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Biomedical subjects

A Gordon

Publications and source records attributed to A Gordon.

At least 37 records · Page 2Linked to original sources
PubMed1996

Skeletal muscle contractile characteristics and fatigue resistance in patients with chronic heart failure.

Whole muscle contractile characteristics and fatigue resistance were studied in male patients with chronic heart failure (n = 6) and in healthy control subjects (n = 6). Maximum voluntary isometric strength in the major muscle groups of leg (plantar flexors and knee extensors) and arm (elbow extensors and elbow flexors), was found to be similar for both groups of subjects. However, a faster isometric twitch time course was observed in the plantar flexor and knee extensor muscles of heart failure chronic patients. The poor resistance to fatigue in the knee extensors of chronic heart failure patients was confirmed in the present study, but using twitch interpolation this was shown not to be due to poor activation. The plantar flexors of chronic heart failure patients also showed a tendency to be less resistant to fatigue, even when the muscle was activated by direct electrical stimulation. The present study shows that independent of muscle strength, patients with chronic heart failure may possess muscles that are faster to contract and less resistant to fatigue. However, it seems this increased fatigability is not due to poor muscle activation.

Chronic Disease↗
PubMed1996

High intensity knee extensor training, in patients with chronic heart failure. Major skeletal muscle improvement.

Skeletal muscle adaptations to high intensity knee extensor strength and/or endurance training in patients with chronic heart failure were investigated. Eleven patients with chronic heart failure were randomized into two groups and exercised the m. quadriceps femoris 3 days/week for 8 weeks. After training, the maximal exercise intensity tolerated on the ergometer cycle was raised from 99 (32) to 114 (40) watts (W, P < 0.05) for all 11 patients. Peak dynamic knee extensor work rate showed the greatest increase after endurance training (40%, P < 0.01). Maximal dynamic and isometric strength were elevated by 40-45% (P < 0.05) after strength training. The cross-sectional area of m. quadriceps femoris was increased in the strength-trained legs (9%, P < 0.05), and the capillary per fibre ratio of m. vastus lateralis was raised by 47 and 58% in the endurance-trained legs (P < 0.05). The oxidative enzyme activity in m. vastus lateralis was significantly raised above 50% after endurance training, whereas glycolytic enzyme activity was unaltered. The peripheral skeletal musculature in patients with chronic heart failure adapts fairly quickly to high intensity knee extensor training. This results in a marked rise in local, and a small rise in total work capacity, indicating maintained plasticity of skeletal muscle in chronic heart failure patients.

Adaptation, Physiological↗
PubMed1996

An assessment of stress among clinical medical students of the University of the West Indies, Mona Campus.

This study looks at sources of stress among the medical students of the University of the West Indies at the Mona campus. Students of the classes 1993 through 1995 were asked to fill out a questionnaire which had been developed for a similar study at the University of Texas in 1983. The return rate was 66%. The results were compared for differences between males and females and between the different year groups. The two most stressful items were rated the same by men and women, i.e., 1) the amount of material to be learned, and 2) examinations and/or grades. There was no statistically significant difference between stress levels by gender in this study. The penultimate clinical year was most stressful. It is hoped that the findings of this study will be the basis for discussion about whether the identified stressors are inherent and necessary to the medical training experience and, if so, how students can be better prepared to cope with them.

Adult↗
PubMed1996

Neuropsychologic deficits and clinical features of posttraumatic temporomandibular disorders.

Previous studies have shown that characteristics of posttraumatic temporomandibular disorders (pTMD) differ considerably from those of nontraumatic or idiopathic temporomandibular disorders (iTMD). Both the rate of recovery and the amount of treatment required appear to be different for both groups. In this blinded study, 14 patients with iTMD and 13 patients with pTMD were examined. Patients submitted to a variety of reaction-time tests and neuropsychologic assessments to test their ability to cope with simple and more complex tasks with and without a variety of cognitive interferences. Clinical examination was used to assess signs of TMD. Eleven of the subjects (six iTMD, five pTMD) consented to a second phase of the investigation, whereby the patients were studied with single-photon emission computerized tomography (SPECT) using 99mTc-hexamethylpropyleneamineoxime (HMPAO). For simple and complex reaction-time tests, the pTMD group was significantly slower than the iTMD group (P < .05 to P < .001). Other neuropsychologic assessment tools such as the Consonant Trigram Test and the California Verbal Learning Test indicated that pTMD patients were more affected by both proactive and retroactive interferences and were more likely to perseverate on a single thought. In clinical examination, pTMD patients demonstrated greater reaction to muscle palpation than did iTMD patients (P < .05). The SPECT results suggested that there were mild differences between the two populations, and further ther studies are required to confirm this finding. The results lend support to the concept that there are differences between pTMD and iTMD populations. It is suggested that although patients with pTMD may have some similarities to those with iTMD, the former population may benefit from being handled somewhat differently and should be assessed and treated using a more broad, multidisciplinary treatment paradigm. These results must be confirmed in studies of larger populations.

Accidents, Traffic↗
PubMed1996

Effects of salmon calcitonin on patients with atypical (idiopathic) facial pain: a randomized controlled trial.

The analgesic properties of salmon calcitonin for the treatment of atypical facial pain (AFP) were investigated. An initial open-label trial of salmon calcitonin in subjects with refractory AFP was followed with a randomized, double-blind, placebo-controlled crossover trial of salmon calcitonin in the management of AFP. Salmon calcitonin (100 IU in 1 mL saline) was administered in an open-label fashion to 13 subjects with refractory AFP five times per week for 6 weeks. In the subsequent randomized investigation, salmon calcitonin (100 IU in 1 mL saline) or placebo (1 mL saline) was delivered three times per week for 3 weeks, with a 1-week washout prior to crossover. The percentage of subjects dropping out (57%) exceeded that reported in other pain studies using calcitonin. Therefore, it was imperative to halt the study for ethical reasons. There was no difference in outcome measures (P > .05) in subjects administered either active drug or placebo, and a high incidence of side effects led to dropout in subjects taking salmon calcitonin. Although salmon calcitonin may have analgesic properties, it is not efficacious for AFP, largely because of the side effects.

Adult↗
PubMed1995

Randomised controlled trial of laparoscopic versus open repair of inguinal hernia: early results.

OBJECTIVE: To establish the safety, short term outcome, and theatre costs of transabdominal laparoscopic repair of inguinal hernia performed as day surgery. DESIGN: Randomised controlled trial. The control operation was the two layer modified Maloney darn. SETTING: Teaching hospital and district general hospital. SUBJECTS: 125 men randomised to laparoscopic or open repair of inguinal hernia. OUTCOME MEASURES: Morbidity, postoperative pain and use of analgesics, quality of life, and theatre costs. Outcome was assessed by questionnaires administered to patients daily for 10 days and at six weeks postoperatively and by outpatient review at six weeks. Return to normal activity was assessed by questionnaire at three months. RESULTS: One vascular complication (2%) occurred in the group that had open repair. Seven complications (12%) including vessel injury and early recurrence arose in the group that had laparoscopic repair (difference in complication rate 10% (95% confidence interval 4% to 18%; P = 0.02). Pain scores and quality of life assessed by the short form 36 showed a significant benefit to the group that had laparoscopic repair in the early postoperative period. Return to normal activity was not significantly different between the two groups. Total theatre costs were higher in the group that had laparoscopic repair (mean cost for laparoscopic repair 850 pounds (622 pounds to 1078 pounds); mean cost for open repair 268 pounds (245 pounds to 292 pounds)). CONCLUSIONS: Because of the greater complication rate and higher theatre costs for laparoscopic repair and the patient outcome preferences expressed, the results of larger trials of clinical and cost effectiveness using recurrence as the primary outcome measure should be known before laparoscopic herniorrhaphy is widely adopted.

Adult↗
PubMed1995

Advanced colorectal cancer treated with combined 5-fluorouracil and folinic acid: the experience within a surgical department.

Thirty-seven patients with advanced colorectal cancer were treated with fluorouracil (5-FU) and folinic acid (FA) (Jan 1990-Dec 1992). Clinical assessment and administration of chemotherapy was incorporated as part of the daily work load of a busy general surgical unit. Records were available for all 37 patients and showed that 13 patients (Treatment failures, Group B) failed to receive more than 3 monthly cycles of treatment, while the remaining 24 received 6 or greater cycles (Treatment completed, Group A). There was no survival advantage demonstrated for the complete study cohort (n = 37) when compared to an historical group (n = 1038) of untreated patients. Median survival in Group A (14.2 months) was significantly greater (chi-squared, P < 0.0001) than survival in Group B (6.7 months). Toxicity was common with 43% experiencing mouth ulcers or stomatitis (13% severe). Three per cent had dose-limiting diarrhoea and myelotoxicity was minimal. There were six partial responses and 16 patients had no change in their disease status while on treatment. Current regimen of 5-FU/FA are well-tolerated with low toxicity but show no survival advantage for advanced colorectal cancer. However, these regimens may be administered within the confines of general surgical practice.

Adenocarcinoma↗
PubMed1995

Lack of role for nitric oxide (NO) in the selective destabilization of endothelial NO synthase mRNA by tumor necrosis factor-alpha.

The constitutive expression of endothelial nitric oxide (NO) synthase (cNOS) is essential for the physiological regulation of vascular tone and structure. The mechanism of downregulation of steady state cNOS mRNA in human umbilical vein endothelial cells exposed to tumor necrosis factor-alpha (TNF-alpha) was investigated by using Northern blot analysis of total cellular RNA. TNF-alpha produced a dose- and time-dependent decrease in cNOS mRNA expression that was near maximal at 10 U/mL and 6 hours of exposure, respectively. In contrast, steady state expression of endothelin-1 and plasminogen activator inhibitor-1 (PAI-1) mRNA was upregulated by TNF-alpha. The pharmacological generation of NO using sodium nitroprusside (10 mumol/L) and S-nitroso-acetylpenicillamine (100 to 400 mumol/L) had no effect on cNOS mRNA levels, and TNF-alpha-induced downregulation of cNOS was not prevented by coincubation with the inhibitors of NO synthesis N omega-nitro-L-arginine methyl ester (1 mmol/L) and NG-monomethyl L-arginine (10 mmol/L). Under control conditions, cNOS and PAI-1 mRNA were stable after treatment with actinomycin D for periods greater than 24 hours, whereas endothelin-1 message was rapidly degraded (half-life, < 1 hour). Pretreatment with TNF-alpha (30 U/mL) selectively reduced that half-life of cNOS mRNA to less than 12 hours without altering the stability of PAI-1 message. TNF-alpha-induced destabilization of cNOS mRNA could be partially prevented by coincubation with cycloheximide (1 mumol/L) but was not reproduced by addition of sodium nitroprusside.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Oxidoreductases↗
PubMed1995

Creatine supplementation in chronic heart failure increases skeletal muscle creatine phosphate and muscle performance.

BACKGROUND: Cardiac creatine levels are depressed in chronic heart failure. Oral supplementation of creatine to healthy volunteers has been shown to increase physical performance. AIM: To evaluate the effects of creatine supplementation on ejection fraction, symptom-limited physical endurance and skeletal muscle strength in patients with chronic heart failure. METHODS: With a double-blind, placebo-controlled design 17 patients (age 43-70 years, ejection fraction < 40) were supplemented with creatine 20 g daily for 10 days. Before and on the last day of supplementation ejection fraction was determined by radionuclide angiography as was symptom-limited 1-legged knee extensor and 2-legged exercise performance on the cycle ergometer. Muscle strength as unilateral concentric knee extensor performance (peak torque, Nm at 180 degrees/s) was also evaluated. Skeletal muscle biopsies were taken for the determination of energy-rich phosphagens. RESULTS: Ejection fraction at rest and at work did not change. Performance before creatine supplementation did not differ between placebo and creatine groups. While no change was seen in the placebo group compared to baseline, creatine supplementation increased skeletal muscle total creatine and creatine phosphate by 17 +/- 4% (P < 0.05) and 12 +/- 4% (P < 0.05), respectively. Increments were seen only in patients with < 140 mmol total creatine/kg d.w. (P < 0.05). One-legged performance (21%, P < 0.05), 2-legged performance (10%, P < 0.05), and peak torque, Nm (5%, P < 0.05) increased. Both peak torque and 1-legged performance increased linearly with increased skeletal muscle phosphocreatine (P < 0.05). The increments in 1-legged, 2-legged and peak torque were significant compared to the placebo group, (P < 0.05). CONCLUSIONS: One week of creatine supplementation to patients with chronic heart failure did not increase ejection fraction but increased skeletal muscle energy-rich phosphagens and performance as regards both strength and endurance. This new therapeutic approach merits further attention.

Administration, Oral↗
PubMed1994

Does patient semen quality alter during an in vitro fertilization (IVF) program in a manner that is clinically significant when specific counseling is in operation?

PURPOSE: It has been shown that the stress of infertility may impair semen quality. Whether counseling can attenuate this affect is unproven. This study examines, in an IVF program setting, where specific counseling is in operation, whether semen collected on the day of oocyte recovery is significantly different from that obtained during the prior clinical suitability assessment of the couple. RESULTS: In the 125 consecutive couples examined, there were no significant overall differences in semen volume or sperm density. There was a significant increase in sperm motility on the day of oocyte retrieval (P < 0.001). Twenty-three patients (18.4%) showed an increase in quality, and 21 (16.8%) a decrease, on the day of oocyte recovery. The environment of production appeared to exert no influence. Fertilization failure occurred in seven couples, three (14%) of whom presented for the first time with decreased semen parameters on the day of IVF. This compares with 1 of 23 (4%) fertilization failure in those whose parameters increased. CONCLUSION: The semen quality of the vast majority of the patients studied in this highly counseled program does not appear to be significantly affected by the superstress of participation in the day of oocyte recovery.

Adult↗