血小板激活因子对大鼠脑血管通透性的影响及药物的保护作用

颈内动脉注射血小板激活因子(PAF),再给伊文思蓝,可见脑实质染色程度加深,而颈内动脉只注射伊文思蓝,脑实质未见染色。而我们合成的新药SZ-1可剂量依赖性地抑制PAF诱导的脑实质伊文思蓝染色程度的加深。在体外培养的脑微血管平滑肌细胞上,PAF能显著刺激~(14)-花生四烯酸的释放,而SZ-1能剂量依赖性地抑制这种释放,提示PAF在脑内产生的损害除与其他因素相关外,还与其刺激花生四烯酸释放有密切关系,SZ-1对PAF引起的脑部损害有保护作用。     

Family demography in a remote rural community in Zambia

A community survey was conducted in a remote rural area of Zambia by The Kasanka Trust whose aims in running a National Park are to include aid to the community living around its borders. Selected results have been extracted from a general report by the Kasanka Trust, including awareness of HIV infection and tuberculosis. The remarkable population dynamics found in this apparently impoverished, poorly served community is highlighted.     

Quality assurance and economical efficiency in ambulatory surgery: The German situation in gynaecological day surgery

In contrast to other countries, gynaecological ambulatory surgery in Germany today is mainly performed in private free-standing units. They perform approximately 98% of all ambulatory operations. A quality assurance programme in gynaecological ambulatory surgery started in the early 1980s and proved the safety of outpatient surgery in experienced hands. Gynaecological ambulatory surgery proved to be far more cost effective than inpatient operations. Independently specialised free-standing units seem to be able to work economically with a high level of quality. Due to the special legal situation in Germany the increasing number of outpatient operations led to a sharp drop in fees for individual operations. Quality assurance consists of many aspects. Most are well established and accepted. Apparently in ambulatory surgery the structural requirements of the operative unit, the organisation of postoperative care, the risk of thrombosis, the risk of infection and other aspects seem to be different to inpatient surgery. Comparative studies are required to investigate these differences. Only then it may be possible to optimise the integration of ambulatory surgery into the health system.     

Haemorrhagic shock encephalopathy syndrome presenting with myoglobinuria

An infant with haemorrhagic shock encephalopathy syndrome (HSES) who in addition presented with hyperpyrexia and myoglobinuria is reported. As rhabdomyolysis is a feature of heat stroke and malignant hyperthermia, the association of HSES with myoglobinuria supports the hypothesis that HSES may be a form of hypermetabolic state triggered by hyperthermia.     

The major and minor group receptor families contain all but one human rhinovirus serotype

Previous studies have assigned 88 human rhinovirus (HRV) serotypes to major and minor receptor groups. Extension of these studies to include the remaining 14 unassigned serotypes indicated that 13 serotypes belong to the major group since their infection of HeLa cells is completely blocked by a monoclonal antibody that recognizes the major group receptor. This result indicates that the major group now accounts for 91 of the 102 known serotypes, while the minor group contains 10 serotypes. One serotype, HRV-87, appears to utilize neither the major nor minor group receptor and may represent a third receptor group. HRV-87 attachment cannot be blocked by other serotypes and displays a binding tropism similar to but distinct from minor group viruses. Unlike major and minor group serotypes, HRV-87 attachment and infection requires the presence of sialic acid on cellular receptors.     

The effects of traumatic brain injury on regional cerebral blood flow in rats

Alterations in cerebral blood flow (CBF) are among the most important secondary pathophysiologic consequences of traumatic brain injury. The present study compared CBF in control rats (n = 20) and in rats that received a calibrated experimental traumatic brain injury (n = 17). The traumatized rats were anesthetized with ketamine (25 mg/kg) and xylazine (10 mg/kg), and prepared for fluid percussion injury (FPI). Twenty-four hours later, the rats were anesthetized with 1% halothane in nitrous oxide-oxygen (70:30) and the left atrium was catheterized via a thoroacotomy. The atrial cannula was used to inject 15 microns radiolabeled microspheres to measure CBF. Following surgery, the concentration of halothane was reduced to 0.5% and the rats were paralyzed with pancuronium bromide (0.1 mg/kg). Thirty minutes later, baseline microsphere determinations were made, and the rats were injured (2.47 +/- 0.08 atm). Each rat received additional injections of microspheres at two of the following four times (T): 5, 15, 30, and 60 min after the brain injury. The procedures for the control group rats were the same as described above except that the rats were not subjected to the craniotomy and the FPI. The traumatized group exhibited heterogeneous decreases in CBF following trauma. Global CBF in this group was 78% (p less than 0.01), 64% (p less than 0.05), 52% (p less than 0.001) of those in the control group at T5, 15, 30, and 60, respectively. In rats, the most prominent cerebral circulatory changes following fluid percussion injury were early reductions of CBF and an increasingly heterogeneous CBF pattern. Hemorrhage, edema, and elevated prostagandin levels are mechanisms that may contribute to these changes.     

Relevance of the rodent model to human aging studies

Rodents have proven to be a useful general model for aging research. Although they are not necessarily appropriate for the study of such specific human age-associated diseases as atherosclerosis, rodents have provided the basis for important age-related findings in many diverse areas, including nutrition, behavior, immunology, physiology, oncology, biochemistry, and neurobiology. Contributions in these areas are briefly reviewed.     

Dialysis decision making in Canada, the United Kingdom, and the United States

This study was designed to determine the extent to which differences in criteria for dialysis patient selection and availability of financial resources cause the wide variation in acceptance rates for dialysis in Canada, the United Kingdom, and the United States. We also sought to determine whether there is agreement among nephrologists in the three countries on which patients should not be offered dialysis. We used a cross-sectional survey of all members of the Canadian Society of Nephrology and the Renal Association of Great Britain, and a randomized sample of 800 members of the American Society of Nephrology. Five case vignettes were presented asking for yes/no decisions on offering or not offering dialysis, together with ranking of factors considered important. We also inquired about dialysis resources and physician demographics. We compared responses by country. More nephrologists from the United Kingdom returned responses (83%) than Canadian (53%) or American (36%) nephrologists. American nephrologists offered dialysis more than Canadian or British nephrologists (three of five cases; P < 0.04 to P < 0.001) and ranked patient/family wishes (three of five cases; P < 0.057 to P < 0.0001) and fear of lawsuit (P < 0.04 to P = 0.0012) higher than British or Canadian nephrologists. Canadian and British nephrologists reported their perception of patients' quality of life as a reason to provide (P = 0.0019) or not provide (P = 0.068 to P = 0.0026) dialysis more often than their American counterparts. Despite these differences, nephrologists from each country did not differ by more than 30% on any decision and ranked factors almost identically. Ten percent and 12% of Canadian and British nephrologists, respectively, but only 2% of American nephrologists, reported refusing dialysis due to lack of resources (P < 0.0001). We conclude that the wide variation in dialysis acceptance rates in the three countries is somewhat influenced by differences in patient selection criteria and withholding of dialysis by nephrologists based on financial constraints, but that other factors, such as differences in rates of patient nonreferral for dialysis, contribute more significantly to the variation. Generally agreed on practice guidelines for dialysis patient selection appear possible.     

Determination of serum bilirubin by skin reflectance: effect of pigmentation

A noninvasive optical technique by which serum bilrubin can be estimated from skin spectral reflectance measurements has been further investigated. The original work on 30 healthy, full-term white infants and an independent study on 14 white and 30 black infants demonstrate that the method has potential not only for clinical use, but also for the study of the transport of bilrubin to, from and within the skin. The objectives of the present study are to evaluate the method on a larger sample population with special attention to natural skin pigmentation effects and the development of a physical model of the tissue to explain the relationship between serum bilrubin concentration and skin reflectance. Reflectance spectra (380-800 nm) and concurrent serum bilirubin measurements were taken on a sample population of 58 white and 45 full-term black infants (1-3 days of age). Multiple linear regression analysis, comprised of six wavelengths gave a correlation coefficient, r = 0.831 for the white infant group. For the black infant group, a five wavelength analysis provided r = 0.877 with the standard error of estimate being +/- 1.46 mg/100 ml for both groups. The model for establishing a physical basis for the relationship shows that a transformed, normalized Kubelka-Monk function xi (460, 510, 420) is linearly related to serum bilrubin concentration. This function is determined from the spectral reflectance values at three wavelengths, 420, 460, and 510 nm. The wavelength combination is such that effects due to hemoglobin and melanin pigments are minimized. Regression analysis showed that r = 0.778 and r = 0.865 for the white and black infant groups, respectively, with standard error of estimates being +/- 1.4 mg/100 ml for both groups. Routine determinations of total serum bilrubin by laboratory methods have standard errors of estimate ranging from +/- 1 to 1.5 mg/100 ml. Thus, the method herein described shows that the relationship between skin reflectance and serum bilrubin in full-term infants is close to the acceptable limits for clinical use. Furthermore, this work shows that skin pigmentation does not obscure this relationship.