Exercise-induced metallothionein expression in human skeletal muscle fibres

Exercise induces free oxygen radicals that cause oxidative stress, and metallothioneins (MTs) are increased in states of oxidative stress and possess anti-apoptotic effects. We therefore studied expression of the antioxidant factors metallothionein I and II (MT-I + II) in muscle biopsies obtained in response to 3 h of bicycle exercise performed by healthy men and in resting controls. Both MT-I + II proteins and MT-II mRNA expression increased significantly in both type I and II muscle fibres after exercise. Moreover, 24 h after exercise the levels of MT-II mRNA and MT-I + II proteins were still highly increased and the MT-II mRNA expression reached a 15-fold increase. As expected, immunohistochemical detection of malondialdehyde (MDA) and nitrotyrosine (NITT) showed that formation of free radicals and oxidative stress were clearly increased in exercising muscle peaking shortly after the end of exercise in both type I and II muscle fibres. This is the first report demonstrating that MT-I + II are significantly induced in human skeletal muscle fibres following exercise. As MT-I + II are antioxidant factors that protect various tissues during pathological conditions, the MT-I + II increases post exercise may represent a mechanism whereby contracting muscle fibres are protected against cellular stress and injury.     

Is MED13L-related intellectual disability a recognizable syndrome?

Introduction

MED13L-related intellectual disability is characterized by moderate intellectual disability (ID), speech impairment, and dysmorphic facial features. We present 8 patients with MED13L-related intellectual disability and review the literature for phenotypical and genetic aspects of previously described patients.

Neonatal sensory deprivation reduces tufted cell number in mouse olfactory bulbs

Quantitative morphometric methods were used in mice to study the effect postnatal olfactory deprivation has on tufted cell size and number. The two layers containing tufted cells, the external plexiform and glomerular layers, are considerably smaller in the deprived olfactory bulbs than in the contralateral, experienced olfactory bulbs. While most of this volumetric deficit may be due to an attenuation of synaptogenesis and dendritic elaboration, an additional factor contributing to the reduced volume of these bulbar layers is a substantial loss of tufted cells. Since tufted cells are generated prenatally, their reduced number in the postnatally deprived olfactory bulb is probably a consequence of retarded migration or cell death.     

Inhibition of rat corneal angiogenesis by 16-kDa prolactin and by endogenous prolactin-like molecules.

PURPOSE: The cornea is an avascular organ, where induction of new blood vessels involves the turn-on of proangiogenic factors and/or the turn-off of antiangiogenic regulators. Prolactin (PRL) fragments of 14 kDa and 16 kDa bind to endothelial cell receptors and inhibit angiogenesis. This study was designed to determine whether antiangiogenic PRL-like molecules are involved in cornea avascularity. METHODS: Sixteen-kDa PRL and basic fibroblast growth factor (bFGF) or anti-PRL antibodies were placed into rat cornea micropockets and neovascularization evaluated by the optical density associated with capillaries stained by the peroxidase reaction and by the number of vessels growing into the implants. Prolactin receptors in corneal epithelium were investigated by immunocytochemistry. RESULTS: bFGF induced a dose-dependent stimulation of corneal neovascularization. This effect was inhibited by coadministration of 16-kDa PRL, as indicated by a 65% reduction in vessel density and a 50% decrement in the incidence of angiogenic responses. Corneal angiogenic reactions of different intensities were induced by implantation of polyclonal and monoclonal anti-PRL antibodies. Corneal epithelial cells were labeled by several anti-PRL receptor monoclonal antibodies. CONCLUSIONS: These findings show that exogenous 16-kDa PRL inhibits bFGF-induced corneal neovascularization and suggest that PRL-like molecules with antiangiogenic actions function in the cornea. PRL receptors in the corneal epithelium may imply that PRL in the cornea derives from lacrimal PRL internalized through an intracellular pathway. These observations are consistent with the notion that members of the PRL family are potential regulators of corneal angiogenesis.     

Nephrotoxicity by dicloxacillin and gentamicin in 163 patients with intertrochanteric hip fractures

Of 163 patients with intertrochanteric hip fractures 87 received 2 g dicloxacillin and 240 mg of gentamicin preoperatively, and 76 patients had no antibiotic prophylaxis. Preoperative antibiotic prophylaxis was not shown to have any significant effect on wound infections. However, 16 reversible and 1 irreversible cases of kidney toxicity were found among patients receiving antibiotic prophylaxis, whereas there were only four cases of reversible kidney damage among the patients not receiving antibiotics.