Schwann cell transplantation is considered one of the most promising cell-based therapy to repair injured spinal cord due to its unique growth-promoting and myelin-forming properties.A the Food and Drug Administration...Schwann cell transplantation is considered one of the most promising cell-based therapy to repair injured spinal cord due to its unique growth-promoting and myelin-forming properties.A the Food and Drug Administration-approved Phase I clinical trial has been conducted to evaluate the safety of transplanted human autologous Schwann cells to treat patients with spinal cord injury.A major challenge for Schwann cell transplantation is that grafted Schwann cells are confined within the lesion cavity,and they do not migrate into the host environment due to the inhibitory barrier formed by injury-induced glial scar,thus limiting axonal reentry into the host spinal cord.Here we introduce a combinatorial strategy by suppressing the inhibitory extracellular environment with injection of lentivirus-mediated transfection of chondroitinase ABC gene at the rostral and caudal borders of the lesion site and simultaneously leveraging the repair capacity of transplanted Schwann cells in adult rats following a mid-thoracic contusive spinal cord injury.We report that when the glial scar was degraded by chondroitinase ABC at the rostral and caudal lesion borders,Schwann cells migrated for considerable distances in both rostral and caudal directions.Such Schwann cell migration led to enhanced axonal regrowth,including the serotonergic and dopaminergic axons originating from supraspinal regions,and promoted recovery of locomotor and urinary bladder functions.Importantly,the Schwann cell survival and axonal regrowth persisted up to 6 months after the injury,even when treatment was delayed for 3 months to mimic chronic spinal cord injury.These findings collectively show promising evidence for a combinatorial strategy with chondroitinase ABC and Schwann cells in promoting remodeling and recovery of function following spinal cord injury.展开更多
Surgery is required in the vast majority of patients with Crohn’s disease (CD) and in approximately one-third of patients with ulcerative colitis (UC). Similar to medical treatments for IBD, significant advances have...Surgery is required in the vast majority of patients with Crohn’s disease (CD) and in approximately one-third of patients with ulcerative colitis (UC). Similar to medical treatments for IBD, significant advances have occurred in surgery. Advances in CD include an emphasis upon conservatism as exemplified by more limited resections, strictureplasties, and laparoscopic resections. The use of probiotics in selected patients has improved the outcome in patients with pouchitis following restorative proctocolectomy for UC. It is anticipated that ongoing discoveries in the molecular basis of IBD will in turn identify those patients who will best respond to surgery.展开更多
Nonalcoholic fatty liver disease or nonalcoholic fatty liver disease(NAFLD) refers to a group of disorders that arise from the accrual of fat in hepatocytes. Although various factors have been associated with the deve...Nonalcoholic fatty liver disease or nonalcoholic fatty liver disease(NAFLD) refers to a group of disorders that arise from the accrual of fat in hepatocytes. Although various factors have been associated with the development of NAFLD, including genetic predisposition and environmental exposures, little is known aboutthe underlying pathogenesis of the disease. Research efforts are ongoing to identify biological targets and signaling pathways that mediate NAFLD. Emerging evidence has implicated a role for micro RNAs(mi RNAs), short single-stranded molecules that regulate gene expression either transcriptionally, through targeting of promoter regions, or post-transcriptionally, by blocking translation or promoting cleavage of specific target m RNAs. Several mi RNAs have been associated with NAFLD, although our understanding of the biology underlying their role is still emerging. The goal of this review is to present an overview of the current state of knowledge of mi RNAs involved in the development of NAFLD across a range of in vitro and in vivo models, including mi RNAs that contribute to pathological mechanisms related to fatty liver in humans. Much less is known about the specific targets of mi RNAs in cells, nor the molecular mechanisms involved in the development and progression NAFLD and related outcomes. More recently, the identification and validation of mi RNA signatures in serum may facilitate the development of improved methods for diagnosis and clinical monitoring of disease progression.展开更多
Objective To investigate the effects of microvesicles(MVs) derived from hypoxia/reoxygenation(H/R)-treated human umbilical vein endothelial cells(HUVECs) on endothelium-dependent relaxation of rat thoracic aortic ring...Objective To investigate the effects of microvesicles(MVs) derived from hypoxia/reoxygenation(H/R)-treated human umbilical vein endothelial cells(HUVECs) on endothelium-dependent relaxation of rat thoracic aortic rings.Methods H/R injury model was established to induce HUVECs to release H/R-EMVs.H/R-EMVs from HUVECs were isolated by ultracentrifugation from the conditioned culture medium.H/R-EMVs were characterized using 1 urn latex beads and anti-PE-CD144 by flow cytometry.Thoracic aortic rings of rats were incubated with 2.5,5,10,20 μg/ml H/R-EMVs derived from H/R-treated HUVECs for 4 hours,and their endothelium-dependent relaxation in response to acetylcholine(ACh) or endothelium-independent relaxation in response to sodium nitroprusside(SNP) was recorded in vitro.The nitric oxide(NO) production of ACh-treated thoracic aortic rings of rats was measured using Griess reagent.The expression of endothelial NO synthase(eNOS) and phosphorylated eNOS(p-eNOS,Ser-1177) in the thoracic aortic rings of rats was detected by Western blotting.Furthermore,the levels of SOD and MDA in H/R-EMVs-treated thoracic aortic rings of rats were measured using SOD and MDA kit.Results H/R-EMVs were induced by H/R-treated HUVECs and isolated by ultracentrifugation.The membrane vesicles(< 1 urn) induced by H/R were CD144 positive.ACh-induced relaxation and NO production of rat thoracic aortic rings were impaired by H/R-EMVs treatment in a concentration-dependent manner(P<0.05,P<0.01).The expression of total eNOS(t-eNOS)was not affected by H/R-EMVs.However,the expression of p-eNOS decreased after treated with H/R-EMVs.The activity of SOD decreased and the level of MDA increased in H/R-EMVs treated rat thoracic aortic rings(P<0.01).Conclusion ACh induced endothelium-dependent relaxation of thoracic aortic rings of rats was impaired by H/R-EMVs in a concentration-dependent manner.The mechanisms included a decrease in NO production,p-eNOS expression and an increase in oxidative stress.展开更多
Objective: To establish a flow cytometric method to detect the alteration of phenotypes and concentration of circulating microvesicles(MVs) from myocardial ischemic preconditioning(IPC) treated rats(IPC-MVs), and to i...Objective: To establish a flow cytometric method to detect the alteration of phenotypes and concentration of circulating microvesicles(MVs) from myocardial ischemic preconditioning(IPC) treated rats(IPC-MVs), and to investigate the effects of IPC-MVs on ischemia/reperfusion(I/R) injury in rats. Methods: Myocardial IPC was elicited by three cycles of 5-min ischemia and 5-min reperfusion of the left anterior descending(LAD) coronary artery. Platelet-free plasma(PFP) was isolated through two steps of centrifugation at room temperature from the peripheral blood, and IPC-MVs were isolated by ultracentrifugation from PFP. PFP was incubated with anti-CD61, anti-CD144, anti-CD45 and anti-Erythroid Cells, and added 1, 2 μm latex beads to calibrate and absolutely count by flow cytometry. For functional research, I/R injury was induced by 30-min ischemia and 120-min reperfusion of LAD. IPC-MVs 7 mg/kg were infused via the femoral vein in myocardial I/R injured rats. Mean arterial blood pressure(MAP), heart rate(HR) and ST-segment of electrocardiogram(ECG) were monitored throughout the experiment. Changes of myocardial morphology were observed after hematoxylin-eosin(HE) staining. The activity of plasma lactate dehydrogenase(LDH) was tested by Microplate Reader. Myocardial infarct size was measured by TTC staining. Results: Total IPC-MVs and different phenotypes, including platelet-derived MVs(PMVs), endothelial cell-derived MVs(EMVs), leucocyte-derived MVs(LMVs) and erythrocyte-derived MVs(RMVs) were all isolated which were identified membrane vesicles(<1 μm) with corresponding antibody positive. The numbers of PMVs, EMVs and RMVs were significantly increased in circulation of IPC treated rats(P<0.05, respectively). In addition, at the end of 120-min reperfusion in I/R injured rats, IPC-MVs markedly increased HR(P<0.01), decreased ST-segment and LDH activity(P<0.05, P<0.01). The damage of myocardium was obviously alleviated and myocardial infarct size was significantly lowered after IPC-MVs treatment(P<0.01). Conclusion: The method of flow cytometry was successfully established to detect the phenotypes and concentration alteration of IPC-MVs, including PMVs, EMVs, LMVs and RMVs. Furthermore, circulating IPC-MVs protected myocardium against I/R injury in rats.展开更多
Objective To investigate the effects of endothelial microvesicles(EMVs) induced by calcium ionophore A23187 on H9c2 cardiomyocytes. Methods Human umbilical vein endothelial cells(HUVECs) were treated with 10 μmol/L A...Objective To investigate the effects of endothelial microvesicles(EMVs) induced by calcium ionophore A23187 on H9c2 cardiomyocytes. Methods Human umbilical vein endothelial cells(HUVECs) were treated with 10 μmol/L A23187 for 30 min. EMVs from HUVECs were isolated by ultracentrifugation from the conditioned culture medium. EMVs were characterized using 1 and 2 μm latex beads and antiPE-CD144 antibody by flow cytometry. For functional research, EMVs at different concentrations were cocultured with H9c2 cardiomyocytes for 6 h. Cell viability of H9c2 cells and the activity of LDH leaked from H9c2 cells were tested by colorimetry. Moreover, apoptosis of H9c2 cells was observed through Hoechst 33258 staining and tested by FITC-Annexin V/PI double staining. Results EMVs were induced by A23187 on HUVECs, and isolated by ultracentrifugation. We identified the membrane vesicles(< 1 μm) induced by A23187 were CD144 positive. In addition, the EMVs could significantly reduce the viability of H9c2 cells, and increase LDH leakage from H9c2 cells in a dose dependent manner(P<0.05). Condensed nuclei could be observed with the increasing concentrations of EMVs through Hoechst 33258 staining. Furthermore, increased apoptosis rates of H9c2 cells could be assessed through FITC-Annexin V/PI double staining by flow cytometry. Conclusion Microvesicles could be released from HUVECs after induced by A23187 through calcium influx, and these EMVs exerted a pro-apoptotic effect on H9c2 cells by induction of apoptosis.展开更多
Permanent loss of vital functions after central nervous system (CNS) injury, e.g., blindness in traumatic optic nerve (ON) injury or paralysis in spinal cord injury, occurs in part because axons in the adult mamma...Permanent loss of vital functions after central nervous system (CNS) injury, e.g., blindness in traumatic optic nerve (ON) injury or paralysis in spinal cord injury, occurs in part because axons in the adult mammalian CNS do not regenerate after injury. Growth failure is due to the diminished intrinsic regenerative capacity of mature neurons and the inhibitory environment of the adult CNS. Neutralizing extracellular inhibitory molecules genetically or pharmacologically yields only limited regeneration and functional recovery, highlighting the critical importance of neuron-intrinsic factors.展开更多
This article reviews the relationship between the spinal dorsal ramus system and low back pain, including the anatomy, clinical findings, pathogenesis and treatment of low back pain mediated by spinal dorsal ramus and...This article reviews the relationship between the spinal dorsal ramus system and low back pain, including the anatomy, clinical findings, pathogenesis and treatment of low back pain mediated by spinal dorsal ramus and zygapophysial (facet) joint syndrome. Each spinal dorsal ramus arises from the spinal nerve and then divides into a medial and lateral branch. The medial branch supplies the tissues from the midline to the zygapophysial joint line and innervates two to three adjacent zygapophysial joints and their related soft tissues. The lateral branch innervates the tissues lateral to the zygapophysial joint line. The clinical pain presentations follow these anatomic distributions, which can be used for localizing the involved dorsal ramus. The diagnosis can be confirmed by performing a single dorsal ramus block that results in relief of pain and muscle spasm. Etiologically, any factor that stimulates the spinal dorsal ramus can cause low back pain, which is distinct from zygapophysial joint syndrome. Clinically, L1 and L2 are the most common sites of dorsal rami involvement. Treatment includes spinal dorsal ramus injection therapy and percutaneous neurotomy. Summarily, irritation of the spinal dorsal ramus system is a potential source of low back pain. Based on the anatomy and clinical presentation, the involved spinal dorsal ramus can be localized and treated.展开更多
Anti-acetylcholine receptor antibodies (AAR) are considered pathognomonic and pathogenetic for myasthenia gravis (MG). AAR detection confirms clinical diagnosis of MG. However, AAR is rarely detected in patients w...Anti-acetylcholine receptor antibodies (AAR) are considered pathognomonic and pathogenetic for myasthenia gravis (MG). AAR detection confirms clinical diagnosis of MG. However, AAR is rarely detected in patients without MG. The underlying pathophysiological mechanisms in a normal subject without MG have not been adequately addressed in previous studies. The present study reports on a case study of a healthy, elderly man with high AAR titers for 14 years. Pathophysiological mechanisms could be due to AAR heterogeneity in specificity, affinity, and multiform, and to muscle variability in response to AAR.展开更多
Epigenetic control of regeneration after spinal cord injury: Com- plete spinal cord injury (SCI) in humans and other mammals leads to irreversible paralysis below the level of injury, due to failure of axonal regen...Epigenetic control of regeneration after spinal cord injury: Com- plete spinal cord injury (SCI) in humans and other mammals leads to irreversible paralysis below the level of injury, due to failure of axonal regeneration in the central nervous system (CNS). Previous work has shown that successful axon regeneration is dependent upon transcription of a large number of regeneration-associated genes (RAGs) and transcription factors (TFs) (Van Kesteren et al., 2011). A prominent theory in the field of axon regeneration is that the large differences in regenerative potential between peripheral nervous system (PNS) neurons, which regenerate well, and CNS neurons, which do not, reflect differences in intrinsic transcriptional net- works, rather than individual genes (Van Kesteren et al., 2011).展开更多
AIM: To assess inter- and intra-rater reliability(agreement) between two region of interest(ROI) methods in pediatric spinal cord diffusion tensor imaging(DTI). METHODS: Inner-Field-of-View DTI data previously acquire...AIM: To assess inter- and intra-rater reliability(agreement) between two region of interest(ROI) methods in pediatric spinal cord diffusion tensor imaging(DTI). METHODS: Inner-Field-of-View DTI data previously acquired from ten pediatric healthy subjects(mean age = 12.10 years) was used to assess for reliability. ROIs were drawn by two neuroradiologists on each subject data twice within a 3-mo interval. ROIs were placed on axial B0 maps along the cervical spine using free-hand and fixed-size ROIs. Agreement analyses for fractional anisotropy(FA), axial diffusivity, radial diffusivity and mean diffusivity were performed using intra-class-correlation(ICC) and Cronbach's alpha statistical methods.RESULTS: Inter- and intra-rater agreement between the two ROI methods showed moderate(ICC = 0.5) to strong(ICC = 0.84). There were significant differences between raters in the number of pixels selected using free-hand ROIs(P < 0.05). However, no significant differences were observed in DTI parameter values. FA showed highest variability in ICC values(0.10-0.87). Cronbach's alpha showed moderate-high values for raters and ROI methods. CONCLUSION: The study showed that high reproducibility in spinal cord DTI can be achieved, and demonstrated the importance of setting detailed methodology for post-processing DTI data, specifically the placement of ROIs.展开更多
Based on previous work, it has been hypothesized that the energetics of ultraviolet (UV) light disrupts effects induced by receptor-binding ligands. If this hypothesis is true, then UV light should (i) disrupt a broad...Based on previous work, it has been hypothesized that the energetics of ultraviolet (UV) light disrupts effects induced by receptor-binding ligands. If this hypothesis is true, then UV light should (i) disrupt a broad variety of endpoints and (ii) disrupt effects produced by ligands that bind to diverse receptor types. This was tested directly in the present study by using ligands selective for four different receptors (one ionotropic, three metabotropic) and three different behavioral endpoints. The selective dopamine D2 receptor antagonist (–)sulpiride (0.1 uM) dose-relatedly decreased spontaneous locomotor velocity, the selective nicotinic acetylcholine receptor agonist nicotine (1, 3, 5 mM) and the selective muscarinic acetylcholine receptor agonist pilocarpine (20, 30, 50 mM) induced seizure-like activity, and the selective-opioid receptor agonist U-50,488H (10 uM) produced physical dependence (manifested as abstinence-induced withdrawal) in planarian models. Each of these diverse ligand and receptor-mediated effects were attenuated by UV light (254 nm = 7.83 × 10–19 J = 4.89 eV). These findings provide further evidence that UV light disrupts ligand-receptor mediated interactions and that UV light might provide a useful tool for examining drug-receptor interactions.展开更多
When any type of product has been ordered to be removed from the marketplace by a governmental regulatory body, that action is a powerful indicator that the product has been determined to be unsafe for further use, th...When any type of product has been ordered to be removed from the marketplace by a governmental regulatory body, that action is a powerful indicator that the product has been determined to be unsafe for further use, thereby branding the product as defective and opening up the possibility of product liability litigation. When the product is a drug or medical device, it is especially serious since the possibility of personal injury (acute and/or chronic) or death may occur. Needless to say, in these situations, product injury litigation will almost surely follow. We review the definition and requisite claims needed to establish drug product liability, and the role that the medical literature, clinical trial data, and even experimental research data can play in product (drug)-injury litigation. We show how each of these resources played a significant role in two well-known cases: Fen-Phen and thimerosal. The ultimate goal of such knowledge is to make better informed decisions about drug safety.展开更多
The ability of the axon to form de novo collateral branches along its length is fundamental to the establishment of complex patterns of connectivity during development and is also a major response of many axonal popul...The ability of the axon to form de novo collateral branches along its length is fundamental to the establishment of complex patterns of connectivity during development and is also a major response of many axonal populations following injury.The emergence of branches is under both positive and negative control by extracellular signals.展开更多
Excess weight is a major risk factor for type-2 diabetes, cardiovascular disease, and other comorbidities. Animal models of feeding provide insight into the problem and provide a means for the discovery and evaluation...Excess weight is a major risk factor for type-2 diabetes, cardiovascular disease, and other comorbidities. Animal models of feeding provide insight into the problem and provide a means for the discovery and evaluation of pharmacotherapeutic treatment. Mammalian models are the most commonly used, but recently non-mammalian models have been utilized (e.g., C. elegans). Planarians provide an intermediate model. They are the earliest extant animal with a primitive brain-like structure and are a convenient model of mammalian behavioral endpoints and drug-induced effects. The purpose of the present study was to determine if a quantitative measure of presumptive feeding behavior could be visualized using an imaging technique. Colored food pellets were prepared and in some experiments, plasmid-delivered green fluorescent protein was added. Both visible and fluorescence microscopy displayed clear indication of internalization of the red dye and localization to the digestive system. This new methodology establishes a convenient way to study normal physiological feeding behavior as well as modifications induced by drugs or other exogenous substances.展开更多
We previously created and investigated a planarian model for the study of drug action, abuse, physical dependence, receptor affinity, the toxicity of heavy metals in wastewater, and seizures. For the present pilot stu...We previously created and investigated a planarian model for the study of drug action, abuse, physical dependence, receptor affinity, the toxicity of heavy metals in wastewater, and seizures. For the present pilot study, we investigated the possibility that this model might be useful for studying certain aspects of drugs used in treatment of Parkinson disease. For the first step, we were interested in finding an in vivo metric for the inhibition of L-DOPA by an inhibitor of DOPA decarboxylase. The direct clinical relevance of the endpoint was of secondary concern during this preliminary phase of model development. Two metrics were explored: L-DOPA-induced inhibition of motility (locomotor velocity) and dopamine-mediated toxicity, which was quantified using a Kaplan-Meier survival curve. L-DOPA produced both dose- and time-related toxicity. The water-soluble DOPA decarboxylase inhibitor benserazide dose-dependently inhibited the effect of L-DOPA, as manifested by a leftward shift in the Kaplan-Meier curve. Additional work was initiated using the more sensitive and a graded metric of spontaneous locomotor velocity. The encouraging results of this pilot study suggest that: 1) planarians contain DOPA decarboxylase or an equivalent enzyme, and 2) the planarian model might be useful for the study of certain aspects of anti-Parkinsonism pharmacotherapy.展开更多
Falls represent a significant contribution to the morbidity and mortality of the elderly population. Because vitamin D is important in bone physiology, the use of vitamin D to restore deficient bone and ameliorate the...Falls represent a significant contribution to the morbidity and mortality of the elderly population. Because vitamin D is important in bone physiology, the use of vitamin D to restore deficient bone and ameliorate the effects of bone fractures due to falls has become a common practice in recent years. Following introduction of widespread use, reports began to emerge that vitamin D not only aided in repair of fall-induced bone fractures, but that it also reduced the occurrence of falls. Vitamin D now has become a routine intervention as a fall-prevention measure. Early analyses found evidence of prevention efficacy (reduced falls), but recent analyses are more equivocal. We retrospectively examined the records of 350 patients in a long-term care facility in which vitamin D administration and the number of falls were recorded as part of a comprehensive database of care. We found a dramatic rise in vitamin D use over the period covered (2006 – 2011) and a corresponding dramatic decrease in the number of falls. However, the number of falls continued to decline after 2008, despite a plateau in number of patients on vitamin D, particularly females. It appears that other factors contribute to the overall decline.展开更多
Two selective phosphodiesterase-4 (PDE4) inhibitors—viz., crisaborole (Eucrisa®, Pfizer) and apremilast (Otezla®, Celgene)—have recently received approval by the United States Food and Drug Administr...Two selective phosphodiesterase-4 (PDE4) inhibitors—viz., crisaborole (Eucrisa®, Pfizer) and apremilast (Otezla®, Celgene)—have recently received approval by the United States Food and Drug Administration for the treatment of related but different dermatologic skin conditions (viz., atopic dermatitis and plaque psoriasis, respectively). The purpose of this review is to summarize the underlying biochemistry and pathophysiology associated with these dermatologic conditions, review the chemistry, pharmacology and safety of each of these products, and present preclinical and clinical evidence that may help explain why these two PDE4 inhibitors offer new treatment options for these skin conditions.展开更多
Background: Trigger finger is characterized by the inability to smoothly flex and extend the digit. Corticosteroids are an accepted non-surgical treatment option and can be delivered via two techniques. While the palm...Background: Trigger finger is characterized by the inability to smoothly flex and extend the digit. Corticosteroids are an accepted non-surgical treatment option and can be delivered via two techniques. While the palmar approach is more commonly used, some have suggested that the mid-axial approach may be less painful for patients and yield higher intrasheath injection rates. The purpose of this study is to compare the accuracy of the palmar and midaxial approaches for delivery of corticosteroids into the flexor tendon sheath using radio-opaque dye in a cadaver model. Methods: A total of 50 injections were performed, 25 via midaxial technique and 25 via palmar technique. A one inch, 25-gauge needle was used to inject 1 mL of Isovue contrast dye into the flexor tendon sheath under live fluoroscopy. The fluoroscopic images were examined after injection to determine intrasheath versus extrasheath delivery of the dye, with visualization of contrast filling the sheath defining a successful injection. Results: The midaxial approach had a success rate of 52% compared to the conventional palmar approach success rate of 36%, p=0.5. The ring finger is the most common location of trigger finger and the rates of success were equal between groups for this digit (80%). Conclusions: Based on our findings, there is no statistical difference in the accuracy of intrasheath injection between the midaxial technique and palmar technique. The midaxial technique can be considered as an alternative to the palmar technique for trigger finger injection.展开更多
Agricultural, pharmaceutical, and other biologically active substances are emptied or leach into waterways and groundwater, where they can dose-relatedly cause pharmacologic or toxic effects on the resident or depende...Agricultural, pharmaceutical, and other biologically active substances are emptied or leach into waterways and groundwater, where they can dose-relatedly cause pharmacologic or toxic effects on the resident or dependent animal species. Standard methods can be used to evaluate the effects of individual substances, but evaluation of combinations of substances is more difficult. The mathematically rigorous method of isobolographic analysis was coupled with a simple in vivo invertebrate model. Planarians were selected because they are the lowest extant species with a centralized nervous system. Neostigmine bromide and monopotassium phosphate (KH2PO4) were selected as representative of two types of potential pollutants. Neostigmine bromide and KH2PO4 individually produced dose-related lethality over a 60-minute observation period with LD50 values of 122 and 70 mM, respectively. The LD50 value of a 1:1 combination of the two was significantly different (p < 0.05) from the isobolographic line of additivity. We used planarians as a representative fresh-water species and joint-action (‘isobolographic’) analysis to examine possible interaction between pollutants. In the demonstrative example reported here, there was a subadditive interaction between a 1:1 fixed-ratio combination of neostigmine bromide (as a representative acetylcholinesterase inhibitor used in pesticides) and potassium phosphate (used in fertilizers and detergents).展开更多
基金supported in part by NIH R01 NS100531,R01 NS103481NIH R21NS130241(to LD)+3 种基金Merit Review Award I01 BX002356,I01 BX003705 from the U.S.Department of Veterans AffairsIndiana Spinal Cord and Brain Injury Research Foundation(No.19919)Mari Hulman George Endowment Funds(to XMX)Indiana Spinal Cord&Brain Injury Research Fund from ISDH(to NKL and LD)。
文摘Schwann cell transplantation is considered one of the most promising cell-based therapy to repair injured spinal cord due to its unique growth-promoting and myelin-forming properties.A the Food and Drug Administration-approved Phase I clinical trial has been conducted to evaluate the safety of transplanted human autologous Schwann cells to treat patients with spinal cord injury.A major challenge for Schwann cell transplantation is that grafted Schwann cells are confined within the lesion cavity,and they do not migrate into the host environment due to the inhibitory barrier formed by injury-induced glial scar,thus limiting axonal reentry into the host spinal cord.Here we introduce a combinatorial strategy by suppressing the inhibitory extracellular environment with injection of lentivirus-mediated transfection of chondroitinase ABC gene at the rostral and caudal borders of the lesion site and simultaneously leveraging the repair capacity of transplanted Schwann cells in adult rats following a mid-thoracic contusive spinal cord injury.We report that when the glial scar was degraded by chondroitinase ABC at the rostral and caudal lesion borders,Schwann cells migrated for considerable distances in both rostral and caudal directions.Such Schwann cell migration led to enhanced axonal regrowth,including the serotonergic and dopaminergic axons originating from supraspinal regions,and promoted recovery of locomotor and urinary bladder functions.Importantly,the Schwann cell survival and axonal regrowth persisted up to 6 months after the injury,even when treatment was delayed for 3 months to mimic chronic spinal cord injury.These findings collectively show promising evidence for a combinatorial strategy with chondroitinase ABC and Schwann cells in promoting remodeling and recovery of function following spinal cord injury.
文摘Surgery is required in the vast majority of patients with Crohn’s disease (CD) and in approximately one-third of patients with ulcerative colitis (UC). Similar to medical treatments for IBD, significant advances have occurred in surgery. Advances in CD include an emphasis upon conservatism as exemplified by more limited resections, strictureplasties, and laparoscopic resections. The use of probiotics in selected patients has improved the outcome in patients with pouchitis following restorative proctocolectomy for UC. It is anticipated that ongoing discoveries in the molecular basis of IBD will in turn identify those patients who will best respond to surgery.
基金Supported by The National Institutes of Health DK091601(JKD and GSG),P30 DK072488(GSG and CDS)the Translational Genomics Research Institute
文摘Nonalcoholic fatty liver disease or nonalcoholic fatty liver disease(NAFLD) refers to a group of disorders that arise from the accrual of fat in hepatocytes. Although various factors have been associated with the development of NAFLD, including genetic predisposition and environmental exposures, little is known aboutthe underlying pathogenesis of the disease. Research efforts are ongoing to identify biological targets and signaling pathways that mediate NAFLD. Emerging evidence has implicated a role for micro RNAs(mi RNAs), short single-stranded molecules that regulate gene expression either transcriptionally, through targeting of promoter regions, or post-transcriptionally, by blocking translation or promoting cleavage of specific target m RNAs. Several mi RNAs have been associated with NAFLD, although our understanding of the biology underlying their role is still emerging. The goal of this review is to present an overview of the current state of knowledge of mi RNAs involved in the development of NAFLD across a range of in vitro and in vivo models, including mi RNAs that contribute to pathological mechanisms related to fatty liver in humans. Much less is known about the specific targets of mi RNAs in cells, nor the molecular mechanisms involved in the development and progression NAFLD and related outcomes. More recently, the identification and validation of mi RNA signatures in serum may facilitate the development of improved methods for diagnosis and clinical monitoring of disease progression.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China(20101202110005)the Natural Science Foundation of Tianjin(11JCZDJC18300)+1 种基金the Research Foundation of Tianjin Municipal Education Commission(20110106)the National Key Basic Research Program of China(973 Program, 2011CB933100)
文摘Objective To investigate the effects of microvesicles(MVs) derived from hypoxia/reoxygenation(H/R)-treated human umbilical vein endothelial cells(HUVECs) on endothelium-dependent relaxation of rat thoracic aortic rings.Methods H/R injury model was established to induce HUVECs to release H/R-EMVs.H/R-EMVs from HUVECs were isolated by ultracentrifugation from the conditioned culture medium.H/R-EMVs were characterized using 1 urn latex beads and anti-PE-CD144 by flow cytometry.Thoracic aortic rings of rats were incubated with 2.5,5,10,20 μg/ml H/R-EMVs derived from H/R-treated HUVECs for 4 hours,and their endothelium-dependent relaxation in response to acetylcholine(ACh) or endothelium-independent relaxation in response to sodium nitroprusside(SNP) was recorded in vitro.The nitric oxide(NO) production of ACh-treated thoracic aortic rings of rats was measured using Griess reagent.The expression of endothelial NO synthase(eNOS) and phosphorylated eNOS(p-eNOS,Ser-1177) in the thoracic aortic rings of rats was detected by Western blotting.Furthermore,the levels of SOD and MDA in H/R-EMVs-treated thoracic aortic rings of rats were measured using SOD and MDA kit.Results H/R-EMVs were induced by H/R-treated HUVECs and isolated by ultracentrifugation.The membrane vesicles(< 1 urn) induced by H/R were CD144 positive.ACh-induced relaxation and NO production of rat thoracic aortic rings were impaired by H/R-EMVs treatment in a concentration-dependent manner(P<0.05,P<0.01).The expression of total eNOS(t-eNOS)was not affected by H/R-EMVs.However,the expression of p-eNOS decreased after treated with H/R-EMVs.The activity of SOD decreased and the level of MDA increased in H/R-EMVs treated rat thoracic aortic rings(P<0.01).Conclusion ACh induced endothelium-dependent relaxation of thoracic aortic rings of rats was impaired by H/R-EMVs in a concentration-dependent manner.The mechanisms included a decrease in NO production,p-eNOS expression and an increase in oxidative stress.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China(20101202110005)the Natural Science Foundation of Tianjin(11JCZDJC18300)the Research Foundation of Tianjin Municipal Education Commission(20110106)
文摘Objective: To establish a flow cytometric method to detect the alteration of phenotypes and concentration of circulating microvesicles(MVs) from myocardial ischemic preconditioning(IPC) treated rats(IPC-MVs), and to investigate the effects of IPC-MVs on ischemia/reperfusion(I/R) injury in rats. Methods: Myocardial IPC was elicited by three cycles of 5-min ischemia and 5-min reperfusion of the left anterior descending(LAD) coronary artery. Platelet-free plasma(PFP) was isolated through two steps of centrifugation at room temperature from the peripheral blood, and IPC-MVs were isolated by ultracentrifugation from PFP. PFP was incubated with anti-CD61, anti-CD144, anti-CD45 and anti-Erythroid Cells, and added 1, 2 μm latex beads to calibrate and absolutely count by flow cytometry. For functional research, I/R injury was induced by 30-min ischemia and 120-min reperfusion of LAD. IPC-MVs 7 mg/kg were infused via the femoral vein in myocardial I/R injured rats. Mean arterial blood pressure(MAP), heart rate(HR) and ST-segment of electrocardiogram(ECG) were monitored throughout the experiment. Changes of myocardial morphology were observed after hematoxylin-eosin(HE) staining. The activity of plasma lactate dehydrogenase(LDH) was tested by Microplate Reader. Myocardial infarct size was measured by TTC staining. Results: Total IPC-MVs and different phenotypes, including platelet-derived MVs(PMVs), endothelial cell-derived MVs(EMVs), leucocyte-derived MVs(LMVs) and erythrocyte-derived MVs(RMVs) were all isolated which were identified membrane vesicles(<1 μm) with corresponding antibody positive. The numbers of PMVs, EMVs and RMVs were significantly increased in circulation of IPC treated rats(P<0.05, respectively). In addition, at the end of 120-min reperfusion in I/R injured rats, IPC-MVs markedly increased HR(P<0.01), decreased ST-segment and LDH activity(P<0.05, P<0.01). The damage of myocardium was obviously alleviated and myocardial infarct size was significantly lowered after IPC-MVs treatment(P<0.01). Conclusion: The method of flow cytometry was successfully established to detect the phenotypes and concentration alteration of IPC-MVs, including PMVs, EMVs, LMVs and RMVs. Furthermore, circulating IPC-MVs protected myocardium against I/R injury in rats.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China(20101202110005)the Natural Science Foundation of Tianjin(11JCZDJC18300)+1 种基金the Research Foundation of Tianjin Municipal Education Commission(20110106)the National Key Basic Research Program of China(973 Program,2011CB933100)
文摘Objective To investigate the effects of endothelial microvesicles(EMVs) induced by calcium ionophore A23187 on H9c2 cardiomyocytes. Methods Human umbilical vein endothelial cells(HUVECs) were treated with 10 μmol/L A23187 for 30 min. EMVs from HUVECs were isolated by ultracentrifugation from the conditioned culture medium. EMVs were characterized using 1 and 2 μm latex beads and antiPE-CD144 antibody by flow cytometry. For functional research, EMVs at different concentrations were cocultured with H9c2 cardiomyocytes for 6 h. Cell viability of H9c2 cells and the activity of LDH leaked from H9c2 cells were tested by colorimetry. Moreover, apoptosis of H9c2 cells was observed through Hoechst 33258 staining and tested by FITC-Annexin V/PI double staining. Results EMVs were induced by A23187 on HUVECs, and isolated by ultracentrifugation. We identified the membrane vesicles(< 1 μm) induced by A23187 were CD144 positive. In addition, the EMVs could significantly reduce the viability of H9c2 cells, and increase LDH leakage from H9c2 cells in a dose dependent manner(P<0.05). Condensed nuclei could be observed with the increasing concentrations of EMVs through Hoechst 33258 staining. Furthermore, increased apoptosis rates of H9c2 cells could be assessed through FITC-Annexin V/PI double staining by flow cytometry. Conclusion Microvesicles could be released from HUVECs after induced by A23187 through calcium influx, and these EMVs exerted a pro-apoptotic effect on H9c2 cells by induction of apoptosis.
基金supported by grants from National Eye Institute,Bright Focus Foundation and Shriners Hospital for Children
文摘Permanent loss of vital functions after central nervous system (CNS) injury, e.g., blindness in traumatic optic nerve (ON) injury or paralysis in spinal cord injury, occurs in part because axons in the adult mammalian CNS do not regenerate after injury. Growth failure is due to the diminished intrinsic regenerative capacity of mature neurons and the inhibitory environment of the adult CNS. Neutralizing extracellular inhibitory molecules genetically or pharmacologically yields only limited regeneration and functional recovery, highlighting the critical importance of neuron-intrinsic factors.
文摘This article reviews the relationship between the spinal dorsal ramus system and low back pain, including the anatomy, clinical findings, pathogenesis and treatment of low back pain mediated by spinal dorsal ramus and zygapophysial (facet) joint syndrome. Each spinal dorsal ramus arises from the spinal nerve and then divides into a medial and lateral branch. The medial branch supplies the tissues from the midline to the zygapophysial joint line and innervates two to three adjacent zygapophysial joints and their related soft tissues. The lateral branch innervates the tissues lateral to the zygapophysial joint line. The clinical pain presentations follow these anatomic distributions, which can be used for localizing the involved dorsal ramus. The diagnosis can be confirmed by performing a single dorsal ramus block that results in relief of pain and muscle spasm. Etiologically, any factor that stimulates the spinal dorsal ramus can cause low back pain, which is distinct from zygapophysial joint syndrome. Clinically, L1 and L2 are the most common sites of dorsal rami involvement. Treatment includes spinal dorsal ramus injection therapy and percutaneous neurotomy. Summarily, irritation of the spinal dorsal ramus system is a potential source of low back pain. Based on the anatomy and clinical presentation, the involved spinal dorsal ramus can be localized and treated.
文摘Anti-acetylcholine receptor antibodies (AAR) are considered pathognomonic and pathogenetic for myasthenia gravis (MG). AAR detection confirms clinical diagnosis of MG. However, AAR is rarely detected in patients without MG. The underlying pathophysiological mechanisms in a normal subject without MG have not been adequately addressed in previous studies. The present study reports on a case study of a healthy, elderly man with high AAR titers for 14 years. Pathophysiological mechanisms could be due to AAR heterogeneity in specificity, affinity, and multiform, and to muscle variability in response to AAR.
基金supported by grants from Shriners Research Foundation grant SHC-85310
文摘Epigenetic control of regeneration after spinal cord injury: Com- plete spinal cord injury (SCI) in humans and other mammals leads to irreversible paralysis below the level of injury, due to failure of axonal regeneration in the central nervous system (CNS). Previous work has shown that successful axon regeneration is dependent upon transcription of a large number of regeneration-associated genes (RAGs) and transcription factors (TFs) (Van Kesteren et al., 2011). A prominent theory in the field of axon regeneration is that the large differences in regenerative potential between peripheral nervous system (PNS) neurons, which regenerate well, and CNS neurons, which do not, reflect differences in intrinsic transcriptional net- works, rather than individual genes (Van Kesteren et al., 2011).
基金Supported by The Shriners Hospitals for Children,No.#8956
文摘AIM: To assess inter- and intra-rater reliability(agreement) between two region of interest(ROI) methods in pediatric spinal cord diffusion tensor imaging(DTI). METHODS: Inner-Field-of-View DTI data previously acquired from ten pediatric healthy subjects(mean age = 12.10 years) was used to assess for reliability. ROIs were drawn by two neuroradiologists on each subject data twice within a 3-mo interval. ROIs were placed on axial B0 maps along the cervical spine using free-hand and fixed-size ROIs. Agreement analyses for fractional anisotropy(FA), axial diffusivity, radial diffusivity and mean diffusivity were performed using intra-class-correlation(ICC) and Cronbach's alpha statistical methods.RESULTS: Inter- and intra-rater agreement between the two ROI methods showed moderate(ICC = 0.5) to strong(ICC = 0.84). There were significant differences between raters in the number of pixels selected using free-hand ROIs(P < 0.05). However, no significant differences were observed in DTI parameter values. FA showed highest variability in ICC values(0.10-0.87). Cronbach's alpha showed moderate-high values for raters and ROI methods. CONCLUSION: The study showed that high reproducibility in spinal cord DTI can be achieved, and demonstrated the importance of setting detailed methodology for post-processing DTI data, specifically the placement of ROIs.
文摘Based on previous work, it has been hypothesized that the energetics of ultraviolet (UV) light disrupts effects induced by receptor-binding ligands. If this hypothesis is true, then UV light should (i) disrupt a broad variety of endpoints and (ii) disrupt effects produced by ligands that bind to diverse receptor types. This was tested directly in the present study by using ligands selective for four different receptors (one ionotropic, three metabotropic) and three different behavioral endpoints. The selective dopamine D2 receptor antagonist (–)sulpiride (0.1 uM) dose-relatedly decreased spontaneous locomotor velocity, the selective nicotinic acetylcholine receptor agonist nicotine (1, 3, 5 mM) and the selective muscarinic acetylcholine receptor agonist pilocarpine (20, 30, 50 mM) induced seizure-like activity, and the selective-opioid receptor agonist U-50,488H (10 uM) produced physical dependence (manifested as abstinence-induced withdrawal) in planarian models. Each of these diverse ligand and receptor-mediated effects were attenuated by UV light (254 nm = 7.83 × 10–19 J = 4.89 eV). These findings provide further evidence that UV light disrupts ligand-receptor mediated interactions and that UV light might provide a useful tool for examining drug-receptor interactions.
文摘When any type of product has been ordered to be removed from the marketplace by a governmental regulatory body, that action is a powerful indicator that the product has been determined to be unsafe for further use, thereby branding the product as defective and opening up the possibility of product liability litigation. When the product is a drug or medical device, it is especially serious since the possibility of personal injury (acute and/or chronic) or death may occur. Needless to say, in these situations, product injury litigation will almost surely follow. We review the definition and requisite claims needed to establish drug product liability, and the role that the medical literature, clinical trial data, and even experimental research data can play in product (drug)-injury litigation. We show how each of these resources played a significant role in two well-known cases: Fen-Phen and thimerosal. The ultimate goal of such knowledge is to make better informed decisions about drug safety.
文摘The ability of the axon to form de novo collateral branches along its length is fundamental to the establishment of complex patterns of connectivity during development and is also a major response of many axonal populations following injury.The emergence of branches is under both positive and negative control by extracellular signals.
文摘Excess weight is a major risk factor for type-2 diabetes, cardiovascular disease, and other comorbidities. Animal models of feeding provide insight into the problem and provide a means for the discovery and evaluation of pharmacotherapeutic treatment. Mammalian models are the most commonly used, but recently non-mammalian models have been utilized (e.g., C. elegans). Planarians provide an intermediate model. They are the earliest extant animal with a primitive brain-like structure and are a convenient model of mammalian behavioral endpoints and drug-induced effects. The purpose of the present study was to determine if a quantitative measure of presumptive feeding behavior could be visualized using an imaging technique. Colored food pellets were prepared and in some experiments, plasmid-delivered green fluorescent protein was added. Both visible and fluorescence microscopy displayed clear indication of internalization of the red dye and localization to the digestive system. This new methodology establishes a convenient way to study normal physiological feeding behavior as well as modifications induced by drugs or other exogenous substances.
文摘We previously created and investigated a planarian model for the study of drug action, abuse, physical dependence, receptor affinity, the toxicity of heavy metals in wastewater, and seizures. For the present pilot study, we investigated the possibility that this model might be useful for studying certain aspects of drugs used in treatment of Parkinson disease. For the first step, we were interested in finding an in vivo metric for the inhibition of L-DOPA by an inhibitor of DOPA decarboxylase. The direct clinical relevance of the endpoint was of secondary concern during this preliminary phase of model development. Two metrics were explored: L-DOPA-induced inhibition of motility (locomotor velocity) and dopamine-mediated toxicity, which was quantified using a Kaplan-Meier survival curve. L-DOPA produced both dose- and time-related toxicity. The water-soluble DOPA decarboxylase inhibitor benserazide dose-dependently inhibited the effect of L-DOPA, as manifested by a leftward shift in the Kaplan-Meier curve. Additional work was initiated using the more sensitive and a graded metric of spontaneous locomotor velocity. The encouraging results of this pilot study suggest that: 1) planarians contain DOPA decarboxylase or an equivalent enzyme, and 2) the planarian model might be useful for the study of certain aspects of anti-Parkinsonism pharmacotherapy.
文摘Falls represent a significant contribution to the morbidity and mortality of the elderly population. Because vitamin D is important in bone physiology, the use of vitamin D to restore deficient bone and ameliorate the effects of bone fractures due to falls has become a common practice in recent years. Following introduction of widespread use, reports began to emerge that vitamin D not only aided in repair of fall-induced bone fractures, but that it also reduced the occurrence of falls. Vitamin D now has become a routine intervention as a fall-prevention measure. Early analyses found evidence of prevention efficacy (reduced falls), but recent analyses are more equivocal. We retrospectively examined the records of 350 patients in a long-term care facility in which vitamin D administration and the number of falls were recorded as part of a comprehensive database of care. We found a dramatic rise in vitamin D use over the period covered (2006 – 2011) and a corresponding dramatic decrease in the number of falls. However, the number of falls continued to decline after 2008, despite a plateau in number of patients on vitamin D, particularly females. It appears that other factors contribute to the overall decline.
文摘Two selective phosphodiesterase-4 (PDE4) inhibitors—viz., crisaborole (Eucrisa®, Pfizer) and apremilast (Otezla®, Celgene)—have recently received approval by the United States Food and Drug Administration for the treatment of related but different dermatologic skin conditions (viz., atopic dermatitis and plaque psoriasis, respectively). The purpose of this review is to summarize the underlying biochemistry and pathophysiology associated with these dermatologic conditions, review the chemistry, pharmacology and safety of each of these products, and present preclinical and clinical evidence that may help explain why these two PDE4 inhibitors offer new treatment options for these skin conditions.
文摘Background: Trigger finger is characterized by the inability to smoothly flex and extend the digit. Corticosteroids are an accepted non-surgical treatment option and can be delivered via two techniques. While the palmar approach is more commonly used, some have suggested that the mid-axial approach may be less painful for patients and yield higher intrasheath injection rates. The purpose of this study is to compare the accuracy of the palmar and midaxial approaches for delivery of corticosteroids into the flexor tendon sheath using radio-opaque dye in a cadaver model. Methods: A total of 50 injections were performed, 25 via midaxial technique and 25 via palmar technique. A one inch, 25-gauge needle was used to inject 1 mL of Isovue contrast dye into the flexor tendon sheath under live fluoroscopy. The fluoroscopic images were examined after injection to determine intrasheath versus extrasheath delivery of the dye, with visualization of contrast filling the sheath defining a successful injection. Results: The midaxial approach had a success rate of 52% compared to the conventional palmar approach success rate of 36%, p=0.5. The ring finger is the most common location of trigger finger and the rates of success were equal between groups for this digit (80%). Conclusions: Based on our findings, there is no statistical difference in the accuracy of intrasheath injection between the midaxial technique and palmar technique. The midaxial technique can be considered as an alternative to the palmar technique for trigger finger injection.
文摘Agricultural, pharmaceutical, and other biologically active substances are emptied or leach into waterways and groundwater, where they can dose-relatedly cause pharmacologic or toxic effects on the resident or dependent animal species. Standard methods can be used to evaluate the effects of individual substances, but evaluation of combinations of substances is more difficult. The mathematically rigorous method of isobolographic analysis was coupled with a simple in vivo invertebrate model. Planarians were selected because they are the lowest extant species with a centralized nervous system. Neostigmine bromide and monopotassium phosphate (KH2PO4) were selected as representative of two types of potential pollutants. Neostigmine bromide and KH2PO4 individually produced dose-related lethality over a 60-minute observation period with LD50 values of 122 and 70 mM, respectively. The LD50 value of a 1:1 combination of the two was significantly different (p < 0.05) from the isobolographic line of additivity. We used planarians as a representative fresh-water species and joint-action (‘isobolographic’) analysis to examine possible interaction between pollutants. In the demonstrative example reported here, there was a subadditive interaction between a 1:1 fixed-ratio combination of neostigmine bromide (as a representative acetylcholinesterase inhibitor used in pesticides) and potassium phosphate (used in fertilizers and detergents).