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Results for “complex diseases”

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At least 523 records · Page 29Linked to original sources
PubMed1996

Fatal Mycobacterium avium complex disease in a patient with acute nonlymphoblastic leukemia.

PURPOSE: The objective of this article was to present the diagnosis of a fatal infection by Mycobacterium avium complex (MAC) in a child with acute myelogenous leukemia, a disease rarely reported in non-HIV infected children. METHODS: Specific identification of MAC was made by culture in BACTEC system from an open lung biopsy. RESULTS: A 5-year-old girl diagnosed with acute nonlymphoblastic leukemia was admitted because of fever during the maintenance phase after achieving a complete remission of her malignancy. A mild dry cough started on day 4 of admission, and a chest roentgenogram revealed a pulmonary infiltrate. An insidious respiratory distress developed and mechanical ventilation was undertaken. An open-lung biopsy, carried out on day 10 of ventilatory support, revealed acid-fast bacilli subsequently grown as MAC. In spite of combined antimycobacterial treatment, the patient followed a downhill course and died on day 41 of hospitalization. CONCLUSION: This report describes a new case of fatal MAC infection in an immunocompromised, non-HIV infected child. MAC must be added to the list of infectious microorganisms that can infect children with acute nonlymphoblastic leukemia. As modern immunosuppressive therapeutic modalities evolve, it is likely that MAC will become a more common and recognized pathogen in the immunocompromised child.

Child, Preschool↗
PubMed2000

Prevalence of coronary artery disease, complex ventricular arrhythmias, and silent myocardial ischemia and incidence of new coronary events in older persons with chronic renal insufficiency and with normal renal function.

In a prospective study of 98 persons > or = 65 years of age with chronic renal insufficiency (serum creatinine > 3.0 mg/dl) for > 1 year and 98 age- and sex-matched persons with normal renal function (serum creatinine < or = 1.2 mg/dl), new coronary events developed at 23-month follow-up in 69 persons (70%) with chronic renal insufficiency and at 48-month follow-up in 24 persons (24%) with normal renal function (p < 0.0001). Significant independent risk factors for new coronary events were age (risk ratio 1.1), prior coronary artery disease (risk ratio 3.5), complex ventricular arrhythmias diagnosed by 24-hour ambulatory electrocardiography (risk ratio 2.5), silent myocardial ischemia diagnosed by 24-hour ambulatory electrocardiography (risk ratio 1.9), and chronic renal insufficiency (risk ratio 3.4).

Aged↗
PubMed2001

The gastro-oesophageal reflux disease complex in sub-Saharan Africa.

Epidemiological and clinical studies that have reported on gastro-oesophageal reflux disease (GERD), Barrett's oesophagus, oesophageal adenocarcinoma and Helicobacter pylori infection in sub-Saharan Africa were reviewed. The data indicate that Barrett's oesophagus is rare and oesophageal adenocarcinoma uncommon in all regions of sub-Saharan Africa studied (South Africa, Ethiopia, Nigeria, Zimbabwe, Kenya and Uganda). Hiatus hernia is also uncommon. There are too few reports of GERD to allow comment. The overwhelming majority of oesophageal cancers are squamous cell type. H. pylori infection is ubiquitous with an overall prevalence of 61-100%. It is concluded that although urbanization has resulted in an increase of risk factors associated with GERD, which would be expected to lead to an increase in this disease among Africans, this increase has not happened. It is believed that the critical factor preventing GERD in black Africans is H. pylori infection, which is usually acquired in childhood, is lifelong and is probably protective for the oesophagus.

Adenocarcinoma↗
PubMed1991

In vitro antimicrobial susceptibility of Pasteurella haemolytica and Pasteurella multocida recovered from cattle with bovine respiratory disease complex.

The antimicrobial susceptibilities of 421 Pasteurella haemolytica and 158 P. multocida isolates recovered from cattle with respiratory disease were determined with a microdilution minimal inhibitory concentration test system. Isolates were analyzed for patterns of resistance to ampicillin, ceftiofur, erythromycin, gentamicin, penicillin, spectinomycin, sulfachlorpyridazine, sulfadimethoxine, tetracycline, and tylosin. All isolates tested were found susceptible to ceftiofur and sulfachlorpyridazine. Pasteurella haemolytica isolates were resistant to ampicillin, penicillin, sulfadimethoxine, tetracycline, and tylosin. Pasteurella multocida isolates were resistant to sulfadimethoxine, tetracycline, and tylosin.

Animals↗
PubMed1995

Comparison of multiple drug therapy regimens for HIV-related disseminated Mycobacterium avium complex disease.

In June 1993, the United States Public Health Service (USPHS) made recommendations for treatment of disseminated Mycobacterium avium complex (MAC) in patients infected with the human immunodeficiency syndrome (HIV). It was suggested that every treatment regimen include either azithromycin or clarithromycin plus one or more of the following drugs: ethambutol, clofazimine, rifabutin, rifampin, ciprofloxacin, or amikacin. This study compares the effect of multiple drug therapy regimens on the survival of patients of the HIV outpatient department of the Medical Center of New Orleans, Louisiana. A retrospective chart review of 122 confirmed cases of MAC was conducted. Three treatment groups were considered: no/monotreatment (n = 40), multitreatment without clarithromycin (n = 32), and multitreatment with clarithromycin (n = 50). Azithromycin, amikacin, and rifabutin were not used in this clinic during the study period. Both multitreatment without clarithromycin (p < 0.03) and multitreatment with clarithromycin (p < 0.005) were significantly protective for survival after adjusting for CD4 cell count at time of diagnosis, nonadherence to treatment, number of concomitant opportunistic infections at diagnosis, and weight loss > 10%. Neither of the groups that received multidrug therapy were significantly less likely to have MAC-related symptoms than the no/mono group at 3 and 6 months postdiagnosis. These findings support the USPHS recommendation for multiple drug treatment either with or without clarithromycin. Prospective controlled clinical trials will clarify the optimal regimen for disseminated MAC disease.

AIDS-Related Opportunistic Infections↗
PubMed2000

Genetic association studies in complex diseases.

Genetic association studies are the most frequent type of study performed in the investigation of the genetic basis of complex cardiovascular conditions. While relatively easy to perform, and having previously correctly identified genetic effects subsequently proven to be due to genetic linkage, interpretation of the results of these studies is not always straightforward. Issues such as population stratification, data-driven subgroup analysis, possible absence of linkage disequilibrium between marker and disease locus, and testing of multiple hypotheses are discussed and the likely place for association studies in a strategy involving studies of a variety of designs geared to finding genetic determinants of disease susceptibility is addressed. Journal of Human Hypertension (2000) 14, 361-367

Clinical Trials as Topic↗
PubMed2006

Systematic re-examination of carriers of balanced reciprocal translocations: a strategy to search for candidate regions for common and complex diseases.

Balanced reciprocal translocations associated with genetic disorders have facilitated the identification of a variety of genes for early-onset monogenic disorders, but only rarely the genes associated with common and complex disorders. To assess the potential of chromosomal breakpoints associated with common/ complex disorders, we investigated the full spectrum of diseases in 731 carriers of balanced reciprocal translocations without known early-onset disorders in a nation-wide questionnaire-based re-examination. In 42 families, one of the breakpoints at the cytogenetic level concurred with known linkage data and/or the translocation co-segregated with the reported phenotype, for example, we found a significant linkage (lod score=2.1) of dyslexia and a co-segregating translocation with a breakpoint in a previously confirmed locus for dyslexia. Furthermore, we identified 441 instances of at least two unrelated carriers with concordant breakpoints and traits. If applied to other populations, re-examination of translocation carriers may identify additional genotype-phenotype associations, some of which may be novel and others that may coincide with and provide additional support of data presented here.

Age of Onset↗
PubMed1992

Dose-response studies in murine mercury-induced autoimmunity and immune-complex disease.

Female SJL/N mice were given either 5.0, 2.5, 1.25, or 0.625 mg mercuric chloride per liter drinking water (ppm HgCl2). Serum antinucleolar antibodies (ANuA) of the IgG class were seen in mice given at least 1.25 ppm HgCl2 for 10 weeks, a dose which corresponded to a mean renal mercury concentration, as measured with atomic absorption spectrophotometry, of 2.4 +/- 0.43 microgram Hg/g wet weight (ppm Hg; means +/- 1 SD). At a dose of 5.0 ppm HgCl2 all mice showed IgG ANuA with a mean titer of 1:846 and a mean renal mercury concentration of 14.8 +/- 3.9 ppm. Significantly increased titers of granular IgG deposits, corresponding to immune-complex (IC) deposits, developed in the renal mesangium of mice given 5.0 ppm HgCl2. Mice with heavy mesangial IgG deposits showed a mild glomerular endocapillary cell proliferation and widening of the mesangium. Renal vessel wall IgG deposits were found only in mice given 5.0 ppm HgCl2, whereas such deposits were seen in splenic and cardiac arteries of mice receiving 1.25 ppm or more of HgCl2. The renal and splenic mercury concentration was significantly increased in all groups of mercuric chloride-exposed mice and correlated with the dose. We conclude that 10 weeks peroral treatment with mercuric chloride in drinking water is able to elicit autoimmunity and IC disease in genetically homogeneous, mercury-sensitive mice at a body burden similar to that reported in some occupationally exposed humans.

Administration, Oral↗
PubMed1988

Cell surface markers and cellular immune response associated with rheumatic heart disease: complex segregation analysis.

A series of functional and cell surface markers associated with a significantly increased risk of rheumatic heart disease were analyzed for the contribution of genetic factors in their presence. Peripheral blood lymphocytes from nine large kindreds from the New Zealand Maori, Polynesian, and Caucasian populations were isolated, purified, and evaluated with lymphocyte surface markers (monoclonals 83S.19.23 and D8103), as well as studied for blastogenic response to a purified group A streptococcal extracellular product, blastogen A. Segregation analysis of blastogenic response and percent of cells positive for these cell surface markers was consistent with genetic control by single major genes; however, the contribution by polygenes varied by marker, indicating heterogeneity of genetic control of identification of cell surface glycoproteins and blastogenic response to streptococcal products.

Antibodies, Monoclonal↗
PubMed2001

Serum interleukin-6 (IL-6), IL-10, tumor necrosis factor (TNF) alpha, soluble type II TNF receptor, and transforming growth factor beta levels in human immunodeficiency virus type 1-infected individuals with Mycobacterium avium complex disease.

To characterize changes in serum cytokine levels in human immunodeficiency virus type 1 (HIV-1)-infected persons with Mycobacterium avium complex (MAC) bacteremia, the levels of IL-1alpha (interleukin-1alpha), IL-6, IL-10, tumor necrosis factor alpha (TNF-alpha), soluble type II TNF receptor (sTNF-RII), and transforming growth factor beta (TGF-beta) in serum were measured in two cohorts of HIV-1-infected persons with MAC bacteremia. The first cohort was part of a MAC prophylaxis study. Patients with bacteremia were matched with controls without bacteremia. Elevated IL-6, IL-10, TNF-alpha, sTNF-RII, and TGF-beta levels were noted at baseline for all subjects, a result consistent with advanced HIV-1 disease. IL-1alpha was not detected. No differences in cytokine levels in serum were noted at baseline and at the time of bacteremia between patients with MAC and controls. In the second cohort, subjects had serum samples collected at the time of MAC bacteremia and thereafter while on macrolide therapy. Serum samples at time of bacteremia were collected from HIV-1-infected persons at a time when neither highly active antiretroviral therapy (HAART) nor MAC prophylaxis was used routinely. MAC treatment resulted in decreased levels of IL-6 and TNF-alpha in serum, which were evident for IL-6 by 4 to 6 weeks and for TNF-alpha by 8 to 16 weeks. Thus, antibiotic treatment for MAC results in decreased levels of IL-6 and TNF-alpha in serum in HIV-1-infected persons who are not on HAART.

AIDS-Related Opportunistic Infections↗
PubMed2000

A general test of association for complex diseases with variable age of onset.

Analysis of age of onset is a key factor in linkage and association studies of some complex genetic traits. Recent methodological developments are mainly concentrated on binary or quantitative traits, in which age of onset information is ignored. We propose a linkage disequilibrium-based Cox model and a robust score test for testing association between a marker and a disease with variable age of onset. The proposed model is semi-parametric, with an unspecified baseline hazard function. Simulation results indicate that the proposed methods have correct error rates and good statistical power, even in the presence of population admixture. This approach offers a solution to the problem of testing for marker associations when there is a variable age of onset.

Age of Onset↗
PubMed2005

Clinical, microbiological, and immunological characteristics in HIV-infected subjects at risk for disseminated Mycobacterium avium complex disease: an AACTG study.

The clinical, microbiologic, and immunologic parameters in HIV-infected subjects first presenting with disseminated Mycobacterium avium complex (DMAC) were determined. Four HIV-positive groups not yet on DMAC treatment were enrolled: 19 subjects with CD4 lymphocyte counts < or =50/microl thought to have DMAC on clinical grounds; 18 subjects newly found to have a positive blood culture for MAC; 25 asymptomatic controls (CD4 cell counts < or =50); and 25 asymptomatic controls (CD4 counts 100-250/microl). Outcome measures include comparisons between groups for clinical characteristics; results of cultures from blood, marrow, and gastrointestinal and respiratory tracts; immunological markers from staining of marrow and flow cytometry of circulating lymphocytes; and cytokine production of PBMCs. Only 21% of the 19 patients entered on suspicion of having DMAC grew MAC from blood or marrow. Neither clinical presentation nor laboratory tests differentiated those culture-positive from those culture-negative patients. However, prior PCP or multiple other opportunistic infections were more common in the DMAC group. MAC was isolated from 82% of marrow and 50% of blood specimens from the DMAC group. Respiratory or gastrointestinal colonization was present in 36% of DMAC subjects, but only 5% of non-DMAC subjects with CD4 counts <50 cells/microl. CD8+ cells were more frequent in bone marrow, and CD4 cells recognizing MAC antigen were more frequent in blood from DMAC subjects vs. controls. Results suggest an early stage of tissue dissemination preceding persistent bacteremia, and mucosal entry without persistence of colonization. MAC-specific T cell responses apparently develop and persist during DMAC, but are dysfunctional or too infrequent to prevent persistence.

Adult↗
PubMed2003

The genetics of adult-onset neuropsychiatric disease: complexities and conundra?

Genetic factors play a major role in the etiology of adult-onset neurodegenerative and neuropsychiatric disorders. Several highly penetrant genes have been cloned for rare, autosomal-dominant, early-onset forms of neurodegenerative diseases. These genes have provided important insights into the mechanisms of these diseases (often altering neuronal protein processing). However, the genes associated with inherited susceptibility to late-onset neurodegenerative diseases, schizophrenia, and bipolar disorder appear to have smaller effects and are likely to interact with each other (and with nongenetic factors) to modulate susceptibility and/or disease phenotype. Several strategies have recently been applied to address this complexity, leading to the identification of a number of candidate susceptibility loci/genes.

Adult↗