Biomedical subjects

I Watanabe

Publications and source records attributed to I Watanabe.

At least 91 records · Page 5Linked to original sources

PubMed1999

Advanced gallbladder carcinoma with liver metastasis showing a favorable response after intra-arterial infusion chemotherapy: report of a case.

A 66-year-old woman visited a local clinic due to general fatigue. After undergoing examinations at our hospital, the patient was diagnosed to have advanced gallbladder carcinoma with metastasis to the liver and cholecystolithiasis, After receiving a cholecystectomy, we performed chemotherapy by the intra-arterial infusion of low-dose cisplatin and 5-fluorouracil via hepatic artery, and observed its marked effect on the tumors by computed tomography. The level of carcinoembryonic antigen decreased from 114.5 ng/ml to 0.8 ng/mg, and carbohydrate antigen 125 decreased from 1 094 U/ml to 75 U/ml. The present result suggests that this therapy may be useful for some selected patients with an advanced gallbladder carcinoma.

Adenocarcinoma↗

PubMed1999

Effect of sandblasting and silicoating on bond strength of polymer-glass composite to cast titanium.

STATEMENT OF PROBLEM: There is little information regarding the mechanical and chemical retention of polymer-glass composite to cast titanium. PURPOSE: This study examined whether sandblasting in conjunction with silicoating improves the bond strength of the polymer-glass composite to cast titanium. MATERIALS AND METHODS: Disk patterns (10 mm in diameter, 2.5 mm thick) were cast with commercially pure titanium (CP Ti) and Type IV gold alloy. Three pretreatments were applied: 50 microm Al(2)O(3) sandblasting (50 SB), 250 microm Al(2)O(3) sandblasting (250 SB), and 600-grit SiC paper polishing (600 SiC). After surface preparation, the Siloc system (silicoating) was applied on the disks. The 50 SB specimens without Siloc system were also prepared as controls. Then sticky tape with a circular hole (4.76 mm diameter) was placed onto the disk to define the bonding area. Artglass (polymer-glass) opaque, dentin, and enamel composites were applied using Teflon matrices and then light-polymerized. Shear bond strength (n = 8) was determined at a crosshead speed of 5 mm/min. Results were analyzed statistically with 2-way ANOVA and the Tukey-Kramer test (alpha=.05). RESULTS: The Siloc system significantly (P <.05) improved the mean shear bond strength of Artglass to both metals in the 50 SB specimens. Statistical differences (P <.05) in shear bond strength were found among surface treatments for the silicoated CP Ti specimens, in which 250 SB specimens yielded the greatest bond strength. The Type IV specimens treated with Siloc system showed no significant differences in shear bond strength between the 50 SB and the 250 SB specimens. CONCLUSION: Sandblasting with coarser alumina particles in conjunction with silicoating significantly enhanced bond strength of polymer-glass composite to cast titanium.

Analysis of Variance↗

PubMed1999

Effect of surface contamination on adhesive bonding of cast pure titanium and Ti-6Al-4V alloy.

STATEMENT OF PROBLEM: There is little information regarding bond strengths of resin cements to cast titanium surfaces contaminated by investment material. PURPOSE: This study examined the effect of surface contamination on the shear bond strength of resin cements to cast titanium and Ti-6Al-4V alloy. MATERIAL AND METHODS: Two types of disks were cast from commercially pure titanium (CP-Ti) and Ti-6Al-4V alloy ingots using an argon-arc pressure casting unit and a phosphate-bonded Al2 O3 /LiAlSiO6 investment. After casting, disks were subjected to 3 surface treatments: (1) cast surface sandblasted (50 microm-sized Al2 O3 ) for 30 seconds; (2) metal surface sanded with silicon-carbide paper (600 grit) after grinding the contaminated cast surface (approximately 200 microm in thickness); and (3) metal surface sandblasted for 30 seconds after treatment 2. Surface structures were examined after each treatment with SEM and optical microscopy. Each type of disk was then bonded with 2 types of luting materials. Bonded specimens were subjected to thermocycling for up to 50,000 cycles, and shear bond strengths were determined after 0 (baseline) and 50,000 thermocycles. Results were statistically analyzed with 3-way ANOVA (P <.05). RESULTS: Microscopic observation of cast CP-Ti and Ti-6Al-4V exhibited noticeable structures on the cast surfaces apparently contaminated with investment material. However, there were no statistical differences (P >.05) in the bond strengths of both cements between contaminated (treatment 1) and uncontaminated surfaces (treatment 3) for both metals at baseline and after 50,000 thermocycles. The bond strength of specimens sanded with silicon-carbide paper (treatment 2) deteriorated dramatically after 50,000 thermocycles. CONCLUSIONS: Contamination of the cast metal surfaces by elements of the investment during casting did not affect bond strengths of the luting materials to CP-Ti and Ti-6Al-4V.

Alloys↗

PubMed1999

Effects of nicardipine-, nitroglycerin-, and prostaglandin E1-induced hypotension on human cerebrovascular carbon dioxide reactivity during propofol-fentanyl anesthesia.

STUDY OBJECTIVE: To investigate the effects of nicardipine-, nitroglycerin-, and prostaglandine E1-induced hypotension on cerebrovascular carbon dioxide (CO2) reactivity over a wide range of arterial CO2 tension (PaCO2) (PaCO2; range 25 to 50 mmHg). DESIGN: Prospective, randomized study. SETTING: Operating room of a university-affiliated hospital. PATIENTS: 36 ASA physical status I and II patients without cerebrovascular disease, hypertension, or diabetes mellitus, undergoing an elective abdominal surgery. INTERVENTIONS: Patients were randomly allocated to one of three groups (nicardipine-, nitroglycerin-, or prostaglandin E1-induced hypotension group; 12 in each group). Anesthesia was induced and maintained with a bolus dose, followed by a continuous infusion of propofol (6.7 +/- 1.5 mg/kg/hr) and fentanyl (1.68 +/- 0.4 micrograms/kg/hr). Deliberate hypotension of mean arterial pressure 55 to 60 mmHg was induced and maintained with a bolus dose, followed by a continuous infusion of nicardipine (6.80 +/- 0.75 micrograms/kg/min), nitroglycerin (3.20 +/- 1.10 micrograms/kg/min), or prostaglandin E1 (0.103 +/- 0.052 microgram/kg/min). MEASUREMENTS AND MAIN RESULTS: Time-averaged mean red blood cell velocity in the right middle cerebral artery (Vmca) at PaCO2 ranging from 25 to 50 mmHg was measured with transcranial Doppler ultrasonography. A minimum of six simultaneous measurements of Vmca and PaCO2 were obtained during baseline and deliberate hypotension in each patient. Absolute slope between Vmca and PaCO2 during baseline and deliberate hypotension was determined individually by linear regression analysis. Absolute slope was treated as the variable, because it yielded a significant close correlation coefficient (r > 0.95; p < 0.05). Comparisons between baseline and deliberate hypotension were made by analysis of variance for repeated measures. Mean absolute slope was significantly reduced from 1.88 +/- 0.57 cm/sec/mmHg (mean +/- SD) to 1.21 +/- 0.46 in the nicardipine group (p < 0.05), from 1.75 +/- 0.69 to 1.35 +/- 0.47 in the nitroglycerin group (p < 0.05), and from 1.95 +/- 0.89 to 1.33 +/- 0.70 (p < 0.05) in the prostaglandin E1 group, respectively. CONCLUSION: Nicardipine-, nitroglycerin-, and prostaglandin E1-induced hypotension attenuate the human cerebrovascular CO2 reactivity during propofol-fentanyl anesthesia.

Adult↗

PubMed1999

Antiplatelet activity of soy sauce as functional seasoning.

In seeking the functionality of foodstuffs applicable to medicine, soy sauce was found to show antiplatelet activity. Therefore, the active components in soy sauce were purified, structurally identified, and studied for their inhibitory effects on the aggregation of human platelets. Aqueous 2-fold diluents of soy sauce inhibited platelet aggregation induced by collagen and epinephrine depending on the dilution factor. Since a basic extract with diethyl ether completely inhibited collagen-induced aggregation, it was subjected to serial extractions and multistep HPLC fractionations for purifying antiplatelet components. The finally obtained isolates were identified as 1-methyl-1,2,3,4-tetrahydro-beta-carboline and 1-methyl-beta-carboline on the basis of EI-MS, (1)H NMR, diode array, and fluorescence spectra. Their spectral data and chromatographic behaviors were the same as those of synthetic ones. 1-Methyl-1,2,3, 4-tetrahydro-beta-carboline showed mean concentrations (n = 5-6) of 4.6, 4.2, 28.6, 11.6, and 65.8 microgram/mL to produce 50% inhibition of the maximal aggregation response induced by epinephrine, platelet-activating factor, collagen, adenosine 5'-diphosphate, and thrombin, respectively. Its inhibitory effect was much greater than that of 1-methyl-beta-carboline on platelet aggregation by all the tested inducers. The quantitative HPLC analysis revealed that the significant amounts of both antiplatelet compounds were uniformly contained in commercially available soy sauce. From these results, soy sauce may be referred to as functional seasoning containing alkaloidal components with the potent preventive effect on thrombus formation.

Carbolines↗

PubMed1999

Influence of segmental and extra-segmental conditioning, stimuli on cortical potentials evoked by painful electrical stimulation.

This study evaluated the effects of two different types of segmental/extra-segmental conditioning stimuli (tonic muscle pain and non-painful vibration) on the subjective experience (perceived pain intensity) and on the cortical evoked potentials to standardized test stimuli (cutaneous electrical stimuli). Twelve subjects participated in two separate sessions to investigate the effects of tonic muscle pain or cutaneous vibration on experimental test stimuli. The experimental protocol contained a baseline registration (test stimuli only), a registration with the test stimuli in combination with the conditioning stimuli, followed by a registration with the test stimuli only. In addition, the effects of the conditioning stimuli were examined at two anatomically separated locations (segmental and extra-segmental). Compared with the test stimulus alone, the perceived pain intensity and peak-to-peak amplitudes of the evoked potentials were unchanged in the presence of non-painful conditioning stimuli at either location. In contrast, a significant decrease of the perceived pain intensity and peak-to-peak amplitudes was found in the presence of painful conditioning stimuli at the extra-segmental sites. Moreover, the topographic maps of the 32-channel recordings suggested that the distribution of the scalp evoked potentials was almost symmetrical around the vertex Cz in the baseline registration. The evoked potentials were generally decreased during hypertonic saline infusion at the extra-segmental sites, but the distribution of the topographic maps did not appear to change. Vibration has previously been shown to inhibit pain, but in the present study the perceived intensity of phasic painful electrical stimuli was unchanged. The reduced perceived pain intensity and the smaller peak-to-peak amplitude of the evoked potential in the presence of extra-segmental conditioning pain are in accordance with the concept of diffuse noxious inhibitory control.

Adult↗

PubMed1999

The effects of ketamine and propofol on neuronal nicotinic acetylcholine receptors and P2x purinoceptors in PC12 cells.

UNLABELLED: We studied the effects of ketamine and propofol on two ligand-gated ion channels mediating fast synaptic transmission through sympathetic ganglia, neuronal nicotinic acetylcholine receptors (nAchRs), and P2X purinoceptors in a rat pheochromocytoma cell line PC12 using whole cell voltage clamp recording. Ketamine and propofol similarly inhibited the nicotine-induced inward current reversibly and dose-dependently at the membrane potential of -60 mV but had no effects on the adenosine triphosphate-induced current. Both anesthetics accelerated the current decay during agonist application, resulting in greater inhibition on the steady current than the peak current. The 50% inhibition concentration values for the steady current were lower than the clinically relevant concentrations for ketamine (2.8+/-0.6 microM) and higher than those for propofol (5.4+/-0.6 microM). Both anesthetics induced an addition of the fast component to the decay phase and an acceleration of the slow component, which suggests an open channel blockade or an enhancement of desensitization as a mechanism. The effects on closed channels seemed to be small because preincubation with the anesthetics did not significantly augment the block. Inhibition was voltage-independent at membrane potentials between -20 and -70 mV and was consistent with a noncompetitive block. Inhibition of the neuronal nAchR-mediated current may lead to the suppression of synaptic transmission in sympathetic ganglia by ketamine, but not by propofol, at the clinically relevant concentrations. However, these results are not consistent with changes in sympathetic nerve activities reported for animals or humans anesthetized with ketamine or propofol, which suggests effects from other systems, such as the central nervous system in vivo. IMPLICATIONS: Ketamine (at smaller than clinically relevant concentrations) and propofol (at larger than clinically relevant concentrations) inhibited neuronal nicotinic acetylcholine receptor-mediated current in PC12 cells, which possess the receptors that resemble those in postganglionic sympathetic neurons. These findings are not consistent with in vivo experiments, which suggests that effects from other systems, such as the central nervous system, are of importance.

Animals↗

PubMed1999

Depressant and convulsant barbiturates both inhibit neuronal nicotinic acetylcholine receptors.

UNLABELLED: Neuronal nicotinic acetylcholine receptors (neuronal nAchRs) are sensitive to many anesthetics, including barbiturates, which suggests that these receptors are potential sites for anesthetic action. Subtle changes in molecular structures of the anesthetic barbiturates can produce compounds with potent convulsant activity. Whereas R(-) isomer of 1-methyl-5-phenyl-5-propyl barbituric acid (MPPB) exerts anesthetic action, S(+)MPPB exhibits pure excitatory effects, including convulsion. 5-(2-cyclohexilidene-ethyl)-5-ethyl barbituric acid is another example of a convulsant barbiturate. We compared the effects of depressant and convulsant barbiturates on the neuronal nAchR-mediated current to determine whether inhibition of neuronal nAchRs contributes to the anesthetic action of barbiturates. Whole cell nicotine-induced currents were recorded in PC12 derived from rat pheochromocytoma, using the conventional whole cell patch clamp technique in the presence and absence of barbiturates. Both depressant and convulsant barbiturates inhibited the nicotine-induced inward current reversibly and in a dose-dependent manner when co-applied with nicotine. All barbiturates accelerated the current decay. There was no significant difference between the concentrations for 50% inhibition for MPPB isomers. There was no correlation between inhibition of ganglionic nAchRs and anesthetic effects of the barbiturates. These results strongly oppose the idea that inhibition of neuronal nAchRs contributes to the anesthetic action of barbiturates. IMPLICATIONS: We found that both convulsant and depressant barbiturates inhibit the current mediated through ganglionic nicotinic acetylcholine receptors in PC12 cells. This finding suggests that the inhibition of neuronal nicotinic acetylcholine receptors does not contribute to the anesthetic action of barbiturates.

Animals↗

PubMed1999

Comparison of the effects of convulsant and depressant barbiturate stereoisomers on AMPA-type glutamate receptors.

BACKGROUND: Alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type glutamate receptors mediate fast excitatory synaptic transmission in the central nervous system. Although barbiturates have been shown to suppress the AMPA receptor-mediated responses, it is unclear whether this effect contributes to the anesthetic action of barbiturates. The authors compared the effects of depressant [R(-)] and convulsant [S(+)] stereoisomers of 1-methyl-5-phenyl-5-propyl barbituric acid (MPPB) on the AMPA and gamma-aminobutyric acid type A (GABA(A)) receptor-mediated currents to determine if the inhibitory effects on AMPA receptors correlate to the in vivo effects of the isomers. METHOD: The authors measured whole-cell currents in the rat cultured cortical neuron at holding potential of -60 mV. Kainate 500 microM was applied as the agonist for AMPA receptors. Thiopental (3-300 microM), R(-)-MPPB or S(+)-MPPB (100-1,000 microM) was coapplied with kainate under the condition in which the GABA(A) receptor-mediated current was blocked. Effects of MPPB isomers on the current elicited by GABA 1 microM were studied in the separate experiments. RESULTS: Thiopental inhibited the kainate-induced current reversibly and in a dose-dependent manner, with a concentration for 50% inhibition of 49.3 microM. Both R(-)-MPPB and S(+)-MPPB inhibited the kainate-induced current with a little stereoselectivity. R(-)-MPPB was slightly but significantly more potent than S(+)-MPPB. In contrast, R(-)-MPPB enhanced but S(+)-MPPB reduced the GABA-induced current. CONCLUSIONS: Both convulsant and depressant stereoisomers of the barbiturate inhibited the AMPA receptor-mediated current despite of their opposite effects on the central nervous system in vivo. Although thiopental exhibited a considerable inhibition of AMPA receptors, the results suggest that the inhibition of AMPA receptors contributes little to the hypnotic action of the barbiturates.

Animals↗

PubMed1999

Effects of naloxone and morphine on acute hypoxic survival in mice.

OBJECTIVE: To investigate a role of the opiate system during acute hypoxic hypoxia, the effects of naloxone and morphine on hypoxic survival rate were investigated in awake adult mice. DESIGN: Prospective, randomized, animal trial. SETTING: University research laboratory. SUBJECTS: Male dd-Y mice (n = 864 in experiment I, n = 144 in experiment II, n = 30 in experiment III). INTERVENTIONS: The animals were placed in an airtight plastic chamber into which a continuous flow of 8 L/min 5% oxygen-95% nitrogen was passed. MEASUREMENTS AND MAIN RESULTS: One and 5 mg/kg naloxone had no significant effect on the survival rate of mice subjected to acute hypoxic hypoxia, whereas 10 mg/kg naloxone decreased the survival rate. On the other hand, 2 and 5 mg/kg morphine was shown to have a protective action against acute hypoxic hypoxia. The protective effects of 5 mg/kg morphine against hypoxia was even antagonized by 5 mg/kg naloxone, which did not itself show any significant effect on the survival rate. The oxygen consumption in the morphine-treated (5 mg/kg) mice was significantly (p < .05) lower (87.0% +/- 4.6%; mean +/- SE) than that in the saline-treated animals. CONCLUSIONS: The present study suggests that the endogenous opiate system does not play a significant role on the pathophysiology caused by acute hypoxic hypoxia and that the improved survival of the hypoxic animals by morphine is at least partly attributable to its depressant effect on oxygen consumption.

Analgesics, Opioid↗

PubMed1999

Crystallization and preliminary X-ray diffraction analysis of cytochrome P450sca-2 from Streptomyces carbophilus involved in production of pravastatin sodium, a tissue-selective inhibitor of HMG-CoA reductase.

Cytochrome P450sca-2 from Streptomyces carbophilus catalyzes the hydroxylation of ML-236B sodium salt to pravastatin sodium, a tissue-selective inhibitor of 3-hydroxy-3-methylglutaryl-coenzymeA (HMG-CoA) reductase. HMG-CoA reductase is a key enzyme in cholesterol biosynthesis. Crystals of the protein were obtained by the vapour-diffusion method, using ammonium sulfate as a precipitant. The crystals belong to the trigonal space group P3121 (or its enantiomorph, P3221) with unit-cell dimensions a = 103.5, c = 79.8 A. Assuming the presence of one molecule in the asymmetric unit, the calculated value of Vm is 2.68 A3 Da-1. A native data set was collected to a resolution of 2.2 A.

Crystallization↗

PubMed1999

Detection of apoptotic cells in human colorectal cancer by two different in situ methods: antibody against single-stranded DNA and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) methods.

We comparatively investigated the extent of apoptotic cell loss in human colorectal cancers evaluated by two methods, namely the conventional terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP)-biotin nick end-labeling (TUNEL) method and immunohistochemistry for single-stranded (ss) DNA. The apoptotic index (AI) obtained with the TUNEL method was higher than that shown by the immunohistochemistry for ssDNA. However, a significant correlation in AIs evaluated by these methods was found. The AIs obtained by both methods were significantly higher in the advanced cancers than in the early cancers. Cellular proliferation activity was assessed in terms of positivity rate (PR) for expression of proliferating cell nuclear antigen (PCNA). The PR of advanced cancers was significantly higher than that of early cancers. The present results indicate that immunohistochemistry for ssDNA is useful (as is the TUNEL method) for evaluation of apoptotic tumor cells in colorectal carcinomas. In addition, it was confirmed that there is a remarkable increase of not only proliferation activity, but also tumor cell apoptosis in the process of progression of colon cancer from early to advanced stages of the disease.

Adult↗

PubMed1999

Effect of clarithromycin regimen for Mycobacterium avium complex pulmonary disease.

We have investigated the efficacy of a clarithromycin-containing four-drug regimen for Mycobacterium avium complex (MAC) pulmonary disease in 46 patients without acquired immunodeficiency syndrome (AIDS). The patients were 14 males and 32 females with a mean age of 60.9 +/- 11.5 yr. Patients received 10 mg/kg/d of clarithromycin plus ethambutol, rifampin, and initial kanamycin and subsequent quinolone for 24 mo. Seven patients (15.2%) were dropped in the first 6 mo. Among 39 patients who received more than 6 mo of therapy, 28 patients (71.8%) converted their sputa to negative: 26 of 31 patients (83.9%) infected with clarithromycin-susceptible strains and two of eight patients (25.0%) with resistant or intermediate strains. The timing of sputum conversion was 3.6 +/- 1.9 mo, with a range of 2 to 9 mo. The conversion rate was significantly lower in patients who were infected with clarithromycin-resistant or intermediate strains, who had had prior therapy (55.0% versus 89.5%), or who were acid-fast bacilli (AFB) smear-positive at entry (60.7% versus 100%). The age and sex of patients, the species of pathogen (M. avium or M. intracellulare), type and extent of the disease, and the use of kanamycin did not significantly affect the conversion rate. Although the regimen was efficacious for newly treated patients, frequent adverse reactions and a low conversion rate of sputum in retreated patients are problems that remain to be solved.

Adult↗

PubMed1999

Nematocidal activity of picrodendrins against a species of diplogastridae.

To develop parasiticides, the nematocidal activity of 22 picrotoxane terpenoids, picrodendrins isolated from the Euphorbiaceae plant Picrodendron baccatum (L.) KLUG et URBAN, was measured using a species of Diplogastridae (Nematoda). Picrodendrin P displayed the most potent nematocidal activity with a minimum lethal concentration (MLC) value of 4.4 x 10(-3) M. The nematocidal activity of picrodendrin P was 9-fold more potent than that of kainic acid (4.0 x 10(-2) M) and santonin (4.0 x 10(-2) M) and 6-fold more potent than that of diethylcarbamazine citrate (3.0 x 10(-2) M). Thus, picrodendrin P may eventually be used as a leading parasiticide. In light of the relationship between the structure of picrodendrins and their nematocidal activities, potent nematocidal activity was found to require the following elements within the picrotoxane skeleton: the gamma-lactone that bridges C-3 and C-5, the epoxide group that bridges between C-6 and C-8, a cis-OCH3 group and a trans-CH2OH group related to carbonyl at alpha-methylene-gamma-lactone ring (C-18), and the absence of 4- and 8-hydroxyl groups. These results are the first demonstration of nematocidal activity for these terpenes and thus are important in furthering our understanding.

Animals↗

PubMed1999

Radiofrequency catheter ablation of coexistent atrioventricular reciprocating tachycardia and left ventricular tachycardia originating in the left anterior fascicle.

Coexistence of supraventricular tachycardia and ventricular tachycardia is rare. A patient with no structural heart disease and wide QRS complex tachycardia with a right bundle block configuration and right-axis deviation underwent electrophysiological examination. A concealed left atrioventricular pathway (AP) was found, and atrioventricular reciprocating tachycardia (AVRT) and left ventricular tachycardia (VT) originating in or close to the anterior fascicle of the left ventricle were both induced. Radiofrequency (RF) catheter ablation of the concealed left AP was successfully performed. Ten months later, VT recurred and was successfully ablated using a local Purkinje potential as a guide. Coexistent AVRT and idiopathic VT originating from within or near the left anterior fascicle were successfully ablated.

Adult↗

PubMed1999

Effect of insulin resistance on the endothelial vasomotor function of the coronary artery of nondiabetic patients.

Attention has been paid to the relationship between insulin resistance and coronary artery disease. The present study investigated the relationship between insulin resistance and the endothelial vasomotor function of the coronary artery of nondiabetic patients with chest pain and a positive exercise tolerance test. Twenty-five nondiabetic patients with chest pain were included. Patients with a steady state plasma glucose (SSPG) level of greater than or equal to 135 mg/dl were placed in the insulin resistant (IR) group, and those with a SSPG level less than 135 mg/dl were placed in the noninsulin resistant (NIR) group. The effect of acetylcholine, papaverine, and isosorbide dinitrate on the vasomotor response of the coronary endothelium was studied. The percent change in diameter of the coronary artery after injection of acetylcholine (20 microg ml(-1) min(-1)) was 84+/-17% in the IR group, and 109+/-18% in the NIR group. The difference in the degree of the vasodilative response is statistically significant (p<0.01). The percent change in coronary flow velocity after injection of acetylcholine (20 microg ml(-1) min(-1)) in the IR group was 120+/-67%, whereas that in the NIR group was 256+/-58%; the increase in coronary artery flow velocity of the IR group was significantly smaller than that of the NIR group (p<0.01). Nondiabetic patients with insulin resistance have endothelial vasomotor dysfunction, which raises an important question as to whether nondiabetic patients with insulin resistance should be treated to prevent the development of coronary heart disease.

Acetylcholine↗

PubMed1999

Molecular cloning and expression of the gene encoding a phospholipase A1 from Aspergillus oryzae.

Phospholipase A1 (PLA1) is a hydrolytic enzyme that catalyzes removal of the acyl group from position 1 of lecithin to form lysolecithin. The genomic DNA and cDNA encoding PLA1 from Aspergillus oryzae were cloned with the mixed deoxyribonucleotide-primed polymerase chain reaction. The PLA1 gene is composed of 1,056 bp and has four exons and three short introns (63, 54, and 51 bp). The deduced amino acid sequence of PLA1 contained the N-terminal sequence of the mature PLA1 analyzed by Edman degradation. PLA1 cDNA has an open reading frame of 885 bp encoding the PLA1 precursor of 295 amino acid residues. The mature PLA1 is composed of 269 amino acid residues, and a prepro-sequence of 26 amino acid residues is at the N-terminal region of the PLA1 precursor. PLA1 has two possible N-glycosylation sites (Asn27 and Asn55). PLA1 has a consensus pentapeptide (-Gly-His-Ser-Xaa-Gly-), which is conserved in lipases. The amino acid sequence of PLA1 showed 47% identity with that of mono- and diacylglycerol lipase from Penicillium camembertii. The PLA1 cDNA was expressed in Saccharomyces cerevisiae KS58-2D, indicating the cloned gene to be functional.

Amino Acid Sequence↗

PubMed1999

Morphometry and acetylcholinesterase activity of the myenteric neurons of the mouse colon in the chronic phase of experimental Trypanosoma cruzi infection.

The myenteric plexus of the proximal colon, midcolon, and distal colon was studied in mice chronically infected with the Y strain of Trypanosoma cruzi by means of histochemical methods for NADH-diaphorase and acetylcholinesterase (AChE) on whole mount preparations. Ganglia of infected mice displayed an irregular distribution, with neurons severely altered in form and were found side by side with slightly degenerated or morphologically normal ones. Significant reductions of at least 36% in the numbers of neurons were recorded in all regions of the colons of infected animals, especially in the distal colon where the neuron number decreased by more than 44%. Measurements of neuron size suggest that the neuronal destruction caused by T. cruzi affected the medium and large neurons. The small neurons apparently were not affected by the infection. The histochemical demonstration of AChE by the direct coloring copper ferrocyanide method showed that in the control animals, most of the neurons of the plexus displayed AChE activity in the cytoplasm although the neurons showed different reaction intensities. The AChE activity was also present, but at a lower intensity, in the myenteric plexus of the colons of infected animals. These results suggest that the T. cruzi infection affects some categories of neurons and implies that some particular enteric neurotransmitter systems could be affected and the potency of their action upon intestinal function consequently reduced.

Acetylcholinesterase↗