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Biomedical subjects

F Dubois

Publications and source records attributed to F Dubois.

At least 163 records · Page 9Linked to original sources
PubMed1990

Effect of short-term fasting on [123I] iodohexadecenoic acid metabolism in the isolated perfused rat heart. Validation of mathematical model by comparison with experimental measurements.

In order to study metabolic modifications induced by short term fasting and their consequences on the uptake and intracellular fate of fatty acids iodine labelled in omega position, rats undergo a 36h fasting. Hearts are perfused in a Langendorff system with a glucose (11 mM) perfusion medium; [123I] hexadecenoic acid (IHA) is injected as a bolus. A comparison between time-activity curves p.i. demonstrates a much faster activity decrease for the hearts fasted animals. The intracellular analysis shows that short fasting did not significantly increase the myocardial uptake of fatty acids, but decreased the storage and increased the degradation of the fatty acids taken up. Mathematical analysis of the myocardial time-activity curves obtained by external detection provided results comparable to those of intracellular analysis. The coefficients of correlation between the values of the aqueous phases, organic phases and free fatty acids measured by intracellular analysis and calculated with the compartmental model are consistently higher than 0.97. Consequently, this experimental model combined with mathematical analysis of the time-course of myocardial radioactivity after 123IHA administration appears to be very promising method for studying the effects of drugs or variations of energy substrate availability on myocardial fatty-acid metabolism.

Animals↗
PubMed1990

[Cholecystectomy with celioscopy. 330 cases].

Laparoscopic cholecystectomy is possible. Under general anesthesia, the optic and the instruments are introduced through 4 trocarsheaths. The cystic duct and artery are dissected and clipped. The gallbladder freed by the retrograde way is removed through the umbilicus. 330 laparoscopic cholecystectomies were done with few and only benign complications. The advantages are the simple post-operative course, the short hospital stay and the minimal parietal traumatism. Some limits remains in case of too much peritoneal adhesions.

Adult↗
PubMed1990

Effect of glucose on the distribution of iodine-123-IHA-16 between esterification and oxidation in canine myocardium.

To evaluate the effect of glucose perfusion on the myocardial metabolism of [123I]-16-iodo-9-hexadecenoic acid (IHA), the latter was injected intravenously into six fasting dogs perfused with a solution lacking glucose (controls) and seven fasting dogs perfused with glucose and insulin. The distribution of myocardial 123I among iodides, free IHA, and esterified IHA was measured in myocardial biopsy specimens. The increase in esterification and decrease in oxidation of IHA due to glucose were quantified using a compartmental mathematical model of myocardial IHA metabolism. Subsequently, in six control and six glucose-perfused dogs, cardiac radioactivity was measured with a scintillation camera for 1 hr following i.v. injection of IHA. Four different methods were used to analyze the myocardial time-activity curves and to calculate the distribution of IHA between oxidation and esterification. Results comparable to those provided by analysis of biopsy specimens can be obtained by considering the curve to be the sum of an exponential and a constant, or by analyzing it with a compartmental mathematical model.

Animals↗
PubMed1990

[A simplified surgical approach in choledochal lithiasis reducing the complexity and severity of this surgery. Study of a series of 153 cases].

The surgical treatment of stones of the common bile duct by transcystic extraction of stones without biliary and peritoneal drainage greatly simplifies biliary surgery. Postoperative course and average hospital stay are similar to those encountered after conventional cholecystectomy. This surgical option was successfully achieved in almost 60% of the 153 patients with stones of the common bile duct of our series, operated between 1981 and 1987. Other patients were treated more conventionally because of failure or impossibility of complete transcystic extraction of stones. A choledochoduodenostomy was performed in 28 patients. In a limited number of patients (n = 12) endoscopic sphincterotomy was associated pre or postoperatively with the surgical treatment. Although 25% of the patients were older than 75 years, there was no operative mortality, which demonstrates that biliary surgery can be performed safely without any vital risk. Successful transcystic extraction of stones simplifies the course of stones of the common bile duct and should be attempt more often.

Adult↗
PubMed1990

[Cholecystectomy under celioscopy].

Cholecystectomy which is the best treatment for gallstones can be performed via laparoscopy in cases of uncomplicated stones. Thirty patients have been operated upon by this technique. The advantages are: small scars, easy recovery and short hospital stay. Nevertheless there are some risks, particularly hemorragic and traumatic complications in the biliary tract, so that operation must be done by a surgeon trained in biliary surgery.

Adult↗
PubMed1990

[Common values of serum selenium in a population in Eastern France].

Eastern France is a low selenium area. Livestock grazing on this soil had low selenium concentration. In human adults, the serum selenium levels were 0.91 +/- 0.14 mumol/l (n = 125) lower than in other european countries except Finland and Greece. However, no adult had serum concentration less than 0.57 mumol/l, a value under which the risk of death from ischemic heart disease or from cancer seem be increased. In infants, serum selenium contents were low, they increased progressively and reached adult levels at about 4 years in our study. In elderly subjects above 70 years old, serum selenium values were significantly (p less than 0.0001) below those of adults (0.83 +/- 0.17 mumol/l). The selenium values diminished when age increases in this population. 4.5 per cent of these subjects had a level under 0.57 mumol/l.

Adolescent↗
PubMed1989

[Cholecystectomy by coelioscopy].

Operative coelioscopy, widely used in gynaecological surgery and appendicectomy, can be helpful in cholecystectomy. Sixty-three patients have been operated upon by this technique which has the advantages of small scars and rapid recovery with shortening of hospital stay. At the moment, its sole indication is cholecystolithiasis without acute complication. The risks associated with this new technique justify a careful selection of its indications and make it imperative for the operator to be a surgeon with wide experience of biliary tract surgery.

Adult↗
PubMed1989

Fate of asialofetuin endocytosed by rat liver.

We have investigated the endocytosis by rat liver of asialofetuin coupled to [125I] tyramine cellobiose: [125I] TCASF. Subcellular distribution of radioactive compounds was established after differential and isopycnic centrifugation and by analysing the fractions by SDS electrophoresis. Labelling secondary lysosomes was performed by injecting rats with Triton WR 1339 four days before injecting the protein. Results show that after being associated with endosomes [125I] TCASF is recovered in organelles where they are subjected to a first degradation, the density of these organelles is practically not affected by Triton WR 1339 injection. Later the degradation products are associated with lysosomes whose density is markedly lowered by Triton WR 1339 treatment. These observations suggest that the first intracellular organelles where [125I] TCASF is subjected to digestion are distinct from the secondary lysosome population. This could be in agreement with the hypothesis that supposes that endosomes acquire enzymes from primary lysosomes before fusion with secondary lysosomes.

Alkaline Phosphatase↗
PubMed1989

Hepatitis delta virus infection in French male HBsAg-positive homosexuals.

The prevalence and serological features of hepatitis delta virus infections were studied in a French population of chronic, non-drug addict, hepatitis B surface antigen carriers: 42 male homosexual patients were compared to 30 nonhomosexuals (20 who evidently had not been exposed to any of the usual hepatitis B virus-hepatitis delta virus risk factors and 10 hemodialyzed patients or kidney allograft recipients). Six of the 42 male homosexuals (14.3%) had at least one serological marker of hepatitis delta virus infection (hepatitis delta antigen, total and/or IgM anti-hepatitis delta antibodies). Serological follow-up was obtained for five of these patients over several months and confirmed the chronicity of the delta infection in at least four of the five subjects. Hepatitis delta antigen and hepatitis delta virus RNA were found in the liver and in the serum, respectively, of four of the five tested patients. Hepatitis B virus DNA was negative in the serum of five of the six hepatitis delta virus-positive homosexuals vs. only eight of 35 hepatitis delta virus-negative homosexuals (p less than 0.02). Human immunodeficiency virus was negative in all of the nonhomosexuals; its prevalence did not differ between the hepatitis delta virus-positive and -negative homosexuals: three were human immunodeficiency virus-positive among the six former vs. 15 among the 36 latter. Human immunodeficiency virus positivity was without obvious influence on hepatitis B virus replication, since among 35 hepatitis delta virus-negative homosexuals hepatitis B virus DNA was found in 80% of the human immunodeficiency virus-positive individuals and 70% of those who were human immunodeficiency virus-negative.

Adult↗
PubMed1989

Hypotensive and peripheral vascular effects in healthy volunteers of repeated oral administration of pinacidil.

The hypotensive and peripheral vascular effects of two different oral formulations of pinacidil were investigated in twelve healthy male volunteers. Arterial blood pressure, heart rate and calf blood flow were measured on Days 1 and 7. The vasodilator activity of both formulations was confirmed by a significant increase in calf blood flow on both days, which was correlated with a significant decrease in diastolic blood pressure. There was no differences between the tablet and the pellet.

Adult↗
PubMed1989

Lipid peroxidation and free radical scavengers in Alzheimer's disease.

Lipid peroxidation products and defenses against free radical damage were determined in serum of 55 patients with senile dementia of the Alzheimer type (SDAT) and compared with values in 24 age-matched healthy control subjects. The following parameters were evaluated: lipid-conjugated dienes and trienes, malondialdehyde, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity in erythrocytes, vitamins E, C and A, zinc, selenium and copper, ceruloplasmin, transferrin and albumin. The results showed a statistically significant decrease in the levels of GSH-Px, vitamins E, C and A, zinc, transferrin and albumin in the SDAT group. On the other hand, most of the deficiencies concern the malnourished subgroup of the SDAT population (SOD, GSH-Px, vitamins E and C, selenium, zinc, transferrin and albumin). Such an alteration of free radical scavengers in the malnourished subgroup of the SDAT population could combine the radical and nutritional hypothesis advanced by some authors.

Aged↗
PubMed1989

Unilateral lung transplantation in end-stage pulmonary emphysema.

Patients with end-stage pulmonary emphysema are usually proposed for either heart-lung or double-lung transplantation. The single-lung transplantation is reversed for patients with pulmonary fibrosis. Patients with emphysema are thought to be unsuitable for single-lung transplantation because of the ventilation-perfusion imbalance that is supposed to occur, the ventilation being preferentially distributed to the native lung when the perfusion is distributed to the transplanted lung. We now report a preliminary success with single-lung transplantation in two consecutive patients with end-stage pulmonary emphysema. Despite the persistence after transplantation of an obstructive syndrome, the clinical status was good, the blood gases were markedly improved, and ventilation-perfusion imbalance did not occur on lung scans. After discharge from the hospital, the patients could return to an almost normal life. Thus, our data support the feasibility of single-lung transplantation in patients with end-stage pulmonary emphysema, and we consider that single-lung transplantation could be the optimal form of lung transplantation in these patients.

Humans↗
PubMed1989

[Primary hyperparathyroidism disclosed by heart arrhythmia].

The authors report a case of primary hyperparathyroidism in a 47 year old woman presenting with cardiac arrhythmias. She had paraoxystic supraventricular tachycardias and rate-dependent ventricular hyperexcitability suggestive of a catecholamine-induced phenomenon which were resistant to antiarrhythmic therapy over a 3 year period; the plasma calcium concentration was 3.30 mmol/l. An ectopic parathyroid adenoma was removed surgically, normalising the biological changes, and no further arrhythmias were detected by Holter monitoring during the 2 year follow-up period. The association of atrial and ventricular arrhythmias seems to be relatively rate in hyperparathyroidism; patients usually present with atrioventricular block and ventricular hyperexcitability. The other cardiovascular abnormalities observed in hyperparathyroidism are hypertension and myocardial hypertrophy. The electrophysiological mechanisms underlying the clinical manifestations remain obscure.

Arrhythmias, Cardiac↗
PubMed1989

[Should a cancer of the bronchi be surgically treated after excision of a cerebral metastasis?].

Between 1964 and 1987 35 patients were operated on for cerebral metastases due to an underlying bronchial carcinoma. In 26 cases (group 1) there was excision of the primary tumour also and in 9 cases combined medical treatment was given with radiotherapy and chemotherapy. The neurological state was improved by the neurosurgical operation in 88% of patients in group 1 and in 66% of patients in group 2. This improvement was maintained in 30% of the patients as long as they survived. 2 patients died following thoracic surgery (7.69%). The median survival was 11 months in group 1 and 9 months in group 2. Three patients in group 1 were living two years after craniotomy whilst. 1 patient in group 2 is still alive four years after the neurosurgical procedure. The heterogeneity of the two groups does not permit a comparative statistical analysis but overall there does not seem to be any difference in duration or quality of life between the two groups. Complementary cerebral radiotherapy did not affect the prognosis.

Adult↗
PubMed1989

[Acute spinal amyotrophy in toxoplasmosis].

A 19 year-old man developed an acute syndrome of the anterior horn of cervical spinal cord during a primo-infection with toxoplasma. The neurological syndrome was completely regressive after treatment with 1 600 mg/day of trimethoprim-sulfamethoxazole for three months.

Acute Disease↗
PubMed1988

Lung exposure to mineral dusts enhances the capacity of lung inflammatory cells to release superoxide.

In vitro exposure of macrophages and neutrophils to inorganic dusts can enhance their oxidative metabolism, however the effects of inorganic dust inhalation on lung-inflammatory cell-oxidative metabolism remain unknown. To address this issue, we studied the superoxide anion release from lung inflammatory cells obtained by bronchoalveolar lavage from 19 sheep exposed repeatedly to UICC chrysotile B asbestos (100 mg) over an 18 month period and 10 sheep exposed to a single exposure of quartz (100 mg) over a 6 month period. Exposure to asbestos and quartz did not induce an increase in the spontaneous release of superoxide from inflammatory cells. However lung-inflammatory cells from sheep exposed to asbestos released much higher levels of superoxide in the presence of phorbol myristate acetate (PMA) than did cells of unexposed sheep. In quartz exposed animals, superoxide release with PMA stimulation remained significantly increased up to 2 months after a single quartz infusion. These results suggest that inorganic dust inhalation primes lung inflammatory cells in vivo and markedly enhances their capacity to release toxic oxygen radicals.

Animals↗