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K Hanada

Publications and source records attributed to K Hanada.

At least 163 records · Page 9Linked to original sources
PubMed1997

Expression of TrkB-like immunoreactivity in non-neural cells of rat periodontal ligament.

The Trk family, a group of high-affinity neurotrophin receptors, is divided into three subtypes, TrkA, TrkB and TrkC. These were originally found in neural elements, and are involved in neural development, maintenance and survival. Recent studies have shown that non-neural cells in vitro also express mRNA encoding some neurotrophin receptors. In our preliminary study, TrkB-like immunoreactivity (LI) was found in the various non-neural cells in the rat periodontal ligament. The present study was undertaken to clarify which cell types express Trk-LI, in particular two types of TrkB-LI, in the periodontal ligament of mature rats, using an immunocytochemical technique with polyclonal antibodies. Intense full-length TrkB-LI was clearly recognized in non-neural cells such as fibroblasts, osteoclasts, odontoclasts and cementoblasts as well as in neural elements. Relatively large cells with many cytoplasmic processes were also frequently immunopositive for full-length TrkB. Immunocytochemistry for TrkB[TK-], a truncated type, also demonstrated a similar immunostaining pattern to that of full-length TrkB in non-neural periodontal cells, and intense positive reactions in endothelial cells. Some non-neural cells were positive for TrkA and TrkC. These findings suggest that neurotrophic factors, the ligands of the Trk family, have certain effects on the proliferation and/or differentiation of non-neural cells, as well as on their neurotrophic functions.

Animals↗
PubMed1997

TP53 mutations in stage I gallbladder carcinoma with special attention to growth patterns.

32 stage I cases of gallbladder carcinoma (GC) were examined to evaluate TP53 mutations with special attention to growth patterns. Their growth patterns were classified into two types: polypoid (P-type) and flat (F-type). 16 cases of GC were classified as P-type and 16 as F-type. p53 immunohistochemistry was performed using a mouse monoclonal anti-p53 antibody. Mutations in exons 5-8 were examined by polymerase chain reaction single strand conformation polymorphism (PCR-SSCP) and direct sequencing. The incidence of p53 immunoreactivity was greater in the cases of F-type (11/16, 69%) than those in P-type (14/16, 25%) (P < 0.05). PCR-SSCP or direct sequencing revealed that TP53 mutations were detected in all cases positive for p53 protein. These results suggest that TP53 mutations may contribute to the carcinogenesis of the F-type GC, and than this pathway in the F-type may differ from that in the P-type GC.

Adenocarcinoma↗
PubMed1997

Basic fibroblast growth factor promotes extension of regenerating axons of peripheral nerve. In vivo experiments using a Schwann cell basal lamina tube model.

Schwann cell basal lamina tubes serve as attractive conduits for regeneration of peripheral nerve axons. In the present study, by using basal lamina tubes prepared by in situ freeze-treatment of rat saphenous nerve, the effects of exogenously applied basic fibroblast growth factor (bFGF) on peripheral nerve regeneration was examined 2 and 5 days after bFGF administration. Regenerating axons were observed by light and electron microscopy using PGP9.5-immunohistochemistry for specific staining of axons. In addition, the localizations of bFGF and its receptor (FGF receptor-1) were examined by immunohistochemistry using anti-bFGF antibody and anti-FGF receptor-1 antibody, respectively. Regenerating axons extended further in the bFGF-administered segment than in the bFGF-untreated control segment. Electron microscopy showed that regenerating axons grew out unaccompanied by Schwann cells. Findings concerning angiogenesis and Schwann cell migration were very similar between the bFGF treated and control nerve segment. bFGF-immunoreactivity was not detected in the control nerve segment. In contrast, bFGF-immunoreactivity was detected on the basal lamina tubes as well as on the plasmalemma of regenerating axons facing the basal lamina in the bFGF treated nerve segment up to 5 days after administration, suggesting that exogenous bFGF can be retained in the basal lamina for several days after administration. FGF receptor was detected on the plasma membrane of regenerating axons where they abutted the basal lamina. These results indicate that bFGF could promote the extension of early regenerating axons by directly influencing the axons, but not via Schwann cells or angiogenesis.

Animals↗
PubMed1997

A multiparametric analysis of occlusal and periodontal jaw reflex characteristics in young adults with normal occlusion.

Periodontal jaw reflex, duration of percussion sounds, tooth mobility, and time-moment analysis of occlusal contacts by the T-scan system was recorded in nine periodontally healthy volunteers. The results showed that (i) reflex responses to the pressure applied to the uppercentageral incisors in the lingolabial direction varied, depending on the background jaw-clenching force (BCF) of the same-sided first molars. The BCF levels to elicit excitatory reflexes were 6-8 Kgf, and inhibitory reflexes were clearly elicited with a BCF of 10 Kgf and beyond. (ii) Duration of percussion sounds via an occlusal sound analyser (4.73-4.84 mS: upper first molars, 4.89-5.00 mS: uppercentageral incisors) and tooth mobility using a 'Periotest' (3.3-3.5: upper first molars, 5.5-5.6: uppercentageral incisors) showed a normal value. (iii) The time moments of occlusal contacts were symmetrical toward the midsagittal axis of the occlusal plane. The centre of the anteroposterior occlusal contacts was located in the first molar regions.

Adult↗
PubMed1997

Photoprotective effect of esterified glutathione against ultraviolet B-induced sunburn cell formation in the hairless mice.

Previously we showed a protective role of endogenous glutathione (GSH) in ultraviolet B (UVB) injury. Moderate UVB exposure to hairless mice receiving oral treatment with buthionine sulfoximine (BSO), an inhibitor of GSH synthesis, resulted in a greater number of SBCs in the epidermis. The evidence led to the hypothesis that increasing the level of endogenous GSH in the skin may reduce the skin damage caused by a high dose of UVB irradiation. Since systemic administration of a reduced form of GSH (reduced GSH) is understood to have poor permeability into the cells, in the current study we investigated transportability of esterified GSH and photoprotective effect of reduced GSH and the esterified derivative against UVB injury in vivo. Oral administration of esterified GSH revealed increased cutaneous GSH level more effectively than did reduced GSH. The number of sunburn cells (SBC) formed was significantly depressed in the skin exposed to UVB in mice treated with esterified GSH as compared with non-GSH- or reduced GSH-treated mice. The suppressive effect of esterified GSH was prominent in BSO-treated animals.

Animals↗
PubMed1997

In vivo transfer of a foreign gene to keratinocytes using the hemagglutinating virus of Japan-liposome method.

The hemagglutinating virus of Japan (HVJ)-liposome method involves the entrapment of DNA and nuclear protein within liposomes and the use of HVJ to enhance liposome fusion with cell membranes. This method has been used successfully for in vivo gene transfer to various types of tissue. In this study, we investigated whether this method transfers genes effectively to normal and malignantly transformed keratinocytes in vivo. We applied HVJ-liposome complex (HLC) containing the beta-galactosidase gene to the tape-stripped skin of hairless rats and detected the enzyme activity in the keratinocytes of the treated skin. Comparison of this method with the naked DNA injection method, which was shown recently to be useful for in vivo gene transfer to keratinocytes, demonstrated that the transfer efficiency of the latter was about 5 times higher than that of the former. We assessed the efficacy of the HVJ-liposome method for gene transfer to transformed keratinocytes by examining the effect of HLC containing the herpes simplex virus thymidine kinase gene on the growth of mouse squamous cell carcinomas. Local injection of HLC into the tumors followed by administration of ganciclovir to mice resulted in tumor growth inhibition. These results indicate that the HVJ-liposome method is suitable for in vivo gene transfer to keratinocytes; also that this method may prove a good tool for basic research into keratinocyte biology and future keratinocyte gene therapy.

Animals↗
PubMed1997

Decrease in class pi glutathione transferase mRNA levels by ultraviolet irradiation of cultured rat keratinocytes.

The effect of ultraviolet (UV) B irradiation on pi class glutathione transferase (GST-P) gene expression was examined in cultured rat keratinocytes. Immunoblotting demonstrated GST-P to be the major GST form in the cells, and it was significantly decreased following irradiation. Northern blot analysis revealed that the mRNA decreased to 10-25% of the initial value 24 h after irradiation at a dose of 40 mJ/cm2. No remarkable changes were observed at earlier time points. Hydrogen peroxide treatment enhanced GST-P mRNA expression, with a 70% increase at 250 microM concentration. Alterations in possible trans-acting factors were examined to clarify the mechanism of repression by UV irradiation. c-Jun mRNA was induced 3.5-fold at 4 h after irradiation, but by 24 h fell to a lower level than that observed initially. c-Fos mRNA was increased 10-fold at 1 h but was completely suppressed at 12 and 24 h. Thus, the changes of c-Jun and c-Fos mRNA differed from that of GST-P mRNA. The level of mRNA for silencer factor-B was decreased to less than 10% at 12 h. UV irradiation of cells transfected with the chloramphenicol acetyltransferase (CAT) reporter gene containing enhancer (GPE I) or silencer regions of the GST-P gene did not suppress CAT activity. Although basal expression of the GST-P gene was mainly dependent on GPE I, altered expression of c-jun, c-fos and other genes coding for factors possibly trans-acting on GPE I did not appear to be responsible for the decreased GST-P mRNA levels.

Animals↗
PubMed1997

Stimulatory effects of basic fibroblast growth factor and bone morphogenetic protein-2 on osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells.

Bone marrow stroma contains multipotential mesenchymal progenitor cells which can differentiate into osteoblastic cells; we refer to these cells as mesenchymal stem cells (MSCs). Basic fibroblast growth factor (bFGF) and bone morphogenetic protein-2 (BMP-2) have been implicated in the osteogenic regulatory process by virtue of their mitogenic and differentiation activities, respectively. This study examines and compares the effects of bFGF and BMP-2 on dexamethasone (Dex)-dependent in vitro osteogenic differentiation of rat marrow-derived MSCs. A 6-day exposure to bFGF markedly stimulated cell growth and induced osteoblastic differentiation as shown by osteocalcin mRNA expression (day 14), bone nodule formation (day 18), and calcium deposition (day 18). These results indicate that bFGF enhances both mitogenic activity and osteogenic development of Dex-treated marrow MSCs. In contrast, BMP-2 did not induce osteogenesis as strongly as bFGF. Thus, exposure to BMP-2 slightly increased bone nodule number and calcium content compared with the control. Exposure of MSCs to both BMP-2 and bFGF induced expression of osteocalcin mRNA and mineralizing bone-like nodules as early as day 11 and resulted in enhancement of bone formation more markedly than either factor alone. Consistent with these results, porous calcium phosphate ceramic cubes implanted in vivo, which were loaded with MSCs pre-exposed to both bFGF and BMP-2, showed higher histologic score for bone formation than those with MSCs pre-exposed to either bFGF or BMP-2 alone. These data indicate that combined treatment with bFGF and BMP-2 synergistically enhances the osteogenic potency of bFGF in rat marrow MSC culture.

Animals↗
PubMed1997

Down-regulation of gap junctional intercellular communication between osteoblastic MC3T3-E1 cells by basic fibroblast growth factor and a phorbol ester (12-O-tetradecanoylphorbol-13-acetate).

To address the relation between osteoblast growth and cell-to-cell communication, we examined the effects of basic fibroblast growth factor (bFGF) and 12-O-tetradecanoylphorbol-13-acetate (TPA), both potent stimulators of osteoblastic proliferation, on gap junctional intercellular communication between osteoblastic MC3T3-E1 cells. The level of intercellular communication was estimated by a photobleaching method. TPA inhibited the degree of intercellular communication in two different time-dependent manners. The early (< 1 h) inhibition by TPA was consistent with an increase in the phosphorylation of connexin 43 (Cx43). The later inhibition was caused by reduction in the total amount of Cx43 on the plasma membrane, due to the decrease in the level of Cx43 transcripts. These qualitative and quantitative modulations by TPA were inhibited by a selective inhibitor of protein kinase C, GF109203X. bFGF also attenuated the gap junctional intercellular communication. However, short exposure (< 5 h) to bFGF did not affect the communication. The fact that the growth factor immediately stimulated the phosphorylation of Cx43 indicates that the phosphorylation site(s) affected by bFGF was not involved in the inhibition of communication. The decrease in the intercellular communication level was detected by the longer exposure (> 8 h) to bFGF and paralleled the decline in the Cx-mRNA level. This inhibitory effect of bFGF was abolished by the addition of a tyrosine kinase inhibitor, herbimycin A. Thus, gap junctional intercellular communication between osteoblasts was down-regulated by osteoblastic mitogens through different mechanisms of the modulation of Cx43.

3T3 Cells↗
PubMed1997

Stimulation of endosteal bone formation by local intraosseous application of basic fibroblast growth factor in rats.

We investigated the effects of local intraosseous application of basic fibroblast growth factor under physiologic conditions. An aqueous solution containing 0 (vehicle), 25, 100, or 400 micrograms of basic fibroblast growth factor was injected via a needle into the ilium of rats. Two weeks later, bone mineral density of the ilium was significantly increased (P < 0.01) with all three doses, and a dose-effect relationship was apparent. Light microscopy revealed proliferation of undifferentiated mesenchymal cells on the endosteal and trabecular surfaces, as well as apposition of newly formed bone on existing trabeculae. Intraosseous injection of basic fibroblast growth factor may be of use for the treatment of osteoporosis.

Administration, Topical↗
PubMed1997

Results of 90 consecutive hepatectomies for hepatocellular carcinoma: a multivariate analysis of survival.

The surgical results and postoperative management of 90 patients with hepatocellular carcinoma (HCC) who underwent hepatectomy were reviewed, and clinical factors relating to HCC were analyzed to determine what type of HCC responds best to hepatectomy. The patients consisted of 69 men and 21 women. Serum anti-hepatitis C virus was positive in 76.9% of patients and hepatitis B surface antigen was positive in 18.9%. The operative procedures consisted of right lobectomy in six patients, left lobectomy in seven, right hepatic segmentectomy in eight, left lateral segmentectomy in 13, two adjoining subsegmentectomy in 17, subsegmentectomy in 29, and partial hepatectomy in 10. Liver cirrhosis was confirmed histopathologically in 63 patients. There were two operative deaths and two other in-hospital deaths. During the follow-up period, HCC recurred in 64 of the remaining 86 patients at the following sites: liver in 56 patients (87.5%), bones in four (6.3%), lymph nodes in three (4.7%), and lung in one (1.6%). Transcatheter arterial chemoembolization was performed in 22 of the patients with recurrence, transcatheter arterial chemoembolization in combination with percutaneous ethanol injection was performed in 14, hepatectomy was performed in six, and irradiation with Linac x-rays was performed in eight. The cumulative 3- and 5-year survival rates were 63.8% and 37.8%, respectively. Univariate and multivariate analyses of factors influencing survival disclosed that having a single HCC nodule of up to a maximal diameter of 4.0 cm, an absence of intrahepatic metastasis, and a functional liver reserve estimated as clinical stage I contributed significantly and independently to increasing the survival rate.

Adult↗
PubMed1997

[A drug revolving fund program for rural villages in the Philippines].

In 1994, a community-based drug revolving fund program was introduced in 10 pilot villages in the province of Tarlac, Philippines, as a component of a health project by the provincial health office and Japan International Cooperation Agency (JICA). The purpose of the program was to set up a cooperative drug store in each community in order to regularly provide rural residents with essential drugs at affordable prices. The following are the results and findings during the first two years of operation. 1. Collaboration with a local NGO facilitated implementation and management of the program, when socio-cultural consideration was necessary. Stable and prompt procurement of drugs was secured on a contract with a commercial wholesaler in Manila. 2. Out of the 105 kinds of pharmaceuticals that were sold both in the cooperative and commercial drug stores, 83% were less expensive than the average market price, and 51% were discounted more than 25% of the market price. 3. The levy of premiums was introduced to increase the cooperative fund with the consent of each community. The amount was 0.1-0.2% of the average family income. However, regular collection of premiums was difficult due to various reasons. The practice of the sales on credit was common in all pilot villages. 4. While the knowledge of community health workers, who were in charge drug sales, was improved after training sessions on rational drug use, it was not at a sufficient level yet. 5. When assisting a community-oriented health program, an exterior organization should try to encourage the community to generate its own solutions to operational difficulties, based on the socio-cultural context in the community.

Community Participation↗
PubMed1996

Long-term lymphohematopoietic reconstitution by a single CD34-low/negative hematopoietic stem cell.

Hematopoietic stem cells (HSCs) supply all blood cells throughout life by making use of their self-renewal and multilineage differentiation capabilities. A monoclonal antibody raised to the mouse homolog of CD34 (mCD34) was used to purify mouse HSCs to near homogeneity. Unlike in humans, primitive adult mouse bone marrow HSCs were detected in the mCD34 low to negative fraction. Injection of a single mCD34(lo/-), c-Kit+, Sca-1(+), lineage markers negative (Lin-) cell resulted in long-term reconstitution of the lymphohematopoietic system in 21 percent of recipients. Thus, the purified HSC population should enable analysis of the self-renewal and multilineage differentiation of individual HSCs.

Animals↗
PubMed1996

Immunocytochemical detection of p53 protein from pancreatic duct brushings in patients with pancreatic carcinoma.

BACKGROUND: It is often difficult to distinguish pancreatic carcinoma preoperatively from chronic pancreatitis. Therefore, we have developed a new method of detecting p53 immunoreactivity in cytologic material obtained by endoscopic retrograde pancreatic duct brushing (ERPDB). METHODS: Twenty-eight patients with prominent strictures of the main pancreatic duct demonstrated by pancreatography including 20 ductal cell carcinoma and 8 chronic pancreatitis were studied. The ability to distinguish between these two groups preoperatively by conventional cytologic examination was compared with p53 immunocytochemistry using ERPDB: RESULTS: The sensitivity, specificity, and overall accuracy of conventional cytologic examination in distinguishing ductal cell carcinoma from chronic pancreatitis were 60%, 100%, and 71% respectively. In comparison, the sensitivity, specificity, and overall accuracy of p53 immunocytochemistry in distinguishing were 90%, 100%, and 93%, respectively. The sensitivity of p53 staining of specimens from patients with carcinoma of the body or tail of the pancreas (90%) was the same for those with tumors of the head of the pancreas (90%). CONCLUSIONS: These results suggest that p53 immunocytochemistry using ERPDB in conjunction with conventional cytologic examination can help differentiate ductal cell carcinoma from chronic pancreatitis preoperatively.

Adenocarcinoma↗
PubMed1996

RNA polymerase I associated factor 53 binds to the nucleolar transcription factor UBF and functions in specific rDNA transcription.

Mouse RNA polymerase I (Pol I) has, besides its 11 bona fide subunits, three polymerase associated factors, termed PAF53, 51 and 49 with respect to the size of each molecule. In order to analyze the function of PAFs, cDNA encoding PAF53 was isolated using an oligonucleotide probe derived from an oligopeptide sequence. The cDNA of PAF53 predicts a polypeptide of 434 amino acids with a sequence similarity to yeast Pol 1 49 kDa subunit. Anti-PAF53 antibody does not block the random transcription activity of Pol I, but blocks specific transcription from mouse ribosomal RNA promoter, demonstrating the requirement of PAF53 in the accurate initiation of Pol I transcription. Moreover, PAF53 interacted with mouse UBF in vitro, as revealed by Far-Western blotting and GST pull down assays. These results, together with the accumulation of PAF53 in the nucleolus of growing cells, suggest that PAF53 is involved in the formation of the initiation complex at the promoter by mediating the interaction between Pol I and UBF for the active rRNA synthesis.

3T3 Cells↗
PubMed1996

Cholecystokinin receptor antagonist, loxiglumide, inhibits invasiveness of human pancreatic cancer cell lines.

Recently, cholecystokinin has been reported to be important in regulating the growth of pancreatic cancer. We investigated the effect of loxiglumide (LXG), a cholecystokinin receptor antagonist, on the invasiveness of two human pancreatic cancer cell lines. Cells were treated with LXG for 24 h, and examined in the invasion assay. The expression and activity of MMP-9 in supernatants from cancer cells were analyzed by Western blotting and zymogram. Interestingly, the invasiveness of cancer cells and expression of MMP-9 were decreased by LXG in a dose-dependent manner. LXG may be a useful therapeutic agent against pancreatic cancer.

Blotting, Western↗