Training adaptations in skeletal muscle of juvenile diabetics

Skeletal muscles from 12 male, juvenile-onset diabetics (JD) and 13 nondiabetics (ND) were studied to determine the effects of endurance training on mitochondrial enzyme activities, lipoprotein lipase (LPL) activity, and the oxidation of lipids (14C-palmityl CoA) in vitro. Ten weeks of endurance running (30 min/day, 5 days/wk) resulted in 11.0 and 12.9% gains in aerobic capacity for the JD and ND groups (P greater than 0.05), respectively. Both groups showed significant (P less than 0.05) increases in muscle LPL, carnitine palmityl transferase, succinate dehydrogenase, and hexokinase activities with training. Though the pretraining capacities for 14C-palmityl CoA oxidation were similar for both ND and JD groups, the diabetics showed a 41% greater improvement in the measurement of muscle lipid oxidation after training than did the ND group. The principal finding of this research was that skeletal muscle of juvenile diabetics who are in moderate insulin balance shows adaptations to endurance training that are similar to those of nondiabetic men.

The indirect role of 2,4-D in the maintenance of apical dominance in decapitated sunflower seedlings (Helianthus annuus L.)

When sufficient 2,4-D to maintain apical dominance for at least 21d was applied to the cut stem interface of sunflower seedlings which had been decapitated in the epicotyl, it could not be detected in the vicinity of the inhibited axillary buds 7d after application. Rather the 2,4-D concentrated at the stump apex where it was associated with formation of meristematic tissue. The results indicate an indirect role for 2,4-D in the maintenance of apical dominance in this system, possibly involving the induced meristematic activity.

Skeletal muscle enzyme activity, fiber composition and VO2 max in relation to distance running performance

Muscle biopsy samples were obtained from the gastrocnemius of 26 well-trained runners of widely varying ability. Portions of the sample were analyzed for succinate dehydrogenase (SDH) activity and for muscle fiber composition. VO2 max was determined during uphill treadmill running. Mean values for muscle SDH activity (14.6 U/g), fiber composition (55% slow twitch) and VO2 max (60.9 ml/kg x min(-1)) were lower than reported previously for groups of elite and sub-elite runners. The physiological data were consistent with the performance ability of the sample [5 : 12,11 : 20 and 36 : 40 (min :s) for 1, 2 and 6 miles, respectively]. Within the sample, performance was most strongly related to VO2 max (r=-0.84,-0.87 and -0.88 for 1, 2, and 6 miles). There was little relationship between muscle SDH activity and either performance (r=-0.11, -0.14, -0.20 for 1,2, and 6 miles) or VO2 max (r=0.23). The relationship between muscle fiber composition and performance was only modestly strong (r=-0.52,-0.54, -0.55 for 1,2, and 6 miles). The results indicate that the primary determinant of cross-sectional differences in running performance is VO2 max. Skeletal muscle metabolism apparently contributes little to these cross-sectional differences and may be of much greater importance to variations in performance within an individual.

Sequence of return of neurological function and criteria for safe ambulation following subarachnoid block (spinal anaesthetic)

Twenty-three adult men were studied during and after subarachnoid block anaesthesia for elective surgery. Measurements were obtained of mean arterial pressure and pulse, both supine and after standing for five minutes, core body (tympanic) and peripheral skin (toe) temperatures and blood flow in the leg. Time of measurements included one hour after the injection of tetracaine and after regression of the block. Results obtained indicate that the sequence of return of neurological activity following tetracaine subarachnoid block is sympathetic nervous system activity, pinprick sensation, somatic motor function followed by proprioception in the feet. This progression provides the basis for recommended criteria which indicate when it is safe for patients who have been subarachnoid block anaesthesia to become ambulatory. These criteria include: (1) return of pinprick sensation in the peri-anal area (sacral 4--5); (2) plantar flexion of the foot (while supine) at pre-anaesthetic levels of strength; and (3) return of proprioception in the big toe, always provided that the patient is not hypovolaemic or sedated.

Prevention of post-anaesthesia shivering

This study involves ventilation of the lungs with warmed humidifed anaesthetic gases during prolonged elective abdominal operations. Tympanic, oesophageal and toe temperatures were compared bewteen twenty warmed and twenty un-warmed patients at various times during operation and recovery. Fifty per cent (10/20) unwarmed patients shivered in the recovery room, while none of the warmed patients shivered. Our data indicate that pulmonary ventilation with warm humidified anaesthetic gases provides heat transfer by the lungs, preventing hypothermia during operation and post -anaesthesia shivering is prevented by maintaining the patient normothermic in both the operating room and the recovery room.