Epidemiology, appropriateness, and cost of vancomycin use

OBJECTIVE: Our purpose was to compare the estimated maternal cerebral perfusion pressure and an index of vascular resistance, the resistance area product, in nonpregnant women with hypertensive pregnant women. STUDY DESIGN: The maternal middle cerebral artery was evaluated by transcranial Doppler ultrasonography in 17 nonpregnant women, 17 pregnant normotensive patients, 20 pregnant patients with chronic hypertension, and 21 pregnant patients with pre-eclampsia (defined by The American College of Obstetricians and Gynecologists criteria) and cerebral blood flow velocities were determined. We calculated estimated cerebral perfusion pressure as [Estimated cerebral perfusion pressure = V mean/(V mean = V diastolic) (Mean blood pressure - Diastolic blood pressure)] modified from Aaslid et al, 1986. Because the diameter of the vessels could not be measured directly, an index of resistance, the resistance area product, was calculated. Resistance area product = Mean blood pressure/mean velocity (Evans et al, 1988). We calculated an index of cerebral blood flow (Cerebral blood flow index) = Estimated cerebral perfusion pressure/resistance area product. RESULTS: Women who were chronically hypertensive and those with pre-eclampsia showed a significant increase in estimated cerebral perfusion pressure and resistance area product compared with nonpregnant and pregnant normotensive women. An estimate of cerebral blood flow (cerebral blood flow index) in nonpregnant women showed that pregnancy resulted in a nonsignificant 18% increase in cerebral blood flow. CONCLUSIONS: Women with chronic hypertension and pre-eclampsia behave similarly by demonstrating significant increases in cerebral perfusion pressure (estimated cerebral perfusion pressure) and cerebrovascular resistance (resistance area product) compared with normotensive and nonpregnant women. Pregnant patients have a minimal increase in cerebral blood flow (18%).     

An overview of pharmacoepidemiology

Pharmacoepidemiology is the application of epidemiological principles and methods to the study of drug effects in human populations. The goal of this discipline is to characterize, control and predict the effects and uses of pharmacological treatment modalities. Pharmacoepidemiology is also concerned with the economic impact and health benefits of unintended drug effects. The increasing importance of pharmacoepidemiology has been created by the need to develop a more accurate portrait of how drugs are used in the general population. Sophisticated and potent drug therapies require surveillance beyond the scope of the carefully controlled clinical trials of Phases I, II and III. Case-control and cohort studies, which allow scientists to evaluate the effects of patient variables on clinical outcomes, provide a wealth of information regarding the study of unexpected drug effects, drug utilization, treatment costs and the individualization of therapy.     

黄铜脱锌腐蚀的研究进展

描述了黄铜脱锌的优先溶解机制、溶解-再沉积机制、双空位机制和渗流机制，介绍了抑制黄铜脱锌腐蚀的方法，分析了As、B元素对抑制黄铜脱锌腐蚀的作用，并结合作者在微量稀土元素对黄铜脱锌腐蚀的影响方面的研究工作，讨论了稀土元素在提高黄铜抗脱锌能力所起的作用和最佳的添加量，这对以后的黄铜脱锌腐蚀研究工作具有很好的指导意义．     

Pregnancy-related hospital use

OBJECTIVES:This article describes provincial variations in women's hospital use during pregnancy, childbirth and the postnatal period. DATA SOURCE: The data were extracted from the Person-Oriented Information Data Base, maintained by Health Statistics Division at Statistics Canada. This data base is comprised of hospital admission data submitted by general and allied hospitals to provincial and territorial governments and is considered complete for each jurisdiction. Data were not available for the Yukon Territory. ANALYTICAL TECHNIQUES: A group of 57,627 women who gave birth during October and November 1993 was identified from hospital admission records using selected ICD-9 and CCP codes. These records were then linked to other hospital admissions that occurred in the six months before and the four months after childbirth. MAIN RESULTS: Approximately 15% of women who gave birth in October and November 1993 were admitted to hospital at least once during the six months before childbirth. Only 4% were re-admitted during the four months after the birth.     

纤维增强铝基复合材料研究进展

综述纤维增强铝基复合材料的研究进展,简介纤维增强铝基复合材料的性能特点、主要制造工艺和应用现状.     

An overview on nucleation theories and models

Several different models for coercivity are discussed. There are two main situations: i) nanocrystalline magnets, with grain size bellow the single domain particle size, and ii) magnets with grain size above single domain particle size. The described theories and models are general, and can be applied in either NdFeB magnets, SmFeCoCuZr or strontium ferrite magnets. The spring effect observed in isotropic nanocrystalline magnets can be explained with the Stoner-Wohlfarth model. Modifications of the StonerWohlfarth model are necessary to take into account the effect of interaction between grains. When the grain size is above the single domain size, energy considerations show that nucleation should occur at the surface of grains. Nucleation is interpreted as a two-step process, where domain wall displacement occurs for grain size above single domain size, after a nucleus is first formed. The effect of grain size on the coercive field is discussed.     

An overview of childhood cancer

The purpose of this article is to present information of interest to nurse practitioners on childhood cancer. It will begin with a brief review of the disease including details of incidence, morbidity, and mortality. Information on the clinical presentation, treatment methods, and prognosis of the most common forms is included. The paper concludes with a brief overview of selected issues related to this disease of interest to the primary care provider.     

The appropriateness of use of percutaneous transluminal coronary angioplasty in New York State

Between 1974 and 1989 we prospectively observed 530 patients with brucellosis. The findings for 62 patients (42 males and 20 females; mean age, 34.7 years) with 63 episodes in which the sacroiliac joint was involved (the most frequent osteoarticular location [11.7%]) were analyzed. Ten of the older patients (mean age, 55.3 years) had concomitant spondylitis. Systemic symptoms were usually important, and characteristic pain and findings of sacroiliitis were observed in approximately 75% of cases. Blood cultures were positive for Brucella melitensis for 44 patients. The most frequent radiographic findings were blurring of articular margins (42 cases) and widening of the sacroiliac space (20 cases). No radiographic anomalies were detected in 13 cases. Results of 99mTc and gallium-67 bone scans were abnormal in approximately 90% of cases (abnormalities were often mild). Overall, clinical, radiographic, and isotopic bone scan findings were sensitive and useful, although they were occasionally minimal or difficult to evaluate, making diagnostic findings confusing or misleading. Brucellar sacroiliitis is a mild disease associated with a good outcome similar to that observed for patients with uncomplicated brucellosis.     

Symposium overview: the use of delayed matching-to-sample procedures in studies of short-term memory in animals and humans

The authors examined the hypothesized association between the body burden of polychlorinated biphenyls (PCB) in women and the risk of low birth weight for their infants. In Sweden, a main exposure route for PCBs and other persistent organochlorine compounds is through the consumption of fatty fish from the Baltic Sea (on the Swedish east coast). A previous comparison between a cohort of consumers of large quantities of fish from the Swedish east coast and a reference population, together with a following analysis based on questionnaire data from a case-control study within the east coast cohort, supported the hypothesized association. In 1995, blood samples were collected from the wives and ex-wives of fishermen from the Swedish east coast (n = 192) who had given birth during the period 1973-1991. Cases (n = 57), i.e., infants with low birth weight (1,500-2,750 g), were matched with controls (n = 135; birth weight, 3,250-4,500 g) on gender, parity, and calendar year of birth. The concentration of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) in plasma was analyzed; it has been suggested that CB-153 is a relevant biomarker of exposure to PCBs. The concentration of CB-153 in the plasma of mothers during the year of childbirth was "estimated" using some alternative plausible kinetic models. For two alternative estimated exposure datasets, which were focused on separately, an increase in the risk of a low birth weight was observed at a CB-153 concentration of 300 and 400 ng/g lipid weight, respectively (adjusted odds ratios of 2.1 (95% confidence interval (CI) 1.0-4.7) and 2.3 (95% CI 0.9-5.9)). The present results strengthen the findings reported previously for this study population.     

传统热连轧生产技术的发展

介绍了传统热连轧新技术,包括无头轧制技术、连铸板坯热送热装和直接轧制技术、铁素体轧制技术、热轧工艺润滑技术、自动化控制技术的特点.传统热连轧机分为粗轧和精轧两部分,使用的板坯厚度一般大于180 mm,最小产品厚度为1.2mm.近年来传统热连轧新技术、新装备的出现推动了炼钢一连铸一轧钢生产的一体化,加速了钢铁生产向连续化、低成本和高质量方向发展,扩大了传统热带轧机的轧制范围,可批量生产0.8mm的超薄带钢.先进的传统热连轧生产技术,是传统热连轧机组改造和发展关键.     

非氰药剂浸金进展

全面回顾已出现的氯化，硫代硫酸盐，溴碘试剂，石硫合剂等非氰浸金药剂，并对它们的操作条件、矿石适应性和浸金结果及完善措施进行评述，在此基础上讨论了浸金药剂科研和工业化的宏观构思。     

An overview on the effectiveness of natural family planning

Recent years have witnessed important developments in natural family planning (NFP), which is based on the observation of fertile and infertile periods of the menstrual cycle, so that the couple is able to know when sexual intercourse may lead to a pregnancy. A review of the main studies regarding the effectiveness of NFP showed a decrease in the Pearl Index and life table values from the early 1980s to date, indicating that progress both in the teaching and in the application of these contraception, methods has been achieved. The main cause of lack of success seems to be the misapplication of NFP rules, whereas the errors due to the method itself are few. Furthermore, it seems that the symptothermal method might give better results than the ovulation method, even though no comparative study has been carried out, and that the first studies on the lactational amenorrhea method show encouraging results. Finally, it seems that NFP is best suited for 'spacers' of pregnancies, rather than for 'limiters'. Indeed, the former are more likely to show good compliance, since the sexual abstinence periods are limited and an unwanted pregnancy is not regarded as a completely negative event.     

Hepatic imaging. An overview

Chronic food restriction reduces blood pressure (BP) and sympathetic support of BP in aortic coarctation hypertension. The purpose of this study was to test the hypothesis that chronic food restriction would reduce sympathetic support of BP mediated by the paraventricular hypothalamic nuclei (PVN). Hypertension was induced in male Sprague-Dawley rats (n=40) by suprarenal aortic coarctation. Rats were assigned to either an ad libitum fed (AL) group or a food restricted (FR) group that received 60% of the food consumed by AL for 3 weeks. One week prior to data collection, catheters were implanted in the left carotid artery and right jugular vein. BP was measured for 2 days prior to, and 7 days after rats in AL and FR groups received either bilateral electrolytic lesions of the PVN (PVNx) or sham lesions (SHAM). Prior to either PVNx or SHAM, FR rats had significantly lower BP (AL=152+/-5; FR=113+/-2 mmHg), less of a depressor response to ganglionic blockade (AL=-58+/-4; FR=-35+/-2 mmHg), and lower plasma norepinephrine levels (AL=758+/-71; FR=380+/-23 pg/ml) compared to AL. PVNx reduced BP in both AL and FR rats (AL-PVNx=105+/-6 mmHg, FR-PVNx=101+/-3 mmHg). PVNx also lowered the depressor response to ganglionic blockade (AL-PVNx=-28+/-5 mmHg, FR-PVNx=-29+/-4 mmHg) and plasma norepinephrine levels (AL-PVNx=372+/-74 pg/ml, FR-PVNx=248+/-31 pg/ml). FR decreased the magnitude of the reductions in resting BP and in sympathetic activity in response to PVNx. These results indicate that intact PVN are required for maintenance of aortic coarctation hypertension, and implicate the PVN as a site involved in BP reductions produced by chronic food restriction.     

Oculoplastic surgery. An overview

BACKGROUND. The interface between the subspecialties of dermatologic surgery and oculoplastic surgery is broad. However, there are many commonly seen oculoplastic conditions that are not foremost in the mind of the dermatologic surgeon. OBJECTIVES. Common oculoplastic problems are detailed in this article and should provide the reader with a basis for understanding the wide spectrum of oculoplastic problems encountered in practice.     

Nosologic groups. An overview

A general analysis is made of the concept of nosologic groups. It is concluded that, even when 'artificial',they may prove to be useful research, didactic and differential diagnosis purposes. Nosologic groupings must, however, progress toward the finding of 'phenotypic communities' whose component syndromes share multiple foci of dysmorphogenetically intimate phenotypic overlap. The concepts of syndrome, anomalad, association, combination, dysplasia, phenotypic community and family of diseases are briefly analysed.