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Biomedical subjects

A Lefebvre

Publications and source records attributed to A Lefebvre.

At least 73 records · Page 4Linked to original sources
PubMed1986

[Peranesthetic monitoring of ventilation in children: value of capnometry].

Continuous measurement of the end-expiratory partial pressure of carbon dioxide (PETCO2) during anaesthesia has been proposed for non-invasive monitoring of arterial PCO2 (PaCO2). The values and the stability of the difference (PaCO2-PETCO2) during anaesthesia were studied for two ventilatory settings in eight children with healthy lungs and normal cardiac function undergoing minor surgery. PaCO2 values were all within a physiological range (30.2-43.6 mmHg). PaCO2-PETCO2 values ranged from 0.2 to 9.9 mmHg. With either mode of ventilation, there was no significant variation in PaCO2-PETCO2. It is concluded that estimation of PaCO2 was reliable during anaesthesia when haemodynamic and ventilatory states were stable, but a first determination of the PaCO2-PETCO2 gradient remained necessary for each child.

Anesthesia, General↗
PubMed1984

Increased 3-hydroxy-3-methyl-glutaryl coenzyme A reductase activity in a virilizing adrenal carcinoma.

HMG-CoA reductase activity was determined on microsomal preparations of an adrenal carcinoma and on a control adrenal obtained from palliative surgery for breast carcinoma. In both tissues we also measured [14C]pyruvate incorporation to study the formation of sterols. The endogenous adrenal content of cholesterol and its esters was quantitated. The content of various steroids was also determined in tissues and media before and after incubations in Krebs-Ringer. The carcinoma had a HMG-CoA reductase activity of 972.0 pmol/mg protein/min vs 13.8 for the control adrenal. The tumor incorporated 4.6 pmol of [14C]pyruvate per mg protein per 90 min into digitonin precipitable sterols compared to 0.5 pmol found for the control gland. Free cholesterol and cholesterol esters in tumoral tissue were 0.09/100 mg and 0.02/100 mg tissue respectively, compared to 0.18 and 2.56 in control tissue. The output of corticosteroids and androgens was very high when calculated for the whole tumor. These results suggest that the carcinoma had acquired a high capacity for de novo synthesis of cholesterol which could have served as substrate for the observed high plasma androgen level.

Adrenal Cortex Hormones↗
PubMed1983

Where did all the "No-Shows" go?

The pilot study examines the demographic profile, referral source, and presenting symptom of 40 families whose child was referred to and accepted for assessment by the Outpatient Psychiatry Department of the Hospital for Sick Children, but who ended up cancelling their initial assessment interview when an appointment time was set. These "No-Show" cases constitute a relatively small (13.6%) proportion of the total population accepted for assessment. the "No-Show" families did not differ markedly from the general intake population in terms of age, and presenting problem. However, girls, suburban residence and lower class background were more prevalent in the "No-Show" group. The length of time spent on the waiting list was given most frequently as the primary reason for cancelling the appointment.

Ambulatory Care↗
PubMed1983

[A hemodialysis bath with bicarbonate improves comfort and ultrafiltration].

To verify if bicarbonate dialysis actually improves the dialytic tolerance of acetate intolerant patients, we have measured the incidence of dialysis with side effects such as headache, nausea, vomiting, hypotension, post-dialytic fatigue at 180 days interval in 2 groups of patients. The first with a good tolerance to acetate, the other with a bad tolerance acetate but put meanwhile for 90 days on a bicarbonate dialysis. While the incidence of side effects did not change in the first group, it decreased by 75% in the second, in spite of a greater weight loss. Thus bicarbonate improves the dialytic tolerance in patients intolerant to acetate as well as ultrafiltration.

Acetates↗
PubMed1983

[Arterial pressure, heart rate and systolic time intervals in patients on long-term hemodialysis dialyzed with a bath containing acetate or bicarbonate].

UNLABELLED: Blood pressure (BP), body weight, heart rate and systolic time intervals (STI) were measured every 6 months during 18 months in a group of 25 patients hemodialyzed with bicarbonate (B), as compared with 25 patients dialyzed with acetate (A). Dialysate Na remained at 140mmol/l. During the dialysis session, the decrease in BP were similar in the 2 groups but tachycardia was observed exclusively with A. The ratio between pre-ejection period (PEP) and left ventricular ejection time (LVET) increased during dialysis similarly in both groups. However predialytic PEP/LVET increased in the A group and decreased in the B group, becoming significantly lower in the Bi group at 18 months. With Bi, the loss of weight was significantly greater during the Hd session for the same decrease in blood pressure. CONCLUSION: 1) During dialysis, the increase of PEP and PEP/LVET seems to be directly connected with the weight loss, and is the same in both groups. 2) The long term decrease of predialysis PEP and PEP/LVET seen with the B group can be explain by a greater degree of water inflation and by an improvement of myocardial contractility.

Acetates↗
PubMed1983

[Comparative effects of hemodialysis using acetate and bicarbonate baths on lipid metabolism].

Cholesterol (C) and triglycerides (T) levels are compared in 54 patients dialysed with acetate during more than 24 months and afterwards dialysed with bicarbonate during more than 18 months. No significant difference appears, either for C or for T. But the number of patients with T levels below 1,5 mmol/l goes up from 19 during acetate dialysis to 31 during bicarbonate dialysis. This does not appear for cholesterol.

Acetates↗
PubMed1982

Psychosocial impact of craniofacial deformities before and after reconstructive surgery.

Pre- and post-operative body image, self-confidence and individual and family adjustment were compared in 250 patients (aged 6 weeks to 39 years) with severe craniofacial deformities. Major congenital deformities of genetic or idiopathic etiology were present in 178 patients and 72 had tumours or other late-onset deformities. The patients and/or parents were interviewed by a child psychiatrist and a social worker as part of the routine pre-operative assessment. In addition to a semistructured interview protocol, the patients and parents were asked to rate the deformity according to Hay's Scale and, when appropriate, to complete the Piers-Harris Self-esteem Inventory. One and two year post-operative reevaluations followed the same protocol. The results indicated that the age of the patient, pre-operative expectations and origin of the decision for surgery (particularly in adolescents) are the most significant predictive factors of post-operative psychosocial improvement.

Adolescent↗
PubMed1981

Intake follow-up of "no service" cases.

At The Hospital for Sick Children in Toronto, an attempt was made to bypass long pre-assessment waiting lists by referring an increasing number of patients to local community resources at the point of the initial intake call. During the pilot study, we contacted 40 families who had been redirected along these lines between January and June 1979. We found that 31 (78%) families had followed our recommendation and most were satisfied with the treatment they were receiving. This suggests that "re-referral" upon intake can often be a highly effective and useful service when provided by a central resource and consultation centre. A further systematic follow-up of all applications to children's mental health clinics, including a careful appraisal of no-show cases (families who are accepted so that we can tailor our services to the specific child psychiatry needs of our varied clientel.

Adolescent↗
PubMed1978

The role of psychiatry in a craniofacial team.

The psychosocial assessment of the child in the context of his family and community is, we believe, an essential factor in the decision for and the timing of major reconstructive surgery. A severe congenital facial deformity does not usually affect a child's body-image, but it can have a great impact on the total self-image (which is related to social reactions). Surgery should be performed ideally before the early school years, when the child is subjected to the most teasing, provided both parents and the patient have realistic expectations and really want the major reconstruction.

Adaptation, Psychological↗
PubMedDate not supplied

P450aldo in hamster adrenal cortex: immunofluorescent and immuno-gold electron microscopic studies.

The zonal distribution of aldosterone synthase cytochrome P450 (P450aldo) in the adrenal cortex of male hamsters was investigated by immunofluorescence and electron microscopy, using an anti-P450aldo peptide antibody. On cryostat sections the immunolocalization of P450aldo was confined to the zona glomerulosa cells. On semi-thin plastic sections, P450aldo was shown to be located in mitochondria. Studies in electron microscopy, using the colloidal gold technique, confirmed that P450aldo was located in mitochondria.

Adrenal Cortex↗
PubMedDate not supplied

The role of calcium channels in hamster CYP11B2 gene expression.

Previous studies have shown that the hamster CYP11B2 gene promoter is under the influence of angiotensin II (AII), cAMP and potassium (K+). However, very little is known about the mechanisms by which these compounds regulate the transcription of the CYP11B2 gene. Therefore we analysed the 5'-flanking region of the hamster CYP11B2 gene using a transient transfection expression system in NCI-H295 adrenocortical cells, which are known to respond to K+, cAMP and AII. The first 486 bp before the transcription initiation site were introduced upstream of the chloramphenicol acetyl transferase gene. NCI-H295 cells transfected with this -486 construct showed increased CAT activity upon treatment by K+, AII, forskolin and cAMP. The calcium channel antagonist nifedipine partially blocked the enhancing effects of AII, forskolin and cAMP by 35%, 30% and 30% respectively, whereas it completely blocked the stimulatory effects of KCl (1). These results thus show the involvement of calcium channels in the regulation of CYP11B2 gene transcription by K+, and their partial involvement in the regulation of this gene by AII, forskolin and cAMP in NCI-H295 cells.

Adrenal Cortex↗