Biomedical subjects

N Nitz

Publications and source records attributed to N Nitz.

5 recordsLinked to original sources

PubMed2006

Chagas disease.

Chagas disease is the clinical condition triggered by infection with the protozoan Trypanosoma cruzi. The infection is transmitted by triatomine insects while blood feeding on a human host. Field studies predict that one third of an estimated 18 million T cruzi-infected humans in Latin America will die of Chagas disease. Acute infections are usually asymptomatic, but the ensuing chronic T cruzi infections have been associated with high ratios of morbidity and mortality: Chagas heart disease leads to unexpected death in 37.5% of patients, 58% develop heart failure and die and megacolon or megaoesophagus has been associated with death in 4.5%. The pathogenesis of Chagas disease appears to be related to a parasite-induced mutation of the vertebrate genome. Currently, treatment is unsatisfactory.

Acute Disease↗

PubMed1999

The role of depression in the association between self-rated physical health and clinically defined illness.

We enrolled 543 elderly participants of a managed care organization in a cross-sectional study to test whether the association between self-rated physical health and clinically defined illness differs for persons who are not depressed compared with persons with minor or serious depression. Depression was measured with the Diagnostic Interview Schedule (DIS). Clinically defined illness was measured with the Chronic Disease Score (CDS), a pharmacy-based measure. Additional variables included age, sex, and self-reported pain and physical function. Self-rated physical health was associated with both minor and serious depression, independent of clinically defined illness; minor depression was no longer significant when self-reported pain and physical function were added to the model. A significant negative correlation between self-rated physical health and clinically defined illness was observed for minor and no depression, but no correlation was seen for serious depression. These results confirm the association between depression and self-rated physical health and emphasize that, for persons with serious depression, self-rated health provides a less accurate picture of clinically defined illness at both ends of the spectrum. Also, a diagnosis of minor depression should not forestall investigation of inconsistencies between patient report and clinical evidence.

Aged↗

PubMed1999

Integration of Trypanosoma cruzi kDNA minicircle sequence in the host genome may be associated with autoimmune serum factors in Chagas disease patients.

Integration of kDNA sequences within the genome of the host cell shown by PCR amplification with primers to the conserved Trypanosoma cruzi kDNA minicircle sequence was confirmed by Southern hybridization with specific probes. The cells containing the integrated kDNA sequences were then perpetuated as transfected macrophage subclonal lines. The kDNA transfected macrophages expressed membrane antigens that were recognized by antibodies in a panel of sera from ten patients with chronic Chagas disease. These antigens barely expressed in the membrane of uninfected, control macrophage clonal lines were recognized neither by factors in the control, non-chagasic subjects nor in the chagasic sera. This finding suggests the presence of an autoimmune antibody in the chagasic sera that recognizes auto-antigens in the membrane of T. cruzi kDNA transfected macrophage subclonal lines.

Animals↗

PubMedDate not supplied

Blood-sucking lice may disseminate Trypanosoma cruzi infection in baboons.

Trypanosoma cruzi (Schyzotrypanum, Chagas, 1909), and Chagas disease are endemic in captive-reared baboons at the Southwest Foundation for Biomedical Research, San Antonio, Texas. We obtained PCR amplification products from DNA extracted from sucking lice collected from the hair and skin of T. cruzi-infected baboons, with specific nested sets of primers for the protozoan kinetoplast DNA, and nuclear DNA. These products were hybridized to their complementary internal sequences. Selected sequences were cloned and sequencing established the presence of T. cruzi nuclear DNA, and minicircle kDNA. Competitive PCR with a kDNA set of primers determined the quantity of approximately 23.9 +/- 18.2 T. cruzi per louse. This finding suggests that the louse may be a vector incidentally contributing to the dissemination of T. cruzi infection in the baboon colony.

Animals↗

PubMedDate not supplied

Progressive chronic Chagas heart disease ten years after treatment with anti-Trypanosoma cruzi nitroderivatives.

A randomized ten-year follow-up study involving 91 Chagas patients and 41 uninfected controls was undertaken to determine the effectiveness of nitroderivative therapy. Anti-Trypanosoma cruzi antibodies were consistently lower one year after treatment than 10 years thereafter (P < 0.001). The blood of all treated and 93.7% of untreated Chagas patients yielded polymerase chain reaction (PCR) product from probes annealing to T. cruzi nuclear DNA, indicating active infection. Competitive PCR showed means +/- standard deviations of 20.1+/-22.6 T. cruzi/ml of blood from untreated and 13.8+/-14.9 from treated Chagas patients, but the differences between means were not statistically significant (P > 0.05). Electrocardiograms recorded a gamut of alterations several-fold more frequent in Chagas patients, regardless of treatment, than in uninfected controls (P < 0.001). These results show that nitroderivative therapy for T. cruzi infections is unsatisfactory and cannot be recommended since it fails to eradicate the parasite or change the progression of heart disease in chronic Chagas patients.

Adult↗