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Biomedical subjects

J R Séguin

Publications and source records attributed to J R Séguin.

At least 19 recordsLinked to original sources
PubMed2004

Salivary cortisol and aggression in a population-based longitudinal study of adolescent males.

Chronic antisocial behaviour in youth has been associated with cortisol, a measure of stress reactivity. However, some studies have found low cortisol levels, while others have found elevated cortisol levels. The present study compared variously defined aggressive subgroups for differences in salivary cortisol. A population-based sample of boys was followed longitudinally from childhood to adolescence. Assessments of different forms of antisocial behaviour were obtained from various informants at several points in time, and cortisol was collected at age 13. Higher cortisol levels were found in boys with conduct disorder (CD) than in boys without CD. In addition, boys with an aggressive form of CD had higher cortisol levels than boys who showed a covert form of CD. Furthermore, reactive aggression was strongly correlated with elevated cortisol. Adolescent boys with chronic reactive aggression and those who scored high on aggressive CD symptoms seem to have a more active hypothalamic-pituitary-adrenal system.

Adolescent↗
PubMed2000

Minor physical anomalies and family adversity as risk factors for violent delinquency in adolescence.

OBJECTIVE: Minor physical anomalies are considered indicators of disruption in fetal development. They have been found to predict behavioral problems and psychiatric disorders. This study examined the extent to which minor physical anomalies, family adversity, and their interaction predict violent and nonviolent delinquency in adolescence. METHOD: Minor physical anomalies were assessed in a group of 170 adolescent boys from low socioeconomic status neighborhoods of Montréal. The boys had been enrolled in a longitudinal study since their kindergarten year, when an assessment of family adversity had been made on the basis of familial status and the parents' occupational prestige, age at the birth of the first child, and educational level. Adolescent delinquency was measured by using self-reported questionnaires and a search of official crime records. RESULTS: Results from logistic regression analyses indicated that both the total count of minor physical anomalies and the total count of minor physical anomalies of the mouth were significantly associated with an increased risk of violent delinquency in adolescence, beyond the effects of childhood physical aggression and family adversity. Similar findings were not found for nonviolent delinquency. CONCLUSIONS: Children with a higher count of minor physical anomalies, and especially a higher count of anomalies of the mouth, could be more difficult to socialize for different and additive reasons: they may have neurological deficits, and they may have feeding problems in the first months after birth. Longitudinal studies of infants with minor physical anomalies of the mouth are needed to understand the process by which they fail to learn to inhibit physical aggression.

Adolescent↗
PubMed1999

Hypersensitivity to social interactions in bulimic syndromes: relationship to binge eating.

This study used a 6- to 22-day experience-sampling procedure to test for hypersensitivity to social interactions in bulimic individuals. Ratings on daily social interactions, self-concepts, moods, and eating behaviors from 55 actively bulimic, 18 formerly bulimic, and 31 noneating-disordered women were obtained. Hierarchical linear modeling analyses showed negative social interactions to be associated with significant increases in self-criticism (SC) and deteriorations in mood in all participants. However, bulimic participants (active or in remission) showed larger increases in SC following negative social interactions than did normal eaters (and thus seemed to be hypersensitive to interpersonal experiences). Additional analyses indicated that binge episodes tended to be preceded by poorer than average social experiences, self-concepts, and moods and followed by deteriorations in self-concept, mood, and social perception. The authors discuss possible perpetuating influences of interpersonal sensitivity in bulimic syndromes.

Adult↗
PubMed1999

Executive functions and physical aggression after controlling for attention deficit hyperactivity disorder, general memory, and IQ.

This study examined the role of ADHD in the association between physical aggression and two types of executive functions. Boys received a cognitive-neuropsychological test battery over the ages of 13, 14, and 15 years. Diagnostic Interview Schedule for Children (DISC 2.25) data were collected from the boys and one parent between ages 14 and 16, and an IQ estimate was obtained at age 15. Three groups, differing in stability and level of physical aggression since kindergarten, were formed: Stable Aggressive, Unstable Aggressive, and Non-aggressive. Composite scores of validated executive function tests of working memory representing subjective ordering and conditional association learning were formed. A MANCOVA (N = 149) using ADHD status, teacher-rated negative emotionality, general memory abilities, and IQ as covariates was performed on the two composite scores. ADHD and teacher-rated emotionality did not provide significant adjustment to the dependent variables. Number of ADHD symptoms was negatively associated only with general memory and IQ. General memory contributed significantly to adjusting for conditional association test scores. Group differences indicated lower conditional association scores for Unstable Aggressive boys relative to the other groups. Both IQ and general memory abilities interacted with subjective ordering within the groups. Specifically, Stable Aggressive boys performed poorly on this measure and did not benefit from increases in IQ whereas Nonaggressive boys performed best and were not disadvantaged by lower general memory abilities. This suggests a relationship exists between aspects of working memory and a history of physical aggression regardless of ADHD and IQ.

Adolescent↗
PubMed1998

Tryptophan depletion, executive functions, and disinhibition in aggressive, adolescent males.

Low serotonin has been associated with aggressive behavior and impulsivity. Executive functions (cognitive abilities involved in the initiation/maintenance of goal attainment) have also been related to aggression. We tested whether dietary depletion of tryptophan, the amino acid precursor of serotonin, would increase disinhibition (impulsivity) in aggressive male adolescents. Cognitive-neuropsychological variables predictive of disinhibition were explored. Stable aggressive and nonaggressive adolescent men received balanced and tryptophan-depleted, amino acid mixtures separately (counterbalanced, double-blind). Commission errors on a go/no-go learning task (i.e., failures to inhibit responding to stimuli associated with punishment/nonreward) measured disinhibition. Aggressive adolescent males made more commission errors as compared to nonaggressives. Lower executive functioning was significantly related to commission errors over and above conventional memory abilities. Tryptophan depletion had no effect on commission errors in the aggressive adolescents, possibly because of a ceiling effect.

Adolescent↗
PubMed1998

Risk for hypertension and pain sensitivity in adolescent boys.

Reduced pain perception has been observed in many studies of spontaneously hypertensive rats and human hypertensive patients. To determine whether a reduced sensitivity to pain could be observed in a group of clearly normotensive individuals who may be at risk for hypertension, a mild to moderate pain stimulus was administered to 177 14-year-old boys. Boys with a normatively elevated resting systolic blood pressure tolerated mechanical finger pressure significantly longer than boys with lower blood pressure. As well, boys with both normatively elevated resting systolic blood pressure and a parental history of hypertension reported significantly less pain during finger pressure than lower risk participants. These findings could not be explained by personality factors and suggest that hypertension-related hypoalgesia is associated with processes involved in the development of the disorder.

Adolescent↗
PubMed1997

Ginkgo biloba extract (EGb 761) pretreatment limits free radical-induced oxidative stress in patients undergoing coronary bypass surgery.

A growing body of evidence supports the trigger role of free radicals in the delayed functional and metabolic myocardial recovery following cardiopulmonary bypass (CPB) in humans, thus opening the field to specific therapies. This clinical study was designed to evaluate, in 15 patients undergoing aortic valve replacement, whether the extent of CPB- and reperfusion-induced lipid peroxidation, ascorbate depletion, tissue necrosis, and cardiac dysfunction is reduced by orally administered EGb 761, a Ginkgo biloba extract with potent in vitro antiradical properties. Patients received either EGb 761 (Tanakan, 320 mg/day, n = 8) or a matching placebo (n = 7) for 5 days before surgical intervention. Plasma samples were obtained from the peripheral circulation and the coronary sinus at crucial stages of the operation (i.e., before incision, during ischemia, and within the first 30 minutes post-unclamping), and up to 8 days postoperatively. Upon aortic unclamping, EGb 761 inhibited the transcardiac release of thiobarbituric acid-reactive species (p < 0.05), as assessed by high-performance liquid chromatography, and attenuated the early (5-10 minute) decrease in dimethylsulfoxide/ascorbyl free radical levels, an electron spin resonance index of the plasma ascorbate pool (p < 0.05). EGb 761 also significantly reduced the more delayed leakage of myoglobin (p = 0.007) and had an almost significant effect on ventricular myosin leakage (p = 0.053, 6 days postoperatively). The clinical outcome of recovery of treated patients was improved, but not significantly, compared with untreated patients. Our results demonstrate the usefulness of adjuvant EGb 761 therapy in limiting oxidative stress in cardiovascular surgery and suggest the possible role of highly bioavailable terpene constituents of the drug.

Adult↗
PubMed1996

Pain sensitivity and stability of physical aggression in boys.

It is unclear whether stably aggressive boys would be characterized by high or low pain sensitivity. Adolescent boys in whom physical aggression, executive functioning, anxiety, and family adversity had been assessed longitudinally formed three groups who differed in stability of physical aggression: stable, unstable, and non-aggressive. Stable aggressives were the least pain sensitive, whereas unstable aggressives were the most pain sensitive. While at low levels of executive functioning pain sensitivity could not be distinguished between the aggressive groups, at high levels unstable aggressives reported even more pain, whereas stable aggressives reported even less pain. Variations in anxiety were associated strongly with pain sensitivity in unstable aggressives. High pain ratings were found in boys who had a moderate level of family adversity, and low pain ratings in boys with low or high adversity. The differences in pain sensitivity between the groups may be motivationally important to the frequency and type of aggression.

Aggression↗
PubMed1995

Use of active shunt for surgical repair of intrapericardial inferior vena caval injury.

We report a case of intrapericardial inferior vena caval disruption due to goring by a bull, and we describe the surgical repair of this uncommon penetrating cardiac injury. Review of the literature indicates that, as with other penetrating cardiac injuries, this rare lesion requires aggressive treatment involving an emergency thoracotomy. The use of an atrial caval active shunt was necessary for successful surgical management, and therefore we conclude that surgical treatment of this lesion is comparable with surgical repair of hepatic veins and retrohepatic vena caval injuries incurred during blunt vascular trauma or penetrating abdominal injuries.

Adult↗
PubMed1995

Cognitive and neuropsychological characteristics of physically aggressive boys.

Cognitive-neuropsychological tests were given to adolescent boys (N = 177) to investigate processes associated with physical aggression. Factor analysis yielded 4 factors representing verbal learning, incidental spatial learning, tactile-lateral ability, and executive functions. Physical aggression was assessed at ages 6, 10, 11, and 12, and 3 groups were created: stable aggressive, unstable aggressive, and nonaggressive. The authors found main effects for only the executive functions factor even when other factors were used as additional covariates in a step-down analysis; nonaggressive boys performed better than stable and unstable aggressive boys. The covariates family adversity and anxiety were both related only to the verbal learning factor. This study highlights the importance of deficits in executive function in the expression of physical aggression relative to other cognitive-neuropsychological functions.

Aggression↗
PubMed1994

Aortic valve repair with fibrin glue for type A acute aortic dissection.

Repair of the acute aortic insufficiency associated with type A aortic dissection is now preferred to valve replacement. This is generally achieved by resuspending the aortic valve using different types of suturing techniques, with sutures usually passing through the aortic wall, which causes bleeding at the suture sites. We suggest, instead, simply injecting fibrin glue between the two dissected layers of the aortic annulus, which achieves resuspension of the aortic valve and reinforces the proximal stump without the need for any sutures. To evaluate the efficacy of this simple technique, the cases of 15 consecutive patients who underwent operative intervention for the treatment of the type A aortic dissection associated with acute aortic insufficiency between January 1989 and July 1993 were reviewed. The mean patient age was 63 +/- 11.2 years (range, 43 to 74 years). All had massive 3+ or 4+ aortic insufficiency, documented pre-operatively by transesophageal echocardiography. None had any history of aortic regurgitation. In all patients, the aortic repair was done in conjunction with a supracoronary replacement of the ascending aorta with a collagen-impregnated graft attached using a running suture, after reinforcement of the dissected tissues with glue. There was one non-valve-related early death (6.7%) and no late mortality. At a mean follow-up of 2.3 years, all patients were in New York Heart Association functional class I and had a mean aortic insufficiency grade of 0.3 (range, 0 to 1+). Follow-up computed tomography in all patients showed closure of the dissecting process on the proximal ascending aorta.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1994

Ascorbyl free radical: a noninvasive marker of oxidative stress in human open-heart surgery.

To assess the development of oxidative stress in cardiac ischemia/reperfusion, the resulting depletion of plasma ascorbate was monitored by electron spin resonance spectroscopic detection of ascorbyl free radical (AFR) in a homogeneous group of 12 patients undergoing aortic valve replacement. Dimethyl sulfoxide (DMSO) was used as an enhancer and stabilizer for AFR in plasma separated from blood samples collected 15 min before incision, 10 min before aortic declamping, and sequentially during the initial 30 min of reperfusion. Plasma DMSO/AFR levels of patients were found to be significantly lower than in healthy subjects (-25%), further decreased upon ischemia (-35%), dropped to their lowest values within the first 10 min of reperfusion (-46%), and did not recover their initial values within 30 min following reflow. Cardiac index measurements revealed a still depressed heart function 4 h postdeclamping and a more delayed tissue injury was evidenced by cardiac myosin and myoglobin release in plasma. DMSO/AFR levels at early reperfusion were slightly (+ 12%) higher in plasma obtained from coronary sinus samples than in plasma from peripheral blood, suggesting an extra ascorbate release from the injured heart tissue. The close analogy between these results and the reported measurements of other plasma markers of oxidative stress, including ascorbate, indicates that the present method could be of great value in clinical practice.

Aortic Valve↗
PubMed1994

Repair of the aortic arch with fibrin glue in type A aortic dissection.

Location of the intimal tear in the aortic arch in type A aortic dissection is for many authors an indication for replacement of the aortic arch, but this operation has a high in-hospital mortality rate: 20% to 40%. Instead, we suggest repairing the aortic arch by injecting fibrin glue, which contains a human sealer protein concentrate, between the two dissected layers under circulatory arrest while replacing the ascending aorta. To evaluate this technique, we reviewed 45 successive patients operated on for type A acute aortic dissection between January 1989 and July 1993, of which 6 had the intimal tear located on or extending into the aortic arch. Mean age was 71 +/- 4.2 years (range 68 to 74). After proximal supracoronary anastomosis with a collagen-impregnated graft, aortic arch repair was achieved by injecting fibrin glue between the two layers, using circulatory arrest at a mean temperature of 22 degrees C, with a mean duration of 24 minutes. This obliterated the dissection in the arch and also the intimal flap. The distal part of the graft was then anastomosed to the proximal portion of the aortic arch at the origin of the innominate artery under circulatory arrest. There were no early or late deaths. All patients were asymptomatic at a mean follow-up of 2.6 years. Follow-up angioscan showed obliteration of the dissection in the aortic arch in all patients; there were two patients with dilatation of the distal aortic arch of 40 and 45 mm.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1993

Heart-rate reactivity and alcohol consumption among sons of male alcoholics and sons of non-alcoholics.

Recent studies have demonstrated that sons of male alcoholics with multigenerational family histories of male alcoholism are characterized by sober heart-rate hyperreactivity to aversive stimuli, susceptibility to alcohol-induced dampening of that hyperreactivity and by increased resting heart rate while intoxicated. Regression analyses indicate that the magnitude of alcohol-induced change in resting and reactive cardiac response is significantly and powerfully associated with the degree of self-reported voluntary alcohol consumption among 85 non-alcoholic males who are either lacking or who have moderate or extensive family histories of male alcoholism. It appears that heightened sensitivity to alcohol-induced increase in resting and decrease in reactive heart rate might mark or underlie familial risk for developing alcoholism.

Adolescent↗
PubMed1992

Hemodynamic effect of calcium channel blockade during anesthesia for coronary artery surgery.

Because the choice of anesthetic technique does not influence the incidence of perioperative myocardial ischemia, reduction of ischemic risk may require specific antianginal therapy. Calcium entry blockers are effective drugs in antianginal therapy. Diltiazem reduces myocardial oxygen demand through decreases in heart rate, inotropy, and systolic function, while increasing myocardial oxygen delivery through coronary vasodilation. These potentially beneficial effects of diltiazem were evaluated in 15 of 29 patients (diltiazem v placebo, double-blind study) scheduled for coronary artery bypass graft surgery. Continuous infusion of diltiazem (0.15 mg/kg bolus followed by 2 micrograms/kg/min), during anesthesia and surgery before cardiopulmonary bypass, significantly reduced the major MVO2 determinants during anesthesia with moderate doses of fentanyl and a benzodiazepine (midazolam in 8 of 14 control patients and 9 of 15 treated patients, or flunitrazepam in the others). Heart rate, mean arterial pressure, and inotropy were decreased during the most stressful events of surgery when plasma diltiazem concentrations were in the therapeutic range (greater than 96 ng/mL). The number of patients with perioperative ischemia was 2 of 15 in the treated group and 4 of 14 in the control group. Provided that diltiazem plasma concentrations are sufficient, it can contribute to lowering the ischemic burden during anesthesia for coronary artery surgery.

Anesthesia, Intravenous↗
PubMed1992

Effects of halothane and isoflurane on transient renal dysfunction associated with infrarenal aortic cross-clamping.

Aortic cross-clamping for reconstructive aortic surgery is associated with impairment of renal function. Halothane or isoflurane was used to assess the influence of volatile anesthesia on renal hemodynamics during aortic surgery. Nineteen patients with normal preoperative creatinine clearances who were scheduled for reconstructive aortic surgery were randomly divided into two groups: halothane group (n = 9) and isoflurane group (n = 10). Induction of anesthesia consisted of midazolam, fentanyl, and pancuronium. Anesthesia was maintained with fentanyl and halothane or isoflurane in nitrous oxide and oxygen (50/50). Systemic hemodynamics were similar in both groups throughout surgery. Before aortic cross-clamping, effective renal plasma flow (ERPF) (131I-hippuran clearance) and glomerular filtration rate (GFR) (99Tc-DTPA clearance) were significantly lower in the halothane group (118.4 +/- 25.6 and 19.7 +/- 5.2 mL/min, respectively) than in the isoflurane group (253.4 +/- 51.5 and 44.9 +/- 8.4 mL/min) (P less than 0.05 for both). During cross-clamping, the renal variables were not markedly affected in either group and remained higher in the isoflurane-anesthetized patients (232.9 +/- 47.1 and 49.5 +/- 1.2 mL/min for ERPF and GFR, respectively) than in the halothane-anesthetized patients (132.4 +/- 31.6 and 14.8 +/- 3.7 mL/min, respectively) (P less than 0.05). After aortic unclamping, ERPF increased markedly in both groups (467.8 +/- 122 and 362.5 +/- 57.7 mL/min in the halothane and isoflurane groups, respectively), as did GFR (74.8 +/- 22 and 71.8 +/- 13.1 mL/min, respectively). These results suggest that anesthesia with halothane is associated with transient renal vasoconstriction during abdominal surgery. In contrast, aortic cross-clamping during isoflurane anesthesia was not associated with renal hemodynamic impairment.

Adult↗
PubMed1992

Does choice of the anesthetic influence renal function during infrarenal aortic surgery?

Reconstructive infrarenal aortic surgery is associated with impairment of renal function owing to vasoconstriction during and after aortic cross-clamping. To assess the influence of anesthetic technique on renal hemodynamics during aortic surgery, 34 patients received one of four anesthetics: isoflurane (n = 10), halothane (n = 9), droperidol (n = 8), and flunitrazepam (n = 7). Supplemental anesthesia consisted of midazolam, fentanyl, nitrous oxide in oxygen (50%), and pancuronium. Before aortic cross-clamping, effective renal plasma flow (ERPF) (131iodohippuran clearance) and glomerular filtration rate (GFR) (99technetium-DTPA clearance) were low in the halothane and flunitrazepam groups (118.4 +/- 25.6 and 170 +/- 35 mL/min for ERPF; 19.7 +/- 5.2 and 26.9 +/- 5.8 mL/min for GFR, respectively) and better preserved in the isoflurane group (253.4 +/- 51.5 and 44.9 +/- 8.4 mL/min, respectively; P less than 0.05 between isoflurane and halothane groups) or in the droperidol group as regards GFR (75.4 +/- 9.4 mL/min, P less than 0.05). During clamping, both renal variables were not markedly affected in any group except in the droperidol group in whom GFR significantly decreased from preclamp value. The GFR was then significantly higher in the isoflurane group (49.5 +/- 9.2 mL/min) than in the halothane and flunitrazepam groups (14.8 +/- 3.7 and 26.5 +/- 10.1 mL/min, respectively; P less than 0.05). After aortic declamping, ERPF and GFR increased markedly in the halothane group, and there was no significant difference between the groups. These results suggest that renal hemodynamics are less altered with droperidol-fentanyl anesthesia during abdominal surgery but not during aortic cross-clamping.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗