT and could have a very beneficial effect when added to the HRT regimen in patients with postmenopausal osteoporosis. Alendronate might also be used in postmenopausal patients with osteoporosis when HRT is contra-indicated or when there is reluctance to use hormonal treatment.

Alendronate↗
PubMed2000

Cost-effective, evidence-based infertility care.

Economic evaluation of health care interventions is becoming increasingly important as the demand for services increases. For unexplained infertility, in-vitro fertilization is not a cost-effective first-line treatment option compared with ovarian stimulation and intrauterine insemination. In clomiphene citrate-resistant polycystic ovarian syndrome, in-vitro fertilization may be cost-effective.

Cost-Benefit Analysis↗
PubMed1999

Melatonin reduces quinolinic acid-induced lipid peroxidation in rat brain homogenate.

The protective effects of melatonin against the neurotoxin, quinolinic acid, were investigated in rat brain homogenate using the thiobarbituric acid assay. Quinolinic acid increased lipid peroxidation in a dose dependent manner. When homogenate was cotreated with melatonin there was a significant decrease in lipid peroxidation. The results of the present report show that melatonin may play a protective role in the brain against the neurohormone quinolinic acid, which has been identified as a causative agent in Huntington's Disease.

Animals↗
PubMed1999

Alterations in cardiac flow parameters in patients with polycystic ovarian syndrome.

The aim of this study was to examine the echocardiographic profiles of patients with polycystic ovarian syndrome (PCOS). Serum concentrations of follicle stimulating hormone, luteinizing hormone, androstenedione, free testosterone, prolactin, DHEA-SO(4) and 17-OH-progesterone, lipid profile (high and low density lipoproteins, triglyceride and total cholesterol) and basal and total insulin after a glucose tolerance test were measured in 35 patients with PCOS and 35 healthy controls matched for body mass index. Doppler, two dimensional M mode echocardiography was performed for the following indices: isovolumetric relaxation time (IVRT), E wave duration time (EVT), A wave duration time (AVT), E wave deceleration time (DT), peak early diastolic flow velocity (PEV), peak late diastolic flow velocity (PAV), E wave velocity time integral (FVI-E), A wave velocity time integral (FVI-A), atrial filling fraction (AFF), ejection fraction (EF), pre-ejection time (PEP), ejection time (ET) and aortic flow velocity time integral (FVI). Androstenedione, free testosterone, low density lipoproteins and cholesterol concentrations were significantly higher in patients with PCOS. There was no difference in basal and total insulin concentrations. IVRT, AVT, FVI-A, AFF, and PEP were higher in patients with PCOS, while PEV, FVI-E, EF, ET, EVT and EVT/AVT were higher in the control group. There was a positive correlation between basal insulin values and IVRT, and between total insulin values and EF. These changes are consistent with a non-restrictive type of diastolic dysfunction and left ventricular stiffness. PCOS may lead to diastolic dysfunction via hyperinsulinaemia and male type dyslipidaemia.

17-alpha-Hydroxyprogesterone↗
PubMed1999

Recombinant versus urinary follicle stimulating hormone for ovarian stimulation in assisted reproduction.

The recent availability of recombinant follicle stimulating hormone (rFSH), with its high level of purity and batch-to-batch consistency has made it an attractive alternative to urinary FSH (uFSH) for ovarian stimulation. Several trials have compared the two preparations, but none had sufficient power to detect a clinically meaningful difference in pregnancy rates. The purpose of this study was to determine the clinical pregnancy rates per started cycle by pooling data from randomized trials which compared the use of rFSH and uFSH in treatment cycles using in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). A thorough search of the literature identified 12 trials which met the inclusion criteria. In four trials, both IVF and ICSI were performed, in seven trials only IVF was performed and in one trial only ICSI was performed. Data were extracted and pooled using the principles of meta-analysis. There was no significant heterogeneity of treatment effect across the trials. The common odds ratio and the risk difference (and their 95% confidence intervals), obtained by pooling the data using a fixed effects model, were 1.20 (1.02-1.42) and 3.7% (0.5-6.9%) respectively, in favour of rFSH. The pregnancy rate with the alpha preparation of rFSH was statistically significantly higher than with uFSH in IVF cycles. The overall conclusion from this meta-analysis is that the use of rFSH in assisted reproduction is preferred over uFSH.

Female↗
PubMed1998

Influence of the antidepressants desipramine and fluoxetine on tryptophan-2,3-dioxygenase in the presence of exogenous melatonin.

The effects of desipramine and fluoxetine were examined on rat hepatic tryptophan-2,3-dioxygenase activity in the presence or absence of exogenous melatonin. Male Wistar rats were treated intraperitoneally over 8 days. The antidepressants were also administered individually and their impact on the enzyme noted. Desipramine reduced basal hepatic tryptophan-2,3-dioxygenase activity in the liver while fluoxetine had no observable effect. However, fluoxetine also prevented the hemin induced elevation in total enzyme activity. Exogenous melatonin (0.25mg/kg/day) for 8 days counteracted the inhibitory effects of both desipramine and fluoxetine at concentrations of 2.5mg/kg/day. Total enzyme activity was restored when melatonin was administered in combination with either drug. The experimental findings indicate that there is chemical antagonism at the surface of the enzyme between melatonin and the antidepressants that abolishes the observed inhibitory effects of the administered compounds.

Animals↗
PubMed1998

Melatonin plays a protective role in quinolinic acid-induced neurotoxicity in the rat hippocampus.

The neuroprotective effect of melatonin against the quinolinic acid-induced degeneration of rat hippocampal neurons was investigated. Three groups of rats were given intrahippocampal injections of either; saline, quinolinic acid or i.p. injections of melatonin prior to and after being injected with quinolinic acid. On the fifth day after the intrahippocampal injections the brains were removed and the hippocampi either sectioned and stained for microscopic examination or used in glutamate receptor binding studies. The results show that melatonin protects hippocampal neurons from quinolinic acid-induced neurodegeneration and partially prevents the decrease in glutamate receptor numbers caused by quinolinic acid. Thus, melatonin has the potential to reduce hippocampal neuronal damage induced by neurotoxins such as quinolinic acid.

Animals↗
PubMed1998

Steroidogenesis in luteinized granulosa cell cultures varies with follicular priming regimen.

During follicular development, a co-ordinated gonadotrophin and endocrine environment is believed to be essential for normal function of the resulting corpus luteum. Whether differences in the gonadotrophins used to promote follicular development can have lasting effects on granulosa cells after they have undergone luteinization and culture, remains to be studied. We measured steroid production under basal and human chorionic gonadotrophin (HCG) stimulation in short and long term cultures of luteinizing granulosa cells obtained from normal ovulatory women undergoing assisted folliculogenesis with either human menopausal gonadotrophin (HMG) or follicle stimulating hormone (FSH). Basal progesterone and oestradiol production by luteinized granulosa cells obtained from follicles stimulated to develop with FSH was significantly greater than that from HMG derived follicles (P < 0.001). In short term cultures, treatment with 10 IU HCG caused a 10-fold increase in progesterone release by cells from FSH stimulated follicles, whereas cells of HMG origin produced only 5-fold more progesterone (P < 0.0001). In cultures that were maintained for 2 weeks, progesterone secretion was reduced, but a similar trend in HCG responsiveness was observed. These experiments demonstrate that the composition of the gonadotrophins used to promote follicular development in vivo leads to differences in granulosa cell steroidogenesis which are evident after luteinization and culture. They additionally support the notion that the environment of follicular development will be reflected in the resulting corpus luteum.

Cells, Cultured↗
PubMed1998

The interaction of melatonin and its precursors with aluminium, cadmium, copper, iron, lead, and zinc: an adsorptive voltammetric study.

Melatonin, a pineal secretory product, and its precursors, tryptophan and serotonin, were examined for their metal binding affinities for both essential and toxic metals: aluminium, cadmium, copper, iron, lead, and zinc. An electrochemical technique, adsorptive stripping voltammetry, showed the varying abilities of melatonin and its precursors to bind the metals in situ. The results show that the following metal complexes were formed: aluminium with melatonin, tryptophan, and serotonin; cadmium with melatonin and tryptophan; copper with melatonin and serotonin; iron(III) with melatonin and serotonin; lead with melatonin, tryptophan, and serotonin; and zinc with melatonin and tryptophan. Iron(II) showed the formation of an in situ complex with tryptophan only. These studies suggest a further role for melatonin in the reduction of free radical generation and metal detoxification, and they may explain the accumulation of aluminium in Alzheimer's disease.

Adsorption↗
PubMed1998

Intravenous immunoglobulin therapy for recurrent spontaneous abortion: a meta-analysis.

PROBLEM: Published randomized trials of the use of intravenous immunoglobulins (IVIG) as a treatment for recurrent spontaneous abortion (RSA) have produced conflicting results. The purpose of this study was to conduct a systematic review of the current evidence to evaluate the effectiveness of IVIG for RSA. METHOD OF STUDY: After a thorough search of the literature, four randomized, double-blind trials comparing IVIG with placebo for treatment of RSA were included in the meta-analysis. Live birth rates for each treatment group were extracted, and the overall odds ratio (OR) and absolute treatment effect for IVIG were calculated. RESULTS: Two of the trials showed an increase in successful pregnancy outcome with IVIG treatment and two did not. The overall OR was 1.48 (95% CI, 0.84-2.60) in favor of IVIG, with an absolute treatment effect of 10.1% (95% CI, -4.8-24.6). Excluding pregnancy failures with an obvious cause produced statistically significant results, but this approach may be subject to bias. CONCLUSION: This meta-analysis suggests that IVIG may have a role in the treatment of recurrent abortion, but as yet no conclusive evidence is available.

Abortion, Habitual↗
PubMed1997

Inhibition of hepatic tryptophan-2,3-dioxygenase: superior potency of melatonin over serotonin.

In view of the biogenic amine deficiency hypothesis of depression and the contentious claim that hepatic tryptophan-2,3-dioxygenase (TDO) is the major peripheral determinant of brain tryptophan, brain serotonin (5-HT), and ultimately melatonin, the regulation of TDO by melatonin and 5-HT is investigated and discussed. It is concluded that TDO activity is regulated differentially by melatonin and 5-HT. Melatonin is a competitive inhibitor of TDO and 5-HT is predominantly an allosteric inhibitor. In the presence of 5-HT the effects of melatonin are nullified. However melatonin alone is a more potent inhibitor of TDO. Melatonin is also shown to be a reversible negative effector of TDO.

Animals↗
PubMed1996

The importance of quality of primary studies in producing unbiased systematic reviews.

BACKGROUND: Traditional and largely qualitative reviews of evidence are now giving way to much more structured systematic overviews that use a quantitative method to calculate the overall effect of treatment. The latter approach is dependent on the quality of primary studies, which may introduce bias if they are of poor methodologic quality. OBJECTIVE: To test the hypothesis that the inclusion of poor-quality trials in meta-analyses would bias the conclusions and produce incorrect estimates of treatment effect. METHODS: An overview of randomized trials of antiestrogen therapy in subfertile men with oligospermia was performed to test the hypothesis. Data sources included online searching of MEDLINE and Science Citation Index databases between 1966 and 1994, scanning the bibliography of known primary studies and review articles, and contacting experts in the field. After independent, blind assessment, nine of 149 originally identified studies met the inclusion criteria and were selected. We assessed study quality independently. Outcome data from each study were pooled and statistically summarized. RESULTS: There was a marginal improvement in pregnancy rate with antiestrogen treatment (odds ratio, 1.6; 95% confidence interval, 0.9 to 2.6). Sensitivity analyses on the basis of methodologic quality demonstrated that poor-quality studies produced a positive effect with treatment, whereas no benefit was observed with high-quality studies. CONCLUSION: The results of a meta-analysis are influenced by the quality of the primary studies included. Methodologically, poor studies tend to exaggerate the overall estimate of treatment effect and may lead to incorrect inferences.

Bias↗
PubMed1996

Plasma glucose and pre-eclampsia.

OBJECTIVE: To determine whether there is a relationship between plasma glucose level in a glucose screening test and the occurrence of pre-eclampsia in non-diabetic pregnant women. METHODS: All pregnant non-diabetic women attending the antenatal clinic at the Aga Khan University Medical Center were screened with a 75 g-2 h glucose challenge test (GCT). From 1988-90, a data base of 1316 cases was compiled for use in this study. Of these, 67 had to be excluded because of one or more abnormal levels in the 75 g-3 h oral glucose tolerance test (GTT) that required treatment to maintain euglycemia. Among the remaining patients (n = 1249) who had no evidence of glucose intolerance and were included in the analysis, there were 42 cases of pre-eclampsia. The association between pre-eclampsia and plasma glucose level in the GCT was evaluated using logistic regression analysis that adjusted for effects of age and gravidity. RESULTS: The odds of having pre-eclampsia were increased by 20% (95% confidence interval 0%-44%) per mmol/l rise in plasma glucose level in the GCT. The same statistic for age was 9% (95% confidence interval 2%-17%), and for primigravidity it was 210% (95% confidence interval 55%-517%). There was no significant interaction between these variables. CONCLUSIONS: Minor degrees of glucose intolerance, age and primigravidity are associated with a higher occurrence of pre-eclampsia in non-diabetic pregnant women.

Adult↗
PubMed1996

Empirical evidence of bias in infertility research: overestimation of treatment effect in crossover trials using pregnancy as the outcome measure.

OBJECTIVE: To determine whether crossover trials with simple pooling of data over different study periods leads to a different estimate of treatment effect compared with parallel group trials in infertility research using pregnancy as the outcome measure. DESIGN: An observational study using nine overviews that included trials with both crossover and parallel group designs. These overviews comprised 17 crossover and 17 parallel group trials. In total, there were 5,291 outcomes including 775 pregnancies. The association between study design and treatment effect estimate was analyzed using multiple logistic regression, controlling for differences in the therapeutic interventions and variations in the methodological quality of the trials. SETTING: Infertile patients in an academic research environment. PATIENTS: Infertile patients undergoing treatment efficacy evaluation in controlled trials. INTERVENTIONS: Random allocation to a variety of treatments including clomiphene citrate, hCG, IUI, tamoxifen, and bromocriptine. MAIN OUTCOME MEASURE: Estimate of bias between study designs, based on the interaction of study design and treatment in the logistic regression model. RESULTS: Crossover trials produced a larger average estimate of treatment effect compared with trials with a parallel group design, overestimating the odds ratio by 74% (95% confidence interval, 2% to 197%). CONCLUSION: The use of a crossover design for evaluating infertility treatments with outcomes that prevent patients from completing later phases of the trial should be avoided because it leads to exaggerated estimates of treatment effect and may result in erroneous inferences and clinical decisions. Furthermore, the type of study design should be taken into account when assessing the methodological quality of therapy trials in infertility.

Bias↗
PubMed1996

Study design for the evaluation of diagnostic tests.

Diagnostic tests, like therapeutic procedures, require proper analysis prior to incorporation into clinical practice. In studying diagnostic tests, an evaluation should be made of the reproducibility, accuracy, variation among those without the disease, and variation among those with the disease. Both diseased and disease-free states should be identified using a gold standard, if available. Three main guidelines can be used in evaluating and applying the results of diagnostic tests: validity of the study, expression of the results, and assessment of the generalizability of the results. Validity requires an independent, blind comparison with a reference standard. Methodology should be fully explained. Results should include sensitivity, specificity, and a receiver operating characteristic plot. Several categories of results should be provided in the form of likelihood ratios. Management decisions can be made on the basis of the posttest probability of disease after including both the pretest probability and the likelihood ratio in the calculation.

Data Interpretation, Statistical↗