Single-Pot Rapid Synthesis of Colloidal Core/Core-Shell Quantum Dots: A Novel Polymer-Nanocrystal Hybrid Material

Colloidal core and core shell Quantum Dots (QD's) are unique and important optoelectronic materials because properties of these QD's can be tailored by configuring core and optimizing shell thickness. In this research work, lead selenide (PbSe) core and PbSe-CdSe (Core-shell) QD's are synthesized using oleic acid as a capping ligand by colloidal route. This simpler, cost-effective and rapid single pot synthesis route for colloidal core-shell quantum dots unlike conventional double-pot approach like cation-exchange and SILAR process has been reported for the very first time. Phase formation of prepared quantum dots is confirmed by XRD analysis, capping ligand presence by IR spectroscopy and morphological information by Scanning electron microscopy respectively. These synthesized inorganic quantum dots are dispersed in Poly (3-hexyl thiophene) polymer for formation of their respective nanocomposites. From PL quenching studies, it was inferred that PbSe-CdSe core-shell quantum dots showed enhanced rate of PL quenching and hence higher value of Stern-Volmer constant (K-SV) than PbSe Core QD's. This confirms that CdSe shell formation on PbSe core significantly passivates the core-surface, increases the stability and enhances the charge transfer mechanism for its potential application in Hybrid Solar cells

Clinical Factors Associated with Long-Term Complete Remission versus Poor Response to Chemotherapy in HIV-Infected Children and Adolescents with Kaposi Sarcoma Receiving Bleomycin and Vincristine: A Retrospective Observational Study

Kaposi sarcoma (KS) is the most common HIV-associated malignancy in children and adolescents in Africa. Pediatric KS is distinct from adult disease. We evaluated the clinical characteristics associated with long-term outcomes. We performed a retrospective observational analysis of 70 HIV-infected children and adolescents with KS less than 18 years of age diagnosed between 8/2010 and 6/2013 in Lilongwe, Malawi. Local first-line treatment included bleomycin and vincristine plus nevirapine-based highly active anti-retroviral therapy (HAART). Median age was 8.6 years (range 1.7-17.9); there were 35 females (50%). Most common sites of presentation were: lymph node (74%), skin (59%), subcutaneous nodules (33%), oral (27%), woody edema (24%), and visceral (16%). Eighteen (26%) presented with lymphadenopathy only. Severe CD4 suppression occurred in 28%. At time of KS diagnosis, 49% were already on HAART. Overall, 28% presented with a platelet count \u3c 100 x 109/L and 37% with hemoglobin \u3c 8 g/dL. The 2-year event-free (EFS) and overall survival (OS) were 46% and 58% respectively (median follow-up 29 months, range 15-50). Multivariable analysis of risk of death and failure to achieve EFS demonstrated that visceral disease (odds ratios [OR] 19.08 and 11.61, 95% CI 2.22-163.90 and 1.60-83.95 respectively) and presenting with more than 20 skin/oral lesions (OR 9.57 and 22.90, 95% CI 1.01-90.99 and 1.00-524.13 respectively) were independent risk factors for both. Woody edema was associated with failure to achieve EFS (OR 7.80, 95% CI 1.84-33.08) but not death. Univariable analysis revealed that lymph node involvement was favorable for EFS (OR 0.28, 95% CI 0.08-0.99), while T1 TIS staging criteria, presence of cytopenias, and severe immune suppression were not associated with increased mortality. Long-term complete remission is achievable in pediatric KS, however outcomes vary according to clinical presentation. Based on clinical heterogeneity, treatment according to risk-stratification is necessary to improve overall outcomes

Endemic Kaposi sarcoma in HIV-negative children and adolescents: an evaluation of overlapping and distinct clinical features in comparison with HIV-related disease

Abstract Background Endemic Kaposi sarcoma (KS) was first described in African children over fifty years ago, but has recently been overshadowed by HIV-related disease. We aimed to evaluate the similarities and differences between endemic HIV-negative and epidemic HIV-positive pediatric KS in a KS-associated herpesvirus-endemic region of Africa. Methods We describe clinical characteristics of 20 HIV-negative children with endemic KS over a six-year period and compare findings with a historical control—an HIV-related pediatric KS cohort from Lilongwe, Malawi. Results The HIV-negative endemic KS cohort was 70% male with a median age of 9.3 years. Lymph node involvement was present in 50%, hyperpigmented skin lesions in 45%, and woody edema in 40%. One patient (5%) presented with oral KS involvement and no patients presented initially with visceral KS. Significant anemia (hemoglobin < 8 g/dL) and thrombocytopenia (platelet count < 100 × 109/L) were found at time of original KS diagnosis in 45 and 40% respectively. In both HIV-negative and HIV-positive cohorts, lymphadenopathy was the most common presentation, prototypical skin lesions were often absent, severe cytopenias were a common clinical feature, and treatment outcomes were similar. Patients with endemic KS demonstrated less frequent oral involvement (5% versus 29%, P = 0.03) and a lower proportion of patients with visceral involvement (0% versus 16%, P = 0.06). Conclusions These data suggest clinical overlap between epidemiological variants. Treatment protocols for pediatric KS in sub-Saharan Africa should be devised to include both endemic HIV-negative and epidemic HIV-related disease to better define the clinical and biological comparison

Pediatric Cancer Recognition Training in Botswana

Delayed presentation of children with cancer is a significant barrier to improving the survival from children’s cancer in low- and middle-income countries (LMICs). Botswana, a country of approximately 2 million people in southern Africa, has only 1 pediatric cancer treatment program, based at Princess Marina Hospital (PMH) in the capital of Gaborone. A pediatric cancer recognition training program was developed that reached 50% of the government hospitals in Botswana teaching 362 health care workers how to recognize and refer children with cancer to PMH. Through evaluation of attendees, limitations in pediatric cancer training and general knowledge of pediatric cancer were identified. Attendees demonstrated improvement in their understanding of pediatric cancer and the referral process to PMH following the workshop

Essential medicines for pediatric oncology in developing countries

The burden of cancer in children in low and middle income countries (LMICs) is substantial, comprising at least 80% of incident cases globally, and an even higher proportion of cancer-related deaths. With survival rates exceeding 80% in high income countries, it is imperative to transfer these successes to LMICs. A major challenge is the poor availability of safe, cost-effective chemotherapy. A list of 51 drugschemotherapeutics, infectious disease agents, and supportive care medicationsis proposed as essential to improving the survival of children with cancer in LMICs with an additional 13 drugs identified as being of further value. Pediatr Blood Cancer 2013; 60: 889891. (c) 2013 Wiley Periodicals, Inc.Baylor Coll Med, Dept Pediat, Hematol Oncol Sect, Houston, TX 77030 USABaylor Coll Med, Dept Pediat, Hematol Oncol Sect, Gaborone, BotswanaMcMaster Childrens Hosp, Hamilton, ON, CanadaUniversidade Federal de São Paulo, Sch Med, Pediat Oncol Inst, São Paulo, BrazilMcMaster Univ, Dept Pediat, Hamilton, ON, CanadaMcMaster Univ, Dept Pathol, Hamilton, ON, CanadaMcMaster Univ, Dept Med, Hamilton, ON, CanadaUniversidade Federal de São Paulo, Sch Med, Pediat Oncol Inst, São Paulo, BrazilWeb of Scienc

Establishing a Pediatric Hematology-Oncology Program in Botswana

Purpose: Annually, 300,000 children are diagnosed with cancer, and the majority of these children live in low- and middle-income countries (LMICs). Currently, there is incomplete information on pediatric cancer incidence, diagnosis distribution, and treatment outcomes in Africa. Since 2007, a pediatric hematology-oncology program has been operating in Botswana through a partnership between the Botswana government, Baylor College of Medicine, and Texas Children’s Hospital. Methods: To better understand patient characteristics and outcomes at Botswana’s only pediatric cancer program, a hospital-based data base—the Botswana Pediatric Oncology Database—was established in 2014. Children younger than 18 years of age at the time of diagnosis who presented between 2008 and 2015 were included. Data for this study were extracted in February 2016. Results: Of the 240 potential enrollees, 185 (77%) children met eligibility for this study. The median age was 6.4 years, and 50.8% were male. Leukemia was the most common malignancy representing 18.9% of the cohort and 88.1% of the total cohort had a histopathologic diagnosis. HIV seropositivity was confirmed in 13.5%. The 2-year overall survival of all pediatric cancer diagnoses was 52.4%. Abandonment of treatment occurred in 3.8% of patients. Conclusion: In the first 9 years of the program, capacity has been developed through a longstanding partnership between Botswana and Baylor College of Medicine/Texas Children’s Hospital that has led to children receiving care for cancer and blood disorders. Although continued improvements are necessary, outcomes to date indicate that children with cancer in Botswana can be successfully diagnosed and treated

Data from: Clinical factors associated with long-term complete remission versus poor response to chemotherapy in HIV-infected children and adolescents with Kaposi sarcoma receiving bleomycin and vincristine: a retrospective observational study

Kaposi sarcoma (KS) is the most common HIV-associated malignancy in children and adolescents in Africa. Pediatric KS is distinct from adult disease. We evaluated the clinical characteristics associated with long-term outcomes. We performed a retrospective observational analysis of 70 HIV-infected children and adolescents with KS less than 18 years of age diagnosed between 8/2010 and 6/2013 in Lilongwe, Malawi. Local first-line treatment included bleomycin and vincristine plus nevirapine-based highly active anti-retroviral therapy (HAART). Median age was 8.6 years (range 1.7–17.9); there were 35 females (50%). Most common sites of presentation were: lymph node (74%), skin (59%), subcutaneous nodules (33%), oral (27%), woody edema (24%), and visceral (16%). Eighteen (26%) presented with lymphadenopathy only. Severe CD4 suppression occurred in 28%. At time of KS diagnosis, 49% were already on HAART. Overall, 28% presented with a platelet count < 100 x 109/L and 37% with hemoglobin < 8 g/dL. The 2-year event-free (EFS) and overall survival (OS) were 46% and 58% respectively (median follow-up 29 months, range 15–50). Multivariable analysis of risk of death and failure to achieve EFS demonstrated that visceral disease (odds ratios [OR] 19.08 and 11.61, 95% CI 2.22–163.90 and 1.60–83.95 respectively) and presenting with more than 20 skin/oral lesions (OR 9.57 and 22.90, 95% CI 1.01–90.99 and 1.00–524.13 respectively) were independent risk factors for both. Woody edema was associated with failure to achieve EFS (OR 7.80, 95% CI 1.84–33.08) but not death. Univariable analysis revealed that lymph node involvement was favorable for EFS (OR 0.28, 95% CI 0.08–0.99), while T1 TIS staging criteria, presence of cytopenias, and severe immune suppression were not associated with increased mortality. Long-term complete remission is achievable in pediatric KS, however outcomes vary according to clinical presentation. Based on clinical heterogeneity, treatment according to risk-stratification is necessary to improve overall outcomes