The effect of acetylcholine on chloride transport across the mouse lacrimal gland acinar cell membranes

The mechanisms of Cl^– transport and the effects of acetylcholine (ACh) and electrochemical Cl^– potential changes across the basolateral plasma membrane on intracellular Cl^– activity in the acinar cells of isolated mouse lacrimal glands were studied using double-barreled Cl^–-selective microelectrodes. In the resting state, the basolateral membrane potential (V _m) was about –40 mV and intracellular Cl^– activity was about 35 mmol/l. Addition of ACh (10^–910^–6 mol/l) hyperpolarizedV _m and decreased the Cl^– activity in a dose-dependent manner. ACh (10^–6 mol/l) hyperpolarizedV _m by 20 mV and decreased the cytosolic Cl^– activity with an initial rate of 16.0 mmol/l · min. Reduction of the perfusate Cl^– concentration to 1/9 control depolarizedV _m and decreased cytosolic Cl^– activity at a rate of 1.9 mmol/l · min. AV _m hyperpolarization of 20 mV produced by DC injection to the adjacent cell decreased Cl^– activity at a rate of 4.6 mmol/l · min. DIDS (1 mmol/l) hyperpolarizedV _m by 8 mV with little change in Cl^– activity and increased the input resistance of the cells by 25%. DIDS decreased the rate of change in Cl^– activity induced by low-Cl^– Ringer to 35% of control, but had no effect on the ACh-evoked decrease in the Cl^– activity. Furosemide (1 mmol/l) slightly hyperpolarizedV _m and decreased Cl^– activity at a slow rate but affected Cl^– movements induced by ACh or low-Cl^– Ringer only slightly. Cl^– uptake into the cells was inhibited partially by furosemide. The present results showed that ACh induces an increase in the Cl^– permeability across the luminal plasma membrane and that the basolateral membrane possesses a DIDS-sensitive Cl^– conductance pathway and a furosemide-sensitive Cl^– uptake mechanism.     

Human Platelets Effectively Kill K-562 Cells, a Chronic Myelogenic Leukemia Cell Line, in vitro

The cytotoxic effect of isolated human platelets on leukemic cells has been examined in order to investigate the role of platelets in host defense systems. K-562 cells (a chronic myelogenic leukemia cell line) showed significant change in their morphology and were killed when they were incubated with platelets in serum-free medium for several hours at 37°C, a condition where no killing of normal peripheral lymphocytes occurred. Some protease inhibitors inhibited the cytotoxicity of platelets against K-562 cells. Our results suggest that platelets may be involved in host defense against neoplasia and that certain proteases are implicated in the cytotoxic effect of platelets.     

Polymer-supported bases, 2. Polystyrene-supported 1,8-diazabicyclo[5.4.0]undec-7-ene as reagent in organic syntheses

Polystyrene-supported 1,8-diazabicyclo[5.4.0]undec-7-ene (PDBU) was prepared by the reaction of lithiated 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) with chloromethylated or ω-bromoalkylated polystyrene resins. PDBU is effective as reagent for dehydrobromination and esterification. The reactivity of PDBU in dehydrobromination is lower than that of DBU. In the case of esterification, PDBU with 19% ring substitution exhibits almost the same reactivity as DBU. PDBU, regenerated from the hydrobromide salt, can be re-used without decrease in reactivity.     

Effects of extracts of Zanthoxylum fruit and their constituents on spontaneous beating rate of myocardial cell sheets in culture

In the course of our studies on naturally occurring cardioactive agents, we investigated the effects of water and methanol extracts of a Chinese crude drug “Huajiao” the dried fruit of Zanthoxylum bungeanum, on the spontaneous beating rate (BR) of embryonic mouse myocardial cell sheets in culture. Both extracts significantly increased the BR. Through bioassay directed fractionation of the extracts, hydroxy-β-sanshool (1b), xanthoxylin (2) and two quercetin glycosides, hyperin (4) and quercitrin (6), were found to increase the BR in a standard medium (2.1 mM Ca²⁺). In a low Ca²⁺ medium (0.5 mM Ca²⁺), these compounds suppressed the decrease of BR, which was induced by low Ca²⁺. Of 16 flavonoids related in structure with hyperin (4) and quercitrin (6), quercetin, isoquercitrin, rutin, myricetin and myricitrin also increased the BR in the standard medium, while kaempferol and luteorin decreased the BR in the standard medium. When compared with control, hydroxy-β-sanshool (1b) and xanthoxylin (2) stimulated 13–15 fold calcium uptake of the cultured myocardial cells, which might have caused the positive chronotropic effect. Hyperin (4) and quercitrin (6) did not affect calcium uptake of the myocardial cells, Na⁺–K⁺ ATPase activity or Ca²⁺-ATPase activity of sarcoplasmic reticulum.     

Novel orthotopic implantation model of human malignant pleural mesothelioma (EHMES-10 cells) highly expressing vascular endothelial growth factor and its receptor

Malignant pleural mesothelioma (MPM) is closely related to exposure to asbestos, and a rapid increase in the number of MPM patients in Japan is estimated in the years 2010-2050. The purpose of the present study was to establish a clinically relevant animal model that shows human patient-like progression of MPM. Here, we demonstrate that a human MPM cell line (EHMES-10) inoculated orthotopically (thoracic cavity) into severe combined immunodeficiency (SCID) mice produces highly vascularized thoracic tumors with pleural dissemination and bloody pleural effusions by 5 weeks, suggesting a patient-like progression of this cell line after orthotopic inoculation. EHMES-10 cells overexpressed vascular endothelial growth factor (VEGF), a molecule responsible for malignant effusions, and its receptor. Treatment with cisplatin, but not gemcitabine, significantly inhibited the production of pleural effusions, but it was not effective for thoracic tumors, consistent with chemotherapy refractory characteristics of MPM in patients. Our patient-like orthotopic model using EHMES-10 cells overexpressing VEGF and its receptor may be useful for examining the molecular pathogenesis of MPM and may contribute to the development of novel treatment strategies for MPM.     

Diaphragmatic hernia in infants following living donor liver transplantation: report of three cases and a review of the literature

DH is a rare complication following LT. This report presents three cases of right-sided DH after LT using a left-sided graft. All of the patients were younger than one yr of age, and they were critically ill owing to their original disease, characterized by biliary atresia, progressive familiar intrahepatic cholestasis, and acute liver failure. DH occurred with sudden onset within three months after LT. All of the cases were promptly diagnosed and treated. A literature review of 24 cases of DH identified four factors associated with DH: left-sided graft, right-sided DH, relatively delayed onset of DH, and age-specific chief complaint. DH following LT should be considered as a potential surgical complication when a left-sided graft is used, especially in small infants with coagulopathy and malnutrition.     

Living‐Related Liver Transplantation for Siblings with Progressive Familial Intrahepatic Cholestasis 2, with Novel Genetic Findings

Progressive familial intrahepatic cholestasis is a syndrome of severe cholestasis progressing to biliary cirrhosis and liver failure that develops in childhood. This report describes two siblings with PFIC‐2 who underwent living‐related liver transplantation from their genetically proven heterozygous parents. Both patients had normal gamma‐glutamyl transpeptidase levels, but showed severe pruritus with sleep disturbance, cholestasis, jaundice and growth failure. Genetic testing of each patient revealed two missense mutations of the bile salt export pump, S901R and C1083Y, which have not previously been associated with PFIC‐2. Usual medical treatment failed to improve their clinical symptoms, and the two siblings underwent living‐related liver transplantation from their heterozygous parents. The transplants improved their clinical symptoms significantly, and the patients have since shown age‐appropriate growth. Electron microscopic findings of the explanted liver of the younger sister revealed dense and amorphous bile, which is characteristic of PFIC‐2. In the cases presented here, living‐related liver transplantation from a heterozygous donor was associated with better quality of life and improvement of growth, and thus appears to be a feasible option for PFIC‐2 patients. Mutation analysis is a useful tool to help decide the course of treatment of PFIC.