Biomedical subjects
Publications and source records attributed to R A Lopes.
Hypervitaminosis A induces the following changes in the rat parotid gland: smaller size acini with lower cells and a smaller number of cytoplasmic granules, decreased acidophilia, and smaller nuclei. The striated ducts show smaller, disorganized cells with smaller nuclei, as well as increased secretion in their lumina. These data were confirmed by morphometric techniques.
Daily administration of 100 I.U. vitamin A/gram body weight to rats, for a period of 15 days, had the following effects: Body weight of rats treated with excess vitamin A was lower (84.0 g) than that of the controls (147.0 g). The weight of the Harderian gland was lower of rats injected with vitamin A (54.0 mg) than for the controls (87.0 mg). Histological examination of the Harderian gland in the hypervitaminotic animal showed smaller acini, lower cells, wide lumina and small nuclei when compared with the controls. These data were confirmed with morphometric techniques.
Testicle lesions and spermatogenetic activity in adult rats submitted to hypervitaminosis A were determined by quantitative studies of the germinal epithelium and of Leydig cells. Hypophysary levels of luteinizing hormone (LH) and relative weights of the adrenals were also determined, and the results were interpreted as being caused by the double mechanism of action (direct and indirect) of vitamin A.
In a previous paper, Lamano Carvalho et al. [4] demonstrated that administration of excess vitamin A doses to adult rats causes decreased testicle mass, focal lesions in the seminal tubule epithelium, and reduction in the relative volume of interstitial tissue and in the nuclear volumes of Leydig cells. The hypervitaminotic animals also showed alterations in the rhythm of spermatogenesis and reduced hypophysary LH levels. In order to determine the possible reversibility of these alterations, the authors allowed the hypervitaminotic animals to recover for 50 or 100 days. After both recovery periods. the focal lesions in the germinal epithelium were still unreversed. On the other hand, the nuclear volume of Leydig cells and the rhythm of spermatogenesis, as well as hypophysary LH levels reverted to normal during the 50 day recovery period.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
In this study, a bibliographic survey is made of all articles, published during the last few years, dealing with allergic reactions to latex. The first article on allergic reactions associated with latex was published in Britain, in 1979. Since then, the number of cases reported have increased (Barton, 1993). Type I allergic reaction (immediate reaction) and Type IV (delayed reaction) are part of the latex allergic process (Steelman, 1995). Contact allergy is due to inadequate washing during manufacture, which results in the retention of water-soluble proteins that cause allergic reactions in susceptible people. A wide variety of allergic reactions that vary from contact dermatitis to anaphylatic shock are described in literature. These finding show that a health team must know the probable implications of latex allergy.
PURPOSE: The aim of this study was to investigate the denture-induced fibrous inflammatory hyperplasia (FIH) that occurs around the borders of an ill-fitting denture, in relation to frequency of the lesion, age and sex distribution, length of denture use, and frequency of dysplasia. MATERIALS AND METHODS: A comprehensive review of FIH diagnosed in patients wearing dentures by the oral pathology diagnostic service at the University of São Paulo over 26 years (1971 to 1996) was undertaken, based on retrospective analysis of the oral histopathologic files. RESULTS: The frequency of FIH was 15% of the total number of pathologies diagnosed at the service of oral pathology in that period. The disorder occurred predominantly in the fifth and sixth decades of life and more often among females, at a proportion of 5:1. The frequency of FIH was higher for a length of denture use of between 1 and 10 years. Dysplasia was found in 4% of cases. CONCLUSION: The knowledge of some aspects of FIH, especially the possible histologic alteration of dysplasia, supports the importance of the diagnosis and treatment of the lesion and suggests that any excised tissue should be submitted to histopathologic evaluation. Education and regular review of patients who have worn dentures are essential if the development of FIH is to be prevented.
Explore the source record for details and available documents.
To analyze comparatively through electromyography (EMG) the orbicularis oculi muscle from normal patients and those indicated to receive eye prosthesis (treated patients), it was studied 24 male patients with a mean age of 32.5 years old, who were divided into 2 groups as follows: 12 individuals with absence of the left eyeball and indicated to receive prosthesis (treated); 12 normal individuals (control). The work was performed in 4 different clinical conditions: initial resting; normal opening and closure of the eyelids; forced opening and closure of the eyelids and final resting, before and after placement of eye prosthesis. The exams were made using an Electromyograph K6-I Light Channel and Surface Electrodes. By the results obtained under the work conditions, we can conclude that: the use of eye prosthesis did not interfere in the clinical conditions of opening and closure of the eyelid; the loss of the eyeball increases the EMG activity of the orbicularis oculi muscle; the use of eye prosthesis for a period of 7 days, was not enough to diminish the muscular activity, even its perfect adaptation been evidenced clinically.
Male rats were subjected to hypervitamin A treatment by daily intraperitoneal injections of 150 UI Arovit per g body weight. Another group of rats were injected intraperitoneally with saline solution for ten days and were used as controls. The results indicated that: 1) the body weight of animals treated with excess vitamin A was decreased; 2) histological analysis of the esophageal epithelium in treated animals showed increased thickness, characterizing a picture of hyperplasia and hypertrophy. On the basis of the results obtained, we suggest that excess vitamin A may act on the esophageal epithelium by direct action on the epithelial structures, stimulating and increase of the mitosis, and on the epithelium (mediated by the adrenals), resulting in increased thickness due to the concentration of a larger number of more immature cells. These alterations were more evident in the lower esophageal third.
In the present study we describe the morphological and morphometric alterations induced by Bolivia strain of the Trypanosoma cruzi in the mouse parotid gland during the acute period of infection. The acinar cells exhibit reduced eosinophilia, greater chromatin condensation, reduced height and consequent dislocation of the nucleus towards the basal pole. Then lumen is reduced. The ducts are dilated and lined with low cylindrical epithelium. The septa are wider. An intense lymphoplasmocytic infiltrate is present. Amastigotes was found in glandular acini cells, striated duct cells, inter and intralobular connective tissue, muscle walls of blood vessels, and inside the striated duct lumen.
A decrease in rat submandibular gland parenchyma could be observed with increasing age, consequent to an apparent increase in the proportion of intralobular ducts. Signs of acinar atrophy were noted with nuclei of smaller volume. A great variety of nuclear sizes and shapes was also observed. The blood vessels were smaller, and the connective tissue was increased. These histological data were confirmed in part by application of the technique of Chalkley. The granulous duct cell height is smaller in old animals.
Daily administration of 150 IU vitamin A/gram of body weight in mice, during 10 days, led the authors to observe: submandibular glands showed acini of slightly reduced size, with lower cells whose contours were not always sharp and containing smaller number of cytoplasmic granules. The nuclei of the acinar cells were reduced in volume. The granulose ducts were similar to those of the controls in size but showed signs of degeneration as well as cell nuclei of reduced volume. The striated ducts were smaller than those of the controls, while the excretory ducts were dilated, with lower cells and nuclei of reduced volume. General examination showed that the hypervitaminotic animals had more abundant connective stroma than the controls. The glandular structures were studied morphometrically and estereologically.
Explore the source record for details and available documents.
Explore the source record for details and available documents.