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Biomedical subjects

A Merino

Publications and source records attributed to A Merino.

At least 19 recordsLinked to original sources
PubMed2001

Apolipoprotein D expression in endometrial carcinomas.

BACKGROUND: Apolipoprotein D is a protein component of the human plasma lipid transport system but is also associated with a more favorable prognosis in breast cancer and ovarian cancer women. This study was undertaken to examine the tumoral expression of apolipoprotein D in endometrial cancer and to analyze the possible correlation with tumor and patients characteristics as well as androgen receptors and its prognostic significance. METHODS: Immunohistochemical evaluation was used to examine apolipoprotein D expression in paraffin blocks from 58 endometrial carcinomas. RESULTS: A total of twenty (34%) tumors stained positively. Staining was localized in tumor cells. No significant correlation was found between apo D expression and patients or tumor characteristics and androgen receptor status. In addition, apolipoprotein D expression was not associated with patient prognosis. CONCLUSIONS: Apolipoprotein D is expressed by a significant percentage of endometrial carcinomas without apparent association with other clinicopathologic parameters or with outcome of patients.

Apolipoproteins↗
PubMed2001

Cell surface human alpha-L-fucosidase.

The acid alpha-L-fucosidase is usually found as a soluble component of lysosomes where fucoglycoconjugates are degraded. In the present investigation, we have demonstrated the existence of a cell surface protein with enzymatic alpha-L-fucosidase activity that crossreacts specifically with a rabbit anti-(alpha-L-fucosidase) Ig. By different approaches, this alpha-L-fucosidase, which represents 10-20% of the total cellular fucosidase activity, was detected in all the tested human cells (hemopoietic, epithelial, mesenchymal). Two bands of approximately 43-49 kDa were observed, although theoretical data support the possibility of having the same genetic origin that the known 50 to 55-kDa Mr alpha-L-fucosidase. We speculate about an alternative traffic pathway for the plasma membrane alpha-L-fucosidase to work on the rapid turnover of glycoproteins.

Animals↗
PubMed2000

Expression and clinical significance of apolipoprotein D in epithelial ovarian carcinomas.

OBJECTIVE: Apolipoprotein D is a protein component of the human plasma lipid transport system but is also associated with a more favorable prognosis in women with breast cancer. This retrospective study was undertaken to examine the tumoral expression of apolipoprotein D in epithelial ovarian cancer and to analyze the possible correlation with tumor and patient characteristics as well as androgen receptors and their prognostic significance. METHODS: Immunohistochemical evaluation was used to examine apolipoprotein D expression in paraffin blocks from 68 epithelial ovarian carcinomas. RESULTS: A total of 18 (26.4%) tumors stained positively. No significant correlation was found between apolipoprotein D expression and patient or tumor characteristics and androgen receptor status. However, apolipoprotein D expression was significantly associated with prognosis in patients with residual tumor greater than 1 cm. Thus, patients with apolipoprotein-D-negative tumors had a poorer overall survival than those with apolipoprotein-D-positive tumors (P = 0.039). In addition, multivariate analysis demonstrated that apolipoprotein D expression was an independent prognostic factor with initial tumor size in this group of patients (P = 0.005). CONCLUSIONS: Our results led us to consider the existence of apolipoprotein D expression by a significative percentage of ovarian carcinomas, and this protein expression might be of clinical usefulness for identifying lesions with different evolution.

Adult↗
PubMed2000

Induction of peroxiredoxins in transplanted livers and demonstration of their in vitro cytoprotection activity.

Peroxiredoxin (Prx)-I and -II belong to a new class of antioxidants. Here, we report that they are induced by ischemia/reperfusion (I/R) in transplanted livers. Hypothesizing that Prxs are induced to protect liver from oxidative damage, we transduced these human genes into murine NIH-3T3 cells. The overexpressed Prxs made the cells more resistant to t-butylhydroperoxide-induced apoptosis. These results indicate that Prx-I and Prx-II are induced by the transplantation process and can protect cells against oxidant damage in tissue culture. Thus, proper genetic manipulations of Prxs may be useful in increasing the success rate of organ transplantation.

3T3 Cells↗
PubMed1999

Masses and pseudomasses of the hand and wrist: MR findings in 134 cases.

OBJECTIVE: To assess the utility of magnetic resonance imaging (MRI) in the investigation of palpable masses in the hand or wrist. DESIGN AND PATIENTS. We retrospectively reviewed the MRI examinations and case records of 134 patients referred because of a palpable mass in the hand or wrist. MRI was performed on a 1.0 T magnet using an extremity coil. Intravenous gadolinium-DTPA was injected when considered appropriate. RESULTS AND CONCLUSIONS: MRI demonstrated the cause of the palpable mass in 126 cases (94.02%). Soft tissue neoplasms were found in 34 cases (25.37%). The majority were benign and included giant cell tumours of tendon sheath, lipomas and hemangiomas and had a characteristic appearance. There were three malignant tumours (myxoid liposarcoma, malignant fibroushistiocytoma and rhabdomyosarcoma). Ganglia were found in 36 cases (26.86%) and non-tumour tendon pathology in 31 cases (23.13%). Less common causes included articular diseases (5.97%) and anatomical variants (4.47%). No focal lesion was present in 8 cases (5.97%). In conclusion, MRI is an accurate diagnostic technique in patients who present with a palpable mass of the hand and wrist.

Hand↗
PubMed1999

Atypical MRI presentation of a small splenic hamartoma.

Hamartomas of the spleen usually appear isointense on T1-weighted MR images and hyperintense on T2-weighted images. We describe a histologically proven case which presented as a small (2.5 cm) focal mass isointense to splenic parenchyma on T1-weighted images and hypointense on both turbo-spin-echo T2 and short T1 inversion recovery images. Dynamic MRI revealed a delayed enhancement during the arterial phase becoming isointense and prolonged on subsequent images. This prolonged enhancement has previously been described as a characteristic pattern in these tumours. The lack of oedema and necrosis and the presence of fibrous tissue in the hamartoma at histopathology likely account for the low signal intensity on all sequences.

Diagnosis, Differential↗
PubMed1999

Efficacy and toxicity of a high-dose G-CSF schedule for peripheral blood progenitor cell mobilization in healthy donors.

An important issue in allogeneic peripheral blood progenitor cell transplantation is the optimization of the regimen of mobilization of progenitor cells from normal donors. It has been shown that for G-CSF doses up to 10 microg/kg/day, a dose-response relationship exists for the degree of progenitor cell mobilization. Formal comparisons with doses higher than 10 microg/kg/day, however, have not been reported. The aim of this study was to compare the mobilization and collection results of two different G-CSF (Filgrastim) schedules: 10 microg/kg/12 h (n = 20; group A) vs 10 microg/kg/24 h (n = 20; group B). Apheresis sessions were started on day 5 (after 4 days of G-CSF). Adverse events consisted of bone pain, headache, and fatigue which required treatment with acetaminophen +/- codeine in both donor groups. Discontinuation of G-CSF administration for intolerable side-effects was not necessary in any case. The increase in peripheral leukocyte and lymphocyte counts x 109/l on day 5 was higher in group A (56.2 (37.1-75.2) and 4.4 (2. 1-14.6), respectively) than in group B (27.5 (13.2-53.9) and 2.6 (1. 9-5.1), respectively) (P < 0.0001 and P = 0.008). Platelets x 109/l decreased in group A from 228 (161-286) before G-CSF administration to 207 (155-328) on day 5 (P = 0.03), whereas no change was observed in group B. Following the first apheresis, a significant decrease in platelet count was observed with both G-CSF schedules without any differences between groups. The number x 106/kg of both nucleated and CD34+ cells collected after the first apheresis session was higher in group A (672 (462-992) and 5.9 (3.4-10.4), respectively) than in group B (427 (319-608) and 3.1 (1.1-6.8), respectively) (P = 0.0003 in both cases). The median number of CD3+cells x 106/kg collected after one apheresis session was similar with both G-CSF schedules (212 (91-430) in group A and 170 (110-291) in group B) (P = NS). In conclusion, the schedule of 10 microg/kg/12 h was well tolerated and resulted in the collection of a higher number of progenitor cells than 10 microg/kg/24 h without increasing the T cell content. This approach could avoid the donor having to undergo a second apheresis, and facilitate further graft manipulation.

Adult↗
PubMed1999

From cytoprotection to tumor suppression: the multifactorial role of peroxiredoxins.

In the past decade, a new family of highly conserved antioxidant enzymes, Peroxiredoxins (Prxs), have been discovered and defined. There are two major Prx subfamilies: one subfamily uses two conserved cysteines (2-Cys) and the other uses 1-Cys to scavenge reactive oxygen species (ROS). This review focuses on the four mammalian 2-Cys members (Prx I-IV) that utilize thioredoxin as the electron donor for antioxidation. The array of biological activities of these proteins suggests that they may be evolutionarily important for cell function. For example, Prxs are capable of protecting cells from ROS insult and regulating the signal transduction pathways that utilize c-Abl, caspases, nuclear factor-kappaB (NF-kappaB) and activator protein-1 (AP-1) to influence cell growth and apoptosis. Prxs are also essential for red blood cell (RBC) differentiation and are capable of inhibiting human immunodeficiency virus (HIV) infection and organ transplant rejection. Distribution patterns indicate that Prxs are highly expressed in the tissues and cells at risk for diseases related to ROS toxicity, such as Alzheimer's and Parkinson's diseases and atherosclerosis. This interesting correlation suggests that Prxs are protective against ROS toxicity, yet overwhelmed by oxidative stress in some cells. Prxs tend to form large aggregates at high concentrations, a feature that may interfere with their normal protective function or may even render them cytotoxic. Imbalance in the expression of subtypes can also potentially increase their susceptibility to oxidative stress. Understanding the function and biological role of Prxs may lead to important discoveries about the cellular dysfunction of ROS-related diseases ranging from atherosclerosis to cancer to neurodegenerative diseases.

Amino Acid Sequence↗
PubMed1998

Electroneutral Na-coupled cotransporter expression in the kidney during variations of NaCl and water metabolism.

The purpose of the present study was to analyze the long-term regulation of renal bumetanide-sensitive Na+-K+-2Cl- cotransporter and thiazide-sensitive Na+-Cl- cotransporter gene expression during changes in NaCl and water metabolism. Male Wistar rats exposed to high or low NaCl intake, saline loading, dehydration, water loading, and furosemide administration during 7 days were studied. Control groups had access to regular food and tap water. Rats were kept in metabolic cages for 4 days before and during the experiment to determine daily urinary electrolyte excretion and osmolarity. At the end of the experiment, creatinine clearance and serum electrolyte levels were also measured. Kidneys were excised and macroscopically subdivided into cortex and outer and inner medulla. Total RNA was extracted from each individual cortex or outer medulla by use of the guanidine/cesium chloride method. The Na+-K+-2Cl- cotransporter expression in outer medulla total RNA was assessed by nonradioactive Northern blot analysis and the Na+-Cl- cotransporter expression in renal cortex total RNA was assessed by semiquantitative polymerase chain reaction. Experimental maneuvers were adequately tolerated, and all groups developed the appropriate renal response to each challenge. However, the level of expression of both cotransporters did not change in any model, except for a 2.8-fold increase in the Na+-Cl- cotransporter expression during dehydration. We conclude that nephron adaptation to 7-day modifications in NaCl and water metabolism does not include changes in the amount of electroneutral sodium-coupled cotransporter gene expression at the mRNA level.

Animals↗
PubMed1998

Magnetic resonance cholangiopancreatography in the evaluation of pancreatic duct pathology.

MR cholangiopancreatography (MRCP) may replace direct pancreatography in the evaluation of the pancreatic duct. The aim of this pictorial review is to demonstrate the usefulness of MRCP in the evaluation of pancreatic duct pathology. The examination technique included coronal, sagittal and axial breath-hold HASTE 2D imaging using a body phase array coil. We present the diagnostic features on MRCP of a variety of benign and malignant disorders of the pancreatic duct, and conclude that MRCP is a suitable method for imaging the pancreatic duct system.

Bile Ducts↗
PubMed1997

Rapid engraftment without significant graft-versus-host disease after allogeneic transplantation of CD34+ selected cells from peripheral blood.

We have prospectively evaluated the feasibility and results of the biotin-avidin immunoadsorption method (Ceprate SC system) for a phase I/II study of T-cell depletion of granulocyte colony-stimulating factor (G-CSF) mobilized peripheral blood progenitor cells (PBPC) for allogeneic transplantation. Twenty consecutive patients, median age, 40 years (21 to 54) and diagnoses of chronic myeloid leukemia in chronic phase (n = 5), acute myeloblastic leukemia (n = 7), acute lymphoblastic leukemia (n = 2), chronic myelomonocytic leukemia (n = 1), refractory anemia with excess of blasts in transformation (n = 3), histiocytosis X (n = 1), and chronic lymphocytic leukemia (n = 1), were conditioned with cyclophosphamide (120 mg/kg) and total body irradiation (13 Gy; 4 fractions). HLA identical sibling donors received G-CSF at 10 microg/kg/d subcutaneously (SC); on days 5 and 6 (19 cases) and days 5 to 8 (1 case) donors underwent 10 L leukapheresis. PBPC were purified by positive selection of CD34+ cells using immunoadsorption biotin-avidin method (Ceprate SC) and were infused in the patients as the sole source of progenitor cells. No growth factors were administered posttransplant. The median recovery of CD34+ cells after the procedure was of 65%. The median number of CD34+ cells infused in the patients was 2.9 (range, 1.5 to 8.6) x 10(6)/kg. The median number of CD3+ cells administered was 0.42 x 10(6)/kg (range, 0.1 to 2). All patients engrafted. Neutrophil counts >500 and >1,000/microL were achieved at a median of 14 days (range, 10 to 18) and 15 days (range, 11 to 27), respectively. Likewise, platelet counts >20,000 and >50,000/microL were observed at a median of 10 days (range, 6 to 23) and 17 days (range, 12 to 130), respectively. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine plus methylprednisolone. No patient developed either grade II to IV acute or extensive chronic GVHD. After a median follow-up of 7.5 months (range, 2 to 22) three patients have relapsed, and one of them is again in hematologic and cytogenetic remission after infusion of the donor lymphocytes. Two patients died in remission: one on day +109 of pulmonary aspergillosis and the other on day +251 of metastasic relapse of a previous breast cancer. Sixteen of the 20 patients are alive in remission after a median follow-up of 7.5 months (range, 2 to 22). In conclusion, despite the small number of patients and limited follow-up, it appears that this method allows a high CD34+ cell recovery from G-CSF mobilized PBPC and is associated with rapid engraftment without significant GVHD, and with low transplant related mortality.

Adolescent↗
PubMed1997

Semi-quantitative PCR: a tool to study low abundance messages in the kidney.

Some specific functions are often localized to unique cellular types or structures in organs such as kidney, brain, blood, and endocrine glands. As a result, it is not uncommon that gene products, although heavily expressed in some cell types within these organs, ultimately appear as low abundance products when total RNA is probed, resulting in decreased power of the conventional Northern blot analysis. To study gene expression in these circumstances, more sensitive techniques like RNAse protection assay and quantitative or semi-quantitative PCR strategies have been developed. In the present study, we provide a detailed description of the semi-quantitative PCR strategy in our laboratory. Using specific primers to amplify fragments from the neuronal isoform of the nitric oxide synthase and the thiazide-sensitive Na+:Cl- cotransporter (low abundance messages in the kidney), we show that the semi-quantitative PCR strategy is a valuable tool when low abundance messages are to be studied.

Animals↗
PubMed1996

Separation of the transcriptional coactivator and antirepression functions of transcription factor IIA.

Human transcription factor IIA (TFIIA) is composed of three subunits (alpha, beta, and gamma). TFIIA interacts with the TATA-box binding protein and can overcome repression of transcription. TFIIA was found to be necessary for VP16-mediated transcriptional activation through a coactivator function. We have separated the coactivator and antirepression activities of TFIIA. A TFIIA lacking the alpha subunit was isolated from HeLa cells. This "mini-TFIIA" interacts with the TATA-box binding protein and can overcome repression of transcription, but it is defective in transcriptional coactivator function.

DNA-Binding Proteins↗
PubMed1996

[Allogeneic transplant of peripheral blood hematopoietic progenitors. Preliminary experience].

Myeloablative treatment followed by allogeneic transplantation of peripheral blood hemopoietic progenitors (alloPBT) was administered to five leukemia patients with a high risk of relapse. The donors subcutaneously received 10 micrograms/kg/day of G-CSF for five days. The tolerance to this medication was good with only complaints of moderate bone pain. Two of the peripheral blood donors had previously been bone marrow donors and both expressed their preference for the new method. The product of peripheral blood leukapheresis contained from one to four-fold more hemopoietic progenitors and approximately ten-fold more T-lymphocytes than the bone marrow received from normal donors. Prophylaxis of the graft versus host disease (GVHD) consisted of cyclosporine A (CsA) in one case and CsA and methotrexate (MTX) in four cases. The bone marrow implantation was verified with a neutrophil count of up to more than 0.5 x 10(9)/l between days 12 to 21 after transplant and a platelet count higher than 20 x 10(9)/l from days 11 to 41 after transplant. Acute GVHD was clinical grade O (two cases), II (one case) and grade III (two cases). In conclusion, alloPBT may be more safely and comfortably performed to the donor. This method may provide rapid recovery of neutrophils and platelets in patients without an apparent increase in the risk of developing graft versus host disease.

Adolescent↗
PubMed1996

Congenital 6-phosphogluconate dehydrogenase (6PGD) deficiency associated with chronic hemolytic anemia in a Spanish family.

Clinical and metabolic studies were performed in four members of a Spanish family with partial (50%) 6 phosphogluconate dehydrogenase (6PGD) deficiency. In all cases the activities of 6 phosphogluconolactone (6PGL) and glutathione reductase (GR) were normal, and the molecular characterization performed in the partially purified 6PGD from the propositus showed normal kinetic and electrophoretic patterns. Two females (the propositus and her sister) suffered from a well-compensated chronic nonspherocytic hemolytic anemia (CNSHA) and exhibited decreased RBC glutathione (GSH) stability with increased oxidative susceptibility, defined by enhanced malonyldialdehyde (MDA) generation "in vitro." The other two members of the family (the propositus's mother and brother) were clinically asymptomatic. In the propositus and her sister, RBC metabolism exhibited a markedly abnormal concentration of glycolytic intermediates, mainly characterized by striking increases in fructose 1,6 bisphosphate (50-fold), dihydroxiacetone-phosphate (20-fold) and glyceraldehyde 3-phosphate (tenfold). Although the precise mechanism of the hemolysis in the two patients is unknown, the enhanced oxidative threat observed in their RBCs may interfere in some way with the glycolytic pathway function, leading to a marked increase in certain metabolic intermediates located before the glyceraldehyde 3 phosphate dehydrogenase (GA3PD) step. Since it seems that GA3PD half-life is modulated by fluctuations of the cytosolic redox status, an "in situ" approach was simulated by using permeabilized RBCs. In these conditions, GA3PD activity was significantly lower in the propositus and her sister than in the asymptomatic members of the family and the simultaneous normal control.

Adult↗
PubMed1996

Allogenic transplants with peripheral blood progenitor cells: a report of six cases.

Six patients with high-risk leukaemia received a myeloablative regimen followed by allogeneic peripheral blood progenitor cells transplantation (PBPCT) from an HLA-identical sibling donor. Donors received 10-12 mu g/kg/day of G-CSF subcutaneously for 5 days. G-CSF was well tolerated except for moderate bone pain. Peripheral blood leukapheresis product contained 1-4 times more CD34+ cells and approximately a log more of T lymphocytes than marrow grafts from normal donors. In the two first cases the leukapheresis product was partially depleted of T-lymphocytes using counterflow centrifugation. No growth-factors were administered post-transplant. GVHD prophylaxis consisted of cyclosporin A (CyA) in one case, and CyA and methotrexate in five cases. All patients engrafted with a neutrophil count reaching more than 0.5 x 10(9)/L by day 12 to 21 post-transplant and a platelet count above 20 x 10(9)/L by day 6 to 41 post-transplant. Acute GVHD was clinical grade 0 (n = 2), I (n = 1), II (n = I), grade III (n = I) and grade IV (n = 1). One case presents an extensive chronic cutaneous GVHD and is currently being treated with methylprednisolone. In conclusion, allogeneic transplants using PBPC can be performed safely. This may result in a rapid neutrophil and platelet engraftment, without an apparent increased risk of GVHD.

Acute Disease↗