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Biomedical subjects

M Horie

Publications and source records attributed to M Horie.

At least 163 records · Page 9Linked to original sources
PubMed1990

Two types of delayed rectifying K+ channels in atrial cells of guinea pig heart.

Whole-cell clamp experiments revealed the double exponential deactivation of the delayed rectifier K+ current in single guinea pig atrial myocytes. Two types of K(+)-selective channels were identified by applying repolarizing voltage pulses to cell-free patches from atrial cell membrane, where inward-rectifier, ATP-sensitive, and muscarinic K+ channels were all inactivated. Under a symmetrical 150 mM K+ condition, single channel conductances of the channels were 10 and 3 pS. The reversal potential obtained from the unitary current-voltage relation coincided with the equilibrium potential for K+. Ensemble averages of both types of single channel currents showed deactivation kinetics upon hyperpolarizing to potentials between -40 and -120 mV. The more positive the pre-pulse potential, the greater was the peak ensemble current. It is concluded that these two channels are responsible for atrial delayed rectifying K+ currents.

Animals↗
PubMed1990

[Endoscopic and fluoroscopic pyeloureterotomy for ureteropelvic junction obstruction and ureteral stricture].

Endoscopic or fluoroscopic pyeloureterotomy was performed in a total of 32 patients (34 ureters) with ureteropelvic junction obstruction (UPJO) or ureteral stricture from March 1985. Cold incision was performed, using a flexible knife over a guidewire, endoscopically on 23 ureters and fluoroscopically on 11 ureters. The mean operation time was 98.9 +/- 48.3 minutes. Twenty-five (74%) of the 34 ureters showed relief of subjective symptoms, normalized urinalysis and radiographical improvement of hydronephrosis with a mean follow-up period of 11.7 +/- 10.0 months (range: 3-43). The clinical results by etiology were as follows: primary UPJO, 13/16 (81%); secondary UPJO, 4/4 (100%); ureteral stricture, 6/7 (85%); obliteration of ureteral implantation, 2/7 (29%). No major complication was noted with this endourological technique. This endourological technique might be clinically useful for the treatment of UPJO and ureteral strictures.

Adolescent↗
PubMed1990

Serum hemolytic activity in dogs infected with Babesia gibsoni.

The hemolytic activity in serum of Babesia gibsoni-infected dogs was examined. When the activity was assayed in a reaction system consisting of similar concentrations of the serum and canine red blood cells to those in blood, significant hemolysis was observed. The activity of the serum of B. gibsoni-infected dogs, either naturally or experimentally, was always higher than that of uninfected animals. Moreover, in the experimental infection with B. gibsoni, the change in serum hemolytic activity was parallel to those of anemia and parasitemia, whereas it was inversely parallel to that of the hematocrit value. The present study revealed the presence of a hemolytic factor(s) in the serum of B. gibsoni-infected dogs, suggesting that the progressive anemia was due to hemolysis by the factor(s).

Anemia, Hemolytic↗
PubMed1990

Metastatic renal tumor from the lung with regional lymph node involvement: a case report.

We report a case of metastatic renal tumor from lung cancer. A 53-year-old man presented with gross hematuria 2 years after treatment of the primary lesion. Investigations suggested a metastatic tumor in the right kidney from the lung which was accompanied with regional lymph node metastasis. Surgical treatment was not performed because of his poor condition and the lymph node involvement. Therefore, the combination chemotherapy of 5-fluorouracil, vincristine and doxorubicin, OK-432 was applied. Although this conservative management was effective, he died of progression 6 months later and an autopsy confirmed the diagnosis of metastatic renal tumor.

Humans↗
PubMed1989

Computed tomographic findings in children with spastic diplegia: correlation with the severity of their motor abnormality.

Computed tomographic findings of 46 children with spastic diplegia examined at nine months to three years of age corrected for preterm births were analyzed. Both the size of the lateral ventricles measured by the width of the anterior horns, and the volume of the extracerebral low-density areas were enlarged in some patients. Both enlargements did not, however, correlate to the severity of the motor abnormality in the patients. The low-density areas of the periventricular white matter, especially adjacent to the trigone, were reduced in many children, probably due to the atrophy of the cerebral white matter having periventricular leukomalacia. The anterior expansion of the white matter reduction from the trigone corresponded to the severe motor abnormality in the children with spastic diplegia.

Atrophy↗
PubMed1989

Dual effects of intracellular magnesium on muscarinic potassium channel current in single guinea-pig atrial cells.

1. The effects of internal Mg2+ ions on the muscarinic acetylcholine (ACh) receptor-mediated K+ currents were investigated in single atrial cells of guinea-pigs, using the whole-cell and inside-out modes of the patch-clamp technique. 2. During cell dialysis in the whole-cell-clamp condition, the depletion of internal Mg2+ increased outward muscarinic K+ currents but decreased inward currents, thereby reducing the inwardly rectifying property of the channels. 3. When inside-out patches were prepared, channel availability was abolished and was reactivated by internal application of guanosine 5'-triphosphate (GTP) or its non-hydrolysable analogue, 5'-guanylyl imidodiphosphate (GppNHp), in the presence of Mg2+. GppNHp led to a recovery of the channels also in the nominal absence of Mg2+ (0[Mg2+]i). 4. The activation of single-channel currents by intracellular GTP and Mg2+ was dose-dependent. Both concentration-response curves were fitted by saturation kinetics with Hill coefficients of 1, and the half-maximum doses were 24 +/- 8 microM for GTP and 67 +/- 14 microM for Mg2+. The effects of Mg2+ on activation of K+ currents were additive with those of GTP, suggesting the presence of two independent binding sites for GTP and Mg2+. 5. The single-channel conductance became virtually ohmic when measured at nominally zero [Mg2+]i while GppNHp was used to recover the channel activity. Micromolar [Mg2+]i reduced the unitary amplitude of single open-channel currents in a dose- and voltage-dependent manner, showing half-blocking doses of 293 microM at +40 mV and 115 microM at +60 mV. 6. Voltage-dependent kinetics of Mg2+ block were described using equations based on Eyring rate theory (Woodbury, 1971; Hille, 1984), where the coefficient for voltage dependence (delta) was 0.63. 7. Intracellular Mg2+, at a physiological concentration, has a dual action on the muscarinic K+ channel: first Mg2+ activates the channel in the presence of GTP through GTP-binding proteins (G proteins), and secondly it blocks outward currents through the channel, thereby causing the inwardly rectifying property.

Acetylcholine↗
PubMed1989

[A case report of scrotal hemangioma].

A 21-year-old man with painless tumor in the right scrotum was seen at our Department. The tumor was resected surgically and histological examination revealed venous hemangioma. This case is 26th case of scrotal hemangioma in Japan.

Aged↗
PubMed1989

[A case of renal cell carcinoma with lung metastases successfully treated by interferon-beta].

A case of renal cell carcinoma with multiple lung metastases successfully treated with interferon (IFN) following nephrectomy is reported. A 46-year-old man consulted our institute complaining of left flank pain for 3 months on June 18, 1983. Macroscopic hematuria consisting of blood clot had also been found 1 week before. For a diagnosis of left renal carcinoma with multiple lung metastases, he was admitted. After total nephrectomy, 30 x 10(6) units per day of natural IFN-beta were administered intravenously every other day for 2 months (total dose; 269 x 10(6) units). One of the pulmonary lesions disappeared, but another increased in size and a new lesion was also found. Therefore, this trial was evaluated to be progression. Thereafter, he was treated with 600 mg/day of carmofur (HCFU) and was in a stable condition. As his lung lesions progressed at 11 months after nephrectomy, 9 x 10(6) units/day of recombinant IFN-beta were additionally administered 5 days a week for 4 weeks. When the treatment was completed (total dose; 180 x 10(6) units), the pulmonary lesions disappeared. The complete response lasted for 9 months. However, on May, 1985, bone metastasis to lumbar vertebra was found and he died on November 4, 1985 without any evidence of relapse at lung field.

Antineoplastic Agents↗
PubMed1988

Effect of the content of divinylbenzene in ion-exchange resins on the chromatographic separation of alpha-cyclodextrin and glucose.

In the chromatographic separation of alpha-cyclodextrin and glucose, the parameters relating to the adsorption equilibria and rate processes of the solutes were evaluated for the sodium forms of cation-exchange resins with contents of divinylbenzene (DVB) of 2, 4, 6 and 8%. By using these parameters, the chromatograms of the solutes were then calculated. It is concluded that the resin with 6% DVB is most suitable for the chromatographic separation of the solutes on a preparative scale.

Chromatography, Ion Exchange↗
PubMed1988

Measurement of specific radioactivity of tryptophan labeled with carbon-14 in plasma by high-performance liquid chromatography with a synchronized accumulating radioisotope detector.

Measurement of specific radioactivity by a high-performance liquid chromatograph with a synchronized accumulating radioisotope detector was conducted. Accuracy of measurement for an authentic sample containing 0.2 nCi of tryptophan labeled with carbon-14 exceeded 95%. In the case of a plasma sample obtained 120 min following intravenous administration of 15 muCi of labeled tryptophan to a rat, the coefficient of variation was 7.0%.

Animals↗
PubMed1988

Measurement of specific radioactivity by high-performance liquid chromatograph with a synchronized accumulating radioisotope detector: determination of turnover rate and pool size of tryptophan in rat.

A high-performance liquid chromatograph with a synchronized accumulating radioisotope detector was used to determine the turnover rate and pool size of tryptophan in rat. The specific radioactivity could be followed for three half-lives on the final slope of the specific radioactivity curve following intravenous administration of 15 muCi of carrier free tryptophan labeled with carbon-14. Remarkable individual differences were noted in turnover rate and in pool size among rats.

Animals↗
PubMed1988

Computed tomographic findings in full-term infants with good prognosis.

To determine the normal neonatal computed tomographic (CT) findings, 121 CT scans of term infants with some neurological symptoms in the neonatal periods and a later good prognosis were studied. The majority of the neonates had asymmetric skulls with backward protrusion of the left occipital bone. In early neonates, the ventricles were small and straight high density lines were commonly seen in the posterior longitudinal cerebral fissure. In many, the left posterior horn was larger than the right one. Periventricular low density areas in the anterior and the posterior horns were noticed. The basal ganglia and the thalamus showed homogeneous density that was the same as that of the cerebellum. About one-third of the neonates had extra-cerebellar low density areas.

Aging↗
PubMed1988

Electrophysiological effects of melperone on isolated rabbit heart muscles.

1. Electrophysiological effects of melperone on isolated atrial and ventricular muscle preparations of the rabbit were studied by a conventional microelectrode technique. 2. Melperone (3.3 microM) prolonged the action potential duration and effective refractory period of the atrial preparations without affecting the maximum rate of depolarization (Vmax). These effects of melperone on action potential duration and effective refractory period were inhibited by a low potassium perfusate (2.7 mM). 3. A high concentration of melperone (16.6 microM) decreased Vmax of atrial preparations. In ventricular muscles, melperone at either concentration decreased Vmax, although the increase in action potential duration was greater than in the atrium. 4. Depression of Vmax of ventricular muscles by melperone was found to be augmented by an increase of stimulation frequency and drug concentration. 5. The rate of onset of rate-dependent block of Vmax in ventricle was increased with drug concentration and frequency of stimulation. However, the time constant of recovery from rate-dependent block was almost constant. The kinetics of rate-dependent block of Vmax by melperone were approximately similar to those of quinidine and disopyramide. Consequently it is concluded that melperone possesses class 1a antiarrhythmic activity as well as class 3 activity.

Action Potentials↗
PubMed1988

Long-term prognosis for patients with variant angina and influential factors.

Two hundred forty-five patients with variant angina were followed for an average of 80.5 months (range, 36-184 months). Survival rate at 1, 3, 5, and 10 years was 98%, 97%, 97%, and 93%, respectively. Survival rate without myocardial infarction at 1, 3, 5, and 10 years was 86%, 85%, 83%, and 81%, respectively. By univarite analysis, ST segment elevation in both the anterior and inferior electrocardiographic leads was the most important factor influencing survival, followed by use of calcium antagonists, left ventricular function, smoking, and alcohol intake. The variables that significantly correlated with survival without myocardial infarction were use of calcium antagonists, left ventricular function, extent and severity of coronary artery disease, coronary artery bypass surgery, and disease activity. Multivariate analysis using the Cox proportional hazards model showed that intake of calcium antagonists, extent and severity of coronary artery disease, and ST segment elevation in both the anterior and inferior leads were significant independent predictors of survival without myocardial infarction. We conclude that long-term prognosis for patients with variant angina is relatively good and that use of calcium antagonists improves it.

Adult↗
PubMed1988

The blood vascular architecture of the extra-adrenal chromaffin body in the adult rat: a scanning electron microscopic study of corrosion casts.

A well developed extra-adrenal chromaffin body with an axis of 200-400 micron was found in seven out of thirty adult male Wistar rats under a stereomicroscope. All seven bodies were located between the left and right kidneys. Blood vascular beds of the five bodies were reproduced with a methacrylate casting medium and observed with a scanning electron microscope. It was revealed that the extra-adrenal chromaffin body contained remarkedly numerous capillaries, which anastomosed with each other to form a conglomerated network. The blood capillaries were of small and uniform caliber and did not represent swollen sinusoids as in the adrenal medulla. The capillary network was denser than that in the adrenal medulla and had no direct vascular linkage with the adrenal cortex or an extra-adrenal cortical body. Histological examination of the two bodies treated with dichromate containing fixatives confirmed that they mainly consisted of chromaffin cells. These findings suggest that in the rat, extra-adrenal chromaffin bodies survive throughout life, actively producing catecholamines.

Adrenal Cortex↗
PubMed1988

Deep plantar arteries of some mammals, with special reference to the plantar metatarsal arteries.

The plantar metatarsal arteries of some mammals were studied. In the dog, raccoon dog and cat, the second proximal perforating branch was fully developed and produced the plantar metatarsal arteries. These plantar metatarsal arteries ran on the plantar surfaces of the interosseous muscles along the metatarsal bones or intermetatarsal spaces, and gave rise to the digital arteries of the second to fifth toes. In the rabbit, a branch of the medial plantar artery ran transversely on the plantar surfaces of the metatarsal bones at a level distal to the bases of these bones, and produced the plantar metatarsal arteries. These plantar metatarsal arteries ran deep in the interosseous muscles along the metatarsal bones or intermetatarsal spaces, and joined with the digital arteries which were derived from the medial plantar artery. The plantar metatarsal arteries could be classified into four kinds of arteries (sM, sI, dM and dI) in relation to the interosseous muscles and metatarsal bones. This classification largely coincides with that of the human hand and foot (Murakami, 1969, 1971), the monkey hand and foot (Nakai et al., 1987; Hinenoya et al., 1987), and the forepaws of some animals, including the dog and cat (Murakami et al., 1987).

Animals↗