Sporadic cyclosporiasis in symptomatic Cuban patients: Confirmation of positive results from conventional diagnostic methods by molecular assay.

In Cuba, there are few studies on cyclosporiasis. Here, we report results from 1247 stool samples from symptomatic patients that were examined by microscopy methods and positive cases confirmed by nested PCR targeting the 18S rRNA gene, followed by sequencing. Seven positive samples, all diagnosed during May-June, were confirmed by the molecular method, indicating an occurrence in this patient cohort of 0.56%.

Differentiation of Leishmania (Viannia) panamensis and Leishmania (V.) guyanensis using BccI for hsp70 PCR-RFLP.

Leishmania panamensis and Leishmania guyanensis are two species of the subgenus Viannia that are genetically very similar. Both parasites are usually associated with cutaneous leishmaniasis, but also have the potential to cause the mucocutaneous form of the disease. In addition, the study of foci and consequently the identification of vectors and probable reservoirs involved in transmission require a correct differentiation between both species, which is important at epidemiological level. We explored the possibility of identifying these species by using restriction fragment length polymorphisms (RFLP) in the gene coding for heat-shock protein 70 (hsp70). Previously, an hsp70 PCR-RFLP assay proved to be very effective in differentiating other Leishmania species when HaeIII is used as restriction enzyme. Based on hsp70 sequences analysis, BccI was found to generate species-specific fragments that can easily be recognized by agarose gel electrophoresis. Using the analysis of biopsies, scrapings, and parasite isolates previously grouped in a cluster comprising both L. panamensis and L. guyanensis, we showed that our approach allowed differentiation of both entities. This offers the possibility not only for identification of parasites in biological samples, but also to apply molecular epidemiology in certain countries of the New World, where several Leishmania species could coexist.

Morphometric changes of Triatoma flavida Neiva, 1911 (Hemiptera:Triatominae) in the transition from sylvatic to laboratory conditions.

The one-generational metric changes occurring in Triatoma flavida (Hemiptera: Triatominae) when carried from its wild habitat (caves) to laboratory, were examined using traditional morphometric techniques. As for other species of Triatoma, Rhodnius or Panstrongylus studied in similar conditions, a significant reduction of head, thorax and wing size was observed. Sexual dimorphism of the wings, while present in the wild sample, was not detected anymore in the laboratory individuals. Biological significance and epidemiological importance are discussed.

Morphometric changes of Triatoma flavida Neiva, 1911 (Hemiptera: Triatominae) in the transition from sylvatic to laboratory conditions

The one-generational metric changes occurring in Triatoma flavida (Hemiptera: Triatominae) when carried from its wild habitat (caves) to laboratory, were examined using traditional morphometric techniques. As for other species of Triatoma, Rhodnius or Panstrongylus studied in similar conditions, a significant reduction of head, thorax and wing size was observed. Sexual dimorphism of the wings, while present in the wild sample, was not detected anymore in the laboratory individuals. Biological significance and epidemiological importance are discussed.

Fueron examinados los cambios morfométricos que ocurrieron en la primera generación de Triatoma flavida cuando fueron llevados desde su hábitat selvático (cuevas) al laboratorio, mediante el uso de técnicas morfométricas tradicionales. Se observó una reducción significativa del tamaño de la cabeza, tórax y alas, como ocurre en otras especies de Triatoma, Rhodnius o Panstrongylus estudiados en condiciones similares. El dimorfismo sexual de tamaño en las alas, aunque presente en los individuos selváticos, no se detectó en los de laboratorio. La significación biológica y la importancia epidemiológica son discutidas.

A novel GT-mismatch binding protein that recognizes strict DNA sequences with high affinity.

Mismatched or damaged base pairs in DNA are mutagenic and both eukaryotes and prokaryotes have a series of repair systems that decrease a spontaneous mutation rate. All exocyclic amino groups of cytosine(C), adenine(A), and guanine(G) contribute to hydrogen bonds for base pairing. High temperature and oxidative stresses increase the deamination of these bases and methylated C. These deaminated sites would be initially recognized by components of DNA repair system. We discovered a novel G/thymine(T)-mismatch binding protein (nGTBP) that bound, with high affinity, to a minimal 14-mer DNA heteroduplex with a strict 5'-TRT GNB-3' sequence (R for purine, N for any bases, and B for "not A," namely for C, G, or T ). This italicized G position mismatched with T could be replaced by hypoxanthine, the deaminated A. The nGTBP, however, barely recognized DNA duplexes individually containing 8-oxo-G, thymine glycol, and 5-methylcytosine.

[Behavior of vaginal trichomoniasis in a group of adolescents]. / Comportamiento de la trichomonosis vaginal en un grupo de adolescentes.

275 adolescents aged 10-19 receiving attention at the infantojuvenile department of pregnancy interruption and of sexually transmitted infections of "Ramón Gonzalez Coro" and "Eusebio Hernández" Gynecoobstetric Teaching Hospitals, both in Havana City, were studied from August, 1999, to September, 2000, aimed at knowing the behavior of the infection caused by Trichomonas vaginalis in this population group. The results yielded 18.1 % of positivity to parasitosis. It was proved by the calculation of relative risk that the adolescents that had an active or past infection due to Trichomonas vaginalis have more possibilities of getting an infection produced by human Papilomavirus than those without this condition. It was demonstrated that 78 (28.3 %) of the total of patients examined had some type of lesion in the uterine cervix. Some risk factors as non using condon, having multiple sexual partners and the early beginning of sexual relations, which may facilitate the adquisition of this parasitosis in a population so vulnerable as the adolescents, were made known.

[Frequency of Trichomonas vaginalis infection in couples with fertility problems]. / Frecuencia de infección por Trichomonas vaginalis en parejas con trastornos de la fertilidad.

One-hundred and seventy two couples which went for the first time to the Infertility Service of the National Institute of Endocrinology from June 1999 to June 2000, were studied to find out the frequency of Trichomonas vaginalis infection in this group, and determine its interaction with a number of clinical and risk variables. The results yielded that 10.5% were positive to the parasite, the prevailing symptom was leukorrea in women and 96.6% of men showed no symptoms. It was highly significant the fact of having a previous pathological history that might be related to infertility and current T. vaginalis infection. This protozoon was frequently associated with Candida sp. and causative agents of bacterial vaginosis in women and Haemophilus influenzae in men. This parasite seems to play an important role as a likely causative agent to be considered in fertility problems.