Antagonistic Effects of OPC-14597, a Novel Antipsychotic Drug,on Quinpirole- and (–)-Sulpiride-induced Changes in Evoked Dopamine Release in Rat Striatal Slices

The effects of a newly synthesized quinolinone derivative, 7-{4-(4-(2,3-dichlorophenyl)-1-piperazinyl) butoxy}-3,4-dihydro-2-(1H)-quinolinone (OPC-14597), a novel antipsychotic drug, on electrically evoked dopamine release in rat striatal slices were investigated. OPC-14597 (0.1–10 μm) had no effect on the dopamine release evoked in the striatal slices. The decrease induced by quinpirole, a dopamine receptor agonist, in evoked dopamine release was attenuated by supervision with OPC-14597 (1 and 10 μm) which by itself had no effect on evoked dopamine release. The increase induced by (–)-sulpiride, a dopamine receptor antagonist, in evoked dopamine release was, moreover, also attenuated by 1 and 10 μm OPC-14597. These findings indicate that OPC-14597 antagonizes both dopamine agonist- and antagonist-induced changes in evoked dopamine release in striatal slices in rats.     

Experience of the treatment with gemcitabine, docetaxel, and carboplatin (GDC) chemotherapy for patients with small-cell carcinoma of the prostate

Small-cell carcinoma of the prostate (SCCP) is a rare entity. Many treatment modalities have been done, but thus far no uniform treatment has been clearly established. We carried out combination chemotherapy with gemcitabine, docetaxel, and carboplatin (GDC) regimen (for two patients with refractory SCCP. Case 1 involved a 53-year-old man diagnosed with SCCP after receiving hormone therapy for prostate cancer (stage D1). Six cycles of GDC chemotherapy was applied. Initially the primary site reduced according with a decline of neuro-specific enolase and with relief of the symptoms; however, bone disease occurred and he died of cancer 13 months after diagnosis of SCCP. Case 2 involved a 69-year-old man complaining of severe anal pain. He underwent a biopsy and a huge prostate tumor showing SCCP was showed. He had pelvic node metastases but no distant lesions, and received four cycles of GDC chemotherapy. He was discharged after receiving subsequent radiotherapy and remained stable for a while; however, he died of possible drug-induced hepatitis. This is the first report of chemotherapy with GDC against patients with SCCP. This regimen raised the possibility that it would intensify the outcome, which had been poorly achieved.     

ATP‐Induced Dormant Pulmonary Veins Originating from the Carina Region After Circumferential Pulmonary Vein Isolation of Atrial Fibrillation

Dormant Pulmonary Veins from the Carina Region . Introduction: Elimination of transient pulmonary vein recurrences (dormant PVs) induced by an ATP injection and ablation at the PV carina region is an effective strategy for atrial fibrillation (AF) ablation. The relationship between dormant PVs and the PV carina region has not been evaluated. Methods: A total of 212 consecutive symptomatic AF patients underwent circumferential PV electrical isolation (CPVEI) with a double lasso technique. They were divided into 2 groups in a retrospective review; Group 1: those given an ATP injection during an intravenous isoproterenol infusion after the CPVEI (n = 106), and Group 2: those in which it was not given after the CPVEI (n = 106). Radiofrequency energy was applied at the earliest dormant PV activation site identified using a Lasso catheter on the CPVEI line and then PV carina region if it was ineffective. Results: After a successful PVEI, 54 patients (51%) in Group 1 had PV reconnections during an ATP injection. Acute PVEI sites were observed on the carina region within the CPVEI line in the right PVs (16%) and left PVs (10%). Dormant PVs were reisolated at the carina region in the right PVs (23%) and left PVs (26%). The distribution of the dormant PV sites, except for the RIPV, significantly differed from that of the acute PVEI sites (P < 0.05). Further, AF recurred significantly in the Group 2 patients as compared to those in Group 1 during 16 ± 6.1 months of follow‐up (P < 0.05). Conclusion: PV carina region origins may partly be responsible for an acute PVEI and potential recurrences. (J Cardiovasc Electrophysiol, Vol. 21, pp. 494‐500, May 2010)     

Retrograde Purkinje Potential Activation During Sinus Rhythm Following Catheter Ablation of Idiopathic Left Ventricular Tachycardia

Idiopathic Left VT and Purkinje Potentials . We describe two patients with idiopathic left ventricular tachycardia that were cured by radiofrequency catheter ablation. Tachycardia was inducible by ventricular stimulation and was verapamil sensitive. Two distinct presystolic potentials (PI and P2) were recorded during tachycardia in the mid-septal or inferoapical area, but only one potential (P2) was recorded during sinus rhythm. After catheter ablation at this site, the PI potential was noted after the QRS complex during sinus rhythm, while the P2 was still observed before the QRS complex. The P1 potential showed a decremental property during atrial or ventricular pacing. These data suggest that Purkinje tissue with decremental properties was responsible for the tachycardia mechanism, and that the reentry circuit involving this tissue is likely to be of considerable size.     

A Case with Occurrence of Antidromic Tachycardia After Ablation of Idiopathic Left Fascicular Tachycardia: Mechanism of Left Upper Septal Ventricular Tachycardia

A 36‐year‐old male presented with verapamil‐sensitive narrow QRS tachycardia. The patient underwent the catheter ablation of common idiopathic left fascicular ventricular tachycardia (ILVT) 2 years ago. During narrow QRS tachycardia, the diastolic and presystolic potentials (P1 and P2) were recorded at the left septum. Activation sequences of P1 and P2 were opposite from those in common ILVT. Entrainment of P1 at the upper septum exhibited concealed fusion and S‐QRS equal to P1‐QRS. Radiofrequency current to P1 suppressed VT. Idiopathic left upper septal VT might be the antidromic macroreentry of the common form of ILVT.     

Diagnosis of renovascular hypertension by echo-Doppler velocimetry

A 13 year old boy suffering hypertension was examined for peripheral plasma renin, angiotensin-I, angiotensin-II and aldosterone. All data were within the normal range. The Captopril test and renal scintigraphy (both with and without Captopril) also showed normal patterns. Echo-Doppler velocimetry of the renal artery revealed that left renal arterial peak flow velocity was fast (3.4 m/s). The patient was therefore diagnosed with left renal arterial stenosis. Angiography demonstrated the duplex of the left renal artery and stenosis of the left lower renal artery. Percutaneous transluminal angioplasty was successfully performed.     

Modulation of (–)-sulpiride-induced increase in electrically-evoked release of dopamine from rat striatal slices

Abstract— (–)-Sulpiride (10 Nm -10 μm ) in the superfusate, dose-dependently increased the electrically-evoked release of dopamine from rat striatal slices. (+)-Sulpiride had little effect on evoked release of dopamine up to 10 μm . Apomorphine inhibited electrically evoked release of dopamine, and this effect of apomorphine was antagonized by (–)-sulpiride. SCH23390 and forskolin had no effect on the (–)-sulpiride-induced increase in evoked release of dopamine. Treatment with the irreversible dopamine-receptor antagonist N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline caused a significant increase in evoked release of dopamine and prevented the (–)-sulpiride-induced increase in the evoked release of dopamine. These results indicate that the (–)-sulpiride-induced increase in evoked release of dopamine is due to antagonism of the activation of dopamine autoreceptors by endogenously released dopamine.     

Time course of saliva and serum melatonin levels after ingestion of melatonin

Abstract Salival and serum melatonin levels after melatonin ingestion were measured by gas chromatography-mass spectrometry. Ingestion of 3 mg melatonin caused a marked increase in serum melatonin (3561 ± 1201 pg/mL) within 20 min, followed by a gradual decrease, but the level still remained higher than the basal level at 240 min after the ingestion. The saliva melatonin 60 min after the ingestion showed the highest level (1177 ± 403 pg/mL) which was one-third of the plasma level. The saliva melatonin level was highly correlated with the serum level throughout the experimental period ( r = 0.82, P = 0.0001). These data indicate that the measurement of saliva melatonin level may be a suitable indicator for the melatonin secretion into general circulation.     

A Patient With Medullary Thyroid Carcinoma Associated With Polyneuropathy

A 41-year-old female with sporadic medullary thyroid carcinoma(MTC) had a sensorimotor polyneuropathy manifested by progressivenumbness and muscle weakness in all of her extremities. Therewas marked improvement in the neurological disorder followingremoval of the MTC. Her endocrine and neurological findingsand the possible relationship between MTC and polyneuropathyare discussed.     

Nontransmural Scar Detected by Magnetic Resonance Imaging and Origin of Ventricular Tachycardia in Structural Heart Disease

Background: Contrast-enhanced magnetic resonance imaging (CMR) identifies scar tissue as an area of delayed enhancement (DE). The scar region might be the substrate for ventricular tachycardia (VT). However, the relationship between the occurrence of VT and the characteristics of scar tissue has not been fully studied.
Methods: CMR was performed in 34 patients with monomorphic, sustained VT and dilated cardiomyopathy (DCM, n = 18), ischemic cardiomyopathy (ICM, n = 10), or idiopathic VT (IVT, n = 6). The VT exit site was assessed by a detailed analysis of the QRS morphology, including bundle branch block type, limb lead polarity, and precordial R-wave transition. On CMR imaging, the transmural score of each of the 17 segments was assigned, using a computer-assisted, semiautomatic technique, to measure the DE areas. Segmental scars were classified as nontransmural when DE was 1–75% and transmural when DE was 76–100% of the left ventricular mass in each segment.
Results: A scar was detected in all patients with DCM or ICM. Nontransmural scar tissue was often found at the VT exit site, in patients with DCM or ICM. In contrast, no scar was found in patients with IVT.
Conclusions: CMR clarified the characteristics and distribution of scar tissue in patients with structural heart disease, and the presence and location of scar tissue might predict the VT exit site in these patients.