Association of geometric factors and failure load level with the distribution of cervical vs. trochanteric hip fractures.

We experimentally studied the distribution of hip fracture types at different structural mechanical strength. Femoral neck fractures were dominant at the lowest structural strength levels, whereas trochanteric fractures were more common at high failure loads. The best predictor of fracture type across all failure loads and in both sexes was the neck-shaft angle. INTRODUCTION: Bone geometry has been shown to be a potential risk factor for osteoporotic fractures. Risk factors have been shown to differ between cervical and trochanteric hip fractures. However, the determinants of cervical and trochanteric fractures at different levels of structural mechanical strength are currently unknown. In addition, it is not known if the distribution of fracture types differs between sexes. The aim of this experimental study on excised femora was to investigate whether there exist differences in the distribution of cervical and trochanteric fractures between different structural mechanical strength levels and different sexes and to identify the geometric determinants that predict a fracture type. MATERIALS AND METHODS: The sample was comprised of 140 cadavers (77 females: mean age, 81.7 years; 63 males: mean age, 79.1 years) from whom the left femora were excised for analysis. The bones were radiographed, and geometrical parameters were determined from the digitized X-rays. The femora were mechanically tested in a side impact configuration, simulating a sideways fall. After the mechanical test, the fracture patterns were classified into cervical and trochanteric. RESULTS: The overall proportion of cervical fractures was higher in females (74%) than in males (49%) (p = 0.002). The fracture type distribution differed significantly across load quartiles in females (p = 0.025), but not in males (p = 0.205). At the lowest load quartiles, 94.7% of fractures in female and 62.5% in males were femoral neck fractures. At the highest quartiles, in contrast, only 52.6% of fractures in females and 33.3% in males were cervical fractures. Among geometric variables, the neck-shaft angle was the best predictor of fracture type, with higher values in subjects with cervical fractures. This finding was made in females (p < 0.001) and males (p = 0.02) and was consistent across all failure load quartiles. CONCLUSIONS: Femoral neck fractures predominate at the lowest structural mechanical strength levels, whereas trochanteric fractures are more common at high failure loads. Females are more susceptible to femoral neck fractures than males. The best predictor of fracture type across all structural strength levels and both sexes was the neck-shaft angle.     

Increased GABA synthesis in skin fibroblasts of patients with Huntington's disease: a possible role of glutamic acid decarboxylase?

Activity of glutamic acid decarboxylase (GAD) was determined in extracts from cultured human skin fibroblasts of patients with Huntington's disease (HD) and compared to an age- and sex-matched control group. The fibroblasts were cultured up to eight passages. In patients suffering from HD a significant increased activity of GAD (～ 3–5 fold compared to age- and sex-matched controls) was found in passages 4–8. This may indicate a defect in the genetic expression of GAD concentration or regulation and/or may indicate that increased levels of glutamate may also be responsible for neuronal degeneration in HD.     

Assessing providers of coronary revascularization: a method for peer review organizations.

OBJECTIVES. Current methods to evaluate quality of care are usually limited to reviews of individual cases or comparisons of hospital mortality rates. We present an alternative method that compares complication rates adjusted for patient characteristics. METHODS. Detailed clinical data that were specifically designed for quality comparisons of providers of revascularization procedures were abstracted from the medical records of 1998 Medicare patients, in 16 hospitals, who had coronary artery bypass surgery and 2091 patients, in 16 hospitals, who had angioplasty. Providers were ranked on the basis of an unadjusted risk, a risk adjusted for detailed clinical information, and a risk adjusted only for patient comorbidities. RESULTS. Complication rates differed significantly and substantially among the hospitals. Clinical adjustment changed the hospital rankings for the bypass surgery hospitals, but not for the angioplasty hospitals. Adjustment for comorbidities did not affect hospital rankings for either procedure. CONCLUSIONS. When sample sizes are limited, adverse outcome rates may be a more sensitive measure of quality of care than mortality rates. Rates that are unadjusted or adjusted only for comorbidities may be inadequate for evaluating some providers of bypass surgery.     

Therapy with central active catechol-O-methyltransferase (COMT)-inhibitors: is addition of monoamine oxidase (MAO)-inhibitors necessary to slow progress of neurodegenerative disorders?

Summary Neurotrophic factors, like e.g. nerve growth factor (NGF), neurotrophin 3 (NT-3) or brain-derived neurotrophic factor (BDNF) promote the survival and function of neurones in the peripheral and central nervous system. Dopamine or other biogenic amines induce the biosynthesis of neurotrophic factors in glial and neuronal cells. Therefore inhibition of enzymes, like the extraneuronal and neuronal located MAO or the predominantly glial situated COMT, which both metabolize catecholamines, may induce an increased biosynthesis of neurotrophic factors. Due to clinical studies especially MAO-B-inhibitors appear to slow the progression of neurological deficits in Parkinson's disease and the cognitive decline in Alzheimer's disease. On the one hand inhibition of COMT alone may also slow the metabolisation of biogenic amines in glial cells and may consequently induce synthesis of neurotrophic factors in glial cells. But on the other hand in vivo and in vitro studies show, that COMT-inhibitors may intensify the metabolisation of catecholamines in neurones by MAO, what may cause an enhanced generation of free radicals. This increase of free radicals may induce lipid peroxidation of membranes and therefore cause accelerated neuronal and glial cell death. For that reason we conclude, that centrally active COMT-inhibitors may only be used together with MAO-inhibitors in the neuroprotective treatment of neurodegenerative disorders. Medical treatment with both inhibitors will have to be performed very carefully due to cytotoxic effects of high catecholamine levels on neuronal and glial cells and due to possible prolongation or potentiation of the activity of several noradrenergic drugs in the periphery.     

Effect of visual training on the vertical vergence amplitude

Visual training has an effect on the vertical vergence amplitudes. Three mature symptomatic patients exhibited a significant increase in the vertical vergence which compensates for the vertical heterophoria. Subjects with normal binocularity and hence no vertical heterophoria did not exhibit increased vertical vergence amplitudes after training.     

Vault Haematoma after Vaginal Hysterectomy: An Invariable Sequel?

Fifty consecutive patients undergoing vaginal hysterectomy were studied prospectively by ultrasound to determine the incidence of vault haematoma and the relationship between its size and the development of postoperative pyrexia; 49 patients (98%) had a vault haematoma and 35 (70%) were febrile postoperatively. Large vault haematomas (mean diameter greater than 5 cm) were invariably associated with significant febrile morbidity, whilst 1 in 3 patients with a small haematoma was afebrile. Colporrhaphy did not influence the likelihood of haematoma formation.