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Biomedical subjects

M J Pereira

Publications and source records attributed to M J Pereira.

At least 19 recordsLinked to original sources
PubMed2001

Quantitative and qualitative interferences of pentoxifillyne on hepatic Schistosoma mansoni granulomas: effects on extracellular matrix and eosinophil population.

Mast cells and eosinophils actively participate in tissue repair and are prominent components of Schistosoma mansoni granulomas. Since pentoxifillyne (PTX) is an immunomodulatory and antifibrotic substance, we aimed to characterize, by morphological techniques, the effect of this drug on fibrosis developed inside murine hepatic schistosomal granulomatous reaction, beyond the quantification of eosinophil and mast cell populations. The drug (1 mg/100 g animal weight) was administrated from 35 to 90 days post-infection, when the animals were killed. The intragranulomatous interstitial collagen network was analyzed by confocal laser scanning microscopy, the number of eosinophils and mast cells was quantified and the results were validated by t-student test. Treatment did not interfere on the granuloma evolution but caused a significant decrease in the total and involutive number of hepatic granulomas (p = 0.01 and 0.001, respectively), and in the intragranulomatous accumulation of eosinophils (p = 0.0001). Otherwise, the number of mast cells was not significantly altered (p = 0.9); however, it was positively correlated with the number of granulomatous structures (r = 0.955). In conclusion, PTX does not affect development and collagen deposition in S. mansoni murine granuloma, but decreases the intragranulomatous eosinophil accumulation possibly due to its immunomodulatory capability, interfering in cellular recruitment and/or differentiation.

Animals↗
PubMed1999

Improving the use of lichens as biomonitors of atmospheric metal pollution.

The data reported on this study supported the hypothesis that the absence of the lichen Ramalina fastigiata near a copper mine site located on the south of Portugal was related to toxic levels of Cu-dust near the centre of the mine. Lichen biodiversity reflected the impact of the copper-mine dust emissions which were more widespread towards the east, correlated with wind direction and frequency. The chemical analysis of R. fastigiata collected at different distances and in different directions from the mine showed that Cu, K and Mg were derived from the centre of the mine site, confirming thus as the major source of atmospheric dust. Total inhibition of PSII photochemical reactions occurred in R. fastigiata both under field and controlled conditions, when intracellular Cu concentrations exceeded a threshold of approximately 2.0 mumol g-1. No samples of this species were found under field conditions beyond the Cu threshold. Thus, the fluorescence parameter Fv/Fm proved to be a good estimator of the survival capacity of R. fastigiata under field conditions and thus a useful parameter in determining the sensitivity of the lichens (photobiont) to Cu pollution. The intracellular location of Cu allowed an explanation of the physiological changes and the survival of the species in the surroundings of the copper-mine.

Air Pollution↗
PubMed1999

Nursing and the health system in Brazil.

The purpose of this article is to describe nursing in the Brazilian health system and to analyze the characteristics of nursing personnel in Brazil. This description includes types of health institutions, services rendered, and the distribution of nursing personnel by professional categories in 1956, 1982, and 1995. Discussion of the challenges facing Brazilian nurses is presented using data from the Brazilian Institute of Geography and Statistics (IBGE), Federal Nursing Board (COFEn), Regional Nursing Board (COREn), and the Brazilian Nursing Association (ABEn). An increase in the number of outpatient units and in diagnostic and therapeutic examinations has led to an increased the demand for nurses. Public health nurses participate in planning, management, sanitary education, health promotion, and supervision of nursing care provided by nursing technicians, assistants, and other helpers.

Brazil↗
PubMed1998

Is the fur gene of Rhizobium leguminosarum essential?

Using primers corresponding to conserved regions of the bacterial regulatory gene fur, a homologue of this gene from the genome of Rhizobium leguminosarum biovar viciae, the nitrogen-fixing symbiont of peas, was isolated and sequenced. The fur gene is normally expressed constitutively, independent of the presence of Fe in the medium, but in one Rhizobium strain it was transcribed at a low level. Attempts to isolate a fur knockout mutant failed, suggesting that the gene is essential for free-living growth. In other bacteria, certain fur mutations confer manganese resistance; however, none of the manganese-resistant mutants of R. leguminosarum which we isolated was corrected by the cloned fur gene. When the cloned R. leguminosarum fur gene was introduced into a fur mutant of Escherichia coli, it caused some Fe-dependent reduction in the amount of siderophore, indicating that it can function heterologously.

Amino Acid Sequence↗
PubMed1998

Quantitative analysis of smooth muscle fibers in corpus cavernosum of human fetuses.

PURPOSE: Quantify objectively the normative distribution and the percentage of smooth muscle fibers in the corpus cavernosum of human fetuses with 24 weeks post-conception (WPC) of gestational age. MATERIAL AND METHODS: We studied 7 penises taken from 7 fresh human fetuses. We analyzed 5 randomized sections from each penis and in every section we analyzed 3 fields, totaling 15 fields per penis and 105 fields for the final results. Immunohistological staining for the smooth muscle fibers was used to accentuate the differences between the intracavernous structures (smooth muscle fibers and collagen fibers). The fields studied were digitized with a final magnification of 450X and a computerized analysis of the smooth muscle fibers was performed with image analyzer software. The percentage of smooth muscle fibers per standard square area was estimated and the mean value was used for each penis. RESULTS: The distribution of smooth muscle fibers in the corpus cavernosum of human fetuses with 24 WPC of gestational age ranged from 17.52% to 27.76% of the total area. The mean value was 22.72% and the standard deviation was 3.56. CONCLUSIONS: Our results show that the percentage of smooth muscle cells in corpus cavernosum of human fetuses with 24 WPC of gestational age is significantly smaller when compared with the data available for adult cadavers.

Fetus↗
PubMed1998

Schistosoma mansoni Sambon, 1907: morphometric differences between adult worms from sympatric rodent and human isolates.

A computer software for image analysis (IMAGE PRO PLUS, MEDIA CYBERNETICS) was utilized in male and females adult worms, aiming the morphological characterization of Schistosoma mansoni samples isolated from a slyvatic rodent, Nectomys squamipes, and humans in Sumidouro, Rio de Janeiro, Brazil and recovered from Mus musculus C3H/He. The following characters for males's testicular lobes were analyzed: number, area, density, larger and smaller diameter, longer and shorter axis and perimeter and extension; for females: area, longer and shorter axis, larger and smaller diameter and perimeter of the eggs and spine; oral and ventral suckers area and distance between them in both sex were determined. By the analysis of variance (one way ANOVA) significant differences (p < 0.05) were observed in all studied characters, except for the density of testicular lobes. Significant differences (p < 0.05) were detected for all characters in the female worms. Data ratify that sympatric isolates present phenotypic differences and the adult female characters are useful for the proper identification of S. mansoni isolates.

Analysis of Variance↗
PubMed1998

Autoradiographic thyroid evaluation in short-term experimental diabetes mellitus.

Previous studies have shown that in vitro thyroid peroxidase (TPO) iodide oxidation activity is decreased and thyroid T4-5'-deiodinase activity is increased 15 days after induction of experimental diabetes mellitus (DM). In the present study we used thyroid histoautoradiography, an indirect assay of in vivo TPO activity, to determine the possible parallelism between the in vitro and in vivo changes induced by experimental DM. DM was induced in male Wistar rats (about 250 g body weight) by a single i.p. streptozotocin injection (45 mg/kg), while control (C) animals received a single injection of the vehicle. Seven and 30 days after diabetes induction, each diabetic and control animal was given i.p. a tracer dose of 125I (2 microCi), 2.5 h before thyroid excision. The glands were counted, weighted, fixed in Bouin's solution, embedded in paraffin and cut. The sections were stained with HE and exposed to NTB-2 emulsion (Kodak). The autohistograms were developed and the quantitative distribution of silver grains was evaluated with a computerized image analyzer system. Thyroid radioiodine uptake was significantly decreased only after 30 days of DM (C: 0.38 +/- 0.05 vs DM: 0.20 +/- 0.04%/mg thyroid, P < 0.05) while in vivo TPO activity was significantly decreased 7 and 30 days after DM induction (C: 5.3 and 4.5 grains/100 micron 2 vs DM: 2.9 and 1.6 grains/100 micron 2, respectively, P < 0.05). These data suggest that insulin deficiency first reduces in vivo TPO activity during short-term experimental diabetes mellitus.

Analysis of Variance↗
PubMed1998

In vitro radioautographic studies of the biodistribution of radiopharmaceuticals on blood elements.

In the present study we evaluated the binding of the radiopharmaceuticals sodium pertechnetate (Na 99mTcO4), methylenediphosphonic acid (99mTc-MDP) and glucoheptonate acid (99mTc-GHA) to blood elements using centrifugation and radioautographic techniques. Heparinized blood was incubated with the labelled compounds for 0, 1, 2, 3, 4, 6 and 24 h. Plasma (P) and blood cells (BC) were isolated and precipitated with 5% trichloroacetic acid (TCA), and soluble (SF) and insoluble fractions (IF) were separated. Blood samples were prepared (0 and 24 h) and coated with LM-1 radioautographic emulsions and percent radioactivity (%rad) in P and BC was determined. The binding of Na 99mTcO4 (%rad) to P was 61.2% (0 h) and 46.0% (24 h), and radioautography showed 63.7% (0 h) and 43.3% (24 h). The binding to BC was 38.8% (0 h) and 54.0% (24 h), and radioautography showed 36.3% (0 h) and 56.7% (24 h). 99mTc-MDP study presented 91.1% (0 h) to P and 87.2% (24 h), and radioautography showed 67.9% (0 h) and 67.4% (24 h). The binding to BC was 8.9% (0 h) and 12.8% (24 h), and radioautography showed 32.1% (0 h) and 32.6% (24 h). 99mTc-GHA study was 90.1% (0 h) to P and 79.9% (24 h), and radioautography showed 67.2% (0 h) and 60.1% (24 h). The binding to BC was 9.9% (0 h) and 20.1% (24 h), and radioautography showed 32.8% (0 h) and 39.9% (24 h). The comparison of the obtained results suggests that the binding to plasma and blood cells in the two techniques used (radioautography and centrifugation) is qualitatively in accordance.

Animals↗
PubMed1998

[Process of communication in learning groups: a multiprofessional experience].

A multiprofessional experience carried out during a pedagogic course for health professionals, most of them dentists, to act on the in-service formation of middle level personnel is reported. The course was developed in group, and its task was to learn the problem posing pedagogy. The study was analyzed according to the Pichon-Rivière's theoretical framework. Data analysis has evidenced the close relationship among operativeness and the explicitness of the human relations ghosts, learning difficulties and communication disorders, evidencing the interdependence among communication and learning.

Communication↗
PubMed1997

[Integrated planning in health: a possibility of participative action].

This paper intends to report an experience with the process of integrated planning in a Basic Health Unit at Riberiao Preto-SP. we selected as our object of analysis the interactions and dialogues that were expressed in the scope of the local health system. Therefore, we sought to consider the individual dynamics of this reality and the social agents involved (teachers, students, directors, health workers and community workers), trying to understand the communicative action according to HABERMAS (1989). We believe that this is an open space in the perspective of widening the level of integrated participation in the administration of public health services.

Attitude of Health Personnel↗
PubMed1996

Using computer systems to enhance case management.

This article describes how an on-line computer system can enhance case management by improving communication within internal departments and adding consistency and objectivity to the referral process. At PacifiCare, the computer system has supported case management's efforts to provide members with cost-effective medical care and has improved satisfaction with the health plan.

California↗
PubMed1986

Solid-phase extraction and high-performance liquid chromatography analysis of lipoxygenase pathway products.

Liquid chromatography methods for quantitation of leukotrienes and HETEs (hydroxyeicosatetraenoic acids) in biological samples are described. Extraction is accomplished by acetonitrile precipitation of proteins followed by selective acetonitrile elution from a solid-phase C18 extraction cartridge. Isocratic elution of extracts from short reverse-phase columns with 3 microns C18-bonded silica results in elution of all components of interest in less than 10 min. The addition of the mobile-phase additives, trifluoroacetic acid and triethylamine, enable the peptido-leukotrienes to be eluted with excellent peak shape and unique elution times. As little as 1 pmol of each metabolite can be detected by uv spectrophotometry with a wavelength change from 280 to 235 nm midway through the chromatographic run. This method is demonstrated by the extraction and analysis of leukotriene and HETE standards from human serum.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMedDate not supplied

In the fluorescent spotlight: global and local conformational changes of small catalytic RNAs.

RNA is a ubiquitous biopolymer that performs a multitude of essential cellular functions involving the maintenance, transfer, and processing of genetic information. RNA is unique in that it can carry both genetic information and catalytic function. Its secondary structure domains, which fold stably and independently, assemble hierarchically into modular tertiary structures. Studies of these folding events are key to understanding how catalytic RNAs (ribozymes) are able to position reaction components for site-specific chemistry. We have made use of fluorescence techniques to monitor the rates and free energies of folding of the small hairpin and hepatitis delta virus (HDV) ribozymes, found in satellite RNAs of plant and the human hepatitis B viruses, respectively. In particular, fluorescence resonance energy transfer (FRET) has been employed to monitor global conformational changes, and 2-aminopurine fluorescence quenching to probe for local structural rearrangements. In this review we illuminate what we have learned about the reaction pathways of the hairpin and HDV ribozymes, and how our results have complemented other biochemical and biophysical investigations. The structural transitions observed in these two small catalytic RNAs are likely to be found in many other biological RNAs, and the described fluorescence techniques promise to be broadly applicable.

2-Aminopurine↗
PubMedDate not supplied

Differences in Brazilian strains of Schistosoma mansoni evaluated by means of morphometric analysis of cercariae of both sexes.

Morphometrics of Brazilian strains (BH, SJ and CMO) of Schistosoma mansoni cercariae were obtained with a computerized image analyzer (IMAGE PRO PLUS, MEDIA CYBERNETICS), considering the following characters: body area, tail, furcae, oral and ventral suckers and distance between them. For statistical analysis, the variance test (one-way Anova) was applied and significant differences of p< 0.05 were considered. All morphometric values in the BH strain were significantly higher (p< 0.05) than in the others. Lower values were obtained in females of SJ strain for all characters, excepting the body area. Only this character showed to be significantly different in males and females of the three strains. Specimens of both sexes in the BH and SJ strains showed significant differences regarding all characters. It was observed that this morphometric analysis permits the characterization of strains and also the sex identification in S. mansoni cercariae. Due to its feasibility, this method can be applied as a tool in laboratories devoid of more complex equipment.

Analysis of Variance↗