Inhibition of inward rectifier K+ currents by angiotensin II in rat atrial myocytes: lack of effects in cells from spontaneously hypertensive rats.

We examined the effects of angiotensin II (Ang II) on inward rectifier K+ currents (IK1) in rat atrial myocytes. [125I]Ang II-binding assays revealed the presence of both Ang II type 1 (AT1) and type 2 (AT2) receptors in atrial membrane preparations. Ang II inhibited IK1 in isolated atrial myocytes with an IC50 of 46 nmol/l. This inhibition was abolished by the AT, antagonist RNH6270 but not at all by the AT2 antagonist PD123319. Treatment of cells with pertussis toxin or a synthetic decapeptide corresponding to the carboxyl-terminus of Gialpha-3 abolished the inhibition by Ang II, indicating the role of a Gi-dependent signaling pathway. Accordingly, Ang II failed to inhibit IK1 in the presence of forskolin, dibutyryl-cAMP or protein kinase A catalytic subunits. In spite of the increased binding capacities for [125I]Ang II, Ang II failed to affect IKI in cells from spontaneously hypertensive rats (SHR). AT, immunoprecipitation from atrial extracts revealed decreased amounts of Gialpha-2 and Gialpha-3 proteins associated with this receptor in SHR as compared with controls. The reduced coupling of AT, with Gialpha. proteins may underlie the unresponsiveness of atrial IK1 to Ang II in SHR cells.     

Pathogenesis of progressive muscular dystrophy: studies on free radical metabolism in an animal model

Evidence to suggest the presence of abnormal metabolism of oxygen free radicals in progressive muscular dystrophy is presented using an animal model. In the superficial pectoral muscles of dystrophic chickens, enzyme activities regulating the metabolism of oxygen free radicals, i.e., catalase, superoxide dismutases and glutathione peroxidase, were significantly elevated within 1 week of hatching. Activities of related enzymes, i.e., glutathione reductase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase were also elevated. In contrast, the specific activity of phosphofructokinase, the rate-limiting enzyme of the glycolytic pathway, was normal during the first 4-week period. These results suggest that there is an increased turnover of oxygen free radicals in the dystrophic muscle. This concept appears important in a further investigation of the pathogenesis and treatment of progressive muscular dystrophies.     

Infantile subcortical leukohypodensity demonstrated by computed tomography

We reviewed the computed tomography scans of 126 term infants, ages 1-6 months; leukohypodensity was found just under the cerebral cortex (subcortical leukohypodensity [SLD]) in 3 infants (2.4%) at 1-3 months of age. On subsequent computed tomography at over 4 months of age, SLD had disappeared and anterior horn predominant dilatation of the lateral ventricles had appeared. Only 1 patient with a distinct SLD had a poor neurodevelopmental outcome: spastic diplegia. SLD in our patients is believed to be closely related to subcortical leukomalacia because of the similar location and age distribution. Transient SLD may be a mild form of cystic SLD which would require careful computed tomography follow-up examination in early infancy.     

The effect of IL-6 on the des-gamma-carboxy prothrombin synthesis in human hepatoma cells.

Effects of several cytokines on des-gamma-carboxy prothrombin (PIVKA II) synthesis in human hepatoma cells were investigated to know the process of PIVKA II production during a liver allograft rejection. Human recombinant interleukin-6 (IL-6) significantly stimulated the PIVKA II synthesis without any influence on the cell proliferation. The effect was almost completely neutralized by the specific anti-IL-6 antibody. Neither tumor necrosis factor (TNF), interleukin-1 (IL-1) nor interferon-gamma (IFN-gamma) had such a stimulative effect. IL-6 appears to stimulate PIVKA II production, and would be a candidate of factors that enhance the production of PIVKA II during a liver allograft rejection.     

A case of progressive muscular dystrophy with numerous arterioluminal vessels

A 48-year-old man had histologically demonstrated cardiac involvement associated with progressive muscular dystrophy. On coronary arteriography, numerous vascular communications between the coronary arteries and the left ventricular chamber were found. These vascular communications are considered to be the arterioluminal vessels. This is the first report of a case of progressive muscular dystrophy with numerous arterioluminal vessels.     

Case of ruptured gastroduodenal arterial pseudoaneurysm with penetration to the duodenum, successfully treated with transcatheter arterial embolization]

A 77-year-old man, who underwent segmental pancreatectomy for intraductal papillary mucinous adenoma in 2001, was referred to our hospital with complaints of hematemesis and melena on January, 2004. Emergency upper gastrointestinal endoscopy showed a pulsating submucosal protrusion in the duodenal bulb, which was identified as a gastroduodenal arterial aneurysm measuring 1.5cm on abdominal CT imaging. Transcatheter arterial embolization of the aneurysm with metallic coils was successfully performed. Periodically repeated endoscopic examination has revealed the coils protruding into the duodenal lumen without any serious complication.     

False positive accumulation in 18F fluorodeoxyglucose positron emission tomography scan due to sarcoid reaction following induction chemotherapy for lung cancer

We present a case of lung cancer that showed false positive accumulation in an ¹⁸F fluorodeoxyglucose positron emission tomography (FDG-PET) scan following induction chemotherapy for suspected metastasis and progression of malignancy. A 66-year-old man was diagnosed with squamous cell carcinoma in the lung, classified as clinical stage IIIA (T2N2M0), and underwent induction chemotherapy. An FDG-PET scan prior to chemotherapy demonstrated accumulation only in the tumor, whereas following treatment it revealed a strong accumulation not only in the tumor, but also in the supraclavicular lymph nodes, which indicated lymph node metastasis. The patient underwent a biopsy of the right supraclavicular lymph node and mediastinoscopy, after which all dissected lymph nodes showed sarcoid reactions and no tumor cells were found pathologically. We concluded that when evaluating the effect of induction chemotherapy for malignancy, a sarcoid reaction might lead to the false positive accumulation of FDG.     

Studies on chemical protectors against radiation. XXIX. Protective effects of methanol extracts of various Chinese traditional medicines on skin injury induced by X-irradiation

In order to investigate useful protective medicines for the relief of skin injury induced by irradiation, 60 methanol extracts of Chinese traditional medicines were used in the test of protective potency on skin injury. ICR male mice at 6 weeks of age were whole-body irradiated with 1100R by using a soft X-ray generator (30 kVp, 10 mA, 190 R/min). Each methanol extract of these medicines was injected intraperitoneally into mice before or after irradiation. The degrees of skin injury were determined by a score system of skin reaction within the observation period from 21st to 40th day after irradiation. Protective potency of each medicine on skin injury was calculated from the maximum mean scores of administrated group and un-administrated group. As a result of these studies, the protective potency was detected in Unsei-in, Kumibinro-to, Keisi-syakuyaku-chimo-to, Keigai-rengyo-to, Gosyuyu-to, Koso-san, Saiko-seikan-to, Syo-kankyo-to, Syo-saiko-to, Syoma-kakkon-to, Sen-kan-meimoku-to, Zokumei-to, Sokei-kakketu-to, Bokuryo-in, Mao-to and Rikkunsi-to by intraperitoneal injection before irradiation. Of these effective medicines, only Unsei-in and Mao-to are shown to have a significant protective effect by intraperitoneal injection after irradiation.     

Clinical experience of biliary tract carcinoma associated with anomalous union of the pancreaticobiliary ductal system

Between 1978 and 1988, 15 patients with gallbladder cancer and 2 patients with bile duct cancer were seen among 49 patients with anomalous union of the pancreaticobiliary ductal system. Radiographic findings revealed two types of this anomalous condition: one in which the pancreatic duct entered the common bile duct (type 1) and one in which the common bile duct entered the pancreatic duct (type 2). In gallbladder cancer, the common bile duct presented no dilatation, or in some patients, mild dilatation, and type-1 anomalous union was frequently found among these patients. In contrast, the two patients with bile duct cancer had cystic dilatation of the common bile duct and type-2 anomalous union. The bile amylase level, which was determined in seven patients, was extremely high in all the patients. Histopathologically, the tumors in most patients showed papillary to papillo-tubular proliferation in the mucosal layer while atypical epithelial hyperplasia was noted in the vicinity of the tumor area. These findings suggest that this congenital anomaly in both ducts results in a loss of the normal sphincteric mechanism of the duodenal papilla, and that chronic relapsing cholecystitis or cholangitis, caused by the reflux of pancreatic juice into the biliary tract, can induced progressive changes to atypical epithelial hyperplasia which may develop into carcinoma.