The nitric oxide pathway in pre-eclampsia: pathophysiological implications

Pre-eclampsia, one of the most significant health problems inhuman pregnancy, complicates 6-7% of all gestations and is theleading cause of fetal growth retardation, infant morbidityand mortality, premature birth and maternal death. Recent researchimplicates free radicals in the pathophysiology of pre-eclampsia.This review covers the biochemistry of nitric oxide (NO) andpossible interactions with other free radicals. Studies in therat show that pregnancy is associated with enhanced productionand responsiveness to NO in both reproductive tissues and bloodvessels. Rats infused with N^G-nitro-L-arginine methyl ester(L-NAME, a NO synthase inhibitor) have been used as an animalmodel of pre-eclampsia, and the effects of steroid hormoneson blood pressure in this model have been tested. Results suggestthat pre-eclampsia may be a state of NO deficiency. However,in humans there seem to be contradictions regarding the involvementof NO in maternal adaptation to pregnancy. It is suggested thatNO may be one of several systems that act in concert to maintaina symbiotic relationship between mother and fetus. However,the input of each system may be genetically determined.     

Surgical sperm retrieval and intracytoplasmic sperm injection as treatment of obstructive azoospermia

Male genital tract obstructions may result from infections, previous inguinal and scrotal surgery (vasectomy) and congenital bilateral absence of the vas deferens (CBAVD). Microsurgery can sometimes be successful in treating the obstruction. In other cases and in cases of failed surgical intervention, the patient can be treated by microsurgical or percutaneous epididymal sperm aspiration (MESA, PESA) or testicular sperm extraction (TESE) and intracytoplasmic sperm injection (ICSI). We present the results of 39 ICSI procedures for obstructive azoospermia in 24 couples. The aetiology of the obstruction was failed microsurgery in 11 patients, CBAVD in nine and genital infections in four. Sperm retrieval was accomplished via MESA in four cases, PESA in 18 cases and via TESE in 11 cases. TESE was only applied when PESA failed to produce enough spermatozoa for simultaneous ICSI. In six patients, the ICSI procedure was performed with cryopreserved spermatozoa after an initial PESA procedure. Fertilization occurred in 47% of the metaphase II oocytes; embryo transfer was performed in 92% of procedures and resulted in a clinical pregnancy in 13/39 procedures. Ongoing pregnancy was achieved in 10/39 procedures. One pregnancy was terminated early after prenatal investigation showed a cytogenetic abnormality (47,XX+18, Edwards syndrome). The other nine pregnancies resulted in the live birth of 10 children, without any congenital abnormalities. Epididymal and testicular retrieved spermatozoa were successfully used for ICSI to treat obstructive azoospermia, and resulted in an ongoing pregnancy in 10 of 24 couples (41.6%) after 39 ICSI procedures, a success rate of 25.6% per treatment cycle and of 27.7% per embryo transfer.      

造血干细胞移植与临床感染的防治

学术背景:造血干细胞移植技术在临床上已得到广泛应用,移植后感染是关系到移植成败的重要因素。目的:探讨造血干细胞移植后各阶段的感染的特点、预防及治疗,以进一步减低造血干细胞移植后感染的发生率及死亡率。检索策略:由作者应用计算机检Medline 1994-01/2007-05关于造血干细胞移植及移植后感染的文章,检索词为"hematopoietic stem cell transplantation,infection",限定语言种类为"English";同时检索中国期刊全文数据库1994-01/2007-05相关文章,检索词"造血干细胞移植,感染,防治",限定语言种类为中文。纳入标准:随机对照研究;实验或临床研究包含平行对照组。排除标准:重复性研究文献评价:初检得到212篇文献,初审后选取与造血干细胞移植后感染有关的文章126篇,删除明显无关及相关性不强的文章,进一步查找全文,29个实验符合标准,予以纳入。29个研究包括324例患者和140个实验动物,分别阐述了造血干细胞移植后感染的原因、途径、特点、种类及各种感染的预防及治疗措施。资料综合:造血干细胞移植后感染发病隐匿,由于患者免疫力低下,感染不易控制,在不同阶段致病菌的种类有所不同,细菌感染普遍,在移植后各个时期均可出现,真菌感染和病毒感染致死性强,故预防和治疗感染至关重要,其治疗分为预防治疗、抢先治疗、经验性治疗和针对治疗。结论:造血干细胞移植后感染的治疗已成为影响移植疗效的一个重要原因,及早的诊断及正确的治疗将成为移植后感染治疗成功的关键。     

Dense red blood cell and oxygen desaturation in sickle‐cell disease

Production of abnormal hemoglobin (HbS) in sickle‐cell disease (SCD) results in its polymerization in deoxygenated conditions and in sickled‐RBC formation. Dense RBCs (DRBCs), defined as density >1.11 and characterized by increased rigidity are absent in normal AA subjects, but present at percentages that vary of a patient to another remaining stable throughout adulthood for each patient. Polymerized HbS has reduced affinity for oxygen, demonstrated by the rightward shift of the oxygen‐dissociation curve, leading to disturbances in oxygen transport. Ninety‐two SCD patients' total RBCs were separated into LightDRBC (LRBC) (d < 1.11 g/mL) and DRBC fractions. Venous blood partial oxygen pressure and RBC‐fraction–deoxygenation and –reoxygenation Hb–oxygen‐equilibrium curves were determined. All patients took a 6‐minute walking test (6MWT); 10 had results before and after >6 months on hydroxyurea. 6MWT time with SpO₂ < 88% (TSpO₂ < 88) assessed the physiological impact of exertion. Elevated mean corpuscular hemoglobin (Hb) concentrations, decreased %HbF, and 2,3‐bisphosphoglycerates in DRBCs modulated Hb–oxygen affinity. Deoxygenation and reoxygenation Hb–oxygen equilibrium curves differed between normal Hb AA and SS RBCs and between LRBCs and DRBCs, with rightward shifts confirming HbS‐polymerization's role in affinity loss. In bivariate analyses, 50% Hb saturation correlated positively with %DRBCs (P < 0.0001, r² = 0.34) and negatively with %HbF (P < 0.0001, r² = 0.25). The higher the %DRBCs, the longer the TSpO₂88 (P = 0.04). Hydroxyurea was associated with significantly shorter TSpO₂ < 88 (P = 0.01). We report that the %DRBCs directly affects SCD patients' SpO₂ during exertion; hydroxyurea improves oxygen affinity and lowers the %DRBCs. Am. J. Hematol. 91:1008–1013, 2016. © 2016 Wiley Periodicals, Inc.     

Larger hip circumference independently contributed to reduced metabolic risks in Tehranian adult women

BACKGROUND: It has been suggested that health professionals may discard measurement of hip circumference from public health screening efforts. Before discarding the hip circumference in epidemiological surveys, it is important to consider whether any important information is likely to be lost. OBJECTIVE: To evaluate the relationship between hip circumference and metabolic risk factors in an urban adult population of Tehranian women. DESIGN: In this population-based cross-sectional study, a representative sample of 5720 women aged 18-74 years, were included. Demographic data was collected; anthropometric indices and blood pressure were measured according to standard protocol. Hypertension was defined based on Joint National Committee VI (JNC VI). Biochemical analysis was conducted on fasting blood samples. Diabetes was defined as fasting plasma glucose (FPG) > or =126 mg/dl or 2-h plasma glucose (2hPG) > or =200 mg/dl. Lipid disorders and components of metabolic syndrome were considered based on Adult Treatment Panel III (ATP III). RESULTS: Mean age of women was 39.9+/-14.6 years. Mean body mass index, waist-to-hip ratio, waist and hip circumferences for subjects were 27.1+/-5.1 kg/m2, 0.83+/-0.08, 86.5+/-13.1 cm and 103.5+/-9.8 cm, respectively. Higher hip circumference was associated with lower levels of serum total- and LDL-cholesterol, serum triglyceride, fasting plasma glucose, 2-h plasma glucose, systolic and diastolic blood pressure. Subjects in the top quintile of hip circumference had higher values of serum HDL-cholesterol concentration compared to those in the lower category. After adjustment for potential confounding variables and anthropometric measures associated with higher hip circumference, a significant decreasing trend was observed for odds of having high LDL-cholesterol (odds ratios among quintiles: 1.00, 0.98, 0.97, 0.95, 0.84, respectively, P for trend=0.04), diabetes (1.00, 0.68, 0.58, 0.45, 0.42, P for trend=0.01), hypertension (1.00, 0.96, 0.82, 0.78, 0.70, P for trend 0.02), low serum HDL-cholesterol (1.00, 1.03, 0.86, 0.82, 0.56, P for trend=0.04), elevated blood pressure (1.00, 0.99, 0.82, 0.70, 0.61, P for trend=0.01) and abnormal glucose homeostasis (1.00, 0.69, 0.66, 0.54, 0.48, P for trend=0.01) among hip circumference quintile categories. Individuals in the upper category of hip circumference had lower odds of having hypercholestrolemia (0.86 vs. 1.00) and high serum triglyceride levels (0.74 vs. 1.00) compared to those in the lowest category. CONCLUSION: Hip circumference is independently and inversely associated with metabolic risk factors. This study underscores the importance of continuing to measure hip circumference in epidemiologic surveys in Tehranian adult women.