Differences in early lineage segregation between mammals.

Two lineage segregation events in mammalian development form the trophectoderm, primitive endoderm, and pluripotent primitive ectoderm. In mouse embryos, Oct4, Cdx2, Nanog, and Gata6 govern these events, but it is unknown whether this is conserved between mammals. Here, the expression patterns of these genes and their products were determined in porcine oocytes and embryos and in bovine embryos. CDX2 and GATA6 expression in porcine and bovine blastocysts resembled that of mouse, indicating conserved functions. However, NANOG expression was undetectable in porcine oocytes and embryos. Some inner cell mass cells in bovine blastocysts expressed NANOG protein. OCT4 protein was undetectable in porcine morulae, but present in both the trophectoderm and the inner cell mass of blastocysts, suggesting that downregulation of OCT4 in the trophectoderm does not precede trophectoderm formation. Combined, the results indicate differences in lineage segregation between mammals.     

Inhibition of thromboxane biosynthesis in splanchnic ischemia shock

Administration of dazoxiben (5 mg/kg, i.v.), which effectively suppressed plasma thromboxane concentrations, decreased the number of dogs that deteriorated into shock following a temporary (3-hr) splanchnic artery occlusion (SAO). Dazoxiben pretreatment also moderated the rise of plasma prostacyclin, but it augmented circulating prostaglandin E2 following the release of SAO. These alterations in arachidonic acid metabolism were accompanied by a moderation in the rise of plasma beta-glucuronidase activity, suggesting a moderation of tissue damage in the ischemic splanchnic region, and mitigation of the progressive hemodynamic deterioration caused by the SAO. The possible existence of causal relationships between the plasma eicosanoid concentrations, extent of damage in the ischemic splanchnic region, hemodynamic deterioration, and ultimate production of circulatory failure in dogs subjected to SAO are discussed.     

CGS 21680C, an A2 selective adenosine receptor agonist with preferential hypotensive activity

CGS 21680C (2-[p-(2-carboxyethyl)phenethylamino]-5'-N-ethyl-carboxamido adenosine) a 2-substituted analog of the riboside uronamide, 5'-N-ethylcarboxamido adenosine and the related analog CGS 21577 (2-phenethylamino-5'-N-ethylcarboxamido adenosine), have high in vitro affinity for brain striatal adenosine A2 receptors (IC50 values = 22 and 13 nM, respectively). Both compounds were considerably less active at A1 receptors with CGS 21577 and CGS 21680C having respective IC50 values of 0.76 and 3.1 microM. The former compound was thus 59-fold selective for A2 receptors whereas CGS 21680C was 140-fold selective. In contrast, the reference A2 selective ligand, CV 1808 (2-phenylaminoadenosine), showed only 8-fold selectivity as an A2 ligand, having an IC50 of 115 nM in the [3H]-5'N-ethylcarboxamide adenosine assay and an IC50 of 910 nM at the N6-[3H] cyclohexyladenosine site. Further examination of CGS 21680C showed that the compound was without effect on binding to 17 other putative neurotransmitter/neuromodulator sites indicating its selectivity as an adenosine receptor ligand. In an isolated perfused working rat heart model, CGS 21680C effectively increased coronary flow with an ED25 value of 1.8 nM. The corresponding value for CGS 21577 was 3 nM whereas that for CV 1808 was 110 nM. The EC25 for eliciting bradycardia for all three compounds was greater than 1000 nM. The effects of all three compounds could be reversed by treatment with the xanthine adenosine antagonist, xanthine amine congener.(ABSTRACT TRUNCATED AT 250 WORDS)     

青少年和成年人无症状阻生智齿干预措施的疗效评价

目的评价在青少年和成人中拔除与保留无症状阻生智齿的效果.方法计算机检索Cochrane口腔健康组资料库(至2004年8月4日),Cochrane中心临床对照试验资料库(CENTRAL),Ovid-MEDLINE(1966～2004年8月4日),PubMed(1966～2004年8月4日)和EMBASE(1974～2004年8月4日).检索无语种限制.同时对主要相关杂志进行手检,并尽力获取正在进行和未发表的研究.纳入比较预防性拔除与保留阻生智齿效果的全部随机对照或临床对照研究.由3位作者分别独立评价所检出文献的相关性、真实性并提取数据,如有不确定性,联系作者以获取关于随机和失访的更多信息.对所有试验均进行了质量评价.结果共纳入3个研究,其中2个已完成的随机对照试验评价了青少年预防性拔除智齿对切牙拥挤的影响,另1个随机对照试验正在进行,但研究者不能提供任何资料,他们准备近期发表文章,如是,其资料将被纳入本评价的更新中.已完成的2个研究结局判断指标不同,不能进行数据合并.结论没有证据支持或反对常规预防性拔除成年人无症状阻生智齿,有一些可靠的证据表明在青少年预防性拔除阻生智齿既不能减少也不能预防切牙拥挤.     

Sociotropic and Autonomous Personality and Stressful Life Events as Predictors of Depressive Symptoms in the Postpartum Period

Measures of stressful life events, sociotropic and autonomous personality, and depressive symptoms were completed by 76 women in the last trimester of pregnancy and 8-weeks postpartum. During pregnancy, women with strong sociotropic or autonomous personality style, or high levels of negative life events (or perceived loss resulting from events) in sociotropic or autonomous domains, tended to report higher levels of depressive symptoms. Cross-sectionally, there was some support for the cognitive diathesis-stress model, but not a congruency model, of depression. Longitudinal results indicated that high levels of sociotropic personality style, sociotropic loss, or autonomous loss resulting from events significantly predicted increases in depressive symptoms from pregnancy to the postpartum period. The interaction between personality styles and life events did not predict depressive symptoms longitudinally, either congruently or incongruently. Negative automatic thoughts mediated the direct effects of personality and life events upon depressive symptoms.     

Renovascular hypertension: the small kidney updated

We report the results of treatment in 57 patients with renovascular hypertension associated with one poorly perfused, small kidney with less than 25 per cent of total 131I-hippurate uptake shown by renography. Arteriography in 29 patients demonstrated occlusion of the artery of the small kidney, and in 28 there was stenosis. In addition, 25 patients had stenosis of the artery supplying the larger contralateral kidney. Stenosis of the arteries of the contralateral kidneys was dilated by percutaneous transluminal arterioplasty in all but one of the 25 patients with bilateral disease of the artery, stenosis of the small kidney could be dilated successfully by percutaneous transluminal arterioplasty in 22 of the 28 patients, and cure or improvement of blood pressure was achieved in 12 of them. Percutaneous transluminal arterioplasty of occluded arteries was generally unsuccessful. In 17 patients with unilateral disease not manageable by percutaneous transluminal arterioplasty, nephrectomy of the small kidney improved blood pressure control without significant deterioration of renal function. Renal function improved in 10 patients with bilateral lesions treated by nephrectomy of the small kidney in combination with contralateral percutaneous transluminal arterioplasty. Histological examination of excised kidneys showed large infarcts or several cholesterol emboli whether percutaneous transluminal arterioplasty had been attempted or not. After observation periods ranging from two to 79 months, 48 patients were normotensive (21 without and 27 with medication) and nine patients were still hypertensive even with medication. This study showed that by using percutaneous transluminal arterioplasty initially if possible, supplemented with nephrectomy and/or medication, normotension without loss of renal function or immediate serious complications could be obtained in the majority of these severely hypertensive patients.     

Thrombin generation during cardiopulmonary bypass: the possible role of retransfusion of blood aspirated from the surgical field

BACKGROUND: In spite of using heparin-coated extracorporeal circuits, cardiopulmonary bypass (CPB) is still associated with an extensive thrombin generation, which is only partially suppressed by the use of high dosages of heparin. Recent studies have focused on the origins of this thrombotic stimulus and the possible role of retransfused suctioned blood from the thoracic cavities on the activation of the extrinsic coagulation pathway. The present study was designed to find during CPB an association between retransfusion of suctioned blood from the pericardium and pleural space, containing activated factor VIIa and systemic thrombin generation. METHODS: Blood samples taken from 12 consenting patients who had elective cardiac surgery were assayed for plasma factor VIIa, prothrombin fragment 1+2 (F1+2), and thrombin-antithrombin (TAT) concentrations. Blood aspirated from the pericardium and pleural space was collected separately, assayed for F1+2, TAT, and factor VIIa and retransfused to the patient after the aorta occlusion. RESULTS: After systemic heparinization and during CPB thrombin generation was minimal, as indicated by the lower than base line plasma levels of F1+2, and TAT after correction for hemodilution. In contrast, blood aspirated from the thoracic cavities had significantly higher levels of factor VIIa, F1+2, and TAT compared to the simultaneous samples from the blood circulation (P < 0.05). Furthermore, after retransfusion of the suctioned blood (range, 200-1600 mL) circulating levels of F1+2, and TAT rose significantly from 1.6 to 2.9 nmol/L (P = 0.002) and from 5.1 to 37.5 μg/L (P = 0.01), respectively. The increase in both F1+2, and TAT levels correlated significantly with the amount of retransfused suctioned blood (r = 0.68, P = 0.021 and r = 0.90, P = 0.001, respectively). However, the circulating factor VIIa levels did not correlate with TAT and F1+2 levels. CONCLUSIONS: These data suggest that blood aspirated from the thoracic cavities during CPB is highly thrombogenic. Retransfusion of this blood may, therefore, promote further systemic thrombin generation during CPB.     

Discriminant validity of the MASQ in a clinical sample

A major weakness of the Mood and Anxiety Symptom Questionnaire (MASQ) is that its discriminant validity has not been demonstrated in a clinical population of anxiety and mood disorder patients. This paper, using 470 anxiety and mood disorder patients, assessed the discriminant validity of the MASQ. The MASQ subscales showed statistically significant discriminant validity, but their maximum ability to discriminate is low at 70%. Overall it was concluded that the MASQ had very weak clinical utility in differentiating anxiety and mood disorder patients, and gave rise to doubts as to the tripartite structure of the MASQ. When using the MASQ, future researchers should be mindful of its limitations when applied in a clinical population.