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Biomedical subjects

A Pereira

Publications and source records attributed to A Pereira.

At least 91 records · Page 5Linked to original sources
PubMed1998

Report of two sibs with Knobloch syndrome (encephalocoele and viteroretinal degeneration) and other anomalies.

We report on two sibs with high myopia, vitreoretinal degeneration (VRD), and occipital encephalocoele or scalp lesion. We review the literature on Knobloch syndrome, discuss possible causes, and suggest a possible involvement of mesoderm in the morphogenesis. One case presents with very early onset of severe eye disease, whereas the other is notable for the very mild scalp defect. In addition, both appear to have an unusual pulmonary lymphatic condition.

Abnormalities, Multiple↗
PubMed1998

Early-stage HIV infection and hepatitis C virus infection are associated with elevated serum porphyrin levels.

BACKGROUND: Porphyria cutanea tarda is known to be associated with HIV infection and hepatitis C virus (HCV). OBJECTIVE: Our purpose was to evaluate whether early infection with HIV, with or without HCV infection, is associated with elevated serum porphyrin levels. METHODS: Serum porphyrin levels were measured in samples obtained from 103 patients with early HIV infection. The results were compared with those of 89 late-stage HIV-positive patients and 78 HIV-negative patients. RESULTS: The highest median porphyrin level was in early-stage HIV-positive/HCV-positive samples, followed in decreasing order by those in early-stage HIV-positive/HCV-negative, late-stage HIV-positive/HCV-positive, late-stage HIV-positive/HCV-negative, HIV-negative/HCV-positive, and HIV-negative/HCV-negative groups. Elevated porphyrin levels were independently associated with early-stage HIV infection (P < .0001) and HCV infection (P = .03). CONCLUSION: This finding suggests abnormal porphyrin metabolism is most noticeable in early-stage HIV infection; it becomes less severe with the progression of HIV disease.

Adult↗
PubMed1998

Myelofibrosis with myeloid metaplasia in young individuals: disease characteristics, prognostic factors and identification of risk groups.

Myelofibrosis with myeloid metaplasia (MMM) is an uncommon disorder in young individuals, for whom haemopoietic stem cell transplantation offers the only possibility of cure. However, although the latter procedure is associated with significant morbidity and mortality, the clinical course of MMM is variable, with some patients surviving for less than a year and others showing an indolent course. Selection of young MMM patients for transplantation or other newer therapies is currently difficult since no prognostic data exists for this subgroup. In the present collaborative study a number of initial clinical and laboratory parameters have been evaluated for prognosis in 121 MMM patients aged 55 years or less. Median survival of the series was 128 months (95% CI 90-172). In the Cox proportional hazard regression model three initial variables were independently associated with shorter survival: Hb <10 g/dl (P <0.0001), the presence of constitutional symptoms (fever, sweats, weight loss) (P=0.001), and circulating blasts >/=1% (P=0.003). Based on the above three criteria, of the 116 patients with complete data, two groups were identified: a 'low-risk' group, characterized by 88 patients with up to one adverse prognostic factor, in whom MMM had an indolent course (median survival 176 months, 95% CI 130-188), and a 'high-risk' group, including 28 patients with two or three factors, who had a more aggressive disease (median survival 33 months, 95% CI 20-42). The above prognostic scoring system showed a high positive predictive value, sensitivity and specificity to predict survival in the series, and could be of help in making treatment decisions in young patients with MMM.

Cause of Death↗
PubMed1998

Identification of R-gene homologous DNA fragments genetically linked to disease resistance loci in Arabidopsis thaliana.

Disease resistance in plants is a desirable economic trait. A number of disease resistance genes from various plant species have been cloned so far. The gene products of some of these can be distinguished by the presence of an N-terminal nucleotide binding site and a C-terminal stretch of leucine-rich repeats. Although these gene products are structurally related, the DNA sequences are poorly conserved. Only parts of the nucleotide binding site share enough DNA identity to design primers for polymerase chain reaction amplification of related DNA sequences. Such primers were used to amplify different resistance-gene-like (RGL) DNA fragments from Arabidopsis thaliana accessions Landsberg erecta and Columbia. Almost all cloned DNA fragments were genetically closely linked with known disease resistance loci. Most RGL fragments were found in a clustered or dispersed multi-copy sequence organization, supporting the supposed correlation of RGL sequences and disease resistance loci.

Amino Acid Sequence↗
PubMed1998

The changing profile of idiopathic myelofibrosis: a comparison of the presenting features of patients diagnosed in two different decades.

In an attempt to ascertain whether the presenting features of idiopathic myelofibrosis (IM) have changed in recent years, 2 groups of patients diagnosed with IM in a single institution in different time periods were compared. The first group included 53 patients diagnosed from 1975 to 1986, and the second included 56 patients diagnosed from 1987 to 1997. No significant differences were observed between the two groups with regard to age, gender, delay from first symptoms to disease diagnosis, peripheral blood hematological values and serum biochemical parameters. Patients diagnosed prior to 1987 presented more often with constitutional symptoms (fever, night sweats, weight loss), but the difference did not reach statistical significance. These latter patients had, however, a higher frequency of splenomegaly (91% vs. 73%, p=0.01) and hepatomegaly (79% vs. 48%, p=0.002), and were more often in the osteosclerotic phase at diagnosis (p=0.05) than patients more recently diagnosed. Finally, no significant differences were found between both groups in either the distribution by prognostic scores or survival. The above results seem to indicate a trend towards a less florid clinical picture of IM at presentation in recent years. This, however, does not result in a longer patient survival.

Adolescent↗
PubMed1998

Respiratory symptoms, lung function and use of health services among unemployed young adults in Spain. Spanish Group of the European Community Respiratory Health Survey.

The association of respiratory symptoms, lung function and use of health services with employment status was examined in Spain, a country with a high rate of unemployment. A population sample comprising 179 unemployed and 1,868 employed subjects aged 20-44 yrs in 1993, was randomly selected from a base population of about 170,000 people in five urban and rural areas of Spain. Subjects completed a questionnaire on respiratory symptoms, sociodemographic and lifestyle factors, occupational exposure and use of health services, and performed a forced spirometry, a methacholine challenge test and blood tests. Unemployed subjects had a higher risk of simple chronic bronchitis (odds ratio=2.06, 95% confidence interval 1.30-3.24) and of bronchitis-type symptoms, than those who were employed. These risks were, in part, due to the higher prevalence of smoking, poorer housing and prior occupational exposures among unemployed than among employed people. Smaller differences were found between employed and unemployed subjects for asthma-type symptoms, atopia and lung function tests. Use of health services among subjects with respiratory symptoms was similar among employed and unemployed subjects, except that the latter consistently reported less frequent contact with specialized practitioners. Unemployed subjects had a higher risk of bronchitis-type symptoms than employed subjects. In Spain's national, free-access healthcare system, the differential use of specialized health services by employment status is likely to imply differences in the characteristics of the healthcare provided.

Adult↗
PubMed1998

[Tracking indices of the blood pressure in a longitudinal study in infants and adolescents].

OBJECTIVE: The objective of this study was to assess the degree of BP Tracking from childhood to adulthood and to evaluate whether high BP levels persist over time and progress to adult hypertension. PATIENTS AND METHODS: Two hundred and twenty-two healthy schoolchildren living in the North of Portugal were assessed at 17 year intervals, starting in 1979 (cohort 1) aged 5 to 18 years, and again in 1996 (cohort 2). Tracking indices (Ti) were calculated as follows: Ti = (2x + y-z) /N/0.89, where x, y and z refer to the total number in the same, adjacent and remote trisections, respectively, and N = x + y + z. If Ti > 1 there is positive tracking. RESULTS AND CONCLUSIONS: For systolic and diastolic blood pressure, all Ti were greater than 1.0. All individuals that remained in the 3rd tertil, 17 years later, weigh more and are more obese than those of the 1st tertil. 56.6% of the individuals that belong to the 3rd tertil are now hypertensive, which means that a significant percentage of the children with high blood pressure in the first survey will be hypertensive in the future.

Adolescent↗
PubMed1998

[Familial aggregation of blood pressure over 17 years in children and young adults].

UNLABELLED: Familial aggregation of blood pressure is well known although its causes remain controversial. The aim of the present study is to evaluate the presence of a familial aggregation for blood pressure and body mass index over a 17-year period, in order to evaluate the importance of a primary prevention strategy beginning in familial environment. DESIGN AND METHODS: A longitudinal cohort study was constructed from two cross-sectional surveys 17 years apart: 1,032 individuals, of both sexes, aged 5 to 24 years were seen in the initial study, and their parents whenever possible. Correlation coefficients and stepwise regression analysis were used to analyse the relationship between parents and children. RESULTS: The correlation between parents' and children BP are: systolic BP-0.34 (p < 0.01) and diastolic BP 0.19 (0.05); and for the anthropometric variables are: height-0.29 (0.01); weight-0.41 (p < 0.01); ponderal index -0.21 (p < 0.05); tricipt skinfold-0.21 (p < 0.05). All the coefficients are statistically significative. The variance of children's SBP and DBP explained through a stepwise regression analysis was 47%. The children's weight, skinfold, ponderal index, and parents' SBP and DBP were accepted by the model. CONCLUSION: The relation between BP and obesity variables suggest that a large proportion of familial aggregation for BP may be explained by aggregation for obesity, still after 17 years.

Adolescent↗
PubMed1998

No association between the serotonin transporter-linked promoter region polymorphism and either schizophrenia or density of the serotonin transporter in human hippocampus.

BACKGROUND: Allelic association case-control analysis of a deletion/insertion polymorphism in the serotonin transporter-linked polymorphic region (5-HTTLPR) has suggested associations with unipolar disorder, bipolar disorder, depression, and Alzheimer's disease. Moreover, the heterozygous long form of the 5-HTTLPR has been associated with increased levels of mRNA for the serotonin transporter (5-HTT) and increased serotonin uptake in lymphoblastic cell lines. This study attempts to determine whether there is an association between 5-HTTLPR genotype and schizophrenia or the binding of [3H]paroxetine to the human hippocampal 5-HTT. MATERIALS AND METHODS: DNA from the cerebellum from 58 schizophrenic and 62 control subjects was used to genotype the 5-HTTLPR. In addition, the relationship between 5-HTTLPR genotype and the affinity and density of [3H]paroxetine binding to the hippocampal 5-HTT was assessed. RESULTS: There were no associations between 5-HTTLPR allotype or genotype and/or the parameters of [3H]paroxetine binding to the hippocampal 5-HTT. CONCLUSIONS: Our data suggest that 5-HTTLPR genotype neither confers an increased susceptibility for schizophrenia nor dictates the expression of the 5-HTT in the human hippocampus.

Carrier Proteins↗
PubMed1998

[Aortic peri-valvular abscess, mycotic aneurysm of Valsalva sinus, and fistula to the right ventricle in a context of acute infectious endocarditis].

Infective endocarditis continues to attract the attention of many physicians. The authors present a case report of a 64 year old man with a history of infective endocarditis of a native aortic valve complicated by a perivalvular abscess, mycotic aneurysm of a sinus of valsalva and acquired aorta-right ventricular shunt.

Aneurysm, Infected↗
PubMed1997

Repeated antidepressant drug treatment, time of death and frequency of handling do not affect [3H]paroxetine binding in rat cortex.

[3H]Paroxetine binding to the serotonin transporter has been shown to be altered in brain tissue from schizophrenic subjects. Some schizophrenic subjects are treated with antidepressant drugs, some of which bind to the serotonin transporter and their time of death is variable. To determine if these confounding factors could affect [3H]paroxetine binding, [3H]paroxetine binding to cortical membrane from rats treated with the antidepressant drugs for 10 or 28 days and in non-treated rats that were killed at different times of the day was measured. Drug treatment, when compared to injection with 0.9% saline and time of death, did not affect [3H]paroxetine binding. Treatment with imipramine [10 days: mean +/- S.D.: 590 +/- 59 fmol/mg protein (P < 0.05); 28 days: 653 +/- 59 fmol/mg protein (P < 0.01)] or mianserin [10 days: 600 +/- 43 (P < 0.05)] caused a significant decrease in the density of [3H]paroxetine binding compared to that in fluoxetine-treated rats (10 days: 820 +/- 211 fmol/mg protein; 28 days: 764 +/- 100 fmol/mg protein). Thus, overall, these data do not suggest changes in [3H]paroxetine binding reported in the human brain tissue would be due to antidepressant drug treatment or time of death.

Animals↗
PubMed1997

[Idiopathic myelofibrosis: initial features, evolutive patterns and survival in a series of 106 patients].

BACKGROUND: Idiopathic myelofibrosis (IM) is an infrequent myeloproliferative disorder with few large series published in the medical literature. Information on the characteristics of more recently diagnosed patients with IM is scarce. PATIENTS AND METHODS: The initial features, evolutive patterns and survival from 106 patients diagnosed with IM in a single institution between 1975 and 1996 were analyzed. RESULTS: Median age of the series was 64 years (range: 17-89); there were 61 males and 55 females. One third of the patients were asymptomatic at IM diagnosis. The most common presenting symptoms were related to hypermetabolism, anemia and splenomegaly. A palpable spleen was noted in 85% of patients, and 66% had hepatomegaly. Anemia was the most frequent hematologic abnormality (50% of cases). Bone marrow biopsy showed cellular phase IM in 50 patients, IM without osteosclerosis in 39, and osteosclerotic IM in the remaining 17. Evolution into acute leukemia was seen in 14 patients (actuarial probability at 7 years: 20%, 95% CI: 0-40%), 8 patients developed portal hypertension, 5 liver failure without portal hypertension and 14 heart failure. With 62 patients having died, the series' median survival was 59 months (95% CI: 41-75). CONCLUSION: IM is usually diagnosed in the old age. From the histologic point of view, a predominance of the cellular phase is observed at disease presentation. In recent years an increased proportion of patients asymptomatic at diagnosis is observed.

Adolescent↗
PubMed1997

Anti-Sia-lb (anti-Gd) cold agglutinins bind the domain NeuNAc alpha2-3Gal in sialyl Lewis(x), sialyl Lewis(a), and related carbohydrates on nucleated cells and in soluble cancer-associated mucins.

Anti-Sia-lb (formerly anti-Gd) cold agglutinins (CAs) recognize sialylated carbohydrates on both adult and neonate red blood cells (RBCs). RBC CA activity inhibition experiments reported here indicate that the domain NeuNAc alpha2-3Gal, as found in sialyllactose, synthetic sialyl(s) Lewis(Le)(x) and sLe(a), sialyllactosamine, sialyl-fucosyllactose, and nonfucosylated sLe(a), constitutes the minimal epitope for these CAs, implicating that these autoantibodies could be able to bind this domain in sLe(x) and sLe(a) and related carbohydrates expressed on nucleated cells and in soluble cancer-related mucins. The following data obtained with the previously characterized monoclonal IgMk anti-Sia-lb CA, GAS, show that this is the case. GAS epitope expression among leukocytes that lack sLe(a) parallels that of sLe(x) determinant as detected by mouse monoclonal antibodies (MoAbs), especially MoAb KM-93. It is also found on epithelial malignant cells bearing both sLe(x) and sLe(a). GAS epitope on these nucleated cells, (1) like that present on RBC, is abolished by sialidase, unaffected by proteases, and inhibited by sialyllactose; and (2) is overlapping and/or proximal to that recognized by anti-sLe(x) MoAb, CSLEX-1, and KM-93. Moreover, CAGAS binds soluble cancer-associated mucins bearing sLe(x) and sLe(a) determinants. This binding is inhibited by sialyllactose and these mucins inhibit the RBC CA activity of CAGAS. The possible significance of anti-Sia-lb (anti-Gd) CAs as autoantibodies directed to carbohydrate ligands of host adhesion molecules that might be receptors of microbial adhesins of some CA-inducing pathogens is discussed.

Agglutinins↗
PubMed1997

[Thrombotic thrombocytopenic purpura and hemolytic uremic syndrome (TTP/HUS). Description of a series of 35 patients].

BACKGROUND: Delay in application of massive plasmapheresis is the main unfavorable prognostic factor in TTP/HUS, and it is mainly due to difficulties in diagnosing this rare illness. The aim of our study is to analyze the clinical presentations of TTP/HUS. METHODS: The clinical and laboratory data of 35 patients with TTP/HUS were analyzed, as well as the treatment used and the patients outcome. Time intervals between the beginning of symptoms, the diagnosis and the start of treatment were also recorded. RESULTS: The median age was 37 (range: 11-77) years old and there were 19 (54%) women. The more frequent antecedent was chemotherapy with mitomycin C and 5-fluorouracil (7 cases). The diagnosis of TTP/HUS was reached after a median of 5 (interval 0-293) days, and only 11 (31%) patients were correctly diagnosed in the first medical attendance. Hemolytic anemia and thrombocytopenia was the most frequent clinical presentation (80% of patients). Neurologic signs or symptoms were found initially in 14 patients, and oligoanuria in 4. No patient presented initially with the so called "clinical pentad" considered to be typical of TTP/HUS. Plasmapheresis was used in 33 cases. A complete remission was attained in 16, a partial remission in 6, and 13 patients died. CONCLUSION: Due the fickleness of some clinical manifestations considered to be typical of TTP/HUS, these disorders should be considered in patients presenting with acute-onset hemolytic anemia and thrombocytopenia.

Adolescent↗