948 research outputs found

    The protein challenge:Matching future demand and supply in Indonesia

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    Indonesia has the fourth largest population in the world and in the coming years food production will need to catch up with its growth. To fulfill the protein demand of this growing population, the productivity of the Indonesian agricultural sector should be increased. This can be achieved either by expanding the agricultural land or by increasing the productivity of existing agricultural land and protein use efficiency. An expansion of agricultural land is not always possible or desirable: large parts of Indonesia comprise forest areas, including tropical rain forests. Consequently, the optimization of the use of existing agricultural land is inevitable. The present manuscript describes and discusses the current protein consumption and production in Indonesia. It presents the levels predicted for 2035, which would imply a strong gap between consumption and production. Alternatives therefore need to be considered to avoid protein shortage in the future. These would include the use of new biomass resources, utilization of agricultural residues as alternative protein sources for feed and other nonfood applications, and biorefining of biomass sources.</p

    The impact of pre-transplantation nephrectomy on quality of life in patients with autosomal dominant polycystic kidney disease

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    PURPOSE: In selected ADPKD patients, a nephrectomy is required in the work-up for a kidney transplantation. Because the impact of this procedure is unknown, we investigated the effect of pre-transplantation nephrectomy on quality of life in this group.METHODS: In this retrospective cohort study all ADPKD patients, ≥ 18 years, who received a kidney transplantation in 2 ADPKD expertise centers between January 2000 and January 2016, were asked to participate. Quality of life was assessed using three validated questionnaires on three time points. Nephrectomy was performed in preparation for transplantation.RESULTS: Two hundred seventy-six ADPKD patients (53 ± 9 years, 56.2% male) were included. 98 patients (35.5%) underwent native nephrectomy in preparation for transplantation, of which 43 underwent bilateral nephrectomy. Pre-transplantation, ADPKD-IS scores were worse in the nephrectomy group vs. no-nephrectomy group (physical: 2.9 vs. 2.3, p &lt; 0.001; emotional: 2.0 vs. 1.8, p = 0.03; fatigue: 3.0 vs. 2.3, p = 0.01). Post-transplantation and post-nephrectomy, ADPKD-IS scores improved significantly in both groups, with a significantly higher improvement in the nephrectomy group. During follow-up, all scores were still better compared to pre-transplantation. Observed physical QoL (ADPKD-IS physical 1.3 vs. 1.7, p = 0.04; SF-36 physical 50.0 vs. 41.3, p = 0.03) was better post-transplantation after bilateral nephrectomy compared to unilateral nephrectomy. In retrospect, 19.7% of patients would have liked to undergo a nephrectomy, while the decision not to perform nephrectomy was made by the treating physician.CONCLUSION: This study shows that pre-transplantation nephrectomy improves quality of life in selected ADPKD patients. Bilateral nephrectomy may be preferred, although the risk of additional complications should be weighted.</p

    Enhancing Jatropha oil extraction yield from the kernels assisted by a xylan-degrading bacterium to preserve protein structure

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    We investigated the use of bacterial cells isolated from paddy crab for the extraction of oil from Jatropha seed kernels in aqueous media while simultaneously preserving the protein structures of this protein-rich endosperm. A bacterial strain—which was marked as MB4 and identified by means of 16S rDNA sequencing and physiological characterization as either Bacillus pumilus or Bacillus altitudinis—enhanced the extraction yield of Jatropha oil. The incubation of an MB4 starter culture with preheated kernel slurry in aqueous media with the initial pH of 5.5 at 37 °C for 6 h liberated 73% w/w of the Jatropha oil. Since MB4 produces xylanases, it is suggested that strain MB4 facilitates oil liberation via degradation of hemicelluloses which form the oil-containing cell wall structure of the kernel. After MB4 assisted oil extraction, SDS-PAGE analysis showed that the majority of Jatropha proteins were preserved in the solid phase of the extraction residues. The advantages offered by this process are: protein in the residue can be further processed for other applications, no purified enzyme preparation is needed, and the resulting oil can be used for biodiesel production

    Production of cyanophycin in Rhizopus oryzae through the expression of a cyanophycin synthetase encoding gene

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    Cyanophycin or cyanophycin granule peptide is a protein that results from non-ribosomal protein synthesis in microorganisms such as cyanobacteria. The amino acids in cyanophycin can be used as a feedstock in the production of a wide range of chemicals such as acrylonitrile, polyacrylic acid, 1,4-butanediamine, and urea. In this study, an auxotrophic mutant (Rhizopus oryzae M16) of the filamentous fungus R. oryzae 99-880 was selected to express cyanophycin synthetase encoding genes. These genes originated from Synechocystis sp. strain PCC6803, Anabaena sp. strain PCC7120, and a codon optimized version of latter gene. The genes were under control of the pyruvate decarboxylase promoter and terminator elements of R. oryzae. Transformants were generated by the biolistic transformation method. In only two transformants both expressing the cyanophycin synthetase encoding gene from Synechocystis sp. strain PCC6803 was a specific enzyme activity detected of 1.5 mU/mg protein. In one of these transformants was both water-soluble and insoluble cyanophycin detected. The water-soluble fraction formed the major fraction and accounted for 0.5% of the dry weight. The water-insoluble CGP was produced in trace amounts. The amino acid composition of the water-soluble form was determined and constitutes of equimolar amounts of arginine and aspartic acid

    Supersite of immune vulnerability on the glycosylated face of HIV-1 envelope glycoprotein gp120

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    A substantial fraction of broadly neutralizing antibodies (bnAbs) in certain HIV-infected donors recognizes glycan-dependent epitopes on HIV-1 gp120. Here, we elucidate how bnAb PGT 135 recognizes its Asn332 glycan-dependent epitope from its crystal structure with gp120, CD4 and Fab 17b at 3.1 Å resolution. PGT 135 interacts with glycans at Asn332, Asn392 and Asn386, using long CDR loops H1 and H3 to penetrate the glycan shield to access the gp120 protein surface. Electron microscopy reveals PGT 135 can accommodate the conformational and chemical diversity of gp120 glycans by altering its angle of engagement. The combined structural studies of PGT 135, PGT 128 and 2G12 show this Asn332-dependent epitope is highly accessible and much more extensive than initially appreciated, allowing for multiple binding modes and varied angles of approach, thereby representing a supersite of vulnerability for antibody neutralization

    Biomass in the manufacture of industrial products—the use of proteins and amino acids

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    The depletion in fossil feedstocks, increasing oil prices, and the ecological problems associated with CO2 emissions are forcing the development of alternative resources for energy, transport fuels, and chemicals: the replacement of fossil resources with CO2 neutral biomass. Allied with this, the conversion of crude oil products utilizes primary products (ethylene, etc.) and their conversion to either materials or (functional) chemicals with the aid of co-reagents such as ammonia and various process steps to introduce functionalities such as -NH2 into the simple structures of the primary products. Conversely, many products found in biomass often contain functionalities. Therefore, it is attractive to exploit this to bypass the use, and preparation of, co-reagents as well as eliminating various process steps by utilizing suitable biomass-based precursors for the production of chemicals. It is the aim of this mini-review to describe the scope of the possibilities to generate current functionalized chemical materials using amino acids from biomass instead of fossil resources, thereby taking advantage of the biomass structure in a more efficient way than solely utilizing biomass for the production of fuels or electricity

    Hundreds of variants clustered in genomic loci and biological pathways affect human height

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    Most common human traits and diseases have a polygenic pattern of inheritance: DNA sequence variants at many genetic loci influence the phenotype. Genome-wide association (GWA) studies have identified more than 600 variants associated with human traits, but these typically explain small fractions of phenotypic variation, raising questions about the use of further studies. Here, using 183,727 individuals, we show that hundreds of genetic variants, in at least 180 loci, influence adult height, a highly heritable and classic polygenic trait. The large number of loci reveals patterns with important implications for genetic studies of common human diseases and traits. First, the 180 loci are not random, but instead are enriched for genes that are connected in biological pathways (P = 0.016) and that underlie skeletal growth defects (P < 0.001). Second, the likely causal gene is often located near the most strongly associated variant: in 13 of 21 loci containing a known skeletal growth gene, that gene was closest to the associated variant. Third, at least 19 loci have multiple independently associated variants, suggesting that allelic heterogeneity is a frequent feature of polygenic traits, that comprehensive explorations of already-discovered loci should discover additional variants and that an appreciable fraction of associated loci may have been identified. Fourth, associated variants are enriched for likely functional effects on genes, being over-represented among variants that alter amino-acid structure of proteins and expression levels of nearby genes. Our data explain approximately 10% of the phenotypic variation in height, and we estimate that unidentified common variants of similar effect sizes would increase this figure to approximately 16% of phenotypic variation (approximately 20% of heritable variation). Although additional approaches are needed to dissect the genetic architecture of polygenic human traits fully, our findings indicate that GWA studies can identify large numbers of loci that implicate biologically relevant genes and pathways.

    Early Steroid Withdrawal Compared With Standard Immunosuppression in Kidney Transplantation - Interim Analysis of the Amsterdam-Leiden-Groningen Randomized Controlled Trial

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    BACKGROUND: The optimal immunosuppressive regimen in kidney transplant recipients, delivering maximum efficacy with minimal toxicity, is unknown. METHODS: The Amsterdam, LEiden, GROningen trial is a randomized, multicenter, investigator-driven, noninferiority, open-label trial in 305 kidney transplant recipients, in which 2 immunosuppression minimization strategies-one consisting of early steroid withdrawal, the other of tacrolimus minimization 6 months after transplantation-were compared with standard immunosuppression with basiliximab, corticosteroids, tacrolimus, and mycophenolic acid. The primary endpoint was kidney function. Secondary endpoints included death, primary nonfunction, graft failure, rejection, discontinuation of study medication, and a combined endpoint of treatment failure. An interim analysis was scheduled at 6 months, that is, just before tacrolimus minimization. RESULTS: This interim analysis revealed no significant differences in Modification of Diet in Renal Disease between the early steroid withdrawal group and the standard immunosuppression groups (43.2 mL/min per 1.73 m2 vs 45.0 mL/min per 1.73 m2, P = 0.408). There were also no significant differences in the secondary endpoints of death (1.0% vs 1.5%; P = 0.737), primary nonfunction (4.1% vs 1.5%, P = 0.159), graft failure (3.1% vs 1.5%, P = 0.370), rejection (18.6% vs 13.6%, P = 0.289), and discontinuation of study medication (19.6% vs 12.6%, P = 0.348). Treatment failure, defined as a composite endpoint of these individual secondary endpoints, was more common in the early steroid withdrawal group (P = 0.027), but this group had fewer serious adverse events and a more favorable cardiovascular risk profile. CONCLUSIONS: Based on these interim results, early steroid withdrawal is a safe short-term immunosuppressive strategy. Long-term outcomes, including a comparison with tacrolimus minimization after 6 months, will be reported in the final 2-year analysis

    T-Cell Epitopes Shared Between Immunizing HLA and Donor HLA Associate With Graft Failure After Kidney Transplantation

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    CD4(+) T-helper cells play an important role in alloimmune reactions following transplantation by stimulating humoral as well as cellular responses, which might lead to failure of the allograft. CD4(+) memory T-helper cells from a previous immunizing event can potentially be reactivated by exposure to HLA mismatches that share T-cell epitopes with the initial immunizing HLA. Consequently, reactivity of CD4(+) memory T-helper cells toward T-cell epitopes that are shared between immunizing HLA and donor HLA could increase the risk of alloimmunity following transplantation, thus affecting transplant outcome. In this study, the amount of T-cell epitopes shared between immunizing and donor HLA was used as a surrogate marker to evaluate the effect of donor-reactive CD4(+) memory T-helper cells on the 10-year risk of death-censored kidney graft failure in 190 donor/recipient combinations using the PIRCHE-II algorithm. The T-cell epitopes of the initial theoretical immunizing HLA and the donor HLA were estimated and the number of shared PIRCHE-II epitopes was calculated. We show that the natural logarithm-transformed PIRCHE-II overlap score, or Shared T-cell EPitopes (STEP) score, significantly associates with the 10-year risk of death-censored kidney graft failure, suggesting that the presence of pre-transplant donor-reactive CD4(+) memory T-helper cells might be a strong indicator for the risk of graft failure following kidney transplantation
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