A rapid colorimetric assay for measuring low concentrations of haemoglobin in large numbers of bovine plasma samples

The aim of this study was to develop a microplate colorimetric assay that could measure low levels (<2mg/mL) of haemoglobin in bovine plasma as a result of haemolytic trauma. The method presented uses the pseudo-peroxidase activity of haemoglobin to catalyse a redox reaction between tetramethylbenzidine (TMB) and hydrogen peroxide in an acidic environment. There is a good linear relationship (r ²=0.999) between the optical density of the reaction product and haemoglobin concentration. The assay is highly repeatable (F=1.219, P=0.303) with an intra- and inter-assay variation ranging from 2.3% to 3.9% and 5.8% to 11.3% respectively for three control samples containing high, medium and low levels of haemoglobin. In conclusion, the method described in this paper provides an accurate, precise measurement of low concentrations of haemoglobin in bovine plasma that enables correction for haemolysis.     

Polypoid stromal lesions of the intestines

Interpretation of intestinal mesenchymal lesions is simplified merely by knowing in which anatomic layer they are usually found. For example, Kaposi sarcoma is detected on mucosal biopsies, whereas inflammatory fibroid polyp is almost always in the submucosa. Gastrointestinal stromal tumours (GIST) are centred generally in the muscularis propria. Schwannomas are essentially always in the muscularis propria. Knowledge of the favoured layer is also most important in interpreting colon biopsies, as many mesenchymal polyps are encountered in the colon. Herein we discuss several mesenchymal lesions and point out some diagnostic pitfalls.     

Histopathology of Barrett esophagus

Barrett esophagus (BE) is a metaplastic, premalignant lesion of the tubular esophagus that carries significant implications and is associated with approximately 0.5% annual cancer incidence. Although gastroesophageal reflux disease is a recognized risk factor, no clear guidelines exist as to who should undergo endoscopic screening for the condition. Histologic requirements for the diagnosis vary by geographic region with some but not all countries requiring the presence of goblet cells. In spite of interobserver variability, histologic assessment of dysplasia is currently the accepted method of surveillance and subsequent patient management is dictated by this evaluation. Though not universal, endoscopic therapy is rapidly replacing esophagectomy in patients with high-grade dysplasia/early carcinoma. This review aims to provide the reader with an overview on this subject with special emphases on the histopathologic features of BE and BE-associated dysplasia as well as evolution and new developments related to therapeutic modalities in patients diagnosed with dysplasia.     

Ossification of the external ear: a case report and review of the literature

A rare case of idiopathic bilateral ossification of the auricular cartilage and cartilage of the external ear canal is reported. The hardening and thickening of the external ear canals with subsequent narrowing and impaired exposure resulted in symptomatic hearing loss because of the recurrent impediment of inspissated cerumen, the removal of which finally became impossible. Surgical resection of the cartilage external ear canal and tragus was indicated to provide a more permanent treatment of conductive hearing loss. Histological examination revealed complete replacement of the fibroelastic cartilage by normal bone structures showing Haversian canals and bone marrow. The present case report is unique because of the involvement of both the auricles and external ear canals, the symptomatic hearing loss and the surgical treatment to relieve symptoms.     

Immigrant parents' perceptions of school environment and children's mental health and behavior

BACKGROUND: Research has increasingly identified the perception of school environment as an influential factor in children's lives. There has been sparse research attention, however, on the potential importance of parents' perceptions of school environment on child adjustment. This study examined the relationship between parents' perceptions of school environment and children's emotional and behavioral problems. METHODS: Data were derived from the New Canadian Children and Youth Study, a study of the children (aged 4‐6 and 11‐13) of immigrant parents. Analyses focused on a subsample of Mainland Chinese, Hong Kong Chinese, and Filipino immigrants in a large metropolitan area. RESULTS: Parental perception of school environment was negatively associated with physical aggression in children even after controlling for child age and gender, parental characteristics, family functioning, and aspects of acculturation. In contrast, parental perception was not significantly related to symptoms of emotional distress in children. There were some ethnic differences in perception of school environment. CONCLUSIONS: Parental perception of school environment is important to the well‐being of the children of immigrant parents, and reinforces the relevance of initiatives to improve the dynamics between parents and schools.