Progressive glomerular injury in the MWF rat is predicted by inborn nephron deficit

It has been suggested that a reduced number of nephrons may predispose to systemic hypertension and glomerular injury. Compensatory hemodynamic changes, due to a low number of glomeruli, might be responsible for glomerular functional and structural changes. It is difficult to evaluate this hypothesis in humans because of limitations in estimating the number of nephrons in the living kidney. The aim of the present study was to estimate nephron number, single glomerular hemodynamics, and glomerular volume in male and female MWF rats, a strain that spontaneously develops systemic hypertension, proteinuria, and glomerulosclerosis. Male and female Wistar rats were used as controls. At 12 to 14 wk of age, male MWF rats developed proteinuria, whereas female MWF and Wistar rats showed normal urinary protein excretion rate. Glomerular number was significantly reduced in male and female MWF rats (13,690+/-1,489 and 12,855+/-1,781 gl/ kidney, respectively) compared with Wistar rats (26,955+/-2,171 and 27,166+/-1,754 gl/kidney, respectively). The mean number of nephrons per unit of body weight was also lower in MWF males (88+/-10) compared with MWF females (139+/-20) and compared with male and female Wistar animals (142+/-14 and 221+/-22 gl/g body wt). Whole-kidney hemodynamic parameters and the number of nephrons were used to calculate single-nephron filtration rate and plasma flow. Both measures were markedly elevated in male MWF rats relative to values obtained in the other three groups. Similarly, glomerular volume was significantly greater in MWF males than in other animals. These results suggest that an inborn deficit of nephrons may be responsible for spontaneous development of later-in-life hypertension and renal dysfunction. The data also indicate the need to investigate the role of this potential pathogenetic factor for human hypertension and kidney disease in humans.     

Functional activity of rat pancreatic endocrine cells in weightlessness and in a suspended state]

Molecular dynamics calculations have been carried out on a model of the LS3 synthetic ion channel in a membrane mimetic environment. In the absence of an external electrostatic field, the LS3 channel, which consists of a bundle of six alpha-helices with sequence Ac-(LSSLLSL)3-CONH2, exhibits large structural fluctuations. However, in the presence of the field, the bundle adopts a well defined coiled-coil structure with an inner pore of water. The observed structural changes induced by the applied field are consistent with the proposed gating mechanism of the ion channel.     

Plasma cell leukemia presenting as a pancreatic mass

A 62-year-old woman presented with a 3-week history of obstructive jaundice. Computed tomography of the abdomen showed marked enlargement of the head of the pancreas and a prominent pancreatic body, suggestive of a neoplasm with associated pancreatitis. The peripheral blood showed an increased number of plasma cells accounting for 50% of the leukocytes. Biopsy specimens of the pancreas, liver, and a peritoneal lymph node showed a diffuse infiltrate of typical and atypical plasma cells (50% of which had cytoplasmic IgG-lambda). Serum and urine protein electrophoresis revealed a monoclonal IgG-lambda spike and Bence Jones-lambda protein, respectively. The bone marrow was diffusely infiltrated by plasma cells. To our knowledge, this is the first reported case of a plasma cell leukemia presenting as a pancreatic mass producing extrahepatic biliary obstruction.     

Increased intraluminal pressure induces DNA synthesis and c-fos expression in perfused rat aorta

The metabolic syndrome is a well-known risk for the development of cardiovascular disease. In the present study the possible importance of an altered visceral adipocyte beta-adrenoceptor function in this syndrome was investigated. In 65 subjects of both sexes undergoing elective surgery for non-malignant disorders, the metabolic syndrome phenotype and the lipolytic sensitivity for various beta-adrenoceptor subtype agonists in omental adipocytes were determined. The study group represented a wide range of abdominal adipose tissue distribution (waist-to-hip ratios 0.76-1.13), but was otherwise apparently healthy. The subjects were divided into three subgroups according to their waist-to-hip (WHR) ratios: 1) WHR < 0.92; 2) WHR 0.92-1.04; 3) WHR > 1.04. The subgroups demonstrated significant differences regarding body mass index, sagittal diameter, systolic and diastolic blood pressures, plasma concentrations of glucose, insulin, triglycerides and HDL-cholesterol (p = 0.005-0.0001). Furthermore, in omental adipocytes beta 3-adrenoceptor sensitivity, but not beta 1-and beta 2-adrenoceptor sensitivities, differed significantly between the WHR subgroups (p = 0.0001). beta 3-adrenoceptor sensitivity was also related to the other components of the metabolic syndrome, although a strong covariation between WHR and beta 3-adrenoceptor sensitivity vs blood pressure and the metabolic parameters was found. The present data provide evidence of a relationship between upperbody obesity and its associated metabolic complications and also, an increased visceral fat beta 3-adrenoceptor sensitivity. We suggest that the latter finding results in an augmented release of non-esterified fatty acids from the visceral fat depot to the portal venous system. This may in turn contribute to the development of the metabolic syndrome.     

Chronic insulin overdosage, hyperinsulinemia, atherosclerosis

Biochemical and immunological indices were studied with regard to insulin dose in 321 patients with diabetes mellitus type I. Overdosage of insulin in these patients induced significantly more frequently clinical manifestations of atherosclerosis, marked shifts in lipid spectrum of the serum and in immunological picture. In diabetics on physiological doses of insulin atherosclerosis is a rare finding, lipid spectrum and immunological indices in stable normoglycemia did not differ much from controls. Implication of chronic insulin overdosage in mechanism of atherosclerosis onset is suggested.     

A case of mosaic Down''s syndrome with two Robertsonian translocations

A 15-year-old girl had bilateral corneal infiltration associated with diabetes insipidus which has been treated for 8 years. The correct diagnosis of histiocytosis X was obtained after histopathological examination. The strict correlation between pathological anatomy and clinical status favoured Hand-Schuller-Christian disease.     

强流质子回旋加速器射频功率源级间功率稳定性研究

本文对强流质子回旋加速器射频功率源固态放大组合与电子管末级间的功率稳定性进行了研究和分析,针对实验中表现出来的不稳定现象进行了计算和仿真。结果表明,灯丝在室温和运行状态下所导致的级间电压驻波比系数（VSWR）分别为1.06和6.89;末级输入调节电容随平行板电容间距变化过于剧烈。通过阻抗匹配仿真、三维电磁场仿真及实验研究解决了由灯丝阻抗变化导致的末级输入端VSWR过大问题,并将输入调节电容的敏感度由每0.5 mm改变10 pF降至每5 mm改变1 pF。     

谈景观设计国际风格实施的本土化

随着景观设计国际交流的日益频繁，越来越多的境外设计师参与到国内景观设计的市场中来。也有越来越多的景观设计项目在自己身上打上了各种不同风格的标签。这有几种原因：一是境外的现代景观设计学科起步较早，有许多设计理念与设计手法值得我们借鉴与学习；二是出于部分国人对西方发达国家的向往或对异域文化的新奇感，同时也由于商业包装的需要，往往要求设计师做出各种不同地域风格的景观设计。在这种潮流驱使下，众多的地产项目，包括市政项目，都采取了中西合作的方式，引进了不少境外的设计。而这些产自境外的设计理念在本土化的过程中，有的成功的被大众接受，成为人们喜欢流连的场所，也有画虎不成反类犬的“四不象”。作为本地的景观设计师，笔者有幸跟几家国际知名的景观设计公司合作过，在这里谈一点心得体会。     

A neurophysiological assessment of the effect of trimetidon on brain function in the cat

Stimulation of the cat brain mesencephalic RF augmented the high-frequency activity in control animals and failed to do so after 4-oxopyrimidine administration. These and some other EEG changes suggest presence of an anxiolytic component in the trimethidone, the latter thus being similar by its effect to 1,4-benzodiazepines and endogenous pyrimidines.     

The influence of retinol, tocopherol and cimetidine on the ulcerogenic effect of Orthofen, indomethacin and naproxen

The influence of retinol, alpha-tocopherol, and cimetidine on ulceration induced by ortophen, indomethacin, naproxen was studied on rats. It was shown that alfa-tocopherol, retinol, and cimetidine reduce the damaging effect of these drugs on the gastroduodenal mucosa of rats thus normalizing the phospholipid content. The influence of alpha-tocopherol and retinol on the side-effects of ortophen was studied in children with rheumatoid arthritis. Ortophen was found to cause gastroduodenal side-effects in more than 30% of patients and decrease the levels of vitamin A and E in children. The use of retinol and alpha-tocopherol in cotherapy decreases the frequency and severity of side-effects and reduces the vitamin deficiency.