TBX 5 gene mutation analysis among Tanzanian children with congenital heart diseases using high-resolution melting assays

Early cardiac development is governed by transcription factor genes. TBX5, a T-box transcription factor gene, plays an important role in the development  of the second heart field during cardiac septation by promoting cell cycle progression through the enhancement of Cdk6 and hedgehog signaling  pathways. TBX5 binds to the promoter region of genes, enhancing the expression of alpha cardiac myosin heavy chain 6 (MYH6), which is a predominant  isoform found in human cardiac tissue. TBX5 gene mutations are postulated to cause congenital heart diseases. A casecontrol TBX5 mutational analysis  was performed to provide insight into the etiology of sporadic congenital heart diseases in our setting. We used a magnetic induction cycler (mic-PCR),  which is a next-generation tool for polymerase chain reaction-high resolution melting assays, to detect mutations in children with sporadic isolated  congenital heart diseases. A retrospective casecontrol study was conducted at the Jakaya Kikwete Cardiac Institute. The peripheral blood samples were  collected, and DNA was extracted using the Quick-DNA Miniprep Kit. The primers were designed using Primer 3 software, validated using the program  BLAST, and checked for hairpin and homo-hetero-dimerization using the IDT oligo analyzer. Real-time polymerase chain reaction (PCR)-high-resolution  melting assays for screening TBX5 gene mutations were done using a magnetic induction cycler. We found two (2) TBX5 mutations in exon 5, among  patients with Atrial-Ventral Septal Defects (ASVD) and Atrial-Septal Defects (ASD) and none among controls. TBX5 exon 5 is a molecular hotspot for  isolated congenital heart diseases.&nbsp

Randomized, Controlled Trial of the Long Term Safety, Immunogenicity and Efficacy of RTS,S/AS02(D) Malaria Vaccine in Infants Living in a Malaria-Endemic Region.

The RTS,S/AS malaria candidate vaccine is being developed with the intent to be delivered, if approved, through the Expanded Programme on Immunization (EPI) of the World Health Organization. Safety, immunogenicity and efficacy of the RTS,S/AS02(D) vaccine candidate when integrated into a standard EPI schedule for infants have been reported over a nine-month surveillance period. This paper describes results following 20 months of follow up. This Phase IIb, single-centre, randomized controlled trial enrolled 340 infants in Tanzania to receive three doses of RTS,S/AS02(D) or hepatitis B vaccine at 8, 12, and 16 weeks of age. All infants also received DTPw/Hib (diphtheria and tetanus toxoids, whole-cell pertussis vaccine, conjugated Haemophilus influenzae type b vaccine) at the same timepoints. The study was double-blinded to month 9 and single-blinded from months 9 to 20. From month 0 to 20, at least one SAE was reported in 57/170 infants who received RTS,S/AS02(D) (33.5%; 95% confidence interval [CI]: 26.5, 41.2) and 62/170 infants who received hepatitis B vaccine (36.5%; 95% CI: 29.2, 44.2). The SAE profile was similar in both vaccine groups; none were considered to be related to vaccination. At month 20, 18 months after completion of vaccination, 71.8% of recipients of RTS,S/AS02(D) and 3.8% of recipients of hepatitis B vaccine had seropositive titres for anti-CS antibodies; seroprotective levels of anti-HBs antibodies remained in 100% of recipients of RTS,S/AS02(D) and 97.7% recipients of hepatitis B vaccine. Anti-HBs antibody GMTs were higher in the RTS,S/AS02(D) group at all post-vaccination time points compared to control. According to protocol population, vaccine efficacy against multiple episodes of malaria disease was 50.7% (95% CI: -6.5 to 77.1, p = 0.072) and 26.7% (95% CI: -33.1 to 59.6, p = 0.307) over 12 and 18 months post vaccination, respectively. In the Intention to Treat population, over the 20-month follow up, vaccine efficacy against multiple episodes of malaria disease was 14.4% (95% CI: -41.9 to 48.4, p = 0.545). The acceptable safety profile and good tolerability of RTS,S/AS02(D) in combination with EPI vaccines previously reported from month 0 to 9 was confirmed over a 20 month surveillance period in this infant population. Antibodies against both CS and HBsAg in the RTS,S/AS02(D) group remained significantly higher compared to control for the study duration. Over 18 months follow up, RTS,S/AS02(D) prevented approximately a quarter of malaria cases in the study population. CLINICAL TRIALS: Gov identifier: NCT00289185

Complex congenital cardiac anomalies in the setting of right isomerism in a 31-month-old infant: a case report

Abstract Background Congenital cardiac defects are not rare among neonates. Prompt assessment for life-threatening anomalies is essential for rapid management decisions and positive outcomes. Extracardiac anomalies can occur in congenital heart defects, and their presence increases morbidity and mortality in these neonates. Case presentation We report a case of a 31- month-old infant black girl in Tanzania who presented with an on-and-off history of difficulty in breathing, easy fatigability, facial and lower-limb swelling, recurrent respiratory tract infections, and failure to thrive. Conclusions Management of patients with heterotaxy syndrome is complex and largely depends on specific anatomy of both cardiac and noncardiac lesions. Cardiac and noncardiac management must be tailored to individual anatomy, including prophylaxis against encapsulated organisms for asplenic patients

Late surgical ventricular septal defect closure in a low middle-income country setting: a case series

Abstract Background Ventricular septal defect (VSD) is the commonest type of congenital heart lesion accounting for up to 40% of congenital heart defects. Well timed VSD closures are reported to yield excellent long-term outcomes. Late surgical VSD closures, particularly from the developing countries, are infrequently reported. Case presentation We report three cases of African children aged between 13 and 14 years who had late VSD presentations. They reported complaints of growth failure and recurrent respiratory infections since early infancy which necessitated frequent visits to primary health care facilities. They were found to have large ventricular septal defects by thoracic echocardiography. Diagnostic cardiac catheterization was done to all three patients to rule out irreversible pulmonary hypertension. After promising cardiac catheterization findings, they all underwent successful surgical VSD repair with good early outcomes. Conclusion VSD surgical closure is ideal in children below 2 years, however, it can be done in children who present at advanced age despite being considered high risk patients. All three of our patients who presented late had successful surgical VSD repairs with promising immediate outcome. The role of genetics in the protection against developing irreversible pulmonary vascular disease in these patients is a possible area for future studies

Safety and immunogenicity of RTS,S/AS02D malaria vaccine in infants.

BACKGROUND: The RTS,S/AS malaria vaccine is being developed for delivery through the World Health Organization's Expanded Program on Immunization (EPI). We assessed the feasibility of integrating RTS,S/AS02D into a standard EPI schedule for infants. METHODS: In this phase 2B, single-center, double-blind, controlled trial involving 340 infants in Bagamoyo, Tanzania, we randomly assigned 340 infants to receive three doses of either the RTS,S/AS02D vaccine or the hepatitis B vaccine at 8, 12, and 16 weeks of age. All infants also received a vaccine containing diphtheria and tetanus toxoids, whole-cell pertussis vaccine, and conjugated Haemophilus influenzae type b vaccine (DTPw/Hib). The primary objectives were the occurrence of serious adverse events during a 9-month surveillance period and a demonstration of noninferiority of the responses to the EPI vaccines (DTPw/Hib and hepatitis B surface antigen) with coadministration of the RTS,S/AS02D vaccine, as compared with the hepatitis B vaccine. The detection of antibodies against Plasmodium falciparum circumsporozoite and efficacy against malaria infection were secondary objectives. RESULTS: At least one serious adverse event was reported in 31 of 170 infants who received the RTS,S/AS02D vaccine (18.2%; 95% confidence interval [CI], 12.7 to 24.9) and in 42 of 170 infants who received the hepatitis B vaccine (24.7%; 95% CI, 18.4 to 31.9). The results showed the noninferiority of the RTS,S/AS02D vaccine in terms of antibody responses to EPI antigens. One month after vaccination, 98.6% of infants receiving the RTS,S/AS02D vaccine had seropositive titers for anticircumsporozoite antibodies on enzyme-linked immunosorbent assay (ELISA). During the 6-month period after the third dose of vaccine, the efficacy of the RTS,S/AS02D vaccine against first infection with P. falciparum malaria was 65.2% (95% CI, 20.7 to 84.7; P=0.01). CONCLUSIONS: The use of the RTS,S/AS02D vaccine in infants had a promising safety profile, did not interfere with the immunologic responses to coadministered EPI antigens, and reduced the incidence of malaria infection. (ClinicalTrials.gov number, NCT00289185.

Elevated blood pressure among primary school children in Dar es salaam, Tanzania: prevalence and risk factors

Abstract Background Whilst the burden of non-communicable diseases is increasing in developing countries, little data is available on blood pressure among Tanzanian children. This study aimed at determining the blood pressure profiles and risk factors associated with elevated blood pressure among primary school children in Dar es Salaam, Tanzania. Methods We conducted a cross sectional survey among 446 children aged 6–17 years from 9 randomly selected primary schools in Dar es Salaam. We measured blood pressure using a standardized digital blood pressure measuring machine (Omron Digital HEM-907, Tokyo, Japan). We used an average of the three blood pressure readings for analysis. Elevated blood pressure was defined as average systolic or diastolic blood pressure ≥ 90th percentile for age, gender and height. Results The proportion of children with elevated blood pressure was 15.2% (pre-hypertension 4.4% and hypertension 10.8%). No significant gender differences were observed in the prevalence of elevated BP. Increasing age and overweight/obese children were significantly associated with elevated BP (p = 0.0029 and p < 0.0001) respectively. Similar associations were observed for age and overweight/obesity with hypertension. (p = 0.0506 and p < 0.0001) respectively. In multivariate analysis, age above 10 years (adjusted RR = 3.63, 95% CI = 1.03–7.82) was significantly and independently associated with elevated BP in this population of school age children. Conclusions We observed a higher proportion of elevated BP in this population of school age children. Older age and overweight/obesity were associated with elevated BP. Assessment of BP and BMI should be incorporated in school health program in Tanzania to identify those at risk so that appropriate interventions can be instituted before development of associated complications