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Biomedical subjects

A Reis

Publications and source records attributed to A Reis.

At least 163 records · Page 9Linked to original sources
PubMed1997

Illiteracy: a cause for biased cognitive development.

Learning to read and write generates new rules within the language processing systems. These new rules significantly change the manner in which some operations are performed. This finding was studied, by comparing the performance of literate and illiterate persons in several tasks. It was found that illiterate individuals (1) had difficulties in repeating pseudowords, (2) were worse at memorizing pairs of phonologically related words compared to pairs of semantically related words, and (3) were unable to generate words according to a formal criterion. Illiterate persons use strategies that are good for semantic processing, but inadequate for phonological analysis, while literate individuals are able to use several parallel running strategies.

Aged↗
PubMed1996

Phenotypic differences in Angelman syndrome patients: imprinting mutations show less frequently microcephaly and hypopigmentation than deletions.

Angelman syndrome (AS) is a relatively frequent disorder of psychomotor development caused by loss of function of a gene from chromosome 15q11-q13, a region subject to genomic imprinting. The AS gene(s) is exclusively expressed from the maternal chromosome. Several kinds of mutations have been found to cause AS. More than half of the cases exhibit a deletion of the maternal 15q11-q13 region. Recently, we and others described a new mutation type, the imprinting mutation, characterised by normal, biparental inheritance but aberrant methylation patterns of the entire chromosomal region. In AS, a paternal imprint is found on the maternal chromosome probably leading to functional inactivation of the AS gene(s). We have now compared the phenotype of 9 AS patients with imprinting mutation to that of nine age-matched ones with a maternally derived deletion. Both groups were evaluated for 19 common AS symptoms. All patients, independently of their molecular findings, showed classical AS symptoms such s mental retardation, delayed motor development, and absent speech. In contrast, for two signs, hypopigmentation and microcephaly, a different distribution among both groups was observed. Only one of nine AS patients with an imprinting mutation, but seven of nine in the deletion control group showed either symptom. Our results suggest that imprinting mutations, in contrast to deletions, cause only incomplete loss of gene function or that maternally derived deletions affect also genes not subject to genomic imprinting. We conclude that AS is caused by loss of function of a major gene that is imprinted but that there are also other genes that contribute to the phenotype when in hemizygous condition.

Albinism, Oculocutaneous↗
PubMed1996

Autosomal dominant spastic paraplegia with anticipation maps to a 4-cM interval on chromosome 2p21-p24 in a large German family.

Autosomal dominant familial spastic paraplegias (AD-FSP) are a group of genetically heterogeneous diseases characterised by a progressive spasticity of the lower limbs. Three loci have already been identified by genetic linkage studies on chromosomes 2p, 14q and 15q. Here we present linkage data from a large German family displaying AD-FSP with anticipation which confirms the existence of the FSP2 locus on chromosome 2p. The recombination events observed in our family define the critical region for the FSP2 gene to be within a 4-cM interval, flanked by markers D2S400 and D2S367. Moreover, clinical data from our family show evidence of anticipation, a phenomenon caused by trinucleotide expansion in several other neurodegenerative diseases.

Chromosome Mapping↗
PubMed1996

Amelioration of pulmonary allograft injury by administering a second rinse solution.

OBJECTIVE: The use of rinse solutions before reperfusing liver allografts has been shown to reduce cell death in rats. Carolina rinse solution (an extracellular solution that contains antioxidants, vasodilators, and other substrates that help prevent ischemia-reperfusion injury) has also been shown to improve liver function clinically in liver transplant recipients. This pilot study evaluates the value of a second pulmonary artery flush before reperfusion of a lung graft. METHODS: Six groups of Sprague-Dawley rats (n = 6 each) were subjected to the following: Group 1 lungs were preserved with modified Euro-Collins solution followed by 24 hours of cold ischemia. Group 2 lungs were treated the same as group 1 but reperfused with blood. Group 3 lungs were preserved in Carolina rinse solution followed by 24 hours of cold ischemia. Group 4 lungs were treated the same as group 3 lungs and then reperfused with blood. Lungs in groups 5 and 6 were preserved with Euro-Collins solution, stored cold for 24 hours, and then rinsed with Euro-Collins or Carolina rinse solution, respectively, before reperfusion with blood. Lungs were subsequently stained with trypan blue solution for 5 minutes. Lung blocks were fixed and embedded in water-soluble methacrylate. Trypan blue--stained nuclei in nonviable endothelial cells and alveolar pneumocytes were counted in 10 different fields. RESULTS: Groups 1 and 3, preserved with Euro-Collins and Carolina rinse solutions for 24 hours but not reperfused with blood, had significantly more viable endothelial cells (groups 1 and 3 vs group 2, p < 0.0001; group 3 vs group 4, p < 0.02) and pneumocytes (group 1 vs groups 2 and 4, group 3 versus group 2, p < 0.0001; group 3 vs group 4; p < 0.035) than groups 2 and 4, which were subsequently reperfused with blood. Groups 5 and 6, which received a second rinse, also had significantly more viable endothelial cells (p < 0.0005) and pneumocytes (p < 0.0001) than control groups, which were not rinsed before reperfusion. CONCLUSIONS: We conclude that damage to pulmonary allografts resulting from prolonged ischemia is accentuated by reperfusion with blood. We also conclude that preservation with a single flush of Euro-Collins or Carolina rinse solution does not offer adequate protection, whereas a second rinse before reperfusion significantly decreases the number of damaged cells within the allograft.

Animals↗
PubMed1996

Linkage of the gene for the triple A syndrome to chromosome 12q13 near the type II keratin gene cluster.

The triple A or Allgrove's syndrome (MIM*231550) is an autosomal recessive disease characterized by the triad of adrenocorticotropic hormone (ACTH) resistant adrenal insufficiency, achalasia and alacrima. Since its first description by Allgrove et al. (1978) more than 70 cases from all over the world have been reported. The syndrome manifests itself during the first decade of life with severe hypoglycaemic episodes which can cause sudden death. The frequent association with neurological disorders presenting as a mixed pattern of upper and lower motor neuropathy, sensory impairment, autonomic neuropathy and mental retardation may result in a severely disabling disease. As an additional feature some patients have hyperkeratosis of their palms and soles. We have performed a systematic genome linkage scan in eight triple A families of which three were consanguineous [including the large highly inbred kindred described by Moore et al. (1991)]. We obtained conclusive evidence for linkage of the triple A syndrome locus to markers on chromosome 12q13 (D12S368, theta max = 0, Zmax = 10.81) with no indication of genetic heterogeneity. Haplotype and multipoint analyses suggest that the gene is located on a chromosomal segment flanked by the markers D12S1629 and D12S312 which are 6 cM apart. This region harbors the type II keratin gene cluster, and potential candidate genes include SCN8A and HOXC genes.

Adrenal Insufficiency↗
PubMed1996

Close mapping of the focal non-epidermolytic palmoplantar keratoderma (PPK) locus associated with oesophageal cancer (TOC).

Focal non-epidermolytic palmoplantar keratoderma (PPK or palmoplantar ectodermal dysplasia type III) is associated with oesophageal cancer in three families: two large pedigrees located in Liverpool, UK and in the midwestern American states and one smaller family from Germany. In these families, the PPK is inherited as autosomal dominant and has a late onset, usually manifesting between 7 and 8 years of age. The disease is characterised by thickening of the pressure areas of the soles, but is not restricted to the feet and also presents with oral leukokeratosis and follicular hyperkeratosis. The disease locus [previously termed the "tylosis oesophageal cancer gene' (TOC) locus] has been mapped to 17q23-qter by linkage analysis. This region is located telomeric to the keratin 16 gene, in which mutations have been identified in focal PPK families who show no increased cancer risk. We describe the close mapping of this locus to the interval between AFMb054zf9 and D17S1603 using haplotype analysis of additional Généthon markers in the region and show that although the American family is unlikely to be related to either of the other two, the UK and German pedigrees may share a common descent. This work provides a basis for positional cloning and candidate gene analysis in order to identify a gene that may be involved in familial oesophageal cancer.

Chromosome Mapping↗
PubMed1996

[Idiopathic pulmonary hemosiderosis].

We report a case of a 23 year-old man admitted to hospital with cough, fever and recurrent episodes of haemoptysis. Laboratory findings, which included a pulmonary biopsy, established the diagnosis of Idiophatic Pulmonary Hemosiderosis (IPH). Despite a number of morphologic, immunologic and ultrastructural studies, the etiology and pathogenesis of this disease remain indetermined. To diagnose an IPH all the other causes of pulmonary hemorrhage must be excluded. This is a rare disease, even more rare in adults. Based on these facts the authors publish this article, which includes the case report and a literature review.

Adult↗
PubMed1995

Palmoplantar keratoderma in association with carcinoma of the esophagus maps to chromosome 17q distal to the keratin gene cluster.

Palmoplantar keratoderma is a group of hereditary disorders of keratinization involving hyperkeratosis of palms and soles. Two different forms of palmoplantar keratoderma have recently been shown to be caused by mutations in the body site-specific keratin 9 gene and in the keratin 1 gene, respectively. Now we have analyzed a large German family with autosomal dominantly inherited palmoplantar keratoderma in association with carcinoma of the esophagus. Linkage to both the type I keratin gene cluster on chromosome 17q distal to the type I keratin genes. Two-point linkage data at D17S801 gave a lod score Zmax - 5.1 at theta = 0.00. Therefore, palmoplantar keratoderma is shown to be heterogeneous clinically as well as genetically and may be caused by mutations in keratins as well as in nonkeratins.

Chromosome Mapping↗
PubMed1995

[Vörner keratosis palmoplantaris diffusa. Clinical, formal genetic and molecular biology studies of 22 families].

In 1901, Vörner described a diffuse keratoderma of palms and soles with autosomal dominant inheritance. Histopathologically, this disease has the typical features of epidermolytic hyperkeratosis. Clinical examination does not allow differentiation between keratoderma of the Vörner type and the keratoderma described by Thost in 1880 and Unna in 1883. Reexamination of the family originally seen by Thost revealed histopathological signs of epidermolytic hyperkeratosis, confirming that keratoderma of the Vörner type is present in this family. The clinical features and variability of this palmoplantar keratoderma were demonstrated on the basis of an examination of 22 families (46 patients). In addition to diffuse hyperkeratosis of palms and soles with a sharp demarcation and erythematous margin, some less well-known features, such as knuckle pad-like keratoses on the finger joints and clubbing of the nails were observed. A genetic analysis of the pedigrees suggests that new mutations causing this disorder rarely occur. Point mutations in the keratin 9 gene, which has been mapped to chromosome 17q21, can be a cause of epidermolytic keratoderma of palms and soles. Five different keratin 9 gene mutations were identified. All these mutations are localized in the highly conserved coil 1A region of the rod domain, which is thought to be relevant for dimer formation in intermediate filaments.

Chromosome Aberrations↗
PubMed1995

Localization of a locus for the striated form of palmoplantar keratoderma to chromosome 18q near the desmosomal cadherin gene cluster.

Palmoplantar keratoderma is a frequent hereditary disorder of keratinization in humans. Various clinically, histopathologically and genetically distinct phenotypes can be diagnosed. Recently, mutations in the keratin genes have been identified in palmoplantar keratoderma: mutations in the keratin 9 gene causing the epidermolytic form, and mutations in the keratin 1 gene in a non-epidermolytic form. We have now investigated a family with the striated form of palmoplantar keratoderma (type Brünauer-Fuhs-Siemens) for linkage to either the type II keratin gene cluster on chromosome 12q or the type I keratin gene cluster on chromosome 17q. After excluding both type I and type II keratin genes we have mapped a locus for this form of palmoplantar keratoderma to chromosome 18q12 with a maximum two-point lod score of 3.3 at theta = 0.00 at D18S536. A cluster of desmosomal cadherin genes has been mapped to this region making them good candidates for this form of PPK. These findings indicate that hyperkeratosis of palms and soles is clinically as well as genetically heterogeneous.

Base Sequence↗
PubMed1995

[Adequacy of of pacemakers responsive to the volume-minute ventilation rate in heart transplantation patients].

PURPOSE: To evaluate in the late post-operative period (PO) the chronotropic response to exercise of patients submitted to orthotopic cardiac transplantation (CT) and the implant of a cardiac pacemaker (PM). METHODS: A rate response ventricular PM (VVI+R) which uses minute ventilation (MV) as a sensor was implanted in five patients in the early PO of CT due to chronotropic incompetence. The patients were 31 to 64 years old and the indication to implant of PM was low ventricular escape rhythm following atrial taquicardia/bradycardia (one case) or sinus bradycardia (4 cases). The study was performed by means of paired exercise tests using Naughton protocol in order to compare the heart rate in VVI (prefixed heart rate) and VVIR+MV (rate response) mode. The duration of the exercise was compared between the two modes of stimulation. RESULTS: In VVI mode the heart rate was significantly lower than in VVIR+MV mode for comparable periods of exercise (101 +/- 12 ppm vs 132 +/- 4 ppm; p < 0.05); in VVIR+MV mode the patients had a prolonged time of exercise as compared to VVI mode (15 +/- 7 min vs 12 +/- 7 min; NS). CONCLUSION: The MV rate response PM provided patients with satisfactory heart during exercise and may be an adequate option to patients submitted to CT who present chronotropic incompetence.

Adult↗
PubMed1995

Plasma endothelin-1 levels in human lung transplant recipients.

Endothelin-1 (ET-1) is a potent vasoconstrictor peptide produced by vascular endothelial cells and is believed to play an important role in the pathophysiology of the pulmonary vasculature. We have investigated the early changes in ET-1 plasma levels in lung transplant recipients at various intervals before and after isolated lung transplantation. The mean plasma ET-1 level immediately before transplantation was 0.8 +/- 0.1 pg/ml. This was significantly increased to 2.6 +/- 0.5 pg/ml shortly after unclamping and vascular reperfusion of the allograft, and remained high 4 h (2.3 +/- 0.5 pg/ml), 6 h (2.4 +/- 0.6 pg/ml), and 12 h (1.7 +/- 0.3 pg/ml) after transplantation. Thereafter, the level of ET-1 started to decline, reaching 1.3 +/- 0.3 pg/ml 24 h and 0.9 +/- 0.3 pg/ml 1 week after transplantation. This early increase in ET-1 plasma level is consistent with our observation of alterations in pulmonary vascular resistance, pulmonary artery pressure and cardiac output early after transplantation. These findings demonstrate that an increase in plasma ET-1 levels shortly after lung transplantation may have a detrimental effect during the postoperative course early after transplantation.

Blood Pressure↗
PubMed1994

Analysis of 133 meioses places the genes for nevoid basal cell carcinoma (Gorlin) syndrome and Fanconi anemia group C in a 2.6-cM interval and contributes to the fine map of 9q22.3.

Four disease genes (NBCCS, ESS1, XPAC, FACC) map to 9q22.3-q31. A fine map of this region was produced by linkage and haplotype analysis using 12 DNA markers. The gene for nevoid basal cell carcinoma syndrome (NBCCS, Gorlin) has an important role in congenital malformations and carcinogenesis. Phase-known recombinants in a study of 133 meioses place NBCCS between (D9S12/D9S151) and D9S176. Haplotype analysis in a two-generation family suggests that NBCCS lies in a smaller interval of 2.6 cM centromeric to D9S287. These flanking markers will be useful clinically for gene tracking. Recombinants also map FACC (Fanconi anemia, group C) to the same region, between (D9S196/D9S197) and D9S287. The recombination rate between (D9S12/D9S151) and D9S53 in males is 8.3% and 13.2% in females, giving a sex-specific male:female ratio of 1:1.6 and a sex-averaged map distance of 10.4 cM. No double recombinants were detected, in agreement with the apparently complete level of interference predicted from the male chiasmata map.

Basal Cell Nevus Syndrome↗
PubMed1994

A YAC contig spanning the nevoid basal cell carcinoma syndrome, Fanconi anaemia group C, and xeroderma pigmentosum group A loci on chromosome 9q.

Nevoid basal cell carcinoma syndrome (NBCCS, Gorlin syndrome) is an autosomal dominant disorder, characterized primarily by multiple basal cell carcinomas, epithelium-lined jaw cysts, and palmar and plantar pits, as well as various other features. Loss of heterozygosity studies and linkage analysis have mapped the NBCCS gene to chromosome 9q and suggested that it is a tumor suppressor. The apparent sensitivity of NBCCS patients to UV and X-irradiation raises the possibility of hypersensitivity to DNA-damaging reagents or defective DNA repair being etiological in the disorder. The recent mapping of the Fanconi anaemia group C (FACC) and xeroderma pigmentosum complementing group A (XPAC) genes to the same region on 9q has led us to begin the molecular dissection of the 9q22-q31 region. PCR analysis of the presence or absence of 10 microsatellite markers and exons 3 and 4 of the XPAC and FACC genes, respectively, allowed us to order 12 YACs into an overlapping contig and to order the markers as follows: D9S151/D9S12P1-D9S12P2-D9S197-D9S196-D9 S280-FACC-D9S287/XPAC-D9S180-D9S6-D9 S176 . Sizing of the YACs has provided an initial estimate of the size of the NBCCS candidate region between D9S12 and D9S180 to be less than 1.65 Mb.

Basal Cell Nevus Syndrome↗