Central common drive to antagonistic ankle muscles in relation to short-term cocontraction training in nondancers and professional ballet dancers

Optimization of cocontraction of antagonistic muscles around the ankle joint has been shown to involve plastic changes in spinal and cortical neural circuitries. Such changes may explain the ability of elite ballet dancers to maintain a steady balance during various ballet postures. Here we investigated whether short-term cocontraction training in ballet dancers and nondancers leads to changes in the coupling between antagonistic ankle motor units. Eleven ballet dancers and 10 nondancers were recruited for the study. Prior to training, ballet dancers and nondancers showed an equal amount of coherence in the 15- to 35-Hz frequency band and short-term synchronization between antagonistic tibialis anterior and soleus motor units. The ballet dancers tended to be better at maintaining a stable cocontraction of the antagonistic muscles, but this difference was not significant (P = 0.09). Following 27 min of cocontraction training, the nondancers improved their performance significantly, whereas no significant improvement was observed for the ballet dancers. The nondancers showed a significant increase in 15- to 35-Hz coherence following the training, whereas the ballet dancers did not show a significant change. A group of control subjects (n = 4), who performed cocontraction of the antagonistic muscles for an equal amount of time, but without any requirement to improve their performance, showed no change in coherence. We suggest that improved ability to maintain a stable cocontraction around the ankle joint is accompanied by short-term plastic changes in the neural drive to the involved muscles, but that such changes are not necessary for maintained high-level performance.

Use of 360-degree assessment of residents in internal medicine in a Danish setting: a feasibility study

BACKGROUND

The aim of the study was to explore the feasibility of 360 degree assessment in early specialist training in a Danish setting. Present Danish postgraduate training requires assessment of specific learning objectives. Residency in Internal Medicine was chosen for the study. It has 65 learning objectives to be assessed. We considered 22 of these suitable for assessment by 360-degrees assessment.

METHODS

Medical departments of six hospitals contributed 42 interns to the study. Each resident was assessed by ten persons of whom one was a secretary, four were nurses and five senior doctors. The assessors spent 14.5 minutes (median) to fill in the forms.

RESULTS

Of the 22 chosen objectives, 15 could reliably be assessed by doctors, 7 by nurses and none by secretaries.

CONCLUSIONS

The method was practical in busy clinical departments and was well accepted by the assessors. Reliability of the method was acceptable. It discrimintated satisfactorily between the good and not so good performers.

Effect of glucose/insulin infusion and magnesium supplementation on serum and muscle sodium and potassium and muscle [3H]ouabain binding capacity in Type 1 diabetes mellitus

Glucose has recently been found to decrease muscle potassium content. The aim of this study was to evaluate the effect of the infusion of glucose and insulin and the effect of magnesium supplementation on serum and muscle sodium and potassium and muscle [3H]ouabain binding capacity in patients with Type 1 diabetes mellitus and in controls. Muscle potassium and sodium content, muscle [3H]ouabain binding capacity and serum potassium and sodium concentrations were determined in 10 patients with Type 1 diabetes mellitus and in 5 controls before and after an euglycaemic, hyperinsulinaemic clamp, and after an intravenous magnesium load test. Nine of the patients with Type 1 diabetes mellitus were restudied after 24 weeks of oral magnesium oxide supplementation. Basic serum and muscle sodium and potassium and muscle [3H]ouabain binding capacity did not differ between groups. The infusion of glucose and insulin reduced muscle potassium content, whereas muscle sodium content was unchanged. There were no differences between groups. Oral magnesium oxide supplementation increased muscle potassium content by 6%. Muscle [3H]ouabain binding capacity was unchanged. In patients with Type 1 diabetes mellitus, the intravenous infusion of magnesium increased serum potassium concentration before but not after oral magnesium oxide supplementation. In controls, the infusion of magnesium did not affect serum potassium concentration. It was found that intravenous infusion of glucose and insulin decreases muscle potassium content, probably by shifting potassium from the muscle cells to the splanchnic organs. Oral magnesium oxide supplementation increases muscle potassium content in patients with Type 1 diabetes mellitus. The increase in serum potassium concentration owing to the intravenous infusion of magnesium could be used in the evaluation of magnesium status in patients with Type 1 diabetes mellitus. This, however, requires further investigation.

Magnesium reduces insulin-stimulated glucose uptake and serum lipid concentrations in type 1 diabetes

A magnesium (Mg) deficit has been described in patients with type 1 diabetes, and it has been related to the development of cardiovascular disease. We tested the hypothesis that type 1 diabetic patients have deficits in dietary Mg intake and that proper long-term (24 weeks) oral Mg supplementation would reduce cardiovascular risk factors. Therefore, the Mg status, dietary Mg intake, and the effect of Mg supplementation were evaluated in 10 type 1 diabetic patients and 5 control subjects. Muscle Mg content was decreased by 7% in the type 1 diabetic patients, and it increased by 5% after 24 weeks of oral MgO supplementation. Acute and chronic Mg supplementation decreased serum total cholesterol, serum low-density lipoprotein (LDL)-cholesterol, and apolipoprotein B. Insulin-stimulated glucose uptake decreased by 35% after 24 weeks of oral MgO supplementation. Eight of 10 patients with type 1 diabetes had a daily intake of Mg below 90% of the recommended daily allowance. In conclusion, a Mg deficit was found in type 1 diabetic patients. The deficit might be due partly to a relatively Mg-deficient diet. Mg repletion was associated with a decrease in atherogenic lipid fractions and a reduced insulin-stimulated glucose uptake.

[Menstruation disorders in insulin-dependent diabetes mellitus--epidemiology and causes]

About 20% of all women with insulin-dependent diabetes mellitus (IDDM) have menstrual irregularities. Eight percent have amenorrhea. Fluctuations in blood glucose and insulin concentration are probably contributing factors, but the irregular menstrual cycles are mainly caused by disorders in the central ovulatory mechanisms. Hypothalamic GnRH release is regulated by several neuropeptides. Dopamine and opiates exert an inhibitory effect, and there is evidence for an abnormally high dopaminergic hypothalamic activity among women with IDDM. There might also be disorders of the opioid, serotonergic and GABA'ergic systems, but the consequences of there possibilities remain uncertain.

[Infertility and pregnancy outcome in women with insulin-dependent diabetes. An epidemiological study]

A questionnaire survey comprising an unselected group of 18-49-year old women with insulin-dependent diabetes mellitus and an age comparable control group was performed. Two hundred and forty-five (94%) of the diabetic women and 253 (88%) of the controls answered questions concerning fertility, pregnancy planning and pregnancy outcome. There was no difference in the cumulative rate of pregnancies in the two groups. The prevalence of involuntary infertility among the diabetic women was 17% and similar to that of controls. Compared to controls, diabetic women had significantly fewer pregnancies (mean 1.4 versus 1.7) and fewer births per pregnancy (70% versus 77%), and significantly more diabetic women were nulliparous (48% versus 38%). Only about half of all pregnancies were planned. In general the diabetic women reported that their diabetes had a negative influence on their attitude towards having children.

Flunarizine versus metoprolol in migraine prophylaxis: a double-blind, randomized parallel group study of efficacy and tolerability

The prophylactic effect of flunarizine and metoprolol was studied in a multi-center randomized, double-blind trial of 149 patients with migraine with or without aura. After a 4-week placebo run-in period, patients were randomly allocated to treatment with flunarizine 10 mg daily or metoprolol 200 mg daily for 16 weeks (parallel group design). Both drugs reduced the number of migraine days per month by 37% (95% confidence interval 21-53%) compared with the placebo run-in period. All efficacy parameters were significantly reduced by both drugs and no significant difference was found between the two drugs at any time of the treatment period. However, calculation of the 95% confidence limits showed that each drug may have a superiority of more than 100% on a single main effect parameter. The most common adverse experiences were day-time sedation (both drugs) and weight gain (flunarizine). Depression was the most serious side-effect occurring in 8% on flunarizine and 3% on metoprolol. We conclude that both drugs are effective in the prevention of migraine attacks but a higher number of dropouts occurred on flunarizine because of depression or weight gain.

TSH, thyroid hormones and nuclear-binding of T3 in mononuclear blood cells from obese and non-obese women

The specific nuclear-binding of T3 (NBT3) in mononuclear blood cells, and the concentrations of TSH, thyroid hormones, and binding proteins were measured after overnight fasting in 12 obese and in 14 non-obese women, none of the subjects were taking any medicine. The concentrations of TSH and free plus bound-T3 (TT3) were significantly higher in the obese (p less than 0.05), concentrations of T4 and binding proteins did not differ. The NBT3 was significantly lower in the obese women; the maximal binding capacity (MBC) was 34.5 +/- 11.6 fmol/mg DNA in the obese subjects and 50.0 +/- 11.6 fmol/mg DNA in the non-obese subjects (p less than 0.02). The binding affinities did not differ. We have previously shown that increasing T3 concentrations within the physiological range down-regulates NBT3. Therefore, the reduced NBT3 in the obese women was probably secondary to the increased TT3 concentration and was not caused by a primary tissue resistance. The higher TSH and TT3 in the obese women could be caused by a greater caloric intake.

Amaurosis fugax in a Danish community: a prospective study

A prospective study of amaurosis fugax was carried out in a Danish community (population 481,000); case ascertainment was based on the collaboration of practicing ophthalmologists and general practitioners. Over a 3-year period we registered 131 cases; the annual incidence of "first amaurosis fugax episodes coming to medical attention" was 8.6 and 6.2 per 100,000 population for men and women, respectively. On the basis of a comparison of the age-incidence curves for cerebral and retinal ischemic attacks, the "true" incidence of amaurosis fugax is estimated to be approximately 14/100,000/yr, or 25-30% of the reported incidence of transient ischemic attacks. Clinical and/or radiologic signs of a carotid lesion on the appropriate side were present in 56% of the patients, and an additional 27% had symptoms or signs of other organic cardiovascular disorders. Forty-three (68%) of the 63 patients who underwent arteriography had an atheromatous lesion apparently amenable to carotid endarterectomy. In spite of the case-finding procedures employed in the study, cases of amaurosis fugax suitable for carotid surgery were thus ascertained at a rate of only 3/100,000/yr. This suggests that surgical treatment of patients with retinal ischemic attacks is of minor importance as a preventive measure against stroke in the community.

Cerebral gumma

A patient presented with symptoms from a tumour in the frontal region. Syphilis had been treated 15 years earlier but the serological tests were inconclusive on this admission. The CT-scan showed oedema surrounding a contrast enhancing tumour. Angiography showed displaced but otherwise normal vessels. Histologically the lesion proved to be a gumma.

Prophylactic treatment of migraine with tolfenamic acid, propranolol and placebo

In 31 patients with at least 3 migraine attacks per month the prophylactic effect of tolfenamic acid 300 mg/day, propranolol 120 mg/day, and placebo was compared in a randomized double-blind cross-over study. The patients were treated for 12 weeks with each drug, but only the last 11 weeks were used for evaluation. Both tolfenamic acid and propranolol significantly reduced the number of attacks, the total duration of attacks and additional drugs taken when compared with placebo. Tolfenamic acid, but not propranolol, significantly reduced the median intensity of pain and the number of attacks confining the patients to their beds when compared with placebo. Only mild adverse reactions occurred with no significant difference between the drugs. It was concluded that the prophylactic effect of tolfenamic acid 300 mg/day in migraine was at least as good as propranolol 120 mg/day.

The long-term effect of verapamil on plasma digoxin concentration and renal digoxin clearance in healthy subjects

Single-dose investigations in healthy subjects have demonstrated substantial impairment of renal and extrarenal clearance of digoxin during coadministration of verapamil. A longitudinal study has been performed to assess the changes in digoxin disposition during long-term verapamil therapy. After one week of verapamil 240 mg/d mean plasma digoxin had risen from 0.21 +/- 0.01 ng/ml (SE) to 0.34 +/- 0.01 ng/ml(p less than 0.01), and renal digoxin clearance had fallen from 197.57 +/- 17.37 ml/min to 128.20 +/- 10.33 ml/min (p less than 0.001). These changes gradually subsided, and after six weeks, renal digoxin clearance had normalized and plasma digoxin had declined to 0.27 +/0 0.02 ng/ml (NS). The 24-h urinary recovery of digoxin increased from 46.46 +/- 3.23% before to 69.78 +/- 3.69% (p less than 0.001) after six weeks of verapamil co-administration, and this elevation persisted throughout the study. The verapamil-induced suppression of renal digoxin elimination disappears over a few weeks of drug exposure, whereas the inhibition of the extrarenal clearance of digoxin seems to persist.

Syphilitic normal pressure hydrocephalus

We report a case of presenile dementia with radiological and cisternographical features suggesting normal pressure hydrocephalus, caused by syphilitic infection. Treatment with penicillin resulted in considerable regression of the neurological and psychological signs.

Incidence of fractures of the vertebral spine in epileptic patients

The incidence of vertebral fractures in 87 epileptic outpatients was 16 per cent. The occurrence of vertebral fractures in epileptics was not correlated to age, state of osteomalacia or to type or number of epileptic seizures.