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Abstract
A sedentary lifestyle may be a risk for hypertension, according to the results of both cross sectional and longitudinal studies. However, exercise may reverse the adverse effects of lack of activity. Many controlled studies have shown that exercise lowers systolic/diastolic blood pressure by at least 10/5 mmHg. Exercise not only improves blood pressure, but also attenuates other risk factors for cardiovascular complications. Dynamic isotonic exercise (e.g., weight lifting). Milder (e.g., brisk walking for 30-60 minutes/day) rather than moderate to severe exercise (e.g., running) is also recommended because of similar effectiveness and better compliance. The underlying mechanism of action of exercise on blood pressure seems to be multifactorial involving a decrease in pressor factors such as plasma norepinephrine, the serum Na/K ratio, endogenous ouabain-like substance and erythrocyte mean corpuscular volume, as well as an increase in depressor factors such as plasma prostaglandin E, serum taurine and urinary dopamine excretion.
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Etsuda H, Mizuno K, Kato R, Arakawa K, Miyamoto A, Nozaki Y, Nakao S, Ohmura H, Okamoto Y, Uehata A. [Adult case of aortopulmonary window with aortic regurgitation: a case report]. KOKYU TO JUNKAN. RESPIRATION & CIRCULATION 1993; 41:1113-5. [PMID: 8256054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A 45-year-old woman was admitted to our hospital because of the evaluation of heart murmur. Her height was 152 cm and body weight was 46 kg. The physical examination showed a grade 4 continuous murmur widely audible on the anterior chest wall. The chest X-ray film was normal. The electrocardiogram showed premature ventricular contractions and left ventricular (LV) hypertrophy. The two dimensional echocardiogram demonstrated the presence of moderate aortic regurgitation (AR), however, aortopulmonary window could not be detected. The aortic valve showed neither atherosclerotic nor rheumatic changes. At cardiac catheterization, pulmonary artery (PA) pressure was 20/11 mmHg and aortic pressure was 133/60 mmHg, and a step-up of O2 saturation between right ventricule and pulmonary artery (PA) was demonstrated. The aortography revealed an aortopulmonary window between the proximal ascending aorta and the main PA, and grade 2 AR. The pulmonary to systemic flow ratio averaged 1.5:1. The coronary artery and the LV wall motion was normal. Aortopulmonary window is a very rare anomaly and often requires operation in childhood because of its large left-to-right shunt in most cases. Neither an asymptomatic adult case with this anomaly nor a case with AR has not been reported so far.
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328
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Yamakawa-Kobayashi K, Kobayashi T, Saku K, Arakawa K, Hamaguchi H. Two novel frameshift mutations associated with the presence of direct repeats of the LDL receptor gene in familial hypercholesterolemia. Hum Genet 1993; 92:331-5. [PMID: 8225312 DOI: 10.1007/bf01247329] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Two novel frameshift mutations were detected in the mutant LDL receptor genes responsible for familial hypercholesterolemia. One was a 5-bp insertion at codon 395 in exon 9, and the other was a one nucleotide deletion at codon 531 in exon 11. Both mutations alter the reading frame and consequently produce a premature stop codon in the region of the mature LDL receptor homologous to the epidermal growth factor (EGF) precursor. With regard to the mechanism responsible for the generation of these frameshift mutations, strand slipped mispairing mediated by short direct repeats is considered to be the most likely. The findings seem to support the hypothesis that a short direct repeat in DNA sequence can have a profound influence on the stability of a given gene and promote human gene mutations.
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329
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Bai H, Saku K, Liu R, Funke H, von Eckardstein A, Arakawa K. Polymorphic site study at codon 347 of apolipoprotein A-IV in a Japanese population. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1174:279-81. [PMID: 8104035 DOI: 10.1016/0167-4781(93)90197-l] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In a population of Japanese subjects, we surveyed codon 347 of the apolipoprotein (apo) A-IV gene and found that the frequency of a rare allele at this point was extremely low compared to that in western populations. Only one of 850 unrelated samples showed mutation at the enzyme recognition site by agarose gel electrophoresis. However, direct sequencing of the coding region revealed that it did not result from the ACT (Thr) to TCT (Ser) mutation which has been reported in western countries, but from an ACT to ACG (Thr) mutation, which does not affect the primary structure of apo A-IV. Two additional family members showed the same point mutation at codon 347.
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Nakashima Y, Nii T, Ikeda M, Arakawa K. Role of left ventricular regional nonuniformity in hypertensive diastolic dysfunction. J Am Coll Cardiol 1993; 22:790-5. [PMID: 8354814 DOI: 10.1016/0735-1097(93)90192-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVES This study investigated 1) the role of left ventricular diastolic nonuniformity in hypertensive left ventricular diastolic dysfunction, and 2) the effects of a calcium channel antagonist on diastolic nonuniformity in hypertensive and normotensive subjects. BACKGROUND Augmented left ventricular diastolic nonuniformity contributes to diastolic dysfunction in hypertrophic cardiomyopathy. Impaired left ventricular diastolic function with preserved systolic function has been recognized in hypertension. Therefore, abnormal ventricular regional nonuniformity might also be involved in hypertensive diastolic dysfunction in a milder form of hypertrophy. METHODS Thirteen patients with established hypertension underwent radionuclide ventriculography before and after nifedipine administration. Indexes of left ventricular function were derived by computer analysis of the time-activity curve. After a computer subdivided the left ventricle into four regions, a time-activity curve of each region was constructed to determine an index of left ventricular diastolic nonuniformity. This index was calculated as the sum of the absolute values of time difference between global and regional peak filling in the septal, the apical and the lateral region. Ten normotensive subjects were studied for comparison. Echocardiography was performed in both groups. RESULTS The two groups were matched for age, gender, heart rate, echocardiographic dimensions and systolic function. In the hypertensive group, left ventricular diastolic filling indexes were impaired, with a negative correlation between peak filling rate and the diastolic nonuniformity index. Although the change in ejection fraction after nifedipine administration was similar in the two groups, the increase in peak filling rate was larger in the hypertensive patients. The diastolic nonuniformity index decreased after nifedipine in the hypertensive but not in the control group. This decrease correlated with improved peak filling rate in the hypertensive group. CONCLUSIONS In hypertensive patients with preserved systolic function, left ventricular diastolic nonuniformity increases, causing early diastolic dysfunction. Decreased diastolic nonuniformity after pharmacologic intervention contributes to lessened ventricular filling dysfunction, regardless of changes in loading conditions in hypertension. Thus, diastolic nonuniformity is an important determinant of left ventricular filling abnormality and might be a target of pharmacologic intervention in hypertensive patients.
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Liu R, Saku K, Kostner GM, Hirata K, Zhang B, Shiomi M, Arakawa K. In vivo kinetics of lipoprotein(a) in homozygous Watanabe heritable hyperlipidaemic rabbits. Eur J Clin Invest 1993; 23:561-5. [PMID: 8243527 DOI: 10.1111/j.1365-2362.1993.tb00966.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In vivo kinetics of lipoprotein(a) [Lp(a)] were investigated in homozygous Watanabe heritable hyperlipidaemic (WHHL) rabbits (an animal model of familial hypercholesterolemia (FH)), and in normolipidemic Japanese White rabbits (controls). 125I-labelled Lp(a) and 131I-labelled LDL were simultaneously injected intravenously. Blood samples were then taken periodically. Kinetic parameters were calculated from the plasma radioactivity decay curves. The fractional catabolic rates (FCRs) of both Lp(a) and LDL (1.355 +/- 0.189 pools per day and 1.278 +/- 0.397 pools per day, respectively) in the WHHL rabbits were significantly (P < 0.005) smaller than those in the control rabbits (2.008 +/- 0.083 pools per day and 2.855 +/- 0.759 pools per day, respectively). In WHHL rabbits, the FCRs of Lp(a) and LDL were similar. However, in control rabbits, the FCR of Lp(a) was significantly (P < 0.01) smaller than that of LDL. In WHHL rabbit organs, the mean ratio of 125I-Lp(a): 131I-LDL, 48 h after injection, normalized to the corresponding isotope ratio in plasma, were 1.525, 1.020, 1.819 and 1.967, in liver, kidney, spleen and bile, respectively. These values were significantly higher than the corresponding values in control rabbits (0.590, 0.677, 0.862 and 0.766, respectively). Our data strongly suggest that Lp(a) clearance is not entirely dependent upon LDL receptors and may be mediated by some other mechanisms.
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Mori T, Arakawa K. [Exercise therapy of atherosclerosis]. NIHON RINSHO. JAPANESE JOURNAL OF CLINICAL MEDICINE 1993; 51:2095-100. [PMID: 8411677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The effect of exercise on the progression of atherosclerotic diseases is reviewed. Prospective studies have reported that a low daily physical activity is associated with a lower incidence of coronary artery disease. Mild aerobic exercise improves survival in patients with coronary artery disease, lowers blood pressure in patients with mild hypertension, improves insulin resistance in diabetes mellitus, lowers weight in obesity and increases HDL-cholesterol and decrease triglyceride in patients with dyslipidemia. Mild exercise therapy may be beneficial in the management of atherosclerotic diseases.
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Arakawa K, Peachey NS, Celesia G, Rubboli G. Component-specific effects of physostigmine on the cat visual evoked potential. Exp Brain Res 1993; 95:271-6. [PMID: 8224052 DOI: 10.1007/bf00229785] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Pattern visual evoked potentials (VEPs) were recorded from the pial surface of the cat primary visual cortex prior to and following the intravenous administration of physostigmine, an agent which blocks the enzyme responsible for the breakdown of synaptically released acetylcholine. The control VEP was composed of a small initial positive deflection (P1), a subsequent large negative wave (N1) and a second large positive wave (P2). Following physostigmine, the amplitude of P1-N1 was diminished whereas that of N1-P2 increased. These effects were long lasting and were blocked by prior treatment with scopolamine, a result consistent with mediation by a muscarinic cholinergic pathway. Waveform subtraction revealed that the physostigmine-sensitive component had a slow, negative polarity waveform while the physostigmine-insensitive component was also slow, but positive in polarity. The fundamental nature of these components remains to be assessed. Nevertheless, the results indicate that waveforms of different polarity combine algebraically to yield the conventional VEP.
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334
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Urabe Y, Ideishi M, Sasaguri M, Ikeda M, Arakawa K. Beneficial effects of a serine protease inhibitor in peripheral vascular disease. Am J Cardiol 1993; 72:218-22. [PMID: 8328387 DOI: 10.1016/0002-9149(93)90163-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Kallikrein, a serine protease known to generate bradykinin (a vasodilating peptide) in alkaline conditions, also generates angiotensin II (a vasoconstricting peptide) in weak acidic conditions. Based on this previous observation, the present study was performed to determine whether ischemic muscle tissue, in which the regional pH must decrease, produces angiotensin II by kallikrein or a similar enzyme, and whether nafamostat (NAF), a serine protease inhibitor, improves local hemodynamics under ischemic conditions caused by exercise in patients with ischemic peripheral vascular disease. NAF was administered intravenously to 20 patients with peripheral vascular disease. Lower-limb thermograms and blood flow were measured before and after exercise. Femoral venous blood of affected limbs was obtained to measure viscosity and humoral variables (i.e., pH, lactate, angiotensin II and bradykinin). Walking distance and subjective symptoms were also recorded. As a control, the same patients repeated this test with saline infusion on a separate day. NAF significantly increased maximal walking distance, improved subjective symptoms during exercise, and attenuated exercise-induced venous lactate and blood viscosity increases, and pH reduction. The blood viscosity increase correlated with the lactate increase. Pretreatment with NAF also resulted in a higher lower-limb skin temperature, and a greater increase of blood flow in the lower limbs after exercise than did pretreatment with saline. The results suggest that kallikrein-like serine protease may exacerbate ischemic symptoms. Changes in plasma bradykinin and angiotensin II in the femoral vein were not detectable, probably because of the lower levels of these peptides in the peripheral circulation.
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335
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Saku K, Zhang B, Hirata K, Okura Y, Bai H, Liu R, Arakawa K. Combined therapy with probucol and pravastatin in hypercholesterolaemia. One year follow-up study. Eur J Clin Pharmacol 1993; 44:535-9. [PMID: 8405008 DOI: 10.1007/bf02440854] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The effect of co-administration of low doses of pravastatin to hypercholesterolaemic patients already receiving long-term probucol treatment (mean 500-1,000 mg/day for 350 days) were investigated. Pravastatin 5 mg/day (Group 1; 12 m, 13 f; mean age 59.1 y) or 10 mg/day (Group 2; 8 m, 11 f; mean age 60.8 y) was administered, and blood was taken after 0, 3, 6, and 12 months. Both groups showed a significant reduction in serum total cholesterol (TC), phospholipid (PL), low density lipoprotein-cholesterol (LDL-C), LDL-triglyceride (TG), LDL-PL, apolipoprotein (apo) B, and apo E after the combined therapy. These levels were reduced more in Group 2 than in Group 1 subjects. In Group 2, significant falls in serum TG and apo CII were also observed. The changes in TC, PL, LDL-C, apo B, apo CII and apo E were dependent upon the dose of pravastatin, as assessed by two-way analysis of variance. Serum high density lipoprotein (HDL)3-C, apo AI and apo AII were slightly but significantly increased in both groups after 12 months of combined therapy, but the increase was not sufficient to reverse the probucol-induced lowering of the HDL level. We conclude that combined therapy resulted in a significant reduction in atherogenic lipoproteins and apolipoproteins, and an increasing dose of pravastatin (5 mg to 10 mg daily) made the lipid lowering effect more prominent. The reduction in serum HDL-C due to long-term probucol administration was not reversed by the addition of pravastatin.
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336
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Taneyama C, Goto H, Kohno N, Benson KT, Sasao J, Arakawa K. Effects of fentanyl, diazepam, and the combination of both on arterial baroreflex and sympathetic nerve activity in intact and baro-denervated dogs. Anesth Analg 1993; 77:44-8. [PMID: 8317745 DOI: 10.1213/00000539-199307000-00009] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The combination of fentanyl and diazepam significantly decreases systemic vascular resistance and blood pressure. We attempted to elucidate the reason the combination of these drugs can reduce blood pressure. In alpha-chloralose-anesthetized dogs, we investigated the effects of fentanyl and diazepam on mean arterial pressure (MAP) and arterial baroreflex control of renal sympathetic nerve activity (RSNA) in both intact (Study 1) and baroreflex-denervated dogs (Study 2). Study 1 included five dogs that received fentanyl 10 micrograms/kg followed by diazepam 0.4 mg/kg after a 10-min interval. Five more received both drugs in reversed sequence. The arterial baroreflex depressor test was performed with sodium nitroprusside before and after administration of each drug. Sensitivity of arterial baroreflex was examined by using the ratio of maximum increase of RSNA to maximum decrease of MAP (delta RSNA/delta MAP). RSNA and MAP significantly decreased only after both drugs had been administered (P < 0.05). Fentanyl alone did not attenuate arterial baroreflex sensitivity. Diazepam after fentanyl and diazepam alone attenuated baroreflex sensitivity to the same extent (P < 0.05). Study 2 comprised 14 dogs that underwent further surgical preparation of bilateral carotid sinus, aortic, and vagal nerve denervations. Seven received fentanyl, 5 and 10 micrograms/kg, and the other seven received diazepam, a total of 0.4 mg/kg. Fentanyl decreased both RSNA and MAP. Diazepam decreased only MAP significantly. The results indicate that fentanyl decreases mainly sympathetic outflow, whereas diazepam attenuates arterial baroreflex. We conclude that these combined effects of fentanyl and diazepam significantly decrease arterial blood pressure.
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Liu R, Saku K, Zhang B, Hirata K, Shiomi M, Arakawa K. In vivo kinetics of oxidatively modified HDL. BIOCHEMICAL MEDICINE AND METABOLIC BIOLOGY 1993; 49:392-7. [PMID: 8347382 DOI: 10.1006/bmmb.1993.1039] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The kinetics of oxidatively modified high-density lipoprotein (HDL) in vivo were investigated. 125I-labeled oxidized (Ox) HDL and 131I-labeled native (N) HDL were injected simultaneously into control and WHHL rabbits. The fractional catabolic rates of 125I-labeled Ox-HDL were significantly greater than those of 131I-labeled N-HDL in both control (2.52 +/- 0.36/day vs 0.94 +/- 0.02/day) and WHHL rabbits (4.07/day vs 1.32/day). Oxidized HDL was catabolized faster than native HDL and was taken up primarily by the liver, spleen, and kidney.
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Zanchetti A, Chalmers JP, Arakawa K, Gyarfas I, Hamet P, Hansson L, Julius S, MacMahon S, Mancia G, Ménard J. The 1993 guidelines for the management of mild hypertension: memorandum from a WHO/ISH meeting. Blood Press 1993; 2:86-100. [PMID: 8180730 DOI: 10.3109/08037059309077535] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Moroe K, Annoura M, Matsuo K, Yamanouchi Y, Kumagai K, Arakawa K. Proarrhythmic effects of class Ic drugs. Clin Ther 1993; 15:559-66. [PMID: 8364947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Three cases managed with class Ic antiarrhythmic drugs but with subsequent aggravation of arrhythmias are reported herein. A 58-year-old man given 300 mg of flecainide for atrial flutter developed sinus arrest and transient ventricular fibrillation. A 42-year-old man with a postoperative condition of tetralogy of Fallot who received 300-mg doses of flecainide for sustained ventricular tachycardia had spontaneous sustained ventricular tachycardia. A 74-year-old man given 150 mg of propafenone for atrial tachycardia developed sustained ventricular tachycardia. The present cases illustrate that class Ic drugs may exacerbate ventricular arrhythmias, and their use may reveal concealed sinus node dysfunction. This may be due to marked slowing of conduction and prolonged ventricular refractoriness, which are characteristic of the class Ic drugs; also, it is probable that the patients' underlying cardiac conditions served as contributing factors.
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340
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Saku K, Mukaino Y, Ying H, Arakawa K. Characteristics of reactive electropermeable points on the auricles of coronary heart disease patients. Clin Cardiol 1993; 16:415-9. [PMID: 8504576 DOI: 10.1002/clc.4960160509] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
In oriental medicine there is a hypothesis related to acupuncture that the auricle is a projection of the functional anatomy of the whole human body. In this study reactive electropermeable points (REPP), that is, points on the skin with low electrical resistance, on the auricle were measured on patients with coronary heart disease using a neurometer LC-M. Our findings correlated positively with the particular points--heart I (shin) and heart II (shinzo)*--named by the Chinese group as being related to the functional anatomy of the heart. The incidence of positive REPP test results at the shin and shinzo points for subjects with acute myocardial infarction (AMI) were extremely high, and positive test results for patients with old myocardial infarction (OMI) and angina pectoris (AP) were also significant. There was no significant difference in the incidence rates of REPP at the shin and shinzo points between the OMI and AP groups. High incidence of positive REPP test results at the lung and heart III (shinyu) points occurred only in the AMI group, and this was significantly high when compared with the control group.
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341
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Saku K, Liu R, Ohkubo K, Bai H, Hirata K, Yamamoto K, Morimoto Y, Yamada K, Arakawa K. In vivo conversion of recombinant human proapolipoprotein AI (rh-Met-proapo AI) to apolipoprotein AI in rabbits. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1167:257-63. [PMID: 8481386 DOI: 10.1016/0005-2760(93)90227-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In vivo conversion of recombinant human proapolipoprotein AI (rh-Met-proapo AI) from E. coli to apolipoprotein (apo) AI was investigated. rh-Met-proapo AI was labeled with 125I, and then administered intravenously to rabbits. Blood was sampled periodically for 6 days. The plasma decay curves of radioiodinated rt-Met-proapo AI were similar to those of human mature apo AI (fractional catabolic rate (FCR); 1.018 +/- 0.090/day vs. 0.976 1 0.031/day, respectively). In vivo conversion of rh-Met-proapo AI to mature apo AI was examined by autoradiography of the isoelectric focusing (IEF) slab gel, i.e., the HDL fraction from each sampling point was semiquantitatively applied to IEF. It was found that the radioactivity of rh-Met-proapo AI migrated to more acidic isoproteins, the conversion was complete within 24 h, and the FCR of rh-Met-proapo AI was 9.20 +/- 1.34/day. Although the plasma decay curves of both human pro (rh-Met-proapo AI) and mature apo AI were significantly steeper than those of rabbit mature apo AI4 and apo AI5 (FCR; 0.703 +/- 0.027/day and 0.795 +/- 0.031/day, respectively), the conversion rate of human rt-Met-proapo AI to mature apo AI in rabbit was assumed to be 1:1. In vitro incubation of rh-Met-proapo AI with rabbit serum produced mature apo AI isoproteins, as determined by the apo AI immunoblotting method. Prediction of the amino acid sequence at the NH2 terminus of rabbit proapo AI showed that the prosegment consisted of an alpha helix with a high probability of a beta turn at Pro9, which is close to that in humans. Thus, (1) the proteolytic cleavage of proapo AI is an extracellular event, (2) the converting enzyme in rabbits can also process human proapo AI, (3) this converting enzyme does not specifically and directly attack the Gln6-Asp7 bond which links the carboxyl-terminal residue of the hexapeptide to the amino-terminal residue of human mature apo AI. The conformation of proapo AI at the NH2 terminus (alpha helix of the prosegment and a beta turn at Pro9) may have a key role in this cleavage, and (4) the examination of rh-Met-proapo AI in rabbits helps to explain the early events of HDL biogenesis.
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Arakawa K, Akami T, Okamoto M, Oka T, Nagase H. Immunosuppression by delta opioid receptor antagonist (naltrindole, NTI). J Neuroimmunol 1993. [DOI: 10.1016/0165-5728(93)90094-f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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344
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Ueda M, Abe Y, Fujiwara H, Fujimoto W, Arakawa K, Arata J, Yoshioka T, Tomoda J, Katayama H. Prominent telangiectasia associated with marked bleeding in CREST syndrome. J Dermatol 1993; 20:180-4. [PMID: 8478499 DOI: 10.1111/j.1346-8138.1993.tb03856.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A 64-year-old woman with CREST syndrome developed prominent telangiectases mimicking hereditary hemorrhagic telangiectasia (HHT) of Osler-Rendu-Weber. We have been following her since she first came to us with discrete telangiectatic mats and Raynaud's phenomenon 11 years ago. Telangiectatic lesions have been seen on her larynx and esophagus in addition to commonly affected sites. She has experienced spontaneous epistaxis and marked bleeding from the lesions on her lips, oral mucous membrane, and soles. This case illuminates new aspects of telangiectasia in CREST syndrome.
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Yokoyama M, Goto H, Ueda W, Hirakawa M, Arakawa K. Modification of intravenous lidocaine-induced convulsions by epinephrine in rats. Can J Anaesth 1993; 40:251-6. [PMID: 8467547 DOI: 10.1007/bf03037037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
We studied intravenous lidocaine-induced convulsions in rats to determine whether added epinephrine influences the provocation of lidocaine toxicity. Wistar rats (200-250 g) were divided into three groups of ten, depending on the concentration of epinephrine added to lidocaine. Group 1: plain 1.5% lidocaine; Group 2: 1.5% lidocaine with 1:200,000 epinephrine; Group 3: 1.5% lidocaine with 1:100,000 epinephrine. After surgical preparation and recovery from anaesthesia, all rats received a continuous i.v. infusion of lidocaine (15 mg.ml-1) at a rate of 4.0 mg.kg-1 x min-1 until generalized convulsions occurred. The epinephrine-treated animals developed acute hypertension after one minute of lidocaine infusion (105 +/- 2 to 141 +/- 2 mmHg in Group 2 and 103 +/- 2 to 151 +/- 2 mmHg in Group 3). The PaO2 values in the epinephrine groups at the onset of convulsions were decreased significantly (88.3 +/- 1.0 to 84.0 +/- 1.5 mmHg in Group 2 P < 0.05 and 86.9 +/- 1.2 to 78.1 +/- 2.4 mmHg in Group 3 P < 0.01). However, these values were still within physiological ranges. Serum potassium concentrations in all groups were decreased P < 0.05, (4.24 +/- 0.09 to 3.52 +/- 0.12 mEq.L-1 in Group 1, 4.02 +/- 0.09 to 3.63 +/- 0.17 mEq.L-1 in Group 2, and 4.15 +/- 0.10 to 3.69 +/- 0.17 mEq.L-1 in Group 3).(ABSTRACT TRUNCATED AT 250 WORDS)
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Arakawa K, Peachey NS, Celesia GG. Spatial frequency response functions obtained from cat visual evoked potentials. ELECTROENCEPHALOGRAPHY AND CLINICAL NEUROPHYSIOLOGY 1993; 88:143-50. [PMID: 7681755 DOI: 10.1016/0168-5597(93)90065-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Visual evoked potentials (VEPs) were obtained from the surface of the cat visual cortex in response to contrast reversing sinusoidal gratings. Gratings of different spatial frequency were presented either separately, using signal averaging to increase the signal-to-noise ratio, or as a spatial frequency sweep, in which spatial frequency was sequentially increased every 5 sec during a 40 sec trial (3.99 Hz) or every 3 sec during a 24 sec trial (6.65 Hz). The second harmonic amplitude- and phase-spatial frequency functions derived from averaging or from sweep trials were similar, indicating that the swept stimulus method can be used to provide a rapid and reliable measure of the VEP-spatial frequency function. Intravenous administration of physostigmine, an acetylcholinesterase inhibitor, evoked a spatial frequency-dependent change in VEP amplitude. At 3.99 Hz, responses to low spatial frequencies were enhanced to a greater extent than were responses to high spatial frequency stimuli. At 6.65 Hz, responses to mid-range spatial frequencies were enhanced to a greater extent than were responses to low and high spatial frequency stimuli. VEP phase at both 3.99 and 6.65 Hz was advanced to a greater degree at the higher spatial frequencies. These results indicate that the swept spatial frequency method may be useful in studying spatial frequency-dependent pharmacological effects on the VEP and support the possibility that pharmacological disruption of the cholinergic visual system can produce such changes.
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Okabe M, Fukuda K, Nakashima Y, Hiroki T, Arakawa K, Kikuchi M. Pathological extent of interventricular septal infarction in patients with acute anteroseptal myocardial infarction with and without right bundle branch block. JAPANESE HEART JOURNAL 1993; 34:121-9. [PMID: 8315810 DOI: 10.1536/ihj.34.121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The purpose of the present study is to elucidate the difference in extent of myocardial infarction (MI) between those cases with and those without right bundle branch block (RBBB) occurring during the course of acute MI. We examined postmortem hearts from 20 patients with acute anteroseptal MI; 10 with (group A) and 10 without RBBB (group B). The extent of MI was studied pathologically in the interventricular septum (IVS) and reconstructed. The longitudinal extent of MI did not distinctly differ between groups A and B. In 5 hearts of group B, the anterior limit of the MI extended as high, or as close to the cardiac base, as in group A hearts. Transmural MI was relatively common and seen more frequently in group A than in group B. However, the MI did not always extend evenly to the left and right ventricular sides in the IVS. Left-sided predominance in extent of the MI was more frequently observed in group B than in group A. Right-sided predominance in the extent of septal MI was relatively rare and was seen in 5 cases at the portion where the right bundle branch came down. Four of these were group A patients. Thus, involvement of the right bundle branch might partly depend on the unevenness of the mural extent of the MI as well as the height of extension of the MI in the IVS.
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348
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Rubboli G, Arakawa K, Celesia GG, Peachey NS, Tomoda H. The effects of physostigmine on the response characteristics of the cat visual evoked potential. Doc Ophthalmol 1993; 84:257-65. [PMID: 8119105 DOI: 10.1007/bf01203658] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Steady-state pattern visual evoked potentials were recorded from the surface of the cat primary visual cortex before and after the intravenous administration of physostigmine, an agent that blocks the enzyme responsible for the breakdown of synaptically released acetylcholine. Under pentobarbital anesthesia, physostigmine increased the amplitude and changed the phase of the second response harmonic of the visual evoked potential, whereas the amplitude and phase of the fourth harmonic were not affected. These effects persisted for 15 to 45 minutes and were blocked by prior treatment with scopolamine or atropine. In addition, scopolamine or atropine administered 5 to 10 minutes after physostigmine returned the visual evoked potential to the baseline state. In comparison, when nitrous oxide was used, physostigmine caused a marked reduction in visual evoked potential amplitude, an effect that was reversed by subsequent atropine. These results indicate that the cholinergic system influences the visual evoked potential via a muscarinic pathway and that this influence is strongly affected by the anesthetic regimen used.
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349
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Miura S, Matauoka H, Tashiro E, Sasaguri M, Ideishi M, Ikeda M, Arakawa K. [A case of idiopathic hyperaldosteronism diagnosed by adrenal imaging]. FUKUOKA IGAKU ZASSHI = HUKUOKA ACTA MEDICA 1993; 84:100-2. [PMID: 8477923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We report a case of idiopathic hyperaldosteronism (IHA) which was differentiated from an aldosterone producing adenoma by the adrenal imaging techniques with computed tomography (CT) and scintigraphy. In this patient, the high basal aldosterone level with the suppressed plasma renin activity typically indicated the diagnosis of primary aldosteronism. However, the differentiation from an aldosterone producing adenoma by responses of plasma aldosterone levels to upright posture, captopril or adrenocorticotropic hormone (ACTH) administration was not definitive. Abdominal CT revealed bilateral adrenal swelling. Adrenal scintillation scanning with 131I-iodocholesterol showed bilateral uptake even after the administration of dexamethasone. Blood sampling from the right adrenal vein was unsuccessful. Blood pressure and serum potassium levels remained unchanged during dexamethasone administration (2 mg/day) over ten days. After the administration of spironolactone and nisoldipine blood pressure and serum potassium levels were normalized. Adrenal imaging is considered to be very useful for the diagnosis of IHA.
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350
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Matsunaga A, Araki K, Moriyama K, Handa K, Arakawa F, Nishi K, Sasaki J, Arakawa K. Detection of a point mutation in cholesteryl ester transfer protein gene by polymerase chain reaction-mediated site-directed mutagenesis. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1166:131-4. [PMID: 8431487 DOI: 10.1016/0005-2760(93)90293-i] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We describe a method for the rapid and non-radioactive examination of DNA samples for a mutation of cholesteryl ester transfer protein using a polymerase chain reaction-mediated site-directed mutagenesis. CETP deficiencies were studied in 554 Japanese subjects (370 men, 184 women) aged between 18 and 91 (mean 48.3 years). By this method, we detected one homozygote and 3 heterozygotes of the CETP deficiency.
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