Operative treatment of ankle fractures in adults: correlation between types of fracture and final results.

By means of a simple and easy classification, namely uni, bi- and trimalleolar ankle fractures, and the localization of the fracture at the level of the fibula; all of the 612 ankle fractures that were surgically treated at the Leuven University Hospital were easily classified. In 590 cases the results were collected 1 year after the operation by means of an evaluation system based on symptoms, clinical findings and radiographic findings. The influence of the type of fracture was analysed and led to the following conclusion: 1. Unimalleolar fractures have a better prognosis than trimalleolar fractures. 2. An isolated medial malleolar fracture gives a worse final result than an isolated lateral malleolar fracture. 3. Multimalleolar fractures, including the medial malleolus, have a worse prognosis than multimalleolar fractures without medial malleolar fractures. 4. Even after perfect internal fixation, the presence of a posterior fragment larger than one-third of the articular surface leads to a worse final result than a small unfixed fragment. 5. Weber's classification may not be useful for prognosis.     

Arginine Vasopressin Immunoreactivity is Decreased in the Hypothalamic Suprachiasmatic Nucleus of Subjects with Suprasellar Tumors

Suprasellar tumors with compression of the optic chiasm are associated with an impaired sleep–wake rhythm. We hypothesized that this reflects a disorder of the biological clock of the human brain, the suprachiasmatic nucleus (SCN), which is located just above the optic chiasm. In order to test this hypothesis, we investigated the expression of two key neuropeptides of the SCN, that is, arginine vasopressin (AVP) and vasoactive intestinal peptide (VIP), as assessed by quantitative immunocytochemistry in post‐mortem hypothalamic tissue of patients with a suprasellar tumor inducing permanent visual field defects. Post‐mortem hypothalamic tissue of 5 patients with a suprasellar tumor inducing permanent visual field defects (acromegaly n = 2, nonfunctioning macro‐adenoma n = 1, macroprolactinoma n = 1, infundibular metastasis of a colorectal adenocarcinoma n = 1) and 15 age‐ and gender‐matched controls was obtained from the Netherlands Brain Bank. Total AVP immunoreactivity in the SCN was lower in patients with a suprasellar tumor than in controls (P = 0.03). By contrast, total VIP immunoreactivity was not different between patients and controls (P = 0.44). Suprasellar tumors leading to permanent visual field defects are associated with reduced AVP, but not VIP immunoreactivity, in the SCN. These findings raise the possibility that selective impairment of the SCN contributes to sleep–wake disturbances in these patients.     

Short‐Term Effect of Estrogen on Human Bone Marrow Fat

Bone marrow fat, an unique component of the bone marrow cavity increases with aging and menopause and is inversely related to bone mass. Sex steroids may be involved in the regulation of bone marrow fat, because men have higher bone marrow fat than women and clinical observations have suggested that the variation in bone marrow fat fraction is greater in premenopausal compared to postmenopausal women and men. We hypothesized that the menstrual cycle and/or estrogen affects the bone marrow fat fraction. First, we measured vertebral bone marrow fat fraction with Dixon Quantitative Chemical Shift MRI (QCSI) twice a week during 1 month in 10 regularly ovulating women. The vertebral bone marrow fat fraction increased 0.02 (95% CI, 0.00 to 0.03) during the follicular phase (p = 0.033), and showed a nonsignificant decrease of 0.02 (95% CI, –0.01 to 0.04) during the luteal phase (p = 0.091). To determine the effect of estrogen on bone marrow fat, we measured vertebral bone marrow fat fraction every week for 6 consecutive weeks in 6 postmenopausal women before, during, and after 2 weeks of oral 17‐β estradiol treatment (2 mg/day). Bone marrow fat fraction decreased by 0.05 (95% CI, 0.01 to 0.09) from 0.48 (95% CI, 0.42 to 0.53) to 0.43 (95% CI, 0.34 to 0.51) during 17‐β estradiol administration (p < 0.001) and increased again after cessation. During 17‐β estradiol administration the bone formation marker procollagen type I N propeptide (P1NP) increased (p = 0.034) and the bone resorption marker C‐terminal crosslinking telopeptides of collagen type I (CTx) decreased (p < 0.001). In conclusion, we described the variation in vertebral bone marrow fat fraction among ovulating premenopausal women. And among postmenopausal women, we demonstrated that 17‐β estradiol rapidly reduces the marrow fat fraction, suggesting that 17‐β estradiol regulates bone marrow fat independent of bone mass. © 2015 American Society for Bone and Mineral Research.     

Torsion biomechanics of the spine following lumbar laminectomy: a human cadaver study

Purpose

Lumbar laminectomy affects spinal stability in shear loading. However, the effects of laminectomy on torsion biomechanics are unknown. The purpose of this study was to investigate the effect of laminectomy on torsion stiffness and torsion strength of lumbar spinal segments following laminectomy and whether these biomechanical parameters are affected by disc degeneration and bone mineral density (BMD).

Methods

Ten human cadaveric lumbar spines were obtained (age 75.5, range 59–88). Disc degeneration (MRI) and BMD (DXA) were assessed. Disc degeneration was classified according to Pfirrmann and dichotomized in mild or severe. BMD was defined as high BMD (≥median BMD) or low BMD (<median BMD). Laminectomy was performed either on L2 (5×) or L4 (5×). Twenty motion segments (L2–L3 and L4–L5) were isolated. The effects of laminectomy, disc degeneration and BMD on torsion stiffness (TS) and torsion moments to failure (TMF) were studied.

Results

Load–displacement curves showed a typical bi-phasic pattern with an early torsion stiffness (ETS), late torsion stiffness (LTS) and a TMF. Following laminectomy, ETS decreased 34.1 % (p < 0.001), LTS decreased 30.1 % (p = 0.027) and TMF decreased 17.6 % (p = 0.041). Disc degeneration (p < 0.001) and its interaction with laminectomy (p < 0.031) did significantly affect ETS. In the mildly degenerated group, ETS decreased 19.7 % from 7.6 Nm/degree (6.4–8.4) to 6.1 Nm/degree (1.5–10.3) following laminectomy. In the severely degenerated group, ETS decreased 22.3 % from 12.1 Nm/degree (4.6–21.9) to 9.4 Nm/degree (5.6–14.3) following laminectomy. In segments with low BMD, TMF was 40.7 % (p < 0.001) lower than segments with high BMD [34.9 Nm (range 23.7–51.2) versus 58.9 Nm (range 43.8–79.2)].

Conclusions

Laminectomy affects both torsion stiffness and torsion load to failure. In addition, torsional strength is strongly affected by BMD whereas disc degeneration affects torsional stiffness. Assessment of disc degeneration and BMD pre-operatively improves the understanding of the biomechanical effects of a lumbar laminectomy.     

The influence of antibiotics on the growth of Candida albicans in the vagina: an experiment with vaginal fluid

The growth of Candida albicans in fluid aspirated from the vagina of 18 women was studied. The growth of C. albicans in the aspirated vaginal fluid to which antibiotics were added proved to be enhanced in 16 out of 18 samples. The growth of C. albicans in Sabouraud medium proved not to be enhanced by the addition of antibiotics. Dilution of the Sabouraud broth and the reduction of the amount of added antibiotics did not change the outcome. It is concluded that enhancement of the growth of C. albicans in the vagina is not due to a direct growth-promoting effect of the antibiotics on the yeast. It is concluded that most probably the growth-promoting effect of antibiotics is obtained by way of an eradication of the bacterial flora harboured in the vagina.     

Airway tone during exercise in healthy subjects: effects of salbutamol and ipratropium bromide

In healthy subjects changes in airway calibre during exercise are conflicting and smaller than in asthmatics. Methodological differences could explain the discrepancies between the results obtained in healthy subjects. Therefore, our aim was to assess during exercise the changes in airway diameter and the effects of 200 microg salbutamol (SAL) or 40 microg ipratropium bromide (IPR) inhalations versus placebo (PLA), using spirometry and respiratory resistance (Rrs). Eight non-asthmatic subjects exercised 9 min at 70 % of their maximal aerobic power after inhalation of 200 microg SAL, 40 microg IPR, or PLA. Maximal flow-volume curves were obtained before and after inhalations, at 3 (E3) and 6 (E6) minutes of exercise, and during recovery. Rrs were measured by impulse oscillometry before and after inhalation, and immediately at the end of exercise. At rest, FEV (1) increased significantly after inhalation of SAL and IPR. Rrs decreased only after SAL. During exercise FEV (1) increased significantly from rest with SAL and IPR while forced mid expiratory flow (FEF (25 - 75)) increased significantly for all conditions. At E6 the rise of FEV (1) and FEF (25 - 75) were greater with SAL compared to PLA and IPR. In all conditions Rrs increased significantly immediately at the end of exercise as compared to rest but less than during flow-matched hyperpnea. It is concluded that a similar bronchodilation was observed during exercise with and without anticholinergic drug which suggests a withdrawal of parasympathetic control of airways during exercise in healthy subjects. Nevertheless, the bronchodilation observed during exercise is not maximal since it can be reinforced by beta (2)-mimetic drug.     

Accounting for flow dependence of respiratory resistance during exercise

Studies of airway function during exercise have produced conflicting results both in healthy and diseased subjects. Respiratory resistance (Rrs) was measured using an impulse oscillation technique. A flow/resistance curve was established for each of 16 healthy males during voluntary hyperventilation (VHV) at rest. Then, Rrs and flow were measured immediately (t(0)) and 90 sec (t(90)) after exercise on a cycle ergometer at 60, 70, and 80% of maximal aerobic power. The flow/resistance relationship at rest during VHV was used to assess the flow dependence of Rrs. Rrs at t(0) was higher than at rest (P <0.01) but lower than Rrs obtained at matched flow during VHV (P <0.05). In healthy subjects, the linear increase in Rrs with VHV indicates airflow dependency of Rrs following Rohrer's equation. The relative decrease in Rrs with exercise suggests bronchodilation. The bronchodilating effect disappeared promptly when exercise was stopped suggesting that it may have been related to a reflex mechanism.     

Dietary fat content alters insulin-mediated glucose metabolism in healthy men

BACKGROUND: A high dietary fat intake is involved in the pathogenesis of insulin resistance. OBJECTIVE: The aim was to compare the effect of different amounts of dietary fat on hepatic and peripheral insulin sensitivity. DESIGN: Six healthy men were studied on 3 occasions after consuming for 11 d diets with identical energy and protein contents but different percentages of energy as fat and carbohydrate as follows: 0% and 85% [low-fat, high-carbohydrate (LFHC) diet], 41% and 44% [intermediate-fat, intermediate-carbohydrate (IFIC) diet], and 83% and 2% [high-fat, low-carbohydrate (HFLC) diet]. Insulin sensitivity was quantified by using a hyperinsulinemic euglycemic clamp (plasma insulin concentration: approximately 190 pmol/L). RESULTS: During hyperinsulinemia, endogenous glucose production was higher after the HFLC diet (2.5 +/- 0.3 micromol x kg(-1) x min(-1); P < 0.05) than after the IFIC and LFHC diets (1.7 +/- 0.3 and 1.2 +/- 0.4 micromol x kg(-1) x min(-1), respectively). The ratio of dietary fat to carbohydrate had no unequivocal effects on insulin-stimulated glucose uptake. In contrast, insulin-stimulated, nonoxidative glucose disposal tended to increase in relation to an increase in the ratio of fat to carbohydrate, from 14.8 +/- 5.1 to 20.6 +/- 1.9 to 26.2 +/- 2.9 micromol x kg(-1) x min(-1) (P < 0.074 between the 3 diets). Insulin-stimulated glucose oxidation was significantly lower after the HFLC diet than after the IFIC and LFHC diets: 1.7 +/- 0.8 compared with 13.4 +/- 2.1 and 19.0 +/- 2.1 micromol x kg(-1) x min(-1), respectively (P < 0.05). During the clamp study, plasma fatty acid concentrations were higher after the HFLC diet than after the IFIC and LFHC diets: 0.22 +/- 0.02 compared with 0.07 +/- 0.01 and 0.05 +/- 0.01 mmol/L, respectively (P < 0.05). CONCLUSION: A high-fat, low-carbohydrate intake reduces the ability of insulin to suppress endogenous glucose production and alters the relation between oxidative and nonoxidative glucose disposal in a way that favors storage of glucose.