Biomedical subjects

H Noda

Publications and source records attributed to H Noda.

At least 19 recordsLinked to original sources

PubMed1992

Chiral separation of barbiturates and hydantoins by reversed-phase high-performance liquid chromatography using a 25 or 50 mm short ODS cartridge column via beta-cyclodextrin inclusion complexes.

A high-performance liquid chromatographic method on a 25 or 50 mm short ODS cartridge column has been developed for the resolution of the enantiomers of some optically active barbiturates and hydantoins in human serum. beta-Cyclodextrin was used in the mobile phase. This method also seems to be an easy and effective way to test whether beta-cyclodextrin would be a useful chiral discriminator for a particular racemate.

Barbiturates↗

PubMed1992

Serial assessment of denervated but viable myocardium following acute myocardial infarction in dogs using iodine-123 metaiodobenzylguanidine and thallium-201 chloride myocardial single photon emission tomography.

Iodine-123 metaiodobenzylguanidine (mIBG) is taken up by sympathetic nerve endings, allowing scintigraphic imaging of myocardial sympathetic innervation. We investigated the denervated but viable canine myocardium after acute myocardial infarction by serial mIBG and thallium-201 chloride (201TlCl) single photon emission tomography (SPET). In 12 dogs, acute myocardial infarction was produced by ligation of the left circumflex coronary artery. Images of mIBG and thallium SPET were obtained 6 h, 1, 4 and 6 weeks later. The defect size was calculated in percentage points from short axial views, and the 123I-mIBG/201TlCl ratio was determined. The uptake ratio was high at 1 week but gradually decreased. Three dogs were killed at each time point, and tissue samples were obtained from infarcted (both 201TlCl and 123I-mIBG defects), peri-infarcted (123I-mIBG defect and 201TlCl normal) and normal myocardium (both mIBG and 201TlCl normal). The changes in tissue content of noradrenaline in these lesions were measured. Noradrenaline tissue content gradually recovered in the peri-infarcted area. However, no recovery was noted in the infarcted area at 6 weeks. We conclude that sympathetic denervation and re-innervation occur following acute myocardial infarction, and the denervated but viable myocardium could be detected non-invasively by combined mIBG and thallium SPET.

3-Iodobenzylguanidine↗

PubMed1992

Nucleotide sequence of capsid protein gene of rice tungro bacilliform virus.

The sequence of 5,028 nucleotides, including one open reading frame (ORF), of rice tungro bacilliform virus (RTBV) dsDNA was determined. The predicted translational product comprises 1,675 amino acids and has Mr of 194,134 (p194). The amino acid sequences of three tryptic fragments from the 32 k capsid protein of RTBV (p32) were found in the predicted translational product indicating that the ORF codes for the RTBV capsid protein.

Amino Acid Sequence↗

PubMed1992

Saccadic dysmetria induced by transient functional decortication of the cerebellar vermis [corrected].

Saccadic dysmetria is seen in patients with cerebellar diseases as well as in monkeys whose vermis and fastigial nucleus are experimentally lesioned. We investigated the oculomotor signs of the vermis by blocking cerebellar impulses with bicuculline injections into the fastigial nucleus. The oculomotor abnormalities associated with the bicuculline treatment (in effect, functional as well as reversible, unilateral decortication of the vermis) were hypometric saccades toward the injection side and gaze deviation toward the opposite side. These oculomotor signs disappeared with the withdrawal of the bicuculline effect.

Animals↗

PubMed1992

Burst discharges of fastigial neurons in macaque monkeys are driven by vision- and memory-guided saccades but not by spontaneous saccades.

Discharges from 61 saccadic burst neurons in the fastigial oculomotor region were recorded for two trained macaque monkeys during vision-guided or memory-guided saccades or spontaneous saccades in the dark. Although these neurons exhibited vigorous, burst discharges during both vision-guided and memory-guided saccades, only weak bursts were observed during spontaneous saccades in the dark. Especially in 10 of the 61 neurons, saccadic burst discharge was almost completely absent during spontaneous saccades in the dark. These findings suggest that the cerebellum plays an important role in the control of vision-guided saccades as well as memory-guided saccades, but not of spontaneous saccades in the dark.

Animals↗

PubMed1992

Burst discharges of mossy fibers in the oculomotor vermis of macaque monkeys during saccadic eye movements.

Mossy fiber activity was recorded from the oculomotor vermis (lobules VIc and VII) during visually guided saccades. Saccade-related activities of 99 mossy fiber units were observed in two alert macaque monkeys. Ninety-six units were characterized by high-frequency bursts of firing in response to visually guided saccades (burst unit). These units were silent during all periods of fixation in any gaze position. Three units showed eye position-related tonic discharges with saccadic bursts. The lead time of saccadic bursts ranged from 2.6 to 80.5 ms (mean 27.9 ms, SD 16.6 ms). About 75% of the burst units exhibited a long lead burst characterized by a slow buildup, while the remaining units showed short lead bursts with a sharp onset. About 80% of the units showed burst in association with contralaterally directed saccades. The remaining units exhibited bursts in association with ipsilateral saccades. Preferred directions in this population covered the entire field including the vertical and the oblique. About 68% of long lead burst units exhibited the movement field which consists of a whole sector of the entire oculomotor range (directional type). About 32% of long lead burst units showed the movement field which is a closed area within the oculomotor range (vectorial type). On the other hand, peak frequency of short lead burst units increased in proportion to saccade amplitude. The end of the burst in all units always preceded the completion of saccade. The end of burst was time-locked to the completion of saccade, so that the lead time from the end of burst to the end of saccade was consistent among these units and, was constant regardless of saccadic amplitude. The duration between the peak and the offset of burst was correlated with the amplitude of saccade (0.63 < or = r < or = 0.83). Long lead burst of mossy fibers was almost comparable to burst activity in the nucleus reticularis tegmenti pontis (NRTP), while short lead burst of mossy fibers closely resembles activity of excitatory burst neurons in the paramedian pontine reticular formation (PPRF). These findings suggest that the cerebellum receives command signal from the superior colliculus via the NRTP and feedback signal from the PPRF.

Animals↗

PubMed1992

Fastigiofugal fibers encoding horizontal and vertical components of saccades as determined by microstimulation in monkeys.

To identify the routes by which oculomotor vermis signals control eye movements (saccadic signals), saccades evoked by microstimulation were studied in the region of the uncinate fasciculus (UF) and juxtarestiform body (JB) in the macaque monkey. Anatomical pathways of axons from the fastigial oculomotor region (FOR) were studied by anterograde transport of wheatgerm agglutinin conjugated horseradish peroxidase (WGA-HRP). The routes were identified by comparing maps of low threshold for evoking saccades with the anatomical map of anterogradely labeled axons arising from the FOR. Microstimulation of a region of the UF and JB demonstrated that saccadic signals are carried exclusively by decussated FOR axons which leave the cerebellum via the contralateral UF. The fibers in the JB do not carry saccadic signals. The horizontal component of saccadic signals is conveyed by fibers in the descending limb of the UF, while the vertical component is conveyed by a smaller group of fibers which separate from the UF and enter the midbrain with the contralateral superior cerebellar peduncle.

Animals↗

PubMed1992

Posterior vermal Purkinje cells in macaques responding during saccades, smooth pursuit, chair rotation and/or optokinetic stimulation.

Anatomical locations of the Purkinje cells (P cells), showing modulations in activity during either saccadic or smooth-pursuit eye movements, during primate chair rotation, or in response to optokinetic stimulation, were studied in the posterior vermes of monkeys trained to move their eyes with a visual target. The majority (68.3%) of the responsive P cells were saccade-related units. They were located exclusively in vermal lobules VIc and VII: the oculomotor vermis. Most P cells sensitive to chair rotation were located in vermal lobules VIa,b and VIII (91.2%), designated as the paraoculomotor vermis. The P cells which modulated activity during smooth-pursuit eye movements, associated with eye position, or during optokinetic stimulation were found in both the oculomotor and paraoculomotor vermis. There were 25 P cells which modulated their activity during smooth pursuit in the oculomotor vermis. Among them, only three responded also to optokinetic stimulation but none was sensitive to chair-rotation stimulation. These findings suggest that the control of saccadic eye movements is the primary function of the oculomotor vermis.

Animals↗

PubMed1992

Peripartum changes in antibody producing capability of lymphocytes from dairy cows.

B-lymphocyte populations and the in vitro antibody producing activity of lymphocytes were measured to evaluate the lymphocyte function of periparturient dairy cows. Changes in B-lymphocyte populations were not significantly different in cows during this period. Significantly decreased numbers of plaque-forming cells were observed in lymphocytes from cows at parturition and 3 days after parturition compared to those in lymphocytes obtained 14 days after parturition.

Animals↗

PubMed1992

Development of lymphocyte blastogenic response in the neonatal period of foals.

The blastogenic response of lymphocytes and serum concentration of cortisol from eighteen foals were evaluated during various stages of the neonatal period. The results of blastogenic responses were expressed by a stimulation index (SI). Blastogenic response to three mitogens was lowest at birth (PHA: 1.17 +/- 0.02, Con A: 1.11 +/- 0.05 and PWM: 1.02 +/- 0.01), then increased gradually with slight variations postpartum. The serum concentration of cortisol was highest at birth (44.0 ng/ml) and decreased rapidly to 19.3 ng/ml within 1 week postpartum, and then was maintained at this level. The high serum concentration of cortisol at birth may be associated with decreased blastogenic response of lymphocytes in foals.

Animals↗

PubMed1992

Reversal of hyperdynamic response to continuous endotoxin administration by inhibition of NO synthesis.

Septic shock is characterized by an increase in cardiac output and a fall in systemic vascular resistance index and mean arterial pressure. Endotoxin alters the smooth muscle function of blood vessels, probably by means of an increased production of the potent vasodilator nitric oxide (NO). The present study was accomplished to determine how the inhibition of NO synthesis influences cardiovascular performance in an ovine model of hyperdynamic endotoxemia. Endotoxemia was induced in five range ewes (41 +/- 2 kg) by continuous infusion of Escherichia coli endotoxin (LPS, 10 ng.kg-1.min-1) over the entire study period. After 24 h of LPS infusion, cardiac output increased from 5.2 +/- 0.3 to 7.9 +/- 0.6 (SE) 1/min (P less than 0.05) and mean arterial pressure and systemic vascular resistance index fell from 92 +/- 5 to 79 +/- 6 mmHg (P = 0.08) and from 1,473 +/- 173 to 824 +/- 108 dyn.s.cm-5.m2 (P less than 0.05), respectively. The pulmonary shunt fraction increased from 0.23 +/- 0.03 to 0.32 +/- 0.03 (P less than 0.05). The intravenous administration of the NO synthase inhibitor N omega-nitro-L-arginine methyl ester (25 mg/kg) 24 h after the start of the LPS infusion changed these values to approximately baseline levels over the subsequent 4 h. Although N omega-nitro-L-arginine methyl ester increased pulmonary arterial pressure and pulmonary vascular resistance (P less than 0.05), right and left ventricular stroke volume index showed no significant changes. It is concluded that NO has a major function in cardiovascular performance in endotoxemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

The role of renal hemodynamics in the antihypertensive action of mepirodipine, a new calcium antagonist.

To evaluate the role of regional hemodynamics in the anti-hypertensive effect of mepirodipine, a new dihydropyridine-derivative calcium antagonist, we measured systemic, renal, hepatic, and forearm hemodynamics in 10 patients with essential hypertension treated with mepirodipine (15 mg/day) for 4 weeks. After the administration of mepirodipine, a significant decline in mean blood pressure (-13.8 +/- 2.3%, p less than 0.01) accompanied by a decrease in systemic vascular resistance (-21.1 +/- 2.6%, p less than 0.01) was observed. Although forearm vascular resistance did not change significantly, both renal (-19.2 +/- 6.7%, p less than 0.01) and hepatic vascular resistance (-17.6 +/- 3.8%, p less than 0.01) decreased considerably. The decrements of mean blood pressure with mepirodipine did not correlate with those of hepatic or forearm vascular resistance but correlated positively with those of renal vascular resistance (r = 0.699, p less than 0.05). Moreover, the increment of renal blood flow with mepirodipine was negatively correlated with the pretreatment level of renal blood flow (r = -0.670, p less than 0.05); renal blood flow increased to a greater extent in patients with lower pretreatment renal blood flow. These findings suggest that the oral administration of mepirodipine in patients with essential hypertension can produce selective vasodilation in the renal vasculature, which may play an important role in the relatively long-term antihypertensive effect of this drug.

Adult↗

PubMed1992

Serological survey of Rhodococcus equi infection in horses in Hokkaido.

Serological survey of Rhodococcus equi infection in horses in Hokkaido was performed using ELISA. Of 2,879 horse sera, 318 (11.0%) gave antibody-positive (OD greater than or equal to 0.3) reactions. The antibody-positive rate of female was significantly higher (p less than 0.01) than that of male, and no statistical difference between Anglo-Arab and thoroughbred was detected in the antibody-positive rate. The maximum antibody-positive rate (27.1%) was shown at 14 years of age. The antibody-positive rates on the 160 farms were found to vary widely from 0 to 78.9%. A significant difference (p less than 0.01) in the antibody-positive rate was detected among horse farms. It was elucidated that 100 (62.5%) out of 160 horse farms had an antibody-positive horse. These results indicate that R. equi was widespread on horse farms, and the level of environmental contamination with R. equi differed among horse farms.

Actinomycetales Infections↗

PubMed1992

[A case with hepatocellular carcinoma effectively treated by continuous hepatic arterial infusion of etoposide, epirubicin and CDDP].

A 53-year-old man who suffered from advanced hepatocellular carcinoma (HCC) was treated with hepatic arterial infusion (HAI) of Etoposide, Epirubicin and CDDP. Treatment consisted of a continuous HAI of Epirubicin (50 mg/body, day 1.7), CDDP (75 mg/body, day 2.8) and Etoposide (80 mg/body, day 4-6). He had two series of infusions and was treated by transarterial embolization using CDDP powder (100 mg) added to lipiodol and aluminum stearate as suspension following HAI. The tumor regression rate was about 60% after HAI, but the remaining tumor seemed to be almost necrotic. AFP and PIVKA-II reached the normal range after TAE. We could not find lipiodol accumulated in tumor on CT carried out eight weeks after TAE. No recurrence has been noticed in the following 8 months. Toxicity was not so severe and was well tolerated.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1992

[High incidence of left ventricular thrombosis and systemic embolism in patients with left ventricular assist system].

The purpose of this study was to determine the incidence of left ventricular (LV) thrombosis and systemic embolism in 14 patients with LV assist systems. Echocardiography was used to detect LV wall motion abnormalities, intracavitary smoke-like echoes and thrombosis, and the effect of anticoagulant therapy was serially examined. During full assist of the circulation, the aortic valve did not open in any patient. Smoke-like echoes were observed in 9 patients (64%) and thrombi in 8 (57%). The thrombus developed within the first 3 assist days. Systemic anticoagulant therapy decreased the thrombus size in only 3 patients, but there was a possibility of intracranial or mediastinal bleeding in other 3 patients. Systemic embolism was noted in 7 of 11 autopsy patients (64%). The characteristic finding was that there were multiple embolized organs, such as the brain, kidneys, spleen and liver, in all patients. Development of a thrombus is a serious complication in all patients with LV assist systems. However, the problem does not lie in the assist system but in the left ventricle of the patient's own heart. It is also noteworthy that systemic anticoagulation is not effective for an LV thrombus. A new method of assisting the failing heart, or a new anticoagulant delivery technique for the LV cavity to prevent LV thrombus development is needed.

Adult↗

PubMed1992

Hemodynamic and endocrine changes associated with hypotensive action of amosulalol in essential hypertension.

To clarify the hemodynamic and endocrine mechanisms of the hypotensive effect of amosulalol, an alpha- and beta-adrenoceptor antagonist, 19 patients with essential hypertension received amosulalol (20-80 mg/day; average 48.4 mg/day) for 16 weeks. Mean blood pressure (MBP) was significantly decreased (105 +/- 1 vs. 120 +/- 1 mm Hg, p less than 0.001), associated with a decrement in heart rate (HR). Although both cardiac index (CI, 3.68 +/- 0.09 vs. 3.91 +/- 0.09 L/min/m2, p less than 0.001) and total peripheral resistance index (TPRI, 2,271 +/- 78 vs. 2,441 +/- 79 dynes.s.cm-5.m2, p less than 0.001) were reduced, changes in TPRI positively correlated with those of MBP (r = 0.9155, p less than 0.001) but the change in CI did not (r = 0.3568, NS). Plasma renin activity (PRA, 0.55 +/- 0.09 vs. 0.95 +/- 0.14 ng/ml/h, p less than 0.05) and aldosterone concentration (4.6 +/- 0.4 vs. 8.6 +/- 0.5 ng/dl, p less than 0.001) were also decreased with amosulalol. Thus, the hypotensive effect of amosulalol may be due mainly to vasodilation by alpha 1-blocking action. In addition, this hypotensive effect may be facilitated by either beta-blocking action such as decreased cardiac output (CO), with suppression of reflex tachycardia or of the renin-angiotensin-aldosterone system.

Adult↗

PubMed1992

Sonomicrometric studies on the effects of long-term pumping of cardiac assist device on the bulk and regional mechanics of the normal left ventricle in goat.

Pneumatically driven, diaphragm type left ventricular assist devices (LVADs) were implanted into 2 goats with normal hearts for approximately 1 month to study the effects of long-term pumping of LVAD on the cardiac mechanics. One sham-operated goat was used to obtain control data. Diameters and myocardial segment lengths of the left ventricle were measured with an ultrasonic displacement meter to calculate the bulk mechanical work (BMW) and regional myocardial mechanical work (RMW), respectively. The LVAD was pumped in the 2:1 drive mode (one counterpulsated pumping in every two cardiac cycles), and was temporarily driven in the 1:1 mode (one pumping in every cardiac cycle) or stopped to obtain the data under these conditions. During the second half of the post-operative period while the animal condition was stable, the BMW in the 2:1 and 1:1 modes were approximately 59% and 72% of that observed under the temporary pump-off condition (0.22 W/(100 g)), respectively. The RMW in the 2:1 and 1:1 modes were 69% and 74% of that obtained during pump-off (6.2 mW/cm3), respectively. The myocyte diameter in the subendocardial layer was reduced by unloading effect of 1-month pumping, whereas those in middle and subepicardial layer showed little change.

Animals↗

PubMed1992

[A new hemodynamic diagram, using COP-PCWP and CI as parameters, after open heart surgery].

In 24 patients subjected to cardio-pulmonary bypass (CPB) operation, changes in colloid oncotic pressure (COP), cardiac index (CI), respiratory index (RI), and pulmonary capillary wedge pressure (PCWP) were measured within a 48 hour period. The patients were divided into two groups according to dose levels of catecholamine. In 18 patients received small catecholamine doses, a stable hemodynamic and respiratory status were maintained. However, 6 patients received catecholamine doses of more than 15 micrograms/kg/min exhibited low COP, low CI, high RI and high PCWP. In this study we designed a new hemodynamic diagram using COP-PCWP and CI as parameters of the cardiac function. We consider that these parameters are more suitable than Forrester's parameters to evaluate the patient's condition before and after open heart surgery.

Adult↗