The effect of a single early high-dose vitamin D supplement on fracture union in patients with hypovitaminosis D: a prospective randomised trial.

AIMS: To evaluate the effect of a single early high-dose vitamin D supplement on fracture union in patients with hypovitaminosis D and a long bone fracture. PATIENTS AND METHODS: Between July 2011 and August 2013, 113 adults with a long bone fracture were enrolled in a prospective randomised double-blind placebo-controlled trial. Their serum vitamin D levels were measured and a total of 100 patients were found to be vitamin D deficient (< 20 ng/ml) or insufficient (< 30 ng/mL). These were then randomised to receive a single dose of vitamin D3 orally (100 000 IU) within two weeks of injury (treatment group, n = 50) or a placebo (control group, n = 50). We recorded patient demographics, fracture location and treatment, vitamin D level, time to fracture union and complications, including vitamin D toxicity. Outcomes included union, nonunion or complication requiring an early, unplanned secondary procedure. Patients without an outcome at 15 months and no scheduled follow-up were considered lost to follow-up. The t-test and cross tabulations verified the adequacy of randomisation. An intention-to-treat analysis was carried out. RESULTS: In all, 100 (89%) patients had hypovitaminosis D. Both treatment and control groups had similar demographics and injury characteristics. The initial median vitamin D levels were 16 ng/mL (interquartile range 5 to 28) in both groups (p = 0.885). A total of 14 patients were lost to follow-up (seven from each group), two had fixation failure (one in each group) and one control group patient developed an infection. Overall, the nonunion rate was 4% (two per group). No patient showed signs of clinical toxicity from their supplement. CONCLUSIONS: Despite finding a high level of hypovitaminosis D, the rate of union was high and independent of supplementation with vitamin D3. Cite this article: Bone Joint J 2017;99-B:1520-5.

HIV-1 protein Vpr causes gross mitochondrial dysfunction in the yeast Saccharomyces cerevisiae.

The biological effects of the HIV-1 accessory protein, Vpr, have been studied in yeast expression systems. In our previous study [1], employing the pCUP1-vpr copper-inducible expression cassette, Vpr was shown to cause growth arrest and structural defects. In this study yeast constitutively expressing vpr, through elevated copy number and/or elevated transcription levels, displayed no growth arrest in fermentative growth conditions while Vpr was produced at much lower levels than in the inducible expression system. However, such cells were respiratory deficient and unable to utilise ethanol or glycerol as the sole carbon source. They exhibited gross mitochondrial dysfunction displayed in the loss of respiratory chain complex I, II, III, IV and citrate synthase activities. The effects on mitochondria required a C-terminal domain of Vpr that contains a conserved amino acid sequence motif HFRIGCRHSRIG. These results suggest that the widely observed phenomenon of 'Vpr-induced growth arrest' in human cells could be due to mitochondrial dysfunction.

The epidemiology of skin tears in the institutionalized elderly.

While skin tears are a common occurrence in the institutionalized elderly population, nothing has been written about this problem. We retrospectively studied all incident reports during a 1-year period at a large, urban, long-term-care facility to identify residents with skin tears. The overall incidence of skin tears was 0.92 per patient per year. The incidence rate for females, but not for males, increased significantly with age (P = 0.012). The mean length of the skin tear was 1.9 cm +/- 1.4 (mean +/- SD). Eighty percent occurred in the upper extremities, with the most frequent location being the forearm. Almost half of the skin tears reported had an unknown cause. Wheelchairs and accidentally bumping into an object each accounted for a quarter of the skin tears where the cause was known. Transfers and falls contributed to a lesser extent. Impaired mental status was no more likely to be present in residents experiencing a skin tear than in all nursing home residents. Twenty-four of the 147 residents with skin tears had four or more tears, accounting for 40% of all skin tears reported. Ninety-seven percent of the episodes resulted in no attending physicians' orders other than the standing orders. Future studies should be designed to determine if there are adverse consequences of skin tears and to suggest programs to reduce their occurrence.