Catalase activity measurement with the disk flotation method

Activity measurements of catalase are usually performed with a spectrophotometric method by monitoring the decrease of H2O2 at 240 nm. A different method presented here uses an instrument named Catalase-meter and yields flotation time data which are expressed in tenth of seconds. For the first time, solutions of catalase of different concentrations were tested simultaneously with the two methods, and the Catalase-meter's flotation data were submitted to correlation with international units calculated from spectrophotometric data. The corresponding calibration curve correlates flotation time data to international units. The r2 values thus obtained for the two calibration curves were 0.960 and 0.929, for a range of activity varying from 9.3 to 144.5 international units/ml.

Initial factors predicting survival in patients with a spinal cord injury

A study is presented of a prospective analysis of survival rates in 157 patients with spinal cord injury consecutively admitted to the Pellegrin Hospital (University Hospital, Bordeaux, France). There was a 20% death rate, occurring in the first three months after injury. Three independent predictors of survival in patients with spinal cord injuries (age, initial conscious level and respiratory assistance) were found by analysis of the course of the disorder.

A strategy for analysing multiple risk factors with application to cervical pain syndrome

When studying the possible effects of several factors in a given disease, two major problems arise: (1) confounding, and (2) multiplicity of tests. Frequently, in order to cope with the problem of confounding factors, models with multiple explanatory variables are used. However, the correlation structure of the variables may be such that the corresponding tests have low power: in its extreme form this situation is coined by the term "multicollinearity". As the problem of multiplicity is still relevant in these models, the interpretation of results is, in most cases, very hazardous. We propose a strategy--based on a tree structure of the variables--which provides a guide to the interpretation and controls the risk of erroneously rejecting null hypotheses. The strategy was applied to a study of cervical pain syndrome involving 990 subjects and 17 variables. Age, sex, head trauma, posture at work and psychological status were all found to be important risk factors.

A Strategy for Analysing Multiple Risk Factors with Application to Cervical Pain Syndrome

When studying the possible effects of several factors in a given disease, two major problems arise: (1) confounding, and (2) multiplicity of tests. Frequently, in order to cope with the problem of confounding factors, models with multiple explanatory variables are used. However, the correlation structure of the variables may be such that the corresponding tests have low power: in its extreme form this situation is coined by the term “multicollinearity”. As the problem of multiplicity is still relevant in these models, the interpretation of results is, in most cases, very hazardous. We propose a strategy - based on a tree structure of the variables - which provides a guide to the interpretation and controls the risk of erroneously rejecting null hypotheses. The strategy was applied to a study of cervical pain syndrome involving 990 subjects and 17 variables. Age, sex, head trauma, posture at work and psychological status were all found to be important risk factors.

Application of a stereoradiographic method for the study of intervertebral motion

A technique of three-dimensional reconstruction along with a method of adjusting anatomic landmarks were used to evaluate movements of the lumbar vertebrae of living subjects. Altogether, 16 subjects took part in the experiment. Each subject was radiographed in an upright standing position, and in each of the following positions: flexion, extension, axial rotation, and lateral bending. The results of the three-dimensional reconstruction procedures and the correction of anatomic landmarks show an adequate level of accuracy for experimentation with living subjects. The mean relative displacements of lumbar vertebrae in rotation are 10 degrees of flexion, 3 degrees of extension, 5 degrees of lateral bending, and 1 degree of axial rotation.

A three-dimensional digitization method to measure trunk muscle lines of action

A method is presented to obtain lines of action of nine major trunk muscles acting on the lumbar spine. The muscles are modeled as one or several linear or curvilinear lines of action obtained by digitizing the origins and insertions of main bundles of muscles. For curvilinear lines of action, points were also digitized along the length of the bundles, and a curve-fitting method was used. Lines of action are displayed graphically for one embalmed cadaver. Tabulated data for unit force vectors and unit moment vectors about the L3-L4 and L4-L5 discs are also presented.

Predictors of non-bedridden survival in dementia

The present study examined non-bedridden survival in 105 patients diagnosed as demented (Alzheimer's disease, multi-infarct dementia, mixed dementia) in a neurological ward. Follow-up observations were made. During the first year, the cumulative mortality rate was 69% compared to a rate of 44% in the second year. The initial disability stage, as assessed by the Dementia Disability Scale, was found to be the only significant predictor of non-bedridden survival. The type of dementia, age, type of diagnosis, and post-hospitalization placement in an institution have not been found to be significant predictors of this evolution.

Scintigraphic study of duodenal-gastric reflux in cases of primary gastropathy, chronic ulcer of the duodenal bulb, and Moynihan's disease

There are several methods for detection of bile in the stomach, but none has proven satisfactory. It appears that the scintigraphic study with quantitation of duodenal-gastric reflux after corrections for the overlap of the stomach by the liver and bowel is more reliable, noninvasive, and physiologic. Fifty-four patients were divided into groups according to their clinical presentation; seven asymptomatic volunteers, 20 patients with duodenal-gastric reflux gastropathy (DRG), 16 patients with recurrent ulcers of the duodenal bulb (RUD), and 11 patients with Moynihan's disease. Each of the 47 dyspeptic patients underwent an endoscopic examination and a scintigraphic study with [99mTc]disofenin for detection and quantitation of duodenal-gastric reflux. Endoscopy revealed the presence of bile in the stomach of 16 out of 20 DRG and four out of 16 RUD, while ten out of 11 patients with Moynihan's disease had clear gastric juice. Most of the DRG cases (15 out of 20) and half of the RUD (eight out of 16) presented reflux greater than 1.5%, while of the 11 Moynhihan, ten presented reflux less than 1.5% and all the asymptomatic volunteer subjects less than 1%. This quantitation method allowed us to perceive clearly the low % of reflux in the "normal asymptomatic" subjects compared with the DRG-type of dyspeptic patients. Among the dyspeptic, the distinction seems more evident between the DRG type and the Moynihan type. Occasionally, the scintigraphic method permits identification of patients with slower gallbladder evacuation (eight out of 47 dyspeptic in our study), adding valuable information for the diagnostic approach to dyspeptic patients.

Prevalence and risk factors of recurrent cervical pain syndrome in a working population

The prevalence and risk factors of recurrent cervical pain syndrome (CPS) was studied in 990 workers examined while undergoing their systematic annual visit of occupational medicine. A prevalence rate of 10.2% was obtained. Using a tree-structured logistic regression analysis, a strong association between age, sex, previous head trauma extension of the neck and strenuous muscular activity during work, and the risk of recurrent CPS was obtained. Finally, an inverse association between strenuous muscular activity during leisure time and the risk of recurrent CPS was found.

Indium-111 leukocyte scanning of the abdomen. Analysis of its value for diagnosis and management of inflammatory bowel disease

Indium-111 leukocyte scanning of the abdomen (IAS) was performed in 10 patients with ulcerative colitis and in 39 patients with Crohn's disease involving the small intestine (in 25 occasions) and/or the colon (17 cases). Radionuclide uptake by the gut was seen in 84% of the patients with active inflammation. We compared the extent of the disease displayed by IAS with the findings obtained by either radiological or endoscopic studies or at surgery. In two-thirds of the patients, the IAS gave an accurate evaluation of the extent of the disease (sensitivity 68%). False-positive IASs were not seen in small bowel disease (specificity 100%), but were observed on 4 occasions on the colon (specificity 86%). The intensity of the radionuclide uptake could not be correlated with the clinical activity of the disease as evaluated by the Crohn's disease activity index. These results suggest that IAS is not superior to the standard procedures used to detect and localize inflammatory bowel disease and that IAS cannot replace these techniques. However, the simplicity of IAS and the complete lack of complications associated with its use render it useful in the evaluation of the extent and distribution of inflammation in some patients, mainly those with severe disease in whom standard diagnostic procedures would be contraindicated.

Moderate prenatal ethanol exposure interacts with strain in affecting brain development in BALB/c and C57BL/6 mice

The development of two forebrain fiber tracts, the corpus callosum and anterior commissure was examined in BALB/cCF and C57BL/6J mice in relation to moderate maternal consumption of ethanol during gestation. Pregnant animals were fed ethanol 10% v/v in the drinking water from days 5 to 19 of gestation, when fetal brain development was assessed. Control animals received an isocaloric sucrose solution and were pair-fed to the experimental animals. An additional ad libitum control group was included. The alcohol treatment did not increase the incidence of the CC being absent in a midsagittal section. In BALB/c animals which had been exposed to ethanol the area of both the corpus callosum and anterior commissure was smaller than in the two control groups, and this effect was independent of the lower brain weight resulting from the treatment. The area of the corpus callosum, adjusted for brain weight, was smaller in both the alcohol-treated and sucrose control C57 animals than in the ad libitum control group; this suggests a nutritional effect. There was no evidence of an effect of ethanol on anterior commissure area or brain weight in C57 animals.

Effects of fasting during gestation on brain development in BALB/c mice

The development of the corpus callosum (CC) was examined in BALB/cCF mice in relation to the effects of a 32-h period of maternal fasting. The treatment was imposed on days 15 and 16 during gestation, which immediately precedes the time when the initial callosal axons cross the midline. The BALB/c strain was used because it is prone to developing a corpus callosum which is either small in size or absent at the midline. A split-litter design was used where fetal brain development was assessed on days 22 and 50 postconception (birth and weaning). The treatment did not increase the incidence of absent CC. On day 22 the midsagittal cross-sectional area of the CC, as well as brain and body weight, were smaller in the experimental group. Covariance analysis showed the effect on brain weight to be related to the overall growth retardation seen in the low body weight. In the control group, CC area and the brain weight were positively correlated, but in the experimental group this was not the case, suggesting the effect on the CC was independent of growth retardation. By day 50 there were no significant differences between the groups on any measure, although the data did show a trend toward a smaller CC in the fasted animals.

Mass Spectrometric Determination of Cane Sugar and Corn Syrup in Maple Syrup by Use of 13C/12C Ratio: Collaborative Study

Use of C3 carbon dioxide (CO2) fixation cycle by the sugar maple (Acer saccharum Marsh.), a dicotyledenous plant, and C4 carbon fixation cycle by 2 monocotyledenous plants, corn and cane, results in a physiological discrimination between 13C and 12C isotopes. Therefore, determination of 13C/12C ratio of maple syrup by mass spectrometry can be used to detect adulteration with cane and corn sugars. Four samples of pure maple syrup and 3 adulterated maple syrup samples were analyzed in a collaborative study. Results indicate that stable carbon isotope analysis can determine authenticity of maple products. Samples with δ13C values less negative than – 23.49%c (parts per thousand) can, with a high degree of confidence (95%), be classified as adulterated. The method has been adopted official first action.

[Development, evaluation and application of a dynamometric system of skates]

The present paper accounts for the elaboration validation and application of a dynamometric system device for ice skates that allows measurements of the forces and the point of application of their resultant on the blade during ice skating. The dynamometric system was built using strain gauges fixed to the frame of the blade and mounted in a Wheatstone bridge network which enabled after proper calibration to record force measurements. The type of frame chosen for the blade and the various modifications that were brought to it appear essential for the applicability of the system. In order to conduct a dynamic study of the "stop" during skating the system was coupled with a cinematographic technique enabling measurements of tridimensional angles of the skates. Two male subjects completed five "stops" at three different determined speeds. Results indicated that dynamometric systems build with frames of modified metal blades were of an adequate precision for measuring forces. Moreover coupling of the system with the cinematographic technique allowing measurements of tridimensional angles provides a powerful and innovative tool for the dynamic study of ice skating.

The evaluation of forearm density with axial tomography

The purpose of the present investigation was to validate axial tomography technique for estimating forearm density. Twenty forearm specimens from six male and four female embalmed human cadavers were used. Segmental mass, volume and density criteria were obtained by weight in air, hydrostatic weight and mass/volume ratio, respectively. Densities of bones and muscles were similarly measured. Segmental density as measured by axial tomography was overestimated by an average of 2.1% and the errors ranged from 0.05 to 4.81%. Results from this study indicated the presence of three density regions in the segment. Moreover, density data were found to be very similar in all zones of the central region of the segment (2/3 of its length) to actual segment density. It is thus actually possible to estimate forearm density in living humans, by taking two scans in the central zone of the segment if data pertaining to tissue densities are available.

Alkaline reflux gastritis: Roux-en-Y diversion is effective

Even though controversy persists over the physiopathology of alkaline reflux gastritis, Roux-en-Y diversion is a well-accepted surgical treatment and was used in 23 patients over a 6-year period at the Hôpital St-Luc in Montreal. Of the 23 patients, 21 had complete relief of symptoms. Objective criteria for the selection of patients who would benefit from operation are still to be defined. The authors discuss the physiopathology through an extensive review of the literature.

Comparison of the healing capacities of sucralfate and cimetidine in the short-term treatment of duodenal ulcer: a double-blind randomized trial

Fifty-nine outpatients with endoscopically proven duodenal ulcer were evaluated for 4-8 wk in a randomized, double-blind trial comparing sucralfate, a sulfated disaccharide, (1 g, 0.5 h before each meal and at bedtime) with cimetidine (300 mg, 0.5 h before each meal and at bedtime). Ulcer symptoms and their relief were recorded by patients in a diary, along with data on cigarette, alcohol, coffee, and drug intake. Duodenoscopy was performed after 4 wk to assess healing, and was repeated after 8 wk if healing had not occurred by the 4-wk evaluation. Twenty-four of 30 patients taking sucralfate (80.0%) and 22 of 29 patients taking cimetidine (75.9%) had their ulcer completely healed after 4 wk. The overall healing rates after 8 wk for the sucralfate and cimetidine groups were 90.0% (27 of 30 patients) and 86.2% (25 of 29 patients), respectively. There were no significant differences between the two treatment groups in ulcer healing, symptom relief, and side effects. Symptoms were relieved equally with respect to time and efficacy. Minor adverse experiences were reported in each treatment group. None of these experiences were serious enough to warrant discontinuation of treatment. These results suggest tha sucralfate is as effective as cimetidine in the short-term treatment of duodenal ulcer.