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Biomedical subjects

E Serra

Publications and source records attributed to E Serra.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Gastric duplication of 3 observations].

Gástric duplicación si an infrequent congenital malformation present in both, neonatal period and childhood, and exceptionally during adulthood. We present here there cases of gastric duplication from patients of different ages, in which it was not possible to make diagnosis before surgery. In all of them cystic form was the predominating one, without communication with gastric lumen (cavity). Diagnosis was performed after laparotomy and histopathological examination.

Child↗
PubMed1999

Biomphalaria glabrata embryonic cells express a protein with a domain homologous to the lectin domain of mammalian selectins.

We have cloned from Biomphalaria glabrata, the intermediate host of the helminth parasite Schistosoma mansoni, a 36-kDa apparent-molecular-mass molecule (BgSel) that shares sequence identity with selectins of the cell-adhesion-molecule superfamily. BgSel exhibited in its C-terminal part a putative C-type lectin domain similar to the selectin lectin domain. Using antibodies to the recombinant BgSel protein, we demonstrated the presence of BgSel in snail hemocytes as well as in the cell line derived from B. glabrata embryos (Bge). Anti-BgSel antibodies specifically recognized a 79-kDa component in Bge-cell-secreted products that was supposed to represent the native form of BgSel, as was confirmed after glycosidase treatment. Lectins are known to be implicated in recognition mechanisms participating in humoral and cellular immunity in molluscs. The possible role of BgSel in the interaction between sporocysts and Bge cells, particularly in the in vitro model of sporocyst development dependent on Bge cell factors, remains to be determined.

Amino Acid Sequence↗
PubMed1999

Dietary chromic oxide does not affect the utilization of organic compounds but can alter the utilization of mineral salts in gilthead sea bream Sparus aurata.

This study was conducted to determine whether the level of chromic oxide supplemented to diets containing gelatinized starch as the carbohydrate source affects digestibility, body composition, growth performances, and liver enzyme activities in gilthead sea bream, Sparus aurata. Gilthead sea bream fingerlings were fed diets containing gelatinized corn starch as the carbohydrate source and several levels of chromic oxide (0, 5, 10 and 20 g/kg) for 6 wk. No effect of dietary chromium level was detected on carbon, nitrogen, or dry matter digestibility. Calcium and phosphorus digestibility were higher in fish fed the diet supplemented with 5 g/kg chromic oxide than in fish fed the other supplemented diets. Dietary chromium did not affect dry matter, carbon, nitrogen, protein, or lipid concentrations in fish. However, fish fed 5 g/kg chromic oxide generally had higher levels of calcium, phosphorus, and ash than fish fed the other Cr-containing diets. Chromium concentration was significantly higher in fish fed the diets with 0.5 and 1% chromic oxide than in fish fed the control diet. Chromium supplementation of the diets did not affect the specific growth rate, the food efficiency ratio, the protein efficiency ratio, or, protein or nitrogen retention of the fish. Blood glucose and the activity of several liver enzymes involved in carbohydrate metabolism were unaffected by dietary chromic oxide. Alanine aminotransferase was lower in the fish fed the diet with 10 g/kg of chromic oxide than in unsupplemented controls. Our results indicate that chromic oxide can be used as a neutral marker in fish nutrition studies involving organic compounds, but not mineral salts.

Animals↗
PubMed1999

Prenatal diagnosis of sporadic neurofibromatosis type 1 (NF1) by RNA and DNA analysis of a splicing mutation.

Neurofibromatosis type 1 (NF1) is one of the most common genetic disorders in humans with an incidence of 1 in 3500. Most of the NF1 mutations reported so far (over 240 mutations) are unique. Specific prenatal diagnosis can only be provided to familial cases by an indirect linkage analysis or to families with a previously identified mutation. Here we report the first prenatal diagnosis in sporadic NF1 by direct characterization of the mutation. We first identified the skipping of exon 10b of NF1 in the mRNA from a woman affected by NF1 and without familial history of the disease. The analysis of genomic DNA identified mutation IVS10b+1G-->A as the cause of the skipping of exon 10b. Chorionic villus sampling (CVS) was performed at 10 weeks of gestation and total RNA was directly extracted from the sample. After reverse transcription (RT) and polymerase chain reaction (PCR) of the cDNA, the skipping of exon 10b was not identified in the CVS upon agarose gel electrophoresis. The fetal origin of the CVS was confirmed via polymorphic markers and the absence of the IVS10b+1G-->A mutation was confirmed by genomic analysis.

Adult↗
PubMed1998

Conservation and divergence of NF-Y transcriptional activation function.

The CCAAT-binding protein NF-Y is involved in the regulation of a variety of eukaryotic genes and is formed in higher eukaryotes by three subunits NF-YA/B/C. We have characterized NF-Y of the trematode parasite Schistosoma mansoni and studied the structure and the function of the SMNF-YA subunit. In this work, we present the cloning and sequence analysis of the B subunit of the parasite factor. SMNF-YB contains the conserved HAP-3 homology domain but the remaining part of the protein was found to be highly divergent from all other species. We demonstrated by transfections of GAL4 fusion constructs, that mouse NF-YB does not contain activation domains while the C-terminal part of SMNF-YB has transcriptional activation potential. On the other hand, the N-terminal parts of SMNF-YA and mouse NF-YA were shown to mediate transactivation; the integrity of a large 160 amino acid glutamine-rich domain of NF-YA was required for this function and an adjacent serine- and threonine-rich domain was necessary for full activity in HepG2, but redundant in other cell types. Transactivation domains identified in SMNF-YB are also rich in serine and threonine residues. Our results indicate that serine/threonine-richsequences from helminth parasites potentiate trans-cription and that such structures have diverged during evolution within the same transcription factor.

3T3 Cells↗
PubMed1998

Characterization of an intracellular receptor for activated protein kinase C (RACK) from the mollusc Biomphalaria glabrata, the intermediate host for Schistosoma mansoni.

A receptor for activated protein kinase C (RACK) was characterized from the mollusc Biomphalaria glabrata, the intermediate host for the human parasite Schistosoma mansoni. This protein was shown to possess structural and functional characteristics of other RACK proteins from various cells and organisms. Its ability to bind mammalian PKCs also confirmed the conservation of PKC and RACK interactive domains throughout evolution. Results of immunolocalization indicated the presence of Bg RACK in the cytoplasm of mollusc hemocytes and B. glabrata embryonic (Bge) cells with a more intense staining around the nucleus. These results are in agreement with the association of RACK proteins with cytoskeletal elements.

Amino Acid Sequence↗
PubMed1998

Clinical and stabilometric monitoring in a case of cerebellar atrophy with vitamin E deficiency.

The authors describe a case of early onset ataxia with cerebellar atrophy and vitamin E deficiency, treated with alpha-tocopherol supplementation and physically rehabilitated by postural biofeedback. Clinical assessments, serum vitamin E levels and postural evaluation by means of a stabilometric platform continued for about 2 years and significant clinical improvement was recorded. Our study confirms that combined physical therapy and vitamin E supplementation may result in improvement of cerebellar function. Motor improvement is directly related to vitamin E serum levels, providing further confirmation that normal vitamin E levels are crucial for proper brain functions.

Adolescent↗
PubMed1998

A clinical variant of neurofibromatosis type 1: familial spinal neurofibromatosis with a frameshift mutation in the NF1 gene.

Spinal neurofibromatosis (SNF) has been considered to be an alternative form of neurofibromatosis in which spinal cord tumors are the main clinical characteristic. Familial SNF has been reported, elsewhere, in three families-two linked to markers within the gene for neurofibromatosis type 1 (NF1) and the other not linked to NF1-but no molecular alterations have been described in these families. We describe a three-generation family that includes five members affected by SNF. All the affected members presented multiple spinal neurofibromas and café au lait spots, one member had cutaneous neurofibromas, and some members had other signs of NF1. Genetic analysis, performed with markers within and flanking the NF1 gene, showed segregation with the NF1 locus. Mutation analysis, performed with the protein-truncation test and SSCP/heteroduplex analysis of the whole coding region of the NF1 gene, identified a frameshift mutation (8042insA) in exon 46, which should result in a truncated NF1 protein. The 8042insA mutation was detected in all five family members with the SNF/NF1 phenotype. To our knowledge, this is the first time that a mutation in the NF1 gene has been associated with SNF. The clinical homogeneity in the severity of the disease among the affected members of the family, which is unusual in NF1, suggests that a particular property of the NF1 mutation described here, a gene closely linked to NF1, or posttranscriptional events are involved in this severe neurological phenotype.

Adult↗
PubMed1997

Deletion analysis of the Schistosoma mansoni 28-kDa glutathione S-transferase gene promoter in mammalian cells--importance of a proximal activator-protein-1 site.

The 1241-bp promoter region of the Schistosoma mansoni 28-kDa glutathione S-transferase gene (Sm28GST) was sequentially deleted and analyzed using the luciferase reporter gene system in different cell lines. The activator protein-1 (AP-1) site located at -231 seems to be responsible for the major part of the promoter activity. The 1241-bp Sm28GST promoter was not, in transient transfection experiments, activated by reagents generating reactive oxygen species, such as hydrogen peroxide (H2O2), 3-methylcholanthrene, and ter-methylhydroquinone, but was significantly stimulated by phorbol 12-myristate 13-acetate, a potent protein kinase C activator. The involvement of the -231 AP-1 site in phorbol 12-myristate 13-acetate stimulation was demonstrated. Moreover, evidence for in vitro and in vivo binding of the -231 AP-1 site to Jun/Fos dimers was obtained using mobility gel shift assays and co-transfection of embryonic F9 cells with Jun/Fos expression plasmids, respectively. The presence in S. mansoni nuclear extracts of components with affinity for the AP-1 site suggests conservation of this regulatory pathway in the parasite.

Animals↗
PubMed1997

Left ventricular pseudoaneurysm with left atrium tamponade: a rare postinfarction complication.

A 65-year-old man was readmitted to the hospital with deep-vein thrombophlebitis 3 weeks after suffering a small infarction. Two days after the patient was readmitted severe symptoms of cardiac failure developed. Transthoracic echocardiographic examination showed an unusual echo-free space adjacent to the lateral wall of the left atrium. No further diagnostic information could be obtained from precordial examinations. Single-plane transesophageal echocardiography demonstrated the presence of a ruptured aneurysm in the posterolateral wall of the left ventricle and a pseudoaneurysm, which was severely compressing the left atrial cavity. On color-flow Doppler examination a tear was detected in the wall of the left ventricular aneurysm close to the posterior atrioventricular sulcus. Pericardial adhesions because of coronary artery bypass grafting performed 10 years before may have contributed to the unusual location of this left ventricular pseudoaneurysm, complicated with left atrium tamponade after myocardial infarction.

Aged↗
PubMed1997

Confirmation of a double-hit model for the NF1 gene in benign neurofibromas.

Neurofibroma is a benign tumor that arises from small or large nerves. This neoplastic lesion is a common feature of neurofibromatosis type 1 (NF1), one of the most common autosomal dominant disorders. The NF1 gene codes for a protein called "neurofibromin." It possesses a region that shares a high homology with the family of GTPase-activating proteins, which are negative regulators of RAS function and thereby control cell growth and differentiation. The evidence points to the NF1 gene being a tumor-suppressor gene. NF1 patients also have an increased incidence of certain malignant tumors that are believed to follow the "two hit" hypothesis, with one allele constitutionally inactivated and the other somatically mutated. Recently, somatic loss of heterozygosity (LOH) has been described for neurofibromas, and mutations in both copies of the NF1 gene have been reported for a dermal neurofibroma. The aim of our study was the analysis of the NF1 locus in benign neurofibromas in NF1 patients. We performed LOH analysis on 60 neurofibromas belonging to 17 patients, 9 of them with family history of the disease and 8 of them sporadic. We have analyzed five intragenic NF1 markers and six extragenic markers, and we have found LOH in 25% of the neurofibromas (corresponding to 53% of the patients). In addition, we found that in the neurofibromas of patients from familial cases the deletions occurred in the allele that is not transmitted with the disease, indicating that both copies of the NF1 gene were inactivated in these tumors. Therefore, the recent reports mentioned above, together with our findings, strongly support the double inactivation of the NF1 gene in benign neurofibromas.

Alleles↗
PubMed1996

Functional analysis of the Schistosoma mansoni 28 kDa glutathione S-transferase gene promoter: involvement of SMNF-Y transcription factor in multimeric complexes.

The ability of the 5' flanking region of the gene encoding the 28 kDa glutathione S-transferase of Schistosoma mansoni gene to promote transcription, was studied in different mammalian cell lines. Results of transient transfection assays showed a strong activity of the -277 to +1 nt region of the Sm28GST gene, comparable to that of well-studied promoters. Deletion analysis indicated that an AP-1 site and two closely located CCAAT (Y1 and Y2) boxes were the principal motifs responsible for the promoter activity. Binding of the NF-Y complex to Y1 and Y2, as well as to a third CCAAT box (Y3) close to the promoter TATA box, was compared in gel shift and super-shift experiments. All of the three Y boxes bound protein complexes from S. mansoni nuclear extracts that were shown to contain the A subunit of the schistosome NF-Y complex (SMNF-YA). Competition assays revealed a differential affinity of the Y1, Y2 and Y3 sequences for NF-Y. The Y1, Y2 and Y3 regions were also shown to activate transcription when included in an heterologous promoter and data obtained strongly suggested the involvement of SMNF-Y in multimeric complexes during this process.

Animals↗
PubMed1996

Cloning of Schistosoma mansoni transcription factor NF-YA subunit: phylogenic conservation of the HAP-2 homology domain.

The CCAAT-binding factor NF-Y (CBF/CP1) is a heteromeric transcription factor involved in the regulation of a variety of eukaryotic genes. We identified NF-Y as the CCAAT activity binding to the promoter region of the gene coding for the 28-kDa glutathione S-transferase of the human parasite Schistosoma mansoni (Sm28GST). We isolated the NF-YA cDNA from S. mansoni (SmNF-YA): the complete 268 amino acid sequence harbors a region in its C-terminal part that shows homology with the subunit interaction and DNA-binding domains of the mammalian NF-YA; the N-terminal region has an amino acid composition reminiscent of the mammalian and echinoderm counterparts, rich in glutamine and hydrophobic residues, but shows no sequence similarity at the primary level. In vitro synthesized SMNF-YA is able to associate with mammalian NF-YB/C subunits in the absence of DNA and to bind to the Sm28GST CCAAT box. Surprisingly, a monoclonal antibody directed against the non-conserved Q-rich activation domain of mammalian NF-YA supershifts and immunoprecipitates SMNF-YA, strongly suggesting structure conservation in the activation domain between divergent species.

Amino Acid Sequence↗