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Biomedical subjects

B H Jacobson

Publications and source records attributed to B H Jacobson.

36 records · Page 2Linked to original sources
PubMed1993

Speech breathing in patients with lung disease.

Lung volumes and breathing patterns used during speech differ from those of quiet respiration and may be expected to vary with different types of lung disease. To test this possibility, 41 patients with asthma, emphysema, or sarcoidosis and 16 healthy subjects completed a speech protocol. Volumes, times, and flow rates were recorded during conversation and during a counting task. A total of 16 measured variables were derived for each breath and analyzed statistically. Alterations in speech breathing were disease and task specific. Discriminant function analysis applied to data from either speech task could correctly classify subjects with more than 50% accuracy, showing that different patterns were significantly disease specific. Compared with healthy subjects during conversation, all patients averaged a more rapid respiratory rate and increased the proportion of time spent on inspiration (Ti/Ttot). During counting, patient groups showed a variety of patterns, most commonly subordinating metabolic need to communication drive and sounding more breathless to observers. Regression analysis was used to determine how strongly changes in measured speech variables related to degree of physiologic impairment. The effect of severity of disease on speech production is distinguishable from the effect of the diagnostic category.

Adult↗
PubMed1992

Effect of caffeine on maximal strength and power in élite male athletes.

Computerized testing of 20 élite male athletes was performed to determine the effect of 7 mg kg-1 caffeine on strength and power of the knee extensors and flexors. Subjects received counterbalanced administrations of either caffeine or a placebo on two separate occasions. Peak torque (T) was measured for knee extension (ET) and flexion (FT) at angular velocities of 30 degrees, 150 degrees and 300 degrees s-1. Additionally, performance for the first 125 ms (TAE) and power (W) were recorded during 300 degrees s-1. Testing sessions were held 1 week apart, at which time the placebo/caffeine administration was reversed. A 2 x 2 repeated measures analysis of variance supplemented with a Neuman-Keuls post hoc test showed the following--significant caffeine-related increases (P < 0.05) for ET at 30 degrees s-1, ET at 300 degrees s-1, and ETAE, and EW at 300 degrees s-1. Dependent t-tests performed for pre- to post-test means showed significant changes for the caffeine group in ET at 30 degrees s-1, FT at 30 degrees s-1, FT at 150 degrees s-1, ET at 300 degrees s-1, FT at 300 degrees s-1, E and FTAE, and EW at 300 degrees s-1. No significant effects were found for the placebo trial in any variable. It was concluded that caffeine can favourably affect some strength parameters in highly resistance-trained males. However, differences in subject fibre type, motivation and caffeine sensitivity need to be elucidated.

Adult↗
PubMed1992

Effect of caffeine on motor performance by caffeine-naive and -familiar subjects.

The purpose of this investigation was to assess the effect of caffeine on selected manipulation skills by caffeine-naive and caffeine-familiar subjects. The subjects were 20 caffeine-naive (less than 90 mg/d) and 20 caffeine-familiar (greater than 750 mg/d) college-age (21 +/- 1.7 yr.) women. Measurements included steadiness error time and frequency, duration of tracing, error time and frequency, and dexterity. Doses of 2.5, 5.0 mg.kg-1 body weight caffeine or a placebo (200 mg. methylcellulose) were administered randomly to all subjects on three separate occasions. A 2 x 3 repeated-measures analysis of variance yielded a significant group difference for steadiness error time between the 5 mg.kg-1 and 2.5 mg.kg-1 dose and between 5 mg.kg-1 and the placebo. For frequency of steadiness errors, the nonuser group posted significant gains for both 5.0 and 2.5 mg.kg-1 over the placebo control. On tracing error time and error frequency, 5.0 mg.kg-1 resulted in significant increases from both 2.5 mg.kg-1 and the placebo group. In the caffeine-naive group, both doses of caffeine led to significant increases in dexterity time from the placebo, and the 5.0 mg.kg-1 dose was significantly different from the 2.5 mg.kg-1 trial. It was concluded that caffeine had detrimental effects on selected performance skills of caffeine-naive women but not in caffeine-familiar women.

Adult↗
PubMed1991

Influence of caffeine on selected manual manipulation skills.

To assess the effects of caffeine on selected manual manipulation skills 16 college-age (21 +/- 1.7 yr.) caffeine-naive women (less than 90 mg/day), having avoided products containing caffeine for four days, reported for testing eight hours postprandial. Measurements included duration and frequency of error for hand steadiness, duration and frequency error for following a tracing pattern, and duration of completing a tweezer-pin placement dexterity test. Caffeine doses of either 2.5 or 5.0 mg/kg body weight or a placebo (200 mg. methylcellulose) were administered randomly to all subjects on three separate occasions using a double-blind format. A 2 x 3 repeated-measures analysis of variance and a Newman-Keuls post hoc test yielded a significant difference in hand steadiness error time from pre- to posttest for 5 mg/kg but not for 2.5 mg/kg or the placebo trial. For frequency of hand steadiness error, significant changes occurred for both 5.0 and 2.5 mg/kg. A dose of 5.0 mg/kg group resulted in significant differences in both tracing error time and error frequency. As both doses of caffeine significantly increased dexterity time, it was concluded that caffeine has detrimental effects on selected performance skills of young caffeine-naive women.

Adult↗
PubMed1991

Influence of two levels of caffeine on maximal torque at selected angular velocities.

The purpose of this study was to determine the effect of two doses of caffeine on peak torque and muscle endurance in the knee extensors and flexors. Twenty males and 16 females were randomly assigned to one of three groups: 600 mg caffeine, 300 mg caffeine, or a control receiving a placebo. Subjects with similar caffeine consumption history were used and all subjects abstained from caffeine usage for 24 hours prior to testing. Subjects were tested for maximal strength and endurance at 75, 180, and 300 degrees per second using a Cybex II Isokinetic Dynomometer interfaced with a Cybex Data Reduction Computer. After pretesting, each subject was given one of three solutions using a double-blind design. Following a one hour rest and absorption period, the subjects were again tested. Data were analyzed using a 3 x 2 repeated measures analysis of variance with a grouping factor at three levels (600 mg vs 300 mg vs 0 mg) and a trial factor at two levels (pre- vs posttest). The following variables were analyzed at all angular velocities: peak torque and subsequent joint angle, peak torque at 30 degrees, and peak torque at 70 degrees. At 300 degrees per second, the dependent variables were total torque for 15 repetitions, total torque for the first 3 repetitions, and total torque for the last 3 repetitions. The results indicated no significant changes from pre- to posttest. It was concluded that maximal strength and endurance was not affected by the two levels of caffeine used in this study and that caffeine may not be considered an ergogenic aid in strength output in subjects naive to resistance training.

Adult↗
PubMed1990

Effects of ingested doses of caffeine on neuromuscular reflex response time in man.

To determine the effect of two doses of caffeine on a caudal (monosynaptic) reflex in humans, 30 subjects were randomly assigned to one of three groups. The groups received one of the following doses of caffeine per kilogram body weight using a double blind, placebo controlled design: 6 mg/kg, 3 mg/kg or a placebo. All of the subjects were similarly caffeine naive and were instructed to fast eight hours, refrain from caffeine for 96 hours, and avoid strenuous exercise 48 hours prior to testing. At the pre-test and post-test all subjects were given three trials of the patellar ligament reflex. Following pre-testing, subjects ingested either the caffeine solutions or an inert solution. After a one hour absorption period, subjects were post-tested. Gain scores were analyzed using a one-way ANOVA among the three groups, and a Newman-Keuls multiple range test was used to compare the three groups. The analysis revealed a significant difference in the gain score of the 6 mg/kg group. The control group had a mean gain of 4.3 msec, the 3 mg/kg group had a mean gain of 11.5 msec, and the 6 mg/kg group had a mean gain of 23.8 msec. Although the 6 mg/kg group was significantly different than the other two groups, a visible but nonsignificant difference was found between the 6 mg and 3 mg groups and the 3 mg and 0 mg groups. It was concluded that a 6 mg/kg dose of caffeine significantly lengthens reflex time in college age students.

Adult↗
PubMed1990

Incidence of sacroiliac joint dysfunction and low back pain in fit college students.

The incidence of low back pain and sacroiliac joint dysfunction and their relationship was studied in a sample of physically fit college students. An incidence of 26.5% was found for low back pain, while an incidence of 19.3% was found for sacroiliac joint dysfunction. This study found no significant relationship between sacroiliac joint dysfunction and low back pain.

Adolescent↗
PubMed1990

Management of voice disorders.

Voice disorders are commonly seen in general medical practice. In some cases voice disorders represent the presenting symptom for serious underlying disease. It is important for clinicians from internal medicine, pediatrics, and family practice to be able to identify those factors in the history or observed vocal symptoms which suggest need for referral for comprehensive voice evaluation as well as to understand the distinct but complementary roles of the specific disciplines (otolaryngology and speech-language pathology) involved in diagnosis and treatment of patients with voice disorders.

Humans↗
PubMed1989

Health and ergogenic effects of caffeine.

The indiscriminate use of caffeine by people of all ages may present health hazards. The public at large needs to be more informed of the presence of caffeine in commonly consumed foods and beverages, particularly by infants, children and pregnant women. It is the responsibility of all consumers to investigate the caffeine content of suspected products so that intake may be objectively monitored. Although doubts still exist about the efficacy of caffeine as an ergogenic aid, particularly for exercise of high intensity and short duration, the IOC and the National Collegiate Athletic Association of the US have adopted bans on the use of caffeine to aid sport performance. Currently, both of these organizations prohibit the concentration of caffeine in urine to exceed 15 micrograms-ml-1. That is to say, only very large amounts of caffeine are not permitted at present. Additional research is needed to confirm or deny the contraindications presented by the ingestion of caffeine on a chronic basis.

Caffeine↗
PubMed1989

Chiropractic management of enuresis: time-series descriptive design.

Researchers have indicated that single-subject experimental designs may be of value in chiropractic clinical practice, allowing for the development of a scientific data base. The purpose of this paper was to employ a single-case time-series descriptive design in a condition (enuresis) not commonly treated in chiropractic practice, but that which is thought by some to be responsive to manipulation.

Adolescent↗
PubMed1988

Effect of ingestion of smokeless tobacco on motor distal latency of the median nerve.

Subjects were 17 men between the ages of 18 and 32 yr. and regular users of smokeless tobacco. Each subject received three treatments consisting of one pouch of Skoal Bandits, one pinch of their regular brand, and a nonnicotine piece of chewing gum. The nervous transmission at the neuromuscular junction in the right thumb was compared before treatment and once every minute for 15 min. after treatment. Repeated-measures analysis of variance indicated a significant increase in the distal latencies for both the brand-name grouping and in the regularly used brand. No such difference was found in a control group when compared to the pretest results. It was concluded that smokeless tobacco ingestion resulted in a delay in the nervous transmission across the neuromuscular junction. This delay was hypothesized to be caused by the enduring binding action of nicotine to the acetylcholine receptor sites, thereby blocking the impulse in some of the faster conducting nerve fibers.

Adolescent↗
PubMed1987

Effects of caffeine on simple reaction time and movement time.

There were 19 males and 11 females with a mean age of 21 +/- 3 years and a mean weight of 72.8 +/- 3.2 kg who participated in an experiment to investigate the effect of caffeine on simple reaction time (RT) and movement time (MT). Subjects were randomly assigned to one of three groups--two experimental groups and one control group. Caffeine was administered using a double-blind format: Group 1, 600 mg caffeine; Group 2, 300 mg caffeine. Group 3, the control group, was given a placebo. All subjects were pre-tested for RT and MT prior to consumption of one of the three solutions. Post-test was conducted subsequent to an absorption period of 45 min. Results indicated a significant effect (p less than 0.05) between pre- and post-test measurements for both RT and MT favoring the 300 mg group. However, no significant effect (p greater than 0.05) was found between pre- and post-test measurements for RT or MT in the 600-mg group.

Adult↗
PubMedDate not supplied

The relationship between perceived stress and self-reported illness-related absenteeism.

PURPOSE: To investigate the association between perceived stress and illness-related work absenteeism. DESIGN: A standardized health profile questionnaire developed by Johnson & Johnson Advanced Behavioral Technologies, Inc., was used to collect demographic and personal health data between June 1988 and January 1993. Chi-square, odds ratio, and stepwise regression tests were used to analyze perceived stress and self-reported absenteeism data. SETTING: Worksite health promotion programs in 250 U.S. companies. SUBJECTS: Subjects consisted of 79,070 employees. MEASURES: Stress data, grouped as low, moderate, and high, were correlated with absenteeism data grouped by annual days missed (None, 1 to 2, 3 to 4, and 5+). RESULTS: Significant relationships were found (p < or = .05) between high stress and absenteeism for both genders. Female workers reported higher stress levels and absenteeism than men. Those with high stress were 2.22 more likely to be absent 5+ days per year than those with low stress. Work, finances, and family were the highest stress sources. Greatest absenteeism predictors were health, legal, social, and financial stress. CONCLUSIONS: These data primarily represented self-selected white workers and may not apply to all employees. However, if high stress relates to absenteeism, these data may provide valuable information for program design in stress management.

Absenteeism↗
PubMedDate not supplied

Interexaminer reliability of the electromagnetic radiation receiver for determining lumbar spinal joint dysfunction in subjects with low back pain.

Twenty subjects (6 male, 14 female) with low back pain were examined by two experienced and licensed chiropractic doctors (E1 and E2). Both examiners examined the patients using a Toftness Electromagnetic Radiation Receiver (EMRR) and by manual palpation (MP) of the spinous processes. Interexaminer reliability was calculated at three sites (L3, L4, L5) for the following combinations: a) E1,MP--E2,MP; b) E1,EMRR--E2,EMRR; c) E1,MP--E2,EMRR; and) d) E2,MP--E1,EMRR, and intraexaminer reliability was calculated for the following variables: e) E1,MP--E1,EMRR; and f) E2,MP--E2,EMRR. Results of a Kappa coefficient analysis for interexaminer reliability of the stated combinations and at the specific sites were: a) -0.071, 0.400, 0.200; b) -0.013, 0.100, -0.120; c) 0.286, 0.300, 0.200; d) -0.081, 0.000, 0.048. These results predominantly indicate a poor to fair interexaminer reliability. The results of a Kappa coefficient analysis for intraexaminer reliability of the stated combinations were: e) 0.111, 0.400, 0.737; f) 0.000, 0.100, 0.368. These results indicate a poor to fair reliability. It was concluded that in subjects with low back pain the EMRR may not be a reliable indicator of spinal joint dysfunction.

Adult↗
PubMedDate not supplied

Influence of a mobile worksite health promotion program on health care costs.

The continued rising cost of health care has prompted some business to invest in mobile worksite health promotion programs, which screen employees for health risk and pursue risk reduction through counseling, health education, and referral to medical treatment. The purpose of this study was to examine the influence of a mobile worksite health promotion program on health care costs. We conducted a five-year retrospective study on 1,325 city employees insured by the City of Mesa, Arizona. Of these, 340 had participated in the CIGNA Health-plan mobile worksite health promotion program for two years. The participants were age-matched and sex-matched with 340 control subjects who were also employed and insured by the city. We analyzed participant and control group health care costs for two years before and two years after program initiation. Repeated measures analysis of variance (2 x 2 MANOVA) indicated a significant decrease in health care costs in both groups (P < .0063). The control group had a 7% decrease, while the participant group decreased 16%. Further analysis showed specific reductions in general sickness, outpatient and inpatient claims, and total claims use. Costs for substance abuse/psychological treatment and for emergency care did not decrease. Benefit-to-cost ratio for the entire program resulted in a $3.6 savings for every dollar spent. Mobile worksite health promotion programs can be effective in reducing employee health care expenditures among both program participants and nonparticipants.

Cost-Benefit Analysis↗