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Biomedical subjects

T Kubo

Publications and source records attributed to T Kubo.

At least 757 records · Page 42Linked to original sources
PubMed1989

Nicotine-induced regional changes in brain noradrenaline and dopamine turnover in rats.

Using high performance liquid chromatography with electrochemical detection, the levels of 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG), 3,4-dihydroxyphenylacetic acid (DOPAC) and 3,4-dihydroxyphenylalanine (DOPA) were determined in various brain regions of the rat 1 h after nicotine administration. Nicotine (1 mg/kg, s.c.) produced an increase in MHPG concentrations in the occipital cortex, hippocampus, striatum, hypothalamus, thalamus, midbrain, pons/medulla and cerebellum. This alkaloid at the same dose also caused an increase in DOPAC concentrations in the hypothalamus, thalamus and pons/medulla. The nicotine-induced increase in MHPG and DOPAC concentrations in the brain regions was inhibited by pretreatment with mecamylamine (5 mg/kg, i.p.) but not by hexamethonium (10 mg/kg, i.p.). Nicotine (1 mg/kg, s.c.) produced an increase in DOPA concentrations under DOPA decarboxylase inhibition with NSD-1015 (200 mg/kg, i.p.) in the hypothalamus, thalamus and pons/medulla. These results indicate that nicotine can increase the turnover of noradrenaline and dopamine in various brain regions of the rat and this effect is mediated via activation of central nicotinic receptors.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1989

Effects of acute nicotine on catecholamine turnover in various rat brain regions.

Acute effects of in vivo nicotine application on turnover rates of noradrenaline (NA), adrenaline (AD) and dopamine (DA) in rat occipital cortex, hippocampus, striatum, hypothalamus, thalamus, midbrain, pons/medulla and cerebellum were examined by determining the amine concentrations by high performance liquid chromatography. The regional turnover rates of catecholamines were evaluated by comparing the decline in concentrations produced by blockade of synthesis. Intraperitoneally injected fusaric acid (80 mg/kg), an inhibitor of dopamine-beta-hydroxylase, significantly decreased NA concentration in all eight regions examined, and AD concentration in the hypothalamus and pons/medulla. alpha-Methyl-p-tyrosine methylester (alpha-MPT, 400 mg/kg), an inhibitor of the tyrosine hydroxylase, induced significant and uneven decreases in regional DA concentrations 1 h after the i.p. injection. alpha-MPT also significantly decreased NA concentration in all the regions except the striatum. Subcutaneously injected nicotine 0.4-1 mg/kg significantly enhanced the fusaric acid-induced decline in NA concentrations in the hippocampus and cerebellum. AD decline in the midbrain by fusaric acid was significantly accelerated by nicotine (0.4 mg/kg), but was not affected by a larger dose (1 mg/kg). In the hippocampus, nicotine (1 mg/kg) significantly enhanced the alpha-MPT-induced decrease in NA concentration, while it reduced the decrease in DA concentration. These findings suggest that nicotine can affect the turnover of brain catecholamine in a regionally specific manner.

Animals↗
PubMed1989

Study on the constituents of Desmodium styracifolium.

Two triterpenoid saponins (1 and 2) were isolated from Desmodii Herba [the dried whole plants of Desmodium styracifolium (Osbeck) Merr. (Leguminosae)] and their chemical structures were characterized as soyasaponin I and a new saponin, 3-O-[alpha-L-rhamnopyranosyl-(1----2)-beta-D-galactopyranosyl- (1----2)-beta-D-glucuronopyranosyl]soyasapogenol E, respectively, by chemical and spectroscopic means.

Chemical Phenomena↗
PubMed1989

Isoproterenol-induced facilitation of norepinephrine release does not primarily involve a local angiotensin II mechanism in guinea pig pulmonary arteries.

We have attempted to clarify whether or not captopril and 1Sar-8Ile-angiotensin II could protect isoproterenol-induced facilitation of norepinephrine release in guinea pig pulmonary arteries loaded with 3H-norepinephrine. Angiotensin I at 1 nM and 30 nM isoproterenol similarly facilitated evoked release of 3H-norepinephrine at 1 Hz. Captopril at 1 microM and 1Sar-8Ile-angiotensin II at 10 nM completely prevented angiotensin I-induced facilitation, whereas these pretreatments produced no effect on isoproterenol-induced facilitation. Isoproterenol-induced facilitation of norepinephrine release does not primarily involve a local angiotensin II mechanism.

1-Sarcosine-8-Isoleucine Angiotensin II↗
PubMed1989

Non-invasive continuous fetal transcutaneous pO2 and pCO2 monitoring during labor.

Continuous measurements of fetal scalp transcutaneous pO2 (tcpO2) and pCO2 (tcpCO2) monitoring were performed for 49 patients for the purpose of the evaluation of the fetal well-being. The equipment used was transcutaneous pO2/pCO2 monitor Micro Gas 7640 (KONTRON, Switzerland), which was inserted through the vagina and attached to the fetal head with a suction ring. Blood was taken from the umbilical vessels and pO2 and pCO2 values were analyzed. The correlation coefficient between pO2 in the umbilical artery and tcpO2 was 0.78 (p less than 0.01), and that between pCO2 in the umbilical artery and tcPCO2 was 0.79 (p less than 0.01). Relationships between the transcutaneous blood gas analysis and FHR patterns were discussed. Increase of pCO2 and decrease of tcpO2 was observed in the cases of variable deceleration, not observed in the case of early deceleration. FHR patterns don't always indicate fetal condition, for example in the case of fetal arrhythmia, especially fetal bradycardia. But tcpO2 monitoring of the fetus affected fetal arrhythmia during labor aids diagnosis of fetal distress by FHR patterns, especially in the case of fetuses affected by fetal bradycardia.

Blood Gas Monitoring, Transcutaneous↗
PubMed1989

Localization and origins of calcitonin gene-related peptide containing fibres in the vestibular end-organs of the rat.

The distribution, origin and fine structure of nerve terminals immunoreactive to calcitonin gene-related peptide (CGRP) were investigated in the vestibular end-organs of the rat by means of immunocytochemistry. Dense plexus of CGRP-like immunoreactive (CGRPI) fibres were observed just beneath the sensory epithelial layers of the ampullary crista of the semicircular canal, and utricular and saccular maculae of the otolith organ. Some CGRPI fibres left the plexus to enter the sensory epithelial layer. Parasagittal transection of the brain just medial to the cochlear nucleus revealed the presence of a few CGPRI fibres in the vestibular end-organs ipsilaterally, indicating that these fibres originate in the central nervous system. A combination of retrograde tracing and immunocytochemistry was then used to identify the origins of CGRPI fibres found in the vestibular end-organs. After injection of fast blue dye (FB) into the vestibular cistern, CGRPI neurons in the area dorsolateral to the genu of the facial nerve were labelled by FB bilaterally. The present ultrastructural study has revealed that most of the CGRPI fibres in the vestibular end-organs form direct contacts with afferent nerve terminals which surround type I vestibular sensory cells.

Acoustic Maculae↗
PubMed1989

Analysis of body sway pattern after alcohol ingestion in human subjects.

Movements of the centre of gravity during 60 s of standing with eyes closed and eyes open were analysed before and after alcohol ingestion up to 8 h in 37 healthy human subjects. Blood alcohol and acetaldehyde concentrations (BAC and BAcHC) were measured simultaneously. Among the parameters analysed, area of posturogram was the most sensitive indicator; it increased to 3.8 times that of the control value at 60 min, after 3.5 ml/kg of ingested whisky (mean BAC of this group was 1.4 mg/ml), with the eyes open. The Romberg ratio, which denotes eyes closed relative to eyes open, remained constant. By contrast, there was little change in stabilometry in cases of 1.2 ml/kg of whisky ingestion (mean BAC at 60 min was 0.58 mg/ml). It is considered that body sway starts to increase when the BAC level exceeds 0.6 mg/ml on average; this value is only higher than the threshold of positional alcohol nystagmus. Correlation coefficients between BAC and each parameter of the stabilogram in the eyes open condition, such as area, X- and Y-axis diameters, and velocity of body sway, were 0.53, 0.45 and 0.48, respectively (p less than 0.01). There was no positive correlation between BAcHC and these parameters.

Acetaldehyde↗
PubMed1989

Altered amino acid levels in brainstem regions of spontaneously hypertensive rats.

The contents of glutamate, gamma-aminobutyric acid (GABA), glycine, beta-alanine and taurine in brainstem regions responsible for blood pressure regulation, the rostral ventrolateral medulla (RVL), the nucleus tractus solitarii (NTS) and the caudal ventrolateral medulla (CVL) regions, were determined in spontaneously hypertensive rats (SHR) as compared with Wistar Kyoto rats. In SHR, the content of glutamate was increased in the RVL, NTS and CVL regions whereas GABA and beta-alanine contents were decreased in the RVL and all the regions studied, respectively. There was no difference between WKY and SHR in glycine and taurine contents in all the regions studied. These results provide evidence suggesting alterations of brainstem amino acid metabolism in SHR.

Amino Acids↗
PubMed1989

Biological properties of streptonigrin derivatives. III. In vitro and in vivo antiviral and antitumor activities.

Antitumor antibiotic streptonigrin (STN-COOH) is a potent inhibitor of avian myeloblastosis virus (AMV) and human immunodeficiency virus reverse transcriptases. The carboxyl group at 2'-position of STN-COOH was modified to give esters, hydrazide, amides and amino acid derivatives for biological studies. Against AMV reverse transcriptase, the hydrazide, amides and amino acid derivatives showed inhibitory activity, which compared favorably to that of STN-COOH, with the ID50 values ranging 2-8 micrograms/ml. In contrast, the esters lacked this activity except for those having a dimethylamino group in the substituent. Splenomegaly caused by Friend leukemia virus infection was significantly inhibited by STN-COOH and STN-COO(CH2)3N(CH3)2, but not STN-CONH(CH2)3N(CH3)2. Doxorubicin-resistant murine lymphoblastoma L5178Y cells showed collateral sensitivity to both STN-COOH and STN-COO(CH2)3N(CH3)2 not only in vitro but also in vivo.

Animals↗
PubMed1989

[Two cases of metastatic renal tumor].

Two cases of metastatic renal tumor are reported, one in a 78-year-old male who had undergone total gastrectomy for gastric carcinoma, and the other in a 45-year-old female who had undergone hysterectomy for cervical carcinoma of the uterus. The chief complaint was flank pain and nephrectomy was performed in both cases. Histopathological examination of the removed specimen revealed metastatic renal tumor the primary site of which was probably the stomach in the first case and cervix uteri in the second case. The literature on metastatic renal tumors in Japan is reviewed.

Adenocarcinoma↗
PubMed1989

[A case of emphysematous pyelonephritis with septic shock recovered by transurethral drainage of pelvis].

A case of emphysematous pyelonephritis with septic shock was present in a 58-year-old diabetic woman. The spontaneous production of gas was present within the right renal pelvis in kidney-ureter-bladder X-ray. The patient's condition deteriorated rapidly after admission, became complicated with acute renal failure, disseminated intravascular coagulation and acute respiratory failure. Transurethral drainage of the pelvis using a 6 Fr. UPJ occlusion balloon catheter and endotracheal intubation with respiratory assistance were performed as a life-saving procedure. The optimal therapy with surgical or conservative approach for such a severe condition is discussed. The use of transurethral drainage of pelvis as a non-invasive treatment is suggested.

Acute Kidney Injury↗
PubMed1989

[Metastatic renal tumor of esophageal carcinoma: report of a case].

In August 1987, a 66-year-old man was hospitalized because of macrohematuria and right flank pain. He had undergone resection of middle and lower part of the esophagus with esophagogastrostomy for esophageal carcinoma on April 16, 1984. Computed tomography revealed a solid, irregular, low density area in the upper pole of the right kidney and the right lobe of the liver. Arteriography showed a hypovascular mass in the upper pole of the right kidney, and several small tumor stains in the liver. At cystoscopic examination, the urinary bladder was normal and blood flowing from bilateral ureters was not seen. Cytological study of urine sediment disclosed squamous cell carcinoma. The patient was treated with systemic chemotherapy, but not improved. He died 6 months later, and the autopsy demonstrated widespread metastasis in various organs including the right kidney and liver. No recurrence was found in the residual esophagus. The kidney is the sixth organ of metastasis following the lung, liver, bone, adrenal, peritoneum and mesenterium. Although metastasis to the kidney is relatively common in autopsy, it is uncommon to be manifest clinically.

Aged↗
PubMed1989

[Fetal therapy in utero by blockage of the umbilical blood flow of acardiac monster in twin pregnancy].

We studied a life-saving method for the unaffected twin in two recent patients who had acardiac monster in twin pregnancy. We succeeded in blocking the umbilical blood flow of the acardiac monster in utero as radical treatment for this abnormality in one of the patients. In case 1, tocolysis and amniocentesis with puncture to the cyst of the acardiac monster were performed to prevent premature labor. However, the patient underwent premature labor at 27 weeks of gestation, and the newborn died. In case 2, fetal treatment was given: A steel coil was placed in the umbilical cord close to the abdominal wall of the acardiac monster under ultrasonographic guidance at 23 weeks of gestation to block blood flow. As a result, no enlargement of the acardiac monster was observed, and the cardiac function of the unaffected fetus improved. At 38 weeks of gestation, the patient delivered a normal baby weighing 2,237g and an acardiac monster weighing 110g. There were no complications in either the mother or newborn. There has been no report describing blockage of the umbilical blood flow of an acardiac monster in utero. Our method is considered efficient and less risky to the mother and the unaffected twin.

Abnormalities, Severe Teratoid↗
PubMed1989

Selective effector coupling of muscarinic acetylcholine receptor subtypes.

Attempts have been made by means of recombinant DNA technology to understand the molecular basis of the functional heterogeneity of the muscarinic acetylcholine receptor (mAChR). Molecularly defined mAChR subtypes have been produced from the cloned DNAs in Xenopus oocytes and NG108-15 neuroblastoma-glioma hybrid cells as transient and stable expression systems, respectively, and agonist-induced cellular responses have been examined. The results obtained provide evidence that mAChR subtypes are selectively coupled with different effector systems, albeit not exclusively.

Animals↗