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Biomedical subjects

J A Rodrigues

Publications and source records attributed to J A Rodrigues.

At least 37 records · Page 2Linked to original sources
PubMed1991

Effects of cannabidiol in animal models predictive of antipsychotic activity.

The effects of cannabidiol (CBD) were compared to those produced by haloperidol in rats submitted to experimental models predictive of antipsychotic activity. Several doses of CBD (15-480 mg/kg) and haloperidol (0.062-1.0 mg/kg) were tested in each model. First, CBD increased the effective doses 50% (or) ED50 of apomorphine for induction of the sniffing and biting stereotyped behaviors. In addition, both CBD and haloperidol reduced the occurrence of stereotyped biting induced by apomorphine (6.4 mg/kg), increased plasma prolactin levels and produced palpebral ptosis, as compared to control solutions. However, CBD did not induce catalepsy even at the highest doses, in contrast to haloperidol. Such a pharmacological profile is compatible with that of an "atypical" antipsychotic agent, though the mechanism of action is uncertain and may not be identical to that of the dopamine antagonists.

Animals↗
PubMed1988

The primary structure of histone H3 from wheat.

Wheat embryo histone H3 has been isolated and purified and the elucidation of the complete amino-acid sequence is described. Peptides were generated by cleavages with CNBr, S. aureus V8 proteinase, endoproteinase Lys-C and trypsin. The peptides were purified by HPLC and the sequence determined by solid-state and gas-phase sequencing methodology. The amino-acid sequence of the protein is identical to pea embryo histone H3 and the sequence deduced from the nucleotide sequence of a wheat embryo histone gene (Tabata T. et al. (1984) Mol. Gen. Genet. 196, 397-400).

Amino Acid Sequence↗
PubMed1985

Evaluation of the frequency of stages VII-VIII and XIV of the tubular cycle of adult rats, 30 d after phenolization of the spermatic cord. Response to chronic administration of hCG.

A study was carried out to evaluate the effect of testicular denervation on the spermatogenetic activity of the testes and on the ability of the germinal epithelium to respond to chronic administration of hCG. Testes of adult rats were denervated by phenolization of the spermatic cord. An increase in the frequency of stages VII-VIII of the tubular cycle was observed 30 d later in phenolized rats treated with hCG, demonstrating an increase in the amount of spermatozoa present in the seminiferous tubules of these animals. The frequency of stage XIV remained unchanged after phenolization of the spermatic cord and/or chronic treatment with hCG, indicating that the rate of reductional divisions remained constant. The results suggest the autonomic nervous system may have some functional significance by participating in a neuroendocrine mechanism and consequently in the spermatogenesis.

Animals↗
PubMed1982

Pubertal maturation of the lh stimulatory response to clomiphene citrate in congenital virilizing adrenal hyperplasia.

To determine the LH release response to clomiphene citrate in children with virilizing congenital adrenal hyperplasia (CAH), we examined six patients with glucocorticoid-treated virilizing CAH, five girls and one boy, chonological age (CA) 4 years 2 months-15 years 9 months and bone age (BA) range 8-18 years. All the patients but one, were treated with nocturnal dexamethasone. Their ages at the onset of treatment ranged from 2 years 6 months to 13 years 8 months. An additional boy (CA = 4 years 3 months and BA = 7-8 years) was studied 10 days after removal of a virilizing adrenal adenoma. Clomiphene citrate (3mg/kg/day) was administered orally in two doses/day for 8 days. Venous blood was collected on days 0, 4, 6 and 8. Two patients were also studied in consecutive years. In three patients no increase was noted over the basal levels of LH, but in the others LH rose during clomiphene administration. In two patients studied in consecutive years, there was detectable shift of LH release pattern. The basal LH levels and the sum of responses (day 4, 6 and 8) to clomiphene citrate and particularly their decimal logarithms were statistically significantly correlated with their respective BA. These results confirm that previous prolonged exposure to elevated concentrations of adrenal sex steroids, in children with treated virilizing CAH, may induce precocious maturation of the hypothalamic pubertal mechanism of LH secretion. This maturation was closely correlated with the degree of skeletal maturation.

Adrenal Hyperplasia, Congenital↗
PubMed1980

Localization of kallikrein in submandibular gland of cat, guinea pig, dog, and man by the immunoperoxidase method.

The sensitive immunoperoxidase method was used to localize kallikrein in the submandibular gland of the cat, guinea pig, dog, and man. In every instance, kallikrein was localized in the apical region of duct cells, a location suggesting its secretion into the duct system. There was no evidence of the enzyme in other cells or interstitial tissue in the gland. The major source of submandibular gland kallikrein, therefore, must be of ductal origin. The classification of kallikreins with the widely distributed group of serine proteases is discussed, as is their possible significance in regulating physiological processes by specific and limited proteolysis.

Animals↗
PubMed1978

Studies on kallikrein in the duct systems of the salivary glands of the cat.

By correlating immunofluorescence light microscopy with electron microscope studies and with kallikrein concentrations under various conditions, we have made the following observations and conclusions about kallikrein in the submandibular and other salivary glands.1. In the submandibular gland, specific immunofluorescence to kallikrein was observed in the luminal region of the striated ducts particularly, but also in the outer epithelial cells of the stratified epithelial collecting ducts. Sympathetic nerve stimulation resulted in a reduction in intensity of specific fluorescence and in its increased localization towards the lumen. The nearly complete elimination of kallikrein from the gland by duct obstruction for four days resulted in complete disappearance of specific fluorescence in the gland. Prolonged parasympathetic nerve stimulation at frequencies which did not reduce the kallikrein concentration of the gland failed to alter the specific immunofluorescence despite copious secretion of saliva. Our results failed to reveal evidence of secretion of kallikrein either into or towards the interstitium of the gland. The luminal layer of stratified epithelial cells in the collecting ducts contained small secretory granules closely resembling those in the striated ducts. Our results are not conclusive, but do suggest that kallikrein is located in these granules whence it is secreted into the lumen of the duct.2. The parotid gland was found to contain much lower concentrations of kallikrein than the submandibular gland. This finding was associated with the presence of far fewer striated ducts in the parotid gland. Otherwise, specific fluorescence and the response to sympathetic nerve stimulation was like that of the submandibular gland. Small secretory granules in the striated and collecting ducts resembled those of the submandibular gland.3. The sublingual gland, like the parotid, had a low concentration of kallikrein and very few striated ducts. These ducts were unevenly distributed and were concentrated in only a few lobules of the gland. Specific immunofluorescence was seen only in sections containing striated ducts.4. The possible physiological role of kallikrein in the salivary glands is discussed.

Animals↗
PubMedDate not supplied

Candida spp. biotypes in the oral cavity of school children from different socioeconomic categories in Piracicaba-SP, Brazil.

Two hundred and thirty-nine (239) Brazilian children, distributed into five distinct socioeconomic categories (A to E) were studied. Saliva samples were analyzed as to flow rate, pH, buffer capacity and microbial parameters. The results revealed the presence of Candida spp. in 47.3% of the samples. The most commonly isolated species was C. albicans, in all socioeconomic categories, followed by C. tropicalis, C. krusei and C. parapsilosis. There was no statistical correlation between secretion rate, buffer capacity and Candida spp. CFU/ml. The prevalence of Candida spp. did not differ substantially among the groups; however the microorganisms were more detected in categories B and C. Among all species, C. albicans was the most prevalent. Only 5% of the sample presented more than one species--C. albicans associated with C. tropicalis, C. parapsilosis or C. krusei. It was possible to detect a significant correlation between caries indices and the socioeconomic categories. All categories presented increased caries indices; however the studied population was considered of low caries risk. There was no positive correlation between the presence of Candida and caries risk in the analyzed population.

Brazil↗
PubMedDate not supplied

In vitro microleakage of glass-ionomer composite resin hybrid materials.

The purpose of this study was to evaluate the microleakage of six glass-ionomer composite resin hybrid materials compared with a glass-ionomer cement and a composite resin. Standardized class 5 dentin cavities were prepared on root surfaces of 240 extracted human teeth that were randomly assigned to eight groups and restored using the following restorative systems: (I) Vitremer, (II) Compoglass, (III) Photac-Fil Aplicap, (IV) Variglass, (V) Dyract, (VI) Fuji II LC, (VII) Ketac-Fil Aplicap, and (VIII) Z100. The teeth were thermocycled, placed in a 2% methylene blue solution, and sectioned with diamond disks. Dye penetration was scored on a scale of 0-3. Results showed no significant differences among groups VIII, IV, I, V, VI, III, and II. There were also no significant differences among groups VI, III, II, and VII.

Acrylic Resins↗
PubMedDate not supplied

Electromyographic analysis of the pectoralis major and deltoideus anterior muscles in horizontal "flyer" exercises with loads.

The effective activity of the pectoralis major and deltoideus anterior muscles in horizontal "flyer" exercises with external loads of 25, 50, 75 and 100% of the maximum load was studied in 11 male volunteers. The electromyographic analysis was done by using MEDI-TRACE-200 surface electrodes connected to a biological signal acquisition mode coupled to a PC/AT computer. The electromyographic signals were processed and the values obtained were normalized through maximum voluntary isometric contraction. It was statistically observed that in all types and loads of this exercise, the muscles presented significant differences in the concentric and eccentric phases. In the concentric phase, when different loads were compared, the muscles were more active with 75 and 100% of the maximum load, while in the eccentric phase, higher activity was observed with 100% of the maximum load. By analyzing each load effect in the concentric phase, it was verified that the muscles on the left side were more active than those on the right side with 25, 75 and 100% of the maximum load.

Adolescent↗
PubMedDate not supplied

Electromyographic analysis of the pectoralis major and deltoideus anterior in the inclined "flying" exercise with loads.

Due to a shortage of textbooks with specific data on muscular activity concerning physical conditioning and sports, we analysed electromyographically the muscles pectoralis major and deltoideus anterior, bilaterally, in inclined "flying" exercises, during the concentric and eccentric phases, with external loads of 25, 50, 75 and 100% of the maximum load. The electromyographic analysis was performed in eleven male volunteers with MEDI-TRACE-200 surface electrodes connected to a six-channel biologic signal acquisition module coupled to a PC/AT computer. The electromyographic signals were processed and the obtained effective values were normalized through maximum voluntary isometric contraction. Statistically, the results showed that all the muscles studied presented significant differences between the concentric and the eccentric phases, with higher electromyographic activity during the concentric phase. By analysing the different loads for each muscle in both phases, significant electromyographic activity was observed for all muscles. When the effect of each load on each muscle during the concentric phase was analysed, it was noticed that the muscles on the left were more active than those on the right side, while in the eccentric phase the muscles had different behavior.

Adolescent↗