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Biomedical subjects

K Goto

Publications and source records attributed to K Goto.

At least 541 records · Page 30Linked to original sources
PubMed1993

[Arteriovenous malformation resembling galenic aneurysm].

A girl who had just turned one year old was transported to our hospital because of an episode of general convulsive seizure. Neurological examinations demonstrated a comatose consciousness level, moderate right hemiparesis and conjugate deviation to the right. CT scan on admission revealed an intracerebral hematoma in the left medial temporal lobe associated with intraventricular hemorrhage in the lateral and third ventricles. MRI also showed the hematoma with evidence of a dilated venous system. Angiography demonstrated a huge venous sac fed by the left posterior choroidal artery and left anterior choroidal artery drained ultimately into the remnant of the tentorial sinus. Firstly, two courses of transfemoral embolization using platinum micro-coils were performed. Initially, the posterior choroidal artery and a branch of the anterior choroidal artery were occluded successfully. Then, two branches from the posterior cerebral artery were occluded one week after the initial procedure. She underwent the operation via the left subtemporal approach. After the CSF removal through the Sylvian fissure, the gentle elevation of the left temporal lobe allowed the visualization of the feeders and the pulsating venous sac. After the complete obliteration of the feeding arteries and removal of the nidus, the interruption was verified by using doppler sonography and intraoperative angiography. Postoperative course was uneventful. The infant was discharged without deficit on the 30th postoperative day. The authors discussed the embryological implications of this type of AVM and the role of endovascular surgery.

Cerebral Veins↗
PubMed1993

[Gallstone classification and analysis of their constituents].

Macroscopic classification of gallstones as proposed by the Japanese Society of Gastroenterology is based on the presence of characteristic structures on the cut surface. According to this classification, gallstones can be broadly divided into three types: cholesterol gallstones, pigment gallstones and rare gallstones. This classification is widely accepted in Japan because of its clinical applicability. A more accurate classification requires analysis of the constituents of gallstone. In particular, infrared absorption spectroscopy has been utilized for this purpose because it enables a rapid and easy analysis, requiring only small amounts of sample. In the selection of patients with gallstones for non-surgical treatment, such as ESWL and dissolution therapy, qualitative diagnosis is necessary. With this in mind, we have attempted to produce CT-Profile curves of individual gallstones, depicting changes in CT values assessed along cross-sectional lines passing from the center of the stone to their maximum diameters. This method allowed qualitative diagnosis almost of all gallstones.

Bilirubin↗
PubMed1993

[Treatment strategy of gallstone patients under special conditions gallstone in the elderly].

We have treated 894 gallstone patients for these five years. The average age was 55.47 and 163 cases (18.2%) were more than 70 year-old. One of the important characteristics of the aged gallstone patients that they often had bile duct stones causing acute obstructive cholangitis. The other was that they accompanied another organ disorders. Early biliary drainage was the best way to avoid multiple organ failure under such conditions. Principally, surgical treatment if it's possible, was most reliable for bile duct stones. Thirty-five patients of bile duct stones were treated with our new surgical procedure. That was primary closure technique of the common bile duct following lithotomy under pre- or intra-operative insertion of naso-biliary drainage catheter. Especially in the elderly, this technique was useful to reduce post operative hospital stay by 19 days compared with the ordinary T-tube drainage.

Aged↗
PubMed1993

High plasma concentrations of endothelin-like immunoreactivities in patients with hepatocellular carcinoma.

The plasma levels of endothelin-like immunoreactivities (ET-IR) of patients with hepatocellular carcinoma (HCC) were compared with those of patients with liver cirrhosis (LC), using a specific radioimmunoassay for endothelin-1. The mean concentration of plasma ET-IR of 21 HCC patients (30.3 +/- 8.5 pg/ml, n = 21) (means +/- SD) was markedly higher than those in LC (22.1 +/- 4.7 pg/ml, n = 16) (p < 0.01), which were also elevated compared with those in normal subjects (9.4 +/- 1.6 pg/ml, n = 91). Moreover, the level of plasma ET-IR reflected the tumor size of HCC patients, which was estimated by the ultrasonic and computed tomographic examinations. Although there was no relation to other biochemical parameters indicating liver function or tumor markers such as alpha-fetoprotein, a good positive correlation was obtained between plasma ET-IR and C-reactive protein (CRP) concentrations of HCC patients (r = 0.805, p < 0.01). We measured the tissue contents of ET-IR in HCC and its adjacent LC tissue, but failed to find any significant difference between the mean content of HCC (0.50 +/- 0.38 ng/g) and LC (0.44 +/- 0.28 ng/g). The endothelial cell damage due to cancer growth may not be responsible for the high concentrations of plasma ET-IR of HCC, because plasma thrombomodulin concentrations were not correlated with plasma ET-IR levels in HCC patients. Our study implies that the high plasma concentration of ET-IR is pathogenomonic to HCC, although the site of production is still debatable.

Aged↗
PubMed1993

[A case report of central pontine myelinolysis associated with serum hyperosmolality after open heart surgery].

A 65-year-old man was admitted with a sudden onset of dyspnea. Severe mitral regurgitation due to torn chordae tendinae was revealed on UCG. Mitral valve replacement was undergone. The postoperative course was complicated with a low cardiac output syndrome which was successfully treated with IABP, catecholamines and vasodilators. However, stupor developed on the 4 th postoperative day, following by tetrapregia on the 8 th day, and deep coma on the 15 th day respectively. Laboratory studies of the 4 th day disclosed the following values, serum sodium 150 mEq/l, blood urea nitrogen 84.7 mg/dl, blood sugar 184 mg/dl and calculated serum osmolality 354 mOsm/l. Cranial CT of the 15 th day showed an obscure low density area in the central pons which was strongly suggestive of central pontine myelinolysis (CPM). His CNS symptoms improved dramatically after administration of thyrotropin-releasing hormone tartrate (TRH-T). A diagnosis of CPM was made on MRI of the 41 st day. He discharged without any neurological deficit on the 62 nd day.

Aged↗
PubMed1993

[Isolated trochlear nerve palsy caused by mixed dural-pial arteriovenous malformation of the anterior cranial fossa: a case report].

A 62-year-old male was admitted to our hospital in May, 1985, with double vision, which had persisted for 1 month. The neurological examination revealed left trochlear nerve palsy. A cerebral angiogram showed an arteriovenous malformation at the anterior cranial fossa. The malformation was mainly fed by the left anterior ethmoidal artery which branched off from the orbital branch of the left middle meningeal artery. There was a marked enlargement of anastomosis between the orbital branch of the middle meningeal artery and the recurrent meningeal branch of the lacrimal artery. Bilateral distal branches of the internal maxillary arteries, bilateral anterior falx arteries and the left fronto-orbital artery were also involved in supplying the AVM. The dilated fronto-orbital vein was the main drainer which emptied into the pterygoid plexus via the uncal vein and the sphenoparietal vein. In June 1985, the nidus involving the dura at the region of the cribriform plate and olfactory bulb was totally removed through a left frontal craniotomy. Postoperatively, the isolated left trochlear nerve palsy improved completely within a few days. This is the first reported case of isolated trochlear nerve palsy caused by a mixed dural-pial arteriovenous malformation of the anterior cranial fossa. We concluded that the etiology of isolated trochlear nerve palsy consisted of nerve compression due to the dilated orbital branch of the middle meningeal artery within the superior orbital fissure.

Carotid Arteries↗
PubMed1992

Level of ETB receptor mRNA is down-regulated by endothelins through decreasing the intracellular stability of mRNA molecules.

Using ROS17/2 rat osteosarcoma cells as a model system, we examined the possibility that endothelin (ET)-induced down-regulation of ETB receptor was accompanied by a decrease in levels of ETB receptor mRNA. Northern blot analysis showed that low doses of ET-1 and ET-3 caused a transient decrease in ETB receptor mRNA in the cells. The maximum decrease in the levels of ETB receptor mRNA (80%) occurred after 2-4 h of exposure of the cells to ETs and was followed by a gradual recovery to control levels by 24 h. The effects were dose-dependent (EC50-1 nM), and ET-1 and ET-3 were almost equipotent in eliciting the response. The addition of either ionomycin, a Ca2+ ionophore, or phorbol dibutyrate, a protein kinase C activator, mimicked the effect of ETs. These results suggested that ETs-induced down-regulation of ETB receptor mRNA was mediated by the activation of ETB receptor and that it may have involved ETB receptor coupled second messenger pathways. We also showed that ETB receptor mRNA had a long intracellular life span which suggested that ETs-induced down-regulation of ETB receptor mRNA may have been due to a decrease in the stability of mRNA, rather than inactivation of the transcription of mRNA.

Animals↗
PubMed1992

Action of endothelin-1 on rat astrocytes through the ETB receptor.

We investigated the effect of ET-1 on the state of rat cerebral astrocytes (AC) differentiation. AC ceased to proliferate and changed into its differentiated state by treatment with dibutyryl cyclic AMP (DBcAMP). The cell growth activity in DBcAMP-treated AC was stimulated by ET-1 in a dose-dependent manner. Over similar dose ranges, ET-1 suppressed the glutamine synthetase activity in DBcAMP-treated AC. The molar potency of ET-1 in this action was at least 3 orders of magnitude higher than that in mitogenic action in AC under the proliferative state previously reported. Northern blot analysis revealed that ETB receptor mRNA level in DBcAMP-treated AC was markedly higher than that in AC untreated with DBcAMP. Consistently, binding studies showed that the Bmax value for [125I]ET-1 in DBcAMP-treated AC was 16 times higher than that in AC untreated with DBcAMP. These results suggest that ET-1 potently induced a retraction of the differentiation state of AC from fully the specialized state and that the high responsiveness of differentiated AC to ET-1 was partly attributed to the high level expression of the ETB receptor.

Animals↗
PubMed1992

Cloning and expression of rat preproendothelin-3 cDNA.

We report here the cloning and expression of a rat full-length cDNA encoding preproendothelin-3 (preproET-3). The predicted rat preproET-3 consisted of 167 amino acid residues. As in other ET-family peptides, the mature rat ET-3 was predicted to be produced through unusual processing from a 41-residue intermediate, the big ET-3 in rat. Transient transfection of COS-7 cells with the cloned preproET-3 cDNA resulted in the production of mature ET-3 and this production was inhibited by phosphoramidon, a metaloprotease inhibitor. This suggested that a phosphoramidon sensitive mechanism was involved in the production of ET-3 in the transfected COS-7 cells. Northern blot analysis showed that an approximately 3.0-kb rat preproET-3 mRNA was expressed in rat tissues, including the eye ball, submandibular gland, brain, kidney, jejunum, stomach and spleen. A 2.0-kb and a 3.3-kb mRNA were also detected in the eye ball and small intestine, respectively. The distinct distribution of rat preproET-3 mRNA from that of preproET-1 mRNA suggested that ET-1 and ET-3 played different roles.

Amino Acid Sequence↗
PubMed1992

Sequential changes in electroencephalogram continuity in very premature infants.

This study was conducted to quantify sequential changes in electroencephalogram (EEG) continuity for 24 h in very premature infants. For a total of 122 days, continuous 2-channel EEG recording was conducted for 28 premature infants from 26 to 33 weeks of conceptional age (CA). None of the infants showed evidence of neurological impairment during hospitalization. Normal neurological outcome was noted at a minimum 12 months of age. By classifying each 5.5 min epoch according to EEG continuity, the number of contiguous epochs of each series of discontinuous type (DTs) and the number of epochs between two series of discontinuous type (IDTIs) were counted at each CA. The duration of DT decreased with increasing CA. The mean duration remained at 13-16 min after 29 weeks CA. The mean duration of each IDTI increased with CA, up to about 1 h at 33 weeks. A constant period of DTs was noted at longer intervals with increasing CA. These changes appear related to the development of sleep state organization with CA.

Brain↗
PubMed1992

Vasoconstrictor effects of endothelin-1 on myocardium microcirculation studied by the Langendorff perfusion method: differential sensitivities among microvessels.

An intravital fluorescence microscope system was used to investigate the pharmacological effects of endothelin-1 (ET-1) on the coronary microcirculation in the isolated beating hearts of rats. The heart was perfused by retrograde aortic steady flow with an oxygenated Krebs-Ringer solution containing FITC-dextran. Changes in diameters of coronary microvessels accompanying the cumulative injection of ET-1 in the perfusate were observed and recorded with a video camera system. Coronary perfusion pressure was also measured during each experiment. Bolus injections of ET-1 (1-300 pmole) elicited a dose-dependent increase in perfusion pressure from 54 +/- 6 mm Hg (mean +/- SEM; n = 10, before the ET-1 injection) to 144 +/- 9 mm Hg (n = 8, at the ET-1 dose of 300 pmole). A dose-dependent narrowing of microvessels was also observed. This vasoconstriction was especially prominent in small-sized arterioles; the maximum vasoconstriction of the smaller arterioles was significantly higher than that of the larger arterioles (P less than 0.05). The response induced by ET-1 dose of 3-10 pmole was significantly larger in arterioles than in postcapillary venules in the diameter range between 10 and 40 microns. The vasoconstriction produced by ET-1 was inhomogeneous. Some part of bifurcations of arterioles showed a prominent localized vasoconstriction, and occasionally showed a complete luminal obstruction. Such a segmental vasospasm might be attributed to localized sensitivities of arterioles to ET-1. These findings suggest that ET-1 may have an important role in governing the coronary resistance and regulating the capillary flow in the myocardium.

Animals↗
PubMed1992

Localization of gene expression of calreticulin in the brain of adult mouse.

The localization of gene expression of calreticulin, a calcium-binding protein in the endoplasmic reticulum, was examined throughout the entire brain of adult mice by in situ hybridization. Calreticulin mRNA is expressed widely and heterogeneously in discrete neurons throughout the brain, but the white matters expressed it weekly or faintly. In the olfactory bulb, the mRNA is expresses moderately in the mitral cells, but weakly in the periglomerular cells and internal granule cells. In the cerebrum, the gene is expressed intensely in the piriform cortex, but weakly in neocortex, the entorhinal cortex and the amygdaloid nuclei. In the hippocampal formation, calreticulin mRNA is expressed intensely in the CA1-CA3 regions but less intensely in the granule cells of the dentate gyrus. The caudate-putamen, thalamic and hypothalamic nuclei, and mammillary nuclei express the mRNA weakly or faintly. In the mesencephalon, pons and medulla, moderate expression of the mRNA is detected in the pontine nuclei and the locus ceruleus. Weak expression of the mRNA is detected in several discrete nuclei and zones such as the substantia nigra, the superior colliculus and the central gray. Expression signals of calreticulin mRNA are faint in the inferior olive. In the cerebellum, calreticulin mRNA is expressed moderately in the Purkinje cells whereas no significant expression is detected in the granule cells. The plexus choroideus of the lateral, third and fourth ventriculi express calreticulin mRNA intensely although no distinct expression of the mRNA is discerned in the ependyma.

Animals↗