gautam thor - Academia.edu (original) (raw)

Papers by gautam thor

Research paper thumbnail of BUSINESS OFFICE FEATURE: Life Science Technologies: Preparing The Proteome For Mass Spectrometry

Science, Feb 20, 2009

C K 2a l p h a1 C K 2a l p h a2 CK2 beta CK2 holoenzyme CKBB CKMB CKMBI type 1 CKMBI type 2 CKMM ... more C K 2a l p h a1 C K 2a l p h a2 CK2 beta CK2 holoenzyme CKBB CKMB CKMBI type 1 CKMBI type 2 CKMM CKMM Type 1 CKMM Type 3 CLK1 CREB-1 CSK R&D Systems Tools for Cell Biology Researchâ„¢

Research paper thumbnail of Characterization of the cell adhesion molecules L1, N-CAM and J1 in the mouse intestine

The EMBO Journal, 1987

Communicated by M.Schachner To gain insight into the cellular and molecular mechanisms underlying... more Communicated by M.Schachner To gain insight into the cellular and molecular mechanisms underlying epithelial cell surface interactions in the adult mouse intestine, we have characterized the cell adhesion molecules Li, N-CAM and Ji by immunocytological, biochemical and cell biological methods. Whereas N-CAM and Ji expression was found to be confined to the mesenchymal and neuroectodemally-derived parts of the intestine, Li was localized in the proliferating epithelial progenitor cells of crypts, but not in the more differentiated epithelial cells of villi. Li was detected in crypt cells by Western blot analysis in the molecular forms characteristic of peripheral neural cells, with apparent mol. wts of 230, 180 and 150 kd. Aggregation of single, enriched crypt, but not villus cells, was strongly inhibited in the presence of Fab fragments of polyclonal LI antibodies. These observations show that Li is not confined to the nervous system and that it may play a functional role in the histogenesis of the intestine in the adult animal.

Research paper thumbnail of Molecular Association of Two Neural Cell Adhesion Molecules Within the Surface Membrane of Cultured Mouse Neuroblastoma Cells

Neuroscience Letters, May 15, 1986

Research paper thumbnail of Methods and apparatus for mass manufacturing two-dimensional binary information on transparent substrates using phase contrast modulated templates

Research paper thumbnail of Families of neural cell adhesion molecules

Research paper thumbnail of Characterization of the cell adhesion molecules L1, N-CAM and J1 in the mouse intestine

The EMBO journal, 1987

Communicated by M.Schachner To gain insight into the cellular and molecular mechanisms underlying... more Communicated by M.Schachner To gain insight into the cellular and molecular mechanisms underlying epithelial cell surface interactions in the adult mouse intestine, we have characterized the cell adhesion molecules Li, N-CAM and Ji by immunocytological, biochemical and cell biological methods. Whereas N-CAM and Ji expression was found to be confined to the mesenchymal and neuroectodemally-derived parts of the intestine, Li was localized in the proliferating epithelial progenitor cells of crypts, but not in the more differentiated epithelial cells of villi. Li was detected in crypt cells by Western blot analysis in the molecular forms characteristic of peripheral neural cells, with apparent mol. wts of 230, 180 and 150 kd. Aggregation of single, enriched crypt, but not villus cells, was strongly inhibited in the presence of Fab fragments of polyclonal LI antibodies. These observations show that Li is not confined to the nervous system and that it may play a functional role in the histogenesis of the intestine in the adult animal.

Research paper thumbnail of Methods and apparatus for mass manufacturing two-dimensional binary information on transparent substrates using phase contrast modulated templates

Research paper thumbnail of Characterization of the cell adhesion molecules L1, N-CAM and J1 in the mouse intestine

The EMBO journal, 1987

To gain insight into the cellular and molecular mechanisms underlying epithelial cell surface int... more To gain insight into the cellular and molecular mechanisms underlying epithelial cell surface interactions in the adult mouse intestine, we have characterized the cell adhesion molecules L1, N-CAM and J1 by immunocytological, biochemical and cell biological methods. Whereas N-CAM and J1 expression was found to be confined to the mesenchymal and neuroectodermally-derived parts of the intestine, L1 was localized in the proliferating epithelial progenitor cells of crypts, but not in the more differentiated epithelial cells of villi. L1 was detected in crypt cells by Western blot analysis in the molecular forms characteristic of peripheral neural cells, with apparent mol. wts of 230, 180 and 150 kd. Aggregation of single, enriched crypt, but not villus cells, was strongly inhibited in the presence of Fab fragments of polyclonal L1 antibodies. These observations show that L1 is not confined to the nervous system and that it may play a functional role in the histogenesis of the intestine ...

Research paper thumbnail of Monoclonal antibody that distinguishes between a phosphorylated, beta 2-microglobulin-associated, and a free, nonphosphorylated, chain of MHC class I

Journal of immunology (Baltimore, Md. : 1950), 1993

We have shown that a mAb, 7.2.14, recognizes a conserved sequence in exon 7 of a number of murine... more We have shown that a mAb, 7.2.14, recognizes a conserved sequence in exon 7 of a number of murine MHC class I molecules. 7.2.14 binding is abolished when the molecule is phosphorylated, presumably at a serine residue in exon 7, whereas treatment of material in cell lysates with alkaline phosphatase increases the intensity of the binding. A genomic construct containing Dd was transfected into human fibroblasts and a clonal cell line expressing high levels of surface MHC was selected. Cell lysates were prepared from surface-iodinated cells and analyzed by using a panel of antibodies. An apparent size heterogeneity was detected in the MHC class I gene product precipitated by different anti-class I MHC antibodies, suggesting that more than one conformational species of Dd was present. This was further investigated regarding the molecules precipitated by antibodies 34-2-12, M1/42, and 7.2.14. After preclearing of surface-iodinated cell lysates by using one antibody, challenge with the ot...

Research paper thumbnail of Life Science Technologies: Preparing The Proteome For Mass Spectrometry

Research paper thumbnail of BUSINESS OFFICE FEATURE: Life Science Technologies: Sanger Who? Sequencing the Next Generation

Research paper thumbnail of Molecular association of two neural cell adhesion molecules within the surface membrane of cultured mouse neuroblastoma cells

Neuroscience Letters, 1986

Research paper thumbnail of Some topological considerations of the optic pathway

Journal of Theoretical Biology, 1983

The contralateral projection of the vertebrate retinotopic map has a component of a mirror or uni... more The contralateral projection of the vertebrate retinotopic map has a component of a mirror or uniaxial inversion in it. Here, a simple hypothesis is proposed which explains how this can come about. The emphasis is on topological considerations, in a global sense, of the overall map. An important feature of the hypothesis is that the optic nerve fibres follow pathways such that they retain their nearest neighbour relationships till they terminate in the optic tectum, i.e. no criss-crossing of the fibres is envisaged. Anatomical evidence for this is already available in the case of the optic tract of frog. Some speculations are also suggested concerning the role of this uniaxial inversion in information processing. The observations of optic tracts of other amphibian and some lower vertebrate systems are also considered.

Research paper thumbnail of Use of large-scale hydrazinolysis in the preparation ofN-linked oligosaccharide libraries: application to brain tissue

Glycoconjugate Journal, 1992

In this report, we describe the preparation of a library of N-linked glycans from whole murine br... more In this report, we describe the preparation of a library of N-linked glycans from whole murine brain obtained by the large-scale hydrazinolysis of an acetone powder of the tissue followed by chromatographic procedures. 84% of the characterized oligosaccharides were found to be anionic, the remainder neutral. The anionic species were successively neutralized by neuraminidase (29~), aq. hydrofluoric acid (30~), and methanolysis (26%), indicating that approximately equal portions were sensitive to desialylation, dephosphorylation and desulfation, respectively. The presence of the sulfated fraction was confirmed by direct 3sSO4 metabolic labelling. A residual partially characterized fraction was :found to be anionic through possession of carboxylic acid groups, unrelated to sialic acid. The purified otigosaccharides, in the absence of their original protein conjugates, were shown to retain those immunological characteristics essential for recognition by a specific monoclonal antibody, LS (4t2), that is known to recognize a carbohydrate epitope present on a number of neural adhesion molecules and functional in neural cell adhesion. These properties confirm the viability of scaling up the size of the hydrazinolysis procedure and adapting it to whole tissue for the production of glycan libraries and for the probing of structures of interest.

Research paper thumbnail of Consequences for retinal growth when vision occurs in S2 space

Biosystems, 1990

We postulate that the process of vision occurs in the S2 space. The retina is endowed with the to... more We postulate that the process of vision occurs in the S2 space. The retina is endowed with the topology of a part of a two-sphere S2, roughly, the topology of a hemisphere. There is a corresponding topology on the tectal surface, induced by the anatomy of the retino-tectal connections. Our analysis predicts the experimentally observed "near-neighbour" relationships between points in the visual field and their representation in the tectum. Further, in this context, topological arguments are presented to indicate that if the normal developing retinal disc in goldfish undergoes a process of deformation, a discontinuity is generated at the retinal surface. This discontinuity makes the differential patterns of the retinal and tectal tissues more compatible, and also enables the retina (which grows throughout the life of the animal) to conveniently connect to the tectum.

Research paper thumbnail of New disc-based technologies for diagnostic and research applications

Psychiatric Genetics, 2002

The role of genotypic analysis in disease diagnostics and drug response assessment is continually... more The role of genotypic analysis in disease diagnostics and drug response assessment is continually expanding. New genomic discoveries combined with new, novel technologies may provide a greater range of testing capabilities in the near future. We describe the application of nanotechnology, in which DNA microarrays have been placed in a microchannel environment that can be read and analyzed in an optical (CD/DVD) disc drive system. The potential exists to combine molecular and immunological applications together into a rapid, low-cost, high-capacity screening platform. The relevance of this technology is discussed in respect to infectious agent detection, pharmacogenomics, neurogenomics and genetic variations associated with neurologic diseases.

Research paper thumbnail of BUSINESS OFFICE FEATURE: Life Science Technologies: Preparing The Proteome For Mass Spectrometry

Science, Feb 20, 2009

C K 2a l p h a1 C K 2a l p h a2 CK2 beta CK2 holoenzyme CKBB CKMB CKMBI type 1 CKMBI type 2 CKMM ... more C K 2a l p h a1 C K 2a l p h a2 CK2 beta CK2 holoenzyme CKBB CKMB CKMBI type 1 CKMBI type 2 CKMM CKMM Type 1 CKMM Type 3 CLK1 CREB-1 CSK R&D Systems Tools for Cell Biology Researchâ„¢

Research paper thumbnail of Characterization of the cell adhesion molecules L1, N-CAM and J1 in the mouse intestine

The EMBO Journal, 1987

Communicated by M.Schachner To gain insight into the cellular and molecular mechanisms underlying... more Communicated by M.Schachner To gain insight into the cellular and molecular mechanisms underlying epithelial cell surface interactions in the adult mouse intestine, we have characterized the cell adhesion molecules Li, N-CAM and Ji by immunocytological, biochemical and cell biological methods. Whereas N-CAM and Ji expression was found to be confined to the mesenchymal and neuroectodemally-derived parts of the intestine, Li was localized in the proliferating epithelial progenitor cells of crypts, but not in the more differentiated epithelial cells of villi. Li was detected in crypt cells by Western blot analysis in the molecular forms characteristic of peripheral neural cells, with apparent mol. wts of 230, 180 and 150 kd. Aggregation of single, enriched crypt, but not villus cells, was strongly inhibited in the presence of Fab fragments of polyclonal LI antibodies. These observations show that Li is not confined to the nervous system and that it may play a functional role in the histogenesis of the intestine in the adult animal.

Research paper thumbnail of Molecular Association of Two Neural Cell Adhesion Molecules Within the Surface Membrane of Cultured Mouse Neuroblastoma Cells

Neuroscience Letters, May 15, 1986

Research paper thumbnail of Methods and apparatus for mass manufacturing two-dimensional binary information on transparent substrates using phase contrast modulated templates

Research paper thumbnail of Families of neural cell adhesion molecules

Research paper thumbnail of Characterization of the cell adhesion molecules L1, N-CAM and J1 in the mouse intestine

The EMBO journal, 1987

Communicated by M.Schachner To gain insight into the cellular and molecular mechanisms underlying... more Communicated by M.Schachner To gain insight into the cellular and molecular mechanisms underlying epithelial cell surface interactions in the adult mouse intestine, we have characterized the cell adhesion molecules Li, N-CAM and Ji by immunocytological, biochemical and cell biological methods. Whereas N-CAM and Ji expression was found to be confined to the mesenchymal and neuroectodemally-derived parts of the intestine, Li was localized in the proliferating epithelial progenitor cells of crypts, but not in the more differentiated epithelial cells of villi. Li was detected in crypt cells by Western blot analysis in the molecular forms characteristic of peripheral neural cells, with apparent mol. wts of 230, 180 and 150 kd. Aggregation of single, enriched crypt, but not villus cells, was strongly inhibited in the presence of Fab fragments of polyclonal LI antibodies. These observations show that Li is not confined to the nervous system and that it may play a functional role in the histogenesis of the intestine in the adult animal.

Research paper thumbnail of Methods and apparatus for mass manufacturing two-dimensional binary information on transparent substrates using phase contrast modulated templates

Research paper thumbnail of Characterization of the cell adhesion molecules L1, N-CAM and J1 in the mouse intestine

The EMBO journal, 1987

To gain insight into the cellular and molecular mechanisms underlying epithelial cell surface int... more To gain insight into the cellular and molecular mechanisms underlying epithelial cell surface interactions in the adult mouse intestine, we have characterized the cell adhesion molecules L1, N-CAM and J1 by immunocytological, biochemical and cell biological methods. Whereas N-CAM and J1 expression was found to be confined to the mesenchymal and neuroectodermally-derived parts of the intestine, L1 was localized in the proliferating epithelial progenitor cells of crypts, but not in the more differentiated epithelial cells of villi. L1 was detected in crypt cells by Western blot analysis in the molecular forms characteristic of peripheral neural cells, with apparent mol. wts of 230, 180 and 150 kd. Aggregation of single, enriched crypt, but not villus cells, was strongly inhibited in the presence of Fab fragments of polyclonal L1 antibodies. These observations show that L1 is not confined to the nervous system and that it may play a functional role in the histogenesis of the intestine ...

Research paper thumbnail of Monoclonal antibody that distinguishes between a phosphorylated, beta 2-microglobulin-associated, and a free, nonphosphorylated, chain of MHC class I

Journal of immunology (Baltimore, Md. : 1950), 1993

We have shown that a mAb, 7.2.14, recognizes a conserved sequence in exon 7 of a number of murine... more We have shown that a mAb, 7.2.14, recognizes a conserved sequence in exon 7 of a number of murine MHC class I molecules. 7.2.14 binding is abolished when the molecule is phosphorylated, presumably at a serine residue in exon 7, whereas treatment of material in cell lysates with alkaline phosphatase increases the intensity of the binding. A genomic construct containing Dd was transfected into human fibroblasts and a clonal cell line expressing high levels of surface MHC was selected. Cell lysates were prepared from surface-iodinated cells and analyzed by using a panel of antibodies. An apparent size heterogeneity was detected in the MHC class I gene product precipitated by different anti-class I MHC antibodies, suggesting that more than one conformational species of Dd was present. This was further investigated regarding the molecules precipitated by antibodies 34-2-12, M1/42, and 7.2.14. After preclearing of surface-iodinated cell lysates by using one antibody, challenge with the ot...

Research paper thumbnail of Life Science Technologies: Preparing The Proteome For Mass Spectrometry

Research paper thumbnail of BUSINESS OFFICE FEATURE: Life Science Technologies: Sanger Who? Sequencing the Next Generation

Research paper thumbnail of Molecular association of two neural cell adhesion molecules within the surface membrane of cultured mouse neuroblastoma cells

Neuroscience Letters, 1986

Research paper thumbnail of Some topological considerations of the optic pathway

Journal of Theoretical Biology, 1983

The contralateral projection of the vertebrate retinotopic map has a component of a mirror or uni... more The contralateral projection of the vertebrate retinotopic map has a component of a mirror or uniaxial inversion in it. Here, a simple hypothesis is proposed which explains how this can come about. The emphasis is on topological considerations, in a global sense, of the overall map. An important feature of the hypothesis is that the optic nerve fibres follow pathways such that they retain their nearest neighbour relationships till they terminate in the optic tectum, i.e. no criss-crossing of the fibres is envisaged. Anatomical evidence for this is already available in the case of the optic tract of frog. Some speculations are also suggested concerning the role of this uniaxial inversion in information processing. The observations of optic tracts of other amphibian and some lower vertebrate systems are also considered.

Research paper thumbnail of Use of large-scale hydrazinolysis in the preparation ofN-linked oligosaccharide libraries: application to brain tissue

Glycoconjugate Journal, 1992

In this report, we describe the preparation of a library of N-linked glycans from whole murine br... more In this report, we describe the preparation of a library of N-linked glycans from whole murine brain obtained by the large-scale hydrazinolysis of an acetone powder of the tissue followed by chromatographic procedures. 84% of the characterized oligosaccharides were found to be anionic, the remainder neutral. The anionic species were successively neutralized by neuraminidase (29~), aq. hydrofluoric acid (30~), and methanolysis (26%), indicating that approximately equal portions were sensitive to desialylation, dephosphorylation and desulfation, respectively. The presence of the sulfated fraction was confirmed by direct 3sSO4 metabolic labelling. A residual partially characterized fraction was :found to be anionic through possession of carboxylic acid groups, unrelated to sialic acid. The purified otigosaccharides, in the absence of their original protein conjugates, were shown to retain those immunological characteristics essential for recognition by a specific monoclonal antibody, LS (4t2), that is known to recognize a carbohydrate epitope present on a number of neural adhesion molecules and functional in neural cell adhesion. These properties confirm the viability of scaling up the size of the hydrazinolysis procedure and adapting it to whole tissue for the production of glycan libraries and for the probing of structures of interest.

Research paper thumbnail of Consequences for retinal growth when vision occurs in S2 space

Biosystems, 1990

We postulate that the process of vision occurs in the S2 space. The retina is endowed with the to... more We postulate that the process of vision occurs in the S2 space. The retina is endowed with the topology of a part of a two-sphere S2, roughly, the topology of a hemisphere. There is a corresponding topology on the tectal surface, induced by the anatomy of the retino-tectal connections. Our analysis predicts the experimentally observed "near-neighbour" relationships between points in the visual field and their representation in the tectum. Further, in this context, topological arguments are presented to indicate that if the normal developing retinal disc in goldfish undergoes a process of deformation, a discontinuity is generated at the retinal surface. This discontinuity makes the differential patterns of the retinal and tectal tissues more compatible, and also enables the retina (which grows throughout the life of the animal) to conveniently connect to the tectum.

Research paper thumbnail of New disc-based technologies for diagnostic and research applications

Psychiatric Genetics, 2002

The role of genotypic analysis in disease diagnostics and drug response assessment is continually... more The role of genotypic analysis in disease diagnostics and drug response assessment is continually expanding. New genomic discoveries combined with new, novel technologies may provide a greater range of testing capabilities in the near future. We describe the application of nanotechnology, in which DNA microarrays have been placed in a microchannel environment that can be read and analyzed in an optical (CD/DVD) disc drive system. The potential exists to combine molecular and immunological applications together into a rapid, low-cost, high-capacity screening platform. The relevance of this technology is discussed in respect to infectious agent detection, pharmacogenomics, neurogenomics and genetic variations associated with neurologic diseases.