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Biomedical subjects

H Ribeiro

Publications and source records attributed to H Ribeiro.

At least 19 recordsLinked to original sources
PubMed2006

Molecular characterization of Portuguese patients with mucopolysaccharidosis type II shows evidence that the IDS gene is prone to splicing mutations.

Mucopolysaccharidosis type II (MPS II) is an X-linked recessive lysosomal storage disease caused by a defect in the iduronate-2-sulfatase gene (IDS). Alternative splicing of the IDS gene can occur and the underlying regulatory mechanism may be rather complex. Nevertheless, little information is available on the role of variations at the IDS locus in the splicing process. Here we report that splice mutations at the IDS locus are an important source of MPS II pathogenicity, accounting for almost 56% of Portuguese cases. Among 16 unrelated Portuguese MPS II patients, 15 different mutations were identified: six intronic splice mutations (c.104-2AG, c.241-2A>G, c.241-1G>A, c.418+1G>A, c.880-8AG and c.1181-1G>C); two exonic splice mutations (c.1006G>lC and c.1122C>T); five missense mutations (D269V, D69V, D148N, R88C and P86L); one nonsense mutation (Q465Ter); one total IDS gene deletion; and one rearrangement involving a IDS gene inversion. Furthermore, nine of the 15 detected mutations affected the usual splicing pattern at the locus. Some of them are responsible for dramatic changes in the splicing mechanism. For example, the substitution mutation, c.418+1G>A, revealed the presence of an exonic sequence inside intron 3. Our study provides evidence that the IDS locus is prone to splicing mutations and that such susceptibility is particularly high in exon 3 and neighbouring regions. Consequently, mutation screening of the IDS gene cannot be restricted to gDNA examination. Unless cDNA analysis is also conducted, misclassifications as silent or missense mutations can be produced and even uncharacteristic splice-site mutations can be misinterpreted as classic splicing defects that may generate severe, unconventional splicing alterations.

Alternative Splicing↗
PubMed2001

Incomplete carbohydrate absorption from fruit juice consumption after acute diarrhea.

We carried out a double-blind, randomized study in 60 children with acute diarrhea to determine their capacity to tolerate commonly consumed fruit juices. Feedings of juice with high fructose/glucose ratios and sorbitol resulted in incomplete carbohydrate absorption and recurrence of diarrhea during the phase immediately after improvement of the illness.

Acute Disease↗
PubMed2000

Diarrheal disease in a developing nation.

Infants and young children from many developing nations face a serious public health threat from diarrhea. In the northeast region of Brazil, diarrheal disease causes significant morbidity and mortality. Although diarrheal deaths in this region have been declining since the early 1980s, the hospitalization rate remains high. Diarrhea may account for 25% of total healthcare costs in northeast Brazil. Many patients become ill because of poor environmental conditions and because their caregivers lack awareness of basic hygiene. Many also return to the hospital after initial treatment because health workers do not provide appropriate preventive and home care instruction to patients in 99% of cases. Antibiotics have no effect in 85-95% of pediatric diarrheal cases in the region. Improvement of preventive home care management in association with probiotic bacteria, which have been effective against several forms of diarrhea in developing nations, may be useful in managing diarrheal disease in infants.

Brazil↗
PubMed2000

Coelomomyces numularius sp. nov. (Blastocladiales: Coelomomycetaceae), a new fungal parasite of Anopheles squamosus (Diptera: Culicidae) from Angola, Africa.

Coelomomyces numularius sp. nov., a fungus parasitizing the larvae of Anopheles squamosus Theobald in southern Angola, Africa, is described and illustrated, with comments on its diagnosis and host specificity. Because of the general surface ornamentation of the resting sporangia, this new species is placed in group V of Bland and Couch. Resting sporangia can be distinguished from other species in group V by their dimensions, unique wall structure, placement of the dehiscence slit, and symmetrical shape.

Angola↗
PubMed1999

A clonal Plasmodium falciparum population in an isolated outbreak of malaria in the Republic of Cabo Verde.

We present the first parasitological, molecular and longitudinal analysis of an isolated outbreak of malaria. This outbreak occurred on Santiago Island (Republic of Cabo Verde), a region where malaria is hypoendemic and controlled, and thus the population is considered non-immune. Blood samples were collected from the inhabitants over 1 month and during cross-sectional surveys in the following year. The presence and nature of the parasites was determined by PCR. Plasmodium falciparum was the only species detected. Genetic analysis revealed that the circulating parasites were genetically homogeneous, and probably clonal. Gametocytes were found throughout this period. Our data suggest that this represented a focal outbreak, resulting in the infection of at least 40% of the villagers with a clonal parasite line. Thus, P. falciparum infections can persist for at least 1 year in a substantial proportion (10%) of the hosts. Implications for malaria control and the interpretation of epidemiological data are discussed.

Africa, Western↗
PubMed1998

[Prevalence of respiratory diseases in the textile industry. Relation with dust levels].

Many workers in the textile industry have respiratory symptoms that are related to their work environment. In this study we observed the dust level conditions of eleven textile industries of the North of Portugal. The dust levels determined were between 0.1 mg/m3 and 1.25 mg/m3, in many cases above the Portuguese standard levels of exposure (VLE). For these dust levels we found a prevalence of 23% of workers with respiratory symptoms with occupational characteristics in 10.8%, and 5.7% presenting byssinosis. Workers exposed to cotton fibres in spinning areas have the highest prevalence of symptoms, and reduction of the FEV1. These characteristics were related to dust levels and were higher in the initial phases of the spinning processes. We found no cases of byssinosis in workers exposed to synthetic fibres, or in workers from weaving areas. Smoking habits were related to the reduction of the FEV1, and severity of respiratory illness but not to the presence of byssinosis.

Dust↗
PubMed1998

[Prenatal cardiology. Suspicion to confirmation].

The mortality rate is high and prognosis is worse among new-borns with prenatal diagnosis of heart malformation, mainly due to factors such as its association with other malformations, and a range of more severe diseases probably resulting from the predominance of the obstetric use of the four chamber view. In this study we retrospectively assessed the range of cardiopathies diagnosed by foetal echocardiography and their evolution, compared with previous years. From January 1994 to December 1995, 1173 foetal echocardiograms were performed at a gestation age of 24 weeks. Sixty-one foetuses (5.2%) had cardiac anomalies, structural in 56 and arrhythmia in 5. The risks and indications were maternal in 37%, foetal in 31%, familial in 17% and environmental in 15%. Three were false negatives (VSD:2; truncus arteriosus: 1). Five died in utero, and 18 were assessed after birth with a mean gestational age of 37 weeks and birth weight of 3 Kg, a caesarean section was performed in 9. All but one were born in central hospitals. Six children were operated on. Two children died, one after surgery. Compared with the four previous years of activity, indication due to foetal risk rose from 6 to 31%, the number of cases diagnosed with heart disease increased from 14 to 30 per year, and the mortality decreased from 59 to 11%. Despite this, we still observe that the vast majority of new-borns who are hospitalised due to a severe heart disease had no prenatal diagnosis, indicating the need to continue our educational policy in this field.

Female↗
PubMed1997

[Respiratory symptoms in the textile industry. Their prevalence in the Vale do Ave].

Some workers in the textile industry have respiratory symptoms related to their occupation. This study is aimed at evaluating the frequency of respiratory symptoms in textile industries in the North of Portugal. We evaluated 3529 workers from 20 factories (19 deal with synthetic fibres and cotton and the other deals with sisal.) Among the workers, there were 34.5% with respiratory symptoms - 24,5% referred nasal symptoms, 22,6% with bronchial symptoms and 12,6% associated both. The workers who dealt with cotton presented a higher frequency of bronchial symptoms (25,0%) than the ones dealing with synthetic fibres (12,7% p < 0,000001). The same was noticed among the workers in the opening and spinning areas, who showed a higher frequency of bronchial symptoms (28,3%) than the ones in weaving areas (12,7% p < 0,000001). We did not find any differences concerning the frequency of symptoms among the workers handling both natural fibres (cotton and sisal). Individually all the symptoms were more frequent among the workers handling natural fibres. The most frequent symptom depended on the fibre. Cough was more frequently mentioned among the workers handling synthetic fibres (9.6%) and cotton (15.7%). Among the workers who handle sisal, dyspnea was the most frequently mentioned (16.9%). Productive cough was the most frequent association (7.2% sisal; 2.8% synthetic; 8.0% cotton), and the association between dyspnea and wheezing the least mentioned (6.4% sisal; 0.5% synthetic; 5.9% cotton). The workers with bronchial symptoms (synthetic fibre and cotton) have more years of exposure and greater smoking habits. In a covariance adjusted for age and smoking habits, the workers with bronchial symptoms, exposed to cotton have more years of exposure.

Adult↗
PubMed1997

New species of Toxorhynchites (Diptera: Culicidae) from Macau (China).

The male holotype and female allotype of Toxorhynchites (Toxorhynchites) macaensis Ribeiro, a new mosquito species from Macau, southern China, are described on the basis of the examination of a type series of 6 males and 7 females. Similarities of the new species with the other species of the Splendens group, to which the new taxon belongs, are discussed and keys to identification of males and females of all the species of the group are provided.

Animals↗
PubMed1996

Clinical, enzymatic, and molecular characterisation of a Portuguese family with a chronic form of GM2-gangliosidosis B1 variant.

Mutations in the hexosaminidase A gene (HEXA) causing the B1 variant of GM2-gangliosidosis result in the presence of a mutant enzyme protein with a catalytically defective alpha subunit. A rare and panethnically distributed mutation, transition G533A (Arg178His), is known to be a common allele among Portuguese patients with the subacute phenotype. We now report the presence of an Arg178His allele in three Portuguese sibs with a chronic form of the disease, who carry the transition G755A (Arg252His) on the second allele. This novel mutation is the first B1 allele to be associated with an adult phenotype.

Adult↗
PubMed1995

Prenatal diagnosis of GM2-gangliosidosis B1 variant.

Prenatal diagnosis in a pregnancy at risk for a juvenile B1 variant of GM2-gangliosidosis was carried out. The biochemical study of the cultured amniocytes and the affected fetal brain is reported. The results obtained show that the sulphated artificial substrate can be used in the diagnosis of B1 variant, but not the neutral one. The accumulation of GM2-ganglioside in the fetal brain of the B1 juvenile form and an infantile form of GM2-gangliosidosis (0 variant) was compared.

Amniocentesis↗
PubMed1994

New species of flea (Siphonaptera: Pulicidae) from Spain.

The male holotype and female allotype of Echidnophaga iberica Ribeiro, Lucientes, Osacar & Calvete, a new species of rabbit flea from the Zaragoza area, northeastern Spain, is described on the basis of examination of a type series of six males and 13 females. Similarities of the new species with other species of the genus Echidnophaga are discussed and a key to identification of the four known Mediterranean species of the genus is provided.

Animals↗
PubMed1993

[The efficacy of isosorbide dinitrate administered in an intravenous bolus in acute cardiogenic pulmonary edema].

STUDY OBJECTIVE: To evaluate the efficacy, safety and tolerability of intravenous (i.v.) isosorbide dinitrate (ISDN) administered as a bolus in the treatment of cardiogenic acute pulmonary edema (CAPE). DESIGN: Clinical, prospective, open, noncontrolled trial. SETTING: Emergency room. PATIENTS AND INTERVENTIONS: Twenty two patients (15 male and 7 female), aged 54 to 80 years (68.4 +/- 6.4) with severe respiratory distress consistent with CAPE were included. The cause of CAPE was chronic ischemic cardiopathy in 13 patients, acute myocardial infarction in four, hypertensive cardiopathy in three and mitral valve disease in two. Patients were excluded from the study because of shock or systolic blood pressure equal or lower than 100 mmHg, severe aortic stenosis, hypertrophic cardiomyopathy and non-cardiogenic pulmonary edema. All patients were placed in the sitting position and received oxygen. Initial therapy consisted of an i.v. bolus of 5 to 10 mg of ISDN. Clinical data were recorded at admission and after 5, 10, 15 and 30 minutes. A new i.v. bolus of ISDN and/or another drug was administered at 5 minutes, when necessary. RESULTS: Fifteen patients treated exclusively with ISDN (in three a second i.v. bolus was necessary) improved markedly. In the remaining seven patients that needed other drugs, the improvement was not so impressive. The mean total dose of i.v. ISDN was 10.34 +/- 3.48 mg. Although all data showed a trend towards improvement, just the following were statistically significant (p < 0.05): pH increased from 7.26 +/- 0.13 to 7.32 +/- 0.9, systolic blood pressure decreased from 192.7 +/- 34.8 mmHg to 155.0 +/- 24.4 mmHg (-19%) and diastolic blood pressure decreased 110.5 +/- 12.7 mmHg to 93.2 +/- 9.1 mmHg (-16%). CONCLUSIONS: In this trial, iv ISDN administered as a bolus in doses ranging from 5 to 20 mg, was effective and safe as a first line agent in the treatment of CAPE. No serious adverse reaction were reported.

Acute Disease↗