Frequency of extrasystoles in healthy male employees.

To determine reference values for ectopic activity 147 actively employed healthy men aged from 15 to 65 years were examined by 24 hour Holter monitoring during their ordinary daily activities. Age was the only risk factor significantly associated with supraventricular and ventricular extrasystoles. During a six year follow up only two men died. In both the frequency of ventricular extrasystoles had been high, but neither of them died from cardiovascular disease. Because the distribution of the frequency of extrasystoles in the study group was highly skewed a percentile distribution was used to determine normal values. This distribution showed that 95% of men aged 15-39 years had less than 2.9 ventricular extrasystoles per hour and the same proportion of men aged 40 years or older had less than 36 ventricular extrasystoles per hour. For field studies values above the 90th percentile (that is more than 10 ventricular extrasystoles per hour for men 40 years or older) may be a more appropriate cut off point.     

A case-control study of motor neurone disease: its relation to heritability, and occupational exposures, particularly to solvents.

Motor neurone disease (MND) was studied in relation to various determinants in a case-control study covering nine counties in southern Sweden. A questionnaire about occupational exposures, medical history, lifestyle factors etc was given to all cases in the age range 45-79 and to a random sample of 500 population controls in the same age range. The questionnaires were answered by 92 cases and 372 controls, a response rate of 85% and 75% respectively. Among men high Mantel-Haenszel odds ratios (MHORs) were obtained for electricity work (MHOR = 6.7, 95% confidence interval (95% CI) 1.0-32.1), welding (MHOR = 3.7, 95% CI 1.1-13.0), and impregnating agents (MHOR = 3.5, 95% CI 0.9-13.1). Heritability with regard to a neurodegenerative disease or thyroid disease seemed to predispose to a risk of developing MND (OR = 2.1, 95% CI 1.0-4.3). The highest OR was found for the combination of such heritability, exposure to solvents, and male sex (OR = 15.6, 95% CI 2.8-87.0), a combination that occurred for seven cases and three controls. Hereditary factors and external exposures had a different distribution among cases with the spinal type of MND than among cases with involvement of the pyramidal tract or bulbar paresis also.     

Sacral and pelvic osteotomies for correction of spinal deformities

Aim

Rett syndrome is a progressive neurodevelopmental disorder that predominantly affects females and is associated with a high incidence of scoliosis and epilepsy. There is scant published work about intraoperative spinal cord monitoring in these patients and little more regarding the rate of perioperative complications. We investigated our institutions’ experience with both.

Methods

We retrospectively reviewed the records of 11 patients with Rett syndrome who underwent surgical correction of scoliosis at our institution between 2004 and 2010.

Results

Eleven patients underwent successful correction of their scoliosis at an average age of 12. Eight of the patients suffered one or more significant complications. The average curve was corrected from 71° to 27°. Successful spinal cord monitoring was achieved in eight of the nine patients where it was attempted. No patient suffered any neurological complications. Average inpatient stay was 18.2 days.

Conclusion

Scoliosis surgery in patients with Rett syndrome carries a very high rate of complications and an average hospital stay approaching 3 weeks. Both caregivers and surgeons should be aware of this when planning any intervention. These patients frequently have useful lower limb function and spinal cord monitoring is a valid tool to aid in its preservation. We would suggest aggressive optimisation of these patients prior to surgery, with an emphasis on nutrition.

     

Oestrogen receptor β is expressed in adult human skeletal muscle both at the mRNA and protein level

Aim: There are two known oestrogen receptors (ER), oestrogen receptor α (ERα) and the recently cloned oestrogen receptor β (ERβ). ERα mRNA has been detected in mouse, rat, bovine and human skeletal muscle. ERβ mRNA has been detected in bovine skeletal muscle. To our knowledge, no study has investigated the expression of oestrogen receptor β in human skeletal muscle. Therefore, the primary aim of the present investigation was to study ERβ mRNA and protein expression in human skeletal muscle. In addition the ERα expression was also studied. Methods: Muscle biopsies were taken from vastus lateralis in six healthy adults (three women and three men). mRNA expression was detected with real‐time PCR (TaqMan) and protein localization by immunohistochemistry. Results: A clear expression of ERα and ERβ mRNA was seen in skeletal muscle in all subjects. The ERα mRNA expression was 180 fold higher compared with that of ERβ mRNA. Immunohistochemistry demonstrated positive staining for ERβ, but not for ERα, with localization to the nuclei of skeletal muscle fibres. On average, 70% of all nuclei were ERβ‐positive. Conclusion: The present study shows for the first time ERβ mRNA and protein expression in human skeletal muscle tissue in both males and females.     

Surface-engineered bacterial cellulose as template for crystallization of calcium phosphate

Bacterial cellulose (BC), produced by Acetobacter xylinum, and cotton linters as reference were surface modified by ozone-induced graft polymerization of acrylic acid and used as a template for crystallization of calcium phosphate. The grafting was verified using attenuated total reflection-infrared radiation (ATR-IR) and electron spectroscopy for chemical analysis (ESCA). ATR-IR revealed an additional absorption band at 1700 cm(-1), corresponding to the carbonyl group in polyacrylic acid. ESCA figures show, apart from the characteristic peaks for cellulose, additional peaks at 285 eV and 289 eV that correspond to groups in acrylic acid. The grafting yield is higher on cotton linters compared with BC, which most likely has to do with differences in crystallinity and reactivity of the different cellulose materials. No morphology difference directly caused by grafting could be seen with scanning electron microscopy (SEM), which might indicate that acrylic acid was grafted as a thin film on the surface of the cellulose micro fibrils. Calcium phosphate was formed on the surface-modified cellulose by first pre-soaking the materials in a saturated Ca(OH)2 and later in simulated body fluid (SBF). The atomic ratio of calcium phosphate was determined by ESCA to be about 1.5 for the different materials. Energy dispersive spectroscopy (EDS) was used to map and verify that the crystals were calcium phosphate. Secondary ion mass spectroscopy (SIMS) was also used to verify the presence of calcium phosphate complex onto BC. SEM images showed the difference in dimension, distribution and morphology of the crystals depending on the materials. Smaller and a greater number of crystals were obtained on the surface-modified BC and larger and fewer crystals on surface-modified cotton linters. Structural and grafting differences between the celluloses may lead to differences in nucleation sites and possibly differences in the morphology of the Ca-P crystals. The BC-calcium phosphate composite is expected to be useful as a scaffold for bone tissue regeneration.     

Pancreatic islet blood flow during euglycaemic, hyperinsulinaemic clamp in anaesthetized rats

Aims: Previous studies have demonstrated that pancreatic islet blood flow is crucially dependent on blood glucose concentration. Thus, hyperglycaemia increases and hypoglycaemia decreases islet blood perfusion, by a combination of nervous and metabolic signals. The aim of the present study was to evaluate if hyperinsulinaemia, without associated hypoglycaemia, affects islet blood flow. Methods: Thiobutabarbital‐anaesthetized Wistar–Furth rats were subjected to an euglycaemic, hyperinsulinaemic clamp, that is they were infused for 60 min with either saline, insulin (18 mU kg^?1 min^?1), glucose (27 mg kg^?1 min^?1) or both glucose and insulin. This was followed by islet blood flow measurements with a microsphere technique. Results: Animals receiving only glucose doubled their blood glucose and serum insulin concentrations, whereas rats receiving only insulin had blood glucose concentrations <2 mmol L^?1 and a 10‐fold increase in serum insulin concentrations. Animals given simultaneous glucose and insulin had normal blood glucose concentrations but a 10‐fold increase in serum insulin concentrations. Total pancreatic blood flow was unaffected in all animals. Islet blood flow was increased in hyperglycaemic and decreased in hypoglycaemic rats compared with control rats. Islet blood flow did not differ between clamped and control rats. Conclusions: Serum insulin concentration per se does not affect islet blood flow, whereas the ambient blood glucose concentration is of major importance in this context.