Emu model of full-range femoral head osteonecrosis induced focally by an alternating freezing and heating insult

The emu, a large bipedal bird with hip joint biomechanics similar to humans, was used to establish an experimental model of femoral head osteonecrosis and subsequent femoral head collapse. Focal lesions were induced in 20 adult male emus using an alternating liquid nitrogen freezing and radiofrequency heating insult. At 2, 4, 8, 12 and 16 weeks post-surgery, hip magnetic resonance imaging (MRI) was performed. Before the emus were sacrificed, barium sulphate was infused to the lower extremity to study blood vessel distribution patterns. Femoral samples were scanned by micro-computed tomography (micro-CT) and evaluated histologically. Hip MRI showed changes from broad oedema to femoral head collapse. Emus developed a crippled gait from post-operative week 6. Micro-CT scans and histology showed human-like osteonecrotic changes with an impaired local blood supply. The protocol resulted in consistent full-range osteonecrosis of the femoral head that may serve as a model for testing potential treatments.

Renal haemodynamics in patients with liver cirrhosis assessed by colour ultrasonography

Colour Doppler flow imaging was used in this prospective, cross-sectional study to analyse renal haemodynamics in 50 cirrhotic patients and 15 healthy controls. Mean renal arterial resistive index (RI) was higher in cirrhotic patients than in healthy controls. Mean RI was also higher in cirrhotic patients with non-refractory ascites than in those without ascites, suggesting that the degree of renal vasoconstriction varies with the severity of ascites. A gradient of RI values across the main renal artery, interlobar artery and interlobular renal artery was retained in cirrhotic patients even in the decompensatory stage with non-refractory ascites but was not present in the decompensatory stage with refractory ascites. The disappearance of this gradient may be an important prognostic factor in the development of hepatorenal syndrome (HRS). An inverse correlation between creatinine clearance and interlobular arterial RI was shown for all cirrhotic patients suggesting that even patients with refractory ascites are in a prophase of HRS.

A U-shaped relationship between ankle-brachial index and carotid intima-media thickness in a Chinese population of Inner Mongolia

AIM

The study was designed to investigate the relationship between ankle-brachial index (ABI) and carotid intima-media thickness (IMT), and provide scientific basis for primary and secondary prevention of atherosclerotic diseases.

METHODS

Participants were recruited for this investigation from Inner Mongolia in China through cluster multistage and random sampling. ABI and carotid-IMT were measured for each subject. Periphery arterial disease (PAD) was defined as an ABI≤0.9 in either leg. ABI values were divided into eight groups at every 0.05, and three carotid-IMT measures were compared among groups separately using analysis of variance (ANOVA) and multivariate linear regression analyses.

RESULTS

The results indicated that the prevalence of PAD among 1236 participants was 1.9%. The average common carotid IMT was 0.70±0.21 mm, internal carotid IMT 0.77±0.24 mm, and carotid artery bifurcation IMT 0.78±0.25 mm. A U-shaped relationship was observed that the values of common carotid, carotid artery bifurcation, and internal carotid arteries IMT were decreased at first then increased as ABI values increased. The U-shaped relationship between ABI and three carotid-IMT measures were remained after adjusting for covariates.

CONCLUSION

The data suggests that carotid IMT values are correlated with ABI values in a U-shaped curve. Increased carotid IMT is correlated with the high prevalence of PAD in population of Inner Mongolia in China.

Effects of pH Values of Hydrogen Peroxide Bleaching Agents on Enamel Surface Properties

This study investigated the influence of pH values of bleaching agents on the properties of the enamel surface. Sixty freshly extracted premolars were embedded in epoxy resin and mesiodistally sectioned through the buccal aspect into two parts. The sectioned slabs were distributed among six groups (n=10) and treated using different solutions. Group HCl was treated with HCl solution (pH=3.0) and served as a positive control. Group DW, stored in distilled water (pH=7.0), served as a negative control. Four treatment groups were treated using 30% hydrogen peroxide solutions with different pH values: group HP3 (pH=3.0), group HP5 (pH=5.0), group HP7 (pH=7.0), and group HP8 (pH=8.0). The buccal slabs were subjected to spectrophotometric evaluations. Scanning electron microscopy investigation and Micro-Raman spectroscopy were used to evaluate enamel surface morphological and chemical composition alterations. pH value has a significant influence on the color changes after bleaching (p<0.001). Tukey's multiple comparisons revealed that the order of color changes was HP8, HP7>HP5, HP3>HCl>DW. No obvious morphological alterations were detected on the enamel surface in groups DW, HP7, and HP8. The enamel surface of groups HCl and HP3 showed significant alterations with an erosion appearance. No obvious chemical composition changes were detected with respect to Micro-Raman analysis. Within the limitations of this study, it was concluded that no obvious morphological or chemical composition alterations of enamel surface were detected in the neutral or alkaline bleaching solutions. Bleaching solutions with lower pH values could result in more significant erosion of enamel, which represented a slight whitening effect.

Olanzapine versus placebo for out-patients with anorexia nervosa

BACKGROUND

Anorexia nervosa (AN) is a serious psychiatric illness associated with significant morbidity and mortality. There is little empirical support for specific treatments and new approaches are sorely needed. This two-site study aimed to determine whether olanzapine is superior to placebo in increasing body mass index (BMI) and improving psychological symptoms in out-patients with AN.

METHOD

A total of 23 individuals with AN were randomly assigned in double-blind fashion to receive olanzapine or placebo for 8 weeks together with medication management sessions that emphasized compliance. Weight, other physical assessments and measures of psychopathology were collected.

RESULTS

End-of-treatment BMI, with initial BMI as a covariate, was significantly greater in the group receiving olanzapine [F(1, 20)=6.64, p=0.018]. Psychological symptoms improved in both groups, but there were no statistically significant group differences. Of the 23 participants, 17 (74%) completed the 8-week trial. Participants tolerated the medication well with sedation being the only frequent side effect and no adverse metabolic effects were noted.

CONCLUSIONS

This small study suggests that olanzapine is generally well tolerated by, and may provide more benefit than placebo for out-patients with AN. Further study is indicated to determine whether olanzapine may affect psychological symptoms in addition to BMI.