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Ravi Tolwani


rtolwani@rockefeller.edu
Ravi Tolwani has led and managed renowned organizations in academia utilizing his medical, life science and business expertise. Most recently, as an associate vice president of The Rockefeller University, Ravi oversaw three profit loss centers consisting of 120 professionals and specialists. Here he established highly successful industry partnerships and adopted new technologies to provide solutions to improve operational efficiency. Additionally, he provided strategic direction to the University has been involved in over $36MM of capital infrastructure investments at the university. Prior to The Rockefeller University he was on faculty at the Stanford University School of Medicine where he maintained a neuroscience laboratory and was uniquely involved in reviewing numerous innovative programs in the life sciences and medical devices. For the past 10 years, Ravi has been an active consultant to numerous biopharma companies and has broad expertise and clear understanding of key challenges faced by companies at different stages of development.

Ravi holds a D.V.M. from Auburn University, a Ph.D. in molecular pathology from the University of Alabama at Birmingham and a M.S. in Management (Sloan Fellow) from the Stanford Graduate School of Business.

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Journal articles

2012
2011
Skye Rasmussen, Melinda M Miller, Sarah B Filipski, Ravi J Tolwani (2011)  Cage change influences serum corticosterone and anxiety-like behaviors in the mouse.   J Am Assoc Lab Anim Sci 50: 4. 479-483 Jul  
Abstract: Environmental variables and husbandry practices can influence physiology and alter behavior in mice. Our study evaluated the effects of cage change on serum corticosterone levels and anxiety-like behaviors in C57BL/6 male mice. We examined the effects of 3 different methods of performing cage transfer and of transferring mice to a clean or a dirty familiar cage microenvironment. The 3 different handling methods were forceps transfer, gentle transfer with gloved hands, and a passive transfer technique that did not involve active handling. Active handling methods and transfer to both clean and dirty cage microenvironments significantly increased serum corticosterone 15 min after cage change; however, at 60 min after cage change, levels were comparable to those of unmanipulated mice. Although the effects were transient, cage change altered anxiety-like behaviors in the open field when behavioral testing was performed on the same day. These results demonstrate that the timing of cage change can influence behavioral results, an effect that is an important consideration for rodent behavioral studies.
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2010
Gordon S Roble, Naomi M Lingenhol, Bryan Baker, Amy Wilkerson, Ravi J Tolwani (2010)  A comprehensive laboratory animal facility pandemic response plan.   J Am Assoc Lab Anim Sci 49: 5. 623-632 Sep  
Abstract: The potential of a severe influenza pandemic necessitates the development of an organized, rational plan for continued laboratory animal facility operation without compromise of the welfare of animals. A comprehensive laboratory animal program pandemic response plan was integrated into a university-wide plan. Preparation involved input from all levels of organizational hierarchy including the IACUC. Many contingencies and operational scenarios were considered based on the severity and duration of the influenza pandemic. Trigger points for systematic action steps were based on the World Health Organization's phase alert criteria. One extreme scenario requires hibernation of research operations and maintenance of reduced numbers of laboratory animal colonies for a period of up to 6 mo. This plan includes active recruitment and cross-training of volunteers for essential personnel positions, protective measures for employee and family health, logistical arrangements for delivery and storage of food and bedding, the removal of waste, and the potential for euthanasia. Strategies such as encouraging and subsidizing cryopreservation of unique strains were undertaken to protect valuable research assets and intellectual property. Elements of this plan were put into practice after escalation of the pandemic alerts due to influenza A (H1N1) in April 2009.
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2009
Skye Rasmussen, Gary Glickman, Rada Norinsky, Fred W Quimby, Ravi J Tolwani (2009)  Construction noise decreases reproductive efficiency in mice.   J Am Assoc Lab Anim Sci 48: 4. 363-370 Jul  
Abstract: Excessive noise is well known to impair rodent health. To better understand the effect of construction noise and to establish effective noise limits during a planned expansion of our vivarium, we analyzed the effects of construction noise on mouse gestation and neonatal growth. Our hypothesis was that high levels of construction noise would reduce the number of live births and retard neonatal growth. Female Swiss Webster mice were individually implanted with 15 B6CBAF1/J embryos and then exposed to 70- and 90-dBA concrete saw cutting noise samples at defined time points during gestation. In addition, groups of mice with litters were exposed to noise at 70, 80, or 90 dBA for 1 h daily during the first week after parturition. Litter size, birth weight, incidence of stillborn pups, and rate of neonatal weight gain were analyzed. Noise decreased reproductive efficiency by decreasing live birth rates and increasing the number of stillborn pups.
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2007
Xiaorong Liu, Ruslan N Grishanin, Ravi J Tolwani, René C Rentería, Baoji Xu, Louis F Reichardt, David R Copenhagen (2007)  Brain-derived neurotrophic factor and TrkB modulate visual experience-dependent refinement of neuronal pathways in retina.   J Neurosci 27: 27. 7256-7267 Jul  
Abstract: Sensory experience refines neuronal structure and functionality. The visual system has proved to be a productive model system to study this plasticity. In the neonatal retina, the dendritic arbors of a large proportion of ganglion cells are diffuse in the inner plexiform layer. With maturation, many of these arbors become monolaminated. Visual deprivation suppresses this remodeling. Little is known of the molecular mechanisms controlling maturational and experience-dependent refinement. Here, we tested the hypothesis that brain-derived neurotrophic factor (BDNF), which is known to regulate dendritic branching and synaptic function in the brain, modulates the developmental and visual experience-dependent refinement of retinal ganglion cells. We used a transgenic mouse line, in which a small number of ganglion cells were labeled with yellow fluorescence protein, to delineate their dendritic structure in vivo. We found that transgenic overexpression of BDNF accelerated the laminar refinement of ganglion cell dendrites, whereas decreased TrkB expression or retina-specific deletion of TrkB, the cognate receptor for BDNF, retarded it. BDNF-TrkB signaling regulated the maturational formation of new branches in ON but not the bilaminated ON-OFF ganglion cells. Furthermore, BDNF overexpression overrides the requirement for visual inputs to stimulate laminar refinement and dendritic branching of ganglion cells. These experiments reveal a previously unrecognized action of BDNF and TrkB in controlling cell-specific, experience-dependent remodeling of neuronal structures in the visual system.
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Ning Liu, Sushama Varma, David Tsao, Eric M Shooter, Ravi J Tolwani (2007)  Depleting endogenous neurotrophin-3 enhances myelin formation in the Trembler-J mouse, a model of a peripheral neuropathy.   J Neurosci Res 85: 13. 2863-2869 Oct  
Abstract: The heterozygous Trembler-J (TrJ/+) mouse, containing a point mutation in the peripheral myelin protein 22 (Pmp22) gene, is characterized by severe hypomyelination and is a representative model of Charcot-Marie-Tooth 1A (CMT1A) disease/Dejerine-Sottas syndrome (DSS). Given that the neurotrophin-3 (NT3)-TrkC signaling pathway is inhibitory to myelination during development, we investigated the role of the NT3-TrkC pathway in myelination and manipulated this pathway to improve myelin formation in the CMT1A/DSS mouse model. Injection of NT3 to the TrJ/+ mice decreased the myelin protein P(0) level in the sciatic nerves. Suppressing the NT3-TrkC pathway with TrkC-Fc, an NT3 scavenger, enhanced myelination in vitro and in vivo in the TrJ/+ mouse. Furthermore, we found that full-length TrkC was expressed in adult TrJ/+ mouse sciatic nerves but was not detected in the wild-type adults, suggesting that the full-length TrkC is a potential target of treatment to enhance myelination in the TrJ/+ mouse.
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Gilmor I Keshet, Ravi J Tolwani, Angelica Trejo, Peggy Kraft, Regis Doyonnas, Carol Clayberger, James M Weimann, Helen M Blau (2007)  Increased host neuronal survival and motor function in BMT Parkinsonian mice: involvement of immunosuppression.   J Comp Neurol 504: 6. 690-701 Oct  
Abstract: We examined the potential of bone marrow transplantation (BMT) to rescue dopaminergic neurons in a mouse model of Parkinson's disease (PD). A BMT from mice transgenic for green fluorescent protein (GFP(+)) given either before or after administration of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) led to the accumulation of transplanted adult GFP(+) bone-marrow-derived cells (BMDC) in the substantia nigra, where dopaminergic neurodegeneration occurs in PD. Post-BMT, mice exposed to MPTP had substantially greater numbers of endogenous tyrosine hydroxylase-positive neuronal cell bodies in the substantia nigra and increased dopamine transporter-positive projections into the striatum compared to controls. Moreover, motor function was restored to normal within 1 month post-MPTP in BMT-treated mice assayed by a rotarod behavioral test. The effect of BMT on PD was indirect, as no evidence of BMDC fusion with or transdifferentiation into dopaminergic neurons was observed. BMDC activated by BMT or associated factors could play a trophic role in rescuing damaged cells. Alternatively, the beneficial effects of BMT are due to immunosuppression reflected by a reduction in the proportion of T-cells and a reduction of T-cell proliferation in BMT mice. These findings highlight that when immunosuppression is required for transplantation studies, the amelioration of symptoms may not be due to the transplant itself. Further, they suggest that the immune system plays a role in the development of characteristics typical of PD.
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2006
D M Bouley, J J McIntire, B T Harris, R J Tolwani, G M Otto, R H DeKruyff, S J Hayflick (2006)  Spontaneous murine neuroaxonal dystrophy: a model of infantile neuroaxonal dystrophy.   J Comp Pathol 134: 2-3. 161-170 Feb/Apr  
Abstract: The neuroaxonal dystrophies (NADs) in human beings are fatal, inherited, neurodegenerative diseases with distinctive pathological features. This report describes a new mouse model of NAD that was identified as a spontaneous mutation in a BALB/c congenic mouse strain. The affected animals developed clinical signs of a sensory axonopathy consisting of hindlimb spasticity and ataxia as early as 3 weeks of age, with progression to paraparesis and severe morbidity by 6 months of age. Hallmark histological lesions consisted of spheroids (swollen axons), in the grey and white matter of the midbrain, brain stem, and all levels of the spinal cord. Ultrastructural analysis of the spheroids revealed accumulations of layered stacks of membranes and tubulovesicular elements, strongly resembling the ultrastructural changes seen in the axons of human patients with endogenous forms of NAD. Mouse NAD would therefore seem a potentially valuable model of human NADs.
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Jianqing Ding, Elizabeth Allen, Wei Wang, Angela Valle, Chengbiao Wu, Timothy Nardine, Bianxiao Cui, Jing Yi, Anne Taylor, Noo Li Jeon, Steven Chu, Yuen So, Hannes Vogel, Ravi Tolwani, William Mobley, Yanmin Yang (2006)  Gene targeting of GAN in mouse causes a toxic accumulation of microtubule-associated protein 8 and impaired retrograde axonal transport.   Hum Mol Genet 15: 9. 1451-1463 May  
Abstract: Mutations in gigaxonin were identified in giant axonal neuropathy (GAN), an autosomal recessive disorder. To understand how disruption of gigaxonin's function leads to neurodegeneration, we ablated the gene expression in mice using traditional gene targeting approach. Progressive neurological phenotypes and pathological lesions that developed in the GAN null mice recapitulate characteristic human GAN features. The disruption of gigaxonin results in an impaired ubiquitin-proteasome system leading to a substantial accumulation of a novel microtubule-associated protein, MAP8, in the null mutants. Accumulated MAP8 alters the microtubule network, traps dynein motor protein in insoluble structures and leads to neuronal death in cultured wild-type neurons, which replicates the process occurring in GAN null mutants. Defective axonal transport is evidenced by the in vitro assays and is supported by vesicular accumulation in the GAN null neurons. We propose that the axonal transport impairment may be a deleterious consequence of accumulated, toxic MAP8 protein.
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2005
Ning Liu, Sushama Varma, Eric M Shooter, Ravi J Tolwani (2005)  Enhancement of Schwann cell myelin formation by K252a in the Trembler-J mouse dorsal root ganglion explant culture.   J Neurosci Res 79: 3. 310-317 Feb  
Abstract: The Trembler-J (TrJ) mouse, containing a point mutation in the peripheral myelin protein 22 gene, is characterized by severe hypomyelination and is a representative model of Charcot-Marie-Tooth 1A disease/Dejerine-Sottas Syndrome. Previous studies have shown that protein kinase inhibitor K252a enhances wild-type Schwann cell myelination in culture. We used a dorsal root ganglion (DRG) explant culture system from the heterozygous TrJ/+ mouse to investigate if myelination could be enhanced by K252a. The TrJ/+ DRG explant cultures replicated some important features of the TrJ/+ mouse, showing reduced myelin protein accumulation, thinner myelin sheaths, and shortened myelin internodes. K252a increased myelin protein accumulation and myelin sheath thickness but did not substantially increase myelin internode length. Furthermore, the TrJ/+ DRG explant culture and sciatic nerves continued to respond to K252a during the stage when myelination is complete in the wild type. A general tyrosine kinase inhibitor, genistein, but not inhibitors of serine/threonine protein kinase inhibitors, had a similar effect to K252a. K252a is therefore able to partially overcome hypomyelination by enhancing mutant Schwann cell myelin formation in the TrJ/+ mouse.
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Ravi J Tolwani, Doug A Hamm, Liqun Tian, J Daniel Sharer, Jerry Vockley, Piero Rinaldo, Dietrich Matern, Trenton R Schoeb, Philip A Wood (2005)  Medium-chain acyl-CoA dehydrogenase deficiency in gene-targeted mice.   PLoS Genet 1: 2. Aug  
Abstract: Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is the most common inherited disorder of mitochondrial fatty acid beta-oxidation in humans. To better understand the pathogenesis of this disease, we developed a mouse model for MCAD deficiency (MCAD-/-) by gene targeting in embryonic stem (ES) cells. The MCAD-/- mice developed an organic aciduria and fatty liver, and showed profound cold intolerance at 4 degrees C with prior fasting. The sporadic cardiac lesions seen in MCAD-/- mice have not been reported in human MCAD patients. There was significant neonatal mortality of MCAD-/- pups demonstrating similarities to patterns of clinical episodes and mortality in MCAD-deficient patients. The MCAD-deficient mouse reproduced important aspects of human MCAD deficiency and is a valuable model for further analysis of the roles of fatty acid oxidation and pathogenesis of human diseases involving fatty acid oxidation.
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S L Green, R J Tolwani, S Varma, G D Shelton (2005)  Absence of mutations in the survival motor neuron cDNA from labrador retrievers with an inherited myopathy.   Vet Rec 157: 9. 250-254 Aug  
Abstract: The clinical phenotype of hereditary myopathy of labrador retrievers is consistent, but the pathological changes within muscle biopsy specimens can vary from type 1 fibre predominance (type 2 fibre deficiency) to dystrophic changes or overt neurogenic atrophy. The condition shares many clinical and pathological features with the mildest form of human childhood spinal muscular atrophy, and the survival motor neuron gene was therefore evaluated in dogs with the disease. Direct sequencing and comparisons of cdna from the gene in seven labrador retrievers homozygous for the disease and four control dogs revealed no nucleotide mutations leading to changes in the deduced amino acid sequences. A single polymorphism was detected in two of the seven affected dogs, which was characterised by a nucleotide substitution at amino acid position 1155 within the non-coding 3' untranslated region of exon 8. Northern blot analysis indicated that there were no differences in the steady state levels of mrna from the gene of the affected labrador retrievers and control dogs.
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2004
Ravi J Tolwani, José M Cosgaya, Sushama Varma, Reza Jacob, Lydia E Kuo, Eric M Shooter (2004)  BDNF overexpression produces a long-term increase in myelin formation in the peripheral nervous system.   J Neurosci Res 77: 5. 662-669 Sep  
Abstract: The neurotrophin brain-derived neurotrophic factor (BDNF) is an endogenous regulator of the myelination process during development in the peripheral nervous system. Enhancement of myelin formation by BDNF is mediated by the neurotrophin receptor p75(NTR). Although this neurotrophin is a positive modulator of myelination during early development, the final effects of BDNF on myelin sheaths after active myelination is completed are largely unknown. Using BDNF transgenic mice, we examined the long-term effects of BDNF on myelination of the peripheral nervous system in vivo. Elevation of BDNF levels in the transgenic mice produced an increase in both the rate and extent of the myelination process. BDNF enhanced and accelerated myelin formation during early development and this increase in myelin content and thickness was maintained in adulthood. Besides enhanced myelination, BDNF also influenced axon caliber size but to a lesser extent. This lagging increase in axon caliber compared to myelin suggests that the axon size is not the only determinant of myelin thickness.
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Manuel A Garcia, Donna M Bouley, Michael J Larson, Barry Lifland, Roberta Moorhead, Mikele D Simkins, Dominic C Borie, Ravi Tolwani, Glen Otto (2004)  Outbreak of Mycobacterium bovis in a conditioned colony of rhesus (Macaca mulatta) and cynomolgus (Macaca fascicularis) macaques.   Comp Med 54: 5. 578-584 Oct  
Abstract: We describe a tuberculosis outbreak caused by Mycobacterium bovis in a conditioned colony of rhesus (Macaca mulatta) and cynomolgus (Macaca fascicularis) macaques. Animals in five rooms were exposed, but most (16/27) infections were confined to the room that housed a mixed population of cynomolgus and rhesus macaques. In this room, rhesus (8/8) and cynomolgus (10/11) macaques naturally exposed to M. bovis were infected at nearly identical rates (Fisher exact test, 2-tailed P = 1). The clinical signs of disease and pathologic lesions in infected macaques, however, were moderately different between the two species. Rhesus macaques were more likely (5/8) to exhibit clinical signs of persistent coughing and inappetance, and had more severe pulmonary lesions. By contrast, clinical signs of disease were seen in only 1 of 19 cynomolgus macaques, and overall, the pulmonary lesions were often focal and less severe, although some still had severe involvement of the lungs similar to that seen in rhesus macaques. These differences should be taken into consideration when developing or evaluating a tuberculosis-screening program. On the basis of observations made during this outbreak, we recommend that alternative screening methods such as the PRIMAGAM test and the ESAT-6 ELISA, be incorporated into the screening program to aid in the identification of infected animals.
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Ravi Tolwani, Catherine Hagan, Jonathan Runstadler, Heather Lyons, Sherril Green, Donna Bouley, Luis Rodriguez, Stephen Schendel, Michael Moseley, David Daunt, Glen Otto, Linda Cork (2004)  Magnetic resonance imaging and surgical repair of cleft palate in a four-week-old canine (Canis familiaris): an animal model for cleft palate repair.   Contemp Top Lab Anim Sci 43: 6. 17-21; quiz 58 Nov  
Abstract: Successful cleft palate repair (palatoplasty) was accomplished in a male canine pup from a kindred with autosomal recessive transmission for a complete cleft palate phenotype. This case represents the potential application of a new animal model for cleft palate repair. This reproducible congenital defect provides a clinically relevant model to improve research into the human anomaly, as compared with previous iatrogenic or teratogenically induced animal models. This case report presents the basis for new repair techniques and for studying the genetic basis of the cleft palate defect.
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Akiko Sato, Brenda Klaunberg, Ravi Tolwani (2004)  In vivo bioluminescence imaging.   Comp Med 54: 6. 631-634 Dec  
Abstract: In vivo bioluminescent imaging (BLI) is a versatile and sensitive tool that is based on detection of light emission from cells or tissues. Bioluminescence, the biochemical generation of light by a living organism, is a naturally occurring phenomenon. Luciferase enzymes, such as that from the North American firefly (Photinus pyralis), catalyze the oxidation of a substrate (luciferin), and photons of light are a product of the reaction. Optical imaging by bioluminescence allows a low-cost, noninvasive, and real-time analysis of disease processes at the molecular level in living organisms. Bioluminescence has been used to track tumor cells, bacterial and viral infections, gene expression, and treatment response. Bioluminescence in vivo imaging allows longitudinal monitoring of a disease course in the same animal, a desirable alternative to analyzing a number of animals at many time points during the course of the disease. We provide a brief introduction to BLI technology, specific examples of in vivo BLI studies investigating bacterial/viral pathogenesis and tumor growth in animal models, and highlight some future perspectives of BLI as a molecular imaging tool.
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2002
Ravi J Tolwani, Sushama Varma, Glen Otto (2002)  Use of molecular methods for genetic monitoring of an institutional mouse breeding colony.   Contemp Top Lab Anim Sci 41: 4. 23-29 Jul  
Abstract: It is important to perform genetic quality control on inbred mouse strains to minimize variability of genetic backgrounds. We used sensitive molecular methods to examine the genetic integrity of inbred mouse substrains maintained at an academic institution. Our goal, in part, was to compare the different molecular genetic monitoring methods to determine which were most sensitive, efficient, and beneficial in our genetic monitoring program. We examined the sensitivity and efficiency of simple sequence length polymorphism (SSLP) analysis of microsatellites and restriction fragment length polymorphism (RFLP) analysis of minisatellites with commercial, human, and synthetic mouse minisatellite probes. Although no polymorphisms were detected with the microsatellite analysis, certain minisatellite probes detected a small degree of polymorphism between our mouse substrains and the commercially available strains used as controls. Minisatellite probes also detected intra-substrain variation within our colonies; this variation probably represents mutations in highly unstable loci rather than genetic variation. Our analysis indicated that the genetic integrity of in-house C57BL/Ka, BALB/cKa, and C3H/Km inbred substrains had remained intact over 35 generations. Genetic monitoring by RFLP minisatellite analysis was more sensitive and efficient in detecting substrain differences than was SSLP microsatellite analysis. On the basis of these results, we established a strategy for future analysis of the in-house breeding colony.
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Glen Otto, Ravi J Tolwani (2002)  Use of microisolator caging in a risk-based mouse import and quarantine program: a retrospective study.   Contemp Top Lab Anim Sci 41: 1. 20-27 Jan  
Abstract: The expanding use of genetically engineered mice has placed increasing demands upon research facilities to import mutant strains from noncommercial sources. Conventional quarantine strategies use relatively large amounts of space per animal and/or require specialized equipment (e.g., cubicles, isolators, and ventilated racks). We have retrospectively assessed a quarantine program instituted 4 years ago that used a small amount of space and minimized the need for special equipment. Shipments presumed, in light of health reports, to be free of agents excluded from our colonies were housed in static microisolator caging in a shared quarantine room. Rather than functioning as an "all-in-all-out" area, the room continually received new shipments, which were released intermittently as multi-shipment groups after testing was performed. Noninvasive testing of the imported mice was combined with nonsurvival sampling of sentinels that had been exposed to shipped animals via direct contact and/or exposure to soiled bedding. During the 4-year period examined, the vast majority of shipments presumed to be free of excluded agents showed no evidence of contamination when screened. When active infection was detected in the shared room, the procedures in place proved sufficient to prevent cross-contamination of other shipments. The use of sentinel animals to detect the shedding of infectious agents during quarantine was found to be an effective strategy that minimized the potential impact of invasive testing on quarantined animals. Although the program we describe is not appropriate for all situations, this type of approach may be considered by institutions wishing to explore alternatives to conventional quarantine strategies during periods of restricted space availability.
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R J Tolwani, P S Buckmaster, S Varma, J M Cosgaya, Y Wu, C Suri, E M Shooter (2002)  BDNF overexpression increases dendrite complexity in hippocampal dentate gyrus.   Neuroscience 114: 3. 795-805  
Abstract: There is increasing evidence that brain-derived neurotrophic factor (BDNF) modulates synaptic and morphological plasticity in the developing and mature nervous system. Plasticity may be modulated partially by BDNF's effects on dendritic structure. Utilizing transgenic mice where BDNF overexpression was controlled by the beta-actin promoter, we evaluated the effects of long-term overexpression of BDNF on the dendritic structure of granule cells in the hippocampal dentate gyrus. BDNF transgenic mice provided the opportunity to investigate the effects of modestly increased BDNF levels on dendrite structure in the complex in vivo environment. While the elevated BDNF levels were insufficient to change levels of TrkB receptor isoforms or downstream TrkB signaling, they did increase dendrite complexity of dentate granule cells. These cells showed an increased number of first order dendrites, of total dendritic length and of total number of branch points. These results suggest that dendrite structure of granule cells is tightly regulated and is sensitive to modest increases in levels of BDNF. This is the first study to evaluate the effects of BDNF overexpression on dendrite morphology in the intact hippocampus and extends previous in vitro observations that BDNF influences synaptic plasticity by increasing complexity of dendritic arbors.
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S L Green, R J Tolwani, S Varma, P Quignon, F Galibert, L C Cork (2002)  Structure, chromosomal location, and analysis of the canine Cu/Zn superoxide dismutase (SOD1) gene.   J Hered 93: 2. 119-124 Mar/Apr  
Abstract: Mutations in Cu/Zn superoxide dismutase (SOD1), a major cytosolic antioxidant enzyme in eukaryotic cells, have been reported in approximately 20% of familial amyotrophic lateral sclerosis (FALS) patients. Hereditary canine spinal muscular atrophy (HCSMA), a fatal inherited motor neuron disease in Brittany spaniels, shares many clinical and pathological features with human motor neuron disease, including FALS. The SOD1 coding region has been sequenced and cloned from several animal species, but not from the dog. We have mapped the chromosomal location, sequenced, and characterized the canine SOD1 gene. Extending this analysis, we have evaluated SOD1 as a candidate for HCSMA. The 462 bp SOD1 coding region in the dog encodes 153 amino acid residues and exhibits more than 83% and 79% sequence identity to other mammalian homologues at both the nucleotide and amino acid levels, respectively. The canine SOD1 gene maps to CFA31 close to syntenic group 13 on the radiation hybrid (RH) map in the vicinity of sodium myo/inositol transporter (SMIT) gene. The human orthologous SOD1 and SMIT genes have been localized on HSA 21q22.1 and HSA 21q21, respectively, confirming the conservation of synteny between dog syntenic group 13 and HSA 21. Direct sequencing of SOD1 cDNA from six dogs with HCSMA revealed no mutations. Northern analysis indicated no differences in steady-state levels of SOD1 mRNA.
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2000
R J Tolwani, K S Waggie, S L Green, A J Tolwani, D M Lyons, A F Schatzberg (2000)  Dilative cardiomyopathy leading to congestive heart failure in a male squirrel monkey (Saimiri sciureus).   J Med Primatol 29: 1. 42-45 Feb  
Abstract: A 17-year-old, 1-kg, colony-housed, male squirrel monkey (Samiri sciureus) developed clinical signs of congestive heart failure. The monkey presented with lethargy, increased heart and respiratory rates, and mild abdominal distention. The clinical history, laboratory analysis, and radiographic findings were consistent with heart failure due to dilative cardiomyopathy. Gross and microscopic examination of the heart confirmed a dilative cardiomyopathy. This is the first report describing congestive heart failure caused by dilative cardiomyopathy in a squirrel monkey. Spontaneous dilative cardiomyopathy may be infrequently observed in the squirrel monkeys because they are not routinely housed in the research environment during their advancing years.
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K S Waggie, R J Tolwani, D M Lyons (2000)  Mammary adenocarcinoma in a male squirrel monkey (Saimiri sciureus).   Vet Pathol 37: 5. 505-507 Sep  
Abstract: A nodule was identified within the right mammary gland of a 16-year-old male squirrel monkey (Saimiri sciureus). The mass was excised and diagnosed as a mammary adenocarcinoma. The monkey developed congestive heart failure 1.5 years later and was euthanatized. At necropsy, a subcutaneous mass was found in the right axillary region. Histologically, the mass was identified as a lymph node whose architecture was effaced by neoplastic cells resembling those of the mammary tumor. Metastasis to internal organs was not observed. This is the first reported case of a mammary tumor in a New World primate and the only known case of mammary cancer in a male nonhuman primate.
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1999
K S Waggie, P J Kahle, R J Tolwani (1999)  Neurons and mechanisms of neuronal death in neurodegenerative diseases: a brief review.   Lab Anim Sci 49: 4. 358-362 Aug  
Abstract: Degenerative diseases of the central nervous system are a heterogenous group of slowly progressive disorders. A common feature of this group, which includes Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis, is gradual loss of specific populations of neurons.
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S L Green, D M Bouley, R J Tolwani, K S Waggie, B D Lifland, G M Otto, J E Ferrell (1999)  Identification and management of an outbreak of Flavobacterium meningosepticum infection in a colony of South African clawed frogs (Xenopus laevis).   J Am Vet Med Assoc 214: 12. 1833-8, 1792-3 Jun  
Abstract: During the summer of 1996, an outbreak of Flavobacterium meningosepticum infection developed in a colony of South African clawed frogs (Xenopus laevis). Clinical signs were consistent with septicemia: ascites, anasarca, dyspnea, extreme lethargy, congestion of web vessels, petechial hemorrhages, and sudden death. Mortality rate reached 35%, and all infections were fatal. The organism was resistant to most antibiotics but was susceptible to enrofloxacin, chloramphenicol, and trimethoprim-sulfadiazine. Treatment with trimethoprim-sulfadiazine was unsuccessful. Although the point source of the infection was not determined, several environmental reservoirs were identified, including a communal water barrel and various pieces of equipment. Molecular strain typing by pulsed-field gel electrophoresis and biochemical analyses revealed that frogs were infected with a single strain of F meningosepticum. Sanitation and management procedures were effective in controlling the outbreak.
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R J Tolwani, M W Jakowec, G M Petzinger, S Green, K Waggie (1999)  Experimental models of Parkinson's disease: insights from many models.   Lab Anim Sci 49: 4. 363-371 Aug  
Abstract: Toxin-induced and genetic experimental models have been invaluable in investigating idiopathic Parkinson's disease (PD). The neurotoxins--reserpine, 6-hydroxydopamine (6-OHDA), 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), and methamphetamine--have been used to develop parkinsonian models in a wide variety of species. Both 6-OHDA and MPTP can replicate the neurochemical, morphologic, and behavioral changes seen in human disease. The unilateral 6-OHDA rat model is an excellent model for testing and determining modes of action of new pharmacologic compounds. The nonhuman primate MPTP-induced parkinsonian model has behavioral features that best approximate idiopathic PD. These induced and genetic models have been used to study the pathophysiology of the degenerating nigrostriatal system and to evaluate novel therapeutic strategies. Important differences within these models provide insights into various aspects of the dopaminergic phenotype and its role as a target in disease. These models provide an avenue to evaluate many anti-parkinsonian compounds, such as levodopa, which was first evaluated in an animal model and is the gold standard of parkinsonian treatment today.
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S L Green, R J Tolwani (1999)  Animal models for motor neuron disease.   Lab Anim Sci 49: 5. 480-487 Oct  
Abstract: Motor neuron disease is a general term applied to a broad class of neurodegenerative diseases that are characterized by fatally progressive muscular weakness, atrophy, and paralysis attributable to loss of motor neurons. At present, there is no cure for most motor neuron diseases, including amyotrophic lateral sclerosis (ALS), the most common human motor neuron disease--the cause of which remains largely unknown. Animal models of motor neuron disease (MND) have significantly contributed to the remarkable recent progress in understanding the cause, genetic factors, and pathologic mechanisms proposed for this class of human neurodegenerative disorders. Largely driven by ALS research, animal models of MND have proven their usefulness in elucidating potential causes and specific pathogenic mechanisms, and have helped to advance promising new treatments from "benchside to bedside." This review summarizes important features of selected established animal models of MND: genetically engineered mice and inherited or spontaneously occurring MND in the murine, canine, and equine species.
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L Notterpek, R J Tolwani (1999)  Experimental models of peripheral neuropathies.   Lab Anim Sci 49: 6. 588-599 Dec  
Abstract: Peripheral neuropathies, disorders of peripheral nerves, result from genetic alterations or from metabolic, inflammatory, infectious, or chemical insults. Experimental animal models, spontaneous or induced, exist for many of the common human peripheral neuropathies. Recent advances in human genetics have led to identification of several specific gene defects involved in heritable neuropathies and have allowed reproduction of the molecular defects in experimental animals.
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S L Green, R J Tolwani, K S Waggie, G M Otto (1999)  Endometriosis and a paraovarian cyst in a rhesus macaque.   Vet Radiol Ultrasound 40: 3. 271-274 May/Jun  
Abstract: We describe endometriosis in an aged rhesus macaque. There was a large mass and a related paraovarian cyst, typical of the disease. Endometriosis is a common finding in nonhuman primate. In this report, we also review the pathophysiology of the disease and summarize the historical and more recent relevant literature. Given the frequency of endometriosis in the rhesus monkey and the long-life spans (15-30 years) of nonhuman primates in captivity, endometriosis should be suspected in animals displaying the earliest signs of the disease: anorexia, dysmenorrhea, menorrhagia, irregular menstrual cycles, or infertility. Despite recent advances in the diagnosis and therapeutic strategies for endometriosis in women, the disease remains a significant cause of morbidity and ultimately, a cause of mortality, in the older nonhuman primate.
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1998
D M Kurtz, R J Tolwani, P A Wood (1998)  Structural characterization of the mouse long-chain acyl-CoA dehydrogenase gene and 5' regulatory region.   Mamm Genome 9: 5. 361-365 May  
Abstract: Long-chain acyl-CoA dehydrogenase (LCAD) is one of four enzymes involved in the initial step of mitochondrial beta-oxidation of straight-chain fatty acids. It is a member of the acyl-CoA dehydrogenase (Acad or ACAD) gene family of enzymes, which also includes very-long-chain (VLCAD), medium-chain (MCAD), and short-chain (SCAD) acyl-CoA dehydrogenases. These enzymes all have similar activity but differ only in the chain length specificity for their substrate. Mitochondrial beta-oxidation provides an important source of energy especially during times of fasting. In order to understand the role of LCAD in this pathway, we have cloned and characterized the entire mouse (Mus musculus) gene encoding LCAD (Acadl). Acadl is a single-copy, nuclear encoded gene approximately 35 kb in size. We have sequenced the entire coding region, all intron/exon boundaries, 1.7 kb of its 5' regulatory region, and mapped the transcription start site. The gene contains 11 coding exons ranging in size from 67 bp to 275 bp, interrupted by 10 introns ranging in size from 1.0 kb to 6.6 kb in size. The Acadl 5' regulatory region, like other members of the Acad family, lacks a TATA or CAAT box and is GC rich. This region does contain multiple, putative cis-acting DNA elements recognized by either SP1 or members of the steroid-thyroid family of nuclear receptors, which has been shown with other members of the ACAD gene family to be important in regulated expression. The characterization of the mouse Acadl gene will allow further study of LCAD in an in vivo model, and how its expression may be coordinated with other members of the Acad gene family.
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R J Tolwani, K Yamamoto, K Waggie, S Green, G Otto, K Takahashi, Y D Rubinstein, R E Pratt (1998)  Hypothermia reduces neurologic deficits associated with placement of a vascular prosthesis in the abdominal aorta of rabbits.   Lab Anim Sci 48: 3. 282-287 Jun  
Abstract: Treatment for atherosclerotic vascular disease in human beings ranges from medical management to interventional therapy, such as angioplasty, atherectomy, and bypass grafting. Recently, bypass grafting with a vascular prosthesis has received increased attention and clinical use. In the course of studies to optimize use of a small-caliber vascular prosthesis, five of six rabbits undergoing implantation of a polytetrafluoroethylene vascular prosthesis in the infrarenal abdominal aorta developed hind limb neurologic deficits, which resulted from focal ischemic damage to the spinal cord attributable to temporary vascular occlusion of the abdominal aorta during placement of the vascular prosthesis. In subsequent studies, induction of systemic hypothermia decreased the rate of development of neurologic deficits from 83 to 9% without any apparent perioperative complications associated with decreased body temperature. We determined that mild hypothermia (rectal temperature of 32 to 35 degrees C), combined with aortic occlusion time of < 40 min, is sufficient to afford protection from ischemic injury to the spinal cord in the rabbit.
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1996
R J Tolwani, S C Farmer, K R Johnson, M T Davisson, D M Kurtz, M E Hinsdale, S Cresci, D P Kelly, P A Wood (1996)  Structure and chromosomal location of the mouse medium-chain acyl-CoA dehydrogenase-encoding gene and its promoter.   Gene 170: 2. 165-171 May  
Abstract: Medium-chain acyl-coenzyme A dehydrogenase (MCAD; mouse gene Acadm; human gene ACADM) catalyzes the initial step of fatty acid beta-oxidation in mitochondria. Inherited MCAD deficiency is an autosomal recessive disorder that occurs at high frequency in humans and is associated with considerable morbidity and mortality. We have cloned and characterized mouse Acadm which spans approximately 25 kb and contains 12 exons. The promoter region does not contain TATA or CAAT boxes and is G + C-rich (60%) within 200 bp of the cap site. A CpG island extends from 5' of the transcription start point into intron 1. The 5' regulatory region and a portion of intron 1 contain several Sp1 consensus sites and three regions containing hexamer DNA sequences that match the binding consensus for steroid/thyroid nuclear receptors. These putative nuclear receptor response elements (NRRE) share DNA sequence homology and electrophoretic mobility shift characteristics with known NRRE in the human ACADM promoter [Carter et al., J. Biol. Chem. 268 (1993) 13805-13810]. We have mapped mouse Acadm to the distal end of chromosome 3. Sequences previously localized to chromosome 8 are shown to be a pseudogene, and an additional pseudogene was identified on chromosome 11.
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1995
M E Hinsdale, S C Farmer, K R Johnson, M T Davisson, D A Hamm, R J Tolwani, P A Wood (1995)  RNA expression and chromosomal location of the mouse long-chain acyl-CoA dehydrogenase gene.   Genomics 28: 2. 163-170 Jul  
Abstract: The cDNA for mouse long-chain acyl-CoA dehydrogenase (Acadl, gene symbol; LCAD, enzyme) was cloned and characterized. The cDNA was obtained by library screening and reverse transcription-polymerase chain reaction (RT-PCR). The deduced amino acid sequence showed a high degree of homology to both the rat and the human LCAD sequence. Northern analysis of multiple tissues using the mouse Acadl cDNA as a probe showed two bands in all tissues examined. We found a total of three distinct mRNAs for Acadl. These three mRNAs were encoded by a single gene that we mapped to mouse chromosome 1. The three transcripts differed in the 3' untranslated region due to use of alternative polyadenylation sites. Quantitative evaluation of a multitissue Northern blot showed a varied ratio of the larger transcript as compared with the smaller transcripts.
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1994
R J Tolwani, S C Farmer, P A Wood (1994)  Molecular cloning and characterization of the mouse medium-chain acyl-CoA dehydrogenase cDNA.   Genomics 23: 1. 247-249 Sep  
Abstract: Medium-chain acyl-CoA dehydrogenase (MCAD) is one of the three straight-chain length-specific dehydrogenases involved in the first step of fatty acid oxidation. Inherited defects of acyl-CoA dehydrogenases occur in humans, and MCAD deficiency is the most common. We have cloned the coding and 3' untranslated sequence of mouse MCAD cDNA. The mouse MCAD cDNA coding region is 1263 bp long with a 3' untranslated region of 576 bp and encodes a 421 amino acid precursor protein. Comparing the nucleotide and deduced amino acid sequences of the mouse MCAD cDNA to rat and human MCAD cDNAs reveals considerable similarity between species. Amino acid residues where substitutions result in human MCAD deficiency are conserved in the mouse. Amino acid residues involved in important enzymatic functions are also conserved.
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1992
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