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Tetsuo Kato

Publications and source records attributed to Tetsuo Kato.

At least 19 recordsLinked to original sources
PubMed2007

Progress report on The Hypertension Objective Treatment Based on Measurement by Electrical Devices of Blood Pressure (HOMED-BP) study: status at February 2004.

The Hypertension Objective Treatment Based on Measurement by Electrical Devices of Blood Pressure (HOMED-BP) Study is the first large-scale intervention trial in Japan using a PROBE design to determine an optimal target blood pressure (BP) level on the basis of self-measured BP at home and optimal initial antihypertensive medication. The registered patients are randomized to one of two different BP levels and to initial antihypertensive regimens (i.e., calcium antagonist [Ca-A], angiotensin-converting enzyme inhibitor [ACE-I], or angiotensin II receptor antagonist [ARB]). At the end of February 2004, 2729, 1687, and 971 patients were recruited, randomized, and followed-up for 12 months or more. Among the 971 patients, mean systolic/diastolic BP levels at randomization in the Ca-A, ACE-I, and ARB groups were 150/90, 152/89, and 151/89 mmHg, respectively. These values reduced after six months of Ca-A-, ACE-I-, and ARB-based treatment (133/81 mmHg, 135/80 mmHg, and 134/79 mmHg, respectively) and further reduced after 12 months (131/80 mmHg, 134/79 mmHg, and 132/79 mmHg, respectively) without any significant differences among groups. In more intensive and less intensive BP-lowering groups, mean systolic/diastolic BP levels at randomization were 151/90 and 150/89 mmHg, respectively. Although BP levels reduced after 6-month (135/80 mmHg and 133/80 mmHg, respectively) and 12-month treatment (133/79 mmHg and 132/80 mmHg, respectively) in each target group, no significant difference in BP values was observed between groups. These results indicate the necessity of additional interventional strategies to improve the achievement of target BP levels, especially in the more intensive BP-lowering group.

Aged↗
PubMed2006

Susceptibility of Actinobacillus actinomycetemcomitans to six antibiotics decreases as biofilm matures.

OBJECTIVES: Actinobacillus actinomycetemcomitans is a major causative agent of chronic and aggressive periodontitis. Freshly isolated strains of A. actinomycetemcomitans display rough-type colonies and initiate biofilm formation on glass surfaces. The purpose of this study was to determine the antibiotic susceptibility of A. actinomycetemcomitans biofilm during different phases of maturation. METHODS: Using 96-well microtitre plates, we determined the antibiotic susceptibility of rough-type strain 310a to concentrations from 0.1 to 10 mg/L each of erythromycin, ofloxacin, ampicillin, cefalexin, tetracycline and minocycline during biofilm formation. Antibiotics were added at the start of the culture (early phase) and after 24 h of cultivation (mature phase). RESULTS: Adding 10 mg/L of ampicillin, 10 mg/L of cefalexin, 0.1 or 1 mg/L of tetracycline, or 0.1 mg/L of minocycline significantly inhibited 310a biofilm formation in the early phase, but not in the mature phase. Although adding 10 mg/L of erythromycin, tetracycline or minocycline reduced biofilm development in the early phase, it enhanced 310a biofilm development in the mature phase. Ofloxacin exerted a strong inhibitory effect in both the early and mature phases of biofilm formation throughout all experiments. CONCLUSIONS: The present study demonstrated that the susceptibility of A. actinomycetemcomitans to many antibiotics decreased after biofilm maturation.

Aggregatibacter actinomycetemcomitans↗
PubMed2006

Adsorption behavior of antimicrobial peptide histatin 5 on PMMA.

Adsorption of antimicrobial peptide histatin 5 on a poly(methyl methacrylate) denture base may serve to prevent biofilm formation, leading to a reduction of denture-induced stomatitis. This study focused on adsorption behavior of histatin 5 onto PMMA surfaces modified using a cold plasma technique and the effectiveness of histatin 5 adsorption for reducing Candida albicans biofilm formation by the quartz crystal microbalance-dissipation (QCM-D) technique. PMMA spin-coated specimens were treated with oxygen (O(2)) plasma using a plasma surface modification apparatus. The amount of histatin 5 adsorbed onto the PMMA treated with O(2) plasma is more than six times greater than that adsorbed onto untreated PMMA. The degree of histatin 5 adsorption had a negative correlation with the contact angle, whereas that of zeta-potential showed no significant correlation. XPS analysis revealed that the introduction of the carboxyl and O(2) functional groups were observable on the O(2) plasma-treated PMMA. Increased surface hydrophilicity and the formation of the carboxyl could be responsible for histatin 5 adsorption on plasma-treated PMMA. There is no significant difference between histatin-adsorbed PMMA and control PMMA for C. albicans initially attached. On the contrary, the amount of C. albicans colonization on histatin-adsorbed PMMA was significantly less than the control.

Adsorption↗
PubMed2006

Periodontopathic bacterial endotoxin-induced tumor necrosis factor alpha production was inhibited by exercise in mice.

The effects of exercise on serum interleukin-6 and tumor necrosis factor alpha levels were investigated using mice. Five-week-old female BALB/c mice (Th2-biased) and C57BL/6 mice (Th1-biased) were divided into exercise and control groups. The exercise group was exercised in a rotating basket type treadmill for 1 h (5 r.p.m.). Blood was collected and the serum was separated immediately after exercise. The serum interleukin-6 and tumor necrosis factor alpha levels were measured using an Endogen ELISA kit. Exercise significantly increased the serum interleukin-6 level in the two strains of mice (P<0.05 and P<0.01). The tumor necrosis factor alpha level was decreased in the exercise group. Next, periodontopathic bacterial endotoxin (lipopolysaccharide) was administered after exercise, and the effects of exercise on the lipopolysaccharide-induced serum interleukin-6 and tumor necrosis factor alpha levels were investigated. Exercise inhibited lipopolysaccharide-induced tumor necrosis factor alpha production, suggesting it has a defensive action against endotoxin shock.

Aggregatibacter actinomycetemcomitans↗
PubMed2006

Changes of immunoresponse in BALB/c mice neonatally treated with periodontopathic bacterial endotoxin.

The aim of this investigation was to analyze the effects of early life exposure to periodontopathic bacterial lipopolysaccharides on immunoresponse. Newborn BALB/c mice were subcutaneously injected with 20 ng lipopolysaccharide of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans or Escherichia coli daily for 2 days, starting within 24 h after birth. The treated mice were given intraperitoneal injections of bovine serum albumin at 180 and 187 days of age. Seventeen hours after each injection, the mice were bled and sera were separated. Their sera were tested in an enzyme-linked immunosorbent assay system. The mean interleukin-4, interleukin-5, interleukin-6 and immunoglobulin E levels in the sera of mice treated neonatally with P. gingivalis lipopolysaccharide were significantly higher than those of the controls. However, in all cases, no significant difference was noted between mice treated neonatally with A. actinomycetemcomitans- or E. coli lipopolysaccharide and control mice. These data suggest that neonatal exposure to P. gingivalis lipopolysaccharide induces changes in immunological responses when the mice reach maturity.

Aggregatibacter actinomycetemcomitans↗
PubMed2005

Murine monoclonal antibody which can distinguish cystatins SA1 and SA2.

To develop a diagnostic trial enabling the selective examination for a target cystatin in human body fluids, we attempted to prepare monoclonal antibodies against human cystatin SA1 (originally cystatin SA) and its variant form (cystatin SA2). BALB/c mice were immunized with recombinant (r-) cystatins SA1 and SA2. Two monoclonal antibodies designated Cys3F11 and Cys2E5 were selected. By ELISA analyses, the Cys2E5 was shown to react with r-cystatin SA2 but also somewhat with r-cystatin SA1 (22% cross-reactivity) and with plasma cystatin C (18% cross-reactivity), indicating a high specificity for cystatin SA2. The Cys3F11 reacted not only with r-cystatin SA1 but also with r-cystatin SA2 (89% cross-reactivity) and plasma cystatin C (47% cross-reactivity). This finding was further emphasized by immunoblotting of human submandibular-sublingual saliva samples. ELISA additivity test suggests that the two monoclonal antibodies bind to distinct epitopes. In conclusion, we have succeeded in producing two antibodies that discriminate the structural differences between salivary cystatins S and SN, which share more than 90% identity in amino acid sequence with cystatin SA.

Amino Acid Sequence↗
PubMed2005

Involvement of periodontopathic anaerobes in aspiration pneumonia.

Increasing evidence has linked the anaerobic bacteria forming periodontopathic biofilms with aspiration pneumonia in elderly persons. In experiments designed to eliminate the potent respiratory pathogens forming biofilms in the oral cavity, we have shown that the mechanical and chemical oral cleansing using povidone-iodine effectively reduced the detection rates and numbers of methicillin-sensitive Staphylococcus species, Streptococcus pneumoniae, and Haemophilus influenzae in patients scheduled to undergo oral surgery requiring endotracheal intubation. We confirmed the pathogenicity of periodontopathic anaerobic bacteria for aspiration pneumonia in an experimental mouse model. Based upon the finding of the coexistence of Porphyromonas gingivalis with Treponema denticola in chronic periodontitis lesions, we innoculated a mixed culture of P. gingivalis and T. denticola into the mouse trachea; the resulting infection induced inflammatory cytokine production and caused pneumonia. In another series of investigations, professional oral health care (POHC), mainly cleansing administered by dental hygienists once a week for 24 months to elderly persons requiring daily care, resulted in the reduction of the number of total anaerobes, Candida albicans, and Staphylococcus species and in the number of cases of fatal aspiration pneumonia. We also found that the POHC treatment of elderly persons for 6 months in the winter season reduced the salivary levels of protease, trypsin-like activity, and neuraminidase and also decreased the frequency of influenza cases.

Aged↗
PubMed2004

Postoperative corticosteroid therapy for bile drainage in biliary atresia--a nationwide survey.

PURPOSE: Members of the Japanese Biliary Atresia Society were surveyed to determine their current practice regarding early use of corticosteroids after Kasai's operation. METHODS: Questions included the patient's background data, dosage, timing, complications, and outcome. Anicteric survival with the native liver was statistically compared between groups categorized by steroid dosage using Kaplan-Meier analysis. RESULTS: Among 54 institutions surveyed, a total of 222 patients with uncorrectable BA were collected from 34 responders, including 208 patients who received steroid therapy and 14 without it. Prednisolone was started during the first postoperative week in 31% and during the second week in 64%. Perforation and peritonitis occurred in 1 patient given 3 mg/kg/d of prednisolone on postoperative day 1. The survival rates of the steroid and nonsteroid groups were 58.0% and 35.7%, respectively (P = .052). The initial dose of prednisolone was or=4.0 mg/kg/d in 108 patients. The survival rates of the group receiving >or=4.0 mg/kg/d and the nonsteroid group were 58.9% and 35.7%, respectively (P = .0494). CONCLUSIONS: (1) Most surgeons use steroids. (2) Although the anicteric survival rate was higher in the steroid group, the number of patients in the nonsteroid group was too small to draw conclusions. (3) The recommended initial steroid dose is >or=4.0 mg/kg/d. (4) Complications are uncommon if administration is not started too early.

Adrenal Cortex Hormones↗
PubMed2004

Cystatin SA, a cysteine proteinase inhibitor, induces interferon-gamma expression in CD4-positive T cells.

Recently, it has been demonstrated that family 2 cystatins upregulate interleukin-6 production by human gingival fibroblasts. In the present study, we investigated the effects of cystatin SA on cytokine production by helper T cells. Human CD4-positive T cells were cultured with phytohemagglutinin in the presence or absence of 0.1 microM recombinant cystatin SA1 or SA2. When the amounts of interleukin-4 (IL-4) and interferon-gamma (IFNgamma) were analyzed in an ELISA system after stimulation with either cystatin, no significantly increased levels of IL-4 were detected. However, the amounts of IFNgamma were significantly increased after stimulation with the cystatins. Our results suggest that salivary family 2 cystatins are involved in immune responses through the cytokine network.

CD4-Positive T-Lymphocytes↗
PubMed2003

Fecoflowmetric evaluation of anorectal function and ability to defecate in children with idiopathic chronic constipation.

Idiopathic chronic constipation (ICC) is one of the most common clinical conditions in children. The pathophysiology is multifactorial and differs from case to case. To investigate the relationship between anorectal motility (ARM) and clinical course in children with ICC, anorectal function was evaluated using fecoflowmetry in nine children aged 2-14 years (mean 6.1). Three were boys and six were girls. Pressure fluctuations in the rectum and anal canal were simultaneously recorded during saline (250-500 ml) infusion into the rectum. The dynamics of defecation were evaluated using recordings of the saline evacuation curve from the rectum in each patient. Seven patients showed periodic contractions of the rectum accompanied (five) or unaccompanied (two) by relaxations of the anal canal during saline infusion. These patients achieved comfortable spontaneous defecation during follow-up periods ranging from 5 to 20 months. The other two exhibited no rectal contractions in spite of relaxations of the anal canal, and did not respond well to long-term medical management. In eight patients segmental fecoflowmetric curves showed a significantly lower flow rate and longer evacuation time than those of controls. Fecoflowmetry is a simple and non-invasive technique for evaluation of the ability to defecate. Disturbances of ARM may play an important role in patients with severe ICC. When evaluating anorectal function in children with chronic constipation, more attention should be paid to ARM and fecodynamics.

Adolescent↗
PubMed2003

Mixed infections with Porphyromonas gingivalis and Treponema denticola cause excessive inflammatory responses in a mouse pneumonia model compared with monoinfections.

Periodontopathic anaerobes such as Porphyromonas gingivalis are frequently found in aspiration pneumonia and lung abscesses. However, defense mechanisms and responses to these bacterial infections in the lung in vivo remain poorly understood. The coexistence of P. gingivalis with Treponema denticola has been found at higher levels and proportions in periodontally diseased sites. We hypothesized that mixed infections with P. gingivalis and T. denticola can cause severe respiratory disease. In the present study, inflammatory responses to mono- and mixed inoculations with P. gingivalis and T. denticola in the bronchoalveolar lavage (BAL) fluid were investigated. Acute pneumonia and lung abscesses in mice with the mixed infection resulted in a 40% mortality rate within 72 h, compared with only 10% mortality for the respective monoinfections. Pulmonary clearance of P. gingivalis was delayed in the mice with mixed infections with P. gingivalis and T. denticola. Tumor necrosis factor alpha (TNFalpha) interleukin-1beta (IL-1beta) and interleukin-6 (IL-6) levels from BAL fluid of mice with mixed infections at 24 h after inoculation were significantly higher than those after P. gingivalis monoinfection (TNFalpha: P < 0.05, Il-1beta: P < 0.001, IL-6: P < 0.05). The chemokine KC level from BAL fluid of mice at 48 h (P < 0.05) and 72 h after mixed infection was also significantly increased when compared with that after P. gingivalis monoinfection (P < 0.001). The present study demonstrates that a mixed infection of P. gingivalis with T. denticola in mouse causes a marked bronchopneumonia and lung abscess in the mouse model.

Abscess↗
PubMed2003

Congenital membranous colonic stenosis--case report of an extremely rare anomaly.

Congenital colonic stenosis is a rare anomaly. Congenital membranous colonic stenosis is more rare. The authors experienced a case of congenital membranous colonic stenosis that was diagnosed and treated successfully. To the authors' knowledge, congenital membranous colonic stenosis has not been reported previously in the literature.

Colonic Diseases↗
PubMed2003

Detection of Campylobacter rectus in periodontitis sites by monoclonal antibodies.

Campylobacter rectus, a gram-negative, microaerophilic, and motile bacterium, has been proposed to play a pathogenic role in human periodontitis. Surface components, such as the flagellum, surface layer (S-layer), and cytotoxin, have been reported as possible virulence factors of the microorganism. In the present study, monoclonal antibodies against surface components of this bacterium were produced to detect and investigate the pathogenic potential of C. rectus in periodontitis. Two monoclonal antibodies, designated CRT-1 and CRT-2, recognized a peculiar 150 kDa S-layer protein by immunoblot analysis. The CRT-2 antibody reacted to all C. rectus strains tested, except for the S-layer negative strain of the species [C. rectus ATCC 33238 S-layer (-) strain]. The CRT-3 antibody reacted to a 60-kDa protein in C. rectus and also cross-reacted with Campylobacter showae ATCC 51164 and CCUG 11641 strains. Using the dot-blot method, we were able to detect C. rectus using the CRT-2 antibody when as few as 103 organisms were present in a subgingival dental plaque sample. Detection of C. rectus in plaque samples correlated significantly with clinical findings such as probing depth (P < 0.001), bleeding on probing (P < 0.001), and gingival index (P < 0.001). These findings indicate that infection by C. rectus may be an important indicator of periodontal disease status.

Antibodies, Monoclonal↗
PubMed2003

Acute hepatitis in a piglet experimentally inoculated with tissue homogenates from pigs with postweaning multisystemic wasting syndrome.

Five 2 day-old colostrum-deprived piglets were inoculated with tissue homogenates from pigs with postweaning multisystemic wasting syndrome. One of the five piglets developed icterus and died 23 days post-inoculation. Histologic examination revealed acute hepatitis. Porcine circovirus type 2 (PCV-2) antigen and nucleic acid were detected in hepatocytes and phagocytic cells. Ultrastructurally, hepatocytes and phagocytic cells had large numbers of cytoplasmic inclusions, which were composed of electron-dense paracrystalline arrays of small non-enveloped viral particles approximately 17 nm in diameter. Apoptotic hepatocytes were confirmed by the TUNEL method and electron microscopic examination. These findings may indicate that hepatocellular necrosis is associated with replication of PCV-2. Apoptosis of hepatocytes also contributes to the pathogenesis of hepatic lesions in this case.

Acute Disease↗
PubMed2003

Evaluation of anorectal function in patients with tethered cord syndrome: saline enema test and fecoflowmetry.

OBJECT: Disturbance in anorectal function is a major factor restricting the activities of daily living in patients with spinal cord disorders. To detect changes in anorectal motilities due to a tethered spinal cord, anorectal functions were evaluated using a saline enema test and fecoflowmetry before and after patients underwent untethering surgery. METHODS: The bowel functions in five patients with a tethered cord syndrome (TCS) were evaluated by performing a saline enema test and fecoflowmetry. The contractile activity of the rectum, the volume of infused saline tolerated in the rectum, anal canal pressure, and the ability to evacuate rectal content were examined. The characteristic findings in anorectal motility studies conducted in patients with TCS were a hyperactive rectum, diminished rectal saline-retention ability, and diminished maximal flow in saline evacuation. A hyperactive rectum was considered to be a major contributing factor to fecal incontinence. In one asymptomatic patient diminished anal squeezing pressure was exhibited and was incontinent to liquid preoperatively, but recovered after surgery. Two patients who underwent surgery for myeloschisis as infants complained of progressive fecal incontinence when they became adolescents. In one patient fecal incontinence improved but in another patient no improvement was observed after untethering surgery. CONCLUSIONS: Fecodynamic studies allow the detection of neurogenic disturbances of the anorectum in symptomatic and also in asymptomatic patients with TCS. More attention should be paid to the anorectal functions of patients with TCS.

Anal Canal↗
PubMed2002

Renal focal tubulointerstitial fibrosis with short bowel syndrome: report of a case.

We report a male patient with short bowel syndrome (SBS) and renal focal tubulointerstitial fibrosis (FTIF). Seven years after surgery, he was introduced to us due to severe undernutrition, an impairment of growth hormone (GH) secretion, and abnormally low levels of plasma citrulline and arginine at 11 years 7 months of age, just before nutritional support using total parenteral nutrition (TPN) was begun. Thereafter, the support was changed to home TPN with GH supplementation. After an improvement of the disorders, GH was stopped at 17 years 3 months of age. However, hyperuricemia appeared and a renal biopsy revealed FTIF at 20 years of age. Home TPN was continued twice a week because the plasma arginine level was still low. His follow-up biopsy at 23 years of age showed morphometric amelioration. Arginine deficiency following SBS may be associated with FTIF. The cause of hyperuricemia after SBS therefore needs to be investigated in detail.

Adolescent↗