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Biomedical subjects

M Takano

Publications and source records attributed to M Takano.

At least 289 records · Page 16Linked to original sources
PubMed1993

G protein beta gamma-subunits inhibit purified adenylate cyclase independent of the activation by Ca2+ and calmodulin.

Adenylate cyclase purified by affinity chromatography was activated about 2.5-fold in a Ca(2+)- and calmodulin-dependent fashion. G protein beta gamma-subunits, an inhibitor in the receptor-mediated inhibition of adenylate cyclase, inhibited the purified cyclase by more than 80%. The extent of beta gamma-induced inhibition was not affected by the activation with Ca2+ and calmodulin. Moreover, the prior addition of the beta gamma-subunits to the cyclase did not prevent the subsequent activation of the enzyme by Ca2+ and calmodulin. We conclude that the beta gamma-subunits inhibit adenylate cyclase activity in a calmodulin-independent mode.

Adenylyl Cyclase Inhibitors↗
PubMed1993

Purification and characterization of recombinant human macrophage colony-stimulating factor expressed in Chinese hamster ovary cells.

We expressed human macrophage colony-stimulating factor (M-CSF) in Chinese hamster ovary (CHO) cells by introducing an expression plasmid coding for a 554-amino-acid M-CSF precursor and dihydrofolate reductase (DHFR) gene, and by amplifying the sequence. A cell line was obtained that secreted approximately 200,000 units/ml after 6 days in culture. The expressed recombinant human M-CSF (rhM-CSF) primarily consisted of two molecular species, a main 80-90 kD M-CSF as a homodimer and a molecular form higher than 150 kD. Purification of a main rhM-CSF gave an apparently homogeneous protein disulfide-bonded from 42-kD subunits, but one of the purified rhM-CSFs was composed of two subunit species with molecular masses of 44 and 42 kD. These purified rhM-CSFs had substantially the same specific activity (1 to 4 x 10(7) units/mg protein). Deglycosylation experiments with the latter rhM-CSF using chemical (trifluoromethanesulfonic acid) and enzymatic methods found a terminal neuraminic acid in addition to N- and O-glycosylation, but the two subunit species did not coalesce into a single molecule.

Amino Acid Sequence↗
PubMed1993

Vitreous hemorrhage associated with acute posterior vitreous detachment--a case report.

A case of vitreous hemorrhage associated with acute posterior vitreous detachment was reported. The patient was a 64-year-old man who complained of floaters in his left eye of one-week duration. His previous medical and ocular histories were unremarkable. Slit-lamp examination with Goldmann three-mirror contact lens showed complete posterior vitreous detachment in both eyes. Ophthalmoscopic examination and fluorescein angiogram revealed a partial defect in retinal blood flow in the midperipheral area of the superotemporal region of the left fundus. On follow-up examination, recovery of the retinal circulation was observed in that region and the vitreous hemorrhage had spontaneously resolved. The diagnosis was made in the left eye of rupture of retinal vein due to vitreous traction associated with acute posterior vitreous detachment without retinal break formation.

Acute Disease↗
PubMed1993

[Alcohol-related problems in mortality in middle-aged urban-dwelling men from cerebro-cardiovascular diseases].

A survey was performed of the life-styles and medical histories of men, who died of cerebro-cardiovascular diseases at ages between 40 and 64 years in Hirakata, Neyagawa, Moriguchi and Kadoma cities in Osaka prefecture. Data was available on 127 of 172 men who died in 1988. Of these, 28 had histories of alcohol-related problems. Analysis showed that the amount of alcohol consumed was associated with disease history and serious alcohol-related problems. 1) Histories of hypertension, cerebrovascular and liver disease were found more often in heavy drinkers with a daily alcohol intake exceeding the equivalent of 46 g pure ethanol compared to either moderate drinkers with a daily alcohol intake of less than 46 g or abstainers. 2) Of 28 subjects with alcohol-related problems, one had been treated at a specialized alcoholic-clinic, two had been admitted to psychiatric hospitals and one subject had consulted a physician at a mental health clinic of the public health center in his community. 3) Although 18 of the 28 subjects with alcohol-related problems had their own regular doctors, they did not appear to have received adequate care. 4) Subjects with alcohol-related problems had histories of cerebrovascular and liver diseases more often than those without alcohol-related problems. 5) Subjects with alcohol-related problems were confronted with unemployment, divorce and housing problems more often than those without alcohol-related problems. With the increasing amount of alcohol consumption in Japan, alcohol-related problems need more attention. There is an urgent need to establish community-based strategies for prevention of alcohol-related problems and to organize a network of multi-disciplinary support teams for those with problems such as alcoholics in urban communities.

Adult↗
PubMed1993

Response of aged neurons to super-hypotonic environment.

Cultured sensory neurons from aged mice (24 months old) lost capability of cell volume auto-regulatory mechanism after the rapid treatment with a hypotonic solution of 1/4 the normal osmolarity or lower. However, they could survive and extend neurites in super-hypotonic media such as 1/4 osmolar and even 1/8 osmolar culture media when the osmolarity was reduced gradually to such a low level.

Aging↗
PubMed1993

[Clinical usefulness of 111In transferrin scintigraphy in colorectal cancer].

As assessment was made regarding the clinical value of 111In transferrin in scintigraphy on 28 lesions in 26 cases of colorectal cancer. The positive rate of colorectal cancer was high: 21 lesions out of the 28 (75%) were found to be positive. As for the location of cancer, there was a tendency for the positive rate to be high in the ascending and transverse colon. There was no obvious trend regarding Borrmann's classification, histological type, or macroscopic depth of invasion. There was a trend for cases in which the maximum diameter of the tumor was large and depth of invasion was in progress to be positive. Ten cases in which a specimen was resected were all shown to be positive by scintigraphy. Radioactivity in the tumorous regions was 4.41 +/- 2.96 times that of the non-tumorous regions. Moreover, tumorous tissue was strongly stained by the immuno-histological staining with anti-Tf.receptor antibody. From the above findings, it was considered that 111In transferrin is clinically useful in scintigraphy, since it is evident that it accumulates in the tissue of colorectal cancer.

Aged↗
PubMed1993

[Airborne Japanese red cedar allergens studied by the immunoblotting technique--comparison with pollen counts obtained by Durham sampling and effect of weather].

We collected airborne particles with Burkard's sampling tape in Toyama from March to July. According to the immunoblotting technique (Takahashi et al, 1990), the airborne pollen allergens were reacted with anti-Cry j I polyclonal antibody and were stained as blue spots. The areas of these spots were measured with a color image analyzer (CIA) and a densitometer. There were significant correlations between the airborne Cry j I allergen spots (CIA and densitometer) and the pollen counts obtained with a Durham sampler (r = 0.624, 0.555, p < 0.001). The airborne Cry j I allergens however, tended to maintain a higher level than the pollen counts (Durham) in May. We theorized that this discrepancy is caused by cross reactivity with other pollen or crushed cedar pollen particles have allergenicity. There was a negative correlation between the Cry j I spots and rainfall. The pollen counts had a negative correlation with rainfall, and a positive correlation with average wind speed. These results suggest that this method is useful in evaluating fluctuations in airborne Cry j I allergen.

Allergens↗
PubMed1993

[Evaluation of the Magic Lite SQ specific IgE kit].

The new IgE specific antibody assay kit (Magic Lite SQ) was evaluated by comparing its results with those obtained by the Phadebas RAST and the skin prick tests. Sera from allergic children were used in the tests. The correlation coefficients between the Magic Lite SQ and the Phadebas RAST were as follows: 0.87 for D.p., 0.89 for D.f., 0.87 for HD1, 0.55 for HD2, 0.76 for orchard grass, 0.93 for cat dander, 0.78 for Alternaria, 0.88 for egg white, 0.75 for egg york, 0.81 for milk, 0.75 for say bean, and 0.60 for shrimp. The concordance rate of the two methods was high, except on the case of HD2. The sensitivity and specificity of Magic Lite SQ to the skin prick test was high, except on the case of HD2 and orchard grass. Dilution tests using samples from D.f. positive patients showed a good linearity and excellent quantitativeness. When mite allergen was added to D.f. positive pool serum, mite specific IgE antibody yielded an excellent inhibition curve of up to a maximum of 96%. Since the Magic Lite SQ requires only a small sample of serum and can completed the test in a short time, it is a useful and specific IgE antibody assay kit.

Child↗
PubMed1993

[A case of achalasia evaluated with esophageal scintigraphy in terms of efficacy with endoscopic pneumatic dilatation].

The therapeutic effects on pneumatic dilatation were evaluated quantitatively by radionuclide transit study using 99mTc-Sn colloid in an achalasia patient. After dilatation, transit time (T3/4) with distilled water has improved from 13.5 seconds to 5.5 seconds. Radionuclide transit study using 99mTc-Sn colloid was a preferable method to evaluate the efficacy of the treatment quantitatively in an achalasia.

Adult↗
PubMed1993

[The usefulness of three dimensional imaging of the myocardium using three heads SPECT camera (PRISM-3000)].

The SPECT unit using a 3 heads camera (PRISM-3000) has an advantage over the conventional one head camera SPECT unit because it can complete full circle scans (360 degrees scans) within a short time, and because the non-circular orbit of the camera heads fitting the individual form of the body has improved the spatial resolution. In addition, the high speed data processing has reduced the time for scan, enabling the three dimensional imaging system clinically applicable. In the present study, this modern technique was used to examined the myocardium in patients with ischemic heart disease so as to evaluate it for usefulness and depict problem to be solved. In patients with myocardial infarction, images obtained with a PRISM-3000 machine could provide more objective information on infarcts than conventional images. In patients with angina pectoris, delayed images obtained 3 hours after exercise by the new method were superior to conventional ones in power of demonstrating redistribution. The setting of the threshold for ischemic lesions at 40-50% hampers the assessment of the severity of ischemia. A new program should be introduced to solve this problem.

Aged↗
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↗