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Biomedical subjects

M Satou

Publications and source records attributed to M Satou.

At least 55 records · Page 3Linked to original sources
PubMed1994

Hydatidiform mole with a surviving coexistent fetus following in-vitro fertilization.

A case of a hydatidiform mole with a surviving coexistent fetus following in-vitro fertilization and embryo transfer is reported. The diagnosis was established at 12 weeks gestation and pregnancy was maintained until 31 weeks, during which time transient hyperthyroidism and lung metastasis developed. No difference was observed in pronucleus formation and early embryonic development between the two embryos, which resulted in a complete mole and a normal fetus. DNA finger-print analysis, karyotype analysis and histopathological examination confirmed that the pregnancy was a twin of a complete mole and a normal conception. DNA fingerprint analysis was performed with a single-locus probe cocktail. All DNA bands from the tumour were of paternal origin, and the bands from the placenta were of paternal and maternal origin.

Adult↗
PubMed1994

[Symptomatic laterality and magnetic resonance imaging (MRI) of the putamen in striatonigral degeneration (SND)].

Asymmetric onset of parkinsonism appears not uncommon in SND. This study quantitatively investigated anatomical asymmetry of the putamen using MRI in relation to symptomatic laterality. Our study comprises six patients with SND, two men and four women, ranging in age from 50 to 77. Duration of illness ranged from 1 to 4 years. The Yahr stage was IV in 3 patients and I, III, or V in the others. The diagnosis of SND was made on medical history, neurological examination and MRI. All patients had asymmetric onset of parkinsonism. They subsequently had variable cerebellar ataxia and/or autonomic failure. All of them responded poorly to L-dopa therapy. MRI revealed the pontine and cerebellar atrophy and abnormalities of the putamen in most of the patients. MRI was performed using a 1.5 Tesla in 5 patients and 0.5 Tesla in one. Inversion Recovery (IR) image were utilized as T1-weighted images and proved optimal in showing anatomic detail. Spin-echo sequences were used to provide T2-weighted images. For measurement of the putaminal area and length in SND patients and 12 normal controls, we used two horizontal slices. One is passing through dorsal portion of the putamen, and the other through the ventral putamen. All the patients had the onset of hemi-parkinsonism and the symptoms progressed dominantly on the side of onset. With T1-weighted IR sequences, putaminal atrophy was demonstrated in all patients, more intense on the contralateral side to more symptomatic limbs. The anatomical asymmetry and the symptomatic laterality were less pronounced in advanced patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

[A case of penetrating chest injury with tension hemothorax by gunshot].

The patient, a 36-year-old male, was admitted with massive hemoptysis. He had two gunshot wounds in the right lateral abdomen and supraclavicular fossa. His chest X-ray showed right tension hemothorax. Emergency thoracotomy and laparotomy were performed. Massive bleeding from the right pulmonary artery (A4+5), lacerations in the diaphragm and injuries of the liver were found. We performed right middle lobectomy, S3 segmentectomy and plication of the diaphragm and liver. He was discharged uneventfully.

Adult↗
PubMed1993

Identifying the ciliary sulcus for suturing a posterior chamber intraocular lens by transillumination.

We describe herein a technique for locating the ciliary sulcus for suturing a posterior chamber intraocular lens. Transscleral illumination with a light-guide fiber placed underneath the iris reveals the ciliary sulcus as a bright area near the limbus, and it allows for a straight needle with 10-0 polypropylene fiber to be easily inserted through the sulcus after making two pairs of radial scleral incisions to fixate the 10-0 polypropylene fiber. We think that this procedure can minimize complications of suturing a posterior chamber intraocular lens and shorten the operation time.

Aged↗
PubMed1993

The role of thallium-201 single photon emission tomography in the investigation and characterisation of brain tumours in man and their response to treatment.

The aim of this study was to characterise brain tumour type and treatment response in relation to the uptake of thallium-201. 201T1 single photon emission tomography (SPET) was performed in 58 patients with brain tumours. Fifty-six patients were utilised for the statistical comparison of the early and delayed 201T1 indices expressed as the ratio of tumour to contralateral cerebral hemisphere uptake. The retention index of 201T1 in the tumour tissue calculated from the early and delayed scans was also analysed. Furthermore, in 56 patients with 58 brain tumours, a comparison was made of the diagnostic value of high 201T1 uptake and gadolinium diethylene triamine penta-acetic acid (Gd-DTPA) enhancement on MRI scans. Although high 201T1 uptake was observed in viable malignant gliomas, brain metastases, meningiomas and malignant teratoma, the viable malignant gliomas could not be differentiated from brain metastases and extracerebral tumours by means of 201T1 indices. 201T1 SPET failed to diagnose a viable ring-enhanced tumour with a thin rim and small tumours of less than 1.5 cm in diameter visualised by Gd-DTPA-enhanced MRI. In spite of this, 201T1 SPET appears to be effective for determination of the malignant viability of tumours.

Brain↗
PubMed1993

Design and synthesis of ETA receptor antagonists and study of ETA receptor distribution.

Many oligopeptides were designed to find ETA receptor antagonists on the hypothesis that an ETA receptor can recognize two hydrophobic parts of ET-1, i.e., Val-Tyr-Phe and Ile-Ile-Trp, over a short distance. They were synthesized from the benzyl ester of the C-terminal amino acid by stepwise chain elongation using the solution method. The binding affinity of the synthetic peptides to the endothelin receptors was examined in porcine cardiac ventricular muscle membrane for ETA receptor and in bovine whole brain membrane for ETB receptor. Hexamethyleneiminocarbonyl-Leu-trp-ala-beta ala-tyr-phe (TTA-386) was selected as an ETA receptor-selective competitive antagonist to ET-1. It competed against ET-1 at ETA receptor sites and showed one-third the binding affinity of ET-1 for ETA receptor and < 1/10,000 the affinity for ETB receptor. It inhibited the ET-1-induced increase of cytosolic free calcium concentration in A-10 cells. The 125I-labeled hexapeptide (125I-TTA-386) was prepared to distinguish the distribution of ETA receptor from ETB receptor. Scatchard plot analysis of saturation binding of 125I-TTA-386 to porcine cardiac membranes showed the same Bmax value as that of 125I-ET-1. Autoradiographic studies showed that ETA receptors are most abundant in the cardiac muscle, intestine, large bowel, spleen, and testis.

Amino Acid Sequence↗
PubMed1993

[Shock wave therapy of the rabbit VX2 bladder cancer--THP-ADM concentration in the tissue after combination therapy of THP-ADM and shock wave].

Tissue concentration of THP-ADM was analysed after the administration of THP-ADM with or without exposure of high energy underwater shock waves (SW) to rabbit bladder VX2 cancer. THP-ADM was administered intravenously (2 mg/kg) or into the urinary bladder (10 mg/body). After the administration of THP-ADM, SW was exposed (6,000-10,000 shots) to VX2 bladder cancer or normal bladder tissue. One hour later, THP-ADM tissue concentration was measured by high performance liquid chromatography method. In intra-venous group, THP-ADM concentration of cancer tissue was significantly lower (p < 0.02) in SW group than that of non-SW group. In bladder instillation group, THP-ADM concentration of normal bladder tissue was significantly higher (p < 0.02) in SW group than that of non-SW group and the average concentration of cancer tissue was higher about three times in SW group than that of non-SW group.

Administration, Intravesical↗
PubMed1993

[Efficacy of myocardial preservation using HTK solution in continuous 120 min cross-clamping method--a comparative study with GIK method].

The aim of this study is to investigate the efficacy of HTK solution in the 120 minutes cross-clamping method in comparison with conventional intermittent cardioplegia using GIK solution. Fifty-four open heart surgery were performed with cardioplegic solution using either HTK solution (HTK) or GIK solution (GIK). In the HTK, HTK (3L) was infused for the initial dose and 1L was added every 60 min after 120 min of cross-clamping. In GIK, 1L of GIK solution was intermittently infused initially and then every 30 min together with continuous cold blood perfusion. The effect of two cardioplegic solution was evaluated by postoperative cardiac function (CI, %SF), released enzymes (CPK), histology and dosage of catecholamine. Postoperative CI was 3.67 +/- 0.76 in HTK, and 4.34 +/- 1.04 in GIK (NS). % SF was 26.0 +/- 5.26 in HTK and 25.6 +/- 0.76 in HTK, and 4.34 +/- 1.04 in GIK (NS). %SF was 26.0 +/- 5.26 in HTK and 25.6 +/- 9.2 in GIK (NS). The CK-MB (IU/dl) level after reperfusion was significantly decreased in HTK at 60 and 180 min after reperfusion. Histology at 60 min of ischemia revealed a significant increase of edema of mitochondria in GIK. Postoperative catecholamine dose was 2.65 +/- 1.3 in HTK and 10.3 +/- 3.4 in GIK (p < -0.01). PH of myocardium was well maintained around 7.4 during cross-clamping in HTK, however, it was decreased in GIK. In conclusion, The HTK method offers a reliable cardiac protection due to effective buffering using Histidine in comparison with GIK.

Cardioplegic Solutions↗
PubMed1992

[A case of transfusion-associated GVHD after total laryngectomy].

We report a case of fatal transfusion-associated graft versus host disease (GVHD) that developed in a patient with laryngeal cancer. After a 39.6Gy irradiation dose, total laryngectomy with right radical neck dissection was performed. The postoperative course was uneventful. However, seven days after blood transfusion, high fever (38.5 degrees C) suddenly appeared. On the ninth day, watery diarrhea and facial erythema were observed. On the 12th day, liver disturbance and pancytopenia developed. The patient died on the 16th day because of overwhelming sepsis. Transfusion-associated GVHD has a mortality rate of more than 90%. Therefore, the most important procedure for preventing GVHD is the use of irradiated blood products. Furthermore unnecessary blood transfusion should be avoided.

Graft vs Host Disease↗
PubMed1992

[A case of venous thrombosis associated with medullary venous malformation].

A 16 year-old girl was admitted to our hospital complaining of headache and vomiting. She was born with an orbital lymphangioma, which was resected partially at a younger age. On admission she had mild confusion and light neck stiffness as neurological positive findings. Enhanced CT scan showed an eight-figure enhancement at the straight sinus and a linear enhancement at the vermis. Angiography showed venous thrombosis spreading in the deep cerebral veins and the right superior ophthalmic vein. Furthermore a medullary venous malformation (MVM) was disclosed in the posterior fossa. Administration of urokinase and glycerol relieved her symptoms gradually. After that treatment, partial recanalization of the deep cerebral veins and the straight sinus and disappearance of the MVM were recognized in the second angiography. In the present case, the MVM played an important role as collateral channel. But, in general, when venous thrombosis occurs, collateral circulation is maintained by cork-screw vessels, not by MVM. In the light of the presence of the lymphangioma, the present case was thought to be a rare condition in the venous system. It appears that residual fetal vessels have existed in the posterior fossa from birth. It is considered that the residual fetal vessels opened and dilated temporally and were recognized as an MVM in angiography, when cerebral venous flow was disturbed by the venous thrombosis.

Adolescent↗
PubMed1991

Local motion processing in the optic tectum of the Japanese toad, Bufo japonicus.

The results of previous behavioral studies can be so interpreted that the prey-catching behavior in the toad is elicited if there is a 'local' motion restricted within a small part of the visual field, while it is suppressed if there is a 'global' motion over a large part of the visual field. This has led us to design experiments to answer a specific question (yet a very essential one for understanding neural processes underlying this behavior): Are there 'local motion detectors' in the toad's visual system that are not activated by 'global' motion over a large part of the visual field but are activated by 'local' motion confined within a smaller part of it? The present study showed that (1) the majority of the toad's tectal neurons exhibit properties of the 'local motion detectors' as defined above, and (2) these properties can be explained from the receptive field structure revealed in the present experiments. Based on these results, we suggest that the tectal 'local motion detectors' are essential for the detection and localization of small moving prey-objects in the natural environment while ignoring the large moving objects or the self-induced motion of the visual field.

Animals↗
PubMed1989

After-effects of moving textured background in motion-sensitive neurons of anuran optic tectum.

Motion-sensitive neurons in anuran optic tectum were shown to respond to a stationary object centered in the excitatory receptive field, if a textured background moved for a while and then stopped ('motion after-response'). This motion after-response was attributed to a post-inhibitory rebound activation derived from effects of masking the excitatory receptive field center surrounded by an antagonistic inhibitory region. It was suggested that a similar rebound activation mechanism may also be involved in a certain type of perceptual motion after-effects in humans.

Action Potentials↗
PubMed1989

Location of forelimb motoneurons in the Japanese toad (Bufo japonicus): a horseradish peroxidase study.

To label the spinal motoneurons innervating the forelimb muscles of the Japanese toad, horseradish peroxidase (HRP) was injected into these muscles or applied to the cut end of the brachial nerves (N. radialis and N. ulnaris). Spatial distribution of the HRP-labeled motoneurons was reconstructed from serial frontal sections of the spinal cord and their location was examined. Motoneurons innervating forelimb muscles were distributed in the lateral cell column from segment 3 to segment 5 of the ipsilateral brachial spinal cord. In the transverse plane of the spinal cord, motoneurons innervating the medial forearm muscles (innervated by N. ulnaris) were located in the more medial part of the lateral cell column, whereas those innervating the lateral forearm muscles and the upper arm muscle (innervated by N. radialis) were located in the more lateral part of the lateral cell column. Along the longitudinal axis of the spinal cord, motoneurons innervating the more anterior (flexor side) forearm muscles were located in the more rostral part of the spinal cord, whereas those innervating the more posterior (extensor side) forearm muscles were located in the more caudal part of the spinal cord. Thus, motoneurons innervating forearm muscles were well organized somatotopically not only in the transverse plane, but also along the longitudinal axis of the spinal cord. Such a somatotopic organization of motoneurons along the longitudinal axis could also be regarded as a functional one; the flexor motoneurons were located rostrally to the extensor motoneurons.

Animals↗
PubMed1989

Tongue-muscle-controlling motoneurons in the Japanese toad: neural inputs from the thalamus.

The anuran tongue is an effector organ specialized for snapping up prey during visually guided prey-catching behavior. As a step toward elucidating the control mechanisms of the tongue movement and overall organization of visually guided behavior, properties of neural inputs from the thalamus (of which electrical stimulation elicited a behavior very similar to the visually guided predator-avoidance behavior under freely behaving conditions) were investigated in paralyzed Japanese toads. Tongue-muscle-controlling motoneurons (tongue-protractor motoneurons (PMNs) and tongue-retractor motoneurons (RMNs)) were identified antidromically, and synaptic inputs in response to electrical stimuli applied to various points in the thalamus (mainly the posterocentral thalamic nucleus) were examined. Hyperpolarizing potentials were evoked in both PMNs and RMNs in response to single electrical stimuli applied to the thalamus contralateral or ipsilateral to the recording side. Since these potentials reversed to depolarizing ones after injecting Cl- ions into the cell interior, these hyperpolarizing potentials were concluded to be the usual fast type of inhibitory postsynaptic potentials (IPSPs). On the other hand, depolarizing potentials which were superimposed on the underlying IPSPs were evoked when repetitive electrical stimuli were applied to the thalamus. The amplitude of these depolarizing potentials was decreased when depolarizing currents were injected intracellularly, while it was increased when hyperpolarizing currents were injected, indicating that these depolarizing potentials are excitatory postsynaptic potentials (EPSPs).(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗
PubMed1989

Medullary reticular neurons in the Japanese toad: morphologies and excitatory inputs from the optic tectum.

1. To elucidate the neural mechanisms that mediate visual responses of optic tectum (OT) to medullary and spinal motor systems, we analyzed medullary reticular neurons in paralyzed Japanese toads (Bufo japonicus). We examined their responses to electrical stimulation of OT, and stained some neurons intracellularly. Responses to stimulation of the glossopharyngeal nerve (IX) were also analyzed. 2. Extracellular single unit recording revealed excitatory responses of medullary neurons to OT and IX stimulation. Among 92 units encountered, 79 responded to OT stimuli, 10 to IX stimuli, and 3 to both. Some units responded to successive stimuli of short intervals with relatively stable lags. 3. Intracellular recording and staining experiments revealed morphologies of reticular neurons that received excitatory inputs from OT. Thirteen units were identified after complete reconstruction of somata and dendrites. Neurons in the nucleus reticularis medius received excitatory inputs from bilateral OT. They had wide dendrites in ventral, ventrolateral and lateral funiculi, and single axons descending in the ipsilateral ventral funiculus as far caudally as the cervical spinal cord. Some collaterals of these axons projected directly to the hypoglossal and spinal motor nuclei. Some neurons in other medullary nuclei (nuc. reticularis superior, pretrigeminal nucleus, nuc. reticularis inferior, and nuc. tractus spinalis nervi trigemini) also responded to the OT stimulation. 4. Activities in bilateral OT converge onto medullary reticular neurons, which may directly control medullary and spinal motor systems.

Action Potentials↗