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Biomedical subjects

I N de Kantor

Publications and source records attributed to I N de Kantor.

At least 19 recordsLinked to original sources
PubMed1998

[Resistance and multiresistance to antitubercular drugs in Argentina and in other Latin American countries].

Resistance of Mycobacterium tuberculosis to both isoniazid (INH) and rifampicin (RPM), the most important antituberculosis drugs, with or without simultaneous resistance to other drugs, is known as multidrug resistance (MDR). It is the main obstacle to attain the cure of patients by the specific treatment, and a threat to the tuberculosis control. Between 1994 and 1997, several Latin American countries undertook countrywide surveys or surveillance programs to determine their primary and acquired drug resistance prevalence rates. These studies followed the WHO/International Union Against Tuberculosis and Lung Diseases (IUATLD) guidelines. Percentages of not previously treated patients with tuberculosis due to MDR strains ranged from null or very small (Uruguay, Cuba, Chile) to 4% or higher (Dominican Republic, Argentina). In Argentina, a remarkable correlation between MDR tuberculosis, AIDS and the assistance in urban reference hospitals for infections diseases was observed. Coincidentally with the survey, nosocomial spread of HIV-related MDR tuberculosis occurred in two of these hospitals situated in Buenos Aires and Rosario. But, at the same time, an alarming emergence of MDR was evidenced among non HIV-infected patients with history of previous antituberculosis treatment. Directly observed treatment (DOT) should be increasingly applied, and drug supply guaranteed. Treatment as well as microscopy services for diagnosis and follow up of patients, should be decentralized from the big specialized hospitals in urban areas to the peripheral health centers, in order to make easier for the patients to attend regularly and receive their medications. These strategies will contribute to increase cure rates and to reduce the tuberculosis transmission.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Nosocomial spread of human immunodeficiency virus-related multidrug-resistant tuberculosis in Buenos Aires.

A steep upsurge of human immunodeficiency virus (HIV)-associated multidrug-resistant tuberculosis (MDR-TB) was recently observed at a referral treatment center in Buenos Aires City. Between January 1994 and June 1995, TB isolates resistant to at least five drugs were recovered from 101 of 272 HIV-infected inpatients. Highly resistant isolates from 77 patients underwent restriction fragment length polymorphism study with IS6110. After cross-contamination was eliminated, a single TB strain was found to have caused disease in 68 patients with a history of on-site exposure. The frequency of smear-positive pulmonary disease was higher among these patients than among non-MDR-TB HIV-infected patients (50/68 vs. 60/148, P < .001), and the 1-year survival was dramatically reduced (5/68 vs. 92/148). The strain involved in the outbreak was traced back to patients hospitalized in 1992. Institutional infection control policies were and may still be inadequate to contain the spread of TB among immunodepressed subjects, as is the case in other large urban hospitals in Argentina.

AIDS-Related Opportunistic Infections↗
PubMed1996

Multidrug resistant tuberculosis outbreak in Buenos Aires. DNA fingerprinting analysis of isolates.

In order to determine the possible relationship among HIV patients coinfected with multidrug resistant tuberculosis strains who had been receiving clinical assistance in our Hospital, clinical and epidemiological information from 28 patients was collected. DNA fingerprinting by restriction fragment length polymorphism (RFLP) pattern was performed on the mycobacterial isolates from these patients, using the restriction enzyme Pvull and IS 6110 as genetic marker. A unique RFLP pattern was found in 10 isolates from 10 different patients who had a disease caused by a single strain. Our findings confirm RFLP as a reliable and useful tool to analyze TB transmission.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Bovine tuberculosis in Latin America and the Caribbean: current status, control and eradication programs.

Out of the approximately 300 million head which constitute the bovine population in Latin America and the Caribbean, 80 million are found in countries where rates of Mycobacterium bovis infection are very low or nil. The remaining 220 million are found in countries with either a moderate to high prevalence or where no recent information is available. Argentina and Brazil, both have huge cattle populations with estimated prevalences higher than 1%, and together may harbour 3.5 million infected cattle. Information on the impact of M. bovis on human health in the Region is scarce and does not include data on infection of children. In Argentina, human tuberculosis of bovine origin was found to be mainly an occupational disease, transmitted by aerosol. Control or eradication has been achieved in several countries in the Region by use of the tuberculin test followed by sacrifice of reactors. In countries such as Cuba, where the prevalence is already very low, area tuberculin testing is being replaced by slaughter surveillance and epidemiological trace-back. Other countries, where the prevalence is high (e.g. Chile, Paraguay, Peru and Argentina), promote regional campaigns based on the decision and active participation of cattle farmers. Recent diagnostic developments based on the in vitro measurement of humoral and cellular immune responses could be an aid in control and eradication campaigns, provided their usefulness is demonstrated in field trials. In heavily infected areas complementary or alternative strategies should also be proposed, aiming at lowering the prevalence rates prior to the application of the test and slaughter method.

Animals↗
PubMed1994

A random sample survey of initial drug resistance among tuberculosis cases in Latin America.

A random sample survey of initial drug resistance among cases of tuberculosis in Latin America was carried out during the second half of the 1980s and the early 1990s. A total of 948 cultures of Mycobacterium tuberculosis isolated from patients presumed never before to have been treated for tuberculosis were collected from 30 randomly selected clusters in Latin America and tested for resistance to isoniazid, streptomycin, rifampicin, ethambutol, and thioacetazone. Initial drug resistance, although unevenly distributed, was detected in all the clusters tested and characterized one out of every six tuberculosis cases. Both single and multiple resistance to streptomycin and to isoniazid were the most prevalent forms throughout the region but were not sufficiently frequent to jeopardize significantly the outcome of short-course chemotherapy. However, localized pockets of high drug resistance occurred throughout the region and are cause for concern, especially in the case of rifampicin.

Antitubercular Agents↗
PubMed1994

[Humoral response to mycobacteria in patients with Crohn disease].

The recent recovery of Mycobacterium paratuberculosis from tissues of patients with Crohn's disease has highlighted the possible etiologic role of this microorganism in the disease. However, the immunological evidence generated by various groups supporting this hypothesis is as yet inconclusive. A specific antibody response might be masked in these patients by the wide antigenic homologies prevailing within the genus Mycobacterium. The present study was undertaken with the purpose of exploring the humoral response to M. paratuberculosis in patients with Crohn's disease, by means of a cross-absorption procedure recently proposed for unveiling the presence of specific antibodies in bovine paratuberculosis. Antibodies IgG to M. paratuberculosis were investigated by enzyme-linked immunosorbent assay in 90 serum samples from 17 patients with Crohn's disease, 23 patients with ulcerative colitis an 14 with other bowel diseases. Samples from 86 subjects without bowel disease (healthy individuals and patients with tuberculosis, mycobacterioses and fungal diseases) were also included as controls. The specificity of these antibodies was explored by the absorption of sera with an ubiquitous Mycobacterium (M. phlei). The results were compared to those obtained by similar ELISA tests employing M. avium or M. tuberculosis as antigens. A faint humoral response to M. paratuberculosis and M. tuberculosis was detected in patients with Crohn's disease. Cross-absorption with M. phlei did not disclose a specific response nor was an increase in antibody levels detected in patients studied periodically. Sera from patients with ulcerative colitis and other bowel diseases also showed a slight reaction to mycobacteria.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Preliminary evaluation of a simple method for detection of bovine tuberculosis: the glutaraldehyde test.

The glutaraldehyde test (GT) is performed by mixing whole blood with a 1.25% glutaraldehyde solution. Gelification time is shorter in tuberculous cattle. This test was performed in blood samples obtained from: (a) 48 cattle with bacteriologically confirmed tuberculous lesions; (b) 61 animals with no evidence of tuberculosis at the time of slaughterhouse inspection, 14 of which had hydatid cysts; (c) 260 tuberculin-negative apparently healthy animals, and (d) 21 cattle, also tuberculin-negative but serologically positive for brucellosis. Sensitivity for detecting tuberculosis was 85.4% (41 of 48 animals). The test was negative in 298 out of 307 healthy animals (97.1% specificity). This specificity decreased when the test was applied in animals with evidence of diseases other than tuberculosis. This simple, rapid and inexpensive method could play a complementary role to the tuberculin test for detecting tuberculous cattle, especially in endemic areas with scarce resources and facilities.

Animals↗
PubMed1992

Evaluation of synthetic pseudo cord-factor-like glycolipids for the serodiagnosis of tuberculosis.

A number of glycolipids were evaluated in an ELISA test for their serodiagnostic usefulness in tuberculosis. One hundred and twelve (112) sera belonging to bacteriologically confirmed TB patients, patients with pathologies other than tuberculosis and healthy individuals were examined against several synthetic "mirror" pseudo cord factors (analogues of trehalose-6,6'-dimycolate or TDM) using natural cord factor and another recently described natural glycolipid (SL-IV) of Mycobacterium tuberculosis as control antigens. Analysis of the results shows that all synthetic "mirror" pseudo cord factors, except one with a short 8-carbon chain, were better recognized by the sera of tuberculosis patients than natural cord factor, with sensitivity and specificity values in the ELISA test similar to those reported for M. tuberculosis species-specific SL-IV. Of all antigens tested in this study, BDA. TDA, a bis(N,N-dioctadecylamide) of "trehalose dicarboxylic acid", [(alpha-D-glucopyranosyluronic acid) (alpha-D-glucopyranosiduranic acid)], showed the highest serodiagnostic discriminating power (93% sensitivity and specificity). We postulate that either these artificial molecules are cross-reactants of similarly structured native glycolipids of M. tuberculosis or that they bear closer resemblance to actual phagosome-lysosome-modified antigens than to native mycobacterial ones.

Cord Factors↗