The Experts below are selected from a list of 192 Experts worldwide ranked by ideXlab platform

Ken Saito - One of the best experts on this subject based on the ideXlab platform.

  • detection of β cell specific dna damage in streptozotocin treated rats by in situ Nick Translation with immunostaining of α cells
    Pancreas, 1995
    Co-Authors: Satoshi Shibata, Yoshihiro Asanuma, Kenji Koyama, Ken Saito
    Abstract:

    In situ Nick Translation with immunostaining of a cells could demonstrate the specific localization of streptozotocin- (STZ) induced DNA damage in β cells using in vivo materials. The extent of DNA damage was determined through autoradiography by counting the number of grains in the nucleus of the α, β, and exocrine cells of the rat pancreas. Subsequently, in situ Nick Translation with immunostaining of α cells was carried out in a pancreas pretreated with STZ. The number of grains observed in the β cells of the STZ-treated groups was significantly higher than that in the control group. DNA damage of pancreatic β cells due to STZ could be detected visually using in situ Nick Translation with immunostaining of α cells. Moreover, it was also possible to compare the DNA damage in the individual cells of the pancreas

  • detection of β cell specific dna damage in streptozotocin treated rats by in situ Nick Translation with immunostaining of α cells
    Pancreas, 1995
    Co-Authors: Satoshi Shibata, Yoshihiro Asanuma, Kenji Koyama, Ken Saito
    Abstract:

    In situ Nick Translation with immunostaining of alpha cells could demonstrate the specific localization of streptozotocin- (STZ) induced DNA damage in beta cells using in vivo materials. The extent of DNA damage was determined through autoradiography by counting the number of grains in the nucleus of the alpha, beta, and exocrine cells of the rat pancreas. Subsequently, in situ Nick Translation with immunostaining of alpha cells was carried out in a pancreas pretreated with STZ. The number of grains observed in the beta cells of the STZ-treated groups was significantly higher than that in the control group. DNA damage of pancreatic beta cells due to STZ could be detected visually using in situ Nick Translation with immunostaining of alpha cells. Moreover, it was also possible to compare the DNA damage in the individual cells of the pancreas.

U. Bianchi - One of the best experts on this subject based on the ideXlab platform.

  • dna strand breaks in ejaculated human spermatozoa comparison of susceptibility to the Nick Translation and terminal transferase assays
    Histochemical Journal, 1998
    Co-Authors: Gian Carlo Manicardi, Davide Bizzaro, Pg Bianchi, U. Bianchi, Antonella Tombacco, Denny Sakkas
    Abstract:

    The Nick Translation and terminal transferase assays have been compared to test their relative efficiency in detecting DNA breakage in ejaculated human spermatozoa. The results have been correlated with the percentage of chromomycin A3 positive sperm, a fluorochrome that is indicative of the protamination state of sperm. Examination of the ejaculated sperm of 30 subjects revealed that the percentage of positivity to the Nick Translation and terminal transferase assays did not differ, even when using different fixatives. It is concluded that the inability of the two assays to distinguish the type of DNA damage, as is possible in somatic nuclei, is most probably linked to the unique nature of sperm chromatin. It is proposed that the presence of the damaged DNA may be the remnants of an imperfect spermiogenesis, probably related to an inadequate protamine deposition. This is supported by the strong correlation between the presence of DNA damage and underprotamination as evidenced by chromomycin A3. © Chapman & Hall

  • DNA STRAND BREAKS IN EJACULATED HUMAN SPERMATOZOA : COMPARISON OF SUSCEPTIBILITY TO THE Nick Translation AND TERMINAL TRANSFERASE ASSAYS
    The Histochemical journal, 1998
    Co-Authors: Gian Carlo Manicardi, Davide Bizzaro, Pg Bianchi, U. Bianchi, Antonella Tombacco, Denny Sakkas
    Abstract:

    The Nick Translation and terminal transferase assays have been compared to test their relative efficiency in detecting DNA breakage in ejaculated human spermatozoa. The results have been correlated with the percentage of chromomycin A3 positive sperm, a fluorochrome that is indicative of the protamination state of sperm. Examination of the ejaculated sperm of 30 subjects revealed that the percentage of positivity to the Nick Translation and terminal transferase assays did not differ, even when using different fixatives. It is concluded that the inability of the two assays to distinguish the type of DNA damage, as is possible in somatic nuclei, is most probably linked to the unique nature of sperm chromatin. It is proposed that the presence of the damaged DNA may be the remnants of an imperfect spermiogenesis, probably related to an inadequate protamine deposition. This is supported by the strong correlation between the presence of DNA damage and underprotamination as evidenced by chromomycin A3. © Chapman & Hall

  • chromosomal localization of a highly repeated ecori dna fragment in megoura viciae homoptera aphididae by Nick Translation and fluorescence in situ hybridization
    Chromosome Research, 1996
    Co-Authors: Davide Bizzaro, Gian Carlo Manicardi, U. Bianchi
    Abstract:

    To investigate the genome of the aphidMegoura viciae at molecular level, we have studied total DNA by agarose gel electrophoresis after cleavage with different restriction endonucleases.EcoRI digestion produced a highly repeated DNA fragment, about 600 bp long. The contribution of thisEcoRI element to the total genome ofM. viciae was estimated at about 6% by means of densitometric scanning of agarose gel photographs. The chromosomal localization of this fragment, investigated by fluorescentin situ hybridization (FISH), constantly showed one large and two narrower fluorescent bands located on the X chromosome, all corresponding to C-positive heterochromatic areas. These results are in full accordance with the data obtained byin situ Nick Translation experiments carried out afterEcoRI digestion, and clearly demonstrate that a substantial amount ofM. viciae heterochromatin consists ofEcoRI fragments which are mainly located on the X chromosome. Using theEcoRI restriction fragment as a molecular probe may prove to be a practical tool for the investigation of taxonomic and evolutionary relationships in this group of insects.

  • chromosomal localization of a highly repeated ecori dna fragment in megoura viciae homoptera aphididae by Nick Translation and fluorescence in situ hybridization
    Chromosome Research, 1996
    Co-Authors: Davide Bizzaro, Gian Carlo Manicardi, U. Bianchi
    Abstract:

    To investigate the genome of the aphid Megoura viciae at molecular level, we have studied total DNA by agarose gel electrophoresis after cleavage with different restriction endonucleases. EcoRI digestion produced a highly repeated DNA fragment, about 600 pb long. The contribution of this EcoRI element to the total genome of M. viciae was estimated at about 6% by means of densitometric scanning of agarose gel photographs. The chromosomal localization of this fragment, investigated by fluorescent in situ hybridization (FISH), constantly showed one large and two narrower fluorescent bands located on the X chromosome, all corresponding to C-positive heterochromatic areas. These results are in full accordance with the data obtained by in situ Nick Translation experiments carried out after EcoRI digestion, and clearly demonstrate that a substantial amount of M. viciae heterochromatin consists of EcoRI fragments which are mainly located on the X chromosome. Using the EcoRI restriction fragment as a molecular probe may be a practical tool for the investigation of taxonomic and evolutionary relationships in this group of insects.

  • Effect of deoxyribonucleic acid protamination on fluorochrome staining and in situ Nick-Translation of murine and human mature spermatozoa.
    Biology of reproduction, 1993
    Co-Authors: Pg Bianchi, Gian Carlo Manicardi, Davide Bizzaro, U. Bianchi, Denny Sakkas
    Abstract:

    A major event in enhancing sperm chromatin stability is the replacement of the histones by protamines during spermiogenesis. In this study, we present results indicating that chromomycin A3 (CMA3 ) can be used to show protamine deficiency in sperm chromatin. Fixed chromatin of mature mouse spermatozoa showed high fluorescence after treatment with ethidium bromide (EB), but was completely unstained after treatment with CMA3. The same chromatin was found to be highly resistant to in situ Nick-Translation. In contrast, a substantial fraction of human spermatozoa were positive for CMA3. The accessibility of CMA to the DNA of human sperm was eliminated if the slides were previously treated with protamine in situ. This treatment did not affect the accessibility of EB to the chromatin. Individual human sperm samples revealed a substantial frequency of spermatozoa with endogenous Nicks, which was found to be the same as the frequency of spermatozoa responding positively to CMA3 staining. Treatment of preparations with protamines prevented the identification of the endogenous Nicks. These data as a whole suggest that CMA3 could represent a useful tool for the detection of protamine deficiency in sperm chromatin. Furthermore, confirmation of experiments relating sensitivity to Nick Translation and positivity to CMA3 may allow an indirect in situ visualization of Nicked and partially denatured DNA, which could correlate with certain forms of male factor infertility.

Satoshi Shibata - One of the best experts on this subject based on the ideXlab platform.

  • detection of β cell specific dna damage in streptozotocin treated rats by in situ Nick Translation with immunostaining of α cells
    Pancreas, 1995
    Co-Authors: Satoshi Shibata, Yoshihiro Asanuma, Kenji Koyama, Ken Saito
    Abstract:

    In situ Nick Translation with immunostaining of a cells could demonstrate the specific localization of streptozotocin- (STZ) induced DNA damage in β cells using in vivo materials. The extent of DNA damage was determined through autoradiography by counting the number of grains in the nucleus of the α, β, and exocrine cells of the rat pancreas. Subsequently, in situ Nick Translation with immunostaining of α cells was carried out in a pancreas pretreated with STZ. The number of grains observed in the β cells of the STZ-treated groups was significantly higher than that in the control group. DNA damage of pancreatic β cells due to STZ could be detected visually using in situ Nick Translation with immunostaining of α cells. Moreover, it was also possible to compare the DNA damage in the individual cells of the pancreas

  • detection of β cell specific dna damage in streptozotocin treated rats by in situ Nick Translation with immunostaining of α cells
    Pancreas, 1995
    Co-Authors: Satoshi Shibata, Yoshihiro Asanuma, Kenji Koyama, Ken Saito
    Abstract:

    In situ Nick Translation with immunostaining of alpha cells could demonstrate the specific localization of streptozotocin- (STZ) induced DNA damage in beta cells using in vivo materials. The extent of DNA damage was determined through autoradiography by counting the number of grains in the nucleus of the alpha, beta, and exocrine cells of the rat pancreas. Subsequently, in situ Nick Translation with immunostaining of alpha cells was carried out in a pancreas pretreated with STZ. The number of grains observed in the beta cells of the STZ-treated groups was significantly higher than that in the control group. DNA damage of pancreatic beta cells due to STZ could be detected visually using in situ Nick Translation with immunostaining of alpha cells. Moreover, it was also possible to compare the DNA damage in the individual cells of the pancreas.

Davide Bizzaro - One of the best experts on this subject based on the ideXlab platform.

  • dna strand breaks in ejaculated human spermatozoa comparison of susceptibility to the Nick Translation and terminal transferase assays
    Histochemical Journal, 1998
    Co-Authors: Gian Carlo Manicardi, Davide Bizzaro, Pg Bianchi, U. Bianchi, Antonella Tombacco, Denny Sakkas
    Abstract:

    The Nick Translation and terminal transferase assays have been compared to test their relative efficiency in detecting DNA breakage in ejaculated human spermatozoa. The results have been correlated with the percentage of chromomycin A3 positive sperm, a fluorochrome that is indicative of the protamination state of sperm. Examination of the ejaculated sperm of 30 subjects revealed that the percentage of positivity to the Nick Translation and terminal transferase assays did not differ, even when using different fixatives. It is concluded that the inability of the two assays to distinguish the type of DNA damage, as is possible in somatic nuclei, is most probably linked to the unique nature of sperm chromatin. It is proposed that the presence of the damaged DNA may be the remnants of an imperfect spermiogenesis, probably related to an inadequate protamine deposition. This is supported by the strong correlation between the presence of DNA damage and underprotamination as evidenced by chromomycin A3. © Chapman & Hall

  • DNA STRAND BREAKS IN EJACULATED HUMAN SPERMATOZOA : COMPARISON OF SUSCEPTIBILITY TO THE Nick Translation AND TERMINAL TRANSFERASE ASSAYS
    The Histochemical journal, 1998
    Co-Authors: Gian Carlo Manicardi, Davide Bizzaro, Pg Bianchi, U. Bianchi, Antonella Tombacco, Denny Sakkas
    Abstract:

    The Nick Translation and terminal transferase assays have been compared to test their relative efficiency in detecting DNA breakage in ejaculated human spermatozoa. The results have been correlated with the percentage of chromomycin A3 positive sperm, a fluorochrome that is indicative of the protamination state of sperm. Examination of the ejaculated sperm of 30 subjects revealed that the percentage of positivity to the Nick Translation and terminal transferase assays did not differ, even when using different fixatives. It is concluded that the inability of the two assays to distinguish the type of DNA damage, as is possible in somatic nuclei, is most probably linked to the unique nature of sperm chromatin. It is proposed that the presence of the damaged DNA may be the remnants of an imperfect spermiogenesis, probably related to an inadequate protamine deposition. This is supported by the strong correlation between the presence of DNA damage and underprotamination as evidenced by chromomycin A3. © Chapman & Hall

  • chromosomal localization of a highly repeated ecori dna fragment in megoura viciae homoptera aphididae by Nick Translation and fluorescence in situ hybridization
    Chromosome Research, 1996
    Co-Authors: Davide Bizzaro, Gian Carlo Manicardi, U. Bianchi
    Abstract:

    To investigate the genome of the aphidMegoura viciae at molecular level, we have studied total DNA by agarose gel electrophoresis after cleavage with different restriction endonucleases.EcoRI digestion produced a highly repeated DNA fragment, about 600 bp long. The contribution of thisEcoRI element to the total genome ofM. viciae was estimated at about 6% by means of densitometric scanning of agarose gel photographs. The chromosomal localization of this fragment, investigated by fluorescentin situ hybridization (FISH), constantly showed one large and two narrower fluorescent bands located on the X chromosome, all corresponding to C-positive heterochromatic areas. These results are in full accordance with the data obtained byin situ Nick Translation experiments carried out afterEcoRI digestion, and clearly demonstrate that a substantial amount ofM. viciae heterochromatin consists ofEcoRI fragments which are mainly located on the X chromosome. Using theEcoRI restriction fragment as a molecular probe may prove to be a practical tool for the investigation of taxonomic and evolutionary relationships in this group of insects.

  • chromosomal localization of a highly repeated ecori dna fragment in megoura viciae homoptera aphididae by Nick Translation and fluorescence in situ hybridization
    Chromosome Research, 1996
    Co-Authors: Davide Bizzaro, Gian Carlo Manicardi, U. Bianchi
    Abstract:

    To investigate the genome of the aphid Megoura viciae at molecular level, we have studied total DNA by agarose gel electrophoresis after cleavage with different restriction endonucleases. EcoRI digestion produced a highly repeated DNA fragment, about 600 pb long. The contribution of this EcoRI element to the total genome of M. viciae was estimated at about 6% by means of densitometric scanning of agarose gel photographs. The chromosomal localization of this fragment, investigated by fluorescent in situ hybridization (FISH), constantly showed one large and two narrower fluorescent bands located on the X chromosome, all corresponding to C-positive heterochromatic areas. These results are in full accordance with the data obtained by in situ Nick Translation experiments carried out after EcoRI digestion, and clearly demonstrate that a substantial amount of M. viciae heterochromatin consists of EcoRI fragments which are mainly located on the X chromosome. Using the EcoRI restriction fragment as a molecular probe may be a practical tool for the investigation of taxonomic and evolutionary relationships in this group of insects.

  • Effect of deoxyribonucleic acid protamination on fluorochrome staining and in situ Nick-Translation of murine and human mature spermatozoa.
    Biology of reproduction, 1993
    Co-Authors: Pg Bianchi, Gian Carlo Manicardi, Davide Bizzaro, U. Bianchi, Denny Sakkas
    Abstract:

    A major event in enhancing sperm chromatin stability is the replacement of the histones by protamines during spermiogenesis. In this study, we present results indicating that chromomycin A3 (CMA3 ) can be used to show protamine deficiency in sperm chromatin. Fixed chromatin of mature mouse spermatozoa showed high fluorescence after treatment with ethidium bromide (EB), but was completely unstained after treatment with CMA3. The same chromatin was found to be highly resistant to in situ Nick-Translation. In contrast, a substantial fraction of human spermatozoa were positive for CMA3. The accessibility of CMA to the DNA of human sperm was eliminated if the slides were previously treated with protamine in situ. This treatment did not affect the accessibility of EB to the chromatin. Individual human sperm samples revealed a substantial frequency of spermatozoa with endogenous Nicks, which was found to be the same as the frequency of spermatozoa responding positively to CMA3 staining. Treatment of preparations with protamines prevented the identification of the endogenous Nicks. These data as a whole suggest that CMA3 could represent a useful tool for the detection of protamine deficiency in sperm chromatin. Furthermore, confirmation of experiments relating sensitivity to Nick Translation and positivity to CMA3 may allow an indirect in situ visualization of Nicked and partially denatured DNA, which could correlate with certain forms of male factor infertility.

Gian Carlo Manicardi - One of the best experts on this subject based on the ideXlab platform.

  • dna strand breaks in ejaculated human spermatozoa comparison of susceptibility to the Nick Translation and terminal transferase assays
    Histochemical Journal, 1998
    Co-Authors: Gian Carlo Manicardi, Davide Bizzaro, Pg Bianchi, U. Bianchi, Antonella Tombacco, Denny Sakkas
    Abstract:

    The Nick Translation and terminal transferase assays have been compared to test their relative efficiency in detecting DNA breakage in ejaculated human spermatozoa. The results have been correlated with the percentage of chromomycin A3 positive sperm, a fluorochrome that is indicative of the protamination state of sperm. Examination of the ejaculated sperm of 30 subjects revealed that the percentage of positivity to the Nick Translation and terminal transferase assays did not differ, even when using different fixatives. It is concluded that the inability of the two assays to distinguish the type of DNA damage, as is possible in somatic nuclei, is most probably linked to the unique nature of sperm chromatin. It is proposed that the presence of the damaged DNA may be the remnants of an imperfect spermiogenesis, probably related to an inadequate protamine deposition. This is supported by the strong correlation between the presence of DNA damage and underprotamination as evidenced by chromomycin A3. © Chapman & Hall

  • DNA STRAND BREAKS IN EJACULATED HUMAN SPERMATOZOA : COMPARISON OF SUSCEPTIBILITY TO THE Nick Translation AND TERMINAL TRANSFERASE ASSAYS
    The Histochemical journal, 1998
    Co-Authors: Gian Carlo Manicardi, Davide Bizzaro, Pg Bianchi, U. Bianchi, Antonella Tombacco, Denny Sakkas
    Abstract:

    The Nick Translation and terminal transferase assays have been compared to test their relative efficiency in detecting DNA breakage in ejaculated human spermatozoa. The results have been correlated with the percentage of chromomycin A3 positive sperm, a fluorochrome that is indicative of the protamination state of sperm. Examination of the ejaculated sperm of 30 subjects revealed that the percentage of positivity to the Nick Translation and terminal transferase assays did not differ, even when using different fixatives. It is concluded that the inability of the two assays to distinguish the type of DNA damage, as is possible in somatic nuclei, is most probably linked to the unique nature of sperm chromatin. It is proposed that the presence of the damaged DNA may be the remnants of an imperfect spermiogenesis, probably related to an inadequate protamine deposition. This is supported by the strong correlation between the presence of DNA damage and underprotamination as evidenced by chromomycin A3. © Chapman & Hall

  • chromosomal localization of a highly repeated ecori dna fragment in megoura viciae homoptera aphididae by Nick Translation and fluorescence in situ hybridization
    Chromosome Research, 1996
    Co-Authors: Davide Bizzaro, Gian Carlo Manicardi, U. Bianchi
    Abstract:

    To investigate the genome of the aphidMegoura viciae at molecular level, we have studied total DNA by agarose gel electrophoresis after cleavage with different restriction endonucleases.EcoRI digestion produced a highly repeated DNA fragment, about 600 bp long. The contribution of thisEcoRI element to the total genome ofM. viciae was estimated at about 6% by means of densitometric scanning of agarose gel photographs. The chromosomal localization of this fragment, investigated by fluorescentin situ hybridization (FISH), constantly showed one large and two narrower fluorescent bands located on the X chromosome, all corresponding to C-positive heterochromatic areas. These results are in full accordance with the data obtained byin situ Nick Translation experiments carried out afterEcoRI digestion, and clearly demonstrate that a substantial amount ofM. viciae heterochromatin consists ofEcoRI fragments which are mainly located on the X chromosome. Using theEcoRI restriction fragment as a molecular probe may prove to be a practical tool for the investigation of taxonomic and evolutionary relationships in this group of insects.

  • chromosomal localization of a highly repeated ecori dna fragment in megoura viciae homoptera aphididae by Nick Translation and fluorescence in situ hybridization
    Chromosome Research, 1996
    Co-Authors: Davide Bizzaro, Gian Carlo Manicardi, U. Bianchi
    Abstract:

    To investigate the genome of the aphid Megoura viciae at molecular level, we have studied total DNA by agarose gel electrophoresis after cleavage with different restriction endonucleases. EcoRI digestion produced a highly repeated DNA fragment, about 600 pb long. The contribution of this EcoRI element to the total genome of M. viciae was estimated at about 6% by means of densitometric scanning of agarose gel photographs. The chromosomal localization of this fragment, investigated by fluorescent in situ hybridization (FISH), constantly showed one large and two narrower fluorescent bands located on the X chromosome, all corresponding to C-positive heterochromatic areas. These results are in full accordance with the data obtained by in situ Nick Translation experiments carried out after EcoRI digestion, and clearly demonstrate that a substantial amount of M. viciae heterochromatin consists of EcoRI fragments which are mainly located on the X chromosome. Using the EcoRI restriction fragment as a molecular probe may be a practical tool for the investigation of taxonomic and evolutionary relationships in this group of insects.

  • Effect of deoxyribonucleic acid protamination on fluorochrome staining and in situ Nick-Translation of murine and human mature spermatozoa.
    Biology of reproduction, 1993
    Co-Authors: Pg Bianchi, Gian Carlo Manicardi, Davide Bizzaro, U. Bianchi, Denny Sakkas
    Abstract:

    A major event in enhancing sperm chromatin stability is the replacement of the histones by protamines during spermiogenesis. In this study, we present results indicating that chromomycin A3 (CMA3 ) can be used to show protamine deficiency in sperm chromatin. Fixed chromatin of mature mouse spermatozoa showed high fluorescence after treatment with ethidium bromide (EB), but was completely unstained after treatment with CMA3. The same chromatin was found to be highly resistant to in situ Nick-Translation. In contrast, a substantial fraction of human spermatozoa were positive for CMA3. The accessibility of CMA to the DNA of human sperm was eliminated if the slides were previously treated with protamine in situ. This treatment did not affect the accessibility of EB to the chromatin. Individual human sperm samples revealed a substantial frequency of spermatozoa with endogenous Nicks, which was found to be the same as the frequency of spermatozoa responding positively to CMA3 staining. Treatment of preparations with protamines prevented the identification of the endogenous Nicks. These data as a whole suggest that CMA3 could represent a useful tool for the detection of protamine deficiency in sperm chromatin. Furthermore, confirmation of experiments relating sensitivity to Nick Translation and positivity to CMA3 may allow an indirect in situ visualization of Nicked and partially denatured DNA, which could correlate with certain forms of male factor infertility.