The world's scientific and social network for malaria professionals
Subscribe to free Newsletter | 9905 malaria professionals are enjoying the free benefits of MalariaWorld today

The MalariaWorld Journal

PhD thesis: Development and demise of Plasmodium liver stage parasites - The hunt for a Genetically Attenuated Malaria Vaccine

July 3, 2013 - 14:19 -- Bart G.J. Knols
Author(s): 
Ivo Ploemen
Reference: 
MWJ 2013, 4, 13

A considerable effort is currently underway to develop a malaria vaccine based on live Plasmodium falciparum sporozoites. The first requisite of a sporozoite vaccine is the guarantee of parasite arrest prior to the onset of the pathogenic blood stage. Immunisation with genetically attenuated parasites (GAP) that arrest in the liver forms a promising approach. Work in this thesis describes the development and characterisation of a P. berghei Δb9Δslarp GAP that fully arrests in the liver. Immunisation of multiple mouse strains with low numbers of Δb9Δslarp GAP resulted in sterile protection. The Δb9Δslarp GAP is there- fore the leading GAP vaccine candidate. Work in this the- sis further describes the effect of varying the parameters of sporozoite inoculation on parasite liver load. These findings provide a rationale for the design of clinical trials aimed at the administration of live attenuated P. falciparum sporozoites.

[Note: Full copy of PhD thesis attached]

Research: Intermittent preventive treatment with sulfadoxine-pyrimethamine versus weekly chloroquine prophylaxis for malaria in pregnancy in Honiara, Solomon Islands: a randomised trial

June 29, 2013 - 12:11 -- Bart G.J. Knols
Author(s): 
Lyndes Wini, Bridget Appleyard, Albino Bobogare, Junilyn Pikacha, Judith Seke, Makiva Tuni, Levi Hou, Jeffrey Hii, James McCarthy, Anna Maria van Eijk
Reference: 
MWJ 2013, 4, 12

Solomon Islands is a malarious nation in the Pacific with all four human Plasmodium species present. Although chloroquine prophylaxis is recommended for pregnant women, itseffectiveness is uncertain because of chloroquine resistance. A parallel-group, open label, individually randomised superiority trial comparing weekly chloroquine prophylaxis (CQ) with intermittent preventive treatment (IPTp) with sulfadoxine-pyrimethamine (SP) was conducted among pregnant women aged 15 to 49 years between August 2009- June 2010. The study shows that the use of SP for IPTp is not suitable for prevention of malaria in pregnancy in Solomon Islands, given the low malaria prevalence and the possible high prevalence of sulfa-allergy. Scaling up of transmission-reducing interventions has probably contributed to the malaria reduction in Honiara.

Read full article: 

Editorial: The Grand Challenges Explorations (GCE) programme

May 27, 2013 - 20:20 -- Bart G.J. Knols
Author(s): 
Alan Magill, Steven Buchsbaum
Reference: 
MWJ 2013, 4, 11

This Editorial accompanies seven research articles for which the research was funded through Grand Challenge Exploration grants. Alan Magill is the newly appointed Director who oversees the development and implementation of strategies for the Gates foundation’s ultimate goal of the eradication of malaria using current tools and strategies as well as developing new generations of vaccines, diagnostics, and anti-malarial therapies to be used in novel and innovative ways. Steven Buchsbaum leads the Discovery & Translational Sciences team’s efforts to expand the Grand Challenges family of grant programs and associated partnerships to enhance their impact.

Read full article: 

GCE Special: Using carnivorous plants to control malaria-transmitting mosquitoes

May 27, 2013 - 20:07 -- Bart G.J. Knols
Author(s): 
Jasper Ogwal-Okeng, Mary Namaganda, Godfrey Sande Bbosa, James Kalema
Reference: 
MWJ 2013, 4, 10

This GCE project set out to develop a novel way of controlling malaria-transmitting mosquitoes by deploying live, insect-eating plants around houses and in mosquito breeding sites. Field surveys were undertaken to collect and identify carnivorous plants. Aldrovanda vesiculosa and Utricularia reflexa were collected from swamps in various locations in Uganda and brought to the laboratory where they were kept in distilled water into which larvae of Anopeheles gambiae were introduced and the impact of the plants studied.

Read full article: 

GCE Special: Plasmodium falciparum infection in “humanised liver” mice

May 27, 2013 - 20:02 -- Bart G.J. Knols
Author(s): 
Jordana G. A. Coelho-dos-Reis, Xiangming Li, Eduardo L. V. Silveira, Rajakumar Mandraju, Soundarapandian Velmurugan, Sumana Chakravarty, Hiroshi Suemizu, Mamoru Ito, B. Kim Lee Sim, Stephen Hoffman, Moriya Tsuji
Reference: 
MWJ 2013, 4, 9

This GCE project aimed to establish “humanised liver” mice capable of supporting the full development of the liver stages of human malaria parasites. This could provide an invaluable opportunity to study various aspects of human malaria without the use of human volunteers. This would include investigating the biology of human malaria parasites in vivo and testing the potency of various agents against human malaria infection. Furthermore, “humanised liver” mice would give us the means by which efficient and economical precursor analysis can be done prior to the more expensive human clinical trials.

Read full article: 

GCE Special: Outdoor mosquito control using odour-baited devices: development and evaluation of a potential new strategy to complement indoor malaria prevention methods

May 27, 2013 - 19:54 -- Bart G.J. Knols
Author(s): 
Fredros O. Okumu, Robert D. Sumaye, Nancy S. Matowo, Stephen P. Mwangungulu, Emmanuel W. Kaindoa, Irene R. Moshi, Edith P. Madumla, Dickson W. Lwetoijera
Reference: 
MWJ 2013, 4, 8

To supplement current malaria prevention methods, and accelerate efforts towards elimination, this GCE project explores the use of outdoor mosquito control devices that mimic real humans, to attract and kill disease-transmitting vectors on a sustained basis. The idea (as envisioned in a GCE Phase I grant (2009) and Phase II grant (2011)) is to lure female Anopheles mosquitoes onto these outdoor ‘pseudo-hosts’, when positioned at optimally selected sites within or around human settlements, and then either trap these mosquitoes, contaminate them with substances that reduce their survival and ability to transmit disease or kill them instantly or within a few days after contact with the devices, thereby reducing exposure to mosquito bites and mosquito-borne pathogens.

Read full article: 

GCE Special: Malaria β-Haematin in blood results in synergistic attenuation enhancement: Studies with a conventional multimode reader and a custom LED device

May 27, 2013 - 19:50 -- Bart G.J. Knols
Author(s): 
Eugene Y. Chan, Kristyn Maiorca, Candice Bae, Nathaniel Sharpe, Vinay Tripuraneni, Julia Z. Sharpe
Reference: 
MWJ 2013, 4, 7

The aim of this GCE project was to develop a non-invasive method for diagnosing malaria. In order to do this, we sought to identify a novel optical property of β-haematin that gives it a robust optical signature. The optical signature needs to be readily detected with light-emitting diodes (LEDs) and photodiodes, which are compatible with low-cost operation in the developing world. The product is envisioned to be similar to a commercial fingertip pulse oximeter, which can be purchased for $20 and can be utilised for thousands of tests with a single battery.

Read full article: 

GCE Special: Development of an RNAi based microalgal larvicide to control mosquitoes

May 27, 2013 - 19:45 -- Bart G.J. Knols
Author(s): 
Anil Kumar, Songjie Wang, Ruguang Ou, Mustapha Samrakandi, Brenda T. Beerntsen, Richard T. Sayre
Reference: 
MWJ 2013, 4, 6

This GCE project explored an RNAi strategy to control mosquitoes and prevent spread of mosquito-borne diseases. The strategy involved delivery of double-stranded RNA(dsRNA) elements to mosquito larvae using unicellular, transgenic algae as vectors. Significantly, microorganisms, including microalgae, are the primary source of nutrition for mosquito larvae in water bodies that serve as the breeding grounds for mosquitoes. This strategy of delivering RNA elements to suppress essential target genes in mosquito larvae has many potential advantages over existing technologies.

Read full article: 

GCE Special: Endectocides for controlling transmission of mosquito-borne diseases

May 27, 2013 - 19:40 -- Bart G.J. Knols
Author(s): 
Massamba Sylla, Kevin C. Kobylinski, Brian D. Foy
Reference: 
MWJ 2013, 4, 5

The aim of this GCE project was to develop a control method that targets the most important variables of vectorial capacity (VC) and the basic reproductive number (Ro) so malaria parasite transmission would be maximally impacted, but that did so by targeting mosquitoes through human blood meals. This would a) target all malaria vectors around a community, regardless of when and where they bite, and b) ensure that the effector molecules directly entered the midgut of mosquitoes rather than needing to be efficiently applied in the environment and then efficiently penetrate the vectors’ cuticle.

Read full article: 

GCE Special: Production of a transgenic mosquito, as a flying syringe, to deliver protective vaccine via saliva

May 27, 2013 - 19:15 -- Bart G.J. Knols
Author(s): 
Hiroyuki Matsuoka
Reference: 
MWJ 2013, 4, 4

In this GCE project it was aimed to put a gene encoding a pathogen protein into a mosquito chromosome, causing it to express the protein in its saliva and inject it into animals orhumans during the blood-feeding process. It was anticipated that the host would develop antibodies to the recombinant protein. If transgenic mosquitoes whose saliva contained a vaccine protein against a disease are released in an area where the disease is prevalent, people that are bitten daily by these mosquitoes would develop antibodies to the vaccine protein, and ultimately the entire community would be ‘vaccinated’ against the disease. In this situation, mosquitoes would play the role of vaccine deliverers.

Read full article: 

Pages

Subscribe to The MalariaWorld Journal