The Experts below are selected from a list of 72 Experts worldwide ranked by ideXlab platform
Yung Hee Kho - One of the best experts on this subject based on the ideXlab platform.
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Bestatin Analogue from Streptomyces neyagawaensis SL-387
Bioscience Biotechnology and Biochemistry, 1996Co-Authors: Myung Chul Chung, Ho Jae Lee, Hyo Kon Chun, Choong Hwan Lee, Su-il Kim, Yung Hee KhoAbstract:A bestatin analogue, (2S,3R)-3-amino-2-hydroxy-4-phenylbuta- noyl-L-valine (AHPA-Val), from the culture filtrate of Streptomyces neyagawaensisSL-387 was obtained in a chemically defined medium containing DL-3-amino-3-phenylpropionic acid. AHPA-Val was 6 times (IC50= 1.2/μ/ml) as strong as bestatin (IC5O= 7.0/μ/ml) against porcine kidney Microsomal Aminopeptidase N, and 4 times (5.6/μ/ml) as strong as bestatin (IC5O= 20.7 /*g/ml) against Aminopeptidase N of human metastatic fibrosarcoma HT1080. To the best of our knowledge, this is the first report on the microbial production of AHPA-Val.
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Bestatin analogue from Streptomyces neyagawaensis SL-387
Japan Society for Bioscience Biotechnology and Agrochemistry, 1996Co-Authors: Myung Chul Chung, Ho Jae Lee, Hyo Kon Chun, Choong Hwan Lee, Su-il Kim, Yung Hee KhoAbstract:A bestatin analogue, (2S,3R)-3-amino-2-hydroxy-4- phenylbutanoyl-L- valine (AHPA-Val), from the culture filtrate of Streptomyces neyagawaensis SL-387 was obtained in a chemically defined medium containing DL- 3-amino-3- phenylpropionic acid. AHPA-Val was 6 times (IC50=1.2 μg/ml) as strong as bestatin (IC50=7.0 μg/ml) against porcine kidney Microsomal Aminopeptidase N, and 4 times (5.6 μg/ml) as strong as bestatin (IC50= 20.7 μg/ml) against amino-peptidase N of human metastatic fibrosarcoma HT1080. To the best of our knowledge, this is the first report on the microbial production of AHPA-Val.ope
Karl-heinz Wrobel - One of the best experts on this subject based on the ideXlab platform.
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Morphogenesis of the bovine rete testis: the intratesticular rete and its connection to the seminiferous tubules
Anatomy and Embryology, 2000Co-Authors: Karl-heinz WrobelAbstract:The development of the intragonadal rete testis and the establishment of the connection between seminiferous and straight testicular tubules was studied using ultrastructural and histochemical methods in 60 bovine embryos and fetuses ranging from day 39 through day 225 post conceptionem. The methodology included a modified acetylcholinesterase (AChE) reaction as a selective marker for pre-Sertoli cells and a modified Microsomal Aminopeptidase (MAP) reaction as a selective marker for the epithelia of rete testis and straight testicular tubules. Between 40 and 45 days, the rete testis is predominantly an extratesticular rete situated in the cranial peduncle of the gonadal fold and in broad contact with the pro/mesonephric giant corpuscle. During this period, the intragonadal rete enters the gonad proper from its craniodorsal pole and extends into the cranial fourth of the testis. Between 60 and 110 days the rete testis attains its definitive position, extending into the central longitudinal axis as far as to the caudal fourth of the testis. For the caudal expansion of the rete testis the preceding proliferation of the mediastinal stroma is an important prerequisite. In the 40 to 45-day-old embryo the area of the testicular cords may be divided into two zones. A narrow outer zone contains plate-like cords with a thick diameter, and a larger central zone is filled with a network of thinner cords. Only the thick outer cords transform into the permanent seminiferous tubules, whereas the thinner cords in the central zone are transitory structures that disappear between 45 and 110 days. One important function of these transitory cords is to establish a continuous system of basal laminae that allows a direct connection between the central ends of the growing seminiferous tubules and the peripheral extensions of the rete testis (future straight testicular tubules). The first true straight testicular tubules become visible between 85 and 110 days. Due to a strong proliferation of the tubulus rectus-cells the straight testicular tubules elongate continuously, and the border between the rete system and the seminiferous tubules is slowly shifted towards the testicular periphery. This shift is not restricted to the prenatal period, but proceeds until after birth. At the cytological level, the formation and elongation of the straight testicular tubules is effected by proliferating cells that advance along the continuous basal lamina into the area of the seminiferous tubules. The pre-Sertoli and germ cells in this zone of invasion are separated from each other and overgrown by the tubulus rectus-cells. Exposed to the special milieu of the straight testicular tubules, pre-Sertoli and germ cells apparently cannot survive and finally disappear.
Myung Chul Chung - One of the best experts on this subject based on the ideXlab platform.
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Bestatin Analogue from Streptomyces neyagawaensis SL-387
Bioscience Biotechnology and Biochemistry, 1996Co-Authors: Myung Chul Chung, Ho Jae Lee, Hyo Kon Chun, Choong Hwan Lee, Su-il Kim, Yung Hee KhoAbstract:A bestatin analogue, (2S,3R)-3-amino-2-hydroxy-4-phenylbuta- noyl-L-valine (AHPA-Val), from the culture filtrate of Streptomyces neyagawaensisSL-387 was obtained in a chemically defined medium containing DL-3-amino-3-phenylpropionic acid. AHPA-Val was 6 times (IC50= 1.2/μ/ml) as strong as bestatin (IC5O= 7.0/μ/ml) against porcine kidney Microsomal Aminopeptidase N, and 4 times (5.6/μ/ml) as strong as bestatin (IC5O= 20.7 /*g/ml) against Aminopeptidase N of human metastatic fibrosarcoma HT1080. To the best of our knowledge, this is the first report on the microbial production of AHPA-Val.
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Bestatin analogue from Streptomyces neyagawaensis SL-387
Japan Society for Bioscience Biotechnology and Agrochemistry, 1996Co-Authors: Myung Chul Chung, Ho Jae Lee, Hyo Kon Chun, Choong Hwan Lee, Su-il Kim, Yung Hee KhoAbstract:A bestatin analogue, (2S,3R)-3-amino-2-hydroxy-4- phenylbutanoyl-L- valine (AHPA-Val), from the culture filtrate of Streptomyces neyagawaensis SL-387 was obtained in a chemically defined medium containing DL- 3-amino-3- phenylpropionic acid. AHPA-Val was 6 times (IC50=1.2 μg/ml) as strong as bestatin (IC50=7.0 μg/ml) against porcine kidney Microsomal Aminopeptidase N, and 4 times (5.6 μg/ml) as strong as bestatin (IC50= 20.7 μg/ml) against amino-peptidase N of human metastatic fibrosarcoma HT1080. To the best of our knowledge, this is the first report on the microbial production of AHPA-Val.ope
Howard Smith - One of the best experts on this subject based on the ideXlab platform.
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Vaccination against Haemonchus contortus with denatured forms of the protective antigen H11
Parasite Immunology, 1997Co-Authors: Edward Albert Munn, Trevor S. Smith, Howard Smith, Fiona M. James, Fiona C. Smith, Stuart J. AndrewsAbstract:As part of a systematic examination of the protective epitopes on H11, groups of sheep were vaccinated with preparations of purified H11 used untreated (group A), or progressively denatured (linearized) by incubation with sodium dodecyl sulphate (SDS) (group B) or by boiling with SDS in the presence of dithiothreitol (group C). All the sheep developed antibodies which bound to the untreated H11. When challenged with 10 000 infective larvae of Haemonchus contortus the mean levels of protection relative to the mean values for adjuvant controls were 99.8%, 85% and 79% for faecal egg counts and 95%, 79% and 54% for worm burden at post-mortem for groups A, B and C respectively. The H11-specific antibodies inhibited the Microsomal Aminopeptidase activity of H11 in vitro up to 80%. The levels of inhibition by sera from individual animals correlated with levels of protection with r2, of 0.69–0.87.
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Cloning and characterization of a Microsomal Aminopeptidase from the intestine of the nematode Haemonchus contortus.
Biochimica et Biophysica Acta, 1997Co-Authors: Trevor S. Smith, Margaret Graham, Edward Albert Munn, Susan Elizabeth Newton, David P. Knox, W. John Coadwell, Danielle Mcmichael-phillips, Howard Smith, W.david Smith, Joanne J OliverAbstract:In order to characterise the integral membrane glycoprotein H11 from the intestinal microvilli of the nematode Haemonchus contortus, cDNA libraries prepared using mRNA from adult worms from the UK and Australia were immunoscreened with anti-H11 sera. Antibodies affinity purified on the protein expressed by insert DNA (295 bp) of a positive clone from a UK library bound specifically to H11. A longer clone (948 bp) was obtained from the Australian library by hybridisation. Using a primer based on sequence common to these, a polymerase chain reaction product of 3.3 kb was generated from cDNA from UK H. contortus. The sequences from the UK and Australian nematodes were essentially identical over the 929 bp region in which both were represented. All three cloned DNAs hybridised to mRNA of about 3.5 kb. Analysis of the deduced amino acid sequence, which showed 32% identity with those of mammalian Microsomal Aminopeptidases, indicated that H11 has a short N-terminal cytoplasmic tail, a single transmembrane region and a long extracellular region with putative N-linked glycosylation sites and the HEXXHXW motif characteristic of Microsomal Aminopeptidases. Microsomal Aminopeptidase activity co-purifies with H11. It is inhibited by bestatin, phenanthroline and amastatin. The recombinant protein has been expressed in active form in insect cells.
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Vaccination against with denatured forms of the protective antigen H11
1997Co-Authors: Howard SmithAbstract:SUMMARY As part of a systematic examination of the protective epitopes on H11, groups of sheep were vaccinated with preparations of purified H11 used untreated (group A), or progressively denatured (linearized) by incubation with sodium dodecyl sulphate (SDS) (group B) or by boiling with SDS in the presence of dithiothreitol (group C). All the sheep developed antibodies which bound to the untreated H11. When challenged with 10 000 infective larvae of Haemonchus contortus the mean levels of protection relative to the mean values for adjuvant controls were 99 . 8%, 85% and 79% for faecal egg counts and 95%, 79% and 54% for worm burden at post-mortem for groups A, B and C respectively. The H11-specific antibodies inhibited the Microsomal Aminopeptidase activity of H11in vitro up to 80%. The levels of inhibition by sera from individual animals correlated with levels of protection with r ,o f 0 . 69‐0 . 87.
Trevor S. Smith - One of the best experts on this subject based on the ideXlab platform.
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Vaccination against Haemonchus contortus with denatured forms of the protective antigen H11
Parasite Immunology, 1997Co-Authors: Edward Albert Munn, Trevor S. Smith, Howard Smith, Fiona M. James, Fiona C. Smith, Stuart J. AndrewsAbstract:As part of a systematic examination of the protective epitopes on H11, groups of sheep were vaccinated with preparations of purified H11 used untreated (group A), or progressively denatured (linearized) by incubation with sodium dodecyl sulphate (SDS) (group B) or by boiling with SDS in the presence of dithiothreitol (group C). All the sheep developed antibodies which bound to the untreated H11. When challenged with 10 000 infective larvae of Haemonchus contortus the mean levels of protection relative to the mean values for adjuvant controls were 99.8%, 85% and 79% for faecal egg counts and 95%, 79% and 54% for worm burden at post-mortem for groups A, B and C respectively. The H11-specific antibodies inhibited the Microsomal Aminopeptidase activity of H11 in vitro up to 80%. The levels of inhibition by sera from individual animals correlated with levels of protection with r2, of 0.69–0.87.
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Cloning and characterization of a Microsomal Aminopeptidase from the intestine of the nematode Haemonchus contortus.
Biochimica et Biophysica Acta, 1997Co-Authors: Trevor S. Smith, Margaret Graham, Edward Albert Munn, Susan Elizabeth Newton, David P. Knox, W. John Coadwell, Danielle Mcmichael-phillips, Howard Smith, W.david Smith, Joanne J OliverAbstract:In order to characterise the integral membrane glycoprotein H11 from the intestinal microvilli of the nematode Haemonchus contortus, cDNA libraries prepared using mRNA from adult worms from the UK and Australia were immunoscreened with anti-H11 sera. Antibodies affinity purified on the protein expressed by insert DNA (295 bp) of a positive clone from a UK library bound specifically to H11. A longer clone (948 bp) was obtained from the Australian library by hybridisation. Using a primer based on sequence common to these, a polymerase chain reaction product of 3.3 kb was generated from cDNA from UK H. contortus. The sequences from the UK and Australian nematodes were essentially identical over the 929 bp region in which both were represented. All three cloned DNAs hybridised to mRNA of about 3.5 kb. Analysis of the deduced amino acid sequence, which showed 32% identity with those of mammalian Microsomal Aminopeptidases, indicated that H11 has a short N-terminal cytoplasmic tail, a single transmembrane region and a long extracellular region with putative N-linked glycosylation sites and the HEXXHXW motif characteristic of Microsomal Aminopeptidases. Microsomal Aminopeptidase activity co-purifies with H11. It is inhibited by bestatin, phenanthroline and amastatin. The recombinant protein has been expressed in active form in insect cells.