The Africa and West Asia agricultural situation. Review of 1966 and outlook for 1967 /

Cover title.

The Africa and West Asia agricultural situation : 1968 midyear review /

"The report updates a more comprehensive report published in April 1968: The Africa and West Asia agricultural situation--review of 1967 and outlook for 1968, ERS-Foreign 221."

The Africa and West Asia agricultural situation : midyear review /

"This bulletin represents an updating of certain information presented in: The Africa and West Asia agricultural situation--review of 1965 and outlook for 1966, ERS-Foreign 153, April 1966."

The Agricultural situation in Africa and West Asia : review of 1973 and outlook for 1974 /

"One of six regional supplements to the World Agricultural Situation, issued in December 1973."

Fifty years in Western Africa; being a record of the work of the West Indian Church on the banks of the Rio Pongo.

Mode of access: Internet.

Transport problems in relation to economic development in West Africa.

"E/CN.14/63."

Notes on the birds of Damara Land and the adjacent countries of South-west Africa.

Bibliography: p. [xxxi]-xxxv.

Black sheep; adventures in West Africa,

"Some of these letters appeared in Woman's work ... Some appeared in the Atlantic Monthly."--Pref.

Tide Tables, Europe and West Coast of Africa, Including Mediterranean Sea

1951-1957 isued as its Serial no.733, etc

European settlements on the west coast of Africa ; with remarks on the slave trade and the supply of cotton /

Reprint of the 1862 ed.

South-West Africa,

Mode of access: Internet.

Quantitative Association Tests of Immune Responses to Antigens of Mycobacterium Tuberculosis: A Study of Twins in West Africa

There is now considerable evidence that host genetic factors are important in determining the outcome of infection with Mycobacterium tuberculosis (MTB). The aim of this study was to assess the role of several candidate genes in the variation observed in the immune responses to MTB antigens. In-vitro assays of T-cell proliferation, an in-vivo intradermal delayed hypersensitivity response; cytokine and antibody secretions to several mycobacterial peptide antigens were assessed in healthy, but exposed, West African twins. Candidate gene polymorphisms were typed in the NRAMP1, Vitamin D receptor, IL10, IL4, IL4 receptor and CTLA-4 genes. Variants of the loci IL10 (-1082 G/A), CTLA-4 (49 A/G) and the IL4 receptor (128 A/G) showed significant associations with immune responses to several antigens. T-cell proliferative responses and antibody responses were reduced, TNF-alpha responses were increased for subjects with the CTLA-4 G allele. The T-cell proliferative responses of subjects with IL10 GA and GG genotypes differed significantly. IL4 receptor AG and GG genotypes also showed significant differences in their T-cell proliferative responses to MTB antigens. These results yield a greater understanding of the genetic mechanisms that underlie the immune responses in tuberculosis and have implications for the design of therapeutic interventions.

Common E protein determinants for attenuation of glycosaminoglycan-binding variants of Japanese encephalitis and West Nile viruses

Natural isolates and laboratory strains of West Nile virus (WNV) and Japanese encephalitis virus (JEV) were attenuated for neuroinvasiveness in mouse models for flavivirus encephalitis by serial passage in human adenocarcinoma (SW13) cells. The passage variants displayed a small-plaque phenotype, augmented affinity for heparin-Sepharose, and a marked increase in specific infectivity for SW13 cells relative to the respective parental viruses, while the specific infectivity for Vero cells was not altered. Therefore, host cell adaptation of passage variants was most likely a consequence of altered receptor usage for virus attachment-entry with the involvement of cell surface glycosaminoglycans (GAG) in this process. In vivo blood clearance kinetics of the passage variants was markedly faster and viremia was reduced relative to the parental viruses, suggesting that affinity for GAG (ubiquitously present on cell surfaces and extracellular matrices) is a key determinant for the neuroinvasiveness of encephalitic flaviviruses. A difference in pathogenesis between WNV and JEV, which was reflected in more efficient growth in the spleen and liver of the WNV parent and passage variants, accounted for a less pronounced loss of neuroinvasiveness of GAG binding variants of WNV than JEV. Single gain-of-net-positive-charge amino acid changes at E protein residue 49, 138, 306, or 389/390, putatively positioned in two clusters on the virion surface, define molecular determinants for GAG binding and concomitant virulence attenuation that are shared by the JEV serotype flaviviruses.