Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0004623 (bacterial infection)
 15,226 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The number of people infected with human immunodeficiency virus (HIV) is gradually increasing in Japan, and the morbidity rate from tuberculosis in the Japanese people is high. Accordingly, the number of cases with both infections is considered to increase in the future. Our hospital has already encountered 31 cases of HIV associated tuberculosis. HIV infects mainly CD4-positive cells. The extreme decrease in the cell count results in serious cellular immunological disorder. CD4-positive cell disorder induces disorders of B lymphocytes, cytotoxic T cells, natural killer cells, and macrophage functions. These destructive conditions show the state of immunodeficiency including macrophage that are most important for defense of acid-fast bacterial infection. Migration and activation of macrophages with cytokines derived from T cells are impaired to induce the following phenomena: hypoplasia of granuloma, failure of tubercule bacillus suppression, the spread to regional lymph nodes (hilar or mediastinal lymph nodes), and hematogenous dissemination. On this occasion, caseous necrosis and cavitation are unlikely to occur, and false-negative tuberculin reaction is often observed. The incidence of severe cases, which include miliary tuberculosis, tuberculous meningitis, etc., and extrapulmonary tuberculosis, are high among acquired immunodeficiency syndrome (AIDS)-associated tuberculosis cases. HIV-infected tuberculosis cases are generally regarded as endogenous exacerbation, but they include primary infection and reinfection as well. Even during the treatment for drug-sensitive strains particularly, some cases may have reinfection with multidrug-resistant bacteria, suggesting that caution should be taken against this point. Conversely, the association of tuberculosis is a factor for the poor prognosis of HIV infection, since it facilitates the development of HIV infection. If the bacteria belong to a drug-sensitive strain, the infection with them responds well to antituberculous drugs, the same as in tuberculosis cases without HIV infection, showing a favorable prognosis. However, the mortality rate of infection with multi-drug-resistant tuberculosis is extremely high. The combined use of a protease inhibitor, i.e., anti-HIV drug, with rifampicin is regarded as contraindication for the treatment because rifampicin strongly induces hepatic cytochrome P-450 and increases the metabolism of protease inhibitors and nonnucleoside reverse transcriptases to markedly decrease the blood concentrations. Accordingly, the treatment for tuberculosis should take priority over that for HIV infection in HIV-infected tuberculosis, and highly active antiretroviral therapy (HAART) may be administered after the treatment of tuberculosis. When HAART is necessary for the treatment during the tuberculosis treatment, rifampicin had better be exchanged to rifabutin because the effect of rifabutin to induce cytochrome P-450 is less potent than that of rifampicin. A report has recently shown that the exacerbation of pyrexia and chest X-ray findings was transiently observed approximately 2 weeks after potent anti-HIV therapy for HIV-infected tuberculosis, which included a protease inhibitor. The reason for the exacerbation has been believed to be that the impaired function of CD4-positive cells is improved by the administration of anti-HIV drugs to raise temporarily the reaction of the vital part to M. tuberculosis. A tuberculin skin test (TST) reaction size of > or = 5 mm of induration is considered positive (i.e., indicative of M. tuberculosis infection) in persons who are infected with HIV. Persons with a TST reaction size > or = 5 mm who have not previously received treatment for M. tuberculosis infection should receive tuberculosis preventive treatment. Prevention by BCG vaccination is regarded as contraindications for HIV-infected patients, because disseminated M. bovis infection may be associated with them. Many HIV-positive patients infected with tuberculosis show uneventful healing, when M. tuberculosis is the sensitive strain. However, since some patients show the rapid course of tuberculosis, clinical physicians keep the early detection of tuberculosis for HIV-infected patients and the association of HIV infection for tuberculosis patients in their mind, respectively.
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PMID:[HIV infection and tuberculosis]. 1265 6

In a transgenic model of multi-stage squamous carcinogenesis induced by human papillomavirus (HPV) oncogenes, infiltrating CD4+ T cells can be detected in both premalignant and malignant lesions. The lymph nodes that drain sites of epidermal neoplasia contain activated CD4+ T cells predominantly reactive toward Staphylococcal bacterial antigens. HPV16 mice deficient in CD4+ T cells were found to have delayed neoplastic progression and a lower incidence of tumors. This delay in carcinogenesis is marked by decreased infiltration of neutrophils, and reduced activity of matrix metalloproteinase-9, an important cofactor for tumor progression in this model. The data reveal an unexpected capability of CD4 T cells, whereby, proinflammatory CD4+ T cells, apparently responding to bacterial infection of dysplastic skin lesions, can inadvertently enhance neoplastic progression to invasive cancer.
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PMID:Immune enhancement of skin carcinogenesis by CD4+ T cells. 1269 93

Dendritic cells (DCs) present microbial antigens to T cells and provide inflammatory signals that modulate T cell differentiation. While the role of DCs in adaptive immunity is well established, their involvement in innate immune defenses is less well defined. We have identified a TNF/iNOS-producing (Tip)-DC subset in spleens of Listeria monocytogenes-infected mice that is absent from CCR2-deficient mice. The absence of Tip-DCs results in profound TNF and iNOS deficiencies and an inability to clear primary bacterial infection. CD8 and CD4 T cell responses to L. monocytogenes antigens are preserved in CCR2-deficient mice, indicating that Tip-DCs are not essential for T cell priming. Tip-DCs, as the predominant source of TNF and iNOS during L. monocytogenes infection, orchestrate and mediate innate immune defense against this intracellular bacterial pathogen.
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PMID:TNF/iNOS-producing dendritic cells mediate innate immune defense against bacterial infection. 1287 39

Rupture of follicular (epidermoid) cysts is believed to be the consequence of bacterial infection. We report a 24-year-old man with idiopathic CD4 lymphopenia and chronic Mycobacterium avium intracellulare infection who developed multiple, recurring painful abscesses over the distal extremities that increased in number and severity when systemic steroid and interferon-gamma treatment was instituted for interstitial lung disease. Cultures were consistently negative for microorganisms, but pathological examination revealed ruptured epidermoid cyst walls with human papillomavirus (HPV) viropathic changes (keratinocytes with perinuclear halos and abundant basophilic keratohyaline granules). Cutaneous examination showed numerous, widespread flat-topped papules and achromic macules over the extremities, head and neck. Nested polymerase chain reaction analysis for HPV DNA revealed that the abscess-related cyst walls harboured epidermodysplasia verruciformis (EV)-associated HPV types 20, 24, alb-7 (AY013872) and 80. His cutaneous lesions harboured HPV types 3, 8 and 80. Similar to past reports, our patient developed an EV-like eruption in the setting of immunodeficiency. In this instance, EV-associated HPV infection of the follicular infundibular epithelium or pre-existing cysts in the setting of immunodeficiency may have led to cystic growth, rupture and subsequent painful inflammation.
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PMID:Recurrent 'sterile' verrucous cyst abscesses and epidermodysplasia verruciformis-like eruption associated with idiopathic CD4 lymphopenia. 1451 Oct

The value of exfoliative urinary cytology for the diagnosis of different pathological conditions in renal transplantation is widely recognized. The method, however, has not yet gained full acceptance, mainly because identification of the different cells is not always possible by means of standard staining techniques. In view of its characteristics, flow cytometry (FC) seems to represent a consistently reliable, rapid and innovative approach for differentialing the various cells present in the urinary sediment and assessing their number. This study gives the examination result of 223 urinary specimens from 127 transplanted patients selected according to pathology. Sediment cells, collected from fresh urine samples, were washed, treated with a lysing solution, resuspended in saline solution and directly analysed in a FACSCAN cytometer. Morphological evaluation showed: a small number of cells in patients with stable renal function; a larger number of cells, with predominance of lymphocytes, during acute rejection episodes; an absolute predominance of neutrophils during bacterial infection; large-sized cellular debris in cases of post-transplant tubular necrosis; and small cell debris in cases of cyclosporine cytotoxicity. Lymphocyte surface-marker evaluation made it possible to differentiate lymphocyte populations observed during acute rejection episodes (cytotoxic T-cell, CD8 and HLA class II and NK cells) from those detected during bacterial infection (T-cell CD4 positive). These results suggest that urinary FC may be a reliable diagnostic tool in clinical renal transplantation.
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PMID:Flow cytometry evaluation of urinary sediment in renal transplantation. 1462 19

Diesel exhaust particles (DEP) have been shown to alter pulmonary immune responses to bacterial infection. Exposure of rats to 100 mg/m(3) DEP for 4 h was found to aggravate Listeria monocytogenes(Listeria) infection at 3 days postinfection, but the bacteria were largely cleared at 7 days postinfection due to the development of a strong T cell-mediated immunity. In the present study, we examined the effects of repeated DEP exposure at lower doses on pulmonary responses to bacterial infection. Brown Norway rats were exposed to DEP by inhalation at 20.62 +/- 1.31 mg/m 3 for 4 h/day for 5 days, followed by intratracheal inoculation with 100,000 Listeria at 2 h after the last DEP exposure. DEP-exposed rats showed a significant increase in lung bacterial load at both 3 and 7 days postinfection. The repeated DEP exposure was shown to suppress both the innate, orchestrated by alveolar macrophages (AM), and T cell-mediated responses to Listeria. DEP inhibited AM production of interleukin- (IL-) 1beta, tumor necrosis factor- (TNF-) alpha, and IL-12 but enhanced Listeria-induced AM production of IL-10, which has been shown to prolong the survival of intracellular pathogens such as Listeria. DEP exposure also suppressed the development of bacteria-specific lymphocytes from lung-draining lymph nodes, as indicated by the decreased numbers of T lymphocytes and their CD4(+) and CD8(+) subsets. Furthermore, the DEP exposure markedly inhibited the Listeria-induced lymphocyte secretion of IL-2 at day 7, IL-10 at days 3 and 7, and interferon- (IFN-) gamma at days 3 to 10 postinfection when compared to air-exposed controls. These results show a sustained pattern of downregulation of T cell-mediated immune responses by repeated low-dose DEP exposure, which is different from the results of a single high-dose exposure where the acute effect of DEP aggravated bacteria infection but triggered a strong T cell-mediated immunity.
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PMID:Suppression of cell-mediated immune responses to listeria infection by repeated exposure to diesel exhaust particles in brown Norway rats. 1465 13

The detection and characterization of antigen-specific T cell populations is critical for understanding the development and physiology of the immune system and its responses in health and disease. We have developed and tested a method that uses arrays of peptide-MHC complexes for the rapid identification, isolation, activation, and characterization of multiple antigen-specific populations of T cells. CD4(+) or CD8(+) lymphocytes can be captured in accordance with their ligand specificity using an array of peptide-MHC complexes printed on a film-coated glass surface. We have characterized the specificity and sensitivity of a peptide-MHC array using labeled lymphocytes from T cell receptor transgenic mice. In addition, we were able to use the array to detect a rare population of antigen-specific T cells following vaccination of a normal mouse. This approach should be useful for epitope discovery, as well as for characterization and analysis of multiple epitope-specific T cell populations during immune responses associated with viral and bacterial infection, cancer, autoimmunity, and vaccination.
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PMID:Detection and characterization of cellular immune responses using peptide-MHC microarrays. 1469 37

CD4 T cells are important for development of long-term immunity to bacterial infections. Here we describe construction of a group A streptococcus (GAS) strain that expresses the model ovalbumin epitope (OVA) on its surface, and the use of this strain in adoptive transfer experiments to study CD4 T cell response to bacterial infection in nasal-associated lymphoid tissue (NALT), which was previously shown to be a specific target for GAS colonization. The OVA(+) GAS, but not the wild-type strain was shown to activate CD4 T cells in an antigen-specific manner both in vitro and in vivo. After intranasal infection of mice with this strain, OVA-specific CD4 T cells were first activated in NALT, which is functionally equivalent to human tonsils, rather than in the cervical lymph nodes. During localized infection, OVA(+) GAS induced rapid and prolonged activation of CD4 T cells at higher magnitudes in the NALT than in draining lymph nodes and spleen, where CD4 T cells underwent little or no activation. In contrast, systemic infection induced significantly higher activation of CD4 T cells in both lymph nodes and spleens, compared to when the infection was localized in NALT. Further investigation of cellular immune responses in NALT during GAS infection using adoptive T cell transfer, combined with the model antigen on the pathogen may ultimately shed light on mechanisms for failure of children to develop protective immune responses following streptococcal tonsillitis.
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PMID:Primary induction of CD4 T cell responses in nasal associated lymphoid tissue during group A streptococcal infection. 1536 1

Transplantation of hands in humans has become an accepted therapeutic modality. A hand transplant is composed of various tissues of different degree of immunogenicity. In addition, skin contains own resident bacterial flora that may become virulent in the ischemic and rejecting graft. Discrimination between skin rejection and bacterial inflammation is difficult. The aim of our experimental study was to investigate the cellular reaction to skin bacteria and alloantigen in the regional lymph nodes draining skin and analyse the changes in cell phenotypes. The study was carried out on rats inoculated into hind-limb paw either with S. epidermidis or allogeneic peripheral blood mononuclear cells. An increase in lymph node weight and cell concentration was observed after bacterial infection. After stimulation with allogeneic cells, node mass increased significantly but its cell number rose much less. The percentage of lymph node W3/13 (leukocytes, T cells), W3/25 (CD4), OX8 (CD8), OX6 (class II), OX12 (B cells), EDI (CD14), CD31 (lymphocytes), OX7 (stem cells), and OX62 (migrating dendritic) cells did not change in both groups compared to controls. There was a significant rise of the CD54 (ICAM I) subset after bacterial infection and increase in percentage of OX8-cytotoxic and decrease of W3/25 (helper) subset after allogeneic stimulation. Lack of major differences between stimulated and control contralateral nodes may be explained by systemic reaction to the tested antigens affecting also nodes on the non-injected side. Comparison of the reaction of bacteria and alloantigen stimulated nodes revealed an increase in percentage of OX6, OX12, CD31, CD54, OX33 and OX62 after infection with S. epidermidis, whereas allostimulation brought about only rise in T (W3/13) cell population. Neither stimulation caused increase in expression of class II antigens on T cells. The obtained results demonstrate evident differences in type of response to bacteria and alloantigens. To what extent can bacterial stimulation enhance allogeneic reaction is now under study. Our data are helpful in understanding differences in the character and kinetics of reaction to both types of antigens and may taken into consideration when planning therapy in recipients of hand allografts, immunosuppressive drugs or antibiotics.
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PMID:The reaction of the regional lymph nodes on the skin bacterial and allogeneic antigens. 1588 40

CD4 and CD8 T cells have been shown to proliferate and differentiate to different extents following antigenic stimulation. CD4 T cells form a heterogenous pool of effector cells in various stages of division and differentiation, while nearly all responding CD8 T cells divide and differentiate to the same extent. We examined CD4 and CD8 T cell responses during bacterial infection by adoptive transfer of CFSE-labeled monoclonal and polyclonal T cells. Monoclonal and polyclonal CD8 T cells both divided extensively, whereas monoclonal CD4 T cells underwent limited division in comparison with polyclonal CD4 T cells. Titration studies revealed that the limited proliferation of transferred monoclonal CD4 T cells was due to inhibition by a high precursor frequency of clonal T cells. This unusually high precursor frequency of clonal CD4 T cells also inhibited the differentiation of these cells. These results suggest that the adoptive transfer of TCR transgenic CD4 T cells significantly underestimates the extent of proliferation and differentiation of CD4 T cells following infection.
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PMID:Clonal competition inhibits the proliferation and differentiation of adoptively transferred TCR transgenic CD4 T cells in response to infection. 1649 62


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