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Biomedical subjects

F Navarro

Publications and source records attributed to F Navarro.

At least 73 records · Page 4Linked to original sources
PubMed1999

Abnormal frequencies of alleles in polymorphic markers of the 17q21 region is associated with breast cancer.

This study was carried out to evaluate the frequencies of alleles of four polymorphic markers in the 17q21 region in breast cancer patients, and their relation to seven pathological parameters. One hundred and sixty-four patients with breast cancer and 102 controls were analyzed. D17S856, D17S855, D17S1323 and D17S1327 polymorphic markers were studied, and used to investigate loss of heterozygosity in this region. The frequencies of alleles at marker D17S856 differed significantly in breast cancer patients and controls, and were related to histologic features considered to indicate a poor prognosis. When present, the pathophenotype of tumors associated with LOH in the 17q21 region is modified.

Alleles↗
PubMed1999

The ILT2(LIR1) and CD94/NKG2A NK cell receptors respectively recognize HLA-G1 and HLA-E molecules co-expressed on target cells.

Previous studies on NK recognition of HLA-G1 employed as targets 721.221 transfectants (.221-G1) that unknowingly co-expressed the HLA-E molecule, subsequently found to be a major ligand for the CD94/NKG2 receptors. In the present study we re-evaluated the relative role played by CD94/NKG2 and ILT2(LIR1) molecules in recognition of HLA-G1 by NK clones. We employed as targets .221-G1 cells and a surface HLA-E-negative transfectant, .221-G1(Eneg), generated by site-directed mutagenesis of the HLA-G1 leader sequence. The antagonistic effects of receptor- (ie. CD94/NKG2A, ILT2) and ligand-specific mAb (i.e. HLA-G, HLA-E) were assessed. In addition, binding of an ILT2-Ig fusion protein to the .221-AEH, expressing only HLA-E, and the .221-G1(Eneg) transfectants was analyzed. Our data demonstrate that NK recognition of cells expressing HLA-G1 involves at least two non-overlapping receptor-ligand systems: the CD94/NKG2 interaction with HLA-E, and the engagement of the ILT2(LIR1) receptor by HLA-G1 molecules.

Antibodies, Monoclonal↗
PubMed1999

Protective role of ubiquinone in vitamin E and selenium-deficient plasma membranes.

We have studied the effects of dietary depletion of vitamin E and selenium on endogenous ubiquinone-dependent antioxidant system. Deficiency induced an increase in both coenzyme Q9 and Q10 in liver tissue, reaching a maximum between 4 and 7 weeks of deficient diet consumption. Cytochrome b5 reductase polypeptide was also enriched in membranes after 5 weeks of deficient diet consumption. Substantial DT-diaphorase activity was found in deficient, but not in control plasma membranes. Deficient membranes were very sensitive to lipid peroxidation, although a great protection was observed after incubation with NAD(P)H. Our results show that liver cells can boost endogenous ubiquinone-dependent protective mechanisms in response to deficiency in vitamin E and selenium.

Animals↗
PubMed1999

A novel family of Ig-like receptors for HLA class I molecules that modulate function of lymphoid and myeloid cells.

We review what is presently known about structure, cellular distribution, biochemical characteristics, and function of a new family of human cell-surface receptors referred to as immunoglobulin-like transcripts (ILTs), leukocyte Ig-like receptors (LIRs), or monocyte/macrophage Ig-like receptors (MIRs). These receptors are genetically, structurally, and functionally related to a group of natural killer (NK) cell receptors for HLA class I molecules known as killer cell Ig-like receptors (KIRs). Distinct ILT/LIR/MIR isotypes are differentially expressed on lymphocytes, monocytes, macrophages, dendritic cells, and granulocytes; at least some of them recognize HLA class I molecules. Whereas some isotypes either inhibit or induce cell activation, others may be secreted as soluble receptors. ILT/LIR/MIR receptors may allow all immune cells to monitor class I expression on other cells and to respond in its absence, just as NK cells do. In addition, they may contribute to homeostasis by establishing activation thresholds that can be overcome only by relevant triggering stimuli and not by bystander cells.

Antibodies, Monoclonal↗
PubMed1999

How do NK cells sense the expression of HLA-G class Ib molecules?

The nature of NK cell receptors involved in recognition of HLA-G1 has remained an unclear issue; we herein review this topic based on our experience. We found no evidence that well characterized p58 and p70 KIRs may interact with HLA-G1. By contrast, our data support that NK recognition of cells expressing HLA-G1 involves at least two non-overlapping receptor-ligand systems: (1) the direct engagement of the ILT2 (LIR1) receptor by HLA-G1; and (2) the interaction of CD94/NKG2A and CD94/NKG2C receptors with the non-classical class I molecule HLA-E, co-expressed on the surface upon binding to a nonamer (VMAPRTLFL) from the HLA-G leader sequence.

Antigens, CD↗
PubMed1999

[Hemodynamic monitoring using esophageal Doppler ultrasonography during laparoscopic cholecystectomy].

PURPOSE: To evaluate the use of a 4-mHz continuous wave esophageal Doppler monitor in the hemodynamic management of 48 ASA I to III patients undergoing laparoscopic cholecystectomy. METHODS: General anesthesia was induced with fentanyl and propofol, maintained with N20 N20/02 and muscle relaxation was provided with atracurium. The lungs were mechanically ventilated. Non invasive arterial blood pressure, heart rate, capnography, arterial blood gas were monitored during CO2 pneumoperitoneum at 15-mmHg. Using the velocity waveform of descending aortic blood flow, the Doppler device estimated changes in cardiac output and systemic vascular resistances. RESULTS: Peritoneal insufflation resulted in a mean 19% decrease in cardiac output (range -49 to +5%; P < 0.05) and a mean 48% increased in systemic vascular resistances (range -7 to +101%; P < 0.01). There was no relationship between changes in cardiac output and mean arterial pressure or PETCO2. The esophageal Doppler provided, in two patients, details of hypertensive peaks (mean arterial pressure > 140 mmHg) which responded to administration of nicardipine. CONCLUSION: The Esophageal Doppler provided an easy-to-handle and non invasive tool to monitor changes in cardiac output during laparoscopic cholecystectomy. However, further comparison with a thermodilution cardiac output technique is required.

Adult↗
PubMed1999

Abdominal laparoscopic approach for thoracic epiphrenic diverticulum.

The true incidence of epiphrenic esophageal diverticulum is unknown. Traditionally, diverticulectomy via a left thoracic approach has represented the gold standard. Trans-hiatal esophageal dissection under laparoscopy is feasible, but has not, to our knowledge, been applied before in the treatment of epiphrenic esophageal diverticulum.

Deglutition Disorders↗
PubMed1999

Delayed gastric emptying after pancreaticoduodenectomy and pancreaticogastrostomy.

OBJECTIVE: To find out which factors influence the development of delayed gastric emptying (DGE) after pancreaticoduodenectomy with pancreaticogastrostomy. DESIGN: Prospective clinical study. SETTING: University hospital, France. SUBJECTS: 88 patients of 103 consecutive patients who had had pancreaticoduodenectomies, November 1991-November 1997. INTERVENTIONS: Whipple resection, and parenteral and enteral nutrition. MAIN OUTCOME MEASURES: Mortality, morbidity, and development of DGE (defined as the need for a postoperative nasogastric tube for 10 days or longer). RESULTS: One patient died, and 44 developed postoperative complications. 36 patients (41%) developed DGE in 21 of whom (58%, 24% of the total) it was in isolation, with no other complication; and 52 (59%) did not. There were significant differences between those who developed DGE and those who did not: 30 men (83%) compared with 6 women (17%) developed DGE compared with 32 (62%) and 20 (38%) (p = 0.03;); 15 (42%) developed a complication as well as DGE compared with 8 (15%) (p = 0.005); 10(28%) who developed DGE required reoperation compared with 4(8%) (p = 0.011); mean (SD) hospital stay was 30(12) days among those with DGE compared with 17 (5) days (p= 0.0001); and their mean (SD) serum protein concentration on day 1 was 46 (1) compared with 51 (7) g/L (p=0.01). Multivariate analysis showed that three factors independently influenced the development of DGE: sex (p = 0.01), the need for reoperation (p = 0.03) and the mean serum protein concentration on day 1 (p = 0.04). CONCLUSION: Postoperative complication and the need for reoperation remain the most common factors linked to the development of DGE. However, in a quarter of patients DGE was not associated with any postoperative complication.

Digestive System Surgical Procedures↗
PubMed1999

Management of intraductal papillary mucinous tumours of the pancreas.

OBJECTIVE: To focus attention on the management and outcome of patients with intraductal papillary mucinous tumours of the pancreas. DESIGN: Retrospective study and analysis of published reports. SETTING: University hospital, France. SUBJECTS: 111 patients (101 published cases and our own 10 cases) divided in two groups: the first including malignant tumours (n = 46), and the second group benign or in situ tumours (n = 61). In 4 patients the type of tumour was not known. MAIN OUTCOME MEASURE: Resectability, mortality and recurrence. RESULTS: More men had benign or in situ tumours [48/61 (79%) compared with 28/46 (61%), p = 0.054]. Pancreatitis was more common among benign than malignant tumours [34/61 (58%) compared with 21/46 (46%), p = 0.33]. In group I, 39 patients had diabetes. A total of 107 patients were operated on: pancreaticoduodenectomy (n = 54, 50%), distal pancreatectomy (n = 25, 23%), total pancreatectomy (n = 4,4%), bypass (n = 2,2%). The type of resection was not mentioned in 22 records (21%). Four patients were not operated on because of their poor general condition. The resectability rate was 98% (105/107). Eleven patients had died at the time of publication. Hospital mortality rate was 3% (n = 3), mainly because 2 of the 4 who had total pancreatectomy died. With a median follow-up of 37 months, recurrence was 5% (n = 5). CONCLUSION: Intraductal papillary mucinous tumours of the pancreas are well known distinctive pancreatic tumours that are usually intraductal but may develop into invasive carcinoma. They should be resected, and have a good prognosis and low recurrence rate.

Adult↗
PubMed1999

Increase in quinolone resistance in a Haemophilus influenzae strain isolated from a patient with recurrent respiratory infections treated with ofloxacin.

The increase in the level of quinolone resistance of Haemophilus influenzae clinical isolates during ofloxacin therapy of a patient with recurrent respiratory infections was investigated. The first isolate (MIC of ciprofloxacin of 2 microg/ml) and the second isolate (MIC of 32 microg/ml) belonged to the same clone, as shown by pulsed-field gel electrophoresis, and the increase in the resistance level was associated with a substitution in Ser-84 to Arg in the ParC protein. These results emphasize the potential risk of development of quinolone-resistant H. influenzae during fluoroquinolone therapy in patients with recurrent respiratory infection.

Amino Acid Substitution↗
PubMed1999

Alcoholic cirrhosis is a good indication for liver transplantation, even for cases of recidivism.

BACKGROUND/AIMS: Alcoholic cirrhosis remains a controversial indication for liver transplantation, mainly because of ethical considerations related to the shortage of donor livers. The aim of this study was to review experience to date, focusing on survival rates and complications, and the effect of alcohol relapse on outcome and alterations in marital and socioprofessional status. METHODS: The results for 53 patients transplanted for alcoholic cirrhosis between 1989 and 1994 were compared with those for 48 patients transplanted for non-alcoholic liver disease. The following variables were analysed: survival, rejection, infection, cancer, retransplantation, employment and marital status, alcoholic recurrence. The same variables were compared between alcohol relapsers and non-relapsers. RESULTS: Recovery of employment was the only significantly different variable between alcoholic (30%) and non-alcoholic patients (60%). Two factors influenced survival in the absence of alcohol recidivism: age and abstinence before transplantation. For all other variables, there were no differences between alcoholic and non-alcoholic patients, and, within the alcoholic group, between relapsers and non-relapsers. The recidivism rate was 32%. CONCLUSION: The data indicate that liver transplantation is justified for alcoholic cirrhosis, even in cases of recidivism, which did no affect survival and compliance with the immunosuppressive regimen. These good results should help in educating the general population about alcoholic disease.

Adult↗
PubMed1999

[Incidence of extended spectrum beta lactamase in Escherichia coli in a university hospital from 1994-1996].

BACKGROUND: The aim of this study was to evaluate the incidence of TEM- and SHV-type extended spectrum betalactamases (ESBLs) in Escherichia coli in a 700-bed teaching hospital between 1994 and 1996. MATERIAL AND METHODS: Strains that presented reduced diameters to third-generation cephalosporins, as identified by disc diffusion techniques, were studied. The betalactamases involved were characterized by determination of the isoelectric point, hydrolysis profile, gene detection by polymerase chain reaction (PCR), and sequencing of the amplified products. RESULTS: 96 strains (1.4%) out of 7,054 strains of E. coli isolated between 1994 and 1996 showed decreased susceptibility to third-generation cephalosporins and only 4 strains (0.06%) produced ESBLs. Two strains produced SHV-2 and two produced TEM-12. CONCLUSIONS: The contribution of ESBL production to resistance to third-generation cephalosporins was low: 0.06% of all the E. coli strains isolated between 1994 and 1996.

Escherichia coli↗