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Biomedical subjects

K J Stewart

Publications and source records attributed to K J Stewart.

At least 37 records · Page 2Linked to original sources
PubMed2000

Neurobehavioural outcomes of penetrating and tangential gunshot wounds to the head.

OBJECTIVE: The objective of this study was to compare penetrating and tangential gunshot wounds to the head with regards to demographic, neurobehavioural and clinical outcome measures. METHODS: Twenty-nine patients with penetrating gunshot wounds (P-GSW) and 11 patients with tangential gunshot wound (T-GSW) to the head admitted to an acute neurotrauma service were compared using standardized neurobehavioural and clinical outcome measures. RESULTS: The mean GCS was 10.5 +/- 0.79 for the P-GSW group and 13.4 +/- 0.72 for the T-GSW group. The mean AIS-CNS for the P-GSW group was 5.00 +/- 0 and for the T-GSW group was 3.7 +/- 0.27. Significance was found on Digit Span (p < 0.05) and Block Design (p < 0.009) subtests. Outcomes between the two groups were similar, except for significant differences were found for acute length of stay (LOS) (P-GSW was 47.72 +/- 13.2 and T-GSW group was 13.0 +/- 1.3, p = 0.005) and for acute care charges (P-GSW group was $150,533 +/- 23,834 and T-GSW group was $70,712 +/- 16,587, p = 0.05). CONCLUSIONS: Initially, a penetrating gunshot wound is a more severe and costly injury than a tangential gunshot wound to the head, however T-GSW possess significant deficits and, if the patient survives past the acute phase of recovery, the two groups have similar functional outcomes. Future standard classification, neuropsychological, and clinical outcome measures.

Adult↗
PubMed2000

Safety and efficacy of resistive training in patients with coronary heart disease.

In the past 10 to 15 years, there have been several studies on the acute and chronic responses to resistive training in patients with cardiovascular disease. As a result, the safety and efficacy of resistive exercise has become more evident. Resistive training appears to be safe and effective for promoting fitness and improving risk factors in patients with coronary heart disease. This review addresses the health and fitness benefits in these patients, the established guidelines regarding inclusion and exclusion into programs, guidelines for resistive training exercise prescriptions, and how these guidelines have evolved in recent years. (c) 2000 by CHF, Inc.

Journal Article↗
PubMed2000

Mycobacterium tuberculosis presenting as sternal osteomyelitis.

A 54-year-old female presented with a presternal abscess and developed axillary lymphadenopathy. Imaging confirmed the presence of sternal osteomyelitis. The osteomyelitis was cured by resection and muscle flap reconstruction. Although tuberculosis was suspected, the organism was only cultured after the fourth surgical procedure. Surgeons should be aware that negative microbiology does not exclude a diagnosis of Mycobacterium tuberculosis.

Diagnosis, Differential↗
PubMed1999

A quantitative analysis of the effect of insulin-like growth factor-1 infusion during mandibular distraction osteogenesis in rabbits.

AIM: To quantify, by histomorphometry, the effects of local insulin-like growth factor-1 (IGF-1) during mandibular distraction at various rates. METHODOLOGY: Mature rabbits underwent bilateral mandibular corticotomy and distraction lengthening. Recombinant IGF-1 was administered to two groups of rabbits via osmotic infusion pumps. Distraction regimes were as follows: Group A, 1 mm/day for 15 days; Group B, as for A plus IGF-1; Group C, 3 mm/day for 5 days; Group D, as for C plus IGF-1; and Group E, sham-operated controls. After a 28-day consolidation period, rabbits were sacrificed and bone deposition quantified using DEXA scanning, three-point bending, histological examination and sampled for histomorphometric analysis. RESULTS: DEXA scanning and three-point bending failed to detect any effect of distraction rate or of IGF-1 infusion. Histological and histomorphometric analysis suggested 1 mm/day to be the ideal distraction rate, as this was associated with greater osteoblastic activity and consistent bony union. However, IGF-1 infusion significantly enhanced osteoblastic activity at both distraction rates and resulted in bony union when distraction was performed at 3 mm/day. CONCLUSIONS: Distraction osteogenesis at a rate of 1 mm/day provides greater osteogenic stimulus than 3 mm/day. Exogenous IGF-1 has a positive influence on osteoblastic activity during distraction. Its effect is probably minimised by high levels of endogenous IGF-1.

Animals↗
PubMed1999

The soft tissue management of children's open tibial fractures.

A series of 49 children admitted with a diagnosis of open tibial fracture was reviewed with particular regard to soft tissue management. Injuries were grouped according to the Gustilo classification. Twenty-two patients had Grade I fractures, 11 Grade II and 16 Grade III (4 Grade IIIa, 11 Grade IIIb and one Grade IIIc). Patients were managed by early lavage and debridement under general anaesthesia, followed by immobilisation. Local transposition flaps were utilised in 10 patients and provided reliable soft tissue cover. A free tissue transfer was performed in only one patient. Complications appeared to be associated with delayed involvement by plastic surgeons.

Adolescent↗
PubMed1998

Mandibular distraction osteogenesis: a comparison of distraction rates in the rabbit model.

The rabbit model has been used to study the effects of different rates of distraction upon mandibular bone. Bilateral distraction was performed at two different rates anterior to the molar teeth. Both experimental groups were significantly inferior to sham operated controls in terms of bone density (DEXA) and mechanical testing. No difference in new bone formation between the two distraction rates was detected by these modalities. However, histological examination revealed non-union to be more common in the rapidly distracted group. This suggests that attempts to shorten the duration of external fixation in clinical mandibular distraction osteogenesis should be by methods other than more rapid distraction.

Absorptiometry, Photon↗
PubMed1998

Distraction osteogenesis in craniofacial surgery: a review.

Distraction osteogenesis is a technique of new bone formation by the gradual separation of bony fragments. The method, although initially developed for limb lengthening, is now being applied in the treatment of craniofacial deformities. A number of principles have been established through careful scientific study to guide clinical practice, such as the ideal rate and rhythm of distraction, the need for periosteal preservation during bone division, a "latent period" of neutral fixation before, and a "consolidation period" after distraction. The technique is being applied in craniofacial surgery particularly for mandibular deformities and offers considerable advantages over previous methods such as osteotomy and inlay bone grafting. Donor site morbidity is avoided, the investing soft tissue envelope is concurrently expanded, and the magnitude of the procedure is less. However, the technique is still in its infancy and requires further modification and refinement before widespread acceptance as a treatment in mainstream craniofacial surgery. Problems with cutaneous scarring and socially undesirable external hardware, particularly in the pediatric population, have led to the emergence of intraoral miniature devices, with the ultimate goal of development of a multiplanar internal autodistractor. Furthermore, many principles well established in leg lengthening, such as the rate and rhythm of distraction, need to be reexamined and the parameters redefined with particular reference to the craniofacial skeleton. Distraction osteogenesis has an expanding role in craniofacial surgery.

Animals↗
PubMed1998

Establishing mechanisms to conduct multi-institutional research--fatigue in patients with cancer: an exercise intervention.

PURPOSES/OBJECTIVES: To describe the process of establishing a multi-institutional interdisciplinary team of oncology researchers and conducting a pilot study of an exercise intervention for fatigue. DATA SOURCES: Project meeting minutes and records, research team members' logs, subjects' research records, the research study proposal, and team members' individual and collective shared experiences. DATA SYNTHESIS: Site investigators established research teams at five academic medical centers. Fifty subjects were enrolled in the study and tested during their cancer treatment. Study methods, including instrumentation, were evaluated carefully and revised. CONCLUSIONS: The multi-institutional network of researchers is an effective and efficient model for testing an intervention to manage fatigue during cancer treatment. IMPLICATIONS FOR NURSING PRACTICE: Exercise is a feasible and potentially beneficial intervention to combat distressing cancer treatment-related fatigue. A pilot study is essential to determine the best methods for conducting a clinical trial and to develop the teams of researchers necessary for such a project.

Exercise Therapy↗
PubMed1997

Effects of single nightly injections of growth hormone-releasing hormone (GHRH 1-29) in healthy elderly men.

Age-related reductions in growth hormone (GH) and insulin-like growth factor-I (IGF-I) may contribute to decreased muscle mass and strength in older persons. The relationship of this phenomenon to skeletal muscle bioenergetics has not been reported. We sought to determine whether administration of GH-releasing hormone (GHRH) would sustain increases in GH and IGF-I and improve skeletal muscle function and selected measures of body composition and metabolism. We measured GH secretion, muscle strength, muscle histology, and muscle energy metabolism by phosphorus nuclear magnetic resonance spectroscopy (31P-NMRS), body composition, and endocrine-metabolic functions before and after 6 weeks of treatment. Eleven healthy, ambulatory, non-obese men aged 64 to 76 years with low baseline IGF-I levels were treated at home as outpatients by nightly subcutaneous self-injections of 2 mg GHRH for 6 weeks. We measured GH levels in blood samples obtained every 20 minutes from 8:00 PM to 8:00 AM; AM serum levels of IGF-I, IGF binding protein-3 (IGFBP-3), and GH binding protein (GHBP); muscle strength; muscle histology; the normalized phosphocreatine abundance, PCr/[PCr + Pi], and intracellular pH in forearm muscle by NMRS during both sustained and ramped exercise; body composition by dual-energy x-ray absorptiometry (DEXA); lipid levels; and glucose, insulin, and GH levels during an oral glucose tolerance test (OGTT). GHRH treatment increased mean nocturnal GH release (P < .02), the area under the GH peak ([AUPGH] P < .006), and GH peak amplitude (P < .05), with no change in GH pulse frequency or in levels of IGF-I, IGFBP-3, or GHBP Two of six measures of muscle strength, upright row (P < .02) and shoulder press (P < .04), and a test of muscle endurance, abdominal crunch (P < .03), improved. GHRH treatment did not alter exercise-mediated changes in PCr/[PCr + Pi] or intracellular pH, but decreased or abolished significant relationships between changes in PCr/[PCr + Pi] or pH and indices of muscle strength. GHRH treatment did not change weight, body mass index, waist to hip ratio, DEXA measures of muscle and fat, muscle histology, glucose, insulin, or GH responses to OGTT, or lipids. No significant adverse effects were observed. These data suggest that single nightly doses of GHRH are less effective than multiple daily doses of GHRH in eliciting GH- and/or IGF-I-mediated effects. GHRH treatment may increase muscle strength, and it alters baseline relationships between muscle strength and muscle bioenergetics in a manner consistent with a reduced need for anaerobic metabolism during exercise. Thus, an optimized regimen of GHRH administration might attenuate some of the effects of aging on skeletal muscle function in older persons.

Aged↗
PubMed1995

Island advancement flaps in the management of anal fissures.

The classic high-pressure fissure responds well to lateral internal sphincterotomy. The management of recurrent fissures and those that occur in patients with weak sphincters is open to debate. An island advancement flap technique used in 21 patients is described with the above criteria. Preoperative median resting anal pressure was 66 (range 43-90) cmH2O and median maximal squeeze pressure was 132 (range 76-193) cmH2O, values that were significantly lower than in controls and those with classic fissure. Endoanal ultrasonography in 15 of these patients showed defects in the anal sphincters. All flaps healed primarily with preservation of sensation. Perfect continence was maintained in all patients. Follow-up was for a median of 18 (range 2-28) months. There were no serious complications. All fissures healed with minimal postoperative discomfort. This procedure provides a useful alternative for symptomatic anal fissures, in which a sphincter-weakening procedure might jeopardize continence.

Adult↗
PubMed1995

A quantitative ultrastructural study of collagen fibrils in human skin, normal scars, and hypertrophic scars.

The diameter-distribution of collagen fibrils in the dermis of human skin and scar tissue has been investigated. In samples of normal skin, normal scar, and hypertrophic scar, prepared for transmission electron microscopy, collagen fibrils were systematically random-sampled and their diameters measured. There was a statistically significant difference between the diameter-distribution of fibrils in the papillary and reticular layers of dermis in normal skin. A similar pattern was found in normal scar, but not in hypertrophic scar.

Adolescent↗
PubMed1995

Power wheelchair range testing and energy consumption during fatigue testing.

The range of a power wheelchair depends on many factors including: battery type, battery state, wheelchair/rider weight, terrain, the efficiency of the drive train, and driving behavior. The purpose of this study was to evaluate the feasibility of three methods of estimating power wheelchair range. Another significant purpose was to compare the current draw on pavement to current draw on an International Standards Organization (ISO) Double Drum tester at one m/sec. Tests were performed on seven different power wheelchairs unloaded, and loaded with an ISO 100 kg test dummy. Each chair was configured according to the manufacturer's specifications, and tires were properly inflated. Experienced test technicians were used for the tennis court tests, and treadmill tests. An ISO 100 kg test dummy was used for the ISO Double Drum test. Energy consumption was measured over a distance of 1500 m for each of the three test conditions. The rolling surface was level in all cases. Repeated measure analysis of variance (ANOVA) revealed a significant difference (p = 0.0001) between the predicted range at maximum speed for the three tests. Post hoc analysis demonstrated a significant difference (p < 0.01) in estimated range at maximum speed between the Double Drum test and the treadmill test, as well as between the Double Drum test and the tennis court test. Our results indicate no significant difference (p > 0.05) between the predicted range at maximal speed between the treadmill and tennis court tests. A simple relationship does not exist between the results of range testing with the Double Drum tester and the tennis court. An alternative would be to permit the use of a treadmill for range testing as simple relationships between all pertinent treadmill and tennis court range data were found. For the Double Drum tester used, the current demand is higher than under normal usage. This presents a problem as current is related to load torque in a power wheelchair. Hence, the Double Drum tester friction must be reduced. The predicted range for the tennis court test at maximum speed ranges from a low of 23.6 km to a high of 57.7 km. The range of the power wheelchair can be improved by the use of wet lead acid batteries in place of gel lead acid batteries.

Electric Power Supplies↗
PubMed1994

Evaluation of methods for determining rearward static stability of manual wheelchairs.

Wheelchair standards have been under development for several years. A set of tests has been approved by the American National Standards Institute (ANSI) and by the International Standards Organization (ISO) but continue to be refined. Static stability is one of the indicators used to evaluate manual wheelchairs and is measured by placing a loaded wheelchair on a platform that is tilted until the wheelchair's front wheels lift off of the platform. Currently, if the wheelchair parking brakes slip, a block is placed behind the rear wheels and the tip angle is measured. The results for eight different wheelchairs with three load cases showed that the rearward tip angle for the block is significantly different (p < 0.05) from that with the brakes alone.

Biomechanical Phenomena↗