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Biomedical subjects

M Takata

Publications and source records attributed to M Takata.

At least 235 records · Page 13Linked to original sources
PubMed1991

DNA diagnosis of hydatidiform mole using the polymerase chain reaction.

We have used the polymerase chain reaction (PCR) technique for the diagnosis of hydatidiform mole, a trophoblastic disease. For this, we targeted the hypervariable 3' flanking region of the APOB gene (APOB/VNTR) because of its high heterozygosity index (0.61) in the Japanese population. We examined seven clinical cases which were tentatively diagnosed as hydatidiform moles. Five of these revealed DNA segments unique to the paternal APOB allele, allowing us to diagnose a complete mole. The PCR technique for targeting the APOB/VNTR appears useful for early diagnosis of hydatidiform mole.

Alleles↗
PubMed1991

Excitation and inhibition of trigeminal motoneurons by palatal stimulation.

Excitation and inhibition of jaw-closing motoneurons (Masseteric and Temporal Motoneurons, Mass. and Temp. Mns) during transient jaw closing, the so-called jaw-closing reflex, and prolonged jaw opening elicited by palatal stimulation were studied. By pressing the anterior palatal surfaces sustained jaw opening was elicited, suggesting that sustained jaw opening results from inhibition of tonic background activity of jaw-closing motoneurons by inhibitory postsynaptic potentials (IPSPs) elicited by mechanical stimulation of the anterior palatal mucosa. Recordings showed that the onset of IPSPs was 80 ms earlier than the onset of jaw opening. Application of diffuse pressure stimulation to the posterior palatal surfaces elicited bursts of spikes triggered on excitatory postsynaptic potentials (EPSPs), suggesting that mechanosensory receptors from the posterior palatal mucosa send excitatory synaptic inputs to jaw-closing motoneurons. Furthermore, it is suggested that mechanosensory inputs from the posterior palatal mucosa may excite neurons in the central pattern generator and provide the motor patterns responsible for jaw closure during the jaw-closing reflex. We have demonstrated that excitation of Mass. Mns innervating the deep masseter muscle mainly contributed to maintaining the occlusal phase of jaw closure during the jaw-closing reflex. However, the onset of EPSPs was 100 to 160 ms (n = 27) earlier than the onset of jaw closure. In studies on spontaneously occurring jaw closure it was demonstrated that there was a proportional increase in the number of spikes of the Temp. Mn and the mechanical response (jaw closure).

Animals↗
PubMed1991

Synaptic efficacy of inhibitory synapses in the reinnervating hypoglossal motoneurons.

The synaptic efficacy of inhibitory synapses in tongue protruder motoneurons reinnervating the tongue retractor muscle was studied in cats. We have demonstrated that the percentage magnitude of a short- and a long-lasting inhibitory postsynaptic potential in the inhibitory postsynaptic potentials produced in the tongue protruder motoneurons, whose axons had been cut but allowed to regenerate to make functional contact with the tongue retractor muscles, by lingual nerve or inferior alveolar nerve stimulation, was rearranged to appear like that exhibited by the tongue retractor motoneurons that normally supply that muscle. In addition, the peak amplitude of the summated afterhyperpolarization in a tongue protruder motoneuron on operated cats at nine months axon-union was in the normal range.

Action Potentials↗
PubMed1991

Interaction between cadmium and copper on ossification of embryonic chick bone in tissue culture.

To investigate the interaction between cadmium and copper in ossification, femurs from 9-day-old chick embryos were cultured for 6 days in the presence of 2 microM cadmium and/or 1 microM copper. It was found that cadmium + copper treatment caused interactively severe damage to osteogenic mesenchymal cells in the periosteum and a severe degenerative change in osteoblasts around the trabecula, resulting in severe impairment of ossification in the diaphysis. Cadmium content was increased by copper; however, copper content was unaffected by cadmium in the diaphysis. It was therefore considered that the copper-induced increase in cadmium content was a primary factor in the interactive toxic effect of the cadmium + copper treatment in ossification.

Animals↗
PubMed1991

Anti-tumor-promotion by principles obtained from Angelica keiskei.

Potent anti-tumor promoter activity has been found in the nonpolar extracts of the root of "Ashita-Ba", Angelica keiskei Koidz. (Umbelliferae), which is eaten as a vegetable in Japan. From this active fraction, two angular furanocoumarins, archangelicin (1) and 8(S),9(R)-9-angeloyloxy-8,9-dihydrooroselol (2), three linear furanocoumarins, psoralen (3), bergapten (4) and xanthotoxin (5), and three chalcones, 4-hydroxyderricin (6), xanthoangelol (7) and a novel chalcone named ashitaba-chalcone (8), were isolated. Among these compounds, two angular type furanocoumarins, 1 and 2, and three chalcones, 6-8, suppressed 12-O-tetradecanoylphorbol-13-acetate (TPA)-stimulated 32Pi-incorporation into phospholipids of cultured cells, whereas coumarins 3-5 were less effective. In addition, chalcones 6 and 7 were proved to have anti-tumor-promoting activity in mouse skin carcinogenesis induced by 7,12-dimethylbenz[a]anthracene (DMBA) plus TPA. Since chalcones 6 and 7 showed calmodulin-interacting property, both chalcones may reveal anti-tumor-promoting activity via the modulation of calmodulin involved systems. These chalcones may be useful to develop the effective method for cancer prevention.

Animals↗
PubMed1991

Prolonged exposure to industrial noise causes hearing loss but not high blood pressure: a study of 2124 factory laborers in Japan.

To determine the role of noise exposure in the etiology of hypertension, a cross-sectional study was performed by measuring the blood pressure of 2124 male laborers working in a noisy factory. The prevalence of hypertension was 10.2% in group I (85-115 dB), 10.9% in group II (less than 85 dB) and 12.5% in group III (office workers). There was no difference in systolic or diastolic blood pressure among the three groups. There were 358, 439 and 71 laborers in groups I, II and III, respectively, all having worked in the same noise area for more than 10 years. Blood pressure was lower 10 years previously in each group, but the degree of increment did not significantly differ among the three groups. The prevalence of hearing loss was 16.5% in group I, which was significantly higher than that in group II (7.5%) and group III (2.8%). Blood pressure of laborers with hearing loss was equal to that of laborers with intact hearing acuity. There was no significant relationship between hearing loss and the prevalence of hypertension. Thus, prolonged exposure to industrial noise contributes to hearing loss. However, elevation of blood pressure was not found in laborers working in a noisy factory. This finding was not consistant with previously reported findings in the rat. An adaptability to prolonged noise in man may account for this discrepancy.

Adult↗
PubMed1991

Effect of the immunosuppressive agent, ciclosporin, on experimental immune complex glomerulonephritis in rats.

Effect of the immunosuppressive agent, ciclosporin (CS), on bovine serum albumin (BSA) nephritis in rats was evaluated. Eight weeks after immunization, 19 male Wistar rats received a daily intravenous dose of BSA (2 mg). Two weeks later, 11 rats received BSA and an oral dose of CS (10 mg/kg), and 8 rats received only BSA for 2 weeks. Urinary protein was measured weekly and serum anti-BSA antibody was measured by passive hemagglutination biweekly. The animals were killed at the 12th experimental week and blood samples and kidney specimens were obtained. BUN and serum creatinine were measured at the time of sacrifice. Kidney specimens were processed for light and immunofluorescent microscopic examination. Urinary protein excretion was significantly less in CS-treated rats than in nontreated controls at the 2nd week after treatment (5.3 +/- 1.3 vs. 25.6 +/- 10.3 mg/day, p less than 0.05). Anti-BSA antibody titers were lower in treated rats than in controls at the 2nd week after the treatment. There were no significant differences in the levels of BUN and serum creatinine between two groups. Glomerular hypercellularity and mesangial widening were milder in treated rats than in controls, and glomerular deposition of BSA was less intense in treated rats than in controls. These results suggest that CS suppressed the antibody production and the development of glomerular changes in rats with immune complex glomerulonephritis.

Animals↗
PubMed1991

Ventricular external constraint by the lung and pericardium during positive end-expiratory pressure.

We studied intra- and extrapericardial surface pressures (Ppe and Pex) over the left ventricle with air-filled flat balloons in six dogs under different levels of positive end-expiratory pressure (PEEP) and left ventricular end-diastolic pressure. Pex reflected lung constraint and the transpericardial pressure (Ppe-Pex) reflected the elastic recoil of the pericardium (pericardial constraint). Under baseline plasma volume conditions with a PEEP of 0 cm H2O, Ppe was 2.4 +/- 0.2 (SEM) mm Hg and Pex was 0.2 +/- 0.1 mm Hg; that is, 91% of Ppe was contributed by the transpericardial pressure. With incremental increases in PEEP, Pex increased and approach Ppe with a decrease in the transpericardial pressure (p less than 0.01). With a PEEP of 20 cm H2O, Ppe was 5.3 +/- 0.1 mm Hg and Pex was 5.0 +/- 0.2 mm Hg; that is, less than 5% of Ppe was contributed by the transpericardial pressure. Under plasma volume-loaded conditions with an increase in PEEP to 20 cm H2O, Pex increased but remained lower than Ppe, with a substantial contribution of transpericardial pressure still present (19%). These results suggest that lung constraint alone can substantially constrain the left ventricle and that the influence of lung constraint, rather than pericardial constraint, may be progressively important with an elevated lung volume produced by either positive- or negative-pressure respiration.

Animals↗
PubMed1991

Sympathetic and renin-angiotensin system in conscious rabbits with two-kidney, one clip hypertension.

We attempted to clarify the contribution of the altered neural mechanism associated with increased angiotensin II to two-kidney, one clip (2K1C) hypertension on the 3rd and 35th days after renal artery stenosis. 2K1C hypertension was produced in 20 rabbits, and a sham operation was performed in 11 rabbits. Sarl, Ile8 angiotensin II (AIIA) infusion tests and baroreflex sensitivity determinations by bolus injection of phenylephrine were performed on the 3rd and 35th days after renal artery stenosis. The blood pressure was 12 mmHg higher in the hypertensive rabbits than in the sham operated rabbits on the 3rd day after clipping. The blood pressure returned to the control level during the infusion of AIIA. On the 35th day after clipping, AIIA-sensitive or AIIA-resistant hypertension developed. The blood pressure was higher in the AIIA-sensitive rabbits than in the AIIA-resistant rabbits (131 +/- 5 vs 116 +/- 4 mmHg, p less than 0.05). The baroreflex sensitivity was lower in the AIIA-sensitive rabbits than in the AIIA-resistant rabbits (1.8 +/- 0.3 vs 2.8 +/- 0.3 msec/mmHg, p less than 0.05). There was no difference in plasma norepinephrine between the two groups on either the 3rd or 35th day. Thus, impaired baroreflex sensitivity was found in the accelerated hypertension seen in the chronic phase of 2K1C hypertension. Neural mechanisms mediated by the peripheral sympathetic nervous system did not appear to contribute to the development of 2K1C hypertension.

Angiotensin II↗
PubMed1991

[Studies on IgG subclass antibodies in adult asthma. 1. Serum antigen specific IgG subclass antibodies in asthmatics with late asthmatic response].

It is clear that immediate asthmatic response is mediated by IgE-dependent mechanisms. However, late asthmatic response is induced by inhalation of antigens without antigen specific IgE antibodies in some asthmatics, especially in intractable asthma induced by Candida antigen. To elucidate the relationship between those bronchial responses and antibodies, antigen specific IgG subclass antibodies in sera from asthmatics were measured and compared with IgE antibody. The results were as follows. 1. Avidin-biotin ELISA (enzyme-linked immunosorbent assay) method was established for the measurement of specific IgG and IgG subclass antibodies to mite or Candida antigen. 2. Serum levels of antigen specific IgG and IgG1 antibodies in asthmatics with LAR provoked by mite or Candida antigen were significantly higher than those in asthmatics without LAR (p less than 0.01). 3. Serum levels of specific IgE antibody to these antigens in asthmatics with LAR provoked by mite or Candida antigen were slightly lower than those in asthmatics without LAR, though the difference is not significant. These results suggest that high serum levels of specific IgG and IgG1 antibodies to these antigens play a role in inducing LAR in asthmatics with LAR.

Adolescent↗
PubMed1990

Cloned suppressor T cells derived from mice tolerized with conjugates of antigen and monomethoxypolyethylene glycol. Relationship between monoclonal T suppressor factor and the T cell receptor.

Cloned Ts cells specific for the Ag, human monoclonal (myeloma) IgG, were derived from spleen cells of mice that had been immunosuppressed by treatment with a tolerogenic conjugate of HIgG and monomethoxypolyethylene glycol. The cloned Ts cells (clone 23.32) suppressed in vitro antibody responses in an Ag-specific and MHC-restricted manner. By FMF with appropriate antibody reagents, these cells were shown to be Thy-1+, CD4-, CD5-, and CD8+ and to express CD3 and the alpha beta-TCR. These results are consistent with the view that Ts cells use Ag recognition structures similar to those reported for Th cells and CTL. A soluble factor (TsF) extracted from the cloned Ts cells also suppressed in vitro antibody responses in an Ag-specific and H-2Kd-restricted manner, i.e., restricted to MHC class I molecules. The suppressive activity of this TsF could be abrogated by addition of mAb H28-710 that reacts with a determinant on the alpha-chain of TCR. Moreover, the TsF bound to and could be recovered from an immunosorbent consisting of the anti-alpha-TCR mAb H28-710 coupled to Sepharose 4B. In contrast, the TsF was not bound by immunosorbents consisting of mAb to the beta-chain of TCR (H57-597) or to V beta 8 (F23.1). It was, therefore, concluded that the TsF of clone 23.32 is serologically related to the alpha-chain of the TCR; however, it is not identical to TCR, because it lacks the determinants expressed on the TCR beta-chain that are recognized by the two anti-beta mAbs used in this study.

Animals↗
PubMed1990

Synaptic efficacy of inhibitory synapses and repetitive firing in the reinnervating trigeminal and hypoglossal motoneurons.

The synaptic efficacy and repetitive firing in masseteric motoneurons after the self-union operation and in tongue protruder motoneurons after their cut axons were reunited to tongue retractor muscles, the styloglossus muscle, were studied in cats. To ensure the correct identification of reinnervating motoneurons, the muscle response produce by an induced spike in a motoneuron by intracellularly injected depolarizing current was recorded. In both masseteric and tongue protruder motoneurons there were no differences on the patterns of postsynaptic potentials produced in reinnervating and non-reinnervating motoneurons by peripheral nerve stimulation, suggesting that the recovery of the synaptic efficacy of inhibitory synapses is time-dependent rather than muscle reinnervation. However, the present study demonstrated that the recovery of processes that control rhythmical firing of motoneurons is probably dependent on muscle reinnervation.

Animals↗
PubMed1990

Structures of Angular Pyranocoumarins of Bai-Hua Qian-Hu, the Root of Peucedanum praeruptorum1.

Three new angular-type dihydropyranocoumarins, peucedanocoumarin I ( 1), peucedanocou-marin II ( 2), peucedanocoumarin III ( 3), and a known coumarin having the same skeleton, pteryxin ( 4), were isolated from the crude drug "Bai-Hua Qian-Hu" of the Q-II type series, which is the root of PEUCEDANUM PRAERUPTORUM Dunn. (Umbelliferae). The chemical structures of 1, 2, and 3 have been established by physicochemical methods to be 3' ( S)-2-methylbutyryloxy-4'-( R)-acetoxy-3',4'-dihydroseselin, 3'( S)-acetoxy-4'( R)-angeloyloxy-3',4'-dihydroseselin, and 3'( S)-acetoxy-4'( R)-tigloyloxy-3',4'-dihydroseselin, respectively.

Journal Article↗
PubMed1990

Captopril-stimulated renal vein renin in hypertensive patients with or without renal artery stenosis.

To examine the efficacy and usefulness of captopril-enhanced renal vein renin (RVR) measurements in detecting the functional significance of renal artery stenosis found in hypertensives, we compared these values in 22 patients with arteriographically documented renovascular hypertension due to unilateral (URVH: 14 patients) or bilateral renal artery stenosis (BRVH: 8 patients) and 12 patients with high renin essential hypertension (EHT). Before captopril administration, RVR ratio was less than 1.5 in 8 patients (36.4%) with renovascular hypertension and all patients (100%) with EHT. Captopril enhanced the lateralization of renal vein renin in renovascular hypertension; the postcaptopril RVR ratio was greater than 2.0 in 18 patients (81.8%) and greater than 1.5 in all the patients (100%). On the other hand, RVR ratio remained unchanged in most patients with EHT. There was no significant difference in the postcaptopril RVR ratios between URVH and BRVH. However, the postcaptopril RVR ratio was higher in atherosclerosis (10 patients) than in fibromuscular dysplasia (11 patients) (P less than .05). Captopril also elucidated contralateral renin suppression as expressed by a contralateral/peripheral renin ratio of less than 1.0, which was associated with a favorable outcome of unilateral surgical intervention. Captopril-stimulated RVR indices were valuable in detecting the functionally significant renal artery stenosis and predicting surgical curability in renovascular hypertension.

1-Sarcosine-8-Isoleucine Angiotensin II↗
PubMed1990

Studies on the anti-tumor-promoting activity of naturally occurring substances. IV. Pd-II [(+)anomalin, (+)praeruptorin B], a seselin-type coumarin, inhibits the promotion of skin tumor formation by 12-O-tetradecanoylphorbol-13-acetate in 7,12-dimethylbenz[a]anthracene-initiated mice.

Since Pd-II [(+)anomalin, (+)praeruptorin B], a seselin-type coumarin, was found to inhibit tumor promoter induced phenomenon in vitro, the effect of Pd-II on the in vivo tumor-promoting action of 12-O-tetradecanoylphorbol-13-acetate (TPA) in 7,12-dimethylbenz[a]anthracene-initiated mouse skin was investigated. Pd-II, applied 40 min before the TPA treatment, at a dose of 10 mumol/painting, completely suppressed tumor formation up to 20 weeks of tumor promotion, without any toxicity. Besides Pd-II, various anti-tumor-promoter coumarins were found in the traditional Chinese medicine Qian-Hu, from which Pd-II was obtained. These coumarins may be useful for the development of an effective method to prevent cancer.

9,10-Dimethyl-1,2-benzanthracene↗