Corticosteroid effect on down regulation in beta adrenergic receptors.
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Journal Article↗
Biomedical subjects
K Ishihara
Publications and source records attributed to K Ishihara.
Prolonged survival of MRL-lpr/lpr mice treated with Tripterygium Wilfordii Hook-F.
MRL-lpr/lpr mice were treated with Tripterygium Wilfordii Hook-F (TWHF), a Chinese herbal medicine successfully used for human rheumatoid arthritis. Dramatic prolongation of survival and the reduction of urinary protein were observed in mice treated with a high dose of TWHF (20 mg/kg, three times a week) compared to the control animals receiving solvent alone. A slight but significant reduction was also seen in the degree of lymphadenopathy and arthritis with the high dose treatment. Surprisingly, no significant difference was present in IgM rheumatoid factor and IgG anti-double-stranded DNA antibody levels or in the histopathology of lupus nephritis. These results indicate the dissociation of histopathological renal disease and the degree of proteinuria or the life span. Although further pharmacological analysis is required, TWHF might be potentially useful for diseases such as systemic lupus erythematosus or nephrotic syndrome.
Animals↗
Haemocompatibility of polymer having phospholipid polar groups evaluated by monoclonal antibody method.
The haemocompatibility of a polymer having the phospholipid polar group, poly(2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate(BMA)), was evaluated by a monoclonal antibody SZ-21 (directing specifically against the membrane glycoprotein complex IIIa of human platelet) radioimmunoassay method. The study showed that poly(MPC-co-BMA) possessed better haemocompatibility than segmented polyurethane (SPEU). Radioactivity of platelets adhered (counts per min/cm) on a polyethylene (PE) tube coated with poly(MPC-co-BMA) was 19.51 +/- 5.58, with albumin; 20.05 +/- 7.29, with SPEU having sulphonated group; 76.10 +/- 18.9, with SPEU; 287.0 +/- 95.0, PE treated by plasma irradiation; 2091 +/- 261, and original PE was 1772 +/- 116. The results were further certified by scanning electron microscopic observations.
Antibodies, Monoclonal↗
Improvement of blood compatibility on cellulose dialysis membrane. I. Grafting of 2-methacryloyloxyethyl phosphorylcholine on to a cellulose membrane surface.
A methacrylate with a phospholipid polar group, 2-methacryloyloxyethyl phosphorylcholine (MPC), was grafted on cellulose membrane for haemodialysis in an aqueous medium using cerium ion (Ce4+) as an initiator. The effects of the concentrations of MPC and Ce4+, and degassing of feed solution on the grafting of MPC on the surface and the membrane properties such as permeability and mechanical strength were examined. The grafted MPC composition depended on the concentrations of both the monomer and initiator in the feed solution. When the grafted MPC distribution was controlled by the monomer concentration, the permeability of the membrane decreased with an increase in grafted MPC distribution. On the other hand, the permeability was not changed from the original membrane's value when the MPC distribution was regulated by Ce4+ concentration. The tensile strength of the membrane did not change during the grafting of MPC and this indicated that the grafting had taken place in the amorphous region of the cellulose. These results suggested that this method is a promising way to improve the blood compatibility of a cellulose membrane without having an adverse effect on the haemodialysis membrane.
Biocompatible Materials↗
Improvement of blood compatibility on cellulose dialysis membrane. 2. Blood compatibility of phospholipid polymer grafted cellulose membrane.
The blood compatibility of a cellulose haemodialysis membrane whose surface was grafted with a methacrylate having a phospholipid polar group, 2-methacryloyloxyethyl phosphorylcholine, was evaluated with attention to platelet adhesion to the membrane surface and complement activation induced by the membrane. When the original cellulose membrane came in contact with platelet-rich plasma for 30 min, numerous platelets adhered to the surface and aggregated. On the other hand, the membrane grafted with 2-methacryloyloxyethyl phosphorylcholine effectively suppressed platelet adhesion and activation. This effect became more pronounced with increasing surface distribution. Especially, the 2-methacryloyloxyethyl phosphorylcholine grafted membranes, whose distribution exceeded 0.27, completely inhibited platelet adhesion, even when the contact time was 180 min. Moreover, the complement activation was also reduced with increased 2-methacryloyloxyethyl phosphorylcholine distribution on the surface of the membrane.
Animals↗
Molecular isoforms of murine CD44 and evidence that the membrane proximal domain is not critical for hyaluronate recognition.
We previously found that the CD44 glycoprotein on some lymphocytes can mediate adhesion to hyaluronate (HA) bearing cells. However, many questions remain about the molecular heterogeneity of CD44 and mechanisms which control its recognition of this ligand. In vitro mutagenesis and DNA sequencing have now been used to investigate the importance of the membrane proximal region of murine CD44 for recognition of soluble or cell surface HA. CD44 with an 83 amino acid deletion in this region mediated binding to soluble ligand and the apparent avidity increased markedly in the presence of a particular antibody to CD44, IRAWB14. The shortened CD44 was however inefficient in mediating adhesion of transfected cells to HA immobilized on cell surfaces. Four new murine isoforms of CD44 were isolated from a carcinoma line by use of the polymerase chain reaction. Only two of them correspond to ones recently discovered in rat and human cells. The longest variant nearly doubled the length of the extracellular portion of the molecule and introduced an additional 20 potential sites for glycosylation. When expressed on T lymphoma cells, all four of the new murine CD44 isoforms were capable of mediating adhesion to HA bearing cells. This result contrasts with a report that a related human CD44 isoform lacks this ability when expressed on B lineage lymphoma cells. The new murine isoforms also conferred the ability to recognize soluble HA and were very responsive to the IRAWB14 antibody. A brief survey of normal murine cell lines and tissues revealed that the hemopoietic isoform was the most abundant species. These findings indicate that the NH2-terminal portion of CD44 is sufficient for HA recognition and that this function is not necessarily abrogated by variations which occur in the membrane proximal domain. They add to the known molecular diversity of CD44 and provide another experimental model in which isoform specific functions can be investigated.
Amino Acid Sequence↗
Left ventricular hypertrophy in a canine model of reversible pressure overload.
OBJECTIVE: The goal of therapy for left ventricular pressure overload should include regression of the associated left ventricular hypertrophy, but this process is incompletely understood. The aim of the study was to characterise the extent and time course of the progression and regression of pressure overload left ventricular hypertrophy in a canine hypertrophy model. METHODS: Six puppies were studied longitudinally with haemodynamic and echocardiographic measurements for 10 months. The study animals underwent ascending aortic banding at nine weeks of age which produced an initial gradient of 30 mm Hg. Subsequent growth led to an increase in gradient and the development of left ventricular hypertrophy. Then thoracotomy was again performed to remove the band. One month later, balloon aortoplasty was performed to remove the residual gradient. The animals were then observed for six months. RESULTS: Growth increased the gradient to 105(SEM 10) mm Hg three months after banding. The left ventricular weight to body weight ratio (g.kg-1), an index of hypertrophy, was 7.2(0.5) after three months of pressure overload. Subsequently the band was surgically removed, reducing the gradient to an average of 58(10) mm Hg. Balloon dilatation of the residual aortic stricture reduced the gradient further to 6(5) mm Hg. Over the ensuing six months, echocardiographic determination of left ventricular mass showed the regression in left ventricular hypertrophy. After six months, left ventricular weight to body weight ratio in the previously banded animals was significantly reduced from 7.2(0.5) to 5.3(0.2) (p less than 0.05). CONCLUSIONS: The model produced over 100% left ventricular hypertrophy, most of which regressed following removal of the pressure overload.
Angioplasty, Balloon↗
Immunohistochemical studies of blood group antigens ABH in cutaneous angiosarcoma.
Eight angiosarcomas were clinicopathologically and immunohistochemically investigated. Four of the angiosarcomas originated in the scalp of the elderly, and four cases were angiosarcomas associated with chronic lymphedema after hysterectomy for uterine carcinoma or after mastectomy for breast carcinoma. Six of the angiosarcomas showed conventional histopathology, whereas the remaining two cases were considered cutaneous epithelioid angiosarcoma. Immunohistochemical studies for blood group antigens ABH were carried out. Three of the conventional angiosarcomas were weakly positive and three were moderately positive with antigens ABH. The antigens were strongly positive in the two epithelioid angiosarcomas. The biologic course of the two epithelioid angiosarcomas was longer than that of the other six cases. This study suggested that the strong positivity of blood group antigens may be one of the characteristics of epithelioid angiosarcoma.
ABO Blood-Group System↗
Changes in Cytokinin Activities and Mass Spectrometric Analysis of Cytokinins in Root Exudates of Rice Plant (Oryza sativa L.) : Comparison between Cultivars Nipponbare and Akenohoshi.
Changes in exudation rate and cytokinin activities in the exudates were measured in two varieties of rice (Oryza sativa L.), cv Nipponbare (a Japanese normal cultivar) and cv Akenohoshi (a high-yielding cultivar). The exudation rates of Akenohoshi, the leaves of which remained green for a longer time, were higher than those of Nipponbare after the booting stage. Cytokinin activities in the exudates of Akenohoshi were higher than those of Nipponbare during the ripening period. Cytokinins in the exudates collected during the middle of the ripening stage were analyzed with mass spectrometry using deuterium-labeled standards. trans-Zeatin, trans-ribosylzeatin, and N(6)-isopentenyladenosine were detected as free cytokinins, and zeatin was detected in the hydrolysates of highly polar fractions ("conjugated zeatin") in the exudates of both cultivars. Conjugated zeatin was the predominant cytokinin in both cultivars. Therefore, we suggest that conjugated zeatin is an important form of cytokinin during the ripening stage. The level of each of the cytokinins in Akenohoshi was higher than that in Nipponbare. Also, we discuss the correlation between the leaf senescence and cytokinin content in root exudates.
Journal Article↗
The factors in influencing the adjustment to shift work.
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Adaptation, Psychological↗
Abnormal calcium current in hippocampal CA3 pyramidal cells of the spontaneously epileptic rat (SER).
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Action Potentials↗
Sebaceous gland and sweat gland carcinomas of the skin. Clinicopathological study and significance of c-erbB-2 oncoprotein expression.
Thirteen sebaceous gland carcinomas and 10 sweat gland carcinomas were examined to elucidate any important histological parameters influencing their prognosis, and the relationship between immunohistochemical expressions of c-erbB-2 oncoprotein and survival of the patients was analyzed. Sebaceous gland carcinomas with vacuolated cytoplasm in more than 50% of whole tumor area, with necrosis, and without lymphoid cell infiltration in tumor nests and stroma had a higher incidence of tumor recurrence and tumor-related death than tumors with vacuolated cytoplasm in 50% or less of whole tumor area (p < 0.01), without necrosis, and with lymphoid cell infiltration in tumor nest and stroma (p < 0.05). Sweat gland carcinomas of all cases with fatal outcomes demonstrated tubular differentiation in 20% or less of whole tumor area, lymphatic permeation and desmoplastic reaction. Three sebaceous gland carcinomas and three sweat gland carcinomas were positive for c-erbB-2 oncoprotein. Two of three sebaceous gland carcinomas, and all three sweat gland carcinomas developed tumor recurrence and ended in tumor-related deaths. Sweat gland carcinomas with c-erbB-2 expression had significantly shorter survival than those with negative immunostain (p < 0.01). Cytoplasmic appearance, tumor necrosis, and lymphoid cell infiltration in tumor nests and stroma of sebaceous gland carcinoma, and tubular differentiation, lymphatic permeation, and growth patterns of sweat gland carcinoma are considered to closely correlate to the prognosis. Immunohistochemically detected c-erbB-2 oncoprotein may be an indicator of bad prognosis.
Adolescent↗
A sensitive enzymatic method (SK-013) for detection and quantification of specific periodontopathogens.
Porphyromonas gingivalis, Bacteroides forsythus, and Treponema denticola have been found to predominate in periodontal pockets of patients with adult periodontitis. These microorganisms hydrolyze the synthetic peptide N-benzoyl-DL-arginine-2-naphthylamide (BANA). In this study, we developed an enzymatic method, designated SK-013, to detect the existence of these microorganisms in subgingival plaque bacteria. This enzymatic method was based on the observation of the hydrolysis of N-carbobenzoxy-glycyl-glycyl-arginyl-3,5-dibromo-4-hydroxyaniline (N-CBz-Gly-Gly-Arg-DBHA) and made more sensitive by adding an enhancing system. The SK-013 was specifically positive for P. gingivalis, B. forsythus, T. denticola, and some strains of Capnocytophaga species, but was not specific for any of the other bacterial strains tested. This SK-013 system may be valuable for detection and quantification of periodontal disease-associated bacteria in subgingival plaque and thus for diagnosis of periodontal infections.
Bacteroides↗
A sensitive enzymatic method (SK-013) for detection of Treponema denticola, Porphyromonas gingivals and Bacteroides forsythus in subgingival plaque samples.
An enzymatic method, SK-013, was developed for rapid detection of the peptidase activity in subgingival plaque samples. This method was found to have specificity for Porphyromonas gingivalis, Treponema denticola, Bacteroides forsythus, and some Capnocytophaga strains. The purpose of this study was to determine whether SK-013 could indicate the presence of periodontopathic bacteria, including T. denticola, P. gingivalis and B. forsythus, which produce trypsin-like enzymes. Subgingival plaque samples were taken from 10 clinically healthy sites and 30 periodontally diseased sites with 3 paper points. SK-013 activity of plaque samples was assayed, and the numbers of T. denticola, P. gingivalis and B. forsythus in the sample were counted by immunofluorescence technique. In diseased sites, the SK-013 activity was significantly correlated with clinical parameters such as Gingival Index, Plaque Index, probing depth and bleeding on probing. A significant correlation was found between the presence of these organisms and SK-013 activity. Correlation coefficients between the presence of T. denticola and SK-013 activity were higher than those with other organisms. These findings indicate that the SK-013 is useful as an indicator of cell population of T. denticola, P. gingivalis and B. forsythus in subgingival plaque.
Bacteroides↗
Cloning and expression of the aspartate carbamoyltransferase gene from Treponema denticola.
Treponema denticola seems to play a central role in the etiology of human periodontal disease. We have cloned an antigenic protein-coding sequence from T. denticola ATCC 33520. The protein-coding region was found to be a 3-kbp HindIII-HindIII fragment. The open reading frame consists of 1,426 bp and codes for a protein with an M(r) of 54,919. The deduced amino acid sequence showed 33.8% homology with that of the aspartate carbamoyltransferase of Escherichia coli. The gene products showed aspartate carbamoyltransferase activity.
Amino Acid Sequence↗
Coronary blood flow after the regression of pressure-overload left ventricular hypertrophy.
Abnormal coronary blood flow (CBF) in long-standing left ventricular (LV) pressure-overload hypertrophy has been associated with ischemia and LV dysfunction. Thus, goals of therapy in pressure overload are not only the relief of the overload itself but also regression in hypertrophy and subsequent improvement in CBF. However, little is known about CBF in humans or in large mammals after the relief of pressure overload, when the hypertrophy has regressed. This study was performed to test the hypothesis that, even 6 months after the relief of pressure overload in the dog, CBF would still be abnormal. Three groups of dogs were studied: 1) normal control dogs (NL group), 2) dogs with LV pressure-overload hypertrophy (LVH group), and 3) dogs that had developed LV pressure-overload hypertrophy but in whom the pressure overload was relieved 6 months before the final study (LVH Reg group). CBF was studied in conscious dogs by use of the radiolabeled microsphere technique at rest, during rapid atrial pacing, and during maximum coronary vasodilation produced by adenosine infusion. The ratio of LV weight (g) to body weight (kg) (LVBW) was 4.2 +/- 0.3 in the NL group, 7.1 +/- 0.6 in the LVH group, and 7.7 +/- 0.5 in the LVH Reg group before pressure-overload relief (p = NS, LVH versus LVH Reg). Six months after removal of the pressure overload, the LVBW in the LVH Reg group had fallen to 5.5 +/- 0.3 (p < 0.05), but this LVBW was still greater than that in the NL group (p < 0.05). During rapid atrial pacing, endocardial and epicardial CBF rose significantly in NL dogs. However, during rapid atrial pacing, endocardial CBF fell from 1.18 +/- 0.22 to 0.7 +/- 0.20 ml/min per gram in the LVH group (p < 0.05) and did not rise in the LVH Reg group. During adenosine infusion, endocardial blood flow increased in NL dogs from 1.63 +/- 0.13 to 4.0 +/- 0.3 ml/min per gram and increased to a similar level in the LVH Reg group. Although CBF increased during adenosine infusion in the LVH group, the increase was less than that in the NL or LVH Reg group (p < 0.05). Minimum coronary vascular resistance was similar in NL dogs (14 +/- 2 units) and LVH Reg dogs (18 +/- 3 units, p = NS) but was significantly elevated (32 +/- 10 units) in LVH dogs (p < 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)
Adenosine↗
YM-14673, a new thyrotropin-releasing hormone analog, augments long-term potentiation in the mossy fiber-CA3 system of guinea pig hippocampal slices.
Effects of a new thyrotropin-releasing hormone (TRH) analog, N alpha-[[(S)-4-oxo-2-azetidinyl]carbonyl]L-histidyl-L-prolinamide dihydrate (YM-14673), which improves experimentally induced memory dysfunction, on long-term potentiation (LTP) in the mossy fiber-CA3 system, were investigated using guinea pig hippocampal slices. At concentrations of 10(-7) M and 10(-6) M, YM-14673 significantly augmented LTP in a concentration dependent manner. The magnitude of effect of 10(-6) M YM-14673 was similar to that of 10(-6) M TRH. As LTP in the hippocampus is regarded as an elementary process of memory and learning, the augmenting effect of YM-14673 on LTP in the present study may contribute to this drug's ability to remedy memory dysfunction.
Animals↗
[Cell growth inhibitory compound from the culture of intestinal lactic acid bacteria].
The influence of the culture supernatants of 1000 strains of intestinal lactic acid bacteria on the growth of HeLa cells was examined. The compound from Enterococcus faecium 3463 showing the strongest cell growth inhibiting effect in these strains was isolated and identified as tyramine. The effect of tyramine was activated by the newborn bovine sera (NBS), but weakly by the fetal bovine sera (FBS). Benzylamine and beta-phenethylamine also showed the NBS-dependent cell growth inhibitory effect against HeLa cells.
Benzylamines↗