Copper vapor laser fragmentation of gallstones: in vitro measurements of wall heat transmission.

Laser fragmentation is a promising new modality in management of retained CBD stones. Recent reports demonstrate the feasibility of lasers for this, but few studies have evaluated their safety (e.g., thermal injury may occur at greater than 43 degrees C). This study was conducted to measure heat transmission from lased bilirubinate and mixed stones to a simulated CBD wall. Four welded thermocouples were passed to the inside wall of 6-mm polyvinyl tubing 90 degrees apart to surround the lumen stone. The thermocouples were interfaced to a computer and temperatures were recorded every 270 msec. The tubing was submerged in a 37 degrees C water bath for all lasing work. A copper vapor laser (wavelength, 510 nm; 5.6 W; 5 kHz; pulse length, 30 ns) was attached to a 650-micron quartz fiber. A stone was "impacted" in the tubing and the laser fiber was pushed against the stone while making multiple passes to fragment it. Thirty mixed gallstones (mean size, 6.9 X 5.1 mm) and 20 bilirubinate gallstones (mean size, 7.1 X 5.2 mm) were fragmented during the study. Maximum temperature (Tmax), duration of Tmax (TmaxD), interval to stone piercing (TiP), and interval to fragmentation (TiF) were measured and comparisons were carried out with the SPSS statistical package using the t test procedure. The Tmax generated during fragmentation of bilirubinate stones (43.4 +/- 1.7 degrees C) was significantly less (P less than 0.002) than the Tmax for mixed stones (54.0 +/- 2.7 degrees C) but both Tmax values represented potentially injurious temperature levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Urban structure and household victimization of the elderly.

This paper examines the relationships of several urban structural characteristics with the rate of household victimization of the elderly in twenty-six U.S. central cities. We find that inter-city variation in two types of household victimization (household burglary and larcency) is highly related to two factors: 1) population density, and 2) socioeconomic conditions. The implications of these findings for further research are discussed.

Hospital postgraduate training: factors affecting prospective interns' ranking of a municipal hospital program in internal medicine.

This study examines the statistical relationship between potential influencing factors and the rank that prospective intern applicants assigned to Boston City Hospital in the National Internship and Residency Matching Program. Types of factors examined include personal considerations, the applicant's experience during the personal interview, hospital attributes, the academic program itself, and perceived house officer experience. A brief questionnaire was mailed to prospective interns ranked by the Department of Medicine. Analysis of questionnaire data indicates that personal reasons and two hospital characteristics, ancillary staff and type of hospital, were predominant influencing factors.

Raw hamburger: an interstate common source of human salmonellosis.

An interstate common-source outbreak of salmonellosis was first detected in the United States in September and October, 1975, when a tenfold increase in Salmonella newport isolates was noted through routine salmonella surveillance by the Colorado Department of Health. Eighteen primary cases with a distinctive antibiotic resistance pattern (tetracycline, streptomycin, and sulfonamides) were evaluated in a case-control study, and illness was found to be associated with eating raw hamburger (p less than .001) from any store of one grocery chain (p less than .001). A Dallas, Texas, processing plant that supplied the Colorado markets also supplied other states, and these other states were alerted. Maryland discovered nine S. newport isolates with the same antibiogram and, as in the Colorado outbreak, illness was associated with eating raw or very rare ground beef from the same grocery chain (p less than .03). A third outbreak of S. newport with the same antibiogram occurred on a Florida military base. S. newport with the same antibiogram and a phage lysis pattern identical to those of the human epidemic isolates was cultured from frozen hamburger recovered in Colorado and Florida. The associated hamburger originated at the same Dallas, Texas, processing plant. A source of the epidemic strain was not identified, but the organism probably originated before delivery to the plant.

Demonstration of agglutinating antibodies against Vibrio parahaemolyticus in the yellow tail flounder (Limanda ferruginea).

Sera from the salt water fish (Yellow tail flounder) and the fresh water fish (rainbow trout) were tested for the presence of circulating antibodies against nine strains of Vibrio parahaemolyticus and one of V. alginolyticus. Thirteen out of 26 flounder sera tested gave agglutinating reactions against one specific strain of V. parahaemolyticus; strain No. 3525. Seven rainbow trout sera tested failed to agglutinate any of the strains tested. All agglutinating activity was lost upon boiling the antigen, therefore, the fish antibodies are due to surface antigens (K-antigens) and not to somatic antigens. The specific V. parahaemolyticus strain No. 3525 belongs to the serological type 03:K30, which might be common to the sea waters of the Eastern United States. The possibility that fish serve as a reservoir to Vibrio parahaemolyticus and its possible implication in the transmission of human disease are discussed.