Herbal medicine use in the districts of Nakapiripirit, Pallisa, Kanungu, and Mukono in Uganda

ABSTRACT: BACKGROUND: Traditional medicine (TM) occupies a special place in the management of diseases in Uganda. Not with standing the many people relying on TM, indigenous knowledge (IK) related to TM is getting steadily eroded. To slow down this loss it is necessary to document and conserve as much of the knowledge as possible. This study was conducted to document the IK relevant to traditional medicine in the districts of Mukono, Nakapiripirit, Kanungu and Pallisa, in Uganda. METHODS: An ethnobotanical survey was conducted between October 2008 and February 2009 using techniques of key informant interviews and household interviews. RESULTS: The common diseases and conditions in the four districts include malaria, cough, headache, diarrhea, abdominal pain, flu, backache and eye diseases. Respondents stated that when they fall sick they self medicate using plant medicines or consult western-trained medicine practitioners. Self medication using herbal medicines was reported mostly by respondents of Nakapiripirit and Mukono. Respondents have knowledge to treat 78 ailments using herbal medicines. 44 species, mentioned by three or more respondents have been prioritized. The most frequently used part in herbal medicines is the leaf, followed by the stem and root. People sometime use animal parts, soil, salt and water from a grass roof, in traditional medicines. Herbal medicines are stored for short periods of time in bottles. The knowledge to treat ailments is acquired from parents and grandparents. Respondents' age and tribe appears to have a significant influence on knowledge of herbal medicine, while gender does not. CONCLUSION: This survey has indicated that IK associated with TM stills exists and that TM is still important in Uganda because many people use it as a first line of health care when they fall sick. Age and tribe influence the level of IK associated with herbal medicine, but gender does not.     

Increased Antibody Affinity Confers Broad In Vitro Protection against Escape Mutants of Severe Acute Respiratory Syndrome Coronavirus

Even though the effect of antibody affinity on neutralization potency is well documented, surprisingly, its impact on neutralization breadth and escape has not been systematically determined. Here, random mutagenesis and DNA shuffling of the single-chain variable fragment of the neutralizing antibody 80R followed by bacterial display screening using anchored periplasmic expression (APEx) were used to generate a number of higher-affinity variants of the severe acute respiratory syndrome coronavirus (SARS-CoV)-neutralizing antibody 80R with equilibrium dissociation constants (K(D)) as low as 37 pM, a >270-fold improvement relative to that of the parental 80R single-chain variable fragment (scFv). As expected, antigen affinity was shown to correlate directly with neutralization potency toward the icUrbani strain of SARS-CoV. Additionally, the highest-affinity antibody fragment displayed 10-fold-increased broad neutralization in vitro and completely protected against several SARS-CoV strains containing substitutions associated with antibody escape. Importantly, higher affinity also led to the suppression of viral escape mutants in vitro. Escape from the highest-affinity variant required reduced selective pressure and multiple substitutions in the binding epitope. Collectively, these results support the hypothesis that engineered antibodies with picomolar dissociation constants for a neutralizing epitope can confer escape-resistant protection.     

Immunogenetic Mechanisms Driving Norovirus GII.4 Antigenic Variation

Noroviruses are the principal cause of epidemic gastroenteritis worldwide with GII.4 strains accounting for 80% of infections. The major capsid protein of GII.4 strains is evolving rapidly, resulting in new epidemic strains with altered antigenic potentials. To test if antigenic drift may contribute to GII.4 persistence, human memory B cells were immortalized and the resulting human monoclonal antibodies (mAbs) characterized for reactivity to a panel of time-ordered GII.4 virus-like particles (VLPs). Reflecting the complex exposure history of the volunteer, human anti-GII.4 mAbs grouped into three VLP reactivity patterns; ancestral (1987–1997), contemporary (2004–2009), and broad (1987–2009). NVB 114 reacted exclusively to the earliest GII.4 VLPs by EIA and blockade. NVB 97 specifically bound and blocked only contemporary GII.4 VLPs, while NBV 111 and 43.9 exclusively reacted with and blocked variants of the GII.4.2006 Minerva strain. Three mAbs had broad GII.4 reactivity. Two, NVB 37.10 and 61.3, also detected other genogroup II VLPs by EIA but did not block any VLP interactions with carbohydrate ligands. NVB 71.4 cross-neutralized the panel of time-ordered GII.4 VLPs, as measured by VLP-carbohydrate blockade assays. Using mutant VLPs designed to alter predicted antigenic epitopes, two evolving, GII.4-specific, blockade epitopes were mapped. Amino acids 294–298 and 368–372 were required for binding NVB 114, 111 and 43.9 mAbs. Amino acids 393–395 were essential for binding NVB 97, supporting earlier correlations between antibody blockade escape and carbohydrate binding variation. These data inform VLP vaccine design, provide a strategy for expanding the cross-blockade potential of chimeric VLP vaccines, and identify an antibody with broadly neutralizing therapeutic potential for the treatment of human disease. Moreover, these data support the hypothesis that GII.4 norovirus evolution is heavily influenced by antigenic variation of neutralizing epitopes and consequently, antibody-driven receptor switching; thus, protective herd immunity is a driving force in norovirus molecular evolution.     

Evolution of the tribe Tropheini from Lake Tanganyika: synchronized explosive speciation producing multiple evolutionary parallelism

One of the most surprising outcomes of recent molecular studies on cichlid fishes of the three Great East African Lakes Victoria, Malawi and Tanganyika, was the stunning rapidity of speciation and cladogenesis at early stages of adaptive radiation. Despite their rapid pace, speciation events were so far intuitively assumed to proceed in a bifurcating and tree-like fashion, even if they could not be resolved by gene phylogenies due to a lack of resolution. On the basis of phylogenetic analyses of the Tropheini, a lineage of endemic rock-dwelling cichlid fishes from Lake Tanganyika, we suggest a pathway of explosive speciation that accounts for a non-bifurcating manner of cladogenesis. This pattern is likely to be the result of the contemporaneous origin of a multitude of founder populations in geographically isolated rock habitats among which gene flow was interrupted simultaneously by a major change of the lake habitat in the form of a rapid rise of the lake level. As a consequence, all new species arising from that vicariance event must exhibit almost equal genetic distances to each other, within the scope of genetic diversity of the founder population(s), even if the actual processes of subsequent speciation and eco-morphological diversification followed independent routes. Our phylogeny also suggests a high frequency of parallel evolution of equivalent trophic specialization in the Tropheini. This phenomenon seems to be an inherent feature of this pathway of speciation, due to the action of similar selective forces on the same set of species colonizing isolated habitats of the same type. Explosive speciation via synchronization of genetic divergence triggered by rapid environmental changes seems to be particularly likely to occur at advanced stages of adaptive radiation, when species are already adapted to particular habitats and have a reduced ability for dispersal.     

Phylogeography and Evolution of the Tanganyikan Cichlid Genus Tropheus Based upon Mitochondrial DNA Sequences

Abstract Lake Tanganyika harbors the oldest and most diverse species flock of cichlid fish. Many species are subdivided into numerous genetically and phenotypically distinct populations. Their present distribution and genetic structure were shaped by a series of lake level fluctuations which caused cycles of isolation and admixis and promoted dispersal events. One of the best examples of this phenomenon is the genus Tropheus. We present a comprehensive mtDNA phylogeny based upon 365 individuals of 55 populations from all over Lake Tanganyika, which suggests an almost-contemporaneous origin of eight major mitochondrial lineages about 700 Ka ago. While the distribution of seven lineages is restricted to particular sections of the lake shore, one lineage was found to have a much more widespread distribution. This particular lineage is subdivided into four sublineages which seem to have originated from a single dispersal event about 400 Ka. By using a molecular clock estimate in combination with geological data we derived a hypothetical scenario for the colonization history of Tropheus. Thereby we show a high degree of concordance between major changes of the lake level in the recent history of Lake Tanganyika and three distinct diversification events in this genus.     

Systemic, Mucosal, and Heterotypic Immune Induction in Mice Inoculated with Venezuelan Equine Encephalitis Replicons Expressing Norwalk Virus-Like Particles

Norwalk-like viruses (NLVs) are a diverse group of single-stranded, nonenveloped, positive-polarity RNA viruses and are the leading cause of epidemic acute gastroenteritis in the United States. In this study, the major capsid gene of Norwalk virus, the prototype NLV, has been cloned and expressed in mammalian cells using a Venezuelan equine encephalitis (VEE) replicon expression system. Upon infection of baby hamster kidney (BHK) cells with VEE replicon particles (VRPs), the Norwalk virus capsid proteins self-assemble to generate high titers of Norwalk virus-like particles (VLPs) that are morphologically and antigenically analogous to wild-type Norwalk virus. Mice inoculated subcutaneously with VRPs expressing the Norwalk virus capsid protein (VRP-NV1) developed systemic and mucosal immune responses to Norwalk VLPs, as well as heterotypic antibody responses to the major capsid protein from another genogroup I NLV strain (NCFL) isolated from a recent outbreak. A second Norwalk virus capsid clone (NV2) containing three amino acid codon mutations from the NV1 clone was also expressed using VEE replicons (VRP-NV2), but upon infection of BHK cells failed to confer VLP self-assembly. Mice inoculated with VRP-NV2 elicited reduced systemic and mucosal immune responses to Norwalk VLPs, demonstrating the importance and potential utility of endogenous VLP presentation for maximum immune induction. Inoculation with either VRP-NV1 or VRP-NV2 resulted in serum antibody responses far superior to the induction in mice dosed orally with VLPs that were prepared using the VEE-NV1 replicon construct, a regimen similar to current models for NLV vaccination. Expression of NLV VLPs in mammalian cells offers a powerful approach for the design of novel NLV vaccines, either alone or in combination with current vaccination models.     

A live attenuated severe acute respiratory syndrome coronavirus is immunogenic and efficacious in golden Syrian hamsters

The immunogenicity and protective efficacy of a live attenuated vaccine consisting of a recombinant severe acute respiratory syndrome (SARS) coronavirus lacking the E gene (rSARS-CoV-ΔE) were studied using hamsters. Hamsters immunized with rSARS-CoV-ΔE developed high serum-neutralizing antibody titers and were protected from replication of homologous (SARS-CoV Urbani) and heterologous (GD03) SARS-CoV in the upper and lower respiratory tract. rSARS-CoV-ΔE-immunized hamsters remained active following wild-type virus challenge, while mock-immunized hamsters displayed decreased activity. Despite being attenuated in replication in the respiratory tract, rSARS-CoV-ΔE is an immunogenic and efficacious vaccine in hamsters.