Robert Heimer

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BACKGROUND Diarrhea remains a common complaint among US patients who seek medical attention. METHODS We performed a prospective study to determine the etiology of diarrheal illness among patients and control subjects of all ages presenting to the emergency departments and outpatient clinics of 2 large academic hospitals in Baltimore, Maryland, and New(More)
AIMS This study assessed overdose and naloxone administration knowledge among current or former opioid abusers trained and untrained in overdose-response in the United States. DESIGN AND PARTICIPANTS Ten individuals, divided equally between those trained or not trained in overdose recognition and response, were recruited from each of six sites (n = 62).(More)
Critical to understanding the spread of the human immunodeficiency virus via needle sharing among drug users is the infectivity, i.e., the conditional probability of infection given injection with a shared, contaminated syringe. A simple mathematical model was constructed that relates infectivity to the prevalence of infection in needles used by drug users,(More)
This study explores the characteristics of Staphylococcus aureus (S. aureus) in swine and their human handlers in a convenience sample of 35 farms in Connecticut. Husbandry practices are clearly different from better-known concentrated animal feeding operations (CAFOs) with less intensive rearing conditions. Nasal samples were collected from 263 pigs and(More)
Pretreatment of L1210 cells with methotrexate in concentrations which produced free intracellular methotrexate and near maximal inhibition of dihydrofolate reductase resulted in an enhancement of intracellular 5-fluorouracil (FUra) accumulation. This enhancement of FUra accumulation was maximum (5-fold increase) after a 6-h exposure to 100 microM(More)
The connective tissue stroma of malignant tumors is a newly formed tissue that supports the growth and progression of neoplastic cells. Proteoglycans are intrinsic components of this complex structure and molecular changes in this class of macromolecules can significantly affect behavioral properties of transformed cells. We report that human colon(More)
We performed a study to determine the duration of survival of HIV-1 in syringes typically used by injectors of illicit drugs (IDUs). We describe the effectiveness of a microculture assay in detecting viable virus in volumes of blood typical of those commonly found inside used syringes. Using this assay and modeling the worse-case situation for syringe(More)
This paper develops a statistical procedure for estimating the HIV infection rate among needle exchange clients without using any self-reported information. Instead, data are accumulated by following the distribution and return of sequentially labeled syringes and by testing a sample of returns for the presence of HIV-1 proviral DNA using polymerase chain(More)
The New Haven needle exchange program experienced a significant decline in the fraction of returned needles containing human immunodeficiency virus 1 (HIV-1) proviral DNA. Is this decline due to the operations of the needle exchange or to a shift in clients? Analysis of demographic and behavioral data revealed that only one variable, the race of(More)
Exposure of L1210 leukemia cells first to 0.1 to 100 micromolar methotrexate and then to 10 micromolar 5-fluorouracil produces a synergistic effect on the number of cells killed in culture. Methotrexate dose-related increases occur in the concentrations of intracellular 5-fluorouracil ribonucleotides and 5-fluoro-2'-deoxyuridylate and in the incorporation(More)