Predifferentiated GABAergic Neural Precursor Transplants for Alleviation of Dysesthetic Central Pain Following Excitotoxic Spinal Cord Injury

Intraspinal quisqualic acid (QUIS) injury induce (i) mechanical and thermal hyperalgesia, (ii) progressive self-injurious overgrooming of the affected dermatome. The latter is thought to resemble painful dysesthesia observed in spinal cord injury (SCI) patients. We have reported previously loss of endogenous GABA immunoreactive (IR) cells in the superficial dorsal horn of QUIS rats 2 weeks post injury. Further histological evaluation showed that GABA-, glycine-, and synaptic vesicular transporter VIAAT-IR persisted but were substantially decreased in the injured spinal cord. In this study, partially differentiated GABA-IR embryonic neural precursor cells (NPCs) were transplanted into the spinal cord of QUIS rats to reverse overgrooming by replenishing lost inhibitory circuitry. Rat E14 NPCs were predifferentiated in 0.1 ng/ml FGF-2 for 4 h prior to transplantation. In vitro immunocytochemistry of transplant cohort showed large population of GABA-IR NPCs that double labeled with nestin but few colocalized with NeuN, indicating partial maturation. Two weeks following QUIS lesion at T12-L1, and following the onset of overgrooming, NPCs were transplanted into the QUIS lesion sites; bovine adrenal fibroblast cells were used as control. Overgrooming was reduced in >55.5% of NPC grafted animals, with inverse relationship between the number of surviving GABA-IR cells and the size of overgrooming. Fibroblast-control animals showed a progressive worsening of overgrooming. At 3 weeks post-transplantation, numerous GABA-, nestin-, and GFAP-IR cells were present in the lesion site. Surviving grafted GABA-IR NPCs were NeuN+ and GFAP−. These results indicate that partially differentiated NPCs survive and differentiate in vivo into neuronal cells following transplantation into an injured spinal cord. GABA-IR NPC transplants can restore lost dorsal horn inhibitory signaling and are useful in alleviating central pain following SCI

Use of amplitude-integrated electroencephalography in decision-making for extracorporeal membrane oxygenation in comatose cardiac arrest patients whose eventual neurologic recovery is uncertain

Comatose cardiac arrest patients frequently experience cardiogenic shock or recurrent arrest. Extracorporeal membrane oxygenation (ECMO) can be used to salvage patients with cardiogenic shock or cardiac arrest refractory to conventional therapies. However, in comatose cardiac arrest patients whose neurologic recovery is uncertain, the use of ECMO is restricted because it requires considerable financial and human resources. Amplitude-integrated electroencephalography is an easily applicable, real-time electroencephalography monitoring tool that has been increasingly used to monitor brain activity in comatose cardiac arrest patients. We describe our experience of using amplitude-integrated electroencephalography in decision-making to place ECMO for comatose cardiac arrest patients whose eventual neurologic recovery appeared uncertain at the time of ECMO placement

Effect of pralidoxime on coronary perfusion pressure during cardiopulmonary resuscitation in a pig model

Objective Pralidoxime is widely used for the treatment of organophosphate poisoning. Multiple studies have reported its vasoconstrictive property, which may facilitate the restoration of spontaneous circulation (ROSC) after cardiac arrest by increasing the coronary perfusion pressure (CPP). 2,3-Butanedione monoxime, which belongs to the same oxime family, has been shown to facilitate ROSC by reducing left ventricular ischemic contracture. Because pralidoxime and 2,3-butanedione monoxime have several common mechanisms of action, both drugs may have similar effects on ischemic contracture. Thus, we investigated the effects of pralidoxime administration during cardiopulmonary resuscitation in a pig model with a focus on ischemic contracture and CPP. Methods After 14 minutes of untreated ventricular fibrillation, followed by 8 minutes of basic life support, 16 pigs randomly received either 80 mg/kg of pralidoxime (pralidoxime group) or an equivalent volume of saline (control group) during advanced cardiovascular life support (ACLS). Results Mixed-model analyses of left ventricular wall thickness and chamber area during ACLS revealed no significant group effects or group-time interactions, whereas a mixed-model analysis of the CPP during ACLS revealed a significant group effect (P=0.038) and group-time interaction (P<0.001). Post-hoc analyses revealed significant increases in CPP in the pralidoxime group, starting at 5 minutes after pralidoxime administration. No animal, except one in the pralidoxime group, achieved ROSC; thus, the rate of ROSC did not differ between the two groups. Conclusion In a pig model of cardiac arrest, pralidoxime administered during cardiopulmonary resuscitation did not reduce ischemic contracture; however, it significantly improved CPP

Autoimmune Hypoglycemia in a Patient with Characterization of Insulin Receptor Autoantibodies

BackgroundType B insulin resistance syndrome is a manifestation of autoantibodies to the insulin receptor that results in severe hyperglycemia and acanthosis nigricans. However, the mechanisms by which these autoantibodies induce hypoglycemia are largely unknown. In this paper, we report the case of patient with type B insulin resistance syndrome who presented with frequent severe fasting hypoglycemia and acanthosis nigricans.MethodsTo evaluate the mechanism of hypoglycemia, we measured the inhibition of insulin binding to erythrocytes and IM9 lymphocytes in a sample of the patient's dialyzed serum before and after immunosuppressive therapy.ResultsIn the patient's pre-treatment serum IgG, the binding of 125I-insulin to erythrocytes was markedly inhibited in a dose-dependent manner until the cold insulin level reached 10-9 mol/L. We also observed dose-dependent inhibition of insulin binding to IM9 lymphocytes, which reached approximately 82% inhibition and persisted even when diluted 1:20. After treatment with glucocorticoids, insulin-erythrocyte binding activity returned to between 70% and 80% of normal, while the inhibition of insulin-lymphocyte binding was reduced by 17%.ConclusionWe treated a patient with type B insulin resistance syndrome showing recurrent fasting hypoglycemia with steroids and azathioprine. We characterized the patient's insulin receptor antibodies by measuring the inhibition of insulin binding

Static and dynamic prognostic factors for hepatitis-B-related acute-on-chronic liver failure

Background/AimsHepatitis-B-related acute-on-chronic liver failure has a poor prognosis. However, the advent of potent oral antiviral agents means that some patients can now recover with medical treatment. We aimed to identify the prognostic factors for hepatitis-B-related acute-on-chronic liver failure including the initial as well as the dynamically changing clinical parameters during admission.MethodsSixty-seven patients were retrospectively enrolled from 2003 to 2012 at Samsung Medical Center. The patients were classified into three categories: Recovery group (n=23), Liver transplantation group (n=28), and Death group (n=16). The Liver transplantation and Death groups were combined into an Unfavorable prognosis group. We analyzed the prognostic factors including the Model for End-Stage Liver Disease (MELD) scores determined at 3-day intervals.ResultsA multivariable analysis showed that the unfavorable prognostic factors were a high initial MELD score (≥28) (odds ratio [OR] =6.64, p=0.015), moderate-to-severe ascites at admission (OR=6.71, P=0.012), and the aggravation of hepatic encephalopathy during hospitalization (≥grade III) (OR=15.41, P=0.013). Compared with the baseline level, significant reductions in the MELD scores were observed on the 7th day after admission in the Recovery group (P=0.016).ConclusionsDynamic changes in clinical parameters during admission are useful prognostic factors for hepatitis-B-related acute-on-chronic liver failure

Prolonged nociceptive responses to hind paw formalin injection in rats with a spinal cord injury

Unilateral lesioning of the spinal dorsal horn with the excitotoxin quisqualic acid (QUIS) leads to robust degeneration of dorsal horn grey matter, and robust pain-related symptoms, such as cutaneous hypersensitivity, persist long after injury. A possible mechanism that underlies the pain-related symptoms is the disruption of dorsal horn inhibitory neuron function, leading to decreased inhibition of nociceptive neurons. Five percent formalin was injected into the hind paw of rats with either a QUIS lesion or sham lesion. Both QUIS-lesioned and sham-lesioned rats displayed bi-phasic hind paw flinches following formalin injection, but a prolonged response was observed in QUIS-lesioned rats. The expression of the immediate-early gene product Fos in the dorsal horn ipsilateral to formalin injection was similar between QUIS- and sham-lesioned rats. In QUIS-lesioned rats, however, there was a marked absence of dorsal horn neurons, particularly GABAergic neurons, compared to sham-lesioned rats. The prolonged nociceptive response observed with a unilateral QUIS lesion may be due to generalized changes in dorsal horn neuron function including a loss of inhibitory neuron function

Enhanced antinociception by nicotinic receptor agonist epibatidine and adrenal medullary transplants in the spinal subarachnoid space

Adrenal medullary transplants in the spinal subarachnoid space can reduce nociception, via the release of catecholamines and other analgesic substances, and this may be enhanced by stimulation of transplanted chromaffin cell surface nicotinic acetylcholine receptors (nAChRs). In addition, spinal nAChRs have been implicated in modulating nociception and can interact synergistically with α-adrenergic agents. Thus, enhanced antinociception by potent nAChR agonists such as frog skin derivative epibatidine in adrenal-transplanted animals could potentially occur via multiple mechanisms, including nicotinic-α-adrenergic synergy and stimulation of chromaffin cell nicotinic receptors. In order to test this, male Sprague–Dawley rats were implanted with intrathecal catheters and either adrenal medullary or control striated muscle transplants in the spinal subarachnoid space at the lumbar enlargement. Animals were tested for nociceptive responses before and after intrathecal injection of several doses of epibatidine using acute analgesiometric tests (tail flick, paw pressure) and the formalin test. After adrenal medullary, but not control, transplantation, nociceptive thresholds to acute noxious stimuli were slightly but consistently elevated, and phase 2 formalin responses decreased. Following intrathecal injection of epibatidine, acute nociceptive response latencies were modestly elevated and phase 2 formalin flinches modestly suppressed in control animals, but only at the highest dose test, with some attendant motor side-effects. In contrast, in adrenal medullary-transplanted animals, epibatidine elevated responses to acute noxious stimuli and markedly suppressed phase 2 formalin responses in a dose-related fashion. The enhanced antinociceptive effect following epibatidine was attenuated with either nAChR antagonist mecamylamine or α-adrenergic receptor antagonist phentolamine. The current results demonstrate that intrathecal injection of the nAChR ligand epibatidine can produce significant antinociception in adrenal-transplanted rats in both acute and tonic nociceptive tests and suggest that the use of nicotinic agents in combination with adrenal medullary transplantation could provide maximal therapeutic benefit by synergistically improving antinociception while avoiding the detrimental side-effects of these agents

Enhanced antinociception by nicotinic receptor agonist epibatidine and adrenal medullary transplants in the spinal subarachnoid space

Adrenal medullary transplants in the spinal subarachnoid space can reduce nociception, via the release of catecholamines and other analgesic substances, and this may be enhanced by stimulation of transplanted chromaffin cell surface nicotinic acetylcholine receptors (nAChRs). In addition, spinal nAChRs have been implicated in modulating nociception and can interact synergistically with alpha-adrenergic agents. Thus, enhanced antinociception by potent nAChR agonists such as frog skin derivative epibatidine in adrenal-transplanted animals could potentially occur via multiple mechanisms, including nicotinic-alpha-adrenergic synergy and stimulation of chromaffin cell nicotinic receptors. In order to test this, male Sprague-Dawley rats were implanted with intrathecal catheters and either adrenal medullary or control striated muscle transplants in the spinal subarachnoid space at the lumbar enlargement. Animals were tested for nociceptive responses before and after intrathecal injection of several doses of epibatidine using acute analgesiometric tests (tail flick, paw pressure) and the formalin test. After adrenal medullary, but not control, transplantation, nociceptive thresholds to acute noxious stimuli were slightly but consistently elevated, and phase 2 formalin responses decreased. Following intrathecal injection of epibatidine, acute nociceptive response latencies were modestly elevated and phase 2 formalin flinches modestly suppressed in control animals, but only at the highest dose test, with some attendant motor side-effects. In contrast, in adrenal medullary-transplanted animals, epibatidine elevated responses to acute noxious stimuli and markedly suppressed phase 2 formalin responses in a dose-related fashion. The enhanced antinociceptive effect following epibatidine was attenuated with either nAChR antagonist mecamylamine or alpha-adrenergic receptor antagonist phentolamine. The current results demonstrate that intrathecal injection of the nAChR ligand epibatidine can produce significant antinociception in adrenal-transplanted rats in both acute and tonic nociceptive tests and suggest that the use of nicotinic agents in combination with adrenal medullary transplantation could provide maximal therapeutic benefit by synergistically improving antinociception while avoiding the detrimental side-effects of these agents