Archivos de investigacion medica最新文献

In 1977 Scully first described the juvenile granulosa cell tumor of the ovary (JGCT) as a special variation of the granulosa cells tumor, which occurs in the two first decades of life, and 97% of the cases show characteristic microscopic and histological features. Five previous cases have been reported concerning the ultramicroscopic characteristics of this ovarian neoplasia. The purpose of this paper is to report the immunohistochemical and ultrastructural characteristics in a case of OJCGT which occurred in a four year old girl with isosexual precocious pseudopuberty. The presence of vimentin and absence of keratin was proven immunohistochemically in this ovarian neoplasia. Intermediate filaments were found ultrastructurally. The combined use of immunohistochemical and ultrastructural techniques has proven to be of extraordinary usefulness for the differential diagnosis between epithelial and non epithelial ovarian tumors and adds a new and highly specific method to characterize and differentiate the cells of embryonic carcinoma, choriocarcinomas and endodermal sinus tumors which are keratin positive.

An in vitro study of the adhesion and invasion of Shigella flexneri was implemented, by means of incubation of laminary cuts of cecal mucosa of Dunkin-Hartley guinea pigs in a suspension of Shigella flexneri, which was isolated from a patient with bacillary dysentery. The laminae were placed in plastic chambers for two hours at 37%C. After this the bacterial suspension was discarded so as to eliminate the bacilli which were not adhered. The epithelium was washed with saline and was processed for analysis with scanning electron microscope. The topology of the mucosa incubated with Shigella flexneri was similar to that of the witnesses. The bacteria which adhered to the mucosa were dispersed individually or in clumps of varied numbers. The main alteration observed upon the epithelial surface were depressions due to a lateral separation of the microvilli which may have originated the endocytic stomas containing bacterias. The results of this study allow the proposition of the use of explants, so as to study the interaction between Shigella flexneri and the intestinal epithelium, with the possibility of modifying different experimental variables.

It is known that malnourished rats show a reduction of body weight gain during postnatal development. However, more data are needed regarding the effects of protein restriction to rats fed a corn-bean and corn diets, on their body and cephalic growth. In the present work, 4 groups of adult female rats were fed during 5 weeks with diets with 23% protein (C); 8% protein (HP); corn (M); and corn-bean (M-F). Rats were mated with adult healthy male rats and the corresponding diets were continued during gestation and suckling periods. At 24 days of age, the pups of HP, M and M-F diet groups, only gained 48%, 30% and 18% respectively, in their body weight, whereas the body-length parameters (LNC and LNRC) showed a reduction of 20%, 35%, and 45%, respectively for the same diet groups. The cephalic measurements showed a significant reduction in the pups of the restricted diets when compared to data obtained in the group under control diet. The degree of alteration in the morphometric parameters was progressively greater with HP, M, and M-F, respectively.

Using a spectrofluorometric method, the concentration of the major monoamines, norepinephrine (NE), dopamine (DA), 5-hydroxytryptamine (5-), and 5-hydroxyindoleacetic (5-HIAA) was determined in cerebrospinal fluid (CSF) of patients with subarachnoid aneurysm before its rupture. DA, 5-HT, and 5-HIAA levels in CSF were found significantly increased when compared with the corresponding values found in persons with no clinical alterations of central nervous system (CNS). No significant differences were seen in NE values in CSF when data from patients with subarachnoid aneurysm were compared to their control subjects. Data obtained suggest that of NE diffusion to CSF could be at a different rate than that of the other monoamines measured. Alternatively, the reuptake of NE could vary in relation with that to the other monoamines in the affected brain tissue during the onset and development of the aneurysm. Results may also indicate a possible accumulation of NE in brain tissue adjacent to the damaged areas as a result of an increased monoaminergic activity, which, could be involved in the pathophysiology of aneurysm rupture.

In previous reports, Feria-Velasco et al. characterized an experimental model of convulsions in rats induced by monosodium glutamate (MSG) with evaluation of the motor behavior and neurochemical parameters. In the present work, MSG injected in toads (Bufo spp) reproduced the model of convulsions with some peculiarities. The electrocorticographic recordings in toads after MSG injection were similar to those obtained in rats after administration of convulsant agents. Most of the toads injected with MSG (81.8%) showed convulsions preceded by an episode of stereotyped movements and signs of hyperexcitability. Latency for convulsions and frequency of convulsive episodes were similar to what has been reported in rats injected with MSG. However, the duration of convulsive period was larger than that seen in rats, and no deaths were recorded in toads. The peculiar feature of amphibia regarding their cerebral structures and their blood-brain barrier (BBB) make the amphibian model, an interesting and valuable one in studying experimentally induced convulsions, as well as the role of BBB in these phenomena.

Nude homozygote nu/nu mice show a deficiency in their cellular immune response, due to the fact that their thymic tissue is very scarce. The purpose of this paper has been to determine whether nu/nu mice, in the presence of T lymphocytes, have the capacity of forming E rosettes with sheep erythrocytes. These mice do present them, although in significantly lower quantities when compared to the nu/+ and normal ones of Balb/c strain. This result confirms previous information which point towards the existence of other types of markers on the surface of T lymphocytes in nu/nu mice.

The athymic nu/nu mice represent a natural model for studying defense mechanisms. This study had the object of evaluating the phagocytic activity of polymorphonuclear leucocytes (PMN) and peritoneal macrophages (PM) in congenitally athymic homozygotic nu/nu mice. The results showed that the chemotaxis, random mobility, ingestion of latex particles and reduction of nitroblue tetrazolium were all normal. Nevertheless, the enzyme myeloperoxidase in the PMN was significantly diminished when compared with Balb/c mice. These results suggest a partial decrease in the oxidative metabolism of the PMN in nu/nu mice.

The formation of fluid, maturation and follicular differentiation are physiological processes unknown to this date. Therefore, changes in the electrophoretic pattern of proteins and glycoproteins in different states of maturation were studied, as well as the volume and protein concentration. Follicular fluid was collected from 43 follicles with a diameter of 2 mm., 45 follicles with a diameter of 5 mm. and 49 of 9 mm. The average of the concentration of protein for the 2 mm. follicles was 106 +/- 56.3 mg/ml of follicular fluid, for the 5 mm. ones 68.3 +/- 37.1 mg/ml and the 9 mm. ones had 52.9 +/- 21.3 mg/ml. In the protein and glycoproteins characterized by electrophoresis, a consistent pattern of 3 bands was found, and none were PAS positive in the 2 mm. follicles. In the 5 mm. follicles a 10 band pattern was found, of which 1 was PAS positive. In the last plane, the 9 mm. pattern was 12 and 2 respectively. The average value of follicular fluid was 5.3 +/- 1.8 microliters, for the 5 and 9 mm. it was 57 mu 25 microliters and 190 +/- 77 microliters respectively. Statistical analysis between volume and size show a highly significant correlation, thus suggesting the use of one of them to extrapolate the other.

Cerebellar morphogenesis as well as somatometric parameters of progenies from mothers exposed to ethyl-ether, chloroform, turpentine or thinner were registered a 24, 48 and 7 hours of age. 1. Mortality rate of 20 and 59% was observed in progenies of thinner or turpentine exposed mothers, correspondingly. 2. Delay of intrauterine growth manifested by body weight, size and cephalic diameter was evident in chloroform exposed groups (P < 0.01). 3. Cerebellar maturation delay was found in thinner or turpentine prenatally exposed litters. 4. The number of Purkinje cells was significantly reduced in ethyl-ether and chloroform exposed groups (P < 0.01). These cells were found less affected by thinner or turpentine exposure (P < 0.01).

Thalassemia has been considered a recessive, autosomic, hereditary disease, characterized by microcytic, hypochromic, hemolytic anemia, which occurs as the consequence of a defect in the synthesis of the globin chains, the two most frequent types are thalassemias a and b, which in their most severe forms are known as Hydrops Fetalis and Major Thalassemia. The patients who bear thalassemia are concentrated to those places on earth where malaria is endemic, including the Mediterranean region, Northern Africa, The Middle East, India, China and Southern Asia. The simple Heterozygotic states in both types of thalassemia are more benign and may go unnoticed or confused with iron deficiency.