Publications by authors named "David McClain"

Ceftolozane-tazobactam, a novel β-lactam/β-lactamase inhibitor, was recently approved for the treatment of complicated urinary tract and intraabdominal infections, as monotherapy and in combination with metronidazole, respectively. Ceftolozane-tazobactam exhibits a wide spectrum of activity against both gram-positive bacteria, gram-negative bacteria including multidrug-resistant (MDR) Pseudomonas aeruginosa, and some anaerobic bacteria. Although not currently approved for any pulmonary indication, studies have demonstrated excellent distribution to epithelial lining fluid, indicating that it may be an alternative agent to use in the treatment of respiratory tract infections caused by MDRP.

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Rift Valley fever (RVF) poses a risk as a potential agent in bioterrorism or agroterrorism. A live attenuated RVF vaccine (RVF MP-12) has been shown to be safe and protective in animals and showed promise in two initial clinical trials. In the present study, healthy adult human volunteers (N=56) received a single injection of (a) RVF MP-12, administered subcutaneously (SQ) at a concentration of 10(4.

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The use of depleted uranium in armor-penetrating munitions remains a source of controversy because of the numerous unanswered questions about its long-term health effects. Although no conclusive epidemiologic data have correlated DU exposure to specific health effects, studies using cultured cells and laboratory rodents continue to suggest the possibility of leukemogenic, genetic, reproductive, and neurological effects from chronic exposure. Until issues of concern are resolved with further research, the use of depleted uranium by the military will continue to be controversial.

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Continuing concern regarding the potential health and environmental effects of depleted uranium and lead has resulted in many countries adding tungsten alloy (WA)-based munitions to their battlefield arsenals as replacements for these metals. Because the alloys used in many munitions are relatively recent additions to the list of militarily relevant metals, very little is known about the health effects of these metals after internalization as embedded shrapnel. Previous work in this laboratory developed a rodent model system that mimicked shrapnel loads seen in wounded personnel from the 1991 Persian Gulf War.

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Inductively coupled plasma mass spectrometry (ICP-MS), coupled with a large-bore direct injection high efficiency nebulizer (LB-DIHEN), was utilized to determine the concentration and isotopic ratio of uranium in 11 samples of synthetic urine spiked with varying concentrations and ratios of uranium isotopes. Total U concentrations and (235)U/(238)U isotopic ratios ranged from 0.1 to 10 microg/L and 0.

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For many types of cells, heat stress leads to an increase in intracellular free calcium concentration ([Ca2+](i)) that has been shown to trigger a wide variety of cellular responses. In T lymphocytes, for example, heat stress stimulates pathways that make them more susceptible to Fas/CD95-mediated apoptosis. Because of our interest in understanding more about the response of lymphocytes to various stressors, we used human peripheral and Jurkat T lymphocytes to investigate the effect of heat stress on calcium homeostasis.

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It is known that radiation can induce a transmissible persistent destabilization of the genome. We have established an in vitro cellular model using HOS cells to investigate whether genomic instability plays a role in depleted uranium (DU)-induced effects. Transmissible genomic instability, manifested in the progeny of cells exposed to ionizing radiation, has been characterized by de novo chromosomal aberrations, gene mutations, and an enhanced death rate.

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Depleted uranium entering the body as a result of inhalation or embedded fragments becomes associated to a great extent with macrophages. As part of our continuing studies on the health effects of internalized depleted uranium, we investigated the effect of soluble depleted uranium-uranyl chloride on the mouse macrophage cell line, J774. Using a cytochemical staining protocol specific for uranium, we found that uranium uptake by the macrophages increased in a time-dependent manner.

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This study measured the ability of a standard smallpox vaccine, given by scarification (by bifurcated needle), to induce primary human vaccinia virus-specific cytotoxic and interferon (IFN)-gamma-producing T lymphocyte responses. Because protection against smallpox may be mediated in part by T cell memory responses induced by vaccination, an analysis of the induction of primary human cytotoxic T lymphocytes (CTL) and IFN-gamma-producing T cell responses was performed. Although smallpox is no longer an epidemic threat under natural conditions, vaccination is still recommended for persons working with vaccinia viruses in the laboratory and for those who may be at risk from the potential use of smallpox virus as a bioterrorism agent.

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The first large-scale combat use of depleted uranium (DU) weapons occurred during the Gulf War, and some U.S. personnel were wounded by DU fragments.

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The health effects of embedded fragments of depleted uranium (DU) are being investigated to determine whether current surgical fragment-removal policies are appropriate for this metal. The authors studied rodents implanted with DU pellets as well as cultured human cells exposed to DU compounds. Results indicate that uranium from implanted DU fragments distributes to tissues distant from implantation sites, including bone, kidney, muscle, and liver.

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