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Biomedical subjects

A Lacroix

Publications and source records attributed to A Lacroix.

At least 55 records · Page 3Linked to original sources
PubMed1998

Phagocytic and metabolic activities of macrophages from mummichog naturally exposed to pulp mill effluents in the Miramichi River.

Chemicals present in bleached kraft pulp mill effluents (BKMES) can modulate the immune response of fish. This work was conducted to determine if mummichogs living downstream from a bleached kraft pulp mill (BKM) had an impaired immune response. Head kidney phagocytes from males and females were tested for their phagocytic and metabolic activities. Mummichogs were captured 4 km (S2) and 39 km (S1) downstream from a BKM in the Miramichi estuary (New Brunswick, Canada) and at two sites located upstream (S3) and 20 km downstream (S4) in a reference estuary, the Bouctouche. Both male and female mummichogs captured at S2 in the Miramichi estuary had a lower phagocytic activity, whereas only females from the same site had a decreased oxidative burst response, indicating a difference between sexes in the susceptibility to pollutants present in the Miramichi. Therefore, the results indicate that mummichogs exposed to BKMES have an impaired immune response and that females are more sensitive than males to the chemicals present in BKMES.

Animals↗
PubMed1998

Qualitative evaluation of courses intended for patients suffering from chronic diseases. New observation method for the continuous training of the healthcare team.

Experience has shown that when teaching patients, healthcare providers concentrate more on information concerning the illness rather than on the handling of treatment. Therapeutic education of patients imposes a precise structure on the pedagogic method and teaching aids. It is essential that, during their clinical practice, care-providers develop teaching methods which encourage a maximum of interaction to help patients learn to manage their own treatment. In this perspective, the authors propose 'analytical observation' as a method of training evaluation for healthcare providers. Three observation charts, as well as an analytical method for evaluation, have been devised. They have been tried and validated during a study whose principal objective was to measure quantitatively the impact of supervision of care-providers in the domain of therapeutic education of patients. The authors conclude that this method has a definite impact on the pedagogic progress of the care-providers. It makes it possible to record and to give a structure to the pedagogic follow-up (inspection, examination, testing) of care-providers. Since patient education plays a key role in therapeutic success, this type of methodology for training and evaluation conforms to the rigorousness essential to any therapeutic undertaking.

Chronic Disease↗
PubMed1998

Epidemiology of sociodemographic characteristics, lifestyle, medical history, and colon cancer: a case-control study among French Canadians in Montreal.

Colon cancer is the second most common cancer in both men and women in North America and other developed countries. In a population-based case-control study of colon cancer among French Canadians in greater Montreal, a total of 402 cases and 668 controls were interviewed. The cancer cases were identified through the admission offices of five major Francophone teaching hospitals in Montreal from 1989 to 1993. The controls, matched by age, sex, place of residence, and language, were selected by a modified random digit dialing method. The results show that subjects who had ever been married had a lower risk for colon cancer (odds ratio [OR]: 0.58; 95% confidence interval [95% CI]: 0.48-0.84) than did individuals who had never been married. A significant association (OR: 1.90; p for trend = 0.003) was found between the height of subjects and the risk of colon cancer. The OR for individuals with a family history of colorectal cancer was 2.78 with a p value of 0.01. A direct and significant association (OR: 2.01) was found among constipation, use of laxatives (OR: 1.41), and the risk of colon cancer. Among women, a suggestive inverse association was detected between the number of full-term pregnancies and the risk of colon cancer in female subjects (the OR for five or more pregnancies was 0.58 with a p for trend of 0.08). There was also a suggestive linear trend (increased age-decreased risk) between age at menarche and the risk of colon cancer. No association was apparent between other sociodemographic characteristics and the risk of colon cancer. In conclusion, married individuals had lower risk for colon cancer, perhaps due to food habits or other characteristics of being single. Higher height and weight history 10 years before the diagnosis of cancer are risk factors for breast cancer, while both current weight and body mass index seem to be protective. Positive family history of colon cancer increased the risk of colon cancer significantly.

Adult↗
PubMed1998

Sociodemographic characteristics, smoking, medical and family history, and breast cancer.

The relationship between sociodemographic characteristics, lifestyle, family history of cancer, medical history, and reproductive factors and breast cancer was investigated in a population-based case-control study of French Canadians in Montreal. In this study, a total of 414 French-Canadian cases and 429 age- and language-matched population controls were interviewed. Ever-married women showed significantly lower risk (OR: 0.64 [0.45-0.92]) for breast cancer, as did smokers (OR: 0.73 [0.55-0.98]), particularly of nonfilter cigarettes (OR: 0.36 [0.17-0.72]). Weight history, both for the year before the diagnosis of breast cancer and 10 years previously, was associated with risk for the disease. A strong inverse relationship was found between the number of full-term pregnancies (OR: 0.48 [0.28-0.82]) and the risk of breast cancer, while the p trend for late age at first pregnancy (p = 0.02) and menopause (p = 0.004) was statistically significant. A history of breast problems (OR: 1.87 [1.34-2.60]) and a history of breast cancer in relatives (OR: 2.95 [1.63-5.34]) were strongly associated with risk. This study confirms the risk factors of late age at first full-term pregnancy, nulliparity, late age at menopause, and positive family history of breast cancer in the etiology of this disease. Perhaps the protective effect of smoking against breast cancer could be due to its antiestrogenic influence.

Adult↗
PubMed1998

Adrenocortical overexpression of gastric inhibitory polypeptide receptor underlies food-dependent Cushing's syndrome.

Abnormal responsiveness of adrenocortical cells to gastric inhibitory polypeptide (GIP) in food-dependent Cushing's syndrome suggested that adrenal expression of ectopic, overexpressed, or mutated GIP receptor (GIPR) underlies this syndrome. The expression of GIPR was studied by RT-PCR in human adrenal tissues from two patients with GIP-dependent Cushing's syndrome (adenoma, bilateral hyperplasia), five fetal or adult controls, one patient with Cushing's disease, and four patients with non-food-dependent cortisol-secreting adenomas or bilateral hyperplasias and compared to that in normal pancreas. Hybridization of the RT-PCR-amplified ribonucleic acids with the human GIPR complementary DNA showed an overexpression of GIPR in the adrenals of the two GIP-dependent Cushing's syndrome patients compared to that in normal adrenal tissues (2-3 orders of magnitude) or pancreas (10-fold); no signal could be seen in adrenal adenomas or macronodular hyperplasia from cases of non-food-dependent Cushing's syndrome. No mutation of the GIPR was identified by sequencing the full-length receptor in GIP-dependent adrenal tissue. New alternative spliced isoforms of the GIPR were found, but are identical in GIP-dependent and normal adrenal tissues. Incubation of adrenal cells with GIP stimulates cortisol secretion in GIP-dependent, but not in normal fetal, adult, or non-food-dependent Cushing's syndrome, adrenals. We conclude that the GIPR overexpression and its coupling to steroidogenesis underlie GIP-dependent Cushing's syndrome.

Adrenal Cortex↗
PubMed1997

Nutritional factors and colon carcinoma: a case-control study involving French Canadians in Montréal, Quebec, Canada.

BACKGROUND: In a population-based case-control study of colon carcinoma and nutrition involving the francophone community in Greater Montreal, a total of 402 cases (200 males and 202 females) and 668 controls (239 males and 429 females) were interviewed. METHODS: Cases from 1989-1993 were identified through the admission offices of 5 major francophone teaching hospitals in Montreal and were ages 35-79 years. Controls matched by age, place of residence, and language were selected by a modified random digit dialing method. Information on dietary intake was collected with a quantitative food frequency questionnaire. RESULTS: No associations were evident between colon carcinoma and total energy, protein, or carbohydrate consumption, whereas a suggestive inverse association was found with total fat intake, with an odds ratio (OR) of 0.78 (P = 0.0637), and with saturated fat intake as well (OR = 0.71, P = 0.0893). A strongly significant inverse association was found with dietary fiber (OR = 0.50, P = 0.0018). The strongest inverse association concerning fiber was found with fiber from vegetable sources (OR = 0.57, P = 0.0096), and a suggestive (although nonsignificant) inverse association (OR = 0.74, P = 0.0687) was found with fiber from fruits. Calcium was inversely associated with risk (OR = 0.69, P = 0.0411), as was dietary intake of vitamin A (OR = 0.67, P = 0.0162), retinol, (OR = 0.069, P = 0.0409), vitamin E (OR = 0.53, P = 0.0028), and alphatocopherol (OR = 0.63, P = 0.0256). Although there was no association demonstrated between dietary beta-carotene intake and risk, a suggestive (although nonsignificant) inverse association with intake of other types of carotene was observed (OR = 0.76, P = 0.0740). No association was found between intake of other nutrients investigated in this study and risk of colon carcinoma. CONCLUSIONS: There is strong evidence from epidemiologic studies that high intake of fat and meat are risk factors for colorectal carcinoma in humans, whereas high intake of vegetable and fruit are inversely associated with risk of colon carcinoma. The findings from this study are in agreement with this observation.

Adult↗
PubMed1997

[Type of birth center and conditions of transfer of neonates under 1500 g or gestational age under 33 weeks].

BACKGROUND: Perinatal care's organization has been widely discussed in France during this last decade. Until now, transfer of high-risk neonates from their birth maternity to a pediatric unit using mobile vehicles led by specialized teams is encouraged in this country. POPULATION AND METHODS: Retrospective analysis of the type of maternities of birth for a population of 717 newborns, weighing less than 1,500 g and/or of gestational age under 33 weeks, extracted from a sample of 84,279 births in 1991. RESULTS: Only 15.6% of studied births took place in a maternity including a special intensive care pediatric unit (international level 3); 58.7% of those newborns where transferred outborn. There was a significant difference between the immediate access of newborns to a level 3 pediatric unit according to the location-of birth: significantly fewer newborns were directly transferred to a level 3 unit when born in a facility that included a level 2 pediatric unit, compared with those born in facilities that included a level 1 or 3 pediatric unit. CONCLUSION: Strong efforts should be made to identify mothers at high risk of giving birth to extremely prematured babies or babies with a very low birthweight so that births could take place in maternities properly equipped for their care. Perinatal care's organization should be built on a hierarchical network of maternities and pediatric services related to the risk of the population. Accreditation of maternities and pediatric services could help moving towards this kind of organization.

Bias↗
PubMed1997

The reliability of recollections of family history: implications for the medical provider.

BACKGROUND: Identification by medical providers of families at higher risks for breast cancer relies on patients' recollection of family histories. While patients seem to report the occurrences of breast cancer in their first-degree relatives accurately, little is known about the precision of reports of ages at diagnosis of cancers in relatives, one of the most revealing clues with regard to hereditary transmission. Moreover, the methods used in previous studies to elicit the family reports render their applicability to the medical setting questionable. METHODS: Confirmatory pathology records were sought and compared with reports of breast cancer events among 125 first-degree relatives by 68 women with breast cancer and 37 women without the disease. RESULTS: Sixty-seven (90.5%) of the reports of the occurrence of breast cancer in relatives by affected women and 32 (97.0%) of those by unaffected women were accurate. Women reporting several affected relatives often overreported the presence of breast cancer events. Nearly 89% of the reports of age at diagnosis were correct within five years. The average error in the reports was 2.0 years. The precision of reports of age at diagnosis did not differ according to the educational level of the proband, the age at which the relative had been diagnosed, or the type of relative affected. However, the mean error in reporting the age at diagnosis of relatives was significantly larger among probands 70 years old or older compared with younger probands. CONCLUSIONS: These results suggest that relying on reports by patients with and without breast cancer should not critically affect the assessment of breast-cancer risks for family members. Nevertheless, verification by examination of pathology records is justified when decisions about patient management and referral for genetic counseling are made based on reports of several affected relatives.

Adult↗
PubMed1997

Laparoscopic adrenalectomy: lessons learned from 100 consecutive procedures.

UNLABELLED: One hundred consecutive laparoscopic adrenal procedures for a variety of endocrine disorders were reviewed. There was no mortality, morbidity was 12%, and conversions was 3%. During follow-up, none had recurrence of hormonal excess. Laparoscopic adrenalectomy is the procedure of choice for adrenal removal except in carcinoma or masses > 15 cm. OBJECTIVE: The authors evaluate the effectiveness of laparoscopic adrenalectomy for a variety of endocrine disorders. SUMMARY BACKGROUND DATA: Since the first laparoscopic adrenalectomy was performed in 1992, this approach quickly has been adopted, and increasing numbers are being reported. However, the follow-up period has been too short to evaluate the completeness of these operations. METHODS: One hundred consecutive laparoscopic adrenal procedures from January 1992 until November 1996 were reviewed and followed for adequacy of resection. RESULTS: Eighty-eight patients underwent 97 adrenalectomies and biopsies. The mean age was 46 years (range, 17-84 years). Indications were pheochromocytomas (n = 25), aldosterone-producing adenomas (n = 21), nonfunctional adenomas (n = 20), cortisol-producing adenomas (n = 13), Cushing's disease (n = 8), and others (n = 13). Fifty-five patients had previous abdominal surgery. Mean operative time was 123 minutes (range, 80-360 minutes), and estimated blood loss was 70 mL (range, 20-1300 mL). There was no mortality, and morbidity was encountered in 12% of patients, including three patients in whom venous thrombosis developed with two sustaining pulmonary emboli. During pheochromocytoma removal, hypertension occurred in 56% of patients and hypotension in 52%. There were three conversions to open surgery. The average length of stay has decreased from 3 days (range, 2-19 days) in the first 3 years to 2.4 days (range, 1-6 days) over the past 16 months. During follow-up (range, 1-44 months), two patients had renovascular hypertension and none had recurrence of hormonal excess. CONCLUSION: Laparoscopic adrenalectomy is safe, effective, and decreases hospital stay and wound complications. Prior abdominal surgery is not a contraindication. Pheochromocytomas can be resected safely laparoscopically despite blood pressure variations. Venous thrombosis prophylaxis is mandatory. The laparoscopic approach is the procedure of choice for adrenalectomy except in the case of invasive carcinoma or masses > 15 cm.

Adenocarcinoma↗
PubMed1997

Abnormal adrenal and vascular responses to vasopressin mediated by a V1-vasopressin receptor in a patient with adrenocorticotropin-independent macronodular adrenal hyperplasia, Cushing's syndrome, and orthostatic hypotension.

The elucidation of gastric inhibitory polypeptide-dependent Cushing's syndrome suggested that ectopic expression or increased responsiveness of other adrenal hormone receptors may underlie ACTH-independent macronodular adrenal hyperplasia (AIMAH) or adrenocortical tumors. We studied a 36-yr-old woman with Cushing's syndrome, AIMAH, and orthostatic hypotension. During upright posture, cortisol and aldosterone were stimulated despite suppression of ACTH and renin. Arginine vasopressin (AVP, 10 U im), under dexamethasone suppression, increased plasma cortisol (3.4-fold), aldosterone (67-fold), and androgens in this patient but not in controls. ACTH 1-24, but not desmopressin acetate, angiotensin II, isoproterenol, or other hormones stimulated steroidogenesis in vivo. Plasma AVP was undetectable initially and increased suboptimally during posture tests after bilateral adrenalectomy. AVP stimulated cortisol production more in dispersed cells from the AIMAH than from a normal adult adrenal (424 vs. 135% at 10 nmol/L). Adrenal V1-AVP receptor presence and mediation of response were shown by RT-PCR and by binding and [Ca+2]i studies. Post adrenalectomy, orthostatic hypotension persisted; a prolonged vasoconstrictive response to AVP was found in vitro in the patient's sc small arteries. We propose that altered adrenal and vascular responses of the V1-AVP receptor-effector pathway underlie this new syndrome.

Adrenal Glands↗
PubMed1997

[Analysis of delivery facilities and conditions in 1991 in mothers of infants with birth weights below 1500 grams and/or gestational age under 33 weeks].

AIMS: To identify maternities (in terms of level of activity and linkage with pediatric services) where, in 1991, mothers gave birth to infants of gestational age less than 33 weeks and/or with birth weight under 1500 g. To analyse factors linked to the probability of choosing a particular maternity as place of delivery for this population and measure the impact of maternal transferts on the rates of deliveries. To estimate the number of neonate transferts which could be avoided with simple recommendations. To propose policies that would allow France to come closer to the results of other reference countries in term of management of obstetrical and neonate care. MATERIAL AND METHOD: We extracted from a retrospective sample of 84,279 births (out of a total of 770,148), 717 infants meeting previously defined criteria and related to the population described above, using univariate and multivariate analysis and logistic regression. RESULTS: The Odds-ratio for a delivery to take place in a maternity with a volume of more than 2000 deliveries a year, compared with those doing less than 300 deliveries, is 4, 12. Only 15.8% of those deliveries took place in maternities linked to a level 3 pediatric unit (i.e where an intensive care neonates unit was located in the same building). 39.5% of births took place in level 1 maternities where no required pediatric service existed. Logistic regression techniques showed that the choice of a maternity for mother referral was more linked to the number of deliveries than to its level of pediatric services. In the studied population, 46% of the difference between the observed number of births in high volume maternities (compared to the expected number) could be explained by a maternal referral. The analysis of deliveries showed that for 34% of mothers who gave birth to a baby in a level 1 or 2 maternity, there was a possibility of being referred easily in a level 3 maternity. CONCLUSION: This study shows that the level of care of mothers at high risk of delivering a very premature and/or hypotrophic infant is far from international standards. Simple actions could double the number of births taking place in adapted maternities. We propose to both obstetricians and pediatrists, a common program to enhance the level of care.

Analysis of Variance↗
PubMed1997

[Orthodontic contribution in sleep apnea].

This study details the role that the orthodontist can play, when faced with sleeping obstructive apneas and snoring phénomena. Of special importance are knowledge of cranio-facial growth, radiographic exam and cephalometric analysis: they mainly help to understand all the aspects of this specific syndrome, and reveal the interest for a neuro-orthodontic or a neuro-surgical orthodontic approach.

Adult↗
PubMed1997

[Chronic osteomatous otitis media: apropos of 2 cases].

Osteomatous chronic otitis media is an extremely rare clinical entity. Fleury has described three types: a massive type, a diffuse attico-antral type, and a localised type. This latter is equivalent to a state of chronic inflammation of the middle or outer ear, accompanied by bony excresscences of osteomatous type. Here we add two additional cases to the few which are to be found in the literature on this subject. We would also like to emphasize the practical-surgical difficulty of treating such cases, with the vital structures of the middle ear hidden (facial nerve, lateral semicircular canal, and ossicles), and would advise the greatest care when tackling these surgically.

Adult↗
PubMed1996

Familial clustering of obesity and breast cancer.

One of the most striking characteristics of breast cancer (BC) is a tendency to familial aggregation. In order to evaluate whether familial clustering of obesity could account, at least in part, for the familial aggregation of BC, we compared the adult body size of entire sets of first-degree relatives belonging to 60 families with two or more cases of BC (case families) and 120 BC-free families (control families). Case families included an index case recently admitted for primary BC who had a confirmed first-degree family history for the disease. Control families included one population-based healthy index control with no family history and age-matched (2:1) to index cases. Index cases and controls, recruited from a pool of participants in a large case-control study, completed a questionnaire covering their own body size history as well as that of each of their first-degree relatives (598 case and 1,128 control relatives) using a validated system of body silhouette drawings. The odds ratio (OR) for premenopausal familial BC associated with having one parent markedly obese compared to none was 0.17 (95% confidence interval [CI] 0.04-0.65), while having both parents obese resulted in an OR of 0.25 (95% CI 0.04-1.56). Obesity among siblings was not related to premenopausal familial BC risk nor was familial obesity a significant predictor of familial BC after menopause. Index cases from both menopausal groups tended to be thinner than their unaffected relatives at age 40 years and thereafter. The inverse relationship between parental obesity and premenopausal BC risk is concordant with the protective effect of obesity on early-onset BC previously reported at the individual level.

Adult↗
PubMed1996

Nutritional factors and prostate cancer: a case-control study of French Canadians in Montreal, Canada.

The relationship between the risk of prostate cancer and dietary intake of energy, fat, vitamin A, and other nutrients was investigated in a case-control study conducted in Montreal (Quebec), Canada. French Canadians aged 35 to 84 years with a recent, histologically confirmed diagnosis of adenocarcinoma of the prostate were identified through the admission offices of five major francophone teaching-hospitals in Montreal from 1989 to 1993. Population-based controls matched for age (+/- five years), language, and place of residence were selected by a modified random-digit dialing method. The study included 232 cases and 231 controls. Information on dietary intake was collected by means of a quantitative dietary history. No association was evident between energy intake and the risk of prostate cancer. In contrast, there was some evidence of an inverse association with intake of total fat, animal fat, monounsaturated fat, and particularly saturated fat (odds ratio = 0.69, 95 percent confidence interval = 0.40-1.18, P = 0.05), while a nonsignificant positive association was found with polyunsaturated fat. In addition, high intake of retinol and vegetable protein (highest cf lowest quartile) was associated with reduced risk, but was not statistically significant. No associations were established between intake of other nutrients and risk. These patterns persisted after adjustment for a number of potential confounding factors.

Adenocarcinoma↗