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Biomedical subjects

J Costa

Publications and source records attributed to J Costa.

At least 73 records · Page 4Linked to original sources
PubMed2000

Pre-treatment with prednisolone does not improve the efficacy of subsequent alpha interferon therapy in chronic hepatitis C.

BACKGROUND/AIMS: Alpha interferon administration is quite disappointing as a single therapy in chronic hepatitis C. A brief course of corticosteroid therapy might increase the effectiveness of subsequent alpha interferon administration, but data on this issue are controversial. METHODS: One hundred and fifty-six consecutive patients with chronic hepatitis C were randomly assigned to be treated blind with tapering doses of oral prednisolone or placebo for 4 weeks. Two weeks after cessation of therapy, patients received alpha interferon (3 MU t.i.w.) for 48 weeks and were followed for 24 additional weeks. Response was defined by the presence of normal alanine aminotransferase (ALT) and negative HCV-RNA in serum. RESULTS: ALT activity decreased during prednisolone administration and rebounded upon withdrawal in 38% of the patients treated with this drug. Significant changes in serum bilirubin were not observed. HCV-RNA serum concentration tended to increase during prednisolone administration and to decrease upon withdrawal. ALT and HCV-RNA did not change during administration of placebo. At the end of interferon administration, 33% of patients treated with prednisolone and 25% of those treated with placebo presented biochemical and virological response. At the end of post-treatment follow-up, response was maintained in 12% and 13% of patients treated with prednisolone or placebo respectively. Response was not related to ALT or HCV-RNA changes observed during the pre-interferon phase of the study. No adverse events related to prednisolone administration were observed. CONCLUSIONS: Prednisolone administration and withdrawal induced a rebound in ALT activity and a decrease in HCV-RNA serum concentration in about one third of the patients with chronic hepatitis C. However, these changes did not enhance the effectiveness of subsequent alpha interferon therapy.

Adult↗
PubMed2000

Cytopenia and past human parvovirus B19 infection in patients with primary Sjögren's syndrome.

OBJECTIVES: To determine the clinical significance of human parvovirus B19 infection in patients with primary Sjögren's syndrome (SS) and to investigate the immunologic and hematologic features related to B19 infection. METHODS: We included 80 consecutive patients with primary SS (74 women and 6 men), with a mean age of 62 years (range, 24 to 87 years) that were seen in our Unit. All patients fulfilled the European Community criteria for SS. As controls, we included 140 consecutive sera samples analyzed for B19 antibodies in our Microbiology Department and obtained from adult inpatients and outpatients of our Hospital. Serum from all patients and controls was tested for antibodies to B19 by enzyme-linked immunosorbent assay (ELISA). Additionally, the presence of B19 DNA in serum and in circulating leukocytes was investigated by nested polymerase chain reaction (PCR). RESULTS: Serological evidence of past B19 infection (positive IgG antibodies without IgM antibodies) was present in 28 (35%) patients with primary SS. None of these patients showed evidence for B19 viremia, and B19 virus DNA was not detected in the circulating leukocytes of IgG-B19(+) patients. Positivity for IgM antibodies to B19 was not detected in any patient. When compared with patients without evidence of past B19 infection, those with primary SS and past B19 infection showed a higher prevalence of cytopenia (57% v 15%; P < .001), and, specifically, of leukopenia (36% v 4%; P < .001). Additionally, when compared with controls positive for IgG-B19, SS patients with these antibodies had a higher prevalence of cytopenia (57% v 13%; P < .001), leukopenia (36% v 3%; P < .001) and thrombocytopenia (21% v 0%; P = .003). CONCLUSIONS: Serological evidence of past B19 infection is associated with the presence of cytopenia in our patients with primary SS. A possible relationship between B19 infection and the presence of cytopenia in primary SS may occur in some patients immunologically or genetically predisposed.

Adult↗
PubMed2000

Long-term egg production and heterosis in quail lines after within-line or reciprocal recurrent selection for high early egg production.

1. Four Japanese quail lines were developed using 13 generations of reciprocal recurrent (lines AA and BB) or within-line selection (lines DD and EE) for high egg number until 98 d of age. In these lines and their reciprocal crosses, egg production, egg weight and mortality were monitored for up to 21 months to evaluate the impact of selection method and line origin on long-term production and heterosis. 2. Both hen-housed total egg number (EN) and hen-day egg laying rate (ELR) were consistently lower in recurrent lines than in lines under within-line selection: after 13 months of test, the difference was -47.1 eggs for EN and -20% for ELR%, whereas mortality was similar at around 20%. 3. Line EE was the best pure line for early egg production (55.2 eggs at 98 d of age) and also gave eggs which were consistently about 2 g larger than those from line DD but it had the highest overall mortality (78.5%) of all lines. On average, line DD laid 399 eggs (EN) over the whole experiment, 84 more than Line EE. 4. Crossbreds from the 2 types of pure lines and line DD had similar patterns and rates of egg production during the whole experiment, as indicated by the similarity of the curves adjusted for those lines by using the monomolecular model for EN and the modified compartmental model for ELR. 5. However, heterosis was higher from recurrent selection lines and it increased more with time than did heterosis from within-line selection lines.

Animals↗
PubMed2000

Entomological fauna from Reserva Biológica do Atol das Rocas, RN, Brazil: I. Morphospecies composition.

Atol das Rocas, the unique atoll in the South-western Atlantic, is located 144 nautical miles (266 Km) northeast from the city of Natal, NE Brazil and 80 nautical miles from Arquipélago de Fernando de Noronha, with geographic co-ordinates 3 masculine51'S and 33 masculine49"W. It's of volcanic origin and coralline formation. The reef is ellipsoid, its largest axis (E-W) is approximately 3.7 km long, and the shortest (N-S) is 2.5 km. Inside the lagoon, there are two islands: the Ilha do Farol and Ilha do Cemitério, which comprehend 7.2 Km2 of emerged area. The Atol das Rocas lodges 143,000 birds, mainly by Sula dactilatra, S. leucogaster, Anous stolidus, A. minuta and Sterna fuscata. Due to their remote location, the islands remain largely undisturbed by the human activities. Aiming to a first characterization of the entomological diversity and the general trophic niches of atoll's entomofauna, three collects were made (1994, 1995 and 1996) utilizing several methods for a wide sample. One thousand six hundred and six insect specimens were collected belonging to eight orders: 1. Coleoptera - 333 individuals of Dermestidae (Dermestes cadaverinus); Tenebrionidae (Phaleria testacea and morphospecies) and Curculionidae (one morphospecies); 2. Dermaptera - 50 individuals of Carcinophoridae (Anisolabis maritima); 3. Diptera - 281 individuals of Ephydridae (Scatella sp. and Hecamede sp.) and Hippoboscidae (one morphospecies); 4. Hymenoptera - 45 individuals of Formicidae (Brachymyrmex sp.); 5. Lepidoptera - 111 individuals of Microlepidoptera (one morphospecies); 6. Mallophaga - 18 individuals in birds (two morphospecies); 7. Orthoptera - 237 individuals of Acrididae (Schistocerca cancellata), Tridactylidae (one morphospecies) and Blattidae (three morphospecies); 8. Thysanoptera -531 individuals (one morphospecies). Also were collected 112 individuals of Arachnida. The taxa of the Order Araneae were represented by the families: 1. Miturgidae (Cheiracanthium inclusum); 2. Salticidae (two morphospecies) and 3. Segestriidae (Ariadna sp.); 4. Theridiidae (Achaearanea sp. and Latrodectus geometricus). For the Order Scorpionida, only samples of Buthidae (Isometrus maculatus) were collected. Through field observations, it was concluded the most insects are detritophagous and/or necrophagous. It is suggested that which the dimension of ecological niches of the insects are a function of the droppings, trash and corpses of birds. A low diversity in the entomofauna of atoll, with its 25 morphospecies, was ascertained.

Journal Article↗
PubMed2000

Natural history of Ctenus medius Keyserling, 1891 (Araneae, Ctenidae) I: observations on habitats and the development of chromatic patterns.

Ctenus medius Keyserling, 1891 is a common species in several spots of Mata Atlântica, however there is a great lack of studies in all aspects of its natural history. This work aims to elucidate aspects of ecotope preference compared to large spiders, and to provide data on the development of chromatic patterns during its life cycle. The observations on the behavior of C. medius were done in the campus of Centro Universitário de Barra Mansa (UBM) by means of observations and nocturnal collections using cap lamps. For observations on the development of chromatic patterns, spiderlings raised in laboratory, hatched from an oviposition of a female from campus of UBM, and others spiderlings collected in field were used. The field observations indicate that: C. medius seems to prefer ecotopes characterized by dense shrub vegetation or herbal undergrowth; Lycosa erythrognatha and L. nordeskioldii seems to prefer open sites; Phoneutria nigriventer seems to prefer shrub vegetation and anthropogenic ecotopes as rubbish hills; Ancylometes sp. seems to prefer ecotopes near streams. Concerning chromatic patterns, it was observed that males and females show well distinct patterns during the last two instars, allowing distinction by sex without the use of a microscope. Through chromatic patterns it was also possible to draw a distinction between C. medius and C. ornatus longer that 3 mm cephalothorax width. 69 specimens of C. medius (males and females) collected in the campus of UBM did not show a striking polymorphism in chromatic pattern, but one among 7 adult females collected in National Park of Itatiaia, showed a distinct chromatic pattern.

Animals↗
PubMed2000

Chromosome homogeneity in populations of Triatoma brasiliensis Neiva 1911 (Hemiptera - reduviidae - triatominae).

Triatoma brasiliensis is the most important vector of Chagas disease in the semiarid zone of the Northeast of Brazil. Several authors have reported the occurrence of four chromatic patterns with morphological, ecological, and genetic differences. In order to determine the existence of cytogenetic differentiation between these chromatic forms, we analyzed their karyotypes and the chromosome behavior during the male meiotic process. Triatoma brasiliensis shows distinct and specific chromosome characteristics, which differ from those observed in all other triatomine species. However, no cytogenetic differences were observed between the four chromatic forms of T. brasiliensis. The lack of chromosome differentiation among them could indicate that the populations of this species are in a process of differentiation that does not involve their chromosomal organization.

Animals↗
PubMed2000

Human immune response to sand fly salivary gland antigens: a useful epidemiological marker?

Antibody (IgG) responses to salivary gland homogenate and to a recombinant salivary protein from the sand fly Lutzomyia longipalpis were investigated using sera from children living in an endemic area of visceral leishmaniasis in Brazil. We classified children into four groups according to their responses to Leishmania antigen: (Group I) positive serology and positive delayed type hypersensitivity (DTH), (Group II) positive serology and negative DTH, (Group III) negative serology and positive DTH, and (Group IV) negative serology and negative DTH. A highly significant correlation was found between anti-salivary gland IgG levels and DTH responses. An L. longipalpis salivary recombinant protein used as an antigen in an enzyme-linked immuno sorbent assay (ELISA) gave a significant but different result. A positive correlation was found between anti-Leishmania IgG and anti-recombinant protein IgG titers. The results indicate that sand fly salivary proteins may be of relevance to the study the epidemiology of leishmaniasis.

Animals↗
PubMed2000

Clinicians are from Mars and pathologists are from Venus.

CONTEXT: Text reports convey critical medical information from pathologists, radiologists, and subspecialty consultants. These reports must be clear and comprehensible to avoid medical errors. Pathologists have paid much attention to report completeness but have ignored the corresponding issue of report comprehension. This situation presents an increasingly serious potential problem. As laboratories are consolidated and as reports are disseminated in new ways (eg, via the World Wide Web), the target audience becomes more diverse and less likely to have any contact with pathologists beyond the written reports themselves. OBJECTIVE: To compare clinician comprehension with pathologist intent in written pathology reports. METHODS: Typical surgical pathology reports relevant to surgeons and covering a range of specimen complexity were taken from our hospital files. Questionnaires based on these cases were administered open-book-examination style to surgical attending physicians and trainees during surgical conferences at an academic medical center. MAIN OUTCOME MEASURES: Scores from questionnaires. RESULTS: Surgeons misunderstood pathologists' reports 30% of the time. Surgical experience reduced but did not eliminate the problem. Streamlined report formatting exacerbated the problem. CONCLUSIONS: A communication gap exists between pathologists and surgeons. Familiarity with report format and clinical experience help reduce this gap. Paradoxically, stylistic improvements to report formatting can interfere with comprehension and increase the number of misunderstandings. Further investigation is required to reduce the number of misunderstandings and, thus, medical errors.

Communication↗
PubMed2000

[Medical and Human Biological Sciences department of the University of Corsica as a tool for public health development].

To overcome the difficulties of access to training in health and the absence of biomedical research, the territorial community of Corsica recommended the implementation of a Department of Medical Sciences and Human Biology within the University of Corsica. It is within the framework of this department that different training courses targeting the full range of actors in the health system were organised, the large majority in agreement with medical faculty from the continent. It is also within this framework that a set of research themes was developed, permitting at full term, a better health management of the population. After four years in existence, we propose an assessment of training actions, and the results of the research work that associated hospital practitioners and university research professors and which allows one to imagine, notably, the development of a research axis in geography and health on the theme, "Genetics-Public Health-Environment in the Islands of the Mediterranean".

Biology↗
PubMed2000

[Distribution and characterization of different populations of Triatoma brasiliensis Neiva, 1911 (Hemiptera, Reduviidae, Tritominae)].

Triatoma brasiliensis Neiva, 1911 is now considered the most important Chagas disease vector in the semiarid zones of northeastern Brazil. Four distinct populations of T. brasiliensis have been identified by multidisciplinary studies: brasiliensis (Caicó, RN), melânica (Espinosa, MG), macromelasoma (Petrolina, PE), and juazeiro (Juazeiro, BA). By scanning electron microscopy of egg exochorion, each population displayed a distinct ornamentation pattern. The brasiliensis, macromelasoma, and juazeiro populations were found in both artificial ecotopes and the wild, while the mel anica population was collected only in the wild. Isoenzymatic analysis detected phenotypic and genetic differences among them, with the melânica population being the most distinct. The brasiliensis population is the most important one from an epidemiological point of view, with the widest geographic distribution, the highest Trypanosoma cruzi infection rate, and occupying a wide variety of ecotopes.

Animals↗
PubMed2000

[Ultrastructural characteristics of glaucomatous trabecular meshwork].

PURPOSE: To compare the normal and glaucomatous trabecular meshwork ultrastructure and to relate the observed changes with the intraocular pressure increase characteristic of the primary open angle glaucoma. METHODS: 21 non glaucomatous trabecular meshworks, aged 23 to 99 years, and 5 from patients diagnosed of primary open angle glaucoma, aged 40 to 65 years, were fixed by Karnovsky's solution and processed and observed by transmission electron microscopy and their morphological characteristics were qualitatively compared. RESULTS: Ultrastructural changes of glaucomatous trabecular meshworks are similar, but much more intense, than those observed in the aged normal trabecular meshworks. These changes are loss of endothelial cells, thickening of basal membranes and trabecular beam central nucleus changes such as an increase of electrodense plaques and collagen degenerative processes. CONCLUSIONS: Ultrastructural changes observed in glaucomatous trabecular meshworks are comparable to an early aging of them. These changes can be related with the mechanisms that increase the intraocular pressure in primary open-angle glaucoma.

Adult↗
PubMed2000

[Morphological alterations of the trabecular meshwork in primary open angle glaucoma].

PURPOSE: In the present essay we have compared the morphology and structure of normal trabecular meshworks and glaucomatous trabecular meshworks with the purpose of obtaining information about the etiopathogeny of primary open angle glaucoma. METHODS: We have observed by conventional light microscopy and scanning electron microscopy a total amount of 20 trabecular meshworks from non-glaucomatous patients and 35 trabecular meshworks from surgical pieces of trabeculectomy performed in patients diagnosed of primary open angle glaucoma. RESULTS: We have observed that glaucomatous trabecular meshworks show morphological and structural alterations of their trabecular beams, as their enlarging, collapse, the partial loss of endothelial cells and the existence of plenty of material accumulated on them, like pigment granules and calcium precipitates. CONCLUSIONS: Glaucomatous trabecular meshworks present morphological and structural alterations which can be related to etiopathogeny of primary open angle glaucoma since they modify the normal conditions of drainage of aqueous humour to Schlemm's channel.

Adult↗
PubMed2000

[Numbers needed for treatment and their respective confidence intervals: useful tools to assess clinical significance and uncertainty associated with medical interventions].

This is a narrative review of a concept--number needed to treat (NNT). The proprieties of NNTs are described. Furthermore NNTs as important tools for medical decision are discussed. In particular, conditions that make calculus and the interpretation of NNTs somewhat more complex are commented. Namely, we consider situations where the results are not primarily binary or are expressed as "time to event" or come from a meta-analysis. The inconsistencies that might occur when NNTs are calculated from meta-analysis are discussed in some detail. Definitions for parameters derived from NNTs, as numbers needed to harm (NNH), unqualified success (NNTUS) and unmitigated failure (NNHUF) are given. Finally the usefulness of NNTs and absolute risk reductions to communicate risk to individual patients are considered. It is concluded that despite NNTs being powerful tools for medical decision, in the case of communicating risks to the individual patient absolute risks might be preferable.

Confidence Intervals↗
PubMed1999

[Analysis of a case of severe congenital toxoplasmosis].

BACKGROUND: To describe a case of severe congenital toxoplasmosis because of inadequate surveillance of a seronegative pregnant woman and to evaluate the usefulness of different microbiological diagnostic methods after birth. METHODS: We applied serology, DNA amplification by one-tube semi-nested PCR, cell culture and mice inoculation analysis. RESULTS: Anti. T. gondii serology was useful for the diagnosis of congenital toxoplasmosis. PCR analysis of neonate cerebrospinal fluid and peripheral blood were positive, and yielded negative results after a few days of specific treatment. Cellular culture and mice inoculation yielded negative results. CONCLUSIONS: Our results suggest that serology and PCR are useful methods for the diagnosis of toxoplasmosis in newborns. Prenatal toxoplasmosis screening and suitable follow up of the seronegative pregnant women are necessary to prevent cases of severe infection in our area.

Acute Disease↗