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S Kohno

Publications and source records attributed to S Kohno.

At least 55 records · Page 3Linked to original sources

Expression of vascular endothelial growth factor and the effects on bone remodeling during experimental tooth movement.

Vascular endothelial growth factor (VEGF) has an ability to induce functional osteoclasts as well as neovascularization. We recently reported that the number of osteoclasts was enhanced by the injection of recombinant human VEGF (rhVEGF) with the application of mechanical force for experimental tooth movement. In this study, the expression of VEGF was detected in osteoblasts on the tension side of the alveolar bone. Moreover, the rate of tooth movement was significantly increased in the rhVEGF injection groups compared with the controls. These results suggested that VEGF, highly expressed by mechanical stimuli, enhances the number of osteoclasts as a paracrine factor, and that the amount of tooth movement is accelerated by both endogenous VEGF and injected rhVEGF.

Analysis of Variance↗

New animal model for studying mastication in oral motor disorders.

To identify the basic parameters of oral behavior in mice, we recorded the three-dimensional jaw movement trajectories and masseter and digastric muscle activities in freely behaving mice eating foods of various textures. Results showed that: (1) there are characteristic jaw movement patterns for food intake and mastication; (2) the pattern in a chewing cycle may be divided into opening, closing, and protruding (power) strokes; and (3) food texture affects basic patterns of jaw movement, muscle activities, and chewing rhythms. The oral motor behavior of mice appears identical to those of other experimental animals, so mice are appropriate animal models for the study of mastication.

Animals↗

Comparative in vitro activity of telithromycin and beta-lactam antimicrobials against bacterial pathogens from community-acquired respiratory tract infections: data from the first year of PROTEKT (1999-2000).

The in vitro activity of telithromycin, a new ketolide, was compared with beta-lactam antimicrobials against pathogens commonly associated with community-acquired respiratory tract infections. These pathogens were collected during 1999-2000 as part of the ongoing PROTEKT surveillance study. Globally, penicillin nonsusceptibility among Streptococcus pneumoniae (n = 3362) was 36.3%, ranging from 21.5% (Australasia) to 68.0% (Far East). Telithromycin showed higher potency (MIC90 0.12 mg/L) than beta-lactams against S. pneumoniae; 99.9% of all and 99.6% of multi-resistant isolates were susceptible to telithromycin. Among Streptococcus pyogenes isolates (n = 1485), 100% were susceptible to beta-lactams, and the telithromycin MIC50 and MIC90 were both 0.015 mg/L. Among Haemophilus influenzae (n = 2948), 16.6% produced beta-lactamase, which reduced the activity of ampicillin, cefaclor and cefprozil. 99.9% of H. influenzae were susceptible to telithromycin and the MIC range for M. catarrhalis was 0.004-0.5 mg/L. The first year results of PROTEKT confirmed high potency for telithromycin against common respiratory tract pathogens, including beta-lactam-resistant strains.

Anti-Bacterial Agents↗

Influence of hemodialysis on echocardiographic Doppler indices of the left ventricle: changes in parameters of systolic and diastolic function and Tei index.

AIMS: Numbers of previous studies have evaluated the influence of dialysis-induced altered loading condition on Doppler-echocardiographic indices of left ventricle in patients with chronic renal failure. It has been suggested that most of Doppler-derived indices are preload-dependent. On the other hand, there are no studies that have evaluated the influence of hemodialysis on Tei index; a new Doppler-derived index obtained by isovolumetric contraction time plus isovolumetric relaxation time divided by ejection time. The aim of this study is to evaluate whether Tei index is also influenced by dialysis-induced altered loading condition as well as other Doppler-derived indices, and to assess the possibility that Tei index is also preload-dependent. PATIENTS AND METHODS: Thirty-two patients with chronic renal failure (21 men and 11 women, aged 48-93 years) on maintenance hemodialysis were evaluated for Doppler-derived indices before and after hemodialysis. We studied parameters of diastolic function (peak velocities of mitral inflow in early diastole (E) and late diastole from atrial filling (A), ratio of A to E (A/E), deceleration time (DT), and isovolumetric relaxation time (IRT)), parameters of systolic function (ejection time (ET), pre-ejection period (PEP), ratio of PEP to ET (PEP/ET), and isovolumetric contraction time (ICT)) and Tei index. RESULTS: Hemodialysis resulted in significant decreases in E, increase in A/E, prolongation of IRT, no change in A and DT; significant prolongation of ICT and PEP, shortening of ET, and increase in PEP/ET and a significant increase in Tei index (0.42 +/- 0.16 vs 0.51 +/- 0.16, p < 0.0001). When patients were subdivided into 2 groups based on weight loss after hemodialysis (> or = 1.5 kg and < 1.5 kg), only the group that lost > or = 1.5 kg had significant change in Tei index before and after hemodialysis (0.40 +/- 0.15 vs 0.52 +/- 0.17, p = 0.0002). CONCLUSION: This study demonstrates that not only most of Doppler-derived indices but also Tei index is affected by dialysis-induced altered loading condition and suggests that Tei index is possibly preload-dependent.

Aged↗

Effect of oral antigen administration on nasal blockage in experimental allergic rhinitis in guinea pigs.

OBJECTIVE AND DESIGN: We evaluated the effectiveness of oral treatment with Japanese cedar pollen on experimental allergic rhinitis in guinea pigs. SUBJECTS: Male Hartley guinea pigs. TREATMENT: From 16 days before the first sensitisation, 1 and 100 mg/time/animal pollen suspension was orally administered twice weekly. Animals were then sensitised and repeatedly challenged with the pollen. METHOD: Guinea pigs were sensitised by intranasal instillation of cedar pollen extracts adsorbed onto Al(OH)3 at a dose of 0.3 microg pollen protein/0.3 mg Al(OH)3/3 microl/nostril twice a day for 7 days. Then the animal was challenged by inhalation with cedar pollen (1.8 mg/nostril) once every week. We evaluated the effects of the oral treatment with antigen on: 1) sneezing frequency, 2) nasal blockage after antigen challenge, 3) nasal hyperresponsiveness to histamine and leukotriene D4, and 4) titres of anaphylactic antibodies. RESULTS: During the course of the high dose administration, several animals died from a possible cytotoxicity, whereas the low dose caused no discernible change. The oral administration of the pollen at both the doses significantly inhibited nasal blockage, and the hyperresponsiveness to the stimuli was also strongly suppressed by the oral treatment. Inhibitory effectiveness did not differ substantially between the 1 and 100 mg/animal-treated groups. In contrast, neither sneezing frequency nor the increasing level of anaphylactic antibodies was influenced by the oral administration. CONCLUSIONS: In this study, we found that the pollen-induced nasal blockage and hyperresponsiveness were suppressed by the oral administration of the pollen in the sensitised guinea pig.

Administration, Oral↗

Phase I study of irinotecan and cisplatin with concurrent split-course radiotherapy in limited-disease small-cell lung cancer.

We conducted a phase I study of irinotecan (CPT-11) and cisplatin with concurrent split-course radiotherapy in limited-disease small-cell lung cancer (LD-SCLC). This study aimed to determine the maximum tolerated dose (MTD) and dose-limiting toxicity (DLT) of this therapy. Four chemotherapy cycles of CPT-11 (days 1, 8 and 15) and cisplatin (day 1) were repeated every 28 days. Radiotherapy of 2 Gy/day commenced on day 2 of each chemotherapy cycle with 20 Gy administered from the first to the third cycles (a total of 60 Gy). 17 patients were enrolled at three dose levels (CPT-11/cisplatin: 40/60, 50/60 and 60/60 mg/m(2)), and 16 were evaluable for toxicity and outcome. 2 of 4 patients at 60/60 mg/m(2) refused continuation of therapy because of general fatigue, and the relative dose intensity of CPT-11 at 50/60 mg/m(2) was approximately 50%. These levels were considered as the MTD. Tumour responses included four complete responses (CR), 11 partial responses (PR) and one no change (NC), and the overall response rate was 93.8% (95% confidence interval: (CI) 71.7-98.9%). This combined modality is tolerable, and CPT-11/cisplatin of 40/60 mg/m(2) in this modality is recommended for phase II study.

Adult↗

Phase I and pharmacokinetic study of paclitaxel and irinotecan for patients with advanced non-small cell lung cancer.

We conducted a phase I study of paclitaxel and irinotecan (CPT-11) in advanced non-small cell lung cancer (NSCLC). This study aimed to determine the maximum tolerated doses (MTD). The pharmacokinetics of CPT-11 and its major active metabolite, SN-38, were also analysed. Patients received paclitaxel (day 1) followed by CPT-11 (days 1, 8 and 15), in a 4-week cycle, and paclitaxel and CPT-11 were escalated from 120 and 40 mg/m(2), respectively. 28 patients were enrolled, who were evaluated for toxicity. 2 of 6 patients at 210 mg/m(2) paclitaxel and 50 mg/m(2) CPT-11, and 2 of 4 at 180 and 60 mg/m(2) developed dose-limiting toxicity (DLT) (neutropenia, fever, neurotoxicity and diarrhoea). The area under the plasma concentration-time curve (AUC) of CPT-11 on day 1 was significantly higher than that on days 8 or 15 at each dose level (P=0.002). The AUC of SN-38 on day 1 was significantly increased using paclitaxel doses >or=150 mg/m(2). A preceding paclitaxel administration changed the pharmacokinetics of CPT-11 and SN-38. However, the toxicity was tolerable. Paclitaxel 180 mg/m(2) and CPT-11 50 mg/m(2) were the recommended doses for further phase II study of this combination.

Adult↗

Effects of ovariectomy on trabecular structures of rat alveolar bone.

An association between postmenopausal osteoporosis and tooth loss has been proposed. However, histomorphometrical changes in alveolar bone following estrogen deficiency are rarely reported with data on microtrabecular structural changes. To clarify the relationship between estrogen deficiency and tooth loss, we histomorphometrically analyzed the trabecular structural changes of mandibular alveolar bone in ovariectomized rats. Twenty-four adult female Fischer rats were used. Eight rats were sacrificed on day 0 (baseline). The remaining 16 rats were divided into two groups. One group was ovariectomized bilaterally (OVX) and the other group was subjected to sham surgery (Sham). After administration of tetracycline and calcein, the animals were sacrificed 60 days after surgery. Bone histomorphometry, node-strut analysis and measurement of thickness of alveolar bone proper were performed on the interradicular septum of the first molar on the sagittal surface. The trabecular bone volume and trabecular number of the OVX group were significantly lower than those of the baseline and Sham groups. All of the bone resorptive and formative parameters of the OVX group were significantly higher (about one-and-a-half times) than those of the Sham group. Several osteoclasts were seen lining the irregular, eroded surface facing the bone marrow in the OVX group. Furthermore, the OVX group tended to have low microtrabecular stiffness and showed significantly thinner distal alveolar bone proper than in the baseline and Sham groups. In summary, estrogen deficiency caused osteoporotic changes and thin alveolar bone proper in the interradicular septum of rat first molar. This phenomenon might accelerate destruction of alveolar bone and tooth loss, especially in elderly women affected by periodontal disease.

Alveolar Process↗

Cysteinyl leukotriene-dependent interleukin-5 production leading to eosinophilia during late asthmatic response in guinea-pigs.

BACKGROUND: Allergic airway eosinophilia is suppressed by cysteinyl leukotriene (CysLT) receptor (CysLT1 receptor) antagonists in several species including humans and guinea-pigs, suggesting that CysLTs are directly or indirectly involved in induction of the response. OBJECTIVE: We examined the effect of CysLT antagonists (pranlukast and MCI-826) on antigen inhalation-induced eosinophilia in peripheral blood and lung, and on IL-5 activity in serum during late increase of airway resistance (late asthmatic response, LAR) in sensitized guinea-pigs. METHODS: Guinea-pigs inhaled ovalbumin (OVA) + Al(OH)3 and OVA mists alternately for sensitization and challenge, respectively, once every 2 weeks. At the fifth challenge, the effects of CysLT antagonists and an anti-IL-5 antibody (TRFK-5) on the occurrence of LAR, and blood and lung eosinophilia, which appeared at 5 h after challenge, were examined. The time-course of IL-5 activity in the serum after the challenge was evaluated by measuring in vitro 'eosinophil survival prolongation activity'. The influence of CysLT antagonists on IL-5 activity was assessed. RESULTS: CysLT antagonists and TRFK-5 completely abolished blood and lung eosinophilia. LAR was suppressed by both MCI-826 and TRFK-5 by 40-50%. Sera obtained from sensitized, challenged animals 3 h and 4 h after challenge induced an obvious prolongation of eosinophil survival. The activity of the sera was completely neutralized by prior exposure to TRFK-5, suggesting that it reflected IL-5 activity. Increased IL-5 activity in the serum was inhibited by both pranlukast and MCI-826 by over 90%. CONCLUSIONS: CysLTs produced after antigen provocation sequentially induced IL-5 production from some immune component cells via CysLT1 receptor activation. Thus, it is likely that CysLTs indirectly cause antigen-induced eosinophilia through IL-5 production.

Animals↗

Elevated levels of thymus and activation-regulated chemokine (TARC) in pleural effusion samples from patients infested with Paragonimus westermani.

To investigate the pathogenic mechanisms of eosinophilic pleural effusion in patients with paragonimiasis, we measured the levels of various chemokines including thymus and activation-regulated chemokine (TARC), eotaxin, RANTES and IL-8 in pleural effusion samples. Samples were obtained from 11 patients with Paragonimus westermani infection, six patients with pleural transudate, eight with tuberculous pleurisy and five with empyema. High percentages of eosinophils were detected in pleural fluid (range 9-100%, median 81%) of patients with paragonimiasis. TARC concentrations in pleural effusions of paragonimiasis were markedly higher than those of other groups. Eotaxin levels were also higher in pleural effusions of paragonimiasis patients, although significant difference was noted only against transudate samples. There was a significant correlation between TARC concentrations and percentages of eosinophils, and between TARC and eotaxin concentrations in pleural effusion. There were also significant correlations between TARC concentration and the titre of anti-P. westermani IgG and between eotaxin concentration and the titre of anti-P. westermani IgG. Our findings suggest that TARC contributes to the pathogenesis of eosinophilic pleural effusion in paragonimiasis.

Aged↗

Surveillance of resistance in bacteria causing community-acquired respiratory tract infections.

Bacterial resistance to antibiotics in community-acquired respiratory tract infections is a serious problem and is increasing in prevalence world-wide at an alarming rate. Streptococcus pneumoniae, one of the main organisms implicated in respiratory tract infections, has developed multiple resistance mechanisms to combat the effects of most commonly used classes of antibiotics, particularly the beta-lactams (penicillin, aminopenicillins and cephalosporins) and macrolides. Furthermore, multidrug-resistant strains of S. pneumoniae have spread to all regions of the world, often via resistant genetic clones. A similar spread of resistance has been reported for other major respiratory tract pathogens, including Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pyogenes. To develop and support resistance control strategies it is imperative to obtain accurate data on the prevalence, geographic distribution and antibiotic susceptibility of respiratory tract pathogens and how this relates to antibiotic prescribing patterns. In recent years, significant progress has been made in developing longitudinal national and international surveillance programs to monitor antibiotic resistance, such that the prevalence of resistance and underlying trends over time are now well documented for most parts of Europe, and many parts of Asia and the Americas. However, resistance surveillance data from parts of the developing world (regions of Central America, Africa, Asia and Central/Eastern Europe) remain poor. The quantity and quality of surveillance data is very heterogeneous; thus there is a clear need to standardize or validate the data collection, analysis and interpretative criteria used across studies. If disseminated effectively these data can be used to guide empiric antibiotic therapy, and to support-and monitor the impact of-interventions on antibiotic resistance.

Africa↗

A case of aceruloplasminaemia: abnormal serum ceruloplasmin protein without ferroxidase activity.

A 34 year old diabetic man with a complete deficiency of serum ferroxidase activity, regardless of the presence of serum ceruloplasmin (Cp), a multicopper ferroxidase protein, is described. The patient had had diabetes mellitus for 13 years, and was also found to have retinal degeneration accompanied by the development of a hearing disturbance of unknown aetiology. Laboratory examination showed markedly increased serum ferritin and low serum iron. Magnetic resonance imaging showed a pronounced hypointensity in the putamen, caudate, cerebellar dentate, and thalamus on T2 weighted images, and also disclosed a low level signal in the liver, suggesting the accumulation of some magnetic substances in the brain and liver. Liver biopsies histochemically identified iron deposition in the hepatocytes. Most of these findings were consistent with the newly established autosomal recessive disease "aceruloplasminaemia", except for the presence of serum Cp and the lack of apparent neurological symptoms. Interestingly, no ferroxidase activity was detected in the patient's serum, whereas suppressed ferroxidase activity was found in his mother's serum. A nucleotide sequence analysis of the Cp gene showed two mutations; a C to T substitution at nucleotide 2701 in exon 16, resulting in a nonsense mutation at amino acid 882 (Arg882ter), and a T to G substitution at nucleotide 2991 in exon 17, resulting in an amino acid alternation at amino acid 978 (His978Gln). The second mutation was also found in the patient's mother. The absence of serum ferroxidase activity despite the presence of serum Cp protein in this compound heterozygote was considered to be due to the production of a non-functional Cp harbouring no ferroxidase activity.

Adult↗

Raised plasma concentrations of alpha-defensins in patients with idiopathic pulmonary fibrosis.

BACKGROUND: Neutrophils are thought to play an important role in the pathogenesis of idiopathic pulmonary fibrosis (IPF). Human neutrophils contain antimicrobial and cytotoxic peptides in the azurophil granules which belong to a family of mammalian neutrophil peptides named alpha-defensins. A study was undertaken to investigate the role of alpha-defensins in the pathogenesis of IPF. METHODS: The concentrations of alpha-defensins (human neutrophil peptides (HNPs) 1, 2, and 3) in plasma and bronchoalveolar lavage (BAL) fluid of 30 patients with IPF and 15 healthy subjects were measured by radioimmunoassay. RESULTS: The concentrations of alpha-defensins in plasma, but not in BAL fluid, were significantly higher in IPF patients than in controls. BAL fluid concentrations of interleukin (IL)-8 in patients with IPF, which were significantly higher than in controls, correlated with those of alpha-defensins. An inverse relationship was seen between plasma alpha-defensin levels and the arterial oxygen tension (PaO(2)) and pulmonary function (vital capacity (%VC), forced expiratory volume in 1 second (FEV(1)), and carbon monoxide transfer factor (%TLCO)) in patients with IPF. Plasma levels of alpha-defensins also correlated with the clinical course in IPF patients with an acute exacerbation. Immunohistochemically, positive staining was observed inside and outside neutrophils in the alveolar septa, especially in dense fibrotic areas. CONCLUSION: These findings suggest that alpha-defensins play an important role in the pathogenesis of IPF, and that the plasma alpha-defensin level may be a useful marker of disease severity and activity.

Bronchoalveolar Lavage Fluid↗

Cytogenetic studies of Hynobiidae (Urodela)XVIII. A ZZ/ZW sex-determining mechanism in a hynobiid salamander species, Hynobius tokyoensis Tago.

The karyotype of Hynobius tokyoensis (2n = 56) was analyzed using three kinds of banding methods to determine the morphological differentiation of the sex chromosomes of this species. Salamanders and egg sacs were collected from seven localities around Tokyo, Japan. Of 28 chromosome pairs, microchromosome No. 21 was identified as a ZZ/ZW-type sex chromosome. The Z chromosome was acrocentric, whereas the W chromosome was submetacentric, with a heterochromatic, elongated short arm. Interestingly, the W chromosome is of three distinct types, W(A), W(B), and W(C), based on R-banding and Ag-NOR patterns. W(A) was detected in five populations from southern habitats, whereas W(B) and W(C) were detected in one population each from northern habitats. W(A), W(B), and W(C) were all found to carry Ag-NORs on their heterochromatic short arms. Considering the karyotypes of other species belonging to the same genus, we discuss the evolution of the sex chromosomes of H. tokyoensis.

Animals↗

The phytochemical lindleyin, isolated from Rhei rhizoma, mediates hormonal effects through estrogen receptors.

Some plant compounds or herb mixtures are popular alternatives to conventional therapies and contain organic compounds that bind to some nuclear receptors, such as the estrogen receptor (ER), to exert various biological effects. We studied the effect of various herbal extracts on ERalpha and ERbeta isoforms. One herbal extract, Rhei rhizoma (rhubarb), acts as an agonist to both ERalpha and ERbeta. The phytochemical lindleyin, a major component of rhubarb, might contribute to this estrogenic activity through ERalpha and ERbeta. 4-Hydroxytamoxifen, an ER antagonist, completely reversed the estrogenic activity of lindleyin. Lindleyin binds to ERalpha in vitro, as demonstrated using a fluorescent polarization assay. The in vivo effect of rhubarb extract was studied using a vitellogenin assay system in the freshwater fish, Japanese medaka (Oryzias latipes). There were marked increases in serum vitellogenin levels in male medaka exposed to rhubarb extract. We conclude that lindleyin, a component of some herbal medicines, is a novel phytoestrogen and might trigger many of the biological responses evoked by the physiological estrogens.

Cells, Cultured↗

Glomerulocystic kidney disease (GCKD) associated with Henoch-Schoenlein purpura: a case report and a review of adult cases of GCKD.

We report on a 71-year-old male with Henoch-Schoenlein purpura (HSP) who developed glomerulocystic kidney disease (GCKD) without congenital abnormality. He had mild renal dysfunction. Renal biopsy findings showed mild proliferation of mesangial cells and matrixes, and tubular atrophy, interstitial fibrosis, cystic dilation of Bowman's capsule and atrophy of the glomerular tuft. The deposition of IgA and C3 in the mesangial area was observed with the fluorescent antibody technique. Therefore he was diagnosed with GCKD-associated HSP. This was the oldest patient among the previous case reports and the patient was the first case to be reported for concurrent GCKD and HSP. In this study, we also reviewed the patient to previously reported adult patients with GCKD.

Aged↗

Transport of 7-ethyl-10-hydroxycamptothecin (SN-38) by breast cancer resistance protein ABCG2 in human lung cancer cells.

Overexpression of breast cancer resistance protein (BCRP) ABCG2 reportedly confers cancer cell resistance to camptothecin-based anticancer drugs, such as topotecan and 7-ethyl-10-hydroxycamptothecin (SN-38: the active metabolite of irinotecan). We have recently shown that SN-38-selected PC-6/SN2-5H human lung carcinoma cells overexpressed BCRP with the reduced intracellular accumulation of SN-38 and SN-38-glucuronide (S. Kawabata et al., Biochem. Biophys. Res. Commun. 280, 1216-1223, 2001). In the present study, we have examined whether BCRP transports SN-38 and/or SN-38-glucuronide in vitro, by using plasma membrane vesicles from the parental PC-6 and resistant PC-6/SN2-5H cells, where SN-38 and SN-38-glucuronide accumulation in membrane vesicles was measured by HPLC. Both SN-38 and SN-38-glucuronide were ATP-dependently transported into membrane vesicles prepared from PC-6/SN2-5H cells, whereas no transport activity was observed in membrane vesicles from PC-6 cells. The kinetic parameters of the transport observed in PC-6/SN2-5H vesicles were K(m) = 4.0 microM, V(max) = 714 pmol/mg/min for SN-38 and K(m) = 26 microM, V(max) = 833 pmol/mg/min for SN-38-glucuronide. These findings suggest that BCRP expressed in PC-6/SN2-5H cells transports both SN-38 and SN-38-glucuronide with a higher affinity toward SN-38.

ATP Binding Cassette Transporter, Subfamily G, Mem↗

Involvement of nitric oxide in pollen-induced biphasic nasal blockage in sensitised guinea pigs.

We have developed a reproducible allergic rhinitis model showing biphasic nasal blockage on repetitive inhalation challenge with Japanese cedar pollen in sensitised guinea pigs. The role of nitric oxide (NO) in inducing nasal blockage was evaluated with this model. N(omega)-nitro-L-arginine methyl ester (L-NAME), a non-selective NO synthase (NOS) inhibitor, intravenously administered before the challenge, significantly inhibited both early and late nasal blockage by approximately 80% and 50%, respectively. When L-NAME treatment was performed after the challenge, the late response was inhibited by approximately 70%. This inhibition was completely reversed by co-administration of L-arginine. However, aminoguanidine and L-N(6)-(1-iminoethyl)lysine, selective inhibitors of inducible NOS, negligibly influenced the degree of nasal blockage. Meanwhile, the alpha-adrenergic agonist, naphazoline, strongly suppressed both early and late nasal blockage. These results indicate that NO, likely produced by constitutive rather than inducible NOS, plays a major role in the occurrence of biphasic nasal blockage, primarily by inducing vasodilatation.

Administration, Intranasal↗