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Biomedical subjects

A Cornet

Publications and source records attributed to A Cornet.

At least 19 recordsLinked to original sources

Fatigue - corrosion of endoprosthesis titanium alloys.

Commercial total hip prostheses often show certain metallurgical faults (porosities, coarse grains, growth dendrites, carbide networks). In order to investigate more accurately the role played by these different parameters in prostheses failure we performed a large number of systematic corrosion, fatigue and fatigue - corrosion tests on these materials and on commercial total hip prostheses. Ultimate strengthes seem to be reached for cast cobalt alloys, whereas titanium alloys, such as Ta 6 V, present very high fatigue limit under corrosion. Thus, rotative bending fatigue - corrosion tests in biological environment provide values about 50 DaN/mm2. This value, is nevertheless appreciably higher than those obtained with stellites and stainless steel. Titanium alloys, because of their mechanical performances, their weak Young's modulus (11000 DaN/mm2) and their relative lightness (4.5. g/cm3), which are associated with a good biocompatibility, seem very promising for permanent implants realisation.

Alloys

Double antibody specificity of lymphoid cells isolated from normal human intestinal mucosa.

Lymphoid cells were isolated from normal human mucosal specimens. A certain fraction of these cells exhibited double antibody specificities at the levels of both light kappa and lambda chains and heavy mu and gamma chains. The variable frequency with which these cells were detected appears to be a characteristic of this population. They represent a very low proportion of the total number of cells isolated.

Antibody Specificity

[Chronic gastritis and intestinal metaplasia (author's transl)].

The diagnosis of chronic gastritis can be made from the macroscopic lesions seen on endoscopy, and the severity of the changes noted in the mucosa after biopsy under direct vision. Gastric intubation can also be used to confirm the pathological results. If the atrophied mucosa shows highly differentiated diffuse intestinal metaplasia, the examinations should be repeated at regular intervals, as they could herald the onset of malignant changes. The authors discovered 312 cases of intestinal metaplasia in 4 920 patients who had been gastroscoped in the Digestive Endoscopy Center of François-Moutier. A total of 157 of them, were noted to have very highly differentiated diffuse lesions, and 54 of these cases had at least yearly repeat gastroscopies. A diagnosis of intrinsic cancer was made in four patients, and this was confirmed by taking serial sections of the specimens removed.

Chronic Disease

[Regressive dysautonomia associating orthostatic hypotension with an invariable pulse and choleriform diarrhea (author's transl)].

The authors describe a case of very severe orthostatic hypotension with an invariable pulse arising during the course of considerable motor diarrhea. The diagnosis of primary dysautonomia was made only after eliminating the many organic causes of diarrhea: microbial, toxic, tumoral endocrine including diabetes. Shy and Drager's syndrome was rejected because of the spontaneously regressive course after a period of 4 years, the patient having had no further signs of orthostatic hypotension.

Cholera

Red cell oxygen affinity in fetal sheep: role of 2,3-DPG and adult hemoglobin.

Studies were carried out during fetal life in sheep to determine the relationship of 2,3-diphosphoglycerate (DPG), the intracellular red cell and extracellular pH, and the switchover to adult hemoglobin synthesis in regulating the position of the fetal red cell oxygen-affinity curve in utero. Adult hemoglobin first appeared near 120 days of gestation. The mean oxygen tension at which hemoglobin is half saturated (P50) prior to 120 days of gestation remained constant at 13.9 +/- 0.3 (SD) Torr and then increased gradually as gestation continued, reaching 19 Torr at term. During the interval of fetal life studied, the level of DPG was 4.43 +/- 1.63 (SD) micromol/g Hb and the deltapH between plasma and red blood cells was 0.227 +/- 0.038 (SD); neither was affected by gestational age. The decrease in the red cell oxygen affinity after 120 days of gestation ocrrelated with the amount of adult hemoglobin present in the fetus (r = 0.78; P less than 0.001). This decrease can be attributed only to the amount of the adult-type hemoglobin present, and not to DPG, or to changes in the deltapH between plasma and red blood cells, because both remained stable during the last trimester.

Animals

Human lymphoid cells of the intestinal mucosa showing specificity for both immunoglobulin light and heavy chains.

The presence of single human lymphoid cells expressing on the one hand both kappa and lambda light chain and on the other hand either both mu and alpha or both mu and gamma heavy chains, was observed in the intestinal mucosa. The variability of the frequency of such cells, both from one subject to another, or in the same sample, is a characteristic of this population.

Humans

[Digestive lesions after abdominopelvic irradiation, in the treatment of cancers of the genital tract].

The authors report 15 cases collected over a few years on a gastroenterology unit, and emphasize the digestive complications occurring after pelvic or abdomino-pelvic irradiation for genital carcinoma. The rectum and pelvic colon are generally affected. The delays of onset after radiotherapy may reach or exceed several months. The vascular lesions, caused by ionising radiation, explain the tissue ischemia and, consequently the failure of local medical treatment. When severe hemorrhage or visceral perforation occur, surgery is necessary. However, sutures often break down on these insufficiently vascularised tissues and re-operation is always associated with a poor prognosis.

Aged

[Non-parasitic cysts of the spleen. 2 cases].

Although splenic cysts are benign, a gradual increase in volume of the liquid mass often leads to diagnosis owing to the large volume. The two cases reported are an example of this. A cure was obtained by splenectomy. It is usually easy to carry out and the prognosis is benign.

Adult

[Practical value of gastric intubation during peptic ulcer. Analysis of 410 cases, after Histalog stimulation].

This study was carried out in 410 subjects, collecting gastric fluid for one hour, after 15 minutes emptying and one hour, after 15 minutes emptying and one hour's study of basal secretion using, as stimulant, Histalog at a maximal dose of 2 mg/kg without exceeding 130 mg. The object of this statistical analysis was to determine the average figures and the standard deviations of the volumes of secretions, together with those of the output of hydrogen ions in 5 groups of subjects: controls (60), gastric ulcers (38), duodenal ulcers (200), patients suspected of duodenal ulcer (60) or affected by dyspeptic syndrome without radiological nor endoscopic lesions (52). In the normal subject, the hydrochloric acid output was situated between 5 and 27 mEq. The diagnosis of duodenal ulcer was very unlikely when secretion was less than 9 mEq in man and almost certain above 30 mEq.

Adult

[New data on the disease induced by laxatives].

The authors report 5 personal case and recall the physiopathological mechanisms of metabolic disorders observed during the abuse of laxatives. They emphasize the fact that electrolyte losses were not only fecal, but also aggravated by frequent use of diuretics or dietary restriction. One may oppose the constant, very marked fall in body potassium to the variation in sodium content of the organism. Oedema formed part of the clinical picture. The withdrawal of drastic laxatives and diuretics, led to rapid recovery of all the symptoms.

Adult

[Caustic burn and adenocarcinoma of the esophagus].

Adenocarcinoma of the esophagus is found almost exclusively at the level of the cardia. It is exceptional to find it in the middle part of the esophagus in the absence of involvement of the cardia. In the long term, caustic burns of the esophagus may favour malignant degeneration. The latter is always squamous cell carcinoma. In our patient, a 28 year old man, a cylindrical carcinoma of the thoracic esophagus was detected four years after the ingestion of concentrated sodium hypochlorite. The caustic burn followed by carcinoma were of special significance in this case owing to the development of an adenocarcinoma.

Adult

The adaptation of the fetal red cells of newborn lambs to extrauterine life: the role of 2,3-diphosphoglycerate and and adult hemoglobin.

The purpose of this study was to determine the interrelationship of the rise and fall of 2,3-diphosphoglycerate (DPG) with the increase in adult hemoglobin and the decrease in red cell oxygen hemoglobin affinity after birth in normal lambs. It was found that the mean maximum DPG level was 26.71 +/- 4.98 mol/g Hb at 7.5 +/- 1.1 days. At the same time the mean P50 and adult hemoglobin level was 27.0 +/- 1.4 mm Hg and 31.1 +/- 11.i%, respectively. In the individual lambs, the level of their maximum DPG correlated inversely with the amount of adult hemoglobin (r-0.77, P less than 0.05). Once the DPG began to decrease, there was an inverse correlation between the DPG and the adult hemoglobin present in the red cell (r = 0.68, P less than 0.001). It appeared that the rise in DPG postanatally is only a compensatory mechanism until an adequate amount of adult hemoglobin is present. This fact was borne out by the second part of the study in which exchange transfusions with adult red cells were performed on five newborn lambs during the first 24 hr after birth and aborted the rise in DPG.

Adaptation, Physiological