Search PubMed⌕ Search

Biomedical subjects

M Yoshino

Publications and source records attributed to M Yoshino.

At least 37 records · Page 2Linked to original sources
PubMed2001

Functional annotation of a full-length mouse cDNA collection.

The RIKEN Mouse Gene Encyclopaedia Project, a systematic approach to determining the full coding potential of the mouse genome, involves collection and sequencing of full-length complementary DNAs and physical mapping of the corresponding genes to the mouse genome. We organized an international functional annotation meeting (FANTOM) to annotate the first 21,076 cDNAs to be analysed in this project. Here we describe the first RIKEN clone collection, which is one of the largest described for any organism. Analysis of these cDNAs extends known gene families and identifies new ones.

Animals↗
PubMed2001

Visualization of blood flow in hepatic vessels and hepatocellular carcinoma using B-flow sonography.

PURPOSE: A B-flow sonographic technique was recently developed to provide direct visualization of blood flow with gray-scale sonography. Compared with color Doppler sonography, B-flow imaging has wideband resolution and a high frame rate. The purpose of this study was to evaluate the usefulness of B-flow sonography for visualizing blood flow in hepatic vessels and tumor vascularity in patients with liver cirrhosis or hepatocellular carcinoma (HCC). METHODS: Twenty-five patients with liver cirrhosis, including 15 with HCC, were studied by B-flow and color Doppler sonography. Blood-flow detection rates in portal veins and hepatic arteries and tumor vascularity in HCC were analyzed, and the 2 methods were compared. RESULTS: Using B-flow, blood flow was visualized in the portal vein in 23 (92%) of 25 patients and was visualized in the hepatic artery separately from the portal vein in 9 (36%) of 25 patients. The blood-flow signals were visualized only within vessels, never "bleeding" outside the vessel's lumen. Blood flow in the portal vein was observed with color Doppler sonography in all 25 patients, but the hepatic artery was never clearly separated from the portal vein. Vascularity within the HCC tumor was detected in 9 (60%) of 15 nodules with B-flow imaging, and fine arteries flowing into the tumor were observed in 6 nodules. Color Doppler sonography detected blood flow in 13 (87%) of the 15 HCC nodules. CONCLUSIONS: Blood flow in hepatic vessels and tumor vessels of HCC were visualized with B-flow sonography. B-flow sonography is a potentially useful technique for the evaluation of liver vascularity and intratumoral vessels.

Aged↗
PubMed2001

A Na+-dependent electrogenic glutamate transporter current in voltage-clamped cells of corpora allata in the cricket Gryllus bimaculatus.

Application of L-glutamate (1 mM) to corpora allata cells of the adult male cricket Gryllus bimaculatus caused a membrane depolarization of 5.9+/-0.3 mV (mean +/- SE) from a resting potential of -62.2+/-1.3 mV (n=57). The underlying mechanism for this depolarization was studied by applying the two-electrode voltage-clamp technique. Application of L-glutamate (1 mM) elicited an inward current that peaked at 8.1+/-0.7 nA (n = 73) at a holding potential of-50 mV. Both L- and D-aspartate also induced an inward current of almost the same amplitude as L-glutamate, whereas D-glutamate failed to induce an inward current. Glutamate receptor agonists, such as kainate, quisqualate, alpha-amino-3-hydroxy-5-methyl isoxazole-4-propionic acid, and N-methyl-D-aspartate, were ineffective in eliciting inward currents. The glutamate-induced inward current did not reverse even when the holding potential was set to +40 mV. The replacement of extracellular Na+ with choline+ eliminated the inward current. These results strongly suggest that the current induced by glutamate is mediated by a glutamate transporter rather than a glutamate receptor. We further examined the effects of 12 amino acid analogs which are known to be selective inhibitors of the mammalian excitatory amino acid transporters (EAATs) on the corpora allata transporter. From the effects of these inhibitors, we conclude that the glutamate transporter expressed in corpora allata cells of the cricket is similar to the high affinity glutamate transporters cloned from human brain, especially EAAT1 and EAAT3. Unlike mammalian transporters, however, serine-O-sulfate has the most potent action, suggesting the unique feature of the glutamate transporter expressed in the corpora allata.

ATP-Binding Cassette Transporters↗
PubMed2001

Single K+ channels in endocrine cells dispersed from the cricket (Gryllus bimaculatus) corpora allata.

Single channel currents were recorded from cell-attached patches of endocrine cells of the adult male cricket corpora allata. Three distinct types of K+ channels were identified; a weak inward rectifier (Type 1), a strong inward rectifier (Type 2) and a weak outward rectifier (Type 3). The type 1 channel had a slope conductance of 191 +/- 9 pS (n = 4) at negative membrane potentials (Vm) and 101 +/- 6 pS (n = 6) at positive Vm. In addition, the channel showed fast open-closed kinetics at negative Vm and slow open-closed kinetics at positive Vm. The open probability (Po) of this channel was strongly voltage-dependent at positive Vm, but less voltage-dependent at negative Vm. The reversal potential was not modified significantly by the substitution of gluconate for external Cl- but was modified after N-methyl-D-glucamine (NMDG+) was substituted for external K+, according to the Nernst equation for a K+-selective channel. The type 2 channel had a slope conductance of 44 +/- 2 pS (n = 5) at negative Vm, but no detectable outward current was observed at positive Vm. This channel showed very slow open-closed kinetics at negative Vm and its Po was not voltage-dependent. The type 3 channel had a limit conductance of 55 +/- 12 pS (n = 3) at negative Vm and 88 +/- 10 pS (n = 3) at positive Vm. This channel showed slow open-closed kinetics at negative Vm and fast open-closed kinetics at positive Vm. The Po for the channel was voltage-dependent at positive Vm but was voltage-independent at negative Vm. These three types of K+ channels may be important for the control of the resting membrane potential, and may thus participate in the regulation of Ca2+ influx and juvenile hormone secretion in corpora allata cells.

Animals↗
PubMed2001

Combination radiotherapy for hepatocellular carcinoma with intraductal tumor thrombus: a case report.

We report the successful treatment of hepatocellular carcinoma (HCC) associated with an intraductal tumor thrombus in a 67-year-old male. Abdominal ultrasonography (US) and computed tomography (CT) revealed intrahepatic biliary dilatation in the left hepatic lobe and an intraductal tumor thrombus. The main tumor lesion was not clearly visualized on abdominal US, dynamic CT, and hepatic angiography. We biopsied the intraductal tumor thrombus under US guidance. Histologically the biopsy specimen was a poorly differentiated HCC We thus diagnosed HCC with intraductal tumor thrombus. The total serum bilirubin level gradually rose to 3.1 mg/dl. This tumor was inoperable because of severe hepatic dysfunction. We chose to treat the patient with radiotherapy aimed only at the intraductal tumor thrombus because the main tumor was unclear. A percutaneous transhepatic biliary drainage (PTBD) tube was inserted into the common bile duct beyond the tumor thrombus and the tube was dilated. Once total serum bilirubin had reached the normal range, a combination of external beam radiation therapy (EBRT) plus an intraluminal brachytherapy, 192Ir boost was administered. The intraductal tumor thrombus was found to have vanished and the PTBD tube was removed. After this treatment, transcatheter hepatic arterial embolization was performed at the point of tumor appearance. This patient had a relatively long survival, approximately 30 months, with no clinical evidence of recurrent disease and biliary drainage was not necessary.

Aged↗
PubMed2001

Aluminum-induced apoptosis in PC12D cells.

The addition of aluminum-maltol complex to PC12D cells induced a time-dependent and concentration-dependent growth inhibition as well as cell death, whereas aluminum chloride or maltol alone did not affect the viability of PC12D cells. Apoptosis of differentiated PC12D cells was assessed by using terminal deoxynucleotidyltransferase-mediated 2'-deoxyuridine-5'-triphosphate nick end labeling (TUNEL) technique to detect DNA strand breaks in situ. The number of TUNEL-positive cells treated with aluminum-maltol increased with time in the treatment cultures. The ability of aluminum ion to elevate intracellular reactive oxygen species was determined by fluorescence in PC12D cells loaded with the oxidant-sensitive dye 2',7'-dichlorofluorescin diacetate. Aluminum ion incorporated to PC 12D cells causes apoptotic cell death by enhancing the generation of reactive oxygen species.

Aluminum↗
PubMed2001

Duodenal tuberculosis with a choledocho-duodenal fistula.

A 22-year-old man visited our hospital (National Cancer Center Hospital East) complaining of fatigue and anorexia. A laboratory investigation demonstrated a biochemical 'picture' of obstructive jaundice. An abdominal CT showed a low density mass in the retropancreatic area with multiple enlarged periportal lymph nodes. Upper gastrointestinal endoscopy revealed active ulceration on the dorsal wall of the descending part of the duodenum, and histopathology of the biopsy specimen revealed an ulcer with reactive inflammatory cell infiltration; no tumor cells were detected. The possibility of neoplasm had been ruled out by the use of CT and angiography. The jaundice recovered spontaneously and the abdominal mass gradually decreased in size. Endoscopic retrograde pancreatography showed no evidence of pancreatic disease; however, endoscopic retrograde cholangiography showed a choledocho-duodenal fistula. This patient showed hypersensitivity against the tuberculin skin test and Mycobacterium tuberculosis was successfully detected in gastric juice by using a polymerase chain reaction method and culture. Biopsy samples obtained from the duodenal ulcer at the second upper gastrointestinal endoscopy showed chronic inflammation with an epithelioid granuloma, suggesting tuberculosis. We thus diagnosed this case as a duodenal tuberculosis with a choledocho-duodenal fistula. To the best of our knowledge, there has been no report available of duodenal tuberculosis being the cause of a choledocho-duodenal fistula.

Adult↗
PubMed2001

Design and evaluation of a single-pivot supported centrifugal blood pump.

In order to develop a centrifugal blood pump that meets the requirements of a long-term, implantable circulatory support device, in this study a single-pivot bearing supported centrifugal blood pump was designed to evaluate its basic performance. The single-pivot structure consisted of a ceramic ball male pivot mounted on the bottom surface of the impeller and a polyethylene female pivot incorporated in the bottom pump casing. The follower magnet mounted inside the impeller was magnetically coupled to the driver magnet mounted on the shaft of the direct current brushless motor. As the motor rotated, the impeller rotated supported entirely by a single-pivot bearing system. The static pump performance obtained in the mock circulatory loop revealed an acceptable performance as a left ventricular assist device in terms of flow and head pressure. The pump flow of 5 L/min against the head pressure of 100 mm Hg was obtained at rotational speeds of 2,000 to 2,200 rpm. The maximum pump flow was 9 L/min with 2,200 rpm. The maximum electrical-to-hydraulic power conversion efficiency was around 14% at pump flows of 4 to 5 L/min. The stability of the impeller was demonstrated at the pump rpm higher than 1,400 with a single-pivot bearing without an additional support at its top. The single-pivot supported centrifugal pump can provide adequate flow and pressure as a ventricular assist device, but its mechanical stability and hemolytic as well as thrombotic performances must be tested prior to clinical use.

Equipment Design↗
PubMed2001

Skin antigens in the steady state are trafficked to regional lymph nodes by transforming growth factor-beta1-dependent cells.

Antigen capturing in the skin and antigen trafficking into regional lymph nodes (LN) initiate immune responses. In this study, employing melanin granule (MG) as an easily traceable antigen in two mouse strains that carried steel factor or hepatocyte growth factor transgenes and had melanocytosis in the epidermis or in the dermis respectively, we investigated the mechanism of antigen trafficking from the skin. MG captured in the epidermis or dermis accumulated in the regional LN, but not other tissues. Only in alymphoplastic mice did MG-laden cells pass through the lymphatics and reached many tissues. Since inflammatory regions were not observed in the skin of either type of transgenic mouse, our developmental system enables us to investigate constitutive capturing and trafficking of insoluble antigens in the steady state. Both dendritic cells and macrophages were laden with MG in the regional LN. To determine which cells traffic antigens to the LN, we prepared double mutants that carried the transgenes and lacked transforming growth factor (TGF)-beta1, since mice lacking TGF-beta1 are reported to be deficient of Langerhans cells. Few MG were observed in the regional LN of these double-mutant mice. We also showed that signaling via macrophage colony stimulating factor receptor or Flt3/Flk2 is not essential for development of the cells for this antigen trafficking. These results indicate that antigens in the epidermis and dermis in the steady state are trafficked into regional LN only by TGF-beta1-dependent cells, which may be a dendritic cell lineage.

Animals↗
PubMed2001

Cloning and functional expression of an E box-binding protein from rat granulosa cells.

Ovarian granulosa cells undergo cell growth and cytodifferentiation during follicular maturation. In a number of tissues, the gene expression that is responsible for the cytodifferentiation is largely dependent on E box(es) located upstream of the responsible genes. In this study, we report on the cloning of cDNA(s) encoding E box (5'-CACGTG-3')-binding protein from a rat granulosa cell cDNA library using a yeast one-hybrid system. When multiple E box sequences were used as target, we obtained a positive clone that encodes the rat homologue of upstream stimulatory factor 2 (USF2). An analysis of the nucleotide sequence and its deduced amino acid sequence reveals that rat USF2 protein consists of 346 amino acid residues and belongs to the basic helix-loop-helix/leucine zipper protein family. Northern blot analysis shows that rat USF2 mRNA exists as multiple forms between 1.6 and 2.2 kilobases. The size of the cloned insert was identical to that of the transcript of maximal length. Electrophoretic mobility shift assays showed that in vitro-translated rat USF2 specifically binds to the E box. In addition, cotransfection experiments with luciferase-reporter constructs in HepG2 cells reveal that the overexpression of rat USF2 leads to an increase of luciferase activity in the E box sequence-dependent manner. Thus, we report molecular cloning, expression, and functional characterization of full-length rat USF2 cDNA.

Amino Acid Sequence↗
PubMed2001

Structure and characterization of the gene encoding alpha subunit of soybean beta-conglycinin.

beta-conglycinin, a soybean seed storage protein, is comprised of three different subunits, a, alpha', and beta. Several candidates for the alpha subunit gene have been isolated, however, the structure of the alpha subunit gene has not been completely determined. Accordingly, it was also unknown which of the gene candidates are functionally active. Here, we have determined the nucleotide sequence and transcription start site of the alpha subunit gene, and compared the structural components with those of the other subunits or other seed protein genes. The a subunit gene, which is located on a 7.6-kb EcoRI fragment, was composed of six exons that had the same organization as those for the alpha' subunit gene. Within a 400 bp upstream region of the transcription start site, four regions (designated as boxes I, II, III, and IV) were found to be conserved among the alpha, alpha', and other seed protein genes. Genomic Southern blot analysis of soybean varieties lacking the alpha subunit gene candidate indicated that the gene characterized in this paper actually encodes the a subunit and is functionally active. In addition, these experiments revealed the presence of an additional gene which is also responsible for the expression of the a subunit.

Amino Acid Sequence↗
PubMed2001

Xanthurenic acid inhibits metal ion-induced lipid peroxidation and protects NADP-isocitrate dehydrogenase from oxidative inactivation.

Vitamin B6 deficiency increases the lipid peroxidation and the synthesis of xanthurenic acid from tryptophan. Antioxidant properties of xanthurenic acid were examined in relation to the coordination of transition metals. Xanthurenic acid inhibited the formation of thiobarbituric acid-reactive substances as a marker of iron-mediated lipid peroxidation and copper-dependent oxidation of low density lipoprotein. NADP-isocitrate dehydrogenase (EC 1.1.1.42), a principal NADPH-generating enzyme for the antioxidant defense system, was inactivated by reduced iron and copper, and xanthurenic acid protected the enzyme from the Fe2+-mediated inactivation. Xanthurenic acid may participate in the enhanced regeneration of reduced glutathione by stimulating the NADPH supply. Xanthurenic acid further enhanced the autooxidation of Fe2+ ion. Other tryptophan metabolites such as kynurenic acid and various quinoline compounds did not inhibit the lipid peroxidation and the inactivation of NADP-isocitrate dehydrogenase, and they showed little or no effect on the Fe2+ autooxidation. The antioxidant properties of xanthurenic acid are related to the metal-chelating activity and probably to the enhanced oxidation of reduced transition metals as a prooxidant, and this action may be due to the electron deficient nature of this compound.

Antioxidants↗
PubMed2001

[Presence of alpha 5 beta 1 integrin and fibronectin in the anterior subcapsular cataract].

PURPOSE: We investigated whether alpha 5 beta 1 integrin and fibronectin were present in myofibroblast-like lens epithelial cells in anterior subcapsular cataract (ASC). METHODS: Nine anterior capsule specimens were obtained from the patients during cataract surgery and frozen for cryostat sections. Six specimens were anterior capsule obtained from cataract with ASC. As a control, three specimens were obtained from cataract without ASC. Alpha-smooth muscle actin (alpha-SMA), alpha 5 beta 1 integrin, and fibronectin were detected by immunohistochemical observation. RESULTS: In all 6 specimens from patients with ASC, the lens epithelial cells around fibrosis tissue included myofibroblast-like lens epithelial cells which were positive for alpha-SMA. alpha 5 beta 1 integrin was detected in these lens epithelial cells. Fibronectin was also detected around these myofibroblast-like lens epithelial cells. Three control specimens showed no immunoreactivity against alpha-SMA, alpha 5 beta 1 integrin, or fibronectin. CONCLUSIONS: Alpha 5 beta 1 integrin and fibronectin may play an important role in myodifferentiation of lens epithelial cells.

Adult↗
PubMed2001

[Appetite and regulation of food intake in uremia].

Anorexia, nausea and vomiting are common symptoms in patients with severe renal failure. Abnormalities in body fluids volume, serum electrolytes concentrations and acid-base balance and accumulations of uremic toxic substances might be primarily contributing to the suppression of appetite. However, the detailed mechanisms that cause appetite suppression in uremia are poorly understood. Impaired gastric emptying, constituents of peritoneal dialysate, plasma high leptin, high cholecystokinin and low neuropeptide Y are also considered to be contributing to appetite suppression in uremia.

Animals↗
PubMed2001

Initial remission-inducing effect of very low-dose cyclosporin monotherapy for minimal-change nephrotic syndrome in Japanese adults.

AIM: Cyclosporin A (CsA) in combination with corticosteroids can be used effectively in steroid-sensitive nephrotic syndrome. However, reports documenting the effectiveness ofCsA monotherapy against such a condition have been scarce. In 11 adults with minimal-change nephrotic syndrome, we have tried very low-dose CsA in the hope of inducing remission without using either corticosteroid or any other immunosuppressive drugs. PATIENTS AND METHODS: Indications for treatment included steroid-sensitive relapsing nephrotic syndrome (7 patients) and first-episode nephrotic syndrome (4 patients). In all patients, corticosteroid and cytotoxic agents had not been given before entry. CsA was administered orally at an initial dose of 2.4 (range 1.5 - 3.1) mg/kg per day. RESULTS: Analysis of the clinical course revealed that 8 of 11 patients entered complete remission after a mean duration of 44 +/- 31 days, whereas 3 patients failed to enter remission to CsA alone, resulting in complete remission combined with methylprednisolone pulse therapy without conventional oral prednisolone. CsA dosages and trough levels between responders and non-responders were similar. Non-responders had much higher levels of serum total cholesterol and higher daily urinary excretion of protein than those of responders, respectively. No patients had significant decrease in creatinine clearance, development of hypertension or suffered from other CsA associated serious side-effects. CONCLUSION: The present data suggest that CsA monotherapy at a very low dose could induce complete remission in adult patients with minimal-change nephrotic syndrome. Conversely, severe hypercholesterolemia would be likely to inhibit the action of CsA against nephrotic conditions.

Adult↗
PubMed2001

[Serial changes in body composition in patients with chronic renal failure on peritoneal dialysis].

Nutritional status is one of the most important factors affecting mortality and morbidity in chronic dialysis patients. There are, however, few data on serial body composition changes in these patients. To investigate serial changes in body composition in patients on peritoneal dialysis, we measured intracellular fluid volume(ICF), extracellular fluid volume(ECF), body protein volume(BPV), body fat volume(BFV) and bone mineral content(BMC) using multifrequency bioelectrical impedance analysis (MF-BIA). MF-BIA was performed in 35 patients, consisting of 21 men and 14 women with a mean age of 51.3 +/- 10.9 years, before and after one year of observation. At the baseline in male patients, ICF was 37.0 +/- 3.4%, ECF 19.7 +/- 1.6%, BPV 20.7 +/- 1.7%, BFV 18.1 +/- 6.6% and BMC 4.5 +/- 0.4% of body weight, and in female patients ICF was 34.4 +/- 2.6%, ECF 17.8 +/- 1.9% BPV 19.0 +/- 1.6%, BFV 24.4 +/- 6.2% and BMC 4.5 +/- 0.4% of body weight. In the group of patients whose body weight increased more than 3 kilograms(n = 9), the increase rate of BFV was 32.3 +/- 20.2%, significantly higher than that of the other segments(p < 0.001). On the other hand, in the group of patients whose body weight decreased more than 3 kilograms(n = 5), each segment showed the same extent of decrease and there was no significant difference in the decrease rates among each segment. In the group of patients whose body weight was stable(n = 21), changes in each body composition segment were extremely small. It could be concluded that the body weight increase is due mainly to increase in BFV and body weight decrease results from a concurrent decrease in each body composition segment in peritoneal dialysis patients.

Adult↗
PubMed2001

Neuropsychological changes after surgical treatment for temporal lobe epilepsy.

PURPOSE: The effect of unilateral temporal lobectomy on seizure frequency is well recognized, but little is known about the neuropsychological changes that occur after surgical treatment. We assessed neuropsychological status in 26 patients with an average age of 35 years before and after unilateral temporal lobectomy for medically intractable TLE. METHODS: Neuropsychological examination to assess cognitive function, memory, attention, visuospatial analysis, language, and emotional functions was performed preoperatively and at 1 month and 1 year after the surgery. RESULTS: At both 1 month and 1 year after the surgery, the patients had improved scores, compared with the preoperative scores, on the Wechsler Adult Intelligence Scale-Revised (WAIS-R: verbal IQ, performance IQ, and full-scale IQ), Wechsler Memory Scale-Revised (WMS-R: verbal, general, and delayed paired associates memory), and Raven Colored Progressive Matrices. In the Minnesota Multiphasic Personality Inventory (MMPI), significant decreases were observed at 1 year after the surgery in the scores for infrequency, hypochondriasis, psychasthenia, and schizophrenia. Patients in whom the seizures had been relieved postoperatively also had improved scores on the WAIS-R, WMS-R, and Raven Colored Progressive Matrices. CONCLUSIONS: These data suggest that neuropsychological improvement postoperatively is influenced by the reduction in the frequency of seizures after surgery.

Adult↗