Elimination of interleukin 6 attenuates coagulation activation in experimental endotoxemia in chimpanzees.

The role of interleukin 6 (IL-6) in the toxic sequelae of sepsis is controversial. To assess the part of IL-6 in inflammatory responses to endotoxin, we investigated eight chimpanzees after either a bolus intravenous injection of Escherichia coli endotoxin (n = 4; 4 ng/kg) or after the same dose of endotoxin with a simultaneous bolus intravenous injection of an anti-IL-6 mAb (30 mg; n = 4). Anti-IL-6 did not affect the induction of the cytokine network (tumor necrosis factor [TNF], soluble TNF receptors types I and II, and IL-8) by endotoxin, nor did it influence the occurrence of a neutrophilic leukocytosis and neutrophil degranulation, as monitored by the measurement of elastase-alpha 1-antitrypsin complexes. In contrast, anti-IL-6 markedly attenuated endotoxin-induced activation of coagulation, monitored with the plasma levels of the prothrombin fragment F1+2 and thrombin-antithrombin III complexes, whereas activation of fibrinolysis, determined with the plasma concentrations of plasmin-alpha 2-antiplasmin complexes, remained unaltered. We conclude that IL-6 does not have a feedback effect on the release of other cytokines after injection of endotoxin, and that it is not involved in endotoxin-induced neutrophilia or neutrophil degranulation. IL-6 is, however, an important intermediate factor in activation of coagulation in low grade endotoxemia in chimpanzees.

Generation and characterization of recombinant bivalent fusion protein r-Cpib for immunotherapy against Clostridium perfringens beta and iota toxemia.

Clostridium perfringens beta (CPB) and iota (CPI) toxaemias result in some of the most lethal forms of haemorrhagic and necrotic enteritis and sudden death syndrome affecting especially neonates. While CPB enterotoxemia is one of the most common forms of clostridial enterotoxemia, CPI enterotoxemia though putatively considered to be rare is an emerging cause of concern. The similarities in clinical manifestation, gross and histopathology findings of both types of toxaemias coupled to the infrequency of CPI toxaemia might lead to symptomatic misidentification with Type C resulting in therapeutic failure due to habitual administration of CPB anti-toxin which is ineffective against CPI. Therefore in the present study, to generate a composite anti-toxin capable of neutralizing both toxaemias, a novel bivalent chimera r-Cpib was constructed by splicing the non-toxic C terminal binding regions of CPB and CPI, via a flexible glycine linker (G4S) by overlap-extension PCR. The fusion protein was characterized for its therapeutic abilities toward CPI and CPB toxin neutralizations. The r-Cpib was found to be non-toxic and could competitively inhibit binding of CPB to host cell receptors thereby reducing its cytotoxicity. Immunization of mice with r-Cpib generated specific antibodies capable of neutralizing the above toxaemias both in vitro and in vivo. Caco-2 cells exposed to a mixture of anti-r-Cpib sera and native CPI or CPB, displayed significantly superior protection against the respective toxins while passive challenge of mice with a similar mixture resulted in 83 and 91% protection against CPI and CPB respectively. Alternatively, mice exposed to a mixture of sham sera and native toxins died within 2-3 days. This work thus demonstrates r-Cpib as a novel bivalent fusion protein capable of efficient immunotherapy against C. perfringens CPI and CPB toxaemia.

Simvastatin inhibits inflammatory properties of Staphylococcus aureus alpha-toxin.

BACKGROUND: Simvastatin, a 3-hydroxy-methylglutaryl coenzyme A reductase inhibitor, has been shown to lower serum cholesterol levels in clinical use. Moreover, statins exert beneficial effects in vascular diseases by inhibition of leukocyte rolling, adherence, and transmigration. The aim of this study was to determine if pretreatment with simvastatin attenuates Staphylococcus aureus alpha-toxin-induced increase in leukocyte-endothelial interactions during exotoxemia. METHODS AND RESULTS: The effects of simvastatin on leukocyte-endothelial cell interactions were observed by intravital microscopy in the rat mesenteric microcirculation. Simvastatin (50 or 100 microg/kg) was administered 18 hours before the study. Activation of microcirculation was induced by bolus administration of 40 microg/kg S aureus alpha-toxin. Exotoxemia resulted in a significant and time-dependent increase in leukocyte rolling, adherence, and transmigration of leukocytes as well as P-selectin expression on the intestinal vascular endothelium. Pretreatment with simvastatin significantly inhibited exotoxin-induced leukocyte rolling from 71+/-10 to 14+/-4.7 cells/min (P<0.01) and adherence from 14+/-3.5 to 0.4+/-0.2 cells (P<0.01). In addition, simvastatin pretreatment significantly inhibited transmigration of leukocytes from 10.5+/-1.2 to 4.2+/-0.9 (P<0.05) cells. Immunohistochemical detection of endothelial cell adhesion molecule P-selectin showed a 50% decrease in endothelial cell surface expression after simvastatin treatment. Furthermore, simvastatin treatment resulted in enhanced expression of endothelial cell NO synthase III in the intestinal microcirculation. CONCLUSIONS: These results demonstrate that simvastatin interferes with exotoxin-induced leukocyte-endothelial cell interactions, which may be relevant in various infectious diseases. Statin treatment may offer a new therapeutic strategy for these clinical conditions.

Distinct biochemical responses of hepatic macrophages and endothelial cells to platelet-activating factor during endotoxemia.

Acute endotoxemia is associated with activation of hepatic macrophages and endothelial cells. These cells release a variety of inflammatory mediators that have been implicated in tissue injury. In the present studies, we analyzed the biochemical responses of these cells to platelet-activating factor (PAF), a lipid autacoid released during hepatic inflammatory responses. To induce acute endotoxemia, rats were injected intravenously with lipopolysaccharide (LPS). Using the calcium sensitive fluorescent indicator dye Indo-1, we found that PAF induced a rapid and transient increase in intracellular calcium in both hepatic macrophages and endothelial cells. Induction of acute endotoxemia resulted in an increase in the amount of calcium mobilized by both cell types. Although endothelial cells from control rats were less responsive to PAF than macrophages, these cells were more sensitive to in vivo endotoxin. PAF was also found to cause a rapid decrease in intracellular pH in hepatic macrophages that was quantified by fluorescence image analysis using the pH sensitive dye SNAFL-calcein. This decrease occurred more rapidly in macrophages from endotoxemic rats. In cells from both control and endotoxemic rats, the effects of PAF on intracellular pH were inhibited by the specific PAF antagonist triazolam. In contrast to hepatic macrophages, PAF had no effect on intracellular pH in endothelial cells from either control or endotoxemic rats. Ligand binding studies demonstrated that both hepatic macrophages and endothelial cells possess high affinity binding sites for PAF. Macrophages expressed 6- to 7-fold more binding sites/cell than endothelial cells and exhibited a higher Kd. Whereas treatment of rats with LPS had no effect on the Kd for PAF binding to macrophages or on the number of binding sites, a significant increase in both of these receptor characteristics was observed in endothelial cells. Taken together, the present data suggest that the biochemical responses of endothelial cells and macrophages to PAF are distinct. Furthermore, cellular activation induced by PAF in endothelial cells appears to be independent of changes in intracellular pH.

Identification of toxemia in patients with Clostridium difficile infection.

Toxemia can develop in Clostridium difficile-infected animals, and correlates with severe and fulminant disease outcomes. Circumstantial evidence suggests that toxemia may occur in patients with C. difficile infection (CDI), but positive diagnosis is extremely rare. We analyzed the potential for C. difficile toxemia in patients, determined its characteristics, and assessed challenges. C. difficile toxins in serum from patients were tested using an ultrasensitive cell-based assay and further confirmed by Rac1 glucosylation assay. The factors that hinder a diagnosis of toxemia were assessed, including investigation of toxin stability, the level of toxins-specific neutralizing antibodies in sera and its effect on diagnosis limits. CDI patients develop detectable toxemia in some cases (2.3%). Toxins were relatively stable in stored sera. Neutralizing anti-toxin antibodies were present during infection and positively correlated with the diagnosis limits. Thus, the masking effect of toxin-specific neutralizing antibodies is the major obstacle in diagnosing C. difficile toxemia using cell-based bioassays.

Attenuation of hepatic neutrophil sequestration by anti-CINC antibody in endotoxic rats.

Cytokine-induced neutrophil chemoattractant (CINC) is a member of the chemokine alpha sub-family. It is induced in rats by tumor necrosis factor-alpha (TNF-alpha), interleukin-1, and lipopolysaccharide and is implicated in neutrophil infiltration in response to inflammatory stimuli. We tested the hypothesis that pretreatment with anti-CINC antibody or by cobra venom factor attenuates hepatic neutrophil accumulation induced by a 90 min infusion of Escherichia coli endotoxin. Changes in the expression of CD11b/c and CD18 and in plasma TNF-alpha levels were also investigated. Cultured hepatocytes and Kupffer cells of endotoxic rats produced significantly more CINC than those of saline-infused controls. CINC generation by Kupffer cells was much lower than generation by hepatocytes. Pretreatment with anti-CINC antibody or cobra venom factor significantly reduced hepatic neutrophil sequestration, but did not affect the up-regulation of CD11b/c and CD18 expression on liver-sequestered neutrophils or plasma TNF-alpha levels. We conclude that CINC-mediated hepatic neutrophil accumulation may not be necessarily associated with up-regulation of neutrophil adhesion molecules or elevated circulating TNF-alpha levels. Attenuation of hepatic neutrophil sequestration by anti-CINC antibody is likely based on blocking of the chemotactic activity of CINC and thus diminishing the chemotactic gradient established in the liver.

Reduction in intestinal leukocyte adherence in rat experimental endotoxemia by treatment with the 21-aminosteroid U-74389G.

OBJECTIVES: To investigate leukocyte adherence in intestinal venules in experimental endotoxemia after treatment with the 21-aminosteroid U-74389G. DESIGN AND SETTING: Prospective, randomized, controlled animal study in an experimental laboratory. SUBJECTS: Twenty-one male Wistar rats weighing 190 +/- 40 g. INTERVENTIONS: The rats were divided equally into three groups: (a) control group, (b) endotoxemia (5 mg/kg lipopolysacharide from Escherichia coli O55:B5), and (c) endotoxemia and U-74389G administration 30 min before (3 mg/kg) and 60 min after endotoxin challenge (1.5 mg/ kg). MEASUREMENTS AND MAIN RESULTS: The distal small intestine of the animals was examined using intravital fluorescence videomicroscopy 2 h after endotoxin challenge. Leukocytes were stained in vivo by means of rhodamine 6G. In the endotoxemic animals we observed a fourfold increase in the count of firmly adherent leukocytes in submucosal post-capillary and collecting venules. Treatment with the 21-aminosteroid U-74389G significantly attenuated the count of sticking leukocytes in the collecting venules (control, 61 +/- 10 cells/mm2; lipopolysaccharide, 237 +/- 42 cells/mm2; U-74389G 125 +/- 9 cells/mm2; p < 0.05). In these venules leukocyte rolling behavior was comparable to that in the control group without endotoxin challenge. CONCLUSIONS: Administration of U-74389G, which has radical scavenging properties, attenuates leukocyte adherence in selected populations of intestinal venules which is found increased during endotoxemia. Thus, 21-aminosteroids may have an impact in the treatment of endotoxin-induced intestinal injury.

Detection of interleukin 1 alpha and 1 beta in rabbit tissues during endotoxemia using sensitive radioimmunoassays.

Interleukin 1 (IL-1) is a primary mediator of a wide variety of immunologic and inflammatory responses, including reactions to microbial infections. To study this cytokine in an animal model, we have developed specific and sensitive radioimmunoassays for the quantitation of rabbit IL-1 alpha and IL-1 beta. The sensitivity (limit of detection at 95% confidence level) of our assay for IL-1 alpha and 1 beta was 20-40 and 40-80 pg/ml, respectively. Recovery of IL-1 from tissues ranged from 75 to 107%, with a mean of 95% for IL-1 alpha and 89% (range 19-98) for IL-1 beta. We employed these assays in in vivo and in vitro studies. In an in vivo model, we measured the amount of rabbit IL-1 alpha and 1 beta protein present in brain, kidney, liver, lung, muscle, and spleen at various times after the injection of endotoxin. IL-1 was found in all tissues studied but largely in the spleen; IL-1 levels were transient, reaching peak levels by 4 h after injection of endotoxin and rapidly decreasing to low levels by 24 h. In similar in vitro studies, IL-1 alpha levels reached peak elevation 6 h after addition of endotoxin, whereas IL-1 beta was maximal at 24 h. IL-1 alpha was detected in all tissues; IL-1 beta was observed primarily in lung, kidney, and spleen. These studies establish the presence of IL-1 in various tissues during endotoxemia.

Leukocyte CD18 monoclonal antibody worsens endotoxemia and cardiovascular injury in canines with septic shock.

We investigated the effects of a murine monoclonal antibody directed against the canine leukocyte CD11/18 adhesion complex (MAb R15.7) in a canine model of septic shock. Awake 2-yr-old purpose-bred beagles were studied 7 days before and 1, 2, 4, and 10 days after intraperitoneal placement of an Escherichia coli-infected fibrin clot. Starting 12 h before clot placement, animals received 0.5-1 mg/kg iv every 12 h (4 doses total) of either MAb R15.7 (MAb group, n = 8) or, as controls, murine serum protein (n = 8). After infected clot placement, all animals received antibiotic (ceftriaxne, 100 mg.kg-1.day-1 for 4 days). Two of eight control animals and four of eight MAb animals died (P = 0.4). During the first 8 h after clot placement, MAb animals, compared with control animals, had greater (P < 0.06) increases in serum endotoxin levels and higher (P < 0.05) neutrophil counts. Day 1 after clot placement, MAb animals, compared with control animals, had decreased (P < 0.05) central venous pressure and arterial pH and increased (P < 0.05) arterial lactate. Day 2 after clot placement, MAb animals, compared with control animals, had decreased (P < 0.05) cardiac index and mean arterial pressure. In summary, MAb R15.7, although associated with increased neutrophil counts, worsened serum endotoxemia, acidosis, and cardiovascular function in this canine model of septic shock. These data suggest that in septic shock, antibody directed against this leukocyte membrane protein complex may be harmful, possibly via impairment of normal leukocyte function.

Does endotoxin play a major role in inducing the depression of macrophage function during polymicrobial sepsis?

BACKGROUND: Endotoxin (ETX) is thought to be the primary inducer of proinflammatory mediator release associated with bacterial sepsis. Furthermore, a number of studies indicate that preexposure of animals to high doses of ETX produces macrophages (M luminal diameters) that are refractory to ex vivo stimulation with ETX. However, it is unknown if levels of ETX comparable to those typically encountered in sepsis induce a similar refractory state in M luminal diameters. DESIGN: To assess this, peritoneal M luminal diameters (PM luminal diameters) were harvested from C3H/HeN mice (ETX sensitive) at 1 hour (early) or 24 hours (late) following cecal ligation and puncture (CLP) to induce polymicrobial sepsis, sham CLP, or laparotomy followed by peritoneal implantation of a minipump delivering either saline or ETX (0.025 microgram/g of body weight, every 24 hours). Peritoneal M luminal diameter cultures were incubated with ETX, either 0 or 10 micrograms/mL, for 24 hours, and their ability to release interleukin-1, interleukin-6, and tumor necrosis factor was assessed by bioassay. RESULTS: Chronic low-dose ETX with 0 microgram of ETX media added produced early (at 1 hour) in vivo activation of PM luminal diameter interleukin-1 release, which was comparable to that seen in mice subjected to CLP. However, unlike PM luminal diameter taken from CLP mice, PM luminal diameters from mice implanted with the ETX minipump at 1 or 24 hours showed no marked decline in their ability to respond to ETX (10 micrograms). Comparable changes were seen for interleukin-6 and tumor necrosis factor release. CONCLUSIONS: Bacterial component(s) other than ETX per se induces the sustained dysfunction in PM luminal diameter capacity to produce proinflammatory cytokines during sepsis and/or peritonitis. Thus, agents directed against ETX alone may not be adequate in the treatment of polymicrobial sepsis.

Systemic and liver cytokine activation. Implications for liver regeneration and posthepatectomy endotoxemia and sepsis.

BACKGROUND: The liver is known to be an important site of tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) production during infection, but local changes in these cytokines after liver resection are unknown. DESIGN: Fischer rats were subjected to 70% hepatectomy or sham operation to determine if hepatic resection alters liver cytokine production and subsequent response to infection. RESULTS: During liver regeneration, circulating IL-6 levels were mildly increased but no expression of TNF-alpha or IL-6 could be detected in the regenerating livers. However, the capacity for the regenerating liver to produce cytokines was intact, since intraperitoneal Escherichia coli endotoxin (2 mg/kg) produced liver cytokine messenger RNA levels in hepatectomized animals comparable to those in pair-fed controls. Systemic response to endotoxin and sepsis was also intact after hepatectomy, as circulating cytokine response was similar between hepatectomized and pair-fed animals after endotoxin administration as well as after cecal ligation and puncture. CONCLUSION: Hepatectomy elicits a circulating cytokine response without effects on liver IL-6 or TNF-alpha production. However, cytokine defense mechanisms are intact during noncomplicated liver regeneration, as indicated by normal TNF-alpha and IL-6 responses to endotoxemia or sepsis. Endotoxemia is a more potent stimulus for liver cytokine production than local trauma or liver regeneration, suggesting that not only the proximity to injury but also the severity and mechanisms of injury determine local cytokine responses.

The metabolic effects of platelet-activating factor antagonism in endotoxemic man.

OBJECTIVE: To determine if the inflammatory phospholipid platelet-activating factor (PAF) participated in the symptomatologic, metabolic, and counterregulatory hormonal responses of human endotoxemia. DESIGN: In a double-blind, placebo-controlled study, five subjects received 10 mg of the PAF antagonist Ro 24-4736 orally, while five control subjects received a placebo. Eighteen hours later, all subjects were administered 4 ng/kg of endotoxin (lipopolysaccharide) intravenously. SETTING: The Clinical Research Center of The New York Hospital-Cornell Medical Center. PARTICIPANTS: Healthy male volunteers. MAIN OUTCOME MEASURES: Repeated measurements of vital signs, symptoms, cytokine and hormone levels, resting energy expenditure, platelet aggregation, and bleeding times were performed during a 24-hour period. RESULTS: Subjects who were pretreated with the PAF antagonist experienced fewer symptoms, including rigors at 1 hour (P < .05) and myalgias at 1 through 4 hours (P < .05) after administration of lipopolysaccharide. This was in concert with a diminished peak cortisol level (668 +/- 107 vs 959 +/- 159 nmol/L in controls; P < .05), epinephrine secretion (1057 +/- 165 vs 2029 +/- 431 nmol/L in controls; P < .05), and almost complete inhibition of PAF-induced platelet aggregation ex vivo. CONCLUSIONS: These findings in the face of unaltered circulating cytokines tumor necrosis factor alpha, interleukin 1 beta, and interleukin 6, as well as the tumor necrosis factor receptor-I s, suggest that PAF may influence some endotoxin-induced, counterregulatory hormonal responses and symptoms through cytokine-independent mechanisms. This study further supports the role of PAF antagonists as an adjunct to cytokine blockade in the treatment of gram-negative sepsis.

Endotoxemia, complement, and white blood cell activation in cardiac surgery: a randomized trial of laxatives and pulsatile perfusion.

Endotoxin activates complement and white blood cells and all are implicated in the pathologic effects of cardiopulmonary bypass (CPB). We investigated if reduction in intestinal bacterial load with a laxative and/or pulsatile perfusion to improve bowel circulation during CPB reduced endotoxemia and complement and white blood cell activation. Sixty patients were randomized to four groups in a 2 x 2 factorial structure: group 1 (no laxative, nonpulsatile perfusion); group 2 (laxative, nonpulsatile perfusion); group 3 (no laxative, pulsatile perfusion); and group 4 (laxative, pulsatile perfusion). Plasma concentrations of endotoxin, C3a and C5a, and granulocyte elastase (GE) were measured before anesthesia, skin incision, and heparin administration; during CPB (1, 30, 60, 90, and 120 minutes and after protamine administration); and after CPB at 3, 6, 12, 24, and 48 hours and 7 days. In all groups there was a small increase in the concentration of endotoxin (overall from 6 ng/L before CPB to 11 ng/L at 90 to 120 minutes; p < 0.001) and significant increases in C3a, C5a, and GE levels but no significant differences among the groups. Endotoxin levels did not correlate with activation of complement or white blood cells. There was a weak correlation between duration of CPB and levels of C3a (r = 0.14; p < 0.03) and GE (r = 0.25; p = 0.001) but not endotoxin or C5a. There was a general correlation between levels of C3a and GE but not in individual patients. In conclusion, CPB results in statistically significant increases in endotoxin, C3a, C5a, and GE during CPB.(ABSTRACT TRUNCATED AT 250 WORDS)

Prophylactic use of human endotoxin-core hyperimmune gammaglobulin to prevent endotoxaemia in colostrum-deprived, gnotobiotic lambs challenged orally with Escherichia coli.

The efficacy of human IgG polyclonal antibody to endotoxin-core in preventing endotoxaemia and subsequent disease was studied in colostrum-deprived gnotobiotic lambs challenged orally at about 5 h old with 10(9) cfu Escherichia coli. Human endotoxin-core hyperimmune gammaglobulin was given intravenously to 5 lambs at 1.9 g IgG/kg bodyweight prior to challenge. Human albumin was given intravenously to 3 control lambs. Bacteraemia was observed in all lambs, but the incidence was lower (P < 0.01) and the onset later (P < 0.05) in gammaglobulin pre-treated lambs. These lambs showed no signs of disease, whereas clinical endotoxaemia, manifesting as watery mouth disease, was diagnosed in 2 of the 3 control lambs which were killed between 18 and 22 h after challenge. Thus, prophylactic treatment of colostrum-deprived lambs with human IgG enriched in endotoxin-core antibodies was effective in reducing the degree of bacteraemia and preventing endotoxaemia, leukopenia and clinical disease following oral challenge with E. coli.

Natural lymphocyte cytotoxicity of women with different symptoms of toxemia.

Natural cytotoxic activity of lymphocytes from 113 pregnant women presenting one or more symptoms of the toxemic triad (E, P or H) was tested. According to the clinical symptoms, groups EH + H, EP + P and PH + EPH were formed. The control group consisted of 56 healthy pregnant patients. Significantly increased cytotoxicity was observed in toxemic pregnancies with proteinuria (group EP + P, 35.8 +/- 14.3%, P less than 0.001) and with proteinuria and hypertension (group PH + EPH, 27.2 +/- 13.3%, P less than 0.001%), but not in the group with hypertension (EH + H, 13.0 + 9.9%), compared to that of controls (11.0 + 11.5%). The relative number of patients with cytotoxicity greater than or equal to 40% was also higher in groups with proteinuria presenting with or without other symptoms of the disease. Increased cytotoxicity in proteinuric form of gestosis seemed to be independent of the incidence of low birthweight deliveries and intra-uterine growth retardation.

Serum tumor necrosis factor alpha concentrations and clinical abnormalities in colostrum-fed and colostrum-deprived neonatal foals given endotoxin.

We examined the effect of infusion of lipopolysaccharide (LPS) on serum tumor necrosis factor alpha (TNF alpha) concentration and clinical attitude in 2- 3-day-old colostrum-fed (CF) and colostrum-deprived (CD) foals. Eleven CF and 8 CD neonatal foals were given a bolus i.v. infusion of Escherichia coli O55:B5 lipopolysaccharide (0.5 microgram/kg of body weight) in sterile saline (0.9% NaCl) solution. Four CF and 2 CD foals were given saline solution alone. Serum IgG concentration and serum anti-LPS IgG(T) antibody titer were determined for each foal prior to infusion. A depression index was used to score clinical abnormalities. Serum TNF alpha concentration was estimated by use of an in vitro cytotoxicity bioassay that used WEHI 164 clone 13 cells as targets. The cytotoxic serum factor was identified as TNF alpha by immunoprecipitation with caprine antisera raised against the 15 NH2-terminal amino acids of human TNF alpha. Tumor necrosis factor alpha was not detected in any preinfusion serum samples nor in any samples from foals given saline solution alone. Serum TNF alpha concentration increased in all LPS-infused foals and peaked between 60 and 90 minutes after infusion. Serum TNF alpha concentrations, expressed as mean percentage of peak serum TNF alpha concentration, persisted longer in CD foals given LPS than in CF foals given LPS. All LPS-infused foals displayed clinical signs of endotoxemia, but mean depression index scores of the CF and CD foals given LPS were not significantly different at any time. Serum TNF alpha concentrations were correlated with depression index scores in both LPS-infused groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of polymyxin B and Salmonella typhimurium antiserum on horses given endotoxin intravenously.

Polymyxin B and an antiserum against an Re mutant Salmonella typhimurium were evaluated for protective effect in an equine model endotoxemia. Six 3- to 5-month-old foals were given endotoxin (0.25 micrograms/kg of body weight) IV after no pretreatment, or pretreatment with polymyxin B (6,000 U/kg, IV) or S typhimurium antiserum (1.5 ml/kg, IV). When given without pretreatment, endotoxin caused transient recumbency and increases in rectal temperature, and heart and respiratory rates. In addition, leukopenia and increases in circulating tumor necrosis factor (TNF) and interleukin 6 (IL-6) activities were detected. Compared with results obtained when endotoxin was given alone, pretreatment with polymyxin B resulted in significantly (P < 0.05) lower maximal plasma TNF and IL-6 activities, and significantly lower rectal temperature and respiratory rate. In contrast, compared with effects of endotoxin given without pretreatment, use of antiserum was associated with significantly (P < 0.05) higher respiratory rate, maximal plasma IL-6 activity, and total TNF response (as determined by areas under curves of plasma TNF vs time). These results indicate that polymyxin B may have potential as a treatment for equine endotoxemia. Salmonella typhimurium antiserum had no positive effect in this model, and, under certain conditions, may exacerbate the actions of endotoxin.

[Effects of sublethal endotoxemia to the hepatic reticuloendothelial system after massive hepatectomy].

Sublethal doses (1mg/kg) of endotoxin (ET) were intravenously administered on the first, third and fifth days after 34%, 70%, and 84% hepatectomies in rats. The same hepatectomy groups of rats without ET administration were made. Survival rates, distribution of Kupffer cells (Kc), regeneration rate of the liver weight, carbon clearance test (K value) and PTAH staining were compared between ET treated and untreated groups. Survival rates of 84% hepatectomy rats with ET injection on the 3rd postoperative day (POD) was significantly lower than those of 70% hepatectomy rats with ET on the 1st or 3rd POD. ET activated reticuloendothelial function of the non-hepatectomized and 34% hepatectomy rats, but reduced the number of the Kc in the central zone, especially in 84% hepatectomized rats. K values and the number of Kc in the central zone showed a good correlationship (r = 0.9) after 70% and 84% hepatectomies. Patchy hepatic necrosis and fibrin clots were observed histologically in the liver, kidney and spleen of rats died after ET administration. In conclusion, sublethal endotoxemia reduces the function and number of Kupffer cells in the regenerating liver and causes postoperative death in the rats with massive hepatectomy.

[Immunologic correction with immunoglobulin of toxemia with exicosis in infants with acute intestinal infections]. / Immunokorrektsiia immunoglobulinom pri toksikoze s éksikozom u detei pervogo goda zhizni s ostrymi kishechnymi infektsiiami.

The clinical course of acute intestinal infections complicated by toxicosis and exicosis was studied in 150 infants undergoing multimodality therapy, including natural human immunoglobulin for intravenous injections. The use of the new complex in the treatment of intestinal toxicoses was accompanied by increasing host immunological reactivity within short periods and decreasing of the treatment duration by 5.0 +/- 1.3 days; there were no persisting and chronic forms of the diseases and fatal outcomes. It was concluded that the use of the immunoglobulin for intravenous injections in the multimodality therapy of intestinal toxicoses in infants made it possible to prevent death in complicated intestinal infections and at the same time to accelerate their recovery.

[Antibiotic therapy of intestinal infections complicated by toxicosis and exicosis in children with immunodeficiency syndromes]. / Antibiotikoterapiia pri kishechnykh infektsiiakh, oslozhnennykh toksikozom i éksikozom u detei s immunodefitsitnym sostoianiem.

Clinical processes of acute intestinal infections complicated by toxicosis and exicosis and some host immunological parameters were studied in infants with secondary immunodeficiency. A special treatment scheme was developed including combined use of antibiotics, human immune globulin administered intravenously and cytochrome C. The scheme provided a decrease in the treatment duration by 8.6 +/- 1.1 days. Advanced and chronic diseases and fatal outcomes were absent. It was concluded that the developed scheme increased host immunological reactivity and efficacy of antibiotic therapy. It was recommended for wide clinical use in pediatric clinical care.