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Biomedical subjects

D Bodian

Publications and source records attributed to D Bodian.

17 recordsLinked to original sources
PubMed2005

Development of comprehensive functional genomic screens to identify novel mediators of osteoarthritis.

OBJECTIVE: The aim of this study was to develop high-throughput assays for the analysis of major chondrocyte functions that are important in osteoarthritis (OA) pathogenesis and methods for high-level gene expression and analysis in primary human chondrocytes. METHODS: In the first approach, complementary DNA (cDNA) libraries were constructed from OA cartilage RNA and full-length clones were selected. These cDNAs were transferred into a retroviral vector using Gateway Technology. Full-length clones were over-expressed in human articular chondrocytes (HAC) by retroviral-mediated gene transfer. The induction of OA-associated markers, including aggrecanase-1 (Agg-1), matrix metalloproteinase-13 (MMP-13), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), collagen IIA and collagen X was measured by quantitative real-time polymerase chain reaction (QPCR). Induction of a marker gene was verified by independent isolation of 2-3 clones per gene, re-transfection followed by QPCR as well as nucleotide sequencing. In the second approach, whole cDNA libraries were transduced into chondrocytes and screened for chondrocyte cluster formation in three-dimensional agarose cultures. RESULTS: Using green fluorescent protein (eGFP) as a marker gene, it was shown that the retroviral method has a transduction efficiency of >90%. A total of 40 verified hits were identified in the QPCR screen. The first set of 19 hits coordinately induced iNOS, COX-2, Agg-1 and MMP-13. The most potent of these genes were the tyrosine kinases Axl and Tyro-3, receptor interacting kinase-2 (RIPK2), tumor necrosis factor receptor 1A (TNFR1A), fibroblast growth factor (FGF) and its receptor FGFR, MUS81 endonuclease and Sentrin/SUMO-specific protease 3. The second set of seven hits induced both Agg-1 and MMP-13 but none of the other markers. Five of these seven genes regulate the phosphoinositide-3-kinase pathway. The most potently induced OA marker was iNOS. This marker was induced 20-500 fold by seven genes. Collagen IIA was also induced by seven genes, the most potent being transforming growth factor beta (TGFbeta)-stimulated protein TSC22, vascular endothelial growth factor (VEGF) and splicing factor 3a. This screening assay did not identify inducers of collagen X. The second chondrocyte cluster formation screen identified 14 verified hits. Most of the genes inducing cluster formation were kinases. Additional genes had not been previously known to regulate chondrocyte cluster formation or any other chondrocyte function. CONCLUSIONS: The methods developed in this study can be applied to screen for genes capable of inducing an OA-like phenotype in chondrocytes on a genome-wide scale and identify novel mediators of OA pathogenesis. Thus, coordinated functional genomic approaches can be used to delineate key genes and pathways activated in complex human diseases such as OA.

Cartilage, Articular↗
PubMed2001

A splice variant of beta-secretase deficient in the amyloidogenic processing of the amyloid precursor protein.

beta-Secretase (BACE) initiates the amyloidogenic processing of the amyloid precursor protein leading to the generation of the beta-amyloid, the main component of Alzheimer's disease senile plaques. BACE is a type I transmembrane aspartyl protease of 501 amino acids. Here we describe a novel BACE mRNA lacking 132 base pairs that is expressed in the pancreas but not in the brain. Sequence alignment indicates that the deleted fragment matches the terminal two-thirds of exon 3. The new BACE variant is short of a 44-amino acid region located between the two catalytic aspartyl residues. Accordingly, a 50-kDa form of BACE (BACE457) is detected in the human pancreas. When expressed in cells, BACE457 colocalizes with the marker for the endoplasmic reticulum BiP. Moreover, BACE457 remains in a proenzymatic and endoglycosidase H-sensitive state, suggesting that its transport along the secretory pathway is blocked at the level of the endoplasmic reticulum. Notably, this novel form of BACE does not contribute to the processing of the amyloid precursor protein. Our findings suggest that tissue-specific splicing of the BACE mRNA may explain the observation that in the human pancreas robust transcription of the BACE gene does not translate into recovered enzymatic activity.

Amino Acid Sequence↗
PubMed1983

Electron microscopic atlas of the simian cochlea.

An electron microscopic atlas of simian cochlear duct structures is presented with the hope that it may help to clarify certain questions of structural-functional relationships. Emphasis is placed on structures directly involved in sensory transduction and in synaptic transmission, at afferent and efferent nerve fiber terminals. A brief discussion is included as an introduction to the possibilities of interpretation of electron microscopic data. Orientation of electron micrographs is assisted by means of numerical coding on light microscopic photographs, and by means of a diagram which combines electron microscopic and light microscopic data.

Animals↗
PubMed1980

Denervation study of synapses of organ of Corti of old world monkeys.

Fine structural characteristics of synapses in the spiral organ of Corti were examined, with reference to differences between inner and outer hair-cell systems, and to location of neurons of origin of efferent axons. Surgical interruption of crossed olivocochlear bundle, of vestibular nerve, of facial nerve, and excision of superior cervical ganglia were used to determine the pathways of different axons. Interruption of the vestibular nerve near the brainstem results in degeneration of all efferent terminals on outer hair cells. Mid-line lesions at, and caudal to, the facial colliculus result in degeneration of about half of these efferent terminals. Efferent synaptic bulbs to the inner hair-cell system are small, of the order of one micron, and form type 2 junctions with afferent dendrites. They tend to have more large dense-core vesicles (about 80 nm) than the large efferent terminals of the outer hair-cell system, and appear to be the terminals of axons in the habenula perforata, which exhibit varicosities laden with large dense core vesicles. The varicosities are unaffected by excision of the superior cervical ganglia. So far as our material can reveal, it appears that the varicosities in the habenula perforata do not survive vestibular root interruption, nor do the efferent processes in the internal spiral bundle or at the base of inner hair cells. Most interestingly, the afferent processes of the inner hair-cell system, as identified for example by their relation to pre-synaptic bodies in the inner hair cells, are subject to a trans-synaptic reaction after severance of the vestibular root. They undergo a dramatic cytological transformation, characterized by increase of volume, engorgement with microtubules, microfilaments, microvesicles of various sizes, and clusters of lysosomes. Thus, both the efferent and afferent terminals of the inner hair-cell system show marked cytological differences from the corresponding terminals of the outer hair cell system.

Afferent Pathways↗
PubMed1980

Presynaptic bodies of auditory hair cells in Old World monkeys.

Presynaptic bodies of auditory hair cells of Old World monkeys are separately differentiated in inner, as contrasted with outer, hair cells. The pre-synaptic bodies of outer cells are spherical and of variable electron density, and are thus similar to those of the labyrinth of vertebrates from fish to man. The difficulty in finding them, as compared with the relative ease of finding the presynaptic bodies of inner hair cells, suggests either that they are not present in all outer hair cells or that they undergo a regression-reconstitution cycle. The presynaptic bodies of simian inner hair cells are almost always ring-shaped. The few exceptions reinforce the impression of a later evolutionary development of the inner hair cell system. In any event, our findings serve to reemphasize the remarkable differentiation of outer and inner hair cell systems, and to deepen the mystery of their separate role in audition.

Animals↗
PubMed1978

Synapses involving auditory nerve fibers in primate cochlea.

The anatomical mechanisms for processing auditory signals are extremely complex and incompletely understood, despite major advances already made with the use of electron microscopy. A major enigma, for example, is the presence in the mammalian cochlea of a double hair cell receptor system. A renewed attempt to discover evidence of synaptic coupling between the two systems in the primate cochlea, postulated from physiological studies, has failed. However, in the outer spiral bundle the narrow and rigid clefts seen between pairs of presumptive afferent fibers suggest the possibility of dendro-dendritic interaction confined to the outer hair cell system. The clustering of afferent processes within folds of supporting cells subjacent to outer hair cells is in contrast to the lack of such close associations in the inner hair cell region. The difference reinforces the suggestion of functional interaction of some sort between the outer hair cell afferent nerve processes.

Afferent Pathways↗
PubMed1977

Chronic progressive poliomyelitis secondary to vaccination of an immunodeficient child.

We investigated an immunodeficient child in whom chronic progressive poliomyelitis developed after she had received live oral poliovirus vaccine. Poliovirus, Type II, was isolated from throat and stool during life and from several sites within the brain at autopsy. The brain isolate was classified as vaccine-like on the basis of temperature sensitivity and antigenic markers. However, in the monkey neurovirulence test, the brain isolate produced moderately severe lesions throughout the spinal cord and brainstem and appeared nonvaccine-like. Thus, the brain isolate demonstrated a dissociation between the antigenic and neurovirulence markers. Our observations suggest that, under unusual circumstances, such as immunodeficiency, attenuated poliovirus can produce a chronic progressive neurologic disease. This case also emphasizes the need to diagnose immunodeficiency as early as possible, so that live-virus vaccines will not be administered.

Agammaglobulinemia↗
PubMed1976

Poliomyelitis and the sources of useful knowledge.

Dr. Richard Ross during his introduction observed that Dr. Bodian made three contributions to the study of poliomyelitis which laid the groundwork essential to the ultimate triumph over the disease by immunization. The first was the identification of three types of poliovirus. This was absolutely basic to the development of a vaccine. The second was the identification of the viremia which occurred before the paralysis began and thus, indicated how it would be possible for an immune response to be effective. The third important contribution was the demonstration that immunity could be developed in primates with very low antibody levels.

Animals↗
PubMed1975

Origin of specific synaptic types in the motoneuron neuropil of the monkey.

An attempt has been made to establish, so far as possible, the specific types of synaptic bulbs on motoneurons which arise from extrinsic (descending and dorsal root) and intrinsic sources (interneurons). This has involved the laborious analysis of thousands of electron micrographs of material from normal motoneuron neuropil, and motoneuron neuropil of animals with lesions of spinal tracts, spinal roots, and motor cortex. Our studies have established that the large synaptic bulbs on dendrites, which are the only type in the spinal cord to possess pre-synaptic synapses (serial synapses), are derived from monosynaptic dorsal root fibers (R bulbs). The presynaptic component of the serial synapse appeared to degenerate at levels below spinal cord transections (P bulbs). By means of transections of spinal cord we have found that descending fibers in the spinal cord terminate as one of at least two distinct classes of synaptic bulbs, one with spheroid synaptic vesicles (S) and one with flattened vesicles (F). There is evidence from several sources that the first type may often be excitatory in function and the second type inhibitory. Only synaptic bulbs with spheroid vesicles show definite signs of degeneration after lesions of the opposite motor cortex. The large (L) synaptic bulbs on motoneuron somata, associated with subsynaptic cisterns, are clearly not derived from the descending systems, or from posterior root fibers.

Animals↗
PubMed1970

An electron microscopic characterization of classes of synaptic vesicles by means of controlled aldehyde fixation.

Examination of variables of aldehyde fixation that may affect the shape of agranular synaptic vesicles has revealed that even brief storage of aldehyde-perfused nervous tissue pieces in cacodylate buffer, prior to hardening in osmium tetroxide, has an unusually severe flattening effect on agranular vesicles of a particular type. These are the vesicles of peripheral cholinergic axon endings, and of certain central synaptic bulbs. Types of synaptic bulbs can now be further defined on the basis of shape of agranular synaptic vesicles under controlled conditions of aldehyde fixation. Previously described "S" bulbs in the spinal cord contain uniformly spheroid vesicles, which are wholly resistant to flattening. Previously described "F" bulbs contain somewhat smaller agranular vesicles that are flattened after aldehyde fixation, even when this is followed by prompt hardening in osmium tetroxide solution. A third type, previously characterized as having irregularly round agranular vesicles after the above treatment, contains only severely flattened vesicles when the osmium tetroxide hardening is preceded by even a brief wash with sodium cacodylate buffer containing sucrose. Moreover, the "third" type is characteristic of all cholinergic peripheral axon endings examined, as well as the large axosomatic ("L") synaptic bulbs of the spinal cord.

Adrenal Glands↗
PubMed1966

Electron microscopy: two major synaptic types on spinal motoneurons.

Two major types of synaptic bulbs are defined on the motoneuron surface of the monkey, on the basis of content of agranular "synaptic" vesicles of two distinct kinds. Both types are present on dendritic as well as perikaryal surface. Because of the approximately equal numbers, the hypothesis that one type is excitatory and the other inhibitory naturally arises.

Animals↗