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Biomedical subjects

K Matsunami

Publications and source records attributed to K Matsunami.

At least 55 records · Page 3Linked to original sources
PubMed1999

Relation between bispectral index and plasma catecholamines after oral diazepam premedication.

The efficacy of anaesthetic premedication has been assessed using sedative scores or a visual analogue scale. However, in both it may be difficult to exclude evaluators' subjectivity or a placebo effect. Plasma concentration of catecholamines may also be useful for the assessment of patient anxiety. Recently bispectral electro-encephalographic analysis has been developed, and the bispectral index monitor has been reported to give measurements which correlate well with the depth of sedation. In the present study, we have examined the relation between bispectral index values and plasma catecholamine concentrations after oral diazepam premedication. Twenty-eight patients scheduled for elective surgery were randomly assigned to one of two groups: diazepam premedication group (group D(+), n = 14) and no premedication group (group D(-), n = 14). The patients were premedicated orally with diazepam 10 mg and roxatidine 75 mg in group D(+), and with roxatidine 75 mg only in group D(-) 90 min before arrival in the operating theatre. After patients arrived in the operating theatre, the bispectral index monitor was applied. Venous blood samples (6 mL) were collected in the case of patients in group D(+) for the measurement of plasma catecholamines levels using high-performance liquid chromatography. The bispectral index level (mean +/- SD) in group D(+): 93.5 +/- 773.5 was significantly lower than that in group D(-): 96.1 +/- 1.8 (P < 0.05). There was a significant correlation between bispectral index and plasma norepinephrine levels (r = 0.567, P < 0.05). The present study suggests that the bispectral index monitor may detect the effect of oral diazepam premedication.

Administration, Oral↗
PubMed1999

[The effect of epidural anesthesia on reducing blood loss during upper abdominal surgery].

We examined the advantage of the combined epidural anesthesia with general anesthesia for the upper abdominal surgery One hundred and thirty-five gastric cancer patients were subjected to the study. They were divided into four groups. Group A (n = 46) and B (n = 44) received distal gastrectomy, and group C (n = 27) and D (n = 18) received total gastrectomy. In group A and C, anesthesia was maintained with combined epidural and general anesthesia. In group B and D, only general anesthesia was administered. We compared group A versus B and groups C versus D. The parameters for the comparisons were intraoperative blood loss, averaged mean blood pressure, surgical operation time, etc. The patient background was not different between group A and B, and also between group C and D. The blood loss and mean blood pressure were significantly lower in groups A and C than in groups B and D. But there was no correlation between the blood loss and mean blood pressure. The results suggest that the fall of the mean blood pressure is one of the causes of reduced blood loss, but the causes may include other complicated parameters. We conclude that the combined use of epidural anesthesia with general anesthesia is useful for reducing the amount of blood loss for upper abdominal surgery.

Aged↗
PubMed1999

[Anesthetic management of a patient with Osler-Weber-Randu disease].

Osler-Weber-Randu disease (Osler disease) is an autosomal dominant disease, sometimes known as hereditary hemorrhagic telangiectasia with its family history. It is not a popular disease and approximately seventy families are known as inheritance lineage in Japan. We experienced anesthetic management of a 49-yr-old woman with Osler disease. She was diagnosed to have the brain abscess following fever and clouding of consciousness for several days and was scheduled for the removal of the abscess. A chest X-ray revealed pulmonary arteriovenous fistula in the right middle lung field. The patient had had life threatening frequent massive bleeding from her nose and/or stomach for the past several years. Her brother and children also had the same symptoms. In addition to Osler disease, the patient had the prolonged coagulation time that was supposed to the due to chronic liver disease. Therefore, fresh frozen plasma (5 units) and platelet concentrates (10 units) were infused during the surgery. Intraoperative blood loss was about 700 grams. We had no difficulties in management of bleeding and respiratory controls during anesthesia.

Anesthesia, General↗
PubMed1999

Effects of hyper +Gz acceleration on brainstem and auditory cortical evoked potentials and cerebral blood flow in anesthetized rats.

Hypergravity acceleration along the long axis of the body (Gz) causes severe cardiovascular dysfunctions. Many studies have been conducted along this line. However, most previous studies used rather a short duration of hyper-Gz application, up to 30 sec, because application of large hyper-Gz brings animals into death. In order to elucidate effects of long duration of Gz application, we made experiments with Gz load for as long as 1000 sec. Cardiovascular dysfunctions and reduction of arterial blood pressure were usually accompanied by reduction of cerebral blood flow, leading subjects into loss of consciousness and into death. Recently, we studied the effects of +Gz load on evoked potentials. The present experiments shows effects of +Gz on brainstem auditory response and auditory evoked potentials.

Acceleration↗
PubMed1998

Expression pattern analysis of SGF-3/POU-M1 in relation to sericin-1 gene expression in the silk gland.

Embryonic and larval expression patterns of the sericin-1 gene and its presumed transcription factor, SGF-3/POU-M1, in the silk gland were analyzed by in situ hybridization and immunohistochemistry. The sericin-1 transcripts were first detected at embryonic stage 26 in an increasing gradient pattern in the middle and posterior part of the middle silk gland (MSG), while at the same stage the SGF-3/POU-M1 was already present in the entire anterior silk gland (ASG) and in the MSG but with a decreasing gradient pattern. The latter expression pattern was consistently maintained through all larval stages, while the sericin-1 expression was detected during the feeding stages but disappeared at the molting stages. These observations suggest that, although the SGF-3/POU-M1 was proposed to be a positive transcription factor for the sericin-1 gene, the protein might function in a negative manner on sericin-1 gene transcription. Alternatively, it is also possible that the sericin-1 gene might require another unidentified factor or mediator for in vivo transcription.

Animals↗
PubMed1998

Regional cerebral blood flow changes in human brain related to ipsilateral and contralateral complex hand movements--a PET study.

The purpose of this study was to investigate the cortical motor areas activated in relation to unilateral complex hand movements of either hand, and the motor area related to motor skill learning. Regional cerebral blood flow (rCBF) was measured in eight right-handed healthy male volunteers using positron emission tomography during a two-ball-rotation task using the right hand, the same task using the left hand and two control tasks. In the two-ball-rotation tasks, subjects were required to rotate the same two iron balls either with the right or left hand. In the control task, they were required to hold two balls in each hand without movement. The primary motor area, premotor area and cerebellum were activated bilaterally with each unilateral hand movement. In contrast, the supplementary motor area proper was activated only by contralateral hand movements. In addition, we found a positive correlation between the rCBF to the premotor area and the degree of improvement in skill during motor task training. The results indicate that complex hand movements are organized bilaterally in the primary motor areas, premotor areas and cerebellum, that functional asymmetry in the motor cortices is not evident during complex finger movements, and that the premotor area may play an important role in motor skill learning.

Adult↗
PubMed1998

Effects of hyper +Gz acceleration on cardiovascular function, visual evoked potentials and cerebral blood flow in anesthetized rats.

Sustained hyper-gravity acceleration, particularly along the long axis of the body of animals or man (Gz), produces significant mal-effects on subjects, and hence it has been well studied, The most common syndromes of Gz application were cardio-vascular de-conditioning, and black-out, red-out, and loss of consciousness, which finally lead subjects into death. However, in most previous studies, the duration of applied Gz was rather short. In the present experiments, we can use longer duration of 1000 seconds. In addition, recent technological innovation make it possible to record directly local cerebral blood flow at a target cortical area with a Laser Doppler flow meter. We used this innovated method to measure local cerebral blood flow of rats in relation to visual evoked potentials (VEPs) under hyper-Gz acceleration. Also we recorded cardio-vascular parameters like heart rate from ECG, systolic and diastolic blood pressure and correlated them with cerebral blood flow and VEPs.

Acceleration↗
PubMed1998

[Psychopathological alteration of the auditory structure in schizophrenia; "the experience of no-sounds"].

According to recent cognitive theories, the greater part of the perceptional meaning and representative meaning are both pre-determined, or pre-organized as a set of meaning, which has a biophysiological and socio-cultural origin. Humans however, drive some kind of sensational Gestalt from each sense organ, and this is incapable of being transformed into language (representative pre-meaning), this enabling us to experience the possibility of truly private meaning in our own right. The author has emphasized this two moments of the meaning, that is, private moments of meaning vs. institutional moments. The author has offered the phenomenological hypothesis of auditory experience and elaborated the relation between these two moments in it. Then, the author has testified its validity in the process of describing and analysing the pathological alteration of auditory sensation in schizophrenia. Auditory space is thought to be differentiated into a three-dimensional structure. That is, a dimension of background, a dimension of signs, and a dimension of symbols, and we accept environmental-sounds, event-sounds, symbolic sounds in each level. Close investigations about 5 schizophrenics revealed that these patients undergo a strange silent experience before the onset of delusional ideas, descriptively and phenomenologically, this phenomenon appeared to be initiated by the deprivation of the dimension of background sounds (referred to as "the experience of no-sounds"). This experiences often occurred especially when they are eager to listen to the surrounding sounds (for example, noises in the neighborhood, classroom chatter), in order to solve their own interpersonal difficulties. Furthermore, the author described the ambivalent nature of patients' thinking in this pathological auditory situation, in which one idea of the polarity of dichotomy was forced to switch to the another one, influenced by an attribute of surrounding sounds. With regard to this aspect, the patients experienced both the physiological changes in the auditory structure as well as the psychological turmoil. The author has emphasized the need to appreciate this ambiguous nature of the psychological context mixed with the physiological context, which is supposed to be very important from psychotherapeutical viewpoint.

Adult↗
PubMed1998

[Effect of the continuous epidural buprenorphine injection in patients after lower extremity arthroplasty].

We studied the analgesic effects of continuous epidural injection of buprenorphine in patients after lower extremity arthroplasty. In these patients anesthesia was maintained only with lumbar epidural anesthesia with 2% mepivacaine. We employed a balloon type continuous infuser (DIB Catheter, 40 ml.day-1) for postoperative analgesia for twenty-four hours. The patients were classified into three groups according to the method of buprenorphine injection and the content of DIB Catheter. First group (group A ; N = 37) received buprenorphine (0.2 mg) with 0.25% bupivacaine (40 ml) for twenty-four hours. Next group (group B ; N = 27) received bolus injection of buprenorphine (0.2 mg) for the first additional epidural injection of local anesthetic and received continuous injection of buprenorphine (0.2 mg) with 0.25% bupivacaine (40 ml) for twenty-four hours. The last group (Group C ; N = 40) also received bolus injection of buprenorphine as in group B, but received continuous buprenorphine infusion with normal saline instead of local anesthetics. The analgesic effect was determined by the postoperative usage of other analgesics (NSAID or pentazocine) by request of patients. In twenty-four hours, the numbers of patients who did not request other analgesics were 6 (Group A. 16%), 9 (Group B. 33%) and 19 (Group C. 48%), respectively. In Group A, 18 patients requested analgesics, but only 8 patients requested in Group C. It was effective for the postoperative analgesia to use the continuous epidural injection with DIB Catheter for patients after lower extremity arthroplasty. It was necessary to give a bolus injection of buprenorphine before the end of surgery for sufficient analgesia, but it was not necessary to add local anesthetics in the content of DIB Catheter.

Adult↗
PubMed1997

Modulation by APGW-amide, an Achatina endogenous inhibitory tetrapeptide, of currents induced by neuroactive compounds on Achatina neurons: amines and amino acids.

1. Modulatory effects of APGW-amide (Ala-Pro-Gly-Trp-NH2), proposed as an inhibitory neurotransmitter of Achatina neurons, perfused at 3 x 10(-6) M on the currents induced by small-molecule putative neurotransmitters were examined by using Achatina giant neuron types, v-RCDN (ventral-right cerebral distinct neuron), TAN (tonically autoactive neuron) and RAPN (right anterior pallial nerve neuron), under voltage clamp. These putative neurotransmitters were ejected locally to the neuron by brief pneumatic pressure. 2. Outward current (Iout) induced by erythro-beta-hydroxy-L-glutamic acid (erythro-L-BHGA) on v-RCDN, which was probably K+ dependent, was enhanced with membrane conductance (g) increase under APGW-amide. From dose (pressure duration)-response curves of erythro-L-BHGA measured in physiological solution (control curve) and with APGW-amide (drug curve), ED50 values of the two curves were nearly comparable, whereas Emax of the drug curve was significantly larger than that of the other. From a Lineweaver-Burk plot of these data, the cross point of the control line and the drug line was on the abscissa. 3. K(+)-dependent Iout caused by dopamine (DA) on v-RCDN was inhibited with a g increase by APGW-amide. The inhibition of this current caused by APGW-amide was mainly in a noncompetitive and partly uncompetitive manner. 4. 5-Hydroxytryptamine (5-HT) produced an inward current (Iin) with two (fast and slow) components on TAN, which was probably Na+ dependent. The fast component of the Iin was inhibited by APGW-amide. The inhibition was mainly in a noncompetitive manner. 5. The currents induced by acetylcholine, gamma-aminobutyric acid and L-glutamic acid on Achatina neuron types were not affected by APGW-amide. 6. The inhibitory effects of APGW-amide on the Iin (fast component) induced by 5-HT were nearly equipotent or a bit stronger than those on the Iout caused by DA. 7. The g increase produced by APGW-amide would be a cause for inhibiting the Iout induced by DA. In addition, we consider that APGW-amide affects intracellular signal transduction systems or ionic channels, thus modulating these currents.

Animals↗
PubMed1997

Modulation by APGW-amide, an Achatina endogenous inhibitory tetrapeptide, of currents induced by neuroactive compounds on Achatina neurons: peptides.

1. Modulatory effects of APGW-amide (Ala-Pro-Gly-Trp-NH2), proposed as an inhibitory neurotransmitter of Achatina neurons, perfused at 3 x 10(-6) M on the currents induced by neuroactive peptides, ejected by brief pressure, were examined by using Achatina giant neuron types, v-RCDN (ventral-right cerebral distinct neuron) and PON (periodically oscillating neuron), under voltage clamp. 2. Outward current (Iout) caused by FMRFamide (Phe-Met-Arg-Phe-NH2) on v-RCDN, which was probably K+ dependent, was inhibited with membrane conductance (g) increase by APGW-amide. From the dose (pressure duration)-response curves of FMRFamide and a Lineweaver-Burk plot of these data, the inhibition caused by APGW-amide was mainly in an uncompetitive manner. 3. Iout caused by APGW-amide on v-RCDN, which was probably K+ dependent, was inhibited with g increase by APGW-amide. The inhibition caused by APGW-amide was partly in a competitive manner and partly in a noncompetitive manner. 4. Iout caused by [Ser2]-Mytilus inhibitory peptide, [Ser2]-MIP (Gly-Ser-Pro-Met-Phe-Val-NH2) on v-RCDN, which was probably K+ dependent, was inhibited with g increase by APGW-amide. Because the modulation of this current was not so marked, a dose-response study of this compound was not carried out. Iin induced by oxytocin on PON was not affected by APGW-amide. 5. From the dose-response curves of APGW-amide, perfused consecutively, the inhibitory effects of APGW-amide on the Iout caused by APGW-amide were stronger than those on the Iout caused by FMRFamide. 6. The inhibition of the APGW-amide-induced Iout on v-RCDN by APGW-amide was partly due to the competition in the receptor sites and partly to the g increase. The inhibition by APGW-amide on the Iout induced by FMRFamide and [Ser2]-MIP would be partly due to the g increase. In addition, we consider that APGW-amide affects intracellular signal transduction systems or ionic channels, thus modulating these currents. 7. The currents modulated by APGW-amide were different from those modulated by achatin-1, another Achatina endogenous neuroexcitatory peptide. We consider that the mechanisms underlying the modulatory effects of APGW-amide are different from those of achatin-I.

Animals↗
PubMed1997

Trajectory formation of the center-of-mass of the arm during reaching movements.

We attempted to identify the invariant kinematic properties of multijoint arm reaching movements in the horizontal plane to explore the planning variable(s) involved in their coordination. Different targets were placed near the perimeter of the workspace boundary, thereby causing variation of size and orientation of the hand stroke. We have a special interest in the trajectory characteristics of the most massive point within the arm system, the center-of-mass of the entire arm system, in addition to those of the hand or joints. The motion of the individual segments (the forearm plus hand and the upper arm) or joints (shoulder and elbow) was modulated in a different way depending on the tasks; thus, there was no invariance in the relationships between paired variables (displacement or velocity) for segment or joint motions. For relatively short hand strokes, the trajectory of the hand and the center-of-mass of the entire arm system were characterized by a nearly straight path, and a smooth, bell-shaped velocity curve along the path, symmetrical about the mid-portion of the movement, starting from nearly zero, growing to a single peak and declining again to nearly zero. However, in large hand strokes the hand path was highly curved and the velocity curve was asymmetric. Although the path of the center-of-mass of the entire arm system also tended to be curved with the increase of the hand stroke, a bell-shaped velocity curve along the path and its typical symmetry were preserved over a wide range of stroke sizes and orientations, and its peak was scaled in proportion to movement distance and movement time. Our findings indicate that it is not valid to postulate solely the joint- or hand-based planning strategies which have been proposed previously. Rather, the planning of the spatial aspects of the motion is largely dependent on the interaction of multiple variables, including those not analysed in this study. The bell-shaped pattern of the center-of-mass velocity profile represents a certain efficiency of movement, since it corresponds to a single accelerative and a decelerative phase of a mass over the movement, with no intermediate force reversals. The simple structure of the center-of-mass velocity profiles may reflect a fundamental organization principle underlying the temporal aspects of movement planning.

Adult↗
PubMed1997

[Squirrel monkey--an ideal primate (correction of prmate) model of space physiology].

Investigation of the vestibulo-ocular system of the squirrel monkey was reviewed in consideration of space motion sickness (SMS), or which is recently more often termed as space adaptation syndrome (SAS). Since the first launching of the space satellite, Sputnik [correction of Sputonik] in October 1957, many experiments were carried out in biological and medical fields. A various kind of creatures were used as experimental models from protozoa to human beings. Rats and monkeys are most favorite animals, particularly the non-human primate seems to be the one, because of its phylogenetic relatives akin to the human beings. Chimpanzees, rhesus monkeys, pig tailed-monkeys, red-faced monkeys and squirrel monkeys have been used mostly in American space experiments. Russian used rhesus monkeys. Among these, however, the squirrel monkey has an advantage of the small size of the body, ranging from 600- l000g in adult. This small size as a primate is very advantageous in experiments conducted in a narrow room of the space satellite or shuttle because of its space-saving. The squirrel monkey has another advantage to rear easily as is demonstrated to keep it as a pet. Accordingly, this petit animal provides us a good animal model in biological and medical experiments in space craft. The size of the brain of the squirrel monkey is extraordinary large relative to the body size, which is even superior to that of the human beings. This is partly owed to enlargement of the occipito-temporal cortices, which are forced to well develop for processing a huge amount of audio-visual information indispensable to the arboreal habitant to survive in tropical forest. The vestibular system of the squirrel monkey seems to be the most superior as well, when judged from it relative size of the vestibular nuclear complex. Balancing on swinging twigs or jumping from tree to tree developed the capability of this equilibrium system. Fernandez, Goldberg and his collaborators used the squirrel monkey to elucidate functions of the peripheral vestibular system. A transfer function was proposed to explain the behaviors of regular and irregular unit activity of vestibular nerve fibers. The physiologic characteristics of the second order vestibular neuron was investigated in combination of electrophysiological and micro-morphological way, with using WGA-HRP methods, in relation to somato-motor and eye movements. Interconnections between vestibular neurons and cerebellum, interstitial nucleus of Cajal, oculomotor nuclear complex, superior colliculus and cervical spinal cord were elucidated. In physiological field of the vestibular system, the vestibulo-ocular reflex is well studied and results obtained from the squirrel monkey experiments were reviewed. The squirrel monkey, particularly the Bolivian, is a unique animal in that it is vulnerable to motion sickness induced by visual-motion stimulation with phase mismatch of the two stimuli. Experimental results of labyrinthectomy or bilateral ablation of the maculae staticae led to the conclusion that both semicircular and otolith organs are involved in the genesis of space motion sickness. On the other hand, destruction of the area postrema, acknowledged as the vomiting center to chemical stimulants, produced controversial results. However, it must be pointed out that the a human subject underwent to resection of the area postrema, became insensitive to administration of apomorphine, a well known chemical stimulant of vomiting. Finally the experiments in space revealed the presence of at least two origins of caloric nystagmus, that is, attributable to convection and non-convection current of the endolymphatic fluid.

Acoustic Maculae↗
PubMed1997

Magnetic resonance evaluation of uterine malformation with corpus agenesis.

Because no treatment is available and its rare prevalence, uterine fundal agenesis is seldom mentioned in the literature. A woman with uterine corpus agenesis, without other genital tract anomalies, presented with primary amenorrhea and infertility. Gonadotropins and ovarian steroids showed normal cyclic variations. A thorough evaluation, including history, physical examination, and appropriate imaging techniques [hysterosalpingography, ultrasonography and magnetic resonance imaging (MRI)] demonstrated extreme accuracy with MRI in the diagnosis of the anatomic defect. MRI permits noninvasive differentiation of uterine anomalies and may spare the patient's diagnostic laparoscopy.

Adult↗
PubMed1996

Study of paired-pulse inhibition of transcallosal response in the pyramidal tract neuron in vivo.

The effects of a specific GABAB receptor antagonist, p-(3-aminopropyl)-p-diethoxymethyl-phosphonic acid (CGP 35348), on pyramidal tract neuron responses to transcallosal stimulation were investigated in the cat motor cortex in vivo. The paired-pulse method was used to obtain more insight into the role of GABAB receptors. At a 200-ms inter-stimulus interval the spike response was inhibited in 75% of the neurons. There was an approximately 40% depression of the mean spike value in the control. CGp 35348 reduced paired-pulse inhibition, while (-)-baclofen increased it. Stronger drug effects on the second stimulation-induced response possibly indicate their presynaptic action on GABAB receptors.

Animals↗
PubMed1996

Blocking effects of promethazine, triprolidine and their analogues on the excitation caused by the peptide, achatin-I.

An Achatina endogenous tetrapeptide, achatin-I (Gly-D-Phe-Ala-Asp), applied by brief pressure, produced an inward current (Iin) on an Achatina giant neurone type, PON (periodically oscillating neurone). Promethazine, triprolidine and their analogues tested, applied by perfusion, showed a tendency to inhibit the Iin, suggesting that the effective structures vary to a wide extent. With respect to promethazine and its analogues, the presence of 2-bromo, 5-oxo, 3-dimethylsulfamido and 2-methoxy weakened the effects. 10-(2-methylamino-2-methylethyl) instead of 10-(2-dimethylamino-2-methylethyl) of promethazine and the azepine ring instead of phenothiazine ring potentiated the effects. From the dose (pressure duration)-response study of achatin-I, the two promethazine analogues, RP 6497 and RP 6549 (the structures are shown in Fig. 1), inhibited the Iin in partly competitive and partly noncompetitive manners. Regarding triprolidine and its analogues, the compounds in Z-configuration seemed to be more effective than those in E-configuration. The presence of 4-methyl in 1-phenyl, and 1-(4-pyridyl) instead of 1-(2-pyridyl) potentiated the effects. 3-Dimethylamino instead of 3-pyrrolidino weakened the effects. The two triprolidine analogues, Trip Der 3 and Trip Der 6 (the structures in Fig. 2), inhibited the Iin in an uncompetitive manner.

Animals↗
PubMed1996

GABAergic characteristics of transcallosal activity of cat motor cortical neurons.

GABAergic characteristics of transcallosal activity of cat pyramidal tract neurons (PTNs) and non-PTNs (nPTNs) were studied with stressing on GABAB receptors. PTNs and nPTNs were further classified into group 1 (< 10 ms) and group 2 (> 10 ms) based on the latency upon transcallosal stimulation. However, mainly the results of group 1 neurons were presented here, due to the small number of group 2 neurons. GABA, bicuculline, CGP 35348 and phaclofen were iontophoretically applied. The spike number to 20 trials of transcallosal stimulation was 8.9 +/- 4.3 (mean +/- S.D.) for group 1 PTNs (n = 14) and 10.4 +/- 4.5 for group 1 nPTNs (n = 38) under the control conditions. CGP 35348, phaclofen and bicuculline significantly increased the spike numbers in both cases. The increase was greater for nPTNs than for PTNs. GABA decreased them. The transcallosal latency was 3.9 +/- 1.1 ms for PTNs under the control conditions. CGP 35348, phaclofen and bicuculline significantly shortened the latency, and GABA elongated it. The transcallosal latency for nPTNs under the control conditions was 2.7 +/- 1.2 ms. This was significantly shortened by application of CGP 35348, phaclofen or bicuculline. GABA restored it. In conclusion, CGP 35348, phaclofen and bicuculline increased spike discharge and shortened the latency upon transcallosal stimulation for both group 1 PTNs and nPTNs.

Animals↗