Biomedical subjects

Y Kohno

Publications and source records attributed to Y Kohno.

At least 217 records · Page 12Linked to original sources

PubMed1992

[Non-verbal auditory agnosia with EEG abnormalities and epilepsy; an unusual case of Landau-Kleffner syndrome].

A case of unusual Landau-Kleffner syndrome was reported. She was an 8 year-old girl and showed non-verbal agnosia, diffuse EEG abnormalities and convulsions. Her responses to both verbal and non-verbal sounds remained inconsistent and unstable. When a continuous spike-wave complexes on EEG was detected, she paid no attention to any sound in spite of her fair consciousness. Auditory brainstem response and magnetic resonance imaging of her brain were normal. Auditory agnosia was correlated well with EEG abnormalities, and valproic acid and clonazepam were effective for EEG improvement. After the EEG improvement, clinical responses to sounds recovered well; firstly she could pay attention to sounds and then she could distinguish between verbal and non-verbal sounds. Finally, she could speak a few words after the learning letters.

Agnosia↗

PubMed1992

[Ultrasonic tissue characterization in hypertrophic cardiomyopathy: analysis of three-layered appearance of the ventricular septum by apical approach].

In normal hearts, two-dimensional echocardiography from the apical window displays the left ventricular wall as a three-layered appearance (TLA): central bright layer and bilateral sonolucent zones. The TLA is considered to reflect the normal myocardial architecture: the predominant latitudinal fiber bundles of the midwall layer, and longitudinal or oblique ones on both sides. We analysed the TLA of the ventricular septum in 20 normal subjects, 20 patients with left ventricular hypertrophy due to pressure load (LVH), and 81 patients with hypertrophic cardiomyopathy (HCM). Of the 81 HCM patients, the layering was often obscure or absent in 53 (65%), whereas LVH patients showed clear TLA as well as normal hearts. In patients with severe layering disorder (n = 30), the age at diagnosis was lower (40 +/- 15 vs 50 +/- 12, p less than 0.05), and familial occurrence (53 vs 11%, p less than 0.01) and severe functional limitation (NYHA greater than or equal to III) were more common (27 vs 4%) than in those with clear TLA (n = 28). The disturbed layering detectable by echocardiography may reflect the disorder of basic myocardial fiber architecture in the ventricular septum, and is likely to become a useful marker of the pathologic severity of the disease.

Adult↗

PubMed1992

[Diagnosis of food allergy based on rectal mucosal cytology].

We performed rectal and/or oral challenge tests on 8 patients with suspected but unproven diagnosis of food allergy based on detailed medical history and findings from radioallergosorbent tests (RAST). The cells appearing in the rectal mucosal smear serially for 48 hours after allergen challenge were examined. The following results were obtained: 1) Significant numbers of not only eosinophils but also mast cells appeared in the rectal smears after challenges with suspected-food allergens, but not with unrelated foods. This confirmed the antigen-specificity of the method. 2) In some cases, the appearance of mast cells and eosinophils was bimodal, suggesting the existence of a later allergic response in addition to an immediate-type reaction. 3) The food-specific appearance of mast cells and eosinophils was observed in association with clinical symptoms after challenge, even in patients whose IgE antibodies to the allergen were negative or commercially unavailable. In conclusion, we propose that rectal mucosal cytology in conjunction with rectal and/or oral challenge tests is a reliable and objective method to diagnose unproven or suspected food allergy.

Child↗

PubMed1992

[Allergy to casein hydrolysate formula. A study of sensitizing allergen].

A six-month old baby, who had been fed for 2 months with casein hydrolysate formula (MA-1) for treatment of milk allergy, developed diarrhea. The baby's RAST score for milk was negative. IgE antibodies to MA-1 but not to MA-1 depleted of lipid (fat-free MA-1), were demonstrated by enzyme-linked immunosorbent assay (ELISA). It was confirmed by the appearance of numerous mast cells and eosinophils in a rectal smear taken after challenge with MA-1 (but not detected after challenge with fat-free MA-1) that some component in the lipid of MA-1 must be an allergen in this patient.

Caseins↗

PubMed1992

[Autoimmune response to thyroglobulin. Proliferative response to thyroglobulin fragments in low responder mice].

Thyroglobulin (Tg) is one of the major thyroid autoantigens involved in autoimmune thyroiditis. The immune response of mice to Tg is genetically controlled by H-2-linked genes. To elucidate the regulation mechanism of autoimmune response to Tg in low responder mice, we studied the proliferative response of lymph node cells (LNC) to mouse Tg (MTg) and enzyme-digested MTg fragments. MTg was treated with Staphylococcus aureus V8 protease followed by separation of the fragments into 6 fractions (Fr1-Fr6: 264,000-17,000) by high performance liquid chromatography (HPLC), LNC from MTg immunized CBA/N (H-2k) mice, a high responder strain, proliferated in response to MTg and all fractions (Fr1-Fr6) of MTg fragments in vitro. In contrast, LNC from MTg immunized BALB/c (H-2d) and B10 (H-2b) mice, low responder strains, did not respond to native Tg but responded well to some smaller Tg fractions (Fr3, 4, 5). In addition, when BALB/c mice were immunized with MTg Fr4 with a molecular weight of 63,000, LNC from BALB/c mice proliferated in response to MTg as well as MTg Fr4. These findings suggest that T cells which are capable of responding to Tg do exist even in low responder mice and that the activation of these autoreactive T cells is suppressed by a regulatory cell subpopulation in low responder mice.

Animals↗

PubMed1992

[Clinical evaluation of 123I-BMIPP myocardial scintigraphy in patients with hypertrophic cardiomyopathy].

123I-BMIPP myocardial scintigraphy was performed in 13 patients with hypertrophic cardiomyopathy and compared with 201Tl myocardial scintigraphy performed within 3 months for evaluating the clinical significance of 123I-BMIPP myocardial scintigraphy. SPECT images were divided into 13 segments and segmental images were visually scored on a 4 (increased tracer uptake) to 0 (severely decreased tracer uptake) scale according to the tracer uptake. In comparison of 123I-BMIPP early images and 201Tl perfusion images, mismatches were seen in about 70% of all segments. The number of segments demonstrating lower myocardial uptake of 123I-BMIPP was larger than that of 201Tl. In hypertrophic regions, the tracer uptake of 123I-BMIPP early images was significantly lower than that of 201Tl images and the lower uptake of 123I-BMIPP delayed images was more marked. In non-hypertrophic regions, no significant difference was seen between the tracer uptakes of 123I-BMIPP early images and 201Tl images but the tracer uptake of 123I-BMIPP delayed images was significantly lower than that of 201Tl images. The mismatch between the tracer uptakes of 123I-BMIPP images and 201Tl images was thought to be a reflection of disordered myocardial fatty acid metabolism. "Washout", the difference between the tracer uptakes of 123I-BMIPP early images and delayed images was also thought to be a reflection of disordered myocardial fatty acid metabolism. These results suggest that 123I-BMIPP is a promising radiopharmaceutical for evaluating disordered myocardial fatty acid metabolism in patients with HCM.

Cardiomyopathy, Hypertrophic↗

PubMed1992

[Successful operation for atrial septal defect in a patient with Gilbert's syndrome].

We report a rare case of atrial septal defect (ASD) with Gilbert's syndrome. The patient was a 34-year-old man, who underwent successfully patch closure for ASD, and annuloplasty for tricuspid valve regurgitation by DeVega's method. Gilbert's syndrome is a disorder characterised by a unconjugated hyperbilirubinemia without other hepatic dysfunction. In our case, there was no evidence of hepatic damage related to hyperbilirubinemia postoperatively. Open heart surgery for patient with Gilbert's syndrome is supposed to be performed rather safely.

Adult↗

PubMed1991

Identification of lamin B2 as a substrate of protein kinase C in BALB/MK-2 mouse keratinocytes.

Protein phosphorylation by activation of protein kinase C was examined using quiescent cultures of the mouse epidermal keratinocyte line BALB/MK-2. Treatment with phorbol ester caused rapid phosphorylation of five proteins with molecular weights of 80,000, 70,000, 40,000, 34,000, 28,000. Of these proteins, the 70,000 molecular weight one (p70) was studied further. Its position on two-dimensional gel suggested that p70 is nuclear envelope lamin B. This possibility was confirmed by the co-migration of p70 with the lamin fraction of mouse liver and its immunoprecipitation with antinuclear lamina antibody. The lamin B fraction consists of lamin B1 and lamin B2. Evidence that p70 is lamin B2 was obtained by peptide mapping and amino acid sequencing. Lamin B2 is the only lamin that shows a substantial increase in phosphorylation on treatment of BALB/MK-2 cells with phorbol ester.

Amino Acid Sequence↗

PubMed1991

Comparison of culture methods for human-human hybridomas secreting anti-HBsAg human monoclonal antibodies.

Human-human hybridomas which secrete a human monoclonal antibody (h-MoAb) against hepatitis B virus surface antigen showed growth associated production kinetics. The rate of h-MoAb production rapidly decreased after cell growth was arrested in a perfusion culture, even if the perfusion rate was increased. A continuous suspended-perfusion culture, in which both culture broth and culture supernatant are continuously harvested and the same volume of fresh medium is continuously fed into the reactor, was developed to maintain continuous growing conditions during cultivation. In this culture system, the production of h-MoAb continued for more than 50 days with an average productivity of 5.0 mg/l of working volume/day. A semicontinuous immobilized-perfusion culture in which parts of the cells are repeatedly removed from the immobilized reactor was another useful technique for the long term cultivation of these h-h hybridomas. As an average h-MoAb production rate, 62 mg/l of immobilized-bed volume/day was achieved for 65 days of cultivation using a ceramic matrix reactor, and 327 mg/l/day was achieved over 47 days of cultivation using a hollow fiber reactor equipped with Cultureflo M. Thus, the antibody productivity per reactor volume per day by the semicontinuous immobilized-perfusion culture was much higher than that of the continuous perfusion culture in an agitation reactor.

Antibodies, Monoclonal↗

PubMed1991

Anti-thyroid peroxidase antibodies in sera from healthy subjects and from patients with chronic thyroiditis: differences in the ability to inhibit thyroid peroxidase activities.

A significant percentage (6.4%) of healthy subjects was found to contain anti-thyroid peroxidase (TPO) antibodies in their sera. However, in contrast with IgG from sera of patients with chronic thyroiditis, IgG from sera of healthy subjects did not inhibit TPO activities both in guaiacol and iodide assays. In addition, anti-TPO antibodies from healthy subjects did not block the inhibition of enzyme activities by anti-TPO antibodies from patients. These findings suggest that anti-TPO antibodies from healthy subjects do not bind to the epitopes relating to substrate-combining sites of TPO. Thus, the specificities of anti-TPO antibodies in healthy subjects may differ from those in cases of chronic thyroiditis.

Adult↗

PubMed1991

The effect of human milk on DNA synthesis of neonatal rat hepatocytes in primary culture.

We studied the effect of human milk on DNA synthesis of neonatal hepatocytes to elucidate the physiologic role of human milk in growth of the liver. Neonatal hepatocytes were isolated from 5-d-old rats and cultured in serum-free medium. Human milk stimulated DNA synthesis of these hepatocytes in a concentration-dependent manner. The stimulatory activity of 7.5% (vol/vol) human milk plus 0.1 mumol/L insulin was five times that of control and was almost the same as that of 20 micrograms/L human epidermal growth factor (hEGF) plus insulin. The effect of human milk was additive with treatment with hEGF and insulin. The milk associated with prolonged jaundice of infants was significantly more active than the milk that was not associated with jaundice, although the concentration of hEGF was not different between the two types of milk. The mitogenic activity of milk was heat-labile, inactivated by DTT and stable after treatment with trypsin. Three peaks of the activity were detected in milk by gel filtration and the fraction containing proteins of molecular weight between 36,000 and 76,000 showed the highest activity. Anti-hEGF antibody did not inhibit this activity completely. These results suggested the presence of mitogens other than hEGF or a more active form of hEGF in human milk. The milk associated with breast-milk jaundice exerts a different influence on cell growth and may affect maturation of the liver function related to bilirubin metabolism. The mitogenic activity of milk might be important for growth and development of the liver in infants.

Animals↗

PubMed1991

The disposition of loxistatin and metabolites in normal and dystrophic hamsters.

1. The absorption, distribution and excretion of loxistatin were studied in normal and dystrophic hamsters. 2. After oral administration of 14C-loxistatin to normal hamsters, the plasma level of radioactivity reached a maximum at 0.5 h and declined with an elimination half-life of 2.3 h. The ratios of metabolites M-1 and M-4, which are pharmacologically active, to the total radioactivity in the plasma were 63% and 25% at 0.5 h after dosing, respectively. 3. After oral administration to hamsters, excretion of radioactivity in urine, faeces and expired air during 120 h were 64%, 28% and 6% of the dose, respectively. 4. The highest radioactivity was observed in kidney followed by liver. From the microautoradiographic study, radioactivity was found to be located in the cardiac and skeletal muscle fibre cells, which are target organs of the drug, in both dystrophic and normal hamsters.

Animals↗

PubMed1991

[Antigenic determinants on ovalbumin and ovomucoid: comparison of the specificity of IgG and IgE antibodies].

To delineate the antigenic determinants on ovalbumin (OA) and ovomucoid (OVM) recognized by specific IgG and IgE antibodies in sera from patients with allergy to hen's egg, we studied the binding activities of IgG and IgE antibodies to native OA or OVM and seven different OA or OVM preparations, i.e. heated OA or OVM (100 degrees C for 3 min and 80 degrees C for 30 min) or 0.3 M NaOH, dithiothreitol (DTT), sodium dodecyl sulfate (SDS), 6 M urea or HCl treated OA or OVM. Eight patients with IgE anti-OA antibodies and 12 patients with IgE anti-OVM antibodies were used in these studies. The binding activities of IgG and IgE antibodies to physically or chemically denatured OA were partially decreased compared with those to native OA, whereas IgG and IgE antibodies in sera from patients bound well to denatured OVM with similar binding activities to native OVM. These results strongly suggest that antibodies to OA recognize partially conformational antigenic determinants on OA, whereas antibodies to OVM mainly recognize sequential antigenic determinants on OVM, and that antigenic determinants of OVM recognized by antibodies in sera from patients are more stable than those of OA under these denaturation conditions. In addition, the binding activities of IgE antibodies to denatured OA or OVM were significantly different from those of IgG antibodies to these OA or OVM, suggesting that the specificities of IgE antibodies to OA or OVM may be different from those of IgG antibodies to OA or OVM.

Adolescent↗

PubMed1991

[Impairment of left ventricular diastolic function during the asymptomatic period in vasospastic angina patients without significant coronary stenosis].

We examined whether recurrent transient ischemia may effect left ventricular systolic and diastolic function or not. Left ventricular systolic and diastolic function during the asymptomatic period was studied by gated radionuclide ventriculography (RNV) in 25 patients with vasospastic angina (VA) who had no significant coronary stenosis, in 25 patients with effort angina (EA), and in 20 controls (C). There was no significant difference among patients in all three groups in regards to systolic indices (Ejection Fraction, Peak Ejection Rate). But diastolic indices (Peak Filling Rate, Time to Peak Filling Rate, 1/3 Mean Filling Rate, 1/3 Filling Fraction) were impaired not only in patients with EA but also in patients with VA. The treatment with nitrates and/or Ca antagonist for 6-24 months did not bring about any changes in these data concerning systolic and diastolic function in patients with VA. Thus, it is suggested that the diastolic function is impaired in patients with VA even during the asymptomatic period, though systolic function remains normal. Recurrent transient ischemia may cause irreversible myocardial injury.

Adult↗

PubMed1991

Quantitative measurements of balloon-to-artery ratios in coronary angioplasty.

To determine the optimal balloon-to-artery ratio in percutaneous transluminal coronary angioplasty (PTCA), the effects of balloon size on the extent of residual stenosis, the incidence of coronary dissection, and the percentage of cases requiring repeat PTCA for restenosis were examined retrospectively. Fifty consecutive patients who underwent elective PTCA for simple and discrete lesion localized in the left anterior descending coronary artery were selected for this study. To measure the absolute cross-sectional area of the adjacent control segment of the artery, we developed a new method of quantitative coronary angiography, a hybrid of cinevideodensitometry and the edge detection method. The balloon-to-artery ratio was calculated as the cross-sectional area ratio between the control segment adjacent to the stenosis and the balloon which was visually selected by the operator during PTCA. Residual stenosis was determined as the percent area of stenosis by our hybrid method using cinevideodensitometry. The balloon-to-artery ratio ranged from 0.4 to 2.4, and a weak but significant inverse correlation (r = -0.51) was observed between the balloon-to-artery ratio and the extent of residual stenosis. In 23 patients whose balloon-to-artery ratios were less than 1.0, residual stenosis was greater (59.9 +/- 11.9% vs 46.0 +/- 19.6%, p < 0.05), and the percentage of repeat PTCA was higher (26% vs 4%, p < 0.05) than in the group of 27 patients whose balloon-to-artery ratios were higher than 1.0. The incidence of coronary dissection was similar in the 2 groups (9% vs 15%, ns). The percent area of stenosis before PTCA, the number of inflations, the inflation pressures, and the inflation times were also similar between these 2 groups. We concluded that the optimal balloon size is slightly more than the control segment dimensions of simple and discrete isolated stenoses of the left anterior descending artery treated at lower inflation pressures, and that an accurate measurement method of the coronary arterial dimensions is necessary to determine this optimal balloon size.

Angioplasty, Balloon, Coronary↗

PubMed1991

[A case of hypertrophic cardiomyopathy with progressive cavity dilatation--a review of serial 201Tl myocardial imaging].

We reviewed 201Tl images of a 32 year old man with dilated hypertrophic cardiomyopathy (DHCM). At 22 years of age, when he was diagnosed as having nonobstructive hypertrophic cardiomyopathy (HCM)IVST; 20mm, Dd; 44mm, EF; 62%), 201Tl images showed only a small defect in the anteroseptal segment. At 27 years of age, when he had the first cardiac symptom as palpitation on exertion, his perfusion defect of 201Tl became wider. At 32 years age, he was hospitalized because of deterioration of congestive heart failure. Echocardiography revealed left ventricular wall thinning(IVST; 6mm), left ventricular cavity enlargement (Dd; 63mm) with a large mural thrombus and reduced left ventricular ejection fraction (EF; 32%). Thus 201Tl images may provide useful information on the process of DHCM from HCM.

Adult↗

PubMed1991

[Assessment of right ventricular afterload in mitral valve diseases with radionuclide angiography].

Right ventricular function at rest and during exercise was studied in 33 patients with mitral valve disease by equilibrium gated radionuclide angiography using 99mTc in vivo labeled red blood cells. Radionuclide measurements of right ventricular ejection fraction (RVEF) were correlated with mean pulmonary arterial pressure (mPAP). RVEF decreased significantly with exercise. There was no significant correlation between RVEF at rest and mPAP. However, mPAP showed significant negative correlation with RVEF during exercise and with the changes of RVEF from rest to exercise. It is concluded that RVEF during exercise in mitral valve disease is affected by right ventricular afterload, and the measurements of RVEF at rest and during exercise by equilibrium gated radionuclide angiography is useful to assess right ventricular afterload.

Adult↗

PubMed1990

Regulation of creatine phosphokinase B activity by protein kinase C.

We previously reported that topical application of 12-o-tetradecanoylphorbol-13-acetate to mouse skin causes phosphorylation of epidermal proteins with molecular weights of 40,000 (p40) and 34,000 (p34). In the accompanying paper, p40 was identified as creatine phosphokinase B. Here we report that both in intact cells and in a cell-free system, phosphorylation of creatine hosphokinase B by protein kinase C resulted in an increase in its ability to catalyze the transfer of the high-energy phosphate of phosphocreatine to ADP, thereby producing ATP. H-7, a specific inhibitor of protein kinase C was found to abolish the increase in enzyme activity. Lineweaver-Burk plot analysis indicated that the increased activity was mostly due to a decreased Km for phosphocreatine. Phosphorylation and activation of creatine phosphokinase B may be a physiological response to maintain ATP balance when a protein kinase C pathway is stimulated.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗