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Biomedical subjects

J M Collard

Publications and source records attributed to J M Collard.

At least 55 records · Page 3Linked to original sources
PubMed1990

Isolation and genetic analysis of Chlamydomonas reinhardtii strains resistant to cadmium.

In Chlamydomonas reinhardtii, cadmium induces reduction of growth, reduction of chlorophyll content, and lethality. The toxicity was higher in a cell wall-deficient strain than in the wild type. By growing the cells on agar medium containing cadmium at concentrations inducing high lethality, stable resistant clones were isolated. The resistance was due to a nuclear mutation (cadAR) which probably preexisted in the wild-type cell population, as suggested by the fluctuation test. A double mutant (cadAR cadBR) was selected on media containing higher concentrations of cadmium. The cadBR mutation, which is unlinked to cadAR, determines a resistance intermediate between the CadAR mutant and the wild-type strain. Both cadAR and cadBR mutations are partially dominant.

Cadmium↗
PubMed1989

[Computed tomography of the esophagus, the stomach and the duodenum. Review of methods and results].

Computed tomography (CT) of the esophagus, the stomach and the duodenum allows characterization of some lesions: lipomas, cysts and duplications, recent haematomas, vascular anomalies. CT is particularly used for the extramural staging of neoplasms: despite important limitations, CT may be useful as staging test to identify a subgroup of patients with definitive metastases or local invasion who therefore have unresectable tumors. CT is helpful for the staging of lymphomas. The importance of this staging classification is reflected in differences in treatment and prognosis. CT is also useful for the follow-up after treatment, the diagnosis of recurrence and postoperative complications.

Esophageal Neoplasms↗
PubMed1988

Severe bleeding from submucosal lipoma of the duodenum.

Two patients with a duodenal lipoma had severe gastrointestinal bleeding. Duodenal lipoma is relatively rare and an even rarer source of severe gastrointestinal bleeding. Endoscopy and routine radiological examination of the gastrointestinal tract may suggest the diagnosis, but computed tomography allows a definitive preoperative diagnosis. Surgery is indicated in order to avoid complications.

Duodenal Neoplasms↗
PubMedDate not supplied

Esophageal resection and by-pass: a 6 year experience with a low postoperative mortality.

From 1984 to 1989, 175 esophageal cancer patients, 10 patients admitted for severe caustic esophagitis, and 1 patient with pyothorax due to iatrogenic perforation of the esophagus underwent an esophageal resection or bypass operation. One hundred sixty-eight esophageal resections were performed on 167 patients; 13 were total, 106 subtotal and 49 distal. Nineteen digestive transplants were pulled up to the neck to bypass the esophagus or re-establish continuity after an esophagectomy made elsewhere. Digestive continuity was restored by a long gastric transplant in 120 patients, a colon segment in 17, a jejunal loop in 35, and a short gastric transplant after limited esophago-gastrectomy in 14 patients. Thirty day mortality was 0 in the whole group. Hospital mortality was 1.2% in the resection group and 10.5% in the bypass group (p = 0.048). Nonfatal postoperative complications consisted of respiratory distress in 33 patients, recurrent nerve palsy in 10, anastomotic fistula in 10 (cervical in 8 and intrathoracic in 2) and anastomotic stenosis in 18 patients. Respiratory complications were more frequent in patients with a cancer of the thoracic esophagus (29/111) than in those operated on for a cancer located in the esophago-gastric junction (4/50) (p less than 0.01). Anastomotic stenosis occurred more frequently in the neck (17/137) than in the chest (1/49) (p less than 0.05). Nine patients were reoperated on for a technical complication; intraabdominal hemorrhage (1), thoracic duct injury (2), acute cholecystitis (1), tight stricture of the esophageal anastomosis (2), jejuno-duodenal anastomotic fistula (2), or stridor related to recurrent nerve palsy (1).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Antimicrobial drug resistance in nontyphoid human Salmonella in Belgium: trends for the period 2000-2002.

In order to assess antimicrobial resistance in nontyphoid human Salmonella in Belgium, the six most important serovars, representing together more than 90% of laboratory confirmed cases, were randomly sampled. From June 2000 until December 2002, a total of 1756 isolates were screened for their antimicrobial resistance profile by the disc diffusion method. S. Hadar strains showed the highest level of antimicrobial resistance. Simultaneous resistance to ampicillin, nalidixic acid, tetracycline and streptomycin was observed in 81.5, 58 and 76.1% of these isolates in 2000, 2001 and 2002, respectively. All S. Hadar isolates resistant to nalidixic acid also displayed decreased susceptibility to ciprofloxacin (MIC50 values of 0.25 microg/mL in 2000-2001 and 0.19 microg/mL in 2002). In 2000, 2001 and 2002, respectively 44.6, 46 and 36.5% of S. Typhimurium isolates were multiresistant (resistant to 4 or more antimicrobial agents). These multiresistant isolates were preferably associated with a few phage types, such as DT104. Complete resistance to ciprofloxacin was detected in three S. Typhimurium isolates and sequencing of the gyrA gene revealed for each isolate two mutations at codons corresponding to Ser-83 and Asp-87. Multiresistance was also common in S. Virchow (7.7%, 15.9% and 29.7%, in 2000, 2001 and 2002, respectively). Resistance to nalidixic acid in S. Virchow isolates increased from 46.2% in 2000 to 80.9% in 2002 and six S. Virchow isolates were detected as cefotaxime resistant. In contrast, the vast majority of S. Enteritidis, S. Brandenburg and S. Derby isolates remained sensitive to almost all antimicrobial agents tested.

Anti-Bacterial Agents↗
PubMedDate not supplied

Combined 24-hour intraluminal pH and bile monitoring of the denervated whole stomach as an esophageal substitute.

BACKGROUND/AIMS: The study aims to evaluate the pH and the presence of bile in the denervated whole stomach pulled up to the neck after subtotal esophagectomy. METHODOLOGY: The pH and the presence of bile in the gastric cavity were monitored by combined 24-hour pH and bilimetry in 16 patients having their whole stomach as an esophageal substitute (i.e., 8 with and 8 without a gastric drainage procedure) and in 25 healthy control subjects. The percentage of time during which pH was < 2 as well as the percentage of time during which bile absorbance was > 0.25 for the total, upright, and supine periods of recording were considered for each subject studied. Seven patients underwent a gastroscopy with biopsies. RESULTS: Intragastric acidity was normal in 50% of patients while it was reduced in the other 50%. Ten of the 16 patients (62.5%), i.e., 4 with (50%) and 6 without (75%) a drainage procedure, had excessive exposure of the gastric mucosa to bile. No significant correlation was found between the existence of a high intraluminal pH profile and excessive bile exposure (p = 0.9163). Bile exposure was significantly higher in whole stomach patients than in controls in both the upright and supine positions, irrespective of the existence or absence of a drainage procedure (p ranging from 0.0272-0.0001). Bile exposure in the supine position tended to be longer in patients without than in those with a drainage procedure (p = 0.0929). Helicobacter pylori-negative chemical gastritis was present in 3 of the 7 patients who underwent a gastroscopy, all 3 having excessive bile exposure and no food retention in the transplant lumen. CONCLUSIONS: Gastric denervation and transposition up to the neck increased exposure of the gastric mucosa to bile, irrespective of the patient's position and of the presence of a gastric drainage procedure. The absence of gastric drainage procedure tends to ensure exposure to bile prolongeLow gastric acidity, if present, is due to a reduction in acid secretion rather than to a buffering effect from duodenal juice having refluxed. Gastritis is more likely to be related to excessive exposure of the gastric mucosa to bile than to food retention.

Adult↗
PubMedDate not supplied

Surgical and multimodal approaches to cancer of the oesophagus: state of the art.

This review article aims to discuss the modalities of oesophageal resection, to define the categories of patients who are most likely to benefit from oesophagectomy with extensive lymph node clearance, and to analyse the eventual contribution of nonsurgical neo-adjuvant or adjuvant therapies to improving long-term survival rates achieved by surgery alone. Both the review of the literature devoted to potentially curative treatment of oesophageal cancer and the authors' own experience indicate that resection of the oesophageal tube en bloc with the locoregional lymph nodes provides patients with the best chance of long-term survival and cure. This is true, even though some of the resected lymph nodes are metastatic. Most phase III comparative studies fail to shown any overall survival improvement following multimodal therapy in comparison with surgery alone, so that there is now no scientific reason for systematic addition of radio- and/or chemotherapy to extensive surgery in potentially resectable neoplastic processes. However, neo-adjuvant radio- and/or chemotherapy is indicated in suspected non-resectable T4 tumors for downstaging and subsequent oesophageal resection in good responders. The benefit in terms of long-term survival and cure that can be expected from adjuvant chemo- and/or radiotherapy after radical resection of a neoplastic process having already spread into a large number of loco-regional lymph node requires objective evaluation by prospective, randomized studies.

Combined Modality Therapy↗
PubMedDate not supplied

Salmonella enterica subspecies houtenae serotype 44:z4, z23:--as a rare cause of meningitis.

Reptiles can carry and shed the bacterium Salmonella without showing any signs of illness. Transmission occurs by ingesting Salmonella after handling a reptile or objects contaminated by a reptile. Young children are especially vulnerable to Salmonella infection and can experience serious complications. We describe a case of reptile-associated Salmonella meningitis in a 2.5-month-old infant.

Animals↗
PubMedDate not supplied

Feasibility and effectiveness of en bloc resection of the esophagus for esophageal cancer. Results of a prospective study.

En bloc resection of the esophagus was attempted by right thoracotomy, laparotomy, and left cervicotomy in 82 patients suffering from an esophageal cancer. Tumors were classified by the depth of wall penetration and node involvement: 21 tumors penetrated at the most into but not through the muscle (W1), and 61 invaded the full thickness of the wall (W2). Twenty-five were associated with normal lymph nodes (N0), 26 with metastatic thoracic nodes only (N1), and 31 with metastatic extrathoracic nodes (N2). Digestive continuity was restored by gastric pull-up in all cases except one in which the transverse colon was used. Thirty day and hospital mortality were 0 and 2.4% (2/82) respectively. Posterior mediastinectomy was feasible in 65 patients but in seven of them an unsuspected metastatic spread was detected during the second step of the operation. It was not feasible in 17 patients owing to the involvement of adjacent mediastinal organs. It was feasible in all W1 tumors and in 72% of W2. Feasibility did not significantly depend on the tumor location or length. Of the 24 palliative operations, 17 were carried out for N2 tumors. After potentially curative mediastinectomy (N = 58), three year survival was 38% and after palliative operation (N = 24), 18 months survival was 11% only. After mediastinectomy, survival dropped as the node involvement and the depth of wall penetration increased (W1: 66%, W2: 28%, N0: 58%, N1: 32% at three years and N2: 17% at 2 years). Overall survival in group N2 was not significantly different from that achieved in palliative cases and no patient classified W2 N2 was alive at 18 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMedDate not supplied

[Reoperation following failure of anti-reflux surgery].

Reoperation is the treatment of choice of failed antireflux procedures. Preoperative full-scale evaluation of both residual anatomy and function of the upper digestive tract is mandatory. Conservative surgery is almost always feasible. Success rate of reoperations is high with experienced teams.

Gastroesophageal Reflux↗
PubMedDate not supplied

[The treatment of perforated gastro-duodenal ulcer].

Seventy-four patients, admitted in emergency for acute perforation of a duodenal or gastric ulcer were reviewed retrospectively: 40 patients with one or several risk factor such as shock, old perforation, severe chronic illness or advanced age and 34 other patients without any risk factor. In this selected population, the surgical treatment, initially performed in 44 cases, consisted of suturing the perforation and draining the peritoneal cavity in all cases but four in which it was associated with a vagotomy (2 cases) or a distal gastrectomy (2 cases). Thirty younger patients admitted without shock, within 6 hours following the onset of the perforation were initially treated by digestive aspiration alone: this medical treatment was successful in 15 patients but required a subsequent laparotomy in the other cases. The overall postoperative mortality is 18% but is zero in the group of patients in whom a medical therapy was initially performed. Long-term follow-up shows that 70% of the patients with a perforated duodenal ulcer and without any anti-inflammatory drug past history at the time of the perforation are free from any symptom. A strategy for the management of perforated duodenal and gastric ulcers, applicable to a non-selected population, is proposed in reference to the surgical literature.

Adult↗