Pacing-induced heart failure causes a reduction of delayed rectifier potassium currents along with decreases in calcium and transient outward currents in rabbit ventricle

OBJECTIVE: Heart failure in patients and in animal models is associated with action potential prolongation of the ventricular myocytes. Changes in several membrane currents have been already demonstrated to underlie this prolongation. However, information on the two components (I(Kr) and I(Ks)) of the delayed rectifier potassium current (I(K)) in rapid pacing induced heart failure is lacking. METHODS AND RESULTS: Action potentials and whole-cell currents, I(K), I(to1), I(K1), and I(Ca-L) were recorded in apical myocytes of left ventricle from 10 rabbits subjected to left ventricular pacing at 350-380 beats/min for 3-4 weeks and 10 controls with sham operation. Action potential duration at 90% repolarization (APD(90)) was prolonged in myocytes from failing hearts compared to controls at both cycle lengths of 333 and 1000 ms. Both E-4031-sensitive and -resistant components of I(K) (I(Kr), I(Ks)) in myocytes from failing hearts were significantly less than those of control hearts; tail current densities of I(Kr) and I(Ks) following depolarization to +50 mV were 0.62+/-0.05 vs. 0.96+/-0.12 pA/pF (P<0.05), and 0.27+/-0.08 vs. 0.52+/-0.08 pA/pF (P<0.05), respectively. There was no significant difference between control and failing myocytes in the voltage- and time-dependence of activation of total I(K), I(Kr) and I(Ks). The peak of L-type Ca(2+) current (I(Ca-L)) was significantly reduced in myocytes from failing hearts (at +10 mV, -9.29+/-0.52 vs. -12.28+/-1.63 pA/pF, P<0.05), as was the Ca(2+)-independent transient outward current (I(to1); at +40 mV, 4.8+/-0.9 vs. 9.6+/-1.3 pA/pF, P<0.05). Steady state I-V curve for I(K1) was similar in myocytes from failing and control hearts. CONCLUSIONS: Decrease of I(K) (both I(Kr) and I(Ks)) in addition to reduced I(to1), may underly action potential prolongation at physiological cycle length and thereby contribute to arrhythmogenesis in heart failure.     

Three‐dimensional fusion images combining CT gastrography and CT angiography for early gastric cancer: Pilot experiences of preoperative simulation prior to totally laparoscopic gastrectomy

We herein report two cases of gastric cancer in which preoperative 3‐D CT gastrography and CT angiography fusion images enabled totally laparoscopic gastrectomy. Case 1 involved a 60‐year‐old woman with a superficial depressed lesion on the greater curvature of the middle gastric body. Case 2 involved a 64‐year‐old woman with a superficial depressed lesion on the posterior wall of the upper gastric body. In both cases, 3‐D fusion images were prepared from enhanced CT scans after the area near the lesions was clipped under preoperative gastroendoscopy. Based on the relative position between the clips and nearby vessels, a resection line was preoperatively determined in each case. Totally laparoscopic distal gastrectomy and totally laparoscopic proximal gastrectomy were performed in cases 1 and 2, respectively, with safe surgical margins. Three‐dimensional fusion images can help in preoperative simulation of totally laparoscopic gastrectomy.     

Comparison of myocardial perfusion by distal protection before and after primary stenting for acute myocardial infarction: angiographic and clinical results of a randomized controlled trial.

OBJECTIVES: To assess the myocardium-reperfusing effect of a distal protection device, GuardWire Plus (GuardWire Plus), in patients with acute myocardial infarction (AMI). BACKGROUND: Distal embolization may result in reduced myocardial perfusion, increasing the risk of non-Q-wave myocardial infarction and death. Distal protection devices may protect the microcirculation from embolic debris, improving short- and long-term clinical outcomes. METHODS: From February 2002 to July 2003, a total of 341 AMI patients at 22 institutions in Japan were enrolled in the present, multicenter, prospective, randomized trial. Patients experiencing AMI within 12 hr of symptom onset, who were considered treatable by stenting and who met the inclusion criteria, were eligible for randomization. Stenting with and without GuardWire Plus was conducted to examine whether the device provides faster and more complete ST-segment resolution, smaller infarct size, and improved myocardial blush score. RESULTS: The rates of slow flow and no-reflow immediately after PCI were 5.3 and 11.4% in the GuardWire Plus and control groups, respectively (P = 0.05). Blush score 3 acquisition rates immediately after PCI were 25.2 and 20.3% in the GuardWire Plus and control groups, respectively (P = 0.26), and the rates at 30 days after PCI were 42.9 and 30.4%, respectively (P = 0.035). CONCLUSIONS: A significant difference was found between the GuardWire Plus and control groups with respect to the total incidence of distal embolization, indicating that GuardWire Plus angiographically improved myocardial perfusion without demonstrating the preventive effect of myocardial damage.     

Immunization of laboratory animals with ultraviolet-attenuated larvae against homologous challenge infection with Trichinella britovi.

Immunogenicity of Trichinella britovi (Japanese isolate, cord ISS 408) muscle larvae irradiated with 5 mJ/cm2 of short wavelength ultraviolet (UV) was studied using homologous challenge infections. SCID mice vaccinated with UV-attenuated larvae showed no resistance, although its congenic CB-17 mice exhibited remarkable immunity. Following challenge vaccinated Mongolian gerbils, Meriones unguiculatus, did not show significant immunity. Use of these animal models vaccinated with UV-attenuated larvae will contribute to the investigation of immune mechanisms against Trichinella infection and also to the development of a vaccine of trichinellosis.     

Metastatic renal cell carcinoma presenting as multiple pleural tumours

A 66-year-old man was admitted with dyspnoea. Chest X-ray and chest computed tomography (CT) demonstrated a left-sided pleural effusion and multiple tumours, suggesting malignant mesothelioma in the left pleural space, but there were no pulmonary lesions. However, abdominal CT revealed a right renal tumour. An ultrasonography-guided needle biopsy of the pleural mass provided evidence of metastatic renal cell carcinoma (RCC). The pleural lesions dramatically decreased in size following right radical nephrectomy and subsequent interferon-alpha treatment. While the thorax is a frequently affected site of RCC, sole pleural metastases are rare and are often secondary to lung involvement. Batson's plexus, a network of vertebral valve-less veins with multiple connections, is likely responsible for the contralateral pleural metastases of RCC.