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Y Inoue

Publications and source records attributed to Y Inoue.

At least 1,171 records · Page 65Linked to original sources
PubMed1993

Na(+)-dependent glutamine transport in the liver of tumour-bearing rats.

In rats with advanced malignant disease, the liver extracted circulating glutamine at a ratio three times faster than the liver of control non-tumour-bearing animals. This augmented uptake occurred in spite of a fall in circulating glutamine levels, implying an increase in hepatocyte plasma membrane transport. Na(+)-dependent glutamine transport activity (System N) was increased nearly two-fold in hepatocyte plasma membrane vesicles from tumour-bearing rats; this increase in System N activity was proportional to tumour size and was due to an increase in carrier Vmax with no change in carrier affinity. Measurement of System N activity in isolated hepatocytes incubated with serum from tumour-bearing rats demonstrated a significant increase in glutamine transport compared with cells incubated with serum from control rats. These data indicate that the liver of rats with advanced malignant disease displays accelerated glutamine consumption. This increased uptake is due, in part, to enhanced carrier-mediated transport activity, and is mediated by a circulating factor(s) that is not present (or inactive) in non-tumour-bearing controls.

Animals↗
PubMed1993

Monoclonal antibody specific to alpha-2-->3-linked deaminated neuraminyl beta-galactosyl sequence.

Fusion of spleen cells from a BALB/c mouse immunized with KDN alpha 2-->3Gal beta 1-->4Glc beta 1-->1Cer ((KDN)GM3) with P3-X63 Ag8.U1 (P3U1) mouse myeloma cells yielded a hybrid cell line that produced monoclonal antibody that bound to (KDN)GM3, but not to Neu5Ac alpha 2-->3Gal beta 1-->4Glc-beta 1-->1Cer ((Neu5Ac)GM3). The specificity of the monoclonal antibody was determined chiefly by the enzyme-linked immunosorbent assay procedure. This antibody was found to react most strongly with (KDN)GM3 and less strongly with a glycoprotein containing a number of KDN alpha 2-->3Gal beta 1-->3-GalNAc alpha 1-->3[8KDN alpha 2-->)n-->6]GalNAc alpha 1-->chains (< n > av = approximately 3). The results indicated that the monoclonal antibody (designated mAb.kdn3G) specifically and effectively recognized a disaccharide structure, KDN alpha 2-->3Gal beta 1-->, and specifically discriminated (KDN)GM3 from (Neu5Ac)GM3. The mAb.kdn3G was used to localize (KDN)GM3 in rainbow trout sperm by the indirect immunofluorescence procedure and the antigen was shown to be mostly, if not completely, associated with the external surface of the entire plasma membrane of rainbow trout sperm. The potential utility of mAb.kdn3G is addressed in searching for KDN-glycoconjugates which contain glycan units having the KDN alpha 2-->3Gal beta 1-->epitope structure.

Animals↗
PubMed1993

Effect of total parenteral nutrition on amino acid and glucose transport by the human small intestine.

OBJECTIVE: The effect of total parenteral nutrition (TPN) on small intestinal amino acid transport activity was studied in humans. SUMMARY BACKGROUND DATA: Studies in humans receiving TPN indicate that a decrease in the activities of the dissacharidase enzymes occurs, but morphologic changes are minimal with only a slight decrease in villous height. METHODS: Surgical patients were randomized to receive TPN (n = 6) or a regular oral diet (controls, n = 7) for 1 week before abdominal surgery. Ileum (5 controls, 5 TPN) or jejunum (2 controls, 1 TPN) were obtained intraoperatively and brush-border membrane vesicles (BBMV) were prepared by magnesium aggregation/differential centrifugation. Transport of L-MeAlB (a selective system A substrate), L-glutamine, L-alanine, L-arginine, L-leucine, and D-glucose was assayed by a rapid mixing/filtration technique in the presence and absence of sodium. RESULTS: Vesicles demonstrated approximately 18-fold enrichments of enzyme markers, classic overshoots, transport into an osmotically active space, and similar 1-hour equilibrium values. TPN resulted in a 26-44% decrease in the carrier-mediated transport velocity of all substrates except glutamine across ileal BBMVs. In the one patient receiving TPN from whom jejunum was obtained, there was also a generalized decrease in nutrient transport, although glutamine was least affected. Kinetic studies of the system A transporter demonstrated that the decrease in uptake was secondary to a reduction in carrier Vmax, consistent with a decrease in the number of functional carriers in the brush-border membrane. CONCLUSIONS: TPN results in a decrease in brush-border amino acid and glucose transport activity. The observation that glutamine transport is not downregulated by 1 week of bowel rest may further emphasize the important metabolic role that glutamine plays as a gut fuel and in the body's response to catabolic stresses.

Adult↗
PubMed1993

Arginine transport in human liver. Characterization and effects of nitric oxide synthase inhibitors.

OBJECTIVE: Arginine transport was characterized and studied in human liver. SUMMARY BACKGROUND DATA: Plasma arginine uptake may regulate hepatocyte intracellular availability and the subsequent biosynthesis of nitric oxide (NO), but little is known about arginine transport across the human hepatocyte plasma membrane. METHODS: The authors characterized plasma membrane transport of 3[H]-L-arginine in hepatic plasma membrane vesicles (HPMVs) and in hepatocytes isolated and cultured from human liver biopsy specimens. They also studied the effects of the NO synthase inhibitors omega-nitro-L-arginine methyl ester (L-NAME) and N-methyl-arginine (NMA) on arginine transport in HPMVs and in cultured cells. RESULTS: Arginine transport was saturable, Na(+)-independent, temperature and pH sensitive, and was inhibited by the naturally occurring amino acids lysine, homoarginine, and ornithine (System y+ substrates). Arginine transport by both vesicles and cultured hepatocytes was significantly attenuated by NO synthase inhibitors, suggesting that the arginine transporter and the NO synthase enzyme may share a structurally similar arginine binding site. Dixon plot analysis showed the blockade to occur by competitive, rather than noncompetitive, inhibition. In vivo treatment of rats with lipopolysaccharide (LPS) resulted in a twofold stimulation of saturable arginine transport in the liver. This LPS-induced hepatic arginine transport activity was also inhibited by L-NAME. These data indicate that arginine transport by human hepatocytes is mediated primarily by the Na(+)-independent transport System y+. CONCLUSIONS: Besides inhibition of the NO synthase enzyme, the ability of arginine derivatives to block NO production may also be due to their ability to competitively inhibit arginine transport across the hepatocyte plasma membrane. The use of selective arginine derivatives that compete with arginine at the plasma membrane level may be a metabolic strategy that can be used to modulate the septic response.

Adult↗
PubMed1993

Growth hormone attenuates Na(+)-dependent hepatic amino acid transport in endotoxemic rats.

The effects of human growth hormone (GH) on hepatic Na(+)-dependent amino acid transport were studied in endotoxin-treated rats. Adult rats received GH (6 mg/kg BW subQ q 12 hours x 4 doses) or vehicle prior to a single dose of Escherichia coli endotoxin (LPS, 7.5 mg/kg BW IP). Four hours after LPS administration, livers were excised and hepatocyte plasma membrane vesicles (HPMVs) were prepared by differential and Percoll density gradient centrifugation. Hepatocyte plasma membrane vesicle transport of [3H]-MeAIB, a highly selective system A substrate, [3H]-glutamine, a selective system N substrate, and [35S]-cysteine, a system ASC substrate, were measured by a rapid mixing/filtration technique. Vesicle purity and functionality were assessed by marker enzyme measurements and classic overshoots and timecourses that showed similar vesicle size. Endotoxin treatment resulted in a two-fold increase in the activities of systems N and ASC, which was the result of an increase in carrier Vmax (Km was unchanged), and a four-fold stimulation of system A. Pre-treatment with GH diminished the endotoxin-induced increase in Na(+)-dependent amino acid transport by 60%-80%; this reduction in carrier-mediated transport activity was a result of a decrease in Vmax, consistent with a decrease in the number of functional transporter proteins in the plasma membrane. Growth hormone treatment attenuates the endotoxin-induced increase in the activities of the major Na(+)-dependent transporters in rat liver. This may diminish hepatic ureagenesis and spare amino acids for peripheral protein synthesis and thereby explain, at least in part, the ability of growth hormone to promote positive nitrogen balance in catabolic states.

Amino Acids↗
PubMed1993

Multifunctional effects of anticomplementary agent K-76 on carrageenan-induced colitis in the rabbit.

In this study the effect of K-76, a sesquiterpene compound with anticomplementary activity isolated from a fungus culture, on carrageenan-induced colitis was studied from biochemical, histological and immunohistopathological aspects. K-76 suppressed epithelial cell loss, crypt abscess formation, inflammatory cell infiltration, mucosal atrophy, and ulceration. Immunohistochemical examination of the colonic mucosa showed that the number of IgG- and IgM-positive plasma cells and the staining intensity for IgG and C3 were increased in carrageenan-induced colitis, but these changes were inhibited by K-76. Besides, serum mucoprotein concentrations and CH50 levels were lower in the animals treated with carrageenan alone. K-76 exerted multifunctional activity, although its mechanisms of action remain obscure.

Animals↗
PubMed1993

Localizing value of seizure manifestations of temporal lobe epilepsies and the consequence of analyzing their sequential appearance.

We investigated the localizing and lateralizing value of principal seizure manifestations in temporal lobe epilepsies (signal symptoms, oroalimentary automatisms, somatomotor manifestations, unilateral dystonic posturing, ictal speech, motionless stare) of 223 complex partial seizures in 50 patients. All the patients had invasive long-term monitoring with the combined implantation of intracerebral electrodes in and subdural electrodes on the bilateral temporal lobes. Postoperative freedom from seizures was ascertained for longer than one year. We found that 35 patients had amygdalohippocampal seizures and 15 had lateral temporal seizures. The value of the manifestations was established in relation to the site and side of seizure origin and to the progression of seizure discharges within the unilateral temporal lobe or to the contralateral cerebral hemisphere. Several signs among the manifestations were found to be reliable in predicting the site or side of the temporal lobe seizure focus. We emphasized the importance of investigating sequential changes of seizure manifestations in relation to ictal EEG findings by means of simultaneous recording.

Amygdala↗
PubMed1993

Inhibition by omega-conotoxin GVIA of the chronotropic responses to sympathetic and parasympathetic nerve stimulation in the isolated, blood-perfused atrium of the dog.

1. We investigated the effects of omega-conotoxin GVIA (omega-CgTX), a blocker of N-type voltage-operated calcium channels, on the chronotropic response to stimulation of the intracardiac sympathetic and parasympathetic nerves in the isolated, blood-perfused right atrium of the dog. 2. omega-CgTX (0.3-3 nmol) itself did not affect the sinus rate significantly, but it inhibited the negative followed by positive chronotropic response to simultaneous stimulation of sympathetic and parasympathetic nerves in a dose-dependent manner. 3. omega-CgTX at higher doses (1-3 nmol) inhibited the positive response to sympathetic stimulation more strongly than the negative response to parasympathetic stimulation. omega-CgTX (3 nmol) abolished the positive chronotropic response to sympathetic nerve stimulation in the atrium treated with atropine, but did not abolish the negative response to selective parasympathetic stimulation. Neither the chronotropic response to noradrenaline nor the response to acetylcholine was affected by omega-CgTX. 4. These results indicate that omega-CgTX inhibits not only the response to sympathetic stimulation but also the response to parasympathetic stimulation in the dog heart and it inhibits the positive chronotropic response to sympathetic stimulation more strongly than the negative chronotropic response to parasympathetic stimulation.

Acetylcholine↗
PubMed1993

Abnormal responses of common variable immunodeficiency patients' B cells to Staphylococcus aureus Cowan I and interleukin-2.

Responses of common variable immunodeficiency patients' B cells to Staphylococcus aureus Cowan I (SAC) and recombinant interleukin-2 (rIL-2) varied in our study. T-cell function and IL-2 production were normal, and intrinsic B-cell defects were suggested. Some patients showed no increase in expression of IL-2 receptors on B cells with SAC stimulation, which may be due to impaired maturation stages. Two patients showed an increased level of B cells with IL-2 receptors, suggesting blocked development of intracellular mechanisms. One patient may have a defect in immunoglobulin isotype switching.

Adult↗
PubMed1993

Normal tension glaucoma: the value of predictive tests.

Fifty-four normal tension glaucoma cases were studied to determine the value of several clinical tests for predicting the progression of the disease. Outflow facility, intraocular pressure (IOP) increase after water drinking, and diurnal changes in IOP were studied. Progression was determined on the basis of changes in visual sensitivity as measured on the Octopus 201. A minimum of four examinations of the central 30 degrees were conducted over a 3- to 7-year period. Progression of visual field defects was seen in 38.5% of eyes that had demonstrated some degree of abnormality in at least one of three clinical tests, while only 10.7% of those eyes that appeared normal on the basis of these tests showed such progression. The difference was significant (p < 0.04). These results suggest that the three clinical tests may be of value in detecting normal tension glaucoma eyes at risk for progression of visual field defects.

Adult↗
PubMed1993

[A study of respiratory infection and sepsis caused by MRSA at Hokusho Central Hospital].

At Hokusho Central Hospital, we studied the isolation rate of methicillin-resistant Staphylococcus aureus (MRSA) from 1985 to 1989; respiratory infection with MRSA, in 1989; and sepsis of MRSA, from 1988 to 1989. The isolation rate of MRSA from sputum increased from 0% in 1985 to 65.4% in 1989. MRSA was isolated mainly from elderly patients in a geriatric ward, with 55 of 67 strains (82%) being isolated from these patients in 1989. MIC80 of isolated MRSA strains was 0.01 microgram/ml to rifampicin, 0.02 microgram/ml to mynomycine, 3.13 micrograms/ml to vancomycin, 12.5 micrograms/ml to ofloxacin and 100 micrograms/ml to imipenem in 1989. One-third of the 60 isolated cases showed respiratory infections including 10 cases of pneumonia and 10 sepsis patients and 11 blood samples in 1988 and 1989, especially 92.9% of S. aureus isolated in 1989 was MRSA. Four of the 6 patients with respiratory infections of MRSA and 1 of the 3 patients with MRSA sepsis were treated successfully by a combination therapy of imipenem/cilastatin and cefazolin.

Aged↗
PubMed1993

[A case of Campylobacter fetus subspecies fetus meningitis].

A 40-year-old male with no history of underlying disease was admitted to Hokusho Central Hospital on May 25, 1991, complaining of high fever and headache. Physical examination on admission revealed a temperature of 38.5 degrees C, a pulse rate of 84 beat/min (relative bradycardia) and no abnormal findings for the chest or abdomen. Slight neck stiffness without Kernig's sign was observed at neurological examination. Laboratory data were: ESR 11 mm/lh, WBC 12000/mm3, C-reactive protein positive. Lumbar puncture showed an initial pressure of 230 mmH2O; CSF revealed a cell count of 2633/3 mm3 with mononuclear pleocytosis, total protein of 76 mg/dl and sugar of 54 mg/dl (CSF:blood glucose ratio 0.47). We initially suspected tuberculous or cryptococcal meningitis, but Campylobacter fetus subsp. fetus (C. fetus) was isolated from the CSF and venous blood on the 27th hospital day. IPM/CS 1 g/day, MINO 200 mg/day and FOM 4 g/day were intravenously administered. This antibiotic therapy was very effective: the patient was soon afebrile, and gradually all signs and symptoms were resolved. C. fetus was sensitive to IMP/CS, MINO, KM, GM, EM, OFLX, CP. The patient was discharged with no complication. He has eaten raw beef frequently before admission, but stool culture for C. fetus was negative.

Adult↗
PubMed1993

Aortic regurgitation: quantitation with MR imaging velocity mapping.

Aortic regurgitation (AR) in five healthy volunteers and 26 patients (mean age, 60.3 years; range, 25-83 years) was quantitatively measured with magnetic resonance (MR) imaging velocity mapping. Cine transverse images of the ascending aorta (32 phases per cardiac cycle) were acquired by using a gradient-echo sequence with a velocity-encoding bipolar pulse applied in the section-selection direction with a 1.5-T MR imaging unit. The aortic flow was calculated by integrating the product of area and mean velocity of the ascending aorta at each phase over a cardiac cycle. The negative and positive velocity values indicated antegrade and regurgitant flow, respectively, which allowed calculation of forward and regurgitant flow. Inter- and intraobserver variation of regurgitant fraction (RF) measurement was small (r = .956, standard error of the estimate [SEE] = 1.2%, n = 31; and r = .998, SEE = 0.35%, n = 10, respectively). RF determined with MR imaging agreed well with Doppler echocardiographic (n = 26) and aortographic (n = 9) grading of AR. Reproducible, quantitative, and noninvasive measurement of AR is possible with MR velocity mapping.

Adult↗
PubMed1993

Characterization of Na(+)-independent glutamine transport in rat liver.

In hepatic plasma membrane vesicles (HPMVs) from rat liver, we observed that approximately 40-45% of Na(+)-independent glutamine uptake occurs by a saturable carrier-mediated process. This component of glutamine uptake is mediated by a transport agency distinct from that of previously described systems for the Na(+)-independent transport of amino acids. Transport of glutamine was electroneutral and occurred into an osmotically active space with negligible membrane binding. The model system L substrate 2-amino-2-norbornane-carboxylic acid (BCH) showed no appreciable inhibition of Na(+)-independent glutamine uptake by HPMVs but effectively inhibited the uptake of leucine, a classic system L substrate, in identical vesicle preparations. Further evidence against system L-mediated glutamine transport was provided by the pH dependence and the lack of trans-stimulation of saturable uptake. Competition experiments with selected amino acids revealed a pattern of inhibition of glutamine transport that was inconsistent with assignment of glutamine entry to systems asc, T, or systems for the Na(+)-independent transport of the charged amino acids. This BCH-noninhibitable transport system in HPMVs was highly selective for glutamine, histidine, and, to a lesser extent, asparagine. Inhibition of Na(+)-independent glutamine transport by leucine was noncompetitive in nature. On the basis of Na+ independence, pH sensitivity, absence of trans-stimulation, and an amino acid selectivity similar to that of the previously described hepatic Na(+)-dependent system N, we have provisionally designated the glutamine transport agency described in this article as system "n."

Amino Acids↗