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Biomedical subjects

K Ishihara

Publications and source records attributed to K Ishihara.

At least 397 records · Page 22Linked to original sources
PubMed1994

[A case of sarcoidosis with systemic lymph node involvement presenting as multiple high-density masses on chest and abdominal CT].

We report a case of sarcoidosis with mediastinal and abdominal lymph node involvement presenting as multiple high-density masses on chest and abdominal CT. The patient was a 43-year-old housewife who came to our hospital because of a dry cough and exertional dyspnea. A chest radiograph showed bilateral diffuse reticulo-nodular shadows and widening of the mediastinum. On CT of the chest and the abdomen, lymph nodes were swollen throughout the mediastinum and the para-aortic area of the abdomen. They appeared as very-high-density masses on plain CT. Bronchoscopy revealed involvement of the bronchial walls. Punch biopsy of the bronchial wall, TBLB, and biopsy of the anterior mediastinal lymph node all revealed non-caseous epithelioid cell granulomas. These granulomas contained lamellated, irregularly shaped and darkly-stained structures (Schaumann bodies) that caused the high density of the involved lymph nodes on CT. This case shows at least a part of the mechanism of calcification of lymph node lesions in patients with sarcoidosis.

Adult↗
PubMed1994

[Effects on bone metabolism of asthma treatment with beclomethasone dipropionate (BDP) inhalation and short term burst of oral steroids].

Inhaled steroids are currently the first-line treatment of chronic asthma. Because each metered dose of beclomethasone dipropionate (BDP) is small (50 micrograms), short term burst or continuous use of oral steroids are combined in moderately to severely asthmatic patients. The effect of these treatments on bone metabolism remains unclear. Bone mineral density (BMD), osteoclacin (OC), PTH, Ca, and ALP were assessed in 130 asthmatic patients. There were 3 groups: the first group [B+R] consisted of 17 patients taking BDP (1190 +/- 536 micrograms/day) and also taking oral steroids (8.0 +/- 3.8 mg/day, 8.11 +/- 5.52 years), the second group [B+S] had 35 patients taking BDP (885 +/- 320 +/- g/day) and short-term bursts of oral steroids (PSL 20-40 mg/day, 3-7 days/course, 7.51 +/- 4.54 courses/year) and the third group [B alone] consisted of patients who were taking BDP (480 +/- 260 micrograms/day) alone. BMD was measured by dual energy X-ray absorptiometry (DEXA). In the [B+R], [B+S], and [B alone] groups, the BMD of vertebra (L1-4) was 0.75, 0.86, and 0.90 g/cm2, respectively. The percentages of predicted values based on age and sex were 92.0, 102.7, and 106.9% respectively. BMD and percent decrease were significantly lower in the [B+R] group than in the [B+S] or [B alone] group. It is likely that this phenomenon is caused by long-term use of oral steroids rather than by BDP inhalation but there is no significant difference between the [B+S] and the [B alone] groups. Daily BDP dose did not correlate with BMD by multiple regression analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1994

Polymeric biomaterials: influence of phosphorylcholine polar groups on protein adsorption and complement activation.

The introduction to polymeric biomaterials of phosphorylcholine polar groups represents an approach towards the development of materials with improved blood compatibility. In this respect, two biomaterials, one a copolymer of butyl methacrylate and 2-methacryloyloxyethylphosphorylcholine (MPC), (poly(BMA-co-MPC) and the other, MPC-grafted Cuprophan, were examined with respect to their influence on protein adsorption and complement activation. Protein adsorption was studied by measurement of the adsorption of radiolabelled single proteins (albumin and fibrinogen), while complement activation was measured using radioimmunoassay for C3a des Arg. The investigation demonstrated that the polymers containing phosphorylcholine polar groups can achieve a marked reduction in protein adsorption and complement activation and supports the utilization of phosphorylcholine polar groups as a means of improving the compatibility of biomaterials for blood-contacting applications.

Adsorption↗
PubMed1994

Prognostic value of immunohistochemical staining for proliferating cell nuclear antigen, p53, and c-erbB-2 in sebaceous gland carcinoma and sweat gland carcinoma: comparison with histopathological parameter.

Thirteen cases of sebaceous gland carcinoma and 10 cases of sweat gland carcinoma were studied using immunohistochemical staining for proliferating cell nuclear antigen (PCNA), c-erbB-2, and p53 to examine correlations among them, and to determine the best predictor of patient prognosis. Many sebaceous gland carcinomas and sweat gland carcinomas showed nuclear accumulation of p53, and patients with tumors showing a PCNA index (percentage of nuclei stained for PCNA) higher than 20%, and a p53 index (percentage of nuclei stained for p53) higher than 10% had short survival. Sebaceous gland carcinomas and sweat gland carcinomas showing c-erbB-2 expression had high PCNA (> 20%) and p53 (> 10%) indices, and were associated with poor prognosis. Histologically, sebaceous gland carcinomas showing a high degree of differentiation and severe nucleolar atypia had high PCNA and p53 indices. A growth pattern of small solid nests and strands, a low degree of differentiation, and the presence of lymphatic permeation in sweat gland carcinoma were often associated with high PCNA and p53 indices. These results suggest that nuclear accumulation of p53 plays an important role in the development of sebaceous gland carcinoma and sweat gland carcinoma. Assessment of PCNA and p53 indices together was very useful for prognostication of patient outcome, using cut-off values of 20% and 10%, respectively, to separate good prognosis from poor. Differentiation of sebaceous gland carcinoma, and c-erbB-2 expression by sweat gland carcinoma were significant independent prognostic indicators.

Adult↗
PubMed1994

Effect on gastric mucus of the proton pump inhibitor leminoprazole and its cytoprotective action against ethanol-induced gastric injury in rats.

The effect of leminoprazole ((+-)-2-[[2-(isobutyl-methylamino)benzyl]sulfinyl]-1H-benzimidazol e, NC-1300-O-3, CAS 104340-86-5), a new compound being developed as an inhibitor of the gastric mucosal proton pump (H+,K(+)-ATPase), on gastric mucus secretion was studied by a biochemical method measuring the gastric mucin content in rats. Oral administration of leminoprazole (30 mg/kg) strongly inhibited the hemorrhagic lesions induced by 60% ethanol containing 0.15 mol/l HCl (acid-ethanol) administered 1 h later. Leminoprazole significantly inhibited the acid-ethanol-induced reduction of the mucin content in the surface mucosa including the mucus gel layer, but no significant effect could be obtained on the reduction of mucin present in the deep layer of the corpus and antral mucosa. Leminoprazole given to rats not treated with acid ethanol accelerated the secretion of deep mucosal mucus and increased significantly the content of soluble mucus which was recovered from the gastric luminal contents to about 200% of control, but failed to produce any significant change in the mucus content present in the surface mucosal and the mucus gel layers. The effect of leminoprazole on gastric mucus secretion might contribute to healing the peptic ulcer diseases and may be involved in the cytoprotective mechanism of this drug.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1994

[The clinico-pathological significance of hematuria in diabetics].

A clinico-pathological study was performed on 154 patients with diabetes mellitus to clarify the significance of glomerular hematuria. Glomerular hematuria was observed in 26 patients (16.9%), of whom 10 had complications of IgA glomerulonephritis and one had membranous nephropathy. The remaining patients (143 cases) were divided into two groups; a hematuria group (15 cases) and a non-hematuria group (128 cases). Patients in the hematuria group showed diabetic retinopathy, hypertension, massive proteinuria and the requirement for insulin therapy more often than those in the non-hematuria group (p < 0.01, p < 0.001, p < 0.001 and p < 0.01, respectively). In addition, the serum creatinine level in the hematuria group was significantly elevated compared to that in the non-hematuria group (p < 0.01). Histologically, patients in the hematuria group exhibited advanced diffuse lesions, nodular lesions, exudative lesions, microaneurysms, crescent formation, capsular adhesion and interstitial lesions more often than those in the non-hematuria group (all, p < 0.001). Furthermore, the vascular index in the hematuria group was significantly higher than that in the non-hematuria group (p < 0.001). It is suggested that glomerular hematuria in diabetic patients indicates the presence of diabetic nephropathy at an advanced stage or coexistence of primary glomerulonephritis.

Adolescent↗
PubMed1994

[Reoperations of extracardiac valved conduit for congenital cardiac defects].

Fifteen of 223 patients who have had extracardiac conduit repair at the Heart Institute of Japan from January, 1970, to April, 1991, have required conduits replacement because of conduit obstruction or infection. The main causes of obstruction were degeneration of the prosthetic valve and proliferative pseudo-intima in the conduit. The interval between initial conduit repair and conduit replacement was 2.2 to 18.3 years (mean 10.5 +/- 4.4). The average pressure gradient through the conduit decreased from 74.7 +/- 42.0 mmHg preoperatively to 12.3 +/- 7.1 mmHg postoperatively (p < 0.05). There was no early and late death. We concluded that xeno-pericardial roll conduits were superior to others and that conduit replacement procedure following the extracardiac conduit repair was safe and effective.

Adolescent↗
PubMed1994

[Can patients with chronic asthma discontinue inhaled corticosteroid?].

As an initial investigation to determine whether or not inhaled corticosteroids can be discontinued, we evaluated the results of discontinuation in patients who had been well controlled with inhaled corticosteroids for more than one year prior to this study. The average dose of BDP which the patients had been inhaling at the start of this study was 365 micrograms/day. To determine the effect of discontinuing inhaled corticosteroids, we compared the patients' peak expiratory flow rates and the frequency of beta-agonist use between the 4-week observation period and follow-up periods of varying duration. Only three out of twenty patients enrolled were able to maintain their discontinuation of BDP, while the remaining seventeen patients restarted after a mean period of 30.8 days. Mean peak flow values began to fall during the first week after discontinuation, and decreased morning peak flow values became significant in the 2nd, 3rd and 4th weeks. The mean peak flow value during the observation period was 85.2% of each patient's personal best, but had dropped to 68.8% of this level just before restarting inhaled corticosteroid. The frequency of beta-agonist use during the study period (2.99 +/- 3.39 times a day) was significantly higher than during the observation period (1.94 +/- 2.95 times a day). This finding strongly suggests that the patients' asthmatic conditions had become unstable during the study period. These results suggest that any decision to discontinue the use of inhaled corticosteroid, even in well controlled patients with chronic asthma, should be taken with great care.

Administration, Inhalation↗
PubMed1994

Ventricular function after anatomic repair in patients with atrioventricular discordance.

Since June 1989, 18 patients with atrioventricular discordant anomalies under 15 years of age underwent anatomic correction, or double switch operation, with 2 hospital deaths (11%). Ages ranged from 1 year 4 months to 12 years (mean 7.2 years) and body weights ranged from 7.1 to 32.5 kg (mean 20.1 kg) at operation. Visceral situs was solitus in 12 and inversus in 6. Ventriculoarterial connection was discordant in 4 and double-outlet in 14. All had associated congenital cardiac anomalies consisting of ventricular septal defect in 17, atrial septal defect in 9, pulmonary atresia in 10, pulmonary stenosis in 6, systemic tricuspid regurgitation in 9, mitral regurgitation in 6, bilateral superior venae cavae in 6, patent ductus arteriosus in 6, Wolff-Parkinson-White syndrome in 2, and congenital atrioventricular block in 1. Previous palliation had been performed 19 times in 11 patients including systemic-pulmonary shunts in 10 patients and pulmonary banding in 1 patient. Anatomic correction consisted in the Mustard procedure in 12 or the Senning procedure in 6 at the atrial level and in external conduit repair in 14, arterial switch operations in 3, or direct anastomosis between the pulmonary artery and right ventricle in 1 at the ventriculoarterial level. The arterial switch operation was indicated in patients with a normal pulmonary valve, and external conduit repair was indicated for patients with pulmonic stenosis or atresia. Anatomic right ventricular end-diastolic volume showed significant reduction from 122.2% +/- 46.3% of normal to 78.8% +/- 24.0%, mainly owing to unloading of the ventricle after the operation (p < 0.0003). Right ventricular ejection fraction remained unchanged (56% +/- 8% to 56% +/- 6%). Anatomic left ventricular end-diastolic volume and left ventricular ejection fraction remained unchanged before and after the operation: volume 134.6% +/- 50.0% of normal to 127.3% +/- 32.8% and ejection fraction from 61% +/- 8% to 56% +/- 8%. Cardiac index averaged 3.1 +/- 0.5 L/min per square meter after the operation. The double switch operation is best indicated in patients with atrioventricular discordance associated with systemic tricuspid regurgitation and/or with poor systemic right ventricular function.

Cardiac Output↗
PubMed1994

The effects of complete versus incomplete mitral valve repair in experimental mitral regurgitation.

Severe mitral regurgitation (regurgitant fraction 0.75 +/- 0.02) was created in eight dogs by our closed-chest chordal rupture technique. After 3 months of chronic mitral regurgitation all indices of contractile function were depressed. Mitral valve repair was then attempted. Postoperative regurgitant fraction was reduced compared with the preoperative value in all eight dogs. Concomitantly, forward cardiac output increased in all dogs and pulmonary capillary wedge pressure fell in all dogs. However, in some dogs, significant regurgitation persisted despite repair. Postoperative regurgitant fraction ranged from 0% to 60%. Postoperative residual regurgitant fraction was related significantly to postoperative cardiac output (r = 0.99), pulmonary capillary wedge pressure (r = 0.77), ejection fraction (r = 0.75), and two indices of contractile function--the mass-corrected end-systolic stress volume relationship (r = 0.87) and end-systolic stiffness (r = 0.93). In general, these parameters returned to their normal values before mitral regurgitation when postoperative regurgitant fraction was less than 30%. Myocytes isolated from the ventricles at the end of study also demonstrated normal contractile function when regurgitant fraction was less than 30%.

Animals↗
PubMed1994

[The youngest case of isolated interruption of the aortic arch without associated cardiac anomalies].

A five-month-old girl was admitted to our institute because of the systolic blood pressure gradient of 42 mmHg between upper and lower extremities. Cineangiography revealed that the brachiocephalic artery originated from ascending aorta, while the left subclavian and left vertebral arteries took their origin from the descending aorta. However, the left common carotid artery was not visualized either on the angiogram or on the digital subtraction angiogram. No other associated cardiovascular anomalies, such as patent ductus or ventricular septal defect, were found. Therefore the diagnosis of isolated interruption of the aortic arch (IAA) Celoria-Patton type C, was made. As the heart failure gradually progressed, the aortic arch reconstruction with a extended polytetrafluoroethylene graft of 10 mm in diameter under extracorporeal circulation utilizing separate ascending aortic cannulation were performed. Her postoperative course was uneventful. The majority of cases with IAA associated with cardiac anomalies require surgical intervention in the neonatal period or in infancy. However, clinical course of isolated IAA generally resembles to that of the post ductal coarctation of the aorta, and most of the isolated interruption is diagnosed in adulthood. The infant is the youngest case with isolated IAA undergone aortic arch reconstruction with success ever reported in the literature.

Aorta, Thoracic↗
PubMed1994

Coaggregation between Porphyromonas gingivalis and Treponema denticola.

To elucidate an ecological profile of several periodontopathogens, the authors examined the coaggregation between cells of Porphyromonas gingivalis and oral bacterial strains including Treponema denticola in vitro. Coaggregation between cells of plaque bacteria was examined by visual assay and phase-contrast microscope. P. gingivalis cells coaggregated with strains of T. denticola and Treponema socranskii subspecies socranskii, but did not coaggregate with T. socranskii subspecies buccale, T. socranskii subspecies paredis, Treponema vincentii, or Treponema pectinovorum. The extracted hemagglutinin from P. gingivalis was active agglutinating T. denticola cells. Addition of serum and saliva somewhat affected the coaggregation, but no effects of tested sugars or amino acids were found. Heat treatment of T. denticola cells did not reduce the coagregation: heat treatment of P. gingivalis cells eliminated it. Growth inhibitory activity among these bacterial species was examined by the stab culture method. Strains of T. denticola ATCC 35404 and 35405 and T. vincentii inhibited the growth of some P. gingivalis strains, but not others. No strain of Treponema was inhibited by black-pigmented anaerobic rods. The coaggregation observed between P. gingivalis and T. denticola indicates the potential importance of their simultaneous existence in human periodontal pockets and development of the disease.

Actinomyces↗
PubMed1993

Stimulation of mucus glycoprotein biosynthesis in rat gastric mucosa by gastrin.

We examined the effects of the gastrin family of peptides on gastric mucus glycoprotein (mucin) biosynthesis in rat gastric mucosa using an organ culture technique. Radiolabeled mucin was obtained from the tissue and culture medium of the corpus and antrum of rat stomach incubated for 5 hr with [3H]glucosamine (GlcN), [14C]threonine (Thr), and [35S]sulfate in vitro. With the addition of 10(-8) and 10(-7) M tetragastrin to the culture medium, [3H]GlcN labeled mucin in the corpus tissue increased to 120-135% that of the control (P < 0.01). The biosynthetic responses to cholecystokinin (CCK)-8 and the 17-peptide gastrin were essentially the same as that to tetragastrin. Tetragastrin 10(-8) M also increased the incorporation of [35S]sulfate into the corpus mucin but failed to change [14C]Thr incorporation. In the antrum, biosynthetic activity showed no significant change with 10(-9) approximately 10(-5) M tetragastrin. Ranitidine, diphenhydramine and omeprazole at 10(-5) M did not suppress the tetragastrin-induced increase in [3H]GlcN incorporation into mucin, but L-365,260 at a concentration of 10(-6) M completely blocked this effect. These results suggest that gastrin stimulates mucin production via CCK-B/gastrin receptors in the oxyntic region of rat gastric mucosa.

Animals↗
PubMed1993

The alpha 1A-adrenergic receptor subtype mediates biochemical, molecular, and morphologic features of cultured myocardial cell hypertrophy.

alpha 1-Adrenergic agonists induce a hypertrophic phenotype in cultured neonatal rat ventricular myocytes. Quantifiable markers of this phenotype include stimulation of phosphoinositide hydrolysis, transcriptional induction of atrial natriuretic factor (ANF) gene expression, and an increase in myocardial cell size. The aim of the present work was to determine which alpha 1-adrenergic receptor subtype mediates the acquisition of these parameters of myocardial cell hypertrophy. Phosphoinositide hydrolysis is inhibited by low concentrations of 5-methylurapidil (log Ki = -8.7) and (+)-niguldipine (log Ki = -10.6). The alpha-adrenergic receptor-induced increase in transcriptional activation of an ANF luciferase reporter gene is inhibited over the same range of concentrations of 5-methylurapidil (log Ki = -8.2) and (+)-niguldipine (log Ki = -11.2) that inhibit phosphoinositide hydrolysis. In addition, the increase in cell size that accompanies alpha-adrenergic receptor stimulation of cultured ventricular myocytes is blocked by similar concentrations of 5-methylurapidil (log Ki = -8.0) and (+)-niguldipine (log Ki = -10.6). In contrast, treatment with the alpha 1B selective antagonist chlorethylclonidine at a concentration of 10 microM had no effect on the adrenergically mediated induction of ANF luciferase reporter gene expression or the adrenergically induced increase in myocardial cell size. These findings demonstrate that pharmacologically identifiable alpha 1A-adrenergic receptors mediate not only the early effects of alpha 1-adrenergic stimulation such as phosphoinositide hydrolysis, but that they activate the signaling pathways that control transcriptional induction of the ANF luciferase reporter gene and an increase in myocardial cell size. Studies using alpha 1-adrenergic receptor cDNAs to delineate and alter the direct interaction of this receptor subtype with proximal signaling molecules, e.g. GTP binding proteins, should provide a powerful means of assessing their role in the induction of the molecular and morphologic parameters of myocardial cell hypertrophy.

Animals↗
PubMed1993

Effects of saiboku-to (TJ-96) on the production of platelet-activating factor in human neutrophils.

Platelet-activating factor (PAF) has been recognized as an important chemical mediator in allergic and inflammatory reactions. Evidence suggests that PAF is deeply involved in the pathogenesis of bronchial asthma, in which PAF induces profound bronchospasms, increased vascular permeability, and eosinophil/neutrophil accumulation in the respiratory tract. The precise pharmacologic mechanisms of Kampo preparations are still obscure, but extensive experience has established their clinical effectiveness for the treatment of patients with allergic and inflammatory disorders. We tried to examine the effects of Saiboku-to (TJ-96), a Kampo prescription, on in vitro PAF production by human neutrophils because this preparation is widely used for the management of patients with bronchial asthma and bronchitis. Saibokuto inhibited in vitro PAF production in a dose-dependent manner. Among the major natural components of Saiboku-to, saiko (Bupleuri radix) and kanzo (Glycyrrhizae radix) showed inhibitory effects on PAF production, whereas ohgon (Scutellariae radix) had no inhibitory effect. Saikosaponin a and c, purified elements extracted from saiko, showed no inhibitory effects, but saikosaponin d and glycyrrhizin, extracted from kanzo, inhibited PAF production dose-dependently. Further studies are needed to evaluate the clinical significance of Kampo medicines in allergic diseases, but our present results suggest that the pharmacologic benefit of Saiboku-to is partially due to its inhibitory effect on PAF production.

Drugs, Chinese Herbal↗
PubMed1993

Indication of possible post-translational formation of disulphide bonds in the beta-sheet domain of human lysozyme.

Lysozyme has two distinct folding domains, and in most molecules the alpha-helical domain folds more quickly than the beta-sheet domain in vitro [Radford, Dobson and Evans (1992) Nature (London) 358, 302-307]. In order to investigate the relationship between the formation of disulphide bonds and protein folding in vivo, we carried out cysteine scanning mutagenesis to shift positions of the disulphide bonds in both the alpha-helical and beta-sheet domains of human lysozyme. Of the constructed mutants (nine in the beta-sheet domain and 13 in the alpha-helical domain), the mutant L79CC81A, in which Leu-79 and Cys-81 in the beta-sheet domain were replaced by Cys and Ala respectively, was secreted by yeast. The rest of the mutants were retained in the insoluble fraction of the cell, probably because of a failure of folding. The distance between the two alpha-carbons at positions 79 and 95 in the wild-type protein is too far to form a disulphide bond, but analysis of the primary structure revealed that the major part of L79CC81A was secreted with a non-native disulphide bond Cys79-Cys95 and two free cysteine residues at positions 65 and 77 in the beta-sheet domain. These results suggest that the beta-sheet domain of human lysozyme can tolerate the shift of locations of disulphide bonds, and the non-native folding of mutated polypeptide chains in in vivo folding. The free residues Cys-65 and Cys-77 formed a disulphide bond in vitro by air oxidation, yielding two isomers. On the basis of our previous results and present study it is suggested that the formation of Cys6-Cys128 is the first step of the in vivo correct folding of human lysozyme, and disulphide bonds in the beta-sheet domain are post-translationally formed in vivo.

Amino Acid Sequence↗
PubMed1993

[Usefulness of enhanced MR angiography by nitroglycerin].

We tried to use nitroglycerin to enhance MR angiography (MRA). Nitroglycerin has an effect to dilate vessels. We made a direct comparison between pre and post enhanced MRA (3 D-TOF technique). MRA after administration of nitroglycerin could depict more details of cortical branches without enhancement of background. So we recommend this method to be used in any examination of MR angiography.

Adult↗