Biomedical subjects

M Takano

Publications and source records attributed to M Takano.

At least 19 recordsLinked to original sources

PubMed1992

The effect of intrathecally administered imiloxan and WB4101: possible role of alpha 2-adrenoceptor subtypes in the spinal cord.

To define the antagonist pharmacology of spinal antinociceptive effects of alpha 2-adrenoceptor agonists, the ability of WB4101 (2-(2,6-dimethoxyphenoxyethyl)-aminomethyl-1,4-benzodioxane) and imiloxan to antagonize the effect of spinal ST-91 (2-[2,6-diethylphenylamino]-2-imidazoline), clonidine and dexmedetomidine was examined. Antinociceptive effects of ST-91 were antagonized by WB4101 and imiloxan; clonidine only by WB4101; and, dexmedetomidine was not antagonized by either antagonist. It is hypothesized that the alpha 2 adrenoceptor subtype alpha 2A is involved in the antinociception of spinal clonidine and dexmedetomidine, and alpha 2B is involved in that of ST-91.

Adrenergic alpha-Agonists↗

PubMed1992

Transport of procainamide in a kidney epithelial cell line LLC-PK1.

Transport of procainamide, an anti-arrhythmic drug, was investigated in LLC-PK1 kidney epithelial cell line. The uptake of procainamide by LLC-PK1 monolayers cultured in plastic dishes was temperature-dependent, saturable and inhibited by organic cations such as cimetidine and N-acetylprocainamide. An aminocephalosporin antibiotic, cephalexin, also inhibited procainamide uptake, but an organic anion, p-aminohippurate, did not. The uptake of procainamide was greater at an alkaline external pH than at an acidic pH. In addition, procainamide uptake increased when intracellular pH was decreased and the uptake decreased when the intracellular pH was increased by ammonium chloride treatment, indicating the involvement of an H+/procainamide antiport system in apical membrane. The basolateral to apical flux of procainamide across LLC-PK1 monolayers cultured on permeable supports was 2.5-times larger than the apical to basolateral flux, and only the former process was inhibited by other organic cations. These findings suggest that LLC-PK1 cells can transport procainamide by the organic cation transport system and that procainamide is transported unidirectionally from basolateral to apical side across the cell monolayers.

Animals↗

PubMed1992

Expression of renal organic cation transporter in Xenopus laevis oocytes.

The expression of the organic cation transport system of rat renal proximal tubules has been studied in Xenopus laevis oocytes injected with poly(A)+ RNA from the rat renal cortex. The effectiveness of the technique was confirmed by examining expression of the Na+/D-glucose co-transporter. Compared with water-injected and non-injected oocytes, the injection of total poly(A)+ RNA resulted in about a 3-fold increase in tetraethylammonium (TEA) uptake activity. TEA uptake by poly(A)(+)-RNA-injected oocytes was time-dependent and was inhibited by cimetidine and HgCl2, but not by p-aminohippurate. After size-fractionation on a sucrose density gradient, a 1.4-2.4 kb poly(A)+ RNA fragment was identified that expressed the organic cation transport system in oocytes. These results demonstrate that the renal organic cation transporter was expressed in oocytes and that this expression system can provide an effective assay procedure for cloning of the organic cation transporter.

Animals↗

PubMed1992

Increased uptake of T-kininogen by the liver in inflammatory conditions.

The distribution of [125I]T-kininogen in the liver of rats was found to be increased by laparotomy-, turpentine- or lipopolysaccharide-induced inflammation, whereas no such increase was observed in other organs or when 125I-labeled carboxymethylated T-kininogen, which does not inhibit cysteine proteinase, was used. These results suggest that the liver plays an important role in clearing T-kininogen from the circulation during inflammation.

Animals↗

PubMed1992

Distribution of the isoprenaline-induced chloride current in rabbit heart.

Current density of the isoprenaline-induced chloride current (ICl) was measured in sino-atrial (SA) node cells and atrial and ventricular myocytes dissected enzymatically from the rabbit heart. In addition to the conventional voltage clamp method the whole-cell patch clamp method using nystatin was employed to avoid run-down of ICl in dialysed cells. Isoprenaline (0.3 microM) failed to induce ICl in the 20 atrial cells examined. The integrity of the beta-adrenergic system was established by recording the response of the Ca2+ current in the same cell. Both isoprenaline and acetylcholine failed to affect the background membrane conductance in the 20 SA node cells studied. Myocytes isolated from the epicardial region of the left ventricular wall showed relatively higher ICl density (24.9 +/- 12.1 microS/microF) than those from the endocardial side (12.3 +/- 8.5 microS/microF). We conclude that beta-receptor-operated ICl is insignificant in atrial and SA node cells.

Action Potentials↗

PubMed1992

Synthesis of lipopolysaccharide by Escherichia coli cells recovering from sublethal heat stress.

Escherichia coli cells exposed to a sublethal heat treatment at 55 degrees C for 15s synthesized lipopolysaccharide during their recovery period after heat stress. As chloramphenicol at least partly inhibited the synthesis of lipopolysaccharide, it is suggested that its synthesis might be in part due to the lipopolysaccharide-synthesizing enzymes produced de novo. The results obtained coincided with our previous finding that the permeability barrier function was repaired by heat-stressed cells.

Adaptation, Biological↗

PubMed1992

Stimulation of angiotensinogen production in primary cultures of rat hepatocytes by glucocorticoid, cyclic adenosine 3',5'-monophosphate, and interleukin-6.

The effects of hormones and cytokines on angiotensinogen production were studied in primary cultured rat hepatocytes. The basal secretion of angiotensinogen decreased during culture. The addition of dexamethasone and (Bu)2cAMP completely prevented this decrease. Angiotensinogen secretion by freshly plated hepatocytes was slightly increased in response to dexamethasone, but after 24 h in culture, hepatocytes no longer responded to dexamethasone alone. When hepatocytes were treated with (Bu)2cAMP, glucagon, or forskolin, angiotensinogen secretion increased in response to dexamethasone in a concentration-dependent manner. 17 beta-Estradiol and T3 failed to stimulate angiotensinogen secretion in either the presence or absence of (Bu)2cAMP. Interleukin-6 (IL-6) exhibited a stimulatory activity on angiotensinogen secretion, which was dependent on the presence of dexamethasone, whereas IL-1 and tumor necrosis factor had no effect in either the presence or absence of dexamethasone and/or (Bu)2cAMP. Unlike primary cultured hepatocytes, angiotensinogen secretion by rat hepatoma H4IIEC3 cells increased in response to dexamethasone alone. This increase was not enhanced by (Bu)2cAMP, but was enhanced by IL-6. Thus, in primary cultures of rat hepatocytes, neither glucocorticoid, cAMP, nor IL-6 alone stimulated angiotensinogen production, but a combination of glucocorticoid and cAMP or of glucocorticoid and IL-6 exhibited a stimulatory activity on angiotensinogen production. These results suggest that angiotensinogen production in the liver is synergistically regulated by these factors, whereas the hepatoma cell line H4IIEC3 lacks the regulatory mechanism of cAMP on glucocorticoid-induced angiotensinogen production.

Angiotensinogen↗

PubMed1992

Inhibition of apical membrane enzyme activities and protein synthesis by gentamicin in a kidney epithelial cell line LLC-PK1.

The mechanism of a gentamicin-induced decrease in apical membrane enzyme activities was investigated in LLC-PK1 cells. Increasing activities of apical membrane enzymes (alkaline phosphatase, aminopeptidase, and gamma-glutamyltransferase) were markedly suppressed by gentamicin during growth in culture. On the other hand, a lesser effect was observed when the activities of these enzymes were decreasing or relatively constant. Gentamicin treatment decreased the maximal enzyme activities of alkaline phosphatase and aminopeptidase, indicating that the number of active enzyme molecules in the apical membrane was decreased by gentamicin. [3H]Leucine incorporation in LLC-PK1 cells was inhibited by gentamicin in a dose-dependent manner, followed by a reduction of total protein. In addition, a well-known protein synthesis inhibitor, cycloheximide, also decreased the apical enzyme activities. These results suggest that the inhibition of protein synthesis by gentamicin is a possible cause of the decreased activities of apical membrane enzymes in LLC-PK1 cells. The inhibition of protein synthesis may be related to the nephrotoxicity induced by aminoglycoside antibiotics.

Animals↗

PubMed1992

Specificity of antibodies to single-stranded (ss) DNA in SLE patients with anti-phospholipid syndrome.

Although the concept of anti-phospholipid syndrome has been proposed in patients with SLE and other rheumatic diseases, the immunological mechanism is still controversial. Recently, the crossreactivity between anti-cardiolipin antibody and anti-ssDNA antibodies has been discussed in relation to this syndrome. In the present study, the specificity such as the avidity and the crossreactivity of anti-ssDNA antibodies was examined to find a clue to clarify the question why all of anti-cardiolipin antibody positive patients do not have any specific clinical features, thrombosis and spontaneous abortion. The avidity of IgG anti-ssDNA antibodies was examined by salt elution studies in solid phase ELISA. The avidity of anti-ssDNA antibodies tended to be lower in 10 patients with specific features than in other 10 patients without those features. The crossreactivity of affinity purified IgG anti-ssDNA antibodies was investigated by competitive ELISA. Purified anti-ssDNA antibodies from 4 patients without specific features were slightly inhibited by negatively charged phospholipids, cardiolipin and phosphatidylserine, whereas purified anti-ssDNA antibodies from 2 patients with specific features, who were considered to have anti-phospholipid syndrome, were little inhibited by these phospholipids. The above results suggest that the specificity of anti-ssDNA antibodies appears, at least partly, in different manners whether specific features are present or absent in anti-cardiolipin antibody positive patients. Moreover, anti-ssDNA antibodies and anti-phospholipid antibodies may form separate groups of antibodies in patients with anti-phospholipid syndrome.

Antibody Specificity↗

PubMed1992

Initial predictors of survival in patients with systemic sclerosis (scleroderma).

We conducted a retrospective study of 86 patients with systemic sclerosis (SSc) to clarify the initial predictors of survival at the first visit to the hospital. A life-table analysis of survival was performed concerning 137 items from their histories, physical examinations, and laboratory data. The observed cumulative survival rates were 78.0 percent at 5 years and 68.2 percent at 10 years. Ten items were found to be the initial predictors of survival in patients with SSc. Of these 10 items, 9 items showed significant differences within 5 years of the first visit to the hospital. Patients with resting electrocardiographic abnormalities, such as atrial or ventricular arrhythmias, or conduction disturbances, pulmonary fibrosis on the chest x-ray films, or decreased vital capacity had significantly lower survival rates. However, patients with anti-centromere antibody had a significantly better survival rate. In addition, males, aged patients over 65 years old, and patients with proteinuria, leucopenia, or hypergammaglobulinemia had significantly lower survival rates. Only patients with proximal scleroderma at the first visit to the hospital had a significantly lower survival rate after 8 years. These results are useful in predicting individual patients at risk of shortened survival and in managing these patients.

Adolescent↗

PubMed1992

[A case of inverted Y ureteral duplication with an ectopic ureterocele].

A 29 year-old male with the complaints of two steps urination and sense of residual urine was admitted. At cystoscopy, a ureterocele was found between the normal left ureteric orifice and the bladder neck. Excretory urography demonstrated a radiolucent area in the bladder and a left lower hydroureter. Retrograde pyelography revealed that the left ureter was divided into two branches. Operative exploration demonstrated that the left ureter was an inverted Y ureteral duplication with an ectopic ureterocele; one opened into the ureterocele and the other into the trigone. We resected the ureterocele wall. Four months later, a voiding cystogram did not show vesicoureteric reflux. Now, he has no symptoms and the results of examination are normal. An inverted Y ureteral duplication is the rarest of all anomalies of the ureter. A review of the literature revealed 36 cases reported previously. Clinical analysis was obtained by reviewing 26 of these cases and adding our own (male 10: female 17, average age: 23 years). Complication included 6 cases of ectopic ureteral opening, 6 with blind-ending branch and 5 with ureterocele. The symptoms of this disease depended on the complicating anomalies. The present case was the 5th one of an inverted Y ureteral duplication with a ureterocele in the world literature.

Adult↗

PubMed1992

[Irritable bowel syndrome in adolescence].

We studied seventy patients, 23 males and 47 females with irritable bowel syndrome in adolescence aged 13-19 yrs, who visited the department of psychosomatic medicine in Takano Hospital during about six year period of April, 1986-July, 1992. Takano Hospital is a coloproctological center in Kumamoto. In the clinical pattern of adolescent patients with irritable bowel syndrome the "gas" pattern was dominant (51.4%). Patients with the gas pattern have severe symptoms of flatus, fullness, rumbling sound and abdominal pain as well as bowel dysfunction, constipation and diarrhea in a classroom. Next, the diarrheal pattern occurred in 20.0%. Diarrheal patients complained of frequent bowel movements and retention feelings before attending school. Recurrent abdominal pain-like pattern was found in 7.1% patients. Clinical symptoms in the adolescent patients seem to derived from a mental tension and stress in a close classroom or before attending school. Many adolescenct patients (67.1%) with irritable bowel syndrome are embarrassed in school-maladjustment; leaving class early, late coming, a long absence, and a withdrawal.

Adolescent↗

PubMed1992

[A case of minimal-sized adenocarcinoma in a fistula-in-ano].

The patient was 47 year-old man with a simple intermuscular fistula-in-ano. Fistulectomy revealed that there was a small mucinous adenocarcinoma. The tumor was small and localized in the wall of the fistula and the muscular invasion was not recognized. The mucin contained a little O-acylated sainomucin, and the origin of the tumor was considered as anal gland cell. This case appears as one evidence that the cancer in fistula-in-ano originates from the anal gland cell in the fistula.

Adenocarcinoma↗

PubMed1992

[Efficacy of early use of continuous isoproterenol inhalation therapy for severe asthma attacks in children].

The aim of this study was to evaluate the efficacy and safety of continuous isoproterenol inhalation therapy for asthma attacks in children. We used l-body isoproterenol (Proternol L) in 22 children with 32 episodes of severe attacks. One of them did not respond to this therapy, and two had complications (atelectasis and pneumothorax). Twenty-nine cases were divided into three subgroups according to their clinical scores; A) scores less than or equal to 4, which meant that they were in the early stage of severe attack (n = 9), B) scores 5-6, which meant impending respiratory failure (n = 17), C) scores greater than or equal to 7, which meant respiratory failure (n = 3). The values of SpO2 at the start of this therapy were 94.8, 91.5, 82.0%, respectively. The more severe their attacks were, the lower their SpO2 levels were. The periods until their scores became zero were 0.78, 6.3, 17.2 hours, respectively. There were significant differences between each period respectively (p less than 0.001, p less than 0.01). Heart rates decreased when their symptoms improved, and other adverse effects were not detected. These results suggest that this therapy is effective and safe for children with severe asthma attacks, especially in the early stage.

Administration, Inhalation↗

PubMed1992

[Correlation of the perfusion scintigram with pulmonary functions in chronic obstructive pulmonary disease].

We carried out ventilation-perfusion scintigraphy and pulmonary function tests in 21 patients with chronic obstructive pulmonary disease. We used 99mTc-macroaggregate for perfusion scintigram and 133Xe gas for ventilation scintigram. We added the radioactivities of rebreathing phase and made lung volume image using computer. Regions of interest (ROIs) were derived from radioactivities in each image. ROIs on lung volume image included each whole lung and those on perfusion image included the areas which had relatively high radioactivity. We counted the area of ROIs on lung volume (L) and perfusion (P) images. Then we used the ratio of perfusion to lung volume (P/L) as a parameter of pulmonary perfusion. P/L had the significant correlations with the vital capacity, the actual FEV1.0, arterial oxygen partial pressure, diffusing capacity, RV/TLC and peak flow rate. These results suggested that P/L was a useful parameter of pulmonary perfusion in chronic obstructive pulmonary disease.

Aged↗

PubMed1992

[Efficacy of continuous isoproterenol inhalation therapy for severe asthma attacks in younger children].

The aim of this study was to evaluate the efficacy of continuous isoproterenol inhalation therapy for severe asthma attacks in younger children, compared with its efficacy in older children. We used l-body isoproterenol (Proternol L) in 31 children with 42 episodes of severe attacks. They were divided into two group according to age: 20 cases under 6 years old (Group A), and 22 cases over 7 years old (Group B). All of the patients except for one in Group B, eventually improved with this therapy. Wood's clinical scores for Group A were significantly higher than those for group B (p < 0.01). In 22 cases whose scores were 5-6, their SpO2 values at the onset of this therapy were 90.8 +/- 3.17 in group A and 92.4 +/- 3.82% in group B. The improvement time of group A (13.6 +/- 16.2 hours) was significantly longer than that of group B (2.5 +/- 5.66, p < 0.01). The nebulized isoproternol doses for group A were 0.47 +/- 0.168 and for group B 0.26 +/- 0.096 mg/kg/saline 500 ml. The dose for group A was significantly higher than that for group B (p < 0.01). We concluded that continuous isoproterenol inhalation therapy was effective even in younger children. But the degree of efficacy was slightly lower in younger children, although they inhaled higher doses of isoproterenal than older children.

Administration, Inhalation↗

PubMed1992

[Preoperative embolization for meningiomas using PVA particles].

Preoperative embolization for highly vascularized and large meningiomas is an indispensable technique for facilitating their surgical removal by decreasing blood loss during the operation. This is a report of 4 large and highly vascularized meningiomas in the skull base, on which embolization of feeders was performed preoperatively by PVA (Polyvinyl alcohol foam) particles (150-250 micron produced by INGENOR CO, Paris) and small strips of gelfoam (0.5 x 0.5 x 3-5mm). Under EEG monitoring, Isosorbide dinitrate was used for prevention and relief of vascular spasm. Lidocaine injection tests (Xylocaine 2%: 50mg mixed in equal volumes with Iopamiron 300) were performed for checking before embolization. In the intracranial portion, standard taper steerable guide wire was changed to seeker flexible soft-tip guide wire. In two cases, the meningioma was located in the medial part of the sphenoidal ridge. In the other two cases, one meningioma was in the lateral part of the sphenoidal ridge and the other was in the olfactory groove. In all 4 cases, we successfully performed embolization without complication. In one case, we had to perform embolization twice, because of revascularization detected by angiography 3 weeks after the first embolization. In this latter case, we had performed central embolization only, by using PVA particles, having left feeder without occlusion (peripheral embolization) using gelfoam. The result suggested that it was also necessary to perform peripheral embolization especially if the tumor is fed by large tortuous and irregular abnormal vessels. Peripheral embolization may prevent PVA particles from washing out and causing progressive thrombosis by PVA particles.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Surface binding and intracellular uptake of gentamicin in the cultured kidney epithelial cell line (LLC-PK1).

Aminoglycoside antibiotics such as gentamicin are taken up by renal proximal tubular cells, yet little is known regarding the biochemical characteristics of the transport process at the cellular level. In this report, cellular handling of gentamicin was studied in the cultured kidney epithelial cell line LLC-PK1. After 2 days of incubation of the cells with gentamicin, cell-associated gentamicin decreased rapidly during the first 30 min when the cells were incubated in gentamicin-free medium, then decreased slowly. The apparent half-life of the latter phase, which should represent release from the intracellular compartment, was about 2.0 days. The rapid release of gentamicin should consist of two components, one is a release from the cell surface membrane and the other from domes. Cell surface binding of gentamicin was dependent on the ambient ionic strength. The intracellular uptake was inhibited by low temperature, neomycin, metabolic inhibitors and reagents which interact with the cytoskeleton. On the other hand, the uptake was not affected by d-glucose, organic cations and an organic anion. Thus, by estimating the intracellular gentamicin separately from the drug localized in other compartments, it is concluded that gentamicin is taken up by LLC-PK1 cells via an adsorptive endocytosis. The endocytosis of gentamicin should be dependent on metabolic energy and cytoskeletal function.

Animals↗