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Biomedical subjects

A S Pinto

Publications and source records attributed to A S Pinto.

At least 19 recordsLinked to original sources

Changes in the masticatory cycle following treatment of posterior unilateral crossbite in children.

In a previous study, we established that young children with unilateral posterior crossbite have a longer mandibular ramus and more superiorly and posteriorly positioned condyles on the crossbite side. In this study, we evaluated chewing cycle shape and duration in 14 of the patients before treatment, and we looked for changes in cycle shape and duration 6 months after treatment with rapid palatal expansion. Mandibular kinematics was recorded while chewing gum using an optoelectric recording system at 100 Hz. Subjects were asked to chew normally for 20 cycles, chew on the crossbite side only for 20 cycles, and chew on the noncrossbite side only for 20 cycles. A special computer program selected the 10 most representative cycles from each series and computed an average duration and an average maximum excursion along 3 orthogonal axes. Multilevel linear models were used to generate an 8th-order polynomial describing average cycle shape and to test for statistically significant differences in shape between the patients and the controls and between the patients before and after treatment. Before treatment, the patients chewed more slowly than did the controls. Treatment shortened their cycle duration to equal control values. Before treatment, the patients also had larger maximum excursions than did the controls and exhibited a reverse-sequence cycle shape when chewing on the crossbite side. Treatment did not alter the patients' abnormal cycle shape. These results suggest that some features of the masticatory kinematics respond to orthodontic treatment alone, but others do not.

Case-Control Studies↗

Morphological and positional asymmetries of young children with functional unilateral posterior crossbite.

This prospective clinical study evaluated the morphological and positional mandibular asymmetry of young patients with functional unilateral posterior crossbite. The sample included 9 girls and 6 boys (8.8 +/- 1.0 years of age), evaluated at the initiation of treatment and approximately 6 months after the retention phase (1.1 +/- 0.2 years after initiation of treatment). Each patient had a complete unilateral posterior crossbite involving 3 or more posterior teeth, a functional shift from centric relation-intercuspal position, and no signs or symptoms of temporomandibular disorder. A bonded palatal expansion appliance was used to rapidly expand the maxilla (1 month) and retain the treatment changes (6 months). Zonograms were used to assess articular joint spaces, and submental vertex radiographs were used to assess morphological and positional asymmetry. The results showed that the mandible was significantly longer on the noncrossbite side than it was on the crossbite side. The asymmetry was most evident for the ramus and involved both the condylar and the coronoid processes. The posterior and superior joint spaces were larger on the noncrossbite side than they were on the crossbite side. After treatment and retention, the mandible showed no significant morphological asymmetries. Mandibular growth was greater on the crossbite side than it was on the noncrossbite side, and the mandible had been repositioned; the crossbite side had rotated forward and medially toward the noncrossbite side. We concluded that unilateral posterior crossbites produce morphological and positional asymmetries of the mandible in young children, and that these asymmetries can be largely eliminated with early expansion therapy.

Cephalometry↗

[Assessment of erectile dysfunction in patients with Parkinson's disease].

Thirty men having Parkinsons disease (PD) and 30 controls were studied prospectively by the use of the International Index of Erectile Function (IIEF) to assess erectile dysfunction (ED). Of the patients with PD (mean age of 59 years), 46.66% referred to the practice of sexual activity. All of the parkinsonians were using antiparkinsonian medication. In the control group (mean age of 63 years), 76.66% referred to the practice of sexual activity, 46.60% to arterial hypertension and 6.66% to diabetes mellitus. The median score for the PD group according to the IIEF was 34, and that for the controls 50. The main differences between the two groups were in the erectile function, orgasmic function and satisfaction with the sexual relationship. The IIEF is a multidimensional scale widely accepted to assess the ED. The data obtained suggest that ED is more frequent among parkinsonians and points out to the role of DP in the genesis of ED.

Adult↗

[Hypocholesterolemic effect of naringin and rutin flavonoids].

Flavonoids are pigments fenolics of plants that possess several biological activities, and many of these are associated with prevention of chronic diseases as cancer and hyperlipidemia. This work had as objective evaluates the effect of the flavonoids naringin and rutin on the metabolism lipidic of chicks hypercholesterolemic. In agreement with the results it can be observed that naringin and rutin reduced the levels of total cholesterol significantly, cholesterol-LDL, cholesterol-VLDL and triglycerols, not presenting, however, reductions in the levels of cholesterol-HDL.

Animals↗

[Job satisfaction in Portuguese physicians in general medicine].

OBJECTIVES: To identify the major areas of GP's job satisfaction and dissatisfaction and to study the most important reasons of GP's job dissatisfaction. DESIGN: Cross-section study. Survey by mail and personal interview. PARTICIPANTS: 1.097 GPs. SETTING: Northern region of the Portuguese Medical Association. MEASUREMENTS AND MAIN RESULTS: 46% of the 385 respondent GPs are dissatisfied with the overall job satisfaction. The rate of pay is the dimension that generates more job dissatisfaction, as also the major area that has the highest level of job dissatisfaction and has significant association with the overall job satisfaction, but has not predictive association with it. The majority declares that it is more adequate a payment system with fixed and variable components. The same regimen of work may generate satisfaction in some GPs, and dissatisfaction in others. Both the authoritarian leadership behavior and the laissez-faire style are almost nonexistent in the health centers of the satisfied GPs, but predominate in the health centers of the dissatisfied GPs. Those leadership styles are not desired by the dissatisfied GPs. CONCLUSIONS: The rate of pay generates more job dissatisfaction, but has not predictive association with the overall job satisfaction. The authoritarian leadership behavior and the laissez-faire style are by themselves generators of GP job dissatisfaction, even if the regime of work by itself does not generate it.

Adult↗

Hypolipidaemic effects of naringenin, rutin, nicotinic acid and their associations.

Atherosclerosis can be defined as being a disease of coronary circulation. The present work evaluates the action of the naringenin, rutin, nicotinic acid, isolated and in association, on the metabolism of lipids. Cholesterol, cholesterol HDL, and triacylglycerols have been dosed after retreat of blood, following the administration of the compounds dissolved in propylene glycol by intraperitoneal route in doses of 5 mg kg-1 body wt. Results evidence that naringenin and nicotinic acid, isolated as well as their association with naringenin and nicotinic acid-rutin, present the largest percentual reduction of cholesterol. On the other hand, the best results for cholesterol-HDL have been obtained with naringenin, while rutin has shown the best triacylglycerols levels.

Animals↗

Compared vectorial transmissibility of pure and mixed clonal genotypes of Trypanosoma cruzi in Triatoma infestans.

A total of 15 mixtures involving 9 different stocks attributed to the 19/20, 32 and 39 major clonal genotypes of Trypanosoma cruzi were used to infect third-instar nymphs of Triatoma infestans via an artificial feeding device. Three biological parameters were considered: (1) the percentage of infected insects (%II), (2) the number of flagellates per insect (NFI), and (3) the percentage of trypomastigotes per insect (%DIF). Genetic characterization by both multilocus enzyme electrophoresis (MLEE) and random amplification of polymorphic DNA (RAPD) indicated that in almost all cases (87%), mixtures remained present after completion of the whole cycle in the insect vector. Two lines of comparison were performed: (1) pure clonal genotypes versus corresponding mixed clonal genotypes and (2) the actual behavior of mixed clonal genotypes versus the expected behavior of the theoretical mixture (i.e. the arithmetic mean of the results observed for each of the two clonal genotypes taken separately). Statistical analyses of the variables were made difficult because of the presence of large standard deviations. Nevertheless, in several cases, mixtures differed significantly from pure clonal genotypes, and in one case the actual mixture differed significantly from the theoretical mixture. In some cases, interaction (either potentialization or reciprocal inhibition) could be suspected.

Animals↗

Distribution of bismuth in the rat after oral dosing with ranitidine bismuth citrate and bismuth subcitrate.

Bismuth preparations are used world-wide for the management of peptic ulcer disease, for eradication of Helicobacter pylori, and in the prevention and treatment of diarrhoea. However neurological toxicity of bismuth has always been a major concern and evidence has been found of the absorption of bismuth. Recent studies have suggested that the absorption of bismuth increases when bismuth salts are used with ranitidine hydrochloride. The absorption and deposition of bismuth as a result of the use of the new drug ranitidine bismuth citrate have not been yet clarified. After 15 days of twice daily oral gavage with bismuth subcitrate, 13.7 mg kg(-1) day(-1) to eight rats, deposition of bismuth was found in all the tissues studied, especially the kidney (30.81 +/- 8.59 microg g(-1) dry weight). A similar pattern of distribution and tissue concentrations was found when bismuth subcitrate was given with ranitidine hydrochloride 8.6 mg kg(-1) day(-1) to another eight rats, although this combination resulted in lower brain levels (3.12 + 1.31 microg g(-1) dry weight) than after administration of bismuth subcitrate alone (4.77 +/- 0.97 microg g(-1) dry weight). When six rats were given ranitidine bismuth citrate by gavage at 22.8 mg kg(-1) day(-1) for 15 days, kidney levels were lower (4.24 +/- 1.75 microg g(-1) dry weight) and brain levels were below detection limits; the bismuth concentrations in the faeces from this group were also significantly lower (1603 +/- 104.0 microg g(-1) dry weight) than for the two other groups. After dosing with bismuth alone or in association with ranitidine hydrochloride, bismuth was detected in several organs and deposition was not influenced by gastric pH. Blood levels correlate poorly with organ deposition and brain deposition was not always associated with encephalopathy. After administration of ranitidine bismuth citrate, significantly lower concentrations of bismuth were found in the kidney and bismuth was not detectable in the brain, suggesting lower bismuth absorption. This was confirmed by higher levels in the faeces after dosing with ranitidine bismuth citrate. Thirty days after dosing with ranitidine bismuth citrate or bismuth subcitrate, bismuth could not be detected in any of the organs examined but could be found in the urine. In conclusion, bismuth was deposited in the kidney, brain, lung and liver of rats after oral dosing with bismuth subcitrate. After oral dosing with an equivalent amount of bismuth in the form of ranitidine bismuth citrate, significantly lower concentrations of bismuth were deposited in the kidney; in the brain bismuth was not detectable.

Administration, Oral↗

[Prevalence of respiratory diseases in the textile industry. Relation with dust levels].

Many workers in the textile industry have respiratory symptoms that are related to their work environment. In this study we observed the dust level conditions of eleven textile industries of the North of Portugal. The dust levels determined were between 0.1 mg/m3 and 1.25 mg/m3, in many cases above the Portuguese standard levels of exposure (VLE). For these dust levels we found a prevalence of 23% of workers with respiratory symptoms with occupational characteristics in 10.8%, and 5.7% presenting byssinosis. Workers exposed to cotton fibres in spinning areas have the highest prevalence of symptoms, and reduction of the FEV1. These characteristics were related to dust levels and were higher in the initial phases of the spinning processes. We found no cases of byssinosis in workers exposed to synthetic fibres, or in workers from weaving areas. Smoking habits were related to the reduction of the FEV1, and severity of respiratory illness but not to the presence of byssinosis.

Dust↗

[Respiratory symptoms in the textile industry. Their prevalence in the Vale do Ave].

Some workers in the textile industry have respiratory symptoms related to their occupation. This study is aimed at evaluating the frequency of respiratory symptoms in textile industries in the North of Portugal. We evaluated 3529 workers from 20 factories (19 deal with synthetic fibres and cotton and the other deals with sisal.) Among the workers, there were 34.5% with respiratory symptoms - 24,5% referred nasal symptoms, 22,6% with bronchial symptoms and 12,6% associated both. The workers who dealt with cotton presented a higher frequency of bronchial symptoms (25,0%) than the ones dealing with synthetic fibres (12,7% p < 0,000001). The same was noticed among the workers in the opening and spinning areas, who showed a higher frequency of bronchial symptoms (28,3%) than the ones in weaving areas (12,7% p < 0,000001). We did not find any differences concerning the frequency of symptoms among the workers handling both natural fibres (cotton and sisal). Individually all the symptoms were more frequent among the workers handling natural fibres. The most frequent symptom depended on the fibre. Cough was more frequently mentioned among the workers handling synthetic fibres (9.6%) and cotton (15.7%). Among the workers who handle sisal, dyspnea was the most frequently mentioned (16.9%). Productive cough was the most frequent association (7.2% sisal; 2.8% synthetic; 8.0% cotton), and the association between dyspnea and wheezing the least mentioned (6.4% sisal; 0.5% synthetic; 5.9% cotton). The workers with bronchial symptoms (synthetic fibre and cotton) have more years of exposure and greater smoking habits. In a covariance adjusted for age and smoking habits, the workers with bronchial symptoms, exposed to cotton have more years of exposure.

Adult↗

Cell surface analysis of trypanosomes of the subgenus Schizotrypanum isolated from bats.

Two stocks (M5, M29) of trypanosomes of the subgenus Schizotrypanum were isolated from the bat Phyllostomus hastatus and analyzed for cell electrophoretic mobility (EPM) and lectin binding surface sites. Epimastigotes from the M5 and M29 stocks presented a mean EPM of around -0.57 and -0.56 microns. s-1.V-1.cm respectively. Differences in the agglutination profiles were detected between epimastigotes or trypomastigotes from the two parasite populations using lectins with specificity for D-GlcNAc, D-GalNAc, D-Gal and D-Man as probe. Major variation was observed between epimastigote forms. Additionally, the D-GlcNAc binding lectins WGA and BS II strongly interacted with the trypomastigote from both M5 and M29 stocks; this fact is evidence that these trypanosomes are distinct from Trypanosoma (Schizotrypanum) cruzi.

Agglutination Tests↗

Schizodeme and zymodeme analysis of trypanosomes of the subgenus Schizotrypanum from the bat.

Two stocks and nine clones of trypanosomes of the subgenus Schizotrypanum were analyzed based on their electrophoretic pattern of EcoR1 digestion products of kinetoplast DNA (k-DNA) minicircles (schizodeme) and isoenzymes (zymodeme). The trypanosome stocks were isolated from Phyllostomus hastatus bats collected in different locations in Minas Gerais State, Brazil. The k-DNA pattern showed major variations between stocks and microvariations among the clones. Furthermore, in one of several cloning attempts, two different populations could be isolated. Among the six enzymes studied, glucose phosphate isomerase presented different patterns for stocks and clones. No similarity was found among bat trypanosomes and Trypanosoma (Schizotrypanum) cruzi standard zymodemes. This shows that bat trypanosomes are distinct from T. (S.) cruzi.

Animals↗

[Immunodeficiency viruses].

In the first part of this article some structural and biological aspects of the HIV viruses are presented, in our opinion among the most interesting ones, connected with the AIDS viruses. Viral infection and its evolution, particularly related with infection by HIV-2, will be presented later, in the light of our experience, obtained over several years work with African people infected by the virus. The AIDS viruses are complex retroviruses, with their own identity, but also with marked structural and biological resemblances to other retroviruses, equally pathogenical for animals. The lentivirinae subfamily to which the AIDS viruses belong includes other agents, usually classified according to the host they infect. In this way, the lentiviruses of the primates contain in the same group, besides those of HIV-1 and HIV-2, viruses that infect monkeys such as SIVMAC, SIVAGM, SIVSMM, etc. The comparative study of molecular genetics and biology of human and animal retroviruses in recent years has permitted significant progress in the understanding of the possible mechanisms that lead to the Immunodepressive Acquired Syndrome that characterizes AIDS. The presence of a gene that deactivates the activated lymphocytes only present in the lentiviruses of the primates, as well as the known tropism of those viruses to CD4 lymphocytes, and not found in the other groups, are biological aspects that are pointed out. We also refer to other characteristics of HIVs such as the cytolytic and sincicial capacity of these viruses in lymphocyte culture. Finally we present an analysis of what we were able to observe in individuals infected by HIV-2 in their own and African habitat.

Acquired Immunodeficiency Syndrome↗

[Immunologic profile of HIV-2 seropositive African individuals (follow-up)].

In the geographic distribution of HIV-2, it is known that this infection is most prevalent in West Africa. Since 1986 we have studied seropositive and seronegative clusters, in Guinea-Bissau with follow-ups in 1988, 1989, 1990 and 1991. Analysis of the results show the high incidence of this infection. 8.51% of the 4,372 people of the general population studied were seropositive, showing the high predominance of HIV-2 infection. Only 4 cases were exclusively reactive to HIV-1 and a slow evolution of HIV-1 infections. In the seroconversions of HIV-2 infections the antibodies appeared first to the core components and secondly to the surface glycoproteins. Some of the laboratory parameters affected in the evolution of the infection include a gradual increase in immunoglobulins and a decrease in CD4 lymphocytes and in the CD4/CD8 ratio. A comparison of these variations in HIV-2 infected people, with or without cross-reactivity to HIV-1, reveals that they are much more evident in exclusively HIV-2 positive people. This fact can indicate that the variants responsible for the cross-reactions are less pathogenic and phylogenetically less developed.

Africa, Western↗

Biological effects of lithium chloride on the insect trypanosomatid Herpetomonas samuelpessoai.

Effects of lithium chloride on growth, differentiation and respiration of Herpetomonas samuelpessoai, cultivated in a synthetic medium were studied both at 28 and 37 degrees C. Low concentration of lithium chloride (15 mM) stimulated growth at 37 degrees C. In addition, the protozoon tolerated high concentrations (60-150 mM) of the salt at both incubation temperatures. In general, 15 mM lithium chloride increased and 150 mM decreased oxygen uptake when glucose, glutamic acid and proline were used as substrates. However, at 28 degrees C after incubation for 96 h, the highest concentration increased oxygen uptake in the presence of glucose. Sodium butyrate induced cell differentiation in H. samuelpessoai both at 28 and 37 degrees C. High concentration (150 mM) of lithium chloride inhibited cell differentiation of H. samuelpessoai induced by both controlled growth conditions and butyrate addition. The results obtained are described in this paper.

Animals↗