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Biomedical subjects

T Mathews

Publications and source records attributed to T Mathews.

At least 37 records · Page 2Linked to original sources
PubMed1992

Physiologic effects of electrical stimulation leg cycle exercise training in spinal cord injured persons.

The purpose of this study was to assess the physiologic training effects of functional electrical stimulation leg cycle ergometer (FES-LCE) exercise in persons with spinal cord injury (SCI) who were previously untrained in this activity. Ten persons with quadriplegia (C5 to C7) and eight with paraplegia (T4 to T11) performed FES-LCE training on an ERGYS I ergometer 10 to 30 minutes per day, 2 or 3 days per week for 12 to 16 weeks (36 total sessions). Training session power output (PO) ranged from 0.0W (no external resistance) to 30.6W. Each subject completed discontinuous graded FES-LCE and arm crank ergometer (ACE) tests before and after training for determinations of peak lower and upper extremity metabolic, pulmonary, and hemodynamic responses. Compared with pretraining, this SCI group exhibited significantly (p less than or equal to .05) higher posttraining peak PO (+45%), oxygen uptake ([O2], + 23%), pulmonary ventilation (+27%), heart rate (+11%), cardiac output ([Qt], + 13%) and significantly lower total peripheral resistance ([TPR], - 14%) during FES-LCE posttests. There were no significant changes in peak stroke volume (+6%), mean arterial pressure ([MAP], - 5%), or arteriovenous oxygen difference ([a-vO2diff], + 10%) during posttraining FES-LCE tests. In addition, no significant differences were noted for the peak level of any monitored variable during ACE posttests after FES-LCE training. The rise in total vascular conductance, implied by the significant decrease in posttraining TPR during FES-LCE tests, denotes that a peripheral circulatory adaptation developed in the persons with SCI during FES-LCE exercise training.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Enhancement of amniotic fluid cell growth for genetic amniocentesis.

The last two decades have witnessed a logarithmic growth in demand for prenatal diagnosis of human disease through amniocentesis. Consequently, culture turn-around-time has become the major concern of all those who are primary care providers for patients seeking help. We report a rapid method for obtaining cytogenetic results from amniocytes as early as 5 days. Early tapping and reducing the turn-around-time during cytogenetic analysis may provide an alternative to chorionic villi sampling.

Amniocentesis↗
PubMed1991

Pentoxifylline in the treatment of distal diabetic neuropathy.

Painful diabetic distal sensory neuropathy is a disabling and common complication of diabetes mellitus. There is evidence that microvascular changes resulting in ischemia to the vasa nervorum may contribute to this problem. Pentoxifylline has been shown to improve circulation through partially occluded peripheral vessels and has been postulated to be of potential benefit. Forty adult type II diabetics were enrolled in a double-blind, placebo-controlled study utilizing pentoxifylline for six months. Visual analog scores, nerve conduction studies, and physical examinations were used to evaluate response to treatment. At the end of the six-month trial, there was no significant difference in the patients' pain between the pentoxifylline- and placebo-treated groups. The authors conclude that pentoxifylline is not useful in the treatment of painful distal diabetic neuropathy.

Diabetes Mellitus, Type 2↗
PubMed1991

Acute hemodynamic responses of spinal cord injured individuals to functional neuromuscular stimulation-induced knee extension exercise.

The purpose of this study was to determine and compare acute hemodynamic responses of spinal cord injured (SCI) quadriplegics (quads), and paraplegics (paras) during a graded-intensity knee extension (KE) exercise test utilizing functional neuromuscular stimulation (FNS) of paralyzed quadriceps muscles. Seven quads and seven paras (N = 14) performed a series of 4-minute stages of bilateral alternating FNS-KE exercise (approximately zero to 70 degree range of motion at the knee and 6 KE/min/leg) at ankle loads of 0, 5, 10, and 15 kg/leg. Physiologic responses were determined with open-circuit spirometry, impedance cardiography, and auscultation. Comparing rest with peak FNS-KE for both groups combined, FNS-KE exercise elicited significant (p less than 0.05) increases in oxygen uptake (130 percent), pulmonary ventilation (120 percent), respiratory exchange ratio (37 percent), arteriovenous oxygen difference (57 percent), cardiac output (32 percent), stroke volume (41 percent), mean arterial pressure (18 percent), and rate-pressure product (23 percent). Heart rate increased significantly by 11 percent from the 5- to the 15-kg/leg stages. Physiologic responses of quads and paras were very similar, except for lower (p less than 0.05) arterial pressures, rate-pressure product, and peripheral vascular resistance in quads. This graded FNS-KE exercise up to the 15-kg/leg load induced relatively small but appropriate increases in aerobic metabolism and cardiopulmonary responses that appear to be safe and easily tolerated by quads and paras. Arterial pressure needs to be monitored carefully in quads to prevent excessive hypertension or hypotension. Although FNS-KE exercise has been shown to elicit peripheral adaptations to improve muscle strength and endurance, it is probably not an effective central cardiovascular training tool for all but the least fit SCI individuals. This information is important for understanding the effects of FNS use during more complex activities such as cycling and ambulation.

Adult↗
PubMed1991

Musculoskeletal responses of spinal cord injured individuals to functional neuromuscular stimulation-induced knee extension exercise training.

This study was conducted to evaluate a newly designed functional neuromuscular stimulation (FNS)-induced knee extension (KE) exercise system that incorporates the most desired features of previously described systems by determining the musculoskeletal responses of spinal cord injured (SCI) individuals to training. A specially designed chair and electrical stimulator were fabricated for FNS-induced KE resistance exercise. Surface electrodes were placed over motor points of the quadriceps muscles, and KE was alternated between legs at an average rate of 6 KE/min/leg. KE testing protocols were developed for pre- and post-training evaluations of performance, and 12 SCI subjects exercise-trained up to three times per week for 36 sessions using a progressive resistance load at ankle level. Pre- and post-training evaluation data were statistically compared using a 0.05 level for significance. Quadriceps muscle performance (strength x repetitions) improved for both legs in all subjects as indicated by significant increases in load resistance and repetitions over the 36-session training period (right leg mean = 1156.0 versus 1624.8 kg.reps, left leg mean = 1127.3 versus 1721.1 kg.reps). In addition, knee range of motion significantly increased (right leg mean = 134 versus 146 degrees, left leg mean = 133 versus 144 degrees). Thigh skinfold, thigh girth, body weight and bone density were not significantly changed. The lack of decrease in bone density in some subjects suggests that the training may retard the rate of bone loss which typically occurs with SCI. No injuries or problems were encountered during testing and training.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Physiologic responses of paraplegics and quadriplegics to passive and active leg cycle ergometry.

The purposes of this study were three-fold: (a) to determine acute physiologic responses of spinal cord injured (SCI) subjects to peak levels of leg cycle ergometry utilizing functional neuromuscular stimulation (FNS) of paralyzed leg muscles, (b) to determine the relative contributions of passive and active components of FNS cycling to the peak physiologic responses, and (c) to compare these physiologic responses between persons who have quadriplegia and those who have paraplegia. Thirty SCI subjects (17 quadriplegics and 13 paraplegics) performed a discontinuous graded FNS exercise test from rest to fatigue on an ERGYS 1 ergometer. Steady-state physiologic responses were determined by open-circuit spirometry, impedance cardiography with ECG, and auscultation. In the combined statistics of both groups, it was noted that peak FNS cycling significantly increased (from rest levels) mean oxygen uptake by 255%, arteriovenous O2 difference VO2 and VE, Q and a-vO2 and VCO by 69%, and stroke volume by 45%, while total peripheral vascular resistance decreased by 43%. Mean peak power output for paraplegics (15 W) was significantly higher than for quadriplegics (9 W), eliciting higher peak levels of pulmonary ventilation and sympathetically mediated hemodynamic responses such as cardiac output, heart rate, and systolic and diastolic arterial blood pressure. Passive cycling without FNS produced no statistically significant increases in physiologic responses above the resting level in either group.

Adult↗
PubMed1985

Radiofrequency hyperthermia as adjuvant therapy following surgical resection of an experimental malignant neoplasm.

Local recurrence after radical surgery is a major problem with many primary solid cancers. The use of radiofrequency hyperthermia (RFHT) as adjuvant therapy to surgery was explored in the Fischer bladder carcinoma (FBCa)/F344 rat tumor system. After subcutaneous innoculation of 34 rats with 10(6) FBCa cells in suspension, RFHT was administered to 17 animals on days 1, 5, 8, and 12. The development of palpable tumors was delayed but not prevented, and tumor growth was retarded in RFHT-treated animals. In another experiment 40 rats were innoculated by subcutaneous trocar injection with a 1 mm3 piece of FBCa. After tumor excision on day 17, adjuvant therapy (untreated control, mitomycin C, RFHT, or RFHT plus mitomycin C) was started on day 20 (10 rats/treatment). The 20 RFHT-treated rats had only 1 incisional recurrence as compared to 9 recurrences in sham-heated rats (P less than 0.005). The authors conclude that RFHT has considerable value as adjuvant therapy to surgery in these tumors. Additional studies of RFHT as adjuvant treatment after surgical excision of tumors are planned.

Animals↗
PubMed1983

Meconium thorax.

A case of meconium thorax resulting from spontaneous perforation of the colon associated with a right Bochdalek's foramen, without herniation, is presented. The baby had immediate respiratory distress postpartum resulting from the meconium in the pleural cavity. No fetal distress was detected, in spite of electrode monitoring in labor, to account for the colonic perforation.

Colonic Diseases↗
PubMed1976

Multiple central nervous system infections in progressive multifocal leukoencephalopathy.

Clinical, pathologic, and immunologic features of two patients with progressive multifocal leukoencephalopathy and multiple coexisting central nervous system infections are presented. Both showed impaired cell-mediated immunity whereas immunoglobulins were normal, suggesting that defective cellular rather than humoral immunity predisposes to progressive multifocal leukoencephalopathy. Continued neurologic deterioration might be due not only to progression of the condition but also to simultaneous opportunistic bacterial and fungal infections that may be amenable to treatment. Unusual features in case 1 included striking neurologic remission for 8 months and a positive brain scan corresponding to a large demyelinated lesion in the frontal lobe.

Brain Diseases↗
PubMed1975

Multiple spine fractures in ankylosing spondylitis.

1. Concomitant cervical and thoracic spine fractures are reported in a patient with advanced ankylosing spondylitis (second reported case). 2. The thoracic T9-10 interspace fracture-dislocation was grossly unstable, as well as the C7-T1 fracture-dislocation. 3. The higher incidence of cord injury following spinal fracture-dislocations in these patients is discussed. 4. The dangers of inadequate postinjury immobilization in those patients fortunate enough to be neurologically intact following spinal fracture are stressed.

Aged↗