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Biomedical subjects

M Kato

Publications and source records attributed to M Kato.

At least 631 records · Page 35Linked to original sources
PubMed1998

cDNA cloning of human DEC-205, a putative antigen-uptake receptor on dendritic cells.

Dendritic cells (DC) are specialist antigen presenting cells which capture antigens in the periphery, migrate centrally, and present the processed antigens in the context of major histocompatibility complex and appropriate co-stimulatory molecules to T lymphocytes for the initiation of an immune response. DEC-205 has been identified as a putative antigen-uptake receptor, which is expressed abundantly on mouse DC. The recently cloned mouse DEC-205 cDNA predicts a molecular structure which has a marked similarity to the macrophage mannose receptor. Using reverse transcriptase-polymerase chain reaction (RT-PCR) and cDNA library screening, we obtained the full coding region of human DEC-205 cDNA from the Hodgkin's disease-derived L428 cell line. The predicted protein structure is a type I transmembrane protein of 1722 amino acids consisting of a signal peptide, cysteine-rich domain, fibronectin type II domain, ten carbohydrate recognition-like domains, transmembrane domain, and a cytoplasmic tail. Human DEC-205 is 77% identical to the mouse protein with completely conserved cysteines. The DEC-205 gene (LY75) was mapped to chromosome band 2q24 by somatic cell hybrid panel analysis and fluorescent in situ hybridization. Northern blot analysis detected 7.8 and 9.5 kilobase DEC-205 transcripts in myeloid, B lymphoid, and Hodgkin's disease-derived cell lines. RT-PCR analysis indicated that immature blood DC contain a barely detectable amount of DEC-205 transcripts but these were markedly increased upon differentiation/activation.

Amino Acid Sequence↗
PubMed1998

Clinicopathologic and immunohistochemical studies of papillary thyroid microcarcinoma presenting with cervical lymphadenopathy.

Although most papillary thyroid microcarcinomas (PMCs) are of little clinical significance, patients with PMCs occasionally have an unfavorable outcome, especially when they present with bulky nodal metastasis or distant metastasis. We have attempted to identify "high-risk" PMCs by evaluating clinical, pathologic, and immunohistochemical prognostic factors. Among 190 patients with a PMC, 156 without clinically apparent nodal metastasis had a benign course. The remaining 34 patients, who presented with cervical lymphadenopathy of at least 1 cm, were studied. Three of the four patients who developed distant metastasis died of the disease, and the other died of local recurrence. All patients who developed distant metastasis or died of the disease had both nodal metastasis of at least 3 cm and a nonencapsulated type of primary lesion. All patients who developed distant metastasis showed both extracapsular extension of the metastatic lesions in lymph nodes and positive staining for transforming growth factor-beta3 (TGFbeta3) (a potent growth inhibitor) in the primary lesion. The Ki-67 (an indicator of cell proliferation) labeling indices in the primary and metastatic nodal lesions of patients who died of cancer were significantly higher than those of the others with nonfatal disease. None of the patients showed P53 (nuclear tumor-suppressor phosphoprotein) overexpression. In conclusion, patients with PMC who have both 3 cm or larger lymphadenopathy and a nonencapsulated type of primary lesion may be regarded as high-risk patients. Immunohistologic positivity for Ki-67 and TGFbeta3 in cancer cells is a potential indicator of aggressively malignant PMC.

Adult↗
PubMed1998

Inhibition of intestinal microflora beta-glucuronidase modifies the distribution of the active metabolite of the antitumor agent, irinotecan hydrochloride (CPT-11) in rats.

PURPOSE: SN-38, a metabolite of irinotecan hydrochloride (CPT-11), is considered to play a key role in the development of diarrhea as well as in the antitumor activity of CPT-11. We have previously found that the inhibition of beta-glucuronidase, which hydrolyzes detoxified SN-38 (SN-38 glucuronide) to reform SN-38, in the lumen by eliminating the intestinal microflora with antibiotics, markedly ameliorates the intestinal toxicity of CPT-11 in rats. In this study we compared the disposition of CPT-11 and its metabolites in rats treated with and without antibiotics. METHODS: Rats were given drinking water containing 1 mg/ml penicillin and 2 mg/ml streptomycin from 5 days before the administration of CPT-11 (60 mg/kg i.v.) and throughout the experiment. CPT-11, SN-38 glucuronide and SN-38 concentrations in the blood, intestinal tissues and intestinal luminal contents were determined by HPLC. RESULTS: Antibiotics had little or no effect on the pharmacokinetics of CPT-11, SN-38 glucuronide or SN-38 in the blood, or in the tissues or contents of the small intestine, which has less beta-glucuronidase activity in its luminal contents. In contrast, antibiotics markedly reduced the AUC1-24 h of SN-38 (by about 85%) in the large intestine tissue without changing that of CPT-11, and this was accompanied by a complete inhibition of the deconjugation of SN-38 glucuronide in the luminal contents. CONCLUSIONS: These results suggest that SN-38, which results from the hydrolysis of SN-38 glucuronide by beta-glucuronidase in the intestinal microflora, contributes considerably to the distribution of SN-38 in the large intestine tissue, and that inhibition of the beta-glucuronidase activity by antibiotics results in decreased accumulation of SN-38 in the large intestine.

Administration, Oral↗
PubMed1998

Effects of sex, height and age on motor evoked potentials with magnetic stimulation.

Magnetic stimulation of the brain and cervical and lumbar spinal roots was performed on 48 healthy subjects in order to investigate the effects of sex, height and age on motor evoked potentials (MEPs). The compound muscle action potentials were recorded from the abductor pollicis brevis and abductor hallucis muscles. The central motor conduction time (CMCT) was measured between the cerebral cortex and the cervical root and also between the cerebral cortex and the lumbar root. A multiple regression analysis was used to determine which of the physical variables, namely sex, height and age, were significant. A significant gender difference was observed in the MEP latencies and CMCT of the leg, but not in those of the hand. Both height and age had a significant effect on the leg MEP latencies with a lesser effect on the hand MEP latencies. The leg CMCT was also significantly influenced by height and age, while the hand CMCT was not. These results thus suggest that physical variables are very important in defining normal MEPs, especially in the lower limbs. Therefore, when we assess motor function in patients with neurological disorders, both the patients and control groups should be matched for sex, height and age distribution.

Adult↗
PubMed1998

Effects of transforming growth factor beta on corneal epithelial and stromal cell function in a rat wound healing model after excimer laser keratectomy.

BACKGROUND: Transforming growth factor beta (TGF-beta) regulates extracellular matrix deposition, cell proliferation, and migration, and is expressed in cornea. TGF-beta is thought to be involved in the corneal wound healing process. METHODS: The central corneal area (3 mm in diameter) of Lewis rats was ablated using PTK mode excimer laser and the wound healing process was observed at 12 and 24 h and 2, 5, 10, and 30 days after treatment. The expression of TGF-beta 1, -beta 2 and -beta 3, TGF-beta type I and type II receptors, alpha 3, alpha 5, beta 4 integrin subunits, laminin and fibronectin was studied immunohistochemically. Antibody neutralizing TGF-beta 1, -beta 2 and -beta 3 was administered intraperitoneally, 50 micrograms daily, for 5 days after the laser treatment to investigate the effects of TGF-beta function blockade. RESULTS: At the leading edge of the regenerating epithelium, no TGF-beta type I and type II receptors and beta 4 integrin subunits were expressed after 24 h. Regenerating epithelium covered the ablated area after 2 days. An abnormal fibrotic layer was formed in the subepithelial area. This layer contained round-shaped cells in the stroma in the early stage (2-5 days after laser ablation) and spindle-shaped fibroblast-like keratocytes after 10 days. Laminin and fibronectin expression increased in the fibrotic layer. The increased stromal cells expressed TGF-beta isoforms and TGF-beta receptors. Neutralizing TGF-beta inhibited the stromal cell increase in the laser ablated area after 5 days. CONCLUSION: TGF-beta may be involved in epithelial cell migration and stromal cell reaction during the corneal wound healing process after excimer laser ablation in rat models.

Activin Receptors, Type I↗
PubMed1998

Physiological significance of hydrophilic and hydrophobic textile materials during intermittent exercise in humans under the influence of warm ambient temperature with and without wind.

The purpose of this present study was to compare the physiological effects of the hydrophilic and hydrophobic properties of the fabrics investigated in exercising and resting subjects at an ambient temperature of 30 degrees C and a relative humidity of 50% with and without wind. Three kinds of clothing ensemble were tested: wool and cotton blend with high moisture regain (A), 100% cotton with intermediate moisture regain (B), 100% polyester clothing with low moisture regain (C). The experiments were performed using seven young adult women as subjects. They comprised six repeated periods of 10-min exercise on a cycle ergometer at an intensity of 40% maximal oxygen uptake followed by 5 min of rest (20 min for the last rest). The experiments comprised two sessions. During session I (first three repetitions of exercise and rest) the subjects were exposed to an indifferent wind velocity and during session II (last three repetitions of exercise and rest) they were exposed to a wind velocity of 1.5 m x s(-1). Rectal temperature and skin temperatures at eight sites, pulse rate and clothing microclimate were recorded throughout the whole period. The main findings can be summarized as follows: rectal temperature during session II was kept at a significantly lower level in A than in B and C. Clothing microclimate humidity at the chest was significantly lower in A than in B and C during session II. Skin and clothing microclimate temperatures at the chest were significantly lower in A than in B and C during session II. Pulse rate was significantly higher in C than in A and B during sessions I and II. It was concluded that the hydrophilic properties of the fabrics studied were of physiological significance for reducing heat strain during exercise and rest especially when influenced by wind.

Adult↗
PubMed1998

Multiple sulphatase deficiency and haemophagocytic syndrome.

A 3-year-old boy with multiple sulphatase deficiency, complicated by a haemophagocytic syndrome, recovered with conventional treatment. Haemophagocytic syndrome can be a complication of many disorders including metabolic diseases, frequently triggered by intracellular viral and bacterial infections or even by drug administration.

Child, Preschool↗
PubMed1998

Telomerase activity significantly correlates with cell differentiation, proliferation and lymph node metastasis in colorectal carcinomas.

Telomerase activity was examined by the telomeric repeat amplification protocol assay, in a total of 37 colorectal adenocarcinomas, including stages A, B and C according to the Astler and Collier classification, and correlated with clinicopathological features. Of 17 stage C lesions, 13 were positive (76.5%; P<0.01), demonstrating a significant correlation with lymph node metastasis. In contrast, only 6 of 20 stage A and B carcinomas were positive (30.0%), this being significantly lower (P < 0.05). Moderately or poorly differentiated subtypes were more predominant in the telomerase-positive than in the telomerase-negative groups (P< 0.05) with greater elevation of mitotic and Ki-67 labeling indices (P < 0.0001). No significant relation was found between telomerase activity and p53 protein accumulation or Bcl-2 protein expression. The good correlation with tumor staging, lymph node metastasis, differentiation, and mitotic and Ki-67 labeling indices suggests that this parameter might have potential application in estimation of prognosis.

Adenocarcinoma↗
PubMed1998

The Aspergillus nidulans CCAAT-binding factor AnCP/AnCF is a heteromeric protein analogous to the HAP complex of Saccharomyces cerevisiae.

The Aspergillus nidulans hapC gene was expressed as a fusion protein with MalE or glutathione-S-transferase (GST) in Escherichia coli, and used for the purification of HapC and the preparation of anti-HapC antiserum. The CCAAT-binding factor AnCP/AnCF contains a component with an approximate molecular mass of 32 kDa that cross-reacts with the antibody. The MalE-HapC fusion protein was able to replace authentic HapC in AnCP when incubated under appropriate conditions. Furthermore, reconstitution experiments with recombinant HapC, yHAP2 and yHAP5 polypeptides showed that all three polypeptides were required for the assembly of a complex capable of binding to CCAAT-containing taaG2 promoter DNA. The relationship between AnCP/AnCF and the Saccharomyces cerevisiae HAP complex is discussed.

Aspergillus nidulans↗
PubMed1998

Neurocalcin-like immunoreactivity in the rat esophageal nervous system.

Neurocalcin is a newly identified neuronal calcium-binding protein. We tried here to investigate the immunohistochemical distribution of neurocalcin in the rat esophagus. Nerve cell bodies having neurocalcin immunoreactivity were found throughout the myenteric plexus. In the myenteric ganglia, two types of nerve terminals showed neurocalcin immunoreactivity. One was varicose terminals containing numerous small clear vesicles and forming a synapse with nerve cells. The other terminals were characterized by laminar or pleomorphic structure and many mitochondria. These laminar terminals were supposed to be sensory receptors of the esophageal wall. In the motor endplates of the striated muscles, nerve terminals containing many small clear vesicles and mitochondria also had neurocalcin immunoreactivity. After left vagus nerve cutting under the nodose ganglia, the number of immunopositive thick nerve fibers, laminar endings and nerve terminals on the striated muscles decreased markedly. Retrograde tracing experiments using Fast Blue showed extrinsic innervation of esophagus from ambiguus nucleus, dorsal motor nucleus of vagus, superior cervical ganglia, celiac ganglia, nodose ganglia and dorsal root ganglia. In the celiac ganglia, nodose ganglia and dorsal root ganglia, retrogradely labeled nerve cells were neurocalcin-immunoreactive. Neurons in the celiac ganglia may project varicose terminals, while nodose and dorsal root neurons project laminar terminals. Although cell bodies of motoneurons in the ambiguus nucleus lacked neurocalcin immunoreactivity, these neurons may contain neurocalcin only in the nerve terminals in the motor endplates. Neurocalcin immunoreactivity is distributed in many extrinsic and intrinsic neurons in the esophagus and this protein may play important roles in regulating calcium signaling in the neurons.

Animals↗
PubMed1998

Sustained induction of hepatocyte growth factor by sensitization with freeze-thawed hepatic tissue.

Hepatocyte growth factor (HGF) is a mitogen for hepatocytes, and has therapeutic potential for fibrotic/cirrhotic liver. Therefore, the induction of HGF in vivo is considered to be useful in the treatment of liver dysfunction caused by cirrhosis, chronic hepatitis, or extensive surgical resection. In this study, we examined the sustained induction of HGF by inoculation of freeze-thawed hepatic tissue (FTHT). Serum from rats inoculated with FTHT increased [3H]thymidine incorporation i.e., increased DNA synthesis, in primary cultured rat hepatocytes. The DNA synthesis was significantly promoted by the addition of the FTHT-sensitized serum, while this DNA synthesis was inhibited by neutralizing anti-rat HGF antibody. The concentration of HGF in the FTHT-sensitized serum was increased by day 3 after the inoculation. The time of HGF induction was dependent on the inoculated volume of FTHT, but peaks of HGF concentration were found on day 5 with different volumes of FTHT. Injurins, inducers of HGF, were also induced in the FTHT-sensitized rats, with their peak levels on day 3. The FTHT inoculated tissue showed inflammatory cell infiltration, which was gradually absorbed, and had completely disappeared by day 14 after the inoculation. Although mild inflammatory cell infiltration was observed in non-freeze-thawed inoculated hepatic tissue (NFHT) a tight capsule formed around the NFHT, and was scarcely phagocytized on day 14. These results suggest that FTHT inoculation induces HGF sustainedly through the increased synthesis of injurins, and that freeze-thawed tissue, which is easily phagocytized, is important for the sustained induction of HGF.

Animals↗
PubMed1998

Thrombotic thrombocytopenic purpura developed suddenly during interferon treatment for chronic hepatitis C.

A 57-year-old man had abnormal hepatic function identified in April 1994. In October 1994, chronic hepatitis C was diagnosed. Based on the findings of a liver biopsy, administration of recombinant interferon (rIFN)-alpha2b was begun. In the 16th week of treatment, the patient experienced headache and fever and developed a markedly decreased, platelet count and hemolytic anemia. He was admitted on May 19, 1995 and thrombotic thrombocytopenic purpura (TTP) was diagnosed. He died on the 3rd hospital day. The causes of TTP have yet to be elucidated, but in this patient the occurrence of TTP appeared to be related to the IFN treatment for chronic hepatitis C.

Antiviral Agents↗
PubMed1998

Expression of manganese superoxide dismutase in esophageal and gastric cancers.

The tumor-killing activity of radiotherapy and chemotherapy for cancer is closely associated with the production of active oxygen, and the relation between therapeutic resistance and active oxygen scavengers produced by the tumor itself is gaining more attention. It is considered that manganese superoxide dismutase (MnSOD) protects host cells from oxidative stress, in synergy with other antioxidant enzymes. In this study, we used a quantitative polymerase chain reaction assay to measure MnSOD mRNA in resected specimens from patients with esophageal and gastric cancers. In both esophageal and gastric cancers, the level of MnSOD mRNA was significantly elevated in cancer tissue compared to non-cancer tissue (P < 0.01). In gastric cancer tissue, the MnSOD mRNA level was significantly higher than in esophageal cancer tissue (P < 0.01). The significance of MnSOD in cancer tissue was investigated further by measuring MnSOD content in resected specimens using an enzyme-linked immunosorbent assay, and by examining its location by an immunohistochemical method. Upregulation of MnSOD in cancer tissue most likely serves as a protective mechanism against anti-cancer therapies known to produce superoxide radicals as a key component of their tumor-killing activity.

Adenocarcinoma↗
PubMed1998

Limb salvage and survival rates among elderly patients with advanced limb ischemia.

The purpose of this study was to clarify the incidence of limb salvage and patient survival rates among elderly patients with advanced leg ischemia. We reviewed the records of 159 patients treated for advanced ischemia over a 15-year period at Aichi Medical University, 74 of whom were aged over 75 years and 85, between 65 and 74 years. There was a collective total of 186 limbs; 82 in the older group and 104 in the younger group. The older group had a greater proportion of women, and a higher incidence of coronary heart disease, pulmonary dysfunction, and acute onset of advanced ischemia than the younger group. Limb salvage was achieved in 73% of the affected limbs in the older group and in 92% of the limbs in the younger group. The poor limb salvage rate in the older group was mainly related to the high initial amputation rate. Early recognition of the sentinel ischemic signs before the ischemia is essential, especially in the elderly. Timely revascularization should be attempted whenever possible, and it should not be abandoned simply because the patient is deemed too old. The 1-, 3-, and 5-year survival rates in the older group were 59%, 28%, and 23%, respectively, which were markedly poorer than the expected survival rates of the age- and sex-matched Japanese population at 1, 3, and 5 years, which were 93%, 79%, and 65%, respectively. Thus, advanced limb ischemia carries a poor prognosis to the point of being life-threatening, and further continuous systemic management with the collaboration of physicians and surgeons must be provided even after the patient has left the hospital.

Aged↗
PubMed1998

Expression of epithelial-cadherin, alpha-catenin and beta-catenin during human intrahepatic bile duct development: a possible role in bile duct morphogenesis.

BACKGROUND/AIMS: Cell adhesion molecules play an important role in the morphogenesis of developing organs. However, little is known about their expression during intrahepatic bile duct development. METHODS: We immunohistochemically investigated the expression of E-cadherin (E-Cad), alpha-catenin (A-Cat) and beta-catenin (B-Cat) during human intrahepatic bile duct development, using 31 fetal livers of various gestational ages. The developmental stages of bile ducts were classified into the ductal plate, migrating biliary cells (remodeling stage), and immature bile ducts (remodeled stage). RESULTS: E-Cad was broadly and strongly expressed in the ductal plate with a cytoplasmic pattern, heterogeneously and weakly expressed in the migrating biliary cells with a cytoplasmic pattern, and broadly and strongly expressed in immature bile ducts with a membranous pattern. A-Cat was broadly and strongly expressed in the ductal plate with a membrane pattern, broadly and moderately expressed in the migrating biliary cells with a membranous pattern, and broadly and strongly expressed in immature bile ducts with a membranous pattern. In contrast, expression of B-Cat was weak or slight in the ductal plate, but B-Cat was expressed broadly and strongly with a membranous pattern in migrating biliary cells and in immature bile ducts. Immature hepatocytes rarely expressed E-Cad and A-Cat, but expressed B-Cat with a membranous pattern throughout development. CONCLUSIONS: These results suggest that E-Cad, A-Cat and B-Cat are involved in the normal developmental morphogenesis of human intrahepatic bile ducts.

Bile Ducts, Intrahepatic↗
PubMed1998

Saphenous vein graft pseudoaneurysm rupture after coronary artery bypass grafting.

An elderly woman underwent coronary artery bypass grafting, which was followed 1 month later by pseudoaneurysmal rupture at the distal anastomosis of a saphenous vein graft. Emergency repair of the suture line dehiscence was made, and the postoperative course was uneventful. Pseudoaneurysm formation of a saphenous vein graft after coronary artery bypass grafting is a rare but potentially lethal complication requiring urgent operative intervention.

Aged↗
PubMed1998

Memory for subject performed tasks in patients with Korsakoff syndrome.

We examined the ability of alcoholic Korsakoff patients to remember verbal and action-related information. Eight Korsakoff patients and eight alcoholic control subjects learned action phrases in either subject-performed tasks (SPTs) or verbal tasks (VTs). Free recall and recognition tests were then administered. Despite the severe anterograde amnesia observed in Korsakoff patients for VTs, their memory performance for SPTs was similarly facilitated over VTs as was the case with alcoholic controls. Domains preserved in this amnesic syndrome may account for the benefit seen when using SPTs in Korsakoff patients. The therapeutic utilization of action events for memory rehabilitation is discussed.

Adult↗