Subkapitale und Humerusschaftfraktur

Conservative treatment with Gilchrist bandage or cuff and collar sling is possible in a large number of humeral head fractures, depending on fracture type (group A extracapsular fractures [Habermeyer], undisplaced fractures [Neer], whether dislocated, whether stable) and patient’s age and level of activity. In younger patients conservative treatment is not advised for fractures with tuberosity dislocation >5 mm. With careful patient selection results are good or very good. Stability should be checked by X-ray examination with image intensifier. Excellent results of modern operative procedures for humeral shaft fractures mean that conservative treatment is no longer the treatment of choice for these, but results are good when patient selection takes account of personality (good compliance is required) and the fractures are of type A1/A2 or C1/C3 (AO). Initial immobilization in a cast is followed by use of a Sarmiento brace for definitive functional treatment. Decisions on operative vs conservative treatment must be individual and take account of each patient’s wishes.     

Changes in phosphocreatine concentration of skeletal muscle during high-intensity intermittent exercise in children and adults

Purpose

The aim of the present study was to test the hypotheses that a greater oxidative capacity in children results in a lower phosphocreatine (PCr) depletion, a faster PCr resynthesis and a lower muscle acidification during high-intensity intermittent exercise compared to adults.

Methods

Sixteen children (9.4 ± 0.5 years) and 16 adults (26.1 ± 0.3 years) completed a protocol consisting of a dynamic plantar flexion (10 bouts of 30-s exercise at 25 % of one repetition maximum separated by 20-s recovery), followed by 10 min of passive recovery. Changes of PCr, ATP, inorganic phosphate, and phosphomonoesters were measured by means of ³¹Phosphorous-magnetic resonance spectroscopy during and post-exercise.

Results

Average PCr (percentage of [PCr] at initial rest (%[PCr]_i)) at the end of the exercise (adults 17 ± 12 %[PCr]_i, children 38 ± 17 %[PCr]_i, P < 0.01) and recovery periods (adults 37 ± 14 %[PCr]_i, children 57 ± 17 %[PCr]_i, P < 0.01) was significantly lower in adults compared to children, induced by a stronger PCr decrease during the first exercise interval (adults ?73 ± 10 %[PCr]_i, children ?55 ± 15 %[PCr]_i, P < 0.01). End-exercise pH was significantly higher in children compared to adults (children 6.90 + 0.20, ?0.14; adults 6.67 + 0.23, ?0.15, P < 0.05).

Conclusions

From our results we suggest relatively higher rates of oxidative ATP formation in children’s muscle for covering the ATP demand of high-intensity intermittent exercise compared to adults, enabling children to begin each exercise interval with significantly higher PCr concentrations and leading to an overall lower muscle acidification.     

Long‐term course of substantia nigra hyperechogenicity in Parkinson's disease

A hyperechogenicity of the (SN+) in transcranial sonography corroborates the diagnosis of idiopathic Parkinson's disease (iPD). Although it is thought to represent a biomarker of the disease that is independent of disease severity and progression, differing results have been reported describing a positive correlation of the size and advancing clinical stage. In 50 parkinsonian patients, transcranial ultrasound and clinical examination was performed twice with a mean time interval of 6.4 years. SN+ did not change in size significantly between the first and second examination, whereas clinical parkinsonian symptoms—as determined by the motor part of the UPDRS—significantly worsened (P < 0.001). We found a highly significant intraindividual correlation in SN+ sizes between both examinations (P < 0.001). The size of SN+ did not correlate with the UPDRS part III at the time of first or second ultrasound examination. Progression of motor symptoms between the first and second investigation did not correlate with the size of SN+ at baseline. Furthermore, even in the subgroup of patients with an interval of ≥8 years between examinations, there was no significant change in SN+ size. SN+ represents a largely stable biomarker in iPD and does not reflect disease progression. The size of SN+ does not predict the further course of the disease. © 2012 Movement Disorder Society     

Pharmacological properties of naturally occurring variants of the human norepinephrine transporter

The human norepinephrine transporter (hNET) gene has five sequence polymorphisms that predict amino acid substitutions in the transporter protein: Val69Ile, Thr99Ile, Val245Ile, Val449Ile, and Gly478Ser. In order to functionally characterize the naturally occurring transporter variants, we used site-directed mutagenesis to establish the hNET variants and compared some basic pharmacological properties (uptake of norepinephrine and its inhibition by the tricyclic antidepressant desipramine) in COS-7 cells transiently expressing variant hNETs and wild-type hNET. None of the hNET variants displayed changes in the potency (Ki) of desipramine for inhibition of norepinephrine uptake. Furthermore, variants Val69Ile, Thr99Ile, ValZ45Ile, and Val449Ile did not affect kinetic constants (Km, Vmax) of norepinephrine uptake. However, COS-7 cells expressing the hNET variant Gly478Ser displayed an approximately four-fold increase in the Km for norepinephrine, while the Vmax was unaffected. The increase in the Km, which is equivalent to a four-fold reduction in the affinity of the variant hNET for its natural substrate norepinephrine, indicates that the glycine in position 478 is part of a substrate recognition domain. The reduced clearance of released norepinephrine by reuptake through the Gly478Ser variant might cause an increase in the synaptic and the circulating concentration of norepinephrine. Elevated norepinephrine concentrations have been associated with human diseases and it will be interesting to explore a possible contribution by the Gly478Ser variant to certain disease states.