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Biomedical subjects

J Leclerc

Publications and source records attributed to J Leclerc.

At least 19 recordsLinked to original sources
PubMed1992

A low-molecular-weight heparinoid compared with unfractionated heparin in the prevention of deep vein thrombosis in patients with acute ischemic stroke. A randomized, double-blind study.

OBJECTIVE: To compare the relative safety and efficacy of a low-molecular-weight heparinoid (ORG 10172) with unfractionated heparin in the prevention of deep vein thrombosis in patients with acute ischemic stroke. DESIGN: Double-blind randomized trial. SETTING: Seven Canadian university-affiliated hospitals. PARTICIPANTS: Eighty-seven patients with acute ischemic stroke resulting in lower-limb paresis. INTERVENTION: Patients received either low-molecular-weight heparinoid, 750 anti-factor Xa units twice daily, or unfractionated heparin, 5000 units subcutaneously twice daily. Treatment was continued for 14 days or until hospital discharge if sooner. MEASUREMENTS: Deep vein thrombosis was diagnosed using 125I-labeled fibrinogen leg scanning and impedance plethysmography. Venography was indicated if either test was positive. Overt hemorrhage, major or minor, was assessed clinically. RESULTS: Venous thrombosis occurred in four patients (9%) given low-molecular-weight heparinoid and in 13 patients (31%) given heparin (relative risk reduction, 71%; 95% CI, 16% to 93%. The corresponding rates for proximal vein thrombosis were 4% and 12%, respectively (relative risk reduction, 63%; P greater than 0.2). The incidence of hemorrhage was 2% in both groups. CONCLUSION: Low-molecular-weight heparinoid, given in a fixed dose of 750 anti-factor Xa units subcutaneously twice daily, is more effective than subcutaneous low-dose heparin for the prevention of deep vein thrombosis in patients with acute ischemic stroke.

Acute Disease↗
PubMed1992

Radioimmunodetection of human bladder tumor xenografts in nude mice with radiolabeled monoclonal antibodies.

The tumor targeting potential of two monoclonal antibodies (mAbs) reacting with growth-regulated surface glycoproteins of human bladder cancer was investigated. The mAb T16 reacts more intensely with stationary cells while the mAb T43 is preferentially reactive with exponentially growing cells. The test target was T24 human bladder cancer cells grown subcutaneously in 30 nude mice. Controls for tumor specificity were human lung cancer cells grown on the contralateral side. Purified mAb's T16 and T43, and Om5, a non-reactive control, were radiolabeled with 131-Iodine and injected intravenously in doses ranging from 50 to 300 microCi in tumor-bearing animals. Consistent images of the bladder cancer xenografts were obtained at 48 and 72 hours with tumors as small as 0.1 gm. High resolution tumor images were obtained only with the reactive antibodies and according to their in vitro specificity. These results demonstrate that the two mAbs T16 and T43 can specifically and sensitively localize human bladder cancer cells in vivo.

Animals↗
PubMed1992

The low molecular weight heparin Enoxaparin inhibits the consumption of factor VII and prothrombin activation in vivo associated with elective knee replacement surgery.

Patients over 40 years of age who undergo elective orthopaedic surgery have a relatively high risk for developing post-surgical deep vein thrombosis (DVT). Prophylactic use of heparin or low molecular weight heparins can reduce the incidence of post-operative DVT by up to 80%. It is not known whether prophylaxis is achieved by inhibition of prothrombin activation or catalysis of thrombin inhibition in vivo. We determined the changes in concentrations of factor VII zymogen and thrombin-antithrombin III (the latter as an index of prothrombin activation) in the plasmas of 129 patients randomized to receive two daily subcutaneous injections of placebo or 30 mg of Enoxaparin after elective knee surgery. Enoxaparin reduced the frequency of post-surgical DVT by 70%. The concentration of factor VII zymogen had decreased by approximately 50% within 24 h after the knee surgery, followed by a gradual increase to near presurgical values. Additionally, post-Enoxaparin plasmas had statistically significant higher concentrations of factor VII zymogen than post-placebo plasmas. Post-Enoxaparin plasmas had significantly lower concentrations of endogenous thrombin-antithrombin III than comparable post-placebo plasmas. Finally, post-Enoxaparin plasmas inactivated exogenous factor Xa and thrombin more effectively than comparable post-placebo plasmas. As Enoxaparin moderated the generation of endogenous thrombin-antithrombin III after elective knee surgery, inhibition of prothrombin activation in vivo by Enoxaparin may be important for its prophylactic antithrombotic effect.

Adult↗
PubMed1991

Prevention of deep vein thrombosis after elective hip surgery. A randomized trial comparing low molecular weight heparin with standard unfractionated heparin.

OBJECTIVE: To determine the relative efficacy and safety of low molecular weight (LMW) heparin (Enoxaparin) compared with standard calcium heparin for the prevention of postoperative deep vein thrombosis in patients undergoing elective hip surgery. DESIGN: A double-blind, randomized, controlled trial. PATIENTS: Six hundred sixty-five consecutive patients undergoing hip replacement at five participating hospitals. INTERVENTIONS: Patients received either fixed-dose LMW heparin, 30 mg subcutaneously twice daily, or fixed-dose standard calcium heparin, 7500 units subcutaneously twice daily; both regimens were started 12 to 24 hours after surgery and continued for 14 days or until discharge if sooner. MEASUREMENTS: All patients had postoperative I-125-fibrinogen leg scanning and impedance plethysmography. If results of one or both tests were positive, then venography was done. Otherwise, venography was done between day 10 and day 14, or sooner if the patient was ready for discharge. RESULTS: Evaluable venograms were obtained in 258 of the 333 patients randomly assigned to receive LMW heparin and in 263 of the 332 patients assigned to receive calcium heparin. For patients with evaluable venograms, thrombosis was detected in 50 patients (19.4%) who received LMW heparin compared with 61 patients (23.2%) who received standard heparin (difference, -3.8%; 95% CI, -11.1% to 3.6%) (P greater than 0.2). Proximal deep vein thrombosis was detected in 5.4% of the patients receiving LMW heparin and in 6.5% of the patients receiving standard heparin (difference, -1.1%; CI, - 5.2% to 3.3%) (P greater than 0.2). For the entire group of 665 patients, venous thrombosis occurred in 17.1% given LMW heparin and in 19.0% given standard heparin. Hemorrhagic complications occurred in 31 patients (9.3%) given standard heparin and in 17 patients (5.1%) given LMW heparin (difference, 4.2%; CI, 0.3% to 8.2%) (P = 0.035). The relative risk reduction was 45%. The rate of major bleeding in the standard heparin group was 5.7% compared with 3.3% in the LMW heparin group (difference, 2.4%; CI, -1.0% to 5.4%) (P = 0.13). The relative risk reduction was 42%. CONCLUSION: Low molecular weight heparin is significantly less hemorrhagic than standard unfractionated heparin; the difference in the rate of deep vein thrombosis, although not statistically significant (P greater than 0.2), favors the use of LMW heparin.

Adult↗
PubMed1989

Effects of protein level, methionine supplementation and carbohydrate type of the diet on liver lipid and plasma free threonine contents in the lactating rat.

Eight groups of 13-15 female rats were fed purified diets after littering. Four groups received a low protein (8% casein) diet (groups 8) and the others, a normal protein (20% casein) diet (groups 20). Carbohydrates were supplied either as starch (groups S) or as starch plus 40% fructose (groups F). Half the animals received a 0.4% methionine supplementation (groups M). Four or five dams per group were sacrificed on days 2, 7 and 14 after littering. The diet intake was increased by methionine supplementation, substitution of starch for fructose and increased protein content, mainly during the second week of lactation. This influenced weight variation of the dams and litter growth. On all days, the plasma levels of cholesterol esters, triglycerides and phospholipids were positively correlated with the dietary protein level. On days 7 and 14, the liver neutral lipid content was increased in rats fed the low protein diets supplemented with methionine (groups 8SM and 8FM) and the normal protein diets containing 40% fructose (groups 20F and 20FM). The plasma free threonine content was positively correlated with the protein level in the diet. On day 14, rats fed a low protein diet had a threonine deficiency, except those in groups 8S and 8F. The plasma free threonine content of these rats was not reduced, possibly due to an impaired utilization of this amino acid. The liver lipidosis observed during lactation, in contrast to that observed during growth with a low protein diet, was not due to a threonine deficiency.

Animals↗
PubMed1987

The relationship between the nasal cycle and axillary sweat production.

Mean inspiratory nasal resistances and mean axillary sweating rates were recorded bilaterally every 30 minutes for a 5-7 hour period in seven subjects. One subject performed the experiment twice. Nasal resistance was measured using either anterior (n = 5) or posterior (n = 2) rhinomanometry and sweating rate was determined using a filter paper technique. The results for seven of the experiments showed that both nasal resistance and axillary sweating rate exhibited periodic reversals in side dominance. The cyclic patterns for nasal resistance and sweating rate were synchronized in phase in two experiments and 180 degrees out of phase in five experiments. These results support the concept of a central governing cycle with peripheral expression effected by the autonomic nervous system.

Adult↗
PubMed1987

Relationship between riboflavin intake and excretion in female rats after weaning of the litter.

Six groups of female rats which gave birth to offspring of 8 young (or adjusted to 8) were fed diets containing 2, 4, 6, 8, 12, or 16 mg of riboflavin per kg of dry matter. Seventeen days after birth, young were withdrawn from the mothers and these were placed in metabolic cages and excreta (urine and feces) were daily collected for 17 days. The activity coefficient of blood glutathione reductase was 1.45 in 17 days old young of group 2 whereas it was 1.12 in young of other groups. The coefficient was 1.09 in female rats at the end of the experiment. 5 and 6 days after excreta collection began urinary excretion of riboflavin reached a peak in females of groups 4 to 16. At the end of the experiment, females which were fed 8 mg of riboflavin/kg or more had an urinary excretion of the vitamin which reached a plateau at 50 micrograms/day. On the other hand fecal excretion of riboflavin markedly increased as the intake did. Data suggested that the intestinal absorption of riboflavin is limited but also that the requirement of riboflavin in lactating rats is 8 mg/kg of diet whereas it is 2 mg/kg for maintenance.

Animals↗
PubMed1985

Pulsatile tinnitus: a dehiscent jugular vein.

A case is reported of a female patient with subjective tinnitus synchronous with her pulse, in the left ear. A dehiscent high seated jugular vein was found in the middle ear. A surgical technique is presented using a septal cartilage homograft to cover the dehiscent vein.

Dilatation, Pathologic↗
PubMed1985

[Methionine supplementation in the diet of the pregnant rat. 2. Riboflavin metabolism and hepatic concentration of water, lipid and protein].

Dietary addition of methionine suppresses the liver lipidosis in gestating rat fed a diet containing 9% by weight of casein. Riboflavin metabolism is not affected by this addition neither in the dam nor in the newborn rat. Riboflavin content in liver increases in the dam along with the protein content of the diet but does not change in the newborn rat.

Animals↗
PubMed1985

[Dietary methionine supplementation in the pregnant rat. 1. Food intake of the dam and body weight of the newborn offspring].

A decrease from 18 to 9% of the dietary casein level induces lower food intake in the gestating female rat and weight loss in the newborn rat. Addition of methionine to the diet containing 9% casein improves food intake in the last period of pregnancy. Body weight of the newborn rat is also increased and becomes identical to that of rats born from mothers fed 18% dietary casein.

Animals↗
PubMed1984

Toxicity testing of pertussis vaccines: effect of increased sensitivity of mice to Bordetella pertussis.

The increased sensitivity to Bordetella pertussis of a line of CD-1 mice used in toxicity-testing and the consequent and needless rejection of several lots of DPT vaccine are described. Apart from changes in the mice the possible presence of an infective agent in the animal house could not be discounted. The usefulness of individual mouse weights in the assay as opposed to group weights and of a reference preparation to monitor the performance of mice is discussed.

Animals↗