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Biomedical subjects

T Kondoh

Publications and source records attributed to T Kondoh.

At least 19 recordsLinked to original sources
PubMed2006

Decreasing urinary PAH metabolites and 7-methylguanine after smoking cessation.

OBJECTIVE: Humans are exposed to various carcinogens by smoking. Urinary metabolites of polycyclic aromatic hydrocarbons (PAH), one of the major carcinogens in cigarette smoke, were measured as the environmental carcinogen exposure marker for humans. We evaluated urinary exposure markers for smoking cessation. METHOD: In this study, we measured cigarette smoke exposure markers, such as urinary cotinine, PAH exposure markers, such as urinary 1-hydroxypyrene (1-OHP), 2-naphthol (2-NP) and 1-naphthol (1-NP), as well as a methylating chemical exposure marker, 7-methylguanine (7-MeG). The before smoking cessation levels of these markers, and the after smoking cessation levels were then compared. Eighteen subjects participated in this smoking cessation program. RESULTS: Levels of all of four markers were found to have decreased by 19-54% after smoking cessation. Urinary cotinine, 1-OHP, 2-NP and 7-MeG levels were found to have significantly decreased after smoking cessation. There were positive correlations between cotinine and three urinary PAH markers and between 1-OHP, 2-NP and 7-MeG. CONCLUSION: PAH metabolites were better biomarkers of smoking cessation than 7-MeG. Analyzing urinary metabolites or urinary DNA adducts is suitable for epidemiological studies.

Adult↗
PubMed2005

Influence of arthroscopically observed fibrous adhesions before and after joint irrigation on clinical outcome in patients with chronic closed lock of the temporomandibular joint.

The aim of this study was to investigate the changes in the state of arthroscopically observed fibrous adhesions (FA) after visually guided irrigation (VGIR) and the influence of FA on clinical outcome in patients with chronic closed lock of the temporomandibular joint (TMJ). Forty-eight TMJs of 48 patients with unilateral chronic closed lock were enrolled in this study. All 48 joints underwent VGIR twice. After the first VGIR (immediately before the second VGIR), clinical outcome was assessed as regards maximal interincisal opening (MIO) and self-evaluated TMJ pain (VAS). Thirty patients were symptom-free (good outcome group) and the remaining 18 patients had symptoms (poor outcome group). In each group, the changes of the MIO, VAS and severity of FA (FA score) after the first VGIR were studied. The influence of FA score in the first and second VGIR on clinical outcome was analyzed by logistic regression analysis. There was no joint with disappearance or reduction of FA after the first VGIR. In both groups, MIO and VAS were significantly improved after the first VGIR even though the state of FA became significantly worse. The multivariate logistic regression analysis showed that the risk of poor outcome for FA scores in the first and second VGIR were 0.89-times (95% CI: 0.33-2.40, P=0.82) and 1.76-times (95% CI: 0.54-5.73, P=0.35), respectively. The dose-response relationships between FA scores in the first or second VGIR were not significant. In conclusion, our results indicate that the presence of FA or a postoperative worsening of FA (including postoperative new FA formation) seems not to affect the clinical outcome as regards MIO and VAS in patients with chronic closed lock of the TMJ.

Adult↗
PubMed2004

Interleukin-1beta increases RANTES gene expression and production in synovial fibroblasts from human temporomandibular joint.

BACKGROUND: Synovial fibroblasts of temporomandibular joint (TMJ) are poorly characterized, although they have important roles in progression of temporomandibular disorders (TMD). In this study, we investigated responses of synovial fibroblasts to interleukin (IL)-1beta. METHODS: We examined gene expression profiles of synovial fibroblasts in response to IL-1beta, using Affymetrix GeneChip. Regulated upon activation normal T-cell expressed and secreted (RANTES) gene expression was confirmed by polymerase chain reaction (PCR) and real-time PCR. RANTES protein levels were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The RANTES was preferentially up-regulated in synovial fibroblasts by IL-1beta. The increase in RANTES gene expression in response to IL-1beta was confirmed by PCR and real-time PCR. Protein level of RANTES in synovial fibroblasts was also increased by IL-1beta. CONCLUSIONS: The RANTES, a cc-type chemokine, has chemotactic effects on lymphocytes and monocytes. Increased gene expression and protein production of RANTES in synovial fibroblasts, in response to IL-1beta, may play an important role in recruitment of inflammatory cells into synovium and progression of synovitis in TMD.

Adolescent↗
PubMed2003

Quantitative analysis of hyperosmotic and hypothermic blood-brain barrier opening.

Hyperosmotic opening of the blood-brain barrier (BBB) by mannitol is being used to enhance drug transport in human brains. Recently, cooling of the solution has been reported to have potential to open the BBB. However, the mechanism in barrier opening and closure remains elusive. We studied the rapid changes in cerebrovascular permeability after hyperosmotic and hypothermic BBB opening in rats, and then demonstrated that the Na+/Ca++ exchange blocker (KB-R7943) prolongs opening. BBB opening was attained by using intra-arterial infusion of hyperosmotic mannitol (1.6 M) and 1.1 M mannitol (which is less hyperosmotic than commonly used mannitol) at 4 degrees in Sprague-Dawley (SD) rats. To measure the changes in cerebrovascular permeability, perfusate-containing [14C]-sucrose was infused intra-arterially at different time points following hyperosmotic and hypothermic stress. Cerebrovascular permeability was then measured with the in situ brain perfusion technique. 1.6 M Mannitol produced opening of the BBB but the duration of the opening was less than 30 minutes. Use of 1.1 M Mannitol at 4 degrees indicated the same results. We then investigated the effect of a Na/Ca ion exchange blocker (KB-R7943) in both hyperosmotic and hypothermic BBB opening. KB-R7943 extended BBB opening up to 30 min without affecting the peak level of BBB permeability at 5 minutes. Our findings represent important experimental information regarding pharmacological manipulation of BBB opening. The possibility of prolonging the transient opening of the BBB has major clinical implications.

Animals↗
PubMed2002

Evolution of lower-hybrid-driven current during the formation of an internal transport barrier.

Evolution of the lower-hybrid(LH)-driven current profile was measured during the formation of an internal transport barrier (ITB) in a reversed magnetic shear discharge. As the ITB developed, the initially centrally peaked LH-driven current profile gradually turned hollow and was sometimes accompanied by an off-axis peak in the electron temperature profile. These observations indicate the concentration of LH power deposition to the ITB for this case as a result of nonlinear coupling between the LH waves and the target plasma.

Journal Article↗
PubMed2002

A new neuromodulatory pathway with a glial contribution mediated via A(2a) adenosine receptors.

A low concentration (10 nM) of adenosine potentiated hippocampal neuronal activity via A(2a) adenosine receptors without affecting presynaptic glutamate release or postsynaptic glutamatergic conductance. Adenosine inhibited glutamate uptake through the glial glutamate transporter, GLT-1, via A(2a) adenosine receptors. In addition, adenosine stimulated GLT-1-independent glutamate release from astrocytes, possibly in response to a rise in intracellular Ca(2+), via A(2a) adenosine receptors involving PKA activation. Those adenosine actions could lead to an increase in synaptic glutamate concentrations responsible for the potentiation of hippocampal neuronal activity. The results of the present study thus represent a novel neuromodulatory pathway with a glial contribution, bearing both inhibition of GLT-1 function and stimulation of glial glutamate release, as mediated via A(2a) adenosine receptors.

Adenosine↗
PubMed2002

Transport distraction osteogenesis following marginal resection of the mandible.

We performed sliding transport distraction osteogenesis (STDO) of an alveolar segment containing an unerupted third molar in the mandible of a 22-year-old man with a benign cementoblastoma. Marginal mandibulectomy including the tumour and the right mandibular second premolar and first and second molars was done. STDO was performed to horizontally reconstruct the alveolar ridge and to restore occlusion with the use of the third molar. After forward horizontal distraction of the alveolar segment, the third molar spontaneously erupted and was gradually moved to the position previously occupied by the second molar.

Adult↗
PubMed2002

Partial inferior turbinectomy during secondary alveolar bone grafting.

This study examined the characteristics and outcome of patients undergoing partial inferior turbinectomy during secondary alveolar bone grafting. Thirty-three of 55 patients with cleft lip and palate or cleft lip and alveolus who underwent secondary alveolar bone grafting concurrently received partial inferior turbinectomy to ensure that the height of the nasal floor was similar on the cleft side and non-affected side. At the time of surgery, patients who underwent turbinectomy were significantly older than those who did not undergo the procedure. The proportion of patients who underwent turbinectomy was significantly higher among patients with cleft lip and palate than among those with cleft lip and alveolus. These differences apparently reflected the developmental stage of the inferior turbinate and the relative severity of alveolar and palatal defects. In most patients who underwent partial inferior turbinectomy, postoperative X-ray films revealed excellent bone formation at the graft site. Our findings suggest that partial inferior turbinectomy during secondary alveolar bone grafting is a very useful procedure that facilitates dissection to the height of the nasal floor, reconstruction of the mucosal nasal floor, and formation of a sufficient bone bridge. It also promotes alveolar cleft closure, especially in patients with wide bone defects.

Adolescent↗
PubMed2002

[Assessment of saphenous vein grafts flow by Doppler echocardiography].

In an effort to evaluate flow characteristics of the saphenous vein grafts (SVG) after coronary artery bypass grafting, we performed duplex scanning of SVG which were anastomosed to the left anterior descending artery in 12 patients, and compared those indexes with 34 internal thoracic artery grafts (ITAG). The SVG were observed with a 7.5 MHz duplex scanner through the anterior intercostal space. The diameter of the vessel, systolic peak velocity, and diastolic peak velocity were recorded in both groups, and systolic flow volume, diastolic flow volume, and velocity ratio were calculated. The systolic and diastolic peak velocity of SVG were predominantly lower than ITAG. No difference in the diameter and flow ratio could not be demonstrated between 2 groups. The flow volume of SVG were also predominantly lower than that of ITAG throughout cardiac cycle. This study reveals that advanced stenotic change were caused in the SVG group and suggest the occurrence of vein grafts disease long after coronary artery bypass grafting.

Aged↗
PubMed2001

Role of glial glutamate transporters in the facilitatory action of FK960 on hippocampal neurotransmission.

We found previously that N-(4-acetyl-1-piperazinyl)-p-fluorobenzamide monohydrate (FK960) facilitated hippocampal neurotransmission in the dentate gyrus of rat hippocampal slices. The present study was conducted to understand the mechanism underlying the facilitatory action of FK960. The facilitation was inhibited by H-89, an inhibitor of cAMP-dependent protein kinase (PKA), but it was not affected by cycloheximide, a protein synthesis blocker. In cultured rat hippocampal neurons, the drug had no effect on either spontaneous miniature excitatory postsynaptic currents or whole-cell membrane currents evoked by glutamate, kainate, or NMDA, suggesting that the facilitatory action of FK960 is not caused by increasing presynaptic transmitter release or excitatory postsynaptic conductances. FK960 inhibited responses of the glial glutamate transporter, GLT-1, expressed in Xenopus oocytes, and a similar effect was found with cultured rat astrocytes. The FK960 action was inhibited in the presence of H-89. The results of the present study thus suggest that FK960 facilitates hippocampal neurotransmission by inhibiting GLT-1 glial glutamate reuptake via a PKA pathway, thereby increasing synaptic glutamate concentrations.

Amino Acid Transport System X-AG↗
PubMed2001

Quantitative analysis of papaverine-mediated blood-brain barrier disruption in rats.

The blood-brain barrier (BBB) is a permeability barrier of interconnected brain capillary endothelial cells. Intraarterial infusion of papaverine relieves cerebral vasospasms by inhibiting smooth muscle contractions and it may simultaneously lead to a disruption of BBB permeability. To date, the mechanism underlying this phenomenon and the quantification of BBB disruption remains elusive. We first examined the changes in cerebrovascular permeability after an intracarotid infusion of papaverine (0.20%) in rats by an in situ brain perfusion technique. We then demonstrated that changes in cerebrovascular permeability depend on the concentration of papaverine. This is the first study in which the degree of BBB disruption was accurately quantified in terms of [(14)C]sucrose and it was demonstrated that papaverine has a prolonged effect on cerebrovascular permeability. This result suggests the importance of in vivo experiments for a precise evaluation of permeability for many other agents, particularly for the central nervous system.

Animals↗
PubMed2001

Selective cholinergic denervation inhibits expression of long-term potentiation in the adult but not infant rat hippocampus.

The present study assessed the role of the cholinergic systems on the expression of perforant path long-term potentiation (LTP) in rat hippocampal slices from the infant and adult brain. To denervate the cholinergic systems, 192 IgG--saporin was injected into the lateral ventricle of the infant (2-weeks-old) and adult (6-weeks-old) rat brain. There, choline acetyltransferase-immunoreactive fibers were barely detectable 2 weeks and 2 months after injection for both the groups. For the infant rats, perforant path LTP was not affected by selective cholinergic denervation; the probability of LTP development was 0.83 (five out of six slices) and 0.78 (seven out of nine slices) at 2 weeks and 2 months later in 192 IgG--saporin-treated slices, as compared with 0.83 at each period in control saline-treated slices. In contrast, the expression of the LTP was blocked by selective cholinergic denervation for the adult rats; the probability of LTP development was 0 (zero out of 10 slices) and 0.38 (three out of eight slices) at 2 weeks and 2 months later in 192 IgG--saporin-treated slices, as compared with 0.8 (eight out of 10 slices) and 0.83 (five out of six slices) at each period in control saline-treated slices. The results of the present study thus suggest that the cholinergic systems play a crucial role in the expression of LTP in the adult brain and that the denervated systems in the infant brain could be compensated by the sprouting of non-cholinergic fibers.

Age Factors↗
PubMed2001

Condition of microcephaly, growth retardation, joint contractures, atopic dermatitis, and mental retardation in two Japanese sisters: a new autosomal recessive MCA/MR syndrome?

We report on two sisters in a family with a hitherto undescribed MCA/MR condition characterized by growth retardation, severe microcephaly, a peculiar facies, congenital contractures of the interphalangeal and patellar joints, atopic dermatitis, and growth and developmental delay. The disorder in the family we describe is similar to but clearly distinguished from tricho-rhino-phalangeal syndromes or Bavinck syndrome. We propose that the condition in the sisters represents a new autosomal recessive MCA/MR syndrome.

Abnormalities, Multiple↗
PubMed2001

The effects of the Na(+)/Ca(++) exchange blocker on osmotic blood-brain barrier disruption.

Osmotic disruption of the blood-brain barrier (BBB) by mannitol is currently being used to enhance drug delivery in human brains. Despite clinical and experimental interest, to date the time course in the early phase of disruption has not been accurately identified. The mechanism in barrier closure also remains elusive. We first studied the rapid change in cerebrovascular permeability after BBB disruption in rats, and then demonstrated that the Na(+)/Ca(++) exchange blocker (KB-R7943) prolongs osmotic disruption. Osmotic BBB disruption was attained by using intra-arterial infusion of hypertonic mannitol in Sprague-Dawley (SD) rats. To measure the changes in cerebrovascular permeability, perfusate containing [14C]-sucrose was infused intra-arterially at different time points following osmotic stress. Cerebrovascular permeability was then measured with the in situ brain perfusion technique. This is the first in vivo study demonstrating that osmotic disruption is prolonged by the Na(+)/Ca(++) exchange blocker, which did not affect the peak level of BBB disruption. The exact time course of cerebrovascular reversibility was studied and the earliest BBB disruption was seen to occur 5 min after osmotic stress. Histopathological examination after osmotic disruption with the Na(+)/Ca(++) exchange blocker showed no neuronal damage in rat brains. Our findings represent important experimental information regarding pharmacological manipulation of BBB disruption. The possibility of prolonging the transient opening of the BBB has major clinical implications.

Animals↗