Hidefumi Kumada

• PhD
• Professor (Associate) at Kanagawa Dental University

Di (2-ethylhexyl) phthalate (DEHP), a typical plasticizer used for polyvinyl chloride (PVC), is eluted from PVC-made blood containers and protects against red blood cell (RBC) hemolysis. However, concerns have arisen regarding the reproductive and developmental risks of DEHP in humans, and the use of alternative plasticizers for medical devices has...

The purpose of this study was to evaluate the antibacterial activity against polymicrobial (PM) biofilms of a condensed tannin extracted from astringent persimmon (PS-M), which is contained in refreshing beverages commercially available in Japan. Salivary PM biofilms were formed anaerobically on glass coverslips for 24 and 72 h and were treated for...

To simulate an oral demineralization environment by multiple species of bacteria by inducing subsurface dentin lesions with a polymicrobial biofilm model. Polymicrobial biofilms consisting of multiple species of bacteria were generated from stimulated saliva using a high-throughput active attachment model. Biofilms were grown on dentin specimens in...

To investigate the in vitro antimicrobial effects of carbamide peroxide (CP) and CP-based home bleaching agents against polymicrobial (PM) biofilms. Using a high-throughput active attachment model, PM biofilms were cultured on glass coverslips by diluting the stimulated saliva of one healthy adult. All experiments were performed anaerobically in Mc...

Background: Although Superabsorbent Polymer (SAP) microsphere has been useful in treatment of multiple and large hepatocellular carcinoma, efficient loading procedure of cisplatin onto SAP was not established. Loading efficiency of cisplatin was evaluated from the viewpoint of passive concentration gradient and ionic strength. Methods: To load cisp...

Objective: Surface pre-reacted glass-ionomer (S-PRG) filler shows ability to release fluoride and other ions (Sr2+, SiO32-, BO33-, Na+, and Al+3). We evaluated the antibacterial effects of an eluate from S-PRG filler on polymicrobial oral biofilm in vitro. Methods: S-PRG filler was suspended in distilled water and the saturated clear supernatant us...

Objective: PancilPS-M (Rilis Co., Ltd, Osaka, Japan) is a food addictive containing condensed tannin extracted from astringent persimmon. The purpose of this study was to examine the antibacterial action of Pancil PS-M on the formation of polymicrobial biofilms. Methods: PancilPS-M was dissolved in distilled water, sterilized and serially diluted f...

Entecavir (ETV) is reported to result in suppression of hepatitis B virus DNA (HBV DNA) replication with minimal drug resistance. However, information on the long-term effect of such therapy on serum hepatitis B surface antigen (HBsAg) level and elimination of HBsAg is not available. ETV therapy was started in 553 nucleos(t)ide-naïve patients with...

Objectives: Porphyromonas gingivalis, which is the major periodontopathic bacterium, possesses trypsin-like enzyme (gingipain). This microorganism is also responsible for oral malodor to produce significantly high volatile sulfur compounds (VSCs), such as hydrogen sulfide (H2S) and methyl mercaptan (CH3SH). The objective of this study is to examine...

Objective: Juzentaihoto (JTX; Shi-Quan-Da-Bu-Tang in Chinese) is one of the herbal medicines, and consists of 10 herbs. JTX is widely prescribed for anemia, rheumatoid arthritis, chronic fatigue syndrome, and inflammatory bowel diseases as a therapeutic medicine in medical field. Some herbal medicines and its ingredients have also been reported to...

Hepatitis C virus (HCV) subtype 1b, which infects approximately 70% of Japanese carriers, is likely to be more eradicable by a telaprevir regimen than subtype 1a because of the higher genetic barrier of Val(36) and Arg(155) substitutions. The aims of this exploratory study were to evaluate the virological response and safety of 24-week oral adminis...

Oral biofilms are composed of complex structured multi-species bacterial communities, which are the causative agents of periodontal diseases. The species Actinomyces naeslundii, formerly known as Actinomyces viscosus, have been isolated from oral cavities and gingival pockets. A. naeslundii is one of the early colonizers, and plays an important rol...

Background : Porphyromonas gulae are black-pigmented anaerobic bacteria isolated from the gingival sulcus of various animal hosts and are distinct from Porphyromonas gingivalis originating in humans. We previously reported the antigenic similarities of 41-kDa fimbriae between P. gulae ATCC 51700 and P. gingivalis ATCC 33277. In this study, to clari...

Objectives: The purpose of the study was to establish a microcosm biofilm model resulting in dentin carious lesions utilizing saliva derived microcosm biofilms in vitro. Methods: A high-through-put biofilm model was used based on active attachment of bacteria to surfaces (Exterkate et al, Caries Research 2010). Biofilms were formed on either dent...

Objective: Actinomyces naeslundii, plays an important role in forming dental biofilms and causes gingival inflammation. Although peptidoglycan, the major cell wall component of Gram-positive bacteria, has been demonstrated to induce inflammatory cytokines, little is known about the association of peptidoglycan with alveolar bone resorption. This s...

Telaprevir in combination with peginterferon and ribavirin is a promising advancement in chronic hepatitis C treatment. However, the safety, tolerability, pharmacokinetics and antiviral profiles of telaprevir alone beyond 2 weeks have not been studied. In a phase 1b study in Japan, 10 treatment-naïve patients infected with hepatitis C virus genotyp...

The aims of this phase III study were to assess the efficacy and safety of telaprevir in combination with peginterferon alfa-2b (PEG-IFN) and ribavirin (RBV) for difficult-to-treat patients who had not achieved sustained virological response (SVR) to prior regimens in Japan. The subjects were 109 relapsers (median age of 57.0 years) and 32 nonrespo...

We have previously reported that azulene-related compounds, and alkaline extract of Sasa senanensis Rehder potently inhibited nitric oxide (NO) production by lipopolysaccharide (LPS)-stimulated mouse macrophages. We investigated here whether they can inhibit pro-inflammatory cytokine production, by activated human gingival fibroblast (HGF). HGF was...

Objectives:Periodontitis is bacteria-induced inflammatory disease with alveolar bone resorption. To clarify the Gram-positive bacteria involvement in periodontitis, we investigated the alveolar bone loss induced by Actinomyces naeslundii in an experimental rat periodontitis model and evaluated the role of peptidoglycan in the differentiation of ost...

Objectives: Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola, which possess the trypsin-like enzymes, have been reported to produce significantly high volatile sulfur compounds (VSCs). The objective of this study is to determine the roles of their protease activity for production of VSCs in saliva. Materials and Methods: Paraf...

Objectives: Stomatitis is generated by various factors such as physical stresses and dental treatments, and bacterial and viral infections, and even anticancer drugs. There is a possibility that stomatitis may be a risk factor for the carcinogenesis. It is therefore very important to establish the in vitro stomatitis model for the search of potenti...

4009 Background: Although some reports have shown that interferon (IFN) can reduce the hepatocarcinogenesis in HCV-related noncirrhotic and cirrhotic patients through reduction or complete remission of inflammatory activity, the effect of IFN therapy without anti-inflammation has not been clear. In patients with HCV genotype 1b(HCV-1b), amino acid...

e14598 Background: The aim of this study was to elucidate whether the histopathological characteristics of hepatocellular carcinoma (HCC) can be predicted from baseline dynamic-CT images. Methods: This retrospective study included 86 consecutive patients with HCC who underwent surgical resection between January 2000 and September 2008. The arterial...

An impact of serum hepatitis B virus (HBV) DNA on hepatocarcinogenesis has not been investigated in a cohort of patients with non-B, non-C cirrhosis. Eighty-two consecutive Japanese patients with cirrhosis, who showed negative hepatitis B surface antigen and negative anti-hepatitis C virus, were observed for a median of 5.8 years. Hepatitis B virus...

Eight anaerobic, pigmented, non-spore-forming, Gram-negative, rod-shaped strains isolated from monkey oral cavities were characterized phenotypically and chemotaxonomically and their phylogenetic positions were determined using 16S rRNA gene sequence analysis. The 16S rRNA gene sequence analysis showed that these isolates represent a single species...

Porphyromonas gulae is black-pigmented anaerobic bacteria associated with canine periodontitis. There is little information available about the specific identify and relative occurrence of pigmented anaerobes in companion animals. Our aim was to clarify the factor involved in the adherence and colonization of the organism in the oral cavity. Fimbri...

A method that allows the quantitation of hepatitis C virus (HCV) RNA is described. The RNA was extracted from serum samples and reverse transcribed. Target cDNA was then co-amplified by nested polymerase chain reaction with a known amount of competitive template at various concentrations. Since this internal control DNA uses the same primers as tho...

A pentaacyl and diphosphoryl lipid A molecule found in the lipid A isolated from Porphyromonas gingivalis lipopolysaccharide (LPS) was chemically synthesized, and its characteristics were evaluated to reconfirm its interesting bioactivities including low endotoxicity and activity against LPS-unresponsive C3H/HeJ mouse cells. The synthesized P. ging...

Adult periodontitis is initiated by specific periodontal pathogens represented by Porphyromonas gingivalis; however, an effective measure for preventing the disease has not yet been established. In this study, the effectiveness of a vaccine composed of fimbriae of P. gingivalis and recombinant cholera toxin B subunit (rCTB) was evaluated using BALB...

The purpose of this study was to develop an acrylic resin with antifungal properties by leveraging the photocatalytic activity of apatite-coated titanium dioxide (Ap-TiO2). Candida albicans was used for antifungal activity assay of the specimen plates under ultraviolet A (UVA) with a black light source. Statistically significant decreases in cell v...

Abstract Periodate-thiobarbituric acid reaction-positive substances were found in the strong acid hydrolysates of the lipopolysaccharide (LPS) from Bacteroides gingivalis 381. They were not identical to 2-keto-3-deoxyoctonate (KDO) in high-voltage paper electrophoresis (HVPE), their electrophoretic mobilities relative to KDO being 1.54 and 1.80, re...

Thymalfasin (thymosin alpha-1; Talpha1) is a 28-amino acid polypeptide that has shown efficacy in the treatment of chronic hepatitis B virus (HBV) infection. The objective of this study was to evaluate the long-term, dose-related efficacy and safety of Talpha1 treatment in chronic hepatitis B patients with positive HBV-DNA and abnormally high alani...

Entecavir (ETV) exhibits potent antiviral activity in patients chronically infected with wild-type or lamivudine-resistant hepatitis B virus (HBV). Among the patients treated in phase II ETV clinical trials, one patient for whom previous therapies had failed exhibited virologic breakthrough while on ETV. Isolates from this patient were analyzed gen...

The biological activity of interferon (IFN) is mediated by the induction of intracellular antiviral proteins, such as 2'-5' oligoadenylate synthetase, dsRNA-activated protein kinase and MxA protein. Among these, MxA protein is assumed to be the most specific surrogate parameter for IFN action. This study was performed to elucidate whether a single...

Mutations in the precore region and core promoter were compared between patients with acute and chronic hepatitis B. There were 69 patients with acute self-limited hepatitis B and 210 with chronic hepatitis B who had been followed for > 15 years. The hepatitis B virus (HBV) of genotypes A, B and C was detected in 14 (23%), 8 (13%) and 28 (45%) of t...

Serum antibody titers against the lipopolysaccharides (LPSs) of Porphyromonas gingivalis and Fusobacterium nucleatum were compared between 9 periodontitis patients and 24 healthy persons. The IgG titers against the LPSs of P. gingivalis ATCC 33277(T) and W50 were clearly higher in the patients than in the healthy persons. However, IgM titers agains...

To identify the influence of hepatitis B virus (HBV) genotype on development of hepatocellular carcinoma (HCC) and clinical outcome in chronic HBV infection, 26 consecutive cirrhotic patients infected with HBV subtype adw were investigated prospectively. HBV serology was undertaken using subtype-specific antibodies against hepatitis B surface antig...

HCV-RNA clearance rates are reported to be about 30-40% of the patients treated with IFN for less than 6 months. But IFN therapy is ineffective for chronic hepatitis C patients with HCV-genotype 1b and a high virus load. We evaluated the efficacy of different IFN therapy compared with standard IFN therapy for chronic hepatitis C patients resistant...

Among 457 elderly patients of 65 years or older with chronic hepatitis or cirrhosis caused by hepatitis C virus, 117 patients underwent interferon therapy for the elimination of hepatitis C virus. A total of 87 patients could be analyzed for the interferon effect, since the remaining 20 patients had still been receiving or just finished the therapy...

Preischaemic treatment with N ‐methyl‐1‐deoxynojirimycin (MOR‐14), an α‐1,6‐glucosidase inhibitor, attenuates glycogenolysis and lactate accumulation during ischaemia and markedly reduces infarct size in rabbit hearts. In the present study, we have investigated whether protein kinase C (PKC), a principal mediator of ischaemic preconditioning, is al...

A new medical irradiation facility has been installed in JRR-4. It was designed to permit selection of neutron energies from thermal neutron to epithermal range by changing the thickness of the heavy water layers. This facility then allows us to continue the thermal neutron irradiation protocol now performed in JRR-2, and to initiate the research a...

Gingival fibroblasts produce proinflammatory cytokines in response to lipopolysaccharide (LPS) from periodontopathic bacteria. Recently it has become evident that the human homologue of DrosophilaToll can transduce intracellular signaling by LPS stimulation. Toll-like receptors (TLRs) have been identified in myeloid cells; however, their role in no...

Hepatitis C virus (HCV) load is one of the most important predictive factors of response to interferon treatment. However, little is known about the mode and determinants of viremia. The mode of viremia was investigated in 78 patients with chronic HCV genotype 1b infection during 1–2 years follow up. Virus load, determined by a branched chain DNA a...

To examine the prevalence of TT virus (TTV) before and after blood transfusion, we retrospectively examined serum samples obtained from 55 patients who received blood transfusions before, during and after resection of hepatocellular carcinoma. TT virus DNA was extracted from serum samples and detected by nested polymerase chain reaction. Before tra...

TT virus (TTV) is a newly identified single-stranded DNA virus. We retrospectively analysed serum samples from sixteen patients, infected with both hepatitis C virus (HCV) and TTV, and who had been treated with interferon. An elevated serum alanine aminotransferase level after interferon was associated with persistence of HCV (abnormal in five of s...

Four hundred and twenty-one patients with hepatocellular carcinoma who firstly underwent transcatheter arterial chemoembolization were divided into three groups as "younger" (32-69yr-old, n = 340), "elderly" (70-79yr-old, n = 74) and "super-elderly" (80-89yr-old, n = 7). Between "younger" and "elderly," clinical stage of underlying liver disease, s...

It has been reported that glomerular cells with apoptosis and positive Fas immunoreactivity are seen in proliferative glomerulonephritis (PGN). Fas induces apoptosis when it binds to Fas ligand (Fas-L) or soluble Fas-L (sFas-L). However, soluble Fas (sFas) blocks apoptosis by inhibiting binding between Fas and Fas-L or sFas-L. That is, Fas, Fas-L,...

It has been reported that glomerular cells with apoptosis and positive Fas immunoreactivity are seen in proliferative glomerulonephritis (PGN). Fas induces apoptosis when it binds to Fas ligand (Fas-L) or soluble Fas-L (sFas-L). However, soluble Fas (sFas) blocks apoptosis by inhibiting binding between Fas and Fas-L or sFas-L. That is, Fas, Fas-L,...

In chronic obstructive pulmonary disease (COPD) which consists of emphysema and chronic bronchitis, alveolar tissue and/or bronchiolar walls are progressively destroyed. This suggests cell death by necrosis and/or apoptosis although no direct evidence of apoptosis has been reported. It was speculated that the apoptosis-related factors are associate...

To assess the biochemical and histological characteristics of hepatitis G virus (HGV) infection, we examined four patients who were infected with HGV only (HGV group), and compared them with 16 patients infected with both HGV and hepatitis C virus (HCV; HGV + HCV group) and 18 patients infected with HCV only (HCV group). Biochemical examination sho...

Interferon (IFN) can reduce hepatitis C virus load and even eliminate the virus in 30-40% of patients. Several predictive factors for eradication of the virus have been reported and a higher dose of IFN tends to result in elimination of the virus. However, a small dose of IFN sometimes is as effective as a large dose in eradicating the virus. The p...

To elucidate the influence of long term interferon administration on the rate of occurrence of hepatocellular carcinoma (HCC) in patients with hepatitis B virus (HBV)-related cirrhosis, the authors analyzed 313 consecutive patients with cirrhosis. Of the 313 patients, 94 underwent long term intermittent administration of interferon for > or = 6 mon...

In order to elucidate the influence of hepatitis B virus on the hepatocellular carcinogenesis in cirrhotic liver, quantitative analysis of precore region of hepatitis B virus was sequentially carried out. Among 191 patients who were diagnosed with cirrhosis in our hospital between 1974 and 1992 and had received no anti-viral therapy, 52 patients we...

To assess the characteristics of a zinostatin derivative, 29 patients with multiple hepatocellular carcinoma of 3 cm or less in diameter were treated with intra-arterial injection of the high molecular weight anti-tumor agent, styrene-maleic acid neocarzinostatin, mixed with Lipiodol. Computerized tomography 3 months after the first therapy showed...

Chemical and biological studies were performed on lipopolysaccharide isolated from Selenomonas sputigena ATCC 33150T, a possible causative agent of periodontal diseases. The sugar components of the lipopolysaccharide of S. sputigena were mannose, galactose, glucose, L-glycero-D-mannoheptose (heptose), 2-keto-3-deoxy-octonic acid, glucosamine and ga...

This study sought to examine plasma levels of soluble Fas/APO-1 receptor (sFas), an inhibitor of apoptosis, and soluble Fas ligand (sFas-L), an inducer of apoptosis, and their relation to each other and to other clinical variables, such as New York Heart Association functional class, tumor necrosis factor (TNF) and interleukin-6 (IL-6) in congestiv...

The lipid A preparation isolated from Porphyromonas gingivalis was found to induce splenocyte mitogenicity and TNF-alpha release from peritoneal macrophages in LPS-unresponsive C3H/HeJ mice to the same extent as in LPS-responsive mice. In order to clarify whether the activation of C3H/HeJ mice was specifically caused by the lipid A and not by conta...

Hepatocellular carcinoma (HCC) occurs in patients with hepatitis C virus-RNA positive chronic liver disease. It is important to prevent HCC with drug administration. A retrospective study was undertaken to evaluate the long term preventive effect of Stronger Neo-Minophagen C (SNMC) on HCC development. SNMC is a Japanese medicine that is commonly ad...

We examined cranial MRI in 62 patients with CLD. Abnormal finding that high intensity area in symmetrical bilateral basal ganglia other than globus pallidum was found on both T-1 weighted images (T1WI) and fat suppression (chemical shift selective) images. This MRI finding was observed in 32 of 41 patients with cirrhosis while 1 of 21 patients with...

Hepatitis C virus (HCV) genotype 1b and high pretreatment virus load are predictive factors of poor response to interferon therapy in patients with chronic hepatitis C. To further examine the factors predicting the response to interferon in patients with genotype 1b infection, we analyzed 110 consecutive patients with HCV who were treated with a to...

The relationship between chemical structure and biological activity of the lipid A from Porphyromonas gingivalis, which we recently isolated and whose complete chemical structure was determined [Kumada et al. (1995). J Bacteriol 177, 2098-2106], was studied. The lipid A exhibited endotoxic activity in all the assay systems tested: Limulus gelation...

After endoscopic ligation to stop bleeding from esophageal varices, new hemorrhage from ulcers at the site of ligation recurred in 2 cases. Octreotide-somatostatin analogue, diminished bleeding effectively. There was no adverse effect of infusing octreotide. Octreotide may have some benefits in achieving the control of variceal bleeding.

To elucidate the influence of portal invasion of hepatocellular carcinoma (HCC) on esophageal varices, consective 181 patients with HCC were studied. On endoscopic findings at the first admission, finding of F1RC (+) were noted in 4 (14.8%), F2RC (+) or over were noted in 13 (48.1%) patients with portal vein invasion. In contrast, F1RC (+) were not...

The immunobiological activities of 75-kDa protein, fimbrial protein and lipopolysaccharide lipopolysaccharide prepared from whole cells of Porphyromonas gingivalis 381 were compared. The 75-kDa protein was mitogenic for BALB/c nu/nu, BALB/c and lipopolysaccharide-responsive C3H/HeN mouse spleen cells and for lipopolysaccharide-non-responsive C3H/He...

Most patients infected with hepatitis C virus (HCV) develop chronic hepatitis. Unfortunately, the pathological evolution of this disease over time is not completely understood. We studied 70 HCV-positive patients, from whom 2 to 10 liver biopsy specimens (mean, 3.9) had been obtained during an interval of 1 to 26 years (mean, 8.8 years). Each biops...

Interferon treatment reduces the serum level of hepatitis C virus (HCV) and improves inflammatory activity, but relapse is frequently observed. In an attempt to develop a new therapeutic strategy that may reduce relapse and cure the disease, we evaluated the effect of corticosteroid priming on lymphoblastoid interferon alfa in an open randomized cl...

To determine the contribution of virus-related factors to long-term remission of chronic hepatitis C infection, we analyzed viral type and viremia level in 185 patients who had undergone a six-month course of interferon- therapy. These virus-related factors were measured by an enzyme-linked immunosorbent assay with use of viral type-specific antige...

The effects of Porphyromonas gingivalis lipopolysaccharide (P-LPS) and Escherichia coli lipopolysaccharide (E-LPS) on the gene expression and production of inflammatory cytokines of human periodontal ligament fibroblasts (HPLF) were examined by a Northern (RNA blot) assay and enzyme-linked immunosorbent assay, respectively. mRNAs for interleukin-6...

The chemical structure of lipid A isolated from Porphyromonas gingivalis lipopolysaccharide was elucidated by compositional analysis, mass spectrometry, and nuclear magnetic resonance spectroscopy. The hydrophilic backbone of free lipid A was found to consisted of beta(1,6)-linked D-glucosamine disaccharide 1-phosphate. (R)-3-Hydroxy-15-methylhexad...

To evaluate portal blood flow in small hepatocellular carcinomas (HCCs) by means of computed tomography during arterial portography (CTAP) and CTAP with hepatic arterial obstruction (CTP-HAO) achieved by means of balloon occlusion. Thirteen patients with small HCC (< 20 mm in diameter) underwent CTAP, CTP-HAO, carbon dioxide-enhanced ultrasound (CE...

We analyzed the Con A affinity of serum AFP in patients with a serum AFP concentration greater than 50ng/ml by antibody affinity electrophoresis and Western blotting to distinguish hepatocellular carcinoma (HCC) from benign chronic liver diseases (CLD). Of 164 patients with HCC, 48 (29.3%) had a single band, while 116 (70.7%) had multiple bands. Al...

We treated 812 patients who had chronic hepatitis C with interferon (IFN) and studied the effects of interferon. We defined complete response as normalization of amino-transferase more than 6 months after termination of IFN. Complete response by means of IFN therapy is dependent to some factors, that is HCV-genotype, quantity of HCV-RNA, histology....

Noting the acid-conditioning effect of minocycline on the root surface, we investigated the ability of minocycline to remove endotoxin on untreated, diseased cementum in vitro. Root surface specimens affected by periodontal disease were immersed in minocycline solution (10 mg/ml, 50 micrograms/ml, and 5 micrograms/ml) for 10 minutes, 1 day, 3 days,...

In order to elucidate the long-term prognosis of liver cirrhosis, we analyzed a total of 795 consecutive patients with viral or alcoholic cirrhosis prospectively. During the observation period (median, 5.8 yr), hepatocellular carcinoma (HCC) developed in 221 patients. Cumulative appearance rates of HCC were 19.4%, 44.3%, and 58.2% at the end of the...

The present study shows that monocyte chemotactic activity in crevicular fluids increases with severity of the disease and that a monocyte chemoattractant, monocyte chemoattractant protein 1 (MCP-1), is expressed as the predominant cytokine of gingival tissues and their fibroblasts treated with Porphyromonas (Bacteroides) gingivalis lipopolysacchar...

To clarify the angiographic features of small hepatocellular carcinoma, we performed digital subtraction angiography in 91 patients with hepatocellular carcinomas of 2 cm or less. Repeated digital subtraction angiography studies were performed in 25 patients whose first angiograms showed no tumor staining. Digital subtraction angiography showed hyp...