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A post-marketing surveillance study reported fatalities following tissue plasminogen activator administration in acute aortic dissection (AAD) with the symptoms of acute ischemic stroke (AIS) patients. Therefore, it is important to discriminate AAD from AIS. The present study aimed to investigate whether fibrinogen/fibrin degradation products (FDP) value can be useful in differential diagnosis between AAD and AIS. The study group comprised 20 AAD patients (10 men and 10 women; age 63.9 ± 13.6 years) and 159 AIS patients (91 men and 68 women; age 74.2 ± 10.6 years) who were transported to our hospital from 2007 to 2012. The AAD cases were further divided into patent-type AAD and thrombosed-type AAD. FDP values were significantly higher in the AAD group than in the AIS group (18.15 [5.2 - 249.9] μg/ml vs. 2.3 [1.5 - 4.45] μg/ml ; P < 0.001). In AAD groups, FDP values were significantly higher in the patent-type AAD group (n = 9) than in the thrombosed type AAD group (n = 11) (293.2 μg/ml [63.1 - 419.6 μg/ml ] vs. 5.6 μg/ml [3.8 - 7.9 μg/ml ]. FDP values were significantly higher in patients with AAD than in those with AIS, especially those with patent-type AAD compared with AIS patients. High FDP values may be a useful marker for differential diagnosis between patent-type AAD and AIS.

Rat melanotrophs express several types of voltage-gated and ligand-gated calcium channels, although mechanisms involved in the maintenance of the resting intracellular Ca

A 47-year-old man was found at his home in a state of cardiopulmonary arrest. His family performed cardiopulmonary resuscitation on him. He was brought to our hospital by ambulance. On arrival, his pupils were dilated and his heart was in a state of ventricular fibrillation. After returning to spontaneous circulation by the cardiopulmonary resuscitation, the electrocardiogram revealed ST elevation at V2-V5. Cardiac catheterizatin revealed a left anterior descending coronary obstruction. Percutaneous coronary angioplasty was performed. On the 26th day after admission, acalculous cholecystitis was found. It was difficult to perform emergent surgery, because the patient was taking an anticoagulant drug. We performed PTGBA (percutaneous transhepatic gallbladder aspiration) on the same day, and the gallbladder inflammation was improved. We consider that PTGBA is an effective treatment for difficult cases of acalcuous cholecystitis.

While magnocellular neurons in the supraoptic nucleus (SON) possess rich Gi/o-mediated mechanisms, molecular and cellular properties of G-protein-activated inwardly rectifying K(+) (GIRK) channels have been controversial. Here, properties of GIRK channels are examined by RT-PCR and whole-cell patch-clamp techniques in rat SON neurons. Patch clamp experiments showed that the selective GABAB agonist, baclofen, enhanced currents in a high K(+) condition. The baclofen-enhanced currents exhibited evident inward rectification and were blocked by the selective GABAB antagonist, CGP55845A, the IRK channel blocker, Ba(2+), and the selective GIRK channel blocker, tertiapin, indicating that baclofen activates GIRK channels via GABAB receptors. The GIRK currents were abolished by N-ethylmaleimide pretreatment, and prolonged by GTPγS inclusion in the patch pipette, suggesting that Gi/o proteins are involved. RT-PCR analysis revealed mRNAs for all four GIRK 1-4 channels and for both GABABR1 and GABABR2 receptors in rat SON. However, the concentration-dependency of the baclofen-induced activation of GIRK currents had an EC50 of 110 µM, which is about 100 times higher than that of baclofen-induced inhibition of voltage-dependent Ca(2+) channels. Moreover, baclofen caused no significant changes in the membrane potential and the firing rate. These results suggest that although GIRK channels can be activated by GABAB receptors via the Gi/o pathway, this occurs at high agonist concentrations, and thus may not be a physiological mechanism regulating the function of SON neurons. This property that the membrane potential receives little influence from GIRK currents seems to be uncommon for CNS neurons possessing rich Gi/o-coupled receptors, and could be a special feature of rat SON neurons.

A significant relationship between lactate clearance and mortality rates in cardiac arrest cases has been reported. However, the relationship between lactate clearance and neurologic outcomes in cardiac arrest cases is not clear. We examined lactate clearance in cardiac arrest cases induced by ventricular fibrillation. We investigated 13 patients with cardiac arrest induced by ventricular fibrillation from April, 2006 to March, 2012 in which therapeutic hypothermia was performed. Patients were classified into two groups: those with a favorable neurologic outcome (n=7) and those with a poor outcome (n=6). We compared lactate clearance levels between the two groups. There was no significant difference in lactate concentrations at admission and 8 or 24 hours lactate clearance between the two groups 8 or 24 hours after admission. This result suggests we may not predict the neurologic outcome of cardiac arrest cases induced by ventricular fibrillation using lactate clearance.

Background In the perioperative period, plasma osmotic pressure, systemic blood pressure, and blood volume often change dramatically. Arginine vasopressin is a key factor in the regulation of these parameters. This study was performed to evaluate the direct and the mechanism of the actions of propofol on arginine vasopressin release from magnocellular neurosecretory neurons in the rat supraoptic nucleus. Methods Somatodendritic arginine vasopressin release from supraoptic nucleus slice preparations was measured by radioimmunoassay. Ionic currents were measured using the whole-cell mode of the patch-clamp technique in supraoptic nucleus slice preparations or in single dissociated supraoptic nucleus neurons of the rat. Results Propofol at concentrations greater than 10(-5) M inhibited the arginine vasopressin release stimulated by potassium chloride (50 mM). This inhibition by propofol was not reversed by picrotoxin, a gamma-aminobutyric acid(A)(GABA(A)) receptor antagonist, whereas arginine vasopressin release induced by glutamate (10(-3) M) was also inhibited by propofol at a clinically relevant concentration (10(-6) M). The latter effect was reversed by picrotoxin. Propofol evoked Cl- currents at concentrations ranging 10(-6) to 10(-4) M. Propofol (10(-6) M) enhanced the GABA (10(-6) M)-induced current synergistically. Moreover, propofol (10(-6) M) prolonged the time constant of spontaneous GABA-mediated inhibitory postsynaptic currents. Furthermore, propofol (10(-5) M and 10(-4) M) reversibly inhibited voltage-gated Ca2+ currents, whereas it did not affect currents induced by glutamate (10(-3) M). Conclusions Propofol inhibits somatodendritic arginine vasopressin release from the supraoptic nucleus, and the enhancement of GABAergic inhibitory synaptic inputs and the inhibition of voltage-gated Ca2+ entry are involved in the inhibition of arginine vasopressin release.

Pituitary adenylate cyclase-activating polypeptide (PACAP) has been reported to stimulate melanotroph secretion, and PACAP-like immunoreactivity and expression of PACAP type I receptor messenger RNA have been identified in the pituitary pars intermedia (PI). The present study showed that PACAP messenger RNA is also expressed in the PI. To examine the mechanism of PACAP action in the PI, cytosolic Ca2+ concentrations ([Ca2+]i) and ionic currents were measured in acutely dissociated rat melanotrophs. In about 40% of the melanotrophs studied, PACAP induced an increase in [Ca2+]i, which was suppressed by extracellular Ca2+ removal; extracellular Na+ replacement; the blocker of L-type Ca2+ channels, nicardipine; or the secreto-inhibitory neurotransmitter, dopamine. The PACAP-induced [Ca2+]i increase was mimicked by activators of protein kinase A (PKA) and protein kinase C (PKC), Sp-diastereomer of cAMP and 1-oleoyl-2-acetyl-sn-glycerol, and was reduced by inhibitors of PKA and PKC, Rp-diastereomer of cAMP and staurosporine. Patch-clamp analysis revealed that PACAP caused inward currents with a reversal potential of -0.8 mV and facilitated voltage-dependent Ba2+ currents. It further revealed that PACAP-induced inward currents were mimicked by 1-oleoyl-2-acetyl-sn-glycerol and inhibited by staurosporine, and that Sp-diastereomer of cAMP facilitated Ba2+ currents. These results suggest that PACAP potentiates Ca2+ entry mechanisms of rat melanotrophs by activation of nonselective cation channels via PKC and facilitation of voltage-dependent Ca2+ channels via PKA.

A 71-year-old man, who was diagnosed with familial amyloidosis type I, was admitted for treatment of severe orthostatic hypotension associated with recurrent syncopal attacks. Head-up tilt testing demonstrated severe orthostatic hypotension (114/72 mmHg in the supine position and 62/34 mmHg in the upright position) with syncope or presyncope. Oral midodorine and fludrocortisone therapies failed to prevent his symptoms. After administration of subcutaneous erythropoietin, his blood pressure drop in the upright position was decreased and symptoms disappeared unassociated with improvement of anemia. Although previous reports have shown that the mechanism by which erythropoietin improves orthostatic hypotension is related to improvement in anemia, other mechanisms may also play a role.

The primary aim for occupational health care is to appropriately control risks related to health problems arising in workplace environments which are caused by work methods. Lowering risks might not always prevent accidents or illnesses; but initial treatment after an accident or of ill workers is crucial work for occupational health care staff. By implementing appropriate initial treatment, it is possible to increase the survival rate of workplace accidents and decrease the rate of illness. Crisis management at the time of an accident is a very important function of occupational health. Thus there is a close relationship between occupational health care and emergency medicine.

A 54 year old man was brought to our hospital by ambulance. He had been injured by falling heavy steel. An examination was performed, and he was diag nosed as having sinking skull, acute extradural hematoma, trauma of the righ eye, right eye laceration, injury of the optic canal (right blind), and multipl fractures. Open fractures were observed in the right ring finger and little finger Simple fractures were observed in the zygomatic bone nasal bone and maxillary bone. An emergency operation (external skeletal fixation, taxis of the skull and maxillary bone, extradural hematoma depletion, suture of right eyelid) was performed. His life was saved by consistent team treatment from preoperation t postoperation. He was discharged from our hospital on foot at 45 days after th operation.

We encountered a case of wide QRS tachycardia with chronic atrial fibrillation in Wolff-Parkinson-White syndrome. Unique features were late onset of syncope attacks associated with this tachycardia at an advanced age of 72 years old without previous documentation of Wolff-Parkinson-White syndrome on electrocardiogram. He had a high likelihood of sudden cardiac death. Catheter ablation using CARTO system easily led to a successful ablation of the accessory pathway. The mechanism of late onset of the wide QRS tachycardia was attributed to possible changes of electrophysiologic properties including the atrio-ventricular node and/or the accessory pathway, and the unique location of the accessory pathway.

The supraoptic nucleus (SON) of the hypothalamus contains cell bodies of two different populations of neurosecretory cells, vasopressin and oxytocin neurones. Release of vasopressin and oxytocin in the neurohypophysis is controlled by the specific electrical activity of these neurones, which is regulated by synaptic inputs into the SON mediated by various neurotransmitters/neuromodulators, such as GABA and glutamate (Decavel & Van den Pol, 1990; Van den Pol et al. 1990; Wuarin & Dudek, 1993). A1 noradrenergic neurones originating from the ventrolateral medulla and directly innervating SON neurones are also thought to play a major role in the regulation of SON neurones (Sawchenko & Swanson, 1981). ATP may serve as a co-transmitter in A1 neurones, because locally applied ATP causes excitation of SON neurones (Day et al. 1993), and A1-induced excitation of vasopressin neurones in the SON was insensitive to adrenergic antagonists (Day et al. 1990), but inhibited by the blocker of P2 receptors suramin (Day et al. 1993; Buller et al. 1996). A study with intracellular recordings of SON neurones in acute hypothalamic explants revealed that ATP evokes membrane depolarization by activating postsynaptic P2 receptors in SON neurones and that non-selective cationic channels are involved in the depolarization (Hiruma & Bourque, 1995). Moreover, it has recently been reported that ATP stimulated vasopressin release from neurohypophysial terminals (Troadec et al. 1998). These lines of evidence suggest that ATP plays a crucial role in the regulation of SON neurones at both the soma and terminals. However, the purinoceptors mediating the ATP-mediated actions and the cellular mechanism of the actions in the SON remain unclear. There are two major classes of P2 purinoceptors, P2X and P2Y receptors. P2X receptors are ligand-gated cation channels composed of multimers of two transmembrane proteins, while P2Y receptors are seven transmembrane receptors coupled with GTP-binding proteins. cDNAs of both classes of P2 receptors have been cloned and classified into P2X1-7 and P2Y1-8 receptors (North & Barnard, 1997). It has been reported that P2X4 and P2X6 receptors are widely distributed throughout the CNS (Collo et al. 1996; Seguela et al. 1996), whereas P2X3 receptors are expressed exclusively in primary sensory neurones (Chen et al. 1995; Cook et al. 1997). The P2 receptor type formerly known as P2Z receptors were shown to be a subclass of P2X receptors and are now termed P2X7 receptors (Surprenant et al. 1996). It is reported that P2X7 receptors exist in non-neuronal cells such as microglia in the brain (Collo et al. 1997). When examined in cells heterologously expressing cloned P2X receptors, P2X4, P2X6 and P2X7 receptors were insensitive to the P2 antagonists suramin and pyridoxal phosphate-6-azophenyl-2′,4′-disulphonic acid (PPADS), which potently blocked responses mediated by P2X2 and P2X3 receptors (Bo et al. 1995; Buell et al. 1996; Collo et al. 1996). On the other hand, ATP-evoked responses in most neuronal preparations were sensitive to the P2X antagonists suramin and PPADS, although P2X4 and P2X6 receptors predominate in most neuronal cells (Collo et al. 1996; Seguela et al. 1996). These results have been interpreted to mean that multiple P2X receptors can be co-expressed in native neuronal cells and can form heteromultimers (North & Barnard, 1997). In fact, it has been shown that P2X2 and P2X3 receptors form heteromultimers in sensory neurones (Lewis et al. 1995; Radford et al. 1997). Another difference detected in the functional properties of heterologously expressed P2X receptors is that P2X1 and P2X3 receptors exhibit currents with rapid desensitization, whereas currents carried by other P2X receptors show little or no desensitization (Lewis et al. 1995; Collo et al. 1996). P2 receptors are known to cause an increase in the cytosolic Ca2+ concentration ([Ca2+]i) in various types of cells via two distinct mechanisms: P2X receptor activation causes membrane depolarization, which results in voltage-dependent Ca2+ entry (Mateo et al. 1998); and P2Y receptor activation induces inositol trisphosphate (IP3)-mediated Ca2+ release from internal stores (Strobaek et al. 1996). Although it has been reported that ATP evokes an increase in [Ca2+]i in cultured hypothalamic neurones (Chen et al. 1994), no attempt has been made to elucidate the effects of ATP on [Ca2+]i in magnocellular neurones in the SON. In the present study, we investigated molecular subtypes and distribution patterns of P2X receptors expressed in the SON by reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization histochemistry. We also studied the function of P2X receptors in SON neurones by examining effects of various purinoceptor agonists and antagonists on [Ca2+]i and ionic currents of acutely dissociated SON neurones using the fura-2 [Ca2+]i-imaging and the whole-cell patch-clamp techniques, respectively.

Prostaglandins (PGs) have been implicated in the regulation of vasopressin (VP) and oxytocin (OT) release in response to various stimuli. To examine the site and mechanism of actions of PGs, we studied effects of PGE2 and PG-receptor agonists on supraoptic nucleus (SON) neurones of rat hypothalamic slice preparations using extracellular recording and whole-cell patch-clamp techniques. PGE2 modulated the electrical activity of more than 80% of the neurones studied. The effects of PGE2 on both phasic and non-phasic neurones were mostly excitatory, and dose-dependent. The effects of PGE2 were mimicked by PGF2alpha or the FP agonist, fluprostenol, whereas PGD2 or the selective EP, IP or TP agonist was less effective or had no effect. The effects of PGE2 were unaffected by the EP1 antagonist, SC-51322, but reduced to 80% of control by the EP1/FP/TP antagonist, ONO-NT-012, which reduced the effects of fluprostenol to 32% of control. Moreover, some neurones responsive to PGE2 did not respond to fluprostenol. Patch-clamp analysis in SON slice preparations revealed that PGE2 at 10(-6) M depolarized the membrane potential by 3.9+/-0.3 mV from the resting membrane potential of -58.4+/-2.2 mV in the current-clamp mode. In the voltage-clamp mode, PGE2 induced inward currents at a holding potential of -70 or -80 mV, while it did not affect spontaneous excitatory postsynaptic currents. PGE2 induced currents also in dissociated SON neurones and the reversal potential of the currents was -35.5+/-0.9 mV, which was similar to that of currents induced by fluprostenol. These results suggest that SON neurones possess at least two types of PG receptors, FP receptors and EP receptors of a subclass different from EP1, EP2, or EP3, and that activation of these receptors leads to the opening of nonselective cation channels, membrane depolarization and increase of the action potential discharge.

1. Voltage-dependent Ca2+ currents of dissociated rat supraoptic nucleus (SON) neurones were measured using the whole-cell configuration of the patch-clamp technique to examine direct postsynaptic effects of GABAB receptor activation on SON magnocellular neurones. 2. The selective GABAB agonist baclofen reversibly inhibited voltage-dependent Ca2+ currents elicited by voltage steps from a holding potential of -80 mV to depolarized potentials in a dose-dependent manner. The ED50 of baclofen for inhibiting Ca2+ currents was 1.4 x 10-6 M. Baclofen did not inhibit low threshold Ca2+ currents elicited by voltage steps from -120 to -40 mV. 3. Inhibition of high threshold Ca2+ currents by baclofen was rapidly and completely reversed by the selective GABAB antagonists, CGP 35348 and CGP 55845A, when the antagonists were added at the molar ratio vs. baclofen of 10 : 1 and 0.01 : 1, respectively. It was also reversed by a prepulse to +150 mV lasting for 100 ms. 4. The inhibition of Ca2+ currents was abolished when the cells were pretreated with pertussis toxin for longer than 20 h or with N-ethylmaleimide for 2 min. It was also abolished when GDPbetaS was included in the patch pipette. When GTPgammaS was included in the patch pipette, baclofen produced irreversible inhibition of Ca2+ currents and this inhibition was again reversed by the prepulse procedure. 5. The inhibition of N-, P/Q-, L- and R-type Ca2+ channels by baclofen (10-5 M) was 24.1, 10.5, 3.1 and 3. 6 %, respectively, of the total Ca2+ currents. Only the inhibition of N- and P/Q-types was significant. 6. These results suggest that GABAB receptors exist in the postsynaptic sites of the SON magnocellular neurones and mediate selective inhibitory actions on voltage-dependent Ca2+ channels of N- and P/Q-types via pertussis toxin-sensitive G proteins, and that such inhibitory mechanisms may play a role in the regulation of SON neurones by the GABA neurones.

Purpose Nifekalant is a pure potassium channel blocker that has been used to treat ventricular tachyarrhythmias since 1999 in Japan. Intravenous amiodarone was approved later than nifekalant in Japan, and it is still unclear which of the two agents is superior. The aim of this study was to compare the efficacy of nifekalant and amiodarone for resuscitation of out-of-hospital cardiopulmonary arrest caused by shock-resistant ventricular fibrillation. Methods From December 2005 to January 2011, ambulance services transported 283 out-of-hospital cardiopulmonary arrest patients to our hospital. Of these, 25 patients were treated with nifekalant or amiodarone in response to ventricular fibrillation that was resistant to two or more shocks. We undertook a retrospective analysis of these 25 patients. Results We enrolled 20 men and 5 women with a mean age (± standard deviation) of 61.1 ± 16.4 years. All 25 patients were treated with tracheal intubation and intravenous epinephrine. Fourteen patients received nifekalant and 11 patients received amiodarone. The rates of return of spontaneous circulation (ROSC) (nifekalant, 5/14, versus amiodarone, 4/11; P = 0.97) and survival to discharge (nifekalant, 4/14, versus amiodarone, 2/11; P = 0.89) were not significantly different between the two groups. The time from nifekalant or amiodarone administration to ROSC was 6.0 ± 6.6 and 20.3 ± 10.0 min, respectively, which was significantly different (P