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Biomedical subjects

K Suyama

Publications and source records attributed to K Suyama.

At least 145 records · Page 8Linked to original sources
PubMed1992

Isolation and structural characterization of a new crosslinking amino acid, cyclopentenosine, from the acid hydrolysate of elastin.

A novel polyfunctional crosslinking amino acid, which was developed slower than lysinonorleucine and faster than desmosine on thin layer chromatography, was isolated from the hydrolysate of bovine aorta elastin. Its proposed structure was verified by ultraviolet spectroscopy, fast atom bombardment mass spectroscopy, and nuclear magnetic resonance spectroscopy. The data indicated it to be a trifunctional amino acid with a cyclopentene structure. The mass spectral analysis indicated a parent compound with a mass of 381 (C18H27N3O6). The proposed structure is one derived from the condensation of three allysine residues. Based on the names of other crosslinking amino acids found in elastin, the trivial name of cyclopentenosine is given to this compound.

Amino Acids↗
PubMed1992

Membrane orientation of Rh(D) polypeptide and partial localization of its epitope-containing domain.

We have previously shown that the effects of various enzyme treatments on Rh antigen-containing polypeptides in situ could be monitored by an antibody preparation which recognizes only these polypeptides following Western blotting. We now have prepared antibodies that specifically react with either the N- or C-terminal ends of Rh-related proteins. Using all three, we have established that the C-terminus of Rh(D) polypeptide is at the cell surface, whereas its N-terminal domain is situated at the cytoplasmic side of the red blood cell membrane. Chymotrypsin digestion of ghosts derived from (-D-/-D-) cells that are devoid of Rh (C/c) and (E/e) antigens produces three major Rh(D)-related fragments: the 20-Kd fragment contains the molecule's C-terminal domain, the 17-Kd fragment its N-terminus, and the 13-Kd fragment neither. However, only the 17-Kd fragment forms an immune-complex with human polyclonal anti-D, indicating that it contains the Rh(D) antigenic domain. Other findings presented here provide further evidence for a unique folding of Rh(D) polypeptide within the cell membrane and suggest that Rh(C/c) and (E/e) polypeptides, when present, may form complexes with it.

Blotting, Western↗
PubMed1992

Significance of ventricular pacing site in manifest entrainment during orthodromic atrioventricular reentrant tachycardia with left-sided accessory pathway.

We examined entrainment by ventricular pacing in six patients during orthodromic atrioventricular reentrant tachycardia (AVRT) utilizing a left-sided lateral accessory pathway. Constant fusion and progressive fusion were demonstrated in all patients by left ventricular pacing during tachycardia, but in none of the patients by right ventricular pacing. When left ventricular pacing was performed during AVRT, the antidromic wave front from the pacing impulse (n) collided with the orthodromic wave front of the previous pacing beat (n - 1) within the ventricle, therefore, constant fusion and progressive fusion were demonstrated in the surface electrocardiographic QRS complexes. On the other hand, when right ventricular pacing was performed during orthodromic AVRT, the antidromic wave front from the pacing impulse (n) collided with the orthodromic wave front of the previous paced beat (n - 1) within the normal atrioventricular pathway, and constant fusion and progressive fusion were therefore not demonstrated. These phenomena were explained by the relationship of the ventricular pacing site and the reentrant circuit. This study demonstrates the importance of the pacing site in manifest entrainment of orthodromic AVRT during ventricular pacing.

Adult↗
PubMed1992

Changes of neuronal transmission in the hippocampus after transient ischemia in spontaneously hypertensive rats and the protective effects of MK-801.

BACKGROUND AND PURPOSE: I studied the mechanism of postischemic neuronal degeneration in the hippocampus by an electrophysiological method. METHODS: Sequential changes of field potentials evoked by perforant path stimulation in the dentate gyrus and the CA1 region of the hippocampus were evaluated in spontaneously hypertensive rats up to 7 days after transient global ischemia induced by bilateral occlusion of the carotid arteries for 20 minutes after electrocauterization of the vertebral arteries. Animals were treated with vehicle or the excitotoxin antagonist (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10 amine (MK-801, 2 mg/kg or 5 mg/kg) intraperitoneally 30 minutes before ischemia. RESULTS: Complete recovery of the population spike was observed in the dentate gyrus within 24 hours after recirculation, followed by a gradual reduction of population spike amplitude. In contrast, population spike in the CA1 region showed partial recovery 24 hours after recirculation, and an abrupt reduction of population spike amplitude occurred on day 2. There was no significant enhancement of population spike amplitude in either region throughout the experiment. Interneuronal recurrent inhibition in the dentate gyrus was enhanced on day 4, and ischemic changes were apparent in the CA1 pyramidal cells on day 7. Pretreatment with 5 mg/kg MK-801 prevented field potential and pathological changes completely in the dentate gyrus and partially in the CA1 region. CONCLUSIONS: My results indicate that pathological changes of the CA1 pyramidal neurons after transient ischemia may not be the result of postischemic overstimulation. However, neuronal transmission in the CA1 region may be persistently impaired during or after transient ischemia.

Animals↗
PubMed1992

Quantitative and qualitative changes of serum albumin in CAPD patients.

This study was conducted to assess quantitative and qualitative changes in serum albumin in CAPD patients. For twenty-six CAPD patients as well as age-, sex- and dialysis history-matched HD patients, biochemical and physiological parameters including urea kinetics were determined. Albumin was qualitatively evaluated by HPLC. The CAPD patients showed significant decreases in serum albumin and the reduced form of albumin accompanied by a lower protein catabolic rate(PCR) compared to the HD patients. Thirty five % of CAPD patients showed mild to moderate hypoalbuminemia, associated with a higher incidence of peritonitis and longer hospital stay. Patients with hypoalbuminemia had less of the reduced form of albumin. A weak positive correlation was found between serum albumin concentration and KT/V, and PCR. Thus, in CAPD patients, there occur quantitative and qualitative changes in serum albumin. Hypoalbuminemia may be a risk factor for peritonitis and is due in part to insufficient dialysis and protein intake. Intermolecular change in albumin may possibly be due to uremia per se.

Adult↗
PubMed1992

[Two cases of hypothyroidism with echocardiographic features similar to cardiomyopathy: one simulates hypertrophic and the other dilated cardiomyopathy].

Two cases of hypothyroidism with echocardiographic features similar to cardiomyopathy were presented. In case 1 (a 68 year-old woman), moderate pericardial effusion and myocardial hypertrophy were observed on admission. In case 2 (a 69 year-old woman), dilation of the left ventricle, hypokinesis of the interventricular septum and the left ventricular free wall, and reduced left ventricular systolic function were observed on admission. These echocardiographic findings were similar to hypertrophic or dilated cardiomyopathy. In the two cases, after recovery to euthyroid state, these echocardiographic abnormalities returned to normal. We concluded that hypothyroidism led to a reversible hypertrophic or dilated cardiomyopathy, and that echocardiographic study was useful for diagnosis and for following up cardiac manifestations of hypothyroidism.

Aged↗
PubMed1992

[The effect of acebutolol and metoprolol on noninvasive ambulatory blood pressure monitoring system in essential hypertension].

We compared the antihypertensive effects of acebutolol and metoprolol during 2-4 weeks of treatment in patients with mild to moderate essential hypertension. Acebutolol (n = 12) significantly decreased conventionally measured blood pressure from 173/100 mmHg to 148/86 mmHg (p less than 0.005), and metoprolol (n = 11) decreased it from 164/106 mmHg to 138/87 mmHg (p less than 0.01). Based on data derived from automated 24-hour ambulatory blood pressure monitoring, both drugs significantly decreased the blood pressure in the early morning (5:00-10:00). Moreover, in the metoprolol group, there were significant falls in day-time blood pressure (7:30-19:30) and night-time blood pressure (23:00-7:00). In contrast, acebutolol showed significant antihypertensive effect on day-time blood pressure, but not effect on night-time blood pressure. The study confirmed the efficacy and character of metoprolol and acebutolol. We must choose an effective beta-blocker when using an automated 24-hour ambulatory blood pressure monitoring system to get adequate blood pressure reduction for the whole 24 hours.

Acebutolol↗
PubMed1992

[Shotgun pellet embolus in the cerebral circulation via the internal carotid artery in the neck; a case report].

A 57-year-old hunter was shot accidentally and admitted to our hospital without any neurological deficits. Plain X-ray films of the neck revealed the presence of several shotgun pellets, one of which was thought to be in the vicinity of the right internal carotid artery at the C1 level. One week later, while surgical removal of pellets was being performed under fluoroscopic control, the pellet entered into the lumen of the artery and migrated to the intracranial vessels. Right carotid angiogram revealed that the pellet occluded in the right angular artery about 1.5cm distal from its outlet. Although embolectomy was performed, we could not get a patency of the vessel. CT scan taken 3 days after operation showed the occurrence of massive cerebral edema. Angiogram taken 2 weeks after confirmed occlusion of the vessel. The patient was discharged with left lower quadrantanopsia one month after the operation. In the literature, 20 similar cases have been hitherto reported and briefly reviewed. Of these 20, 6 cases died of cerebral infarction. We believe that embolectomy is warranted as soon as possible when patients show a condition building up to a stroke.

Carotid Artery, Internal↗
PubMed1991

Silica gel high-performance liquid chromatography for the determination of cross-links in elastin.

A high-performance liquid chromatographic (HPLC) procedure for the determination and preparation of desmosine (DES) and isodesmosine (IDE), the major cross-links of elastin, has been developed. Hydrolysates of elastin are treated with a SEP-PAK silica-gel small column and then separated on a silica-gel normal phase column using n-propanol-water-25% ammonia (9:3:0.06, v/v/v) followed by detection at 275 nm. The quantitative yields of DES and IDE are 7.98 +/- 0.47 and 6.44 +/- 0.51 (mean +/- S.D., n = 10) mg/g dry weight, respectively, in bovine ligamentum nuchae. Preparations of cross-links are carried out by means of a preparative column (240 mm x 10 mm), using the same solvent system.

Amino Acid Sequence↗
PubMed1991

[Recurrent hyperkalemia in the course of rheumatoid arthritis--a case report].

A 69-year-old woman with advanced rheumatoid arthritis (RA) suffered two episodes of hyperkalemic hyperchloremic metabolic acidosis (HCMA). Plasma renin activity (PRA) and plasma aldosterone concentration (PAC) were markedly suppressed in the first episode occurring in paralell with the administration of metoprolol during piroxicam and lobenzarit (CCA) therapy. Rechallenge with diclofenac sodium and CCA lead to the second hyperkalemia, but no significant suppression of the renin-aldosterone axis was seen at that time. This suggests that the different mechanisms contribute to the development of these episodes, including the tubulo-interstitial injury which is not uncommon in RA. The combined use of nonsteroidal anti-inflammatory drugs (NSAIDs) and beta-adrenergic blockers may increase the risk of life-threatening hyperkalemia through their suppressive effect on the renin-aldosterone system, whereas the concomitant administration of CCA with NSAIDs through the impairment in the renal tubular function. These drugs should be most carefully given to patients with a latent defect in renal potassium excretion.

Adrenergic beta-Antagonists↗
PubMed1991

[Patients resuscitated from cardiopulmonary arrest: clinical and electrophysiologic study].

Clinical and electrophysiologic studies (EPS) were carried out in 12 patients who were resuscitated from cardiopulmonary arrest (CPA). They were 8 males and 4 females, ranging from 33 to 73 years of age with a mean of 55 years. Underlying diseases included old myocardial infarction (OMI) with aneurysm (An) in 6 patients, variant angina, arrhythmogenic right ventricular dysplasia, Romano-Ward syndrome, complete atrioventricular block in one each, and diseases of unknown etiology in 2. Ergonovine-provocative coronary angiography (CAG) was performed in 3 patients, and EPS including ventricular tachycardia study was performed in 7. Coronary artery spasm was induced in one patient during CAG; sustained monomorphic ventricular tachycardia in 4 patients; and repetitive ventricular response in 2 of 7 patients examined by EPS. The causes of cardiopulmonary arrest were clearly demonstrated by the above-described examinations in 3 cases of clinically unidentified etiology. Drug therapy was performed in 6 patients during EPS (1.7 drugs/case), which was effective in one, ineffective in 3, and undetermined in 2. Of 2 patients whose surgical treatment was unsuccessful, atrial pacing with propranolol administration was used in a patient with Romano-Ward syndrome. The remaining patients were followed up medically. Cardiopulmonary arrest recurred in 3 patients and resuscitation was not successful in any of them; one with OMI and the other 2 with idiopathic ventricular fibrillation who refused EPS and died suddenly 10 months and 12 months after their initial resuscitation. Cardiac arrest did not recur in any of those who underwent complete examinations and were treated with medications, however, it recurred in 3 of 5 patients without complete medications. As a whole, cardiopulmonary arrest recurred in 3 of 12 patients (25%) within one year after the onset of symptoms. To reduce the possibility of the recurrence of arrest and improve prognosis in patients with previous successful cardiac resuscitation, intensive examinations for the causes, therapy including EPS and ergonovine CAG, full medications and surgical treatment may be helpful.

Adult↗
PubMed1990

Isolation and characterization of new cross-linking amino acid "allodesmosine" from hydrolysate of elastin.

A new pentafunctional cross-linking amino acid, termed allodesmosine, was isolated from bovine ligamentum nuchae elastin. This compound was a very hygroscopic, white amorphous solid with a faint yellow tinge, soluble in aqueous solvents but not dry methanol; it was characterized by UV, FAB mass and NMR spectroscopy. The compound was shown by UV and 1H-NMR to have a pyridinium ring structure similar to desmosine. Mass spectral analysis indicated a parent compound with a mass of 655. We postulated that it arose by condensation of a reduced aldol condensation product of allysine, allysine and lysine.

Amino Acids↗
PubMed1990

Enzymatic evidence for differences in the placement of Rh antigens within the red cell membrane.

Intact erythrocytes of different Rh genotypes were subjected to various enzyme treatments, the effects of which were monitored by separating the membrane proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and performing Western blotting using an antibody preparation that recognizes only Rh-related polypeptides. We found that treatment of intact cells with either phospholipase A2 or proteases such as papain did not alter the size of Rh antigen-containing polypeptides. In contrast, phospholipase A2 treatment followed by papain digestion cleaved a fraction of these polypeptides. This cleavage appears, from such digestions of Rh(D) positive and negative cells of different genotypes, to occur solely at the extracellular domain of Rh(D) polypeptide, while the extracellular domains of other Rh antigen-containing polypeptides are unaffected. Digestion of red blood cell ghosts and inside-out vesicles with trypsin showed that Rh(D), (C/c), and (E/e) antigen-containing polypeptides span the lipid bilayer having cytoplasmic domains susceptible to the action of proteases. The size of the cleavage products at the cytoplasmic domain of -D-/-D- cells was found to differ from that of other Rh(D) positive genotypes, due possibly to a difference in folding of Rh(D) polypeptide at its cytoplasmic domain and within the cellular membrane of these cells.

Blotting, Western↗
PubMed1990

[Clinical application of Therasonic lithotripsy treatment system for upper urinary tract calculi].

Extracorporeal shock wave lithotripsy (ESWL) using a Therasonic lithotripter was performed on 30 patients with urinary tract calculi between July, 1989 and February, 1990. The results obtained in 31 cases (one patient had bilateral renal stones) were presented. There were 22 inpatients and 8 outpatients in this series. The stone location was: renal pelvis in 15 cases, renal calyces in 10 cases, parenchyma or diverticulum of renal calyces in 3 cases, ureteropelvic junction in 1 case, and upper ureter in 2 cases. Sixteen cases (52%) became stone-free and residual stones (less than or equal to 4 mm) remained in 9 cases (overall effective rate 81%) at one month after the treatment. There were no serious complications including bacteremia and renal hematoma. We concluded that Therasonic lithotripter is useful in the management of upper urinary tract calculi.

Adult↗
PubMed1989

[Multiple myeloma presenting as a mass lesion in the frontal bone. Case report].

The patient, a 51-year-old male, was hospitalized for evaluation of a frontal subcutaneous mass. There were no signs of intracranial hypertension and no neurological deficit. His general medical status was normal, but he had been diagnosed as having immunoglobulin G (IgG) lambda type multiple myeloma by bone marrow aspiration and immunoelectrophoresis. A plain skull X-ray showed a large bony defect and multiple punched-out lesions in the frontal bone. Computed tomography showed an epidural high-density mass with marked homogeneous enhancement. Carotid angiography showed a hypervascular tumor fed by the bilateral external carotid arteries. At surgery, a reddish tumor was detached from the dura mater and totally resected. The pathological diagnosis was IgG lambda type plasmacytoma. After 40-Gy radiation and chemotherapy, the postoperative course over the following year was uneventful. Although the prognosis of multiple myeloma is poor, that of solitary intracranial plasmacytoma is reportedly good. However, since there is a high incidence of transition from solitary plasmacytoma to multiple myeloma, patients with intracranial plasmacytoma should be followed for a long period.

Combined Modality Therapy↗