Linearity study on detection and quantification limits for the determination of avermectins using linear regression

In this study, linear relationships between response and concentration were used to estimate the detection limit (DL) and quantification limit (QL) for five avermectins: emamectin, abamectin, doramectin, moxidectin, and ivermectin. Estimation of DL and QL was based on the standard deviation of residual and y-intercept of the regression line at low concentrations of avermectins, using the dispersive solid-phase extraction procedure. Avermectin extracts were analyzed using liquid chromatography tandem mass spectrometry. Based on the regression slope, DL and QL were higher at concentrations of 0.3–0.4 μg/kg and 1 μg/kg, respectively, for all avermectin compounds. Linearity assessment was performed by linear regression, which incorporated a regression model, outlier rejection, and evaluation of the assumption with a significant test. For all avermectins, there is a significant correlation between response and concentration in the range 1–15 μg/kg, and the y-intercept passes through origin (zero).     

Lengthening of Massive Intercalary Cortical Allograft After Successful Graft Incorporation in Skeletally Immature Bone with Critical-Sized Defect: A Case Report with 6-year Follow-up

Bone allograft serves as an alternative to overcome the limitation of autograft. Some concerns, such as graft rejection, infection, and low union rate, arise from the use of bone allograft since the graft is a non-living and foreign material. We reported a case of critical-sized bone defect in a skeletally immature patient treated with massive intercalary allograft that not only did it show union but also graft incorporation that allowed for subsequent bone lengthening at the site of the incorporated massive allograft. To our knowledge, there has been a report of lengthening of free-vascularized fibular autograft but not the nonvascularized one. Massive intercalary allograft that incorporates well to the host could be an option to treat critical-sized bone defect.     

Perceived Importance of Breast Cancer Risk Factors: A Survey on 386 Physicians in China

There are varying definitions of women at high risk of breast cancer across different institutions, and there are reports suggesting that the breast cancer risk assessment tools have not been well integrated into clinical practice. In this study, we tried to investigate the perceived importance of different breast cancer risk factors by physicians in China. A cross-sectional survey involving 386 anonymous physicians was conducted using a 20-item, 5-point Likert scale questionnaire. The Kruskal-Wallis test and post-hoc pairwise comparisons were used to compare the differences in response. Most of the respondents were either breast surgeons/specialists (n=161; 41.7%) or medical oncologists (n=151; 39.1%), and the results showed that the breast cancer risk factors were not perceived as equally important. The weighting of each risk factor also varied depending on the physician’s medical specialty, location of practice, and the number of years of clinical experience.  This study provides a more updated insight into the perceptions of physicians in China toward the breast cancer risk factors, as well as underlines the potential improvements in breast cancer risk assessment strategies that can be done.     

Ocular Tuberculosis Initially Presenting as Central Retinal Vein Occlusion

A 23-year-old man presented with central retinal vein occlusion. The retinal haemorrhages worsened and signs of retinal vasculitis appeared later as vision dropped from 6/60 to Counting Fingers. No signs of systemic disease were observed. Routine Mantoux test and chest radiograph were negative for tuberculosis. Fundus flourescein angiogram confirmed presence of retinal vasculitis. Both systemic and topical corticosteroid therapy were ineffective. Polymerase chain reaction analysis of vitreous fluid showed presence of Mycobacterium tuberculosis. A full 6-month course of antituberculosis therapy was given and inflammation subsided. Vision improved to 3/60. This is a rare case of ocular tuberculosis without evidence of systemic infection, presenting first as a central retinal vein occlusion.