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Biomedical subjects

A Dumont

Publications and source records attributed to A Dumont.

At least 55 records · Page 3Linked to original sources
PubMed1991

Irreversible renal failure associated with triamterene.

A 66-year-old man was admitted with acute oliguric renal failure. The patient was known to have chronic heart failure (ejection fraction 13%) and his medication included furosemide, digoxin and triamterene. Physical examination was unremarkable, and blood pressure was 170/80 mm Hg. Serum creatinine was 1,173 mumol/l. Renal ultrasound, CT scan and angiogram were normal. Despite correction of potential reversible factors and discontinuation of triamterene, renal function did not improve. Renal biopsy showed tubular obstruction with deposition of birefringent crystals and interstitial lymphocytic infiltration; the crystals emitted a blue autofluorescence at 425 nm, typical of triamterene. Renal tissue contained large amounts of triamterene (6.44 mg/g kidney at the initial biopsy and 400 micrograms/g kidney 5 months later). Triamterene has been previously reported to cause acute reversible renal failure, but to our knowledge, this is the first case of irreversible renal failure due to intratubular obstruction by triamterene crystal deposition.

Acute Kidney Injury↗
PubMed1991

[Leiomyosarcoma of the superior vena cava. Case report].

Leiomyosarcoma of the blood vessels is a rare malignant tumor, and its localization in the superior vena cava is exceptional. We had the opportunity to study such a case and we compared our clinical, histological and ultrastructural results with those of 5 other reported cases.

Aged↗
PubMed1990

Ultracytochemical study of lytic complex insertion in the glycocalyx of red cells during immune hemolysis mediated by complement.

Ruthenium red (RR), a cationic dye and an ultrastructural tracer of cell membrane permeability, was used on sheep red blood cells after lysis produced by a specific antibody and guinea pig complement. In addition to the opacification of the glycocalyx, RR stained structures related to lytic complexes, which appeared as rod-like structures with variable dimensions (generally 45 nm in width, 75 nm in height) inserted in the glycocalyx of red cells. They extended across the external layer of the trilaminar plasma membrane without reaching the internal layer or the cytoplasm. RR staining visualized the internal configuration of the lytic complexes and revealed small channels measuring 10 nm in diameter localized within the complexes. These lytic complexes are thought to correspond to membrane attack complex of complement. To the best of our knowledge, this is the first report of ultrastructural positive staining of lytic complexes in thin sections, allowing visualization of their internal configuration and their insertion in the plasma membrane glycocalyx.

Animals↗
PubMed1990

Evoked otoacoustic emissions in newborn hearing screening.

Evoked otoacoustic emissions (EOEs) were recorded in a group of normally hearing neonates (n = 100 ears) to study the basic properties of EOEs and the parameters influencing them. The results obtained with EOE recordings were compared with those of behavioral screening investigations. The main properties of EOEs in neonates are: 1. EOEs can be recorded in 98% of the tested ears or neonates; 2. there were no statistically significant variations in EOE detection thresholds of neonates between the ages of 1 and 4 days; 3. no statistical difference in the EOE threshold was found between males and females; 4. all EOEs exhibited a broadband spectrum with high-component frequencies; 5. EOEs demonstrating narrowband frequency peaks super-imposed on the broadband component had detection thresholds lower than EOEs without narrowband frequency peaks. EOEs can be used as a screening test. The main clinical interest of this test is to detect the presence (i.e., normal auditory peripheral function) or the absence (i.e., pathological peripheral auditory function) of EOEs in response to a 30-dBHL click stimulation. The results of this study have important applications concerning the possible clinical use of EOEs for screening peripheral auditory dysfunction in neonates.

Audiometry, Evoked Response↗
PubMed1988

Dialysis-related beta 2 microglobulin-amyloid arthropathy. Improvement of clinical symptoms after a switch of dialysis membranes.

Amyloidosis containing beta 2 microglobulin (beta 2m) and joint pains are frequent complications of long-term hemodialysis. In a prospective study the authors planned to act on dialysis arthropathies (DA) by improving beta 2m depuration: for 8 patients suffering from DA we replaced usual cuprophane membranes (CU) by high permeability polyacrylonitrile membranes (PAN). DA was diagnosed on the presence of severe disabling arthralgias in the absence of any other obvious etiology, and on the presence of at least 3 among 6 criteria. The efficacy of the switch of DM was assessed on 6 criteria including the patient's own evaluation at the end of the study and a joint pain severity index. Clinical evaluation and beta 2m measurement were carried out at the start of the trial and after a mean duration of dialysis on PAN of 6 months. An improvement in joint symptomatology and a decrease of joint severity index were noted in the 8 cases. Our results suggest that the change of DM has a favorable influence on DA. This improvement could result either from a better beta 2m depuration or from a better biocompatibility of PAN than the CU previously used.

Amyloidosis↗
PubMed1988

Enumeration of free-living aerobic n(2)-fixing h(2)-oxidizing bacteria by using a heterotrophic semisolid medium and most-probable-number technique.

A heterotrophic semisolid medium was used with two sensitive assay methods, C(2)H(2) reduction and O(2)-dependent tritium uptake, to determine nitrogenase and hydrogenase activities, respectively. Organisms known to be positive for both activities showed hydrogenase activity in both the presence and absence of 1% C(2)H(2), and thus, it was possible to test a single culture for both activities. Hydrogen uptake activity was detected for the first time in N(2)-fixing strains of Pseudomonas stutzeri. The method was then applied to the most-probable-number method of counting N(2)-fixing and H(2)-oxidizing bacteria in some natural systems. The numbers of H(2)-oxidizing diazotrophs were considerably higher in soil surrounding nodules of white beans than they were in the other systems tested. This observation is consistent with reports that the rhizosphere may be an important ecological niche for H(2) transformation.

Journal Article↗
PubMed1988

[Osteoarthropathy of hemodialysis: development at 2 years after passage on high permeability membrane].

In a group of 80 patients dialyzed at the same dialysis center, dialysis arthropathy was diagnosed in ten of them. Before commencing the study all ten patients were undergoing hemodialysis with cuprophan membrane (CU). We then replaced CU with high permeability membrane (polyacrylonitrile AN 69 Hospal or polysulfone) in eight of these ten patients. Clinical and radiological evaluation as well as bêta 2 microglobulin measurement were performed at the onset of the study and at one year and two years intervals after replacing the dialysis membrane. An improvement of joint symptomatology was noted in all patients. However, the radiological abnormalities appeared unchanged or aggravated and the mean serum concentration of bêta 2 microglobulin was lower at the end of the study but not significantly.

Adult↗
PubMed1988

Scintigraphic study of duodenal-gastric reflux in cases of primary gastropathy, chronic ulcer of the duodenal bulb, and Moynihan's disease.

There are several methods for detection of bile in the stomach, but none has proven satisfactory. It appears that the scintigraphic study with quantitation of duodenal-gastric reflux after corrections for the overlap of the stomach by the liver and bowel is more reliable, noninvasive, and physiologic. Fifty-four patients were divided into groups according to their clinical presentation; seven asymptomatic volunteers, 20 patients with duodenal-gastric reflux gastropathy (DRG), 16 patients with recurrent ulcers of the duodenal bulb (RUD), and 11 patients with Moynihan's disease. Each of the 47 dyspeptic patients underwent an endoscopic examination and a scintigraphic study with [99mTc]disofenin for detection and quantitation of duodenal-gastric reflux. Endoscopy revealed the presence of bile in the stomach of 16 out of 20 DRG and four out of 16 RUD, while ten out of 11 patients with Moynihan's disease had clear gastric juice. Most of the DRG cases (15 out of 20) and half of the RUD (eight out of 16) presented reflux greater than 1.5%, while of the 11 Moynhihan, ten presented reflux less than 1.5% and all the asymptomatic volunteer subjects less than 1%. This quantitation method allowed us to perceive clearly the low % of reflux in the "normal asymptomatic" subjects compared with the DRG-type of dyspeptic patients. Among the dyspeptic, the distinction seems more evident between the DRG type and the Moynihan type. Occasionally, the scintigraphic method permits identification of patients with slower gallbladder evacuation (eight out of 47 dyspeptic in our study), adding valuable information for the diagnostic approach to dyspeptic patients.

Adult↗
PubMed1986

The V-shaped artifact of the gallbladder wall.

Among 20,000 patients who had undergone abdominal or gallbladder sonographic examinations, 36 had a short V-shaped artifact originating from an hyperechoic focus in the gallbladder wall. Associated symptoms were varied and nonspecific. The 10 gallbladders excised because of associated cholelithiasis showed a thickened wall, and seven patients had diverticulosis of the wall with impacted stones. In vitro sonographic examination of five gallbladders reproduced the "V" artifact and showed that it originated from a small intramural cholesterol stone. The V artifact should be distinguished from the larger comet-tail and ring-down artifacts, which arise from metal or gas.

Adult↗
PubMed1986

[Erosive disk diseases of chronic hemodialysis patients. 3 cases of cervical localization].

The authors report three new cases of erosive disk disease in chronically hemodialysed patients. The cases included one man and two women, who were diagnosed, on the basis of cervical or shoulder pain, as having spinal injuries involving pinched disks, punched-out lesions and incipient condensation. Discal puncture was carried out in only one patient, and proved futile. All three patients were followed-up for periods of at least one year. These three cases raise the problem of erosive disk disease in long-term dialysis patients; several other cases have been reported recently. The etiology remains obscure, but the part played by amylosis, by apatite microcrystals and by the duration of dialysis treatment are all discussed. It would appear that a novel disease entity is indeed involved, one for which, although several etiologic factors can be suggested, it has not been possible to definitely identify any single cause as the exclusive origin of the lesions detected.

Adult↗
PubMed1986

[Current aspects of the osteoarticular pathology of hemodialysis patients. Results and discussion of a rheumatological survey].

In a prospective study, 80 patients undergoing long-term hemodialysis, 30% more than ten years, were evaluated for joint function and radiographic abnormalities; 58 patients (72%) had clinical symptoms; non-specific arthralgia was the most frequent; 15 patients had inflammatory pain (shoulders 9, hands 3) and diminution of finger mobility (10). Radiological examinations showed 40 abnormal findings in 23 patients (28%): erosive arthropathies of fingers (4), and multiple geodes of the carpus (8), of the humeral head (7) or of the hip (9). We also detected spondylolisthesis (4), erosive arthropathy of cervical (6) or lumbar (2) spine. Pathological study of synovial biopsies was performed in 16 cases. Amyloidosis was found in 4 samples taken routinely. In 2 other cases the biopsy was done on the basis of lesions seen on x-rays: we found amyloidosis in the synovial membrane in both patients and in the bone in one. In 8 patients we found C3 deposits positive in immunofluorescence. These results underline the role of amyloidosis in the mechanism of some arthropathies in long-term hemodialysis patients.

Adult↗
PubMed1985

Comparative hepatic response to bromobenzene and allyl alcohol in the vitamin D-replete and vitamin D-depleted rat.

Vitamin D-depleted and vitamin D-replete rats were treated with allyl alcohol (AA) or bromobenzene (BB). The severity of the hepatotoxicity was evaluated by the serum concentrations of aspartate aminotransferase, alanine aminotransferase and sorbitol dehydrogenase, the histomorphological appearance of the lesions, and the amount of cytochrome P-450 destroyed. The activity of the monooxygenases was also evaluated. All parameters indicated that vitamin D depletion alone did not lead to any signs of liver toxicity nor did it modify the pattern of toxicity of either AA or BB. However, the intensity of the response in the periportal (AA treatment) and in the centrilobular (BB treatment) zones was modified by the depletion. Vitamin D depletion was accompanied by increased hepatic damage due to AA while BB resulted in less hepatic damage in vitamin D-depleted compared to vitamin D-replete animals. The metabolic profile of the liver mixed function oxidases indicated that its intraacinar distribution was modified by the depletion. Although the overall activity toward the substrates studied was not changed by vitamin D depletion, two out of the three enzyme activities studied suggested that vitamin D-depleted rats were poorer "centrilobular metabolizers" and better "periportal metabolizers" than vitamin D-replete rats. These observations correspond to increased periportal and decreased centrilobular toxicity in vitamin D-depleted animals. These results suggest that vitamin D depletion associated with severe hypocalcemia may be associated with an intraacinar modulation of enzyme systems as well as with an intraacinar difference in the susceptibility of the liver to certain chemicals.

1-Propanol↗
PubMed1984

Quantitative analysis of diethyl-IDA reflux. Comparison of controls and dyspeptic, gastric ulcerated, and gastrectomized patients.

The administration of a radioactive tracer through the liver cell and the elimination of bile following an induced vesicular contraction permits duodenogastric reflux to be objectively diagnosed without intubation. This quantitative study of the reflux using 99mTC diethyl-IDA is based on 214 patients and demonstrates: 1) a frequent association with the gastric ulcer, 2) a considerable frequency in gastric resection surgery with duodenogastric anastomosis, 3) a constant occurrence in gastric resection surgery using jejunogastric anastomosis. These findings point to the involvement of biliopancreatic reflux in the genesis of gastric ulcer as well as gastritis and carcinoma of the gastric stump.

Duodenogastric Reflux↗