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Biomedical subjects

M J Gerard

Publications and source records attributed to M J Gerard.

12 recordsLinked to original sources
PubMed1999

Post-effects of long-term hand vibration on visuo-manual performance in a tracking task.

Movement precision and performance time were evaluated through a visuo-manual tracking task performed before and after 10-min hand vibration exposure. Constant displacement amplitude vibration of 0.2 and 0.3 mm peak to peak at 90, 150, 300 Hz were applied to the hand z-axis by a vertical handle. During exposure a grip force of 5% MVC was exerted for 5 s and then relaxed for 25 s while maintaining fingers-handle contact. The tracking task consisted in moving a ring (phi = 9 mm) attached to a thin rod held between the index finger and thumb along a zig-zagged wire (phi = 3.7 mm). Alterations of tracking errors (ring-wire contact) and tracking time were analysed as a function of the vibration parameters. The tasks were performed by ten healthy participants. Vibration induced a significant increase in tracking errors (ring-wire contact) and a significant decrease in tracking time. These impairments decayed with time after vibration exposure. The recovery period was > 5 min but < 10 min with the exception of 90 Hz vibration, for which recovery could be > 10 min. The number of tracking errors was neither influenced by vibration frequency nor by amplitude. The tracking time decreased as frequency increased and recovery was related to the displacement amplitude. The subjective rating of the performance on a visual analogue scale indicated that the subjects tended to perceive the task as being easier after vibration exposure. Vibration applied to the non-dominant hand while the participant performed the tracking task had no effect. These results show that vibration similar to hand-tool vibration affects precision and velocity control of visually guided hand movements. Furthermore, these performance decrements were not consciously perceived.

Adult↗
PubMed1998

Screening for prostate cancer in asymptomatic men: clinical, legal, and ethical implications.

PURPOSE/OBJECTIVES: To describe the opposing recommendations of the major medical organizations related to screening for prostate cancer and to explore the impact of these opposing recommendations on advanced practice nurses (APNs) who are in a position to decide who gets screened and when. DATA SOURCES: Published medical, legal, and economic articles, published legal verdicts and settlements, case law, and news reports. DATA SYNTHESIS: The national recommendations for screening for prostate cancer are conflicting and have legal, economic, and ethical implications for healthcare practitioners. Both the current early diagnostic tests, age- and race-based prostate specific antigen ranges, and the resultant treatment have significant problems and further contribute to the national controversy about whether to screen asymptomatic men. Lack of coverage for early detection of prostate cancer by many managed-care plans and Medicare also contribute to the dilemma practitioners face. However, electing not to screen "at-risk" men may subject APNs to charges of negligence or other legal theories. CONCLUSIONS: Present recommendations by the leading national medical, cancer, and policy organizations related to prostate cancer screening are contradictory. Adding to this national quagmire is the lack of financial support from Medicare and most health maintenance organization plans to pay for early detection of prostate cancer. These conflicting recommendations place APNs in a legally and ethically precarious position. APNs and nurses with patient education responsibilities should individualize decision-making and counsel their asymptomatic patients who may be at risk for prostate cancer about the benefits and complications of screening. IMPLICATIONS FOR NURSING PRACTICE: Considering the multiple implications of the decision to screen for prostate cancer, counseling patients who may be at risk for the disease and involving them and their spouses may be the best approach in deciding whether to screen for prostate cancer in asymptomatic men.

Age Distribution↗
PubMed1996

Effects of key stiffness on force and the development of fatigue while typing.

An experiment was conducted to investigate the effect of key stiffness on the development of fatigue, keyboard reaction forces, and muscle electromyography (EMG) responses. Six subjects typed continuously for 2 hours on each of two keyboards (0.28 N or 0.83 N resistance keys, presented in random order). Keyboard reaction force and root mean square finger flexor and extensor EMG were recorded for 2 minutes at 250 Hz for every 10 minutes subjects typed. After typing for 2 hours subjects were given a 2-hour rest break and then typed on the remaining keyboard for an additional 2 hours Fifty-four percent more peak force, 34% more peak finger flexor EMG, and 2% more peak finger extensor EMG were exerted while using the 0.83 N keyboard. Peak and 90th percentile values showed similar trends and were well correlated for force and finger flexor and extensor EMG. Subjects typed much harder than necessary (4.1 to 7.0 times harder on the 0.28 N keyboard and 2.2 to 3.5 times harder on the 0.83 N keyboard) to activate the keys. Fatigue was observed on the 0.83 N keyboard during 2 hours of continuous typing, but the trends were mild. It appears that the ratio of typing force to flexor EMG may not be a sensitive enough indicator of fatigue for low-force high repetition work.

Adult↗
PubMed1991

Prophylactic efficacy of maprotiline on unipolar depression relapse.

BACKGROUND: Although antidepressant medications have been in use for about 30 years, the question remains about their utility in the prophylaxis of recurrent depression. The purpose of this study was to evaluate the efficacy of maprotiline, a tetracyclic antidepressant, for depression prophylaxis. METHOD: We conducted a vast, prospective, multicenter, double-blind, placebo-controlled study of 1141 outpatients suffering from depression and treated with maprotiline or placebo for 1 year. The very large size of the study population allowed for the testing of two drug doses. The study design included a pre-inclusion treatment phase that assured that all study patients had recently suffered from a depressive episode and were in remission at the time they were randomized into two treatment groups (1 and 1/2 tablet of maprotiline 75 mg) and two control groups (1/2 and 1 tablet of placebo). RESULTS: The actuarial relapse rate at 1 year was 16% for maprotiline 75 mg, 1 tablet; 23.8% for maprotiline 75 mg, 1/2 tablet; 31.5% for 1 tablet placebo, and 37.5% for 1/2 tablet placebo. The difference between each group is statistically significant, except for the difference between the two placebo groups. The actuarial incidence of adverse drug reactions during the year was not statistically significant between the treatment and control groups. CONCLUSIONS: This study demonstrates maprotiline's prophylactic effectiveness for depressive relapses, the 75-mg dose being more effective than the 37.5-mg dose. The patients' tolerance of maprotiline therapy was satisfactory at both doses with prolonged prescription.

Adolescent↗
PubMed1989

[Can weight gain during weaning from smoking be limited using nicotine gum?].

One hundred subjects smoking more than 20 cigarettes per day were divided into two groups allocated at random to either nicotine gum or a placebo gum. Forty-eight subjects stopped smoking, irrespective of the treatment received. The magnitude of weight gain after given up smoking and the benefits of nicotine gum were evaluated. Weight gain was found to increase in ex-smokers compared with persistent smokers, but the increase was less pronounced in subjects who chewed nicotine than in those who chewed the placebo, although the difference was not statistically significant. However, enough gum must be chewed for the appetite and feeling of hunger to be reduced.

Adult↗
PubMed1985

Regulation of deoxyglucose uptake by adrenocorticotropic hormone in cultured neurons.

The influence of ACTH and some of its N-terminal related peptides was investigated on the uptake of (3H)-2-deoxy-D-glucose in pure cultures of neurons from chick embryo cerebral hemispheres. ACTH influences deoxyglucose uptake in a time and dose-dependent fashion. The stimulation of deoxyglucose uptake is observed after a delay of 6-8 h and requires active protein synthesis. ACTH does not affect deoxyglucose in non-neuronal cells (astroglial cells, hepatocytes, myoblasts, fibroblasts). The effect of various peptide hormones, neuropeptides and growth factors, active in the central nervous system or other tissues, has also been examined. None of these were able to stimulate deoxyglucose uptake, suggesting that the regulation of hexose uptake in neurons is specific for the ACTH-related peptides.

Adrenocorticotropic Hormone↗
PubMed1983

Influence of adrenocorticotropic hormone on the growth of isolated neurons in culture.

The present study reports the influence of adrenocorticotropic hormone (ACTH) on the development of cultured neurons from chick embryo cerebral hemispheres. Cultures were initiated in serum-supplemented medium and then transferred to serum-free hormonally-defined medium containing various concentrations of ACTH1--24. The effects of ACTH on the light microscopic features, metabolic activity and permeation properties were examined. The results demonstrate that ACTH exerts a trophic action on the neurons.

Adrenocorticotropic Hormone↗
PubMed1976

Clindamycin and diarrhea.

Of 298 outpatients receiving clindamycin for a variety of indications, diarrhea developed in ten (3.4%); none were diagnosed as having pseudo-membranous colitis. This is well within the range of relative frequencies of diarrhea development (0% to 22.2%) reported in 45 previous studies. Reliance solely on computer-recorded instances of diarrhea yielded a substantial underestimate of diarrhea occurence, but the rate was still significantly higher (P less than .05) in clindamycin users than in nonusers.

Acne Vulgaris↗
PubMedDate not supplied

The effects of keyswitch stiffness on typing force, finger electromyography, and subjective discomfort.

The effects of keyswitch stiffness and key action on typing force, electromyography (EMG), and subjective preference were examined. Each subject's own keyboard (with an audible key click and key activation force of 0.72 N) and three keyboards with no key click that were identical in design but had different key activation forces (0.28 N, 0.56 N, and 0.83 N) were used. Subjects (24 female transcriptionists) typed on each keyboard for 15 min while typing force and left hand surface EMG of the finger flexor and extensor muscles were monitored. Subjects then used one of the keyboards at their workstations for 7 workdays and were monitored again. This procedure was repeated for all four keyboards. Typing force and finger flexor and extensor EMG activity were highest for the 0.83 N keyboard. Lowest EMG values were for the 0.28 N and the 0.72 N audible key click keyboards. Baseline (10th percentile) and median (50th percentile) extensor EMG values were significantly higher than flexor EMG values. Peak (90th percentile) EMG values were comparable for flexors and extensors. Mean subjective discomfort was significantly higher for the 0.83 N keyboard at the fingers (36% higher), lower arm (40% higher), and overall (39% higher). Seventeen of 24 subjects preferred the 0.72 N keyboard, 4 the 0.28 N keyboard, and 3 preferred the 0.56 N keyboard. Results suggest that increasing make force causes typing force and EMG to increase but that the ratio of 90th centile typing force to make force decreases as make force increases. Subjective discomfort was significantly higher for the keyboard with 0.83 N make force. Buckling spring keyboards have better feedback characteristics, which may be responsible for a decrease in the amount of typing force and EMG produced.

Adult↗