Nuclear abnormalities in buccal mucosa cells of patients with type I and II diabetes treated with folic acid.

Diabetes mellitus (DM) is characterized by high blood glucose. Excessive production of free radicals may cause oxidative damage to DNA and other molecules, leading to complications of the disease. It may be possible to delay or reduce such damage by administration of antioxidants such as folic acid (FA). The objective of this study was to determine the effect of FA on nuclear abnormalities (NAs) in the oral mucosa of patients with DM. NAs (micronucleated cells, binucleated cells, pyknotic nuclei, karyorrhexis, karyolysis, abnormally condensed chromatin, and nuclear buds) were analyzed in 2000 cells from 45 healthy individuals (control group) and 55 patients with controlled or uncontrolled type I or II DM; 35 patients in the latter group were treated with FA. Samples were taken from the FA group before and after treatment. An increased rate of NAs was found in patients with DM in comparison with that of the control group (P<0.001). FA supplementation in patients with DM reduced the frequency of NAs (20.4 ± 8.0 before treatment vs. 10.5 ± 5.2 after treatment; P<0.001). The type I and type II DM and controlled and uncontrolled DM subgroups were analyzed in terms of sex, age, and smoking habit. The significantly reduced frequencies of buccal mucosa cells with micronuclei, binucleation, pyknosis, karyorrhexis, karyorrhexis+abnormally condensed chromatin, karyolysis, and nuclear buds produced by FA supplementation in DM patients (P<0.02) are consistent with the idea that free radicals are responsible for the increased frequency of NAs in DM patients.

Molecular diagnosis of Chagas' disease and use of an animal model to study parasite tropism.

Chagas' disease, which is an important health problem in humans, is caused by the protozoan Trypanosoma cruzi. The cellular and molecular mechanisms, involved in the selective tropism of T. cruzi to different organs remain largely unknown. In this study we designed a PCR-based molecular diagnosis method in order to study the tropism and growth kinetics of T. cruzi in a murine model infected with parasites isolated from an endemic area of Mexico. The growth kinetics and parasite tropism of T. cruzi were also evaluated in the blood and other tissues. We observed that T. cruzi isolates from the Western Mexico showed a major tropism to mouse heart and skeletal muscles in this murine model.

Genotype and virulence correlation within Mexican stocks of Trypanosoma cruzi isolated from patients.

Five Trypanosoma cruzi stocks were isolated from infected patients in the central state of Jalisco, Mexico. Parasites were isolated by direct inoculation of infected blood into BALB/c mice. The five stocks of T. cruzi were analyzed for in vitro growth, and for virulence and parasitic load in vivo. Furthermore, a genetic analysis based on restriction fragment length polymorphism associated with a repetitive element from the rRNA gene spacer was performed. No differences in in vitro growth or in parasitic load in vivo were found among the stocks. While three stocks showed low virulence for mice, the other two stocks killed 80 and 100% of the infected mice. In addition, Southern blot of total DNA hybridized with a repetitive element from the rRNA gene spacer showed two clearly distinct patterns that correlated with the observed ability of the stocks to kill infected mice. Our results show a correlation among the ability to kill BALB/c mice, the genetic pattern and clinical symptoms produced by the different stocks in the infected patients.