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1.
Minerva Chir ; 67(3): 249-55, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22691829

ABSTRACT

AIM: The purpose of the present study was to determine whether in vivo electroporation could achieve selective blockade of apoptosis in a rat liver cirrhosis model. METHODS: A dimethylnitrosamine (DMN)-induced rat liver cirrhosis model was used. In vivo electroporation was performed after portal vein infusion of plasmid DNA. pFas-Fc plasmid DNA was used to block the apoptotic pathway. pUC/HGF and pCAGGS/EGFP were used as positive and negative controls, respectively. Liver collagen content was evaluated by hydroxyproline assay two weeks after gene transfer. Terminal deoxynucleotidyltransferase dUTP nick end-labeling was simultaneously performed in the liver to evaluate suppression of apoptosis. Survival analysis was performed using 10 rats that received the sFas gene, 10 that received the HGF gene, and 13 that received the GFP gene. RESULTS: The apoptotic cell index in the DMN-injected liver was significantly lower in rats that received the sFas gene compared with the negative control. The collagen content of the DMN-injected liver was also lower in rats that received the sFas gene compared with the negative control. There was no significant difference in the apoptotic cell index and collagen content of rats that received the sFas and HGF genes. Ten weeks after the initiation of DMN treatment, the survival rates with the sFas, HGF, and GFP genes were 56%, 100%, and 0, respectively. CONCLUSION: Selective blockade of apoptosis by in vivo electroporation-mediated gene transfer improved the apoptotic cell index, hydroxyproline content, and survival rate. Soluble Fas gene therapy using in vivo electroporation can be a safe and efficient therapy for liver cirrhosis in rats.


Subject(s)
Apoptosis/genetics , DNA/administration & dosage , Electroporation , Gene Transfer Techniques , Liver Cirrhosis/genetics , Liver Cirrhosis/prevention & control , Animals , Infusions, Intravenous , Male , Plasmids , Portal Vein , Rats , Rats, Sprague-Dawley
2.
Prague Med Rep ; 113(4): 303-208, 2012.
Article in English | MEDLINE | ID: mdl-23249663

ABSTRACT

Pneumothorax, defined as the presence of air in the pleural space, is usually classified as spontaneous or traumatic; it is unusual for pneumothorax to be categorized as being acute or chronic. Even if conservative treatment is chosen, the pneumothorax is cured when air in the pleural space dissolves into the venous blood. A 50-years-old Japanese man with no prior medical history was referred to our department with a right pneumothorax and two rightsided pulmonary nodules on chest X-ray and CT. The chest radiographs of past mass screening which was taken four years ago showed right pneumothorax and right-sided pulmonary nodules. From then, all chest radiograph and chest computed tomography showed right pneumothorax and pulmonary nodules. But he underwent no medical interventions. We designed to perform an operation for a treatment of right pneumothorax and the diagnosis of pulmonary tumors. We underwent right upper lobectomy and pleural decortication under video assisted thoracic surgery. We obtained pathological diagnosis of inflammatory pseudotumor and surrounding atelectasis. He was cured from pneumothorax and pulmonary tumors. A unique case of spontaneous pneumothorax presenting with a pleural air space that was confirmed by chest radiographs and computed tomography examinations over a 4-year period is reported.


Subject(s)
Multiple Pulmonary Nodules/diagnosis , Multiple Pulmonary Nodules/surgery , Pneumothorax/diagnosis , Granuloma, Plasma Cell/diagnosis , Granuloma, Plasma Cell/surgery , Humans , Male , Middle Aged , Pneumothorax/surgery
3.
Kyobu Geka ; 63(5): 355-7, 2010 May.
Article in Japanese | MEDLINE | ID: mdl-20446601

ABSTRACT

We describe a case of Stanford type A acute aortic dissection. Replacement of the ascending aorta and aortic arch was performed using an "arch 1st technique". Following the completion of replacement, hypotension of the left superficial temporal artery pressure was detected. Ultrasonography revealed dissection of the left common carotid artery (LCCA) and compressive occlusion of the true lumen. Reconstruction of the LCCA was performed in the neck. The patient did well after the operation without any neurological abnormalities.


Subject(s)
Carotid Artery Diseases/diagnostic imaging , Carotid Artery Diseases/surgery , Carotid Artery, Common/surgery , Aged , Aortic Dissection/surgery , Aorta/surgery , Aorta, Thoracic/surgery , Aortic Aneurysm/surgery , Humans , Male , Ultrasonography
4.
Physiol Res ; 69(6): 1029-1038, 2020 12 22.
Article in English | MEDLINE | ID: mdl-33251809

ABSTRACT

Antifreeze proteins are an effective additive for low-temperature preservation of solid organs. Here, we compared static hypothermic preservation with and without antifreeze glycoprotein (AFGP), followed by nonfreezing cryopreservation of rat hearts. The heart was surgically extracted and immersed in one of the cardioplegia solutions after cardiac arrest. Control rat hearts (n=6) were immersed in University of Wisconsin (UW) solution whereas AFGP-treated hearts (AFGP group) (n=6) were immersed in UW solution containing 500 ?g/ml AFGP. After static hypothermic preservation, a Langendorff apparatus was used to reperfuse the coronary arteries with oxygenated Krebs-Henseleit solution. After 30, 60, 90, and 120 min, the heart rate (HR), coronary flow (CF), cardiac contractile force (max dP/dt), and cardiac diastolic force (min dP/dt) were measured. Tissue water content (TWC) and tissue adenosine triphosphate (ATP) levels in the reperfused preserved hearts were also assessed. All the parameters were compared between the control and AFGP groups. Compared with the control group, the AFGP group had significantly (p<0.05) higher values of the following parameters: HR at 60, 90, and 120 min; CF at all four time points; max dP/dt at 90 min; min dP/dt at 90 and 120 min; and tissue ATP levels at 120 min. TWC did not differ significantly between the groups. The higher HR, CF, max dP/dt, min dP/dt, and tissue ATP levels in the AFGP compared with those in control hearts suggested that AFGP conferred superior hemodynamic and metabolic functions. Thus, AFGP might be a useful additive for the static/nonfreezing hypothermic preservation of hearts.


Subject(s)
Antifreeze Proteins/pharmacology , Cardioplegic Solutions/pharmacology , Cryopreservation/methods , Heart , Adenosine Triphosphate/metabolism , Animals , Male , Models, Animal , Rats , Rats, Wistar , Transplants/supply & distribution
5.
Eur Surg Res ; 42(3): 181-8, 2009.
Article in English | MEDLINE | ID: mdl-19246925

ABSTRACT

BACKGROUND/AIMS: Recent reports have demonstrated that some patients are unable to undergo scheduled liver resection after preoperative portal vein embolization due to insufficient hypertrophy of the future remnant liver. The present study examined whether two-stage portal vein ligation (PVL) increases hypertrophy of the future remnant liver compared to conventional PVL in rats. METHODS: Rats were divided into 3 groups: group A, ligation of left primary branch; group B, ligation of right and left primary branches; group C, ligation of the left primary branch, followed by 2-stage PVL 7 days postoperatively. To evaluate liver regeneration, the proliferating cell nuclear antigen labeling index (LI), mitotic index (MI) in the caudate lobe and weight ratio of caudate lobe to body weight were measured. RESULTS: The weight ratio of caudate lobe to body weight was significantly higher in group C than in groups A or B 14 days postoperatively. In groups A and B, LI and MI in the caudate lobe peaked 2 days postoperatively, then decreased to preoperative levels by 7-8 days postoperatively, but remained significantly elevated until 10-14 days postoperatively in group C. CONCLUSION: Two-stage PVL increases hypertrophy of the future remnant liver compared to conventional PVL in rats.


Subject(s)
Liver Regeneration , Portal Vein/surgery , Alanine Transaminase/blood , Animals , Aspartate Aminotransferases/blood , Atrophy , Bilirubin/blood , Embolization, Therapeutic , Hepatectomy , Humans , Hypertrophy , Ligation/methods , Liver Circulation , Liver Neoplasms/pathology , Liver Neoplasms/physiopathology , Liver Neoplasms/surgery , Liver Regeneration/physiology , Male , Rats , Rats, Sprague-Dawley
6.
Oncogene ; 25(20): 2839-49, 2006 May 11.
Article in English | MEDLINE | ID: mdl-16407843

ABSTRACT

This study provides evidence for the importance of p21(CDKN1A) for the repair of replication-mediated DNA double-strand breaks (DSBs) induced by topoisomerase I. We report that defects of p21(CDKN1A) and p53 enhance camptothecin-induced histone H2AX phosphorylation (gammaH2AX), a marker for DNA DSBs. In human colon carcinoma HCT116 cells with wild-type (wt) p53, gammaH2AX reverses after camptothecin removal. By contrast, gammaH2AX increases after camptothecin removal in HCT116 cells deficient for p53 (p53-/-) or p21(CDKN1A) (p21-/-) as the cells reach the late-S and G2 phases. Since p21-/- cells exhibit similar S-phase arrest as wt cells in response to camptothecin and aphidicolin does not abrogate the enhanced gammaH2AX formation in p21-/- cells, we conclude that enhanced gammaH2AX formation in p21-/- cells is not due to re-replication. The cell cycle checkpoint abrogator and Chk1/Chk2 inhibitor 7-hydroxystaurosporine (UCN-01) also increases camptothecin-induced gammaH2AX formation and inhibits camptothecin-induced p21(CDKN1A) upregulation in HCT116 wt cells. TUNEL (terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling) assays demonstrate that gammaH2AX formation in late S and G2 cells following CPT treatment corresponds to DNA breaks. However, these breaks are not related to apoptotic DNA fragmentation. We propose that p21(CDKN1A) prevents the collapse of replication forks damaged by stabilized topoisomerase I cleavage complexes.


Subject(s)
Cyclin-Dependent Kinase Inhibitor p21/physiology , DNA Repair/physiology , DNA Replication , DNA Topoisomerases, Type I/pharmacology , DNA/metabolism , Protein Kinase Inhibitors/pharmacology , Staurosporine/analogs & derivatives , Aphidicolin/pharmacology , Apoptosis/drug effects , Chromosome Breakage , Colonic Neoplasms/drug therapy , Colonic Neoplasms/metabolism , Cyclin-Dependent Kinase Inhibitor p21/antagonists & inhibitors , DNA/genetics , DNA Damage/drug effects , HCT116 Cells , Histones/metabolism , Humans , In Situ Nick-End Labeling , Phosphorylation/drug effects , Protein Kinase C/antagonists & inhibitors , S Phase/drug effects , Staurosporine/pharmacology , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/physiology
7.
Kyobu Geka ; 60(1): 69-71, 2007 Jan.
Article in Japanese | MEDLINE | ID: mdl-17249542

ABSTRACT

Anaphylactic shock related to aprotinin has been reported to be induced exclusively in the presence of IgE antibody. And the possibility of anaphylactic shock induced by anti-aprotinin IgG antibody alone was controversial. In this paper, we describe the first case of anaphylactic shock induced by aprotinin-specific IgG antibody alone. A 55-year-old man underwent surgical repair of the descending aorta with the use of aprotinin at 2 months after first aprotinin usage. Immediately after initiation of cardiopulmonary bypass with the continuous infusion of aprotinin, clinical symptoms of anaphylactic reaction were found. Postoperative drug lymphocyte stimulation test for aprotinin and aprotinin-specific IgE antibody were negative, but aprotinin-specific IgG antibody was 163 mg/l and positive.


Subject(s)
Anaphylaxis/immunology , Antibodies/blood , Aprotinin/immunology , Immunoglobulin G/blood , Humans , Male , Middle Aged
8.
Cancer Res ; 61(1): 172-7, 2001 Jan 01.
Article in English | MEDLINE | ID: mdl-11196156

ABSTRACT

We have established a human myelogenous leukemia cell line (HL60/AD) that is 10-fold cross-resistant to both 1-beta-D-arabinofuranosylcytosine (ara-C) and daunorubicin; the cell line was isolated from HL60 by simultaneous treatment with these two agents at low drug concentrations attainable in clinical trials. HL60/AD was found to have multiple resistance mechanisms. With regard to ara-C, HL60/AD cells showed decreased deoxycytidine kinase activity but did not show elevation of cytidine deaminase activity or a decrease in ara-C influx. With regard to daunorubicin, a decrease in topoisomerase II activity was found. A decrease in intracellular accumulation of daunorubicin was also found. P-glycoprotein was not detected, but the multidrug resistance-associated protein was expressed. Furthermore, an increase of total cellular glutathione (GSH) content was found. Interestingly, the resistance of HL60/AD cells not only to daunorubicin but also to ara-C was markedly reversed by treatment with L-buthionine-(S,R)-sulfoximine (BSO), a potent inhibitor of GSH synthesis. After exposure of HL60/AD to ara-C, mitochondrial membrane potential and reactive oxygen intermediates showed no significant change, but a considerable loss of mitochondrial membrane potential and an increase in reactive oxygen intermediate generation were caused by pre-incubation with BSO. Neither elevation of GSH nor reversal of resistance by BSO was found in ara-C-resistant HL60 cells that were selected only with ara-C. These findings suggest that in addition to the summation of the mechanisms of resistance to each agent reported previously, an increased level of GSH plays an important role in the cross-resistance induced in HL60/AD cells by simultaneous exposure to both drugs.


Subject(s)
Antibiotics, Antineoplastic/pharmacology , Antimetabolites, Antineoplastic/pharmacology , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Cytarabine/pharmacology , Daunorubicin/pharmacology , Drug Resistance, Multiple , HL-60 Cells/drug effects , ATP Binding Cassette Transporter, Subfamily B, Member 1/biosynthesis , ATP-Binding Cassette Transporters/biosynthesis , Antibiotics, Antineoplastic/administration & dosage , Antibiotics, Antineoplastic/pharmacokinetics , Antimetabolites, Antineoplastic/administration & dosage , Antimetabolites, Antineoplastic/pharmacokinetics , Buthionine Sulfoximine/pharmacology , Cytarabine/administration & dosage , Cytarabine/pharmacokinetics , Cytidine Deaminase/metabolism , DNA Fragmentation , DNA Topoisomerases, Type I/metabolism , Daunorubicin/administration & dosage , Daunorubicin/pharmacokinetics , Deoxycytidine Kinase/metabolism , Dose-Response Relationship, Drug , Drug Interactions , Glutathione/antagonists & inhibitors , Glutathione/biosynthesis , HL-60 Cells/cytology , HL-60 Cells/metabolism , Humans , Intracellular Membranes/drug effects , Intracellular Membranes/physiology , Membrane Potentials/drug effects , Mitochondria/drug effects , Mitochondria/physiology , Multidrug Resistance-Associated Proteins , Proto-Oncogene Proteins c-bcl-2/biosynthesis , Reactive Oxygen Species/metabolism , Topoisomerase I Inhibitors , bcl-X Protein
9.
Biochim Biophys Acta ; 1169(3): 217-24, 1993 Sep 08.
Article in English | MEDLINE | ID: mdl-7548113

ABSTRACT

Sphingosine is known to regulate a variety of cellular functions through protein kinase C-dependent or independent pathways. In an attempt to investigate differential functions of diacylglycerol kinase (DGK) isozymes, we tested the effect of sphingosine on DGK operating in intact Jurkat cells, a human T-cell line. We found that phosphatidic acid (PA) synthesized from endogenous diacylglycerol (DG) and exogenously added short-chain DGs like dioctanoylglycerol were markedly enhanced by approx. 20 microM sphingosine. Further studies such as the use of protein kinase C down-regulated cells, mass measurements of cellular DGs, analysis of molecular species of PA and the effect of exogenous DG on the conversion of endogenous DG to PA suggested that sphingosine directly activated cellular DGK having a broad specificity toward DG molecular species.


Subject(s)
Phosphotransferases (Alcohol Group Acceptor)/metabolism , Sphingosine/pharmacology , Calcimycin/pharmacology , Cell Line , Concanavalin A/pharmacology , Diacylglycerol Kinase , Diglycerides/metabolism , Diglycerides/pharmacology , Enzyme Activation/drug effects , Humans , Isoenzymes/metabolism , Phosphatidic Acids/biosynthesis , Phosphorylation , Protein Kinase C/deficiency , T-Lymphocytes/enzymology
10.
Biochim Biophys Acta ; 1088(2): 292-300, 1991 Feb 16.
Article in English | MEDLINE | ID: mdl-2001402

ABSTRACT

The membrane-bound alcohol dehydrogenase (ADH) from Acetobacter polyoxogenes NBI1028 is composed of a 72 kDa subunit and a 44 kDa cytochrome c subunit. The amino acid sequences of the two regions of the 72 kDa subunit were determined to prepare oligonucleotides for the purpose of amplification of a DNA fragment corresponding to the intermediate region by the polymerase chain reaction. A 0.5 kb DNA fragment thus amplified was used as the probe to clone a 7.0 kb PstI fragment coding for the whole 72 kDa subunit. Nucleotide sequencing and immunoblot analysis revealed that the cloned fragment contained the full structural genes for the 72 kDa and the 44 kDa subunits and they were clustered with the same transcription polarity. The predicted amino acid sequence of the gene for the 72 kDa subunit showed homology with that of the 72 kDa subunit from ADH of A. aceti and those of methanol dehydrogenase from methylotrophic bacteria. The 72 and 44 kDa subunits contained one and three typical haem binding sequences, respectively.


Subject(s)
Acetobacter/genetics , Alcohol Dehydrogenase/genetics , Genes, Bacterial , Multigene Family , Acetobacter/enzymology , Alcohol Dehydrogenase/metabolism , Amino Acid Sequence , Base Sequence , Cell Membrane/enzymology , Cloning, Molecular/methods , Escherichia coli/genetics , Macromolecular Substances , Molecular Sequence Data , Molecular Weight , Oligonucleotide Probes , Plasmids , Restriction Mapping , Sequence Homology, Nucleic Acid
11.
Cell Signal ; 10(5): 349-54, 1998 May.
Article in English | MEDLINE | ID: mdl-9692678

ABSTRACT

The relation between spontaneous contraction, Ca2+ oscillations, and sarcoplasmic reticulum (SR) function was studied in cultured neonatal rat cardiac myocytes. Spontaneous contraction and Ca2+ oscillations were irregular at day 2 of culture but became regular at day 6 of culture in neonatal rat cardiac myocytes. The rate of spontaneous contraction and the frequency of Ca2+ oscillations were decreased by verapamil and were abolished in the absence of extracellular Ca2+ at both day 2 and day 6 of culture. Ryanodine and thapsigargin increased the rate of contraction and the frequency of Ca2+ oscillations at day 2 of culture but did not affect contractions and Ca2+ oscillations at day 6 of culture. Ultrastructural observation showed that the structure of SR developed less at day 6 of culture. The present results suggest that spontaneous contraction and Ca2+ oscillations are due mainly to extracellular Ca2+ influx but not to Ca2+ release from SR in neonatal rat cardiac myocytes.


Subject(s)
Heart/physiology , Myocardial Contraction/physiology , Sarcoplasmic Reticulum/physiology , Animals , Animals, Newborn , Calcium/metabolism , Calcium/pharmacology , Cells, Cultured , Myocardium/cytology , Myocardium/metabolism , Rats , Rats, Wistar , Ryanodine/pharmacology , Sarcoplasmic Reticulum/metabolism , Thapsigargin/pharmacology
12.
Transplant Proc ; 37(4): 1845-7, 2005 May.
Article in English | MEDLINE | ID: mdl-15919483

ABSTRACT

We investigated the potential donors from cases without lung procurement in spite of considering procurement as the donor. We reviewed 207 cases considered for lung procurement. Donors were divided into 2 groups according to whether or not their lungs were harvested: 50 did and 157 did not. We investigated their age, gender, donor management periods, blood pressure, heart rate, P/F ratio, PCO2, HCO3, positive end-expiratory pressure (PEEP), respiratory rate, abnormal findings in the chest X-ray, blood chemistries, sputum culture, and intravenous administration of steroid. Univariable or multivariable logistic regression analysis was used to predict lung harvesting by various factors. Univariable logistic regression analysis revealed maximum heart rate (HR) and respiratory rate (RR), maximum, minimum, and average P/F ratio, and abnormal findings in the chest X-ray, to be predictors to perform transplant. The maximum HR and RR of the non-harvest group are higher than those of the harvest group. Multivariable logistic regression analysis revealed average P/F ratio only to be a predictor to transplant. We divided the non-harvest group into 2 groups according to whether or not their P/F ratio was >300: 55 did (P/F 300 group) and 102 did not (P/F 299 group). Between P/F 299 group and the harvest group, univariable logistic regression analysis revealed maximum HR, maximum and minimum RR, maximum PEEP, maximum, minimum, and average P/F ratio, and abnormal findings in the chest X-ray to be predictors to transplant. Maximum HR, PEEP, and maximum and minimum RR of the P/F 299 group are higher than those of the harvest group. Maximum, minimum, and average P/F ratio of the P/F 299 group are lower than those of the harvest group. The average PCO2 of P/F 299 group is higher than that of the harvest group. The rate of abnormal findings in the chest X-ray of the P/F 299 group is higher than that of the harvest group. Multivariable logistic regression analysis revealed average P/F ratio only to be a predictor to transplant. There were no predictors between the P/F 300 group and the harvest group in both univariable and multivariable logistic regression analyses. Furthermore, there were no different factors between the P/F 300 group and the harvest group. Our study showed that 35.5% of the non-harvest group had a P/F ratio of >300 and had no difference compared with the harvest group. Our data suggest that potential donors existed in the non-harvest group and increased the number of lung procurement to 27.3% from 13.0% of all donors.


Subject(s)
Lung , Pneumonectomy , Tissue and Organ Harvesting , Blood Pressure , Female , Humans , Male , Patient Selection , Positive-Pressure Respiration , Regression Analysis , Retrospective Studies
13.
Kyobu Geka ; 58(11): 997-1001, 2005 Oct.
Article in Japanese | MEDLINE | ID: mdl-16235850

ABSTRACT

We created a method using handmade branched graft to do the aortic arch surgery easier and safer. We made the branched graft using 12 and 8 mm vascular graft. A 77-year-old man with Stanford type A aortic dissection was operated with this method under deep hypothermia. After aortic root manipulation, perfusion of the aortic arch was stopped and selective cerebral perfusion was established. Left subclavian artery (LSCA) was anastomosed to one of the branches. The perfusion of the LSCA was re-started via one of its branches. Respectively, left common carotid artery and brachiocephalic artery reconstruction and reperfusion were performed in a same fashion. After distal anastomosis, anastomosis between the branched graft and main graft was performed consecutively. Postoperative course was uneventful and there was no complication. The treatment of our branched graft was easier than that of ready-made 4-branched graft. We could perform the operation under clear view for its movability with minimal cerebral ischemic time.


Subject(s)
Aorta, Thoracic/surgery , Aortic Aneurysm, Thoracic/surgery , Aortic Dissection/surgery , Blood Vessel Prosthesis Implantation/methods , Aged , Anastomosis, Surgical , Blood Vessel Prosthesis Implantation/instrumentation , Brachiocephalic Trunk/surgery , Carotid Artery, Common/surgery , Humans , Male , Subclavian Artery/surgery
14.
Kyobu Geka ; 58(2): 89-92; discussion 92-5, 2005 Feb.
Article in Japanese | MEDLINE | ID: mdl-15724468

ABSTRACT

From April to December 2002, 40 patients underwent coronary artery bypass grafting (CABG) using the St. Jude Medical (Minneapolis) Symmetry bypass system (aortic connector system: ACS). 59 proximal anastomoses (51 saphenous vein grafts, 8 radial artery grafts) were performed with the ACS. One saphenous vein graft occluded during operation. Postoperative evaluation of the anastomotic patency was carried out by angiography in 45 grafts. Five of the saphenous vein grafts were occluded (5/38). One patient who was shock state before operation presented with postoperative unconsciousness. Another patient died at 8th postoperative day caused by ventricular fibrillation. We conclude that the ACS produces a simple, quick way of performing the proximal anastomosis without the need for clamping the aorta, allows reducing risk of embolization by aortic manipulation. However, it is necessary to discuss sufficiently using the ACS, because the graft patency with the ACS is lower than with standard suturing technique.


Subject(s)
Anastomosis, Surgical/instrumentation , Aorta/surgery , Coronary Artery Bypass/instrumentation , Vascular Patency , Aged , Aged, 80 and over , Coronary Disease/surgery , Female , Graft Occlusion, Vascular/etiology , Humans , Male , Middle Aged , Postoperative Complications , Radial Artery/transplantation , Saphenous Vein/transplantation
15.
Cell Calcium ; 10(8): 519-25, 1989.
Article in English | MEDLINE | ID: mdl-2559809

ABSTRACT

The effects of the beta-adrenoceptor agonist, isoprenaline, on Ca2+ mobilization and inositol phosphate formation in parotid acinar cells were examined. Isoprenaline (2 microM) failed to increase cytosolic [Ca2+] in acinar cells, as measured by Fura-2 fluorescence, even in the presence of a phosphodiesterase inhibitor. Likewise, neither the 8-bromo nor the dibutyryl derivatives of cAMP (both at 2 mM concentration) increased [Ca2+]i. However, in confirmation of results previously published, a higher concentration of isoprenaline (200 microM) increased cytosolic [Ca2+]i of rat parotid acinar cells, from 104 +/- 4 nM to 151 +/- 18 nM. The increase in [Ca2+]i in response to isoprenaline, while transient in the absence of extracellular Ca2+, was sustained in Ca2(+)-containing medium. This isoprenaline-stimulated Ca2+ signal was more potently antagonized by phentolamine than by propranolol, suggesting that the higher concentration of isoprenaline activated alpha-adrenoceptors. Furthermore, the Ca2+ signal generated in response to the alpha-adrenoceptor agonist, phenylephrine, also was blocked by the same concentrations of propranolol necessary to block the effects of isoprenaline, suggesting that propranolol may block alpha-adrenoceptors under certain experimental conditions. The high concentration of (-)isoprenaline (200 microM) also increased inositol (1,4,5) trisphosphate and inositol (1,3,4) trisphosphate formation 45% within 30 s. Analogous to the increase in intracellular Ca2+, the formation of inositol phosphates stimulated by isoprenaline was more potently antagonized by the alpha-adrenoceptor antagonist, phentolamine, than by the beta-adrenoceptor antagonist, propranolol, again suggesting that isoprenaline interacts with alpha-adrenoceptors on parotid cells. Thus, the effects of isoprenaline on [Ca2+]i do not appear to be mediated by cAMP.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Calcium/metabolism , Inositol 1,4,5-Trisphosphate/metabolism , Parotid Gland/metabolism , Receptors, Adrenergic, beta/physiology , 8-Bromo Cyclic Adenosine Monophosphate/pharmacology , Animals , Benzofurans , Bucladesine/pharmacology , Cytosol/metabolism , Fluorescent Dyes , Fura-2 , Isoproterenol/pharmacology , Methacholine Chloride , Methacholine Compounds/pharmacology , Parotid Gland/drug effects , Phentolamine/pharmacology , Propranolol/pharmacology , Rats , Receptors, Adrenergic, beta/drug effects , Spectrometry, Fluorescence
16.
Cell Calcium ; 11(1): 11-7, 1990 Jan.
Article in English | MEDLINE | ID: mdl-2138056

ABSTRACT

The rate of Ca2+ extrusion across the plasma membrane of rat parotid acinar cells was determined by measuring the decay of the intracellular calcium concentration, [Ca2+]i, following the addition of EGTA to agonist stimulated cells. In the presence of extracellular Ca2+, the muscarinic cholinergic receptor agonist, methacholine, rapidly increased [Ca2+]i (peaking within 5 s), which then decreased to a higher steady state level. This elevated steady state level was dependent on extracellular Ca2+ concentration. Likewise, thapsigargin, a non-phorbol ester tumor promoter that does not increase inositol phosphates, gradually increased [Ca2+]i, peaking within 1 min and then declining to a new elevated plateau level which was also dependent on extracellular Ca2+. [Ca2+]i, elevated by methacholine or thapsigargin, was rapidly decreased by the addition of EGTA by a process the kinetics of which depended on the value of [Ca2+]i before the addition of EGTA. That is, [Ca2+]i increased as a function of the extracellular Ca2+ concentration and also the apparent half-time for Ca2+ extrusion following the addition of EGTA to cells was increased as the [Ca2+]i increased. This presumably reflects the saturable nature of the Ca2+ extrusion mechanism. The steady state [Ca2+]i in cells stimulated with methacholine or thapsigargin in nominally Ca2+ free medium was similar to the steady state [Ca2+]i in unstimulated cells in normal, Ca2(+)-containing medium. Under these similar [Ca2+]i conditions, stimulated and unstimulated cells showed a similar time course of decay upon addition of EGTA. In addition, neither methacholine nor phorbol myristate acetate decreased the sustained elevation of [Ca2+]i induced by ionomycin.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Calcium/metabolism , Parotid Gland/metabolism , Animals , Biological Transport, Active/drug effects , Calcium-Transporting ATPases/antagonists & inhibitors , Carcinogens/pharmacology , Cell Membrane/metabolism , Egtazic Acid/pharmacology , In Vitro Techniques , Kinetics , Methacholine Chloride , Methacholine Compounds/pharmacology , Microsomes/enzymology , Parotid Gland/cytology , Parotid Gland/drug effects , Rats , Receptors, Muscarinic/drug effects , Receptors, Muscarinic/metabolism , Terpenes/pharmacology , Thapsigargin
17.
Cell Calcium ; 13(1): 49-58, 1992 Jan.
Article in English | MEDLINE | ID: mdl-1371721

ABSTRACT

The characteristics of Ca2+ entry activated by surface receptor agonists and membrane depolarization were studied in the rat pancreatoma cell line, AR4-2J. Ca2+ mobilization activated by substance P, bombesin, or muscarinic receptor stimulation was found to involve both Ca2+ release and entry. In addition, depolarization of the surface membrane of AR4-2J cells with elevated concentrations of K+ activated Ca2+ entry. Ca2+ entry induced by membrane depolarization was inhibited by the L-channel antagonist, nimodipine, while that due to surface receptor agonists was not inhibited by this agent. The microsomal Ca(2+)-ATPase inhibitor, thapsigargin, caused both depletion of the agonist-sensitive intracellular Ca2+ pool and sustained Ca2+ influx indistinguishable from that produced by bombesin or methacholine. These results confirm that, unlike the pancreatic acinar cells from which they are presumably derived, AR4-2J cells express voltage-sensitive, dihydropyridine-inhibitable Ca2+ channels. However, in contrast to previous reports with this cell line, in the AR4-2J cells in use in our laboratory, and under our experimental conditions, surface receptor agonists (including substance P) do not cause Ca2+ influx through voltage-sensitive Ca2+ channels. Instead, we conclude that agonist-activated Ca2+ mobilization is initiated by (1,4,5)IP3-mediated intracellular Ca2+ release and that Ca2+ influx is regulated primarily, if not exclusively, by the state of depletion of the (1,4,5)IP3-sensitive intracellular Ca2+ pool.


Subject(s)
Calcium Channels/metabolism , Calcium-Transporting ATPases/metabolism , Calcium/metabolism , Signal Transduction/drug effects , Animals , Bombesin/pharmacology , Calcium Channels/drug effects , Calcium-Transporting ATPases/antagonists & inhibitors , Fura-2 , Inositol 1,4,5-Trisphosphate/metabolism , Methacholine Chloride/pharmacology , Nimodipine/pharmacology , Rats , Substance P/pharmacology , Terpenes/pharmacology , Thapsigargin , Tumor Cells, Cultured/metabolism
18.
Gene ; 89(2): 163-9, 1990 May 14.
Article in English | MEDLINE | ID: mdl-2373366

ABSTRACT

Genomic DNAs encoding the horseradish peroxidase (HRP) isozymes, prxC2 and prxC3, were cloned and sequenced. By comparing the sequences of the HRP isozyme-encoding genes, prxC1a and prxC1b and their cDNA [Fujiyama et al., Eur. J. Biochem. 173 (1988) 681-687], , it was concluded that prxC2 and prxC3 consisted of four exons and three introns as in the prxC1 gene family. The position of introns in coding regions were the same in all four prx genes. Genes prxC2 and prxC3 coded for 347 and 349 amino acid (aa) residues, respectively, including putative signal sequences at the N termini. In the flanking regions of both genes, putative promoters and polyadenylation signals were found. Nucleotide sequence homology in the coding region was 71% between prxC1a and prxC2, and 66% between prxC1a and prxC3. The aa sequence homologies in plant and microbial peroxidases were compared.


Subject(s)
Genes, Plant , Horseradish Peroxidase/genetics , Isoenzymes/genetics , Peroxidases/genetics , Amino Acid Sequence , Base Sequence , Cloning, Molecular , Molecular Sequence Data , Plants/enzymology , Plants/genetics , Sequence Homology, Nucleic Acid
19.
Gene ; 127(1): 47-52, 1993 May 15.
Article in English | MEDLINE | ID: mdl-8486287

ABSTRACT

The recA+ gene of Acetobacter polyoxogenes was cloned as a gene that conferred methyl methanesulfonate resistance (MMSR) on the RecA- Escherichia coli HB101. The cloned recA+ gene also conferred (i) resistance to UV irradiation, (ii) enhanced intrachromosomal recombination, and (iii) permitted prophage phi 80 induction in E. coli recA- lysogens. Nucleotide sequence determination revealed that the recA product consists of 348 amino acids (aa) corresponding to 38 kDa, and shows significant similarity to RecA proteins from other Gram- bacteria. Next, a portion of recA from Acetobacter aceti was cloned by using polymerase chain reaction with oligodeoxyribonucleotide primers design based on the A. polyoxogenes recA sequence. Due to availability of efficient host-vector and transformation systems in A. aceti, recA mutants of A. aceti were obtained by transformation-mediated gene replacement with the cloned A. aceti recA gene which was inactivated by insertion of the kanamycin-resistance-encoding gene from pACYC177. The recA mutants obtained in this way showed similar phenotypes to those of E. coli recA strains, such as increased sensitivity to MMS and to UV irradiation, and decreased homologous recombination.


Subject(s)
Acetobacter/genetics , Mutagenesis , Rec A Recombinases/genetics , Transformation, Bacterial , Amino Acid Sequence , Base Sequence , Cloning, Molecular , DNA, Bacterial , Escherichia coli/genetics , Genes, Bacterial , Molecular Sequence Data , Restriction Mapping , Sequence Homology, Amino Acid
20.
Free Radic Biol Med ; 31(5): 615-23, 2001 Sep 01.
Article in English | MEDLINE | ID: mdl-11522446

ABSTRACT

Puromycin aminonucleoside induces apoptosis and increases 4-hydroxy-2-nonenal (HNE) in cultured glomerular epithelial cells. We have previously reported the detachment of cultured glomerular epithelial cells (GECs) from their substrata by puromycin aminonucleoside (PAN) treatment. In this study we explored whether or not apoptosis was involved in the mechanisms of the detachment. DNA fragmentation on gel electrophoresis was clearly shown by 10(-3) M PAN treatment of GECs. Nuclear staining by Hoechst 33342 indicated the greatest number of apoptotic cells at 10(-3) M PAN for 48 h treatment. Similarly, TUNEL methods revealed maximal apoptotic cells at 10(-3) M PAN for 48 h treatment. Caspase-3 (like) protease activity increased at 10(-3) M PAN, and decreased at 2 x 10(-3) M PAN for 48 h treatment as well as at 10(-3) M PAN for 60 h treatment. Pretreatment with 2'-deoxycoformycin (DCF), inhibitor of adenosine deaminase, abolished these effects of PAN on cultured GECs. PAN treatment increased HNE, a lipid peroxide adduct, modified protein in cultured GECs, which was also prevented by pretreatment by DCF. These results for the first time indicate that the PAN-induced detachment of GECs from culture substrata is mediated at least in part through apoptosis via oxidative stresses by adenosine deaminase activity.


Subject(s)
Aldehydes/metabolism , Antibiotics, Antineoplastic/pharmacology , Apoptosis/drug effects , Cysteine Proteinase Inhibitors/metabolism , Kidney Glomerulus/drug effects , Puromycin Aminonucleoside/pharmacology , Adenosine Deaminase Inhibitors , Animals , Blotting, Western , Caspase 3 , Caspases/metabolism , Cell Division/drug effects , Cell Nucleus , Epithelial Cells/drug effects , Epithelial Cells/metabolism , In Situ Nick-End Labeling , Kidney Glomerulus/cytology , Kidney Glomerulus/metabolism , Male , Pentostatin/pharmacology , Rats , Rats, Sprague-Dawley
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