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R Miquel

Publications and source records attributed to R Miquel.

32 records · Page 2Linked to original sources
PubMed1999

[Non-gastric mucosa-associated lymphoid tissue (MALT) lymphomas: analysis of 14 patients].

BACKGROUND: Mucosa-associated lymphoid tissue (MALT) lymphomas are a well defined group of B-cell non-Hodgkin's lymphomas, that arise in a wide variety of extranodal sites, most frequently in the stomach and related to Helicobacter pylori infection. The aim of the present study was to analyze the presenting features, natural history and outcome in 14 patients with non-gastric MALT lymphoma. PATIENTS AND METHODS: The main clinical data, treatment and outcome were recorded for the 14 patients with non-gastric MALT lymphoma diagnosed at a single institution in a 12 year period. The median age was 68 years and 13 patients were females. Diagnosis was made according to the REAL classification criteria. RESULTS: The initial location was thyroid (3 patients), parotid (three), submaxilar gland (three), skin (two), Waldeyer's ring (one), breast (one), lung (one), small bowel (one), liver (one) and ovary (one). At diagnosis 3 patients had > or = 2 extranodal involved sites. Autoimmune disorders were present in 5 patients: Hashimoto's thyroiditis (three), Sjögren's syndrome (one) and both (one). Two patients had a poor performance status (ECOG > 1) and B-symptoms. Five patients (36%) were in stage IV, two of them because of bone marrow infiltration. All patients had a normal serum LDH level, and 5 had high beta 2-microglobulin level. The treatment consisted in surgical resection (2 patients), surgery and radiotherapy (one), surgery and chemotherapy (two), chemotherapy and radiotherapy (two) and chemotherapy alone (7 patients, three of them with doxorubicin-containing regimens). Twelve patients were evaluable for response. Complete response, partial response and failure rates were 75, 17 and 8%, respectively. Two of the 11 responders progressed, one of them with advanced stage disease. The actuarial 4-year disease-free survival was 77% (CI 95%: 47-100%). After a median follow-up of 3.4 years, 100% of the patients were alive. CONCLUSION: Non-gastric MALT lymphomas may be associated with autoimmune disorders, may present as disseminated disease and have a very good outcome.

Adult↗
PubMed1999

Primary nodal marginal zone lymphomas of splenic and MALT type.

The existence of primary nodal marginal zone lymphomas (MZL) is controversial, as is their relationship to putative extranodal counterparts. Most nodal lymphomas with monocytoid B cell/marginal zone differentiation exhibit the morphologic and immunophenotypical characteristics of extranodal MALT-lymphomas. Splenic marginal zone lymphoma (SMZL) is also of putative marginal zone derivation, but it differs immunophenotypically from MALT lymphoma. To clarify the relationship between nodal and extranodal MZLs and to investigate the possible existence of a nodal variant of SMZL, 36 MZL initially considered to be primary nodal neoplasms were examined. Other low-grade lymphomas with marginal zone differentiation were excluded (small lymphocytic lymphoma/chronic lymphocytic leukemia [SLL/CLL], follicular lymphoma, and mantle cell lymphoma). Six nodal MZLs showed morphologic and phenotypic characteristics similar to those of SMZL, whereas 30 tumors were more similar to MALT-type lymphomas. The six tumors with SMZL features showed a polymorphic infiltrate surrounding residual germinal centers with absent or very attenuated mantle cuffs. These lymphomas were IgD positive (6/6) but cyclin D1 (0/5), CD5 (0/6), and CD23 (0/6) negative. Five of these patients came for treatment in stage I or II. No patient manifested splenomegaly, peripheral blood, and/or bone marrow infiltration either at diagnosis or during follow-up. Lymph nodes from 30 patients with MALT-type features showed a perisinusoidal and perivascular infiltration of monocytoid/centrocytoid cells and residual germinal centers with a relatively well-preserved mantle cuff. The neoplastic cells were negative for IgD (0/17), cyclin D1 (0/8), and CD5 (0/12). Seven of 16 (44%) patients with a detailed history and clinical follow-up had evidence of extranodal lymphoma. These observations suggest that most nodal B cell lymphomas with marginal zone differentiation are of the MALT type and that they are frequently associated with an extranodal component. In addition, a primary nodal counterpart of splenic MZL also exists, and may occur in the absence of splenomegaly.

Adult↗
PubMed1998

Is it possible to control hyperphosphataemia with diet, without inducing protein malnutrition?

Dietary intervention, phosphate (P) removal during dialysis and, especially, phosphate binders are current methods for the management of hyperphosphataemia. Ideally, the amount of P absorbed from the diet should equal the amount of P removed during dialysis, and this must occur in the context of an adequate protein intake. We evaluated the relationship between P intake and protein intake in 60 stable chronic uraemic patients (mean age 55+/-15 years, 25% diabetics, 68% males) on standard 4 h haemodialysis. The dietary counselling was relatively free for protein and calories. Nutrient intake was recorded during a 5 day period, and average daily ingestion of P and proteins was calculated using a computerized diet analysis system. A highly significant correlation was observed between protein and P intake. The mean daily ingestion of P and proteins was 998+/-316 mg and 64+/-19 g (1+/-0.4 g/kg/day), respectively. For an optimal protein diet of 1-1.2 g/kg/day, the P intake was 778-1444 mg. The amount of P removed by haemodialysis, extrapolated to an average week, is 250-300 mg/day. Since approximately 40% of P ingested is absorbed from the gut by uraemic patients treated with intestinal P binders, 750 mg of P intake should be the critical value above which a positive balance of P may occur. This value corresponds to a protein intake of 45-50 g per day (>0.8 g/kg body weight/day for a 60 kg patient). In patients undergoing standard chronic haemodialysis, a neutral P balance is difficult to achieve, despite phosphate binder therapy, when protein intake is >50 g. Additional protein restriction, in order to obtain a neutral balance, may impose the risk of protein malnutrition.

Adult↗
PubMed1997

[Severe Plasmodium falciparum malaria. Description of 5 cases].

In the last few years a considerable number of imported malaria has been reported in Spain, probably due the increased tourism to areas with endemic malaria, particularly with P. falciparum. This is the species more frequently associated with severe complications and the only one capable of causing cerebral malaria. In this report we review five cases of malaria which required intensive care because of their severity. None of the patients had received chemoprophylaxis. In all cases the admission criterion to the intensive care unit was the organic failure of one or more systems (renal failure and disseminated intravascular coagulation [DIC] mainly) or the presence of changes in the central nervous system. Parasitemia at admission was higher than 5% in all patients. One patient died on account of cerebral malaria. Only one patient had severe complications not directly associated with malaria. In patients who already have severity criteria, a negative parasitemia test during the clinical course does not necessarily implies a clinical improvement nor does it exclude the emergence of complications. On the other hand, a low parasitemic degree is never a contraindication for admission to the intensive care unit when severity criteria are present.

Adult↗
PubMed1996

Overexpression of the 67-kD laminin receptor correlates with tumour progression in human colorectal carcinoma.

The high affinity 67-kD laminin receptor (67LR) is a cell surface protein whose expression is increased in a number of human carcinoma models. To date, 67LR expression in colorectal carcinomas has been examined in a small number of cases. 67LR expression has been immunohistochemically analysed in a large series of human colorectal neoplasms, using the MLuC5 monoclonal antibody. The study included 59 samples of non-neoplastic mucosa, 45 polyps (11 hyperplastic, 34 adenomas), 196 carcinomas, and lymph node metastases of 87 carcinomas. Epithelial cells of normal mucosa and hyperplastic polyps were negative or showed weak positivity in the paranuclear and apical areas of the cytoplasm. In adenomas and carcinomas, the staining was stronger, with a membranous or cytoplasmic pattern. The expression of 67LR correlated significantly with the progression from normal mucosa (22 per cent) to adenoma (44 per cent), carcinoma (61 per cent), and lymph node metastasis (75 per cent) (P < 0.0001). Expression of the laminin receptor showed a tendency to be more frequently positive in advanced stage (III+IV; 67 (III+IV; 67 per cent) when compared with early stage (I+II) carcinomas (54 per cent). The difference, however, was not statistically significant (P = 0.058). In addition, 14 out of 28 (50 per cent) primary carcinomas without 67LR expression became positive in lymph node metastases, while most (86 per cent) of the MLuC5-positive primary carcinomas were also immunoreactive in metastases. In conclusion, these results indicate that 67LR is up-regulated in the progression of human colorectal carcinomas and may play a role in the local and metastatic progression of these tumours.

Adenocarcinoma↗
PubMed1996

Expression of retinoblastoma gene product (pRb) in mantle cell lymphomas. Correlation with cyclin D1 (PRAD1/CCND1) mRNA levels and proliferative activity.

Mantle cell lymphomas (MCLs) are molecularly characterized by bcl-1 rearrangement and constant cyclin D1 (PRAD-1/CCND1) gene overexpression. Cyclin D1 is a G1 cyclin that participates in the control of the cell cycle progression by interacting with the retinoblastoma gene product (pRb). Inactivation of the Rb tumor suppressor gene has been implicated in the development of different types of human tumors including some high grade non-Hodgkin's lymphomas. To determine the role of the retinoblastoma gene in the pathogenesis of MCLs and its possible interaction with cyclin D1, pRb expression was examined in 23 MCLs including 17 typical and 6 blastic variants by immunohistochemistry and Western blot. Rb gene structure was studied in 13 cases by Southern blot. Cytogenetic analysis was performed in 5 cases. The results were compared with the cyclin D1 mRNA levels examined by Northern analysis, and the proliferative activity of the tumors was measured by Ki-67 growth fraction and flow cytometry. pRb was expressed in all MCLs. The expression varied from case to case (mean, 14.1% of positive cells; range, 1.3 to 42%) with a significant correlation with the proliferative activity of the tumors (mitotic index r = 0.85; Ki-67 r = 0.7; S phase = 0.73). Blastic variants showed higher numbers of pRb-positive cells (mean, 29%) than the typical cases (10%; P < 0.005) by immunohistochemistry and, concordantly, higher levels of expression by Western blot. In addition, the blastic cases also had an increased expression of the phosphorylated protein. No alterations in Rb gene structure were observed by Southern blot analysis. Cyclin D1 mRNA levels were independent of pRb expression and the proliferative activity of the tumors. These findings suggest that pRb in MCLs is normally regulated in relation to the proliferative activity of the tumors. Cyclin D1 overexpression may play a role in the maintenance of cell proliferation by overcoming the suppressive growth control of pRb.

Aged↗
PubMed1994

Prognostic significance of the loss of heterozygosity of Nm23-H1 and p53 genes in human colorectal carcinomas.

BACKGROUND: Nm23 is a gene associated with low tumor metastatic potential and has been proposed to be a metastasis suppressor gene. Nm23 is localized on chromosome 17q21.3-22, whereas the p53 suppressor gene is on 17p13. Allelic deletions of chromosome 17 have been related to the progression of colorectal carcinomas. The purpose of this study was to analyze the allelic deletions of Nm23 and p53 in colorectal carcinomas and to assess their prognostic significance in the evolution of the patients. METHODS: Allelic deletions of Nm23 and p53 genes were studied in 56 colorectal carcinomas using different restriction fragment length polymorphisms. DNA ploidy and proliferative activity of the tumors were studied by flow cytometry. Actuarial disease free and overall survival were analyzed by the Kaplan--Meier method, and the curves were compared with the log rank test. RESULTS: Thirty-eight patients were heterozygous for Nm23 gene (68%), and 9 of them (24%) exhibited a loss of heterozygosity in the tumor sample. One of the homozygous patients showed a loss of both Nm23 alleles. Allelic deletions of 17p13 were found in 63% of the 41 informative patients. All patients' tumors that had loss of heterozygosity of the Nm23-H1 locus also had allelic losses on the short arm of chromosome 17 (17p13) and in other loci on 17q. No relationship was found between localization, invasion, lymph node metastasis, or proliferative index of the tumors and the allelic deletions of the Nm23-H1 or 17p13 locus. Nm23-H1 deletions were relatively more frequent in poorly differentiated adenocarcinomas (P = 0.03). A significant association between 17p13 deletions and DNA aneuploidy was found (P = 0.016). A similar tendency was observed with Nm23-H1 deletions (P = 0.051). Loss of Nm23-H1, but not of 17p13, was significantly associated with a shorter disease free (P = 0.025) and overall (P = 0.04) patient survival. CONCLUSIONS: Allelic deletions of Nm23-H1 are significantly associated with a more aggressive behavior of colorectal carcinomas. The loss of this gene seems to be part of extensive deletions of chromosome 17, and it is also associated with DNA aneuploidy. More studies are needed to determine whether Nm23-H1 or a gene linked to this locus is the specific target of the progression of these tumors.

Adenocarcinoma↗
PubMed1994

Cathepsin B expression in colorectal carcinomas correlates with tumor progression and shortened patient survival.

Cathepsin B is a lysosomal cysteine proteinase that has the ability to degrade several extracellular matrix components at both neutral and acidic pH and has been implicated in the progression of several human and rodent tumors. We have studied the expression of cathepsin B in human colorectal tissues using a monospecific polyclonal rabbit antibody raised against human liver cathepsin B. In immunoblots of normal and neoplastic colorectal tissues this antibody specifically recognized only cathepsin B. We studied 101 cases of formalin-fixed, paraffin-embedded tissue (15 normal mucosa, 17 adenomas, and 69 carcinomas). Epithelial cells of normal mucosa and adenomas were either negative or showed a weak granular reactivity located in the paranuclear and apical cytoplasm of superficial cells. Small clusters of histiocytes were also positive in the region of the superficial area of the lamina propria. In carcinomas, increased expression of cathepsin B correlated with advanced stage of the disease. Increased immunoreactivity of cathepsin B in malignant cells was associated with either a diffuse cytoplasmic staining or was polarized to the basal pole of the cells. This is in contrast to the punctate paranuclear staining pattern observed in normal colonic mucosal cells. In tumor stromal cells, increased expression of the enzyme correlated with neoplastic progression. Expression of high levels of cathepsin B in the tumor epithelial cells was associated with a significantly shorter survival of the patients. In conclusion, our results indicate that cathepsin B expression is up-regulated in human colorectal carcinomas compared with normal mucosa and adenomas and correlates with tumor progression.

Adenoma↗
PubMed1993

Clinico-pathological correlations in meningiomas: a DNA and immunohistochemical study.

We have studied 41 meningiomas classified histologically as benign, atypical or anaplastic. There were 26 females and 15 males and the mean age was 53 years. 36 tumours were supratentorial, 4 infratentorial and one spinal. Flow cytometry was performed on paraffin-embedded tissue using a selective staining technique for DNA. The ploidy index of DNA and percentage of cells in the S and G2/M phases were calculated. Results were correlated with clinical, histological and immunohistological data. 16/41 tumours were found to be diploid, 17/41 aneuploid and 8/41 could not be analysed. Significant correlations were found between aneuploid tumours and some qualitative features such as recurrence, pleomorphism, high cellular density, mitotic activity and brain and soft tissue infiltration. A high proliferative index appeared to be associated with clinical aggressiveness. No particular correlation between the expression of cytokeratin and epithelial membrane antigen markers and flow cytometry was found. Our results suggest that DNA flow cytometry in meningiomas may be of value in predicting the behaviour of these neoplasms and confirm that epithelial pattern in meningiomas is not linked to increased anaplasia or poor prognosis.

Adult↗
PubMed1991

Loss of heterozygosity of p53 gene and p53 protein expression in human colorectal carcinomas.

The p53 gene is a tumor suppressor gene located on chromosome 17p. Deletions of this chromosome and point mutations of p53 have been implicated in the development of colonic neoplasms. We have analyzed the loss of heterozygosity of the human p53 tumor suppressor gene in 40 cases of colorectal carcinoma using two restriction fragment length polymorphisms detected by BglII and AccII restriction enzymes. p53 gene product expression was studied immunohistochemically in 64 colorectal carcinomas, 18 adenomas, and 40 normal colonic mucosae using an anti-human p53 monoclonal antibody (Pab 1801) and the avidin-biotin-peroxidase complex technique. Twelve of the 40 patients (30%) were polymorphic for the p53 gene. In ten of these informative patients (83%), the tumor samples showed the loss of one allele when compared with normal colorectal samples of the same patient. One of the homozygous patients showed a loss of both p53 alleles. p53 immunostaining was observed in 43 of 64 carcinomas (67%) but only in two adenomas (11%). These two positive adenomas showed areas of carcinoma in situ. The normal mucosa was always negative. No relation could be found between p53 immunostaining and the degree of differentiation, the extension of the tumor, or the Ki-67 proliferative index. Mucinous carcinomas and right-side carcinomas were less p53 immunoreactive (25% and 52%, respectively) than the usual adenocarcinomas (73%) and distal tumors (72%). These findings suggest that p53 may be a target of chromosome 17 deletions and that this gene may play a role in the malignant transformation of adenomas. BglII and AccII restriction fragment length polymorphism analysis of the p53 gene may be a useful and direct technique to detect allelic loss of this gene in tumors.

Adenocarcinoma↗
PubMedDate not supplied

[Intestinal occlusion due to pancreatitis mimicking stenosing neoplasm of the splenic angle of the colon].

Colonic involvement in patients with severe acute pancreatitis or chronic pancreatitis is common and complications such as paralytic ileus, segmental necrosis and pancreatic-colonic fistulae have been described. However, mechanical occlusion of the colon due to pancreatitis is infrequent. We present the case of a 45-year-old man with occlusion of the colon secondary to asymptomatic pancreatitis mimicking a locally advanced stenosing neoplasm of the splenic angle. Ten years prior to the present episode the patient had presented acute alcoholic pancreatitis complicated by a pseudocyst requiring surgery. The current reason for admission was abdominal colic pain and constipation with onset 5 days previously. Contrast enema was administered showing colonic occlusion caused by stenosis at the splenic flexure, suggesting the presence of a neoplasm. Urgent laparotomy showed the presence of a tumor originating in the colon that infiltrated the splenic hilum. Subtotal colectomy and en-bloc splenectomy were performed. Histopathological analysis showed pericolonic inflammation and fibrosis secondary to pancreatitis; the colonic mucosa showed no tumoral infiltration. To date, fewer than 30 cases of this infrequent complication have been published.

Acute Disease↗