Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Continuous infusion of a gram-negative bacterial endotoxin in relatively small doses into rats by means of an implanted osmotic pump was studied. The model system was designed to examine the effects of endotoxin on the blastogenic response of spleen cells to the endotoxin itself and to a nonspecific T-cell mitogen, concanavalin A (Con A). Rats were implanted with an osmotic pump which delivered saline for the first 42 hr to provide postsurgical recovery before the onset of endotoxin infusion. Previous studies had shown that during the first 1-4 days after administration of endotoxin marked alterations of metabolism and some changes in physiologic parameters such as blood pressure and in vitro myocardial performance occurred. In the present study the blastogenic responsiveness of spleen cells to endotoxin itself as well as to the nonspecific T-cell mitogen Con A was markedly decreased after several days of continuous administration of endotoxin. Control animals receiving only saline for the same period of time showed a similar depression of blastogenic responsiveness to the lipopolysaccharide (LPS), as well as to Con A, however, with a delay of 2-4 days before comparable levels of suppression became evident. These results indicate that marked alterations of immune competence as measured by blastogenesis of spleen cells to Escherichia coli LPS and to a mitogen such as Con A may occur after implantation of an osmotic pump, with or without continuous infusion of endotoxin. Further studies seem warranted to determine the role of the foreign body reaction to the osmotic pump as well as to the endotoxin administered by the pump.
 ...
PMID:Suppressed in vitro blastogenic responsiveness of rat spleen cells after continuous infusion of endotoxin by an implanted osmotic pump. 330 92

The effect of chronic treatment with an immunostimulating agent, bestatin, on age-associated immune decline was assessed in C57BL/6 mice. Animals were given weekly doses of bestatin (100 micrograms/mouse, i.p.) from 7 months of age until death, and immune responses (natural killer cell activity, T cell cytotoxicity in vitro and in vivo, delayed-type hypersensitivity reaction, lymphoproliferative responses to mitogens, production of interleukin-2, macrophage functions) were tested at 11, 15, and 20 months. Most of the functions were reduced in 15-17-month-old mice, but evidence of reduced macrophage activities appeared only in limiting conditions (low lipopolysaccharide stimulation for interleukin-1 production and low concentration of macrophages in the cytostatic test). Bestatin administration produced a transient increase in natural killer (NK) cell activity and in vivo T cell cytotoxicity, followed (15-20 months of age) by a depression of NK and T cell-mediated responses. Only macrophage functions were stimulated in 20-month-old bestatin-treated mice. This unresponsiveness coincides with an accelerated mortality of bestatin-treated mice and a significant increase in the number of spontaneous tumor-bearing animals. The stimulation of T cells by bestatin seems to be mediated by a primary activation of macrophages to release immune mediators. Several reasons for the bestatin-induced immunodepression can be postulated including a high dose of bestatin, leading to toxicity or unresponsiveness; induction of suppressor cells; and overproliferation of T cells due to the mitogenic activity of bestatin, which may act as a promoting factor for tumor development.
 ...
PMID:Acceleration of age-associated immune decline and mortality by early repeated administration of bestatin to C57BL/6 mice. 348 72

Two abortifacient proteins, alpha- and beta-momorcharin, have been purified from the seeds of the bitter melon (Momordica charantia). It was found that non-cytotoxic concentrations of these plant proteins can significantly inhibit the mitogenic responses of mouse splenocytes to concanavalin A, phytohaemagglutinin and lipopolysaccharide in a dose-dependent manner. In addition, the alloantigen-induced lymphoproliferation and the in vitro generation of a primary cytotoxic lymphocyte response were severely suppressed in the presence of these proteins. In contrast, the cytolytic activity of cytotoxic lymphocytes and natural killer cells was unimpaired by in vitro exposure to momorcharin. On the other hand, a clear decrease in the functional capacity of macrophages, such as the cytostatic and phagocytic activities, was observed under similar conditions. In vivo studies have shown that single injections of nontoxic microgram amounts of momorcharin into mice resulted in a significant depression of the delayed-type hypersensitivity response as well as the humoral antibody formation to sheep red blood cells. Similarly, the thioglycollate-induced in vivo migration of macrophages was also suppressed. Interestingly, the in vivo activation of natural killer cells was not appreciably affected. Our data suggests that the observed potent immunosuppressive effect of alpha- and beta-momorcharin is unlikely to be due to direct lymphocytotoxicity or due to a shift in the kinetic parameter of the immune response.
 ...
PMID:The immunosuppressive activities of two abortifacient proteins isolated from the seeds of bitter melon (Momordica charantia). 349 34

Twenty-one parasite-naive dogs were infected with 60,000 protoscolices of Echinococcus granulosus. Transformation of peripheral lymphocytes was investigated before and 29 days after the infection, immunoglobulin concentration and anti-hydatid fluid protein (HFP) titers in serum and feces before and at 35 days of infection, skin reactivity to HFP at 36 days, and characteristics of the parasites at 40 days. The infection caused a significant depression of the spontaneous, lipopolysaccharide-stimulated, and purified protein derivative-stimulated blastogenesis. Responses to phytohemagglutinin were unchanged and reactivity to concanavalin A was enhanced with the infection. Only the concentrations of IgG and IgA in the serum and IgA in the feces increased significantly after infection. Fifteen (71%) dogs produced significant serum titers of anti-HFP hemagglutinins but copro-antibodies were detectable in only 3 dogs at minimum titers. Titers were abolished by treatment with 2-mercaptoethanol. The serum of 11 (52%) dogs transferred passive cutaneous anaphylaxis to guinea pigs but none transferred skin reactivity to pups or rabbits. Five and 1 (but not 0.2) micrograms of HFP caused skin reactivity in 4 parasite-naive dogs. Nineteen (90.5%) infected dogs reacted significantly to skin inoculation of 0.2 microgram of HFP at 0.5 hours and 13 (62%) at 6 hours. The 7 dogs with the highest anti-HFP serum titers or the greatest skin reactivity at 6 hours had significantly less mature or fewer tissue parasites, respectively, than the 7 dogs with the smallest responses. Since there was evidence that the specific immunity was still developing at the time of the study, these results indicate that immunological diagnosis of, and artificial immunization against, canine echinococcosis are feasible.
 ...
PMID:Humoral immunity in the prepatent primary infection of dogs with Echinococcus granulosus. 352 Oct 67

The antibody response to lipopolysaccharide (LPS) and trinitrophenol-LPS (TNP-LPS) was investigated in mice after tolerance induction to chemically reactive hapten 2-4-6-trinitrobenzene sulphonic acid. The depression of the anti-TNP IgM response elicided by LPS was moderate and lasted 1 week. Depression of the response to TNP-LPS was severe and lasted 5 weeks. Tolerant mice given LPS 7 days after tolerance induction, at a time when it elicited a normal response, and challenged with TNP-LPS 2 weeks later, exhibited the same depression of their anti-TNP response as tolerant mice not given LPS. Furthermore, the anti-TNP IgM elicided by TNP-LPS in normal mice was of higher avidity than that observed with LPS. These results suggest that the anti-TNP response elicided by LPS cannot account for the overall immune status of tolerant mice.
 ...
PMID:Hapten-specific unresponsiveness in mice. IV.--Significance of anti-hapten antibody responses elicited by E. coli lipopolysaccharides in tolerant mice. 352 30

Endotoxemia is a frequent complication of many health disorders. It is characterized by systemic release of a variety of endogenous inflammatory mediators which effect cardiovascular depression, reductions in organ blood flow, tissue ischemia and derangements in cellular metabolism leading to death. During a continuous intravenous infusion of Escherichia coli lipopolysaccharide, the chronology of alterations in hepatosplanchnic blood flow, hepatic carbohydrate metabolism and pancreatic insulin secretion has been studied in awake Yucatan miniature pigs (Sus scrofa). Endotoxic shock in this model is characterized by reductions in portal venous and hepatic arterial blood flow, early transient increases in pancreatic insulin secretion, increases in the 3H-glucose-derived rates of glucose appearance and disappearance, profound hypoglycemia, hyperlactatemia and metabolic acidosis. Reductions in hepatic oxygen delivery are compensated for by enhanced oxygen extraction efficiency, but hepatic gluconeogenesis continues at an inadequate rate to compensate for increased glucose utilization. Experimental therapies including lidocaine, naloxone, captopril, dichloroacetate and glucagon each effect specific improvements in cardiovascular or metabolic function, but none significantly alter the composite derangements responsible for lethality in this model.
 ...
PMID:Endotoxemia in Yucatan miniature pigs: metabolic derangements and experimental therapies. 353 41

The effects of intra-articular injection of small amounts of E. coli lipopolysaccharide (LPS) into the intercarpal joint of 5 ponies were studied. The LPS induced predictable changes all of which were analogous to acute bacterial infection, except that the development of signs occurred sooner after the LPS injection, and subsided within 36 hours. Fever was monophasic and peaked at 5-7 hours. The ponies exhibited depression, reduced or absent appetite, increased pulse and respiration rates, and lameness. The lameness became evident between 1 and 2 hours after injection, at which time warmth, articular effusion, and resentment to palpation of joint flexion were evident. Hematological changes included neutrophilic leucocytosis, and changes in copper, iron and zinc serum concentrations. The synovial fluid total protein, leucocyte, and alkaline phosphatase levels increased within 2 hours. The mucin precipitation, total protein and leucocyte counts in synovial fluid remained elevated long after clinical and hematological changes had subsided. The model is useful for the study of some aspects of infectious joint disease.
 ...
PMID:An induced synovitis disease model in ponies. 355 39

The immunogenicity and cross-protectivity of potassium thiocyanate (KSCN) extracts from Type A Pasteurella multocida strains were evaluated in mice. Mice administered KSCN extracts showed signs of depression for several hours following immunization. These extracts induced protection against challenge with the virulent homologous bacterium although many of the surviving mice were clinically ill up to 72 h after challenge exposure. There was no consistent reciprocal protection between different strains of the serotype indicating lack of correlation between serotype and cross-immunogenicity. Antigenic analysis of KSCN extracts by crossed immunoelectrophoresis techniques revealed greater than or equal to 25 different antigenic components. When the antigenic content of P-2383 and P-1062 KSCN extracts were compared, most antigenic components were common to both; however, two strain-specific and antigenic components were identified with homologous and heterologous antisera. One component present in each of the extracts gave a precipitation line similar to that produced by a crude lipopolysaccharide extracted from the organism. This component was isolated by sucrose density gradient centrifugation. The component isolated from P-2383 KSCN extract sedimented rapidly, indicating a high molecular weight material, and contained 12% carbohydrate and 27% protein. Immunization of mice with this component induced resistance to challenge with the homologous strain and some degree of protection against certain heterologous strains.
 ...
PMID:Immunogenicity of potassium thiocyanate extract of type A Pasteurella multocida. 372 63

Six-week-old female CD-1 mice were administered the n-butylester of 2,4-dichlorophenoxyacetic acid (2,4-D). The 2,4-D ester was applied dermally at dosages ranging from 0 to 500 mg/kg (2,4-D content) in the acute studies and 0 to 300 mg/kg in the 3 week subacute studies. Following acute exposure, antibody production against sheep red blood cells was suppressed at higher exposure levels. Evidence of clinical toxicity, myotonia and depression, and histopathological alterations in the central nervous system including perivascular edema and ganglial cell necrosis, was also seen in the mice. No alterations were observed in the T- and B-lymphocyte proliferative responses induced by concanavalin A, a T-lymphocyte mitogen, or Escherichia coli lipopolysaccharide, a B-lymphocyte mitogen. Subacute 2,4-D ester exposure which produced minimal clinical or pathological alterations, had no effect on antibody production, but did enhance the B- and T-lymphocyte proliferative responses. The immunosuppressive effects of acute 2,4-D ester exposure which were observed in this study, were unlikely a direct immunological alteration, but rather a secondary manifestation of the clinical syndrome. Since the subacute exposure levels may be more comparable to occupational or environmental exposure, it is unlikely that 2,4-D esters will have any major immunotoxicological significance in agricultural communities.
 ...
PMID:The effect of topically applied n-butylester of 2,4-dichlorophenoxyacetic acid on the immune response in mice. 376 Apr 56

Acute hypoxia is known to cause a marked reduction in intestinal and peripheral blood flow, in favor of blood flow to the brain and heart. Complete occlusion of the intestinal circulation is known to damage the gut wall, allowing potentially lethal endotoxins present within the intestines to escape into the circulation. We examined here whether the breathing of a hypoxic gas mixture could lead to sufficient damage of the intestinal wall to cause endotoxemia. Six anesthetized monkeys breathed air for 1 hr, then an hypoxic mixture (FIO2 = 0.13) containing N2O for 1 h and, finally, 100% O2. Plasma endotoxin concentrations were determined by two methods. After approximately 40 min of hypoxia, the plasma endotoxin level rose significantly from 0.39 to 1.60 ng X ml-1 (p less than 0.001) and then subsided to near control levels. Control monkeys breathing air only or 70% N2O in oxygen (FIO2 = 0.3) for 3 h showed no such elevation in plasma endotoxin concentration. We conclude that hypoxia leads to a temporary endotoxemia in primates. Reticuloendothelial system depression by whole body X-irradiation (200 rads) increased both the magnitude and duration of the hypoxia-induced endotoxemia. Prior administration of equine anti-lipopolysaccharide (anti-LPS) hyperimmune plasma greatly reduced the magnitude of the induced endotoxemia. Since endotoxemia may be lethal, the use of anti-LPS as possible prophylaxis should be considered in persons breathing artificial atmospheres or where acute hypoxia may be a danger.
 ...
PMID:Hypoxia-induced endotoxemia in primates: role of reticuloendothelial system function and anti-lipopolysaccharide plasma. 379 22


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>