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Biomedical subjects

J M Round

Publications and source records attributed to J M Round.

At least 37 records · Page 2Linked to original sources
PubMed1987

Growth hormone deficiency in adults--an indication for therapy?

Case studies are presented for two patients, one with isolated hGH deficiency and one with multiple hormone deficiencies. The patients were studied 3 months before, and 3 and 9 months after discontinuing hGH therapy, at 19 and 18 years of age, respectively. Strength in the quadriceps femoris, cross-sectional area of the quadriceps muscles and cross-sectional muscle fibre area were measured. In the patient with multiple hormone deficiencies, clear decreases in all three parameters were evident after discontinuing hGH treatment. There were no significant changes in the other patient. Reasons for these differences are discussed.

Adolescent↗
PubMed1986

Growth, bone maturation, and biochemical changes in Brazilian children from two different socioeconomic groups.

A study of blood biochemistry related to skeletal growth in 900 Brazilian children aged 7 to 17 yr is reported. Two groups were studied, a privileged and underprivileged sample. Anthropometry and measures of bone maturation in the control group were comparable with American and British standards. Underprivileged children showed growth impairment and delay in bone maturation. No signs of rickets were found in either group. Plasma calcium, magnesium, vitamin D, and total protein did not differ in the two groups of Brazilian children. Plasma alkaline phosphatase and inorganic phosphorus were abnormal in the underprivileged children. Alkaline-phosphatase activity and phosphorus levels did not fall towards adult levels after the predicted age of the adolescent spurt for underprivileged children. Menarche was delayed in the underprivileged girls.

Adolescent↗
PubMed1986

Experimental human muscle damage: morphological changes in relation to other indices of damage.

The effects of eccentric exercise have been examined in human calf and biceps muscles. Release of muscle creatine kinase and uptake of technetium pyrophosphate have been followed for up to 20 days after the exercise and the results are related to the morphological changes seen in needle biopsy samples. The response to exercise was variable, all subjects developing pain and tenderness in the exercised muscles after 1-2 days and this was followed, in most subjects, by a large increase in plasma creatine kinase 4-6 days after the exercise. This was paralleled by an increased uptake of technetium pyrophosphate into the exercised muscle. Biopsies of the affected muscles showed little or no change in the first 7 days after the exercise but later degenerating fibres were seen, as well as infiltration by mononuclear cells and eventually, by 20 days, signs of regeneration. Very extensive changes were seen in the calf muscle of one subject; changes in the biceps were qualitatively similar but not so severe. In the severely affected calf muscle type II fibres were preferentially damaged. Mononuclear cell infiltration both between and within degenerating fibres was maximal well after the time of peak plasma creatine kinase and it is likely that in eccentrically exercised muscle infiltrating mononuclear cells act to scavenge cellular debris rather than to cause damage to the muscle.

Adult↗
PubMed1986

Stability of catecholamines in whole blood, plasma, and platelets.

Checking catecholamine stability in whole blood, plasma, and platelets, we found that specimens stored at room temperature or frozen for periods ranging from 1.5 h to three weeks show no significant difference in measured catecholamine concentration. The implications of these findings are discussed.

Adrenal Gland Neoplasms↗
PubMed1984

Effect of nutrition on vitamin D status: studies on healthy and poorly nourished Brazilian children.

A cross-sectional study was carried out of 412 healthy and 226 chronically malnourished children in Recife, Brazil. Anthropometric measurements, x-rays of hands and wrists, and biochemical data related to skeletal growth were obtained. Levels of plasma 25 hydroxyvitamin D were measured in both groups of children and both showed higher concentrations than those reported for normal European children. The high levels of 25 hydroxyvitamin D found in these two groups of Brazilian children are probably the result of the intense solar radiation in this part of Brazil and argue against the diet being an important source of vitamin D in poorly nourished children. Some bone abnormalities were seen in the underprivileged group of children but in view of our findings these were more likely to be a result of protein-energy malnutrition than rickets.

25-Hydroxyvitamin D 2↗
PubMed1984

Weight reduction in boys with muscular dystrophy.

Many children with muscular dystrophy are overweight, and although weight control is pursued in some centres it is unusual to encourage severe dietary restriction for fear that it might lead to accelerated loss of muscle. In this study, two overweight boys with muscular dystrophy were monitored by whole-body nitrogen balance, total body potassium, strength and functional measurements during calorie restriction. Both patients were found to have a transient loss of nitrogen on commencing the low calorie intake: thereafter, weight loss was not found to have any deleterious effect on muscle bulk or function in either patient. It is suggested that controlled weight-reduction in obese children with muscular dystrophy is a safe and practical way of losing excess fat, which can improve mobility and self-esteem, and may possibly effect longevity.

Adolescent↗
PubMed1984

The neuromuscular features of acromegaly: a clinical and pathological study.

A study of the neuromuscular features of acromegaly was performed in six patients. Clinical assessment was supplemented by quadriceps force measurements, plasma creatine kinase (CK) activities, electromyography (EMG) and nerve conduction studies. Muscle mass was measured by urinary creatinine/height indices (CHI) and cross sectional area (CSA) of thighs and calves on computed tomography. Quadriceps force/unit cross sectional area was derived. Needle biopsies of vastus lateralis were studied by histochemical and ultrastructural methods. Mean fibre area (MFA) and fibre type proportions were measured. Most of the subjects studied had muscle pain and proximal muscle weakness confirmed by quadriceps force measurements. This occurred in the absence of muscle wasting, as shown by cross sectional area measurements and normal or raised creatinine/height indices. "Myopathic" features were demonstrated by needle biopsy in half the patients and occasionally by electromyography and raised plasma creatine kinase activity. Abnormalities on needle biopsy included variation in fibre size, type 2 fibre atrophy and large type 1 MFA relative to type 2 MFA. Electronmicroscopy showed the non-specific findings of increased glycogen accumulation, excess lipofuscin pigment and myofilament loss.

Acromegaly↗
PubMed1983

Size and composition of the calf and quadriceps muscles in Duchenne muscular dystrophy. A tomographic and histochemical study.

Calf and quadriceps muscle size and composition have been examined in 5 control subjects and 12 boys (aged 7-18 years) with Duchenne muscular dystrophy using computed tomography (CT) and quantitative histochemistry of needle biopsy samples of muscle. In assessing the size of leg muscles it was found that in control subjects the muscle cross-sectional area was related to the cross-sectional area of the femur. The calf muscles in the patients were enlarged both relative to the quadriceps and absolutely when related to the cross-sectional area of the femur used as an index of stature. The enlargement of the calf was the result of accumulations of fat and connective tissue in the presence of relatively normal (compared to femur size) amounts of muscle tissue. Although hypertrophied muscle fibres were a feature of the biopsy samples in the calf the extent of this was insufficient to contribute appreciably to the total muscle enlargement.

Adolescent↗
PubMed1983

Effect of treatment of Cushing's syndrome on skeletal muscle structure and function.

The time course of recovery in the myopathy of Cushing's syndrome was studied before and after removal of a pituitary adenoma at hypophysectomy in three patients and an adrenal adenoma in another. Serial measurements were performed of quadriceps force, total muscle mass/body weight, individual fibre size on needle biopsies of the lateral muscle mass of the thigh and skeletal muscle cross-sectional area (CSA) and force/unit CSA on computed (CT) scans of thighs and calves. All patients were weak, and recovery was slow but substantial except in one patient who had persistent Cushing's syndrome. An accompanying increase in overall and type II mean fibre area (MFA) occurred after surgery in the patients with a pituitary adenoma, as did an increase in skeletal muscle CSA and force/unit CSA in both patients having CT scans. The only patient with pronounced muscle wasting showed severe type II fibre atrophy with a reduced total muscle mass/body weight, but muscle morphology and total muscle mass were normal in the other patients. Only in this patient was a significant increase in total muscle mass/body weight noted after surgery. These findings suggest that the increase in muscle mass which may follow hypophysectomy in Cushing's syndrome is due to an increase in individual cell size.

Adult↗
PubMed1983

The effect of high-resistance training on the strength and cross-sectional area of the human quadriceps.

Seventeen volunteers performed unilateral strength-training of the quadriceps with high-resistance, low-repetition, dynamic exercise, thrice weekly for an average of 5 weeks. Both before and after the training period, bilateral measurements were made of isometric quadriceps strength, quadriceps cross-sectional area (by ultrasound scanning), and thigh circumference. There were no significant changes in the untrained thighs. The trained quadriceps increased their isometric strength by more than they changed their cross-sectional area (mean increments = 15% and 6% respectively). Quadriceps hypertrophy was underestimated by measurements of thigh circumference and could not be predicted from them. We conclude that studies of localized muscle growth require direct measurements of the size of the muscle(s) concerned. Nevertheless, these may still underestimate the improvements in strength produced by high-resistance training.

Adult↗
PubMed1983

Muscle morphology and metabolism in hypothyroid myopathy: effects of treatment.

Needle biopsies from vastus lateralis in untreated hypothyroid patients with muscle weakness confirmed by quadriceps force measurements (n = 11) were repeated when the patients had taken L-thyroxine for a mean period of 9.2 months (range 5.3-13.3 months, n = 8) and had been continuously biochemically euthyroid for a mean period of 4.9 months (range 2-11 months). Biopsies were analysed biochemically for mitochondrial function. On light microscopy, histochemical examination, mean fibre areas and fibre percentages of type I and type II fibres were determined. Electronmicroscopy was also performed. Abnormalities on light microscopy occurred in eight patients of which type II fibre atrophy was the commonest and of the remainder two patients showed a myopathic electromyogram (EMG) and a raised plasma creatine kinase activity and one ultrastructural change on biopsy. After treatment resolution of pathological changes was often slow and half the patients had persistent abnormalities when rebiopsied. The type I mean fibre area was significantly increased in the eight hypothyroid females (p less than 0.05) and type II mean fibre areas tended to be low and in females this was significant (p less than 0.05). After treatment the type I mean fibre area was significantly reduced (p = 0.05). The type II mean fibre area also tended to fall but this was not significant (p greater than 0.05). No change in the fibre percentages occurred. A myopathic EMG, a raised plasma creatine kinase activity, ultrastructural changes and low mitochondrial enzyme activities on needle biopsy were other common findings and their significance is discussed.

Aged↗
PubMed1982

The effect of knee injury on the number of muscle fibres in the human quadriceps femoris.

By means of ultrasound scanning, bilateral measurements of the cross-sectional area of the quadriceps muscle groups were made in 14 young adults with unilateral thigh muscle wasting after knee injury. Needle biopsy specimens from the lateral mass of the muscle were used to estimate the myofibre cross-sectional area for both quadriceps of each subject. 2. The cross-sectional area of the quadriceps of each patient's injured limb was always smaller than that of the contralateral muscle. The wasting was largely localized to the quadriceps, with relative sparing of the other thigh muscles. 3. None of the biopsies showed any abnormality apart from the reduction in fibre size. In each case, the injured limb's reduced quadriceps cross-sectional area was associated with a reduced mean fibre area. 4. The ratio of the cross-sectional area of a muscle to its mean fibre area is a reduced mean fibre area. 4. The ratio of the cross-sectional area of a muscle to its mean fibre area is a function of the number of fibres it contains. The ratio varied considerably from patient to patient but there was close agreement between the values obtained for the two limbs of each patient. 5. The quadriceps wasting produced by knee injury was due to muscle fibre atrophy. There was no evidence for a change in the number of fibres in the muscle.

Adult↗
PubMed1982

A flexible microprocessor system for the measurement of cell size.

A flexible system for the measurement of length and area is described. The system consists of the Reichert Jung MOP-1 area measuring device interfaced with a Commodore PET computer. Its use is illustrated by the planimetric measurement of cross sectional areas in histochemical preparations of normal and diseased muscle. While measurements are being made data can be displayed on the computer screen either in numerical form or as a frequency histogram together with simple statistical analyses. Hard copy can be obtained from an attached printer. Mean values for fibre area in normal human skeletal muscle are reported. An alternative, widely used method of calculating fibre area from the lesser diameter was found to give a consistent underestimate of approximately 30% when compared with our planimetric method. In diseased muscle with abnormally shaped fibres the discrepancy is even larger; such fibres can be identified using a "form factor" which relates the area of a cell to its perimeter. This rapid, accurate and flexible system is also suitable for the measurement of many different types of graphical record.

Biopsy, Needle↗
PubMed1977

Serum lecithin-cholesterol acyltransferase activity in children with familial hyperbetalipoproteinaemia.

Serum (non-fasting) was obtained from 71 healthy school children (12-14 years) and from 16 children with the heterozygous form of familial hyperbetalipoproteinaemia being treated by diet or ion-exchange resin. The activity of lecithin-cholesterol acyltransferase (EC 2.3.1.43) expressed as nmol cholesterol esterified/hour/ml serum did not change with increasing concentrations of unesterified cholesterol in the healthy children. In children with familial hyperbetalipoproteinaemia, lecithin-cholesterol acyltransferase activity was higher than in the healthy children and this activity increased with increasing concentrations of unesterified cholesterol.

Acyltransferases↗
PubMed1973

Plasma calcium, magnesium, phosphorus, and alkaline phosphatase levels in normal British schoolchildren.

In a cross-sectional survey 624 schoolchildren were screened for plasma calcium, inorganic phosphate, and alkaline phosphatase levels. Plasma magnesium and alkaline phosphatase isoenzymes were also estimated in some cases.No significant difference was found between adult and childhood values for calcium and magnesium. Levels of alkaline phosphatase and inorganic phosphorus varied with both age and sex. The magnitude of these variations in normal ranges is of clear importance in assessing data from individual paediatric or adolescent patients.

Adolescent↗