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Objective: To investigate the cause of increasing rates of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection at a university hospital., Design: Review of data collected by prospective hospital wide surveillance regarding rates of nosocomial MRSA colonization and infection., Setting: A 700-bed university hospital providing primary and tertiary care., Patients: Patients admitted to the hospital between 1986 and 1993 who were found to be infected or colonized with MRSA., Main Outcome Measurement: Rates of MRSA infection and colonization., Results: MRSA infection or colonization was identified in 399 patients (0.18%) admitted during the 8-year study. There was no correlation between the annual rates of MRSA and methicillin-sensitive Staphylococcus aureus (MSSA) infections (P = .66). The frequency of both nosocomial and non-nosocomial cases increased significantly over the last 4 years of the study (P < .001 for trend). The ratio of patients who had acquired MRSA nosocomially to those admitted who already were infected or colonized decreased significantly during the study period (P = .002 for trend). There was a significant increase in the frequency of patients with MRSA being transferred from nursing homes and other chronic care facilities (P = .011). A cost-benefit analysis suggested that surveillance cultures of patients transferred from other healthcare facilities would save between $20,062 and $462,067 and prevent from 8 to 41 nosocomial infections., Conclusions: An increase in the incidence of nosocomial MRSA infection was associated with an increased frequency of transfer of colonized patients from nursing homes and other hospitals. The lack of correlation between rates of MRSA and MSSA infections suggested that MRSA infections significantly increased the overall rate of staphylococcal infection. Screening cultures of transfer patients from facilities with a high prevalence of MRSA may offer significant benefit by preventing nosocomial infections and reducing patient days spent in isolation.

Background: In 1990, the Centers for Disease Control and Prevention recommended substituting dust-mist particulate respirators for simple isolation masks in acid-fast bacillus isolation rooms, reasoning that air leaks around the simple masks could result in a higher rate of purified protein derivative skin-test conversion. In 1993, a Centers for Disease Control and Prevention draft guideline proposed that high-efficiency particulate air filter respirators be used instead of dust-mist particulate respirators. Epidemiologic data were not available to assess the importance of these changes or their cost-effectiveness., Methods: The University of Virginia was affiliated with a tuberculosis hospital from 1979 until 1987. We surveyed physicians who had served as residents in internal medicine during this period regarding purified protein derivative skin-test history. duration of work at the tuberculosis sanatorium, and any history of unprotected exposures to patients with active pulmonary or laryngeal tuberculosis. Patients with active tuberculosis at the sanatorium were isolated in negative-pressure rooms with UV lights. Physicians wore simple isolation masks in these rooms., Results: Responses were received from 83 former resident physicians. Fifty-two physicians had worked on the tuberculosis wards for a total of 420 weeks, with no subsequent skin-test conversions (95% CI 0 to 1 conversion/8 physician-years)., Conclusions: These data document a low risk of occupational transmission of Mycobacterium tuberculosis to physicians who wear simple isolation masks in negative-pressure ventilation rooms with UV lights. This low rate predicts that the additional protective efficacy and cost-effectiveness of the more expensive high-efficiency particulate air filter respirators and the respiratory protection program will be low.

The epidemiological pattern of visceral leishmaniasis in north-eastern Brazil is changing. The disease was typically seen in rural, endemic areas, but is now occurring as an epidemic in the city of Natal where 316 cases have been reported since 1989; 49% were in children less than 5 years of age. The principle clinical and laboratory findings were weight loss, fever, hepato-splenomegaly, anaemia, leucopenia and hypergammaglobulinaemia. Elevated transaminases and hyperbilirubinaemia were also observed. The diagnosis was confirmed in 87% of cases by identifying amastigotes in aspirates from bone marrow or spleen. Five isolates were identified as Leishmania (L.) chagasi by isoenzyme analysis. The mortality rate was 9%; all deaths occurred during the first week in hospital. One person had concurrent human immunodeficiency virus infection. Among 210 household contacts and neighbours of patients from the endemic area examined for evidence of L. (L.) chagasi infection, 6 additional cases of visceral leishmaniasis were diagnosed. Thirty-eight percent of house-mates and neighbours gave a positive Montenegro skin test reaction, indicating prior subclinical infection.

Since 1980, more than 10,000 sites in the United States have been shown to contain soil which has elevated concentrations of various xenobiotics. Since that time, guidelines for deciding whether the level of contamination is worthy of concern have been proposed or promulgated by dozens of local, state, and federal regulatory agencies. Unfortunately, there has been little consistency in the guidelines suggested for each soil contaminant. For example, (a) the basis or rationale for some of the cleanup levels is unclear, (b) approaches to setting cleanup levels vary between states and agencies, (c) cleanup objectives often vary among agencies within the same state, and (d) the cleanup levels are usually set in a scientifically haphazard manner. This paper proposes that the most cost-effective and efficient way to quickly regulate contaminated soil is to establish "safe" concentrations for each chemical for the seven most common exposure scenarios. These exposure scenarios include (1) residential, (2) industrial, (3) agricultural, (4) recreational, (5) groundwater, (6) wildlife and aquatic species, and (7) runoff/erosion of particulates to waterways. The scientific approach and rationale for calculating the cleanup criteria are illustrated by evaluating dioxin and benzene, toluene, and xylene (BTX). The methods suggested here indicate that levels of dioxin of 25 and 50 ppb in residential and industrial soils, respectively, should be acceptable. The predominant concern for the agricultural and recreational scenarios is the runoff of particulates to waterways. For BTX, benzene will dictate the degree of cleanup and the primary hazard at most residential sites will be the inhalation of vapors. Benzene concentrations of 2.5, 14, and 250 ppm should be acceptable for residential, industrial, and recreational soils, respectively. Depending on the depth to groundwater and aquifer use, protection of groundwater may be the driving concern for establishing BTX cleanup levels and must be determined using site-specific factors.

Convenient, reliable tests of cure for genital chlamydial infections have not been evaluated. Cervical appearance, endocervical Gram stain, enzyme immunoassay, and culture for Chlamydia trachomatis were evaluated during a pretreatment visit and at two subsequent randomized test-of-cure visits for 64 nongravid women with endocervical C trachomatis of 3544 patients screened. There were no useful correlations between C trachomatis resolution and cervical appearance. Endocervical Gram stain was determined to be unreliable for test-of-cure use. Both C trachomatis culture and enzyme-linked immunosorbent assay (ELISA) were shown to be effective for test-of-cure evaluation. The ELISA test became reliably negative 10 days after initiation of treatment and 1 to 5 days after the clearance of viable organisms detected by culture (P = .03). Convenience and cost considerations favor antigen detection methods. This study suggests that antigen detection methods can be used for situations in which test of cure is indicated, such as therapy noncompliance, circumstances supporting reinfection, pregnancy, complicated infections, requests for psychological reassurance, and evidence of persistent cervicitis.

2,5-Hexanedione (2,5-HD) pretreatment potentiated CHCl3-induced hepatotoxicity. 2,5-HD significantly increased hepatic cytochrome P-450, NADPH cytochrome c reductase, aniline hydroxylation, p-nitroanisole O-demethylation, and aminopyrine N-demethylation in both male and female mice. 2,5-HD pretreatment potentiated CHCl3-induced centrilobular necrosis and increased serum alanine amino transferase (ALT) activity by 20 times more than CHCl3 alone. Similarly, 2,5-HD pretreatment potentiated CDCl3-induced hepatotoxicity as well as CCl4-induced hepatotoxicity in male mice, but did not potentiate trichloroethylene-, 1,1,2-trichloroethane-, or perchloroethylene-induced hepatotoxicity. In female mice, 2,5-HD pretreatment potentiated CHCl3- and CDCl3-induced hepatotoxicity as well as trichloroethylene-, 1,1,2-trichloroethane-, and carbon tetrachloride-induced hepatotoxicity, but not perchloroethylene-induced hepatotoxicity. 2,5-HD pretreatment had no preferential effect on either CHCl3- or CDCl3-induced hepatotoxicity in females. However, phenobarbital pretreatment did differentiate CHCl3- and CDCl3-induced hepatotoxicity in females. 2,5-HD-induced potentiation of halocarbon hepatotoxicity is sex dependent.

An IR camera has been built at the University of California at Berkeley for astronomical observations. The camera has been used primarily for high angular resolution imaging at mid-IR wavelengths. It has been tested at the University of Arizona 61- and 90-in. telescopes near Tucson and the NASA Infrared Telescope Facility on Mauna Kea, HI. In the observations the system has been used as an imager with interference coated and Fabry-Perot filters. These measurements have demonstrated a sensitivity consistent with photon shot noise, showing that the system is limited by the radiation from the telescope and atmosphere. Measurements of read noise, crosstalk, and hysteresis have been made in our laboratory.

The ability of a personal computer software system to predict actual serum phenobarbital concentrations (SPC) in outpatients taking phenobarbital chronically was assessed by comparing actual with predicted SPC for accuracy, bias, and precision. Data for a four-year period were collected on patients at an outpatient clinic's pharmacokinetic consultation service. The study group included 50 adults and children with at least one SPC taken at a known time after dose administration. Input variables were weight, sex, height, age, concomitant drugs and diseases, phenobarbital dosage regimen, and the time and reported value of all SPC. Initially, SIMKIN (SIMulated KINetics) simulated dosing regimens on the basis of literature estimates of pharmacokinetic parameters; SPC were then estimated for these regimens and compared with actual values. One or two additional SPC were added to the input data and analyzed, and the predicted SPC compared with actual values. Although SIMKIN's accuracy and bias as measured by regression analysis and mean prediction error, respectively, were within clinically acceptable limits, the precision was not. However, these results are limited by the population studied. Patient compliance, concomitant phenytoin therapy, changes in phenobarbital pharmacokinetic parameters with chronic dosing, and disease interactions may significantly affect predictive ability. The clinical effects of these factors need to be evaluated to further improve predictions.

Twenty patients with pathologically proved non-resectable bronchogenic carcinoma were treated with 100 aerosolized BCG (Tice strain) doses in addition to conventional treatment. The procedure is based on findings that, generally BCG must be closely associated with neoplastic cells to be effective as an immunotherapeutic agent. Bronchogenic malignancy, usually of mucosal origin, is logically treated in this manner. We report here the findings and developments of 10 patients who were treated at least five times each (for a total of 81 treatments) and pertinent experience relating to these and another 10 patients treated a total of 19 times. Local and systemic reactions were frequent and consisted of fever, cough, dyspnea, nausea, vomiting, anorexia, and malaise. Four of the 20 patients (20%) had reactions with the first treatment; by the fourth treatment 6 of 6 (100%) were affected. Prednisone given prophylactically reduced the intensity and the frequency of reactions. There were no severe side effects, obvious BCG infections, or significant changes in pulmonary or liver functions or hematologic values. No patient acquired purified protein derivative sensitivity, although 3 persons converted other skin tests to positive. There was no improvement in actuarial survival time.

In a retirement community group of 73 relatively fit elderly white persons, a cross-sectional study of 53 different blood tests was conducted. The five test categories for blood values were hematology, chemistry, thyroid function, protein electrophoresis, and immunology. Fifteen percent of the blood findings were outside the range accepted as normal by the examining laboratories. Most of the subjects showed between 5 and 10 "abnormal" values within the five test categories. Since the findings were fairly predictable in view of the patho-anatomic changes that accompany aging, and since the manifestations of disease were at most subclinical, only minor alterations in individual management were needed. Subsequent appropriate clinical re-evaluation of these subjects during a six-month follow-up revealed no striking changes. It would appear that the ranges of "normal" reference values may need to be expanded. Although cross-sectional laboratory studies are useful, longitudinal studies seem essential if clinicians are to attain a more valid perspective.