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M LeBlanc

Publications and source records attributed to M LeBlanc.

49 records · Page 3Linked to original sources
PubMed1990

Determinants of improved outcome in small-cell lung cancer: an analysis of the 2,580-patient Southwest Oncology Group data base.

We analyzed the 2,580-patient Southwest Oncology Group (SWOG) small-cell lung cancer data base from 1976 to 1988 in order to (1) determine the prognostic value of favorable demographic and tumor-related factors and therapy programs using Cox multivariate analyses in limited- and extensive-stage disease (LD, ED), and (2) define patient subgroups with significantly different survivals using recursive partitioning and amalgamation (RPA) analysis to refine the current two-stage system. Cox multivariate models were applied to 1,363 patients in six LD trials: good performance status, female sex, age less than 70 years, white race, and normal lactate dehydrogenase (LDH) were significant favorable independent predictors. Concurrent chemoradiotherapy was also a strong independent predictor of survival. For 1,217 patients in four ED trials, a normal LDH, treatment with an intensive multidrug regimen, and a single metastatic lesion were favorable independent variables in the Cox model. RPA analysis of 1,137 patients in recent LD and ED trials resulted in a regression tree in which the most important prognostic split was LD versus ED. Normal or abnormal LDH, absence or presence of a pleural effusion, and age less than 70 or greater than or equal to 70 years were important in LD, but only LDH was significant in ED. The terminal nodes of the regression tree were amalgamated to form four distinct prognostic subgroups with median survivals of 19.0, 12.5, 10.5, and 6.3 months (P less than .0001). The best survival occurred for younger patients with "true" LD: no effusion and normal LDH. The two intermediate patient subgroups had either LD or ED but still lived significantly longer than those patients with true ED (elevated LDH). This analysis suggests that although several factors were independent prognostic variables in LD in the Cox models, a smaller number of variables can be used to form important prognostic subgroups through RPA. The LDH emerged as a highly significant factor, but performance status and sex did not. A refinement of the current staging system should be made if our results can be confirmed with a combined-group data base analysis.

Adult↗
PubMed1988

The predictive power of first-grade peer and teacher ratings of behavior: sex differences in antisocial behavior and personality at adolescence.

Peer and teacher assessments of aggression, social withdrawal, and likability using the Pupil Evaluation Inventory were recorded for 104 French Canadian girls and boys in grade 1. Self-reported delinquency and personality measures were administered to these children when they were in junior high school 7 years later. Linear regression analyses revealed significant predictive differences between the grade 1 assessment of girls and boys: For antisocial behavior, teacher and peer assessments of boys were equally good predictors, and the combination of the two assessments did not improve prediction; for girls, peer and teacher assessments taken separately were weak predictors, but, taken together, they were better predictors for girls than for boys; for personality, peers were better predictors than teachers both for girls and for boys. When categorical analyses were used to predict extreme antisocial behavior, peer and teacher assessments were equally good predictors for girls and boys. The use of peer and teacher ratings together, however, decreased the number of false positives. The implications of these findings for research and clinical work are discussed.

Antisocial Personality Disorder↗
PubMed1988

Preliminary assessment of three new designs of prosthetic prehensors for upper limb amputees.

At present, upper-limb amputees have a basic choice of a hook or a hand for the prosthetic prehensor. In the USA about two-thirds of upper-limb amputees wear hooks and about one-third wear hands. Either of these options represents a compromise. The hook is more functional and the hand is more cosmetic. Some amputees solve the dilemma by having one of each and interchanging them as work and social situations dictate. However, they would prefer to have one acceptable prehensor, and they want one which is functional, is attractive, and does not necessarily have to look like a hand. In an attempt to meet the desires of upper-limb amputees, three prosthetic prehensors or "terminal devices" have been designed and developed into models. This article describes the preliminary assessment of these new designs.

Amputees↗
PubMed1988

Use of prosthetic prehensors.

Estimates are given of the type and number of prosthetic prehensors - both hooks and hands - used in the USA, United Kingdom, West Germany and Sweden by upper limb amputees. Implications are made for differences between countries and for thorough assessment of amputees before clinical fittings.

Germany↗
PubMed1987

Refresher education policy: results of a survey.

Occupational Therapy experiences chronic manpower shortage. This is in part, due to loss of trained,experienced manpower. In many cases, female occupational therapists, like other women, drop-out of the work force to re-enter later. In an attempt to delineate refresher education policy for re-entering, a mail survey of randomly selected members of Ontario occupational therapists and occupational therapy managers was conducted. The results of the survey suggested refresher education should be mandatory after an absence of 3-5 years, should be under the jurisdiction, at least in part, of the provincial association, should be oriented to specialists training and have a variety of formats including clinical practice.

Data Collection↗
PubMed1986

Radial partition immunoassay applied to automated quantification of human choriogonadotropin with use of two monoclonal antibodies.

We describe a novel application of radial partition immunoassay to quantification of human choriogonadotropin (hCG). In this "sandwich"-type assay, two monoclonal antibodies, specific for different sites on the intact molecule are used. The solid phase consists of tabs of glass-fiber filter paper containing a pre-immobilized antibody specific for the alpha subunit of hCG. The patient's sample is first applied directly to the central "reaction zone" of the tab, allowing hCG to bind to the solid-phase antibody. Then a buffered solution containing enzyme-labeled Fab' fragments of a monoclonal antibody specific for the beta subunit of hCG is applied, initiating "sandwich" formation. Finally, a wash buffer containing a fluorogenic substrate is applied, eluting unbound conjugate to the tab periphery. Bound enzyme conjugate is quantified by measuring the rate of increase in fluorescence. Rates are converted to clinical units by comparison with a stored calibration curve. Elapsed time from sample application to results is less than 8 min. Specific performance characteristics of this assay are reported.

Antibodies, Monoclonal↗
PubMed1983

Zinc metabolism in testicular feminization and surgical cryptorchid testes in rats.

Rats with testicular feminization (Tfm) had been reported to have a testis specific zinc deficiency. In this report it is demonstrated that this organ specific zinc deficiency was not corrected by intraperitoneal zinc administration. Normal littermates on the other hand showed a positive testicular response to zinc administration. The increased testicular zinc level in control animals returned to normal 1 week after the zinc treatment probably due to the fast turnover of this element in the testis. Not only surgically induced cryptorchidism but also surgical cryptorchidism and epididymodeferentectomy (to simulate Tfm conditions in normal adult rats) caused a drastic reduction in testicular zinc level. Unlike in Tfm rats, however, the decrease in zinc content in operated animals was not accompanied by a corresponding decrease in alkaline phosphatase activity. Zinc concentration and alkaline phosphatase activity in plasma or other organs were not affected by the surgical procedure. The testicular copper content in the operated animals was higher than that of the unoperated controls.

Alkaline Phosphatase↗
PubMedDate not supplied

Data acquisition system for dialysis machines. A model for membrane hydraulic permeability.

Membrane permeability is a key determinant of dialyzer performance; in vivo, membrane hydraulic permeability is affected by the formation of a protein cake on its surface, reducing ultrafiltration and convective fluxes. The purpose of this work was to evaluate the real hydraulic permeability of high flux polysulfone membrane under conditions of hemodiafiltration, and to consequently develop a mathematical model to estimate ultrafiltration Kuf and protein adsorption Kc coefficients. The DIB08 data acquisition system adapted to the Fresenius 2008E dialysis machine (Fresenius, Bad Homburg, Germany) allowed the recording of useful information for dialysis quantification, which was then processed by a bedside computer. The system was able to evaluate Kuf(t) profile, by calculation from the transmembrane pressure over time (TMP(t)) and ultrafiltration rate (Quf):Kuf (t) = Quf/TMP (t). Subsequent modeling of Kuf involved the determination of two key parameters: Kufhd (dialyzer permeability during diffusion only) (in mL/h/mmHg), and Kc (protein adsorption coefficient) (in mL/h/mmHg2). The model chosen was the following: Kuf (t) = Kuf0 x (1 - (Kc/Kuf0) x In(t + 1)) where Kuf0 represents the initial Kuf obtained at the beginning of the session. Thirty-one sessions were evaluated by real kinetic analysis, from which the mathematical model was derived. It included 27 postdilutional on-line hemodiafiltration and four hemodialysis sessions performed in four patients with nonreused HF80s dialyzers. For the analysis, three subgroups were defined: Group 1, first session of the week (Monday or Tuesday); Group 2, second session of the week (Wednesday or Thursday); and Group 3, third session of the week (Friday or Saturday). Results of Kuf and Kc obtained by real kinetic analysis are presented. The midweek session was associated with a higher membrane hydraulic permeability, most likely relative to lesser ultrafiltration rates and an associated relative decrease in membrane protein coating, represented by Kc. The described data acquisition system allowed the assessment of real time membrane hydraulic permeability and the subsequent development of a mathematical model to estimate this fundamental parameter as it functions to hemodialyzer performance.

Adult↗
PubMedDate not supplied

[Anatomoclinical study of 29 cases of acute necrotizing encephalitis. Demonstration of herpes virus in 24 cases].

The authors studied the cerebral lesions in 29 cases of acute necrotizing encephalitis. Electron microscopy showed the presence of typical herpes virus particles in 24 cases. In 16 of them the virus had been isolated from specimens of the brain taken by biopsy and in 8 other cases from autopsy specimens. In 3 acute cases the search for the virus was negative and it was not carried out in the two cases with prolonged evolution. Only 6 patients have survived. Some peculiar varieties have beeen observed, i.e. two adolescents had temporal and almost entirely unilateral lesions, and two aged females had severely hemorrhagic necrotic areas which could have been confounded with vascular lesions. In these two later cases typical particles were present. Finally, one case showed within the same nuclei at once typical herpes virus particles and other viral structures of vermicular form, the origin of which could not be precised.

Adolescent↗
PubMedDate not supplied

The design of a compliant composite crutch.

Ambulation by crutches takes up to twice the energy of normal gait and can lead to injuries of the hands and arms. The compliant composite forearm crutch described in this article seeks to address these problems. The new crutch is made of a single composite piece and has an S-curve in the main body to provide shock absorption and return of energy with the goal of reducing impact and repetitive injuries. It is lighter and, we expect, more durable than current crutches due to the lack of interfacing parts. The new forearm cuff design provides retention of the crutch on the arm without a pivot. The contoured forearm cuff with wrist supports and padding is intended to provide added comfort and support. These features are integrated into an aesthetic, high-tech-looking design in charcoal/black color. (See Figure 1) Initial testing with seven users yielded favorable response to function and appearance. Quantitative analysis has identified improvements needed for future iteration in design. These include 1) making the wrist supports more narrow and placed down one inch, 2) optimizing the stiffness of the top curve of the S-shape, and 3) testing the crutch for motion and energy requirements in use.

Biomechanical Phenomena↗
PubMedDate not supplied

Correlates of condom use in the young adult population in Ontario.

OBJECTIVES AND METHODS: Data from the Ontario Health Survey were used to identify sociodemographic, lifestyle and sexual history characteristics associated with the use of condoms for protection against sexually transmitted diseases (STDs) in randomly selected adults between the ages of 16 and 44 years who had had two or more sexual partners in the 12 months before the survey (n = 2,699). RESULTS: Forty-two percent reported not having used condoms for protection against STDs. Those most likely to use condoms were 16 to 24 years of age, males, students, non-binge-drinkers, urban residents, and those at higher risk for HIV/AIDS. Of those who used condoms, 68% did not use them consistently. Individuals most likely to always use condoms were 16 to 24 years of age, males, students, non-binge-drinkers, and those with secondary school education. Age, gender, occupational activity, and non-binge-drinking were common correlates of both condom use and consistent use. CONCLUSIONS: Public health messages should be focused on people with multiple sex partners who are not using condoms for STD protection, including rural residents, those with high levels of education, and those over 34 years of age.

Adolescent↗
PubMedDate not supplied

Direct determination of blood recirculation rate in hemodialysis by a conductivity method.

Blood recirculation is one of the key factors of decreasing dialysis efficiency. Determination of recirculation rate (R) is necessary to optimize effective dialysis delivery and to monitor vascular access function. R can be directly measured by a conductivity method in paired filtration dialysis (PFD), a double-compartment hemodiafiltration system that permits direct access to plasma water via the ultrafiltration stream. Measurement of R, in this system, involves the first of two conductivity sensors integrated in a urea monitor (UMS, BelIco-Sorin, Mirandola, Italy), and two saline injections. The rise in conductivity (deltaC1) induced by a 2.7 ml bolus of hypertonic saline 20% (mg/dl) in the arterial line serves for calibration, and is followed by an equivalent injection into the venous line, giving rise to deltaC2. The ratio deltaC2/deltaC1 equals R. A comparison between R values obtained with this method and with the low-flow technique in 31 chronic dialysis patients during 138 PFD sessions is reported. Mean R+/-SD by the conductivity method was 5.1+/-2.0 and 5.7+/-2.0% after 65 and 155 minutes of PFD (correlation coefficient, r = 0.75), whereas it was 6.4+/-4.9% and 5.5+/-4.6% after 30 sec of low blood pump flow for urea and creatinine markers, respectively (r = 0.35). After 120 sec of low flow, mean R increased to 9.0+/-5.1 and 8.8+/-4.6% for urea and creatinine, respectively (r = 0.45). Considerable discrepancies were found in R values measured simultaneously with the two blood markers. Statistically significant differences were found between the two measurement modalities (blood-side and conductivity); the correlation coefficients (r) varied between 0.28 and 0.41. The observed differences in mean R results do not seem considerable from a clinical perspective. The best agreement between blood-side and conductivity R measurements was obtained with Rcreat after 30 sec of low flow. Overall, a wider distribution was found in R values from blood-side determinations, most likely consequent to variability in the dosing method. The conductivity method appears more accurate and simple in assessing total R, and can be readily automated and integrated into the dialysis machine. The authors, therefore, recommend evaluation of R using methods not based on chemical blood concentration values.

Adult↗