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Biomedical subjects

Y Tanabe

Publications and source records attributed to Y Tanabe.

At least 199 records · Page 11Linked to original sources
PubMed1993

Diabetes mellitus-associated glycogen storage hepatomegaly: report of a case and review of the Japanese literature.

A huge hepatomegaly was seen in a 30-yr-old female diabetic who was treated with high dose of insulin for her uncontrollable food ingestion. The liver function at the peak of the hepatic enlargement showed a moderate increase of transaminases, alkaline phosphatase, and gamma-glutamyl transpeptidase. The histology of the enlarged liver revealed PAS-positive granules in enlarged hepatocytes, indicating the presence of massive glycogen storage. On admission, she was maintained under a calorie-restricted diet and received approximately 15 to 20 units per day of insulin supplement. At one month after admission, a marked shrinkage of her enlarged liver and restoration of normal liver function were observed concomitantly with the return of fair control of her blood sugar levels. One year later, she had an episode of diabetic ketoacidosis which subsequently was treated with a continuous low-dose infusion of insulin; however, she showed neither hepatomegaly nor liver dysfunction during this episode. There have been 20 cases reported of Japanese diabetics with marked hepatomegaly, in whom the vigorous treatment of diabetic ketoacidosis with insulin seemed to be a trigger of the enlarged liver. This has occurred mostly in patients with insulin-dependent diabetes mellitus. We present a case of non-insulin-dependent diabetes mellitus with glycogen storage hepatomegaly, presumably due to excessive insulin supplements. This suggests that glycogen storage hepatomegaly in diabetics may not be only due to an acute restoration from diabetic ketoacidosis, but may also be due to an overinsulinization in an attempt to maintain a euglycemic condition in spite of excess food intake.

Adult↗
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

[Serial MR imaging of possible Pelizaeus-Merzbacher disease].

We performed serial magnetic resonance imaging (MRI) toward 4 male children with possible Pelizaeus-Merzbacher disease (PMD). They were clinically suspected as PMD on the basis of typical neurological, electrophysiological and MRI examinations. MRI revealed that myelinated fibers were localized in brainstem, cerebellum, internal capsule, optic radiation and proximal corona radiata in case 1, while myelinated fibers were almost absent in case 2-4. On repeated MRI investigation, we found no further extension of myelination in case 1 and the absence of myelination in case 2-4. This study demonstrated that myelination in the brain is arrested immediately after birth in case 1, while no myelination developed before birth in case 2-4. It was speculated that MRI in case 1 and case 2-4 might correspond to neuropathologic findings of classical and connatal form as reported in the literature.

Child, Preschool↗
PubMed1993

[Anaesthetic management of pediatric renal transplantation for chronic renal failure].

We evaluated the preoperative and intraoperative general condition of 33 pediatric kidney recipients. Eighteen patients were anaesthetized with lumbar epidural anaesthesia. Ten patients were with nitrous oxide-oxygen-halothane, 5 cases were with NLA. Preoperatively many children had cardiovascular and metabolic complications. For example 39% of patients had history of hypertension. Sixty-seven percent of patients were found to have cardiomegaly (cardio-thoracic ratio > 50%) with chest X-ray film. Seven of 9 patients undergoing echocardiogram had abnormality of cardiac wall motion, valvular impairment, pericardial effusion. In forty-eight percent of patients, hyperlipidemia was found. During operation we could not maintain the cardiovascular stability following intratracheal intubation and manipulation of vena cava or abdominal aorta under NLA or nitrous oxide-oxygen-halothane anesthesia. Epidural analgesia inhibited the cardiovascular fluctuation following these surgical stresses. We concluded that epidural analgesia is the best anaesthesia for pediatric renal transplantation and phentolamine or PGE1 are useful to maintain cardiovascular stability and transplanted kidney function.

Adolescent↗
PubMed1993

Signal transduction, pharmacological properties, and expression patterns of two rat metabotropic glutamate receptors, mGluR3 and mGluR4.

The metabotropic glutamate receptors are coupled to intracellular signal transduction via G-proteins and consist of a family of at least five different subtypes, termed mGluR1-mGluR5. We studied the signal transduction mechanism and pharmacological characteristics of the rat mGluR3 and mGluR4 subtypes in Chinese hamster ovary cells permanently expressing the cloned receptors. Both mGluR3 and mGluR4 inhibit the forskolin-stimulated accumulation of intracellular cAMP formation in response to agonist interaction. Consistent with the high degree of sequence similarity to mGluR2, mGluR3 closely resembles mGluR2 in its agonist selectivity; the potency rank order of agonists is L-glutamate > trans-1-aminocyclopentane-1,3-dicarboxylate > ibotenate > quisqualate. mGluR4 is totally different in its agonist specificity from any other member of the metabotropic receptors. This receptor potently reacts with L-2-amino-4-phosphonobutyrate (L-AP4) in a stereo-selective manner and moderately responds to L-serine-O-phosphate. mGluR4 thus corresponds well to the putative L-AP4 receptor characterized from brain preparations. Blot and in situ hybridization analyses indicated that both mRNAs are widely distributed in the rat brain. mGluR3 mRNA is highly expressed in neuronal cells of the cerebral cortex and the caudate-putamen, and in granule cells of the hippocampal dentate gyrus. The expression pattern of mGluR4 mRNA is more restricted, and this expression is prominent in the cerebellum, olfactory bulb, and thalamus. Furthermore, the mGluR3 mRNA, unlike the other mRNAs for the metabotropic receptors, is highly expressed in glial cells throughout the brain regions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Treatment of tuberculous bronchial stenosis with expandable metallic stents.

Gianturco expandable metallic stents were placed in 5 patients with dyspnea on exercise due to tuberculous bronchial stenosis. The stents were placed after dilatation with a 10-mm diameter high pressure balloon catheter. In all 5 patients, obstructive changes disappeared following the procedure, and dyspnea on exercise improved markedly. No complications related to the procedure were encountered. At follow-up during a period of up to 38 months, 2 patients showed bronchial restenosis at 11 and 17 months, respectively, after stent placement. Restenosis by granulomatous tissue was successfully treated by laser ablation. One patient showed slight one-day hemoptysis 26 months after stent placement.

Adult↗
PubMed1993

[A girl with Down syndrome complicated by moyamoya disease and symptomatic atlanto-axial instability].

We reported a girl of Down syndrome with both moyamoya disease and spinal cord compression due to atlanto-axial instability. At the age of 3 years, she presented with muscle weakness of gradual onset, and could not walk without support. On admission, at the age of 6, she presented with spastic paraparesis with predominance on the right side. To explain her neurological manifestations, we performed cranial MRI first, and found multiple infarctions with predominance on the right hemisphere, the occlusive changes of internal carotid and middle cerebral arteries, and signal void flow signs in basal ganglia, which suggested moyamoya disease. Although diagnosis of moyamoya disease was confirmed by cranial angiography, discrepancy between clinical manifestations (right-side dominant spasticity) and MRI findings (right-side dominant infarctions) could not be explained. Thereafter, we performed cervical MRI, which showed severely compressed lesions with predominance on the right side, corresponding to her clinical manifestations. It is essential to perform not only cranial but also cervical MRI for a patient with Down syndrome presenting neurological complications.

Atlanto-Axial Joint↗
PubMed1993

[MRI and autopsy findings in the brain of a child born with extreme prematurity].

We present the brain autopsy and MRI findings in a four-year-old boy who was born at 23 weeks of gestational age and 700 gram of birthweight and experienced an episode of cardiac arrest at 10 months of age. Neuropathological study showed the findings compatible with cardiac arrest syndrome, the gliosis or neuronal loss of extensive cerebral lesions including the cerebral white matter and cortex, basal ganglia, cerebellum and hippocampus, and large ulegyric formation in the bilateral parietal and occipital lobes, as well as the periventricular leukomalacia, which characterize hypoxic-ischemic insult in the brain of preterm infant. MRI performed eight months before his death demonstrated prominent atrophy and periventricular and parenchymal hyperintensity of the bilateral occipital lobes consistent with the above pathological findings.

Atrophy↗
PubMed1992

Immediate effects of percutaneous transvenous mitral commissurotomy on pulmonary hemodynamics at rest and during exercise in mitral stenosis.

Hemodynamics were evaluated during exercise in 33 patients with mitral stenosis who underwent percutaneous transvenous mitral commissurotomy (PTMC). PTMC was performed using an Inoue balloon. Each patient underwent a supine ergometer exercise test before and on the day after PTMC. Ergometer work load was started at 20 W and increased in increments of 20 W at 3-minute intervals until terminated by the patient's fatigue or shortness of breath. Mitral valve area increased by 0.8 +/- 0.4 cm2 (1.1 +/- 0.3 to 1.9 +/- 0.4 cm2, p less than 0.001). Mean mitral pressure gradient decreased (12 +/- 5 to 6 +/- 2 mm Hg, p less than 0.001). Pulmonary arterial pressure significantly decreased and the cardiac index significantly increased both at rest and during exercise after PTMC. Before PTMC, the increases in pulmonary arterial pressure, total pulmonary resistance and pulmonary arteriolar resistance during exercise were greater in patients with a mitral valve area less than 1.0 cm2 than in patients with an area greater than or equal to 1.0 cm2. After PTMC, total pulmonary resistance still increased during exercise. However, pulmonary arteriolar resistance did not change during exercise in patients with a mitral valve area greater than or equal to 1.5 cm2, whereas it increased in patients with an area less than 1.5 cm2. An enlarged mitral valve area greater than or equal to 1.5 cm2, which may prevent pulmonary vasoconstriction and permits a greater increase in pulmonary blood flow during exercise, is considered a good result immediately after PTMC.

Cardiac Catheterization↗
PubMed1992

[Clinical evaluation of stent placement for tracheal and bronchial stenosis].

Expandable metallic stents were successfully introduced in 7 patients, including 4 with left main bronchial stenosis caused by bronchopulmonary tuberculosis, 2 with main bronchial stenosis caused by lung cancer and one with tracheal stenosis caused by adenoid cystic carcinoma. The length of stenosis was 1.5-5 cm. The stents were 1.5-2.5 cm long with barbs, and their full expanded diameter was 1.5 cm. Balloon dilatation was performed before stenting in all cases. The stents were inserted by using a 10-12 Fr catheter. In all patients except the one with tracheal stenosis, stents were introduced under local anesthesia without any difficulties. No migration of stents occurred. After stent placement, there were no respiratory difficulties, and radionuclide lung perfusion scan and chest radiographic findings such as lung atelectasis showed marked improvement in three cases. Combined therapy of stent placement and bronchial arterial infusion chemotherapy showed marked effectiveness in one case with lung cancer. Expandable metallic stents were very useful in eliminating tracheobronchial stenosis symptoms.

Adult↗
PubMed1992

Serial MRI in Fukuyama type congenital muscular dystrophy.

Serial MRI of the brain of a female infant with Fukuyama type congenital muscular dystrophy (FCMD) is presented. Initial MRI revealed diffuse abnormal signal in the cerebral white matter extending peripherally. On follow-up studies, the abnormal signals disappeared or decreased from the posterior to anterior, and from central to peripheral. These changes in signal intensity correlate well with the process of myelination as demonstrated in histochemical studies. It appears that the abnormal signals in FCMD are caused by delayed myelination. When abnormal signal intensity is seen in the cerebral white matter of a developmentally delayed infant, serial MRI may be used to follow the course of the illness.

Ankle Joint↗
PubMed1992

Radiosensitization by 2-nitroimidazole nucleoside analog RP-170: radiosensitizing effects under both intravenous and oral administration.

The radiosensitizing activity, pharmacokinetics and toxicity of RP-170, 2-nitroimidazole nucleoside analog, were investigated and compared with those of etanidazole (SR-2508). An intravenous administration (i.v.) of 100 mg/kg of RP-170 or the same dose of etanidazole showed an equal sensitizer enhancement ratio (SER) of about 1.4 to solid EMT6 tumor under in vivo-in vitro assay and a virtually equal SER of 1.4-1.5 to solid SCC VII tumor under tumor growth delay assay. As predicted from the low partition coefficient, lower drug levels in neural tissue and more rapid serum elimination of RP-170 and etanidazole produced lower acute toxicity than lipophilic sensitizers (e.g., misonidazole). The major advantage of RP-170 over etanidazole is that it has a second route of administration. In contrast to etanidazole, in which the administration route is limited to intravenous injection, with RP-170 oral administration also exhibited effective distribution to tumors, sensitizing radiation activity to solid EMT6 and SCC VII tumors. Moreover, LD50 in mice of RP-170 (4.3 g/kg on i.v.) was increased to 5.2 g/kg by oral administration. This availability of two routes of administration indicates RP-170 as a promising hypoxic cell radiosensitizer for clinical use.

Administration, Oral↗
PubMed1992

A family of metabotropic glutamate receptors.

Three cDNA clones, mGluR2, mGluR3, and mGluR4, were isolated from a rat brain cDNA library by cross-hybridization with the cDNA for a metabotropic glutamate receptor (mGluR1). The cloned receptors show considerable sequence similarity with mGluR1 and possess a large extracellular domain preceding the seven putative membrane-spanning segments. mGluR2 is expressed in some particular neuronal cells different from those expressing mGluR1 and mediates an efficient inhibition of forskolin-stimulated cAMP formation in cDNA-transfected cells. The mGluRs thus form a novel family of G protein-coupled receptors that differ in their signal transduction and expression patterns.

Amino Acid Sequence↗
PubMed1992

Low-dose etoposide: a potential therapy for myelodysplastic syndromes.

Four patients with refractory anaemia with excess blasts in transformation (RAEB-t) and seven patients with acute leukaemia (AL) transformed from myelodysplastic syndromes (MDS) were treated with etoposide (50 mg, 2 h infusion, two to seven times per week) for at least 4 weeks. Of 10 assessable patients, three RAEB-t patients achieved partial response and one AL patient achieved complete remission. Three of the four responders were resistant to prior repeated low-dose cytarabine therapy. The responders did not require transfusions for 2-9 months while continuing on etoposide therapy. The side-effects were mild and well tolerated. Three possible mechanisms, i.e. a cytotoxic effect, differentiation-induction of malignant cells, and prolongation of blood cell survival by destroying the reticuloendothelial system, may explain the effects of etoposide. We conclude that low-dose etoposide is a potential therapy for MDS and atypical leukaemia.

Acute Disease↗
PubMed1992

Agonist analysis of 2-(carboxycyclopropyl)glycine isomers for cloned metabotropic glutamate receptor subtypes expressed in Chinese hamster ovary cells.

1. 2-(Carboxycyclopropyl)glycines (CCGs) are conformationally restricted glutamate analogues and consist of eight isomers including L- and D-forms. The agonist potencies and selectivities of these compounds for metabotropic glutamate receptors (mGluRs) were studied by examining their effects on the signal transduction of representative mGluR1, mGluR2 and mGluR4 subtypes in Chinese hamster ovary cells expressing the individual cloned receptors. 2. Two extended isomers of L-CCG, L-CCG-I and L-CCG-II, effectively stimulated phosphatidylinositol hydrolysis in mGluR1-expressing cells. The rank order of potencies of these compounds was L-glutamate > L-CCG-I > L-CCG-II. 3. L-CCG-I and L-CCG-II were effective in inhibiting the forskolin-stimulated adenosine 3':5'-cyclic monophosphate (cyclic AMP) accumulation in mGluR2-expressing cells. Particularly, L-CCG-I was a potent agonist for mGluR2 with an EC50 value of 3 x 10(-7) M, which was more than an order of potency greater than that of L-glutamate. 4. L-CCG-I evoked an inhibition of the forskolin-stimulated cyclic AMP production characteristic of mGluR4 with a potency comparable to L-glutamate. 5. In contrast to the above compounds, the other CCG isomers showed no appreciable effects on the signal transduction involved in the three mGluR subtypes. 6. This investigation demonstrates not only the importance of a particular isomeric structure of CCGs in the interaction with the mGluRs but also a clear receptor subtype specificity for the CCG-receptor interaction, and indicates that the CCG isomers would serve as useful agonists for investigation of functions of the mGluR family.

Amino Acids, Dicarboxylic↗