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Biomedical subjects

H Furuya

Publications and source records attributed to H Furuya.

At least 145 records · Page 8Linked to original sources
PubMed1996

[A case of central homonymous hemianopsia due to cerebral infarction of the occipital tip].

A 54-year-old man was admitted to the hospital because of the restriction of the right visual field. Goldmann's visual field test revealed the right central hemianopsia. MRI showed the infarction of the left occipital lobe tip. Cerebral angiography showed the occlusion of the left calcarine artery but no abnormality in the branches of the middle cerebral artery (MCA). The occipital lobe tip receives the projection from the macular area and is supplied by both calcarine artery and a branch of MCA. Therefore, cases of central homonymous hemianopsia due to vascular disorders have been relatively rare and the macular vision is usually spared. In contrast to the above knowledge, only one artery occlusion resulted in the central hemianopsia in our case. Poor anastomosis between PCA and MCA in the occipital tip of our patient may explain occurrence of the infarction of that area.

Cerebral Infarction↗
PubMed1996

[Anesthetic management for a patient with pheochromocytoma using magnesium sulfate and epidural block].

A 54-year-old woman with pheochromocytoma was anesthetized using magnesium sulfate infusion. Anesthesia was induced with thiopental and fentanyl, and maintained with 0.5% sevoflurane in nitrous oxide/oxygen and 60 mg.hr-1 of epidurally infused lidocaine. Muscle relaxation was achieved with intermittent administration of vecuronium under neuromuscular monitoring. Magnesium 2 g was infused prior to the tracheal intubation and followed by continuous infusion of 2 g.hr-1. These anesthetic techniques made hemodynamic state stable, and no additional vasoactive agents were needed. However, the infusion rate of magnesium was reduced to a half because of PQ interval prolongation. Magnesium is believed to be useful for anesthetic management for patients with pheochromocytoma, but the proper dose and the way of administration should be further investigated for their safe clinical use.

Adrenal Gland Neoplasms↗
PubMed1996

[A Japanese family with probably autosomal dominant adult-onset leukodystrophy].

We report here a family with leukodystrophy clinical features of which are characterized as adult onset, probably autosomal dominant inheritance, hyperreflexia, cerebellar ataxia, autonomic dysfunction and no peripheral nerve involvement. T2-weighted brain MRI revealed diffuse high signal areas in the cerebral white matter. The disorder in our subjects can be distinguished from most leukodystrophies in terms of genetic inheritance, clinical manifestations and laboratory data. Our family is quite similar to the kindred which Eldridge et al. described in 1984 as "hereditary adult-onset leukodystrophy simulating chronic progressive multiple sclerosis". Our family is the third report of this type of leukodystrophy and the first among non-Irish/Scottish family.

Age of Onset↗
PubMed1996

Effects of ethyl alcohol administration to THA rat dams during their gestation period on learning behavior and on levels of monoamines and metabolites in the brain of pups after birth.

Children born from chronic alcoholic mothers have shown behavioral teratogenic effects more frequently than morphological malformations. To investigate the possible mechanisms and evaluate maternal alcohol dosage levels to induce behavioral dysfunctions, we gave pregnant Tokai High Avoider (THA) rats 0, 5, 10, and 20% ethanol (EtOH) as drinking water during the gestation period. We evaluated the brain function of pups born of alcohol-administered dams. Sidman avoidance behavior test and the levels of monoamines (nor-adrenalin, dopamine, and serotonin) and metabolites (3, 4-dihydroxyphenyl acetic acid, homovanillic acid, and 5-hydroxyindole acetic acid) in whole brain were examined for neurobehavioral and neurochemical effects. EtOH-exposed THA offsprings showed high pre- and postnatal mortality, growth deficits, and brain weight reductions. Compared with the results of the same conditioning experiment using Wistar rats, the THA rat may have higher susceptibility to the effects of in utero EtOH exposure than Wistar rats. EtOH-exposed THA pups exhibited deficits in avoidance operant learning that were not shown in Wistar rats. We also observed the increased levels of all monoamines that were assumed to be related with the deficit of learning, the decreased levels of 3, 4-dihydroxyphenyl acetic acid and homovanillic acid, and the unchanged levels of 5-hydroxyindole acetic acid in pups from dams administered 10 and 20% EtOH. However, contrary alteration of monoamines and their metabolites were shown in pups from 5% EtOH-administered dams.

Animals↗
PubMed1996

Tyrosine phosphorylation of p130Cas in cell adhesion and transformation.

Integrins comprise the major class of receptors used by cells to interact with the extracellular matrix. Integrin/matrix interactions play a critical role in a variety of biological processes, including embryonic development, wound healing, tumor metastasis, cell growth and differentiation. It is now evident that integrins can transduce biochemical signals across the plasma membrane to the cell interior. Protein tyrosine phosphorylation has attracted much attention as an important regulator for integrin-mediated signal transduction. Recently, we have identified a novel signaling molecule, p130Cas, which participates in integrin-mediated signal transduction. p130Cas was originally identified as a protein hyperphosphorylated in cells expressing transforming gene products p47v-crk (v-Crk) and p60v-crk (v-Src). In this brief review, we will discuss about a role of p130Cas in signal transduction triggered by cell adhesion and transformation.

Cell Adhesion↗
PubMed1995

Stretching mesangial cells stimulates tyrosine phosphorylation of focal adhesion kinase pp125FAK.

Mechanical loading of cultured mesangial cells has been shown to induce both increased production of matrix proteins and cell proliferation. This in vitro phenomenon has been implicated in the progression of glomerular sclerosis observed in a variety of glomerular diseases. However, it is not yet known how cells sense mechanical stress and transfer this sense into biochemical and biological events. In this study, we show that mesangial stretching rapidly stimulates tyrosine phosphorylation of non-receptor tyrosine kinase pp125FAK. Since pp125FAK is a major constituent of focal adhesions, our findings suggest that the focal adhesion may be a site where mechanical forces are translated into biochemical events, and that pp125FAK may play an important role in this signaling cascade.

Animals↗
PubMed1995

Integrin-mediated cell adhesion promotes tyrosine phosphorylation of p130Cas, a Src homology 3-containing molecule having multiple Src homology 2-binding motifs.

p130Cas (Cas) has been recently identified as a 130-kDa protein that is highly phosphorylated on tyrosine residues and is stably associated with p47v-crk (v-Crk) and p60v-src (v-Src) oncogene products in cells transformed by the respective genes. Cas is a novel signaling molecule having a single Src homology (SH) 3 domain and a cluster of multiple SH2-binding motifs. While the tight association of Cas with v-Crk and v-Src is strongly suggestive of a significant role in regulating cellular transformation, the function of Cas in normal untransformed cells is totally unknown. We report here that cell adhesion to fibronectin rapidly promotes tyrosine phosphorylation of Cas in human and rat fibroblast cell lines. The response was equally induced by cell adhesion to plates coated with vitronectin, laminin, and collagen but not by cell attachment to nonspecific substrate poly-L-lysine. The kinetic profile of Cas phosphorylation was almost identical with that of tyrosine phosphorylation of focal adhesion kinase pp125FAK (Fak), which is well known to be activated subsequent to integrin-mediated cell adhesion. Adhesion-dependent Cas phosphorylation was completely inhibited by treating cells with cytochalasin D, an agent that disrupts polymerization of actin stress fibers. These results suggest that tyrosine phosphorylation of Cas is stimulated by normal cell adhesion in close association with Fak phosphorylation and the formation of actin stress fibers. In v-Src- or v-Crk-transformed cells, however, the tyrosine phosphorylation of Cas is markedly increased in an adhesion-independent manner that is insensitive to treatment with cytochalasin D. Thus, Cas plays a role in signaling pathways mediated by cell adhesion as well as by transformation. We propose that Cas may amplify and propagate integrin-mediated signals by interacting with SH2-containing molecule(s).

Animals↗
PubMed1995

Adrenoleukodystrophy: the restoration of peroxisomal beta-oxidation by transfection of normal cDNA.

In order to elucidate the function of ALDP [a protein encoded by the gene responsible for adrenoleukodystrophy (ALD)], normal ALDP cDNA, inserted in an expression vector driven by chicken beta-actin promotor, was transfected into ALD fibroblasts. In a transient expression system, the fatty acid composition did not change even though the ALDP was newly synthesized based on the findings of a western blot analysis. In a stable expression system, 3 cell lines were strongly positive for ALDP. In these cells the level of very long chain fatty acid (C26:0) turned out to be as low as those of the control, while the activities of C24 beta-oxidation, as checked by two different methods, became normal. From these results, it is concluded that ALDP is indispensable for the function of peroxisomal beta-oxidation, and thus the treatment of ALD may be possible by the supplementation of ALDP.

ATP Binding Cassette Transporter, Subfamily D, Mem↗
PubMed1995

Pituitary adenylate cyclase activating polypeptide (PACAP) stimulates growth hormone release from GH3 cells through type II PACAP receptor.

Effect of pituitary adenylate cyclase activating polypeptide (PACAP) on growth hormone (GH) release from GH3 cells was studied in a dynamic superfusion system. PACAP-38 and PACAP-27 stimulated GH release from superfused GH3 cells. The stimulatory effect of PACAP-38 was comparable to those of vasoactive intestinal polypeptide (VIP) and PACAP-27 at a concentration of 1 nM, but the duration of action was more prolonged in PACAP-38 than in the other two peptides. PACAP(6-38), a selective antagonist of PACAP, as well as a VIP antagonist blunted the GH release induced by PACAP-38 and VIP. An antagonist of GH-releasing factor (GRF) at a concentration of 1 microM, however, did not affect the GH release induced by PACAP-38. These findings suggest that PACAP and VIP stimulate GH release from GH3 cells through type II PACAP receptor but not through the GRF receptors.

Animals↗
PubMed1995

Molecular analysis of X-linked adrenoleukodystrophy patients.

A molecular analysis of 4 Japanese adrenoleukodystrophy (ALD) patients was carried out, according to the recently published report on ALD gene cDNA. In a Southern blot analysis, we were not able to detect a large deletion in all patients. In a Northern blot analysis, no mRNA was detected in one patient, while the others had normal mRNA in both size and amount. Three patients had missense mutations including; 534Pro-->Leu (1987C-->T), 660Arg-->Trp (2364C-->T), and 512Gly-->Ser (1920G-->A), respectively. These mutations existed in the C-terminal region conserved in the ATP-binding cassette superfamily of transporters. In a Western blot analysis using polyclonal antibodies against the C-terminal peptide as well as the whole peptide of ALD protein, no 80 kDa protein was found in any of the 4 patients, which was observed in the control cells. The ALD protein in 3 patients with a missense mutation might be degraded immediately after translation because of the unstable higher structure or by the disruption of the hitherto unknown targetting signal to the peroxisome. The molecular analysis of the ALD gene as done in this study is thus considered to be the first step to further elucidate the pathogenic mechanism of ALD.

Adrenoleukodystrophy↗
PubMed1995

Effect of continuous subcutaneous administration of a small dose of granulocyte colony stimulating factor (G-CSF) by the use of a portable infusion pump in patients with non-Hodgkin's lymphoma receiving chemotherapy.

The effects of continuous subcutaneous infusion (CSI) of human granulocyte-colony stimulating factor (G-CSF) on the absolute neutrophil count (ANC) and serum G-CSF level were examined in 11 patients with non-Hodgkin's lymphoma (NHL) during cytotoxic chemotherapy. Recombinant G-CSF (rG-CSF) was subcutaneously infused using a portable infusion pump at a constant flow rate of 1 microgram/20 microliters/h for 14 days starting 2 days after the end of the second course of chemotherapy. The ANC was lowered after the chemotherapy without rG-CSF infusion whereas the duration of neutropenia and the nadir level of the ANC after the chemotherapy were ameliorated by the combined administration of rG-CSF (mean +/- S.E., 0.6 +/- 0.5 days vs. 4.7 +/- 1.9 days, P < 0.05; 455 +/- 135/microliter vs. 1906 +/- 598/microliter, P < 0.05). Serum G-CSF levels increased after the start of rG-CSF infusion, reaching a mean peak value of 418.5 +/- 128.5 pg/ml at the 8th day, and then returned to the basal level (35.6 +/- 13.5 pg/ml) immediately after the end of continuous infusion of rG-CSF. Although a slight increase in serum G-CSF was obtained in the patients after the chemotherapy without rG-CSF administration, the mean serum level was much lower than that in the patients after the chemotherapy with rG-CSF administration (88.2 +/- 24.8 pg/ml vs. 199.6 +/- 20.6 pg/ml, P < 0.01). No notable side effects of the CSI of rG-CSF were noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Effects of sevoflurane on the middle latency auditory evoked response and the electroencephalographic power spectrum.

We investigated the effects of sevoflurane on the middle latency auditory evoked response (MLR) and the power spectrum of the electroencephalogram (EEG) in 10 elective surgical patients. The MLR and the EEG power spectrum were recorded with a surface electrode placed at the central (Cz) scalp location. End-tidal sevoflurane concentrations of 0%, 0.25%, 0.5%, 0.75%, 1.0%, and 1.5% in 50% nitrous oxide and oxygen were studied. The Na, Pa, and Nb components of the MLR increased in latency and decreased in amplitude in a dose-dependent manner at increasing concentrations of sevoflurane. The latencies for Na, Pa, and Nb increased in a linear fashion (correlation coefficients: r = 0.81, r = 0.81, and r = 0.89, respectively). The EEG delta power was dominant with increasing sevoflurane concentration, and was significantly increased at sevoflurane concentrations of 1.0%-1.5%. The beta power, median power frequency (MPF), and 95% spectral edge frequency (SEF) decreased significantly according to the increases by 0.5% sevoflurane. Regarding the changes evoked by 0.25% sevoflurane, the Nb latency of the MLR responded significantly under 0.75% of sevoflurane. At these low concentrations of sevoflurane, the MLR seemed to be more sensitive to changes in anesthetic concentration than the various EEG variables.

Anesthetics↗
PubMed1995

Preoperative evaluation for risk of venous air embolism in the sitting position.

We report a patient with meningioma and radiological findings of erosive bony change, who developed venous air embolism via the diploic vein in the eroded inner table of the skull during craniotomy in the sitting position. The findings in our case suggest that preoperative radiological imaging evaluation can increase an awareness of the possibility of venous air embolism.

Aged↗
PubMed1995

Do recently developed techniques for skull base surgery increase the risk of difficult airway management? Assessment of pseudoankylosis of the mandible following surgical manipulation of the temporalis muscle.

We report our experience with anesthetic care for six patients with pseudoankylosis of the mandible following neurosurgical procedures, four of whom required fiberoptically guided intubation for anesthesia. We suggest that the development of operative approaches and reconstruction techniques in skull base surgery may increase the risk of difficult airway due to limitation of mouth opening.

Adult↗
PubMed1995

Potassium secretion is inhibited by metabolic acidosis in rabbit cortical collecting ducts in vitro.

The role of metabolic acidosis in the regulation of transepithelial potassium transport was examined in rabbit cortical collecting ducts (CCD) using in vitro isolated tubular microperfusion and conventional microelectrode techniques. Basolateral metabolic acidosis, created by reduction of bicarbonate concentration from 25 to 5 meq/l, pH 7.40 to 6.80, depolarized the transepithelial voltage significantly (-6.5 +/- 1.0 to -2.7 +/- 1.3 mV). Basolateral acidosis also suppressed net potassium secretion (-14.3 +/- 2.1 to -9.0 +/- 1.7 pmol.min-1.mm-1). Electrophysiological study in CCD cells demonstrated that basolateral metabolic acidosis depolarized transepithelial voltage and apical and basolateral membrane voltage with an increase of transepithelial and fractional apical resistance. Basolateral acidosis did not affect the 22Na efflux nor 86Rb efflux. The inhibitory action of basolateral acidosis on net potassium secretion remained in the presence of luminal barium and in the absence of bicarbonate. Ouabain could not abolish the effect of basolateral acidosis on transepithelial voltage completely. These data lead us to conclude that basolateral acidosis affects multiple transport pathways, and it inhibits mainly apical barium-sensitive potassium transport. Additionally, it inhibits apical sodium conductance, barium-insensitive potassium transport, and stimulates a ouabain-insensitive electrogenic transport pathway to some degree.

Acidosis↗
PubMed1995

Effective treatment of drug-induced agranulocytosis using recombinant human granulocyte colony stimulating factor in pregnancy.

Drug-induced immune system mediated agranulocytosis is a rare but potentially life-threatening condition. There have been only a few reports on the drug-induced agranulocytosis during pregnancy. We present a case of agranulocytosis after prolonged intravenous infusion of ritodrine hydrochloride and additional administration of indomethacin suppositories, effectively treated using recombinant human granulocyte colony stimulating factor without any infection in a mother with twin-to-twin transfusion syndrome. Recombinant human granulocyte colony stimulating factor may have a potential use for drug-induced agranulocytosis during pregnancy.

Adult↗
PubMed1995

A case of Sheehan's syndrome associated with severe anemia and empty sella proved 48 years after postpartum hemorrhage.

A 68-year-old woman was admitted to our hospital for severe normochromic and normocytic anemia. She had a history of prolonged postpartum hemorrhage at the age of 20 yr. Her menses were resumed thereafter and she gave birth to two other children, but her lactation was poor. She had no subjective symptom until the age of 63 yr when she complained of weakness and cold intolerance. Laboratory examination at admission revealed severe anemia (Hb 7.2 g/dl) with relatively low serum erythropoietin (EPO 20.4 mIU/ml) and panhypopituitarism. Empty sella was also found by magnetic resonance imaging (MRI). Hb levels were corrected by replacement with levothyroxine (75 micrograms/day) and hydrocortisone (10 mg/day), which was accompanied by an increase in serum EPO levels. These findings indicate that this is a very rare case of Sheehan's syndrome with severe anemia and empty sella proved at the longest reported interval of 48 yr after the provoking delivery, and that serum EPO levels are increased by replacement with glucocorticoid and thyroxine in panhypopituitarism.

Anemia↗