Assessment of the value of repeated point-prevalence surveys for analyzing the trend in nosocomial infections.

OBJECTIVE: To assess the value of repeated point-prevalence surveys in measuring the trend in nosocomial infections after adjustment for case mix. SETTING: A 3,500-bed teaching facility composed of 4 acute care hospitals. METHODS: From May 1992 to June 1996, eight point-prevalence surveys of nosocomial infections were performed in the hospitals using a sampling process. The trend of adjusted nosocomial infection rates was studied for the four surveys that collected data on indwelling catheters. Adjusted rates were calculated using a logistic regression model and a direct standardization method. RESULTS: From 1992 to 1996, a total of 20,238 patients were included in the 8 point-prevalence surveys. The nosocomial infection rate decreased from 8.6% in 1992 to 5% in 1996 (P < .001). The analysis of adjusted nosocomial infection rates included 9,600 patients. Four independent risk factors were identified: length of stay greater than 12 days, hospitalization in an intensive care unit, presence of an indwelling urinary catheter, and history of a surgical procedure. After adjustment for case mix, the nosocomial infection rate still showed a downward trend (from 7.2% in 1993 to 5.1% in 1996; P = .02). CONCLUSION: Adjusted prevalence rates of nosocomial infections showed a significant downward trend during the period of this study.     

Evaluation of a disinfection procedure for hysteroscopes contaminated by hepatitis C virus.

We assessed the ability of a standard disinfection procedure to eliminate hepatitis C virus (HCV) from the air-water channel of hysteroscopes. The residual HCV RNA remaining after the disinfection procedure was measured by polymerase chain reaction. When correctly applied to hysteroscopes, the standard disinfection procedure was sufficient to eliminate the risk of HCV transmission.     

Neoplastic transformation of hamster brain cells in vitro by polyoma virus.

The transformation of cultivated hamster brain cells by polyoma virus is reported. The transformed cell line contained polyoma virus-specific nuclear, surface and transplantation antigens. Subcutaneous and intracranial inoculations revealed high tumorigenicity of the cells. Brain-specific S 100 protein was found in these tumors with immuno-peroxidase staining, suggesting that they were of a nervous nature. Both in vivo and in vitro, the cells had glial features as studied by phase contrast, light and electron microscopy. Type-H virus-like particles were found in the tumor cells and might have played a role in the viral transformation.     

Spontaneous Cerebrospinal Fluid Leaks in Congenital and Acquired Temporal Bone Defects—A Long-Term Follow-Up

Twelve patients presenting with tegmen defects and requiring surgical repair were retrospectively reviewed from 1982 to 1993. One half of the patients presented with a cerebrospinal fluid leak at some time in the course of their illness. Nine cases were considered to be acquired, secondary to previous mastoid surgery or trauma. All 9 had encephalocoeles. Three spontaneous leaks were considered congenital; 2 of these patients had encephalocoeles. This report represents a long-term follow-up of these cases, with an average follow-up of 7,6 years. Computed tomography and magnetic resonance imaging technology, as well as contrast studies, have tremendously aided in diagnosis and planning of surgical repair. Nine repairs were done through a dual transmastoid and middle fossa approach, with the other 3 done via a transmastoid approach only. We favored temporalis muscle flaps and temporalis fascia over synthetic materials for defect repairs. The long-term results and complications are discussed.     

Immunology of central nervous system tumors

With progress in cellular immunology and the development of hybridoma technology, the idea of manipulating host-tumor immune interactions to improve the prognosis of brain tumors has aroused renewed interest. Although no brain tumor-specific antigens have been found, and in spite of the wide antigenic heterogeneity of brain tumor cells, some monoclonal antibodies possessing restricted specificity have been isolated and their potential clinical applications investigated. One of the most pronounced changes in the cellular immune responses of brain tumor patients is a profound depression of the T4-helper lymphocytes. Clinical and laboratory trials are under way to assess the ability of lymphokines, such as gamma-interferon or interleukin-2, to restore immunologic competence in these patients and potentiate a specific anti-tumor immunologic response. Recent work suggests that the endothelium-astrocyte complex may have a pivotal role in assisting the escape of brain tumors from the host's immunologic responses, since it is responsible for the intracerebral sequestration of antigens and local anti-tumor responses. In this review, the data on the antigenic properties of central nervous system tumors and the host's humoral and cellular immune responses to them are analyzed and potential immunologic therapies are discussed.     

Subcutaneous implantation method for chronic glucocorticoid replacement therapy

A procedure is described for replacing glucocorticoids by subcutaneous implantation of pellets formed from molten corticosterone and cholesterol. Hormone dose is controlled by varying the ratio of these two substances in the pellet. The method produces stable blood and brain corticosterone levels in the physiological range within 3 days and is shown to reinstate normal brain glycerolphosphate dehydrogenase activity in previously adrenalectomized rats. The procedure appears to be well-suited to long-term psycho- and neuro-endocrine studies.     

Appearance of EEG changes reminiscent of a secondary generalized epilepsy in a rhesus monkey inoculated with a strain of kuru.

In a group of rhesus monkeys (Macaca mulatta) inoculated intracerebrally and intravenously with a strain (Enage strain rhesus L6 56) of kuru already passaged in rhesus monkeys, 1 monkey presented the typical EEG pattern of epileptogenic encephalopathy reminiscent of the Lennox-Gastaut syndrome. This observation provides no direct evidence for the viral origin of epilepsies of this type. It does, however, show that it is possible to induce an epileptogenic encephalopathy by an unconventional infectious agent.     

Serological diagnosis of Mediterranean boutonneuse fever

Mediterranean spotted fever is a rickettsiosis due to R. conori. The authors have tested 2 serological reactions available in this disease: Weil-Felix (WF) and indirect immunofluorescent antibody test IF. IF, tested on 184 sera is sensitive (100% of positivity 30 days after the onset of the disease) and specific if a four fold in two sera is obtained at a level upper than: 80. The WF tested on 112 sera is not specific and its sensitivity is poor.