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Biomedical subjects

S Takagi

Publications and source records attributed to S Takagi.

At least 37 records · Page 2Linked to original sources
PubMed2004

AUC of Calvert's formula in targeted intra-arterial carboplatin chemoradiotherapy for cancer of the oral cavity.

We investigated whether intra-arterial administration of carboplatin using Calvert's formula is useful for avoiding thrombocytopenia in targeted chemoradiotherapy in patients with squamous cell cancer of the oral cavity and oropharynx. Carboplatin was infused intra-arterially under digital subtraction angiography in 28 patients. In the first group of patients, the dose of carboplatin was calculated according to the body surface area (BS group). In the second group, the dose was calculated using Calvert's formula (AUC group). The value for AUC (area under concentration vs time curve; mg ml(-1) min(-1)) in the formula was set at 4.5. All patients received concurrent radiotherapy (30 Gy) and were given oral tegafur-uracil (UFT((R)), 400-600 mg day(-1)). The AUC group showed a significantly lower percentage platelet reduction than the BS group (49.0+/-22.0 vs 65.1+/-23.2%; P=0.045) and also tended to have a higher platelet nadir count (10.9+/-4.2 vs 8.4+/-5.8 x 10(4); P=0.27) without reducing the antitumour effect. The value of 4.5 for target AUC is recommended clinically. However, AUC of Calvert's formula could not predict thrombocytopenia associated with intra-arterial chemoradiotherapy due to the variability of the actual AUC.

Adult↗
PubMed2004

Expression of osteoclast differentiation factor and osteoclastogenesis inhibitory factor in rat osteoporosis induced by immunosuppressant FK506.

Immunosuppressant drugs are currently required by transplant recipients for the remainder of their lives, despite the many adverse effects associated with these therapies. Acute osteoporosis is one such effect, and a reproducible osteoporosis model has been established through the administration of the immunosuppressant drug FK506 in rats. The cause of this osteoporosis has been shown to be abnormal osteoclast proliferation, altering the process of bone remodeling. However, the reasons why FK506 induces osteoclast proliferation and whether this process is mediated by cytokine changes or an increase in bone resorption factors have been unclear. An investigation was therefore conducted focusing on the recent discoveries of osteoclast differentiation factor (ODF) and osteoclastogenesis inhibitory factor (OCIF). These factors led to elucidation of the osteoclast differentiation-maturation mechanism. An osteoporosis model was produced in rats utilizing intramuscular FK506 injection (1 mg/kg) for 28 consecutive days. Trabecular bone resorption was observed inferior to enchondral ossification in the FK506 group, and tartrate resistant acid phosphatase (TRAP) staining revealed a clear increase in osteoclasts at the site of enchondral ossification, relative to the control group. Real-time PCR and in situ hybridization (ISH) demonstrated minimal differences in OCIF expression between control and the treatment groups. However, Real-time PCR revealed clearly increased ODF expression in the treatment group. ODF expression was also shown to be increased in the treatment group using ISH. This was histologically consistent with a region of osteoclast proliferation inferior to enchondral ossification. The results of this study support the hypothesis that FK506-mediated osteoporosis occurs by action of the drug on osteoclasts, promoting expression of ODF messenger ribonucleic acid (mRNA) and thus prompting osteoclast differentiation and maturation.

Animals↗
PubMed2004

Reduction in dentin permeability using mildly supersaturated calcium phosphate solutions.

Treatments that obturate dentin tubules have been used for reducing dentin hypersensitivity. The objective of this study was to determine the effects of multiple treatments with a mildly supersaturated calcium phosphate solution on the hydraulic conductance (Lp) of partially occluded dentin discs in vitro. The treatment solution contained 6.5 mmoll(-1) each of calcium and phosphate, 0.25 mmoll(-1) fluoride, 30 mmoll(-1) KCl, and 50 mmoll(-1) HEPES buffer (pH adjusted to 7.0). The mean baseline Lp (in microlcm(-2)min(-1) H(2)O cm(-1)) was 0.108+/-0.041 (mean +/- S.D.; n=9, microlcm(-2)min(-1) H(2)O cm(-1) = 10.20 microlcm(-2)min(-1)KPa(-1)) and after five consecutive treatments, the mean relative Lp, presented as percentage of baseline, were 71+/-11, 58+/-10, 46+/-18, 40+/-14, and 25+/-10, respectively. The Lp values of the baseline and treatment groups were significantly (P<0.05) different. Consecutive treatments appeared effective in further reducing Lp of dentin discs.

Calcium Phosphates↗
PubMed2004

Mapping of a disease susceptibility locus in chromosome 6p in Japanese patients with ulcerative colitis.

Ulcerative colitis (UC) is a multifactorial disorder with both genetic and environmental factors. HLA-B*52 and DRB1*1502 are reported to be strongly associated with UC in Japan. However, the actual susceptible gene has not been identified yet. In this study, to map precisely the susceptible locus for UC, we performed association mapping in the chromosome 6p using 24 microsatellite markers distributed over 16 Mb. A total of 183 patients with UC and 186 healthy controls (HC) were included in this study. In all, 15 markers around the human leukocyte antigen (HLA) region showed statistical significance in the genotypic differentiation test concerned with the allelic distribution between the UC and HC. Especially, the markers between the centromeric region of HLA class I and the telomeric region of class III showed remarkably low P-values and the allele239 of C2-4-4 in class I marker showed the strongest association (Pc=2.9 x 10(-9): OR=3.74, 95% CI=2.50-5.60). Furthermore, we found strong linkage disequilibrium (LD) between the allele239 of C2-4-4 and HLA-B*52 in haplotype analysis. These results provide evidence that, in Japanese, important determinants of disease susceptibility to UC may exist in HLA, especially between the centromeric region of class I and the telomeric region of class III, under the strong LD with HLA-B*52.

Adult↗
PubMed2003

Observation of a liquid-gas-type transition in the pyrochlore spin ice compound Dy2Ti2O7 in a magnetic field.

Low temperature magnetization measurements on the pyrochlore spin ice compound Dy2Ti2O7 reveal that the ice-rule breaking spin flip, appearing at H approximately 0.9 T applied parallel to the [111] direction, turns into a novel first-order transition for T<0.36 K which is most probably of a liquid-gas type. T-linear variation of the critical field observed down to 0.03 K suggests the unusual situation that the entropy release across the transition remains finite [approximately 0.5 (J/K) x mol-Dy] as T-->0, in accordance with a breaking of the macroscopic degeneracy in the intermediate "kagomé ice" state.

Journal Article↗
PubMed2003

Treatment of a plunging ranula with fenestration and continuous pressure.

We present a new method of fenestration and continuous pressure as a simple, effective and uninvasive procedure for the treatment of plunging ranulas. We have recently used in four female patients, aged 10-29 years old. After treatment, the patients remained symptom-free and assessment by magnetic resonance imaging (MRI) showed regression of the ranula in all cases. The procedure resulted in satisfactory healing and we advocate it as a simple and effective treatment that is better for patients than conventional treatment.

Adolescent↗
PubMed2003

Hypothetical mechanism of prostaglandin E1-induced bronchoconstriction.

In general, prostaglandin E1 (PGE1) is thought to relax smooth muscles in the airway and to inhibit muscle constriction. We hypothesized that, under the specific conditions, PGE1 induces bronchoconstriction, resulting in the promotion of inflammation. Examples of the specific conditions where this mechanism may occur include cases where patient who are susceptible to inflammation receive a continuous infusion of PGE1 during induced hypotension or during treatment for intraoperatively abnormal hypertension.

Administration, Topical↗
PubMed2003

A new short-acting non-depolarizing muscle relaxant (SZ1677) without cardiovascular side-effects.

BACKGROUND: In order to facilitate rapid tracheal intubation, the development of a rapid onset, short duration, non-depolarizing muscle relaxant without cardiovascular side-effects would be a significant accomplishment in the field of anesthesiology. The aim of the present study was to test the action of a new non-depolarizing muscle relaxant (SZ1677) on neuromuscular transmission, muscarinic (M2, M3) receptors and cardiovascular reactions and to compare it with clinically used muscle relaxants. METHODS: Neuromuscular transmission was studied by recording muscle contractions elicited by indirect electrical stimulation, using (i). in vitro isolated phrenic nerve-hemidiaphragm preparation of mice, rats and guinea pigs and (ii). in vivo sciatic nerve-anterior tibial muscle preparation of anesthetized rats, guinea pigs and cats. Cardiovascular effects of muscle relaxants were evaluated on the grounds of their effects on changes of blood pressure and heart rate induced by electrical stimulation of the right vagal nerve in anesthetized cats. To study postsynaptic antimuscarinic affinity of muscle relaxants on M3 receptors, oxotremorine-induced contractions of longitudinal muscle strip of guinea pig ileum were registered in their presence and absence. RESULTS: One of more than 120 newly synthesized non-depolarizing muscle relaxants compounds, 1-3[alpha-hydroxy-17beta-acetyloxy-2beta-(1,4-dioxa-8-azaspiro[4,5]dec-8-yl)-5alpha-androstane-16beta-il] -1-(2-propenyl)pyrrolidinium bromide (SZ1677), excelled with its advantageous pharmacological properties: relatively short duration of action, no accumulation and lack of unwanted side-effects. Pharmacodynamic studies show that SZ1677 is a non-depolarizing neuromuscular blocking agent with a relatively short duration and rapid onset of action in a variety of laboratory animal species. It is without cumulative effect, does not reduce blood pressure, and fails to produce tachycardia. Significant cardiac vagal blocking effects were not observed even at concentrations or dosages of 8 times the ED90. This compound, unlike many other muscle relaxants, does not have atropine-like effects on human atrial tissue; it does not increase the release of NA from sympathetic innervation in the heart. In all practical ways, at least from the vantage point of the preclinical study, SZ1677 compares favorably with all presently available short-acting muscle relaxants, including rapacuronium. CONCLUSION: In experiments, SZ1677 proved to be a short-acting neuromuscular blocking compound having a large safety margin between the doses required to produce neuromuscular block and those likely to lead to cardiovascular side-effects.

Androstanes↗
PubMed2003

Attenuation of hypercapnic carbon dioxide chemosensitivity after postinfarction exercise training: possible contribution to the improvement in exercise hyperventilation.

OBJECTIVE: To elucidate the responsible mechanisms of increased slope of minute ventilation relative to carbon dioxide production (VE/VCO(2)) during exercise after acute myocardial infarction without overt signs of heart failure, patients who had an acute myocardial infarction were examined after participating in a three month supervised exercise training programme. DESIGN: Exercise testing, hypercapnic CO(2) chemosensitivity measurement (rebreathing method), and pulmonary function test were repeated at entry and after three months in 50 acute myocardial infarction patients with neither symptoms nor signs of heart failure who completed the training programme. Ten patients who performed initial inhospital training served as controls. RESULTS: Age, peak oxygen uptake, left ventricular ejection fraction, CO(2) chemosensitivity, respiratory parameters (percentage of predicted normal vital capacity (%VC), forced expiratory volume in one second, and carbon monoxide transfer factor (%TLCO)) were all significantly correlated with VE/VCO(2) slope. Multivariate regression analysis showed that age (beta = 0.29, p = 0.01), %TLCO (beta = -0.27, p = 0.01), and CO(2) chemosensitivity (beta = 0.49, p < 0.001) were independent determinants of VE/VCO(2) slope. After three months, there was no significant change in these parameters in the control group. Peak oxygen uptake, %TLCO, and %VC and attenuation in CO(2) chemosensitivity increased significantly in the training group. The VE/VCO(2) slope decreased marginally (p = 0.11). The changes in VE/VCO(2) slope were correlated only with those in CO(2) chemosensitivity (r = 0.50, p < 0.001). CONCLUSION: After acute myocardial infarction, exercise hyperventilation is seen in association with aging, enhanced hypercapnic CO(2) chemosensitivity, and reduced TLCO, even in the absence of overt heart failure. The correlation of VE/VCO(2) attenuation after training with the reduction in CO(2) chemosensitivity suggests that exercise training may reduce increased VE/VCO(2) slope, at least partially by reducing CO(2) chemosensitivity.

Breath Tests↗
PubMed2003

[Showing no increase of C-reactive protein and developing non-bacterial median chest wound dehiscence after coronary artery bypass grafting].

A 72-year-old male underwent coronary artery bypass grafting for 3 vessels disease. After the operation, the peak C-reactive protein (CRP) level was 0.85 mg/dl and CRP levels stayed very low. Forty days after the operation the patient developed a progressive median chest wound dehiscence but the bacterial cultures were negative. In spite of conventional therapies such as debridement of necrotic tissue or irrigation, the wound granulation was underdeveloped. After 6 months an epidermis had developed to cover the wound.

Aged↗
PubMed2002

Neuroleptic malignant syndrome with prolonged catatonia in a dopa-responsive dystonia patient.

The authors describe a patient with dopa-responsive dystonia who developed neuroleptic malignant syndrome with prolonged catatonia following treatment with neuroleptic agents. Use of these agents probably expanded the patient's neuronal dysfunction beyond the nigrostriatal system to involve multiple dopaminergic systems. Electroconvulsive treatment alleviated the prolonged catatonia.

Adult↗
PubMed2002

Laparoscopic hepatectomy for extrahepatic growing tumor. Surgical strategy based on extrahepatic growing index.

BACKGROUND: This article describes the operative procedures, varying difficulties, and required instrumentation for performing laparoscopic hepatectomy (LH) on the basis of a lesion's extrahepatic growing (EG) index, as calculated by computed tomography (CT). METHODS: Laparoscopic partial hepatectomy cases were divided into the following two groups: an EG tumor group (n = 11) and an intrahepatic tumor group (n = 8). The surgical procedures, operative results, and laparoscopic instrumentation for these two groups were compared based on the EG index (/cm2; maximum diameter of tumor pedicle/maximum vertical diameter of tumor/area of the tumor). RESULTS: The mean operative time was significantly shorter and the mean blood loss was significantly less in the EG tumor group than in the intrahepatic tumor group. In addition, in the EG tumor group, there were significant differences in mean operative time and mean blood loss related to the values associated with the EG index (p <0.05, P <0.01). The selection of laparoscopic instruments was based on the EG index, as follows: (a) lesions with an EG index >5/cm2 underwent resection in combination with a microwave tissue coagulator and an ultrasonic surgical aspirator (13 cases, including intrahepatic tumor cases); (b) lesions with an EG index of 5-15/cm2 underwent resection in combination with a microwave tissue coagulator and laparosonic coagulating shears (four cases); (c) lesions with an EG index <%15/cm2 underwent resection with a laparoscopic linear stapler (two cases). CONCLUSION: Our preliminary experience leads us to believe that it is useful to calculate the EG index by CT scan before formulating the technical strategy for a subsequent LH procedure.

Bile Duct Neoplasms↗
PubMed2002

Adsorption and adsorption mechanism of rice bran for chloroform from tap water.

We have found that rice bran effectively adsorbed chloroform from tap water. The amount of chloroform adsorbed was plotted against the equilibrium concentration of chloroform in solution on a logarithmic scale. A linear relationship was obtained, indicating that the adsorption reaction was a Freundlich type. The removal of chloroform by rice bran was attributed to the uptake into intracellular particles called spherosomes.

Adsorption↗
PubMed2002

Relationship between insulin resistance and accumulation of coronary risk factors.

We examined correlations between the frequency of insulin resistance and the accumulation of coronary risk factors in residents of rural comities in Japanese, using simple criteria for determination of insulin resistance based on evaluation by the euglycaemic-hyperinsulinaemic glucose clamp (GC) method. The subjects were 376 men and 589 women living in two rural communities in Japan. We measured body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), triglyceride (TG), HDL cholesterol (HDL), and homeostasis model assessment (HOMA-R). Correlations between HOMA-R and those parameters were examined. To assess the existence of insulin resistance in these subjects, we used a practical index based on the GC method. The subjects with value of HOMA-R >or= 1.73 have insulin resistance. In addition, the HOMA-R was divided into five quantiles based on the frequency distribution (0.60 or below, from 0.61 to 0.82, from 0.83 to 1.18, from 1.19 to 1.69, and 1.70 or higher), to examine the concentration of risk factors in each group. In total, 74 (19.6%) of the men and 119 (20.3%) of the women had insulin resistance (HOMA-R >or= 1.73). It was found that the higher the HOMA-R, the higher was the number of coronary risk factors, such as hypertension, obesity, hypertriglyceridaemia and hypo HDL cholesterolaemia. The number of coronary risk factors was particular high in subjects with HOMA-R >or= 1.70. HOMA-R in the case of no glucose loading is a useful and practical index for evaluation of insulin resistance and coronary risk factors in the epidemiological study.

Adult↗
PubMed2002

Inhibitory effects of Choto-san (Diao-teng-san), and hooks and stems of Uncaria sinensis on free radical-induced lysis of rat red blood cells.

The present study is designed to test our hypothesis that the ingestion of Uncaria sinensis (US), the main medicinal plant of Choto-san (Diao-teng-san, CS), would protect red blood cell (RBC) membrane from free radical-induced oxidation if polyphenolics in US could be absorbed and circulated in blood. When incubated with RBC suspension, Choto-san extract (CSE) and Uncaria sinensis extract (USE) exhibited strong protection for RBC membrane against hemolysis induced by 2,2-azo-bis (2-amidinopropane) dihydrochloride (AAPH), an azo free-radical initiator. The inhibitory effect was dose-dependent at concentrations of 50 to 1000 microg/mL. Ingestion of 200 mg of USE was associated with a significant decrease in susceptibility of RBC to hemolysis in rats. Furthermore, caffeic acid, an antioxidative hydroxycinnamic acid, was identified in rat plasma after administration of URE.

Amidines↗