The Experts below are selected from a list of 4422 Experts worldwide ranked by ideXlab platform

Mallar M Chakravarty - One of the best experts on this subject based on the ideXlab platform.

  • longitudinal characterization of neuroanatomical changes in the Fischer 344 Rat brain during normal aging and between sexes
    Neurobiology of Aging, 2021
    Co-Authors: Dana Goerzen, Caitlin Fowler, Gabriel A Devenyi, Dan Madularu, Mallar M Chakravarty
    Abstract:

    Abstract Animal models are widely used to study the pathophysiology of disease and to evaluate the efficacy of novel interventions, crucial steps towards improving disease outcomes in humans. The Fischer 344 (F344) wildtype Rat is a common experimental background strain for transgenic models of disease and is one of the most frequently used models in aging research. Despite frequency of use, characterization of agerelated neuroanatomical change has not been performed in the F344 Rat. To this end, we present a comprehensive longitudinal examination of morphometric change in 73 brain regions and at a voxel-wise level during normative aging in vivo in a mixed-sexcohort of F344 Rats. We identified the greatest vulnerability to aging within the cortex, caudoputamen, hindbrain, and internal capsule, while the influence of sex was strongest in the caudoputamen, hippocampus, nucleus accumbens, and thalamus, many of which are implicated in memory and motor control circuits frequently affected by aging and neurodegeneRative disease. These findings provide a baseline for neuroanatomical changes associated with aging in male and female F344 Rats, to which data from transgenic models or other background strains can be compared.

  • longitudinal characterization of neuroanatomical changes in the Fischer 344 Rat brain during normal aging and between sexes
    bioRxiv, 2021
    Co-Authors: Caitlin Fowler, Dana Goerzen, Gabriel A Devenyi, Dan Madularu, Jamie Near, Mallar M Chakravarty
    Abstract:

    Animal models are widely used to study the pathophysiology of disease and to evaluate the efficacy of novel interventions, crucial steps towards improving disease outcomes in humans. The Fischer 344 (F344) wildtype Rat is a common experimental background strain for transgenic models of disease and is also one of the most frequently used models in aging research. Despite frequency of use, characterization of neuroanatomical change with age has not been performed in the F344 Rat. To this end, we present a comprehensive longitudinal examination of morphometric change in 73 brain regions and at a voxel-wise level during normative aging in a mixed-sex cohort of F344 Rats. We identified age- and sex-related changes in regions such as the cortex, hippocampus, cingulum, caudoputamen, and nucleus accumbens, which are implicated in memory and motor control circuits frequently affected by aging and neurodegeneRative disease. These findings provide a baseline for neuroanatomical changes associated with aging in male and female F344 Rats, to which data from transgenic models or other background strains can be compared.

  • an mri derived neuroanatomical atlas of the Fischer 344 Rat brain
    Scientific Reports, 2020
    Co-Authors: Dana Goerzen, Caitlin Fowler, Gabriel A Devenyi, Jurgen Germann, Dan Madularu, Mallar M Chakravarty, Jamie Near
    Abstract:

    This paper reports the development of a high-resolution 3-D MRI atlas of the Fischer 344 adult Rat brain. The atlas is a 60 μm isotropic image volume composed of 256 coronal slices with 71 manually delineated structures and substructures. The atlas was developed using Pydpiper image registRation pipeline to create an average brain image of 41 four-month-old male and female Fischer 344 Rats. Slices in the average brain image were then manually segmented, individually and bilaterally, on the basis of image contrast in conjunction with Paxinos and Watson's (2007) stereotaxic Rat brain atlas. Summary statistics (mean and standard deviation of regional volumes) are reported for each brain region across the sample used to geneRate the atlas, and a statistical comparison of a chosen subset of regional brain volumes between male and female Rats is presented. On average, the coefficient of variation of regional brain volumes across all Rats in our sample was 4%, with no individual brain region having a coefficient of variation greater than 13%. A full description of methods used, as well as the atlas, the template that the atlas was derived from, and a masking file, can be found on Zenodo at www.zenodo.org/record/3700210. To our knowledge, this is the first MRI atlas created using Fischer 344 Rats and will thus provide an appropriate neuroanatomical model for researchers working with this strain.

  • an mri derived neuroanatomical atlas of the Fischer 344 Rat brain
    bioRxiv, 2019
    Co-Authors: Dana Goerzen, Caitlin Fowler, Gabriel A Devenyi, Jurgen Germann, Dan Madularu, Mallar M Chakravarty
    Abstract:

    Abstract This paper reports the development of a high-resolution 3-D MRI atlas of the Fischer 344 adult Rat brain. The atlas is a 60 μm isotropic image volume composed of 256 coronal slices with 71 manually delineated structures and substructures. The atlas was developed using Pydpiper image registRation pipeline to create an average brain image of 41 four-month-old male and female Fischer 344 Rats. Slices in the average brain image were then manually segmented, individually and bilaterally, on the basis of image contrast in conjunction with Paxinos and Watson’s (2007) stereotaxic Rat brain atlas. Summary statistics (mean and standard deviation of regional volumes) are reported for each brain region across the sample used to geneRate the atlas, and a statistical comparison of a chosen subset of regional brain volumes between male and female Rats is presented. On average, the coefficient of variation of regional brain volumes across all Rats in our sample was 4%, with no individual brain region having a coefficient of variation greater than 13%. A full description of methods used, as well as the atlas, the template that the atlas was derived from, and a masking file, can be found at Zenodo at https://doi.org/10.5281/zenodo.3555556. To our knowledge, this is the first MRI atlas created using Fischer 344 Rats and will thus provide an appropriate neuroanatomical model for researchers working with this strain. HIGHLIGHTS ⍰ Open-access high-resolution anatomical MRI template for Fischer 344 Rat brain. ⍰ Segmented atlas of 71 regions for use as a tool in Fischer 344 preclinical research paradigms. ⍰ Analysis of population variability of regional brain volumes. ⍰ Analysis of sex-differences in regional brain volumes KEYWORDS: Fischer 344; Structural MRI; Segmentation; Rat brain template; Digital brain atlas; Sex-differences;

  • an mri derived neuroanatomical atlas of the Fischer 344 Rat brain for automated anatomical segmentation
    bioRxiv, 2019
    Co-Authors: Dana Goerzen, Caitlin Fowler, Gabriel A Devenyi, Jurgen Germann, Dan Madularu, Mallar M Chakravarty
    Abstract:

    Abstract This paper reports the development of a high-resolution 3-D MRI atlas of the Fischer 344 adult Rat brain. The atlas is a 60 μm isotropic image volume composed of 256 coronal slices with 98 manually delineated structures and substructures. The atlas was developed using Pydpiper image registRation pipeline to create an average brain image of 41 four-month-old male and female Fischer 344 Rats. Slices in the average brain image were then digitally segmented, individually and bilaterally, on the basis of image contrast in conjunction with Paxinos and Watson’s (2007) stereotaxic Rat brain atlas. Summary statistics (mean and standard deviation of regional volumes) are reported for each brain region across the sample used to geneRate the atlas, and a statistical comparison of a chosen subset of regional brain volumes between male and female Rats is presented. On average, the coefficient of variation of regional brain volumes across all Rats in our sample was 5%, with no individual brain region having a coefficient of variation greater than 14%. A full description of methods used, as well as the atlas, the template that the atlas was derived from, and a masking file, can be found at https://www.nearlab.xyz/Fischer344atlas. To our knowledge, this is the first MRI atlas created using Fischer 344 Rats and will thus provide an appropriate neuroanatomical model for researchers working with this strain. Graphical Abstract HIGHLIGHTS Open-access high-resolution anatomical MRI template for Fischer 344 Rat brain. Segmented atlas of 98 regions for use as a tool in Fischer 344 preclinical research paradigms. Analysis of population variability of regional brain volumes. Analysis of sex-differences in regional brain volumes

Dan Madularu - One of the best experts on this subject based on the ideXlab platform.

  • longitudinal characterization of neuroanatomical changes in the Fischer 344 Rat brain during normal aging and between sexes
    Neurobiology of Aging, 2021
    Co-Authors: Dana Goerzen, Caitlin Fowler, Gabriel A Devenyi, Dan Madularu, Mallar M Chakravarty
    Abstract:

    Abstract Animal models are widely used to study the pathophysiology of disease and to evaluate the efficacy of novel interventions, crucial steps towards improving disease outcomes in humans. The Fischer 344 (F344) wildtype Rat is a common experimental background strain for transgenic models of disease and is one of the most frequently used models in aging research. Despite frequency of use, characterization of agerelated neuroanatomical change has not been performed in the F344 Rat. To this end, we present a comprehensive longitudinal examination of morphometric change in 73 brain regions and at a voxel-wise level during normative aging in vivo in a mixed-sexcohort of F344 Rats. We identified the greatest vulnerability to aging within the cortex, caudoputamen, hindbrain, and internal capsule, while the influence of sex was strongest in the caudoputamen, hippocampus, nucleus accumbens, and thalamus, many of which are implicated in memory and motor control circuits frequently affected by aging and neurodegeneRative disease. These findings provide a baseline for neuroanatomical changes associated with aging in male and female F344 Rats, to which data from transgenic models or other background strains can be compared.

  • longitudinal characterization of neuroanatomical changes in the Fischer 344 Rat brain during normal aging and between sexes
    bioRxiv, 2021
    Co-Authors: Caitlin Fowler, Dana Goerzen, Gabriel A Devenyi, Dan Madularu, Jamie Near, Mallar M Chakravarty
    Abstract:

    Animal models are widely used to study the pathophysiology of disease and to evaluate the efficacy of novel interventions, crucial steps towards improving disease outcomes in humans. The Fischer 344 (F344) wildtype Rat is a common experimental background strain for transgenic models of disease and is also one of the most frequently used models in aging research. Despite frequency of use, characterization of neuroanatomical change with age has not been performed in the F344 Rat. To this end, we present a comprehensive longitudinal examination of morphometric change in 73 brain regions and at a voxel-wise level during normative aging in a mixed-sex cohort of F344 Rats. We identified age- and sex-related changes in regions such as the cortex, hippocampus, cingulum, caudoputamen, and nucleus accumbens, which are implicated in memory and motor control circuits frequently affected by aging and neurodegeneRative disease. These findings provide a baseline for neuroanatomical changes associated with aging in male and female F344 Rats, to which data from transgenic models or other background strains can be compared.

  • an mri derived neuroanatomical atlas of the Fischer 344 Rat brain
    Scientific Reports, 2020
    Co-Authors: Dana Goerzen, Caitlin Fowler, Gabriel A Devenyi, Jurgen Germann, Dan Madularu, Mallar M Chakravarty, Jamie Near
    Abstract:

    This paper reports the development of a high-resolution 3-D MRI atlas of the Fischer 344 adult Rat brain. The atlas is a 60 μm isotropic image volume composed of 256 coronal slices with 71 manually delineated structures and substructures. The atlas was developed using Pydpiper image registRation pipeline to create an average brain image of 41 four-month-old male and female Fischer 344 Rats. Slices in the average brain image were then manually segmented, individually and bilaterally, on the basis of image contrast in conjunction with Paxinos and Watson's (2007) stereotaxic Rat brain atlas. Summary statistics (mean and standard deviation of regional volumes) are reported for each brain region across the sample used to geneRate the atlas, and a statistical comparison of a chosen subset of regional brain volumes between male and female Rats is presented. On average, the coefficient of variation of regional brain volumes across all Rats in our sample was 4%, with no individual brain region having a coefficient of variation greater than 13%. A full description of methods used, as well as the atlas, the template that the atlas was derived from, and a masking file, can be found on Zenodo at www.zenodo.org/record/3700210. To our knowledge, this is the first MRI atlas created using Fischer 344 Rats and will thus provide an appropriate neuroanatomical model for researchers working with this strain.

  • an mri derived neuroanatomical atlas of the Fischer 344 Rat brain
    bioRxiv, 2019
    Co-Authors: Dana Goerzen, Caitlin Fowler, Gabriel A Devenyi, Jurgen Germann, Dan Madularu, Mallar M Chakravarty
    Abstract:

    Abstract This paper reports the development of a high-resolution 3-D MRI atlas of the Fischer 344 adult Rat brain. The atlas is a 60 μm isotropic image volume composed of 256 coronal slices with 71 manually delineated structures and substructures. The atlas was developed using Pydpiper image registRation pipeline to create an average brain image of 41 four-month-old male and female Fischer 344 Rats. Slices in the average brain image were then manually segmented, individually and bilaterally, on the basis of image contrast in conjunction with Paxinos and Watson’s (2007) stereotaxic Rat brain atlas. Summary statistics (mean and standard deviation of regional volumes) are reported for each brain region across the sample used to geneRate the atlas, and a statistical comparison of a chosen subset of regional brain volumes between male and female Rats is presented. On average, the coefficient of variation of regional brain volumes across all Rats in our sample was 4%, with no individual brain region having a coefficient of variation greater than 13%. A full description of methods used, as well as the atlas, the template that the atlas was derived from, and a masking file, can be found at Zenodo at https://doi.org/10.5281/zenodo.3555556. To our knowledge, this is the first MRI atlas created using Fischer 344 Rats and will thus provide an appropriate neuroanatomical model for researchers working with this strain. HIGHLIGHTS ⍰ Open-access high-resolution anatomical MRI template for Fischer 344 Rat brain. ⍰ Segmented atlas of 71 regions for use as a tool in Fischer 344 preclinical research paradigms. ⍰ Analysis of population variability of regional brain volumes. ⍰ Analysis of sex-differences in regional brain volumes KEYWORDS: Fischer 344; Structural MRI; Segmentation; Rat brain template; Digital brain atlas; Sex-differences;

  • an mri derived neuroanatomical atlas of the Fischer 344 Rat brain for automated anatomical segmentation
    bioRxiv, 2019
    Co-Authors: Dana Goerzen, Caitlin Fowler, Gabriel A Devenyi, Jurgen Germann, Dan Madularu, Mallar M Chakravarty
    Abstract:

    Abstract This paper reports the development of a high-resolution 3-D MRI atlas of the Fischer 344 adult Rat brain. The atlas is a 60 μm isotropic image volume composed of 256 coronal slices with 98 manually delineated structures and substructures. The atlas was developed using Pydpiper image registRation pipeline to create an average brain image of 41 four-month-old male and female Fischer 344 Rats. Slices in the average brain image were then digitally segmented, individually and bilaterally, on the basis of image contrast in conjunction with Paxinos and Watson’s (2007) stereotaxic Rat brain atlas. Summary statistics (mean and standard deviation of regional volumes) are reported for each brain region across the sample used to geneRate the atlas, and a statistical comparison of a chosen subset of regional brain volumes between male and female Rats is presented. On average, the coefficient of variation of regional brain volumes across all Rats in our sample was 5%, with no individual brain region having a coefficient of variation greater than 14%. A full description of methods used, as well as the atlas, the template that the atlas was derived from, and a masking file, can be found at https://www.nearlab.xyz/Fischer344atlas. To our knowledge, this is the first MRI atlas created using Fischer 344 Rats and will thus provide an appropriate neuroanatomical model for researchers working with this strain. Graphical Abstract HIGHLIGHTS Open-access high-resolution anatomical MRI template for Fischer 344 Rat brain. Segmented atlas of 98 regions for use as a tool in Fischer 344 preclinical research paradigms. Analysis of population variability of regional brain volumes. Analysis of sex-differences in regional brain volumes

Qifeng Yang - One of the best experts on this subject based on the ideXlab platform.

  • intraperitoneal photodynamic therapy for an ovarian cancer ascite model in Fischer 344 Rat using hematoporphyrin monomethyl ether
    Cancer Science, 2007
    Co-Authors: Kun Song, Beihua Kong, Li Li, Qifeng Yang, Xun Qu
    Abstract:

    With limited treatment options, intraperitoneal spread of ovarian cancer is a common problem leading to high morbidity. Intraperitoneal photodynamic therapy combined with debulking surgery to treat residual disease is an alternative choice for clinicians. Hematoporphyrin monomethyl ether (HMME) is a promising second-geneRation photosensitizer developed in China. Our study was designed to investigate the phototoxicity of HMME on ovarian cancer. NuTu-19, a cell line derived from adenocarcinoma of Fischer 344 Rat, and its allogeneic graft ascites tumor model was used in this study. HMME was confirmed to be localized in cytolysosome, and HMME-based photosensitization induced direct necrosis as well as mitochondria damage. The photocytotoxicity of HMME was both light- and drug dose-dependent and no significant dark cytotoxicity was observed in NuTu-19 cells. With the ascite tumor-bearing Fischer 344 Rat model, HMME-based intraperitoneal photodynamic therapy was proved to be useful in improving the prognosis of ovarian cancer. Thus, this study provides evidence that HMME-based photodynamic therapy is an effective adjuvant therapy for ovarian cancer. (Cancer Sci 2007; 98: 1959–1964)

  • intraperitoneal photodynamic therapy for an ovarian cancer ascite model in Fischer 344 Rat using hematoporphyrin monomethyl ether
    Cancer Science, 2007
    Co-Authors: Kun Song, Beihua Kong, Qifeng Yang, Yongqing Wei
    Abstract:

    With limited treatment options, intraperitoneal spread of ovarian cancer is a common problem leading to high morbidity. Intraperitoneal photodynamic therapy combined with debulking surgery to treat residual disease is an alternative choice for clinicians. Hematoporphyrin monomethyl ether (HMME) is a promising second-geneRation photosensitizer developed in China. Our study was designed to investigate the phototoxicity of HMME on ovarian cancer. NuTu-19, a cell line derived from adenocarcinoma of Fischer 344 Rat, and its allogeneic graft ascites tumor model was used in this study. HMME was confirmed to be localized in cytolysosome, and HMME-based photosensitization induced direct necrosis as well as mitochondria damage. The photocytotoxicity of HMME was both light- and drug dose-dependent and no significant dark cytotoxicity was observed in NuTu-19 cells. With the ascite tumor-bearing Fischer 344 Rat model, HMME-based intraperitoneal photodynamic therapy was proved to be useful in improving the prognosis of ovarian cancer. Thus, this study provides evidence that HMME-based photodynamic therapy is an effective adjuvant therapy for ovarian cancer.

Kun Song - One of the best experts on this subject based on the ideXlab platform.

  • intraperitoneal photodynamic therapy for an ovarian cancer ascite model in Fischer 344 Rat using hematoporphyrin monomethyl ether
    Cancer Science, 2007
    Co-Authors: Kun Song, Beihua Kong, Li Li, Qifeng Yang, Xun Qu
    Abstract:

    With limited treatment options, intraperitoneal spread of ovarian cancer is a common problem leading to high morbidity. Intraperitoneal photodynamic therapy combined with debulking surgery to treat residual disease is an alternative choice for clinicians. Hematoporphyrin monomethyl ether (HMME) is a promising second-geneRation photosensitizer developed in China. Our study was designed to investigate the phototoxicity of HMME on ovarian cancer. NuTu-19, a cell line derived from adenocarcinoma of Fischer 344 Rat, and its allogeneic graft ascites tumor model was used in this study. HMME was confirmed to be localized in cytolysosome, and HMME-based photosensitization induced direct necrosis as well as mitochondria damage. The photocytotoxicity of HMME was both light- and drug dose-dependent and no significant dark cytotoxicity was observed in NuTu-19 cells. With the ascite tumor-bearing Fischer 344 Rat model, HMME-based intraperitoneal photodynamic therapy was proved to be useful in improving the prognosis of ovarian cancer. Thus, this study provides evidence that HMME-based photodynamic therapy is an effective adjuvant therapy for ovarian cancer. (Cancer Sci 2007; 98: 1959–1964)

  • intraperitoneal photodynamic therapy for an ovarian cancer ascite model in Fischer 344 Rat using hematoporphyrin monomethyl ether
    Cancer Science, 2007
    Co-Authors: Kun Song, Beihua Kong, Qifeng Yang, Yongqing Wei
    Abstract:

    With limited treatment options, intraperitoneal spread of ovarian cancer is a common problem leading to high morbidity. Intraperitoneal photodynamic therapy combined with debulking surgery to treat residual disease is an alternative choice for clinicians. Hematoporphyrin monomethyl ether (HMME) is a promising second-geneRation photosensitizer developed in China. Our study was designed to investigate the phototoxicity of HMME on ovarian cancer. NuTu-19, a cell line derived from adenocarcinoma of Fischer 344 Rat, and its allogeneic graft ascites tumor model was used in this study. HMME was confirmed to be localized in cytolysosome, and HMME-based photosensitization induced direct necrosis as well as mitochondria damage. The photocytotoxicity of HMME was both light- and drug dose-dependent and no significant dark cytotoxicity was observed in NuTu-19 cells. With the ascite tumor-bearing Fischer 344 Rat model, HMME-based intraperitoneal photodynamic therapy was proved to be useful in improving the prognosis of ovarian cancer. Thus, this study provides evidence that HMME-based photodynamic therapy is an effective adjuvant therapy for ovarian cancer.

Donald M Caspary - One of the best experts on this subject based on the ideXlab platform.

  • alteRations of gabaa receptor subunit mrna levels in the aging Fischer 344 Rat inferior colliculus
    The Journal of Comparative Neurology, 1997
    Co-Authors: Joseph C Milbrandt, Chyren Hunter, Donald M Caspary
    Abstract:

    The inhibitory neurotransmitter, gamma-aminobutyric acid (GABA) is critically involved in shaping neuronal responses to simple and complex acoustic stimuli in the central auditory structure, the inferior colliculus (IC). Studies in Rat and human suggest that age-related changes in markers for GABA neurotransmission occur in the IC. In particular, these changes include findings indicative of an age-related increase in the efficacy/potency of GABA to inhibit ligand binding at the GABAA receptor picrotoxin site in the Fischer (F344) Rat IC. Such changes in GABAA receptor modulation suggest the potential for an alteRation in GABAA receptor subunit composition in the old Rat IC. To test this idea, the present study used in situ hybridization to quantify age-related changes in GABAA receptor subunit mRNA levels in the three major subdivisions of the IC in the F344 Rat: dorsal cortex (DCIC), external cortex (ECIC), and the central nucleus (CIC). In support of earlier findings of an age-related change in GABAA receptor modulation, the present study found: (1) GABAA receptor subunit mRNA levels were significantly altered in the IC of old Rats, and (2) age-related changes in subunit levels appeared to be regionally selective and subunit specific. A highly significant increase in the level of the gamma 1 subunit mRNA was observed with little change in the levels of the alpha 1, beta 2, and gamma 2 subunit mRNAs. A nonstatistically significant increase in alpha 2 subunit mRNA was also observed. This observed increase in alpha 2 subunit mRNA could be important since previous expression studies have shown that the alpha 2 and gamma 1 subunits coassemble and are incorpoRated into GABAA receptors which appear to be more sensitive to GABA. If the observed changes in subunit mRNA levels with age correlate well with enhanced GABAA receptor function in the IC of old Rats, this, in turn, may represent a compensatory mechanism in response to presynaptic GABAergic changes.

  • age related decrease in gabab receptor binding in the Fischer 344 Rat i inferior colliculus
    Neurobiology of Aging, 1994
    Co-Authors: Joseph C Milbrandt, Roger L Albin, Donald M Caspary
    Abstract:

    Quantitative receptor autoradiography was used to assess GABAB receptor binding in three primary subdivisions of the inferior colliculus (IC): dorsal cortex (DCIC), external cortex (ECIC), and the central nucleus (CIC) of 3-, 18-20-, and 26-month-old Fischer 344 Rats. GABAB binding sites were localized using [3H]GABA in the presence of a satuRating concentRation of isoguvacine, a selective GABAA receptor agonist, to displace [3H]GABA bound to GABAA receptor sites. In the three IC subdivisions examined, GABAB receptor binding was significantly reduced in 26-month-old Rats when compared to 3-month-old Rats (DCIC, -44%; ECIC, -36%; CIC, -32%; p < 0.05). For comparison, GABAB binding was determined in the portion of cerebellum located in the recess of the IC. In the molecular layer of this region, there was no statistically significant differences in receptor binding between 3, 18-20-, and 26-month-old Rats. In addition, there was not a significant age-related change in the cross-sectional area of the IC. These findings provide additional evidence to support the existence of selective age-related changes in GABA neurotransmitter function in the Rat IC.