A histological and immunohistochemical study of the effects of N-acetyl cysteine on retinopathy of prematurity by modifying insulin-like growth factor-1

Retinopathy of prematurity (ROP) is a vasoproliferative disorder that occurs in premature infants and may lead to permanent visual impairment. We investigated both the possible protective role of N-acetyl cysteine (NAC) for preventing ROP and the role of IGF-1 in the disorder. Forty-five newborn rats were divided into three groups. Group 1 was raised in room air as controls. Group 2 was exposed to 60% oxygen for 14 days after birth, then transferred to room air. Group 3 was exposed to the same conditions as group 2, but received intraperitoneal injections of NAC on postnatal days 7–17. After 35 days, both eyes of all rats were processed for histology. Some sections were stained with hematoxylin and eosin to assess structural changes and other sections were immunostained to determine the location of IGF-1. Frozen sections also were prepared and stained for adenosine triphosphatase to detect retinal blood vessels. Compared to the controls, more blood vessels, many of which were abnormal, and increased IGF-1 expression were observed in group 2. In group 3, abnormal blood vessels and IGF-1 expression were less evident. NAC appeared to be an effective vascular-protective agent for ROP by decreasing IGF-1 expression.     

Immunohistochemical localization of androgen receptors in female mole rat (Spalax leucodon) tissues

Androgens exert their effects through androgen receptors (AR) in tissues. We investigated the distribution of AR in female mole rat tissues. Tissues were excised, fixed with 10% formalin and embedded in paraffin. Sections were stained after microwave antigen retrieval for immunohistochemistry. Immunostaining of AR immunostaining was detected in the nucleus or cytoplasm of the cells in the cerebral cortex, cerebellum, anterior pituitary, lung, liver, uterus and skin. Granulosa and some thecal cells in the ovary, cardiac muscle cells and adipose cells exhibited a nuclear reaction for AR. In the kidney, labeling of AR was restricted to the cytoplasm of tubule cells. We found that AR could be detected using immunohistochemistry in the nucleus or cytoplasm or both in the presence of androgens.     

Senescence and human chromosome changes

Summary A girl with slight psychomotor retardation, microphthalmia, and colobomata of the left eye, a hypotrophy of the right arm and a surnumerary digit on the right hand is described. The routine chromsome analysis and a G-banding analysis revealed an elongated long arm of chromosome 10. An extra light and dark band was present proximally. Both parents had normal chromosomes. While the visual comparison of the abnormal with the normal chromosome 10, did not enable the extra bands of the normal bands q21 and q22 to be distinguished. However, measurements of length, surface area, and relative reflection of the different light and dark bands of the long arm on tracings or directly on the normal and abnormal chromosomes, enabled us to precisely locate the extra bands and to determine that the abnormal chromosome was a result of an insertional translocation. The value of such measurements is discussed.     

Blood groups and H-Lea salivary secretion of Brazilian Cayapo Indians

Five hundred and twenty-six individuals from four populations were studied in relation to the ABO, MNSs, P, Rh, Lutheran, Kell, Lewis, Duffy, Kidd, Diego and I systems, as well as for the Wright antigen of blood groups. The H-Le^a salivary secretion of 406 of them was also investigated. Considering the gene markers which show variation in South American Indians, the Cayapo frequencies are in the middle of the distribution range for genes L^Ms, R¹ (CDe), R² (cDE), P¹, Jk^a, Di^a and Se but present high values of Le and Fy^a and low ones of L^MS, L^Ns, R^o (cDe) and/or r (cde), L^NS and R^z (CDE). Unusual findings in relation to previous studies are the high prevalence of Le (a+) persons (which, however, could be expected since the frequency of gene Se is not too high) and the presence of one Lu (a+) and one PP₁ (Tj^a) (?) individuals. Comparison of the pattern of inter-village variation in relation to these polymorphisms with those furnished by historical, demographic and morphological data gives in general reasonable concordance, but some results are difficult to interpret. New approaches and further multidisciplinary studies are needed to obtain a clearer picture of the genetic relationships present among different tribes of South American Indians as well as to understand how polymorphisms are created and maintained in human populations.     

Fingerprints of Whites and Negroes from Southern Brazil

Studies on 1,115 individuals (451 Whites, 240 Light Mulattoes, 236 Dark Mulattoes and 188 Negroes) from Pôrto Alegre, Brazil are reported. The differences among those subgroups are not large and there is not a clear gradient when we consider samples with increasing Negro ancestry. The most marked difference between Whites and the total Negroid group occurred in the prevalence of radial loops. Comparison with Portuguese and African series indicates that no single factor can fully explain the observed distributions. But the values of Dankmeijer's index are exactly those expected on the assumption of 50% White admixture in the Pôrto Alegre Negro, in agreement with previous investigations.     

Chromosome relationships in three representatives of the genusHolochilus (Rodentia,Cricetidae) from Brazil

The G- and C-banded karyotype ofHolochilus brasiliensis collected in central Brazil (2n=55, AN=56, acrocentric X and Y) can be regarded as the most representative of the ancestral form of the genus.H. magnus (2n=52, AN=58, acrocentric X and Y) andH. brasiliensis vulpinus (2n=40, AN=56), both living in southern Brazil, would be in different phases of chromosome number reduction due to centric fusions.H. magnus, in addition, shows an X of variable morphology and a metacentric Y. This fact, coupled with its distinct morphology and restricted distribution, suggests that it may represent a distinct trend in the genus' main evolutionary line.     

Occurrence of a rare variant of superoxide dismutase in Brazil

During a paternity test performed in Porto Alegre, Brazil, a rare variant of superoxide dismutase, probably SOD A2, was found in a Caucasian child and the putative father. Studies of 1,700 unrelated white individuals from the same and nearby cities had never disclosed such a variant, which was also absent in 2,480 persons of other ethnic groups living in different regions of Brazil. The presence of this rare phenotype in the child and putative father led to the assignment of a very high probability of paternity to the latter.     

Interdisciplinary approaches to the human biology of South Amerindians

I briefly review the early attempts to establish interdisciplinary investigations in human biology, emphasizing those involving South American Indians. Also considered are (1) the interest in studying host-parasite relationships and the effects of culture changes in the affected populations, (2) the need for the development of appropriate intra-ethnic standards in the study of growth and other quantitative traits, (3) the similarities and dissimilarities of cultural and biologic rates of change, and (4) the purposes of multivariate comparisons. Despite difficulties arising from human nature itself, integrated approaches may yield significant clues to the understanding of evolutionary processes in South American Indians in particular or in our species as a whole.