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Biomedical subjects

Y Nishida

Publications and source records attributed to Y Nishida.

At least 361 records · Page 20Linked to original sources
PubMed1988

Effect of etizolam (Depas) on production of superoxide anion by platelet-activating factor and N-formyl-methionyl-leucyl-phenylalanine-stimulated guinea pig polymorphonuclear leukocytes.

Effect of etizolam on platelet activating factor (PAF) and N-formyl-methionyl-leucyl-phenylalanine (FMLP)-induced superoxide anion (O2-) production in guinea pig polymorphonuclear leukocytes (PMNL) was investigated. Etizolam showed the inhibitory effect on PAF-induced O2- production concentration dependently, with an IC50 value of 4.7 microM, but it had no inhibitory effect on FMLP-induced O2- production at 100 microM. These results suggest that etizolam has a selectively strong inhibitory effect on PAF-induced O2- production in guinea pig PMNL.

Animals↗
PubMed1988

[Painful ophthalmoplegia: the Tolosa-Hunt syndrome and orbital pseudotumor syndrome].

We experienced 9 patients with "painful ophthalmoplegia", which included 7 cases of the Tolosa-Hunt syndrome (2 males and 5 females, with ages ranging from 36 to 65 years) and 2 cases of the orbital pseudotumor syndrome (2 females aged 42 and 68). The diagnosis of these syndromes was based upon Hunt's criteria and the presence of the intraorbital mass on the brain CT scan. Main manifestations of both syndromes were periorbital pain and ipsilateral oculomotor nerve palsies. Out of 9 cases, 1 patient with Tolosa-Hunt syndrome and 1 patient with the orbital pseudotumor syndrome had bilateral retro-orbital pain and ophthalmoplegia. Pain preceded the ophthalmoplegia except in one patient with Tolosa-Hunt syndrome. Total paralysis of the extraocular muscles supplied by the oculomotor nerve was noted in all the nine patients, and mydriasis was observed on the affected side in 4 of 7 patients with Tolosa-Hunt syndrome and 2 patients with the orbital pseudotumor syndrome. Neurological involvement was not only the oculomotor nerve but also the other cranial nerves; the optic nerve (in 4 cases with Tolosa-Hunt syndrome and 2 cases with the orbital pseudotumor syndrome), the abducens nerve (in 3 cases with Tolosa-Hunt syndrome and 1 case with the orbital pseudotumor syndrome), and the first division of the trigeminal nerve (in 2 cases with Tolosa-Hunt syndrome). Six patients with Tolosa-Hunt syndrome and 2 patients with the orbital pseudotumor syndrome had palpebral edema. Visual disturbance and palpebral edema were severer in the patients with the orbital pseudotumor syndrome. After corticosteroid hormone was administered, there was diminution of the pain within 2 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones↗
PubMed1988

Induction of cytosolic aspartate aminotransferase by a high-protein diet.

Induction of cytosolic aspartate aminotransferase (glutamic oxaloacetic transaminase) was observed in rat liver on administration of a high-protein diet. The enzyme activity in the liver of rats given 60% and 80% protein diet increased to 1.8- and 1.9-fold that in the liver of rats maintained on 20% protein diet, with about 2-fold increases in the levels of functional sGOT mRNA, measured by in vitro translation. Whereas the activity of mitochondrial aspartate aminotransferase did not increase. Induction of cytosolic aspartate aminotransferase was also detected immunocytochemically.

Animals↗
PubMed1987

Differential inhibitory effects of auranofin on leukotriene B4 and leukotriene C4 formation by human polymorphonuclear leukocytes.

Auranofin (AF) is a newly introduced oral gold compound having antirheumatic properties, and its efficacy in the treatment of bronchial asthma is now under investigation. In this study, we examined the effects of AF on leukotriene (LT) formation by human polymorphonuclear leukocytes (PMNs) stimulated with the calcium ionophore A23187. AF inhibited LTC4 formation in a dose-dependent manner with an IC50 (concentration required to produce 50% inhibition of control) of 3.2 microM. In contrast, LTB4 formation was not prevented by AF at concentrations up to 6 microM, but it was reduced to 59 +/- 4% (mean +/- SE, N = 3) of control by an 8 microM concentration. As a next step, we explored the mechanisms of the differential inhibitory effects of AF using cell-free systems. When arachidonic acid (AA) and reduced glutathione (GSH) were used as substrates, AF inhibited LTC4 synthesis more effectively (IC50 = 14 microM) than LTB4 synthesis (IC50 = 100 microM). However, LTB4 and LTC4 syntheses from LTA4 were affected only slightly by AF within the concentrations tested (3-100 microM). These results in the cell-free systems indicate that the inhibition of LT formation was caused by a reduction of LTA4 synthesis and that the differential inhibitory effects can be ascribed to the higher Km value of glutathione S-transferase for LTA4 than that of LTA4 hydrolase in PMNs. In accordance with this hypothesis, LTC4 synthesis was more dependent than LTB4 synthesis on LTA4 concentrations within 25-100 microM, and AA-861, a 5-lipoxygenase inhibitor, caused similar differential inhibitory effects on the formation of LTs by intact PMNs. The inhibitory effect of AF on LT formation at physiological concentrations may play some role in the efficacy of this drug.

Animals↗
PubMed1987

Localization of myoglobin in human muscle cells by immunoelectron microscopy.

The localization of myoglobin in human skeletal muscle cell was studied by immunoelectron microscopy. The Fab'-horseradish peroxidase (HRP) conjugate was prepared by the maleimide method recently developed by Ishikawa et al. This method gave better recovery and less polymerization of HRP than the periodate method. By the direct immunoperoxidase method using this conjugate, myoglobin was shown to be localized in the I-band region of skeletal muscle cells. The outer membrane of mitochondria and triads stained intensely, but A-bands were not stained. Myonuclei and intermyofibrillar spaces were also not stained. The localization of myoglobin in the I-band implies its function in energy generation.

Histocytochemistry↗
PubMed1987

Suppression of human polymorphonuclear leukocyte phagocytosis by adenosine analogs.

The effects of adenosine analogs on human polymorphonuclear leukocyte (PMN) phagocytosis to latex beads or sheep red blood cells were investigated in an in vitro experiment. The purine compounds such as N6-phenylisopropyladenosine (PIA), 5'-N-ethylcarboxamido-adenosine (NECA), an A2 adenosine receptor agonist, and adenosine as high as 2 mM had no effect on PMN phagocytosis. In contrast, 2',5'-dideoxyadenosine (DDA), a P-site adenosine receptor agonist, and 5'-methylthioadenosine (MTA), a naturally occurring purine nucleoside, caused profound inhibition of phagocytic function of PMNs in a dose-dependent manner. Dipyridamole, which blocks purine nucleoside uptake, reversed the suppression due to MTA. Theophylline, an R-site receptor antagonists did not prevent the effect of MTA. These results suggested that phagocytosis of PMNs is suppressed by stimulation of the P-site adenosine receptors.

Adenosine↗
PubMed1987

Effect of pentobarbital anesthesia on renal sympathetic nerve activity in the rabbit.

The effects of pentobarbital (PB) anesthesia on arterial pressure, heart rate, and renal nerve activity (RNA) were studied in chronically instrumented intact rabbits and rabbits with sinoaortic baroreceptor denervation (SAD). In intact rabbits, PB caused an initial decrease in mean arterial pressure from 82 +/- 2 to 42 +/- 5 mm Hg, which then returned to the control level within 5 min. RNA increased by 144 +/- 19% in response to hypotension induced by PB then also returned to the control level within 5 min. Heart rate increased by 56 +/- 10 from 244 +/- 11 beats/min and remained elevated for 60 min. Sensitivities of baroreflex control of heart rate and RNA were markedly impaired by PB anesthesia. In SAD rabbits, PB caused hypotension (-46 +/- 5 mm Hg), which lasted for 15 min. RNA decreased initially by 80 +/- 5%, then gradually returned toward the control level. However, at 45 min after injection of PB, RNA was still depressed significantly. Tachycardia induced by PB was abolished by SAD, i.e. heart rate actually decreased by 53 +/- 10 beats/min. These results suggest that in intact rabbits steady-state effects of PB were: no change in mean arterial pressure or RNA, and tachycardia, all due to baroreflex compensation. However, in the absence of baroreflex compensation, PB elicited hypotension, bradycardia, and a decrease in RNA.

Anesthesia↗
PubMed1987

The longest-lived patient with homozygous familial hypercholesterolemia secondary to a defect in internalization of the LDL receptor.

The authors report the longest-lived patient with homozygous familial hypercholesterolemia, the seventh case of a defect in internalization of low-density lipoprotein (LDL). The patient is a 57-year-old man, whose plasma total cholesterol (TC) and LDL-cholesterol (LDL-C) concentrations were 465-660 mg/100 ml and 461 mg/100 ml, respectively, while his plasma high-density lipoprotein-cholesterol (HDL-C) was 13.6-16.9 mg/100 ml. He was the product of a consanguineous marriage, and his parents, brothers, and a sister had mild hypercholesterolemia. His coronary angiogram revealed diffuse coronary artery narrowing. Receptor studies revealed that his fibroblasts bound as much LDL as normal cells, but could not internalize or degrade LDL.

Apoproteins↗
PubMed1987

Cellular DNA rearrangements and early developmental arrest caused by DNA insertion in transgenic mouse embryos.

Insertional mutagenesis was investigated in a transgenic mouse strain (HUGH/4) derived from a fertilized egg injected with plasmid DNA containing the human growth hormone gene. Lethality occurred in homozygous embryos and was traced to the egg cylinder stage on days 4 to 5 of gestation, shortly after implantation. The mutation is on chromosome 12 and is distinct in location and integration pattern from another mutation also leading to lethality of homozygotes in the egg cylinder stage. Based on this and other evidence, relatively many genes may be recruited to activity near the time of implantation and may therefore present a large target of vulnerability to mutagenesis. The single insert in HUGH/4, consisting of approximately three tandem copies of plasmid sequences, is flanked by mouse cellular sequences that have undergone rearrangements, including a probable deletion. The data suggest the hypothesis that DNA rearrangements, which appear to be commonplace in transgenic mice, may arise because the initial insertional complex is unstable; stepwise changes may then be generated until a more stable conformation is achieved.

Animals↗
PubMed1987

Lack of neural control of atrial natriuretic peptide release in conscious dogs.

To determine whether or not cardiac nerves control the release of atrial natriuretic polypeptide (ANP), we examined the effects of intrapericardial cardiac denervation on circulating ANP in conscious dogs. Base-line level of circulating ANP in six cardiac-denervated (CD) dogs (191 +/- 24 pg/ml) was not significantly different from that in seven intact (INT) dogs (196 +/- 18 pg/ml). Three percent dextran-40 in saline (18 ml/kg, 20% of estimated blood volume) was infused over 5 min, and the elevated left atrial pressure (LAP; approximately 8 mmHg) was maintained by supplemental infusion over 40 min. The increase in circulating ANP after infusion in the CD dogs (462 +/- 61 pg/ml) was not significantly different from that in the INT dogs (435 +/- 73 pg/ml). The regression line relating circulating ANP (normalized with regard to the control value) with the change in LAP in the INT dogs was not significantly different from that in the CD dogs. These results suggest that the cardiac nerves do not control the tonic release of ANP or the volume expansion-induced release of ANP.

Animals↗
PubMed1987

Focal fatty change of the liver adjacent to the falciform ligament: CT and sonographic findings in five surgically confirmed cases.

Five cases of surgically confirmed focal fatty infiltration of the liver were detected by CT and sonography. In all five cases, the abnormality was located at the anterolateral edge of the medial segment of the liver. It was seen as a small area of low attenuation adjacent to the falciform ligament on CT and as an echogenic area next to the ligamentum teres on sonography. Dynamic CT performed during infusion of contrast medium via the superior mesenteric artery (arterial portography) showed portal blood flow within the lesion and was useful for excluding the presence of a hepatic tumor. Focal fatty infiltration of the liver adjacent to the falciform ligament constitutes a diagnostic pitfall on CT and sonography.

Fatty Liver↗