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Biomedical subjects

K Takeda

Publications and source records attributed to K Takeda.

At least 1,135 records · Page 63Linked to original sources
PubMed1986

Analysis of viral antigens in giant cells of measles pneumonia by immunoperoxidase method.

The localization of measles virus proteins was analyzed by immunoperoxidase method using both monospecific and monoclonal antibodies. In Vero cells infected with the Edmonston or EB-L strain, the former being a laboratory strain and the latter a fresh isolate from a measles patient, nucleocapsid protein was located in the nuclei, and matrix protein, phosphoprotein, haemagglutinin and fusion protein were located in the cytoplasm. In the lung tissues of eight cases with measles giant cell pneumonia, the similar findings were obtained. The presence of haemagglutinin on the surface of giant cells at the luminal side was also noticed. Histopathologically, measles giant cells had nuclear and cytoplasmic eosinophilic inclusion bodies with some differences in appearance. The significance of localization of viral proteins is discussed in comparison with histopathological findings in measles giant cells.

Antibodies, Monoclonal↗
PubMed1986

Earlobe crease and coronary heart disease in Japanese.

To evaluate whether a significant statistical correlation exists between earlobe crease (EC) and coronary heart disease (CHD), 1000 Japanese adult patients (573 males, 427 females) were examined for the presence or absence of EC, clinical or angiographic evidence of CHD, and the following coronary risk factors: male sex, age over 50 years, obesity, hypertension, diabetes mellitus, cigarette smoking, and hyperlipidemia. Patients were divided into two groups according to clinical evidence of CHD: 237 patients with angina pectoris and/or myocardial infarction (CHD+ group); 720 patients without evidence of CHD (CHD- group). Coronary angiography was performed on 200 patients from this sample population; these patients were also divided into two groups: 119 patients with greater than 50% luminal narrowing of at least one major coronary artery (stenosis+ group); 81 patients with no significant atherosclerotic changes in the coronary arteries (stenosis- group). EC was present in 58 of 237 CHD+ patients (24.5%) but in only 35 of 720 CHD- patients (4.8%; P less than 0.001); it was present in 31 of 199 stenosis+ patients (26.1%) but in only 3 of 81 stenosis- patients (3.7%; P less than 0.01). EC was also found to correlate significantly with some coronary risk factors; the correlations between the presence of EC and the presence of CHD and coronary risk factors were investigated by multivariate analysis. In a multivariate setting, the existence of CHD and an age of over 50 years was significantly related to the presence of EC. To investigate the relationship between EC and advancing age, all patients were separated into age-groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Construction and characterization of new cloning vectors derived from Streptomyces griseobrunneus plasmid pBT1 and containing amikacin and sulfomycin resistance genes.

Three cryptic plasmids, designated pBT1 (5.6 kb), pBT2 (9.7 kb), and pBT3 (16.6 kb), were isolated from Streptomyces griseobrunneus ISP5066 and physically characterized. pBT1 and pBT2, which differ by a 4.1-kb segment, are high copy-number plasmids (40-100 copies per chromosome) that coexist with each other. pBT3 is a low copy-number plasmid. Vectors containing amikacin (or kanamycin) and sulfomycin (or thiostrepton) resistance genes from Streptomyces litmocidini ISP5164 and Streptomyces viridochromogenes subsp. sulfomycini ATCC 29776, respectively, were constructed from pBT1. One such vector, pBT37, has unique restriction sites for cloning, including BglII, XhoI, PvuII, ClaI, and SacI, with the PvuII and ClaI sites allowing clone recognition by insertional inactivation of sulfomycin resistance. Since many Streptomyces species were very sensitive to amikacin and sulfomycin, these resistance genes serve as useful selective markers. pBT37 could transform several Streptomyces strains that produce antibiotics such as tetracyclines, macrolides, beta-lactams, and aminoglycosides. This plasmid is a potentially useful vector for cloning antibiotic biosynthetic genes.

Amikacin↗
PubMed1986

Sex determination from buccal mucosa and hair root by the combined treatment of quinacrine staining and the fluorescent Feulgen reaction using a single specimen.

In order to determine sex using a single specimen, buccal mucosa and hair roots obtained from male and female individuals were used. The specimens were first stained with quinacrine for the detection of the Y-chromatin, and subsequently were stained by the fluorescent Feulgen reaction using acriflavine for the detection of the X-chromatin. In the male specimens, the frequency of fluorescent spots of quinacrine-positive bodies was high, whereas that of acriflavine-positive spots was low. On the other hand, in the female specimens, the frequency of quinacrine-positive spots was very low, while that of the acriflavine-positive spots was high. These specimens were air-dried and were allowed to stand at room temperature for periodical observations. The result was that sex difference was distinguishable for 4 months by the combined treatment method.

Coloring Agents↗
PubMed1986

Modulation by verapamil of hormonal action on the Henle's loop of mice.

In order to know the role of cytosolic calcium in the modulation of the hormone action on sodium chloride transport across the thick ascending limbs of Henle's loop, we examined whether verapamil, a blocker of cellular calcium entry, can modulate the effects of arginine vasopressin (AVP) or glucagon in stimulating transepithelial voltage (Vt) and cyclic AMP generation in the mouse medullary thick ascending limb (MAL). The pretreatment of the renal tubule with 5 X 10(-5)M verapamil reduced the Vt stimulated with 200 microU/mliter AVP from 1.7 +/- 0.3 mV to 0.4 +/- 0.4 mV (N = 7, P less than 0.05). The changes in Vt were well correlated with those of unidirectional Cl flux from the lumen to the bath. However, verapamil did not influence the Vt stimulated with 10(-3) M dibutyryl cyclic AMP. The pretreatment of the MAL with 10(-5) M verapamil also inhibited the cyclic AMP generation in the MAL from 72.1 +/- 17.9 to 50.6 +/- 13.6 fmoles/mm/7 min (N = 7, P less than 0.05) as well as in the medullary collecting tubule from 147.6 +/- 46.6 to 121.2 +/- 41.6 fmoles/mm/7 min (N = 4, P less than 0.05). The effect of verapamil in inhibiting the AVP-stimulated cAMP was dose-dependent: the cAMP generation was inhibited by 28.9 +/- 6.8 and 61.1 +/- 9.3% with 10(-5) M and 10(-4) M verapamil, respectively. When verapamil was added to the medium simultaneously with AVP, the generation of cyclic AMP was unaffected.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Carcinogenicity of N-alkyl-N-(1-hydroperoxyalkyl) nitrosamines after intravenous injections in F344 rats.

As model compounds of alpha-hydroxy N-nitrosamines, four alpha-hydroperoxy N-nitrosamines were tested for their carcinogenic potential in F344 rats by i.v. injections. Correlation between chemical structure and carcinogenic potencies with respect to target organs was examined. Compounds used in this study were N-methyl-N-(hydroperoxymethyl)nitrosamine (MHPMN), N-ethyl-N-(1-hydroperoxyethyl)nitrosamine (EHPEN), N-propyl-N-(1-hydroperoxypropyl)nitrosamine (PHPPN) and N-butyl-N-(1-hydroperoxybutyl)nitrosamine (BHPBN). All chemicals were dissolved in distilled water and rats received 10 X 1 weekly i.v. injections of these chemicals (10 X 1 weekly injection of 5 mg/kg of MHPMN or equimolar amounts of other chemicals). Lung tumors were detected in all groups of both sexes and the incidences were 100% in each group. Thyroid tumors were also observed with relatively high incidences in treated groups except BHPBN. In the control group, tumors were observed mainly in the testis or uterus, and only two lung tumors and one thyroid tumor were observed in females. Histologically, all lung tumors in the MHPMN group were adenocarcinomas, squamous cell carcinomas or a mixture of both types. In the EHPEN, PHPPN and BHPBN groups, especially in females, incidences of carcinomas decreased as the length of the alkyl chain of the compounds, and most of lung tumors in females of the PHPPN and BHPBN groups were adenomas. Many of the thyroid tumors observed in the treated groups were follicular adenomas/carcinomas, whereas C-cell adenomas were the most common type of spontaneous thyroid tumors in this strain of rats. These target organs were similar to those of alpha-acetoxy N-nitrosamines reported previously. The results indicate that the carcinogenic activities of these chemicals depend on the length of the alkyl chain and that organ specificity of these chemicals may differ from those of their mother compounds.

Animals↗
PubMed1986

Centrally induced cardiovascular and sympathetic responses to adrenocorticotrophic hormone.

To investigate the effects of adrenocorticotrophic hormone on central cardiovascular regulation, an intracerebroventricular injection of the drug was given to male Wistar rats. With doses of 1 microgram and 10 micrograms per rat, blood pressure began to rise within 1 min, attaining a maximum value 5-10 min later. Both heart rate and abdominal sympathetic nerve activity increased simultaneously with the rise in blood pressure. Injection into the fourth ventricle or intravenous administration of the drug elicited no appreciable cardiovascular responses. These results suggest that endogenous adrenocorticotrophic hormone produced locally in the hypothalamus may participate in central cardiovascular regulation by increasing sympathetic outflow.

Action Potentials↗
PubMed1986

Cardiovascular and sympathetic responses to ouabain injected into the hypothalamus in rats.

To investigate the effects of sodium-potassium activated adenosine triphosphatase inhibition on central cardiovascular regulation a microinjection of ouabain was given into the hypothalamus of urethane anaesthetised rats. Doses of 0.01-1.0 micrograms per rat injected into the posterior hypothalamus produced a rise in blood pressure within 1 min, the maximum rise occurring 15-20 min later in a dose dependent manner. Both heart rate and abdominal sympathetic nerve activity increased with the rise in blood pressure. Ouabain injected into either the anterior preoptic hypothalamus or the ventromedial hypothalamus produced no notable cardiovascular responses. These results suggest that an endogenous digitalis like substance produced in the hypothalamus as a result of sodium loading may participate in central cardiovascular regulation by increasing sympathetic outflow in the discrete area of the brain, as does ouabain.

Action Potentials↗
PubMed1986

Lipid peroxidation in experimental septic rats.

We previously reported increased lipid peroxide and decreased alpha-tocopherol levels in the blood of critically ill septic patients. To clarify these results, we investigated lipid peroxidation in experimental septic rats and severely traumatized rats. In septic rats, both platelet count and plasma alpha-tocopherol decreased significantly, while lipid peroxide in plasma and major organs significantly increased. Serum transaminases also increased significantly. Traumatized rats had a significant but transient decrease in platelet count and a continuous decrease in plasma alpha-tocopherol; lipid peroxide did not change significantly in the plasma but increased significantly in the lung and kidney. Serum transaminases of traumatized rats showed transient increases. Thus, although traumatic stress caused lipid peroxidation similar to sepsis in the major organs, plasma lipid peroxide did not change.

Animals↗
PubMed1986

Germination of Bacillus cereus spores induced by purine ribosides and their analogs: effects of modification of base and sugar moieties of purine nucleosides on germination-inducing activity.

Purine riboside and some of its analogs were tested for their ability to induce germination of Bacillus cereus T spores. Hypoxanthine and adenine showed no germination-inducing activity either in the present or absence of D-ribose or its phosphorylated derivatives. Purine riboside and 18 analogs with modified purine base were all able to induce germination of the spores to various extents. In contrast to this, the requirement for the sugar moiety in the purine riboside appeared to be more stringent. Only those nucleosides that contained either D-ribose or deoxy-D-ribose, and certain species of azole derivatives such as 5-aminoimidazole-4-carboxamide covalently linked to the C(1') of the sugar actively induced germination.

Bacillus cereus↗
PubMed1986

Hypotension and hypothalamic depression produced by intracerebroventricular injections of GABA in spontaneously hypertensive rats.

To determine the central effects of 4-Amino-n-butyric acid (GABA), pressor and sympathetic nerve responses to electrical stimulation of the ventromedial hypothalamus were recorded following the intracerebroventricular (ICV) injection of GABA. In normotensive Wistar rats, anesthetized with urethane, ICV injections of GABA (50-200 micrograms) reduced sympathetic nerve activity, arterial blood pressure, and heart rate in a dose-dependent manner. Graded electrical stimulation of the ventromedial hypothalamus (50, 100, 150 microA) increased not only mean blood pressure but also the rate of sympathetic nerve firing, and both responses were attenuated by GABA pretreatment (100, 200 micrograms, ICV). In spontaneously hypertensive rats (SHR), ICV-injected GABA also reduced sympathetic and cardiovascular activity, but the magnitude of depressor responses was significantly larger in SHR than in normotensive Wister Kyoto controls (WKY). Pressor and sympathetic nerve responses elicited by ventromedial hypothalamic stimulation were initially larger in SHR than in WKY, but upon subsequent ICV injection of GABA, hypothalamic responsiveness in SHR was inhibited more prominently and became comparable to that in WKY. These results suggest that by depressing hypothalamic function, centrally injected GABA decreases sympathetic nerve activity to thereby lower blood pressure and heart rate, and in SHR, ICV-injected GABA reversed hypothalamo-sympathetic hyperactivity and thus attenuated hypertension.

Animals↗
PubMed1986

Hypotensive responses to centrally administered taurine in DOCA-salt hypertensive and spontaneously hypertensive rats.

The present study was designed to investigate the short-term effects of intracerebroventricularly-administered taurine in DOCA-salt hypertensive (DOCA), spontaneously hypertensive (SHR) and their respective normotensive control rats anesthetized with urethane. Blood pressure, heart rate and sympathetic nerve activity were consistently decreased following the injection of taurine 150 micrograms per rat in hypertensive rats as well as in normotensive controls of the two groups. Percent changes from the baselines in blood pressure, heart rate and sympathetic nerve activity were significantly larger in DOCA-salt hypertensive rats than those in sham operated rats. In contrast, percent changes in blood pressure and sympathetic nerve activity were not significantly different between spontaneously hypertensive rats and normotensive wistar kyoto rats. These result show that the responses of blood pressure, heart rate and sympathetic nerve activity to intracerebroventricular taurine are different between spontaneously hypertensive rats and DOCA-salt hypertensive rats. It appears that augmented vasodepressor responses to taurine in DOCA-salt hypertensive rats, as compared to spontaneously hypertensive rats, are due to enhanced inhibition of the sympathetic outflow.

Animals↗
PubMed1986

Enhanced renal sympathetic nerve activity in response to salt loading in rats.

To analyze the conflicting data on the relationship between sodium intake and sympathetic activity, the effects of a chronically excessive intake of sodium on renal sympathetic activity and blood pressure were investigated in normotensive rats. Renal sympathetic activity was estimated by urinary excretion of free norepinephrine (NE) and the turnover of NE in the kidneys. Blood pressure increased in rats receiving a high sodium diet when compared with that of the basal sodium diet. Urinary-free NE, epinephrine (E) and dopamine (DA) excretions in rats receiving a high sodium diet were enhanced significantly from those in the basal sodium diet. The turnover of NE in the kidneys was more enhanced in the high sodium group than in the basal sodium group. By blocking the sympathetic tone with ganglionic blockade, hexamethonium, enhanced excretion of urinary NE and elevation of blood pressure in response to salt loading were blocked to the levels of the basal sodium diet. These results suggest that a chronically excessive intake of sodium enhances the renal sympathetic and adreno-medullary activities, leading to a rise in blood pressure in normotensive rats.

Animals↗
PubMed1986

Cardiotonic and coronary vasodilatatory effects of amrinone in the canine heart-lung preparation with a support dog as compared with those of dobutamine.

Analysis of the relative magnitude of the positive inotropic and chronotropic effects and the coronary vasodilating effects of amrinone conducted in the canine heart-lung preparation with a support dog in comparison with those of dobutamine demonstrated that amrinone was a preferential coronary vasodilator rather than a selective positive inotropic agent. An in vitro experiment in the canine papillary muscle suggested the initiation of the slow response action potential as a mechanism of the positive inotropic effect of amrinone.

Aminopyridines↗
PubMed1986

The significance of duration of salt loading on cardiovascular response and urinary excretion of catecholamine in rats.

To analyze the conflicting data on the relationship between sodium intake and catecholamine release, the effect of the duration of high sodium loading on cardiovascular response and catecholamine release was examined in conscious rats. Urinary excretions of norepinephrine (NE), and dopamine (DA) were measured frequently over a 4 week period. Male Wistar rats at 4 weeks of age were given a diet containing either basal (0.3%) or high (3.1%) sodium content. Systolic blood pressure was measured weekly by the tail cuff method. Twenty-four hour urine collections were made for analysis of catecholamines in metabolic cages every other day during the initial 2 weeks and once a week in the following 2 weeks of salt loading. High sodium intake resulted in a rise in blood pressure and a reduction in heart rate. Bradycardia was significant during the initial 2 weeks and not significant during the following 2 weeks after the initiation of salt loading. Urinary excretion of NE did not change during the initial 2 weeks of salt loading but increased significantly following the 2 week period after salt loading. Urinary excretion of DA increased diphasically, showing the first peak at 1 week after salt loading and the second peak at 4 weeks after the initiation of salt loading. These results suggest that the heart rate and urinary excretion of catecholamine are influenced by the duration of salt loading. When we estimate the effect of salt loading on cardiovascular response and urinary excretion of catecholamine, we should draw attention to the importance of the duration of salt loading, because this duration of time further elicites delayed response in the sympathetic nervous system.

Animals↗
PubMed1986

Acute effects of captopril on the baroreflex of normotensive and spontaneously hypertensive rats.

When captopril was injected intravenously in urethane anesthetized rats, a hypotensive effect accompanied by bradycardia was obtained, while an intravenous (i.v.) injection of prostaglandin I2 (PGI2), which induced hypotension of the same magnitude as the hypotensive effect obtained with captopril, caused a marked tachycardia. Simultaneously, sympathetic nerve activity recorded from abdominal sympathetic nerves was unchanged following injection of captopril, while it was significantly increased during hypotension induced by PGI2. The bradycardia, but not the hypotensive effects induced by captopril was abolished by i.v. pretreatment with atropine. Intracisternal injection of a small dose of captopril inhibited reflex tachycardia during hypotension induced by PGI2 and prolonged the hypotensive effect, while intravenous administration of this dose did not inhibit the reflex tachycardia induced by PGI2. In spontaneously hypertensive rats (SHR), the hypotensive effect of captopril was increased partly, however, the accompanying bradycardia was significantly reduced. These findings suggest that captopril inhibits the baroreflex and centrally activates the cardiac vagal nerve. Moreover in SHR, the effect of captopril on cardiac vagal activity was disturbed.

Animals↗