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Biomedical subjects

M Morey

Publications and source records attributed to M Morey.

At least 19 recordsLinked to original sources
PubMed2001

Modulation of the Ras/MAPK signalling pathway by the redox function of selenoproteins in Drosophila melanogaster.

Modulation of reactive oxygen species (ROS) plays a key role in signal transduction pathways. Selenoproteins act controlling the redox balance of the cell. We have studied how the alteration of the redox balance caused by patufet (selD(ptuf)), a null mutation in the Drosophila melanogaster selenophosphate synthetase 1 (sps1) gene, which codes for the SelD enzyme of the selenoprotein biosynthesis, affects the Ras/MAPK signalling pathway. The selD(ptuf) mutation dominantly suppresses the phenotypes in the eye and the wing caused by hyperactivation of the Ras/MAPK cassette and the activated forms of the Drosophila EGF receptor (DER) and Sevenless (Sev) receptor tyrosine kinases (RTKs), which signal in the eye and wing, respectively. No dominant interaction is observed with sensitized conditions in the Wnt, Notch, Insulin-Pi3K, and DPP signalling pathways. Our current hypothesis is that selenoproteins selectively modulate the Ras/MAPK signalling pathway through their antioxidant function. This is further supported by the fact that a selenoprotein-independent increase in ROS caused by the catalase amorphic Cat(n1) allele also reduces Ras/MAPK signalling. Here, we present the first evidence for the role of intracellular redox environment in signalling pathways in Drosophila as a whole organism.

Alleles↗
PubMed2001

Autologous stem-cell transplantation for Hodgkin's disease: results and prognostic factors in 494 patients from the Grupo Español de Linfomas/Transplante Autólogo de Médula Osea Spanish Cooperative Group.

PURPOSE: To analyze clinical outcome and significant prognostic factors for overall (OS) and time to treatment failure (TTF) in a group of 494 patients with Hodgkin's disease (HD) undergoing autologous stem-cell transplantation (ASCT). PATIENTS AND METHODS: Detailed records from the Grupo Español de Linfomas/Transplante Autólogo de Médula Osea Spanish Cooperative Group Database on 494 HD patients who received an ASCT between January 1984 and May 1998 were reviewed. Two hundred ninety-eight males and 196 females with a median age of 27 years (range, 1 to 63 years) received autografts while in complete remission (n = 203) or when they had sensitive disease (n = 206) or resistant disease (n = 75) at a median time of 26 months (range, 4 to 259 months) after diagnosis. Most patients received high-dose chemotherapy without radiation for conditioning (n = 443). The graft consisted of bone marrow (n = 244) or peripheral blood (n = 250). RESULTS: The 100-day mortality rate was 9%. The 5-year actuarial TTF and OS rates were 45.0% (95% confidence interval [CI], 39.5% to 50.5%) and 54.5% (95% CI, 48.4% to 60.6%), respectively. In multivariate analysis, the presence of active disease at transplantation, transplantation before 1992, and two or more lines of therapy before transplantation were adverse prognostic factors for outcome. Sixteen patients developed a secondary malignancy (5-year cumulative incidence of 4.3%) after transplantation. Adjuvant radiotherapy before transplantation, the use of total-body irradiation (TBI) in the conditioning regimen, and age > or = 40 years were found to be predictive factors for the development of second cancers after ASCT. CONCLUSION: ASCT achieves long-term disease-free survival in HD patients. Disease status before ASCT is the most important prognostic factor for final outcome; thus, transplantation should be considered in early stages of the disease. TBI must be avoided in the conditioning regimen because of a significantly higher rate of late complications, including secondary malignancies.

Adolescent↗
PubMed2001

The Drosophila selenophosphate synthetase (selD) gene is required for development and cell proliferation.

To study the function of selenoproteins in development and growth we have used a lethal mutation (selD(ptuf)) of the Drosophila homologous selenophosphate synthetase (selD) gene. This enzyme is involved in the selenoprotein biosynthesis. The selD(ptuf) loss-of-function mutation causes aberrant cell proliferation and differentiation patterns in the brain and imaginal discs, as deduced from genetic mosaics, patterns of gene expression and analysis of cell cycle markers. In addition to that, selenium metabolism is also necessary for the ras/MAPKinase signal tansduction pathway. Therefore, the use of Drosophila imaginal discs and brain and in particular the selD(ptuf) mutation, provide an excellent model to investigate the role of selenoproteins in the regulation of cell proliferation, growth and differentiation.

Animals↗
PubMed2001

Correction of deficient CD34+ cells from peripheral blood after mobilization in a patient with congenital erythropoietic porphyria.

Congenital erythropoietic porphyria (CEP) is an inherited disease due to a deficiency in the uroporphyrinogen III synthase (UROS), the fourth enzyme of the heme pathway. It is characterized by accumulation of uroporphyrin I in the bone marrow, peripheral blood, and other organs. The onset of most cases occurs in infancy and the main symptoms are cutaneous photosensitivity and hemolysis. For severe transfusion-dependent cases, when allogeneic cell transplantation cannot be performed, autografting of genetically modified primitive/stem cells is the only alternative. In the present study, efficient mobilization of peripheral blood primitive CD34(+) cells was performed on a young adult CEP patient. Retroviral transduction of this cell population with the therapeutic human UROS (hUS) gene resulted in both enzymatic and metabolic correction of CD34(+)-derived cells, as demonstrated by the increase in UROS activity and by a 53% drop in porphyrin accumulation. A 10-24% gene transfer efficiency was achieved in the most primitive cells, as demonstrated by the expression of enhanced green fluorescent protein (EGFP) in long-term culture-initiating cells (LTC-IC). Furthermore, gene expression remained stable during in vitro erythroid differentiation. Therefore, these results are promising for the future treatment of CEP patients by gene therapy.

Antigens, CD34↗
PubMed2001

In silico identification of novel selenoproteins in the Drosophila melanogaster genome.

In selenoproteins, incorporation of the amino acid selenocysteine is specified by the UGA codon, usually a stop signal. The alternative decoding of UGA is conferred by an mRNA structure, the SECIS element, located in the 3'-untranslated region of the selenoprotein mRNA. Because of the non-standard use of the UGA codon, current computational gene prediction methods are unable to identify selenoproteins in the sequence of the eukaryotic genomes. Here we describe a method to predict selenoproteins in genomic sequences, which relies on the prediction of SECIS elements in coordination with the prediction of genes in which the strong codon bias characteristic of protein coding regions extends beyond a TGA codon interrupting the open reading frame. We applied the method to the Drosophila melanogaster genome, and predicted four potential selenoprotein genes. One of them belongs to a known family of selenoproteins, and we have tested experimentally two other predictions with positive results. Finally, we have characterized the expression pattern of these two novel selenoprotein genes.

Amino Acid Sequence↗
PubMed2000

Spinal flexibility and balance control among community-dwelling adults with and without Parkinson's disease.

BACKGROUND: One area of research that requires further elaboration is the relationship between impairments and functional limitations. By identifying specific contributors to functional limitations, it may be possible to establish intervention strategies, including exercise approaches, that can delay or ameliorate decline in function. The association between impaired spinal flexibility and functional limitations has not been studied in depth. The purposes of this study were to determine (a) the associations between spinal flexibility and functional limitations; (b) the relative contribution of spinal flexibility to specific functional limitations; and (c) how disease state (Parkinson's disease [PD] vs no PD) modified these relationships. METHODS: Participants included 251 community-dwelling adults, 56 of whom were with diagnosed PD and 195 were without PD or other specific disorders. Measures included spinal flexibility (i.e., functional axial rotation [FAR]) and configuration (i.e., thoracic kyphosis and lumbar lordosis), functional limitations (i.e., functional reach, supine-to-stand time, 10-m walk, and 360 degrees turn). RESULTS: Canonical correlation (Can R) demonstrated significant associations between spinal measures and functional limitations (Can R = .488, p = .0001). After controlling for age, gender, race, body mass index, comorbidity, confidence, and depression, a multivariate regression model demonstrated that spinal flexibility contributed significantly to functional reach (R2 = .334 for the overall model, p = .0001). Based on the parameter estimate of 0.026, the results prediet that FAR accounts for a 4.6-inch difference in reach distance between the least and most flexible of the participants. In addition, there were significant differences between almost all measurements for the PD compared with the non-PD participants. CONCLUSION: Results clearly implicate spinal flexibility as a contributor to functional reach, a measure of functional limitation and an established measure of balance control. Further work is needed to determine the extent to which spinal flexibility can be improved and the effect of that improvement on balance.

Aged↗
PubMed2000

Co-existence of hereditary spherocytosis and a new red cell pyruvate kinase variant: PK mallorca.

BACKGROUND AND OBJECTIVE: A partial red blood cell (RBC) pyruvate-kinase (PK-R) deficiency was found in a patient with concomitant hereditary spherocytosis (HS) and chronic hemolytic anemia. Clinical, biological and molecular studies were performed in the patient, his parents and a brother, in order to characterize the specific PK-R gene mutation and the inheritance mechanism of the transmission of both red cell defects in this particular family. DESIGN AND METHODS: Conventional biological studies were used to identify the PK-LR gene mutation responsible for hereditary transmission of PK-R deficiency and HS. The family study was completed with genotypic and RBC membrane protein analyses in the patient and his family. RESULTS: Molecular study of the PK deficiency was performed in all the family members and demonstrated a heterozygous condition for the 1516 G->A (506Val->Ile) mutation at the PK-LR gene in both the patient and his mother. Since this mutation has not been reported previously, it is provisionally named PK "Mallorca". The study of RBC membrane proteins demonstrated the existence of partial band 3 and protein 4.2 deficiencies in the propositus and his father but not in the mother and brother, who were also studied. These results support the dominant mode of inheritance of HS and PK-LR gene in this family. INTERPRETATION AND CONCLUSIONS: HS and PK deficiency are not exceptional in Spain. The co-existence of both RBC defects in the same patient, however, is very rare; only a few cases have been described to date. Our findings suggest that performing an elementary RBC enzyme survey in all patients with HS would help to determine the real frequency of this apparently rare association.

Amino Acid Substitution↗
PubMed1999

[Molecular study of red cell pyruvate kinase deficiency in 15 patients with chronic hemolytic anemia. Group of Erythropathology of Hematology and hemotherapy Association of Spain (HHAS)].

BACKGROUND: Identification of RBC pyruvate-kinase (PK) gene mutations by polymerase chain reaction (PCR) and single strand conformation polymorphism (SSCP) followed by PK gene sequencing in positive cases has been assessed and the results obtained with a preliminary study of 15 unrelated patients of Spanish origin are presented. PATIENTS AND METHODS: Patients have been classified into two different groups: group 1, propositus (15 cases), and group 2, relatives of the patients included in group 1 (10 males and 5 females). In group 1, a PCR was followed by SSCP and sequencing, and in group 2, the PCR was followed by digestion with specific restriction endonucleases (PCR-ER). RESULTS: Group 1: from 15 patients included in the study 2 were identified as homozygous, 4 as heterozygous and 9 as compound heterozygous. In this group, were identify 26 affected alleles with 11 different mutations: T1456 10 alleles (38.6%), T721 3 alleles (11.6%), A1010, C514, C1015 and T1223 2 alleles (7.7%), and C1070, A1291, T1508, A1595 y T1675 one allele. Relatives from 8 out of 15 patients from group 1 showed the following pattern: homozygous (one case), heterozygous (10 cases), compound heterozygous (2 cases) and normal (2 cases). CONCLUSIONS: SSCP procedure followed by direct gene sequencing in positive cases is fast and simple enough to allow the identification of PK deficient variants, avoiding the need of biochemical characterisation of semipurified deficient enzyme, which is more cumbersome and time consuming. In addition, the PCR-ER method is a very useful tool for screening of the most frequent molecular variants, as well as, for the detection of the carrier condition of this enzymopathy (family studies).

Amino Acids↗
PubMed1999

Long-term storage at -80 degrees C of hematopoietic progenitor cells with 5-percent dimethyl sulfoxide as the sole cryoprotectant.

BACKGROUND: Hematopoietic progenitor cells (HPCs) can be cryopreserved and stored below -120 degrees C in liquid nitrogen or at -80 degrees C in mechanical freezers. STUDY DESIGN AND METHODS: The feasibility of long-term storage of HPCs at -80 degrees C was investigated. The studies included a comparison of 5- and 10-percent dimethyl sulfoxide (DMSO) as cryoprotectant at various lengths of storage time. Mononuclear cell (MNC) recovery and viability and colony-forming unit-granulocyte-macrophage (CFU-GM) and burst-forming unit-erythroid (BFU-E) recovery assays were performed. The peripheral blood HPCs of 24 consecutive patients included in the program of autologous transplantation were studied. RESULTS: The MNC viability decreased progressively with the length of time from cryopreservation, reaching 32 percent after 31 months of storage. The recovery rates of CFU-GM and BFU-E also decreased progressively with the duration of frozen storage, to 50 and 43.5 percent, respectively, after 12 months and to 0 percent (both) after 24 months. At 6 months of storage, MNC viability was 80 percent, and CFU-GM and BFU-E recovery was 63.5 and 80.5 percent, respectively. There were no differences between MNCs cryopreserved with 5- or 10-percent DMSO in terms of cell viability. There were no differences between CFU-GM recovery or BFU-E recovery from HPCs cryopreserved in 5- or 10-percent DMSO. Patients given HPCs stored in these conditions for periods ranging between 123 and 202 days showed a complete and rapid hematologic recovery. CONCLUSION: HPCs can be cryopreserved at -80 degrees C with 5-percent DMSO and stored at -80 degrees C no longer than 6 months. A 5-percent DMSO concentration is comparable to a with 10-percent concentration in terms of recovery and MNC viability.

Adolescent↗
PubMed1999

Fatal laryngeal injury in an achondroplastic dwarf secondary to airbag deployment.

We report the case of an unrestrained driver with achondroplastic dwarfism who suffered a fatal anterior neck injury when her airbag deployed as she rear-ended another vehicle at 30-40 mph. Her short stature and short limbs required her to sit within a handbreadth of the steering wheel, which probably allowed the airbag or airbag cover to strike her neck as it opened. This is the first reported case of fatal injury to a driver with achondroplastic dwarfism.

Accidents, Traffic↗
PubMed1998

Molecular characterization of the PK-LR gene in pyruvate kinase deficient Spanish patients. Red Cell Pathology Group of the Spanish Society of Haematology (AEHH).

The PK-LR gene has been studied in 12 unrelated patients with red cell pyruvate kinase deficiency and hereditary nonspherocytic haemolytic anaemia (CNSHA). The entire codifying region of the R-type PK gene and the flanking intronic regions were analysed by single-stranded conformation polymorphism (SSCP) followed by direct sequencing of abnormal DNA. 10 different mutations were identified in 22/24 alleles at risk. Eight of these were missense mutations that caused the following single amino acid changes: G514C (172Glu-Gln), G1010A (337Arg-Gln), G1015C (339Asp-Gln), T1070C (357Ile-Thr), C1223T (408Thr-Ile), G1291A (431Ala-Thr), C1456T (486Arg-Trp) and G1595A (532Arg-Gln). Two were nonsense mutations: G721T (241Glu-Stop) and C1675T (559Arg-Stop). 7/22 alleles demonstrated the same C1456 --> T mutation. The study of the polymorphic site at nucleotide (nt) 1705 performed in all cases disclosed a 1705 C/C mutation in 10 and a 1705 A/C mutation in three. This is the first report on the presence of several different L-type PK gene mutations within Spanish population. Furthermore, from the PK gene mutations found, six were unique and not previously described (1015C, 1070C, 1223T, 1291A, 1595A and 1675T) and one (C1456T) seems to be predominant in Spain. Interestingly, no case with the 1529A mutation commonly found in Northern European populations was present here.

Adolescent↗
PubMed1997

Autologous stem cell transplantation for poor prognosis Hodgkin's disease in first complete remission: a retrospective study from the Spanish GEL-TAMO cooperative group.

Although more than 50% of Hodgkin's disease patients are cured with conventional chemotherapy, many will relapse and eventually die from their disease. Many efforts have been made to identify poor prognostic factors that could be useful in selecting high-risk patients in 1st CR who may benefit from high-dose chemo/radiotherapy. However, the role of early transplantation in 1st CR remains unclear. We have retrospectively analyzed the results obtained with this procedure in 22 hospitals belonging to the Spanish GEL/TAMO cooperative group. Twenty-seven patients, of whom 19 were males, underwent autologous transplantation for Hodgkin's disease in 1st CR between January 1987 and January 1996. Remission had been achieved after one (n = 22) or two (n = 5) lines of treatment. Twenty-four patients had advanced stage disease, 12 patients bulky mediastinal disease, nine bone marrow involvement and 18 had extranodal disease. Peripheral blood was used as the source of hematopoietic stem cells in 15 patients, BM in nine, and both in three. All but three patients received chemotherapy-based conditioning regimens (16 CBV, four BEAM and four BEAC), while three were conditioned with CY and TBI. There were no transplant-related deaths. Median (range) times to recover >0.5 x 10(9)/l neutrophils and >50 x 10(9)/l platelets were 14 (8-56) days and 16 (8-240) days, respectively. With a median follow-up of 30 (8-66) months, 21 patients are alive and in continuous CR. Four patients who relapsed after transplant at 8, 17.5, 22 and 26 months achieved a second CR with conventional chemotherapy; one patient relapsed 92 months post-transplant and died 5 months afterwards. Another patient died 30.5 months post-transplant from a secondary malignancy. In conclusion, high-dose therapy in poor prognosis Hodgkin's disease in 1st CR was well tolerated with no transplant-related mortalities. Although the follow-up of this series is relatively short, our results seem promising. Nevertheless, late relapses can occur, and the role of this procedure vs conventional treatment in very high-risk patients should be assessed in prospective randomized studies.

Adolescent↗
PubMed1996

Cryopreservation of hematopoietic progenitor cells with 5-percent dimethyl sulfoxide at -80 degrees C without rate-controlled freezing.

BACKGROUND: Cryopreservation of hematopoietic cells with the rate-controlled method is used in the majority of centers. In recent years, there has been a trend toward the simplification of the process. STUDY DESIGN AND METHODS: A simplified method for cryopreservation was developed with 5-percent dimethyl sulfoxide (DMSO) as the sole cryoprotectant without rate-controlled freezing. Experiments were done with progressive concentrations of DMSO, ranging from 0 to 10 percent. With DMSO concentrations from 5- to 10-percent, the best recovery and viability for hematopoietic progenitor cells were observed. Hematopoietic progenitor cells with plasma and 5-percent DMSO were frozen and stored in a -80 degrees C mechanical freezer. Ten patients with solid and hematologic malignancies underwent transplantation with autologous hematopoietic progenitor cells. RESULTS: The median number of transfused mononuclear cells and CD34+ cells was 3.70 (3.1-8.2) x 10(8) per kg and 1.70 (0.8-6.5) x 10(6) per kg, respectively. The median number of transfused colony-forming units-granulocyte-macrophage was 12.45 (3.4-55.3) x 10(4) per kg. All patients showed rapid and sustained engraftment. The mean times to reach a neutrophil count of 0.5 x 10(9) per L and a platelet count of 50 x 10(9) per L were 11.50 +/- 1.70 and 13.90 +/- 3.98 days, respectively. All patients are alive and without transfusion requirements in complete remission 2 to 8 months after transplantation. CONCLUSION: This simplified cryopreservation technique will be useful for institutions without rate-controlled freezing facilities. Moreover, this method diminishes the amount of DMSO infused to patients, as well as its toxicity.

Adolescent↗
PubMed1996

Correlation of trisomy 12 with proliferating cells by combined immunocytochemistry and fluorescence in situ hybridization in chronic lymphocytic leukemia.

Conventional G-banding and fluorescence in situ hybridization (FISH) were performed on peripheral blood samples of 340 consecutive untreated cases of chronic lymphocytic leukemia (CLL) for the detection of trisomy 12 and other chromosome abnormalities. These findings were correlated with the proliferative activity of CLL lymphocytes assessed by the monoclonal antibody Ki-67. Cytogenetic analysis displayed a normal karyotype in 131 (38.5%) cases, trisomy 12 in 68 (20%), 31 by G-banding and an additional 37 cases by FISH, other clonal abnormalities in 47 (14%), and no metaphases in 94 (27.5%). The percentage of Ki-67-positive cells was significantly higher in cases with trisomy 12 (4.1 +/- 4.48) than in cases with a normal karyotype (1.5 +/- 2.0), those with other clonal abnormalities (1.35 +/- 1.37) and cases with no metaphases (1.14 +/- 1.6) (P< 0.0001). Cases with trisomy 12 were associated with more advanced clinical stage, atypical morphology and a higher percentage of Ki-67+ve cells than cases lacking trisomy 12 (P< 0.0001). Although there was no direct correlation between the percentage of trisomic and proliferating cells, the combination of immunocytochemistry and FISH showed that most Ki-67-positive cells were trisomic for chromosome 12. Our results suggest that the association of trisomy 12 with a higher proliferative activity supports the view that this abnormality is a secondary event associated with disease progression in CLL.

Adult↗
PubMed1995

A simplified method for cryopreservation of hematopoietic stem cells with -80 degrees C mechanical freezer with dimethyl sulfoxide as the sole cryoprotectant.

A simplified method for cryopreservation was developed with 10% dimethylsulfoxide (DMSO) as the sole cryoprotectant without rate-controlled freezing. This method produced high recovery rate for mononucleated cells (87%) and elevated trypan blue viability (90%). Autologous peripheral blood stem cells (PBSCs) and bone marrow cells with plasma and 10% DMSO were frozen and stored in a -80 degrees C mechanical freezer. Eleven patients with solid and hematological malignancies were transplanted with autologous bone marrow or PBSCs. The median number of infused mononuclear cells (MNC) and CD34+ cells were 3.63 x 10(8)/Kg and 4.80 x 10(6)/Kg, respectively. The median number of infused post-thawing CFU-GM was 20 x 10(4)/Kg. All patients showed a rapid and sustained engraftment. The mean times to reach a neutrophil count of 0.5 x 10(9)/L and a platelet count of 50 x 10(9)/L were 11 and 13 days, respectively. All patients are alive and 10 in unmaintained complete remission for 3-9 months after transplantation. These results show the efficacy of this simplified cryopreservation technique that will be useful for institutions without rate-controlled freezing facilities.

Adult↗
PubMed1992

Cortical dendritic pathology in human immunodeficiency virus encephalitis.

Previous neuropathological and morphometric studies of the cerebral cortex of patients with human immunodeficiency virus encephalitis (HIVE) have shown a decrease in the population of large neurons, moderate loss in synaptophysin immunoreactivity, and pathological changes in dendrites. To further characterize and quantify alterations in the dendritic tree of neocortical pyramidal neurons, we performed a modified Golgi impregnation technique on Formalin fixed blocks from the frontal cortex of 5 HIVE cases, 5 human immunodeficiency virus seropositive control cases without encephalitis, and 5 human immunodeficiency virus seronegative controls. Apical dendrites of HIVE cases were dilated, vacuolated, and tortuous with decreased length and branching. Basal and oblique dendrites also showed these alterations, but to a lesser extent. Some dendrites presented lacunae and filopodia consistent with remodeling. Computer aided quantification of HIVE cases showed a 40-60% decrease in spine density throughout the entire length of dendrites. Laser confocal imaging of Golgi impregnated sections displayed aberrant spines in regions of abnormal second order dendritic branches. These observations support the role of primary dendritic damage in HIVE in contrast to other neurodegenerative disorders where the primary pathology is presynaptic.

AIDS Dementia Complex↗