Impure Hydrazone Preparation from Chicken Dung

Hydrazones are strong reducing agents. Some hydrazones like hydrazine are is highly toxic and unstable and are therefore found dissolved in water. Chicken dung contains amines and uric acid that are potential sources of hydrazones. This paper reports on the use of chicken dung as an important raw material for the industrial hydrazones. In this study, we investigated the conversion of amine to amide compounds in chicken dung and later chlorine treatment to produce impure hydrazones. In the preparation, 1.0 kg of the chicken dung was soaked in 2.0 litres of distilled water for fifteen days. After filtration, the leachate obtained was treated with chlorine gas. The chemical conversion of the compounds in the chicken dung leachate before and after chlorination was monitored using FT-IR and MS. A sample of pure hydrazine hydrate was analyzed using the two techniques and the spectra obtained was used as a reference standard.  The findings of this study indicate that chicken dung is rich in amine-containing compounds that can be converted to amide derivatives under ambient conditions. A comparison of FT-IR and MS data before and after chlorination indicated the formation of hydrazones. The findings of this study provide some scientific rationale for using chicken dung as an alternative source of industrial hydrazones. Keywords: Hydrazones, amines, amides, chicken dung. DOI: 10.7176/CMR/12-7-02 Publication date:September 30th 202

Factors influencing farmer-to-farmer extension of forage legume technology

Forage legumes have been introduced to farmers in Central Kenya between 1980 and 2002 through various Institutional and Projects’ efforts. The adoption rate of these forages among farmers has been found to be rather low, with the NDDP reporting only 1.9 % of farms surveyed and an ICRAF report indicating that the technology was only reaching 1 % of smallholder farms. An evaluation of adoption of Calliandra and Desmodium was conducted to identify farm characteristics affecting the likelihood of sharing of Desmodium and Calliandra technologies as well as to characterise the spread or diffusion of the technology from the original contact groups and the effect of distance from those groups. Three groups of farmers were approached. A first generation who received planting material from the distributors, a second generation who received planting materials from the former, and a randomly selected group of farmers at various distances from the first contacts. Informal discussions were held with the farmers and formal questionnaires filled. Out of the 133 first generation farmers contacted 64.7% still had Desmodium and 89.5% still had Calliandra. More farms in the contact sub-locations had the plants than the sub-locations further away. The small sample size of those with the forages could not allow effect of distance to be worked out. Tobit estimates of effects of farmer attributes influencing sharing of planting materials shows that the status of the household head in the community positively affected the likelihood of giving out planting material. The technology has a rather slow spread as indicated by percentages of farms with the forages. For better adoption and spread proponents of the technology should have the technology introduced to farmers who have substantial positions in farmer groups or have been bestowed community responsibility

Priming Cross-Protective Bovine Viral Diarrhea Virus-Specific Immunity Using Live-Vectored Mosaic Antigens

Bovine viral diarrhea virus (BVDV) plays a key role in bovine respiratory disease complex, which can lead to pneumonia, diarrhea and death of calves. Current vaccines are not very effective due, in part, to immunosuppressive traits and failure to induce broad protection. There are diverse BVDV strains and thus, current vaccines contain representative genotype 1 and 2 viruses (BVDV-1 & 2) to broaden coverage. BVDV modified live virus (MLV) vaccines are superior to killed virus vaccines, but they are susceptible to neutralization and complement-mediated destruction triggered by passively acquired antibodies, thus limiting their efficacy. We generated three novel mosaic polypeptide chimeras, designated NproE2123; NS231; and NS232, which incorporate protective determinants that are highly conserved among BVDV-1a, 1b, and BVDV-2 genotypes. In addition, strain-specific protective antigens from disparate BVDV strains were included to broaden coverage. We confirmed that adenovirus constructs expressing these antigens were strongly recognized by monoclonal antibodies, polyclonal sera, and IFN-γ-secreting T cells generated against diverse BVDV strains. In a proof-of-concept efficacy study, the multi-antigen proto-type vaccine induced higher, but not significantly different, IFN-γ spot forming cells and T-cell proliferation compared to a commercial MLV vaccine. In regards to the humoral response, the prototype vaccine induced higher BVDV-1 specific neutralizing antibody titers, whereas the MLV vaccine induced higher BVDV-2 specific neutralizing antibody titers. Following BVDV type 2a (1373) challenge, calves immunized with the proto-type or the MLV vaccine had lower clinical scores compared to naïve controls. These results support the hypothesis that a broadly protective subunit vaccine can be generated using mosaic polypeptides that incorporate rationally selected and validated protective determinants from diverse BVDV strains. Furthermore, regarding biosafety of using a live vector in cattle, we showed that recombinant human adenovirus-5 was cleared within one week following intradermal inoculation

The effect of bovine viral diarrhea virus (BVDV) strains on bovine monocyte-derived dendritic cells (Mo-DC) phenotype and capacity to produce BVDV

BACKGROUND: Dendritic cells (DC) are important antigen presentation cells that monitor, process, and present antigen to T cells. Viruses that infect DC can have a devastating impact on the immune system. In this study, the ability of bovine viral diarrhea virus (BVDV) to replicate and produce infectious virus in monocyte-derived dendritic cells (Mo-DC) and monocytes was studied. The study also examined the effect of BVDV infection on Mo-DC expression of cell surface markers, including MHCI, MHCII, and CD86, which are critical for DC function in immune response. METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from bovine blood through gradient centrifugation. The adherent monocytes were isolated from PBMCs and differentiated into Mo-DC using bovine recombinant interleukin-4 (IL-4) and granulocyte-macrophage colony-stimulating factor (GMCSF). To determine the effect of BVDV on Mo-DC, four strains of BVDV were used including the severe acute non-cytopathic (ncp) BVDV2a-1373; moderate acute ncp BVDV2a 28508-5; and a homologous virus pair [i.e., cytopathic (cp) BVDV1b TGAC and ncp BVDV1b TGAN]. The Cooper strain of bovine herpesvirus 1 (BHV1) was used as the control virus. Mo-DC were infected with one of the BVDV strains or BHV-1 and were subsequently examined for virus replication, virus production, and the effect on MHCI, MHCII, and CD86 expression. RESULTS: The ability of monocytes to produce infectious virus reduced as monocytes differentiated to Mo-DC, and was completely lost at 120 hours of maturation. Interestingly, viral RNA increased throughout the course of infection in Mo-DC, and the viral non-structural (NS5A) and envelope (E2) proteins were expressed. The ncp strains of BVDV down-regulated while cp strain up-regulated the expression of the MHCI, MHCII, and CD86 on Mo-DC. CONCLUSIONS: The study revealed that the ability of Mo-DC to produce infectious virus was reduced with its differentiation from monocytes to Mo-DC. The inability to produce infectious virus may be due to a hindrance of virus packaging or release mechanisms. Additionally, the study demonstrated that ncp BVDV down-regulated and cp BVDV up-regulated the expression of Mo-DC cell surface markers MHCI, MHCII, and CD86, which are important in the mounting of immune responses

Immunogenic and Invasive Properties of Brucella melitensis 16M Outer Membrane Protein Vaccine Candidates Identified via a Reverse Vaccinology Approach

Brucella is the etiologic agent of brucellosis, one of the most common and widely distributed zoonotic diseases. Its highly infectious nature, the insidious, systemic, chronic, debilitating aspects of the disease and the lack of an approved vaccine for human use in the United States are features that make Brucella a viable threat to public health. One of the main impediments to vaccine development is identification of suitable antigens. In order to identify antigens that could potentially be used in a vaccine formulation, we describe a multi-step antigen selection approach. We initially used an algorithm (Vaxign) to predict ORF encoding outer membrane proteins with antigenic determinants. Differential gene expression during acute infection and published evidence for a role in virulence were used as criteria for down-selection of the candidate antigens that resulted from in silico prediction. This approach resulted in the identification of nine Brucella melitensis outer membrane proteins, 5 of which were recombinantly expressed and used for validation. Omp22 and Hia had the highest in silico scores for adhesin probability and also conferred invasive capacity to E. coli overexpressing recombinant proteins. With the exception of FlgK in the goat, all proteins reacted to pooled sera from exposed goats, mice, and humans. BtuB, Hia and FlgK stimulated a mixed Th1-Th2 response in splenocytes from immunized mice while BtuB and Hia elicited NO release from splenocytes of S19 immunized mice. The results support the applicability of the current approach to the identification of antigens with immunogenic and invasive properties. Studies to assess immunogenicity and protective efficacy of individual proteins in the mouse are currently underway

Reshaping Antibody Diversity

SummarySome species mount a robust antibody response despite having limited genome-encoded combinatorial diversity potential. Cows are unusual in having exceptionally long CDR H3 loops and few V regions, but the mechanism for creating diversity is not understood. Deep sequencing reveals that ultralong CDR H3s contain a remarkable complexity of cysteines, suggesting that disulfide-bonded minidomains may arise during repertoire development. Indeed, crystal structures of two cow antibodies reveal that these CDR H3s form a very unusual architecture composed of a β strand “stalk” that supports a structurally diverse, disulfide-bonded “knob” domain. Diversity arises from somatic hypermutation of an ultralong DH with a severe codon bias toward mutation to cysteine. These unusual antibodies can be elicited to recognize defined antigens through the knob domain. Thus, the bovine immune system produces an antibody repertoire composed of ultralong CDR H3s that fold into a diversity of minidomains generated through combinations of somatically generated disulfides