Effects of body mechanics training on performance of repetitive lifting.

OBJECTIVE: To measure the efficacy of body mechanics instruction (BMI) in patients with low back pain. METHOD: The effect of BMI was measured in four participants with back injuries using a standardized lifting protocol. Static strength, weight lifted, number of lifts completed, and motion analysis data to describe the body mechanics were measured before and after work hardening to evaluate treatment effects. The participants' performances were compared with 52 controls from an earlier study. RESULTS: Starting postures, characterized by degrees of hip and knee flexion, varied by participant but favored a squat lift in three participants when compared with the controls. Dynamic motion synchrony of the hip and knee joints was similar to controls in three of the four participants. Posttest data revealed significant changes in static strength, dynamic endurance, and lifting speed. CONCLUSION: Intensive instruction in body mechanics provided during the work-hardening treatment produced major changes in lifting styles, in terms of both starting postures and dynamic aspects of repetitive lifting. The computerized measurement procedures used in this study permitted more careful and detailed analyses of body mechanics, particularly dynamic aspects, than is possible with observational methods. This study demonstrated some of the inherent intricacies in isodynamic lifting and suggests additional areas of performance that may be important to address in BMI.     

Microdroplet tracking using biplane digital subtraction angiography for cerebral arteriovenous malformation blood flow path and velocity determinations.

High-speed biplane angiography is used to determine the path and velocity of microdroplets of contrast material in three dimensions. By allowing more accurate determination of detailed blood flow in feeding vessels and draining veins of cerebral arteriovenous malformations than available with standard angiography, the new method offers the potential for more accurate treatment and further study of neurovascular/cerebrovascular hemodynamics. The first study of the method is presented.     

Human Gastric Alcohol Dehydrogenase: Its Inhibition by H2-Receptor Antagonists, and Its Effect on the Bioavailability of Ethanol

Two types of alcohol dehydrogenase isoenzymes (differing in their affinity for ethanol, sensitivity to 4-methylpyrazole, and electrophoretic migration) have been identified in the human stomach. At the high ethanol concentrations prevailing in the gastric lumen during alcohol consumption, the sum of their activities could account for significant oxidation of ethanol. In vitro, these activities were inhibited by cimetidine and ranitidine, but not by famotidine. In vivo, therapeutic doses of cimetidine (but not of famotidine) increased blood ethanol levels when ethanol was given orally, but not when it was given intravenously, indicating a significant contribution of the gastric ADH to the bioavailability and thereby the potential toxicity of ethanol.     

Prognostic significance of nuclear deoxyribonucleic acid ploidy patterns in resected hepatic metastases from colorectal carcinoma

Nuclear deoxyribonucleic acid (DNA) ploidy studies of paraffin-embedded archival tumor specimen blocks were performed by flow cytometry on extracted nuclei from 101 surgically resected hepatic metastases from colorectal cancer. In 28 patients, the corresponding primary carcinoma of the metastases was also studied. Tumor clinicopathology and clinical course of the patients were reviewed. Preparation of paraffin-embedded tissue specimens was performed by the technique of Hedley et al. and stained with propidium iodide according to the method of Vindelov et al. Eighty-eight of 101 metastatic tumors and 26 of 28 primary tumors yielded evaluable DNA histograms. Twenty-six metastases showed a DNA diploid pattern, 25 showed a significantly increased 4C peak (DNA tetraploid/polyploid), and 37 had a DNA aneuploid peak. Ploidy pattern was constant between primary and metastases in 84.6% of tumors. No significant relationship between host and tumor characteristics and ploidy pattern was found except for a correlation between grade 3 metastases and DNA aneuploid. Survival of patients with DNA aneuploid metastases was significantly less than that of patients with DNA diploid metastases (p = 0.03). However, among DNA nondiploid metastases, survival was significantly less for low DNA index metastases (less than or equal to 1.5) than for high DNA index (greater than 1.5) metastases (p less than 0.05). Flow cytometric DNA ploidy measurements may have prognostic value for patients with resected hepatic metastases from colorectal carcinoma.     

Effect of Abstinence on the Blood Acetaldehyde Response to a Test Dose of Alcohol in Alcoholics

Following an acute dose of alcohol (0.15 g/kg intravenously), blood levels of acetaldehyde were significantly higher in nonabstinent alcoholics than in controls. After 2 weeks of abstinence, this blood acetaldehyde response significantly decreased in alcoholics and the acetaldehyde returned towards levels comparable to those observed in nonalcoholics. These results suggest that elevated blood acetaldehyde levels in the alcoholics are secondary to the chronic alcohol consumption rather than reflecting a primary preexisting defect.     

Potentiation of ethanol-induced hepatic vitamin A depletion by phenobarbital and butylated hydroxytoluene

Administration of ethanol, phenobarbital or butylated hydroxytoluene (BHT) each resulted in significantly lower hepatic vitamin A than in untreated controls. When ethanol was combined with either phenobarbital or BHT, a striking potentiation of the depletion was observed, resulting in hepatic vitamin A values of less than 5% of normal, whether expressed per gram of liver or per 100 g body wt. These effects were observed for both retinol and retinyl esters, measured by high pressure liquid chromatography. By contrast, lung levels of retinol and retinyl esters were significantly higher in rats treated with ethanol, but remained unchanged in rats treated with phenobarbital or butylated hydroxytoluene compared with control animals.     

Kappa Delta Award paper. Tissue fluid pressures: from basic research tools to clinical applications

The two basic research tools developed to measure tissue fluid pressure (wick catheter) and osmotic pressure (colloid osmometer) have undergone extensive validation and refinement over the past 20 years. Using these techniques, basic science investigations were undertaken of edema in Amazon reptiles, pressure-volume relations in animals and plants, adaptive physiology of Antarctic penguins and fishes, edema in spawning salmon, tissue fluid balance in humans under normal conditions and during simulated weightlessness, and orthostatic adaptation in a mammal with high and variable blood pressures--the giraffe. Following and sometimes paralleling this basic research have been several clinical applications related to use of our colloid osmometer and wick technique. Applications of the osmometer have included insights into (a) reduced osmotic pressure of sickle-cell hemoglobin with deoxygenation and (b) reduced swelling pressure of human nucleus pulposus with hydration or certain enzymes. Clinical uses of the wick technique have included (a) improvement of diagnosis and treatment of acute and chronic compartment syndromes, (b) elucidation of tissue pressure thresholds for neuromuscular dysfunction, and (c) development of a better tourniquet design for orthopaedics. This article demonstrates that basic research tools open up areas of basic, applied, and clinical research.