More than 10 years of unrecognized nosocomial transmission of legionnaires' disease among transplant patients

OBJECTIVE: To investigate a cluster of cases of legionnaires' disease among patients at a hospital. SETTING: A university hospital that is a regional transplant center. DESIGN: Retrospective review of microbiology and serology data from the hospital laboratories and prospective surveillance via the radiology department; a case-control study and environmental sampling within the hospital and from nearby cooling towers. RESULTS: Diagnosis of seven cases of legionnaires' disease in the first 9 months of 1996 led to recognition of a nosocomial outbreak that may have begun as early as 1979. Review of charts from 1987 through September 1996 identified 25 culture-confirmed cases of nosocomial or possibly nosocomial legionnaires' disease, including 18 in bone marrow and heart transplant patients. Twelve patients (48%) died. During the first 9 months of 1996, the attack rate was 6% among cardiac and bone marrow transplant patients. For cases that occurred before 1996, intubation was associated with increased risk for disease. High-dose corticosteroid medication was strongly associated with the risk for disease, but other immunosuppressive therapy or cancer chemotherapy was not. Several species and serogroups of Legionella were isolated from numerous sites in the hospital's potable water system. Six of seven available clinical isolates were identical and were indistinguishable from environmental isolates by pulsed-field gel electrophoresis. Initial infection control measures failed to interrupt nosocomial acquisition of infection. After extensive modifications to the water system, closely monitored repeated hyperchlorinations, and reduction of patient exposures to aerosols, transmission was interrupted. No cases have been identified since September 1996. CONCLUSIONS: Legionella can colonize hospital potable water systems for long periods of time, resulting in an ongoing risk for patients, especially those who are immunocompromised. In this hospital, nosocomial transmission possibly occurred for more than 17 years and was interrupted in 1996, after a sudden increase in incidence led to its recognition. Hospitals specializing in the care of immunocompromised patients (eg, transplant centers) should prioritize surveillance for cases of legionnaires' disease. Aggressive control measures can interrupt transmission of this disease successfully.     

Exact polarised rib waveguide analysis

An exact Fourier operator transform method (F-OPT) is presented for finding the polarised mode propagation constants of a rib waveguide with any number of supporting layers and an arbitrary cladding. The implementation is of the order of one hundred times faster than the finite difference method for the same accuracy of the normalised propagation constant     

Transfer impedance of braided coaxial cables under applied longitudinal torsion

The surface transfer impedance ZT of several braided coaxial cables was measured under applied longitudinal torsion to determine the electromagnetic shielding characteristics of the cables under such conditions. The results cover the frequency range 100 kHz to 150 MHz with torsion angles varying between 0°, +360° m?1 and ?180°m?1. It was found that ZT increases with torsion angle and depending on the degree of optimisation in the braid, increases of up to 800% can occur at a torsion angle of 360° m?1. Further, when a cable is returned to its original position, after being subjected to torsion, the resulting value of ZT is higher than the original value.     

Iterative methods of solution for the elliptic fourth boundary value problem

A special form of the elliptic fourth boundary value problem has been investigated by Hockney (1965). The techniques used, however, are valid only for a Laplacian operator on a square mesh. In this paper, a more general solution process is introduced for a wide range of problems.     

The effect of strain rate on the cyclic response of metals

Monotonie and cyclic strain hardening parameters were measured for five alloys: 7075-T6 aluminum; 6061-T651 aluminum, an α/β brass (alloy 365); copper-l. pct beryllium (alloy 172); and martensitic 4340E steel. Cyclic measurements were made under fully reversed strain control at constant strain rate. A maximum strain of ±0.015 and strain rates of 0.003, 0.03, 0.10, and 0.30 s^-1 were used. The cyclic stress-strain coefficientsK’ and exponentsn’ were found to be independent of strain rate and had the values: 7075-T6 (105 ksi, 0.06); 6061-T651 (60 ksi, 0.06); brass (132 ksi, 0.21); copper-beryllium (165 ksi, 0.13); 4340E steel (300 ksi, 0.19). Adiabatic heating imposed an upper limit < 0.3 s^-1) on the strain rate at which isothermal cyclic strain hardening tests could be performed. Formerly with Midwest Research Institute     

Peer acceptance and school-related variables in an integrated junior high school.

Interracial peer acceptance at the junior high school level was related to 9 predictor variables: grade point average (GPA), IQ, attendance, self-concept of academic ability, sex, race, age, years in the school, and classroom racial composition. 322 7th- and 8th-grade students from predominantly lower-middle-class backgrounds were administered modified Syracuse Scales of Human Relations, measuring academic and social acceptance. Analysis of variance results show that White Ss slightly preferred Whites for the satisfaction of their academic and social needs. However, with stepwise multiple regression analysis, race was not a significant predictor variable for academic or social acceptance by White Ss. GPA and sex were the most prominent predictors of acceptance. Black Ss accepted both Black peers and White peers equally for academic interaction but preferred Blacks for social interaction. Race was a significant predictor variable for academic and social acceptance by Black Ss. However, race was secondary to GPA and/or sex for academic acceptance by Black females and Black males. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of L-dopa on the activity of methionine adenosyltransferase: relevance to L-dopa therapy and tolerance

L-dopa, the major treatment for Parkinson's disease (PD), depletes S-adenosyl-L-methionine (SAM). Since SAM causes PD-like symptoms in rodents, the decreased efficacy of chronic L-dopa administered to PD patients may result from a rebound increase in SAM via methionine adenosyl transferase (MAT), which produces SAM from methionine and ATP. This was tested by administering intraperitoneally saline, or L-dopa to mice and assaying for brain MAT activity. As compared to controls, L-dopa (100 mg/kg) treatments of 1 and 2 times per day for 4 days did not significantly increase MAT activity. However, treatments of 3 times per day for 4 and 8 days did significantly increase the activity of MAT by 21.38% and 28.37%, respectively. These results show that short interval, chronic L-dopa treatments significantly increases MAT activity, which increases the production of SAM. SAM may physiologically antagonize the effects of L-dopa and biochemically decrease the concentrations of L-dopa and dopamine. Thus, an increase in MAT may be related to the decreased efficacy of chronic L-dopa therapy in PD.     

Absorption of simple nutrients from the in vivo neurally isolated canine jejunum and ileum

BACKGROUND: The effects of intestinal transplantation on enteric absorptive function are not well understood. Our aim was to determine the effects of in situ isolation of the jejunoileum, a large animal model of jejunoileal autotransplantation, on absorption of simple nutrients from the jejunum and ileum separately. METHODS: Four groups of dogs were prepared with modified Thiry-Vella loops: group 1, neurally intact jejunum; group 2, neurally isolated jejunum; group 3, neurally intact ileum; and group 4, neurally isolated ileum. Intestinal loops were perfused with five different isosmolar solutions of NaCl alone, 30 mmol/L glucose, 2.5 mmol/L glycine, 2.5 mmol/L phenylalanine, and 5 mmol/L oleic acid at 1 to 2 weeks and 8 to 9 weeks after operation. RESULTS: Net absorption of water and electrolytes, glucose, glycine, phenylalanine, and oleic acid were not different statistically between neurally intact and neurally isolated intestinal loops at either time point. Ileal loops absorbed more than jejunal loops. CONCLUSIONS: Absorption of simple nutrients from the canine jejunum and ileum is not altered by this model of intestinal autotransplantation. These observations suggest that the extrinsic denervation that accompanies intestinal transplantation does not affect the transport systems for glucose, glycine, phenylalanine, or oleic acid.