Biomedical subjects

S Dennis

Publications and source records attributed to S Dennis.

49 records · Page 3Linked to original sources

PubMed1989

Dynamic EMG analysis of torque transfer in professional baseball pitchers.

Fifteen professional baseball pitchers underwent active pitching motion analysis of the abdominal oblique, rectus abdominis, lumbar paraspinous and gluteus maximus muscles bilaterally via surface electrode evaluation. Baseline resting and isometric maximum values were obtained and active data referenced against these for comparison. The muscle activity then was measured during the pitching sequence and analyzed in each of the five pitching phases. The abdominal oblique, lumbar paraspinous and rectus abdominis contralateral to the pitching arm and the ipsilateral gluteus maximus all had increases in activity level of 75 to 100% during the active pitching motion. Using these data indicating specific muscle group patterns with clinical and performance data, we hope to minimize injuries and maximize pitching performance.

Abdominal Muscles↗

PubMed1989

Comparison of disc space heights after anterior lumbar interbody fusion.

Thirty-one consecutive patients underwent anterior interbody fusion of 40 levels of the lumbar spine using autogenous, autologous, or mixed iliac crest graft. Each patient's disc space height was measured preoperatively, immediately postoperatively, and an average of 29 months postoperatively. The immediate postoperative radiograph demonstrated an average increase in disc space height of 89%, or 9.5 mm for each operated level. The late radiographic evaluation, from 7 to 54 months postoperatively, showed an average decrease of 1%, or 0.1 mm for each level. At late follow-up, no correlation could be found between the time from the operation and disc space height. One hundred percent of patients developed disc space height decreases during the postoperative period, with 46% of levels being narrower than their preoperative height at last follow-up. Loss of distraction is a normal postoperative occurrence of the procedure. Disc space distraction is temporary with anterior interbody fusion.

Adult↗

PubMed1988

Use of site-directed mutagenesis to investigate the basis for the specificity of hirudin.

Regions of hirudin important for its inhibitory activity with thrombin have been examined by site-directed mutagenesis. Since thrombin has a primary specificity for basic amino acids, each of the three basic residues and the histidine in hirudin were mutated to glutamine. Mutation of Lys-47 caused a small increase (9-fold) in the dissociation constant whereas the other mutations were without effect. These results indicate that hirudin is different from most other inhibitors of serine proteases in that interactions with the primary specificity pocket of its target enzyme are not crucial to its inhibitory activity. The acidic nature of the carboxyl region of hirudin was found to be important for its interaction with thrombin. Single and multiple mutations of carboxyl-terminal glutamate residues (57, 58, 61, and 62) to glutamine caused increases in the dissociation constant. This value increased with the number of mutations and reached a maximum of 61-fold when all four glutamate residues were mutated. Kinetic studies indicated that in all cases where an increase in dissociation constant was observed, it was predominantly due to a decrease in the association rate constant.

Amino Acid Sequence↗

PubMed1985

Diet and exercise training effects on resting metabolic rate.

The decline in resting metabolic rate (RMR) during periods of caloric restriction is a well documented phenomenon. The purpose of this study was to determine if either 30 min of daily self-selected aerobic activity (Group D) or prescribed exercise training performed every other day (Group P) for 12 weeks can prevent the decrease in RMR during caloric restriction for weight loss. Seventy-eight adult subjects (38 M, 40 F) whose weights were 15-35 percent above the upper limit for age, sex and frame were randomly assigned to three treatment groups. All three groups followed the same 1200, 1500 or 1800 kcal/d (5023, 6279, 7534 kJ) diet exchange plan. Group C (Control) followed no exercise program, while D and P exercised as described above. Maximal oxygen consumption (VO2 max, m10(2)/kg X min-1) predicted from the Bruce Test increased by 0.08 +/- 7, 9 +/- 12 and 12 +/- 9 percent in groups C, D and P, respectively. The increases for D and P were significantly higher than for C (P less than 0.01). RMR (m10(2)/kg X min-1) increased by 2 +/- 9, 4 +/- 7 and 10 +/- 9 percent in groups C, D and P respectively. The percent change for group P was significantly greater than that for groups C and D (P less than 0.05). There was a significant relationship across all subjects between the % delta in VO2 max and % delta in RMR (r = 0.307, P less than 0.01). However, the association between these two variables was stronger for females than for males.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1984

Interferon kinetics and adverse reactions after intravenous, intramuscular, and subcutaneous injection.

Three groups of six subjects each received a single 36 X 10(6) U dose of recombinant leukocyte A interferon (rIFN-alpha A) as a 40-min infusion, an intramuscular injection, or a subcutaneous injection. Blood samples were collected at specific times after dosing for analysis of rIFN-alpha A serum concentrations by an enzyme immunoassay method, ELISA. The rIFN-alpha A was rapidly distributed and moderately eliminated (t 1/2 = 5.1 hr) after intravenous infusion. The maximum concentrations at the end of intravenous infusion were tenfold the maximum concentrations after intramuscular and subcutaneous injections. Renal tubular secretion or extrarenal elimination was suggested by clearance values of 1.8 times the glomerular filtration rate. After intramuscular and subcutaneous injection, rIFN-alpha A was absorbed slowly (time to reach maximum concentration ranged from 4 to 8 hr), which resulted in prolonged serum concentrations. Estimated bioavailability was more than 80% for both intramuscular and subcutaneous injection shares qualitatively the same adverse reactions, the reactions differ in severity and duration. The adverse effects appear to be related to route of administration of herpes labialis were also noted. There were no significant clinical laboratory abnormalities of medical concern. Although rIFN-alpha A injected by intravenous infusion or intramuscular or subcutaneous injection shares qualitatively the same adverse reactions, the reactions differ in severity and duration. The adverse effects appear to be related to route of administration.

Adult↗

PubMed1981

The laxative effects of lactulose in normal and constipated subjects.

We compared lactulose syrup to a placebo (5% sucrose syrup) in 42 normal and 24 chronically constipated volunteers. The study in normal subjects was double-blind and had a crossover design of two dose levels, 30 and 60 ml/day, whereas the study in constipated subjects was a double-blind parallel study of 60 ml/day dose. Lactulose syrup produced clinically and statistically significant increases in the frequency, weight, volume, and water content of stools and produced stools of softer consistency compared to baseline values, as well as to a sucrose-treated control group in both normal and constipated subjects. The study in normals suggests that the laxative effects are dose-related. Adverse effects reported were tolerable and were extensions of the pharmacologic effects of the drug. We concluded that lactulose is an effective laxative that affects the character of the colonic fecal content, thereby inducing evacuation of feces in people with constipation.

Adolescent↗

PubMedDate not supplied

Lansoprazole: administration of the contents of a capsule dosage formulation through a nasogastric tube.

A single-dose, open-label, randomized, crossover bioavailability study was conducted in 24 healthy adult male volunteers to assess an alternative method of administration of lansoprazole capsules. The results of 22 subjects were analyzed. Subjects received regimen A (granules from a 30-mg capsule mixed with apple juice and administered through a nasogastric tube) or regimen B (an intact 30-mg capsule) during the first study period. The regimens were reversed during the second period 1 week later. Blood samples were obtained over 12 hours and pharmacokinetic variables were determined. No statistically significant differences in mean time elapsed to peak concentration, mean peak concentration, area under the curve (AUC)0-t, and AUC0-infinity were detected between regimens by using analysis of variance. Bioavailability was assessed by the 90% confidence interval of the two one-sided tests on the natural logarithm of AUC. The 90% confidence interval for the AUCzero-infinity ratio was 0.955 to 1.140 for regimens A to B. These results indicate similar bioavailabilities between the two regimens and demonstrate that lansoprazole capsules may be administered by mixing the capsule contents with apple juice for administration through a nasogastric tube.

2-Pyridinylmethylsulfinylbenzimidazoles↗

PubMedDate not supplied

The effects of fixed and articulated ankle-foot orthoses on gait patterns in subjects with cerebral palsy.

Twenty-one subjects with spastic diplegic cerebral palsy were studied to quantify the effects of fixed and articulated ankle-foot orthoses (AFOs) on gait and delineate criteria for their use. Children underwent gait analysis under three conditions, fixed AFOs (FAFOs), articulated AFOs (AAFOs), and shoes alone. Greater dorsiflexion occurred at initial contact with both FAFOs and AAFOs than shoes alone. Dorsiflexion at terminal stance was greatest in AAFOs. Plantarflexor power generation at preswing was preserved in AAFOs. No differences were found in knee position during stance. Knee-extensor strength was positively related to knee extension during stance. No relationships were found between dorsiflexion range of motion, calf spasticity and strength, and peak dorsiflexion during stance. AAFOs are appropriate for subjects with varying degrees of calf spasticity, as long as adequate passive range of motion is available. These findings can be applied primarily to children who do not have a preexisting tendency to crouch.

Adolescent↗

PubMedDate not supplied

Incidence of cervical spinal stenosis in professional and rookie football players.

Sagittal canal/vertebral body ratios were measured on cervical spine lateral radiographs of 124 professional football players and 100 rookie football players. A total of 894 levels were measured in 224 players. Thirty-two percent (40) of the 124 professional football players, and 34% of the 100 rookies had a ratio of less than 0.80 at one or more levels from C3 to C6. The 0.80 ratio has been considered indicative of cervical spinal stenosis. This is the first time that the incidence of spinal stenosis, as determined by Torg's ratio, has been demonstrated in a population of professional and rookie football players. Because one-third of this population has cervical spinal stenosis as determined by the Torg ratio, other factors should be considered in the evaluation of a player with a transient quadriplegic episode when making continued play decisions.

Football↗

PubMedDate not supplied

Building a safety culture.

This is the first article in a series of seven based on the Seven Steps to Patient Safety (National Patient Safety Agency (NPSA) 2004a). It is aimed at enhancing nurses' and midwives' knowledge about patient safety, including strategies and tools that are available to improve the quality of health care. This article outlines the patient safety agenda and emphasises the importance of creating an open and fair culture in the NHS.

Humans↗

PubMedDate not supplied

Integrating risk management into working practice.

The aim of this article, the third in this series on the Seven Steps to Patient Safety (National Patient Safety Agency (NPSA) 2004), is to explore how risk management can be integrated into the culture of a healthcare organisation and the working practices of clinicians, managers and their immediate teams.

Health Facility Administration↗

PubMedDate not supplied

Close observation: how to improve assessments.

Close observation on an acute psychiatric ward is an intervention of restraint. It is intended to ensure the safety and well-being of the patient. This article presents research into the prescription of dose observation and sets out to offer a model for prescribing and reviewing this intervention.

Dangerous Behavior↗

PubMedDate not supplied

An audit of treatment withdrawal in one hundred patients on a general ICU.

The audit found that 72.6% of patients who died had treatment withdrawn. Three organ failures were most often present in patients when treatment was withdrawn. Withdrawal of treatment did not mean the cessation of care. Variation in involvement was demonstrated with different consultants.

Adolescent↗