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Biomedical subjects

T Kumazawa

Publications and source records attributed to T Kumazawa.

At least 325 records · Page 18Linked to original sources
PubMed1989

[Experimental and clinical evaluations of flow cytometric DNA-aneuploidy for the determining malignancy of head and neck tumors].

Using flow cytometry, basic experiments and clinical trials to investigate DNA aneuploidy were performed. The site of the peak in the DNA histogram was found to be unstable in the flow cytometric assay. However, relatively stable DNA indices can be obtained if only internal standards, such as human lymphocytes, etc., are added to the samples, thus results in a more precise detection of aneuploidy. In 11 cases of head and neck tumors, DNA aneuploidy was observed in six out of seven cases that were histopathologically diagnosed as being malignant tumors, showing a correlation with the pathological studies as a whole. Further clinical studies may prove that the present method can be useful for the pathological, supplementary diagnostic and prognostic evaluations.

Aneuploidy↗
PubMed1988

Positive inotropic and chronotropic effects of pancuronium and vecuronium in the canine blood-pefused papillary muscle and sinoatrial node preparations.

The positive inotropic and chronotropic potencies of pancuronium (Pc) and vecuronium (Vc) were compared with developed tension of the isolated papillary muscle (DT) and sinoatrial rate of the sinoatrial node preparation (SAR). Both Pc and Vc caused dose-dependent positive inotropic and chronotropic effects. Pc showed much more potent effect than Vc on DT (0.1, 0.3 mg; P << 0.05) or SAR (0.03, 0.1, 0.3 mg; P << 0.05). DT and SAR were increased by Pc and Vc, and the increase in DT was inhibited by propranolol or tetrodotoxin. These results suggest that the cardiac effects of Pc or Vc may be mediated by release of norepinephrine from the synpathetic nerve endings.

Journal Article↗
PubMed1988

Effects of volatile anesthetics on cardiac metabolism in the low-pressure perfused rat heart.

Effects of halothane, enflurane and isoflurane on the myocardial metabolism were studied in the rat heart-lung preparation. Hearts were perfused at a low perfusion pressure (SBP 50 mmHg, DBP 30 mmHg) with succinate or glutamate as substrates. Thirty minutes after the perfusion, intramyocardial ATP, pyruvate, lactate and glycogen were measured enzymatically. Although there was no significant difference in ATP levels of hearts with either substrate, and whether or not volatile anesthetics were present, 1% halothane and 1.5% isoflurane reduced the L/P ratio when succinate was substrate (24.46 +/- 4.81, 17.68 +/- 9.10 vs 39.82 +/- 10.83), and 2% enflurane decreased it when glutamate was substrate (22.25 +/- 10.99 vs 38.44 +/- 6.55). The glycogen levels in volatile anesthetics groups were lower than control when succinate was substrate. The improvement of energy demand-supply balance by inhalation anesthetics may be stronger than their inhibition of electron transport in mitochondria under certain ischemic conditions.

Journal Article↗
PubMed1988

Liposomes as model for taste cells: receptor sites for bitter substances including N-C=S substances and mechanism of membrane potential changes.

Various bitter substances were found to depolarize liposomes. The results obtained are as follows: (1) Changes in the membrane potential of azolectin liposomes in response to various bitter substances were monitored by measuring changes in the fluorescence intensity of 3,3'-dipropylthiocarbocyanine iodide [diS-C3(5)]. All the bitter substances examined increased the fluorescence intensity of the liposome-dye suspension, which indicates that the substances depolarize the liposomes. There existed a good correlation between the minimum concentrations of the bitter substances to depolarize the liposomes and the taste thresholds in humans. (2) The effects of changed lipid composition of liposomes on the responses to various bitter substances vary greatly among bitter substances, suggesting that the receptor sites for bitter substances are multiple. The responses to N-C=S substances and sucrose octaacetate especially greatly depended on the lipid composition; these compounds depolarized only liposomes having certain lipid composition, while no or hyperpolarizing responses to these compounds were observed in other liposomes examined. This suggested that the difference in "taster" and "nontaster" for these substances can be explained in terms of difference in the lipid composition of taste receptor membranes. (3) It was confirmed that the membrane potential of the planar lipid bilayer is changed in response to bitter substances. The membrane potential changes in the planar lipid bilayer as well as in liposomes in response to the bitter substances occurred under the condition that there is no ion gradient across the membranes. These results suggested that the membrane potential changes in response to bitter substances stem from the phase boundary potential changes induced by adsorption of the substances on the hydrophobic region of the membranes.

Benzothiazoles↗
PubMed1988

Morphological differences between secretory cells of wet and dry types of human ceruminous glands.

Morphological differences between secretory cells of the wet and dry types of human ceruminous glands were examined. The heights of secretory cells varied from tall and medium to low in both wet- and dry-type glands. The two gland types differed in morphologic features of the tall cells and the cells of medium height. The Golgi apparatus was well developed in the tall cells and fairly well developed in the cells of medium height in the wet-type gland, whereas it was generally small in the corresponding cells of the dry type. Light granules were abundant in the tall cells and in the cells of medium height in the wet-type gland, whereas light granules were rare in these cells in the dry-type gland. Furthermore, the light granules in the wet-type gland cells were observed in close relation to a well-developed Golgi apparatus, and sometimes showed a morphologic appearance suggesting exocytosis. Apical protrusions, probably related to apocrine secretion, were generally large and round and bore "microvilli and light granules" or "very few microvilli and no light granules" in the tall cells of the wet-type gland. However, the protrusions of the tall cells of the dry-type gland were generally large and slender and possessed no microvilli and no granules. The protrusions were not observed in the cells of medium height or in low cells in either type of gland. The results show that eccrine secretion characterizes the wet-type gland, but it is not clearly evident in the dry-type gland. This differences may be related to differences in composition between the wet and dry cerumens.

Adult↗
PubMed1988

Positive and negative ion mass spectrometry of antiepileptic hydantoins and their analogs.

Positive ion electron impact (PIEI), positive ion chemical ionization (PICI), and negative ion chemical ionization (NICI) mass spectra of seven compounds of hydantoins and their analogs are presented; their probable fragmentation modes are also presented. In the PIEI mode, intensities of molecular ions differed according to different compounds. Cleavage at outsides of both carbonyl groups was commonly observed for all compounds. In the PICI mode, all compounds showed [M + 1]+ quasi-molecular ions constituting the base peaks. In the NICI mode, [M - 1]- quasi-molecular anions were the base peaks except for trimethadione and paramethadione. All negative spectra showed anions at m/z 42 due to [NCO]-; these peaks seem useful for screening of antiepileptics. An extraction procedure for the anti-epileptics from human urine or plasma, and their separation by gas chromatography (GC), are also presented to serve for their actual identification by GC/mass spectrometry.

Anticonvulsants↗
PubMed1988

An anionic charge barrier in the guinea pig cochlea.

A charge barrier has been found in the glomerular basement membrane of the kidney and plays an important role in the filtration of solutes. In the present study, we used electron microscopy to localize anionic sites of a similar charge barrier in the guinea pig cochlea. Polyethyleneimine (PEI) was used as a cationic marker to detect anionic sites. Our results showed a localization of PEI with regular interspaces, indicating the anionic sites to the charge in the capillary basement membrane of the stria vascularis and the spiral ligament, and in the basal lamina of Reissner's membrane and the spiral prominence. This charge barrier, as well as structural size barrier, may play an important role in the maintenance of normal inner ear functions.

Animals↗
PubMed1988

Respiratory changes induced by activation of testicular afferents in dogs.

Reportedly, more than 90% of the testicular afferents of the dog are of the polymodal type. The possible involvement of these afferents in modulation of respiration was studied using anesthetized dogs, which had been vagotomized and with both common carotid arteries ligated. Electrical stimulation of the superior spermatic nerve at an intensity of 1/5 Tc (Tc: threshold intensity for C-fiber activation) induced no substantial changes in respiration, while above 1/2 Tc it induced an increase in minute expiratory volume (VE), or a decrease followed by an increase in VE. The pattern of respiratory change was converted from the former to the latter by increasing the stimulation frequency while maintaining the same intensity. Mechanical stimulation of the testis through a stimulator with a tip of 1 cm in diameter caused an increase of VE at 200 g and a decrease followed by an increase of VE above 500 g. Intra-arterial injection of bradykinin (3 x 10(-6) M), hypertonic saline (1.5 M) and high K+ solution (180 mM) to the spermatic artery induced similar respiratory changes. Pneumograms showed a shift in end-expiratory position even at stimulus intensities without significant VE changes. Phrenic nerve recordings from some artificially ventilated dogs, revealed an prolongation of the first expiratory phase followed by augmentation of phrenic activity, mostly an increase in respiratory rate. Comparison between afferent activities and reflex respiratory changes suggests that above described two types of respiratory changes are brought about by the activities of testicular polymodal receptors.

Animals↗
PubMed1988

In vitro inhibition of human platelet monoamine oxidase by phenothiazine derivatives.

Nineteen phenothiazines were tested for in vitro inhibition of human platelet type B monoamine oxidase (MAO). The inhibition potency was highly dependent on structures of their side chains. The inhibition was most potent for drugs with (hydroxyethyl-piperazinyl)propyl chains followed in decreasing order by those with (N-methylpiperazinyl)propyl, (2-dimethylamino-2-methyl)ethyl and 3-dimethylaminopropyl chains. Kinetic analyses were carried out for promazine, promethazine, perazine and perphenazine as representatives of each group; the four drugs showed competitive inhibition, and Ki values of 124, 31.4, 19.2 and 22.6 microM, respectively.

Blood Platelets↗
PubMed1988

Synthesis and antiulcer activity of 5,11-dihydro[1]benzoxepino[3,4-b]pyridines.

A series of substituted 5,11-dihydro[1]benzoxepino[3,4-b]pyridines was synthesized and evaluated for antiulcer activity in water immersion/restrained stress ulcer assay in rats. Structure-activity relationships are described. Most of the tested compounds exhibited low affinity to the muscarinic acetylcholine receptor. The molecular features for the best activities are the 2-(diethylamino)ethylenediamine group at the 5-position of the oxepin ring and an oxepin skeleton rather than a thiepin or a pyran skeleton. Methyl and chlorine substitution on the benzene ring reduced the activity. Compound 11, 5-[[2-(diethylamino)ethyl]amino]-5,11-dihydro[1]benzoxepino [3,4-b]pyridine trihydrochloride was selected for further evaluation. Synthesis and antiulcer activity of optically active 11 is described. There were no statistically significant differences between (+)-, (-)-, and (+/-)-11. Compound 11 showed weak antisecretory activity in pylorus-ligated rats. It is now under clinical evaluation as KW 5805.

Animals↗
PubMed1988

Otitis media with effusion and tubal tonsil (video).

Carbon dioxide laser surgery was performed on children aged 5 to 11 years, on whom either adenoidectomy or tonsilloadenoidectomy had been performed to restore their hearing. We examined 177 ears 18 to 24 months after surgery. Thirty ears (17%) were diagnosed as having otitis media with effusion. Analysis of the endoscopic findings revealed 51% marked tubal tonsil hypertrophy and 33% adenoid tissue hypertrophy. Subjects were operated upon in the dorsal position for a duration of point one second at an amplitude of 15 watts. Six months after surgery, most patients' hearing had returned to almost normal. The tympanograms which were taken 6 months after surgery showed good results in almost every case. Otitis media with effusion was found to have recurred in 3 ears. The effect of adenoidectomy is apparently dependent upon age, the size of adenoids, and the influence of allergies and sinusitis. Furthermore, our cases suggested that tubal tonsil hypertrophy was one of the factors found in recurrent otitis media with effusion in older children. It can thus be inferred that endoscopic examination of the postnasal space is recommended in children with recurrent otitis media with effusion after adenoidectomy, and that carbon dioxide laser surgery is a reliable therapeutic method in the topical treatment of this disease.

Adenoidectomy↗
PubMed1988

Participation of autonomic nerve in tonsillar focal infection.

Participation of the autonomic nerve in tonsillar focal infection was investigated by measuring neurotransmitters, receptors and microvibration. In focal infection patients, the volume of norepinephrine in the tonsil increased significantly and the number of a-adrenergic receptors decreased. These findings suggest that the focally infected tonsil exhibits a high degree of sympathetic nerve activity. The ratio of N-type in microvibration decreased systematically, which indicates some imbalance or immaturity of the autonomic nervous system in focal infection patients. Based on this data, the production mechanism of tonsillar focal infection was speculated from the point of view of the autonomic nerve.

Autonomic Nervous System↗
PubMed1988

Clinical evaluation of S-CMC syrup applied in the treatment of otitis media with effusion. Double blind comparative test with placebo.

We carried out a double blind comparative trial with placebo serving as control using 250 cases of infant otitis media with effusion (OME) in order to objectively evaluate the clinical usefulness of S-carboxymethylcysteine (S-CMC), an oral mucolytic agent, against OME. The results obtained were as follows. 1) Global improvement rate, when judged in items of overall improvement, was 79.8% in S-CMC group and 58.2% in placebo group, S group being significantly better when compared to P. 2) The degree of improvement in each item for evaluation revealed significantly better results in S group compared to P, in both objective findings of the effusion amount and its property, and in audiological findings. 3) Adverse reactions observed in 3 cases (2.5%) in S group and in 2 (1.5%) in P group were not serious, and were eliminated through suspension or discontinuation of the medication. The results obtained suggested the usefulness of S-CMC when used in the treatment of OME.

Administration, Oral↗
PubMed1988

Observations on electrophysiologically characterized receptive fields of thin testicular afferent axons: a preliminary note on the analysis of fine structural specializations of polymodal receptors.

The sparse distribution of thin, principally unmyelinated sensory axons confined largely to the planar tunica vasculosa of the testis provides a suitable model for examining the fine structure of electrophysiologically characterized nerve fiber terminals. The marked sites of polymodal receptors of canine testis using the in vitro preparation devised by Kumazawa et al. (1987) were examined in serial sections traced to the terminal with the electron microscope, revealing the first micrographs of a characterized polymodal receptor ending. The inferred role of these terminals in nociception, their organelle content, and the problems encountered in interpreting our initial findings are considered in the context of the variety of morphological patterns and functional roles of thin sensory axons.

Animals↗
PubMed1988

Determination of beta-phenylethylamine in catfish (Parasilurus asotus) tissues by gas chromatography/mass spectrometry.

1. beta-Phenylethylamine (PEA) was detected and quantitated in tissues of the catfish, Parasilurus asotus, by very specific and sensitive gas chromatography/mass spectrometry. 2. The selected ion monitoring was made with a strong quasi-molecular ion of the pentafluoropropionic derivative of PEA in the positive chemical ionization mode. 3. PEA was found in all tissues tested ranging from 2.8 to 38.2 ng/g wet wt tissue. It was highest in the spinal cord, followed by the skin, brain and intestine.

2-Hydroxyphenethylamine↗
PubMed1988

Rapid isolation of benzodiazepines with Sep-Pak C18 cartridges.

A rapid method for isolation of various benzodiazepines from human samples with Sep-Pak C18 cartridges before wide-bore capillary gas chromatography is described. The drugs dissolved in alkaline samples were directly applied to the cartridges and eluted with hexane/isopropanol (9:1). The recoveries were excellent for all drugs in urine samples, but were somewhat lower for some drugs in plasma samples. The latter problem could be easily circumvented by using a deproteinization process before their application to the cartridge. We can recommend the Sep-Pak C18 cartridges for isolation of benzodiazepines because of their simplicity and rapidity.

Benzodiazepines↗