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Biomedical subjects

S Handa

Publications and source records attributed to S Handa.

At least 307 records · Page 17Linked to original sources
PubMed1987

High maintenance rate of sinus rhythm after cardioversion in post-thyrotoxic chronic atrial fibrillation.

We performed rhythm conversion on 33 euthyroid patients with post-thyrotoxic atrial fibrillation who do not revert spontaneously to sinus rhythm from atrial fibrillation. The duration of atrial fibrillation ranged from 9 to 59 months (mean 25 +/- 14). The protocol of rhythm conversion was to first attempt pharmacological conversion with disopyramide and then to perform electrical cardioversion on the non-converters. Of 33 patients, 25 were converted to sinus rhythm (6 by disopyramide and 19 by electrical cardioversion), resulting in 8 non-converters. However, it was later discovered that cardioversion had been applied to 4 of the 8 non-converters when these patients had had a recurrence of thyrotoxicosis. These 4 patients were subjected to a second electrical cardioversion after attaining the euthyroid state. Sinus rhythm was restored in all 4 patients, giving a cardioversion rate of 88%. The sinus rhythm was maintained in 25 of the total 29 converters (86%) at the time of follow-up (10-68 months, mean 35 +/- 19 months). Our studies suggest that cardioversion should be encouraged for thyrotoxic atrial fibrillation, even if the duration of atrial fibrillation is long-standing, since there is excellent maintenance of sinus rhythm and even delayed application of cardioversion may improve its success rate.

Adult↗
PubMed1987

Glycolipids of the bovine pineal organ and retina.

Neutral and acidic glycolipids from the bovine pineal organ and neutral glycolipids from the bovine retina were characterized. The chemical structures of the isolated glycolipids were determined by means of carbohydrate analysis, methylation analysis, enzyme treatment, fatty acid analysis, long chain base analysis, mass spectrometry, NMR spectroscopy, and IR spectroscopy. GM3, GD3, and GT1 were the major bovine pineal organ gangliosides, GD3 accounting for 75% of the total gangliosides. Galactosylceramide, glucosylceramide, and lactosylceramide were found in both the bovine pineal organ and retina. Sulfatide was also present in both tissues. It had already been reported that the major bovine retina ganglioside was GD3 (Handa, S. & Burton, R.M. (1969) Lipids 4, 205-208). The glycolipid patterns of the two tissues were very similar to each other and quite different from those of other tissues.

Animals↗
PubMed1987

Application of liposomes to generation of monoclonal antibody to glycosphingolipid: production of monoclonal antibody to GgOse4Cer.

Liposomes were applied to the immunization with GgOse4Cer and screening for production of monoclonal antibody to GgOse4Cer. Four-week-old and 22-week-old Balb/c mice were immunized with GgOse4Cer and Salmonella minnesota R595 lipopolysaccharides incorporated liposomes which were composed of dipalmitoyl-phosphatidylcholine and cholesterol. Since antibody response to GgOse4Cer was higher in 22-week-old than 4-week-old Balb/c mice after immunization, 22-week-old Balb/c mice were used for the immunization prior to generation of the monoclonal antibodies to GgOse4Cer. The screening of monoclonal antibodies was performed by complement-dependent liposome immune lysis assay using GgOse4Cer-containing liposomes. Six kinds of monoclonal antibodies, AG-1, -2, -3, -4, -5, and -6, of the IgM class were established. The specificities of the monoclonal antibodies obtained were defined by complement-dependent liposome immune lysis assay using various glycosphingolipids incorporated in liposomes and by thin-layer chromatography (TLC) with immunostaining. All of the monoclonal antibodies reacted only with GgOse4Cer in the liposome immune lysis assay. In addition, the monoclonal antibodies reacted only with GgOse4Cer in the TLC immunostaining. However, none of the monoclonal antibodies obtained was capable of removing natural killer activity from C3H/He mice spleen cell suspensions in vitro. Liposomes may be useful in the procedures of immunization and screening for generation of antiserum and monoclonal antibody to GSLs.

Animals↗
PubMed1987

Lack of effect of thymus and spleen on the incubation period of Creutzfeldt-Jakob disease in mice.

Genetically athymic and asplenic (Lasat), athymic (Nude), asplenic (Dh) or normal littermate (Hetero) mice with a BALB/c genetic background were injected either intracerebrally or intraperitoneally with a 1% or 10% homogenate of mouse brains infected with the Fukuoka 1 strain of the Creutzfeldt-Jakob disease (CJD) agent. As there were no significant differences in incubation periods among the five groups (Lasat, Nude, Dh, Hetero and BALB/c) inoculated with the same dilution, via the same route, it was concluded that cell-mediated immunity dependent on the thymus plays no significant role in host defence against the CJD agent, and the spleen, a critical site of agent replication, is apparently not an obligatory source from which infection spreads to the central nervous system.

Animals↗
PubMed1987

Solute Accumulation in Tobacco Cells Adapted to NaCl.

Cells of Nicotiana tabacum L. var Wisconsin 38 adapted to NaCl (up to 428 millimolar) which have undergone extensive osmotic adjustment accumulated Na(+) and Cl(-) as principal solutes for this adjustment. Although the intracellular concentrations of Na(+) and Cl(-) correlated well with the level of adaptation, these ions apparently did not contribute to the osmotic adjustment which occurred during a culture growth cycle, because the concentrations of Na(+) and Cl(-) did not increase during the period of most active osmotic adjustment. The average intracellular concentrations of soluble sugars and total free amino acids increased as a function of the level of adaptation; however, the levels of these solutes did not approach those observed for Na(+) and Cl(-). The concentration of proline was positively correlated with cell osmotic potential, accumulating to an average concentration of 129 millimolar in cells adapted to 428 millimolar NaCl and representing about 80% of the total free amino acid pool as compared to an average of 0.29 millimolar and about 4% of the pool in unadapted cells. These results indicate that although Na(+) and Cl(-) are principal components of osmotic adjustment, organic solutes also may make significant contributions.

Journal Article↗
PubMed1987

[Contraction of the interventricular septum in right ventricular overload studied by two-dimensional echocardiography].

This study clarified the relationship between right ventricular (RV) overload and contraction of the interventricular septum using two-dimensional echocardiography. Seventeen patients with atrial septal defect (RV systolic pressure: 36 +/- 14 mmHg), 13 with mitral stenosis (49 +/- 19 mmHg), nine with primary pulmonary hypertension (87 +/- 21 mmHg) and 17 normal subjects (23 +/- 3 mmHg) were evaluated using two-dimensional echocardiography and cardiac catheterization. The circumferential lengths of the septum (Civs) and the left ventricular (LV) free wall (Cfw) were measured in the LV short-axis view at the level of the papillary muscles. In normal subjects, Civs was 3.4 +/- 0.5 cm and Civs/Cfw was 0.40 +/- 0.07. All patients with RV overload had longer Civs and greater Civs/Cfw as compared with the normal subjects. There was no significant difference in the Cfw among the cases with mitral stenosis and primary pulmonary hypertension and the normal subjects. Cfw in atrial septal defect was shorter than in the normal subjects. The percent contraction of Civs was decreased in mitral stenosis and primary pulmonary hypertension as compared with the normal subjects. No significant difference was found in the percent contraction of Civs between the normal subjects and the 11 patients with atrial septal defect with normal RV systolic pressure. However, in six patients with atrial septal defect with high RV systolic pressure, the percent contraction of Civs was decreased. There was an inverse correlation between RV systolic pressure and the percent contraction of Civs (r = -0.39, p less than 0.01), and RV ejection fraction (r = -0.52, p less than 0.01) defined by multiplegated equilibrium scintigraphy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Reversal of depressant effects of propranolol on the left ventricular pump function by nifedipine in dogs with chronic ischaemia.

The aim of this study was to clarify the combined effects of propranolol and nifedipine on the regional wall motion and haemodynamic variables of the heart in dogs with chronic ischaemia. After an injection of propranolol the heart rate and stroke volume significantly decreased (from 128(18) beats X min-1 to 113(12) beats X min-1 and from 15.1(3.1) ml to 12.2(2.6) ml respectively) and the left ventricular end diastolic pressure and systemic vascular resistance in systole increased significantly (from 7.3(1.5) mmHg to 10.0(1.8) mmHg and from 8.61(1.42) kPa X litre-1 X min-1 to 11.80(1.59) kPa X litre-1 X min-1 respectively). In the regional myocardium the end diastolic length increased significantly in both border and normal zones (7(3)% and 4(2)% respectively) and the percentage systolic shortening in the normal zone decreased significantly from 18.0(3.1)% to 15.1(2.9)%. In the border and infarcted zones the percentage systolic shortening or systolic lengthening did not change. The administration of nifedipine resulted in significant decreases in left ventricular systolic pressure and in systemic vascular resistance (from 122(17) mmHg to 105(14) mmHg and from 11.80(1.59) kPa X litre-1 X min-1 to 6.63(1.24) kPa X litre-1 X min-1 respectively) and stroke volume increased to 18.2(4.4) ml. The percentage systolic shortening in the border and normal zones improved significantly to 9.8(3.2)% and 19.2(3.7)% respectively without any change in end diastolic length and left ventricular end diastolic pressure. In the infarcted zone no significant change in systolic lengthening or end diastolic length was seen. Thus impaired left ventricular pump function induced by propranolol was reversed by nifedipine.

Animals↗
PubMed1986

Glycosphingolipids of normal bovine and enzootic bovine leukosis lymph node cells.

We analyzed glycosphingolipids from normal lymph node cells of seven cattle and lymph node cells of eight cattle with enzootic bovine leukosis. The neutral glycosphingolipids and gangliosides were analyzed by thin-layer chromatography. Both normal and tumorous lymph node cells had GlcCer, LacCer, and GbOse3Cer as major neutral glycosphingolipids. In the ganglioside fraction, GM3 was the predominant component in both normal and tumorous lymph node cells, and another component, ganglioside Gx fraction, was also prominent in tumorous lymph node cells. The structure of this ganglioside Gx fraction was elucidated by thin-layer chromatography, sugar analysis, neuraminidase digestion, and permethylation studies. This ganglioside Gx fraction was found to be a mixture of four ganglioside species. The structures of individual gangliosides Gx (1 to 4) were characterized as follows. 1: GD3, NeuAc alpha 2-8NeuAc alpha 2-3Gal1-4Glc-Cer. 2: GD3, NeuAc alpha 2-8NeuGc alpha 2-3Gal1-4Glc-Cer. 3: GD3, NeuGc alpha 2-8NeuAc alpha 2-3Gal1-Glc-Cer. 4: GD3, NeuGc alpha 2-8NeuGc alpha 2-3Gal1-4Glc-Cer. These GD3 species may be formed as a result of the induced synthesis inassociation with malignant transformation.

Animals↗
PubMed1986

Biochemical properties of N-methylamides of sialic acids in gangliosides.

A simple and rapid method for the preparation of N-methylamides ( - CONHCH3) of sialic acids in gangliosides and biochemical properties of the modified gangliosides are described. The sialic acid carboxyl groups of gangliosides were esterified with CH3I-dimethylsulfoxide, followed by heating with monomethylamine. The modified gangliosides were chemically identified by TLC, IR spectroscopy, GLC-mass spectrometry and NMR spectroscopy. The N-methylamide derivative of GM1 produced a high titer IgG antibody. The antibody weakly cross-reacted with the methylester of GM1 and its reductive derivative but did not react with the intact GM1. A monoclonal antibody (M2590) specific for GM3 did not react with carboxyl-modified GM3 (methylester, N-methylamide, and reduced GM3), but it reacted with modified GM3 which contains the C7-analog of the sialic acid. Clostridium perfringens and Arthrobacter ureafaciens sialidases did not hydrolyze the N-methylamide derivatives, methylesters or reductive derivatives of the gangliosides and, furthermore, these derivatives did not inhibit the actions of these sialidases.

Amides↗
PubMed1986

Proline accumulation and the adaptation of cultured plant cells to water stress.

The transfer of cultured tomato cells (Lycopersicon esculentum cv VFNT-Cherry) to a low water potential environment resulted in an increased dry weight to fresh weight ratio accompanied by a rapid accumulation of proline. Proline content continued to increase as osmotic adjustment and growth occurred. The initial increase in proline concentration was accompanied by a drop in turgor. However, proline levels continued to increase with a gain in turgor during osmotic adjustment. Thus, the accumulation of proline depended not only on cell water potential, or on the initial loss of turgor but more closely on cell osmotic potential. The ultimate level of proline depended on the level of adaptation. Proline levels remained high after more than 100 cell generations in low water potential media, but declined rapidly after transfer to media with a less negative water potential. Addition of exogenous proline to the medium during water stress and during osmotic downshock alleviated the normally resulting inhibition of growth. The results suggest a positive role for proline accumulation in adaptation of cells to changing external water potentials.

Journal Article↗
PubMed1986

Metabolic changes associated with adaptation of plant cells to water stress.

Suspension cultured cells of tomato (Lycopersicon esculentum Mill. cv VFNT Cherry) adapted to water stress induced with polyethylene glycol 6000 (PEG), exhibit marked alterations in free amino acid pools (Handa et al. 1983 Plant Physiol 73: 834-843). Using computer simulation models the in vivo rates of synthesis and utilization and compartmentation of free amino acid pools were determined from (15)N labeling kinetics after substituting [(15)N]ammonium and [(15)N]nitrate for the (14)N salts in the culture medium of cell lines adapted to 0% and 25% PEG. The 300-fold elevated proline pool in 25% PEG adapted cells is primarily the consequence of a 10-fold elevated rate of proline synthesis via the glutamate pathway. Ornithine was insufficiently labeled to serve as a major precursor for proline. Our calculations suggest that the rate of proline synthesis only slightly exceeds the rate required to sustain both protein synthesis and proline pool maintenance with growth. Mechanisms must operate to restrict proline oxidation in adapted cells. The kinetics of labeling of proline in 25% PEG adapted cells are consistent with a single, greatly enlarged metabolic pool of proline. The depletion of glutamine in adapted cells appears to be a consequence of a selective depletion of a large, metabolically inactive storage pool present in unadapted cultures. The labeling kinetics of the amino nitrogen groups of glutamine and glutamate are consistent with the operation of the glutamine synthetase-glutamate synthase cycle in both cell lines. However, we could not conclusively discriminate between the exclusive operation of the glutamine synthetase-glutamate synthase cycle and a 10 to 20% contribution of the glutamate dehydrogenase pathway of ammonia assimilation. Adaptation to water stress leads to increased nitrogen flux from glutamate into alanine and gamma-aminobutyrate, suggesting increased pyruvate availability and increased rates of glutamate decarboxylation. Both alanine and gamma-aminobutyrate are synthesized at rates greatly in excess of those simply required to maintain the free pools with growth, indicating that these amino acids are rapidly turned over. Thus, both synthesis and utilization rates for alanine and gamma-aminobutyrate are increased in adapted cells. Adaptation to stress leads to increased rates of synthesis of valine and leucine apparently at the expense of isoleucine. Remarkably low (15)N flux via the aspartate family amino acids was observed in these experiments. The rate of synthesis of threonine appeared too low to account for threonine utilization in protein synthesis, pool maintenance, and isoleucine biosynthesis. It is possible that isoleucine may be deriving carbon skeletons from sources other than threonine. Tentative models of the nitrogen flux of these two contrasting cell lines are discussed in relation to carbon metabolism, osmoregulation, and nitrogenous solute compartmentation.

Journal Article↗
PubMed1986

Strategy to manage pump failure due to chronic pulmonary diseases--pathophysiology and treatment of right ventricular overload.

The pathophysiology and treatment of pump failure with right ventricular overload due to chronic pulmonary diseases were discussed. When right ventricular overload occurs hypertrophy and dilatation of right ventricle follows and the heart as a whole, including left ventricle, is altered in morphology and function. Therapeutic measures for right ventricular overload are the key to management and treatment of pump failure. Pulmonary hypertension, as an etiological factor, is discussed and is divided into two categories, that is, mild to moderate pulmonary hypertension with hypoxia due to chronic obstructive lung disease, and severe pulmonary hypertension due to pulmonary vascular disease. In each category, effects of oxygen inhalation and vaso-dilating agents were evaluated. Oxygen did not decrease pulmonary vascular resistance in the state of chronic hypoxia, though a vasodilating agent was effective. In pulmonary vascular disease, vaso-dilating agents were effective to decrease pulmonary vascular resistance and pulmonary artery pressure, though the effect was less than 30% down in resistance.

Alprostadil↗
PubMed1986

Analysis of the thymic microenvironment by monoclonal antibodies with special reference to thymic nurse cells.

Two hybridoma cell lines secreting monoclonal antibodies against stromal tissues of mouse thymus were produced using the spleen cells of BALB/C mice immunized with newborn thymic homogenate of C57BL/6 mice emulsified in Freund's complete adjuvant. The monoclonal antibody Th-3 reacted with stromal cells in the thymic cortex and the monoclonal antibody Th-4 reacted with stromal cells in the thymic medulla. The stromal cells revealed by Th-3 showed a meshwork structure in the cortex, and formed a monolayered border at the cortical surface and around the vasculature. Each mesh of this structure was connected to each other, forming a complex labyrinth and being open toward the medullary area. Neither lymphoid cells nor any cells in any other organs were reacted with this Th-3 antibody. However, the reactivity of Th-3 with the thymic cortical stromal cells was observed not only in C57BL/6 mice which had been used as source of antigen, but also in other strains of mice such as C3H and BALB/C. Immunoelectron microscopy revealed that Th-3 monoclonal antibody was reactive with some component, diffusely present in the cytoplasm of cortical epithelial cells. The pattern of Th-3 positive meshwork in the thymic cortex was quite similar to that stained by either anti-IA or anti-IE antibody, but the Th-3 positive reaction was not inhibited by these anti-IA and anti-IE antibodies. Thymic nurse cells prepared by the method of Wekerle were positive for Th-3 antibody. On the contrary, Th-4 reacted only with epithelial cells in the thymic medulla. It was suggested that Th-3 monoclonal antibody detected some antigen specific to so called thymic nurse cells.

Animals↗