Effects of chemotactic peptide f-Met-Leu-Phe (FMLP) on C3b receptor (CR1) expression and phagocytosis of microspheres by human neutrophils

FMLP caused maximal upregulation of CR1 on neutrophils at a concentration of 10(-8) M but caused maximal enhancement of CR1-dependent phagocytosis of C3b.IgG-coated microspheres only at a concentration of 10(-6) M. There were positive correlations between FMLP-mediated upregulation of CR1 and FMLP-mediated enhancement of phagocytosis (correlation coefficient = 0.73, slope = 2.2) and between FMLP-mediated upregulation of CR1 and FMLP-mediated increase in total cell-associated microspheres (correlation coefficient = 0.88, slope = 1.3). The phagocytic capacity of both untreated and 10(-6) M FMLP-treated neutrophils was completely inhibited by fluid phase C3b and partially inhibited by aggregated IgG. The data suggest that CR1 upregulation is required but is not sufficient for maximal phagocytosis by the leukocytes. The data also suggest that FMLP at the higher concentrations may impart a phagocytic function to CR1, activate other phagocytic receptors, elicit phagocytosis-inducing mediators or may elicit a separate mechanism of phagocytosis. During the study, it was observed that there was considerable individual variation among different neutrophil preparations with respect to CR1 expression and binding and phagocytic capacity.

The effect of high lipid diet on in vitro prostaglandin E2 and thromboxane B2 production by splenic macrophages

Feeding animals a diet high in linoleic acid for 7 days had no effect on the in vitro production of PGE2 by unstimulated macrophages. Feeding animals the high linoleic acid diet for 30 days greatly increased the production of PGE2 by macrophages when they were unstimulated, but decreased the production of PGE2 when they were stimulated with LPS. Feeding animals a diet high in linoleic acid for 30 days increased the production of TxB2 by macrophages when they were unstimulated, but decreased the production of TxB2 when they were stimulated. Normal, unstimulated splenic macrophages produced almost 80 times more TxB2 than PGE2. However, when the macrophages were stimulated the ratio decreased to six or less because of a greater increase in PGE2 production. The high linoleic acid diet did not inhibit the antibody dependent cellular cytotoxicity of macrophages.

Comparison of scar contracture with the use of microskin and Chinese-type intermingled skin grafts on rats

Wounds that were measured precisely 4 x 5 cm in size were created over the dorsal surfaces of rats. The defects were grafted with the use of either the microskin or Chinese technique of intermingled auto/allograft with an expansion ratio of 10:1. The size of the grafted wound of each rat was recorded on the fifth graft day after grafting and then weekly for 11 weeks. The extent of scar contracture on each rat was calculated weekly as a percentage of the original size. The results showed that the scar contracture associated with the Chinese type of intermingled auto/allograft transplantation was less than that associated with the microskin technique. The healing process in both forms of grafting was uneventful.

Differential effects of three enteral dietary regimens on selected outcome variables in burn patients

A modular tube feeding recipe (MTF) was designed to meet the unique nutritional needs of burn patients, applying principles previously documented in our burned guinea pig model. MTF, a high-protein, low-fat, linoleic acid-restricted formulation is enriched with omega-3 fatty acids, arginine, cysteine, histidine, vitamin A, zinc, and ascorbic acid. Fifty patients, 3 to 76 years of age with burns ranging from 10 to 89% total body surface area were prospectively randomized into three groups which blindly compared MTF to two enteral regimens widely utilized in the nutritional support of burns. Age, percent total and third-degree burn, resting energy expenditure, and calorie and protein intake were similar in all groups. Data analysis demonstrated significant superiority of MTF in the reduction of wound infection (p less than 0.03) and length of stay/percent burn (p less than 0.02). MTF was also associated with a decreased incidence of diarrhea, improved glucose tolerance, lower serum triglycerides, reduced total number of infectious episodes and trends toward improved preservation of muscle mass, although statistical significance was not achieved. Seventy percent of deaths occurred in the group supported with an inherently large dose of fat and linoleic acid. Combining these observations, it is believed that MTF is effective in modulating an improved response to burn injury.

Arginine supplementation and its effect on established peritonitis in guinea pigs

To evaluate the efficacy of supplemental arginine with nutritional support in the presence of sepsis, eighty-eight gastrostomized female Hartley guinea pigs were implanted with osmotic pumps effusing an Eschericia coli/Staphylococcus aureus mixture. Animals were randomized and infused for two weeks with isocaloric and isovolumetric diets containing 0%, 2%, 4%, or 6% supplemental arginine as arginine hydrochloride. Survival was 12/22 (54%) in 0%, 9/22 (41%) in 2% and 4%, and 2/22 (9%) in 6%. Analysis by chi-square test of independence was significant (p = 0.0141) with 6% survival lower than the others. Median survival was 11 days in 0%, 8 days in 2% and 6%, and 9 days in 4%. Median survival was longer in 0% than in 2% or 6% (Kruskal-Wallis ANOVA: p = 0.02). Nitrogen balance was significantly lower in 6% compared to 0% on days 2 through 10, and lower than 2% and 4% on days 6 and 9. Nitrogen balance was higher in 0% than in 2% on days 4, 6, 10, and 13. Serum albumin and C3 were lower in all experimental groups than normal controls (ANOVA: p = 0.01). Comparison of liver, spleen, adrenals, gastrocnemius, and carcass weights, cell-mediated immunity as determined by contact sensitivity to DNFB, and transferrin showed no significant differences. There was a positive dose-response effect seen amongst the experimental groups for the amino acids arginine, ornithine, and citrulline in relation to the amount of supplemental arginine. This study suggests that dietary arginine supplementation does not enhance survival in a guinea pig model of established peritonitis.

Prolonged survival of reconstituted skin grafts without immunosuppression

Reconstituted skin composed of a cultured allogeneic epithelial sheet (CAES) and a cultured allogeneic dermis (CAD) was evaluated in a rat model to determine whether it could survive for a prolonged period without immunosuppression. Additionally, free CAD grafts were evaluated for their suitability as dermal substitutes. Male Buffalo rats were used as donors and male Lewis rats as recipients. Split-thickness skin obtained from Buffalo rats was separated into epidermis and dermis by means of Dispase II enzyme. The epidermal layers were minced and trypsinized. Then dispersed single keratinocytes were inoculated onto a irradiated 3T3 cell feeder layer. After a suitable period, a confluent cultured keratinocyte layer was detached and provided CAES grafts. Cultured allogeneic dermis grafts were prepared from cultures of the dermal component. Cultured allogeneic dermis grafts, covered by split thickness isografts (STIG) or local skin flaps, became revascularized at a rate of 94.6% and 90.9%, respectively, 7 days after grafting. However, only 25% of CAD grafts covered by synthetic materials became vascularized. Four types of wound coverage were compared including: (1) CAES grafts, (2) CAES over CAD grafts, (3) split-thickness isografts, and (4) STIG over CAD grafts. In groups 2 and 4, CAD grafts were applied 7 days before CAES grafts or STIG. Grafts of groups 1 and 2 were successful in only 36.7% and 31.1% of the animals and resulted in a high rate of wound contracture--72.4%, 66.7%, respectively. On the other hand, in groups 3 and 4, higher average rates of revascularization (92.0% and 88.3%) and lower rates of wound contracture (25.4% and 24.2%) were obtained.(ABSTRACT TRUNCATED AT 250 WORDS)

Technology and structure of nursing organizations

Theory building and theory application in nursing administration enable the nurse executive to work more effectively at the managerial task. Alexander and Mark apply a model that allows for comparison and contrast between various nursing units based on the nature of their work as assessed on the variables of technology and structure. In this model, technology is assessed on three dimensions: instability, variability, and uncertainty; and structure is assessed as to vertical participation, horizontal participation, and formalization. Cases studies clarify the model and show its application.

Variable infection risk following allogeneic blood transfusions

These studies address infection risk of allogeneic transfusion in an untraumatized, nonseptic rodent model. A' Segaloff Cancer Institute rats served as blood donors and Lewis rats as recipients. Lewis rats' delayed-type hypersensitivity (DTH) response and their ability to clear subdermal Staphylococcus aureus abscesses and Candida albicans pyelonephritis were measured as tests of the effect of transfusions. The effect of pharmacological immunosuppression with either cortisone acetate or cyclosporine provided a "yardstick" to measure the magnitude of transfusion effects. Repeated transfusions at 1-week intervals diminished DTH response to recall antigens (keyhole limpet hemocyanin), but otherwise they showed no evidence of immunosuppression in these experiments. In contrast, we found that transfusions by themselves produced mild immunostimulation. Subcutaneous Staphylococcus abscesses were smaller in animals receiving transfusions. The magnitude of immunostimulation from one transfusion was sufficient to reverse the immunosuppressive effect of cyclosporine by about 50% in a Candida pyelonephritis infection. These studies suggest that blood transfusions have complex interactions with different components of the immune response. T-cell function is impaired by repeated transfusions (diminished DTH response), but other inflammatory responses are accentuated. This suggests that blood transfusions may harm immune response in traumatized animals by causing excessive complement activation or cytokine release.

Effect of intraluminal antibiotics on translocation of Candida albicans in burned guinea-pigs

Guinea-pigs were pretreated orally with various antibiotics and given 3 x 10(10) Candida albicans by gastric lavage followed by a 40 per cent TBSA full skin thickness burn. The mesenteric lymph nodes, liver and spleen were cultured for the presence of viable organisms. Caecal contents were quantitatively cultured for aerobic bacteria and C. albicans. Clindamycin and penicillin G were the greatest promoters of translocation followed by the combination streptomycin/bacitracin. The mechanism for antibiotic-induced translocation is multifactorial centering on intestinal flora, anaerobic spectrum of the antibiotic and host defense as well as microbe virulence. The systemic use of broad-spectrum antibiotics, particularly those with strong anaerobic activity, should not be taken too lightly. A severely immunocompromised patient on this type of therapy may be prone to a severe fungal infection. This study reaffirms the concept that translocation from the gastrointestinal barrier is a potential source of life-threatening nosocomial infection.

The effect of free radical scavengers on outcome after infection in burned mice

Thermal injury generates free radicals from various cellular populations, and modulation of free radical activity with scavengers may improve outcome. Balb/c mice were infected with Ps. aeruginosa the day after burn injury and mortality rates observed. Tocopherol was given by gavage daily for 4 days starting 2 days before burn. Survival was improved in the groups receiving 25 and 250 IU/kg compared to control. In other groups, tocopherol was given after burn, but mortality rates were not changed. Treatment with the oxygen radical scavengers ascorbic acid, and a combination of superoxide dismutase and catalase had no effect on mortality. We conclude that ascorbic acid, superoxide dismutase, and catalase do not appear to benefit survival after thermal injury and infection in this murine model. Tocopherol given in high doses of at least 25 IU/kg by gavage preceding injury and continued thereafter for 2 days did improve survival, but this benefit was not seen if tocopherol was not started until after injury.

The effect of dietary fatty acids on response to Pseudomonas infection in burned mice

Since fatty acids influence prostaglandin synthesis, and since both fatty acids and prostaglandins modulate immune function, we investigated the hypothesis that manipulation of dietary fats would affect survival after infection in a murine burn model. Mice were fed for 2 to 3 weeks with diets containing different types and amounts of fat. They were then subjected to a 20% flame burn and infected with Pseudomonas aeruginosa. Survival in the group fed 40% of total calories as fish oil had significantly higher mortality than those fed safflower oil. This difference was not noted at lower fat levels. Similar groups of animals were sacrificed the day after injection. Splenic macrophage production of PGE2 was significantly lower in the fish-oil group, but production of LTB4 and TXB2 were not affected. In vitro tests of T- and B-cell function were not different amongst groups. We conclude that manipulation of dietary fats can alter outcome in this murine model of infection after thermal injury.

Comparison of abilities of recombinant interleukin-1 alpha and -beta and noninflammatory IL-1 beta fragment 163-171 to upregulate C3b receptors (CR1) on human neutrophils and to enhance their phagocytic capacity

Both recombinant IL-1 alpha and -beta caused an upregulation of C3b receptors (CR1) on human neutrophils and caused a receptor-mediated enhancement of phagocytosis of C3b.IgG-coated microspheres by these leukocytes. The alpha and beta forms of the recombinant cytokine were of comparable potency regarding CR1 upregulation, although both generally had less than 25% of the potency of FMLP in this respect. Recombinant IL-1 beta was slightly more potent than the alpha form of the cytokine regarding phagocytosis of opsonized microspheres and, again, both forms were less potent than FMLP in causing an enhancement of phagocytosis by neutrophils. The synthetic noninflammatory immunostimulatory nonapeptide corresponding to residues 163-171 of IL-1 beta was completely inert with respect to upregulation of CR1 on neutrophils and the enhancement of phagocytosis by these cells. Thus this domain in the intact IL-1 beta molecule apparently is not involved in CR1 upregulation and the ensuing enhancement in phagocytosis by neutrophils, although it is apparently important in the immunostimulatory activity regarding the proliferation of lymphocytes.

A long-term study and correlation of lymphocyte and neutrophil function in the patient with burns

Twenty-five patients were studied to determine the effects of thermal injury on neutrophil bactericidal function and superoxide release and on lymphocyte proliferation. Neutrophils in patients with burns had depressed killing of Staphylococcus aureus for more than 150 days after burn injury, but killing of Escherichia coli returned to normal. FMLP-stimulated superoxide release by neutrophils in patients with burns was depressed for over 100 days after burn injury, whereas superoxide release by neutrophils in patients with burns stimulated with serum-opsonized zymosan was depressed for 42 days after burn injury. In patients with burns lymphocyte proliferation, with phytohemagglutinin as a mitogen, was suppressed for up to 85 days after injury, then returned to normal. The mixed lymphocyte response was suppressed up to 170 days after injury.

Nutritional immunomodulation in burn patients

A series of laboratory experiments in thermally injured guinea pigs has shown that feeding by the enteral route immediately after injury results in a decreased metabolic response by preventing loss of the GI barrier to the entrance of intestinal endotoxin and bacteria. Feeding by the iv route or giving crystalline amino acids instead of intact protein does not prevent atrophy of the intestine, nor does it prevent the hypermetabolic response. Optimal diets for nutritional support of burn patients contain 20% of energy from whey protein, 2% from arginine, 0.5% from cysteine, and 0.5% from histidine. Lipids comprise 15% of nonprotein calories with 50% fish oil (high in omega-3 fatty acids) and 50% safflower oil (high in linoleic acid). In a prospective clinical study, administration of this new diet was found to reduce wound infection (p less than .03), shorten hospital stay (p less than .02), and reduce death (p less than .06) when compared to other standard enteral formulations.

Failure of orthoclone OKT3 retreatment in a pancreas transplant recipient with antimurine antibodies

Orthoclone OKT3 is a murine monoclonal antibody that blocks the generation and function of T lymphocytes. It has been shown to be effective in reversing acute cellular rejection in solid organ transplants. However, potential development of antimurine antibodies restricts the duration that the drug can be used and the ability to reuse the drug. The case reported in this article illustrates the failure of retreatment with OKT3 when high titer (1:3200) antimurine antibodies are present. Lack of efficacy of the drug was documented by virtually undetectable circulating OKT3 levels in plasma, no decrease in T3 lymphocytes, and organ rejection. OKT3 should only be reused when immune monitoring (antimurine antibody status, lymphocyte subsets, and OKT3 plasma levels) is performed before, during, and after its use. Patients with high-titer anti-OKT3 antibody should not be retreated with OKT3.

Flow cytometric analysis of neutrophil subsets in thermally injured patients developing infection

The expression of CD11b (CR3, complement receptor type three), CD16 (FcR, Fc IgG receptor), and CD35 (CR1, complement receptor type one) on neutrophils obtained from thermally injured patients was examined using immunofluorescence and flow cytometry. Because defects in neutrophil function have been related to an increased risk of infection and death following thermal injury, we compared changes in neutrophil subpopulations following thermal injury with the onset of infection. Neutrophils from 34 patients with large thermal injuries were monitored weekly for CD11, CD16, and CD35. Changes in the cell surface antigens over time were compared with the incidence of bacteremia and pneumonia. Although the percentages of CD16+ CD11+ neutrophils were suppressed in almost all patients, the changes which occur in each individual patient rather than the actual values appear to be of major importance. Patients developing bacteremia or pneumonia displayed a significant reduction in both the percentage and absolute number of CD16+ CD11+ neutrophils compared to their preinfection values. The values did not increase until the infections were completely cleared. Patients remaining free of bacteremia or pneumonia usually had lower than normal percentages of CD16+ and CD11+ neutrophils with no predictable pattern being noted. The percentage of CD35+ neutrophils dropped within 1 week following thermal injury in all patients but did not correlate with the onset of infections.

Selenium toxicosis in three California sea lions (Zalophus californianus)

Selenium poisoning occurs worldwide in nearly all domestic animals. Acute selenium poisoning is associated with feeding high levels or injecting excessive amounts of selenium and is usually fatal. The acute poisoning may cause gastrointestinal disturbance, muscle weakness, depression of the central nervous system, prostration and death (1-2). Chronic selenium poisoning in cattle, sheep and horses may result from the consumption of seleniferous plants over an extended period of time. Chronic selenium results in ataxia, incoordination, partial blindness, paralysis, loss of hair or wool, abnormal hoof growth and possibly abnormal changes in behavior (1). There is little information regarding the clinical signs and pathology of selenium toxicosis in marine mammals. Likewise, there is little information regarding normal tissue levels or toxicologically significant levels of selenium in these species. The results of these investigations in sea lions, based on clinical signs, pathologic findings and tissue levels of selenium, suggest subacute or chronic selenium poisoning was most likely from dietary fish high in selenium.

Concomitant administration of cyclosporin and ketoconazole in renal transplant recipients

18 renal transplant recipients receiving cyclosporin, prednisone, and azathioprine were given ketoconazole, a potent inhibitor of the cytochrome P-450 enzyme system. Within a month ketoconazole-induced blockade of cyclosporin metabolism allowed a significant reduction (451 vs 106 mg/day; 77%) of the mean dose of cyclosporin without altering cyclosporin whole blood trough levels, although maximum blood levels were almost halved. This dose reduction was maintained in patients followed up for up to 13 months. Renal and hepatic function were unchanged after the addition of ketoconazole. This drug interaction has the potential to reduce dramatically expenditure on cyclosporin in transplant recipients.

The basics of immunological tests

This review article describes the cells and the humoral factors of the immune system. It also explains what tests are available to assess the immune functions of patients. Each test listed states the amount of blood needed and the time required to perform the assays.