Nitazoxanide in the treatment of Ascaris lumbricoides in a rural zone of Colima, Mexico.

Intestinal parasites in Mexico are an endemic problem. A study was conducted in children, teenagers and adults in a rural community in Colima, Mexico to examine the prevalence and intensity of Ascaris lumbricoides infection and to evaluate the parasitological and clinical efficacy of nitazoxanide (NTZ). Two hundred and eighty children, teenagers and adults participated in this study. Parasitological diagnosis from faeces was confirmed by three consecutive stool samples using the floatation concentration Faust method. Egg counts were performed as described by the Kato-Katz technique before and after treatment. A questionnaire was systematically applied to obtain information about socio-economic status and hygienic habits. One hundred and six participants (38%) were diagnosed as harbouring intestinal parasites, and 86 of them (81%) were infected with A. lumbricoides. All patients with ascariasis infections underwent a complete physical examination before and after NTZ treatment. NTZ resolved 88% of the ascariasis cases, with a 89% clinical efficacy, and there was a 97.5% reduction in the levels of morbidity. The most intense infections for A. lumbricoides were found in housewives, and statistically significant associations were found between ascariasis and the absence of drainage and living in houses with dirt floors.

Centromeric association of a microchromosome Y in two male patients.

We characterized two Y-ring microchromosomes (MC) found in an azoospermic patient with Turner stigmata (case A) and a male infant with hypospadias (case B). The karyotypes, as assessed by banding, FISH, and STRs/STSs analyses, were 46,X,r(Y).ish r(Y)(p11.3q11.222)(SRY+,DYZ3+) and 46,X,+r(Y)/45,X.ish r(Y)(p 11.2q11.2)(Xp/Yp-,SRY+,DYZ3+) respectively. In both cases, we evaluated the association of each MC with the centromere of the nearest and second nearest chromosomes in G-banded metaphases by means of measuring the intervening distance according to two criteria: < or =1 time or < or =3 times the size of the MC in each metaphase. The case A's MC was associated 84 times in 98 cells according to the latter or less strict criterion and two times in 98 cells according to the strict criterion; the corresponding values for case B were 84 and two in 95 cells respectively. The centromeric association appears to be related to centromeric attraction mediated by heterochromatin or centromere-specific proteins, the replication time, and the Rabl orientation.

Topology of constitutional reciprocal translocations in metaphase.

We studied in 39 carriers of 26 reciprocal translocations (including five de novo and seven of indeterminate occurrence) the metaphase localization of the derivative chromosomes, their normal non-homologous counterparts (here called A and B), and two control pairs (C and D). In eight familial translocations, we analysed two to five carriers. We digitally captured 10 G-banded lymphocyte metaphases per individual and measured in microns the largest diameter (d) of the metaphase and six intercentromeric distances: (1) der A<-->der B (problem distance 1, pd1), (2) der A<-->B (pd2), (3) der B<-->A (pd3), (4) A<-->B (control distance 1, cd1), (5) the smaller distance between C and D (cd2) and (6) the largest distance between C and D (cd3); in addition, the average between C and D (cd4) was calculated. We used the formula Delta = 100(cd - pd)/d 12 times per metaphase, compared each pd vs. each cd, and tested the differences by the Wilcoxon matched-pair test. Although, in the whole sample there were not significant differences respect to cd1, this distance emerged as the proper control. In the eight familial translocations, the three pd vs. cd1 comparisons revealed that in 19/24 times the pd was smaller but only once reached significance (cd1 vs. pd2 in t[3;4]). In the analysis per individual the pd was smaller than cd1 in 19 (pd1), 22 (pd2) and 22 (pd3) cases although only twice reached significance. We conclude that in some translocations, the derivative chromosomes actually lie close from each other or from a normal non-homologous counterpart.

Human papillomavirus in tonsillar and nasopharyngeal carcinoma: isolation of HPV subtype 31.

We retrospectively studied biopsy specimens obtained from 16 patients who had carcinoma of the tonsil or nasopharynx. Polymerase chain reaction testing detected the presence of human papillomavirus (HPV) in 13 samples (81.3%)--six tonsillar and seven nasopharyngeal. Eleven of the 13 positive samples (84.6%) contained HPV subtype 31. We believe that this is the first report of the presence of HPV subtype 31 in these carcinomas. In addition to the significant association between tonsillar and nasopharyngeal cancer and HPV, our analysis of descriptive variables confirmed the association between the incidence of these neoplasms and poor oral hygiene and low socioeconomic status in older adults.

C-anaphases (common variant) are unrelated to colchicine and phytohemagglutinin.

We evaluated the effect of different concentrations of colchicine (0.0, 0.1, 0.3, 0.5 microgram/ml) and phytohemagglutinin (PHA) (0.10, 0.15, 0.20 microgram/ml) on the rate of C-anaphases in lymphocyte cultures from five healthy individuals with the common variant of C-anaphases. For each of the 12 possible combinations, two subjects were randomly tested. The frequency of these variant figures was < 3%; a single-culture (out of six with the colchicine concentration of 0.1 microgram/ml) lacked C-anaphases. Multiple variance and Student's t tests revealed, as the only significant difference, a decrease with the colchicine concentration of 0.3 microgram/ml compared with the cultures without colchicine (p < 0.05), which exhibited the greatest ratio of C-anaphases. The PHA had no influence on the frequency of C-anaphases. We conclude that the common variant of C-anaphases is unrelated to the colchicine and PHA concentrations tested; moreover, our data confirm the occurrence of such a mitotic variant in colchicine-free cultures.