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Biomedical subjects

S Kohno

Publications and source records attributed to S Kohno.

At least 37 records · Page 2Linked to original sources

Influence of the inclination of the plate of an intra-oral tracing device on the condylar position registered by tapping movement.

The object of this study was to determine the best inclination of the intra-oral tracing device to get optimum condylar position with the registration of tapping movement. Three appliances with different tracing plate inclinations were used in five healthy subjects. The tracing plates were set at 0 degrees to occlusal plane (horizontal); at the angle formed by drawing a line from condylar point to the stylus position at occlusal plane (inclined); then at the angle half to inclined (half-inclined). Subjects made Gothic arch and tapping movements (n = 30) at a 30 mm interincisal distance with the head Camper plane horizontal. The incisal and condylar points were tracked with a 6-degree-of-freedom jaw movement tracking system. The location of gothic arch apex, the distribution and mean position of 30 tapping points from intercuspal position were analyzed in incisal and condylar point between the appliances. Data were analyzed with repeated measures one-way anova. Results showed that mean position of tapping points were significantly different among the appliances. Half-inclined appliance recorded tapping points in a convergent area nearer to intercuspal position (IP) than other appliances. In all appliances, the contact points of the tapping movement were anterior to Gothic arch apex.

Adult↗

Comparison of condylar positions at intercuspal and reference positions in patients with condylar bone change.

The purpose of this study was to investigate the condylar displacement from intercuspal position (IP) to reference position (RP), using a jaw movement measuring system with 6 d.f. and helical computed tomography (CT). The 19 patients included in the present study were divided into a group with bilateral condylar bone change (10 subjects, including the sub-groups with flattening and osteophyte formation) and a group with no condylar bone change (9 subjects). The results showed that the bone change group had significantly more superior, posterior and absolute horizontal IP to RP slides than the no bone change group. There was also a significant difference in the amount of antero-posterior and supero-inferior condylar IP-RP displacements related to the type of condylar bone change within the bone change group. The osteophyte sub-group showed the largest posterior displacement, and the flattening sub-group showed the largest superior displacement. These results suggested that this large IP-RP difference in the bone change group might be related to their temporomandibular joint (TMJ) pathology, and it might therefore be useful to keep this difference in mind as one of the clinical indices suggesting the presence of TMJ osteoarthritis (OA).

Adult↗

Virulence of metallo-beta-lactamase-producing Pseudomonas aeruginosa in vitro and in vivo.

We evaluated the virulence of Pseudomonas aeruginosa carrying bla(IMP), a metallo-beta-lactamase gene, and the efficacy of ceftazidime, imipenem-cilastatin, and ciprofloxacin in the endogenous bacteremia model. The presence of bla(IMP) did not practically change the virulence of the parent strain, and ciprofloxacin was effective against infection with P. aeruginosa carrying bla(IMP).

Animals↗

Effects of sex hormone disturbances on craniofacial growth in newborn mice.

It is well-known that sex hormones influence bone metabolism. However, it remains unclear as to how sex hormones affect bone growth in newborn mice. In this study, we performed orchiectomy (ORX) and ovariectomy (OVX) on newborn mice, and examined the effects on craniofacial growth morphometrically. ORX and OVX were performed on five-day-old C57BL/6J mice. Four weeks after surgery, lateral cephalograms were taken of all of the mice, with the use of a rat and mouse cephalometer. Cephalometric analysis of the craniofacial skeleton was performed by means of a personal computer. Inhibition of craniofacial growth was found in the experimental groups but not in the sham-operated groups. In the nasomaxillary bone and mandible, the amount of growth was significantly reduced. These results suggest that craniofacial growth is inhibited by sex hormone disturbances not only in puberty but also immediately after birth.

Age Factors↗

Pirfenidone attenuates expression of HSP47 in murine bleomycin-induced pulmonary fibrosis.

Heat shock protein (HSP) 47, a collagen-specific molecular chaperone, is involved in the processing and/or secretion of procollagen. The present study was undertaken to investigate whether treatment with the antifibrotic drug pirfenidone attenuates the bleomycin (BL)-induced overexpression of HSP47 in the lungs. Male ICR mice were intravenously injected with BL or saline (SA). Pirfenidone or control drug (CD) was administered 14 days after commencement of BL or SA, and continued throughout the course of the experiment. The mice were randomly divided into three experimental groups: 1) SA-treated with CD (SA group); 2) BL-treated with CD (BL group); and 3) BL-treated with pirfenidone (pirfenidone group). Lungs of the pirfenidone group showed a marked reduction of fibrotic lesions compared with the corresponding BL group. Immunohistochemical studies showed that BL treatment significantly increased the number of macrophages, myofibroblasts, HSP47-positive type II pneumocytes and HSP47-positive interstitial spindle-shaped cells. Treatment with pirfenidone significantly reduced the number of these cells compared with the corresponding BL group. Furthermore, treatment with pirfenidone significantly suppressed the BL-induced increase of the positive ratio of HSP47 and alpha-smooth muscle actin to interstitial spindle-shaped cells. The present study results showed that pirfenidone inhibited heat shock protein 47-positive cells and myofibroblasts, the principal cells responsible for the accumulation and deposition of extracellular matrix seen in pulmonary fibrosis.

Analysis of Variance↗

Immunokinetics in severe pneumonia due to influenza virus and bacteria coinfection in mice.

Coinfections of bacteria and influenza are a major cause of excessive mortality during influenza epidemics. However, the mechanism of the synergy between influenza virus and bacteria are poorly understood. In this study, mice were inoculated with influenza virus, followed 2 days later by inoculation with Streptococcus pneumoniae. The kinetics of viral titres, bacterial numbers and the immune response (cytokine and chemokine production) were also analysed. Short-term survival correlated with pathological changes in the lungs of infected mice. Influenza virus or S. pneumoniae infection alone induced moderate pneumonia; however, severe bronchopneumonia with massive haemorrhage in coinfected mice, which caused death of these mice approximately 2 days after inoculation with S. pneumoniae, was noted. Intrapulmonary levels of inflammatory cytokines/chemokines, type-1 T-helper cell cytokines and Toll-like receptors, and the related mitogen-activated protein kinase signalling molecules (phosphorylated extracellular signal-regulated kinase -1 and - 2, p38 and c-Jun N-terminal kinase), were increased in coinfected mice. These results suggest that immune mediators, including cytokines and chemokines, through Toll-like receptors/mitogen-activated protein kinase pathways, play important roles in the pathology of coinfection caused by influenza virus and Streptococcus pneumoniae.

Animals↗

Ghrelin enhances gastric motility through direct stimulation of intrinsic neural pathways and capsaicin-sensitive afferent neurones in rats.

BACKGROUND: Ghrelin may stimulate gastric motility via the vagal nerve pathway. However, the mechanism of ghrelin-induced changes in gastrointestinal motility has not yet been clearly defined. The present study was designed to investigate whether ghrelin accelerates gastric emptying via capsaicin-sensitive afferent neurones and directly affects the enteric neuromuscular function. METHODS: Gastric emptying of nutrient solids was assessed after intravenous administration of saline or ghrelin in conscious rats. The effects of ghrelin on gastric emptying were also examined in rats pretreated with capsaicin. Gastric emptying and intestinal transit of non-caloric liquids were evaluated using 51Cr solution. The effects of ghrelin on spontaneous contractile activities of isolated strips from stomach and jejunum were also investigated and the influence of ghrelin on motor responses to carbachol and electrical field stimulation was examined. RESULTS: Ghrelin significantly accelerated gastric emptying of both nutrient solids and non-caloric liquids in conscious rats. The intestinal transit of non-caloric liquids was also enhanced by ghrelin. Pretreatment with capsaicin prevented the ghrelin-induced acceleration of gastric emptying of nutrient solids. Ghrelin did not modulate spontaneous and carbachol-induced contractions of strips of gastric body, gastric antrum and jejunum. However, electrical field stimulation-induced contractions were significantly enhanced by ghrelin in the gastric body. CONCLUSIONS: The results suggest that the stimulatory effects of ghrelin on gastric motility are mediated by direct stimulation of the enteric neural pathway and capsaicin-sensitive afferent neurones.

Afferent Pathways↗

High-dose rabeprazole-amoxicillin versus rabeprazole-amoxicillin-metronidazole as second-line treatment after failure of the Japanese standard regimen for Helicobacter pylori infection.

BACKGROUND: There is currently no optimal second-line treatment after failure of Helicobacter pylori triple therapy. AIM: To determine effective salvage therapy after failure of lansoprazole-amoxicillin-clarithromycin. METHODS: After failure of lansoprazole-amoxicillin-clarithromycin 123 out-patients were randomized to receive either 2-week rabeprazole (20 mg b.d.) + amoxicillin (1000 mg b.d.) (RA group) or 1-week rabeprazole (10 mg b.d.) + amoxicillin (750 mg twice b.d.) + metronidazole (250 mg b.d.) (RAM group). Eradication was assessed by the 13C-urea breath test. We also evaluated cytochrome p450 (CYP) 2C19 genotype status, determined by polymerase chain reaction - restriction fragment length polymorphism, and susceptibility to clarithromycin and metronidazole. RESULTS: On an intention-to-treat basis, H. pylori infection cure was achieved in 37 of 63 (59%) patients in the RA group and in 49 of 60 (82%) patients in the RAM group. Per protocol-based eradication rates in the RA and RAM groups were 66% (37/56) and 88% (49/56), respectively. In both analytic sets there were significant differences between the treatment groups (P < 0.01 in each). Mild adverse events were observed in eight and five patients from the RA and RAM groups, respectively. Genetic predisposition of CYP2C19 and antibiotic resistance did not influence the treatment outcome either regimen. CONCLUSIONS: The rabeprazole + amoxicillin + metronidazole therapy yielded satisfactory results. In contrast, the cure rate in high-dose rabeprazole + amoxicillin was below an acceptable level.

2-Pyridinylmethylsulfinylbenzimidazoles↗

Effects of insulin-like growth factor-I on the expression of osteoclasts and osteoblasts in the nasopremaxillary suture under different masticatory loading conditions in growing mice.

It is well accepted that mechanical loading inhibits bone resorption and increases in vivo bone formation. It is also known that cyclic mechanical loading, in particular, can enhance bone formation significantly. These findings suggest a significant role for mechanical stimuli in bone remodelling mediated by various local growth factors including insulin-like growth factor-I (IGF-I). Earlier studies showed that the nasal bone length and premaxillary bone width were significantly greater in mice fed a solid diet rather than a granulated diet, and that these dimensions increased significantly in a solid-diet group treated with IGF-I. The present study sought to examine the effect of IGF-I on the expression of osteoclasts and osteoblasts in the nasopremaxillary suture subjected to different masticatory loadings. For the solid-diet groups, the numbers of tartrate-resistant acid phosphatase (TRAP)-positive osteoclastic cells and osteoblasts were significantly greater in the group injected with IGF-I than in the animals injected with physiological saline. In the groups fed a granulated diet, no significant differences in the numbers of TRAP-positive osteoclastic cells and osteoblasts were found over the entire experimental period between mice injected with either IGF-I or physiological saline. It is shown that IGF-I significantly induces the expression of osteoclasts and osteoblasts and the subsequent bone remodelling, and that the effect may be additive as compared to that of mechanical masticatory loading, which seems to be more important in bone remodelling in terms of the numbers of osteoclasts and osteoblasts.

Acid Phosphatase↗

Long-term efficacy and safety of clarithromycin treatment in patients with diffuse panbronchiolitis.

Diffuse panbronchiolitis (DPB) can now be cured with long-term erythromycin treatment. Our group conducted a prospective open trial of long-term treatment with a macrolide antibiotic, clarithromycin. We studied ten patients who were treated for 4 years with oral clarithromycin (200 mg once a day). Pulmonary function test, blood gas analysis, comprehensive improvement score, and bacterial culture of sputum were examined at 3, 6, 12 months, and at 2, 3, 4 years after the initiation of the therapy. Pulmonary function improved in most of the patients within 6 months: the forced expiratory volume in one second showed a maximal increase from a mean (SE) value of 1.74 (0.12) l at baseline to 2.31 (0.22) l at 6 months (P < 0.01) and the volume (l) of forced vital capacity also showed a maximal increase within 6 months. The partial pressure of arterial oxygen at rest significantly increased at 3-6 months. The comprehensive improvement score also reached maximum within 6 months in nine of the patients. The majority of patients have developed sputum culture in which bacteria were negative within 6 months after the therapy. All of the patients maintained a stable condition with continued therapy, and no side effects of clarithromycin were observed during the study. This prospective study demonstrated that 6-month treatment with clarithromycin might be necessary to improve the clinical conditions of patients with DPB and the drug could be safely used for a long term.

Adult↗

Bronchial hyperresponsiveness and airway inflammation in adolescents with asymptomatic childhood asthma.

BACKGROUND: About 70% of childhood asthmatics become free of asthma-related symptoms during adolescence. Little is known about bronchial hyperresponsiveness (BHR) and airway inflammation in young adults with "outgrown" childhood asthma. METHODS: We studied 61 nonsmoking medical students (18 intermittent mild asthmatics, 23 students with outgrown childhood asthma but free of asthma-related symptoms for 10 years (asymptomatic asthmatics) and 20 healthy students). BHR and lung function were measured, and induced sputum samples analyzed for eosinophil count, eosinophilic cationic protein (ECP), granulocyte-macrophage colony stimulating factor (GM-CSF), and tumor necrosis factor-alpha (TNF-alpha). RESULTS: BHR was still present in most asymptomatic asthmatics, but it was milder compared with healthy students. Only three subjects with previous asthma had no BHR and no signs of airway inflammation. Percentages of eosinophil, and ECP, TNF-alpha and GM-CSF concentrations in induced sputum of mild asthmatics and asymptomatic asthma groups were higher than in the healthy group. In asymptomatic asthmatics group, the duration of asthma, sputum eosinophil percentage, and the level of TNF-alpha in sputum correlated significantly with BHR. CONCLUSIONS: Only a few subjects with longstanding asymptomatic asthma could be considered as cured; most asymptomatic asthmatics continued to exhibit BHR and signs of airway inflammation. The outcome of childhood asthma and BHR was associated with the degree of airway inflammation and the duration of childhood asthma.

Adolescent↗

Pranlukast, a cysteinyl leukotriene receptor 1 antagonist, attenuates allergen-specific tumour necrosis factor alpha production and nuclear factor kappa B nuclear translocation in peripheral blood monocytes from atopic asthmatics.

BACKGROUND: The cysteinyl leukotriene receptor 1 (cysLTR1) antagonists are useful for oral treatment of bronchial asthma. The underlying mechanism of cysLTR1 antagonists on inhibition of inflammatory cytokine production is yet to be determined. OBJECTIVE: The present study was designed to determine the effect of pranlukast, a cysLTR1 antagonist, on production of inflammatory cytokines by allergen-stimulated peripheral blood monocytes (PBM) from atopic asthmatics. METHODS: PBM were obtained from normal control (n = 10) and Dermatophagoides farinae (Der f) allergen-sensitized atopic asthmatics (n = 12), and were cultured in the presence of Der f allergen. The production of TNF-alpha and nuclear-translocation of nuclear factor kappa B (NF-kappa B) was determined. In atopic asthmatics, pranlukast, tacrolimus or dexamethasone was added before stimulation by Der f. The additive effect of pranlukast and dexamethasone was also determined. RESULTS: PBM from atopic asthmatics cultured with Der f exhibited a significant increase in TNF-alpha production and nuclear translocation of NF-kappa B compared with normal control (P < 0.01). Pranlukast, tacrolimus and dexamethasone significantly inhibited production of TNF-alpha and nuclear-translocation of NF-kappa B in PBM of atopic asthmatics (P < 0.01). An additive effect of pranlukast on low-dose dexamethasone was also demonstrated. However, LTD4 did not induce TNF-alpha production or NF-kappa B nuclear translocation. CONCLUSION: Our results suggest that pranlukast may inhibit TNF-alpha production via suppression of NF-kappa B activation through pathways distinct from cysLTR1 antagonism.

Adult↗

Clinicopathological analysis of 143 primary malignant lymphomas in the small and large intestines based on the new WHO classification.

AIM: To study the clinicopathological and immunohistochemical features of 143 cases of primary small and large intestinal non-Hodgkin's lymphoma (NHL) in Japanese patients who presented between 1981 and 2000. METHODS AND RESULTS: The new World Health Organization (WHO) classification was used to classify NHL. The patients included 109 males and 34 females, with an average age of 54.1 years. Tumour sites were as follows: ileocaecal (n = 51, 35.7%), ileum (n = 29, 20.3%), rectum (n = 13, 9.1%), and duodenum (n = 11, 7.7%). Macroscopically, 124 cases (86.7%) were classified as tumorous type, 12 (8.4%) as diffuse infiltration type (erosion, superficial ulceration), five (3.5%) as polyposis type, and only two cases (1.4%) as ulceration type. Immunohistochemically, 122 lesions (85.3%) were of B-cell phenotype and 21 lesions (14.7%) were of T-cell phenotype. According to the WHO classification, of the B-cell lymphomas, 84 cases (68.9%) were large cell, 16 (13.1%) were Burkitt, 10 (8.2%) were marginal zone B-cell lymphomas of mucosa-associated lymphoid tissue (MALT), and seven (5.7%) were mantle cell tumours. Among the T-cell lymphomas, 15 (71.4%) were of unspecified type, two (9.5%) were natural killer type, two were anaplastic large-cell lymphomas, one was lymphoblastic, and one was an adult T-cell leukaemia lymphoma. The survival rate for T-cell lymphomas was poorer than for B-cell lymphomas. Among the B-cell lymphomas, mantle cell lymphoma tended to have a poorer prognosis, whereas MALT lymphomas had a better prognosis than other B-cell tumour types. CONCLUSIONS: Our retrospective study of patients with primary malignant lymphomas in the small and large intestines has illustrated the clinical features and outcomes of patients with this disease.

Adolescent↗

Mandibular movement and frontal craniofacial morphology in orthognathic surgery patients with mandibular deviation and protrusion.

The present study was conducted to investigate the relationship between mandibular movement (lateral excursion and masticatory movements) and craniofacial morphology in 16 patients with mandibular deviation, using a six degrees-of-freedom measuring device. (i) Mandibular deviation was found to be significantly related to frontal maxillary and occlusal plane angles. (ii) Three-dimensional non-working condylar and incisal path lengths were longer during the lateral excursion to the non-deviated side than to the deviated side, and the incisal path moved antero-inferior. (iii) The lateral motion range of the incisal path was wider during masticatory movement on the non-deviated side than on the deviated side, and the molar and non-working condylar path lengths corresponding to the lateral range of the incisal path were also longer on the non-deviated side. The group with posterior crossbite showed a significantly smaller horizontal range of incisal path, and also significantly smaller frontal projected incisal and molar path angles during masticatory movement on the deviated side than on the non-deviated side. These results suggest that lateral excursion and masticatory movements could be related to craniofacial morphology and posterior crossbite.

Adolescent↗

Detection of Legionella DNA by PCR of whole-blood samples in a mouse model.

A detection system for Legionella DNA in blood samples based on the PCR was developed and evaluated in A/J mice with experimentally induced Legionella pneumonia. Primers were designed to amplify a 106 bp DNA fragment of the 16S rRNA gene specific to Legionella species. The PCR system could detect clinically relevant Legionella species including Legionella pneumophila, Legionella micdadei, Legionella bozemanae, Legionella dumoffii, Legionella longbeachae, Legionella gormanii and Legionella jordanis. The sensitivity of the PCR system was 20 fg extracted DNA. In the mouse model, the blood PCR was compared with results obtained by PCR on bronchoalveolar lavage fluid (BALF) samples, cultures of blood and BALF and detection of Legionella urinary antigen. Blood PCR was positive until 8 days after infection, while BALF PCR became negative on day 4. These results indicate that PCR using blood samples may be a useful, convenient and non-invasive method for the diagnosis of Legionella pneumonia.

Animals↗

High serum concentrations of surfactant protein A in usual interstitial pneumonia compared with non-specific interstitial pneumonia.

BACKGROUND: The pathological diagnosis of interstitial lung diseases (ILD) by surgical lung biopsy is important for clinical decision making. There is a need, however, to use serum markers for differentiating usual interstitial pneumonia (UIP) from other ILD. Surfactant protein (SP)-A, SP-D, KL-6, sialyl SSEA-1 (SLX), and sialyl Lewis(a) (CA19-9) are useful markers for the diagnosis and evaluation of activity of ILD. We have investigated the usefulness of these proteins as markers of UIP. METHODS: Serum and bronchoalveolar lavage (BAL) fluid levels of the above five markers were measured in 57 patients with various forms of ILD (19 with UIP, 12 with non-specific interstitial pneumonia (NSIP), eight with bronchiolitis obliterans organising pneumonia (BOOP), and 10 with sarcoidosis), eight patients with the control disease (diffuse panbronchiolitis (DPB)), and nine healthy volunteers. RESULTS: Serum levels of SP-A, SP-D, and KL-6 in patients with UIP and NSIP were significantly higher than in healthy volunteers. In particular, the serum levels of SP-A in patients with UIP were significantly higher than in patients with NSIP (p<0.0001, mean difference -58.3 ng/ml, 95% confidence interval -81.6 to -35.0), and BAL fluid levels of SP-D in patients with UIP were significantly lower than in patients with NSIP (p=0.01, mean difference 322.4 ng/ml, 95% confidence interval 79.3 to 565.5). CONCLUSION: Serum SP-A levels may be clinically useful as a biomarker to differentiate between UIP and NSIP.

Adult↗

Increased concentrations of human beta-defensins in plasma and bronchoalveolar lavage fluid of patients with diffuse panbronchiolitis.

BACKGROUND: Human beta-defensin (HBD)-1 and -2 are antimicrobial peptides present in the respiratory tract. Recent reports have indicated reduced activity of beta-defensins in cystic fibrosis, suggesting that beta-defensins may play an important role in the pathological process of chronic respiratory tract infection. Diffuse panbronchiolitis (DPB) is a progressive disease characterised by frequent episodes of superimposed infection, typically caused by Pseudomonas aeruginosa. The aim of this study was to elucidate the role of these antimicrobial peptides in this disease. METHODS: The concentrations of HBD-1 and HBD-2 in plasma and bronchoalveolar lavage (BAL) fluid from 33 patients with DPB and 30 normal adults were measured by radioimmunoassay. Localisation of HBD-2 was investigated immunohistochemically in an open lung biopsy specimen obtained from a patient with DPB. RESULTS: High concentrations of HBD-1 and HBD-2 were noted in BAL fluid from DPB patients. Increased plasma concentrations of HBD-2, but not HBD-1, were found in patients with DPB compared with control subjects. In patients with DPB the HBD-2 concentration in BAL fluid correlated significantly with the numbers of cells recovered from the BAL fluid (total cells, neutrophils, and lymphocytes) and with the BAL fluid concentration of IL-1beta. Synthetic HBD-2, but not HBD-1, had dose dependent bactericidal activity against P aeruginosa. Treatment of 14 patients with macrolides significantly reduced BAL fluid concentrations of HBD-2 but not HBD-1 or plasma concentrations of HBD-1 and HBD-2. Immunohistochemistry of lung tissue showed localisation of HBD-2 in the epithelia of the distal bronchioles. CONCLUSIONS: These results indicate that beta-defensins, particularly HBD-2, participate in antimicrobial defence in the respiratory tract in DPB, and that the BAL fluid concentration of HBD-2 may be a useful marker of airway inflammation in patients with DPB.

Adult↗