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Biomedical subjects

P Thibault

Publications and source records attributed to P Thibault.

At least 55 records · Page 3Linked to original sources
PubMed2000

Evaluation of FDG uptake by renal malignancies (primary tumor or metastases) using a coincidence detection gamma camera.

UNLABELLED: The aim of this study was to evaluate the usefulness of FDG scanning using an ordinary gamma camera equipped with coincidence detection (CDET) for 2 renal cancer indications: characterization and staging of renal masses before nephrectomy and search for recurrence after nephrectomy. METHODS: Between September 1997 and June 1998, a whole-body scan and at least 1 tomoscintigram were obtained on 23 occasions in 22 patients (fasting for at least 6 h) using a Prism XP 2000 CDET gamma camera; scanning was begun 45 min after intravenous injection of 150-250 MBq FDG. RESULTS: Postoperative histologic evidence was obtained from 13 of 16 patients who underwent FDG using a CDET gamma camera before renal surgery; 4 renal masses did not accumulate FDG (3 true-negatives, 1 false-negative), whereas 9 renal tumors accumulated FDG (8 true-positives, 1 false-positive). In the other 3 patients, only 1 extrarenal site of FDG uptake was checked and confirmed on histologic examination: a bone metastasis from renal cell carcinoma in 2 cases and lymph node metastasis from a squamous cell carcinoma (3 true-positives). The primary local and regional staging of the malignant renal tumors was accurate in the 9 patients who underwent nephrectomy (8 true-negatives, 1 true-positive). The primary distant staging was positive in 1 case (focus in the chest corresponding to a probable true-positive on follow-up). In the 7 examinations performed because of suspected recurrence of renal cell carcinoma several months after nephrectomy, metastases were visualized by FDG in 4 patients, confirmed by biopsy in 2 patients, and confirmed by conventional imaging or follow-up (or both) in 2 patients. The other 3 patients had negative FDG scans, corresponding to probable true-negative results on follow-up. CONCLUSION: FDG using a CDET gamma camera can be used effectively for the staging and restaging of renal tumors and might be useful for characterization of the primary renal tumor in doubtful cases.

Carcinoma, Renal Cell↗
PubMed2000

[Radiotherapy of localized prostatic cancer: follow-up of 48 patients. G.C.C.P. (Cooperative Group for the Study of Prostatic Cancer)].

OBJECTIVE: To evaluate the safety and long-term efficacy of curative-intent radiation therapy in patients with apparently localized prostate cancer. METHOD: 48 patients with T < 3 M0 prostate cancer recruited between 1981 and 1985 received regular clinical follow-up for at least ten years or until their death. Radiation therapy was given according to the protocols established by Ray and Bagshaw. RESULTS: Radiation therapy was safe and effective in most patients. The rate of escape phenomenon was less than 10% after two years. Tumor control rates were greater than 80% after five years and 50% after ten years. Unfortunately, local remission, even when prolonged, did not necessarily indicate a complete cure: 20% of local recurrences developed five to 11 years after radiation therapy. CONCLUSION: Radiation therapy may be the best first-line treatment in men older than 75 years of age and in those whose life expectancy seems shorter than ten years, but should probably not be considered curative.

Aged↗
PubMed2000

[Epididymal gaseous abscess after BCG treatment].

The authors report a case of unilateral epididymitis with caseous abscess after BCG-therapy for superficial bladder tumour. The severity of the lesions required orchidectomy, followed by four-agent tuberculostatic therapy.

Abscess↗
PubMed2000

[Peroperative erection in lower urologic surgery].

Erection is a rare event during lower urinary tract surgery. When it is extremely refractory, endoscopy is impossible and the lower urinary tract surgery may need to be deferred. The development of erection during spinal anaesthesia is due to manipulations before complete installation of sensory block or incomplete blockade of sacral segments (S2 to S4) supplying the nervi erigentes. The mechanism of erection during general anaesthesia remains poorly elucidated. General anaesthesia may suppress central or peripheral sympathetic control of flaccidity. The peripheral target could be the smooth muscle of the cavernous tissue, either by a direct action or via alpha-adrenergic receptors. Psychogenic and reflexogenic stimuli have also been proposed, possibly facilitated by amplification of sensations during stage II anaesthesia. The various treatments are based on experience acquired in the field of priapism. Systemic treatments such as ketamine an beta 2 mimetics or benzodiazepines are not always effective and are associated with considerable adverse effects. Intracavernous injections of alpha-adrenergic drugs constitute the treatment of choice. Phenylephrine and etilefrine are preferred because of their rapid efficacy and particularly their only moderate cardiovascular adverse effects.

Anesthesia↗
PubMed2000

[Predictive factors of successful treatment of lower caliceal calculi with Edap LT02 extracorporeal lithotripsy].

OBJECTIVE: To determine the predictive factors of success of extracorporeal shock-wave lithotripsy (ESWL) for lower caliceal stones. PATIENTS AND METHODS: The case files of 100 patients with a single stone in the lower pole of the kidney, ranging in size from 6 to 25 mm, treated by EDAP LTO2 extracorporeal lithotripsy between 1994 and 1997, were studied. Pretreatment intravenous urography was reviewed to assess the characteristics of the stone, to measure the pyelocaliceal angle and to study the anatomy of the lower pole of the kidney. RESULTS: The overall stone-free rate at 3 months was 57%. The success rate was 67.18% for stones smaller than 1 cm and 38.88% for stones larger than 1 cm. Stones denser than bone were successfully treated in 45.5% of cases, those less dense than bone were successfully treated in 71.11% of cases. The success rate was 86.04% when the pyelocaliceal angle was greater than 90 degrees and 35.08% when this angle was less than 90 degrees. The stone-free rate was 75% when the caliceal stalk was less than 3 cm and 37.5% when the stalk was greater than 3 cm. CONCLUSION: In this series, the size of the stone, its density, the pyelocaliceal angle and the length of the caliceal stalk were predictive elements of the success of ESWL for lower caliceal stones. The pyelocaliceal angle was the most significant factor. A very dense stone on the plain abdominal film with a diameter of 1 cm or more and presenting unfavourable anatomical factors should be treated by percutaneous nephrolithotomy as the first-line procedure.

Adult↗
PubMed2000

[Pelvic endometriosis with ureteral obstruction. Case report].

The authors report 1 clinical case of pelvic endometriosis. The urinary symptoms and the radiological appearance of endometriosis with compression of the ureter are non specific. The diagnosis was established by histological examination of the resection specimen. The authors describe the therapeutic approach based on radical surgery designed to eradicate the endometriosis, while remaining as conservative as possible in order to allow subsequent pregnancy, and the place of urological surgery combined with medical treatment with LHRH analogue.

Adult↗
PubMed2000

[Balloon catheter parieto-renal dilatation in percutaneous kidney surgery].

OBJECTIVE: To compare two techniques of parieto-renal dilatation for percutaneous surgery: Alken dilators and balloon catheter. MATERIAL AND METHODS: This prospective, non-randomized study was conducted between July 1999 and April 2000 in 20 patients undergoing percutaneous renal surgery. 10 patients were dilated with a balloon catheter (NephroMax, Boston Scientific) and the other 10 patients were dilated with Alken metal dilators. Statistical analysis was performed with the Mann-Whitney test. RESULT: The dilatation time and x-ray exposure time were shorter during balloon catheter dilatation (statistically significant difference) and the two techniques were associated with a comparable morbidity. CONCLUSION: Balloon catheter parieto-renal dilatation significantly decrease dilatation and x-ray exposure times and very considerably simplifies this operative step, essential to the success of percutaneous surgery.

Adult↗
PubMed1999

A complex family of highly heterogeneous and internally repetitive hyperactive antifreeze proteins from the beetle Tenebrio molitor.

We have previously identified a Thr- and Cys-rich thermal hysteresis (antifreeze) protein (THP) in the beetle Tenebrio molitor that has 10-100 times the freezing point depression activity of fish antifreeze proteins. Because this 8.4 kDa protein is significantly different in its properties from THP preparations previously reported from this insect, a thorough search was undertaken for other antifreeze types. Many active proteins were observed, but all appeared to be isoforms of the THP that differed in their number of 12-amino acid repeats (consensus sequence CTxSxxCxxAxT), amino acid substitutions, and N-linked glycosylation. Mass spectral analysis has matched most of these isoforms with cDNA sequences of 17 different clones from a larval fat body library that encode eight different mature THPs containing 84, 96, or 120 amino acids. Genomic Southern blots suggest there may be 30-50 tightly linked copies of the gene, which is a signature consistently seen with unrelated fish antifreeze protein genes, and one that has been associated with the need to rapidly increase gene product in response to climate change. A three-dimensional model is proposed for the fully disulfide-bonded structure of T. molitor THP, which can accommodate addition or deletion of 12-amino acid repeats. The structure is a beta-helix that places most of the Thr in a regular array on one side of the protein to form a putative ice-binding surface.

Amino Acid Sequence↗
PubMed1999

Integration of microfabricated devices to capillary electrophoresis-electrospray mass spectrometry using a low dead volume connection: application to rapid analyses of proteolytic digests.

This report describes the development of a compact and versatile, micromachined chip device enabling the efficient coupling of capillary electrophoresis to electrospray mass spectrometry (CE-ESMS). On-chip separation provides a convenient means of achieving rapid sample cleanup and resolution of multicomponent samples (typically 2-5 min) prior to mass spectral analysis. A low dead volume connection facilitating the coupling of microfabricated devices to CE-ESMS was evaluated using two different interfaces. The first configuration used disposable nanoelectrospray emitters directly coupled to the chip device via this low dead volume junction, thereby providing rapid separation of complex protein digests. The performance of this interface was compared with that of more traditional configurations using a sheath flow CE-ESMS arrangement where a fused-silica capillary of varying length enabled further temporal resolution of the multicomponent samples. The sensitivity and analytical characteristics of these interfaces were investigated in both negative and positive ion modes using standard peptide mixtures. The separation performance for synthetic peptides using a chip coated with amine reagent ranged from 26,000 to 58,000 theoretical plates for a sheath flow CE-ESMS interface comprising a 15-cm CE column. Replicate injections of a dilution series of peptide standards provided detection limits of 45-400 nM without the use of on-line preconcentration devices. The reproducibility of migration time ranged from 0.9 to 1.5% RSD whereas RSDs of 5-10% were observed on peak areas. The application of these devices for the analysis of protein digests was further evaluated using on-line tandem mass spectrometry.

Amino Acid Sequence↗
PubMed1999

Post-translational processing of two alpha-amylase inhibitors and an arcelin from the common bean, Phaseolus vulgaris.

Mass spectrometric methods were used to investigate the proteolytic processing and glycopeptide structures of three seed defensive proteins from Phaseolus vulgaris. The proteins were the alpha-amylase inhibitors alphaAI-1 and alphaAI-2 and arcelin-5, all of which are related to the seed lectins, PHA-E and PHA-L. The mass data showed that the proteolytic cleavage required for activation of the amylase inhibitors is followed by loss of the terminal Asn residue in alphaAI-1, and in all three proteins, seven or more residues were clipped from the C-termini, in the manner of the seed lectins. In most instances, individual glycoforms could be assigned at each Asn site, due to the unique masses of the plant glycopeptides. It was found that alphaAI-1 and alphaAI-2 differed significantly in their glycosylation patterns, despite their high sequence homology. These data complement the previous X-ray studies of the alpha1-amylase inhibitor and arcelin, where many of the C-terminal residues and glycopeptide residues could not be observed.

Amino Acid Sequence↗
PubMed1999

Des-Arg9-bradykinin metabolism in patients who presented hypersensitivity reactions during hemodialysis: role of serum ACE and aminopeptidase P.

Bradykinin (BK) has been proposed as the principal mediator of hypersensitivity reactions (HSR) in patients dialyzed using negatively charged membranes and concomitantly treated with angiotensin-converting enzyme (ACE) inhibitors. We investigated the metabolism of exogenous BK added to the sera of 13 patients dialyzed on an AN69 membrane with a history of HSR (HSR+ patients) and 10 others who did not present such a reaction (HSR- patients) while dialyzed under the same conditions. No significant difference in the t1/2 of BK was found between the patient groups. However, the t1/2 of generated des-Arg9-BK was significantly increased (2.2-fold) in HSR+ patients compared to HSR-subjects. Preincubation of the sera with an ACE inhibitor (enalaprilat) significantly increased the t1/2 of both BK and des-Arg9-BK in both groups. There was no significant difference between the groups with respect to the t1/2 of BK, but there was a significantly greater increase (3.8-fold) in the t1/2 of des-Arg9-BK in HSR+ patients compared to HSR-subjects. The level of serum aminopeptidase P (APP) activity showed a significant decrease in the HSR+ sera when compared to HSR-samples. In HSR- and HSR+ patients, a significant inverse relation (r2 = 0.6271; P < 0.00005) could be calculated between APP activity and des-Arg9-BK t1/2. In conclusion, HSR in hemodialyzed patients who are concomitantly treated with a negatively charged membrane and an ACE inhibitor can be considered as a multifactorial disease in that a decreased APP activity resulting in reduced degradation of des-Arg9-BK may lead to the accumulation of this B1 agonist that could be responsible, at least in part, for the signs and symptoms of HSR.

Acrylic Resins↗
PubMed1999

Sialic acid in the lipopolysaccharide of Haemophilus influenzae: strain distribution, influence on serum resistance and structural characterization.

A survey of Haemophilus influenzae strains indicated that around one-third of capsular strains and over two-thirds of non-typeable strains included sialic acid in their lipopolysaccharides (LPS). Mutation of the CMP-Neu5Ac synthetase gene (siaB) resulted in a sialylation-deficient phenotype. Isogenic pairs, wild type and siaB mutant of two non-typeable strains were used to demonstrate that sialic acid influences resistance to the killing effect of normal human serum but has little effect on attachment to, or invasion of, cultured human epithelial cells or neutrophils. We determine for the first time the site of attachment of sialic acid in the LPS of a non-typeable strain and report that a small proportion of glycoforms include two sialic acid residues in a disaccharide unit.

Bacterial Adhesion↗
PubMed1999

[Comparison of biomechanical properties of the vaginal fixation in bladder neck suspensions according to the Burch technique and a percutaneous technique].

UNLABELLED: Bladder neck suspension or colpo-suspension can be performed via retropubic or percutaneous transvaginal approaches. A higher success rate is observed for retropubic procedures. One of the hypotheses proposed, but not yet verified, is that the retropubic approach allows better quality vaginal fixation than the percutaneous approach. OBJECTIVE: The objective of this study was to compare the biomechanical properties of vaginal fixation according to the Burch procedure and according to a percutaneous technique (Vesica; Boston Scientific). MATERIAL AND METHODS: We performed bladder neck suspension according to the Burch technique (2 points) on the left and according to the Vesica percutaneous technique on the right, on 6 fresh cadavers (mean age 8-5 years), using the same suture material. Vaginal fixations were subsequently excised. The depth of penetration into the vagina was measured and a computerized traction test (Lloyd Instruments, France) was performed on these fixations. The maximum force of traction before rupture was measured. RESULTS: No significant difference was demonstrated for any of the measurements. CONCLUSION: Vaginal fixation of bladder neck suspension performed according to the Burch technique or via a percutaneous technique (Vesica) present equivalent biomechanical properties.

Aged↗
PubMed1999

[Emphysematous pyelonephritis: apropos of a case and review of the literature].

Based on a case report and a review of the literature, the authors describe the features of emphysematous pyelonephritis. This rare disease with a poor prognosis constitutes a difficult clinical diagnosis. The positive diagnosis is based on urgent computed tomography. The reference treatment is emergency nephrectomy in an intensive care context.

Emergencies↗
PubMed1999

[Outpatient treatment of pelvic ureteral calculi with extracorporeal lithotripsy. Report of a series of 200 patients consecutively treated].

OBJECTIVE: To demonstrate the feasibility of first-line outpatient treatment of symptomatic stones of the pelvic ureter (sometimes immediately following an episode of renal colic), without anaesthesia, by extracorporeal shock-wave lithotripsy using a latest generation apparatus (EDAP LT02) with concomitant dual guidance. PATIENTS AND METHODS: The mean age of the patients was 45 years. The mean stone diameter was 7 mm (range: 3 to 25 mm). Lithotripsy was performed under dual ultrasound and fluoroscopic guidance. All patients were reviewed at 3 months with follow-up and x-rays. RESULTS: Fragmentation was considered to be complete in 79% of cases, partial in 10.5% of cases and absent in 10.5% of cases. Overall, 87% of stones were completely eliminated at 3 months. The only complication was fever of 38.5 degrees C requiring urinary tract drainage and subsequent ureteroscopy. Complementary treatment was necessary in 26 cases: ureteroscopy (n = 20), alkalinization (n = 1), Dornier ESWL (n = 5). CONCLUSION: ESWL by EDAP LT02 allows first-line outpatient treatment of stones of the pelvic ureter with a satisfactory success rate.

Adult↗