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

Drug resistance to sulphadoxine-pyrimethamine in Plasmodium falciparum malaria in Mlimba, Tanzania

BACKGROUND: Sulphadoxine-pyrimethamine (SP) has been and is currently used for treatment of uncomplicated Plasmodium falciparum malaria in many African countries. Nevertheless, the response of parasites to SP treatment has shown significant variation between individuals. METHODS: The genes for dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) were used as markers, to investigate parasite resistance to SP in 141 children aged less than 5 years. Parasite DNA was extracted by Chelex method from blood samples collected and preserved on filter papers. Subsequently, polymerase chain reaction (PCR) and restriction fragment length polymorphism (PCR-RFLP) were applied to detect the SP resistance-associated point mutations on dhfr and dhps. Commonly reported point mutations at codons 51, 59, 108 and 164 in the dhfr and codons 437, 540 and 581 in the dhps domains were examined. RESULTS: Children infected with parasites harbouring a range of single to quintuple dhfr/dhps mutations were erratically cured with SP. However, the quintuple dhfr/dhps mutant genotypes were mostly associated with treatment failures. High proportion of SP resistance-associated point mutations was detected in this study but the adequate clinical response (89.4%) observed clinically at day 14 of follow up reflects the role of semi-immunity protection and parasite clearance in the population. CONCLUSION: In monitoring drug resistance to SP, concurrent studies on possible confounding factors pertaining to development of resistance in falciparum malaria should be considered. The SP resistance potential detected in this study, cautions on its useful therapeutic life as an interim first-line drug against malaria in Tanzania and other malaria-endemic countries

Data from: Quantifying past and present connectivity illuminates a rapidly changing landscape for the African elephant

There is widespread concern about impacts of land-use change on connectivity among animal and plant populations, but those impacts are difficult to quantify. Moreover, lack of knowledge regarding ecosystems before fragmentation may obscure appropriate conservation targets. We use occurrence and population genetic data to contrast connectivity for a long-lived mega-herbivore over historical and contemporary time frames. We test whether (i) historical gene flow is predicted by persistent landscape features rather than human settlement, (ii) contemporary connectivity is most affected by human settlement and (iii) recent gene flow estimates show the effects of both factors. We used 16 microsatellite loci to estimate historical and recent gene flow among African elephant (Loxodonta africana) populations in seven protected areas in Tanzania, East Africa. We used historical gene flow (FST and G'ST) to test and optimize models of historical landscape resistance to movement. We inferred contemporary landscape resistance from elephant resource selection, assessed via walking surveys across ~15 400 km2 of protected and unprotected lands. We used assignment-based recent gene flow estimates to optimize and test the contemporary resistance model, and to test a combined historical and contemporary model. We detected striking changes in connectivity. Historical connectivity among elephant populations was strongly influenced by slope but not human settlement, whereas contemporary connectivity was influenced most by human settlement. Recent gene flow was strongly influenced by slope but was also correlated with contemporary resistance. Inferences across multiple timescales can better inform conservation efforts on large and complex landscapes, while mitigating the fundamental problem of shifting baselines in conservation

Papilio sp.

Slope (in degrees), untransformed (i.e., slope^1); Albers Equal Area projection (Africa

Contemporary CubeRoot_1overRSPF Resistance Matrix

Cumulative resistance matrix from "contemporary" resistance model, (1/RSPF)^0.3

Multiplicity of infections and level of recrudescence in Plasmodium falciparum malaria in Mlimba, Tanzania

African Journal of Biotechnology Vol. 5 (18), pp. 1655-1662, 18 September 2006, © 2006 Academic JournalsPolymorphism and antigenic variation are important biological survival strategies of malaria parasites determining the episode, outcome and implications of treatment interventions. In P. falciparum, polymorphic antigens are associated with the asexual blood-stage; merozoite surface protein 2 (MSP2). The MSP2 genes have been invaluable in post-treatment discrimination of parasite resurgence from new infection, especially in high transmission areas. We performed polymerase chain reaction (PCR) on DNA extracted from blood samples of 141 malaria-infected infants, followed by restriction fragment length polymorphism (RFLP) of PCR products. The findings showed multiplicity of infections of single to six infections with an average of 2.58 infections per patient. Single infections of either 3D7 or FC27 allelic families of the MSP2 gene occurred in 51 patients (50.5%) out of all PCR-RFLP successful samples (n = 101). Out of 15 (10.6%) follow up samples with resurgent parasitaemia, 3 (20%) samples had recrudescent infections while 12 (80%) had variable results. Our findings provide an insight on the prevalence of the genetic determinants of suphadoxine-pyrimethamine (SP) resistance in Mlimba during the study period, and in the face of rapidly spreading resistance, calls for the periodic surveillance in order to timely detect early warning signal of the deteriorating SP cure rate

Ele_RSPF_Data

Elephant and random locations, with covariates scored from GIS, as employed in the habitat mode

Distance to Water GIS raster layer

Albers Equal Area (Africa) projection. Distance to water (untransformed) in kilometers, based on Africover Rivers layer with modifications