Effects of a 10-week dry-land strength and conditioning program in physical capacities and start of previously federated and regular swimming practitioners / Efecto de un programa de entrenamiento de fuerza y acondicionamiento en seco sobre las habilidades físicas en practicantes federados en natación / O efeito de um programa de treino de força e condicionamento em seco nas capacidades físicas e partida em praticantes regulares de natação previamente federados

The aim of this study was to evaluate the effects of a 10-week strength and conditioning (S&C) program in physical capacities and start in previously federated and regular swimming practitioners. 16 swimmers (9 male, 17.00±2.16 years of age, 179.14±5.76 cm of height and 69.79±3.11 kg of weight; 7 female, 15.86±2.34 years of age, 163.86±4.98 cm of height and 60.19±3.60 kg of weigh) were equality, but randomly separated in two groups (control group and experimental group, CG and EG, respectively). In the pre-test, swimmers performed three starts in two different models, grab start and track start, the best start was registered. Kinematic parameters of the swimming start and time at 15 m were determined. Flexibility, countermovement jump and 3 kg medicine ball throw were also assessed. In post-test, 10-weeks after a regular 2-sessions week specific dry-land S&C program of 60 min was performed by the EG, all tests were repeated. Flexibility, strength and muscular power gains were significant in EG, contrarily to CG. Swimming start flight phase variables improved more in EG compared to CG, with specificities observed in grab and track start but not a linear consequence with performance in 15-m mark in both groups. A 10-week dry-land S&C program can provide benefits in physical capacities in regular swimming practitioners, fact that may improve the initial phase of the swimming start, prior to the underwater moment, which should deserve attention by the coaches in daily training aiming performance enhancement at 15 m. (AU)

El propósito de esto estudio fue evaluar el efecto de un programa de fuerza y acondicionamiento (F&A) en seco de 10 semanas sobre las habilidades físicas y el salto en practicantes habituales de natación previamente federados. 16 nadadores (9 masculino, 17.00±2.16 años de edad, 179.14±5.76 cm de altura y 69.79±3.11 kg de peso and 7 mujer, 15.86±2.34 años de edad, 163.86±4.98 cm de altura y 60.19±3.60 kg de peso) fueron equitativamente, pero al azar divididos en dos grupos (control y experimental, respectivamente, GC e GE). En el pre-test realizaron tres saltos en dos modelos, grab start e track start, siendo el mejor registrado. Se han determinado parámetros cinemáticos del salto en natación y el tiempo a los 15 m. También se evaluaron la flexibilidad, el salto con contramovimiento y el lanzamiento de una pelota medicinal de 3 kg. En el post-test, 10 semanas después de un programa de F&A en seco con 2 sesiones semanales de 60 min interpretado por GE, las pruebas se repitieron. Las mejoras de flexibilidad, fuerza y potencia muscular fueron significativas en el GE, en contraste con el GC. Las variables de la fase de vuelo en el salto mejoraron más en el GE en comparación con el CG, con especificidades observadas en el grab start e track start, pero no una consecuencia lineal con el rendimiento a 15 m en ambos grupos. Un programa de F&A seco de 10 semanas puede promover beneficios en las habilidades físicas de nadadores habituales, hecho que puede mejorar la fase inicial del salto en la natación, previa al momento subacuático, que debe merecer la atención de los entrenadores en las sesiones diarias con el objetivo de a una mejora del rendimiento a 15 m. (AU)

O objetivo deste estudo foi avaliar o efeito de um programa de força e condicionamento (F&C) em seco de 10 semanas nas capacidades físicas e salto em praticantes regulares de natação previamente federados. 16 nadadores (9 masculinos, 17.00±2.16 anos de idade, 179.14±5.76 cm de altura e 69.79±3.11 kg de peso; 7 femininos, 15.86±2.34 anos de idade, 163.86±4.98 cm de altura e 60.19±3.60 kg de peso) foram equitativamente, mas de forma aleatória divididos em dois grupos (controlo e experimental, respetivamente, GC e GE). No pré-teste, nadadores realizaram três saltos em dois modelos, grab start e track start, sendo registado o melhor. Foram determinados parâmetros do salto na natação e o tempo aos 15 m. Flexibilidade, salto em contramovimento e lançamento de bola medicinal de 3 kg foram também avaliados. No pós-teste, 10 semanas após programa de F&C em seco com 2 sessões semanais de 60 min realizado por GE, testes foram repetidos. As melhorias de flexibilidade, força e potência muscular foram significativas no GE, contrariamente ao GC. As variáveis da fase inicial do salto associadas ao voo melhoraram mais no GE comparativamente ao GC, com especificidades observadas no grab start e track start, mas não uma consequência linear com o desempenho aos 15 m em ambos os grupos. Um programa de F&C em seco de 10 semanas pode promover benefícios nas capacidades físicas de praticantes regulares de natação, facto que pode melhorar a fase inicial do salto na natação, anterior ao momento subaquático, que deve merecer atenção pelos treinadores nas sessões diárias visando uma melhoria de desempenho aos 15 m. (AU)

Testis of the lizard Mabuya carinata: a light microscopic and ultrastructural seasonal study.

Histomorphology and ultrastructure of the testis during breeding and nonbreeding phases of the reproductive cycle of the lizard Mabuya carinata are studied. Observations of the ultrastructural features of the testis during breeding and nonbreeding phases of the reproductive cycle reveal a prenuptial type of spermatogenesis and a clearcut discontinuous spermatogenic cycle. Seminiferous tubules are enlarged and there is active spermatogenesis as shown by the presence of all the stages of spermatogenesis (spermatogonia to spermatids) and spermatozoa during the breeding phase (November). During the nonbreeding phase (April) only spermatogonia and Sertoli cells are seen in the shrunken seminiferous tubules. Leydig cells and Sertoli cells show distinct changes in the morphological appearance with hypertrophy of the cells in breeding phase and atrophy of the cells in the nonbreeding phase of the reproductive cycle. The present study suggests that Sertoli cells and Leydig cells functions are synchronous in the lizard M. carinata.

Ultrastructural study of the epididymis and the vas deferens and electrophoretic profile of their luminal fluid proteins in the lizard Mabuya carinata.

The light microscopy, histochemical and TEM studies of the epididymis and the vas deferens revealed the presence of PAS positive secretory granules in the epithelial cells lining the lumen of these organs. One dimensional SDS gel electrophoretic pattern of luminal fluid proteins and the total protein content of the testis, three regions of the epididymis and the vas deferens of the lizard, Mabuya carinata were studied during breeding and nonbreeding season of the reproductive cycle. During breeding season, 25 protein bands in the testicular luminal fluid, 26 in the anterior epididymal luminal fluid and 28 in the middle and posterior epididymal luminal fluid were found. Ten new protein bands appeared in the anterior epididymal region whereas five new protein bands appeared in the middle region of the epididymis indicating regional difference in protein secretions of the epididymis. Vas deferens luminal fluid showed the highest number of protein bands (32) and the highest total protein content (9.07 mg/ml) compared to the testis and the epididymis. Four new protein bands appeared in the vas deferens. Number of protein bands in the luminal fluids of testis, epididymis and the vas deferens were significantly reduced during nonbreeding season compared to those of the breeding season. Consistent with the decrease in the number of protein bands, there was a significant reduction in the total protein concentration in all the tissue samples during nonbreeding season. The results indicate seasonal differences in number of proteins secreted and quantity of proteins in the luminal fluid of male reproductive tract of M. carinata. This is the first study in reptiles revealing appearance of new proteins in epididymis, and vas deferens by conducting simultaneous electrophoretic profile of testicular, epididymal and vas deferens luminal contents.

Light microscopical and ultrastructural studies on the vas deferens of the lizard Mabuya carinata.

Adult male lizards (Mabuya carinata) were studied during breeding and non breeding seasons to determine the regional and seasonal differences if any in the vas deferens and to compare ultrastructural features of luminal epithelial cells with those of endotherms. The vas deferens of the lizard is a convoluted tube extending from the epididymis to the hemipenis passing over the kidney. Based on morphometric data of luminal diameter and epithelial cell height three distinct regions viz; proximal, middle and distal regions were identified in the vas deferens. The epithelium is surrounded by a thin layer of lamina propria, many layers of circular smooth muscle fibers and an outer layer of visceral pleuro peritoneum. Based on cell and nuclear morphology and ultrastructure, five different cell types viz; principal cell, basal cell, mitochondria rich cell, halo cell and narrow cell were identified in the epithelium during both breeding and non breeding season. Principal cells and basal cells were more abundant in both seasons. The types of luminal epithelial cells of vas deferens of M. carinata and their ultrastructural features are similar to those of mammals. Further, vas deferens of M. carinata differs from mammals in having only circular smooth muscles in contrast to circular and longitudinal muscles of mammalian vas deferens. To the best of our knowledge this is the first report describing cell types of vas deferens, their ultrastructure and ultrastructural seasonal variations in reptiles.

Mouse chromosome 6 in Rb translocations: consequences in singly and doubly heterozygous males.

Previously it has been shown that male mice heterozygous for the Rb(6.16) translocation show a transmission distortion of the segregants in resulting zygotes, particularly for sexually active animals (Aranha and Martin-DeLeon, 1991). Sperm bearing the translocation have an impaired fertilizing ability, compared to chromosomally normal sperm, and this dysfunction is potentiated in X-bearing cells leading to a sex ratio distortion. Since earlier data suggested that a deficiency of Chromosome 6 was associated with sperm dysfunction (Zackowski and Martin-DeLeon, 1989), the present study was designed to determine the uniqueness of the coupling of the distortions for the Rb(6.16) translocation and the effect of 0 and 2 copies of Chr 6 on sperm function. First cleavage metaphases, resulting from chromosomally normal females that were mated to sexually active or rested Rb(6.15) or Rb(2.8) heterozygous males, were sequentially G- and C-banded. For unaged sperm from sexually active Rb(6.15) males, cytogenetic analysis showed that the ratio of normal (90) to balanced (37) zygotes deviated significantly (P < 0.001) from 1:1, as did the sex ratio, 46X:81Y (P < 0.01). The latter distortion was related to a deficiency of X-bearing sperm with the translocation (8X:29Y). Both segregation and sex ratio distortions disappeared for aged sperm (69:50, 51X:68Y) and a contingency table showed that segregant type was related to sperm age (P < 0.05). For the Rb(2.8) the ratio of normal to balanced zygotes (65:46) was not significantly different from 1:1 for unaged sperm, and although the ratio from aged sperm was 62:39, there was no relationship between segregant type and sperm age (P > 0.05). There was also no sex ratio distortion for either unaged or aged sperm (P > 0.05). To generate zygotes with sperm complements containing 0 and 2 copies of Chr 6, males doubly heterozygous for Rb(6.16) and Rb(6.15) were mated to chromosomally normal females. No zygotes were recovered and the males were shown histologically to have azoospermia and spermatogenic arrest. The results support the conclusion that the presence of Chr 6 in Rb translocations specifically affects segregant and sex ratio distributions. They also indicate, that as the common arm in compound heterozygotes, this chromosome grossly affects spermatogenesis.

Segregation analysis of the mouse Rb(6.16) translocation in zygotes produced by heterozygous female carriers.

The segregation products in zygotes of females heterozygous for the mouse Rb(6.16) translocation were studied. Of 191 first-cleavage metaphase zygotes recovered from 16 females mated to chromosomally normal males, 132 were cytogenetically analyzed after sequential G- and C-banding. There were no products of adjacent segregation, since the six chromosomal imbalances were unrelated to the translocation. Alternate segregation was seen in 126 (95.5%) of the zygotes, with 85 being chromosomally normal and 41 carrying the translocation. These results indicate preferential alternate segregation and a significant deviation from the Mendelian 1:1 ratio (P < 0.005) for reciprocal alternate segregants, as seen earlier for males with this translocation. However, the approximately 2:1 ratio for normal-to-balanced segregants in females is lower than the ratios consistently seen for males. This supports the notion that there are different underlying causes of the distortion in the sexes.

Evidence for differential maturation of reciprocal sperm segregants in the murine Rb(6.16) translocation heterozygote.

The fertilizing ability of unaged sperm and those aged experimentally in the cauda by surgically ligating the corpus epididymis in males carrying the Rb(6.16) translocation was studied. Chromosomally normal females were inseminated with unaged sperm delivered by males mating at 3-day intervals, and aged sperm were studied after matings on 6-14 postoperative days. The sperm chromosome complement was analyzed in first-cleavage metaphase zygotes after sequential G- and C-banding of the chromosomes. Of 283 metaphasic zygotes in the control group, 183 (or 64.7%) were analyzed and showed a ratio of 2.7:1 for chromosomally normal and balanced segregants of the translocation, deviating significantly (P less than 0.001) from the expected 1:1. The ratio of X- to Y-bearing sperm also deviated from expected (P less than 0.01) mostly due to a significant deficiency (P less than 0.05) of balanced sperm that were X-bearing. Fertilized oocytes were recovered from matings of 10 males on days 6-8 postoperatively, and, of 139 metaphasic one-cell zygotes, 101 (or 72.3%) were analyzed. These showed a Mendelian ratio of 1:1 for normal and balanced segregants. The sex ratio in the aged group (57Y:41X) also showed no deviation from 1:1. The results, which reveal significant physiological distortions for both the segregation and the sex ratios in males heterozygous for the Rb(6.16) translocation, suggest that differential maturation of the translocation-bearing sperm and the chromosomally normal reciprocal exists. The findings further support the concept that sperm chromosomal complement affects their maturation and function, and that factors on chromosome 6 and the X or Y chromosome additively affect sperm function.

The murine Rb(6.16) translocation: evidence for sperm selection and a modulating effect of aging.

The segregation products of the Rb(6.16) translocation were studied at first cleavage metaphase. Male mice heterozygous for the translocation mated at 3- and 14-day intervals to superovulated random-bred ICR females. Chromosome preparations of the recovered one-cell embryos were sequentially G- and C-banded and male and female complements analyzed cytogenetically. Of the 309 zygotes analyzed from both mating groups, no unbalanced segregants of the translocation were observed. In the 3-day group there was a highly significant difference (P less than 0.001) from the expected 1:1 ratio between sperm with normal (70.5%) and balanced segregants (26.2%) of alternate segregation. In the 14-day group the level of significance for the difference was ten times lower (P less than 0.01) as normal segregants were observed in 56.4% of the sperm and balanced ones in 36.5%. A comparison of the two groups using a 2 x 2 contingency table showed that segregant type was related to mating frequency (P less than 0.05). There was a highly significant distortion (P less than 0.01) of the sex ratio, with 178 Y-bearing and 131 X-bearing sperm in the combined populations. When sex ratio was analyzed according to mating intervals, the distortion was significant (P less than 0.01) only for the 3-day group. An analysis of the sex ratio according to the segregant type showed no significant deviation from 1:1 for type 1 segregants, which had normal chromosomes, while type 2 segregants, with the translocation, had a deficiency of X-bearing sperm. This deficiency was significant (P less than 0.05) only for the 3-day population. Analysis of meiotic preparations showed no association between the translocation trivalent and the X-Y bivalent. Our results, obtained under physiological conditions, provide definitive evidence for sperm selection and support previous findings that aging of sperm can modify the effect of selection.