Search PubMed⌕ Search

Biomedical subjects

A Pereira

Publications and source records attributed to A Pereira.

At least 145 records · Page 8Linked to original sources
PubMed1995

Development of a database system for electrophysiological signals.

A relational database system was developed to store electrophysiological signals recorded with different Evoked Potentials (EP) recording equipment produced by the Cuban Neurosciences Center. The system has several functions such as storage of EP recording parameters, data retrieval with a flexible query mechanism, database backup, and data transfer from one database to other. A complete set of functions facilitates EP analysis, either for clinical or research purposes. It is also useful as a clinical information management tool.

Databases, Factual↗
PubMed1994

Characterization of a monoclonal IgMK (IgMGAS) anti-Gd cold agglutinin (CA). Its coexistence with a monoclonal IgG3K (IgGGAS) without CA activity that might be clonally related to IgMGAS.

A monoclonal IgMK (IgMGAS) cold agglutinin (CA) of the infrequent anti-Gd specificity, found in a patient with Waldenström macroglobulinemia, has been characterized. IgMGAS uses a VH gene homologous (93.7%) to the reported VH251 germ-line, one of the two functional genes of the VH5 family, with differences in both framework regions and complementary determining regions (CDR). The VL gene is homologous to the reported 15AVK1 germ-line gene, recently described in an anti-i CA, with differences mostly clustered in CDR. In the patient's serum, IgMGAS coexisted with a monoclonal IgG3K (IgGGAS) that lacked CA activity but expressed the private idiotopes found on IgMGAS. Both Ig lacked reactivity with antibodies detecting VH1 or VHIII or VKIII subgroup regions or the VH4-21 gene product that is expressed by anti-I/i CAs. The K chains from both Igs showed the same isoelectrical mobility. Moreover, the k chains from both serum Igs showed the same N-terminal amino acid sequence. This sequence was identical to that predicted by the nucleotide sequence of VK1GAS gene segment, including one discrepancy at position 15 (Ile for Val) with respect to the consensus VK1 subgroup regions. Although these data do not exclude a possible independent clonal origin, they are consistent with the notion that IgGGAS might be clonally related to IgMGAS.

Aged↗
PubMed1994

Segregation analysis and RFLP mapping of the R1 and R3 alleles conferring race-specific resistance to Phytophthora infestans in progeny of dihaploid potato parents.

Phytophthora infestans (Mont.) de Bary is the most important fungal pathogen of the potato (Solanum tuberosum). The introduction of major genes for resistance from the wild species S. demissum into potato cultivars is the earliest example of breeding for resistance using wild germplasm in this crop. Eleven resistance alleles (R genes) are known, differing in the recognition of corresponding avirulence alleles of the fungus. The number of R loci, their positions on the genetic map and the allelic relationships between different R variants are not known, except that the R1 locus has been mapped to potato chromosome V. The objective of this work was the further genetic analysis of different R alleles in potato. Tetraploid potato cultivars carrying R alleles were reduced to the diploid level by inducing haploid parthenogenetic development of 2n female gametes. Of the 157 isolated primary dihaploids, 7 set seeds and carried the resistance alleles R1, R3 and R10 either individually or in combinations. Independent segregation of the dominant R1 and R3 alleles was demonstrated in two F1 populations of crosses among a dihaploid clone carrying R1 plus R3 and susceptible pollinators. Distorted segregation in favour of susceptibility was found for the R3 allele in 15 of 18 F1 populations analysed, whereas the R1 allele segregated with a 1:1 ratio as expected in five F1 populations. The mode of inheritance of the R10 allele could not be deduced as only very few F1 hybrids bearing R10 were obtained. Linkage analysis in two F1 populations between R1, R3 and RFLP markers of known position on the potato RFLP maps confirmed the position of the R1 locus on chromosome V and localized the second locus, R3, to a distal position on chromosome XI.

Alleles↗
PubMed1994

Neural cell-adhesion molecule (CD 56)-positive, t(8;21) acute myeloid leukemia (AML, M-2) and granulocytic sarcoma.

A 49-year-old man with t(8; 21) acute myeloid leukemia relapsed 8 months after successful induction chemotherapy with a paraspinal granulocytic sarcoma. There was no evidence of leukemia in the bone marrow at relapse. At initial presentation, the blasts co-expressed CD 15, CD 33, CD 34, CD 45, CD 19, and CD 56 (a neural cell-adhesion molecule). Expression of certain cell-adhesion molecules on leukemic blasts may determine a tendency to develop extramedullary relapse. The co-expression of CD 56 may have a role in the predisposition of t(8; 21) AML to develop GS.

Antigens, CD↗
PubMed1994

Long-term survivors in chronic granulocytic leukaemia: a study by the International CGL Prognosis Study Group. Italian Cooperative CML Study Group.

The purpose of the present work were to identify the initial characteristics associated with long-term survival in chronic granulocytic leukaemia (CGL) and to analyse the accuracy of prognostic models in identifying long-term survivors. 813 Philadelphia (Ph) chromosome-positive, nonblastic CGL patients from six American and European institutions, the majority treated conventionally, with a minimum follow-up > 10 years, were studied. Stepwise logistic regression was performed to ascertain the association between the initial clinicohaematological variables and survival > or = 8 years, and a prognostic index was derived. The usefulness of both Sokal's and the new prognostic index to identify long-term survivors was assessed by calculating their positive and negative predictive accuracies, sensitivity and specificity. Median survival of the series was 45 months (range 1-255), with 784 patients (96.4%) having died and 109 (13.4%) surviving 8 years or longer. Younger age, smaller spleen, platelets < or = 600 x 10(9)/l, and lower blood blast percentage were associated with survival > or = 8 years; platelets < or = 600 x 10(9)/l and lower blood blast percentage were the predictive factors in patients 50 years old or younger. Two-thirds of long survivors belonged to Sokal's low-risk group, but the positive predictive accuracy and specificity for prolonged survival of Sokal's index were very low. This was also the case for the new predictive index.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Pleural effusion in multiple myeloma.

We report the first case of IgA-kappa multiple myeloma presenting as a myelomatous and eosinophilic pleural effusion with increased adenosine deaminase activity. In a review of the literature, 80 percent of myelomatous pleural effusions are due to IgA multiple myeloma.

Bone Neoplasms↗
PubMed1994

Salmonella typhi meningitis.

Whereas typhoid fever is still an endemic disease in some parts of the world, meningeal involvement in this disease is a rare occurrence. We report a case of Salmonella typhi meningitis in a 70-year-old woman. The patient was treated with ampicillin and the only sequela was right-sided deafness.

Aged↗
PubMed1994

[Functional ability and quality of life in rheumatoid arthritis: use of the Functional Independence Measure and the Reintegration to Normal Living Index].

Functional disability and quality of life were evaluated using the Functional Independence Measure and the Reintegration to Normal Living Index, respectively, in 57 subjects (15 men and 42 women) with a mean disease duration of 15 years. Scores on both these nonspecific scales correlated with those obtained using instruments specifically designed for rheumatoid arthritis (ARA index, Lee index) and with a number of clinical parameters including patient age, disease duration and number of affected joints. Functional ability was correlated with quality of life in this study and in others performed using other evaluation tools. Nonspecific assessment scales are useful for comparing function and quality of life in various diseases.

Activities of Daily Living↗
PubMed1994

[Significance of the persistence of ST segment elevation in anterior infarction].

OBJECTIVE: Persistent ST segmentary elevation in anterior myocardial infarction was classically attributed to ventricular aneurysm. This association is now considered controversial. We studied the association between this electrocardiographic finding and the left ventricular wall motion abnormalities and global function. DESIGN: Retrospective study. SETTING: Patients admitted to Hospital de Pulido Valente Coronary Care Unit in Lisbon with anterior myocardial infarction who were submitted to angiographic study. PATIENTS: 94 patients were included in the study. METHODS: The global ejection fraction, the regional wall motion abnormalities, the coronary artery disease extension, the patency and the proximal involvement of the left anterior descending artery were investigated. RESULTS: 56 of the 94 patients (60%) had persistent ST segment elevation and 38 (40%) had isoelectric ST segment. The ejection fraction was markedly depressed in the group with elevated ST segment (36.2 SD 17.6) in contrast with the group with isoelectric ST segment (49.3 SD 14.8) (p < 0.001). The group with persistent ST segment elevation had more advanced degrees of left ventricular asynergy (42/58-75%) than the group with isoelectric ST segment (12/38-32%) (p = 0.02). The other studied angiographic variables did not differ between the two groups. CONCLUSIONS: The group with persistent ST segment elevation was associated with advanced degrees of left ventricular asynergy and greater left ventricular function depression. The ventricular aneurysm was exclusive of the first group.

Adult↗
PubMed1994

[Atrial myxoma. Apropos a clinical case].

The authors report a case of a 61-years-old woman with hypertension and palpitations, who was diagnosed as having a left auricular myxoma. This diagnosis was established by echocardiography and confirmed afterwards by an histological survey. On the basis of this case the authors reviewed the subject and discuss the role of echocardiography in the diagnosis and follow-up of this kind of patients.

Arrhythmias, Cardiac↗
PubMed1994

[A left intraventricular thrombus in an adolescent. Its relationship to the anticardiolipin antibody syndrome].

The authors are going to present the clinical case of a 14-years-old female patient who has got an anticardiolipin antibodies syndrome, a theme to which they add some ideas concerning physiopathology and diagnosis criteria. They'd like to emphasise the echocardiographic observation, which allowed them to find out and follow the evolution of a left sided intraventricular thrombus, the real cause for the systemic thrombosis.

Adolescent↗
PubMed1993

Significant correlation between 14C-5-HT uptake by and 3H-paroxetine binding to platelets from healthy volunteers.

The lack of correlation between 5-HT uptake by platelets and the ability of platelet membrane to bind antidepressant drugs, particularly imipramine, has been reported. However, more recently it has been suggested that 3H-paroxetine could be a better drug with which to study the platelet 5-HT uptake mechanism in disease states. We have therefore compared the ability of platelet-rich plasma (PRP) from normal individuals to take up 5-HT with the ability of platelet membranes to bind paroxetine. A significant correlation was apparent between the Vmax of 14C-5-HT uptake by PRP and the Bmax of 3H-paroxetine binding to platelet membrane from 30 individuals (r = 0.6468, p = 0.0001). Furthermore, this correlation was highly significant in the 20 female (r = 0.7768, p = 0.00006) but not in the 10 male volunteers. There was also a significant association between Vmax and Bmax and the month of blood sampling but this did not totally account for the correlation between Vmax and Bmax. The simultaneous measurement of 5-HT uptake by PRP and paroxetine binding to platelet membranes from both depressed patients and matched controls should be carried out to confirm and extend these findings.

Adult↗
PubMed1993

Transposon tagging of a male sterility gene in Arabidopsis.

Transformation of the well-studied maize transposable elements into other plant species should enable transposon tagging methodology to be used for the isolation of interesting genes in the heterologous host. Here we describe the isolation of a transposon-tagged male sterile mutant in Arabidopsis thaliana using the maize Enhancer-Inhibitor transposable element system introduced into Arabidopsis. The mutant lacks pollen, preventing normal self-fertilization, a characteristic important for production of hybrid seed in many crop plants. We have identified an Enhancer-transposase-mediated Inhibitor element insertion responsible for the male sterile phenotype, and isolated the corresponding gene named MALE STERILITY 2. Critical evidence that the Inhibitor-element-containing gene is involved in the male sterile phenotype is provided by the DNA sequences of new excision-derived alleles from independent stable fertile and male sterile progeny of the original mutant.

Amino Acid Sequence↗
PubMed1993

Anti-Sa cold agglutinin of IgA class requiring plasma-exchange therapy as early manifestation of multiple myeloma.

The case of a patient (Col) with multiple myeloma presenting as chronic cold agglutinin (CA) syndrome is reported. The CA (Col) was a monoclonal IgA/k paraprotein which recognizes an antigen fully expressed in adult and newborn erythrocytes, sialidase sensitive and partially resistant to proteases. Hemagglutination-inhibition studies showed that immunodominant N-acetylneuraminic acid bound alpha 2-->3 to O-glycans of glycophorins represents the CA(Col) epitope. These serological and biochemical findings fit with the anti-Sa specificity, of which only two previous examples are known. The clinical manifestations of CA (Col) were characterized by marked acrocyanosis, generalized livedo reticularis, and incapacitating dyspnea, but only mild hemolysis. Plasma-exchange therapy was effective in quickly removing the CA and relieving the associated clinical manifestations, but such benefit was only temporary. This is the first reported example of anti-Sa CA of IgA isotype and the first case of IgA CA syndrome treated by plasma exchange.

Anemia, Hemolytic, Autoimmune↗
PubMed1993

IgA cold agglutinins recognize Pr and Sa antigens expressed on glycophorins.

Three cases of IgA kappa cold agglutinins (CAs) were studied. One had anti-Pr1 specificity, one had anti-Pra, and one had anti-Sa. The CAs recognize O-glycans of glycophorins. The findings supplement previous data on anti-Pr1 specificities of four IgA kappa CAs. Because all IgA kappa CAs described recognize O-glycans of glycophorins, a close association between the CA IgA isotype and specificities for O-glycans becomes apparent. It is unlikely, however, that the striking association reflects interrelations between IgA CA structure and specificity, because anti-Sa specificity and all anti-Pr subspecificities were originally defined with IgM CAs.

Adult↗