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G Maartens

Publications and source records attributed to G Maartens.

8 recordsLinked to original sources
PubMed1992

A comparative study of the polymerase chain reaction and conventional procedures for the diagnosis of tuberculous pleural effusion.

Preliminary reports by ourselves and others suggest that amplification of mycobacterial DNA by the polymerase chain reaction (PCR) is a sensitive and rapid diagnostic test for tuberculosis. We recently described a PCR assay with a 336 bp repetitive sequence specific for Mycobacterium tuberculosis as the DNA target, which gave encouraging results in culture-positive smear-negative clinical specimens. In the present prospective study of patients with pleural effusions we compared PCR of the pleural fluid with conventional procedures. 84 adult patients with pleural effusions were divided into 4 groups. In group A (44 patients), M. tuberculosis was detected by culture of pleural fluid, pleural biopsy or extrapleural source. In group B (6 patients), tuberculous infection was confirmed by histology (group A excluded). Group C (3 patients) had clinical evidence of tuberculosis. Group D (31 patients) had no evidence of active M. tuberculosis infection. Analysis of the pleural fluid confirmed a sensitivity for PCR of 81%. The sensitivity of pleural fluid culture, culture of pleural biopsy, and histology of biopsy was 52.8%, 69.8% and 77.3% respectively. There were however 7 PCR positive results within group D; 6 of these were in patients with malignant effusions. We conclude that for the diagnosis of M. tuberculosis PCR is more sensitive than laboratory culture as determined by the analysis of pleural fluids. Positive PCR results among patients with malignant effusions may be false-positives or the result of latent tuberculous infections. PCR should remain an investigational procedure until prospective studies in high and low prevalence areas have critically evaluated the specificity of the assay.

Adult↗
PubMed1992

Cytolytic T-cell activity against mycobacterial antigens in HIV.

OBJECTIVES: The declining incidence of tuberculosis (TB) in developed countries has recently been reversed with the advent of HIV disease. This study proposes to document in vitro T-cell responses to mycobacterial antigens in HIV-infected individuals. DESIGN: T-cell-mediated immunity is recognized as one of the mechanisms of defence against TB. The cellular immunodeficiency and the importance of TB in the context of HIV disease has prompted use of in vitro assays of lymphocyte proliferation and cytolytic activity. METHODS: Peripheral blood mononuclear cells isolated from 29 HIV-infected patients (four with recent TB) and 11 healthy volunteers were stimulated with purified protein derivative (PPD). The responding blasts were presented to autologous antigen-primed macrophages to measure specific cytolytic T-lymphocyte (CTL) activity in vitro. RESULTS: T-cell proliferative responses were significantly lower in late stages of HIV disease. The degree of specific CTL activity was higher in healthy individuals than in Centers for Disease Control (CDC) stage II-III (P = 0.037), and CDC stage IV patients (P = 0.029). CONCLUSIONS: The clinical presentation of TB tends to be typical in early stages of HIV disease and atypical in late stages. The manifestations reflect the degree of immunodepression. This study documents the declining proliferative and cytolytic T-cell-mediated responses in HIV patients with progression of immunodeficiency.

Adolescent↗
PubMed1992

T-lymphocyte responses to Pneumocystis carinii in healthy and HIV-positive individuals.

Pneumocystis carinii pneumonia (PCP) is a well-recognized cause of morbidity in patients with impaired T-cell function. In this study of cellular immunity to P. carinii, peripheral blood mononuclear cells from 25 HIV antibody-positive (HIV+) patients and 11 healthy individuals were stimulated in vitro with P. carinii antigen. The responding T-cell blasts were cocultured with autologous P. carinii antigen-pulsed macrophages to measure P. carinii-specific cytolytic T-lymphocyte activity (CTL). T-cell blasts from two healthy donors were used to generate P. carinii-specific clones by limiting dilution. T cells from HIV+ patients proliferated less to P. carinii antigen than T cells from healthy volunteers. In contrast, the level of specific cytotoxicity was identical in all groups when equal numbers of CTLs were used. Within the group of symptomatic patients, CTL activity was higher in those with a history of PCP (p = 0.033). Pneumocystis carinii antigen-specific T-cell clones proved to be CD4+ and MHC class II restricted; six of eight clones tested showed P. carinii-specific cytolytic activity. Cell-mediated immune response to P. carinii in healthy individuals include CD4+, class II MHC-restricted T cells with P. carinii-specific cytotoxicity. There is an increasing loss of P. carinii-specific proliferative responses in HIV+ patients as disease progresses, but a cytotoxic response is still detected in the absence of proliferation.

Adolescent↗
PubMed1991

The clinical presentation and diagnosis of invasive fungal infections.

The frequency of invasive fungal infections is increasing owing to the increasing numbers and improved survival of immuno-compromised patients. The fungi responsible for these infections are predominantly opportunistic pathogens. The clinical features and diagnosis of the four commonest infections (invasive candidosis and aspergillosis, cryptococcosis and mucormycosis) are discussed. Particular emphasis is given to the identification of risk factors for these infections, which are different for each disease. As these organisms are common contaminants or commensals, definitive diagnosis requires culture from sites that are normally sterile or histological demonstration of tissue invasion. Definitive diagnosis is not always possible, in part owing to the severe nature of patients' underlying illnesses. A high proportion of cases are diagnosed post mortem because of difficulties in establishing a diagnosis. Clinical diagnoses thus need to be made early in the course of these infections, but a high index of suspicion and knowledge of the clinical manifestations are required.

Animals↗
PubMed1991

Tuberculous pleural effusions: increased culture yield with bedside inoculation of pleural fluid and poor diagnostic value of adenosine deaminase.

A prospective study of 111 adult patients with a pleural effusion was carried out in an area with a high prevalence of tuberculosis to compare the yield of bedside with laboratory inoculation of pleural fluid, and the yield and speed of a radiometric mycobacterial culture system (BACTEC) with that of conventional culture. The use of adenosine deaminase activity in pleural fluid as a diagnostic test for tuberculosis was also evaluated. In the 62 cases of tuberculosis confirmed histologically or by culture, or both, the BACTEC system had the same culture yield as conventional mycobacterial culture (positive in 14 cases-23%), but was significantly faster (18 versus 33 days). Bedside inoculation had a culture yield significantly higher than laboratory inoculation in the 24 patients tested (11 versus four). The remaining three diagnostic categories were malignant (28), miscellaneous (10), and undiagnosed (11). Median adenosine deaminase activity was significantly higher in tuberculous effusions than in any of the other categories, but there was considerable overlap between the groups. It is concluded that the BACTEC system is significantly faster than conventional mycobacterial culture and that bedside inoculation of pleural fluid substantially increases culture yield. Adenosine deaminase does not provide as valuable a diagnostic test of pleural tuberculosis as has been suggested.

Adenosine Deaminase↗
PubMed1990

Miliary tuberculosis: rapid diagnosis, hematologic abnormalities, and outcome in 109 treated adults.

PURPOSE: The purpose of this study was to determine the clinical and laboratory characteristics, diagnostic methods, and prognostic variables in adults treated for miliary tuberculosis in the rifampicin era. PATIENTS AND METHODS: Computerized records of our community-based university teaching hospital over a 10-year period (1978 to 1987) were analyzed. A total of 109 patients were identified, including 12 who did not have miliary nodules on the chest radiograph (all of whom were shown to have hematogenous dissemination). Predisposing conditions were present in 46 patients. RESULTS: Clinical features were similar to those of previously reported series. Hematologic abnormalities were common: leukopenia (less than 4 x 10(9)/L) was present in 16 of 107 patients (15%), thrombocytopenia (less than 150 x 10(9)/L) in 24 of 104 (23%), and lymphopenia (less than 1.5 x 10(9)/L) in 82 of 94 (87%). Pancytopenia was found in six patients, three of whom recovered. Disseminated intravascular coagulation occurred in four patients, all of whom died. Adenosine deaminase levels were elevated in only seven of 11 serosal exudates and in seven of 12 samples of abnormal cerebrospinal fluid. Fiberoptic bronchoscopy was diagnostic in 44 of 51 patients (86%), bone marrow examination in 19 of 22 (86%), and liver biopsy in all 10 patients. Twenty-six patients (24%) died of miliary tuberculosis a median of 6 days after starting treatment. Survivors were followed up for a median of 51 weeks. Stepwise logistic regression identified aged (greater than 60 years), lymphopenia, thrombocytopenia, hypoalbuminemia, elevated transaminase levels, and treatment delay as independent predictors of mortality. CONCLUSIONS: Miliary tuberculosis commonly causes hematologic derangements, some of which are helpful prognostically. Fiberoptic bronchoscopy compares favorably to liver and bone marrow biopsy in sputum smear-negative cases. Mortality remains high and treatment should be begun as soon as the diagnosis is suspected.

Adolescent↗
PubMed1986

Syncope in the elderly. Report of 3 cases with sick sinus syndrome.

Three cases of arrhythmia-induced syncope in the elderly are reported. The patients all showed some features of the sick sinus syndrome and had aortic ejection murmurs. Ventricular tachycardia occurred in 2 patients. The importance of trying to record an arrhythmia during a syncopal attack is stressed, as are the adverse effects of many drugs commonly prescribed in this age group. The relationship between the arrhythmias found and their association with aortic stenosis are discussed.

Aged↗