High-grade obstruction of the proximal extrahepatic bile duct: an unusual complication of duodenal ulcer disease.
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Adenoma, Bile Duct↗
Biomedical subjects
C H Kim
Publications and source records attributed to C H Kim.
Labeling by [3H]1,3-di(2-tolyl)guanidine of two high affinity binding sites in guinea pig brain: evidence for allosteric regulation by calcium channel antagonists and pseudoallosteric modulation by sigma ligands.
Equilibrium binding studies with the sigma receptor ligand [3H]1,3-di(2-tolyl)guanidine ([3H]DTG) demonstrated two high affinity binding sites in membranes prepared from guinea pig brain. The apparent Kd values of DTG for sites 1 and 2 were 11.9 and 37.6 nM, respectively. The corresponding Bmax values were 1045 and 1423 fmol/mg of protein. Site 1 had high affinity for (+)-pentazocine, haloperidol, (R)-(+)-PPP, carbepentane, and other sigma ligands, suggesting a similarity with the dextromethorphan/sigma 1 binding site described by Musacchio et al. [Life Sci. 45:1721-1732 (1989)]. Site 2 had high affinity for DTG and haloperidol (Ki = 36.1 nM) and low affinity for most other sigma ligands. Kinetic experiments demonstrated that [3H]DTG dissociated in a biphasic manner from both site 1 and site 2. DTG and haloperidol increased the dissociation rate of [3H]DTG from site 1 and site 2, demonstrating the presence of pseudoallosteric interactions. Inorganic calcium channel blockers such as Cd2+ selectively increased the dissociation rate of [3H]DTG from site 2, suggesting an association of this binding site with calcium channels.
Animals↗
Disruption of the gene encoding subunit VI of yeast cytochrome bc1 complex causes respiratory deficiency of cells with reduced cytochrome c levels.
A double mutant of Saccharomyces cerevisiae, in which CYCL gene is deleted and the chromosomal copy of the 17 kDa protein gene is disrupted, has been constructed. This mutant cannot grow on nonfermentable carbon sources, but normal growth can be restored by complementation of either mutation with a yeast vector containing either the wild-type 17 kDa protein gene or the CYCl gene. These results show that although the 17 kDa protein, subunit VI of yeast cytochrome bc1 complex is dispensable for yeast mitochondrial respiration in cells with the wild-type levels of cytochrome c, the 17 kDa protein is essential for respiration when the level of cytochrome c is limited, indicating that is plays a role in electron transport. This glycerol- phenotype of the double mutant can serve as the basis for further genetic studies on the function of the 17 kDa protein in yeast mitochondria and may provide insight into the physiological function of the hinge protein, the counterpart of the yeast 17 kDa protein, in beef heart mitochondria.
Blotting, Southern↗
Voltage-dependent sodium channels in synaptoneurosomes: studies with 22Na+ influx and [3H]saxitoxin and [3H]batrachotoxinin-A 20-alpha-benzoate binding. Effects of proparacaine isothiocyanate.
22Na+ influx and binding of [3H]saxitoxin ([3H]STX) and [3H]batrachotoxin-A 20-alpha-benzoate ([3H]BTX-B) were studied in guinea pig cerebral synaptoneurosomes. STX and tetrodotoxin (TTX) completely blocked the stimulation of sodium influx induced by 1 microM BTX. The IC50 values for STX and TTX closely matched the Ki values for inhibition of [3H]STX binding, suggesting that the sites labelled by [3H]STX are associated with a population of BTX-sensitive channels. BTX induced a dose-dependent stimulation of sodium influx in synaptoneurosomes (EC50 280 nM). The potency of BTX for stimulation of sodium influx was increased (EC50 24 nM) in the presence of 0.6 microgram/ml scorpion venom without any change in maximal influx. In contrast, specific binding of [3H]BTX-B to synaptoneurosomes was minimal in the absence of scorpion venom, but it was increased several fold in the presence of 60 micrograms/ml scorpion venom. With proparacaine isothiocyanate (PROPRIT), an irreversible local anesthetic, the inhibition of [3H]BTX-B binding by PROPRIT did not occur in parallel with an inhibition of sodium influx induced by BTX. Preincubation of synaptoneurosomes with 10 microM PROPRIT for 10 min resulted in approximately 70% inhibition of [3H]BTX-B binding in the presence of scorpion venom. Such preincubation did not alter BTX-induced sodium uptake in synaptoneurosomes. Preincubations of synaptoneurosomes with 100 microM PROPRIT for 10 min completely inhibited [3H]BTX-B binding, and under these conditions BTX-induced sodium influx was reduced only by 50%. The results indicate that virtual elimination of binding sites labeled by [3H]BTX-B in the presence of scorpion venom by PROPRIT has little effect on sodium influx induced by BTX.(ABSTRACT TRUNCATED AT 250 WORDS)
Amphibian Proteins↗
Cloning and expression of raw-starch-digesting alpha-amylase gene from Bacillus circulans F-2 in Escherichia coli.
The raw potato-starch-digesting alpha-amylase gene of Bacillus circulans F-2 was cloned for the first time in Escherichia coli C600, using plasmid pYEJ001. The recombinant plasmid, named pYKA3, has a 5.4 kb insert from a chromosome of the donor bacterium. Subcloning of this amylase gene gave plasmid pHA300 which carried 3.15 kb of the inserted DNA. The transformed bacterium, E. coli C600 (pYKA3), produced the amylase in the periplasmic space, whereas it is secreted outside the cell in the donor bacterium. The cloned raw-starch-digesting alpha-amylase has a molecular weight of 93,000 on SDS-PAGE, and its action pattern was absolutely the same as that of the potent raw-starch-digestible amylase produced by B. circulans F-2. The periplasmic amylase produced by the transformed E. coli (pHA300) could digest raw starch granules such as potato, corn and barley raw starch granules, indicating that the raw-starch-digesting amylase is active in E. coli. Furthermore, this amylase crossreacted with the rabbit antiserum raised against the raw potato-digesting alpha-amylase of B. circulans F-2. From these results it was concluded that the cloned amylase is the same amylase protein as B. circulans F-2 amylase, which has a potent raw-starch digestibility. Thus, this paper is to our knowledge the first describing the molecular cloning of raw-starch-digesting alpha-amylase from Bacillus species and its successful expression in E. coli.
Bacillus↗
Procaine isothiocyanate: an irreversible inhibitor of the specific binding of [3H]batrachotoxinin-A benzoate to sodium channels.
[3H]Batrachotoxinin-A benzoate ([3H]BTX-B) binds with high affinity to sites on voltage sensitive sodium channels in synaptoneurosomes from guinea pig cerebral cortex. Local anesthetics competitively antagonize the binding of [3H]BTX-B. An irreversible local anesthetic, procaine isothiocyanate (PRIT) and a tritiated derivative [( 3H]PRIT) have been prepared. PRIT inhibits the binding of [3H]BTX-B in a noncompetitive, irreversible manner (apparent Ki = 13 microM) whereas the parent compound, procaine, inhibits in a competitive, reversible manner (Ki = 40 microM). The dissociation rate of [3H]BTX-B from sites on the sodium channel is greatly accelerated in a concentration dependent manner in the presence of PRIT. A 50% increase in the dissociation rate of [3H]BTX-B is achieved in the presence of 0.98 microM PRIT. [3H]PRIT binds irreversibly to three proteins in synaptoneurosomes with apparent molecular weights of 20, 42, and 68 kDa. Protection studies with procaine and other local anesthetics suggest that only the 68 kDa species was related to local anesthetic binding.
Anesthetics, Local↗
The potent opioid agonist, (+)-cis-3-methylfentanyl binds pseudoirreversibly to the opioid receptor complex in vitro and in vivo: evidence for a novel mechanism of action.
The present study demonstrates that pretreatment of rat brain membranes with (+)-cis-3-methylfentanyl [(+)-cis-MF], followed by extensive washing of the membranes, produces a wash-resistant decrease in the binding of [3H]-[D-ala2,D-leu5]enkephalin to the d binding site of the opioid receptor complex (delta cx binding site). Intravenous administration of (+)-cis-MF (50 micrograms/kg) to rats produced a pronounced catalepsy and also produced a wash-resistant masking of delta cx and mu binding sites in membranes prepared 120 min post-injection. Administration of 1 mg/kg i.v. of the opioid antagonist, 6-desoxy-6 beta-fluoronaltrexone (cycloFOXY), 100 min after the injection of (+)-cis-MF (20 min prior to the preparation of membranes) completely reversed the catatonia and restored masked delta cx binding sites to control levels. This was not observed with (+)-cycloFOXY. The implications of these and other findings for the mechanism of action of (+)-cis-MF and models of the opioid receptors are discussed.
Animals↗
Wash-resistant inhibition of phencyclidine- and haloperidol-sensitive sigma receptor sites in guinea pig brain by putative affinity ligands: determination of selectivity.
Several putative affinity ligands, based on the structures of phencyclidine etoxadrol, 5-methyl-10,11-dihydro-5H-dibenzo[a,d] cycloheptene-5,10-imine (MK801) and 1,3-di-(2-methylphenyl)guanidine (DTG) were evaluated in vitro for their ability to produce a wash-resistant inhibition of phencyclidine and sigma receptor sites in homogenates of the brain of the guinea pig. All the phencyclidine-based ligands, including 1-[1-(3-isothiocyanatophenyl)cyclohexyl]piperidine (Metaphit) and (+/-)-N-(2-isothiocyanatoethyl) MK801 [(+/-)-MK801-NCS], produced a wash-resistant inhibition of binding sites for phencyclidine, labelled by [3H]-1-[1-(2-thienyl)cyclohexyl]piperidine ([3H]TCP) and sigma binding sites, labelled by [3H]DTG. The DTG-based ligands, 1-(4-isothiocyanato-2-methylphenyl)-3-(2-methylphenyl)guanidine (DIGIT) and 1-(4-[2-(2-isothiocyanatoethoxy)ethoxy]-2-methyl-phenyl)-3-(2- methylphenyl)guanidine (DIGIE), produced a wash-resistant inhibition of sigma sites, at concentrations as small as 1 microM and also inhibited binding sites for phencyclidine at larger concentrations (100 microM). Both 1-(3-isothiocyanatophenyl)-1-ethyl-4-(2-piperidyl)-1,3-dioxolane (ETOX-NCS) and 1-[1-(3-bromoacetyloxyphenyl)cyclohexyl]-1,2,3,6-tetrahydropyri din e (Bromoacetyl-PCP) were the most potent and selective inhibitors of the binding of [3H]TCP, while DIGIT was the most selective inhibitor of the binding of [3H]DTG. Future studies will examine the selectivity of these agents in vivo after intracerebroventricular administration.
Affinity Labels↗
Recurrent benign esophageal strictures treated with self-bougienage: report of seven cases.
Self-bougienage has rarely been used in the treatment of recurrent benign esophageal strictures. Nonetheless, it has proved to be a useful alternative technique in carefully selected patients. Herein we report our experience with seven symptomatic patients who were treated with self-bougienage for recurrent benign esophageal strictures. These seven patients (six men and one woman; mean age, 66.9 years) had had dysphagia for a mean of 37.9 months and had undergone a mean of 6.7 endoscopic dilations before their involvement in a self-bougienage program. During a mean follow-up period of 36.3 months (range, 10 to 78 months) after initiation of self-bougienage treatment, all seven patients became asymptomatic and remained free of dysphagia. No complications occurred in any patient, and no further endoscopic dilations were necessary. Our results suggest that self-bougienage can provide long-term symptomatic relief in selected patients with recurrent benign esophageal strictures.
Aged↗
Gastroparesis after a presumed viral illness: clinical and laboratory features and natural history.
Gastroparesis after a viral infection has rarely been reported. In this article, we describe the clinical features and long-term outcome of 7 patients who had gastroparesis after a presumed viral illness and who were identified in a retrospective review of 103 consecutive cases of gastroparesis seen at our institution from 1977 through 1988. The three male and four female patients with gastroparesis after a suspected viral illness were young (mean age, 26.9 years) and healthy before the onset of the illness, which manifested as low-grade fever, fatigue, and myalgia with or without diarrhea. A mean of 4.5 days after spontaneous resolution of the viral illness, persistent nausea, vomiting, and epigastric pain developed in these patients. In all seven patients, delayed emptying of the gastric contents was substantiated. Autonomic neuropathy was found in all three patients who underwent autonomic function tests. During a mean follow-up of 32.3 months, five of the seven patients had complete resolution of gastroparetic symptoms, and the other two had considerable improvement of their condition. We conclude that postviral gastroparesis is uncommon, is frequently associated with autonomic dysfunction, and is associated with an apparently excellent prognosis.
Acute Disease↗
Anti-opioid receptor antibody recognition of a binding site on brain and leukocyte opioid receptors.
Opioid receptors reportedly exist on neuronal tissue of central and peripheral origin as well as on cells of the immune system. Previously, an opioid receptor has been purified from the neuroblastoma x glioma hybrid cell line, NG108-15 cells. In an effort to compare these results with opioid receptors isolated from primary neuronal tissue, we employed a methodology based on the molecular recognition theory to develop a monoclonal antibody which was used to isolate and biochemically characterize murine brain opioid receptors. We herein report the purification of an opioid receptor from mouse brain with a molecular weight of 65,000 daltons (range was 62-70 kD under reducing conditions) using a monoclonal antibody to an (the) opioid receptor. In situ labeling experiments with the delta-class selective opioid receptor affinity ligand, cis-(+)-3-methylfentanylisothiocyanate (SUPERFIT) of brain membrane confirmed these observations. Moreover, SUPERFIT, when coupled to the binding site, could block the recognition of the receptor by the monoclonal antibody. However, the selective, mu-class opioid receptor affinity reagent, 2-(p-ethoxybenzyl)-1-N,N-diethylaminoethyl-5-isothiocyanatobenz imidazole was ineffective at masking the binding site from recognition by the monoclonal antibody. Likewise, opioid-like receptors were purified from murine leukocytes which migrated at a molecular weight of 58,000 daltons under nonreducing conditions and 70,000 daltons under reducing conditions. In addition, immunoaffinity-purified receptor is shown to specifically bind the delta-class-selective opioid ligand, cis-(+)-3-methylfentanylisothiocyanate as well as the endogenous opioid peptides, beta-endorphin and [Met]-enkephalin.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Pulmonary diffuse alveolar septal amyloidosis--diagnosed by transbronchial lung biopsy.
Diffuse alveolar septal involvement is a rare form of pulmonary amyloidosis. Antemortem diagnosis is unusual, and most of the reported cases were diagnosed at autopsy. It has recently been reported that transbronchial lung biopsy via a flexible fiberoptic bronchoscope was a relatively safe method to confirm diffuse alveolar septal amyloidosis. We report a case of pulmonary diffuse alveolar septal amyloidosis confirmed by transbronchial lung biopsy. The patient's chief complaints were dyspnea on exertion and epigastric pain aggravated over a one-year period, while a chest roentgenogram showed bilateral diffuse interstitial infiltration. This case also showed nephrotic syndrome, cardiac arrhythmia, congestive heart failure, a tingling sensation in both hands and multiple nodules in the gastrointestinal tracts, suggesting involvement of the kidney, heart, peripheral nerves and gastrointestinal tracts. We propose that when diffuse interstitial lung disease is present with systemic signs such as nephrotic syndrome or cardiac arrhythmia, amyloidosis should be considered as a possible diagnosis. Also, transbronchial lung biopsy may be a useful confirmative diagnostic tool.
Amyloidosis↗
[3H]1,3-Di(2-tolyl)guanidine labels two high affinity binding sites in guinea pig brain: evidence for allosteric regulation by calcium channel blockers and sigma ligands.
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Animals↗
Pseudoirreversible binding of opiates to opioid receptor subtypes in rat brain: a quantitative study.
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Animals↗
Acute gastroparesis associated with thyrotoxicosis.
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Adult↗
Thermodynamic and spectroscopic characteristics of the cytochrome bc1 complex. Role of quinone in the behavior of cytochrome b562.
Cytochrome b562 does not behave as a single independent thermodynamic component in preparations of purified quinol cytochrome c reductase. This effect is much more pronounced in quinone sufficient preparations; in such preparations, the epr spectrum of the cytochrome is Eh sensitive, with a peak shift from g = 3.42 to 3.48 occurring as the potential is lowered from 100 mV to 0 mV. The peak shift is dependent on the presence of quinone and can be restored to quinone-depleted preparations by supplementation with ubiquinol 2 if phospholipid depletion is not too severe. The results suggest that cytochrome b562 is strongly interacting with the Qc quinone binding site.
Binding Sites↗
Electron transfer between liposomal cytochrome c1 and cytochrome c: catalytic implications of electrostatic potentials.
Kinetics measurements of the electron transfer between ferricytochrome c and liposomal ferrocytochrome c1 (with and without the hinge protein) were performed. The observed rate constants(kobs) of electron transfer between liposomal ferrocytochrome c1 and ferricytochrome c at different ionic strengths were measured in cacodylate buffer, pH 7.4, at 2 C. The effect of ionic strength on the rate constant(kobs) of electron transfer between liposomal cytochrome c1 and cytochrome c is far greater than that in the solution kinetics (Kim, C.H., Balny, C. and King, T.E. (1987) J. Biol. Chem. 262, 8103-8108). The result demonstrates that the membrane bound cytochrome c1 creates a polyelectrolytic microenvironment which appears to be involved in the control of electron transfer and can be modulated by the ionic strength. The involvement of electrostatic potentials in the electron transfer between the membrane bound cytochrome c1 and cytochrome c is discussed in accord with the experimental results and a polyelectrolyte theory.
Cytochrome c Group↗
Effect of the hinge protein on the heme iron site of cytochrome c1.
X-ray absorption spectroscopic (XAS) studies on cytochrome C1 from beef heart mitochondria were conducted to identify the effect of the hinge protein [Kim, C.H., & King, T.E. (1983) J. Biol. Chem. 258, 13543-13551] on the structure of the heme site in cytochrome c1. A comparison of XAS data of highly purified "one-band" and "two-band" cytochrome c1 [Kim, C.H., & King, T.E. (1987) Biochemistry 26, 1955-1961] demonstrates that the hinge protein exerts a rather pronounced effect on the heme environment of the cytochrome c1: a conformational change occurs within a radius of approximately 5 A from the heme iron in cytochrome c1 when the hinge protein is bound to cytochrome c1. This result may be correlated with the previous observations that the structure and reactivity of cytochrome c1 are affected by the hinge protein [Kim, C.H., & King, T.E. (1987) Biochemistry 26, 1955-1961; Kim, C.H., Balny, C., & King, T.E. (1987) J. Biol. Chem. 262, 8103-8108].
Animals↗