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Biomedical subjects

I Abreu

Publications and source records attributed to I Abreu.

11 recordsLinked to original sources
PubMed2006

Ultrastructure and germination of Vitis vinifera cv. Loureiro pollen.

The cultivar Loureiro of Vitis vinifera is one of the most economically important, recommended in almost the totality of the Região Demarcada dos Vinhos Verdes. In vineyards, the grape productivity of this cultivar is normal while in others it is extremely low. The aim of this work was to study the morphology and germination of Vitis vinifera cv. Loureiro pollen with high and low productivity. The pollen grain was examined under light, transmission and scanning electron microscopy. Typically V. vinifera pollen present three furrows but in the cultivar Loureiro we found tricolporated and acolporated (without furrows or pores) pollen grains. Both pollen types present generative and vegetative cells with the usual aspect and a dense cytoplasm rich in organelles. In the acolporated pollen a continuous exine layer and an irregular intine layer were observed. Differences were found in the starch accumulation, since only in tricolporated pollen abundant plastids filled with numerous starch granules were observed. To determine the causes of the low productivity of this cultivar we tested pollen viability by the fluorochromatic reaction and pollen germinability by in vitro assays. We observed that the acolporated pollen grain is viable, but no germination was recorded.

Cell Survival↗
PubMed2006

Influence of human leucocyte antigen-DRB1 on the susceptibility to rheumatoid arthritis and on the production of anti-cyclic citrullinated peptide antibodies in a Portuguese population.

OBJECTIVE: To clarify the influence of the HLA-DRB1 locus on the susceptibility to rheumatoid arthritis and the production of anti-cyclic citrullinated peptide antibodies (anti-CCP) in a Portuguese population. METHODS: 141 patients with rheumatoid arthritis fulfilling the American College of Rheumatology 1987 revised criteria for rheumatoid arthritis were compared with 150 healthy controls. Human leucocyte antigen (HLA)-DRB1 locus genotyping was assessed by polymerase chain reaction reverse probing assays and sequence-specific primers. Anti-CCP antibodies were quantified by ELISA in patients with rheumatoid arthritis. Frequencies between groups were compared by the two-sided Fisher's exact test and considered significant if p<0.05. RESULTS: The HLA-DRB1*04 and HLA-DRB1*10 groups were highly associated with rheumatoid arthritis (p<0.001 and p = 0.031, respectively). High titres of anti-CCP antibodies were largely associated with the presence of HLA-DRB1*04/10. CONCLUSION: The well-recognised susceptibility alleles to rheumatoid arthritis, HLA-DRB1*04, were associated with rheumatoid arthritis in Portuguese patients. The relatively rare DRB1*10 was also associated with rheumatoid arthritis, as was described previously in other southern European countries. Both groups were associated with high anti-CCP titres, reinforcing its relevance to disease onset.

Adult↗
PubMed2005

Multiplexed immunoassay for detection of rheumatoid factors by FIDISTM technology.

Our objective was to (i) compare FIDIS Rheuma, a new multiplexed immunoassay designed for simultaneous detection of IgM class rheumatoid factors (RF) directed against Fc determinants of IgG from humans and animals, with agglutination and ELISA (conventional methods) and (ii) evaluate the clinical sensitivity and specificity of biological markers for rheumatoid arthritis (RA). To do this, FIDIS technology was employed using the Luminex system. It consists of distinct color-coded microsphere sets, a flow cytometer, and digital signal processing hardware and software. Agglutination and ELISA tests were performed with commercial kits. The study included 134 samples from RA patients and 105 from healthy blood donors. For human specificity, we compared FIDIS with latex agglutination and ELISA. Relative sensitivities were 98.9% and 88.5% and specificities were 90.2% and 94.6%, respectively. For animal specificity, we compared FIDIS with Waaler-Rose and ELISA. The results were 84.9% and 71.9% for the sensitivities and 97.5% and 98.4% for the specificities, respectively. Detection of IgG anti-CCP by ELISA and IgG antikeratin by immunofluorescence was also determined in order to compare their clinical sensitivity and specificity with IgM-RF, according to the method used. The results were: IgG anti-CCP 72.3%, 97.2%; IgG antikeratin 36.6%, 100%; latex agglutination 66.4%, 97.2%; Waaler-Rose 55.9%, 96.3%; FIDIS human 73.9%, 92.1%; FIDIS animal 49.2%, 97.2%; ELISA human 93.2%, 95.5%; and ELISA animal 74.6%, 91.3%. The results showed the efficiency of FIDIS with analytical performance equivalent to the conventional methods, but having the advantage of giving quantitative results (IU/mL).

Agglutination Tests↗
PubMed2004

Immunolocalisation of arabinogalactan proteins and pectins in Actinidia deliciosa pollen. Short communication.

The cell wall composition of germinating pollen grains of Actinidia deliciosa was studied by immunolocalization with monoclonal antibodies against arabinogalactan proteins (AGPs) and pectins. In ungerminated pollen, the JIM8 epitope (against a subset of AGPs) was located in the intine and in the cytoplasm, while the MAC207 epitope (against AGPs) was located only in the exine. After germination, the JIM8 and MAC 207 epitopes were located in the cytoplasm and in the pollen tube wall. The Yariv reagent that binds to AGPs was added to the germination medium inducing a reduction or inhibition in pollen germination. This indicates that AGPs are present in the growing pollen tube and play an important role in pollen germination. To identify the nature of the pectins found in pollen grains and tubes, four monoclonal antibodies were used. The JIM5 epitope (against unesterifled pectins) was located in the intine, more intensely in the pore region, and along the pollen tube wall, and the JIM7 epitope (against methylesterified pectins) was also observed in the cytoplasm. After germination, the JIM5 epitope was located in the pollen tube wall; although, the tube tip was not labelled. The JIM7 epitope was located in the entire pollen tube wall. LM5 (against galactans) showed a labelling pattern similar to that of JIM5 and the pattern of LM6 (against arabinans) was similar to that of JIM7. Pectins show different distribution patterns when the degree of esterification is considered. Pollen tube wall pectins are less esterified than those of the pollen tube tip. The association of AGPs with pectins in the cell wall of the pollen grain and the pollen tube may play an important role in the maintenance of cell shape during pollen growth and development.

Actinidia↗
PubMed1994

[Viral infection and fibromyalgia].

Fibromyalgia (FM) is a very frequent syndrome of unknown cause, characterized by generalized pain, fatigue and a number of tender points to palpation. Among the several etiopathogenic hypotheses discussed, the association of FM with some viral infections has been the object of multiple studies due to its relation and similarity with the chronic fatigue syndrome, acknowledges as being related, although not exclusively, with the chronic infection by the Epstein-Barr virus. Many individual descriptions of association between infection with the human parvovirus B19 and FM led us to carry out this study, comparing the serology for that virus in 52 patients with FM and 39 healthy controls. The titers of specific IgG anti-parvovirus B19 antibodies, indicating previous infection with that virus, were determined in all 91 individuals through ELISA method and at the same laboratory. Results revealed, though not significantly, a greater prevalence of positive titers, of which the mean was also higher, in patients than in controls. When comparing the women from both groups, this tendency was even less perceptible. These data imply that there is no etiologic association between infection with the human parvovirus B19 and FM.

Adult↗
PubMed1982

Fine structure of seminiferous tubules from prenatally irradiated rats.

The ultrastructure of the seminiferous tubules was studied in rats that had been subjected to whole body irradiation on the 19th day of gestation. The seminiferous tubules from 3 months-old irradiated animals are devoid of germ cells and contain only Sertoli cells. Compared with controls of the same age, the seminiferous tubule basal membrane is thickened and multilayered and several alterations are observed in the Sertoli cells. The most characteristic of these alterations are: (a) an abnormal number of nuclear heterochromatin clumps, (b) the presence of numerous cytoplasmic vacuoles and various sized lipid droplets, (c) elaborate interdigitations and junctions between adjacent cells, and (d) the presence of anomalous ectoplasmic specializations disposed perpendicularly to the Sertoli cell membrane.

Animals↗
PubMedDate not supplied

[Rapid diagnosis of principal respiratory viruses in the city of Havana, 1995-97].

Acute respiratory diseases (ARD) are the most common infections in humans and difficult to prevent. Viruses have been recognized as predominant ethiological agents. In Cuba, ARD constitute a major problem of health and are the first cause of morbidity and important cause of mortality. In this paper, rapid diagnosis was performed to 516 clinical samples which arrived to the Reference Respiratory Viruses Laboratory of the Pedro Kourí Institute of Tropical Medicine (IPK) from different parts of Havana City during 1995, 1996 and 1997. The results obtained have shown 218 positive samples (Influenza A, 89; respiratory syncytial virus 52; Influenza B, 45; Adenovirus, 13; human parainfluenza virus(HPIV)-1, 6; HPIV-2, 3 and HPIV-3, 10). Influenza A was the virus most frequently found in adults, whereas in closed population of teen-agers and adults, Influenza B was frequently found. Furthermore, respiratory syncytial virus was the most important pathogen in children's under 1 year of age.

Adolescent↗