A study using demographic data of genetic drift and natural selection in an isolated Mediterranean community: Bayárcal (La Alpujarra, south-east Spain).

Natural selection and genetic drift are two evolutionary mechanisms that can be analysed in human populations using their fertility and mortality patterns, and their reproductive size and isolation, respectively. This paper analyses the models of natural selection and genetic drift in Bayárcal, south-east Spain, and compares them with the observed models in the rest of the Alpujarran region. Demographic data were obtained from a sample of 77 families (48.45% of the population, with 547 inhabitants). The genetic drift and natural selection action was evaluated with the Coefficient of Breeding Isolation (CBI of Lasker and Kaplan) and Crow's index, respectively. The CBI (23.23/12.61) suggests that genetic drift is near to acting, and Crow's index (I=0.58) is slightly higher than that observed in the rest of La Alpujarra. Although the reproductive isolation of Bayárcal is not effective enough for genetic drift to act, it is near when marital migrants inside the Bayárcal valley are considered as a native population. The natural selection pattern is not different from that of the rest of La Alpujarra, but it tends towards the model of developing communities, where the demographic transition has not yet begun.

Effects of experimental diabetes on the structure and ultrastructure of the coagulating gland of C57BL/6J and NOD mice.

Diabetes mellitus can lead to reproductive disorders that in turn result in weakened fertility brought about by morphofunctional changes in the testes and accessory sex glands. However, doubts persist concerning the basic biology of the secretory epithelial cells and the stroma of the coagulating gland of diabetic mice. Thus, the objective of the present study was to analyze the histological and ultrastructural changes associated with stereology of the coagulating gland of mice with alloxan-induced diabetes, and of spontaneously diabetic mice. Sixteen mice of the C57BL/6J strain, and eight non-obese diabetic (NOD) mice were used. The animals were divided into three groups: 1) control (C), 2) alloxan diabetic (AD), and 3) NOD. Thirty days after the detection of diabetic status in group 2, all of the animals were killed and then perfused with Karnovsky's solution through the left cardiac ventricle. The coagulating gland was then removed and processed for morphometric study by light microscopy and electron microscopy. The results showed thickening of the stroma, atrophy of secretory epithelial cells, and disorganization of the organelles involved in the secretory process in both NOD and alloxan-induced mice. Thus, it may be concluded that the coagulating gland suffered drastic morphological changes, and consequently impaired glandular function, in the presence of diabetes mellitus type I in both NOD and AD mice.

Ultrastructural study of the ventral lobe of the prostate of mice with streptozotocin induced diabetes (C57BL/6J).

Morphological and functional changes caused by diabetes in the accessory sex organs and especially the prostate have been reported by several investigators. The aim of the present study was to examine the possible deleterious effects of experimentally induced diabetes on the secretory epithelium of the ventral prostate of mice. Sixteen adult male C57BL/6J mice were divided into two groups. The diabetic group received a streptozotocin injection of 75 mg/kg, while the control group received only 0.1 ml citrate buffer, i.p. After 30 days, the diabetic state was ascertained, the animals were sacrificed and the ventral lobe of the prostate was collected for histological and ultrastructural examination. The results showed reduction in glandular epithelium cell height, increased numbers of cytoplasmic vacuoles and thickening of the extracellular matrix. In conclusion, experimental diabetes has harmful effects on the secretory epithelial cells of the ventral lobe of the prostate of mice.

Working conditions of Chagas' disease patients in a large Brazilian city.

This study evaluated the working conditions of Chagas' disease patients in the city of Campinas, São Paulo, focusing on two-hundred-fifty patients with steady employment and treated at the University Hospital (HC-FCM/Unicamp): 98% were working-age and 77.6% were men. The origin of the patients reflected the migratory process occurring among this population. Most of the patients had limited professional skills, while 63.6% had not finished primary school and 21.6% were illiterate. However, 63.6% were regularly employed under duly processed work contracts. Their jobs were mainly in general services (21.6%) and heavy industry (21.2%). Some 55% of the patients reported a monthly income less than or equal to U$100.00, and 40.4% reported having been fired at least once during the last ten years, in 8.9% of the cases because of a diagnosis of Chagas' disease. Of the patients undergoing pre-hiring physical examinations (57.2%), 9.1% were refused, 92.3% of whom due to positive serology for T. cruzi. Finally, 78.4% reported not belonging to a labor union. The study demonstrated the precarious working conditions and discrimination experienced by workers with Chagas' disease.

Anatomy of the ostia venae hepaticae and the retrohepatic segment of the inferior vena cava.

In 30 normal adult livers the retrohepatic segment of inferior vena cava had a length of 6.7 cm and was totally encircled by liver substance in 30% of cases. Altogether 442 ostia venae hepaticae were found, averaging 14.7 per liver and classified as large, medium, small and minimum. The localisation of the openings was studied according to the division of the wall of the retrohepatic segment of the inferior vena cava into 16 areas.

Electromyographic study of the longissimus dorsi and iliocostalis lumborum muscles during knee flexion and extension on a plain and on a tilt Roman table.

The objective of this paper was to analyse the activity of the longissimus dorsi and the iliocostalis lumborum muscles--components of the erector spinae muscle--in order to determine: their action potentials during the use of a plain and a tilt Roman table; 2) to compare the action potentials of the two muscles; 3) to verify if the action potential of these two muscles remain constant during the arc of movement--knee flexion and extension--divided into angle ranges, and 4) to compare the action potentials of the muscles in movements performed in a free manner and against resistance. Twenty-three young volunteers were studied electromyographically and each muscle received a needle electrode (Mise) and a surface electrode. The results showed that the table model did not determine any difference in the action potential of the muscles and that, on average, the iliocostalis lumborum muscle developed a slightly higher action potential than the longissimus dorsi muscle during the free flexion of knees on the plain table. In more than 70% of the cases, there was no difference between the action potential of the muscles over the various angle ranges of knee flexion and extension. Relatively higher action potentials were recorded during knee flexion and extension against resistance than during the same movements performed in a free manner. This shows that the paravertebral musculature responds better to an overload (8 kg) imposed on the knee flexor group, confirming the stabilizing role of the longissimus dorsi and iliocostalis lumborum muscles during knee flexion and extension on a Roman table.

Ultrastructural aspects of and observations on the permeability of the rat mesentery to colloidal iron.

In works already published, it was made clear that many researches were interested in the absorption phenomena, permeability and structure of the visceral mesothelial tissue. Attention was concentrated on the mesentery and observations were made using the application of lanthanum nitrate and osmium-amine. The penetration of lanthanum nitrate is impeded by the basement membrane situated between the connective and mesothelial tissues. The heavy salt moves through and not between the mesothelial cells by passive diffusion. No reaction was observed in general with osmium-amine, with the exception of a few cases. In those instances, the osmium-amine reacted not only in the outer surface of the mesentery, but also penetrated with no visible reaction all the way to the connective tissue where it was detected in the elastic layer. In this paper, the colloidal iron was employed using different techniques, and depositions were detected in the surface of the mesentery, in the mesothelial cells and also in the connective tissue. A final conclusion that the permeability of different layers of tissues is of great variety and has a definite capacity for selectivity is suggested.

Influência dos hormônios testiculares sobre a regeneraçâo óssea em fraturas da tíbia de ratos / Influence of testicular hormones over bone regeneration in rats tibial fractures

Foram estudados 32 ratos machos Wistar, com aproximadamente 120 dias, pesando em média 280 gramas. Os animais foram divididos em dois grupos (grupo controle e grupo submetido a orquiectomia) de 16 ratos cada um, e cada rato foi mantido em gaiola individual, durante toda a experiência. O trabalho foi desenvolvido em 3 etapas distintas 1ª etapa: Os animais do grupo controle, foram mantidos em condiçöes normais de um biotério, sem restriçöes. Os animais do grupo submetido a orquiectomia, foram anestesiados com éter etilico por inalaçäo, e posteriormente submetidos a orquiectomia bilateral através de uma incisäo longitudinal mediana na bolsa escrotal 2ª etapa: Os animais petencentes à ambos os grupos foram anestesiados com éter etílico por inalaçäo e submetidos a fratura na porçäo média da diáfise tibial. Os animais pertencentes ao grupo orquiectomizados foram submetidos à 2ª etapa trinta dias após a primeira cirúrgia (orquiectomia). 3ª etapa: Metade dos animais de ambos os grupos, após o 8§ dia e a outra metade após o 12§ da fratura, foram sacrificados e a tibia fraturada foi retirada. Após a remoçäo estas foram fixadas em formol a 10% durante 48 horas, em seguida foram colocadas no descalcificados (E.D.T.A. 10%), onde permaneceram 45 dias. Após a descalcificaçäo as peças foram incluidas em parafina, cortadas numa espessura de 7 micrômetros e os cortes corados pela Hematoxilina Eosina. Observando as lâminas, montadas pelos métodos histológicos convencionais, verificamos que: 1§ o calo ósseo consequente à fratura dos animais orquiectomizados, era constituído de fibrocartilagem, e dos animais näo orquiectomizados, era constituído por cartilagem calcificada apresentando regiöes osteogênicas; 2§ o periósteo e o endosteo parecem participar ativamente no processo de regeneraçäo do tecido ósseo; 3§ o processo de ossificaçäo foi mais intenso e mais acentuado em animais näo orquiectomizados. 4§ Portanto, houve diferença acentuada no processo de fraturar entre os animais dos dois grupos; em decorrencia disto talvez possamos sugerir que, os hormonios testiculares agem diretamento sobre o tecido ósseo em relaçäo a síntese da matriz orgânica

Morphological aspects and observations about the permeability of the rat mesentery to the osmium-amine.

In a previous work we felt that many authors were interested in observing the permeability and structure of the mesentery employing many techniques and analysing the material from different points of view. Our collaboration, at that time, was limited to the study of the permeability of the mesentery to the lanthanum nitrate and we came to a final conclusion that the penetration of the heavy salt is impeded by the presence of a basement membrane, localized between the mesothelial and connective tissue layers and that it was continuous to the basal lamina, located between neighbouring mesothelial cells; we could then observe that the lanthanum traveled through the cytoplasm and not in between mesothelial cells. In this paper we analyze the behavior of the mesentery in relation to the osmium-amine and we compare it to the observations made in our previous work. Generally speaking, we were unable to observe any reaction in any of the structures of the mesentery, except for some special cases. In those not very common cases, employing special techniques, we came to the conclusion that the osmium-amine reacts in the periphery (outer surface) of the mesentery and also penetrates, sometimes with no visible reaction, all the way to the elastic layer, where a reaction can be detected.

Morphological aspects and observations about the permeability of the rat mesentery to the lanthanium Nitrate. Some comparisons with the morphology of the human mesentery.

A review in the classic literature showed that many authors were interested about the permeability and structure of the mesentery. With the evolution of new techniques, this subject came back in different research areas. The purpose of this paper concentrates in the study of the permeability of the mesentery and of other small intestine layers of the rat to the lanthanium nitrate. Some comparisons are also made with the morphology of the human mesentery. Human and rat mesentery were used in different methods, and an ultrastructural study was performed. However, in all techniques employed in our paper, we could not observe a single area of the basement membrane that was penetrated by the lanthanium nitrate. We may conclude that the penetration of the lanthanium nitrate is impeded by the basement membrane and that this penetration is also impeded in the intercellular space of the mesothelial layer by the presence of a basal lamina, which is continuous with the basement membrane, as we can see in some of our sections.

Histological and histochemical appearance of livers and kidneys of rats after long-term treatment with different concentrations of sodium fluoride in drinking water.

After a review of the controversies in the literature, a histologic and histochemical study of the livers and kidneys of 48 albino rats was performed. The animals were placed on a diet containing 1 ppm NaF in demineralized drinking water, or 1, 10 or 100 ppm NaF in tap water during 90 or 180 days. The rats treated with fluoride did not present any abnormalities with respect to weight gain, morphology, behavior, and macroscopic appearance of the livers and kidneys compared to the control animals. Microscopic examination failed to reveal any morphologic alterations in either the cells or the mitochondria of the livers and kidneys. Histochemically, the polysaccharides, the protein reactive groups and the acid and alkaline phosphatases also failed to present any visible alterations. With respect to the lipids, the kidneys and livers of the rats treated for 90 days did not show any fat deposition, whereas those treated for 180 days showed zones of deposition of lipids in the livers and kidneys with different frequencies when compared with the control animals. The association between lipid infiltration and the presence of fluoride in the drinking water, however, was statistically significant only in the livers, hence, the hypothesis that fluorinated water accelerated this process in the treated animals cannot be excluded.

Electromyographic study of the subclavius muscle.

The electromyographic study of the subclavius muscle (SM) was performed in 31 different movements, in 12 subjects (10 male and 2 female) aged from 17 to 28 years. The action potentials were obtained with an electromyograph Teca TE 4. Our findings suggest that the SM acts mainly on the stability of the sternoclavicular joint; with more or less intensity according to the degree of the clavicular interaction with the movements of the peripheral parts of the superior limb. The SM seems to act as a substitute for the ligaments of the sternoclavicular joint.