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C Correia

Publications and source records attributed to C Correia.

At least 19 recordsLinked to original sources
PubMed2006

SEPT2 is a new fusion partner of MLL in acute myeloid leukemia with t(2;11)(q37;q23).

We have identified a new mixed lineage leukemia (MLL) gene fusion partner in a patient with treatment-related acute myeloid leukemia (AML) presenting a t(2;11)(q37;q23) as the only cytogenetic abnormality. Fluorescence in situ hybridization demonstrated a rearrangement of the MLL gene and molecular genetic analyses identified a septin family gene, SEPT2, located on chromosome 2q37, as the fusion partner of MLL. RNA and DNA analyses showed the existence of an in-frame fusion of MLL exon 7 with SEPT2 exon 3, with the genomic breakpoints located in intron 7 and 2 of MLL and SEPT2, respectively. Search for DNA sequence motifs revealed the existence of two sequences with 94.4% homology with the topoisomerase II consensus cleavage site in MLL intron 7 and SEPT2 intron 2. SEPT2 is the fifth septin family gene fused with MLL, making this gene family the most frequently involved in MLL-related AML (about 10% of all known fusion partners). The protein encoded by SEPT2 is highly homologous to septins 1, 4 and 5 and is involved in the coordination of several key steps of mitosis. Further studies are warranted to understand why the septin protein family is particularly involved in the pathogenesis of MLL-associated leukemia.

Amino Acid Sequence↗
PubMed2006

Bacterial nitrate reductases: Molecular and biological aspects of nitrate reduction.

Nitrogen is a vital component in living organisms as it participates in the making of essential biomolecules such as proteins, nucleic acids, etc. In the biosphere, nitrogen cycles between the oxidation states +V and -III producing many species that constitute the biogeochemical cycle of nitrogen. All reductive branches of this cycle involve the conversion of nitrate to nitrite, which is catalyzed by the enzyme nitrate reductase. The characterization of nitrate reductases from prokaryotic organisms has allowed us to gain considerable information on the molecular basis of nitrate reduction. Prokaryotic nitrate reductases are mononuclear Mo-containing enzymes sub-grouped as respiratory nitrate reductases, periplasmic nitrate reductases and assimilatory nitrate reductases. We review here the biological and molecular properties of these three enzymes along with their gene organization and expression, which are necessary to understand the biological processes involved in nitrate reduction.

Bacteria↗
PubMed2006

Evaluation of a new IOL scleral fixation technique without capsular support.

PURPOSE: The purpose of this study was to compare a new intraocular lens (IOL) scleral fixation technique (scleral incision) with the scleral flap surgical technique as regards to efficacy, surgical complications, advantages, disadvantages, and surgery costs in cases with no capsular support. MATERIAL AND METHODS: This was a retrospective study conducted on thirty patients (30 eyes), ten of whom were aphakic, eleven had traumatic cataract, seven had post-phacoemulsification complications, and two had lens luxation. The patients were divided into two groups (I - scleral incision technique and II - scleral flap technique) of fifteen patients each, during a study period lasting eighteen months. The great majority of the procedures were performed under general anesthesia and by the same surgeon. Statistical analysis was done using SPSS. The numerical variables were compared using the t test and the categorical ones using the Fisher exact test. We performed multifactorial analysis to build a model that could predict and compare the complications associated with each technique. An explicative model was built using logistic regression. RESULTS: We observed a threefold higher rate of complications associated with the scleral flap technique when compared to the scleral incision technique. This difference was particularly relevant as regards the occurrence of free scleral flap and hyphema. No statistically significant differences were observed regarding vitreous hemorrhage, choroidal hemorrhage, retinal detachment, difficulty in the external pulling of the Prolene suture, breaking of the Prolene suture, and anterior chamber collapse. We found a significant association between intraoperative complications and the technique used (higher number of complications with the scleral flap) and also with some systemic diseases (patients with hypertension had more intraoperative complications). The number of late complications resulting from the scleral flap technique was much higher than those observed with the scleral incision technique; however, the number of the cases we studied is insufficient to reach statistical significance. CONCLUSION: The duration of the procedure using the IOL scleral incision technique is significantly lower than using the scleral flap technique. Intraoperative complications were significantly associated with the technique used: more frequent with scleral flap. Late complications were mainly associated with systemic and previous ocular diseases.

Eye Diseases↗
PubMed2005

A7445G mtDNA mutation present in a Portuguese family exhibiting hereditary deafness and palmoplantar keratoderma.

Mitochondrial DNA (mtDNA) A7445G point mutation has been shown to be responsible for familial nonepidermolytic palmoplantar keratoderma (NEPPK) associated with deafness without any additional features. To date, only a few cases have been described. We report a Portuguese pedigree presenting an inherited combination of NEPPK and sensorineural deafness compatible with maternal transmission. Clinical expression and age of onset of NEPPK and deafness were variable. Normal expression patterns of epidermal keratins and filaggrin, intercellular junction proteins including connexin 26, loricrin and cornified envelope proteins, were observed. Molecular analysis revealed that all the affected members, previously screened for Cx26 mutations with negative results, presented the mtDNA A7445G point mutation in the homoplasmic form. To our knowledge, this is the fifth family in whom inherited NEPPK and hearing loss are related to this mitochondrial mutation.

Adult↗
PubMed2003

Interstitial irradiation for CNS lesions.

In this study, we investigated the efficacy of brachytherapy in the treatment of 138 patients with intracranial neoplasms of the CNS. Of the total number of patients, 50 presented with glioblastoma multiforme, 45 presented with low-grade glioma, 19 presented with anaplastic astrocytoma, 23 presented with metastases and 1 presented with meningioma. During the execution of this study, seeds of 125I (10-20 mCi) were inserted into the lesions to aim the irradiation at a low dose of 60 Gy in the margin of benign lesions or 1 cm beyond the radiological border of malignant lesions, which were visualized on CT scan. The results of this procedure were evaluated in terms of the survival rates, which were assessed by Kaplan-Meier curves. Significant relationships were not observed between the volume and location of the lesions, the whole-brain radiotherapy and chemotherapy, and the survival time of the patients. A low Karnofsky Index score and older age were associated with a short survival time. In light of the above, it was concluded that interstitial irradiation is a safe and effective method of treatment for brain tumors.

Adult↗
PubMed2002

An evaluation of the usefulness of two terminology models for integrating nursing diagnosis concepts into SNOMED Clinical Terms.

OBJECTIVES: We evaluated the usefulness of two models for integrating nursing diagnosis concepts into SNOMED Clinical Terms (CT). METHODS: First, we dissected nursing diagnosis term phrases from two source terminologies (North American Nursing Diagnosis Association Taxonomy 1 (NANDA) and Omaha System) into the semantic categories of the European Committee for Standardization (CEN) categorical structure and ISO reference terminology model (RTM). Second, we critically analyzed the similarities between the semantic links in the CEN and ISO models and the semantic links used to formally define diagnostic concepts in SNOMED CT. RESULTS: Our findings demonstrated that focus, bearer/subject of information, and judgment were present in 100% of the NANDA and Omaha term phrases. The Omaha term phrases contained no additional descriptors beyond those considered mandatory in the CEN and ISO models. The comparison among the semantic links showed that SNOMED CT currently contains all but one of the semantic links needed to model the two source terminologies for integration. In conclusion, our findings support the potential utility of the CEN and ISO models for integrating nursing diagnostic concepts into SNOMED CT.

Classification↗
PubMed2001

[Vasculitic neuropathy in Wegener granulomatosis: case report].

The neurologic involvement during Wegener granulomatosis reaches 15-50% of patients, however as initial symptomatology is not commented in the literature. We describe a patient with Wegener's granulomatosis and mononeuritis multiplex, emphasizing the fact that neurologic manifestations anticipated systemic symptoms, and also focusing on the diagnostic contribution of sural biopsy and the good outcome of neurologic disease.

Aged↗
PubMed2001

An evaluation of the utility of the CEN categorical structure for nursing diagnoses as a terminology model for integrating nursing diagnosis concepts into SNOMED.

We evaluated the utility of the CEN Categorical Structure for Nursing Diagnoses as a terminology model for integrating nursing diagnosis concepts into SNOMED. First, we dissected nursing diagnosis term phrases from two source terminologies (North American Nursing Diagnosis Association (NANDA) Taxonomy 1 and Omaha System) into the semantic categories of the CEN categorical structure. Second, we critically analyzed the similarities between the semantic links in the CEN model and the semantic links used to formally define diagnostic concepts in SNOMED RT and SNOMED CT. Our findings demonstrated that focus, bearer, and judgment were present in 100% of the NANDA and Omaha term phrases. The Omaha term phrases contained no additional descriptors beyond those considered mandatory in the CEN model. In contrast, at least 3% of NANDA diagnoses included a term in each semantic category of the categorical structure. The comparison among the semantic links showed that neither SNOMED RT and SNOMED CT currently contain all the semantic links needed to model the two source terminologies for integration. In conclusion, our findings support the potential utility of the CEN categorical structure as a terminology model for dissecting nursing diagnostic concepts for integration into SNOMED RT and SNOMED CT. However, in order to accomplish this task, appropriate semantic links must be added to SNOMED RT and SNOMED CT.

Nursing Diagnosis↗
PubMed2001

The SNOMED RT Procedure Model.

BACKGROUND: SNOMED RT represents a fundamental change from prior versions of SNOMED. The logic-based structure of SNOMED RT enables concepts to be defined more explicitly, providing an opportunity to address inconsistencies and ambiguities present in prior SNOMED concept definitions. OBJECTIVES: Create a unifying organizational strategy for all SNOMED RT procedures, and remove ambiguities in procedure concept definitions. METHODS: A comprehensive model of procedures was developed, based on a set of guiding principles and a review of known existing models. RESULTS: All SNOMED RT procedures are categorized by a common set of "root procedures" (high level atomic actions), and are more explicitly defined by a shared set of defining relationships. CONCLUSIONS: While the objectives have largely been met, open issues continue to be addressed. The similarity between procedure models of SNOMED RT and the U.K. s Clinical Terms Version 3 is proving to greatly facilitate the full integration of the two terminologies into a merged vocabulary to be known as SNOMED Clinical Terms (SNOMED CT), slated to be released in the near future.

Clinical Medicine↗
PubMed2000

Differences in phenotype, growth factor requirements, pattern of expression of adhesion molecules and rate of apoptosis displayed by three new myeloid sister leukemic cell lines.

We established three new human myeloid cell lines from one patient, in the presence of granulocyte-macrophage colony-stimulating factor (UPM1-GM), interleukin-3 (UMP1-IL-3) or without exogenous growth factors (UPM1). The 3 lines were characterized by phenotypic, genotypic and functional studies. These cell lines may provide useful tools to study different aspects of leukemic cell biology

Apoptosis↗
PubMed1999

Cross-linking between cytochrome c3 and flavodoxin from Desulfovibrio gigas.

Tetraheme cytochrome c3 (13 kDa) and flavodoxin (16 kDa), are small electron transfer proteins that have been used to mimic, in vitro, part of the electron-transfer chain that operates between substract electron donors and respiratory electron acceptors partners in Desulfovibrio species (Palma, N., Moura, I., LeGall, J., Van Beeumen, J., Wampler, J., Moura, J. J. G. (1994) Biochemistry 33, 6394-6407). The electron transfer between these two proteins is believed to occur through the formation of a specific complex where electrostatic interaction is the main driving force (Stewart, D., LeGall, J., Moura, I., Moura, J.J.G., Peck, H.D., Xavier, A.V., Weiner, P.K. and Wampler, J.E. (1988) Biochemistry 27, 2444-2450, Stewart, D., LeGall, J., Moura, I., Moura, J.J.G., Peck, H.D., Xavier, A.V., Weiner, P., Wampler, J. (1989) Eur. J. Biochem. 185, 695-700). In order to obtain structural information of the pre-complex, a covalent complex between the two proteins was prepared. A water-soluble carbodiimide [EDC (1-ethyl-3(3 dimethylaminopropyl) carbodiimide hydrochloride] was used for the cross linking reaction. The reaction was optimized varying a wide number of experimental parameters such as ionic strength, protein and cross linker concentration, and utilization of different cross linkers and reaction time between the crosslinker and proteins.

CME-Carbodiimide↗
PubMed1999

Unexpected pattern of beta-globin mutations in beta-thalassaemia patients from northern Portugal.

We characterized the genetic nature of beta-thalassaemia in northern Portugal. Of the 164 patients studied three were beta-thalassaemia major cases (one IVS-1-6/beta degrees 39 and two homozygous IVS-1-110). The analysis of the frequency of each mutation in the families revealed that the codon 6(-A) mutation was unexpectedly frequent (40%) and associated with the beta-globin haplotype E, and not with the usual European and North African CD6(-A) haplotypes. In contrast, the frequency of IVS-1-6 (8%) and beta degrees 39 (19%) was found to be lower than in the rest of the country. The frequency of all other mutations was similar to previous reports for central/southern Portugal. Six families carried none of the most frequent mutations in the Mediterranean area. These families were studied by gene sequencing, revealing that three families carried a previously described mutation (CD16 G --> A). The remaining families carried previously unidentified mutations: one showed an 86 bp insertion in exon 2 (named HGSA) and two showed a deletion of a cytidine in codon 11 (CD11(-C)). The results, showing a high frequency (82%) of beta degrees mutations, strongly indicates that genetic counselling should be intensified as a means of preventing the spread of the severe mutations found.

Adolescent↗
PubMed1997

Selection of homogeneous populations for genetic study: the Portugal genetics of psychosis project.

Molecular genetic studies of psychiatric disorders must face the possibility that despite the significant contribution of genetic factors to the expression of syndromes like schizophrenia, these syndromes may be a heterogeneous collection of genetic and non-genetic illnesses. These illnesses may be etiologically distinct from each other and still share many clinical features in common. Linkage studies of families with multiple affected members tend to favor the selection of genetic forms of a syndrome but can still represent a heterogeneous set of different genetic illnesses. To limit the potential genetic heterogeneity of a study sample, we selected a population that was geographically isolated and was historically relatively genetically homogeneous. We then assessed the relative level of homogeneity utilizing a surname analysis of the population of the Azores, mainland Portugal, rural USA, and urban USA. The average number of families with the same last name corrected for population size in the Azores is 30.88, in Coimbra it is 21.42, compared to 1.13 in a rural American population and 0.38 in an urban American population. The results of this analysis indicate that the Azores have the highest degree of homogeneity, and mainland Portugal has a high degree of homogeneity.

Azores↗
PubMed1994

Congenital sensory neuropathy with anhidrosis.

A 6-year-old girl had congenital sensory neuropathy with anhidrosis (CSNA), one of the five variants of a group of very rare genetic disorders of the peripheral nervous system--hereditary sensory neuropathies (HSN). Clinical, laboratory, and physiopathologic aspects are discussed. Dermatologic findings of anhidrosis and self-mutilation suggest the diagnosis.

Child↗
PubMed1993

Cytogenetic findings in eleven gastric carcinomas.

We describe the results of the cytogenetic study of 10 primary adenocarcinomas of the stomach and one lymph node metastasis of a gastric adenocarcinoma after direct harvesting or short-term in vitro culture. All cases showed a variable number of numerical and/or structural clonal cytogenetic aberrations. Polysomy of chromosomes 2 and 20 were the most common numerical abnormalities. Rearrangements of chromosomes 1, 3, 7, and 13 were each observed in more than half the cases. Chromosomes 3 and 13 were the chromosomes more often exhibiting structural cytogenetic aberrations. In five tumors, rearrangements of chromosome 6 resulting in partial deletion of 6q were noted (common deleted region 6q21-22-->qter). The recurrent markers observed in our series were an i(8q) and an i(17q) in three and two cases, respectively. Double minutes (dmin) or homogeneously staining regions (hsr) were evident in three tumors. Contrary to the recent claim that structural abnormalities affecting 11p13-p15 were specifically involved in gastric cancer, we detected rearrangements of this region in only two cases.

Adenocarcinoma↗
PubMed1993

Thyroid nodular hyperplasia: chromosomal studies in 14 cases.

Cytogenetic study of 14 thyroid nodular hyperplasias revealed a hyperdiploid karyotype in two cases (14%) and a normal chromosomal complement in the remaining cases. Some of the numerical alterations found were identical to the ones considered characteristic of a subset of thyroid adenomas (+5, +7, +9, +12, +14, and +16). Our findings suggest that the cytogenetic events involved in the pathogenesis of thyroid hyperplastic lesions and benign tumors may be closely related, which supports the hypothesis of a biologic "continuum" between these two types of lesions.

Adult↗
PubMed1992

Loss of Y chromosome in gastric carcinoma. Fact or artifact?

Loss of chromosome Y has been reported in gastric cancer cells together with other chromosomal abnormalities. We noted loss of chromosome Y and near-diploid karyotypes in five cases of gastric adenocarcinoma, but DNA flow cytometry performed on fresh tumor tissue showed aneuploid peaks in four of them. Our findings suggest that loss of the Y chromosome in gastric cancer probably reflects the karyotype of a subpopulation of stromal cells and not a neoplasia-related chromosomal aberration.

Adult↗