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Biomedical subjects

E Villar

Publications and source records attributed to E Villar.

At least 19 recordsLinked to original sources

Conservative treatment with transurethral resection, neoadjuvant chemotherapy followed by radiochemotherapy in stage T2-3 transitional bladder cancer.

PURPOSE: Organ preservation has been investigated in patients (p) with infiltrating transitional cell carcinoma (TCC) of the bladder over the past decade as an alternative to radical cystectomy. This is a trimodal schedule study, including transurethral resection of bladder tumor (TURB), neoadjuvant chemotherapy and concomitant radiochemotherapy (RTC). PATIENTS AND METHODS: From April 1996 until August 2005, 29 evaluable patients (p) with T2-T3NXM0 bladder cancer were enrolled. After a transurethral resection of bladder tumor (TURB), we administered 2 cycles of induction chemotherapy with CMV (15 p) or Gemcitabine-Cisplatin (14 p) followed by radiotherapy 45 Gy 1.8 Gy/fraction and two cycles of concomitant cisplatin 70 mg/m(2). 2-3 weeks later, a cystoscopy with tumor-site biopsy was performed. If complete histological response, p were treated with consolidation radiotherapy until 64.8 Gy. For p with residual or recurrent tumor, cystectomy was performed. RESULTS: We included 28 men and 1 women (median age 63, range 39-72 years) with PS (ECOG) 0-1. The stage was: 21 p T2; 6 p T3a; and 2 p T3b. Toxicity was higher in CMV compared with Gem- Cis: grade (3/4) neutropenia 4/15 (26%) vs 1/14 (7%); febrile neutropenia 3/15 (20%) vs 1/14 (7%); grade (3/4) trombocytopenia 2/15 (13%) vs 1/14 (7%). Toxicities with concomitant RCT were low-moderate: urocystitis (26%) and enteritis (18%). RESPONSE: microscopically complete TURB was obtained in 20 p (69%), but not in 9 p (31%) (7 microscopic, and 2 macroscopic residual tumor). We found a complete histologic response after induction RCT in 25 p (86%). After a median follow-up of 69.4 months (m) (range: 8-97.7), there were 8 deaths, with a overall survival of 72%. Furthermore 14 of 29 p (48%) were alive with intact bladder, and median survival time with intact bladder was 63.6 m (50.1-77.2); were predictive of best outcome T2 stage vs T3 (p < 0.0001), and complete histologic resection in initial TURB vs residual tumor (p = 0.0004). CONCLUSIONS: Combined treatment provide high response rates and can be offered as an alternative option to radical cystectomy in selected patients with TCC. Patients with T2 stage and complete histologic resection in initial TURB had the best outcome.

Adult↗

Prediction of relapse by day 100 BCR-ABL quantification after allogeneic stem cell transplantation for chronic myeloid leukemia.

Chronic myeloid leukemia (CML) relapse after allogeneic stem cell transplantation (SCT) is a relatively frequent situation, which is correlated to disease status, time from diagnosis to transplant and T-cell depletion. We evaluated the potential for early minimal residual disease (MRD) BCR-ABL quantification to predict relapse of CML patients receiving allogeneic SCT. Minimal residual disease was analyzed by real-time quantitative reverse transcriptase-polymerase chain reaction (RQ-PCR) at day 100 (d100) in 38 patients with >1 year follow-up after conventional non-T-cell-depleted SCT. Normal ABL control values from 1724 follow-up blood samples were used to define an RQ-PCR amplifiability index and the limits of reliable use of BCR-ABL ratios. We then compared the 14 patients with a high-level d100 BCR-ABL/ABL ratio (> or = 10(-4)) to that of the 24 patients with a negative/low-level ratio (<10(-4)). Despite being comparable for all classical parameters, the incidence of relapse was significantly higher in the high MRD group (11/14 (79%)) compared to that of the low/negative MRD group (7/24 (29%)) (P = 0.009), with d100 MRD values representing an independent risk factor of relapse and disease-free survival, but not of overall survival, in multivariate analysis. These data should facilitate risk-adapted post-transplant immunosuppression and/or tyrosine kinase inhibitor therapy based on an early evaluation of MRD.

Adolescent↗

Chronic renal failure and end-stage renal disease are associated with a high rate of mortality after heart transplantation.

The aim of the study was to analyze the etiology, the factors for progression of chronic renal failure to end-stage-renal disease (ESRD), and the influence of ESRD on the survival rate among a cohort of 59 heart transplant patients (HTP) referred for the management of chronic renal failure (CRF). At the time of the first nephrology consultation (6 +/- 4.25 years after cardiac transplantation) the mean creatininemia was 261.5 +/- 99 micromol/L and mean creatinine clearance (Cockcroft formula) was 32 +/- 15 mL/min. The cause of CRF were calcineurin inhibitor toxicity in 38.9% of patients, vascular events in 15.2%, hemolytic uremic syndrome in 5%, membranous glomerulopathy in 3.3%, diabetes in two patients, focal/segmental glomerulosclerosis in 3.3%, renal hypoplasia in 1.7%, and unknown in 27%. Evolution to ESRD occurred in 38.9% of patients: 17 patients started hemodialysis, three peritoneal dialysis, and two received a preemptive kidney transplantation. Creatininemia (micromol/L) at the time of nephrology referral was 229.2 +/- 72.6 versus 315.8 +/- 113.4 (P < .001) and creatinine clearance (mL/min) was 34.9 +/- 15.1 versus 27.3 +/- 13.7 (P = .049) for patients with CRF versus ESRD, respectively. Both proteinuria (g/24 hours) of 1 +/- 2.2 versus 2.3 +/- 1.8 (P = .02) and tobacco use in 35.1% versus 54.4% (P = .045) were significantly associated with progression of CRF, while age at the time of heart transplantation, cause of cardiac failure and renal failure, high blood pressure, type 2 diabetes, dyslipidemia, alcoholism, cirrhosis, and cerebral vascular accident were not. Death occurred in 18 HTP: 50% of patients with ESRD and 18.5% of patients with CRF-a 2.6 relative risk of of death in HTP patients with ESRD compared with HTP with CRF only (P < .01).

Adult↗

Weekly irinotecan (CPT-11) in 5-FU heavily pretreated and poor-performance-status patients with advanced colorectal cancer.

Irinotecan (CPT-11) is an effective drug in patients with advanced colorectal cancer (CRC). Little is known about its efficacy and safety in previously treated patients with poor performance status. We prospectively evaluated the antitumor efficacy and safety of CPT-11 monotherapy in this setting. Thirty-four patients with poor performance status (Karnofsky score between 60 and 80) and/or progressing on one or more previous 5-FU-based chemotherapy lines for advanced colorectal adenocarcinoma were enrolled in this study. Treatment consisted of irinotecan (CPT-11) at 100 mg/m(2) administered as a 60-min iv infusion every week for four consecutive weeks followed by a 2-wk rest period until disease progression or unacceptable toxicity. The overall objective response rate (WHO criteria) for the 34 patients included was 20.6% [95% confidence interval (CI): 6.3%-34.9%]. Stable disease was obtained in 13 patients (38.2%) and 14 patients (41.2%) progressed. The median time to disease progression was 5.5 mo (range: 0.9-17.5) and the median survival was 8.3 mo (95% CI: 1.7-16.9). Overall, weekly CPT-11 was well tolerated with grade 3/4 neutropenia as the main hematological toxicity (11 patients: 32.4%; 14 infusions: 3.3%), and delayed diarrhea (10 patients: 29.4%; 16 infusions: 3.8%) as the main grade 3/4 non-hematological toxicity. In conclusion, weekly CPT-11 at 100 mg/m(2) for four consecutive weeks followed by a 2-wk rest period showed antitumor efficacy and may be safely administered to heavily pretreated patients with advanced colorectal cancer and a poor performance status. Weekly CPT-11 monotherapy may be considered as a therapeutic option for this population of patients.

Adenocarcinoma↗

[A tool to predict the resources necessary for the whole hemodialysis population].

Predicting the resources necessary for the treatment of terminal renal insufficiency requires an understanding of the needs of the whole dialysis population. This study evaluates the advantages of a complete evaluation grid for care needs (CG, 47 items) compared with a simplified version (SG) and with the data obtained from REIN (R) as a tool for predicting the required resources. Compared to CG, the two other classifications under-estimate the level of care needed and the prevalence of patients who have at least one condition resulting in an 'excess' of needs. In a system with three types of structures, the theoretical distribution of patients according to the CG is: in structure A (permanent medical presence): 43.4% (vs 39 for SG and 21% for R); in structure B (intermediate): 34% (vs 31.5 and 24.7% respectively); and in structure C (independent): 22.3% (vs 29.5 and 53.5%) of patients. The care needs scores of populations assigned by R to home dialysis are incompatible with the resources allocated to it. With a certain number of adjustments and qualifications, a population study using a simplified needs grid could enable a prediction of the resources which need to be provided. The patients' records which take precedence in the future REIN should be modified in order to make possible a regular evaluation of the appropriateness of the resources allocated.

Adult↗

Fusogenic activity of reconstituted newcastle disease virus envelopes: a role for the hemagglutinin-neuraminidase protein in the fusion process.

Enveloped viruses, such as newcastle disease virus (NDV), make their entry into the host cell by membrane fusion. In the case of NDV, the fusion step requires both transmembrane hemagglutinin-neuraminidase (HN) and fusion (F) viral envelope glycoproteins. The HN protein should show fusion promotion activity. To date, the nature of HN-F interactions is a controversial issue. In this work, we aim to clarify the role of the HN glycoprotein in the membrane fusion step. Four types of reconstituted detergent-free NDV envelopes were used, on differing in their envelope protein contents. Fusion of the different virosomes and erythrocyte ghosts was monitored using the octadecyl rhodamine B chloride assay. Only the reconstituted envelopes having the F protein, even in the absence of HN protein, displayed residual fusion activity. Treatment of such virosomes with denaturing agents affecting the F protein abolished fusion, indicating that the fusion detected was viral protein-dependent. Interestingly, the rate of fusion in the reconstituted systems was similar to that of intact viruses in the presence of the inhibitor of HN sialidase activity 2,3-dehydro-2-deoxy-N-acetylneuraminic acid. The results show that the residual fusion activity detected in the reconstituted systems was exclusively due to F protein activity, with no contribution from the fusion promotion activity of HN protein.

Animals↗

Mode of action of two inhibitory peptides from heptad repeat domains of the fusion protein of Newcastle disease virus.

Peptides derived from heptad repeat (HR) sequences of viral fusion proteins from several enveloped viruses have been shown to inhibit virus-mediated membrane fusion but the mechanism remains unknown. To further investigate this, the inhibition mechanism of two HR-derived peptides from the fusion protein of the paramyxovirus Newcastle disease virus (NDV) was investigated. Peptide N24 (residues 145-168) derived from HR1 was found to be 145-fold more inhibitory in a syncytium assay than peptide C24 (residues 474-496), derived from HR2. Both peptides failed to block lipid-mixing between R18-labeled virus and cells. None of the peptides interfered with the binding of hemagglutinin-neuraminidase (HN) protein to the target cells, as demonstrated by hemagglutining assays. When both peptides were mixed at equimolar concentrations, their inhibitory effect was abolished. In addition, both peptides induced the aggregation of negatively charged and zwitterionic phospholipid membranes. The ability of the peptides to interact with each other in solution suggests that these peptides may bind to the opposite HR region on the protein whereas their ability to interact with membranes as well as their failure to block lipid transfer suggest a second binding site. Taken together these results, suggest a mode of action for C24 and N24 in which both peptides have two different targets on the F protein: the opposite HR sequence and their corresponding domains.

Amino Acid Sequence↗

Monte Carlo estimation of absorbed dose to organs in computed tomography.

This paper proposes a method to estimate absorbed doses to organs in explorations using computed tomography. This Monte Carlo-based method is a generalization of a previous method applied to conventional diagnostic radiology and is also applicable to radiotherapy techniques using photons or electrons. This study is applied to the estimation of absorbed doses to different parts of the head in a simple head CT examination. Simulation was performed for different arrangements (monoenergetic beam, spectrum, different number of histories, etc.). Comparison of the results with experimental doses measured in a human phantom by thermoluminescent dosimeters indicates that the method is capable of adequately estimating doses to organs in computed tomography.

Absorption↗

Abnormal expression of acid glycosidases in seminal plasma and spermatozoa from infertile men with varicocele.

The activities of acid beta-glucuronidase, alpha-mannosidase, alpha-glucosidase, alpha-galactosidase, beta-galactosidase and beta-N-acetylglucosaminidase were analysed in seminal plasma and spermatozoa from 26 infertile men with varicocele and from 36 men of normal fertility. Semen samples from ten men with non-obstructive azoospermia were used as control specimens that contained the other components of semen. Spermatozoa were solubilized by both physical (homogenization) and chemical (Triton-X100) methods to obtain the soluble and non-soluble fractions. The activities of several glycosidases measured both in seminal plasma and spermatozoa were directly correlated with the numbers of spermatozoa and sperm motility, confirming previous studies. As some infertile patients with varicocele have normal semen parameters, whereas others have low numbers of spermatozoa and low sperm motility, the varicocele patients were prospectively divided into two groups: one (n = 15) with normal spermiograms and the other (n = 11) with abnormal spermiograms. The activities (expressed in mU ml(-1)) of alpha-mannosidase, beta-galactosidase and beta-N-acetylglucosaminidase in seminal plasma of normozoospermic infertile patients with varicocele were significantly higher than those of fertile controls, but not when expressed in U per 10(8) spermatozoa. The activities of beta-glucuronidase, alpha-mannosidase, beta-galactosidase and beta-N-acetylglucosaminidase in seminal plasma when expressed in U per 10(8) spermatozoa in varicocele patients with abnormal spermiograms were significantly higher than in those of men of normal fertility. The activity of alpha-mannosidase in the soluble fraction of sperm homogenates, expressed as U per 10(8) spermatozoa, was significantly higher in infertile patients with varicocele and abnormal spermiograms than in controls. In the non-soluble fraction of spermatozoa from infertile patients with varicocele, there was an increase in the expression of beta-galactosidase and beta-N-acetylglucosaminidase activities compared with the fraction of spermatozoa from fertile subjects. In summary, infertile patients with varicocele displayed an overexpression of acid alpha-mannosidase, beta-galactosidase and beta-N-acetylglucosaminidase activities in seminal plasma and spermatozoa that may be associated with functional defects in spermatozoa as these glycosidases play an important role in mammalian fertilization.

Acetylglucosaminidase↗

[Epidemiology and etiology chronic renal insufficiency].

End-stage renal failure (ESRF) is a medical and a public health problem in France and in developed countries due to the increased incidence (100 per million of persons (pmp) in France, in 1998 /year) and prevalence rates (600 pmp in 1998; +8%/year) and due to the high cost of the renal replacement therapy (RRT). This increase is mainly due to the increased incidence and prevalence of type 2 diabetic and vascular nephropathies that represent more than 50% of the ESRF causes. This progression is the consequence of an access to RRT for patients older than 60, of the population ageing, and of a better prevention and management of cardio-vascular complications in elderly ans diabetic patients. More than 30% of the patients are referred too late, leading to an increased morbi-mortality. Clear recommendations are required to make an early diagnosis of renal failure (plasma creatinine > or = 137 mumol/L in man and > or = 104 mumol/L in woman), mainly in the group of at risk patients and in order to improve the management of these patients before the end-stage renal disease.

Aged↗

Membrane glycoproteins of Newcastle disease virus: nucleotide sequence of the hemagglutinin-neuraminidase cloned gene and structure/function relationship of predicted amino acid sequence.

The nucleotide sequence of the glycoprotein hemagglutinin-neuraminidase (HN) gene of the Newcastle disease virus (NDV) strain Clone-30 has been determined. The open reading frame of the HN gene contains 1731 nucleotides and encodes a protein of 577 amino acids. Three highly conserved patterns among all paramyxovirus HN glycoproteins, and one additional conserved species-specific region are present. The protein contains five potential N-glycosylation sites, all but one located in the C-terminal external domain. The secondary structure prediction shows that the C-terminal external domain is mostly arranged in beta-sheets, while alpha-helices are predominantly located in the N-terminal domain. The nucleotide sequence data of the HN gene reported in this paper has been deposited in the GenBank database, under accession number AF098289.

Amino Acid Sequence↗

Thermally induced conformational changes in horseradish peroxidase.

Detailed differential scanning calorimetry (DSC), steady-state tryptophan fluorescence and far-UV and visible CD studies, together with enzymatic assays, were carried out to monitor the thermal denaturation of horseradish peroxidase isoenzyme c (HRPc) at pH 3.0. The spectral parameters were complementary to the highly sensitive but integral method of DSC. Thus, changes in far-UV CD corresponded to changes in the overall secondary structure of the enzyme, while that in the Soret region, as well as changes in intrinsic tryptophan fluorescence emission, corresponded to changes in the tertiary structure of the enzyme. The results, supported by data about changes in enzymatic activity with temperature, show that thermally induced transitions for peroxidase are irreversible and strongly dependent upon the scan rate, suggesting that denaturation is under kinetic control. It is shown that the process of HRPc denaturation can be interpreted with sufficient accuracy in terms of the simple kinetic scheme N -->k D where k is a first-order kinetic constant that changes with temperature, as given by the Arrhenius equation; N is the native state, and D is the denatured state. On the basis of this model, the parameters of the Arrhenius equation were calculated.

Calorimetry↗

Recombinant Newcastle disease virus as a vaccine vector.

A complete cDNA clone of the Newcastle disease virus (NDV) vaccine strain Hitchner B1 was constructed, and infectious recombinant virus expressing an influenza virus hemagglutinin was generated by reverse genetics. The rescued virus induces a strong humoral antibody response against influenza virus and provides complete protection against a lethal dose of influenza virus challenge in mice, demonstrating the potential of recombinant NDV as a vaccine vector.

Animals↗

Comparative calorimetric study of non-amyloidogenic and amyloidogenic variants of the homotetrameric protein transthyretin.

Familial amyloidotic polyneuropathy (FAP) is an autosomal dominant hereditary type of amyloidosis involving amino acid substitutions in transthyretin (TTR). V30M-TTR is the most frequent variant, and L55P-TTR is the variant associated with the most aggressive form of FAP. The thermal stability of the wild-type, V30M-TTR, L55P-TTR and a non-amyloidogenic variant, T119M-TTR, was studied by high-sensitivity differential scanning calorimetry (DSC). The thermal unfolding of TTR is a spontaneous reversible process involving a highly co-operative transition between folded tetramers and unfolded monomers. All variants of transthyretin are very stable to the thermal unfolding that occurs at very high temperatures, most probably because of their oligomeric structure. The data presented in this work indicated that for the homotetrameric form of the wild-type TTR and its variants, the order of stability is as follows: wild-type TTR approximately > T119M-TTR > L55P-TTR > V30M-TTR, which does not correlate with their known amyloidogenic potential.

Amyloid Neuropathies↗

Overexpression of clusterin in human breast carcinoma.

Clusterin has been implicated in numerous processes including active cell death, immune regulation, cell adhesion and morphological transformation. The purpose of this study was to examine clusterin expression in a large series of breast carcinomas by immunohistochemistry and in situ hybridization. The study included 40 samples of non-neoplastic glandular epithelia, 42 benign lesions, 15 atypical intraductal hyperplasias, 35 carcinomas in situ, 114 invasive carcinomas, and lymph node metastases from 40 patients. Epithelial normal cells were always negative for clusterin expression and only 19% of the benign lesions presented positive staining. In contrast to the benign lesions, however, the frequency of clusterin positive samples increased in atypical hyperplasias (47%, P = 0.08), intraductal carcinomas (49%, P = 0.01) and invasive carcinomas (53%, P < 0.001). Positive staining presented a cytoplasmic pattern, except in 3 cases of invasive carcinomas which had nuclear staining. Clusterin mRNA by in situ hybridization confirmed the specific cellular pattern of clusterin expression by immunohistochemistry. Clusterin expression was associated with large tumor size (P = 0.04), estrogen and progesterone receptor negative status (P = 0.02 and P = 0.001, respectively) and with the progression from primary carcinoma to metastatic carcinoma in lymph nodes (80% metastatic nodes had positive expression) (P = 0.004). Ten of 15 (67%) primary carcinomas without clusterin expression became positive in lymph node metastases, while most (22 of 25, 88%) of the clusterin-positive primary carcinomas were also immunoreactive in metastases. In survival analysis, clusterin expression did not represent a prognostic indicator by uni- or multivariate analysis. The increased clusterin expression in breast carcinomas tended to correlate inversely with the apoptotic index (P = 0.09) which indicates that clusterin gene expression is not a prerequisite to cellular death by apoptosis. From these results, we suggest that clusterin may have a role in tumorigenesis and progression of human breast carcinomas.

Adult↗

Abnormalities in sperm acid glycosidases from infertile men with idiopathic oligoasthenoteratozoospermia.

OBJECTIVE: To analyze and compare acid beta-glucuronidase, alpha-mannosidase, alpha-glycosidase, alpha-galactosidase, beta-galactosidase, and beta-N-acetylglucosaminidase activities in fertile and infertile patients. DESIGN: An observational, controlled, clinical study. SETTING: A university tertiary hospital. PATIENT(S): Thirty-six fertile controls, 24 infertile oligoasthenoteratozoospermic (OAT) patients, and 10 azoospermic patients, who served as negative controls. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Analysis of the six glycosidase activities in seminal plasma and in solubilized spermatozoa. RESULT(S): alpha-galactosidase and beta-galactosidase activities in spermatozoa were significantly correlated with the serum levels of gonadotropins both in fertile controls and in OAT patients. The relative contribution of alpha-galactosidase and beta-galactosidase from the soluble fraction of spermatozoa to the total activity measured in the ejaculate of OAT patients was significantly lower than in fertile controls. The activities of beta-galactosidase and beta-N-acetylglucosaminidase in the soluble fraction of spermatozoa from OAT patients were significantly lower than in fertile controls. In seminal plasma, the activity of alpha-mannosidase from OAT patients was significantly higher than in fertile controls. The activity of beta-N-acetylglucosaminidase in the nonsoluble fraction of spermatozoa from OAT patients was three times higher than in fertile controls. CONCLUSION(S): The abnormalities in the distributions and contents of alpha-galactosidase, beta-galactosidase, and beta-N-acetylglucosaminidase in sperm suggest possible functional defects in spermatozoa from OAT infertile patients.

Acetylglucosaminidase↗