Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024312 (lymphopenia)
 4,859 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have developed a rabbit model of toxic shock syndrome that uses a subcutaneous infusion pump to administer toxic shock syndrome toxin 1 (TSST-1). A dose of 150 micrograms, infused at a constant rate over a period of 7 days, resulted in a characteristic illness highlighted by fever, conjunctival hyperemia, cachexia, and lethargy. The illness was uniformly fatal, with a mean interval until death of 3.2 +/- 0.4 days. Serial determinations of serum chemistries confirmed the multisystem nature of this illness. Rabbits developed profound hypocalcemia, with levels falling from 15.5 +/- 0.2 to 7.6 +/- 0.4 mg/dl under the influence of TSST-1. Blood urea nitrogen and creatinine rose dramatically, in the setting of oliguria or anuria. Serum glutamicpyruvic transaminase was the most reliable indicator of hepatic dysfunction, with the mean rising from 48 U/liter before administration of TSST-1 to 546 U/liter among rabbits surviving 2 days of the infusion. Creatine phosphokinase also rose dramatically in 10 of 16 rabbits. Rabbits demonstrated relative neutrophilia and lymphopenia as well as an increase in the partial thromboplastin time. Histopathologic examination demonstrated disease of multiple organs, particularly the liver, spleen, and lymph nodes, all of which demonstrated inflammation, thrombosis, hemorrhage, and erythrophagocytosis. The concurrent administration of prednisolone with TSST-1 prevented death in four of four rabbits and greatly lessened the morbidity. Rabbits were not protected from morbidity or mortality by the concurrent administration of polymyxin B. We believe that a constant, subcutaneous infusion of TSST-1 in rabbits provides a reproducible model for studying the pathogenesis of TSS.
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PMID:A rabbit model of toxic shock syndrome that uses a constant, subcutaneous infusion of toxic shock syndrome toxin 1. 357 Apr 55

Toxic shock syndrome toxin 1 (TSST-1) was purified to apparent homogeneity by chromatofocusing and affinity chromatography. The amino acid composition of the toxin was very similar to that reported for TSST-1 by other investigators. The amino-terminal amino acid was serine. A partial specific volume of 0.73 ml/g was calculated for the toxin from the amino acid data, and a molecular weight of 19,200 +/- 1,300 was determined by hydrodynamic methods. New Zealand white rabbits of both sexes were equally susceptible to the lethal effects of the toxin; however, older rabbits (greater than 12 months) were far more susceptible than young adults or weanlings. The 50% lethal dose of TSST-1 in older rabbits was 50 to 60 micrograms/kg when injected subcutaneously and 20 to 30 micrograms/kg when injected intravenously. Enhancement of lethal endotoxin shock by TSST-1 could not be demonstrated when both toxins were injected subcutaneously; however, lethal shock did occur when endotoxin (10 micrograms/kg) was injected intravenously after TSST-1 had been injected by either the subcutaneous (50 to 60 micrograms/kg) or the intravenous (20 to 30 micrograms/kg) route. Endotoxin alone was not lethal at a dose of 500 micrograms/kg of body weight when injected subcutaneously. When injected intravenously, endotoxin at a dose of 500 micrograms/kg was not lethal in weanling males or in females in any age group; however, young (6 to 7 months) and adult (greater than 12 months) males were killed by endotoxin doses as low as 45 to 50 micrograms/kg. Histopathologic studies of rabbits by both sexes which died as a result of TSST-1 alone or in combination with endotoxin showed extensive damage to organs rich in lymphoid and mononuclear phagocytic cells such as the thymus, mesenteric lymph nodes, liver, and spleen. Severe congestion of these organs as well as erythrophagocytosis and lymphoid depletion in the spleen and mesenteric lymph nodes were noted. Congestion and hemorrhage were also found in the heart, lungs, trachea, and thymus. The systemic pathology produced by TSST-1 was strikingly similar to that seen in humans who had died of toxic shock syndrome and in rabbits with subcutaneous chamber inoculated with toxic shock case strains of Staphylococcus aureus. Rabbits that were not killed by the toxin suffered a very rapid and severe leukopenia followed by leukocytosis with a left shift. Lymphopenia was also noted as was a mild but persistent anemia. With the exception of the early leukopenia, very similar hematologic findings have been noted in humans with toxic shock syndrome.
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PMID:Affinity purification of staphylococcal toxic shock syndrome toxin 1 and its pathologic effects in rabbits. 394 96

The present investigation was undertaken to examine the characteristics of purified toxic shock syndrome toxin-1 (staphylococcal enterotoxin F) given intravenously to dwarf goats (dose, 0.02 to 20 micrograms kg-1). Rectal temperature, heart rate, rumen motility, plasma zinc and iron concentrations, and certain other blood biochemical and hematological values were studied and compared with the changes seen after intravenous administration of staphylococcal enterotoxin B (dose, 0.02 to 0.5 micrograms kg-1). Similar changes such as fever, tachycardia, inhibition of rumen contractions, drop in plasma zinc and iron concentrations, lymphopenia, and a decrease in serum alkaline phosphatase activity were observed. In contrast to the effects of toxic shock syndrome toxin-1, staphylococcal enterotoxin B induced colic, watery diarrhea with pseudomembranes, hemoconcentration, and a more pronounced increase in blood urea nitrogen. The results obtained demonstrate that (i) in the goat staphylococcal enterotoxin B is much more potent than toxic shock syndrome toxin-1 and (ii) the goat is a useful model to study the gastro-intestinal effects caused by staphylococcal enterotoxin B. The present finding that no clear relationship could be found between the temperature response and the alterations in zinc and iron levels in plasma support the theory that the febrile reactions and the changes in plasma trace metals are mediated by different polypeptides released by activated macrophages.
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PMID:Comparative observations of fever and associated clinical hematological and blood biochemical changes after intravenous administration of staphylococcal enterotoxins B and F (toxic shock syndrome toxin-1) in goats. 650 Jun 95

Group A streptococcus (GAS) bacteraemia is often associated with soft-tissue infection, with significant morbidity and mortality. Little is known concerning the differences between adults and children with GAS bacteraemia. Records for 98 of 116 cases of GAS bacteraemia (60 adults and 38 children, aged 7 days to 96 years) occurring during a 10-year period (1993-2002) were located and reviewed. GAS bacteraemia comprised 0.6% of all bacteraemias in adults, compared to 3.3% in children (p < 0.001). The rate of adult GAS bacteraemia was two cases/1000 hospitalisations, compared to 13/1000 in children (p < 0.001). Seventy-six (78%) patients had concomitant tissue involvement, with skin or soft-tissue infection being the most common (62%). Fifty-three (88%) of 60 adults and five (13%) of 38 children had underlying conditions (p < 0.001). Twelve patients died, only one of whom was a child. Parameters associated with mortality were older age, lower temperature, hypotension, a need for surgical intervention, toxic shock syndrome, disseminated intravascular coagulation, thrombocytopenia, lymphopenia, hypocalcaemia, renal failure and acidosis (p < 0.05).
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PMID:Group A streptococcus bacteraemia: comparison of adults and children in a single medical centre. 1644 54

Most clinical isolates of Staphylococcus aureus harbour genes encoding superantigenic toxins that bind the Vbeta domain of T-cells, but little information is available concerning superantigenic toxin production during staphylococcal toxic shock syndrome (TSS) and septic shock. This prospective study investigated 14 patients with staphylococcal TSS or septic shock; the toxin gene profile of each isolate was determined and flow-cytometry was used to identify the discriminant Vbeta signature (DVbetaS) of each superantigenic toxin in vitro. Attempts were also made to identify in-vivo production of superantigenic toxin DVbetaS in patients' blood. The DVbetaS identified in vitro were: toxic shock syndrome toxin (TSST)-1, Vbeta 2; staphylococcal enterotoxin (SE), Vbeta 9, Vbeta 22; SEB, Vbeta 3, Vbeta 14, Vbeta 17; SED, Vbeta 1, Vbeta 8; egc, Vbeta 5.3, Vbeta 7.1, Vbeta 9, Vbeta 23; and SElK, Vbeta 5.1. The DVbetaS of TSST-1 and SEB were detected in patients with menstrual and non-menstrual TSS, respectively, whereas no Vbeta signature was detected during septic shock. All patients with septic shock (but only one patient with TSS) had lymphopenia and/or impaired cellular immunity. Detection of a superantigenic toxin DVbetaS may help to show which toxin is produced during staphylococcal TSS, thus confirming the diagnosis and hastening the administration of anti-toxin therapy. In contrast, this approach failed to demonstrate superantigenic toxin involvement in cases of septic shock. In this latter condition, a superantigenic toxin may not be produced by S. aureus, or its production may occur without expansion of targeted T-cells because of T-cell apoptosis and/or anergy.
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PMID:Analysis of superantigenic toxin Vbeta T-cell signatures produced during cases of staphylococcal toxic shock syndrome and septic shock. 1837 92

Staphylococcal toxic shock syndrome toxin 1 (TSST-1) is the major cause of toxic shock syndrome and is important in the pathophysiology of staphylococcal septic shock. Our study about the biological effects of TSST-1 in the rabbit 3 and 6 h and 7 days postinjection provides evidence that TSST-1 induces leukopenia, lymphopenia, and monocytopenia as a result of extravasation of cells in a Vss-unrestricted manner. Cells in the circulation, reduced significantly in numbers, show the same phenotypic distribution as before TSST-1 injection. Three hours post-in vivo TSST-1 injection, we demonstrated compartmentalization of the response. By quantitative RT-PCR, the induction of mRNA expression of TH1 and inflammatory cytokines in the spleen and lung and a complete lack of induction in PBMC could be shown. Proliferation assays revealed that 3 h after TSST-1, PBMC were neither activated nor responsive to in vitro restimulation, even when IL-2 was added. In contrast, 7 days later, PBMC and spleen cells were anergic: showing no response to TSST-1 but a vigorous response upon addition of IL-2. The results presented extend our understanding of the pathophysiology of toxic and septic shock as a result of superantigen toxin-producing Staphylococcus aureus. Demonstration of compartmentalization of the response proves that erroneous conclusions could be drawn by the exclusive analysis of PBMCs. The results reveal further that in nonresponsiveness to the antigen, different immunological mechanisms may be operational. Measurements of the induction of cytokine gene activation provide important complementary information to that of serum cytokine levels.
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PMID:Analysis of the early response to TSST-1 reveals Vbeta-unrestricted extravasation, compartmentalization of the response, and unresponsiveness but not anergy to TSST-1. 1892 5

Toxic shock syndrome (TSS) and septic shock (SS) share many clinical signs of an exacerbated inflammatory response. In this report, we investigated whether TSS presents similar features of delayed immunosuppression as described in SS. Five children with TSS from paediatric intensive care units in a university hospital were monitored. TSS cases were defined by the association of standardized clinical signs of TSS and confirmed by measurement of specific Vbeta expansions corresponding to toxin gene profile of the isolated strains. As in SS, an increased percentage of circulating regulatory T cells (Treg) was observed in patients with TSS. However, in contrast to SS, neither lymphopenia nor decreased HLA-DR expression on monocytes was measured. In conclusion, whereas SS and TSS exhibited similar clinical presentation, the present observation suggests that respective pathophysiological mechanisms induce different immune alterations. Future studies must isolate and better characterize the phenotypic and functional properties of Treg subsets during TSS to understand the mechanisms sustaining their increase, especially the putative role of superantigens.
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PMID:Assessment of cellular immune parameters in paediatric toxic shock syndrome: a report of five cases. 2258 69

The cytokine IL-15 is required for natural killer (NK) cell homeostasis; however, the intrinsic mechanism governing this requirement remains unexplored. Here we identify the absolute requirement for myeloid cell leukaemia sequence-1 (Mcl1) in the sustained survival of NK cells in vivo. Mcl1 is highly expressed in NK cells and regulated by IL-15 in a dose-dependent manner via STAT5 phosphorylation and subsequent binding to the 3'-UTR of Mcl1. Specific deletion of Mcl1 in NK cells results in the absolute loss of NK cells from all tissues owing to a failure to antagonize pro-apoptotic proteins in the outer mitochondrial membrane. This NK lymphopenia results in mice succumbing to multiorgan melanoma metastases, being permissive to allogeneic transplantation and being resistant to toxic shock following polymicrobial sepsis challenge. These results clearly demonstrate a non-redundant pathway linking IL-15 to Mcl1 in the maintenance of NK cells and innate immune responses in vivo.
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PMID:Innate immunodeficiency following genetic ablation of Mcl1 in natural killer cells. 2511 82