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Clinical and immunologic aspects of egg donation pregnancies: a systematic review

Posted: October 13, 2010 at 3:44 pm

BACKGROUND

Egg donation (ED) makes it possible for subfertile women to conceive. Pregnancies achieved using ED with unrelated donors are unique, since the entire fetal genome is allogeneic to the mother. The aims of this review were to evaluate the consequences of ED pregnancies and to place them in the special context of their atypical immunologic relationships.

METHODS

This review comprised an online search of English language publications listed in Pubmed/Medline, up to 29 January 2010. Seventy-nine papers met inclusion criteria. Using the literature and the authors’ own experience, the relevant data on pregnancy outcome and complications, placental pathology and immunology were evaluated.

RESULTS

Multiple studies document that ED pregnancies are associated with a higher incidence of pregnancy-induced hypertension and placental pathology. The incidence of other perinatal complications, such as intrauterine growth restriction, prematurity and congenital malformations, is comparable to conventional IVF. During pregnancy, both local and systemic immunologic changes occur and in ED pregnancies these changes are more pronounced. There is almost no information in the literature on the long-term complications of ED pregnancies for the mother.

CONCLUSIONS

ED pregnancies have a higher risk of maternal morbidity. Owing to the high degree of antigenic dissimilarity, ED pregnancies represent an interesting model to study complex immunologic interactions, as the fully allogeneic fetus is not rejected but tolerated by the pregnant woman. Knowledge of the immune system in ED pregnancies has broader significance, as it may also give insight into immunologic aspects of tolerance in solid organ transplantation.

Recommendation and review posted by Guinevere Smith

Inhibin B and anti-Mullerian hormone as markers of persistent spermatogenesis in men with non-obstructive azoospermia: a meta-analysis of diagnostic accuracy studies

Posted: October 13, 2010 at 3:44 pm

INTRODUCTION

A non-invasive test, which could predict the presence of sperm during a testicular sperm extraction (TESE) procedure in men with non-obstructive azoospermia (NOA), would be of profound clinical importance. Inhibin B (Inh-B) and anti-Müllerian hormone (AMH) have been proposed as direct markers of Sertoli cell function and indirect markers of spermatogenesis.

METHODS

A search was conducted in the electronic databases MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials from inception through June 2009. Thirty-six different studies reported data on the predictive value of one or more index markers (serum Inh-B: 32 studies, seminal Inh-B: 5 studies, serum AMH: 2 studies, seminal AMH: 4 studies) and were included in the systematic review. Nine studies, which had serum Inh-B as index marker, met the predefined criteria and were included in the meta-analysis.

RESULTS

Serum Inh-B demonstrated a sensitivity of 0.65 (95% confidence interval [CI]: 0.56–0.74) and a specificity of 0.83 (CI: 0.64–0.93) for the prediction of the presence of sperm in TESE. When the pre-test probability of 41% was incorporated in a Fagan’s nomogram, resulted in a positive post-test probability of 73% and a negative post-test probability of 23% for the presence of sperm in TESE.

CONCLUSIONS

Serum Inh-B cannot serve as a stand-alone marker of persistent spermatogenesis in men with NOA. Although limited, evidence on serum AMH and serum/seminal AMH do not support their diagnostic value in men with NOA.

Recommendation and review posted by Guinevere Smith

Physiological pathways and molecular mechanisms regulating uterine contractility

Posted: October 13, 2010 at 3:44 pm

BACKGROUND

Uterine contractile activity plays an important role in many and varied reproductive functions including sperm and embryo transport, implantation, menstruation, gestation and parturition. Abnormal contractility might underlie common and important disorders such as infertility, implantation failure, dysmenorrhea, endometriosis, spontaneous miscarriage or preterm birth.

METHODS

A systematic review of the US National Library of Medicine was performed linking ‘uterus’ or ‘uterine myocyte’ with ‘calcium ion’ (Ca2+), ‘myosin light chain kinase’ and ‘myosin light chain phosphatase’. This led to many cross-references involving non-uterine myocytes and, where relevant, these data have been incorporated into the following synthesis.

RESULTS

We have grouped the data according to three main components that determine uterine contractility: the contractile apparatus; electrophysiology of the myocyte including excitation-contraction coupling; and regulation of the sensitivity of the contractile apparatus to Ca2+. We also have included information regarding potential therapeutic methods for regulating uterine contractility.

CONCLUSIONS

More research is necessary to understand the mechanisms that generate the frequency, amplitude, duration and direction of propagation of uterine contractile activity. On the basis of current knowledge of the molecular control of uterine myocyte function, there are opportunities for systematic testing of the efficacy of a variety of available potential pharmacological agents and for the development of new agents. Taking advantage of these opportunities could result in an overall improvement in reproductive health.

Recommendation and review posted by Guinevere Smith

Effects of isoflavones on breast density in pre- and post-menopausal women: a systematic review and meta-analysis of randomized controlled trials

Posted: October 13, 2010 at 3:44 pm

BACKGROUND

Isoflavones from soy and red clover exert modest hormonal effects in women, but the relevance to risk of breast cancer is unclear. The aim of this meta-analysis was to assess the effects of isoflavone-rich foods or supplements on a biomarker of breast cancer risk, women’s mammographic density.

METHODS

Electronic searches were performed on The Cochrane Library, Medline and EMBASE (to June 2009), and reference lists and trial investigators were consulted to identify further studies. Randomized controlled trials (RCTs) of isoflavone-rich foods or supplements versus placebo with a duration of at least 6 months were included in our analysis. Inclusion/exclusion, data extraction and validity assessment were carried out independently in duplicate, and meta-analysis used to pool study results. Subgrouping, sensitivity analysis, assessment of heterogeneity and funnel plots were used to interpret the results.

RESULTS

Eight RCTs (1287 women) compared isoflavones with placebo for between 6 months and 3 years. Meta-analysis suggested no overall effect of dietary isoflavones on breast density in all women combined [mean difference (MD) 0.69%, 95% confidence interval (CI) –0.78 to 2.17] or post-menopausal women (MD –1.10%, 95% CI –3.22 to 1.03). However, there was a modest increase in mammographic density in premenopausal women (MD 1.83%, 95% CI 0.25–3.40) without heterogeneity but this effect was lost in one of three sensitivity analyses.

CONCLUSIONS

Isoflavone intake does not alter breast density in post-menopausal women, but may cause a small increase in breast density in premenopausal women. Larger, long-term trials are required to determine if these small effects are clinically relevant.

Recommendation and review posted by Guinevere Smith

Bone fractures after menopause

Posted: October 13, 2010 at 3:44 pm

BACKGROUND

Every year 30% of individuals above age 65 fall, and falls are the principal cause of bone fractures. To reduce fracture incidence requires both prevention of falls and maintenance of bone strength.

METHODS

PubMed searches were performed, for studies of the epidemiology of fractures, bone physiology, endocrine effects, osteoporosis measurement, genetics, prevention and effectiveness. Topic summaries were presented to the Workshop Group and omissions or disagreements were resolved by discussion.

RESULTS

Ageing reduces bone strength in post-menopausal women because estrogen deficiency causes accelerated bone resorption. Bone mineral density (BMD) decreased more than 2.5 standard deviation below the mean of healthy young adults defines osteoporosis, a condition associated with an increased risk of fractures. Risk factors such as age and previous fracture are combined with BMD for a more accurate prediction of fracture risk. The most widely used assessment tool is FRAXTM which combines clinical risk factors and femoral neck BMD. General preventive measures include physical exercise to reduce the risk of falling and vitamin D to facilitate calcium absorption. Pharmacological interventions consist mainly in the administration of inhibitors of bone resorption. Randomized controlled trials show treatment improves BMD, and may reduce the relative fracture risk by about 50% for vertebral, 20–25% for non-vertebral and up to 40% for hip fractures although the absolute risk reductions are much lower.

CONCLUSIONS

Although diagnosis of osteoporosis is an important step, the threshold for treatment to prevent fractures depends on additional clinical risk factors. None of the presently available treatment options provide complete fracture prevention.

Recommendation and review posted by Guinevere Smith

Severe Low Blood Sugar Won’t Harm Brain

Posted: October 13, 2010 at 3:06 pm

(HealthDay News) — People with type 1 diabetes don’t need to worry that they may have brain function problems in the future if they’ve had a bout or two of severe hypoglycemia (low blood sugar), a new study suggests.

Researchers found that while serious hypoglycemic episodes did sometimes occur as a result of aggressive diabetes control, those low blood sugar events didn’t have any effect on cognitive function.

“Hypoglycemia did not seem to predict the advent of worsening cognitive function,” said the study’s lead author, Dr. Alan Jacobson, director of the behavioral and mental health research program at the Joslin Diabetes Center in Boston.

“Of course, it goes without saying that hypoglycemia can be a serious problem,” he added. “But, if you’ve had a more severe hypoglycemia event, at least it appears that you don’t have to worry that 10 years later you may have trouble doing your job or thinking,” he said.

Results of the study were published in the May 3 New England Journal of Medicine. Read more…

Detox cleansing

Recommendation and review posted by Guinevere Smith


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