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Atsbeha G, Mekonnen T, Kebede M, Haileselassie T, Goodwin SB, Tesfaye K. Genetic architecture of adult-plant resistance to stripe rust in bread wheat ( Triticum aestivum L.) association panel. Front Plant Sci 2023; 14:1256770. [PMID: 38130484 PMCID: PMC10733515 DOI: 10.3389/fpls.2023.1256770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Accepted: 11/15/2023] [Indexed: 12/23/2023]
Abstract
Stripe rust, caused by Puccinia striiformis f. sp. tritici, is a severe disease in wheat worldwide, including Ethiopia, causing up to 100% wheat yield loss in the worst season. The use of resistant cultivars is considered to be the most effective and durable management technique for controlling the disease. Therefore, the present study targeted the genetic architecture of adult plant resistance to yellow rust in 178 wheat association panels. The panel was phenotyped for yellow rust adult-plant resistance at three locations. Phonological, yield, yield-related, and agro-morphological traits were recorded. The association panel was fingerprinted using the genotyping-by-sequencing (GBS) platform, and a total of 6,788 polymorphic single nucleotide polymorphisms (SNPs) were used for genome-wide association analysis to identify effective yellow rust resistance genes. The marker-trait association analysis was conducted using the Genome Association and Prediction Integrated Tool (GAPIT). The broad-sense heritability for the considered traits ranged from 74.52% to 88.64%, implying the presence of promising yellow rust resistance alleles in the association panel that could be deployed to improve wheat resistance to the disease. The overall linkage disequilibrium (LD) declined within an average physical distance of 31.44 Mbp at r2 = 0.2. Marker-trait association (MTA) analysis identified 148 loci significantly (p = 0.001) associated with yellow rust adult-plant resistance. Most of the detected resistance quantitative trait loci (QTLs) were located on the same chromosomes as previously reported QTLs for yellow rust resistance and mapped on chromosomes 1A, 1B, 1D, 2A, 2B, 2D, 3A, 3B, 3D, 4A, 4B, 4D, 5A, 5B, 6A, 6B, 7A, and 7D. However, 12 of the discovered MTAs were not previously documented in the wheat literature, suggesting that they could represent novel loci for stripe rust resistance. Zooming into the QTL regions in IWGSC RefSeq Annotation v1 identified crucial disease resistance-associated genes that are key in plants' defense mechanisms against pathogen infections. The detected QTLs will be helpful for marker-assisted breeding of wheat to increase resistance to stripe rust. Generally, the present study identified putative QTLs for field resistance to yellow rust and some important agronomic traits. Most of the discovered QTLs have been reported previously, indicating the potential to improve wheat resistance to yellow rust by deploying the QTLs discovered by marker-assisted selection.
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Affiliation(s)
- Genet Atsbeha
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, Adama, Ethiopia
| | - Tilahun Mekonnen
- Institute of Biotechnology, Addis Ababa University, Addis Ababa, Ethiopia
| | - Mulugeta Kebede
- Department of Plant Biology and Biodiversity Management, Addis Ababa University, Addis Ababa, Ethiopia
| | | | - Stephen B. Goodwin
- USDA-Agricultural Research Service, Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, United States
| | - Kassahun Tesfaye
- Institute of Biotechnology, Addis Ababa University, Addis Ababa, Ethiopia
- Bio and Emerging Technology Institute. Affiliated with the Institute of Biotechnology, Addis Ababa, University, Addis Ababa, Ethiopia
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Yirgu M, Kebede M, Feyissa T, Lakew B, Woldeyohannes AB, Fikere M. Single nucleotide polymorphism (SNP) markers for genetic diversity and population structure study in Ethiopian barley (Hordeum vulgare L.) germplasm. BMC Genom Data 2023; 24:7. [PMID: 36788500 PMCID: PMC9930229 DOI: 10.1186/s12863-023-01109-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 01/31/2023] [Indexed: 02/16/2023] Open
Abstract
BACKGROUND High-density single nucleotide polymorphisms (SNPs) are the most abundant and robust form of genetic variants and hence make highly favorable markers to determine the genetic diversity and relationship, enhancing the selection of breeding materials and the discovery of novel genes associated with economically important traits. In this study, a total of 105 barley genotypes were sampled from various agro-ecologies of Ethiopia and genotyped using 10 K single nucleotide polymorphism (SNP) markers. The refined dataset was used to assess genetic diversity and population structure. RESULTS The average gene diversity was 0.253, polymorphism information content (PIC) of 0.216, and minor allelic frequency (MAF) of 0.118 this revealed a high genetic variation in barley genotypes. The genetic differentiation also showed the existence of variations, ranging from 0.019 to 0.117, indicating moderate genetic differentiation between barley populations. Analysis of molecular variance (AMOVA) revealed that 46.43% and 52.85% of the total genetic variation occurred within the accessions and populations, respectively. The heat map, principal components and population structure analysis further confirm the presence of four distinct clusters. CONCLUSIONS This study confirmed that there is substantial genetic variation among the different barley genotypes. This information is useful in genomics, genetics and barley breeding.
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Affiliation(s)
- Mihret Yirgu
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, P.O.Box 1888, Adama, Ethiopia. .,Department of Plant Science, College of Agriculture and Natural Resource, Madda Walabu University, P.O.Box 247, Robe, Oromia, Ethiopia.
| | - Mulugeta Kebede
- grid.7123.70000 0001 1250 5688Department of Plant Biology and Biodiversity Management, College of Natural and Computational Sciences, Addis Ababa University, P.O.Box 3434, Addis Ababa, Ethiopia
| | - Tileye Feyissa
- grid.7123.70000 0001 1250 5688Institute of Biotechnology, Addis Ababa University, P.O.Box 1176, Addis Ababa, Ethiopia
| | - Berhane Lakew
- grid.463251.70000 0001 2195 6683Holetta Agricultural Research Center, Ethiopian Institute of Agricultural Research, Holetta, Ethiopia
| | | | - Mulusew Fikere
- grid.1003.20000 0000 9320 7537Institute of Molecular Bioscience, University of Queensland, Brisbane, Australia
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Yirgu M, Kebede M, Feyissa T, Lakew B, Woldeyohannes AB. Morphological variations of qualitative traits of barley ( Hordeum vulgare L.) accessions in Ethiopia. Heliyon 2022; 8:e10949. [PMID: 36262303 PMCID: PMC9573889 DOI: 10.1016/j.heliyon.2022.e10949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/16/2022] [Accepted: 09/29/2022] [Indexed: 11/17/2022] Open
Abstract
Ethiopian barley germplasm is a potential source of useful traits to fight the production challenges of barley farming and to enhance yield productivity in favorable and marginal environments. A study was carried out to assess the distribution and patterns of 17 qualitative trait variations among 85 Ethiopian barley accessions using an alpha lattice design with two replications. The Shannon-Weaver diversity (H') index was used to estimate morphological diversity. Fifteen morphological traits of barley accessions originating from various regions of origins and altitude ranges were polymorphic. However, two traits including stem branching and lemma awn were monomorphic. The highest (0.94) overall mean of H' was obtained for glume colour, kernel row and kernel shape. The estimated H' ranged from 0.41 to 0.99 across regions, and 0.52 to 0.99 across altitude ranges with an overall mean of 0.76. The analysis of variance of H' showed significant variation for most studied traits. Principal components analysis revealed that eight traits were the major loading on the first two principal components that describe 38.3% of the total morphological variance. Heat map analysis based on morphological traits of barley accessions was also grouped into three distinct clusters. Thus, the present finding confirmed that the Ethiopian barley accessions showed vast morphological variations across the region of origins and altitude ranges. Based on the result, further evaluation is ongoing to exploit specific gene variations through phenotyping and genotyping trait association.
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Affiliation(s)
- Mihret Yirgu
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, P.O. Box 1888, Adama, Ethiopia
- Department of Plant Science, College of Agriculture and Natural Resource, Madda Walabu University, P.O. Box 247, Robe, Oromia, Ethiopia
- Corresponding author.
| | - Mulugeta Kebede
- Department of Plant Biology and Biodiversity Management, College of Natural and Computational Sciences, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
| | - Tileye Feyissa
- Institute of Biotechnology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
| | - Berhane Lakew
- Holetta Agricultural Research Center, Ethiopian Institute of Agricultural Research, Holetta, Ethiopia
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Senbeta D, Kebede M. Investigation of promoter regions, motifs, and CpG islands in the regulation of gene expression in Trametes hirsuta strain 072. J Genet Eng Biotechnol 2021; 19:160. [PMID: 34661793 PMCID: PMC8523640 DOI: 10.1186/s43141-021-00261-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 10/02/2021] [Indexed: 11/29/2022]
Abstract
Background In silico analysis of transcription start sites, promoter regions, transcription factors and their binding sites, and CpG islands for the Trametes hirsuta strain 072 genome were performed to understand the regulation mechanisms of gene expression and its genetic variations in the genomes. Therefore, a computational survey was carried out for the Trametes hirsuta strain 072 genome with the open reading frames from the National Center for Biotechnology Information database. Seventeen functional sequences were used to analyze promoter regions and their regulatory elements. Result The present study revealed that 94% of Trametes hirsuta strain 072 genes contained more than two TSSs. Among these identified TSSs, a TSS with the highest predictive score was considered to determine a promoter region of the genes. Moreover, a total of five common candidate motifs such as MotI, MotII, MotIII, MotIV, and MotV were identified. Among these motifs, motif IV was investigated as the common promoter motif for 41.17% of genes that serve as binding sites for transcription factors (TFs) involved in the expression regulation of Trametes hirsuta strain 072 genes. Motif IV was also compared to registered motifs in publically available databases to see if they are similar to known regulatory motifs for TF using TOMTOM web server. Hence, it was revealed that MotIV might serve as the binding site mainly for the leucine zipper TF gene family to regulate a gene expression of Trametes hirsuta strain 072. Regarding CpG island determination, it was concluded that there is no CpG island in both promoter and gene body regions of the Trametes hirsuta strain 072 genome. Conclusions This study provides a better insight into further molecular characterization which aimed to efficiently exploit a white rot fungus, Trametes hirsuta strain 072, for several biotechnological applications aimed to revitalize a severely contaminated environment.
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Affiliation(s)
- Dinku Senbeta
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, P.O. Box 1888, Adama, Ethiopia. .,Department of Biology, College of Natural & Computational Science, Adigrat University, P.O. Box 50, Adigrat, Ethiopia.
| | - Mulugeta Kebede
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, P.O. Box 1888, Adama, Ethiopia
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Kebede A, Kebede M. In silico analysis of promoter region and regulatory elements of glucan endo-1,3-beta-glucosidase encoding genes in Solanum tuberosum: cultivar DM 1-3 516 R44. J Genet Eng Biotechnol 2021; 19:145. [PMID: 34591228 PMCID: PMC8484425 DOI: 10.1186/s43141-021-00240-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 09/02/2021] [Indexed: 01/01/2023]
Abstract
Background Potato (Solanum tuberosum L.) is one of the most important food crops in the world. Pathogens remain as one of the major constraints limiting potato productivity. Thus, understanding of gene regulation mechanism of pathogenesis-related genes such as glucan endo-1,3-beta-glucosidase is a foundation for genetic engineering of potato for disease resistance and reduces the use of fungicides. In the present study, 19 genes were selected and attempts were made through in silico methods to identify and characterize the promoter regions, regulatory elements, and CpG islands of glucan endo-1,3-beta-glucosidase gene in Solanum tuberosum cultivar DM 1-3 516 R44. Results The current analysis revealed that single transcription start sites (TSSs) were present in 12/19 (63.2%) of promoter regions analyzed. The predictive score at a cutoff value of 0.8 for the majority (84.2%) of the promoter regions ranged from 0.90 to 1.00. The locations for 42% of the TSSs were below −500 bp relative to the start codon (ATG). MβGII was identified as the common promoter motif for 94.4% of the genes with an E value of 3.5e−001. The CpG analysis showed low CpG density in the promoter regions of most of the genes except for gene ID102593331 and ID: 102595860. The number of SSRs per gene ranged from 2 to 9 with repeat lengths of 2 to 6 bp. Evolutionary distances ranged from 0.685 to 0.770 (mean = 0.73), demonstrating narrower genetic diversity range. Phylogeny was inferred using the UPGMA method, and gene sequences from different species were found to be clustered together. Conclusion In silico identified regulatory elements in promoter regions will contribute to our understanding of the regulatory mechanism of glucan endo-1,3-beta-glucosidase genes and provide a promising target for genetic engineering to improve disease resistance in potatoes. Supplementary Information The online version contains supplementary material available at 10.1186/s43141-021-00240-0.
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Affiliation(s)
- Atnafu Kebede
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, P.O. Box 1888, Adama, Ethiopia. .,Department of Biology, College of Natural and Computational Sciences, Dire Dawa University, P.O. Box 1362, Dire Dawa, Ethiopia.
| | - Mulugeta Kebede
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, P.O. Box 1888, Adama, Ethiopia
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Bantihun G, Kebede M. In silico analysis of promoter region and regulatory elements of mitogenome co-expressed trn gene clusters encoding for bio-pesticide in entomopathogenic fungus, Metarhizium anisopliae: strain ME1. J Genet Eng Biotechnol 2021; 19:94. [PMID: 34156573 PMCID: PMC8218090 DOI: 10.1186/s43141-021-00191-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Accepted: 06/08/2021] [Indexed: 02/07/2023]
Abstract
Background Pest control strategies almost entirely rely on chemical insecticides, which cause environmental problems such as biosphere deterioration and emergence of resistant pests. Bio-pesticide is an alternative approach, which uses organisms such as entomopathogenic fungi, Metarhizium anisopliae, to control pests. Screening such potential organism at a molecular level and understanding their gene regulation mechanism is an important approach to reduce emergence of pesticide resistance and worsening of the biosphere. Understanding promoter regions which play a pivotal role in gene regulation is crucial. In particular, identification of the promoter regions in M. anisopliae Strain ME1 remains poorly understood. To our knowledge, the mitogenome trn gene clusters of M. anisopliae Strain ME1 were not characterized. Here, we used machine learning approach to identify and characterize the promoter regions, regulatory elements, and CpG island densities of 15 protein coding genes of entomopathogenic fungi, M. anisolpliae Strain ME1. Results The current analysis revealed multiple transcription start sites (TSS) for all utilized sequences, except for promoter region genes of Pro-cob and Pro-nad5. With reference to the start codon (ATG), 85.3% of TSS was located above – 500 bp. Based on the standard predictive score at cut off value of 0.8a, the current study revealed 54.7% of predictive score greater than or equal from 0.9 promoter prediction score. Expectation maximization algorithm output identified five candidate motifs. Nonetheless, of all candidate motifs, MtrnI was revealed as the common promoter region motif with a value of 76.9% both in terms of size of binding sites and with an E value of 9.1E−054. Accordingly, we perceived that MtrnI serve as the binding site for tryptophan cluster with P value 0.0044 and C4 type zinc fingers functions as the binding site to regulate gene expression of M. anisopliae Strain ME1. The analysis revealed that mitogenome trn gene clusters of M. anisopliae Strain ME1 showed homologues evolutionary ancestor supported with a bootstrap value of 100%. Conclusion Identified common candidate motifs and binding transcription factors through in silico approach are likely expected to contribute for better understanding of gene expression and strain improvement of M. anisopliae Strain ME1 for its bio-pesticides role.
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Affiliation(s)
- Getachew Bantihun
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, P.O. Box 1888, Adama, Ethiopia.
| | - Mulugeta Kebede
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, P.O. Box 1888, Adama, Ethiopia
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Tadesse M, Kebede M, Girma D. Genetic Diversity of Tef [ Eragrostis tef (Zucc.)Trotter] as Revealed by Microsatellite Markers. Int J Genomics 2021; 2021:6672397. [PMID: 33977102 PMCID: PMC8087483 DOI: 10.1155/2021/6672397] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 04/06/2021] [Accepted: 04/07/2021] [Indexed: 11/29/2022] Open
Abstract
Genetic variability is the fundamental prerequisite of any crop-breeding program to develop superior cultivars. There are about 350 Eragrostis1 species, of which, tef is the only species cultivated for human consumption. Currently, the Ethiopian Biodiversity Institute (EBI) collected over five thousand tef accessions from different geographical regions, diverse in terms of climate and elevation, which are uncharacterized yet. The objective of this study was to evaluate the genetic diversity among 64 tef accessions using 10 selected polymorphic simple sequence repeats (SSRs) markers. A total of 314 alleles were detected with an average of 14.5 alleles per locus and amplicon size ranged from 90 bp-320 bp. The mean value of polymorphic information content (PIC) was 0.87, appearing polymorphic for all loci. The lowest Fst value (0.05) was recorded among the studied tef populations. The mean value of major allele frequency and the number of effective alleles were 0.33 and 3.32, respectively. The mean value of gene flow (Nm) and Shannon's information index (I) was 4.74 and 1.65, respectively. The observed (Ho) and expected (He) heterozygosities varied from 0.34 to 0.56 and from 0.58 to 0.76, respectively. The cluster analysis has grouped the 64 tef accessions into three distinct clusters based on their similarity. The PCoA analysis showed that clustering is basing on the geographical origin of accessions. Analysis of molecular variance revealed 56%, 39% and 5% of the total variation due to variation within populations, among individuals and among populations, respectively. Structure bar-plot also inferred three gene pools, but with high level of admixtures. Thus, the present study shows that the identified tef accessions could be of great interest for the initiation of a planned breeding and conservation programs.
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Affiliation(s)
- Mahilet Tadesse
- Adama Science and Technology University, Department of Applied Biology, P. O. Box 1888, Adama, Ethiopia
- Ethiopian Institute of Agricultural Research, Debre Zeit Agricultural Research Center, P. O. Box 32, Debre Zeit, Ethiopia
| | - Mulugeta Kebede
- Adama Science and Technology University, Department of Applied Biology, P. O. Box 1888, Adama, Ethiopia
| | - Dejene Girma
- Ethiopian Institute of Agricultural Research, National Agricultural Biotechnology Research Center, P.O. Box 249, Holetta, Ethiopia
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Aman Beshir J, Kebede M. In silico analysis of promoter regions and regulatory elements (motifs and CpG islands) of the genes encoding for alcohol production in Saccharomyces cerevisiaea S288C and Schizosaccharomyces pombe 972h. J Genet Eng Biotechnol 2021; 19:8. [PMID: 33428031 PMCID: PMC7801573 DOI: 10.1186/s43141-020-00097-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 11/17/2020] [Indexed: 11/10/2022]
Abstract
BACKGROUND The crucial factor in the production of bio-fuels is the choice of potent microorganisms used in fermentation processes. Despite the evolving trend of using bacteria, yeast is still the primary choice for fermentation. Molecular characterization of many genes from baker's yeast (Saccharomyces cerevisiaea), and fission yeast (Schizosaccharomyces pombe), have improved our understanding in gene structure and the regulation of its expression. This in silico study was done with the aim of analyzing the promoter regions, transcription start site (TSS), and CpG islands of genes encoding for alcohol production in S. cerevisiaea S288C and S. pombe 972h-. RESULTS The analysis revealed the highest promoter prediction scores (1.0) were obtained in five sequences (AAD4, SFA1, GRE3, YKL071W, and YPR127W) for S. cerevisiaea S288C TSS while the lowest (0.8) were found in three sequences (AAD6, ADH5, and BDH2). Similarly, in S. pombe 972h-, the highest (0.99) and lowest (0.88) prediction scores were obtained in five (Adh1, SPBC8E4.04, SPBC215.11c, SPAP32A8.02, and SPAC19G12.09) and one (erg27) sequences, respectively. Determination of common motifs revealed that S. cerevisiaea S288C had 100% coverage at MSc1 with an E value of 3.7e-007 while S. pombe 972h- had 95.23% at MSp1 with an E value of 2.6e+002. Furthermore, comparison of identified transcription factor proteins indicated that 88.88% of MSp1 were exactly similar to MSc1. It also revealed that only 21.73% in S. cerevisiaea S288C and 28% in S. pombe 972h- of the gene body regions had CpG islands. A combined phylogenetic analysis indicated that all sequences from both S. cerevisiaea S288C and S. pombe 972h- were divided into four subgroups (I, II, III, and IV). The four clades are respectively colored in blue, red, green, and violet. CONCLUSION This in silico analysis of gene promoter regions and transcription factors through the actions of regulatory structure such as motifs and CpG islands of genes encoding alcohol production could be used to predict gene expression profiles in yeast species.
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Affiliation(s)
- Jemal Aman Beshir
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, P.O. Box 1888, Adama, Ethiopia
- Ethiopian Sugar Corporation, Sugar Academy, Wonji, Ethiopia
| | - Mulugeta Kebede
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, P.O. Box 1888, Adama, Ethiopia
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Teshome S, Kebede M. Analysis of regulatory elements in GA2ox, GA3ox and GA20ox gene families in Arabidopsis thaliana: an important trait. BIOTECHNOL BIOTEC EQ 2021. [DOI: 10.1080/13102818.2021.1995494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Affiliation(s)
- Shiferaw Teshome
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, Adama, Ethiopia
- Department of Biotechnology, College of Natural and Computational Science, Wolaita Sodo University, Sodo, Ethiopia
| | - Mulugeta Kebede
- Department of Applied Biology, School of Applied Natural Science, Adama Science and Technology University, Adama, Ethiopia
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Sime G, Tilahun G, Kebede M. Assessment of biomass energy use pattern and biogas technology domestication programme in Ethiopia. African Journal of Science, Technology, Innovation and Development 2020. [DOI: 10.1080/20421338.2020.1732595] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Getachew Sime
- Department of Biology, College of Natural Sciences, Hawassa University, Ethiopia
- Department of Plant Sciences, Norwegian University of Life Sciences (NMBU), Norway
| | - Girma Tilahun
- Department of Biology, College of Natural Sciences, Hawassa University, Ethiopia
| | - Mulugeta Kebede
- Departmentof Applied Biology, Adama Science and Technology University, Ethiopia
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Kebede M, Greyling JPC, Schwalbach LMJ. Effect of season and supplementation on percentage live sperm and sperm abnormalities in Horro (Zebu) bulls in sub-humid environment in Ethiopia. Trop Anim Health Prod 2008; 39:149-54. [PMID: 18318353 DOI: 10.1007/s11250-007-4297-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
A total of 32 Horro (Bos indicus) bulls, with an average initial body weight and age of approximately 211 kg and 6 years were evaluated. The bulls were divided into two treatment groups. One group was given a supplementary concentrate at a rate of 1.5 kg/day and the second group served as the control and received no supplementation. The observation period lasted for 50 weeks. Semen was collected every two weeks by mean of electrical stimulation with the aid of an electro-ejaculator. The percentage of abnormal sperm (total abnormalities, head, midpiece and tail) remained lower in the supplemented group than in the non-supplemented group. The percentage of live sperm tended to be higher in the supplemented group throughout the 50-week trial period. Until week 17 of the trial there were no significant differences; however, starting at week 18 there were significant differences between the two treatment groups except for week 26. Thereafter, significant differences were recorded until week 38; from week 40 no significant differences were observed between the two groups in respect of percentage of live sperm (except for week 48). Season (week) during which the semen samples were collected had no significant effect on the percentage of abnormal sperm in both treatment groups (supplemented and non-supplemented). At the start of the trial the nutritionally supplemented group had a higher occurrence of sperm abnormalities (11.4% +/- 1.1%) compared to 8.3% +/- 1.3% in the control group. Thereafter, sperm abnormalities declined rapidly in the supplemented group (except for week 50). The sperm abnormalities for the non-supplemented group showed a tendency to increase during the entire observation period.
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Affiliation(s)
- M Kebede
- Oromia Agricultural Research Institute, Bako Agric. Research Centre, P.O. Box 03, West Shoa, Bako, Ethiopia.
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Aston-Mourney K, Wong N, Kebede M, Zraika S, Balmer L, McMahon JM, Fam BC, Favaloro J, Proietto J, Morahan G, Andrikopoulos S. Increased nicotinamide nucleotide transhydrogenase levels predispose to insulin hypersecretion in a mouse strain susceptible to diabetes. Diabetologia 2007; 50:2476-85. [PMID: 17922105 DOI: 10.1007/s00125-007-0814-x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Accepted: 07/17/2007] [Indexed: 01/02/2023]
Abstract
AIMS/HYPOTHESIS Insulin hypersecretion may be an independent predictor of progression to type 2 diabetes. Identifying genes affecting insulin hypersecretion are important in understanding disease progression. We have previously shown that diabetes-susceptible DBA/2 mice congenitally display high insulin secretion. We studied this model to map and identify the gene(s) responsible for this trait. METHODS Intravenous glucose tolerance tests followed by a genome-wide scan were performed on 171 (C57BL/6 x DBA/2) x C57BL/6 backcross mice. RESULTS A quantitative trait locus, designated hyperinsulin production-1 (Hip1), was mapped with a logarithm of odds score of 7.7 to a region on chromosome 13. Production of congenic mice confirmed that Hip1 influenced the insulin hypersecretion trait. By studying appropriate recombinant inbred mouse strains, the Hip1 locus was further localised to a 2 Mb interval, which contained only nine genes. Expression analysis showed that the only gene differentially expressed in islets isolated from the parental strains was Nnt, which encodes the mitochondrial proton pump, nicotinamide nucleotide transhydrogenase (NNT). We also found in five mouse strains a positive correlation (r2 = 0.90, p < 0.01) between NNT activity and first-phase insulin secretion, emphasising the importance of this enzyme in beta cell function. Furthermore, of these five strains, only those with high NNT activity are known to exhibit severe diabetes after becoming obese. CONCLUSIONS/INTERPRETATION Insulin hypersecretion is associated with increased Nnt expression. We suggest that NNT must play an important role in beta cell function and that its effect on the high insulin secretory capacity of the DBA/2 mouse may predispose beta cells of these mice to failure.
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Affiliation(s)
- K Aston-Mourney
- The University of Melbourne Department of Medicine (AH/NH), Heidelberg Repatriation Hospital, Heidelberg Heights, Melbourne, VIC, Australia
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13
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Fam BC, Morris MJ, Hansen MJ, Kebede M, Andrikopoulos S, Proietto J, Thorburn AW. Modulation of central leptin sensitivity and energy balance in a rat model of diet-induced obesity. Diabetes Obes Metab 2007; 9:840-52. [PMID: 17924866 DOI: 10.1111/j.1463-1326.2006.00653.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
AIM The aim of this study was to further explore the time-dependent changes in leptin sensitivity using a rat model of dietary fat-induced obesity and to investigate the potential mechanisms governing these changes. METHODS We used male, adult Sprague-Dawley rats that were fed either a standard laboratory chow diet (3% fat) or a high-saturated fat (HF) diet (60% fat) for 2 or 5 weeks. Energy balance (body weight, energy intake and energy expenditure); sensitivity to central leptin and central alpha-melanin stimulating hormone (alpha-MSH) administration and expression levels of hypothalamic ObRb, signal transducers and activators of transcription factor (STAT)-3 phosphorylation, suppressor of cytokine signalling-3 (SOCS-3), proopiomelanocortin (POMC) processing hormones (prohormone convertase-1 and prohormone convertase-2) and neuropeptide Y (NPY) were measured. RESULTS After 2 weeks of feeding HF diet, there was an increase in total energy intake (TEI) but a reduction in food intake as measured by the mass of food ingested. Body weight at this time was not significantly different between the two diet groups; however, white adipose tissue (WAT) weight was significantly greater in the HF-fed rats than in the chow-fed rats. In addition, spontaneous physical activity levels were increased, but no changes were observed in resting energy expenditure. Furthermore, chow-fed lean rats responded to central leptin administration by reducing the energy intake by approximately 67 kJ compared with saline treatment (p < 0.05), while the HF-fed diet-induced obese (DIO) rats responded by reducing their energy intake by approximately 197 kJ compared with saline treatment (p < 0.05). After 5 weeks of feeding HF diet, TEI remained significantly higher, body weight was significantly increased by 5% in the HF-fed rats and WAT weight was significantly heavier in HF-fed rats than in the chow-fed lean rats. After leptin treatment, the chow-fed lean rats reduced their energy intake by approximately 97 kJ (p < 0.05); yet, leptin had no significant effect in the HF-fed DIO rats. ObRb protein expression, STAT-3 phosphorylation levels, content and messenger RNA (mRNA) expression of NPY, SOCS-3 mRNA and protein expression and energy intake response to central alpha-MSH administration were not altered after HF diet feeding. CONCLUSION These results suggest that early in the course of HF diet-induced weight gain, there was a period of central leptin hypersensitivity, and as the obesity progresses, central leptin insensitivity develops. This insensitivity does not appear to be explained by a downregulation of ObRb protein levels, reduced leptin signalling, an increase in either SOCS-3 or NPY expression or reduced function of the melanocortin system. The effect of an HF diet on other actions of leptin such as its effect on the endocannabinoid system should be investigated.
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Affiliation(s)
- B C Fam
- Department of Medicine, Austin and Repatriation Medical Centre, University of Melbourne, Heidelberg, Victoria, Australia.
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14
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Kebede M, Ehrich D, Taberlet P, Nemomissa S, Brochmann C. Phylogeography and conservation genetics of a giant lobelia (Lobelia giberroa) in Ethiopian and Tropical East African mountains. Mol Ecol 2007; 16:1233-43. [PMID: 17391409 DOI: 10.1111/j.1365-294x.2007.03232.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Lobelia giberroa is a giant rosette plant growing in the afro-montane belt of the afro-alpine environment, a unique and little-studied ecosystem occupying the high mountains of eastern Africa. We analysed amplified fragment length polymorphisms (AFLPs) from 11 mountain systems in Ethiopia and Tropical East Africa to infer the phylogeographical history of the species. A total of 191 individuals were investigated from 25 populations. Principal coordinate analysis and population structure analyses revealed three major phylogeographical groups: the Ethiopian mountains and one group on each side of the Rift Valley in Tropical East Africa, respectively: Elgon-Cherangani and Kenya-Aberdare-Kilimanjaro-Meru. Analysis of Molecular Variance showed 55.7% variance among the three groups, suggesting an old divergence. Together with a clear geographical substructure within the main groups, this pattern indicates gradual expansion and supports the montane forest bridge hypothesis, stating that the area occupied by forest was larger and more continuous in previous interglacials and earlier in the present interglacial. Genetic diversity was lower in Ethiopia than in the other two main groups, possibly due to an ancient founder effect when Ethiopia was colonized from the south.
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Affiliation(s)
- Mulugeta Kebede
- Department of Biology, Addis Ababa University, Addis Ababa, Ethiopia.
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15
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Zraika S, Aston-Mourney K, Laybutt DR, Kebede M, Dunlop ME, Proietto J, Andrikopoulos S. The influence of genetic background on the induction of oxidative stress and impaired insulin secretion in mouse islets. Diabetologia 2006; 49:1254-63. [PMID: 16570159 DOI: 10.1007/s00125-006-0212-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Accepted: 12/23/2005] [Indexed: 10/24/2022]
Abstract
AIMS/HYPOTHESIS We determined whether high-glucose-induced beta cell dysfunction is associated with oxidative stress in the DBA/2 mouse, a mouse strain susceptible to islet failure. MATERIALS AND METHODS Glucose- and non-glucose-mediated insulin secretion from the islets of DBA/2 and control C57BL/6 mice was determined following a 48-h exposure to high glucose. Flux via the hexosamine biosynthesis pathway was assessed by determining O-glycosylated protein levels. Oxidative stress was determined by measuring hydrogen peroxide levels and the expression of anti-oxidant enzymes. RESULTS Exposure to high glucose levels impaired glucose-stimulated insulin secretion in DBA/2 islets but not C57BL/6 islets, and this was associated with reduced islet insulin content and lower ATP levels than in C57BL/6 islets. Exposure of islets to glucosamine for 48 h mimicked the effects of high glucose on insulin secretion in the DBA/2 islets. High glucose exposure elevated O-glycosylated proteins; however, this occurred in islets from both strains, excluding a role for O-glycosylation in the impairment of DBA/2 insulin secretion. Additionally, both glucosamine and high glucose caused an increase in hydrogen peroxide in DBA/2 islets but not in C57BL/6 islets, an effect prevented by the antioxidant N-acetyl-L: -cysteine. Interestingly, while glutathione peroxidase and catalase expression was comparable between the two strains, the antioxidant enzyme manganese superoxide dismutase, which converts superoxide to hydrogen peroxide, was increased in DBA/2 islets, possibly explaining the increase in hydrogen peroxide levels. CONCLUSIONS/INTERPRETATION Chronic high glucose culture caused an impairment in glucose-stimulated insulin secretion in DBA/2 islets, which have a genetic predisposition to failure, and this may be the result of oxidative stress.
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Affiliation(s)
- S Zraika
- Department of Medicine (AH/NH), University of Melbourne, Heidelberg Repatriation Hospital, Heidelberg Heights, VIC 3081, Australia
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16
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Dortet L, Nguyen-Khoa T, Kebede M, Coulloc'h J, Massy Z, Lacour B. [Evaluation of lipoperoxidation in hemodialysis patients with a simple test using the "Free Oxygen Radical Monitor"]. Ann Biol Clin (Paris) 2004; 62:707-11. [PMID: 15563431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2004] [Accepted: 08/24/2004] [Indexed: 05/01/2023]
Abstract
Incidence of cardiovascular events is higher in hemodialysis (HD) patients than in general population. Oxidative stress represents a major specific risk factor of accelerated atheroma particularly in association with inflammation and malnutrition. The aim of our study is to evaluate a simple test of lipid peroxidation measurement using the "Free Oxygen Radical Monitor" (FORM) (Callegari, Italy). The results obtained in HD patients were compared to standard oxidative stress markers, such as thiobarbituric acid reacting substances, carbonyls and vitamin E in plasma, and glutathione, oxidized to reduced form ratio, in erythrocytes. In conclusion, the FORM system presents no sufficient sensibility and specificity to determine oxidative stress in HD patients.
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Affiliation(s)
- L Dortet
- Laboratoire de biochimie A, Hôpital Necker-Enfants Malades, Paris
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17
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Lemma T, Hassen A, Kebede M, Aboma G, Galmesa U. Effect of Pre-market Feeding of Maize Stover and Concentrate on Fattening Performance, Carcass Trait and Market Value of Grazing Horro Cows. Journal of Applied Animal Research 2001. [DOI: 10.1080/09712119.2001.9706754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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18
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Nguyen-Khoa T, Massy ZA, De Bandt JP, Kebede M, Salama L, Lambrey G, Witko-Sarsat V, Drüeke TB, Lacour B, Thévenin M. Oxidative stress and haemodialysis: role of inflammation and duration of dialysis treatment. Nephrol Dial Transplant 2001; 16:335-40. [PMID: 11158409 DOI: 10.1093/ndt/16.2.335] [Citation(s) in RCA: 162] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Oxidative stress has long been demonstrated in haemodialysis patients. However, the factors influencing their oxidative status have not been characterized extensively in these patients. Therefore, the present study was designed to investigate the influence of a large number of factors known to be associated with oxidative stress. METHODS In the present cross-sectional study, we determined the plasma levels of lipid and protein oxidation markers in 31 non-smoking haemodialysis patients and 18 non-smoking healthy subjects, together with various components of the antioxidant system at the plasma and erythrocyte level. RESULTS No influence of age, diabetes or iron overload on oxidative markers and plasma and erythrocyte antioxidant systems was detected in these haemodialysis patients. The lack of an association between iron overload and oxidative status may be related to the lower level of plasma ascorbate in haemodialysis patients, since ascorbate favours the generation of free iron from ferritin-bound iron. Interestingly, plasma C reactive protein (CRP) levels measured by highly sensitive CRP assay were correlated positively with plasma levels of thiobarbituric acid reactive substances (r=0.38, P<0.04) and negatively with plasma alpha-tocopherol levels (r=-0.46, P<0.01). Moreover, significant inverse correlations were observed between duration of dialysis treatment and plasma levels of alpha-tocopherol (r=-0.49, P<0.02) and ubiquinol (r=-0.40, P<0.05). CONCLUSIONS Our results suggest that inflammatory status and duration of dialysis treatment are the most important factors relating to oxidative stress in haemodialysis patients.
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Affiliation(s)
- T Nguyen-Khoa
- Biochemistry A and INSERM U507, Necker Hospital, Paris
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19
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Nguyen-Khoa T, Massy ZA, Witko-Sarsat V, Canteloup S, Kebede M, Lacour B, Drüeke T, Descamps-Latscha B. Oxidized low-density lipoprotein induces macrophage respiratory burst via its protein moiety: A novel pathway in atherogenesis? Biochem Biophys Res Commun 1999; 263:804-9. [PMID: 10512761 DOI: 10.1006/bbrc.1999.1438] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Oxidized low-density lipoproteins (oxLDL) play a crucial role in atherogenesis mainly via their capacity to bind and to activate macrophages. However, the role of the protein LDL moiety in this process is not yet established. In this study, human LDL were exposed to hypochlorous acid (HOCl), a selective protein oxidant, or copper sulfate (CuSO(4)), a major lipid oxidant, and tested for their capacity to activate the NADPH-oxidase of human THP-1- and U937-derived macrophages as measured by lucigenin chemiluminescence (CL). Compared to native LDL which had no effect, HOCl-oxLDL triggered potent CL responses in both U937 and THP-1 cells but only when these were fully differentiated into macrophages by phorbol myristate acetate. In contrast, Cu-oxLDL only triggered a moderate CL response of U937 cells and had little effect on THP-1 cells. While delipidation did not affect HOCl-oxLDL-induced CL response it abolished that induced by Cu-oxLDL. Interestingly, U937 cells showed higher CL responses to both types of oxLDL than THP-1 cells, a finding which could be related to their higher expression of the scavenger receptor CD36. Taken together these results strongly support the role of the protein moiety in oxLDL-induced macrophage activation.
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20
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Helton MR, Arndt J, Kebede M, King M. Do low-risk prenatal patients really need a screening glucose challenge test? J Fam Pract 1997; 44:556-561. [PMID: 9191628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
BACKGROUND It is common practice to routinely screen pregnant women for gestational diabetes. The screening technique typically used is the 1-hour 50-g oral glucose tolerance test (OGTT), with a subsequent 3-hour 100-g OGTT for women whose 1-hour test was positive. This process can be both time-consuming and inconvenient for patients. Additionally, its sensitivity and specificity are estimated to be 70% and 87% respectively, and data about the effect of screening and treatment on low-risk pregnancy outcomes are limited. The objective of this study was to reassess the value of routine screening of all pregnant patients with a 1-hour glucose challenge test. METHODS At a university-based family practice center with a predominantly low-risk population, a retrospective analysis was performed of all patients (n = 595) who received prenatal care and gave birth between January 1988 and December 1993. Among women in whom gestational diabetes was diagnosed on the basis of glucose tolerance testing, we identified those with risk factors for the disease, and examined whether a selective screening program based on risk factors alone would have resulted in correct diagnoses of gestational diabetes. RESULTS Of the 595 patients, 544 (91.4%) were screened with a 1-hour 50-g OGTT. This initial screening test was positive in 76 women (12.8%). Of these, 58 (76.3%) then had a 3-hour 100-g OGTT, and 13 received a diagnosis of gestational diabetes. Nine of these 13 women had risk factors for gestational diabetes. We determined that less than 1% of prenatal patients without risk factors for gestational diabetes were ultimately found to have gestational diabetes. CONCLUSIONS Screening with a 1-hour 50-g OGTT only those women who have identifiable risk factors for gestational diabetes is a reasonable approach to identifying the disease in a low-risk population. All pregnant women should have a thorough history taken to determine whether they have risk factors for gestational diabetes.
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Affiliation(s)
- M R Helton
- Department of Family Medicine, School of Medicine, University of North Carolina at Chapel Hill 27599-7595, USA
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21
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Ives TJ, Manzewitsch P, Regnery RL, Butts JD, Kebede M. In vitro susceptibilities of Bartonella henselae, B. quintana, B. elizabethae, Rickettsia rickettsii, R. conorii, R. akari, and R. prowazekii to macrolide antibiotics as determined by immunofluorescent-antibody analysis of infected Vero cell monolayers. Antimicrob Agents Chemother 1997; 41:578-82. [PMID: 9055996 PMCID: PMC163754 DOI: 10.1128/aac.41.3.578] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The in vitro susceptibilities of Bartonella (Rochalimaea) henselae, B. quintana, B. elizabethae, Rickettsia akari, R. conorii, R. prowazekii, and R. rickettsii to different concentrations of azithromycin, clarithromycin, dirithromycin, erythromycin, and roxithromycin in Vero cell cultures were evaluated. Bartonella and Rickettsia spp. were allowed to initiate infection of the antibiotic-free Vero cell monolayers, which were maintained in 16-chamber microscope slides in the absence of antibiotics at 32 degrees C in a CO2-enriched atmosphere. The monolayers were then incubated for 3 h to allow for initial host cell intracellular penetration by infecting species. After inoculation, inocula were replaced and tested with media containing 12 different concentrations of each antibiotic in replicate (10 wells of each antibiotic dilution) for each species, and the monolayers were reincubated. Tetracycline served as the control. Growth status of Bartonella spp. and Rickettsia spp. was determined by evaluation of immunofluorescent staining bacilli. Five days later, when antibiotic-free, control-infected cell monolayers demonstrated significant fluorescence, media were removed for all cell monolayers, the monolayers were fixed, and all specimens were stained with standard indirect immunofluorescent antibody reagents. Fluorescent foci were enumerated by counting such foci on random fields visualized with an epifluorescence microscope. The extent of antibiotic-induced focus inhibition was recorded for each dilution of antibiotic and compared with that of an antibiotic-negative control. Effective antibiotic dilution endpoints for inhibition of Bartonella and Rickettsia proliferation, as judged by absence of increase of significant fluorescence (as compared with no-growth controls), were enumerated by determining the number of cell culture chambers at various antibiotic dilutions that were negative or positive for significant Bartonella- or Rickettsia-specific fluorescence. All of the macrolide agents tested were readily active against all three Bartonella organisms, and azithromycin, clarithromycin, and roxithromycin may have potential in the treatment of Rickettsia infections. Animal model-based clinical trials are warranted to define the specific treatment role of the newer macrolide antibiotics.
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Affiliation(s)
- T J Ives
- School of Pharmacy, University of North Carolina at Chapel Hill 27599-7595, USA.
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22
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Tepper RS, Ives TJ, Kebede M. Recurrent bacterial vaginosis unresponsive to metronidazole: successful treatment with oral clindamycin. J Am Board Fam Pract 1994; 7:431-2. [PMID: 7810359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- R S Tepper
- Student Health Service, University of North Carolina at Chapel Hill 27599-7595
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23
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Curtis P, Kim-Foley S, Kebede M. Urine sampling technique. Br J Gen Pract 1993; 43:260-1. [PMID: 8373653 PMCID: PMC1372427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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24
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Curtis P, Skinner B, Varenholt JJ, Addison L, Resnick J, Kebede M. Papanicolaou smear quality assurance: providing feedback to physicians. J Fam Pract 1993; 36:309-312. [PMID: 8454978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
BACKGROUND The effective management of Papanicolaou (Pap) smears depends on the reliability and accuracy of obtaining and interpreting the specimen. Provider sampling error is one of the important factors contributing to inadequate specimens. Feedback on provider performance may be an effective way to improve the quality of Pap smears. METHODS A pilot study in a university-based residency program involving resident and faculty physicians was initiated to assess the impact of feedback on performance of Pap smears. After establishing adequacy and inadequacy criteria and recording adequacy rates for 3 months, individual and group feedback was implemented. No formal educational intervention on Pap smear technique was undertaken. RESULTS The quality of 836 Pap smears performed by 9 faculty and 13 resident physicians showed continued improvement in both sampling and slide preparation to 90% adequacy over a 9-month period. This improvement, though clinically useful, was not statistically significant owing to the relatively small numbers of smears performed by each physician. This form of feedback may be useful in both practice and educational settings. CONCLUSIONS Feedback without any formal educational intervention led to a clinically useful trend of improvement in the quality of Pap smears, which has been sustained since the study began. This type of simple feedback may be useful in practice settings and particularly valuable in pinpointing areas for improvement for learners in residency programs.
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Affiliation(s)
- P Curtis
- Department of Family Medicine, School of Medicine, University of North Carolina, Chapel Hill 27599
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25
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Curtis P, Varenholt JJ, Skinner B, Addison L, Resnick J, Kebede M. Development of a Pap smear quality-assurance system in family practice. Fam Med 1993; 25:135-9. [PMID: 8458544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND AND OBJECTIVES To improve the effectiveness of cervical cancer screening, quality assurance programs can be designed to ensure that normal Pap smear results are dealt with appropriately and that Pap smears yielding inadequate specimen material are brought to a physician's attention. The objective of this study was to use a new Pap Smear Quality Assurance (PAPQA) system to determine and monitor the performance of physicians in a family practice over a two-year period. METHODS We developed a PAPQA system designed to gather data and report on: 1) Pap smear adequacy, 2) reporting of abnormal results to physicians, and 3) follow-up of patients who had abnormal Pap smear results. We followed these parameters for two years. RESULTS Over a two-year period, 2,771 cervical Pap smears were performed, of which 64% were normal. The percentage of Pap smears that yielded adequate specimen material improved from 82% to 91%, an improvement we attributed to feedback the system provided to physicians. Overall, Pap smear results and follow-up appeared in the medical record of 94% of patients who had abnormal findings. However, during the second year, the quality assurance system detected a deterioration in documentation of results and follow-up plans that coincided with moving the practice to a new facility. The operating cost for this program was approximately $950 per year. CONCLUSIONS Quality assurance programs can effectively monitor physicians' performance in dealing with abnormal Pap smears, can detect deteriorations in performance, and can improve some aspects of performance through feedback reporting to physicians.
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Affiliation(s)
- P Curtis
- Department of Family Medicine, University of North Carolina, Chapel Hill
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Kebede M, Chengappa MM, Stuart JG. Isolation and characterization of temperature-sensitive mutants of Streptococcus suis: efficacy trial of the mutant vaccine in mice. Vet Microbiol 1990; 22:249-57. [PMID: 2353447 DOI: 10.1016/0378-1135(90)90112-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A model of experimental Streptococcus suis infection was developed in young mice. Minimum lethal dose (MLD) values were calculated for four virulent serotypes (1/2, 1, 2, 3) of S. suis using this model. Temperature-sensitive (ts) mutants of S. suis serotypes 1/2 and 1-8 were isolated and characterized on the basis of their growth kinetics and reversion rates. Ts mutants of S. suis 1/2, 1, 2, and 3 were tested as vaccines against the virulent homologous and heterologous challenges in mice. The protection provided was evaluated by analyzing the clinical signs, death or survival. Homologous but not heterologous protection was noted in all mice vaccinated with the mutant strains. Ts mutants of S. suis 1/2 provided 100% protection against challenge by virulent strains of S. suis 1/2, 1, and 2.
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Affiliation(s)
- M Kebede
- Department of Biological Sciences, Murray State University, KY 42071
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