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Biomedical subjects

G Legros

Publications and source records attributed to G Legros.

At least 19 recordsLinked to original sources

Expression of receptors for atrial natriuretic peptide on the murine bone marrow-derived stromal cells.

Atrial natriuretic peptide (ANP) receptors were identified on both murine bone marrow-derived stromal cell lines A-3 and ALC and primary cultured cells using [125I]ANP binding assays and Northern blot analyses. The binding of [125I] ANP to the stromal cells was rapid, saturable, and of high affinity. The dissociation constants between ANP and its receptors on these cells showed no difference among cell types, while maximal binding capacity values were different among cell types. Competitive inhibition of [125I]ANP binding with C-atrial natriuretic factor, specific for ANP clearance receptor (ANPR-C), revealed that most of [125I]ANP-binding sites corresponded to ANPR-C. Northern blotting data corroborated that bone marrow-derived stromal cells expressed ANPR-C. However, in ALC cells, ANP biological receptors (either ANPR-A or ANPR-B), the mol wt of which is approximately 130K, were detected, and cGMP was accumulated after stimulation with ANP. On the other hand, in another stromal cell clone, A-3 cells, the expression of biological receptor was not detected in the affinity cross-linking and competitive inhibition experiments using [125I]ANP. However, A-3 cells accumulated cGMP by responding to ANPR-B-specific ligand, C-type natriuretic peptide. These results suggest that ALC cells equally express ANPR-A and ANPR-B, while A-3 cells express ANPR-B dominantly. Although the physiological roles of these receptors in the bone marrow is still not resolved, ANP is expected to play a role in the regulation of stromal cell functions in bone marrow.

Animals

Cytology: a simple, rapid, sensitive method in the diagnosis of Helicobacter pylori.

Cytology and the rapid urease test on gastric biopsies may diagnose Helicobacter pylori (H. pylori) infection within an hour. We evaluated the sensitivity and reproducibility of touch cytology (imprints from biopsies). In 19 patients with duodenal ulcer, biopsies were obtained from the antrum, fundus, and bulb. H. pylori was diagnosed in 42 sites on smears: 28 by culture and 23 by histology. H. pylori was present in the antrum and fundus in 16 and in the bulb in 11. Assessment of paired antral biopsies in 29 additional patients with or without touch cytology (imprints) before specimens were sent for histology or culture revealed no difference for the presence of H. pylori. A second reading of the 58 smears by a second observer revealed agreement on the presence or absence of H. pylori in 53 (91%). In conclusion, touch cytology is a simple rapid, sensitive, and reproducible diagnostic method for H. pylori that does not alter the quality of biopsies for subsequent culture or histologic examination. For the first time, diagnostic methods have been compared on the same biopsies, eliminating sampling variation.

Biopsy

Touch cytology, a useful diagnostic method for diagnosis of upper gastrointestinal tract infections.

Candida albicans, Campylobacter pylori, and Giardia lamblia are microorganisms that are frequently found in the upper gastrointestinal tract. A cytological smear of biopsies obtained at endoscopy was compared with the pathologic examination of biopsies. Candida albicans was found in 55 patients, Campylobacter pylori in 54, Giardia lamblia in 31; cytology was positive in 43, 46, and 22 cases, respectively, and biopsy in 29, 43, and 22 cases. Cytology was thus the only positive test in 26 cases with Candida albicans (47% of the 55 cases), in 11 cases of Campylobacter pylori (20%), and in nine cases of Giardia lamblia (29%). We believe that the cytological smear of biopsies (touch cytology) is a quick and sensitive method for diagnosing infections of the upper gastrointestinal tract, increasing the diagnostic yield obtained by biopsy alone.

Campylobacter Infections

[Evaluation of per-endoscopic cytology in the identification of Campylobacter pylori on gastric mucosa].

The presence of Campylobacter pylori on gastric mucosa was evaluated by touch cytology of gastric biopsies in a series of 100 patients. Results were compared to biopsy cultures. Of 43 culture-positive patients, cytology was positive in 37 (86 p. 100). Cytology was positive in 16 of 57 culture-negative patients, who had peptic ulcer and/or gastritis on biopsy, conditions widely associated with the presence of Campylobacter pylori. Cytologic examination, yielding quick results, is thus a sensitive diagnostic method for Campylobacter pylori. In addition, retrospective studies of previous specimens are possible: among 11 patients with a follow up of more than one year, three of the four Campylobacter pylori carriers subsequently developed an ulcer.

Bacteriological Techniques

Blunt diaphragmatic rupture.

Diaphragmatic injury is often a missed diagnosis in patients with multiple trauma. For this reason, mortality can be high. From 1970 to 1981, 32 patients with diaphragmatic injuries were seen at Maisonneuve-Rosemont Hospital. Twenty-four of the patients (22 men and 2 women aged 18 to 79 years) had blunt abdominal or thoracic trauma causing diaphragmatic disruption. Rupture occurred 20 times on the left side of the diaphragm, and 3 times on the right side. There was one pericardiophrenic rupture. Motor vehicle accident was the most common cause of trauma. On arrival, 21 patients had acute diaphragmatic rupture. Clinical signs and radiography permitted early diagnosis in 15 patients, whereas diagnosis was made later in 3 other patients because of deterioration of vital signs. In two patients, diagnosis was made at laparotomy for another reason. Four patients were operated on for post-traumatic chronic diaphragmatic hernia. The abdominal approach was used in 18 patients, the thoracic approach in 4, and the thoracoabdominal approach in 2. Three patients died, two of whom had a late diagnosis. Fourteen patients had no complications. Diaphragmatic trauma can be easily managed surgically when diagnosis is made early after trauma. It must always be looked for in patients with multiple trauma.

Accidents, Traffic

Retained and recurrent bile duct stones. Surgical or nonsurgical removal?

An experience with 69 patients who underwent 72 common bile duct reoperations for retained or recurrent choledocholithiasis is presented. The mean age of the patients was 57 years, and 35 patients had associated conditions. In this series six patients (8.3%) had minor complications and no patient developed major complications or died. Two (2.9%) patients developed recurrent choledocholithiasis. In recent years, nonoperative removal of retained stones through a T-tube by mechanical extraction or chemical dissolution, and removal of retained or recurrent stones by endoscopic sphincterotomy has gained widespread popularity. Retained or recurrent choledocholithiasis should be managed on an individual basis. Reoperation has a good success rate, low morbidity and mortality rates. It should be considered as the treatment of choice in low risk patients, in whom a retained stone cannot be mechanically extracted through a T-tube, and in patients with recurrent choledocholithiasis diagnosed after removal of the T-tube.

Adult

Sacrococcygeal tumour in infancy.

A newborn infant delivered after 33 1/2 weeks' gestation was operated on for sacrococcygeal teratoma. This tumour contained an unusual intra-abdominal cystic component that caused pulmonary problems. Amniography and echography were useful for diagnosing this lesion in utero.

Adult

Pancreatic trauma: a new diagnostic approach.

The difficulties encountered in the diagnosis of solitary pancreatic injury when there is no other indication for surgical exploration of the abdomen are discussed. We suggest that endoscopic transduodenal pancreatography is a reliable diagnostic tool of great help in evaluating such injuries with little morbidity.

Abdominal Injuries