Search PubMed⌕ Search

Biomedical subjects

S Evrard

Publications and source records attributed to S Evrard.

At least 55 records · Page 3Linked to original sources
PubMed1993

Distribution of pheophorbide A in normal tissues and in an experimental pancreatic cancer in rats.

The in vivo administration and distribution of a potent new photosensitizer, pheophorbide A (PH-A), was investigated in rats. The spectral characteristics were determined. This hydrophobic compound was solubilized by an ethanol/phosphate-buffered saline (PBS) mixture (v/v) and sonicated immediately before i.v. administration. Tissue distribution and the affinity of PH-A for an acinar pancreatic tumor were determined in Lewis rats for up to 48 h after a single i.v. administration of 3 mg kg-1 body wt. Methanol-extracted PH-A was quantitatively determined by fluorescence spectrophotometry at 665.6 nm. The PH-A uptake pattern showed that the reticulo-endothelial system is the major target of PH-A, followed by the gut and then the lung and pancreas. PH-A concentrations in skin were very low. The presence of an enterohepatic cycle was suggested by the PH-A biliary output, intestinal uptake and blood concentrations. Tumor PH-A retention was longer than pancreatic retention. The ratio of tumoral to peri-tumoral pancreas PH-A was 6.7:1, 24 h after i.v. administration. With its similar tissue pattern, better absorption spectrum and lower skin toxicity, PH-A could be a more potent photosensitizer than hematoporphyrin derivatives.

Animals↗
PubMed1992

In vitro resistance of artificial connective tissues to human bile and pancreatic juice.

The resistance of connective tissue generated from elastin, placenta extracts and human collagen was tested by in vitro incubation with bile and pancreatic juice to investigate the potential use in human digestive surgery. The resistance, determined by macroscopical and microscopical examinations, has been directly compared to those of bovine collagen matrices (Spongel, Pangen, Helistat, Translagen). Only the compact and cross-linked human collagen patch resisted both bile and pancreatic juice. All other biomaterials tested dissolved either in bile or in pancreatic juice. The in vivo behaviour of this new human collagen matrix and its involvement in gastrointestinal wound healing must now be investigated.

Animals↗
PubMed1992

Watershed cerebral infarcts: retrospective study of 24 cases.

Twenty-four patients presenting an acute stroke with watershed cerebral infarct on CT scan or MRI were included in this retrospective study. Age was 63 +/- 14 years (mean +/- SD), and sex ratio was 2 men for 1 woman. Main clinical features were: in anterior location, lower limb weakness and frontal syndrome with transcortical motor aphasia in left lesions or spatial dyscalculia in right ones; in posterior location, brachiofacial weakness with constant quadranopsia and hypoesthesia, and Gerstmann syndrome in left lesion. There was no distinctive feature for subcortical and multiple infarcts. In bilateral infarcts, there were one pseudobulbar syndrome, and 2 pseudo brainstem syndromes with neuropsychological signs. Aetiologies were severe carotid artery disease in 14 cases, severe cardiopathy in 6, isolated cerebral angiitis in 1, essential thrombocythemia in 1, protein C deficiency with sickle cell disease in 1, and cholesterol emboli in 1 anatomical case. CBF performed in carotid artery occlusions or tight stenoses showed evidence of haemodynamic changes. Microembolic process can be proposed in the case with cholesterol emboli. Preventive treatment is discussed.

Cerebral Infarction↗
PubMed1992

[Cancer of the stomach: for a revised strategy].

The "revisionist" approach to therapy of gastric cancer needs a previous demonstration of the qualitative comparability of Japanese and western treatments of gastric adenocarcinoma. Early gastric cancer is far more common in Japanese than in Occidentals, but its character is the same, and for identical stages and treatments, the prognosis is the same. But many western studies show serious methodological deficiencies (staging, anatomopathological examination...), as well as a serious lack of interest in adjuvant therapy, a potential source of progress. We propose a 4-point therapeutic approach inspired by the Japanese example: a greater methodological rigor, standardization of lymphadenectomies, the definition of therapeutic subgroups to receive optimal treatments, the development of new adjuvant treatments.

Chemotherapy, Adjuvant↗
PubMed1992

[Validation of the measurement of hepatic volume by three-dimensional computed tomography].

The aim of this work was to verify experimentally the reliability of 3D CT scan in measuring hepatic volumes. Eight livers were dissected from corpses. The referring liver volume was determined by measure of its hydric shift. The correlation coefficient R was 0.93 (p < 0.001) on 5 mm/5 mm 3D sections, 0.92 (p < 0.001) on 10 mm/10 mm 3D sections and 0.94 (p < 0.0006) on 5 mm/10 mm 3D sections. The paired t-test also showed a 5% risk correlation between the two measurements. Although in vivo imaging is slightly different from in vitro, 3D CT scan seems to be a reliable method to determine an hepatic volume without increased X-ray irradiation.

Humans↗
PubMed1992

[Is cholecystectomy by celiovideoscopy dangerous in the initial period? Prospective study of 100 initial cases].

The aim of this study was to prospectively study the complication rate of our 100 initial laparoscopic cholecystectomies. The ultimate goal was to obtain a morbidity rate comparable to open cholecystectomy. No major complications were noticed. The conversion rate to open cholecystectomy was 8%, slightly higher in comparison with the literature. Absence of major complications could be explained by: a) indications limited to symptomatic non complicated cholelithiasis; b) assistance at the beginning of our experience of gynecologists used to laparoscopic techniques; c) conversion to open cholecystectomy in case of technical difficulties. Application of these principles allows the digestive surgeon to start laparoscopic cholecystectomy without submitting the patient to additional risks.

Adolescent↗
PubMed1991

[Incidental disclosure of an adrenal tumor. Diagnostic and therapeutic procedure].

Among upper abdominal computed tomography (CT) scans, 0.6 per 1000 fortuitously reveal an adrenal tumour, an "image pathology" now known as "adrenal incidentaloma". Should the clinician avoid useless, iatrogenic surgery or run the risk of failing to identify a malignant adrenocortical tumour? We outline a clinical procedure aimed at distinguishing between solid vs liquid, secreting vs non-secreting and primary vs metastatic tumour. Nevertheless, in the end the diagnosis may be uncertain, in which case tumour size becomes the deciding factor. For tumours of less than 3 cm close surveillance is advocated, whereas surgery is necessary for tumours larger than 3 cm; for tumours in between these sizes only the individual clinician can decide.

Adrenal Gland Neoplasms↗
PubMed1991

[Photodynamic therapy in oncological digestive tract surgery].

Photodynamic therapy is a useful new antitumoral treatment, since it is relatively selective and noniatrogenic. The photosensitizers become preferentially localized in the tumoral tissue, where their excitation by light causes the production of free cytotoxic radicals. If haematoporphyrin derivatives are the most widely used photosensitizers, numerous molecules are being tested. Now used as a palliative photodynamic therapy could logically be used as adjuvant treatment in curative surgical excision. The practical utility of peroperative photodynamic therapy in gastroenterological surgery is being evaluated experimentally and clinically.

Chlorophyll↗
PubMed1991

Malnutrition and body weight loss after biliopancreatic bypass in the rat.

In this study designed to investigate the nutritional state induced by biliopancreatic bypass in the rat, the pancreatico-biliary secretions were diverted via the duodenum and jejunum into the distal ileum, the remaining intestine being directly anastomosed to the stomach after antrectomy. Bypassed animals lost weight: it was only 56 percent of that of controls after 36 days and death by cachexia resulted within two months of the procedure. The reduced food intake (16 percent less than control) at the 36th postoperative day cannot by itself explain the weight loss, since pair-fed rat weights did not differ statistically from controls at 36 days. Protein-energy malabsorption occurred: drops in serum protein concentration (25 percent less than control), triglycerides (40 percent less) and total cholesterol (28 percent less) were recorded from the 12th postoperative day on. Biliopancreatic bypass may be an adequate procedure of treatment for morbid obesity simultaneously aggravated by metabolic disorders.

Analysis of Variance↗
PubMed1989

[Primary hyperparathyroidism. Apropos of 102 recent exploratory cervicotomies: diagnostic and clinical pitfalls].

The authors report on various diagnostic pitfalls on 102 patients having undergone exploratory cervicotomy for primary hyperparathyroidism. A false positive diagnostic error was made on 2% of the cases, bringing to 100 the number of patients with a confirmed diagnosis of primary hyperparathyroidism. False negative diagnosis was made on 4% of the patients: two late diagnoses leading to an acute toxic state and death postoperatively in both cases; two pure psychiatric variants leading to repetitive hospitalizations in psychiatry. Error in diagnosis because of a masking effect was made in 4% of the cases:--one association with a clear cell nephro--epithelioma--one association with a multiple myeloma--two associations with a benign monoclonal gammapathy. The absence of hypercalcemia, a diagnostic pitfall in the modern form of this disease was found in 7% of the cases. PTH hypersecretion which is virtually a constant finding in the normocalcemic form of the disease obviates in most cases the need of a bone biopsy and quantitative histomorphometric analysis. The association with another endocrinopathy was found in 12% of the cases (2 MEN I, 1 MEN II, 9 hyperthyroidism). Because of its high frequency in the aged (22% greater than 75 years) the diagnosis of this disease is difficult for its signs are mimicked as well by the aging process. The preoperative topographic diagnostic error is avoided since there doesn't seem to be any test which would preclude the normal surgical procedure of carefully exploring all 4 topographic sites of the parathyroid. Surgical errors can be numerous but minimized with the increasing experience of the operator. Histological errors are seen mainly in the normocalcemic variety where only electron microscopy can detect the typical signs of cellular hyperactivity.

Aged↗
PubMed1989

Pancreatic lithiasis: a rare cause of gastrointestinal hemorrhage.

The rare instance of a gastrointestinal hemorrhage caused by a lithiasis of the duct of Wirsung is described. The world literature records only 13 other cases. Pancreatic calculi cause hemorrhage by either migrating through the pancreatic parenchyma to perforate the duodenum, ulcerating the vessels of the periductal parenchyma, or rupturing the pancreas. The usual sign of this complication of chronic calcifying pancreatitis, difficult to diagnose, is repeated gastrointestinal hemorrhages and sometimes pain, as in epigastric colitis. The immediate therapy is control of the hemorrhage. With transcatheter occlusive techniques, radical surgery can be postponed until it is more tolerable.

Adult↗
PubMed1986

[Mechanical sutures in digestive surgery. A critical study].

An objective review of the experimental and clinical literature comparing stapled- and hand-sutured anastomoses in gastrointestinal surgery is presented. Experimental studies support the hypothesis that stapled-sutured lines heal by primary intention, thus avoiding the inflammatory time lag, and resulting in a stronger wound during the first post-operative week. In contrast, manual sutures always produce an early inflammatory reaction with a transitory rise in collagenase activity in the submucosa, which explains the particular fragility of the anastomosis during that phase. Nevertheless, it was difficult to find a concordance between this histological quality of the stapled suture line and clinical results. In oesophageal surgery, a slightly higher rate of stenosis and a lower rate of anastomotic leakage were observed. In gastric and colorectal surgery, the superiority of the stapled suture was not proved. However, in colorectal randomized studies, the presence of "withdrawn" group for which the stapler was the only technically possible alternative, provides undeniable proof that this technique is an indispensable adjunct in modern digestive surgery. Conversely, its value seems negligible in surgery of the small bowel or of the intraperitoneal colon where manual suturing remains the technique of choice.

Acute-Phase Reaction↗
PubMedDate not supplied

Occupational risk to surgeons of unrecognized HIV infection in a low-prevalence area.

Data are available on the occupational risk to surgeons of the human immunodeficiency virus (HIV) for areas of high HIV prevalence but not for low-risk areas and particularly for unrecognized HIV infection. The 40-year cumulative occupational risk to surgeons caring for patients with unknown HIV serologies in a low-prevalence area was estimated. From May 1989 to May 1991, 4119 consecutive patients with unknown HIV status, hospitalized in our department, were proposed for testing; 100% complied. Acquired immunodeficiency syndrome (AIDS) patients and known seropositive patients operated on during this period were excluded from the study. The prevalence of unknown HIV infection was 0.07%. Taking into account the rate of parenteral injuries, the rate of contamination after an infected parenteral injury, and the total number of operations performed during a 40-year career, we estimated the cumulative risk of unknown HIV infection in our area to be 1%. This risk must be added to those of caring for known infected patients. In high-risk areas (cumulative risk 10%), a high standard of infection control is required for every surgical procedure, even if it is expensive or of doubtful efficacy. It is unrealistic to apply this standard in a low-risk area. HIV testing with informed consent of the patient is an imperfect guard against infection but has the advantage of alerting the surgeon to the risk of contamination on a case-by-case basis; it also offers the seropositive patient the best possibility for a longer life expectancy.

France↗
PubMedDate not supplied

Idiopathic eosinophilic oesophagitis: atypical presentation of a rare disease.

A 72 year-old man presented severe dysphagia and weight loss of recent onset. Repeated oesophageal endoscopy and biopsies with macroforceps were normal. Oesophageal manometry disclosed features compatible with achalasia. Oesophageal EUS endoscopy localized an infiltrating process between muscular layers of the oesophageal wall and CT scan delimited a circular thickening in the inferior part of the oesophagus. Because of severe clinical presentation mimicking a possible oesophageal neoplasm like a lymphoma, partial oesophagectomy was performed and revealed eosinophilic oesophagitis. This unusual presentation emphasizes that idiopathic eosinophilic oesophagitis must be proposed in the differential diagnosis of dysphagia, even in old patient without apparent oesophageal lesion at endoscopy.

Aged↗