Concordant childhood acute lymphoblastic leukemia in monozygotic twins

Two 4-year-old monozygotic Chinese, female twins developed concordant childhood acute lymphoblastic leukemia (ALL) within an interval of about 2 weeks. Based on morphology and cytochemistry findings of the bone marrow blast cells, a diagnosis of ALL, L1 was made. Immunophenotyping showed the blast cells of both twins expressed similar antigens, i.e. HLA-DR, CD10, CD13, CD19, CD22 and CD34. Identical blood group, same HLA (human leucocyte antigen) genotype, sex and similar appearance suggest that the twins are monozygotic. Since the bone marrow leukemic cells of both twins were identical in morphology and expressed the same antigens with almost similar percentages of positivity, it is likely that the blast cells were derived from the same single clone. Based on the single clone hypothesis, the leukemogenic event must have arisen in utero in one twin and the cells from the abnormal clone then spread to the other twin via shared placental anastomoses.     

Establishing and managing a periodontal biobank for research: the sharing of experience

Periodontal bio‐repositories, which allow banking of clinically validated human data and biological samples, provide an opportunity to derive biomarkers for periodontal diagnosis, prognosis and therapeutic activities which are expected to improve patient management. This article presents the establishing of the Malaysian Periodontal Database and Biobank System (MPDBS) which was initiated in 2011 with the aim to facilitate periodontal research. Partnerships were established with collaborating centres. Policies on specimen access, authorship and acknowledgement policies were agreed upon by all participating centres before the initiation of the periodontal biobank. Ethical approval for the collection of samples and data were obtained from institutional ethics review boards. A broad‐based approach for informed consent was used, which covered areas related to quality of life impacts, genetics and molecular aspects of periodontal disease. Sample collection and processing was performed using a standardized protocol. Biobanking resources such as equipment and freezers were shared with the Malaysian Oral Cancer Database and Tissue Bank System (MOCDTBS). In the development of the MPDBS, challenges that were previously faced by the MOCDTBS were considered. Future challenges in terms of ethical and legal issues will be faced when international collaborations necessitate the transportation of specimens across borders.     

Work function modification of PEDOT:PSS by mixing with barium acetylacetonate

Poly(3,4-ethylenedioxythiophene)polystyrene sulfonate (PEDOT:PSS) is often used as a hole injection and extractor for various organic electronic devices. This study investigated whether it is possible to n-dope PEDOT:PSS with barium acetylacetonate (Ba(acac)₂) to change its work function so that to be more suitable for electron injection and extraction. Molecular dynamics simulations suggested that barium cations can interact with the aromatic rings of PEDOT and the negatively charged sulfonate in PSS. At high doping concentration, we found that PEDOT became dedoped and precipitated resulting in a clear solution after filtration. The absence of the absorption peak of PEDOT at 263 nm indicates the removal of PEDOT after filtration. The shift in O 1s to a lower binding energy as seen in X-ray photoelectron spectroscopy suggested that the polystyrene sulfonic acids are being ionized to form barium polystyrene sulfonate (Ba–PSS). By spin-coating the solution on top of indium tin oxide, the work function can be adjusted to as low as 3.6 eV. The ability of such a mixture to inject and extract electrons is demonstrated using 2,7-bis(diphenylphosphoryl)-9,9′-spirobifluorene as an electron transporting layer. We attributed the lowering of the work function as the result of the formation of an interfacial dipole as large as 1.37 eV at the ITO/Ba–PSS interface.

Modification of poly(3,4-ethylenedioxythiophene)polystyrene sulfonate as electron injection layer.     

Immunity in young adult survivors of childhood leukemia is similar to the elderly rather than age‐matched controls: Role of cytomegalovirus

Many treatment complications that occur late in childhood cancer survivors resemble age‐related comorbidities observed in the elderly. An immune phenotype characterized by increased immune activation, systemic inflammation, and accumulation of late‐differentiated memory CD57⁺CD28^? T cells has been associated with comorbidities in the elderly. Here, we explored if this phenotype was present in young adult leukemia survivors following an average of 19 years from chemotherapy and/or radiotherapy completion, and compared this with that in age‐matched controls. We found that markers of systemic inflammation—IL‐6 and human C‐reactive protein and immune activation—CD38 and HLA‐DR on T cells, soluble CD (sCD)163 from monocytes and macrophages—were increased in survivors compared to controls. T‐cell responses specific to cytomegalovirus (CMV) were also increased in survivors compared to controls while CMV IgG levels in survivors were comparable to levels measured in the elderly (>50years) and correlated with IL‐6, human C‐reactive protein, sCD163, and CD57⁺CD28^? memory T cells. Immune activation and inflammation markers correlated poorly with prior chemotherapy and radiotherapy exposure. These data suggest that CMV infection/reactivation is strongly correlated with the immunological phenotype seen in young childhood leukemia survivors and these changes may be associated with the early onset of age‐related comorbidities in this group.     

Clinical features and treatment outcome of children with myeloid antigen coexpression in B-lineage acute lymphoblastic leukemia: a study of 151 Malaysian children

The purpose of the study was to evaluate the incidence of myeloid antigen coexpression and its prognostic significance in childhood acute lymphoblastic leukemia (ALL) in Malaysia. A retrospective study was conducted of all ALL cases (< or = 12 years old) diagnosed and treated in University Hospital, Kuala Lumpur, Malaysia between 1 January 1992 and 30 May 1995, with available immunophenotype data. Presenting features and treatment outcome of 39 B-lineage ALL patients with myeloid antigen coexpression (My+B) were compared with 112 B-lineage ALL patients without myeloid antigen coexpression (My-B) for similarity in demographic, clinical and laboratory features and their treatment outcome. My+B and My-B patients were treated with a uniform treatment protocol. Myeloid antigen coexpression was defined as more than 30% isolated leukemic cells positive for CD13 and/or CD33. The ages at diagnoses ranged from 2 months to 12 years. Median age was 4 years. The incidence of myeloid antigen coexpression was 23 per cent. Univariate analyses showed that presenting features were similar between My+B and My-B with regard to age, sex, race, FAB morphology, white cell count, hemoglobin level, platelet count, liver/spleen size, central nervous system or mediastinal involvement, presence of lymphadenopathy, and proportion of blast cells detected in the marrow. Treatment outcome were not significant between the two groups. The 2-year event free survival was achieved in 44 per cent of My+B and 57 per cent of My-B (p = 0.11). The 2-year overall survival rates were 62 per cent for My+B vs. 77 per cent for My-B (p = 0.08). This study demonstrates that myeloid antigen coexpression is fairly common and constitutes 23 per cent of childhood ALL within the Malaysian population and that it is not an adverse risk factor in childhood ALL.     

Pattern of Epstein-Barr virus association in childhood non-Hodgkin's lymphoma: experience of university of malaya medical center

The pattern of childhood non-Hodgkin's lymphoma (NHL) usually differs in adults. The most common subtypes are lymphoblastic, Burkitt's and anaplastic large cell lymphoma. Recent data indicate that a higher risk of developing lymphoma is associated in children of certain ethnic origins. The difference is probably related to the underlying etiological factors of these diseases, and Epstein-Barr virus (EBV) is a strong candidate. The present study aims to determine the disease pattern of childhood lymphomas in the University Hospital Kuala Lumpur, for a direct comparison to the reported data of adults from the same medical center. A total of 69 and 34 childhood NHL and Hodgkin's lymphomas, respectively, were retrieved. The most common subtypes were lymphoblastic (23 cases), Burkitt's (25 cases) and anaplastic large cell lymphomas (9 cases). Epstein-Barr virus association was more prevalent in B-cell (23%) than T-cell (12%) lymphomas. The most common EBV-associated tumor was Burkitt's lymphoma, and there was an increased risk of EBV association for Burkitt's lymphoma in Chinese patients. In conclusion, the pattern of childhood lymphoma in Malaysia is relatively similar to children elsewhere in the world. The EBV association of B- and T-NHL differs between children and adults from the same medical center because of differences in the subtype composition in these two age groups.     

Successful treatment of Candida albicans endocarditis in a child with leukemia--a case report and review of the literature

Candida species is now being increasingly recognised as an important cause of endocarditis especially in immunocompromised patients. A case of Candida albicans endocarditis in a child with acute lymphoblastic leukemia (ALL) is reported. The child did not have a central venous catheter at any time. Treatment consisted of intravenous amphotericin B and fluconazole for 3 weeks followed by oral fluconazole for 2 weeks. No surgical resection was necessary. We highlight here the importance of echocardiography in the management of prolonged febrile neutropenia and discuss the dilemma of continuing chemotherapy in such patients.     

An unceasing problem: soil-transmitted helminthiases in rural Malaysian communities

Despite great development in socioeconomic status throughout 50 years of independence, Malaysia is still plagued with soil-transmitted helminthiases (STH). STH continue to have a significant impact on public health particularly in rural communities. In order to determine the prevalence of STH among rural Orang Asli children and to investigate the possible risk factors affecting the pattern of this prevalence, fecal samples were collected from 292 Orang Asli primary schoolchildren (145 males and 147 females) age 7-12 years, from Pos Betau, Kuala Lipis, Pahang. The samples were examined by Kato-Katz and Harada Mori techniques. Socioeconomic data were collected using pre-tested questionnaires. The overall prevalence of ascariasis, trichuriasis, and hookworm infections were 67.8, 95.5 and 13.4%, respectively. Twenty-nine point eight percent of the children had heavy trichuriasis, while 22.3% had heavy ascariasis. Sixty-seven point seven percent of the children had mixed infections. Age > 10 years (p = 0.016), no toilet in the house (p = 0.012), working mother (p = 0.040), low household income (p = 0.033), and large family size (p = 0.028) were identified as risk factors for ascariasis. Logistic regression confirmed low income, no toilet in the house and working mother as significant risk factors for ascariasis. The prevalence of STH is still very high in rural Malaysian communities. STH may also contribute to other health problems such as micronutrient deficiencies, protein-energy malnutrition and poor educational achievement. Public health personnel need to reassess current control measures and identify innovative and integrated ways in order to reduce STH significantly in rural communities.