Language as a barrier to the acquisition of anatomical knowledge

The language of instruction for medical students at the University of Hong Kong is English, which is their second language. This presents a potential barrier to their academic learning. We have studied the extent of this problem by looking at the amount of terminology students have to assimilate during their anatomy course and the way in which the terminology is structured and explained (this provides, more generally, an indication of the factual loading to which medical students are exposed). We have also investigated the effect of the quality of students' language skills on their examination results in anatomy class tests and MBBS exams. It was found that students' entrance levels in English correlated well with their final examination results and that the quality and quantity of their English also correlated highly with scores in class tests. On this basis, we conclude that language is one of the most important barriers to students' academic success in the department and that current teaching materials may not be appropriate.     

Neu／c─erbB─2癌基因在颊粘膜上皮良性及恶性病变中的表达及其定量研究

目的：观察Ｎｅｕ／ｃ－ｅｒｂＢ－２癌基因在颊粘膜上皮良性、癌前以及癌变状态下的表达，并确立图像分析系统定量的方法．方法：用三种抗Ｎｅｕ抗体，通过微波暴露抗原，进行标准化的ＥｌｉｔｅＡＢＣ染色，并通过半定量及图像分析系统确立Ｎｅｕ基因在不同标本病变中的表达．结果：Ｎｅｕ基因在恶变组有高表达（６３．５％），以转移和复发的病变反应强度最高．此外，在癌前病变中也有较高的表达（５６．３％）．结论：本研究建立的免疫组化定量方法检测Ｎｅｕ基因表达的系统精确、可靠、重复性好，选取的指标可充分反映Ｎｅｕ基因表达的量以及细胞的阳性表达率．结果证实了Ｎｅｕ基因与口腔鳞癌的癌变关系密切，在癌变的早期以及转移和复发的病变中有较高的表达．     

rasp21癌蛋白在颊粘膜上皮癌前及癌变中表达的定量分析

通过建立图像分析系统对免疫组化染色结果进行定量，观察了ｒａｓｐ２１在口腔颊粘膜上皮由正常、炎症、癌旁上皮到鳞癌的变化过程的表达并进行分析。结果显示，ｐ２１由癌旁上皮开始表达水平明显提高，到高分化鳞癌达到最大值，而在中等及稍差分化的鳞癌、发生转移的鳞癌表达水平下降。组织学也显示了在趋于分化成熟及高分化的上皮细胞中ｐ２１表达水平高。提示了ｐ２１的高表达与上皮细胞的增殖及转移与否关系不大，而与上皮细胞的分化状态有关。此外，结果还显示了所采用的综合了阳性反应程度及细胞阳性率两方面含义的定量指标—阳性指数（ＰＩ）的可靠性和精确性。     

Endothelium-dependent contractions occur in the aorta of wild-type and COX2-/- knockout but not COX1-/- knockout mice

The present experiments were designed to determine whether or not endothelium-dependent contractions can be evoked in the aorta of the mouse, and if so, whether or not deleting the COX1 gene affects the response. Sex differences in the response were also examined. Rings of murine aorta were suspended in a Halpern-Mulvany myograph for recording of isometric force. In the aorta of the male wild type C57BL/b6 mice (36-40 weeks old), both acetylcholine and the calcium ionophore caused endothelium-dependent increases in force in the presence of L-NAME, and these were inhibited by valeryl salicylate (a selective COX1 inhibitor) and S18886 (a selective antagonist of TP receptors). Such endothelium-dependent contraction was absent in the aorta of COX1 knockout mice and present in that of COX2 knockout mice. Similar results were obtained in aortas of female wild-type, COX2 and COX1 knockout mice. These experiments reveal the existence of EDCF-mediated contractions in arteries of the mouse. These contractions, as in the aorta of the spontaneously hypertensive rat, are caused by endogenous agonists(s) of TP receptors produced by cyclooxygenase 1, because they are observed in the aortas of COX2 knockout mice but not in aortas of COX1 knockout mice. The present study provides direct evidence that COX1 is indeed the isoform of cyclooxygenase responsible for the production of EDCF.     

Inhaled fluticasone in bronchiectasis: a 12 month study

BACKGROUND: The clinical efficacy of inhaled corticosteroid (ICS) treatment has not been evaluated in bronchiectasis, despite the presence of chronic airway inflammation. METHODS: After three consecutive weekly visits, 86 patients were randomised to receive either fluticasone 500 mug twice daily (n = 43, 23F, mean (SD) age 57.7 (14.4) years) or matched placebo (n = 43, 34F, 59.2 (14.2) years) and reviewed regularly for 52 weeks in a double blind fashion. RESULTS: 35 and 38 patients in the fluticasone and placebo groups completed the study. Significantly more patients on ICS than on placebo showed improvement in 24 hour sputum volume (OR 2.5, 95% CI 1.1 to 6.0, p = 0.03) but not in exacerbation frequency, forced expiratory volume in 1 second, forced vital capacity, or sputum purulence score. Significantly more patients with Pseudomonas aeruginosa infection receiving fluticasone showed improvement in 24 hour sputum volume (OR 13.5, 95% CI 1.8 to 100.2, p = 0.03) and exacerbation frequency (OR 13.3, 95% CI 1.8 to 100.2, p = 0.01) than those given placebo. Logistic regression models revealed a significantly better response in sputum volume with fluticasone treatment than with placebo among subgroups of patients with 24 hour sputum volume <30 ml (p = 0.04), exacerbation frequency 5 (p = 0.03). CONCLUSIONS: ICS treatment is beneficial to patients with bronchiectasis, particularly those with P. aerurginosa infection.     

Alteration of apoptosis in cleft palate formation and ectomesenchymal stem cells influenced by retinoic acid

It has been shown that apoptosis is involved in normal embryonic development. The aim of the present study was to elucidate the role and alteration of apoptosis in the pathogenesis of cleft palate induced by retinoic acid (RA) and the ectomesenchymal stem (EMS) cells influenced by RA. RA was administered by gavage to pregnant C57BL/6N strain mice in the experimental group, and the control group received oil alone. Pregnant mice were killed at set periods of time thereafter and histologically analyzed. EMS cells explanted from the palatal shelves of embryonic mice were cultured and characterized by immunohistochemistry, growth curves and population-doubling time. The alterations of apoptosis of EMS cells and developing palatal shelves influenced by RA were evaluated by the terminal deoxynucleotidyl transferase-mediated UTP-biotin nick end-labeling (TUNEL) method. RA-treated mice showed formation of cleft palates resulted from the small size of the palatal shelves and their failure to lift. TUNEL staining showed that the number of apoptotic mesenchymal cells in palatal shelves in the RA-treated mice was increased significantly when compared with the control group. The primary culture of EMS cells proceeded successfully. The population-doubling time of RA-treated cells was much longer compared with non-treated EMS cells. RA also dramatically increased the number of apoptotic cells in EMS cells in vitro. We concluded that EMS cells are the crucial cells in palate development. RA could inhibit the proliferation and induced the apoptosis of EMS cells. The inhibition of growth and excess apoptosis of EMS cells may contribute to the formation of cleft palate and other orofacial congenital malformations.     

Expression of HIF-1alpha, VEGF and VEGF receptors in the carotid body of chronically hypoxic rat

We examined the protein expression and localization of HIF-1alpha, VEGF, VEGF receptors in the carotid body (CB) of rats breathing 10% inspired oxygen for up to 4 weeks. The immunoreactivity (IR) of HIF-1alpha was distributed numerously in the nuclei of glomus (type-I) and other cells since hypoxia for 1 day, but was faint and scattered in the normoxic CBs. Cytoplasmic staining of the VEGF was intense in glomus cells of the hypoxic but not the normoxic group. The IR levels of HIF-1alpha and VEGF reached plateau at 4 weeks, and the IRs of VEGFR-1 and VEGFR-2 were strongly positive in the hypoxic group. Yet, the expression of VEGFR-1-IR was mild, whereas the VEGFR-2-IR was intense in normoxic CBs, suggesting an upregulation of VEGFR-1 but not VEGFR-2 in hypoxia. Hence, HIF-1 may activate the expression of VEGF and VEGFR-1 in the CB and the expression of VEGF in the chemoreceptors may play a paracrine role in the vascular remodeling during chronic hypoxia.     

Ciliary assessment in bronchiectasis

Bronchiectasis is a common condition among the Oriental population and affected patients suffer from chronic sputum production punctuated by recurrent infective exacerbations. Cilia are minute structures present on the surface of respiratory and other epithelial cells that beat continuously to maintain a sterile mucosal surface in the respiratory tract. Patients with primary ciliary dyskinesia could potentially develop recurrent sinotrachrobronchitis, bronchiectasis, serous otitis media, hydrocephalus, and male infertility. The assessment of cilia has, however, received little attention until recently and generally involves elaborate methods that require complex and expensive technology. This brief article discusses application of the saccharine test, light microscopy assessment of ciliary beat, and transmission electron microscopy assessment of the ultrastructure of cilia. The rationale and indications for ciliary assessment are also listed along with illustrations showing ciliary structure, equipment required for sampling and assessment of cilia, and transmission electron micrographs of ciliary ultrastructural abnormalities.     

Techniques for rapid quantitative assessment of activity levels in small-group tutorials

Two techniques for the rapid quantitative analysis of student participation in small-group teaching were investigated. In the first approach an observer, who also acted as a `critical friend', recorded the length of individual contributions using a computer keyboard as a simple timing device. In the second approach, small-group sessions were recorded with a portable stereophonic audiotape recorder. The teacher was recorded on one channel, all students on the other. A computer program produced automated analysis of these small group interactions by computing relative amount of speech on each channel. Simple analysis produced automatically by the programs revealed the overall style of the tutorial – variably `mini-lectures' by teachers with very little participation by the student body, rapid `question and answer' sessions with about equal teacher/student body involvement or `mini-presentations' by students with the teacher offering sparse comments in the manner of a facilitator. By presenting results in a graphic format, teachers can be given rapid objective feedback on their teaching style. Coupled with short verbal/non-verbal quizzes at the end of tutorials and information from other assessments, the value of using levels of participation as a measure of the efficiency of such small-group sessions can itself be assessed.