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Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Endotoxin-neutralizing activity may be an important property for antibiotics to be used in severe sepsis. Several antibiotics, belonging to different classes, were evaluated as to their endotoxin-neutralizing ability, using the inhibition of an in vitro metachromatic assay for lipopolysaccharides and a murine generalized Shwartzman reaction model. Gentamicin, amikacin, and sisomicin have been found to share significant in vitro antiendotoxin activity at an antibiotic/endotoxin ratio as low as 1.0/5 (by weight) and to reduce the murine generalized Shwartzman reaction at an antibiotic/endotoxin ratio of 3.3/5.
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PMID:Aminoglycosides modify the in vitro metachromatic reaction and murine generalized Shwartzman phenomenon induced by Salmonella minnesota R595 lipopolysaccharide. 175 42

In short, bacterial sepsis is associated with a number of peripheral manifestations involving the skin and soft tissues. The pathogenesis of the lesions observed is not fully understood and is almost certainly multifactorial. In ecthyma gangrenosum, the presence of large numbers of gram-negative bacilli in the walls of small blood vessels without a substantial inflammatory response suggests that either the bacteria themselves or bacterial products are responsible for tissue damage. Endotoxin probably plays a prominent role in producing these lesions. That Pseudomonas and Aeromonas species seem to cause ecthyma out of proportion to their prevalence as a cause of bacteremia might suggest that the endotoxin of these organisms has a special predilection for skin and subcutaneous structures. More likely, it indicates that other bacterial substances, such as exotoxins or proteases, are involved. The absence of PMN leukocytes is thought to play a permissive role, allowing unopposed bacterial proliferation. Lesions of symmetric peripheral gangrene characteristically do not have bacteria present. The presence of intravascular fibrin accumulation probably resembles the generalized Shwartzman phenomenon. However, the gangrenous lesions themselves more likely result from systemic hypotension and the resulting hypoperfusion of the tissues than from vessel obstruction. In lesions associated with vigorous inflammatory response, bacterial products may damage tissue either directly or by attracting leukocytes that, in turn, release substances that cause further tissue damage. An etiologic role for endotoxin or the gram-positive bacterial cell wall is likely, since endotoxin is known to produce similar lesions in the localized Shwartzman reaction. Favoring a role for other bacterial substances is the predisposition of V. vulnificus to cause cellulitis or of C. fetus to cause inflammation of the major vessels during sepsis; the mechanisms for these reactions are entirely unknown. It is interesting that in most instances in which peripheral lesions are caused by sepsis, either a large number of bacteria or an intense inflammatory response by PMNs is present, but not both. In both kinds of lesion, the tendency to involve blood vessels by different pathogenetic mechanisms contributes to the evolution of the disease process. In intensely inflamed lesions, veins and arteries can be shown histologically to be occluded. In the absence of inflammation, bacterial invasion of vessel walls or simply the presence of bacterial products adjacent to the vessel may produce spasm. As noted, the pathogenetic significance of thrombosis observed in the lesions of DIC remains unclear.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Cutaneous manifestations of bacterial sepsis. 252 95

We have developed a new model of disseminated intravascular coagulation in rats based on the induction of immunosuppression by prolonged high-dose dexamethasone treatment. Most models of disseminated intravascular coagulation are based on the generalized Shwartzman reaction, which is observed characteristically in experimental animals after two separate inoculations of bacterial endotoxins. These produce massive deposition of thrombi in the microcirculation and significant hemorrhagic and ischemic phenomena. We have demonstrated that the administration of glucocorticosteroids at the specific doses and intervals can adequately replace the first (preparatory) injection of endotoxin. For this reason, we have attempted to experimentally simulate a frequent clinical situation, such as sepsis secondary to peritonitis, by intraperitoneal inoculation of Escherichia coli and hog gastric mucin into rats pretreated with dexamethasone. This inoculation was equivalent to the second injection of endotoxin in the Shwartzman model (triggering inoculation). A typical picture of disseminated intravascular coagulation induced by bacterial endotoxins developed, as demonstrated by the anatomopathologic, microbiologic, and hematologic studies performed. These results were then compared to those obtained in rats treated exclusively with dexamethasone or given, in addition, an effective antibiotic therapy.
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PMID:Dexamethasone-prepared Escherichia coli-induced disseminated intravascular coagulation. Animal model. 355 37

A clinicopathological study was undertaken in 15 cases of massive hepatic necrosis after shock. The GOT and GPT level exceeded 1000 units in 10 cases. The 15 cases consisted of 3 diagnosed as fulminant hepatitis clinically and 12 diagnosed as disseminated intravascular coagulation (DIC) or multiple systemic organ failure (MOF) from the unremarkableness of liver dysfunction. It was noteworthy that sepsis and surgery were closely associated with these lesions. The weight of the liver at autopsy ranged from 800 to 2,700 g. Liver necrosis was macroscopically characterized by clear demarcation of the necrotic areas sharply separated from the surrounding liver parenchyma, showing the appearance of so-called "map-like necrosis". Microscopically, the lesions in these subjects showed mainly the pattern of centrilobular necrosis. As observed in the burn shock case (case 12), the shock which provoked in different phases of time seemed to have repeated its attack. These liver necroses were considered to result from severe systemic circulatory disturbance or intrahepatic circulatory disturbance. The possibility is indicated that the generalized or univisceral Shwartzman reaction, and repeated and combined severe shock participated in the pathogenesis. Fibrin thrombi aggrevate tissue perfusion and accelerate anoxia. Heparin therapy seemed effective in these cases if administered at an appropriate time.
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PMID:Fatal hepatic necrosis after shock. 371 91

Late skeletal deformities following meningococcemia associated with disseminated intravascular coagulation are rare. Two basic lesions have been described: epiphyseal avascular necrosis and epiphyseal-metaphyseal defects. These occur primarily in the lower extremities and result in angular deformity and leg length inequality. We recently encountered these lesions in a child 3 years following sepsis. The etiology appears to be acute vascular thrombosis of epiphyseal and metaphyseal vessels mediated through the generalized Shwartzman reaction. An increased incidence of these deformities may be anticipated as more children survive fulminant meningococcemia.
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PMID:Late skeletal deformities following meningococcal sepsis and disseminated intravascular coagulation. 404 19

Thrombocytopenia is characteristically associated with septicemia and hemolytic uremic syndrome (HUS), a subset of which has been shown to be associated with endotoxemia and shigellosis. An experimental model that closely resembles these clinical conditions is the generalized Shwartzman reaction modified with a continuous intravenous infusion of endotoxin for 5 hr in rabbits. In addition to exhibiting the triad of HUS (thrombocytopenia, hemolytic anemia, and azotemia), these animals also had circulating platelet aggregates, leukocytosis, lipidemia, hemoglobinemia, hyperfibrinogenemia, and prolonged partial thromboplastin time. Platelets that remained in circulation were chemically exhausted in serotonin content and functionally impaired in aggregation activities. Plasma from animals during thrombocytopenia and platelet functional deficiency had no effect of the aggregation responses of normal platelets. Although the single triggering event of endotoxin infusion was stopped at hour 5, recovery from abnormalities was only partial on day 2 and within normal limits by day 3. In vitro studies supported platelet exhaustion as a mechanism for decreased platelet function after endotoxin infusion. The presence of circulating platelet aggregates and exhausted platelets suggested that the process of platelet activation took place at as long as 24 hr after the cessation of LPS infusion. Endotoxin and other mechanism(s) are likely to be operative in the pathogenesis leading to platelet activation. Further studies to reveal the mechanism of platelet exhaustion in the experimental model may help our understanding of corresponding events in clinical endotoxic injury and HUS associated with endotoxemia.
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PMID:Impaired and exhausted platelets in modified generalized Shwartzman reaction: an analogue of hemolytic uremic syndrome associated with endotoxemia. 664 55

The possibility that experimental diabetes could prepare for the generalized Shwartzman reaction was investigated in female Sprague-Dawley streptozotocin-induced diabetic rats. After 48 hours, 1 week, and 9 weeks of diabetes, the rats were injected with 2 mg/kg of endotoxin, and the animals were sacrificed 2, 4, 8, and 24 hours after endotoxin. Ninety percent of the diabetic animals given endotoxin developed massive glomerular capillary fibrin deposition accompanied by marked decrease in platelet count. The age- and sex-matched nondiabetic control rats had no such changes. This marked susceptibility to endotoxin, previously only reported in pregnant rats, was present as early as 1 week of diabetes. The degree of glycemic control greatly influenced the susceptibility of diabetic rats to the generalized Shwartzman reaction. Only 28% of the diabetic animals given insulin once daily (4.6 +/- 0.3 units, mean +/- SEM) and maintaining a blood glucose level of 269 +/- 19 mg/dl developed glomerular thrombi. In contrast, the diabetic animals that did not receive insulin and had a blood glucose level of 617 +/- 21 mg/dl all developed fibrin thrombi. We conclude that the diabetic state in rats induces a unique susceptibility to the generalized Shwartzman reaction following a single injection of endotoxin, which varies with the severity of the diabetic state. Although the pathogenesis is unclear, this phenomenon may reflect abnormalities in the glomerular capillary wall and/or the coagulation system that may be important in the development of microvascular complications. Furthermore, this phenomenon may, in the animal model, mirror the increased risk of the diabetic patient to intravascular coagulation with bacterial sepsis.
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PMID:Shwartzman reaction in streptozotocin-induced diabetic rats. 671 72

Plasma fibronectin is a nonspecific opsonin which mediates phagocytosis of particulate matter by macrophages. Fibronectin depletion results in depression of reticuloendothelial system phagocytic function. This may potentiate microvascular embolization and sludging in critical illness. It has been hypothesized that sepsis is a major cause of fibronectin depletion. To explore this hypothesis, plasma fibronectin concentrations were measured in rats with intraabdominal abscesses and in rabbits subjected to the generalized Shwartzman reaction (spaced doses of endotoxin). In both groups of animals there was a significant increase (P less than 0.05) rather than decrease in fibronectin concentrations at times when sepsis and disseminated intravascular coagulation were manifest. This study does not support the hypothesized relationship between sepsis and fibronectin depletion. Until the kinetics of fibronectin production and utilization are further delineated, caution must be exercised in the interpretation of immunoreactive plasma fibronectin levels.
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PMID:Plasma fibronectin concentration in animal models of sepsis and endotoxemia. 682 8

Strain Y3343 isolated from a goat with septicemia and polyarthritis was studied. The strain was virulent and induced septicemia, polyarthritis and coagulopathy in two goats. Limulus amebocyte lysate active material was present in plasma, but not in higher titre in inoculated goats. Sonicated mycoplasma material induced a dramatic somatic cell response in the mammary gland of cows and goats and marked clotting of the cows' milk, but it did not clot limulus amebocyte lysate or kill chick embryos. Phenol-water extract clotted limulus amebocyte lysate and induced somatic cell response in cows but not in goats. The phenol-water extract did not kill chick embryos, was not pyrogenic in rabbits or goats, and did not induce generalized Shwartzman reaction or change the leukocyte kinetics in rabbits. It therfore appears that the virulence mechanisms of strain Y3343 can not be explained on the basis of factors with strong endotoxin activity.
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PMID:Biological effects of sonicated suspension and phenol-water extract of Mycoplasma mycoides subspecies mycoides in goats. 704 90

Induction of leukocytopenia by cytotoxic drugs protects against the generalized Shwartzman reaction induced by endotoxin. To elucidate the relationship between leukocyte number and in haemostatic and fibrinolytic disturbances in human sepsis, we studied 32 septic patients with abnormal leukocyte counts. Twenty patients had sepsis in the setting of leukopenia after chemotherapy for haematological malignancies. Twelve patients with leukocytosis developed sepsis associated with benign disorders. Concentrations of thrombin-antithrombin III complex (TAT), plasminogen activator inhibitor-1 (PAI-1) and plasma thrombomodulin (TM) in the leukocytosis group of (12.0 +/- 11.0, 40.2 +/- 27.0 and 5.5 +/- 2.3 ng/ml, respectively) were significantly elevated compared to the leukopenia group of (3.8 +/- 2.3, 18.0 +/- 15.0 and 3.1 +/- 1.0 ng/ml, respectively) and controls (3.3 +/- 0.4, 10.5 +/- 5.3, 3.0 +/- 0.5 ng/ml, respectively). On the other hand, there were no significant differences in these values between leukopenia group and controls. Thus leucocytes may play important roles in thrombin generation, PAI-1 release and injury to endothelial cells.
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PMID:Haemostatic and fibrinolytic parameters in septic patients with leukopenia or leukocytosis. 772 Aug 38


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