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)

Heat-killed Pseudomonas aeruginosa inhibit antibody response in C57BL/6 mice. The depression of this response is dependent on the dose of bacteria injected, on the time interval between microorganism injection and antigen administration, and on the nature of the antigen used. Cell transfer experiments provide evidence that suppressor cells are not operative in this model. Furthermore, the results show that P. aeruginosa induces a marked dose-dependent proliferation of spleen cells in vivo, and the in vitro targets of this proliferative effect are B lymphocytes. It is suggested that whole, heat-killed P. aeruginosa in vivo also behave as cell mitogens on B lymphocytes which, when strongly stimulated to proliferate, temporarily lose their capacity to mount a normal antibody response.
 ...
PMID:Depression of the antibody response in Pseudomonas aeruginosa-injected mice. 11 Jun 94

The depression of contact sensitivity to oxazolone in mice infected with Pseudomonas aeruginosa was studied. In oxazolone-sensitized mice, P. aeruginosa infection affects cell proliferation in the lymph nodes draining the site of sensitization. This impaired cell proliferation does not seem to be due to an altered lymphocyte reactivity, since lymph node and spleen cells from infected animals show a normal mitotic responsiveness to both T and B cell mitogens. In addition, the draining lymph nodes and spleens of mice exhibiting a depressed response to oxazolone contain a cell population able actively to suppress the response to the same antigen of syngeneic recipients sensitized immediately before the cell transfer. These suppressor cells require antigenic stimulation and appear to act on the induction phase of contact sensitivity.
 ...
PMID:Pseudomonas aeruginosa infection depresses contact sensitivity to oxazolone by enhancing suppressor cell activity. 15 2

The cellular basis of depression of contact sensitivity to oxazolone in mice injected with Pseudomonas aeruginosa was studied. Cells from draining lymph nodes of mice sensitized with oxazolone 18 h previously were able to induce contact sensitivity to normal mice when administered in their footpads. In contrast, cells from draining lymph nodes of P. aeruginosa-injected and oxazolone-sensitized donors failed to induce contact sensitivity when injected in the footpad of normal mice and were capable of actively blocking the immunizing process brought about by lymph node cells from sensitized mice when injected together in the footpad of normal recipients. The P. aeruginosa-induced suppressor cells required antigenic stimulation, had precursors sensitive to cyclophosphamide, and did not affect the effector mechanisms of contact sensitivity. Thus, the results suggest that P. aeurginosa depresses contact sensitivity to oxazolone by enhancing the activity of suppressor cells which normally arise during the sensitization process and which affect the afferent limb of the immune response, probably by inhibiting the normal recruitment of T lymphocytes in the draining lymph nodes.
 ...
PMID:Depression of contact sensitivity by Pseudomonas aeruginosa-induced suppressor cells which affect the induction phase of immune response. 15 63

Alveolar macrophage (AM) phagocytic activity and glucose metabolism were evaluated during lung tumour growth in adult rats challenged i.v. with 10(5) viable Walker 256 tumour cells. Phagocytosis was estimated by the in vitro uptake of (14)C-labelled Pseudomonas aeruginosa and glucose oxidation was evaluated by (14)CO(2) production from 1-(14)C-glucose. AM were harvested by lung lavage from rats prior to and at 7 and 21 days following i.v. tumour-cell challenge. Macroscopic lung tumour nodules were not observed by 7 days after tumour challenge. However, 3 weeks after tumour challenge, tumour nodules were clearly identifiable on the surfaces of the lungs. One week after the i.v. tumour challenge a marked increase in the number of AM was evident. The in vitro phagocytosis of (14)C-labelled Pseudomonas aeruginosa was unaltered at that time, but became progressively depressed thereafter. Three weeks after tumour challenge, this decrease in phagocytic activity was evident when cells were incubated in normal serum, and was furtheri ntensified by serum obtained from tumour-bearing animals. Glucose oxidation by AM in either the resting condition or during bacterial phagocytosis was clearly decreased at both 1 and 3 weeks following i.v. tumour challenge. These findings indicate that the growth of pulmonary metastases is associated with a depression of alveolar macrophage bacterial phagocytic capacity, perturbations in serum opsonic activity and distinct alterations in macrophage energy metabolism. The metabolic dysfunction may impair pulmonary macrophage host defences against lung tumour growth.
 ...
PMID:Inhibition of phagocytosis and glucose metabolism of alveolar macrophages during pulmonary tumour growth. 59 70

The effect of Pseudomonas aeruginosa infection on contact sensitivity to 2-phenyl-4-ethoximethylene-oxazolone (oxazolone) and on antibody response to sheep erythrocytes, horse erythrocytes, and Escherichia coli 0111:B4 lipopolysacharide was investigated in outbred C57BL/6 mice. Injection of 0.5 and 0.2 median lethal doses significantly depressed contact sensitivity to oxazolone, whereas injection of 0.5 median lethal dose of heat-killed microorganisms did not. The filtrate of a 24-h broth culture did not affect contact sensitivity as well. Antibody production against sheep erythrocytes, horse erythrocytes, and lipopolysaccharide (evaluated as plaque-forming cells and circulating hemagglutinin and hemolysin titers) was found to be significantly enhanced both in animals injected with living bacteria and in those which received heat-killed microorganisms. The simultaneous occurrence of depression of cell-mediated immunity and potentiation of humoral response suggests that P. aeruginosa might interfere at different levels of the host immunological responsiveness.
 ...
PMID:Depression of contact sensitivity and enhancement of antibody response in Pseudomonas aeruginosa-infected mice. 81 24

Female rats were treated with several administration regimens of methylprednisolone, cobra venom anti-complementary factor, and cyclophosphamide in conjunction with polyvinyl sponge implantations. The effect of these drugs on host factors active against bacteria was evaluated with Staphylococcus aureus ATCC 25933, Escherichia coli K-12, and Pseudomonas aeruginosa CDC 7725. One of two implants in each animal was infected with 10(8) of one of the three bacteria, and bacterial and granulocyte content was determined in the infected and control sponges after 48 h. The single large dose of methylprednisolone decreased staphylococcal and E. coli clearance while promoting dissemination of P. aeruginosa. A low chronic dose of the steroid inhibited E. coli chemotaxis only. A higher dose of the steroid administered chronically interfered markedly with S. aureus and E. coli curtailment by the host while leading to enhanced dissemination of P. aeruginosa, accompanied by a precipitous decline in granulocytes. Results with cobra factor resembled the higher chronic dose of steroid enhancing, especially the dissemination of the pseudomonad and its anti-granulocytic propensity. Cyclophosphamide depression of granulocytes revealed the rat's ability to curtail the proliferation of particular S. aureus and E.coli strains even in the absence of leukocytes. This treatment resulted in the rapid spread of P. aeruginosa, leading to the death of some experimental animals. These experiments underline the versatility of this animal model in the study of host and microbial factors influential in infectious disease.
 ...
PMID:Rat polyvinyl sponge model for the study of infections: host factors and microbial proliferation. 82 14

Pseudomonas aeruginosa infection depresses contact sensitivity to 2-phenyl-4-ethoximethylene-oxazolone (oxazolone), and enhances the antibody response to sheep erythrocytes (SRBC) in the mouse. Anti-oxazolone antibody titres were found not to be significantly different in infected and uninfected animals; thus, the major circulating classes of antibodies do not seem to be responsibile for the observed depression of skin reactivity. Low dose (20 mg/Kg) cyclophosphamide (CY) pretreatment induced a further potentiation of antibody response to SRBC, and prevented depression of contact sensitivity in infected mice. On the other hand, when infected animals were pretreated with high doses (200 mg/Kg) of CY, antibody production was completely suppressed, whereas contact sensitivity was unaffected. Since CY treatment is known to selectively inhibit B lymphocytes, and since it can abrogate the infection-induced depression of reactivity to oxazolone, it is suggested that suppressor cells, which may have B-cell characteristics, are stimulated during P. aeruginosa infection in the mouse.
 ...
PMID:Evidence for suppressor cell activity associated with depression of contact sensitivity in Pseudomonas aeruginosa infected mice. 99 63

Two recent cases of cervical necrotizing soft-tissue infection are herein presented. Case 1. A 52-year-old man with uncontrolled diabetes was hospitalized because of an erythematous swelling of the left side of his neck and high grade fever. Fetid yellowish pus exuded from the left parotid area. The swelling extended from the left temporal area to the left supraclavicular fossa, with necrosis of the parotid gland, sternocleidomastoid, masseter and a portion of the strap muscles. Wound cultures revealed Staphylococcus aureus and alpha-hemolytic streptococcus. No anaerobic bacteria were detected. Treatment consisted of intravenous administration of antibiotics, control of diabetes with insulin, and debridement of the necrotic tissue, which left an epidermal defect in the initially swollen area. Transfer of a forearm free flap was done after the growth of healthy granulation tissue over the affected area. Case 2. A 55-year-old woman with rheumatoid arthritis was transferred to our hospital after tracheotomy performed in another hospital because of dyspnea due to severe crepitant swelling of her cheeks and submandibular areas bilaterally, and her left temporal area. A copious amount of fetid pus exuded from the incisions made in the left temporal area, left cheek, and right submandibular area. There were bilateral diffuse rales. Culturing the pus revealed alpha-hemolytic streptococci, while MRSA and Pseudomonas aeruginosa were detected from cultures of sputum. No anaerobic bacteria were found. After intravenous administration of antibiotics, infected wounds and pneumonia were ameliorated, and necrotic subcutaneous tissue and fascia were debrided. The patient was discharged with a residual depression in her left cheek and a scar on her left temporal area.
 ...
PMID:[A report of two cases of cervical necrotizing soft-tissue infection]. 140 20

Although often not considered, the heart is one of the targets of multiple organ failure in sepsis and septic shock, with myocardial depression being a prominent component of this "acute septic cardiomyopathy". Hypotheses concerning the etiology of this depression are increasingly elucidated on a cellular level, including dysfunction of the beta-adrenoceptor/G protein/adenylate cyclase system, calcium channel blockade by cardiodepressant factor, contractile impairment by activated leucocytes, as well as inhibition of protein synthesis by Pseudomonas exotoxin A. In the search for "mechanisms of myocardial depression in sepsis", isolated cardiomyocytes may play a role as research tools with respect to: a) discrimination between direct and indirect cardiodepressant effects; b) identifying not only the acute, but also chronic toxin- and mediator-induced cardiodepression; c) clarification of the mechanism of action of cardiodepressant bacterial toxins and sepsis mediators; d) establishment of in vitro models of leucocyte-mediated cardiodepression in sepsis.
 ...
PMID:Mechanisms in acute septic cardiomyopathy: evidence from isolated myocytes. 166 46

Using the emulsion technique, we have studied nucleation of ice in aqueous solutions containing silver iodide or Pseudomonas syringae. Using a Differential Scanning Calorimeter (DSC), we determined characteristic temperatures of nucleation, and also rates of nucleation at selected temperatures. The freezing point depression induced by added solute is linearly related to the lowering of both homogeneous and heterogeneous nucleation temperature. Nucleation kinetics depend on a fifth power function of the temperature. Solute is found to affect the parameters of this relationship in different ways, dependent upon the nature of the catalytic site for ice nucleation. We have also studied the effect of composition on the linear propagation velocity (LPV) of ice in undercooled solutions contained in a U-tube. We have determined velocities in a range of concentrations of sugar solution at the same undercooling, and also as a function of undercooling. The role of added polymer has also been investigated. It is affected by the sugar concentration.
 ...
PMID:Effect of solute on the nucleation and propagation of ice. 174 27


1 2 3 4 5 6 7 8 Next >>