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J Turcotte

Publications and source records attributed to J Turcotte.

At least 19 recordsLinked to original sources
PubMed1997

A population-based, randomized clinical trial on back pain management.

STUDY DESIGN: Population-based randomized clinical trial. OBJECTIVES: To develop and test a model of management of subacute back pain, to prevent prolonged disability. SUMMARY OF BACKGROUND DATA: The present management of back pain seems inadequate, and development of innovative models has been urged. METHODS: A model for the treatment of subacute work-related back pain has been developed and evaluated in a population-based randomized clinical trial. Workers (n = 130) from eligible workplaces in the Sherbrooke area (N = 31), who had been absent from work for more than 4 weeks for back pain, were randomized, based on their workplace, in one of four treatment groups: usual care, clinical intervention, occupational intervention, and full intervention (a combination of the last two). The duration of absence from regular work and from any work was evaluated using survival analysis. Functional status and pain were compared at study entry and after 1 year of follow-up. RESULTS: The full intervention group returned to regular work 2.41 times faster than the usual care intervention group (95% confidence interval 1.19-4.89; P < 0.01). The specific effect of the occupational intervention accounted for the most important part of this result, with a rate ratio of return to regular work of 1.91 (95% confidence interval = 1.18-3.10; P < 0.01). Pain and disability scales demonstrated either a statistically significant reduction or a trend toward reduction in the three intervention groups, compared with the trend in the usual care intervention group. CONCLUSIONS: Close association of occupational intervention with clinical care is of primary importance in impeding progression toward chronicity of low back pain.

Adolescent↗
PubMed1995

A role for ultraviolet A in solar mutagenesis.

It is well established that exposure to solar UVB (290-320 nm) gives rise to mutations in oncogenes and tumor suppressor genes that initiate the molecular cascade toward skin cancer. Although UVA (320-400 nm) has also been implicated in multistage photocarcinogenesis, its potential contribution to sunlight mutagenesis remains poorly characterized. We have determined the DNA sequence specificity of mutations induced by UVB (lambda > 290 nm), and by UVA (lambda > 350 nm), at the adenine phosphoribosyltransferase locus of Chinese hamster ovary cells. This has been compared to results previously obtained for stimulated sunlight (lambda > or = 310 nm) and 254-nm UVC in the same gene. We demonstrate that T-->G transversions, a generally rare class of mutation, are induced at high frequency (up to 50%) in UVA-exposed cells. Furthermore, this event comprises a substantial proportion of the simulated sunlight-induced mutant collection (25%) but is significantly less frequent (P < 0.05) in cells irradiated with either UVB (9%) or UVC (5%). We conclude that the mutagenic specificity of broad-spectrum solar light in rodent cells is not determined entirely by the UVB component and that UVA also plays an important role.

Adenine Phosphoribosyltransferase↗
PubMed1994

Management of occupational back pain: the Sherbrooke model. Results of a pilot and feasibility study.

OBJECTIVES: The aim was to combat occurrence of chronic occupational back pain. METHODS: A multidisciplinary model to manage back pain that includes both clinical and ergonomic approaches has been developed. Early detection, early clinical and ergonomic evaluations, and early active treatment make up the cornerstone of management. Detection of cases starts after four weeks of absence from work. An ergonomic intervention is implemented at six weeks. A medical specialist is involved at eight weeks. If return to work is not possible after 12 weeks, a functional recovery therapy followed by a therapeutic return to work is implemented. A multidisciplinary team decides if return to original or modified work is possible or if vocational rehabilitation is necessary. This model has been implemented by the investigators in the Sherbrooke (Quebec, Canada) area, and is presently being evaluated through a randomised trial in 31 industrial settlements (about 20,000 workers). A cluster randomisation of industries and workers will allow separate testing of ergonomic and clinical interventions. RESULTS: One year after implementation, 31 of 35 of the eligible industrial sites participated in the study and 79 of 88 of the eligible workers affected by recent back pain had agreed to participate. Ergonomic and clinical interventions have been implemented as planned. Only three workers dropped out. Hence this global clinical and ergonomic management programme has been shown to be feasible in a general population. CONCLUSION: A global management programme of back pain joining ergonomic and clinical intervention with a multidisciplinary approach has not been tested yet. Linking these two strategies in a same multidisciplinary team represents a systemic approach to this multifactorial ailment. During the first year of this trial we did not find any conflict between these two interventions from the employer's or worker's point of view.

Adult↗
PubMed1988

Immunocytochemical localization of estrogen-induced progestin receptors in guinea pig brain.

By using a combination of monoclonal antibodies to progestin receptors and a double-bridge peroxidase-antiperoxidase technique, a sensitive immunocytochemical method was developed for visualizing progestin receptor immunoreactivity (PR-IR) in brains of estrogen-primed guinea pigs. PR-IR neurons were observed throughout the hypothalamus and preoptic area. They were seen in largest numbers in the arcuate nucleus, periventricular preoptic regions, medial preoptic nucleus, medial preoptic area and in the ventrolateral area of the hypothalamus. Lower numbers of PR-IR positive cells were detected in the bed nucleus of stria terminalis, paraventricular nucleus and lateral hypothalamus with scattered cells seen throughout the hypothalamus and preoptic area. The PR-IR was mostly intranuclear with lighter staining in neuronal processes. Electron microscopy confirmed the predominantly intranuclear localization and further demonstrated that the reaction product was dispersed throughout the nucleus, but not associated with the nucleolus. Few PR-IR cells were observed in the absence of estradiol priming, and the reaction product was much lighter than in the presence of estradiol. Progesterone injection was without apparent effect on intensity of the PR-IR.

Animals↗
PubMed1987

Further evidence of noradrenergic regulation of rat hypothalamic estrogen receptor concentration: possible non-functional increase and functional decrease.

The regulation of estrogen receptors by the alpha 2-noradrenergic system was studied. A single injection of the alpha 2-noradrenergic antagonist, yohimbine, caused a biphasic effect on the concentration of cytosol estrogen receptors in the mediobasal hypothalamus and anterior pituitary gland. A short-latency increase was seen at 1.5-3 h, followed by a longer-lasting decrease at 8-16 h. Scatchard analysis revealed that the apparent, short-latency increase is in the concentration of binding sites, not in the affinity of the receptor for [3H]estradiol. The increase in the concentration of cytosol estrogen receptors is not blocked by pretreatment with the alpha 2-noradrenergic agonist, clonidine. In addition, no increase is detected in the concentration of cell nuclear estrogen receptors accumulating in response to a saturating dose of estradiol. Therefore, the apparent increase in the concentration of cytosol estrogen receptors may not represent a functional increase in receptors. The decrease in the concentration of estrogen receptors, which occurs 8-16 h after yohimbine treatment, is also seen after injection of the alpha 2-adrenergic antagonist, idazoxan, and is not due to a change in the in vitro rate of association of the receptors with [3H]estradiol. Furthermore, the decrease seems to be a functional decrease in the concentration of receptors capable of cell nuclear accumulation in response to estradiol injection, as indicated by the results of experiments in which the concentration of cell nuclear estrogen receptors was assayed after estradiol injection. These experiments provide further support for the hypothesis that the alpha-noradrenergic system, and perhaps specifically the alpha 2-subtype, is involved in decreasing the concentration of estrogen receptors in parts of the brain and pituitary gland. This interaction provides a mechanism by which the environment could regulate the sensitivity of certain neurons to estradiol. However, the finding that the initial increase in the concentration of cytosol estrogen receptors after yohimbine treatment is not followed by the predicted increase in cell nuclear estrogen receptors after estradiol injection raises questions about the physiological relevance of the apparent increase under some conditions.

Adrenergic alpha-Agonists↗
PubMed1987

Small apomorphine-induced increase in the concentration of cytosol estrogen receptors in female rat hypothalamus and pituitary.

A series of experiments was performed to investigate the previously-reported modulation of estradiol binding in female rat brain and pituitary gland by drugs that influence the dopaminergic system. Injection of the dopamine agonist, apomorphine, at minimum doses of 1-2 mg/kg body weight caused slight increases (in most cases, less than 10%) in the concentration of cytosol estrogen receptors in the mediobasal hypothalamus and anterior pituitary gland without influencing the concentration in the preoptic area. However, after subsequent injection of a saturating dose of estradiol, the level of nuclear estrogen receptors accumulating did not differ significantly between apomorphine-treated animals and vehicle-injected controls. These results extend, in part, previous reports that have shown an apomorphine-induced increase in the concentration of [3H]estradiol in brain and pituitary cell nuclei after an injection of [3H]estradiol. However, we failed to observe differences in the concentration of cytosol estrogen receptors as large as would be expected by previous work, and we failed to observe differences in the concentration of nuclear estrogen receptors after estradiol injection.

Animals↗
PubMed1985

Severe myositis and myocarditis in progressive systemic sclerosis.

A 22-year-old woman with progressive systemic sclerosis developed severe myositis and life threatening myocarditis. Her myocarditis responded to intravenous pulse methylprednisolone therapy. We stress the usefulness of echocardiography in establishing the diagnosis and following the course of myocarditis.

Adult↗
PubMed1984

Surgical reconstruction of the proximal vertebral artery.

The authors have reviewed their experience in the management of 55 patients admitted to Henry Ford Hospital with symptoms of vertebrobasilar insufficiency and associated proximal vertebral artery stenosis or occlusion. In 48 patients, the symptoms occurred as multiple repeated events, five of which resulted in permanent deficits. The remaining seven patients had single events, four of which caused permanent deficit. These patients had been treated unsuccessfully with antiplatelet agents (37 cases) and with anticoagulant drugs (15 cases) before surgery. Most patients had multiple angiographic abnormalities, including bilateral vertebral stenosis in 19 cases, unilateral vertebral stenosis and contralateral occlusion in 18, unilateral vertebral hypoplasia and contralateral stenosis in 10, subclavian artery stenosis with steal in seven, and bilateral vertebral artery occlusion in one case. Posterior communicating arteries could not be demonstrated angiographically in 18 patients. Thirty-four patients had associated stenotic or occlusive lesions of the internal carotid artery. Forty-eight underwent a vertebral-to-carotid artery transposition. Of these, 18 had an associated carotid endarterectomy and seven had a vertebral artery endarterectomy immediately before the transposition. Two patients had saphenous vein grafts, one from the subclavian and one from the common carotid artery to the vertebral artery. Other surgical procedures included vertebral artery ligation in one case, transposition of the vertebral artery to the thyrocervical trunk in two cases and to the subclavian artery in one case, and endarterectomy of the origin of the vertebral artery in one case. All but two patients had complete resolution of their symptoms: one had persistent dizziness and the other had syncopal episodes. Complications included transient Horner's syndrome (30 cases) which became permanent in four cases, vocal cord paralysis (three cases), elevated hemidiaphragm without respiratory difficulty (two cases), and superficial would infection (one case). There were no deaths. Although the presentation of patients with vertebrobasilar insufficiency is generally characteristic, we believe that a specific diagnosis can be established only by angiographic means. Anticoagulants have been used to alleviate symptoms in some cases but are ineffective in solving the primary hemodynamic problem. Surgical reconstruction of the affected area deserves further evaluation in the management of these patients.

Adult↗
PubMed1982

Differing effects of ursodeoxycholic or chenodeoxycholic acid on biliary cholesterol saturation and bile acid metabolism in man. A dose-response study.

A dose-response study comparing ursodeoxycholic and chenodeoxycholic acid was carried out in six men with asymptomatic radiolucent gallstones present in well-visualizing gallbladders. The study tested the effects of a low (averaging 6 mg/kg/day) or medium dose (averaging 11 mg/kg/day) of each bile acid on the cholesterol saturation of bile as well as on bile acid metabolism, as inferred from biliary and fecal bile acid composition. Ursodeoxycholic acid, at low or medium doses, induced bile desaturation in most patients, whereas chenodeoxycholic acid did not. Despite the greater desaturation efficacy of ursodeoxycholic acid, biliary bile acids became less enriched with the administered bile acid during ursodeoxycholic acid treatment than during chenodeoxycholic acid treatment. Both bile acids were nearly completely 7-dehydroxylated to lithocholic acid by colonic bacteria, but biliary lithocholic increased only slightly (and similarly) with each bile acid. Fecal bile acid composition suggested that administered ursodeoxycholic acid suppressed endogenous bile acid synthesis much less than chenodeoxycholic acid. The results indicate that ursodeoxycholic acid and chenodeoxycholic acid have similar but not identical effects on bile acid metabolism, but that for a given dose, ursodeoxycholic acid is a more potent desaturating agent than chenodeoxycholic acid. The results suggest that cholesterol gallstone dissolution with ursodeoxycholic acid should occur with a dose of 8-10 mg/kg in most nonobese patients.

Aged↗
PubMed1981

Peritransplant fluid collections. Ultrasound evaluation and clinical significance.

Gray-scale ultrasonography was used to detect, localize, and guide percutaneous aspirations of peritransplant fluid collections. Fifty-one (51%) transplant recipients had abnormal fluid collections; 18 of these patients required surgery. Analysis of the 23 proved fluid collections (10 lymphocytes, 7 abscesses, 4 urinomas, and 2 hematomas) revealed certain sonographic and temporal patterns. Lymphoceles were the most common cause of an obstructed transplant and were usually septated. Most of the undiagnosed fluid collections were small and crescentic and were located in the abdominal wall. They usually did not enlarge or resolve on serial ultrasound examinations. A role for ultrasound in the management of peritransplant fluid collections is proposed.

Abscess↗
PubMed1979

Extended treatment with antithymocyte globulin (ATGAM) in renal allograft recipients.

Twenty renal allograft recipients were treated with antithymocyte globulin (ATGAM; ATG) for up to 16 weeks in addition to azathioprine and prednisone, while 20 controls received no ATG. The ATG group showed a lower incidence of first rejection episodes during the first month after transplantation, and also a better functional graft survival rate up to 2 years after transplantation. The results in this early ATG trial were better than those in subsequent trials which used 14-day treatment regimens. Longer treatment deserves another look.

Antilymphocyte Serum↗
PubMed1977

Radioimmunoassay of bile acids: development, validation, and preliminary application of an assay for conjugates of chenodeoxycholic acid.

A rapid, sensitive, precise radioimmunoassay for conjugates of chenodeoxycholic (chenic) acid has been developed and validated. Immunogen was prepared with chenylglycine couples to bovine serum albumin, emulsified in Freund's complete adjuvant, and injected intracutaneously in rabbits. Antibodies of moderate titer (used at 1:7500 final dilution) were obtained. Tracer of high specific activity was prepared by reductive tritiation of delta11-chenylglycine. The binding step required 1 hr at room temperature; separation of bound tracer was achieved by addition of ammonium sulfate. The limit of sensitivity of the assay was about 20 nmoles per liter, and the lower limit of the working range was 0.4 mumole per liter. The assay was validated by measuring levels in samples of fasting state serum to which known amounts of chenylglycine had been added; the assay was also validated by means of gas-liquid chromatography on sera from jaundiced patients. The median fasting state serum level in 56 Caucasians and blacks was 0.9 mumole per liter (upper limit of normal (95% confidence) being 2.3), which is in the same range as that reported by others using gas-liquid chromatography. A 5- to 10-fold increase in levels of chenyl conjugates was observed 1 hr after the ingestion of a liquid meal in healthy persons.

Ammonium Sulfate↗
PubMed1977

Radioimmunoassay of unsulfated lithocholates.

A simple, rapid, precise radioimmunoassay for total unsulfate species of lithocholate (lithocholyglycine, lithocholyltaurine, and lithocholate) in serum is described. Antiserum was raised in rabbits by injection of lithocholylglycine coupled to bovine serum albumin (prepared by a carbodiimide method) and emulsified in complete Freund's adjuvant; antisera capable of measuring 40-120 pmol at 1:400 dilution were obtained. The tracer was [11, 12-3[H]lithocholyglycine. The radioimmunoassay featured a 2-hr binding step at 42 decrease C and a 1-hr separation step using polyethylene glycol. The antibody had the following relative specificities: lithocholyglycine and lithocholytaurine, 1; lithocholate, 1.5; chenodeoxycholyglycine, 20; and deoxycholylglycine, 55. There was no binding of various other free or conjugated sulfated and unsulfated bile acids. The mean fasting-state level in 50 healthy subjects was 0.3 mu mol/l (0.14 microgram/ml), but 11 of the 50 subjects had level too low to measure by this technique.

Antibody Specificity↗