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1.
Tech Coloproctol ; 23(10): 973-980, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31535238

ABSTRACT

BACKGROUND: Anastomotic leakage (AL) is one of the most troublesome complications in colorectal surgery. Recently, near-infrared fluorescence (NIRF) imaging has been used intraoperatively to detect sentinel lymph nodes and visualize the blood supply at the region of interest (ROI). The aim of this study was to evaluate the role of visualization and quantification of bowel perfusion around the anastomosis using NIRF system in predicting AL. METHODS: A prospective study was conducted on patients who had laparoscopic surgery for colorectal cancer at our institution. Perfusion of the anastomosis was evaluated with NIRF imaging after intravenous injection of indocyanine green (ICG). The time course of fluorescence intensity was recorded by an imaging analyzer We measured the time from ICG injection to the beginning of fluorescence (T0), maximum intensity (Imax), time to reach Imax (Tmax), time to reach Imax 50% ([Formula: see text]) and slope (S) after the anastomosis. RESULTS: Tumor locations were as follows; cecum: 2, ascending colon: 2, transverse colon: 7, descending colon: 1, sigmoid colon: 2, rectosigmoid colon: 3 and rectum: 6 (one case with synchronous cancer). All operations were performed laparoscopically. Four patients were diagnosed with or suspected to have AL (2 patients with grade B anastomotic leakage after low anterior resection, 1 patient with minor leakage in transverse colon resection and 1 patient needing re-anastomosis intraoperatively in transverse colon resection). T0 was significantly longer in the AL group than in patients without AL (64.3 ± 27.6 and 18.2 ± 6.6 s, p = 2.2 × 10-3). CONCLUSIONS: Perfusion of the anastomosis could be successfully visualized and quantified using NIRF imaging with ICG. T0 might be a useful parameter for prediction of AL.


Subject(s)
Anastomotic Leak/diagnostic imaging , Colorectal Neoplasms/surgery , Intraoperative Care/methods , Perfusion Imaging/methods , Surgical Stomas/blood supply , Aged , Aged, 80 and over , Anastomosis, Surgical/adverse effects , Anastomosis, Surgical/methods , Anastomotic Leak/etiology , Colectomy/adverse effects , Colectomy/methods , Colon/blood supply , Colon/diagnostic imaging , Colon/surgery , Coloring Agents , Female , Fluorescence , Humans , Indocyanine Green , Infrared Rays , Laparoscopy/adverse effects , Laparoscopy/methods , Male , Middle Aged , Prospective Studies , Rectum/blood supply , Rectum/diagnostic imaging , Rectum/surgery , Surgical Stomas/adverse effects
2.
Am J Transplant ; 15(10): 2565-75, 2015 Oct.
Article in English | MEDLINE | ID: mdl-26012352

ABSTRACT

Unpreventable allograft rejection is one of the main problems in pancreatic islet transplantation (PIT). Therefore, it is imperative to develop a more effective immunosuppressive strategy. The blockade of transcription factors has been a central part of T cell-depleting immunosuppressive therapies, as typified by the use of calcineurin inhibitors. The inhibition of activator protein-1 (AP-1) offers a novel strategy for immunosuppression in PIT, although to date, no reports on the effects of AP-1 inhibition are available. In this study, we investigated the immunosuppressive effects of T-5224, a c-Fos/AP-1-selective inhibitor, on murine T cells activated by αCD3+αCD28 mAbs. T-5224 inhibited proliferation, CD25 up-regulation, and the production of IL-2 and interferon-γ. In addition, T-5224 blocked the nuclear translocation of c-Fos/AP-1 in activated murine T cells. In BALB/c (H-2(d) )-to-C57BL/6J (H-2(b) ) mouse PIT, the 2-week administration of T-5224 prolonged survival of 600 islet allografts in a dose-dependent manner. When combined with a 2-week low-dose tacrolimus, the T-5224 treatment markedly prolonged allograft survival to over 300 days, while the efficacy was indeterminate when transplanted islet allograft mass was reduced to 300. We conclude that the c-Fos/AP-1 inhibition by T-5224 is a potentially attractive strategy for allogeneic PIT.


Subject(s)
Benzophenones/therapeutic use , Graft Rejection/prevention & control , Immunosuppressive Agents/therapeutic use , Islets of Langerhans Transplantation/immunology , Isoxazoles/therapeutic use , Animals , Benzophenones/pharmacology , Graft Rejection/immunology , Immunosuppressive Agents/pharmacology , Isoxazoles/pharmacology , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Proto-Oncogene Proteins c-fos/antagonists & inhibitors , T-Lymphocytes/drug effects , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Transcription Factor AP-1/antagonists & inhibitors , Transplantation, Homologous
3.
Br J Surg ; 101(9): 1084-91, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24975853

ABSTRACT

BACKGROUND: Pancreaticoduodenectomy (PD) is associated with a high incidence of postoperative complications including pancreatic fistula. This randomized clinical trial compared the incidence of pancreatic fistula between the isolated Roux-en-Y (IsoRY) and conventional reconstruction (CR) methods. METHODS: Patients admitted for PD between June 2009 and September 2012 in a single centre were assigned randomly to CR or IsoRY. The primary endpoint was the incidence of pancreatic fistula (grade A-C) defined according to the International Study Group on Pancreatic Fistula. Secondary endpoints were complication rates, mortality and hospital stay. Multiple logistic regression analysis was performed to identify factors associated with pancreatic fistula. RESULTS: Some 153 patients were randomized, 76 to CR and 77 to IsoRY; two patients from the IsoRY group were excluded after randomization. Pancreatic fistula occurred in 26 patients (34 per cent) in the CR group and 25 (33 per cent) in the IsoRY group (P = 0·909). The number of patients with a clinically relevant pancreatic fistula (grade B or C) was similar in the two groups (10 and 11 patients respectively; P = 0·789), as were complication rates (42 versus 40 per cent; P = 0·793) and mortality (none in either group; P = 0·999). Soft pancreas was the only independent risk factor for pancreatic fistula (odds ratio 4·42, 95 per cent confidence interval 1·85 to 10·53; P <0·001). CONCLUSION: This study showed that IsoRY reconstruction does not reduce the incidence of pancreatic fistula compared with CR. REGISTRATION NUMBER: NCT00915863 (http://www.clinicaltrials.gov/) and UMIN000001967 (http://www.umin.ac.jp/).


Subject(s)
Pancreatic Fistula/etiology , Pancreaticoduodenectomy/methods , Aged , Anastomosis, Roux-en-Y/adverse effects , Anastomosis, Roux-en-Y/methods , Female , Humans , Male , Multivariate Analysis , Pancreaticoduodenectomy/adverse effects , Postoperative Complications/etiology , Risk Assessment , Risk Factors
4.
J Clin Invest ; 81(2): 414-9, 1988 Feb.
Article in English | MEDLINE | ID: mdl-3276728

ABSTRACT

Human hepatocyte growth factor (hHGF) has been purified approximately 209,000-fold with 18% yield from plasma of a patient with fulminant hepatic failure. The purification involves heat treatment of plasma, ammonium sulfate precipitation, and chromatography on Affi-Gel Blue, heparin-Sepharose, and hydroxylapatite. Purified hHGF shows several bands with molecular weights between 76,000 and 92,000. Each band shows growth-stimulating activity on cultured hepatocytes which is proportional to the intensity of the band. After reduction of the sample with 2-mercaptoethanol, SDS-PAGE yields two chains with molecular weights of 31,500-34,500 and 54,000-65,000. The effect of hHGF on DNA synthesis by hepatocytes is half-maximal at 3.5 ng/ml. hHGF stimulates proliferation of cultured hepatocytes more effectively than human epidermal growth factor (hEGF) or insulin, and the effect of hHGF is additive or synergistic with the maximal effects of hEGF and insulin. These results suggest that hHGF is a new growth factor which is different from hEGF.


Subject(s)
Hepatitis B/physiopathology , Liver Regeneration , Proteins/isolation & purification , Cell Division/drug effects , Cells, Cultured , Chromatography , Epidermal Growth Factor/pharmacology , Hepatitis B/pathology , Humans , Insulin/pharmacology , Interleukin-6 , Liver/cytology , Molecular Weight , Proteins/pharmacology
5.
Circ Res ; 86(3): 275-80, 2000 Feb 18.
Article in English | MEDLINE | ID: mdl-10679478

ABSTRACT

The expression of coxsackievirus and adenovirus receptor (CAR) was dominant in the brains and hearts of mice until the newborn phase. There is no detailed information concerning the relation between the expression of CAR and development of hearts. It is also uncertain whether CAR is able to be induced in adult hearts after cardiac injury. We demonstrated that CAR was abundant in the hearts of newborn rats but was barely detectable in the hearts of adult rats. The expression of CAR in rat hearts with experimental autoimmune myocarditis, which was induced by immunization of purified cardiac myosin, was serially investigated. Active myocarditis was observed from day 15 after immunization. By immunohistochemistry, cardiomyocytes were strongly stained for CAR antibody from days 24 to 42. CAR mRNA was also detected from days 18 to 30 by using reverse transcription-polymerase chain reaction. In the next experiment, the induction of CAR on isolated cardiomyocytes was investigated. CAR was barely detectable in cultured cardiomyocytes by Western blot analysis after isolation. This molecule gradually appeared along with the creation of clusters and beating of cardiomyocytes. Furthermore, the induction of CAR in cultured cardiomyocytes increased after supplement with conditioned medium of rat splenocytes activated by concanavalin A. In conclusion, rat CAR is expressed strongly in the hearts of newborn rats and is suppressed in those of adult rats. The expression of CAR is enhanced during the active phase of experimental autoimmune myocarditis and is induced by inflammatory mediators. CAR may play a role in cell-to-cell contact and adhesion of cardiomyocytes.


Subject(s)
Autoimmune Diseases/metabolism , Myocarditis/metabolism , Myocardium/metabolism , Receptors, Virus/metabolism , Aging/metabolism , Animals , Animals, Newborn/metabolism , Autoimmune Diseases/pathology , Cells, Cultured , Coxsackie and Adenovirus Receptor-Like Membrane Protein , Immunohistochemistry , Myocarditis/pathology , Myocardium/cytology , Myocardium/pathology , RNA, Messenger/metabolism , Rats , Rats, Inbred Lew , Receptors, Virus/genetics , Reverse Transcriptase Polymerase Chain Reaction , Swine
6.
Cancer Res ; 61(7): 3016-21, 2001 Apr 01.
Article in English | MEDLINE | ID: mdl-11306481

ABSTRACT

We previously reported that the retroviral vector expressing the herpes simplex virus-thymidine kinase gene under the control of 0.3-kb human alpha-fetoprotein (AFP) gene promoter (AF0.3) provided the cytotoxicity to ganciclovir (GCV) in high-AFP-producing human hepatoma cells but not in low-AFP-producing cells. Therefore, specific enhancement of AFP promoter activity is likely to be required to induce enough cytotoxicity in low-AFP-producing hepatoma cells. In this study, we constructed a hybrid promoter, [HRE]AF, in which a 0.4-kb fragment of human vascular endothelial growth factor 5'-flanking sequences containing hypoxia-responsive element (HRE) was fused to AF0.3 promoter. By means of the reporter gene transfection assay, hypoxia-inducible transcriptions that were mediated by [HRE]AF promoter were detected in low- and non-AFP-producing human hepatoma cells, but not in nonhepatoma cells. When the herpes simplex virus-thymidine kinase gene controlled by [HRE]AF promoter was transduced into hepatoma and nonhepatoma cells by a retroviral vector, the exposure to 1% O2 induced GCV cytotoxicity specifically in the hepatoma cells. Moreover, in nude mice bearing solid tumor xenografts, only the tumors consisting of the virus-infected hepatoma cells gradually disappeared by GCV administration. These results indicate that the hypoxia-inducible enhancer of the human vascular endothelial growth factor gene, which is directly linked to human AFP promoter, involves selective and enhanced tumoricidal activity in gene therapy for hepatocellular carcinoma.


Subject(s)
Carcinoma, Hepatocellular/therapy , Enhancer Elements, Genetic , Gene Expression Regulation, Neoplastic , Genetic Therapy , Liver Neoplasms/therapy , Promoter Regions, Genetic , alpha-Fetoproteins/genetics , Animals , Carcinoma, Hepatocellular/genetics , Carcinoma, Hepatocellular/immunology , Cell Hypoxia/genetics , Endothelial Growth Factors/genetics , Ganciclovir/toxicity , Genetic Vectors/genetics , Humans , Liver Neoplasms/genetics , Liver Neoplasms/immunology , Lymphokines/genetics , Male , Mice , Mice, Inbred BALB C , Mice, Nude , Retroviridae/genetics , Simplexvirus/enzymology , Simplexvirus/genetics , Thymidine Kinase/genetics , Thymidine Kinase/metabolism , Transcriptional Activation , Transduction, Genetic , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth Factors , alpha-Fetoproteins/biosynthesis
7.
Cancer Res ; 61(12): 4779-83, 2001 Jun 15.
Article in English | MEDLINE | ID: mdl-11406552

ABSTRACT

Cyclin D1, one of the G(1) cyclins, is frequently overexpressed in several types of carcinomas and is thought to play an important role in tumorigenesis and tumor progression including hepatocellular carcinoma. We constructed a retrovirus vector-carrying rat cyclin D1 cDNA in the reverse orientation, resulting in expression of antisense (AS) cyclin D1 mRNA. For efficient transduction of this recombinant retrovirus, two-step gene transfer was performed. The rat hepatoma cell line (dRLh84) was infected with this recombinant retrovirus after preinfection with adenovirus expressing the retrovirus receptor. In the rat hepatoma cells, AS cyclin D1 mRNA was expressed, inducing a decrease in the expression of endogenous cyclin D1 mRNA and an inhibition of cell growth. Moreover, two-step gene transfer of AS cyclin D1 into s.c. hepatoma xenografts resulted in inhibition of tumor growth and prolonged animal survival. In the virus-infected tumor xenografts, expression of cyclin D1 was immunohistochemically inhibited, and apoptosis of hepatoma cells was detected. These findings suggest that transduction of AS cyclin D1 is useful as an adjunct to standard treatments for hepatocellular carcinoma.


Subject(s)
Cyclin D1/genetics , DNA, Antisense/genetics , Genetic Therapy , Liver Neoplasms, Experimental/genetics , Animals , Blotting, Northern , Cell Division/physiology , Cyclin D1/biosynthesis , DNA, Antisense/administration & dosage , Gene Transfer Techniques , Humans , Immunohistochemistry , Liver Neoplasms, Experimental/pathology , Liver Neoplasms, Experimental/therapy , Male , Mice , Mice, Inbred BALB C , Mice, Nude , RNA, Messenger/genetics , Rats , Rats, Wistar , Retroviridae/genetics , Transduction, Genetic , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
8.
Biochim Biophys Acta ; 1431(2): 384-94, 1999 May 18.
Article in English | MEDLINE | ID: mdl-10350614

ABSTRACT

The three-dimensional structure of alpha-conotoxin ImI, a potent antagonist targeting the neuronal alpha7 subtype of nicotinic acetylcholine receptor (nAChR), has been investigated by NMR spectroscopy. On the basis of 181 experimental constraints, a total of 25 converged structures were obtained. The average pairwise atomic root mean square difference is 0.40+/-0.11 A for the backbone atoms. The resulting structure indicates the presence of two successive type I beta-turns and a 310 helix for residues Cys2-Cys8 and Ala9-Arg11, respectively, and shows a significant structural similarity to that of alpha-conotoxin PnIA, which is also selective for the neuronal nAChR.


Subject(s)
Conotoxins , Mollusk Venoms/chemistry , Oligopeptides/chemistry , Drug Design , Hydrogen-Ion Concentration , Magnetic Resonance Spectroscopy/methods , Models, Molecular , Molecular Structure , Oligopeptides/genetics , Receptors, Nicotinic/chemistry , Solubility , Stereoisomerism , Structure-Activity Relationship , Temperature
9.
Biochim Biophys Acta ; 1203(2): 243-50, 1993 Dec 08.
Article in English | MEDLINE | ID: mdl-8268207

ABSTRACT

We performed molecular dynamics (MD)/free energy perturbation (FEP) calculations to reproduce the experimental free energy difference of denaturation for staphylococcal nuclease mutant Met32-->Ala (M32A) and to predict the stability of the mutant Met32-->Leu (M32L). The calculated free energy difference of denaturation for the M32A of -1.9 kcal/mol was in good agreement with the experimental value. In the M32A, a small hydrophobic core formed by three aromatic rings (Tyr-27, Phe-34, Phe-76) in a wild-type crumbled as a result of exposure to water. The van der Waals interactions in the native state of the M32A were weaker than those of the wild-type, which strongly suggests that the Met-32 is important for the stability of the enzyme. The M32L has not been available yet, but is expected to retain the small hydrophobic core. The free energy difference of denaturation for the M32L was calculated to be 1.6 kcal/mol. The MD/FEP simulation showed that the native state structure of the M32L was only slightly changed when compared with that of the wild-type. It was suggested that the M32L is more stable than the wild-type because the electrostatic interactions in the denatured state are more disadvantageous than those in the native state.


Subject(s)
Micrococcal Nuclease/chemistry , Enzyme Stability , Micrococcal Nuclease/genetics , Molecular Structure , Point Mutation , Protein Denaturation , Thermodynamics
10.
Biochim Biophys Acta ; 1163(1): 81-8, 1993 Apr 21.
Article in English | MEDLINE | ID: mdl-8476933

ABSTRACT

The stability of two mutants G88V (Gly-88-->Val) and A69T (Ala-69-->Thr) of staphylococcal nuclease was analyzed by molecular dynamics simulations. The calculated free energy differences of denaturation for G88V and A69T were -1.1 and -2.8 kcal/mol, respectively. These values are in good agreement with the experimental values. The free energy differences divided into electrostatic and van der Waals components were analyzed. These two mutants are mainly destabilized due to van der Waals interactions. There is little difference between the electrostatic contribution to the free energy change in the native state and that in the denatured state. In each mutant structure, a small cavity appears in the vicinity of the perturbed residue. It is suggested that intramolecular van der Waals interactions of the mutants are weaker than those of the wild-type. Furthermore, analyses of the contributions of each residue near the perturbed residue and of water to the free energy difference of denaturation suggest that the interaction between water and the perturbed residue plays a very important role in the stability of staphylococcal nuclease, and that a small hydrophobic core consisting of the three aromatic rings (Tyr-27, Phe-34, Phe-76) and the side chain of Met-32 is also important for the stability.


Subject(s)
Micrococcal Nuclease/chemistry , Alanine , Amino Acid Sequence , Computer Simulation , Enzyme Stability , Glycine , Micrococcal Nuclease/genetics , Micrococcal Nuclease/ultrastructure , Models, Molecular , Molecular Sequence Data , Mutation , Protein Denaturation , Thermodynamics , Threonine , Valine
11.
Biochim Biophys Acta ; 1434(1): 18-30, 1999 Sep 14.
Article in English | MEDLINE | ID: mdl-10556556

ABSTRACT

It is well known that the subdomain III A (site II) of human serum albumin (HSA) binds a variety of endogenous and exogenous substances. However, the nature of the microenvironment of the binding site remains unclear. Ketoprofen (KP), an arylpropionic acid NSAID which contains a benzophenone moiety, was used as a photoaffinity labeling agent to label the binding region. Subsequent CNBr cleavage of the photolabeled HSA revealed that the 11.6 kDa and 9.4 kDa fragments contained most of the incorporated radioactivity. Competition experiments showed that the 11.6 kDa fragment contains the common binding region for site II ligands. This fragment was redigested with Achromobacter lyticus protease I (AP-I) and the amino acid sequence of the photolabeled peptide was determined to be XCTESLVNRR, which corresponds to the sequence 476C-485K of HSA. The complete amino acid sequence of the corresponding AP-I digested HSA peptide encompasses residues 476 to 499, which form helices 5 and 6 of subdomain III A. The HSA-Myr X-ray crystallography data showed that helix 5 is involved to the least extent in ligand binding. A docking model provided further support that helix 6 represents the photolabeled region of KP.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/chemistry , Ketoprofen/chemistry , Serum Albumin/genetics , Affinity Labels , Amino Acid Sequence , Chromatography, High Pressure Liquid , Cyanogen Bromide , Indicators and Reagents , Ligands , Models, Molecular , Molecular Sequence Data , Peptide Fragments/chemistry , Serum Albumin/chemistry
12.
Biochim Biophys Acta ; 1343(2): 327-34, 1997 Dec 05.
Article in English | MEDLINE | ID: mdl-9434122

ABSTRACT

The conformation of alpha-conotoxin MI, a potent antagonist of the nicotinic acetylcholine receptor, has been investigated in aqueous solution. Two-dimensional NMR experiments and simulated annealing calculations provide the overall topology of alpha-conotoxin MI; then molecular dynamics simulation with the explicit solvent water was followed in order to obtain a more reliable solution structure. The resulting conformation indicates the presence of a 3(10) helix and a type I beta-turn for residues Pro6-Cys8 and Gly9-Try12, respectively, and shows a significant structural similarity to that of alpha-conotoxin GI, which has biological activity similar to that of MI. The present study provides a molecular basis for the alpha-conotoxin-receptor interaction.


Subject(s)
Conotoxins , Mollusk Venoms/chemistry , Nicotinic Antagonists/chemistry , Peptides, Cyclic/chemistry , Protein Conformation , Computer Simulation , Crystallography, X-Ray , Hydrogen Bonding , Models, Molecular , Nicotinic Antagonists/metabolism , Nicotinic Antagonists/pharmacology , Nuclear Magnetic Resonance, Biomolecular , Peptides, Cyclic/metabolism , Peptides, Cyclic/pharmacology , Protein Structure, Secondary , Protein Structure, Tertiary , Receptors, Nicotinic/metabolism , Sequence Homology, Amino Acid , Water
13.
Circulation ; 102(23): 2829-35, 2000 Dec 05.
Article in English | MEDLINE | ID: mdl-11104740

ABSTRACT

BACKGROUND: Clinical manifestations of acute myocarditis, with distinct onset, vary from asymptomatic to fatal. The predictors of the course of the disease in patients with acute myocarditis at initial presentation have not yet been established. In this study, we examined the predictive values of various parameters in the disease course of patients with myocarditis. METHODS AND RESULTS: Twenty-one consecutive patients who had been diagnosed as having acute myocarditis by histological examinations were analyzed. The patients with myocarditis were divided into the survival group (n=13) and the fatal group (n=8). We examined the parameters of the clinical state, hemodynamic variables, required therapies, biochemical laboratory data, and cytokines. The control groups were composed of 23 patients with old myocardial infarction and 20 healthy volunteers. The fatal group had lower blood pressure and higher pulmonary capillary wedge pressure compared with those values in the survival group. Mechanical ventilation support was more frequently required in the fatal group. Serum levels of soluble Fas (sFas) and soluble Fas ligand (sFasL) were significantly higher in the myocarditis group than in the 2 control groups. Furthermore, levels were significantly higher in the fatal group than in the survival group for sFas (13.93+/-4.77 versus 3.77+/-0.52 ng/mL, respectively; P:<0.001) and sFasL (611.4+/-127.7 versus 269.5+/-37.3 pg/mL, respectively; P:<0.05). Other clinical states, hemodynamic variables, required therapies, and biochemical laboratory parameters were not different between the 2 groups. CONCLUSIONS: Elevation of sFas and sFasL levels at initial presentation appear to be a good serological marker to predict the prognosis of acute myocarditis.


Subject(s)
Membrane Glycoproteins/blood , Myocarditis/diagnosis , fas Receptor/blood , Acute Disease , Adult , Aged , Apoptosis , Comorbidity , Fas Ligand Protein , Female , Humans , Hypertension/epidemiology , Male , Myocardial Infarction/blood , Myocardial Infarction/diagnosis , Myocarditis/blood , Myocarditis/epidemiology , Prognosis , Pulmonary Wedge Pressure/physiology , Survival Analysis , Tumor Necrosis Factor-alpha/analysis
14.
J Mol Biol ; 212(1): 197-209, 1990 Mar 05.
Article in English | MEDLINE | ID: mdl-2157020

ABSTRACT

We present a calculation of the relative changes in binding free energy between the complex of ribonuclease T1 (RNase Tr) with its inhibitor 2'-guanosine monophosphate (2'GMP) and that of RNase T1-2'-adenosine monophosphate (2'AMP) by means of a thermodynamic perturbation method implemented with molecular dynamics. Using the available crystal structure of the RNase T1-2'GMP complex, the structure of the RNase T1-2'AMP complex was obtained as a final structure of the perturbation calculation. The calculated difference in the free energy of binding (delta delta Gbind) was 2.76 kcal/mol. This compares well with the experimental value of 3.07 kcal/mol. The encouraging agreement in delta delta Gbind suggests that the interactions of inhibitors with the enzyme are reasonably represented. Energy component analyses of the two complexes reveal that the active site of RNase T1 electrostatically stabilizes the binding of 2'GMP more than that of 2'AMP by 44 kcal/mol, while the van der Waals' interactions are similar in the two complexes. The analyses suggest that the mutation from Glu46 to Gln may lead to a preference of RNase T1 for adenine in contrast to the guanine preference of the wild-type enzyme. Although the molecular dynamics equilibration moves the atoms of the RNase T1-2'GMP system about 0.9 A from their X-ray positions and the mutation of the G to A in the active site increases the deviation from the X-ray structure, the mutation of the A back to G reduces the deviation. This and the agreement found for delta delta Gbind suggest that the molecular dynamics/free energy perturbation method will be useful for both energetic and structural analysis of protein-ligand interactions.


Subject(s)
Adenosine Monophosphate/metabolism , Exoribonucleases/metabolism , Guanine Nucleotides/metabolism , Guanosine Monophosphate/metabolism , Amino Acid Sequence , Aspergillus oryzae/enzymology , Computer Graphics , Hydrogen Bonding , Models, Molecular , Molecular Sequence Data , Ribonucleases , Sequence Homology, Nucleic Acid , Software , Thermodynamics
15.
J Mol Biol ; 178(2): 389-414, 1984 Sep 15.
Article in English | MEDLINE | ID: mdl-6387152

ABSTRACT

The crystal structure of the complex of a bacterial alkaline serine proteinase, subtilisin BPN', with its proteinaceous inhibitor SSI (Streptomyces subtilisin inhibitor) was solved at 2.6 A resolution. Compared with other similar complexes involving serine proteinases of the trypsin family, the present structure is unique in several respects. (1) In addition to the usual antiparallel beta-sheet involving the P1, P2 and P3 residues of the inhibitor, the P4, P5 and P6 residues form an antiparallel beta-sheet with a previously unnoticed chain segment (residues 102 through 104, which was named the S4-6 site) of subtilisin BPN'. (2) The S4-6 site does not exist in serine proteinases of the trypsin family, whether of mammalian or microbial origin. (3) Global induced-fit movement seems to occur on SSI: a channel-like structure in SSI where hydrophobic side-chains are sandwiched between two lobes becomes about 2 A wider upon complexing with subtilisin. (4) The complex is most probably a Michaelis complex, as in most of the other complexes. (5) The main role of the "secondary contact region" of SSI seems to be to support the reactive site loop ("primary contact region"). Steric homology of the two contact regions between the inhibitors of the SSI family and the pancreatic secretory trypsin inhibitor-ovomucoid inhibitor family is so high that it seems to indicate divergent evolutionary processes and to support the general notion as to the relationship of prokaryotic and eukaryotic genes put forward by Doolittle (1978).


Subject(s)
Bacterial Proteins , Endopeptidases , Subtilisins , Amino Acid Sequence , Crystallography , Macromolecular Substances , Models, Molecular , Molecular Conformation , Protease Inhibitors , Serine Endopeptidases , Subtilisins/antagonists & inhibitors
16.
J Immunol Methods ; 244(1-2): 163-73, 2000 Oct 20.
Article in English | MEDLINE | ID: mdl-11033029

ABSTRACT

A sandwich enzyme-linked immunosorbent assay (ELISA) using rabbit anti-hepatocyte growth factor (HGF) IgG for human HGF, also known as the scatter factor, has previously been developed for determining increases in serum HGF levels in various liver diseases. The sensitivity limit of the ELISA is, however, approximately 0.2 ng/ml sample, and HGF concentrations in about 50% of normal subjects are not accurately measurable by this method, because the mean level of HGF in normal serum is close to the sensitivity limit. In the present study, chicken Fab' from egg yolk anti-HGF immunoglobulin Y and rabbit Fab' from rabbit anti-HGF IgG were conjugated with beta-D-galactosidase. With these conjugates as the second antibodies, we developed two sandwich ELISAs for human HGF and found that the sensitivities were about 20 pg/ml with the former conjugate and 2 pg/ml with the latter. The HGF concentration in sera from 138 normal subjects determined by the ELISA with the rabbit conjugate was 244+/-65 (SD) pg/ml serum, and it correlated very well with the number of leukocytes. Moreover, the ELISA with the rabbit conjugate permitted the determination of HGF levels in urine from normal subjects without first concentrating the sample. The determination of HGF in various biological fluids other than blood and urine by these ELISAs may aid the diagnosis and prognosis of various diseases.


Subject(s)
Enzyme-Linked Immunosorbent Assay/methods , Hepatocyte Growth Factor/blood , Hepatocyte Growth Factor/urine , Adult , Animals , Chickens , Female , Humans , Immunoconjugates , Immunoglobulin Fragments , Immunoglobulins , Male , Middle Aged , Rabbits , Reference Values , Sensitivity and Specificity , beta-Galactosidase
17.
Br J Pharmacol ; 130(7): 1489-95, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10928949

ABSTRACT

The cardioprotective properties of carvedilol (a vasodilating beta-adrenoceptor blocking agent) were studied in a rat model of dilated cardiomyopathy induced by autoimmune myocarditis. Twenty-eight days after immunization, surviving Lewis rats (32/43=74%) were divided into three groups to be given 2 mg kg(-1) day(-1) (Group-C2, n=10) or 20 mg kg(-1) day(-1) (Group-C20, n=10) of carvedilol, or vehicle (0.5% methylcellulose, Group-V, n=12). After oral administration for 2 months, body weight, heart weight (HW), heart rate (HR), rat alpha-atrial natriuretic peptide (r-ANP) in blood, central venous pressure (CVP), mean blood pressure (mean BP), peak left ventricular pressure (LVP), left ventricular end-diastolic pressure (LVEDP), +/-dP dt(-1) and area of myocardial fibrosis were measured. Values were compared with those for normal Lewis rats (Group-N, n=10). Two out of 12 (17%) rats in Group-V died from day 28 to day 42 after immunization. No rat died in Groups-C2, -C20 and -N. Although the CVP, mean BP, LVP and +/-dP dt(-1) did not differ among the three groups, the HW, HR and r-ANP in Group-C2 (1.14+/-0.03, 339+/-16 and 135+/-31) and Group-C20 (1.23+/-0.04, 305+/-8 and 156+/-24) were significantly lower than those in Group-V (1.36+/-0.04 g, 389+/-9 beats min(-1) and 375+/-31 pg ml(-1), respectively). The LVEDP in Group-C2 was significantly lower than that in Group-V (7.4+/-1.4 and 12.2+/-1.2 mmHg, respectively, P<0. 05). The area of myocardial fibrosis in Group-C2 was smaller than that in Group-V (12+/-1 and 31+/-2%, P<0.01). These results indicate that a low dose of carvedilol has beneficial effects on dilated cardiomyopathy.


Subject(s)
Carbazoles/therapeutic use , Cardiomyopathy, Dilated/prevention & control , Myocarditis/complications , Propanolamines/therapeutic use , Vasodilator Agents/therapeutic use , Animals , Body Weight/drug effects , Cardiomyopathy, Dilated/etiology , Cardiomyopathy, Dilated/pathology , Carvedilol , Disease Progression , Endomyocardial Fibrosis/physiopathology , Endomyocardial Fibrosis/prevention & control , Heart/drug effects , Hemodynamics/drug effects , Male , Organ Size/drug effects , Rats , Rats, Inbred Lew , Ventricular Function, Left
18.
Environ Health Perspect ; 104 Suppl 5: 1051-8, 1996 Oct.
Article in English | MEDLINE | ID: mdl-8933054

ABSTRACT

Fuzzy adaptive least-squares (FALS), a pattern recognition method recently developed in our laboratory for correlating structure with activity rating, was used to generate quantitative structure-activity relationship (QSAR) models on the carcinogenicity of organic compounds of several chemical classes. Using the predictive models obtained from the chemical class-based FALS QSAR approach, the rodent carcinogenicity or noncarcinogenicity of a group of organic chemicals currently being tested by the U.S. National Toxicology Program was estimated from their chemical structures.


Subject(s)
Carcinogenicity Tests , Carcinogens/toxicity , Animals , Carcinogens/chemistry , Least-Squares Analysis , Mice , Rats , Structure-Activity Relationship
19.
Cardiovasc Pathol ; 4(2): 127-31, 1995.
Article in English | MEDLINE | ID: mdl-25850911

ABSTRACT

A 45-year-old-woman with giant cell myocarditis showing high titer of circulating antiheart antibodies is reported. She experienced two recurrences of myocarditis and repeatedly responded to immunosuppressive therapy using prednisolone. The titer of antiheart antibodies went up and down appropriately according to the clinical responses to immunosuppressive therapy. This case suggested that giant cell myocarditis might be related to autoimmunity.

20.
Surgery ; 119(5): 505-10, 1996 May.
Article in English | MEDLINE | ID: mdl-8619204

ABSTRACT

BACKGROUND: Hepatocyte growth factor (HGF) plays a key role in the regulation of liver regeneration after hepatocyte damage. Changes in HGF production reflect the status of the regeneration process. METHODS: Serum concentrations of HGF and energy substrates were measured during and after liver transplantation in 30 recipients. RESULTS: In the patients with compromised grafts (group A) HGF concentrations were persistently high after reperfusion, whereas in the patients with well-functioning grafts (group B), HGF concentrations decreased rapidly and remained low 4 hours after reperfusion. The patients in group A who died had persistently high concentrations of HGF. The surviving patients with reversible primary graft dysfunction in group A exhibited low concentrations 48 hours after reperfusion. The decrease in HGF concentration preceded the decrease in aspartate aminotransferase concentration. The metabolic parameters that reflect carbohydrate metabolism by the graft paralleled the changes in HGF. CONCLUSIONS: HGF may be more sensitive and specific in predicting early graft function than prothrombin time, ratio, aspartate aminotransferase, or arterial ketone body ratio. The determination of HGF levels after liver transplantation may yield valuable information for evaluating early graft function and making an early decision to repeat a graft procedure in an acutely ill patient.


Subject(s)
Hepatocyte Growth Factor/blood , Liver Transplantation , Adolescent , Adult , Aged , Aspartate Aminotransferases/metabolism , Female , Humans , Lactates/metabolism , Lactic Acid , Liver/physiopathology , Liver Circulation , Male , Middle Aged , Osmolar Concentration , Postoperative Period , Pyruvates/metabolism , Pyruvic Acid , Reperfusion , Survival Analysis
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