Cytogenetic analysis in the spermatogenesis of Triatoma melanosoma (Reduviidae; Heteroptera)

Triatomines are of great concern in public health because they are vectors of Chagas’ disease. This study presents an analysis of the species Triatoma melanosoma. The cytogenetic characteristics of triatomines include holocentric chromosomes, post-reductional meiosis in the sex chromosomes and nucleolar fragmentation in the meiotic cycle. The methodology utilized consisted of the techniques of lacto-acetic orcein staining and silver ion impregnation. The organs analyzed were adult testicles. The results enabled to classify the chromosomes by number and size, being three large, eight medium and one small heterochromosome. The three largest chromosomes and the heterochromosomes showed heteropyknotic chromatin in meiosis. The heterochromosomes in 8.05% of the cells in metaphase I behaved as pseudobivalents, contrasting with 91.95% of the cells with individualized sex chromosomes, confirming the achiasmatic nature of these chromosomes. However, the pseudobivalents occurred prominently in metaphase II (78.38%), this fact probably is related to the post-reductional nature of the sex chromosomes. The nucleolus in T. melanosoma persisted until the diplotene phase after which it began to fragment. Nucleolar corpuscles were observed in metaphases I and II and during anaphases I and II, these characteristics being related to the phenomenon of nucleolar persistence. In the initial spermatids, peripheral silver ion impregnation occurred, which could be analogous to the pre-nucleolar corpuscles observed after fragmentation. Thus, this study extends our knowledge of the characteristics of triatomines, in particular, heteropyknotic degree, kinetic activity, formation of sex chromosome achiasmatic pseudobivalency, confirmation of the fragmentation phenomenon, and post-meiotic nucleolar reactivation.

Spectrophotometric analysis of resazurin reduction test and semen quality in men.

The resazurin reduction test (RRT) was performed on semen samples obtained from 225 untreated subfertile and 10 pregnancy confirmed fertile males. The results of RRT were determined visually using resazurin colour chart and again the extent of resazurin reduction in each sample was additionally read by spectrophotometer to assess the quality of samples. Absorption spectra was scanned for resazurin and resorufin and two most sensitive wavelengths (572 and 600 nm) were selected. The ratio of the two optical densities was used as a probe to discriminate the various grades of semen samples. In azoospermic samples, RRT ratio ranges from 0.7 to 1.16, in oligoasthenozoospermic samples from 1.10 to 1.35, in oligozoospermic samples from 1.5 to 2.0 (characterised visually as grades from 1-4) in normozoospermic and proven fertile samples from 2.25 to 5.9 (characterized visually as grades from 5 to 11). The highest correlation of RRT ratio was observed with sperm motility (r = 0.889, P < 0.001), followed by concentration (r = 0.848, P < 0.001) morphology (r = 0.660, P < 0.001) and viability (r = 0.544, P < 0.01). The test ratio had a positive predictive value of 95% for a sperm concentration of > 20 x 10(6)/ml and motility > 40% and a negative predictive value of 90% for a sperm concentration of < 20 x 10(6)/ml and motility < 40%. Therefore the evaluation of RRT results using spectrophotometric ratio method may provide a tool for obtaining a wider range of seminological diagnosis more accurately than the routine semen analysis. It is suggested that the method is simple and reliable, it can be performed in any andrology laboratories.

Synthesis and reactions of 2-chloromethyl-6-iodo-3, 1-benzoxazin-4-one with amines

Certain quinazolinones were reported to exert antimicrobial activity[1]. Consequently, in continuation of our previous work on the reaction of 3,1-benzoxazin-4-ones with amines,[2-5], 2-chloromethyl-6- iodobenzoxazin-4-one was synthesized and allowed to react with amines hoping to obtain 4-quinazolinones for evaluation as antimicrobial agents. 5-Iodoanthranilic acid was chloroacetylated to give I which was cyclodehydrated to yield the corresponding 3,1-benzoxazin-4- one II Compound II was allowed to react with different aromatic amines to produce 3-aryl-2-chloromethyl-6-iodoquinazolin-4-ones IIIa-t. Structures of compounds III [Scheme 1] were confirmed by microanalytical and spectroscopic data [Table1 and 2]

Synthesis and reactions of 2-chloromethyl-3,1-benzoxazin 4-ones with amines

In continuation of our previous works on the reaction of 3,1 - benzoxazin -4 - ones with amines [1,4], it has been found interesting to synthesize 6 - bromo and 6,8 - dibromo - 2 - chloro - methyl - 3, 1 - benzoxazin - 4 - ones IIa, b and to then study their reactions with a variety of amines. Accordingly, 5-bromo and 3,5-dibromoanthranilic acids were chloroacetylated to give I which were cyclodehydrated to the corresponding benzoxazinones IIa, b. Reaction of IIa, b with aromatic amines, ammonia and/or hydrazine hydrate in ethanol or dioxane produced the 2- chloromethyl -4-quinazolinones IIIa-p, presumably through the attack of the amines on the electrophilic C-2 of the benzoxazinone ring system, regardless the amount of the amine used. Structures of III were confirmed by microanalytical and spectroscopic data [table 1]. Evidence was investigated by conversion of III to the corresponding salicylate esters IV via their reaction with sodium salicylate