Biomedical subjects

John Olson

Publications and source records attributed to John Olson.

6 recordsLinked to original sources

PubMed2006

Ten-year comparison of BMI, body fat, and fitness in the workplace.

BACKGROUND: Overweight, obestity, and lack of fitness in America is reported to be increasing at an accelerated pace. This national trend has serious health and economic ramifications not only for the general population but also directly for industry. Obesity in the workplace has resulted in increased expenses to industry: directly through increased medical costs and indirectly through decreased productivity. The intent of this study is to define changes in fitness and body fat percentage in a working population in an isogeographical area over the past decade. METHODS: Data accumulated during a routine post-offer testing program were divided into two groups composed of new industry hires tested from 1990 to 1992 and from 2000 to 2002. Body fat was measured with a standard skinfold. The body fat percentage and body mass index (BMI) from year 1990 were compared to those from year 2000. Fitness was assessed through an individual's ability to perform a timed maximum number of sit-ups and squats. RESULTS: There was no significant difference in the BMI between the year 1990 group and the year 2000 group (P = 0.132 for females and P = 0.110 for males). There was a significant increase in body fat percentage from the 1990 group to the 2000 group (P = 0.000 for females and P = 0.000 for males). A significant decrease in fitness was observed for both males and females during the 10-year interval of the study. CONCLUSIONS: Percent body fat appears to be a better indicator than BMI for utilization in industry for evaluation of obesity in the workplace. The differences in significance levels between BMI and percent body fat suggest that a decrease in leisure-time fitness activities could potentially contribute to the trend toward obesity. This study demonstrates that strength and/or fitness are important indicators that industry should monitor in order to improve the health and fitness of the workforce. Direct measurement of percent body fat and fitness indices are a more precise means than BMI for monitoring the workforce especially if employers are going to reward healthy behavior.

Adult↗

PubMed2005

Post-offer, pre-placement testing in industry.

BACKGROUND: Pre-placement testing was implemented during World War II. Its current use has been reshaped by economic factors, litigation, legislation, and advances in medicine. In response to a request from a local industry intent upon lowering their work-related injuries, a post-offer screening program was developed and implemented. The aim of this study was to develop a testing protocol for determining physical capacity that could be adapted for a post-offer, pre-placement program. METHODS: Functional capacity evaluation (FCE) testing was used to determine the physical capacity of 2,482 uninjured, healthy prospective new employees of a large food production plant. A comprehensive medical history and 20 different anthropometric, fitness, strength, and lifting tests were administered to all new hires in the first phase of this study to determine if injury incidence could be estimated through functional screening testing. The second study was designed to determine the effectiveness of the application of a post-offer, pre-placement program in an electrical equipment manufacturing facility. RESULTS: Strength testing alone was of no predictive value for work injury incidence. There was a strong correlation of physical capacity to physical job requirements. If an employee had the physical capability to perform the essential functions of the job, there was a lower injury rate as compared to the employee not demonstrating the physical strength or ability to perform the essential functions of the job. The incidence of low back injuries in those workers with the physical capabilities to perform the required functions of their job was 3%. However, among those workers who did not demonstrate the strength or physical abilities to perform their job, there was a 33% incidence of low back injuries. CONCLUSIONS: This study indicates that physical capacity testing that compares lifting ability to job lifting requirements correlates to work injury incidence. The application of appropriate post-offer, pre-placement testing is shown to be a cost-effective method to lower the incidence of work-related injuries.

Adult↗

PubMed2005

Allurin, a 21 kD sperm chemoattractant, is rapidly released from the outermost jelly layer of the Xenopus egg by diffusion and medium convection.

Allurin, a 21 kD protein from Xenopus laevis egg jelly, has been demonstrated to attract sperm by video microscopy and by quantitative chemotaxis chamber assays. Here, we use immunocytochemistry to demonstrate that this sperm chemoattractant is located in the outermost layer of egg jelly (J3) and is rapidly released into the surrounding medium. SDS-PAGE analysis and Western blotting confirm the appearance of allurin in the medium within 1.5 min and separation of proteins in the medium by anion exchange FPLC, shows that nearly half of the allurin released over a 12-hr period is discharged in the first 5 min. The kinetics of allurin release from J3 and its appearance in the medium were quantitatively accounted for, by computer simulation of mathematical diffusion and convection models. Comparison of simulation data to quantitative measurements of allurin appearance in the medium suggests that allurin, although larger than most chemoattractants, is effectively dispersed by a combination of diffusion and medium mixing at the jelly surface during spawning. Our model further predicts that the innermost jelly layer, J1, is less permeable to allurin than the other layers, allowing it to act as a "reflector" to speed up allurin discharge.

Algorithms↗

PubMed2004

Use of the Laryngeal Tube in two unexpected difficult airway situations: lingual tonsillar hyperplasia and morbid obesity.

PURPOSE: The 2003 ASA Practice Guidelines for Management of the Difficult Airway suggest the early use of the Laryngeal Mask Airway and Combitube as rescue airway devices in the cannot ventilate-cannot intubate situation, switching the focus from laryngoscopy and intubation to ventilation and oxygenation. The Practice Guidelines are not intended as standards but as recommendations. Multiple new alternative airway devices were described in the last ten years. The Laryngeal Tube (LT) is a new Food and Drug Administration approved supraglottic airway device. The device is in use in Europe since 1999 and in the United States since 2002. CLINICAL FEATURES: We report two cases in which the LT was used to solve two unexpected difficult airway situations. The first case ("cannot intubate-inadequate mask ventilation") involved an undiagnosed lingual tonsillar hyperplasia and the LT provided the means to ventilate and administer the anesthetic. In the second case ("cannot ventilate-cannot intubate") we report the successful use of the LT to rescue the airway in a morbidly obese patient. In both cases an endotracheal tube was ultimately inserted using an awake fibreoptic technique with the patient in the sitting position. CONCLUSIONS: In these clinical situations of unexpected difficult airway with significant periglottic obstruction the LT provided adequate ventilation after the first insertion. The LT may complement the laryngeal mask airway in difficult airway management. Further research is needed to define the role of the LT in the management of difficult airways.

Aged↗

PubMed2004

Nonoccupational noise: exposures associated with routine activities.

Efforts to characterize nonoccupational noise exposures have focused primarily on infrequent, episodic events. Few studies have assessed noise levels resulting from routine daily activities. In the current study, 112 construction workers wore datalogging noise dosimeters and simultaneously completed activity logs during two phases of data collection. The 81 subjects monitored in phase 1 received logs listing numerous preselected occupational and nonoccupational activities, while the 31 subjects monitored in phase 2 used free-field logs and reported nonoccupational activities in greater detail. Nearly all of the 221,439 1-min intervals of nonoccupational L(eq) level and activity reporting were below 70 dBA; only a small percentage exceeded 80 dBA. The primary contributor to nonoccupational noise exposure was traveling in a car or bus, while time at home contributed the least. One hundred seventy 24-h L(eq) levels were computed from the 1-min noise level data. The percentage of phase 2 workday L(eq(24)) levels which exceeded 80 dBA was higher than that of the nonworkday levels. The mean L(eq(24)) level of phase 2 workdays was higher than that of nonworkdays, and the difference was statistically significant. Routine nonoccupational noise exposures contributed much less to total noise dose than occupational exposures in the subjects evaluated.

Adult↗

PubMed2003

Spatial channels of visual processing in cortical blindness.

Blindsight is the ability of some cortically blind patients to discriminate visual events presented within their field defect. We have examined a fundamental aspect of visual processing, namely the detection of spatial structures presented within the field defect of 10 cortically blind patients. The method outlined is based on the detection of high-contrast stimuli and is effective in flagging a 'window of detection' in the spatial frequency spectrum, should it exist. Here we report on the presence of a narrowly tuned psychophysical spatial channel optimally responding to frequencies less than 4 cycles/ degrees in eight out of 10 patients tested. The two patients who did not show any evidence of blindsight appear to have intact midbrain structures, but have lesions that extend from the occipital cortex to the thalamus. In addition, we have recorded subjective reports of awareness of the visual events in each trial. Detection scores of eight blindsight patients were subsequently subdivided based on the subjective reports of awareness. It appears that the psychophysical spatial channel-mediating responses in the absence of any awareness of the visual event have a narrower frequency response than those involved when the patients report some awareness of the visual event. The findings are discussed in relation to previous reports on the incidence of blindsight and performance on tasks involving spatial processing.

Adult↗