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Biomedical subjects

K Amano

Publications and source records attributed to K Amano.

At least 343 records · Page 19Linked to original sources
PubMed1984

[The incidence of postoperative epilepsy and prophylactic anticonvulsants in patients with intracranial aneurysm].

The occurrence of epileptic seizures is not rare after craniotomy. The authors examined the incidence of postoperative epilepsy in 150 patients of intracranial aneurysm. Anticonvulsants were given to all patients after operation, but in 12 cases anticonvulsants were discontinued because of liver dysfunction. One hundred and eight out of 138 cases (78%) were prescribed polypharmaceutically, and 30 of 138 cases (22%) were monopharmaceutically. The daily dose of anticonvulsants was as follows; diphenylhydantoin (DPH) was 150-300 mg, phenobarbital (PB) was 50-100 mg, valproic acid (VPA) was 600-1200 mg, and carbamazepin (CBZ) was 200-600 mg. Postoperative epilepsy occurred in 14 of 150 cases (9.3%); 13 cases with anticonvulsants, and 1 case without anticonvulsants. The site of aneurysm was as follows; 6 cases (10.3%) of AC aneurysm, 3 cases (9.7%) of MC aneurysm, 1 case (2.4%) of IC aneurysm, and 4 cases (21.1%) of multiple aneurysm. The interval between operation and epileptic seizure was ranged 2 to 57 months (mean 19.8 months); in 7 cases (50%) within 1 year, and in 13 cases (93%) within 3 years. The authors emphasize that prophylactic use of anticonvulsants is effective to control subclinical epileptic seizures, prescribing anticonvulsants to all patients after craniotomy in general. The medication of anticonvulsants for 3 years would be necessary for avoiding postoperative epileptic seizure.

Adult↗
PubMed1984

[Gangliogliomas in cerebral hemisphere].

Gangliogliomas are rare central nervous system neoplasms. The clinical features, radiological findings and surgical results in 6 histologically proven cases of gangliogliomas in the cerebral hemisphere are reviewed. The ages varied between 8 and 58 years old at the time of diagnosis. Five patients had seizure disorders without focal neurological deficit or clinical signs of increased intracranial pressure. These 5 patients had been treated as epilepsy for 6 months to 12 years. The other one patient had right sided motor weakness and left homonymous hemianopsia without seizure disorder. Plain roentgenograms of the skull revealed abnormal calcification in 3 out of 6 patients. Angiography showed an avascular mass in all 6 patients. CT scan were examined in 5 patients. In 3 patients the tumor were isodense, 2 of which demonstrated contrast enhancement. The other 2 showed low density lesion. One showed a single large cyst and another ill-defined low density containing high density calcification. In all 5 patients mass effect was slight. Three tumors were located in the temporal lobe and another 3 in the parietal lobe. At surgery total removal was accomplished in 3 patients. One patient had subtotal removal and 3 patients partial removal. Histological study revealed figures characteristic to the ganglioglioma. The predominant glial cell was astrocytic in 4 cases and oligodendroglial component was found in the other 2 cases. All patients either completely or nearly asymptomatic at the follow up for 1 to 12 years. The clinical study in 6 cases, along with a review of the literature suggest that these epileptogenic neoplasms should be aimed at surgical removal or total extirpation if possible.

Adolescent↗
PubMed1984

[The use of echocardiography in predicting clinical courses of mitral regurgitation].

We analyzed the relation of left ventricular size and performance to clinical courses and surgical outcomes using echocardiography. Group A consisted of 19 patients with mitral regurgitation (MR) who presented congestive heart failure of grade III or IV, and group B consisted of 58 patients with MR whose cardiac function was grade I or II. Clinical follow-up spanned one to nine years, with an average of 4.5 years. At the initial examination, the average end-diastolic LV dimension (LVDd) and its index (LVDdI), left atrial dimension (LAD) and its index (LADI) and cardiothoracic ratios (CTR) were significantly greater in group A (LVDd 61.2 +/- 7.1 mm, LVDdI 41.5 +/- 6.9 mm/m2, LAD 51.4 +/- 8.4 mm, LADI 35.4 +/- 11.1 mm/m2, CTR 63.4 +/- 8.6%) than in group B (LVDd 52.0 +/- 7.9 mm, LVDdI 35.0 +/- 6.4 mm/m2, LAD 37.2 +/- 9.6 mm, LADI 25.4 +/- 6.5 mm/m2, CTR 48.9 +/- 4.4) (p less than 0.001). The LVDd and LAD were less in mitral valve prolapse than in rheumatic MR or MR due to flail mitral valves. In rheumatic MR, congestive heart failure did not become prominent until the left ventricle and atrium were markedly enlarged. In group A, patients whose LVSVI were over 40 ml/m2 and LAD were over 50 mm took clinical downhill courses under medical treatment and were referred for surgery. The risk of death (medically or surgically) was higher in patients whose LAD, LVSVI or CTR was markedly increased (LAD greater than 70 mm, LVSVI greater than 60 ml/m2 or CTR greater than 70%). The rates of change in LAD and LVDd were 1.6 and 0.9 mm/year in group B, but they became accelerated after the onset of congestive heart failure, and were 2.6 and 6.4 mm/year in group A. In surgical cases, the LVDd returned to the normal range postoperatively, but their LAD remained in the abnormal range in all but one case. We concluded that echocardiography is an indispensable method for a follow-up study of MR and that it may be helpful in predicting individual clinical courses and surgical effects.

Adolescent↗
PubMed1983

Echophonocardiographic study of the initial low frequency component of the first heart sound.

To investigate the genesis of the initial low frequency component of the first heart sound that precedes the high frequency vibrations associated with closure of the atrioventricular valves, echophonocardiograms of 36 persons were recorded. These included 10 normal subjects and 26 patients with various types of heart disease including mitral valve replacement. Electrocardiograms demonstrated normal sinus rhythm in 23 subjects, atrial fibrillation in 9, complete atrioventricular block in 2 and atrial flutter in 2. In the phonocardiogram, the low frequency component of the first heart sound followed the onset of the QRS complex and preceded the first high frequency component of this sound. The low frequency component occurred simultaneously with the beginning of the final fast closing movement of the mitral valve on the echocardiogram and was found both in normal rhythm and in arrhythmias. However, in arrhythmias its intensity varied on a beat to beat basis, being loudest after a short RR interval or when atrial systole occurred very close to the expected time of ventricular systole. In patients in whom apexcardiograms were recorded, the low frequency component was coincident with or very close to the onset of ventricular systole. It is concluded that the low frequency component of the first heart sound represents vibrations caused by contraction of the left ventricle and deceleration of antegrade blood flow across the mitral valve. Neither atrial contraction nor mitral valve tension is necessary for the production of this soft initial component.

Adolescent↗
PubMed1983

Structural requirements of endotoxic glycolipid for antitumor and toxic activity.

Endotoxic glycolipids extracted from the polysaccharide heptose-less Re mutant of Salmonella typhimurium were hydrolyzed with alkaline and acid reagents. Treatment with hydroxylamine caused the liberation of all O-ester linked fatty acids and resulted in abrogation of the toxicity (lethality to chick embryos) and ability to regress tumors (line-10 tumors in strain 2 guinea pigs). Treatment with dilute sodium hydroxide caused partial removal of O-ester linked fatty acids without loss of these activities. Toxicity and tumor-regressive potency were retained after removal of 2-keto-3-deoxyoctonate (KDO) by exposing the glycolipids to sodium acetate solution at pH 4.5. The majority of the glycolipids of the endotoxic extracts were rendered non-toxic but retained antitumor activity when hydrolyzed with boiling 0.1 N hydrochloric acid, which split KDO and glycosidic phosphate from the glycolipid molecules. Non-toxic glycolipid fractions possessing antitumor activity were separated from the acid hydrolysate by means of preparative thin layer chromatography. It was concluded that glycosidic bound phosphate and at least a portion of the fatty acids of the lipid A moiety are essential for toxicity, but that this phosphate is not an essential structural feature for tumor-regression activity.

Animals↗
PubMed1983

Partial characterization of peptidoglycan-associated proteins of Legionella pneumophila.

The proteins associated with the peptidoglycan (PG) of Legionella pneumophila are resistant to proteolysis by trypsin, protease VI and proteinase K. These protease-resistant proteins are associated with the PG noncovalently and covalently. Analysis of cell walls and PG-protein complex by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions revealed one major protein (38.5K) and several minor Coomassie and silver staining components. The 38.5K protein seemed to be a major component which was co-purified with the PG. The cleavage of the PG-protein complex by 1 N NaOH treatment yielded PG free of proteins which was subjected to alkali hydrolysis. This association of PG and protease-resistant covalently-bound proteins may be an important structural and functional determinant of resistance to both environmental conditions and intracellular digestion of L. pneumophila by eukaryotic cells.

Bacterial Proteins↗
PubMed1983

Peptidoglycan of Legionella pneumophila: apparent resistance to lysozyme hydrolysis correlates with a high degree of peptide cross-linking.

Peptidoglycan (PG) from Legionella pneumophila was composed of muramic acid, glucosamine, glutamic acid, alanine, and meso-diaminopimelic acid in a molar ratio of 0.8:0.8:1.1:1.7:1. Partially purified PG contained trypsin-insensitive proteins which were extracted by 1 N NaOH hydrolysis without apparent dissolution of the PG. Lysozyme hydrolysis of purified PG or cell walls caused an increase in reducing groups which correlated with roughly 70 to 100% digestion of disaccharides. However, there was no significant decrease in turbidity during lysozyme hydrolysis of purified PG or cell wall. Additionally, 80 to 90% of the meso-diaminopimelic acid epsilon-amino groups were not susceptible to dinitrophenylation. Collectively, the PG of L. pneumophila was sensitive to lysozyme hydrolysis and insensitive to alkali dissolution, and 80 to 90% of the NH2 groups of meso-diaminopimelic acid were apparently involved in cross-linkages between peptides.

Alanine↗
PubMed1983

[Stereotactic metrizamide cervical myelography].

A new apparatus is made for metrizamide cervical myelography. One part of the apparatus is a frame for immobilizing the head and the other is an assembly for guiding spinal needle insertion by lateral puncture. The head frame is made of concave plastic and three rubber discs for immobilizing the forehead and bilateral temporal region. The second piece of apparatus for guiding spinal needle insertion is movable in three directions: up and down, right and left and forward and backward. The sterilized guide made of acrylic is attached. The spinal needle is inserted along the groove of this sterilized guide. The apparatus makes it possible to locate the insertion point easily for the metrizamide cervical myelography by lateral C1-C2 puncture method in prone position, since the location of the tip of the inserted needle can be determined by the aid of lateral cervical x-ray and 10 mm scale, even if image intensifier of TV display screen is not available.

Adult↗
PubMed1983

Mitral valve prolapse in five members of a family including the identical twins.

A family in which the five members including the identical twins had a mitral valve prolapse was described. None of these members had any known stigmata of Marfan syndrome and their auscultatory findings were different each other. M-mode echocardiograms disclosed a midsystolic buckling of the mitral valve in the identical twins, their parents and the mother's brother, but all were asymptomatic. Electrocardiograms revealed a wandering pacemaker in two members. The index case was a 13-year-old girl whose apical late systolic murmur was detected incidentally by the mass screening examination for cardiac diseases. Both the inhalation of amyl nitrite and injection of methoxamine induced the augmentation of this murmur and made it holosystolic. The identical twin of the index case had multiple apical non-ejection clicks. However, a mitral regurgitant murmur was not induced by pharmacological provocations. Two-dimensional echocardiograms revealed prolapse of both the anterior and posterior mitral valve leaflets in both of them. Their mother had a late systolic click and the mother's brother had a cardiopulmonary murmur. The abnormal auscultatory findings were not observed in their father. This familial study suggested the genetic background and the various clinical manifestations of mitral valve prolapse.

Adolescent↗
PubMed1983

[Detection of coronary sinus by parasternal two-dimensional echocardiography and the clinical significance].

To investigate the potential of a new method for detecting coronary sinus (CS), two-dimensional (2-D) echocardiography was satisfactorily performed on 80 consecutive cases, of which the coronary sinus was detected in 74 by adopting parasternal three-chamber approach. These 74 cases were classified into four groups; 25 normal individuals, 7 patients with atrial septal defect (ASD) but without tricuspid insufficiency (TI), 13 with TI and 29 with other cardiac diseases. We measured diastolic maximum diameter of CS on 2-D echocardiograms. The mean diameter of the CS was significantly increased in ASD (9.0 mm) and TI (12.4 mm) comparing with normal control (6.7 mm). The enlargement of CS seemed to correlate with right-sided volume overload. Although there were three exceptional cases, we could observe the CS during the whole cardiac cycle only in patients with TI. We conclude that CS is excellently detected in over 90% of cases by a new parasternal approach and that the diameter of CS would be a new screening index of right-sided volume overload.

Adolescent↗