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T Kitamura

Publications and source records attributed to T Kitamura.

At least 361 records · Page 20Linked to original sources
PubMed1996

Up-regulation of cystatin C by microglia in the rat facial nucleus following axotomy.

Cystatin C, a cysteine proteinase inhibitor, is expressed in the central nervous system (CNS) as well as many other organs of mammals. However, little is known concerning whether its expression is regulated under pathological conditions of the CNS and what types of cells are responsible for this regulation. We performed differential hybridization screening of cDNA libraries derived from the rat facial nucleus and found a cDNA of rat cystatin C to be up-regulated following facial nerve axotomy. In situ hybridization using an RNA probe for rat cystatin C revealed that cystatin C mRNA in the facial nucleus was markedly increased in amount by day 7 after axotomy and was then decreased to the normal level by day 50. The intense signal for cystatin C mRNA in the damaged facial nucleus was localized in the glial cells which had the morphological characteristics of microglia. Light and electron microscopic immunohistochemistry using a rabbit antibody specific for cystatin C confirmed that microglia in the damaged facial nucleus were strongly positive for cystatin C. The immunoreactivity was also found in the extracellular space, consistent with the fact that cells producing cystatin C generally secrete this protein. These results demonstrate that cystatin C is markedly up-regulated by microglia in response to axotomy and is probably secreted by these cells into the extracellular space, suggesting that this proteinase inhibitor has (a) significant function(s) in the processes of neuronal degeneration, regeneration, and/or repair subsequent to axotomy.

Animals↗
PubMed1996

DNAM-1, a novel adhesion molecule involved in the cytolytic function of T lymphocytes.

Intercellular adhesion molecules play an important role in the generation of T lymphocyte-mediated immune responses. Here, we describe a novel accessory molecule, DNAX accessory molecule-1 (DNAM-1), that is constitutively expressed on the majority of peripheral blood T lymphocytes. DNAM-1 is a 65 kDa transmembrane glycoprotein consisting of 318 aa including two immunoglobulin-like domains. Anti-DNAM-1 monoclonal antibody (MAb) inhibits T and NK cell-mediated cytotoxicity against a variety of tumor cell targets and blocks cytokine production by alloantigen-specific T cells. In addition, DNAM-1 is a tyrosine-phosphorylated signal-transducing molecule that participates in primary adhesion during cytotoxic T lymphocyte (CTL)-mediated cytotoxicity.

Amino Acid Sequence↗
PubMed1996

Effects of rebamipide on bile acid-induced inhibition of gastric epithelial repair in a rabbit cell culture model.

BACKGROUND: Anti-ulcer agents exert various functional effects on gastric epithelial cells. AIM: The effects of a novel gastro-cytoprotective agent (rebamipide) on epithelial restoration following bile acid damage were assessed using primary cultured rabbit gastric epithelial cells. METHODS: Rebamipide was added to complete confluent cell sheets with deoxycholic acid just after creating a cell-free wound (2 mm2). The restoration was monitored and analysed by phase contrast microscopy and an image analyser for 48 h. The migration speed was measured during the initial 3 h after wounding. Cell proliferation was detected by staining for bromodeoxyuridine (BrdU) at 12-h intervals. The labelling index was calculated per unit area. The major cytoskeletal protein actin was detected by immunohistochemical staining. RESULTS: In the controls, restoration was completed 48 h following wounding. Deoxycholic acid retarded this process. The addition of rebamipide to deoxycholic acid abolished the bile acid-induced retardation. The migration speed was 26 microns/h in the controls. 15 microns/h in the deoxycholic acid group and 27 microns/h in the deoxycholic acid plus rebamipide group. In the controls, BrdU-positive cells, which were rarely detected in the initial 24 h, were maximal at 36 h (labelling index 1.7%). In the deoxycholic acid group, proliferation was inhibited (peak labeling index; 0.5% at 48 h). Actin-containing stress fibres were detected throughout the cells and the periphery of the lamellipodia in the controls, and were disrupted in the deoxycholic acid-treated group. Rebamipide prevented these effects. CONCLUSIONS: Deoxycholic acid significantly retarded restoration by the inhibition of both cell migration and proliferation, potentially through an effect on the cytoskeleton. Rebamipide protected the mucosal cells from bile acid mediated injury.

Actins↗
PubMed1996

Platelet-derived growth factor accelerates gastric epithelial restoration in a rabbit cultured cell model.

BACKGROUND & AIMS: Growth factors play an important role in gastric wo und repair. The aim of this study was to assess the role of platelet-derived growth factor (PDGF) in gastric epithelial restoration. METHODS: PDGF-BB (1-50 ng/mL) was added to confluent cultures of rabbit gastric epithelial cells after wounding. Regrowth of the epithelial cells was monitored for 48 hours. The speed of cell migration was measured, and cell proliferation was detected by using a 5-bromodeoxyuridine (BrdU) staining technique. The labeling index was calculated for a 0.05-mm(2) area around the wound. RESULTS: After wounding, cells at the wound edge formed lamellipodia and showed ruffling movements. The addition of PDGF-BB significantly accelerated cell migration and proliferation as well as gastric restoration. Migration speed was 21 microm/h in control cultures and 32 microm/h and 40 microm/h in cultures containing 10 ng/mL and 50 ng/mL of PDGF-BB, respectively. In control cultures, BrdU-positive cells were rarely detected in the initial 24 hours after wounding, and maximum labeling occurred at 36 hours (labeling index, 3.4%). Cultures containing PDGF-BB showed maximum labeling at 24 hours (labeling index, 6.9%). CONCLUSIONS: PDGF-BB dose-dependently accelerated the migration rate and proliferation of cultured gastric epithelial cells after wounding. Therefore, PDGF-BB may play a role in gastric epithelial cell restoration during healing of gastric mucosal lesions.

Animals↗
PubMed1996

Application of a suture anchor technique for flap fixation to bone.

The authors have developed a technique for fixation of a flap to underlying bone. Their technique involves an anchor system which has been used for tenodesis and ligament repair in orthopedic bone and joint surgery. The anchor technique provides reliable fixation with simplicity of application. A wider use of this technique in reconstructive flap surgery is expected.

Bone and Bones↗
PubMed1996

Prevalence of mood and anxiety disorders in a working population in Japan.

To learn the prevalence of mood and anxiety disorders (as defined by the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised) in a working population in Japan, we analyzed data from a population-based survey. Among 140 respondents who had a job, 8% experienced any of seven mood and anxiety disorders in the past 6 months and 19% had in their lifetime. The 6-month and lifetime prevalence rates of major depressive episodes were 4% and 14%, respectively. The 6-month and lifetime prevalence rates of phobic disorders were both 4%. The lifetime prevalence rates for other anxiety disorders were 1% or less. The 6-month rate of any disorder, as well as 6-month and lifetime rates of phobic disorders, was higher in white-collar employees than in self-employed workers (P < 0.05). The multiple logistic regression confirmed the tendency after controlling for sex and age, although the result was not significant (P > 0.05).

Adolescent↗
PubMed1996

Geographical distribution of the human polyomavirus JC virus type A and B and isolation of a new type from Ghana.

The JC polyomavirus (JCV) is ubiquitous in humans infecting children asymptomatically, then persisting in renal tissue. Since JCV DNA can be readily isolated from urine, it should be a useful tool with which to study the evolution of DNA viruses in humans. We showed that JCV DNA from the urine of Japanese, Taiwanese, Dutch and German patients can be classified into A and B types, based upon restriction fragment length polymorphisms (RFLPs). This work was extended in the present study. We established multiple JCV DNA clones from the UK, Spain, Italy, Sweden, South Korea, People's Republic of China, Malaysia, Indonesia, Mongolia, India, Sri Lanka, Saudi Arabia, Ethiopia, Kenya, Zambia, South Africa and Ghana. Using type-specific RFLPs, most clones except the four clones from Ghana were classified as either type A or B. We constructed a molecular phylogenetic tree for the Ghanaian clones and several representative type A and B clones. According to the phylogenetic tree, the Ghanaian clones constituted a major new group, tentatively named type C. From the findings presented here and elsewhere, the following conclusions were drawn: (i) type A is prevalent only in Europe; (ii) type B is found mainly in Asia and Africa; and (iii) type C is localized to part of Africa. Our findings should help to clarify how JCV evolved in humans.

Base Sequence↗
PubMed1996

Efficacy of ursodeoxycholic acid in combination with interferon-alpha in treating chronic hepatitis C: results of a long-term follow-up trial.

Ursodeoxycholic acid (UDCA) has recently been combined with interferon (IFN) in the treatment of individuals with chronic hepatitis C. However, whether its addition results in a long-term favourable response to IFN remains unclear. A prospective randomized trial of IFN alone versus IFN plus UDCA was therefore undertaken in 52 patients with chronic hepatitis C. All patients received a 24 week course of IFN-alpha (6 x 10(6) U/day for 2 weeks and then three times a week for 22 weeks) and half also received UDCA (600 mg/day) with IFN and then alone for 48 additional weeks. Normalization of serum alanine transaminase (ALT) concentrations at 0, 24 and 48 weeks after cessation of IFN therapy was apparent in 77, 42 and 42% of patients in the IFN-alone group and in 77, 54 and 42% of patients in the IFN plus UDCA group, respectively. There was no significant difference between the two groups with regard to response rate to IFN and the addition of UDCA to IFN treatment had no significant effect on hepatitis C virus (HCV) viraemia. During the follow-up period, 10 of 20 patients with normal serum ALT at the end of IFN treatment relapsed in the IFN-alone group compared with 11 of 20 patients in the IFN plus UDCA group. Among these relapsed patients, serum ALT concentration was significantly lower in the IFN plus UDCA group than in the IFN-alone group during the follow-up period. Twenty-four weeks after cessation of IFN therapy, the percentage of patients with HCV-RNA in their serum who showed a normalization of serum ALT concentrations was significantly higher in the IFN plus UDCA group than in the IFN-alone group (44 vs 6%). Thus, although the addition of UDCA was not associated with a favourable long-term response to HCV viraemia, it did reduce the risk and the severity of relapse following the cessation of IFN therapy.

Alanine Transaminase↗
PubMed1996

Evaluation of ethanol on gastric epithelial restoration in vitro.

Ethanol exerts damaging effects on gastric mucosa and delays ulcer healing. To investigate the effect of ethanol on the wound repairing process, we used a wound repair model using primary cultured gastric mucosal cells. A confluent monolayer gastric mucosal cell sheet consisting mainly of mucous cells was wounded to make a cell-free area of constant size. Cell-free area was restored with time after wounding and monitored every 12 hr using a computer image analyzer to observe epithelial cell restoration quantitatively in the presence and absence of ethanol (2.0%). It was found that, although the control wound was completely repaired in 36 to 48 hr, the group treated with 2.0% ethanol showed a significant delay of repair. In the control, 5-bromodeoxyuridine-positive cells appeared around the wound in 24 to 36 hr. In contrast, the group treated with 2.0% ethanol showed no 5-bromodeoxyuridine-positive cells during the experiment. In conclusion, 2.0% ethanol retarded the repair of gastric mucosal restoration by inhibiting the initial gastric cell migration, followed by inhibition of proliferation of cells.

Animals↗
PubMed1996

Structural and functional features of bile canaliculi in adult rat hepatocyte spheroids.

Spheroids of adult rat hepatocytes are spherical cell aggregates which retain three-dimensional architecture and hepatocyte specific functions. In this study, we investigated the detailed structure and function of bile canaliculi in spheroids. Hepatocytes were prepared from adult rat liver and cultured with epidermal growth factor (50 ng/ml). Hepatocytes formed floating spheroids 4 days after inoculation. The morphology of hepatocyte spheroids was investigated after fluorescent staining for actin using confocal laser scanning microscopy and electron microscopy. To study the function of bile canaliculi, the transcellular transport of fluorescein diacetate was observed. These experiments were performed in a control group and in a group treated with the actin inhibitor cytochalasin B. In a control group, spheroids contained bile canalicular structures which were surrounded by actin filaments. Added fluorescent dye was secreted and pooled in bile canaliculi. Cytochalasin B caused marked distention of bile canaliculi and prominent accumulation of secreted fluorescent dye in dilated bile canaliculi. This phenomenon was based on the impairment of contractile movement of bile canaliculi. These results demonstrate that hepatocyte spheroids maintain functional and morphological peculiarity, and therefore this model may be useful in investigation of the mechanism of bile formation and intrahepatic cholestasis.

Actins↗
PubMed1996

Clinical and psychosocial correlates of antenatal depression: a review.

In contrast to the considerable research on postnatal depression, less attention has been paid to that occurring during pregnancy-antenatal depression (AD). However, recent investigations have studied depression among pregnant women not necessarily requiring psychiatric hospitalization but needing psychological support and help. A controlled study showed that the rate of AD was significantly higher than that of depression among non-pregnant women: the reported incidence varies between 4 and 29%. AD was found to be associated with: (1) obstetric factors (first pregnancy, first delivery, and past history of abortion); (2) early experience (loss of father); (3) personality (high neuroticism score); (4) attitudes towards the present pregnancy (perplexity of the husband); (5) accomodation factors (non-detached housing, and expected crowdedness after birth of the child, and (6) social support (low level of intimacy with the husband). Differential effects of these factors in the development of AD are to be studied in future research, particularly in conjunction with investigation of hormonal variables.

Depressive Disorder↗
PubMed1996

Psychosocial study of depression in early pregnancy.

BACKGROUND: The psychosocial correlates of depression during pregnancy were explored. METHOD: Pregnant women attending the antenatal clinic of a general hospital (n = 1329) received a set of questionnaires including Zung's Self-Rating Depression Score (SDS). SDS high scores (> 49) (the cases: n = 179) were compared with low scores (< 38) (the controls; n = 343). RESULTS: The cases were characterised by: first delivery; more nausea, vomiting, and anorexia; more menstrual pains and premenstrual irritability; early paternal loss; lower maternal care and higher paternal overprotection; higher public self-consciousness score; more smoking and use of medication in pregnancy; unwanted pregnancy; negative psychological response to the pregnancy by the woman and husband; poor intimacy by the husband; and having remarried. CONCLUSIONS: Depression in early pregnancy is determined mainly by psychosocial factors.

Adult↗
PubMed1996

A rapid- and short-acting hypoglycemic agent KAD-1229 improves post-prandial hyperglycemia and diabetic complications in streptozotocin-induced non-insulin-dependent diabetes mellitus rats.

We investigated therapeutic effects of a rapid- and short-acting non-sulfonylurea hypoglycemic agent, calcium (2S)-2-benzyl-3-(cis-hexahydro-2-isoindolinylcarbonyl)propionate dihydrate (KAD-1229), on streptozotocin (STZ)-induced non-insulin-dependent diabetes mellitus (NIDDM) rats. The effects exerted by KAD-1229 on the post-prandial plasma glucose rise in STZ-induced mild NIDDM (mNIDDM) rats were different from those of sulfonylureas. When KAD-1229 with liquid meal (10 kcal/kg) was given to the mNIDDM rats, the plasma glucose migration was similar to that of normal healthy rats. On the contrary, glibenclamide had little or no effect on the plasma glucose rise 0.5-1 hr after oral administration, and its effect was only evident 2-5 hr after dosing. Tolbutamide showed similar hypoglycemia to that induced by glibenclamide at 2-5 hr with insufficient efficacy at 0.5 hr. Gliclazide sufficiently suppressed the level of post-prandial plasma glucose. However, its complete inhibition of post-prandial plasma glucose was associated with the extra-hypoglycemia 1-5 hr after oral administration. We also tested the efficacy of KAD-1229 in more severe STZ-induced NIDDM (sNIDDM) rats to elucidate the effects of the drug on the long-term glycemic controls and diabetic complications. When the sNIDDM rats were treated with 10 mg/kg KAD-1229 twice a day for about 17 weeks, increases in fasting plasma glucose and hemoglobin A1c were inhibited. Furthermore, treatment with KAD-1229 suppressed the development of microalbuminuria and cortical cataract. We conclude that the rapid- and short-acting insulinotropic agent KAD-1229 is able to improve the deterioration in the glycemic controls and inhibit the development of diabetic complications in STZ-induced NIDDM rats.

Albuminuria↗
PubMed1996

Protective immunity induced with the antigens fractionated by affinity chromatography from the second generation schizonts of Leucocytozoon caulleryi.

A crude extract of the 2nd generation schizonts (2GS) of Leucocytozoon caulleryi and chicken serum containing serum-soluble antigens were applied to an immunoaffinity column using immunoglobulin of chickens recovered from L. caulleryi infections. The fractionated antibody-bound proteins showed several bands between 70 kDa and 35 kDa by the electrophoretic analysis. By immunization of chickens, the fractionated proteins conferred the protection at varying degrees comparable to that conferred by the unfractionated original materials. These results indicated that antiserum against 2GS can recognize the proteins involved in protective immunity.

Animals↗
PubMed1996

Effects of wortmannin, a novel myosin light-chain kinase inhibitor, on bile canalicular contraction in vitro and in vivo.

BACKGROUND: The cytoskeletal system is believed to play an important role in normal bile formation. The effects of wortmannin, a new myosin light-chain kinase inhibitor, on bile canalicular contraction and bile flow have been observed. METHODS: The bile canalicular contraction of cultured hepatocyte doublets was investigated, using an image analyzer with a phase contrast microscope, and the intracellular Ca2+ concentration was measured, using microscopic fluorometry. We also investigated bile flow by in vivo intraportal infusion of the drug in rats. RESULTS: Treatment with wortmannin inhibited norepinephrine-induced canalicular contraction and caused a decrease in bile flow without changing systematic and portal blood pressure. Morphologic examination of the electron microscopic study showed that most bile canaliculi were dilated, with loss of microvilli, but no other apparent damage was seen in parenchymal hepatocytes. CONCLUSIONS: These data suggest that the integrity of the phosphorylation system of myosin is essential for normal bile flow.

Androstadienes↗