缓蚀剂Nm—1在中原油田的应用

介绍了缓蚀剂Ｎｍ－１的缓蚀作用机理及现场应用情况。实践表明，该缓蚀剂能有效地抑制聚合物钻井液中氧和盐对钻具的腐蚀，减少因钻具腐蚀引起的事故。     

A breast cancer case-control study in Girona, Spain. Endocrine, familial and lifestyle factors

This study was designed to explore risk factors for breast cancer with emphasis on the detection of clinical markers of the hormonal imbalance during the perimenarche. Three hundred and thirty women diagnosed with breast cancer and 346 population controls were identified and interviewed in Girona, Spain between 1986 and 89. Cases were more likely than controls to have had long menstrual periods in the first 5 years after menarche [odds ratio (OR) = 3.0], to experience menopause at a late age (OR = 1.5) and to report acne during adolescence (OR = 1.6). Family history of breast cancer was associated with an increased risk (OR = 2.3). Cases reported a lower use of drug treatments for anxiety and sleep disorders than controls. Moderate alcohol drinkers and smokers were at lower risk for breast cancer. No statistically significant association with breast cancer was observed for number of children, age at last pregnancy, oral contraceptive use, hormonal treatment after menopause and weight perception during the teenage years. Hormonal changes in the years following menarche may be relevant to breast cancer risk. The roles of menstrual period length and acne during adolescence should be further explored.     

U-83836E prevents kainic acid-induced neuronal damage

Tsukuba College of Technology is the first national university established as an institute of higher education for the visually and hearing impaired. We have been systematically conducting a University Personality Inventory (UPI) survey on our students since 1989 to understand their mental health. In this study, we compared the UPI scores of the new students of Tsukuba College of Technology in 1993 and 1994 with unimpaired students from the University of Tsukuba (control group), but found no significant difference in the UPI scores of the visually impaired and the control group. However, we noticed a significant difference in the average UPI scores between the hearing impaired and the control group. The visually impaired group were divided into four subgroups, UPI scores descended in order from degree 1 (total blindness), to degrees 2 and 3 (amblyopia), to degree 4 (visual acuity > or = 0.3). The UPI scores of the degree 4 subgroup were significantly lower than those of the control group. An investigation of the items for which the check rate was at least 50% showed that the visually impaired students had a variety of psychological problems, most of which seemed to concern depression or anxiety as did the normal control group. The number of affirmative responses increased with low visual acuity. The only one belonging to the 'lie' scale item was observed in the group of hearing impaired students. Thus, comparing these three groups from the viewpoint of mental health, we noticed the hearing impaired group was slightly different from the other two groups, but the visually impaired group was similar to the normal control group.     

Severe and unexpected occurrence of water-electrolyte disorders in the postoperative period

Paradoxical cerebral embolism (PCE) through a patent foramen ovale (PFO) should be considered as a cause of ischemic stroke, particularly in young patients without an alternative cause for stroke. PCE is even more important that it is potentially treatable. However, PCE remains often presumed because it rests upon the rarely demonstrated findings of a deep venous thrombosis and a thrombus lodged in the PFO. Recent studies have shown a rather low stroke recurrence rate in patients with PFO and stroke but suggest that some subgroups of patients with a higher stroke recurrence risk-exist according clinical, echocardiographical and radiological characteristics. For these subgroups, it seems that a more invasive treatment should be required. There are four therapeutic options; antiaggregants, anticoagulation, transcatheter closure of PFO, and surgical closure of PFO. However, these treatments have yet to be evaluated in clinical trials.     

Ethanol induces apoptosis in cerebellar granule neurons by inhibiting insulin-like growth factor 1 signaling

The ability of ethanol to interfere with insulin-like growth factor 1 (IGF-1)-mediated cell survival was examined in primary cultured cerebellar granule neurons. Cells underwent apoptosis when switched from medium containing 25 mM K+ to one containing 5 mM K+. IGF-1 protected granule neurons from apoptosis in medium containing 5 mM K+. Ethanol inhibited IGF-1-mediated neuronal survival but did not inhibit IGF-1 receptor binding or the neurotrophic action of elevated K+, and failed to potentiate cell death in the presence of 5 mM K+. Inhibition of neuronal survival by ethanol was not reversed by increasing the concentration of IGF-1. Significant inhibition by ethanol (15-20%) was observed at 1 mM and was half-maximal at 45 mM. The inhibition of IGF-1 protection by ethanol corresponded to a marked reduction in the phosphorylation of insulin receptor substrate 1, the binding of phosphatidylinositol 3-kinase (PI 3-kinase), and a block of IGF-1-stimulated PI 3-kinase activity. The neurotrophic response of IGF-1 was also inhibited by the PI 3-kinase inhibitor LY294002, the protein kinase C inhibitor chelerythrine chloride, and the protein kinase A inhibitor KT5720, but unaffected by the mitogen-activated protein kinase kinase inhibitor PD 98059. These data demonstrate that ethanol promotes cell death in cerebellar granule neurons by inhibiting the antiapoptotic action of IGF-1.     

Male germ cell transplantation: present achievements and future prospects

Germ cells are unique, since their surviving descendants can undergo meiosis and differentiate into gametes, which transmit genetic material from one generation to another. We now know that male germ cells, whether they be primordial germ cells in gonadal ridges, gonocytes, or stem spermatogonia, are transplantable. The donor cells can be transferred by direct microinjection into the seminiferous tubules, rete testis or efferent ducts, depending on the recipient species. Following transplantation, the donor cells undergo spermatogenesis in the host's seminiferous tubules in rats and mice, and have even sired offspring in mice. Interspecific germ cell transfer is possible if the recipient's immune system is defective; nude or SCID mice can even produce rat spermatozoa. However, the major obstacle restricting widespread use of this new technology is its extremely low success rate. This article discusses some ideas for improving the success rate of the transfer technique, and considers several potential applications.     

Pachydermoperiostosis. An ultrastructural study

BACKGROUND: Pachydermoperiostosis (PDP) is a rare genetically determined disease belonging to the group of hypertrophic osteoarthropathies. Its aetiopathogenesis remains unclear. Most hypotheses favour an exogenous stimulation of fibroblasts. METHODS: A clinically typical patient with PDP was studied by electron microscopy with particular reference to the dermis and its cellular constituents. Fibroblasts from involved skin were cultured and studied in comparison with control cells. RESULTS: Remarkable modifications of the structure of the dermis were observed, encompassing irregular caliber of collagen fibres, extracellular deposits of microfibrils and of amorphous granular substance corresponding to the Alcian blue positive deposits seen by conventional histochemistry. The in vitro growth of fibroblasts was normal. CONCLUSION: Authors reviewed aetiopathogenic hypotheses. Our data suggest a genetically determined alteration of extracellular matrix production by fibroblasts as a possible explanation for the development of PDP.     

Relation of the levels of systemic prostaglandins and hemodynamic changes present during orthotopic transplant of the liver]

The aim of this study is to investigate the role of prostaglandins (PGI2 and TXA2) in relation with the hemodynamic alterations occuring after graft reperfusion in patients undergoing OLT. A total of 40 patients with liver cirrhosis were studied. Systemic 6-keto-PGF1 alpha and TXB2, stable metabolites of PGI2 and TXA2 respectively, were determined at the radial artery, at four different surgical stages: basal, hepatectomy, anhepatic, and 10 minutes after graft reperfusion. Overall results showed that 6-keto-PGF1 alpha levels were significantly elevated during hepatectomy (1143 +/- 204) when compared to values in the basal stage (p = 0.007). During hepatectomy, 6-keto-PGF1 alpha levels did not correlate to systemic vascular resistance index (SVRI), neither with the cardiac index (IC) nor with the medial arterial pressure (MAP) in the same stage. During the anhepatic stage, only IRVS was inversely correlated with 6-keto-PGF1 alpha levels (p = 0.004): there was no relation with MAP and CI. During reperfusion no correlations were observed between 6-keto-PGF1 alpha levels and MAP, CI or SVRI. We conclude that systemic PGI2 levels are very high in cirrhotic patients undergoing OLT. The absence of correlation between the magnitude of changes in hemodynamic parameters and 6-keto-PGF1 alpha levels during reperfusion of the new liver suggests that other factors must play a role in these hemodynamic changes.     

Validation of cardiovascular fitness field tests in children with mental retardation

The validity of the 600-yard walk/run, the 20-m shuttle run, and a modified 16-m shuttle run was determined to measure aerobic capacity (VO2peak) in children with mild and moderate mental retardation. Practice sessions for all tests were conducted. All field tests were very reliable, and VO2peak was significantly related to them all. A stepwise multiple regression showed that field test performance, body mass index (BMI), and gender, but not age, were also significant predictors of VO2peak. All field tests were valid and reliable indicators of aerobic capacity, suggesting that these tests can be used to predict VO2max in children with mild and moderate mental retardation.