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Biomedical subjects

G T Peer

Publications and source records attributed to G T Peer.

4 recordsLinked to original sources

Lethal Staphylococcus aureus-induced shock in primates: prevention of death with anti-TNF antibody.

A successful experimental treatment for gram-positive sepsis to our knowledge has not been achieved. The objectives of this study were to develop a nonhuman primate model of lethal gram-positive sepsis employing the micro-organism Staphylococcus aureus and to determine the efficacy of treatment using monoclonal antibody (MAb) to tumor necrosis factor alpha (TNF). The antibody was administered intravenously, 15 mg/kg, 30 minutes after the beginning of a 2-hour infusion of S. aureus, 4 x 10(10) colony forming units/kilogram. The baboons infused with S. aureus demonstrated the release of the cytokines TNF and interleukin-6 (IL-6), but endotoxin was not observed in the plasma at any time. Treatment with antibody to TNF abolished the rise in serum TNF levels and reduced the increased levels of IL-6. Treatment with MAb to TNF prevented multiple organ failure and achieved permanent (> 7 day) survival of all baboons.

Animals

DEGR-factor Xa blocks disseminated intravascular coagulation initiated by Escherichia coli without preventing shock or organ damage.

One of the aims of research in the area of thrombosis has been to design an effective anticoagulant that would function in a predictable and direct manner. In evaluating the role of coagulation in sepsis we used factor Xa blocked in the active center with [5-(dimethylamino)1-naphthalenesulfonyl]-glutamylglycylarginyl+ ++ chloromethyl ketone (DEGR-Xa). We infused 1 mg/kg of DEGR-Xa together with LD100 concentrations of Escherichia coli (4 x 10(10) organisms/kg) into five baboons. As controls, we infused E coli alone into five baboons. The inflammatory, coagulant, and cell injury responses to E coli of both the treated and control groups were lethal and were similar in every respect except for the complete inhibition of the consumption of fibrinogen in the DEGR-Xa group. The half life of DEGR-Xa was approximately 10 hours and 2 hours, as determined by isotopic and enzyme-linked immunosorbent assays, respectively. These results for the first time demonstrate that, although coagulation occurs in E coli sepsis, fibrin formation per se did not influence the lethal outcome in this model. These results also show the effectiveness of DEGR-Xa as an anticoagulant and raise the possibility that it could serve as an alternative to anticoagulants currently in use.

Amino Acid Chloromethyl Ketones

Survival of primates in LD100 septic shock following therapy with antibody to tumor necrosis factor (TNF alpha).

The purpose of this study was to determine the efficacy of treatment with anti-TNF monoclonal antibody in preventing the deleterious effects of sepsis in a nonhuman primate. Experiments were carried out on anesthetized baboons intravenously infused with a lethal dose of Escherichia coli (E. coli). Twelve baboons (six control and six experimental) received 2 hr infusions of E. coli. The experimental group was administered a bolus of anti-TNF antibody, 15 mg/kg, 30 min after beginning the E. coli infusion. Control baboons lived an average of 19 hr (12-34 hr). All antibody-treated baboons survived more than 7 days with a significantly improved quality of life compared to the control group. Although some adverse changes occurred during the monitoring period in surviving baboons, they maintained nearly normal arterial pressures, and serum urea nitrogen and creatinine concentrations. The severe histopathologic changes in lungs, liver, adrenals, kidneys, and spleen documented at death in baboons receiving E. coli only were absent after 7 days in baboons given E. coli and early post-treatment with antibody to TNF.

Animals

Staphylococcus aureus-induced shock: a pathophysiologic study.

The purpose of the present study was to determine the effects of lethal intravenous infusions of Staphylococcus aureus (SA) in adult dogs. Animals were maintained under anesthesia for 6 hr and observed until death following the 1-hr infusions of SA organisms. Findings unique to SA administration compared to those with Escherichia coli were the absence of significant necrosis of the mucosal intestinal glands of the small and large intestines; widespread intravascular colonization of bacteria in lung, heart, kidney and adrenal tissues often associated with neutrophil sequestration, microabscess formation, and necrosis; relative constant blood pressure, fibrinogen, fibrin degradation products (FDP), serum glutamic pyruvic transaminase (SGPT), blood (serum) urea nitrogen (BUN), creatinine, pH, and PO2, all of which remained relatively unchanged for 6 hr. Rapid early increases were observed in temperature, respiration rate, lactate, and hematocrit, while PCO2, platelet and white blood cell concentrations decreased. Results suggest unique qualitative differences in responses to Staphylococcal-induced shock compared to those caused by gram-negative bacteria.

Animals