Blood flow variation in human muscle during electrically stimulated exercise bouts

OBJECTIVES: To evaluate, with a high spatial resolution, the blood flow variations in human skeletal muscle during neuromuscular electric stimulation (NMES) and hence to gain better understanding of the mechanisms of muscle spatial recruitment during NMES. DESIGN: One thigh was submitted to 3 stimulation bouts of different durations (S1=4min, S2=8min, S3=12min) with a workload corresponding to 10% of quadriceps maximal isometric voluntary torque. SETTING: A cyclotron research center at a Belgian university. PARTICIPANTS: Ten healthy male volunteers. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants were studied with positron emission tomography and H(2)(15)O. Tissue blood flow was evaluated during the last 4 minutes of each stimulation bout in multiple regions of interest (ROIs) selected in the transverse section of the stimulated thigh. RESULTS: Mean tissue blood flow was significantly lower during S1 (5.9+/-1.3mL. min(-1). 100g(-1)) than during S2 (10.6+/-3.4mL. min(-1). 100g(-1)) and S3 (11.6+/-3.7mL. min(-1). 100g(-1)) (P<.05). For each ROI, an arbitrary tissue blood flow activation level of 5mLmin(-1)100g(-1) was fixed. The mean percentage of activated ROIs reached 42.4%, 62.7%, and 63.6% during S1, S2, and S3, respectively. Between S1 and S3, the newly recruited ROIs were preferentially located far from the electrode. CONCLUSION: During NMES, new muscular regions situated far from the stimulation site are recruited. These recruitment mechanisms are particular and contrast with the recruitment of motor units seen during voluntary contraction.     

GABAergic modulation in the substantia nigra of the striatal dopamine release and of the locomotor activity in rats exposed to helium pressure

Helium-oxygen pressure induces in rodents an increase of both locomotor and motor activity (LMA) and of the striatal dopamine release, which could result from a decrease of GABA transmission in the substantia nigra. The effects of the GABA(A) receptor agonist muscimol and of the GABA(B) receptor agonist baclofen on the striatal dopamine release were measured using differential pulse voltammetry. Behavioural studies were performed in freely moving rats using actimetry. Whatever the drug used under helium pressure, bilateral administration in the substantia nigra pars reticulata (SNr) or in the substantia nigra pars compacta (SNc) counteracted the evoked dopamine release. However, only the baclofen reduced the LMA, while the muscimol administration in the SNr, but not in the SNc, increased it. These results indicate that different subtypes of GABA receptors would be involved in the control of the DA release and in the occurrence of LMA under helium pressure.     

The effect on vision of associated treatments in patients taking vigabatrin: carbamazepine versus valproate

PURPOSE: To evaluate the effect on visual function of a concomitant antiepileptic drug (AED) in patients treated with vigabatrin (VGB). METHODS: Sixty-four consecutive patients with a history of partial seizures currently treated with VGB with either carbamazepine (CBZ) or valproate (VPA) were examined with automated kinetic perimetry, static perimetry, electrooculogram (EOG), and electroretinogram (ERG). An original device based on kinetic perimetry was developed to quantify the area of perception for each isopter. RESULTS: Fifty-two patients were finally included. The results showed a significant difference in patients treated with VGB-VPA compared with patients treated with VGB-CBZ concerning the mean defect of static perimetry and the peripheral and midperipheral isopter (III 4e and III 1a Goldmann equivalent, respectively) in kinetic perimetry. EOG and ERG results did not differ significantly between the two groups. CONCLUSIONS: The visual impairment due to visual field constriction was more important in patients treated with VGB and VPA compared with patients treated with VGB and CBZ. The origin of this difference between the two associations could not be related to any particular retinal electrophysiologic abnormality.     

Psychological correlates of functional status in chronic fatigue syndrome

Background: The present study was designed to test a cognitive model of impairment in chronic fatigue syndrome (CFS) in which disability is a function of severity of fatigue and depressive symptoms, generalized somatic symptom attributions and generalized illness worry. Methods: We compared 45 CFS and 40 multiple sclerosis (MS) outpatients on measures of functional ability, fatigue severity, depressive symptoms, somatic symptom attribution and illness worry. Results: The results confirmed previous findings of lower levels of functional status and greater fatigue among CFS patients compared to a group of patients with MS. Fatigue severity was found to be a significant predictor of physical functioning but not of psychosocial functioning in both groups. In CFS, when level of fatigue was controlled, making more somatic attributions was associated with worse physical functioning, and both illness worry and depressive symptoms were associated with worse psychosocial functioning. Conclusions: Our findings support the role of depression and illness cognitions in disability in CFS sufferers. Different cognitive factors account for physical and psychosocial disability in CFS and MS. The SF-36 may be sensitive to symptom attributions, suggesting caution in its interpretation when used with patients with ill-defined medical conditions.     

Effects of plaque composition on vascular remodelling after angioplasty in the MultiVitamins and Probucol (MVP) trial

BACKGROUND: The antioxidant probucol reduced coronary restenosis in the MultiVitamins and Probucol (MVP) trial by improving vascular remodelling. Whether calcification limits the extent of adaptive vessel enlargement is not known. OBJECTIVE: To determine whether plaque composition at the dilated site affects probucol-induced vascular remodelling after angioplasty. PATIENTS AND METHODS: Beginning 30 days before percutaneous transluminal coronary angioplasty (PTCA), 317 patients received either probucol, vitamins, probucol and vitamins, or placebo. Patients were then treated for six months after PTCA. Intravascular ultrasound (IVUS) was performed post-PTCA and at follow-up in 94 patients (111 segments). The cross-section for serial analysis was the one at the angioplasty site with the smallest lumen area at follow-up. Quantitative analysis consisted of measurements of lumen area and external elastic membrane (EEM) area. The selected cross-section was also divided into five regions according to the type of plaque present (calcific, fibrotic, hypoechoic, fibrohypoechoic or normal). Plaque characterization scores (PCS) (PCS for arc, area, inner perimeter and outer perimeter) were calculated using weighting factors. RESULTS: There were no interactions between potential PCS covariates and probucol main effect on changes in lumenal, EEM and wall area. There were no significant PCS covariates in the model for change in EEM as they were all removed using a backward stepwise procedure. The last potential covariate (area PCS) had a significance level of P=0.48. In contrast, probucol significantly influenced the change in EEM over time (P=0.003). CONCLUSION: Plaque composition at the dilated site does not appear to influence probucol-induced vascular remodelling after angioplasty.     

Assessment of a structured in-hospital educational intervention addressing breastfeeding: a prospective randomised open trial

Objective To determine whether a single one-to-one in-hospital education session could increase the rate of breastfeeding at 17 weeks.
Design A prospective, randomised, parallel group, open trial.
Setting A level two maternity hospital in France.
Sample Breastfeeding mothers who were employed outside the home prenatally and were delivered of a healthy singleton.
Intervention A structured one-to-one in-hospital education session.
Methods One hundred and six mother–infant pairs were allocated to the intervention group and 104 to the control group (receiving usual verbal encouragement). A total of 93 mother–infant pairs in the intervention group and 97 in the control group provided complete data for final evaluation of efficacy.
Main outcome measure Rate of breastfeeding at infant age of 17 weeks.
Results There was no significant difference between the two groups in the rate of any breastfeeding (34.4% in the intervention group vs 40.2% in the control group, relative risk = 0.86 [0.52–1.40]), and in the rate of exclusive breastfeeding (14.0% in the intervention group vs 14.4% in the control group, relative risk = 0.97 [0.42–2.22]).
Conclusion Our findings suggest that a single in-hospital educational intervention has no effect on the breastfeeding rate at four months. Guidance provided by maternity staff should be reinforced by a long term multifaceted support programme in countries with a low to intermediate rate of breastfeeding.     

Parathyroid function and growth in 22q11.2 deletion syndrome

OBJECTIVE: To determine the frequency and expression of hypoparathyroidism and the factors of short stature in 22q11.2 deletion syndrome to optimize clinical care. STUDY DESIGN: Cross-sectional study of 39 patients 9.7 +/- 0.8 (2.5-20) years of age. RESULTS: The congenital abnormalities were cardiac defects in 33 of 39, thymus hypoplasia in 15 of 18 evaluated, and craniofacial dysmorphy in all; 15 patients (39%) had had one or more seizures. Before evaluation, 12 patients were hypocalcemic, with (n = 4) or without clinical manifestations, diagnosed before 1 month in 10 cases, at 3 months or 12 years in two others. At evaluation, 9 patients were hypocalcemic, 5 of 9 had been hypocalcemic, and 8 others had parathyroid hormone (PTH) concentrations low for their ionized calcium. One had high PTH without hypocalcemia and 2 were hypercalcemic. The values were below -2 SD at birth for weight and/or height in 26% of cases and at evaluation for height and body mass index in 23% and for insulin-like growth factor-I in 37%. CONCLUSIONS: Parathyroid function was abnormal in 27 of 39 (69%) patients. This was not diagnosed in the majority. Short stature was probably due to intrauterine growth restriction, underweight, and growth hormone deficiency, as suggested by low insulin-like growth factor I.