Partial characterization of a hepatocyte growth factor from rat platelets.

Rat serum has been shown to stimulate DNA synthesis in primary cultures of adult rat hepatocytes 2-3 times more potently than serum from several other mammalian sources, including humans. Parallel to its stimulation of thymidine incorporation into DNA, rat serum increased the total DNA content of the hepatocyte cultures over time, and also increased the frequency of nuclear labeling and mitosis. Moreover, normal rat serum, derived from whole blood (NRS), stimulated DNA synthesis in hepatocytes twice as effectively as platelet-poor rat serum, derived from plasma (ppNRS).

Methodologic issues in hospital epidemiology. III. Investigating the modifying effects of time and severity of underlying illness on estimates of cost of nosocomial infection.

Published estimates of extra cost and prolongation of hospital stay attributed to nosocomial infection obtained from epidemiologic comparisons are almost twice as large as judgements in studies based on subjective impressions. It is possible that this disparity may result from confounding by time and severity of underlying illness. Whether the effects of time and secondary disease diagnoses modified the results of an epidemiologic comparison of infected patients and comparison subjects matched on primary diagnosis and operation have been investigated.

Difference between 1-84 parathyroid hormone and the 1-34 fragment on renal tubular calcium transport in the dog.

Acute clearance studies were performed in chronically thyroparathyroidectomized dogs to determine similarities and differences between the effects of 1-34 and 1-84 parathyroid hormone (PTH) on urinary calcium excretion. In a small (physiological) dose, 1-84 PTH caused no mean change in percentage calcium excretion, while the 1-34 fragment was frankly calciuric. At this dose, the two hormone preparations were equally phosphaturic.

Urban tuberculosis: some modern problems.

During a six-month period in 1980, tuberculosis was detected in 70 patients at our municipal hospital. Clinical and epidemiologic features of the disease continue to reflect those noted decades ago. Management of these patients was complicated by difficulty in confirming the diagnosis and relapse in patients resisting chemotherapy, although organisms resistant to antituberculosis drugs were infrequent.

Hepatocyte DNA replication: effect of nutrients and intermediary metabolites.

Isolated adult rat liver parenchymal cells maintained in serum-free medium are stimulated by insulin and epidermal growth factor (EGF) to undergo DNA synthesis. Pyruvate, lactate, and, to a lesser extent, several other intermediary metabolites strikingly enhance DNA synthesis both under serum-free culture conditions and in the presence of dialyzed rat serum. High concentrations (2-50 mM) of these low-molecular-weight metabolites are necessary to produce optimal stimulation.

Role of aminoglycosides in face of introduction of new beta-lactam antibiotics in treatment of nosocomial infection.

Aminoglycosides often are employed for empiric therapy of nosocomial infection because of their activity against a wide spectrum of gram-negative aerobic bacilli (GNAB). New beta-lactam antimicrobials also are active against many GNAB. As toxicity appears less likely for the beta-lactams than for aminoglycosides, their use might be preferable if susceptibility profiles were equivalent.

Antimicrobial resistance in hospital organisms and its relation to antibiotic use.

Organisms causing nosocomial infection are frequently resistant to antimicrobial agents. Studies of the reasons for this have been hindered by difficulties in defining terms, by selection biases, by artifacts produced by study methods, and by failure to control for confounding variables. Major factors leading to increased prevalence of resistant organisms in hospitals are changes in organisms causing nosocomial infection (due in part to changes in characteristics of hospital populations and in procedures and instruments used in patient care), increasing prevalence of resistance in bacteria causing community-acquired infection, and use of antimicrobial agents.

Nursery salmonellosis: delayed recognition due to unusually long incubation period.

A nursery outbreak of diarrheal illness caused by Salmonella nienstedten initially involved seven infants cared for in one nursery; secondary infection subsequently affected one infant cared for in the same nursery as well as four other infants. Recognition of the outbreak was delayed due to an unusually long incubation period. The period from last known exposure to onset of diarrhea ranged from two to 18 days, with a median of ten days.

Pyruvate promotion of DNA synthesis in serum-free primary cultures of adult rat hepatocytes.

Pyruvate (2 to 60 mM), acting alone and in conjunction with insulin and epidermal growth factor (EGF), enhances DNA synthesis in primary monolayer cultures of adult rat liver parenchymal cells. Lactate can replace pyruvate in stimulating DNA synthesis. Several other intermediary metabolites (oxaloacetate, alpha-ketoglutarate, alpha-ketobutyrate, succinate, fumarate, and malate), though less potent than pyruvate and lactate, also elevate DNA synthesis, whereas alanine at similar concentrations is inhibitory.

Parathyroid hormone: effects of the 3-34 fragment in vivo and vitro.

The biologically active fragment ofparathyroid hormone, consisting of residues 1-34, and its in vitro antagonist, fragment 3-34, were administered separately or in combination to chronically thyroparathyroidectomized dogs. These fragments were also studied in vitro with dog renal cortical membranes. Fragment 3-34 inhibited the stimulation of adenylate cyclase by fragment 1-34 in vitro, but had no agonist or antagonistic effects on renal phosphate transport in vivo.

Thymine salvage, mitochondria, and the evolution of the herpesviruses.

The salvage of thymine is an apparently ubiquitous feature of free-living lifeforms as well as of mitochondria, chloroplasts and most of the large DNA viruses. Assumptions and data are described which explain the evolution of thymine salvage in prokaryotes, animal cells, and large DNA viruses, in terms of deoxythymidine kinase and its relationship to mitochondria. Specifically, it is suggested that regulation of deoxythymidine kinase (by end-product inhibition) has evolved as a means of assuring a constant supply of thymine compounds for the mitochondria and that the degree to which this regulation is present in the deoxythymidine kinases of the various herpesviruses correlates with the degree of dependence of their replicative cycle on the continued health of the mitochondria of their host cells.

Employment factors in outpatient recovery of alcoholics: a multivariate study.

This study examined the effects of patient and treatment variables on alcoholic outpatient recovery over a one year period. One-hundred-seventy-four subjects, dichotomized by age (less than or equal to 42 or greater than 42) and employment status (employed or unemployed), were randomly assigned to one of three treatment groups (medical check-up, medication, or multi-therapy). Seventy-eight percent of these subjects were available for follow-up.

DEET (N,N-diethyltoluamide) does not affect sperm number, viability and head morphology in male rats treated dermally.

DEET (N,N-Diethyltoluamide) was applied dermally to groups of 80 Sprague Dawley rats 5 days/week for 9 weeks (63 days), at three dose levels, (100, 300, and 1000 mg/kg). The undiluted material was applied with micropipettes to shaved patches. There was no run off and the material wet out onto the skin.

Pseudomonas aeruginosa peritonitis associated with contaminated poloxamer-iodine solution.

Pseudomonas aeruginosa was responsible for four cases of peritonitis and one of wound infection at the catheter site in outpatients on chronic peritoneal dialysis. All organisms had the same antimicrobial susceptibilities and serotype. Culture surveys showed that a strain of Ps.

Cost and benefit--a critical issue for hospital infection control. Fifth Annual National Foundation for Infectious Diseases Lecture.

New patterns of health care financing have made it essential for infection control practitioners to become familiar with information on cost of nosocomial infection and cost effectiveness ("benefit") of the procedures and devices used to control hospital infection. Even the lowest estimates of cost show the considerable economic impact of nosocomial infection. Studies to date separate control procedures and practices into categories of proven efficacy, likely efficacy, lack of efficacy, and those for which cost of implementation is likely to outweight any benefit that might result.

High cost nosocomial infections.

The average charge per patient due to nosocomial infection for 215 nosocomial infections in 183 study patients was $693. These cost, however, were concentrated in very few patients; 5% of patients accounted for nearly one-third of total charges. The 10% of patients with highest nosocomial infection cost were patients on Medical or Surgical services; these services were utilized in 71% of patients with nosocomial infection and accounted for 86% of the attributable charges.

In vitro reassembly of vesicular stomatitis virus skeletons.

Vesicular stomatitis virus (VSV) has been disrupted with nonionic detergent plus 0.5 M NaCl under conditions which result in solubilization of the viral glycoprotein (G), matrix protein (M), and lipids, leaving the nucleocapsid in a highly extended state. Dialysis of these suspensions to remove NaCl was found to result in reassociation of nucleocapsids with M protein.