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Nosocomial infections are a major source of revenue loss, morbidity, and even mortality to surgical patients. This review presents current issues regarding nosocomial infections and nosocomial pneumonias. This study is a literature review that presents material on nosocomial infections in general and details regarding Clostridium difficile and vancomycin-resistant enterococcus infections. Nosocomial infections, including pneumonias, are serious medical complications, and prevention by strict adherence to barrier precaution is the most important means of protecting the patient from hospital-acquired bacterial flora.

• The exposure of third-year medical students to blood and blood products in the operating room was assessed with a questionnaire distributed at the end of their clerkship in surgery. Sixty-six (68%) of ninety-seven students reported having been exposed to blood in the operating room during their 3-month rotation in surgery. During the year there was a decrease in the exposure rate that correlated with the students' knowledge of universal precautions (r=.96). Consistent with this observation was a significant decrease in the exposure rate from the first quarter of the year to the last quarter (88% vs 56% of the students). Of the 32 students stuck or cut in the operating room, 21 (66%) were injured by the surgeon. These data underscore the risk to medical students during their clerkships and the important role that universal precautions had in their protection.(Arch Surg. 1993;128:36-39)

• We investigated the cause of the reduced leukotriene B4 (LTB4) production seen in neutrophils from patients with established adult respiratory distress syndrome compared with control neutrophils. Lymphocytes/monocytes from controls were found to synergistically enhance the amount of LTB4 produced when incubated with neutrophils. This synergistic effect was not seen in cells from patients with adult respiratory distress syndrome. Fatty-acid analysis of neutrophils from patients with adult respiratory distress syndrome and controls showed remarkable similarity in all quantities of fatty acids measured except for arachidonic acid, where there was a 22% reduction in patients' cells compared with controls. Assay of the rate of generation of LTB4 and its degradation product, 20-hydroxy LTB4, revealed that reduced LTB4 generation in patients' neutrophils was not due to increased degradation of LTB4 by hydroxylase enzymes. When the amount of LTB4 being generated per milliliter of whole blood was analyzed in the patients with adult respiratory distress syndrome and compared with controls, it was determined that the potential to generate LTB4 in patients in the intensive care unit was three to five times greater than in controls.(Arch Surg. 1989;124:1451-1455)

• In an in vivo study of five normal volunteers infused with endotoxin (20 U/kg of US reference endotoxin lot EC-5), increased neutrophil (PMN) generation of leukotriene B4 and chemotaxis to leukotriene B4 were found concomitantly with elevated plasma tumor necrosis factor (TNF) levels. To clarify the role of TNF in PMN activation, neutrophil responsiveness after in vitro treatment with TNF was examined. Neutrophils from seven normal subjects were incubated with TNF for 30 minutes and tested for chemotaxis to leukotriene B4, formyl-methionyl-leucyl-phenylalanine and zymosan-activated serum, or the calcium ionophore A23187 to assess leukotriene B4 generation. A range of 10−13 to 10−9 mol/L of TNF was used for these assays. When 10−9 mol/L of TNF was used, the amount of leukotriene B4 that was produced was significantly greater than in control cells. The effect of TNF on PMN chemotaxis was uniformly inhibitory for the three stimuli at 10−10 mol/L compared with untreated cells. At a picomolar range, PMN migration to leukotriene B4, but not to zymosan-activated serum or formyl-methionyl-leucyl-phenylalanine, was significantly increased over that of PMNs not exposed to TNF. This suggests that TNF has a specific facilitatory effect on PMN responsiveness for both leukotriene B4 production and chemotaxis to leukotriene B4 and may be the same signal for this phenomenon in endotoxemic patients.(Arch Surg 1988;123:1454-1458)

• Twenty-one male homosexuals were followed up by repeated lymph node biopsy for a mean (±SEM) follow-up of 99±18 weeks. Four histologic patterns were seen on biopsy: explosive follicular hyperplasia (EFH), follicular involution (FI), a mixed pattern of EFH with FI in the same node, and lymphocyte depletion. Patients with FI and lymphocyte depletion had mean survival times that were significantly less than those for the subjects with EFH. The percentage of lymph node follicles with suppressor cell clusters (T8) in EFH lymph nodes was significantly higher (43% vs 8%) than in nodes from patients without risk for human immunodeficiency virus infection. Helper/suppressor T-cell ratios in control nodes were 1.6; in EFH nodes, 0.97; and in FI nodes, 0.88. A remarkable 33% of patients in this lymphadenopathy group ultimately developed large-cell (B-cell) lymphoma, suggesting that the follicular stimulation noted histologically played a role in the development of this neoplasm. These data show that there is a progressive destruction of lymph node follicles that correlates with the progression of the disease and that lymph node histologic features may provide important prognostic information.(Arch Surg 1988;123:1349-1352)

• Previous studies have shown that the decreased neutrophil migratory responsiveness seen in burned patients correlates with the extent of thermal injury and the extent of the neutrophil-specific granule deficiency. To understand better the relationship between the neutrophil dysfunction, degranulation, and thermal injury, a rabbit model was studied. Eighteen rabbits were burned over 20% of their surface area. Assay of peripheral blood heterophils disclosed decreased migratory activity compared with preburn levels and decreased lysozyme content vs preburn levels, but no change in the β-glucuronidase content. The specific binding of tritiated formyl-methionyl-leucyl-phenylalanine to peripheral blood heterophils was increased fivefold over that of control cells. These studies indicate that, following thermal injury, there is a selective decrease of specific granule contents and an increase in chemoattractant binding to the cell and also suggest an abnormality in chemoattractant receptor processing. The rabbit provides a convenient model for the study of compromised host defenses following thermal injury.(Arch Surg 1988;123:752-755)

We must point out that the ad hoc AIDS Committee at Cornell University Medical College was formed 6 months before Dr Jones' publication in JAMA. Safety issues with respect to human immunodeficiency virus exposure had been raised by many different medical school faculty, including Dr Roberts who was instrumental in setting up the committee.The committee made many recommendations regarding student conduct on the floors and in the operating rooms. One serious concern was related to the availability of disability insurance. Since students technically are not employees, insurance to cover their "disability" is not applicable. In this context, Dr Vergilio responded to a specific question about disability insurance with the comment that "an ad hoc AIDS Committee... is currently examining this problem in the hope offormulating a policy...." Indeed, a standing Committee on AIDS (one of 14 of the dean's committees) was recommended by the ad hoc committee and established