Induced pluripotent stem cells (iPSC) are derived from human somatic cells through ectopic expression of transcription factors. This landmark discovery has been considered as a major development towards patient-specifi c iPSC for various biomedical applications. Unlimited self renewal capacity, pluripotency and ease of accessibility to donor tissues contribute to the versatility of iPSC. The therapeutic potential of iPSC in regenerative medicine, cell-based therapy, disease modelling and drug discovery is indeed very promising. Continuous progress in iPSC technology provides clearer understanding of disease pathogenesis and ultimately new optimism in developing treatment or cure for human diseases.

Background/Aims: Differential diagnosis between aggressive osteoblastoma and low grade osteosarcoma may be very diffi cult or even impossible on a small biopsy. This study was designed to assess the usefulness of immunoexpression of COX-2 and osteocalcin in the differential diagnosis of the two tumour types. Methods: Immunostaining of COX 2 and osteocalcin were studied in 9 osteoblastomas and 30 osteosarcomas. Results: All osteoblastomas and 11/20 (55%) high-grade osteosarcomas showed COX-2 immunoreactivity. All low grade osteosarcomas were COX-2 negative. COX-2 was signifi cantly higher (p<0.002) in osteoblastomas 9/9 (100%) than in osteosarcomas 13/30 (43%) and in aggressive osteoblastomas versus low grade osteosarcomas (p<0.01). Osteocalcin was found in tumour cells of all osteosarcomas and osteoblastomas and in the osteoid matrix of 84% of osteosarcomas and 78% of osteoblastomas. Strong osteocalcin was signifi cantly higher (p<0.02) in osteoblastomas (78%) than in osteosarcomas (27%). Conclusion: COX-2 is a valuable marker in distinction between osteosarcoma and osteoblastoma. Negative COX-2 could confi rm the diagnosis of low grade osteosarcoma versus aggressive osteoblastoma. Intensity and distribution of osteocalcin may indicate the degree of osteoblastic differentiation.

CD133, a marker which has been advocated to mark colorectal carcinoma “stem or tumour initiating cells” is amongst the frequently studied markers in colorectal cancer. A study was conducted at the Department of Pathology, University of Malaya Medical Centre to determine the expression of CD133 in 56 archived, formalin-fi xed, paraffi n-embedded colorectal adenocarcinoma in comparison with adjacent benign colorectal epithelium by immunohistochemical staining for CD133 expression. CD133 immunopositivity was determined as staining at the glandular luminal surface or in the intraluminal debris. Expression was semiquantitated for (1) proportion of CD133 immunopositivity in the malignant or adjacent benign colorectal epithelium and (2) intensity of staining. The fi nal score of CD133 immunopositivity was arbitrarily taken as proportion of CD133 immunopositivity multiplied by intensity of staining in both the malignant and adjacent benign colorectal epithelium.CD133 expression was observed in signifi cantly increased frequency in 49 (87.5%) colorectal adenocarcinoma compared with 15 (26.8%) of the adjacent benign colorectal epithelium (p<0.05). In terms of immunopositivity score (proportion of CD133 immunopositivity multiplied by intensity of staining), colorectal adenocarcinoma had a mean arbitrary score of 8.5 which was signifi cantly higher than the mean immunopositivity score of 0.5 of the adjacent benign colorectal epithelium (p<0.05). In addition, the maximum immunopositivity score for the adjacent benign colorectal epithelium was 4, while 38 (67.9%) of colorectal adenocarcinoma had scores >4. This study shows that CD133 is able to mark colorectal adenocarcinoma but it is still unclear at this juncture whether CD133 is indeed a marker for colorectal adenocarcinoma “stem cells”.

Infection with Helicobacter pylori cagA-positive strains is associated with gastroduodenal diseases. The CagA protein is injected into gastric epithelial cells and supposedly induces morphological changes termed the ‘hummingbird phenotype’, which is associated with scattering and increased cell motility. The molecular mechanisms leading to the CagA-dependent morphological changes are only partially known. The present study was carried out to investigate the effect of CagA variants on the magnitude of gastric epithelial cell morphological changes. Recombinant 3’ terminal domains of cagA were cloned and expressed in a gastric epithelial cell line and the hummingbird phenotype was quantifi ed by microscopy. The 3’ region of the cagA gene of Malaysian H. pylori isolates showed six sub-genotypes that differed in the structural organization of the EPIYA repeat sequences. The percentage of hummingbird cells induced by CagA increased with duration of transfection. The hummingbird phenotype was observed to be more pronounced when CagA with 4 EPIYA motifs rather than 3 or 2 EPIYA motifs was produced. The activity of different CagA variants in the induction of the hummingbird phenotype in gastric epithelial cells depends at least in part on EPIYA motif variability. The difference in CagA genotypes might infl uence the potential of individual CagAs to cause morphological changes in host cells. Depending on the relative exposure of cells to CagA genotypes, this may contribute to the various disease outcomes caused by H. pylori infection in different individuals.

Serotyping is not suffi cient to differentiate between Salmonella species that cause paratyphoid fever from the strains that cause milder gastroenteritis as these organisms share the same serotype Salmonella Paratyphi B (S. Paratyphi B). Strains causing paratyphoid fever do not ferment d-tartrate and this key feature was used in this study to determine the prevalence of these strains among the collection of S. Paratyphi B strains isolated from patients in Malaysia. A total of 105 isolates of S. Paratyphi B were discriminated into d-tartrate positive (dT+) and d-tartrate negative (dT-) variants by two lead acetate test protocols and multiplex PCR. The lead acetate test protocol 1 differed from protocol 2 by a lower inoculum size and different incubation conditions while the multiplex PCR utilized 2 sets of primers targeting the ATG start codon of the gene STM3356. Lead acetate protocol 1 discriminated 97.1% of the isolates as S. Paratyphi B dT+ and 2.9% as dT- while test protocol 2 discriminated all the isolates as S. Paratyphi B dT+. The multiplex PCR test identifi ed all 105 isolates as S. Paratyphi B dT+ strains. The concordance of the lead acetate test relative to that of multiplex PCR was 97.7% and 100% for protocol 1 and 2 respectively. This study showed that S. Paratyphi B dT+ is a common causative agent of gastroenteritis in Malaysia while paratyphoid fever appears to be relatively uncommon. Multiplex PCR was shown to be a simpler, more rapid and reliable method to discriminate S. Paratyphi B than the phenotypic lead acetate test.

Molecular pathogenesis of chronic myeloid leukemia (CML) is well established and molecular monitoring for patients with CML has become an important practice in the management of patients on imatinib therapy. In the present study, we report the use of RQ-PCR method for detection of BCR-ABL fusion gene for our CML cases. We performed a two-step RQ-PCR on bone marrow aspirates or peripheral blood of 37 CML patients. Quantitative expression of BCR-ABL fusion gene was carried out relative to the expression of a housekeeping gene as endogenous control to compensate for uneven cell numbers, RNA quality, or variations in reverse transcription effi ciencies. Twenty-four of these patients were pre-treated with hydroxyurea or alpha interferon prior to the imatinib therapy. Their BCR-ABL fusion gene levels were monitored for 18 months. All samples processed were evaluable. The PCR amplifi cation effi ciency of the ABL gene is 90.5% (0.2158) and the BCR-ABL gene, 93.4% (0.1573).

Background: The role of oxygen free radicals in the initiation, promotion and progression of carcinogenesis and the protective role of anti-oxidant defenses have been the subject of much speculation in the recent past with confl icting reports in the literature. Objectives: The aim of this study was to measure the concentration/levels of serum total proteins, albumin and advanced oxidation protein products as markers of oxidative stress in sera of patients with an oral pre-cancerous lesion and frank oral cancer. Materials and methods: The study consisted of sera analysis of 30 new patients of histologically proven well-differentiated, oral squamous cell carcinoma and 10 patients, clinically diagnosed with a potentially malignant epithelial lesion, speckled leukoplakia, aged between 40 to 60 years, in addition to 25 healthy controls. One way analyses of variance were used to test the difference between groups. The normality of data was checked before the statistical analysis was performed. Results: The study revealed variations in sera levels of albumin and advanced oxidation protein products to be statistically signifi cant (p < 0.001). Conclusion: The results obtained emphasize the need for more studies with larger sample sizes to be conducted before a conclusive role could be drawn in favour of sera levels of total protein, albumin and advanced oxidation protein products as markers of diagnostic signifi cance and of the transition from the various oral pre-cancerous lesions and conditions into frank oral cancers.

We present a case of a papillary tumour at the cerebellopontine angle in a 41-year-old man. He presented with left-sided facial and ear pain associated with dizziness, nystagmus and hearing loss. CT scan of the temporal bone showed a destructive tumour at the left cerebellopontine angle. Surgical excision was performed and the diagnosis of the endolymphatic sac tumour was made. Endolymphatic tumour is a low grade adenocarcinoma that originates from the endolymphatic sac. The defi nitive diagnosis requires a combination of clinical features, radiological fi nding and pathological correlation.

Haemoglobin Constant Spring (Hb CS) mutation and single gene deletions are common underlying genetic abnormalities for alpha thalassaemias. Co-inheritance of deletional and non-deletional alpha (α) thalassaemias may result in various thalassaemia syndromes. Concomitant co-inheritance with beta (β) and delta (δ) gene abnormalities would result in improved clinical phenotype. We report here a 33-year-old male patient who was admitted with dengue haemorrhagic fever, with a background history of Grave’s disease, incidentally noted to have mild hypochromic microcytic red cell indices. Physical examination revealed no thalassaemic features or hepatosplenomegaly. His full blood picture showed hypochromic microcytic red cells with normal haemoglobin (Hb) level. Quantitation of Hb using high performance liquid chromatography (HPLC) and capillary electrophoresis (CE) revealed raised Hb F, normal Hb A2 and Hb A levels. There was also small peak of Hb CS noted in CE. H inclusions was negative. Kleihauer test was positive with heterocellular distribution of Hb F among the red cells. DNA analysis for α globin gene mutations showed a single -α-3.7 deletion and Hb CS mutation. These fi ndings were suggestive of compound heterozygosity of Hb CS and a single -α-3.7 deletion with a concomitant heterozygous δβ thalassaemia. Co-inheritance of Hb CS and a single -α-3.7 deletion is expected to result at the very least in a clinical phenotype similar to that of two alpha genes deletion. However we demonstrate here a phenotypic modifi cation of α thalassemia presumptively as a result of co-inheritance with δβ chain abnormality as suggested by the high Hb F level.

Renal cell carcinoma (RCC) metastases to the pancreas are reported to be rare. Isolated multiple pancreatic metastases are even rarer. We report a 68-year-old asymptomatic male patient who presented with multiple metastatic nodular lesions in the pancreas demonstrated by computerized tomography 3.5 years after radical nephrectomy performed for clear cell RCC. Spleen-preserving total pancreatectomy was performed. Gross examination revealed fi ve well-demarcated tumoral nodules in the head, body and tail of the pancreas. Histopathological examination revealed clusters of epithelial clear cells, immunohistochemically positive for CD10 and vimentin, and negative for CK19 and chromogranin, supporting a diagnosis of metastatic RCC. The patient has remained well at 29 months post-resection, in agreement with recent experience that radical resection for multiple isolated metastatic nodular lesions can achieve improved survival and better quality of life.