Publications by authors named "Vaskar Das"

Background: The ketamine metabolite (2R,6R)-hydroxynorketamine ([2R,6R]-HNK) has analgesic efficacy in murine models of acute, neuropathic, and chronic pain. The purpose of this study was to evaluate the α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) dependence of (2R,6R)-HNK analgesia and protein changes in the hippocampus in murine pain models administered (2R,6R)-HNK or saline.

Methods: All mice were CD-1 IGS outbred mice.

View Article and Find Full Text PDF

Tropomyosin receptor kinase A (TrkA/NTRK1) is a high-affinity receptor for nerve growth factor (NGF), a potent pain mediator. NGF/TrkA signaling elevates synovial sensory neuronal distributions in the joints and causes osteoarthritis (OA) pain. We investigated the mechanisms of pain transmission as to whether peripheral sensory neurons are linked to the cellular plasticity in the dorsal root ganglia (DRG) and are critical for OA hyperalgesia.

View Article and Find Full Text PDF

Background: Disk herniation is a primary cause of radicular back pain. The purpose of this study was to evaluate the antiallodynic effective dose in 50% of the sample (ED 50 ) and dorsal root ganglion (DRG) protein modulation of a peripheral direct adenosine monophosphate kinase alpha (AMPKα) activator (O304) in a murine model of lumbar disk puncture.

Methods: Male (n = 28) and female (n = 28) mice (C57BL6/J) were assessed for hind paw withdrawal threshold (PWT) and burrowing.

View Article and Find Full Text PDF

Rice (Oryza sativa L.) straw, an agricultural waste of high yield, is a sustainable source of fermentable sugars for biofuel and other chemicals. However, it shows recalcitrance to microbial catalysed depolymerization.

View Article and Find Full Text PDF

Although degenerative disc disease (DDD) and related low back pain (LBP) are growing public health problems, the underlying disease mechanisms remain unclear. An increase in the vascular endothelial growth factor (VEGF) levels in DDD has been reported. This study aimed to examine the role of VEGF receptors (VEGFRs) in DDD, using a mouse model of DDD.

View Article and Find Full Text PDF

Background And Objectives: Intervertebral disc herniation is one of the common causes of low back pain. Adenosine monophosphate (AMP)-activated protein kinase (AMPK) activator drugs have been shown to reduce pain in several animal models. The present study examines if early treatment with the drug metformin, an indirect AMPK activator, and/or O304, a new direct AMPK activator, can reduce the mechanical hypersensitivity that develops after lumbar disc puncture in mice.

View Article and Find Full Text PDF

Background: Astilbe rivularis L. is an indigenous medicinal plant growing in high altitude of Darjeeling Himalayan region of India and Nepal. The plant rhizome has been used traditionally as medicine by local tribes to treat various ailments including infectious and other diseases.

View Article and Find Full Text PDF

Background And Objectives: AMP-activated protein kinase (AMPK) activator drugs decrease hypersensitivity in mice with pain. This study examines if postsurgery treatment with the prototype AMPK activator metformin and a new mechanism-specific AMPK activator, O304, after plantar hindpaw incision in mice, would reduce mechanical hypersensitivity and produce changes in the AMPK pathway in the dorsal root ganglion (DRG).

Methods: To create postoperative pain, an incision was made in the left plantar hindpaw.

View Article and Find Full Text PDF

Osteoarthritis (OA) is a painful and debilitating disease. A striking feature of OA is the dramatic increase in vascular endothelial growth factor (VEGF) levels and in new blood vessel formation in the joints, both of which correlate with the severity of OA pain. Our aim was to determine whether anti-VEGF monoclonal antibodies (mAbs) - MF-1 (mAb to VEGFR1) and DC101 (mAb to VEGFR2) - can reduce OA pain and can do so by targeting VEGF signaling pathways such as Flt-1 (VEGFR1) and Flk-1 (VEGFR2).

View Article and Find Full Text PDF

Background: Metformin, an adenosine monophosphate (AMP)-activated protein kinase activator, as well as a common drug for type 2 diabetes, has previously been shown to decrease mechanical allodynia in mice with neuropathic pain. The objective of this study is to determine if treatment with metformin during the first 3 weeks after fracture would produce a long-term decrease in mechanical allodynia and improve a complex behavioral task (burrowing) in a mouse tibia fracture model with signs of complex regional pain syndrome.

Methods: Mice were allocated into distal tibia fracture or nonfracture groups (n = 12 per group).

View Article and Find Full Text PDF

Background And Objectives: Ketamine has been shown to reduce chronic pain; however, the adverse events associated with ketamine makes it challenging for use outside of the perioperative setting. The ketamine metabolite (2R,6R)-hydroxynorketamine ((2R,6R)-HNK) has a therapeutic effect in mice models of depression, with minimal side effects. The objective of this study is to determine if (2R,6R)-HNK has efficacy in both acute and chronic mouse pain models.

View Article and Find Full Text PDF

An extracellular L-asparaginase was isolated and purified from Bacillus megaterium MG1 to apparent homogeneity. The purification procedure involved a combination of ammonium sulfate precipitation, ion-exchange chromatography, and gel filtration techniques, resulting in a purification factor of 31.52 fold with a specific activity of 215 U mg.

View Article and Find Full Text PDF

Environmental disruption of the circadian rhythm is linked with increased pain due to osteoarthritis (OA). We aimed to characterize the role of the clock gene in OA-induced pain more systemically using both genetic and pharmacological approaches. Genetically modified mice, (bmal1f/fNav1.

View Article and Find Full Text PDF

Discogenic low back pain (DLBP) is extremely common and costly. Effective treatments are lacking due to DLBP's unknown pathogenesis. Currently, there are no in vivo mouse models of DLBP, which restricts research in this field.

View Article and Find Full Text PDF

Chronic low back pain is a major cause of disability and health care costs. Effective treatments are inadequate for many patients. Animal models are essential to further understanding of the pain mechanism and testing potential therapies.

View Article and Find Full Text PDF

Background And Objectives: Complex regional pain syndrome is a challenging disease to treat. Recently, a mouse fracture model of complex regional pain syndrome has been developed that has many signs of the clinical syndrome. However, many aspects of the sensory neuron biochemistry and behavioral and pharmacological characterization of this model remain to be clarified.

View Article and Find Full Text PDF

Background: The pentacyclic lupane-type (6-6-6-6-5 type) triterpenoid, Betulinic acid (BA) is a potent inhibitor of topoisomerases and is of immense interest as anticancer drugs. However, the compound being highly lipophilic, has limited in vivo uptake capacity. BA derivatives with halogen substituent at C-2 have improved membrane permeability and cytotoxicity against cancer cells.

View Article and Find Full Text PDF

Intraarticular steroid injection has been the mainstay of short-term treatment of knee osteoarthritis (OA) pain. However, the duration of therapeutic effect from a single injection is not as long as desired. In this study we use a viscous formulation of triamcinolone acetate (TCA) in hyaluronic acid to prolong the anti-allodynia effect of that steroid.

View Article and Find Full Text PDF

We herein report the anti-diabetic effect of the natural friedelan tritepenoid, 4-oxa-3, 4-secofriedelan (cerin), isolated from cork tissue of Quercus suber L. and its oxygenated derivative, 4-oxa-3, 4-secofriedelan-3-oic acid (cerin(ox)) in streptozotocin (STZ)-induced diabetic rat. Male Sprague Dawley rats were randomized into four groups: non-diabetic control (Group I), STZ-induced diabetic rats (Group II), STZ-induced diabetic rats treated with cerin (Group III), and STZ-induced diabetic rats treated with cerin(ox), (Group IV).

View Article and Find Full Text PDF

Pathological pain is an enormous medical problem that places a significant burden on patients and can result from an injury that has long since healed or be due to an unidentifiable cause. Although treatments exist, they often either lack efficacy or have intolerable side effects. More importantly, they do not reverse the changes in the nervous system mediating pathological pain, and thus symptoms often return when therapies are discontinued.

View Article and Find Full Text PDF

The purpose of this chapter is to provide a brief introduction to the anatomy and physiology of pain pathways from peripheral nociceptors to central nervous system areas involved in the perception and modulation of pain. This chapter also provides a short introduction to major types of persistent pain: neuropathic and inflammatory persistent pain, and gives an overview of some important molecular targets that are thought to mediate these types of pain. These targets, which include ion channels, receptors, and some neurotransmitters, are further discussed in the context of their relevance as potential drug targets for the better treatment of pain in patients with persistent pain.

View Article and Find Full Text PDF