De novo assembly and transcriptome analysis of five major tissues of Jatropha curcas L. using GS FLX titanium platform of 454 pyrosequencing

<p>Abstract</p> <p>Background</p> <p><it>Jatropha curcas </it>L. is an important non-edible oilseed crop with promising future in biodiesel production. However, factors like oil yield, oil composition, toxic compounds in oil cake, pests and diseases limit its commercial potential. Well established genetic engineering methods using cloned genes could be used to address these limitations. Earlier, 10,983 unigenes from Sanger sequencing of ESTs, and 3,484 unique assembled transcripts from 454 pyrosequencing of uncloned cDNAs were reported. In order to expedite the process of gene discovery, we have undertaken 454 pyrosequencing of normalized cDNAs prepared from roots, mature leaves, flowers, developing seeds, and embryos of <it>J. curcas</it>.</p> <p>Results</p> <p>From 383,918 raw reads, we obtained 381,957 quality-filtered and trimmed reads that are suitable for the assembly of transcript sequences. <it>De novo </it>contig assembly of these reads generated 17,457 assembled transcripts (contigs) and 54,002 singletons. Average length of the assembled transcripts was 916 bp. About 30% of the transcripts were longer than 1000 bases, and the size of the longest transcript was 7,173 bases. BLASTX analysis revealed that 2,589 of these transcripts are full-length. The assembled transcripts were validated by RT-PCR analysis of 28 transcripts. The results showed that the transcripts were correctly assembled and represent actively expressed genes. KEGG pathway mapping showed that 2,320 transcripts are related to major biochemical pathways including the oil biosynthesis pathway. Overall, the current study reports 14,327 new assembled transcripts which included 2589 full-length transcripts and 27 transcripts that are directly involved in oil biosynthesis.</p> <p>Conclusion</p> <p>The large number of transcripts reported in the current study together with existing ESTs and transcript sequences will serve as an invaluable genetic resource for crop improvement in jatropha. Sequence information of those genes that are involved in oil biosynthesis could be used for metabolic engineering of jatropha to increase oil content, and to modify oil composition.</p

Review Article: Prospect and Progress of Malaria Vaccine Development

Malaria kills one child every 30 seconds in Africa. The development of a safe vaccine remains an urgent unmet need which could greatly control and even lead to the eradication of the disease. The success recorded in the recent vaccine trials have given some ray of hope that a safe and effective vaccine against malaria will soon be produced. In this article, we bring together important published information on the status of malaria vaccine development and reviewed some field trials and the obstacles as well as prospect for effective malaria vaccination. Key words: Malaria vaccine, prospect, review Afr. J. Clin. Exper. Microbiol. 2005; 6(2): 145-15

The roles, Challenges and institutionalization of institutional review boards

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Allelic Diversity of Merozoite Surface Protein 2 Gene of P Falciparum among Children in Osogbo, Nigeria

The genetic diversity of Plasmodium falciparum (P falciparum) infections in humans is implicated in the pathogenesis of malaria. This study provides the first estimate of the genetic diversity and genotype multiplicity of Plasmodium falciparum infection in children with uncomplicated P falciparum malaria in Osogbo, Nigeria. One hundred and one isolates were used for analysis of parasite population polymorphism and genotyped by nested-PCR of merozoite surface protein 2 (MSP2) block 3. Amplicons were obtained for all the 101 genotyped samples in MSP2 PCR with 9 alleles varying in size between 300 and 800 base pair. Thirty-three (31.7%) samples had FC27 allele while 27 (26.7%) had 3D7 allele and 35 (34.7%) had mixed alleles (3D7+FC27). The Multiplicity of Infection (MOI) in the population was 1.6. Children in the age group of > 4–8 years had the highest number of different genotypes in their samples (1.8). The number of MSP2 bands per isolate was lower in the older age group (1.3) but the difference was not statistically significant. Children with parasite density range 5001–10 000 had the highest MOI of 2 while those with parasite density range 1000–5000 had the lowest of 1.5. In conclusion, the present study shows that the field isolates are highly diverse in respect of MSP2 and multiplicity of infection was neither age nor parasite density dependent in the study population. Keyword: Genetic diversity, MSP2, Nigeria, plasmodium falciparum. Diversidad Alélica del Gen de la Proteína de Superficie del Merozoíto 2 del P Falciparum entre los Niños de Osogobo, en Nigeria RESUMEN La diversidad genética de las infecciones por Plasmodium falciparum en los humanos se halla implícita en la patogénesis de la malaria. Este estudio proporciona un primer estimado de la diversidad genética y multiplicidad del genotipo de la infección por Plasmodium falciparum en los niños con malaria por P falciparum malaria sin complicaciones en Osogbo, Nigeria. Ciento un aislados fueron usados para el análisis del polimorfismo de la población parasitaria, y genotipificados mediante reacción en cadena de la polimerasa (RCP) anidada de la proteína de superficie del merozoíto 2 (MSP2) bloque 3. Se obtuvieron amplicones para las 101 muestras genotipificadas con RCP de MSP2, con 9 alelos variando en tamaño entre 300 y 800 par de bases. Treinta y tres (31.7%) muestras tenían el alelo FC27 mientras 27 (26.7%) tenían el alelo 3D7 y 35 (34.7%) tenían alelos mezclado (3D7+FC27). La multiplicidad de infección (MOI) en la población fue 1.6. Los niños en el grupo etario de > 4–8 años tenían el número más alto de genotipos diferentes en sus muestras (1.8). El número de bandas de MSP2 por aislado era más bajo en el grupo etario de mayor edad (1.3) pero la diferencia no era estadísticamente significativa. Los niños con un rango de densidad parasitaria 5001–10 000 tenían el MOI más alto equivalente a 2, mientras aquéllos con rango de densidad parasitaria 1000–5000 tenían el MOI más bajo equivalente a 1.5. En conclusión, el presente estudio muestra que los aislados de campo son altamente diversos con respecto al MSP2, y que la multiplicidad de la infección no depende ni de la edad ni de la densidad parasitaria de la población en estudio. Palabras claves: Diversidad genética, MSP2, Nigeria, plasmodium falciparum

Malaria and HIV co-infection and their effect on haemoglobin levels from three healthcare institutions in Lagos, southwest Nigeria

Background: Malaria and human immunodeficiency virus (HIV) are two major infections with enormous public health consequence. Together, they are endemic in many developing countries with anaemia being the most frequent haematological consequence of the infections.Objective: To determine the prevalence of malaria and HIV co-infection as well as anaemia among selected patients from three health-care institutions in Lagos, Nigeria.Methods: A cross-sectional study of 1080 patients was carried out to  determine the prevalence of malaria and HIV coinfection as well as anaemia. Blood sera from each of the patients were screened for malaria parasites, HIV-1 and HIV-2 using Giemsa stain, Cambridge Biotech  Recombigen HIV-1/HIV-2 rapid device, respectively while haemoglobin estimation was performed using cyanmethemoglobin method.Results: Our data showed that the total number of malaria infected  patients were significantly higher in HIV sero-positive patients 47.7% (31/65) when compared with their HIV sero-negative counterparts 25.8% (262/1015) P = 0.047. The result also revealed that 25.8% (8/31) of the patients co-infected with malaria and HIV had anaemia as compared to 11.1% (29/262) infected with malaria alone. Multivariable logistic  regression analysis showed that patients with dual infection of malaria and HIV were twice likely to be anaemic than those infected with malaria alone [adjusted OR 2.4, 95% CI, 1.3 to 2.7, P = 0.014].Conclusion: Our data indicated a higher prevalence of malaria in HIV infected patients and also revealed that patients coinfected with malaria and HIV were more likely to be anaemic.Keywords: Malaria, malaria and HIV co-infection, anaemia, parasite densit

Effect of Water Extract Of Tetrapleura Tetraptera (Aidon) On Haematological And Biochemical Parameters in Rats infected With Trypanosoma Brucei

This study investigated whether water extract of Tetrapleura tetraptere has trypanocidal effect against T.brucei in laboratory rats. Studies also examined its effect on the weight, haematological parameters as well as the blood chemical analyses of the infected animals. Results showed that oral administration of the water extract to the infected rats significantly reduced the parasite load, also weight loss was significantly lower in the infected and treated rats than the untreated ones. These positive observations were accompanied by reduced leukocytosis, improved state of anaemia and increased packed cell volume, all of which are indices of recovery from the state of cell toxicity arising from parasitemia. The tolerance of the extract by the animal was evaluated by the determination of the blood chemistries. Results revealed that there was no significant difference in the concentrations of the blood glucose, total protein, uric acid and unconjugated bilirubin in the uninfected but treated rats compared with the "neat" rats which were neither infected nor treated. However, conjugated bilirubin and creatinine values were significantly increased. It was also observed that when the infected animals were treated with the extract, the blood levels of total protein, uric acid, creatinine and unconjugated bilirubin decreased slightly, but consistently, as against the untreated rats. These observations indicate the beneficial effects of the plant extract and suggest that the T. tetraptera may contain active substance(s) which could have therapeutic effect against trypanosome infection. Nigerian Quarterly Journal of Hospital Medicine Vol. 9, No. 1 (1999) pp. 66-7

Human African trypanosomes: challenges posed to the human immune system.

Human infection by either Trypanosoma brucei gambiense (Tbg) or Trypanosoma brucei rhodesiense (Tbr) and the establishment of disease is made possible by the intermittent switching of their variant surfaceglycoprotein (VSG) and expression of serum resistance associated (SRA) protein (by Tbr) which nullifies the lytic action of the normal human serum. The ability to switch expression from one VSG to the other is recognized to be the major mechanism that permits the parasite to evade the otherwise efficient host antibody, hence preventing parasite elimination and allowing the establishment of a chronic infection. These changes were reported to: disable the host’s capacity to mount a protective anti-parasite antibody response and prevent the development of effective B-cell memory against encountered variant antigenic parasite types (VATs). Both B cell-mediated antibody response and the Th1 cell responses leading to the production of interferon-gamma (IFN-ϒ) are required for maximum host resistance to trypanosomes, with IFN-ϒ acting to induce macrophage trypanolytic and trypanostatic activities. High levels of both tumor necrosis factor alpha (TNFα) and interleukin 10 (IL-10) have been associated with trypanosomal infection. Trypanosomal genetics (including the parasite’s intrinsic characteristics), human immune response polymorphisms and geographical locations are important elements that describe the severity or mildness of HAT. As the parasite devices ways to evade thehuman immune system, and in the absence of a suitable vaccine, surveillance, prompt diagnosis and treatment with available drugs and vector control efforts will go along way in reducing the incidence of HAT.Keywords: African trypanosomes, Variant surface glycoprotein, Serum resistance associated (SRA) protein, Trypanosomal genetic polymorphisms, Immune response polymorphism

Rational use of Jatropha curcas L. in food and medicine:from toxicity problems to safe applications

<p>Jatropha curcas L. has become an important plant for biorefinery and production of biodiesel. From its ethnobotanical use, the plant is known for several activities which are associated with high toxicity. The latest development in engineering technology enables detoxification of native oil and other parts of the plant for new pharmaceutical purposes. Hence a revised look to the rich metabolic spectra of partly structurally rare secondary compound becomes an interesting field of research to be explored. In this review, we discuss recent developments in the technology of detoxification process and give insight about how this ethnomedicinal plant can be applied to new fields of experimental medicine. The review highlights recent data on biological activities and discusses concepts and strategies for turning a poison plant into a valuable crop with high pharmaceutical potential.</p>