Comparison of the HbH inclusion test and a PCR test in routine screening for α thalassaemia in Hong Kong

Aim - To compare the haemoglobin (Hb) H inclusion test with a polymerase chain reaction CPCR) test in routine screening for or thalassaemia. Methods - Ninety nine peripheral blood samples from Chinese patients with mean corpuscular volume below 80fl were screened for a thalassaemia using the HbH inclusion test and by PCR utilising primers bridging the common deletion breakpoint of the South East Asian (--SEA/) deletion. Results - The HbH inclusion test was positive in 78 (79%) patients, 73 (93.7%) of whom carried the (--SEA/) deletion on analysis of their DNA by PCR, as did one patient with a negative HbH inclusion test. Conclusions - These results suggest that in areas with a high prevalence of the (--SEA/) deletion, such as Hong Kong, the HbH inclusion test can be replaced by PCR as the investigation of choice in screening for a thalassaemia.published_or_final_versio

「問題導向學習」教案之品質改善：香港大學醫學院一年級生之經驗與回饋

To improve the quality of paper cases used for problem-based learning in the medical curriculum of the University of Hong Kong, Year 1 students were asked at the end of the year to fill in a questionnaire which addresses specific issues related to problem based learning. In addition, for each of the 6 new cases of PBL which were introduced into the first year, tutorials groups were asked to rate which of the learning objectives as specified in the cased were covered under the 4 themes: Biology of Health and Disease (Knowledge Component); Doctors and Patients (Clinical and communication Skills); Medicine and the Community (Societal and Population Medicine) and Professional Development (Medical Ethics and Law). Over eighty percent of the students found the PBL process to facilitate self directed learning and contributed to their learning. Over forty percent found there was unequal representation of the 4 themes with the issue of Professional Development to be the most inadequately covered. Various factors can be identified for the under representation and inadequate coverage of professional development issues. Possible solutions may include case modifications to ensure a fairer balance of 4 themes, alternative formats of enhancing the discussion of professional development issues, tutor training and coaching the students to address professional development issues

The person behind the white coat: building a medical humanities core curriculum for medical students

E-posterCONTEXT: In a healthcare environment increasingly overwhelmed by new technology, commercialism and efficiency, which leaves patients lost, unheard and discontented, medical schools are seeking to bring balance to their curricula. The introduction of the medical humanities (or health humanities) can help to broaden the understanding of the human condition – a necessity for those in the caring professions. INTERVENTION: Following four years of pilot work, a Medical Humanities Planning Group was formed to design and implement a six-year compulsory medical humanities programme for medical students. Using an outcomes-based approach to student learning, the curriculum was built around five themes - narrative medicine, culture, spirituality and healing, history of medicine, death, dying and bereavement, and humanitarianism. We present our experience of the first year of the curriculum which took place from September 2012 – May 2013 in which students explored “the person behind the white coat” through reading and writing, performance, visual arts and film. OBSERVATIONS: A variety of reflective tasks, including creative artwork and performing a re-imagined script, students enabled students to demonstrate their understanding of “the person behind the white coat.” The contribution of colleagues from all disciplines in the medical faculty, the university at large and community partners was instrumental to the success of the first year programme. DISCUSSION: A medical humanities curriculum has meaning if it is a compulsory part of the core curriculum and is assessed. It can be sustainable with a broad base of teaching support.postprin

Cytokine combinations on the potential of Ex Vivo expansion of murine hematopoietic stem cells

Local Scholarship Awardees - Poster Sessions: no. 9DMM 2011 entitled: Re-engineering Regenerative MedicineThe limited number of hematopoietic stem cell (HSC) in human bone marrow and cord blood has led to experimental approaches using cytokines for ex vivo expansion of HSC. Here, we studied the expansion of murine hematopoietic stem cells with different cytokine combinations and characterized the hematopoietic gene expression profile of expanded cells, aiming to facilitate the development of optimal HSC culture condition. Murine HSC with immunophenotype Lineage-Sca-1+c-Kit+ (LSK) were cultured in five different cytokine combinations ...postprin

Comparison of haemoglobin H inclusion bodies with embryonic ζ globin in screening for α thalassaemia

Aims - To compare the haemoglobin (Hb) H inclusion test with immunocytochemical detection of embryonic ζ chains in screening for a thalassaemia. Methods - Blood samples from 115 patients with relevant clinical history and hypochromic microcytic indexes were screened using the HbH inclusion test and the Variant Hemoglobin Testing System (BioRad, Hercules, CA, USA). Results - The HbH inclusion test was positive in 61 of 115 cases, three of whom had HbH disease confirmed by electrophoresis. The remaining 58 had α thalassaemia 1. All three HbH cases and 56 of 58 cases of a thalassaemia 1 expressed embryonic ζ chains, giving a specificity of 96.7%. Fifty four of 115 cases had a negative HbH inclusion test, of whom 50 had β thalassaemia trait and three had iron deficiency. No diagnosis was reached for the remaining patient. Conclusion - The immunocytochemical test is as sensitive as the HbH inclusion test in screening for a thalassaemia. The presence of ζ chains is highly specific for a thalassaemia I incorporating the (--/SEA) deletion. The specificity and simplicity of the immunocytochemical test make it the test of choice in screening for α thalassaemia.published_or_final_versio

Heating performance improvement and field study of the induction cooker

Author name used in this publication: K. W. E. ChengAuthor name used in this publication: K. W. ChanRefereed conference paper2008-2009 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe

N-ras mutations in myelodysplastic syndromes in Hong Kong Chinese

Hong Kong Chinese patients with myelodysplastic syndromes were screened for the presence of N-ras mutation by using the polymerase chain reaction/dot blot hybridization technique. Three of 20 (15%) cases studied were found to harbour mutant N-ras in the bone marrow mononuclear cell population. One case of refractory anaemia with excess of blasts and with excess of blasts in transformation had substitution of arginine for glutamine at codon 61. A second case of refractory anaemia with excess of blasts had substitution of serine for glycine at codon 12. In this patient, mutant N-ras was detected in a follow up sample taken two months later although there was no change in the blast percentage compared with the presentation sample. Our study showed that N-ras mutation is an infrequent finding in Hong Kong Chinese myelodysplastic syndrome patients. An N-ras mutation is not necessarily accompanied by an alteration in the haematological picture.published_or_final_versio

Derivative chromosome 9 deletions in chronic myeloid leukaemia: Interpretation of atypical D-FISH pattern

Background/Aims: New molecular cytogenetic techniques are increasingly applied as a routine investigative tool in haematological malignancies, both at diagnosis and subsequent monitoring. This report describes the interpretation of atypical signal patterns encountered using BCR-ABL dual colour dual fusion fluorescence in situ hybridisation (D-FISH) translocation probes in chronic myeloid leukaemia (CML). Methods: Interphase FISH experiments were carried out using BCR-ABL D-FISH probes in 46 patients with CML at diagnosis and during subsequent disease monitoring. Atypical hybridisation signal patterns were characterised by molecular cytogenetic techniques and correlated with conventional karyotyping. Results: Two patients showed atypical interphase D-FISH patterns with one orange, one green, and one fusion (1O1G1F) signal. The presence of BCR-ABL gene fusion was documented by a dual colour single fusion (S-FISH) probe. The submicroscopic deletion of the ABL-BCR fusion gene on the derivative chromosome 9 in these cases was subsequently characterised by metaphase FISH on relocated G banded metaphases. Conclusions: Atypical interphase D-FISH patterns should not be interpreted in isolation and should be considered in conjunction with other cytogenetic or molecular genetic investigations.published_or_final_versio

Detection and characterisation of β-globin gene cluster deletions in Chinese using multiplex ligationdependent probe amplification

Background: Deletions in the β-globin cluster causing thalassaemia and hereditary persistence of fetal haemoglobin (HPFH) are uncommon and difficult to detect. Data in Chinese are very scarce. Aims: To use a recently available technique to investigate the frequencies and nature of β-globin cluster deletions in Chinese. Methods: 106 subjects with phenotypes of thalassaemia or HPFH and suspected to have deletions in the β-globin cluster were studied. A commercially available kit employing multiplex ligation-dependent probe amplification (MLPA) was used to screen for deletions. Gap PCR and direct nucleotide sequencing were used to characterise deletions detected. Results: 17 deletions in the β-globin cluster were found in 17 patients: 8 of Chinese (Aγδβ)0 thalassaemia, 7 of Southeast Asian (Vietnamese) deletion and 2 of Thai (Aγδβ) 0 thalassaemia. The only type of deletion detected in δβ-thalassaemia was Chinese (Aγδβ) 0 thalassaemia. The deletional form of HPFH was rarely seen in only 1 case of Thai (Aγδβ)0 thalassaemia. Deletions presenting as β-thalassaemia trait and raised HbF were all of the Southeast Asian (Vietnamese) deletion type. When these deletions were co-inherited with classical β-thalassaemia mutations in compound heterozygous states, the phenotypes could be very variable. Conclusions: In the Chinese population, there are only relatively few types of deletions seen in the β-globin cluster. MLPA is a fast and effective way of screening for these deletions. Characterisation of these deletions allows the development of simpler and more specific PCR-based tests for routine diagnostic use. Accurate prediction of phenotype is not always feasible. The molecular defects in many cases of HPFH still await discovery.published_or_final_versio

Structural and Functional Brain Remodeling during Pregnancy with Diffusion Tensor MRI and Resting-State Functional MRI

Although pregnancy-induced hormonal changes have been shown to alter the brain at the neuronal level, the exact effects of pregnancy on brain at the tissue level remain unclear. In this study, diffusion tensor imaging (DTI) and resting-state functional MRI (rsfMRI) were employed to investigate and document the effects of pregnancy on the structure and function of the brain tissues. Fifteen Sprague-Dawley female rats were longitudinally studied at three days before mating (baseline) and seventeen days after mating (G17). G17 is equivalent to the early stage of the third trimester in humans. Seven age-matched nulliparous female rats served as non-pregnant controls and were scanned at the same time-points. For DTI, diffusivity was found to generally increase in the whole brain during pregnancy, indicating structural changes at microscopic levels that facilitated water molecular movement. Regionally, mean diffusivity increased more pronouncedly in the dorsal hippocampus while fractional anisotropy in the dorsal dentate gyrus increased significantly during pregnancy. For rsfMRI, bilateral functional connectivity in the hippocampus increased significantly during pregnancy. Moreover, fractional anisotropy increase in the dentate gyrus appeared to correlate with the bilateral functional connectivity increase in the hippocampus. These findings revealed tissue structural modifications in the whole brain during pregnancy, and that the hippocampus was structurally and functionally remodeled in a more marked manner.published_or_final_versio