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Biomedical subjects

K Otsuka

Publications and source records attributed to K Otsuka.

At least 127 records · Page 7Linked to original sources
PubMed2000

Hepatocyte growth factor is a predominant chemoattractant for gingival epithelial cells produced by radicular cyst-derived fibroblast-like cells.

To clarify whether fibroblasts could be involved in the pathogenesis of periodontal pocket formation, the chemotactic activity of radicular cyst-derived fibroblast-like cell (RCF)-conditioned medium (RCF-CM) for gingival epithelial cells was examined using a modified Boyden chamber assay. RCF-CM possessed significant chemotactic activity, which was decreased markedly by treatment with anti-human hepatocyte growth factor (HGF) antibody. Furthermore, the chemotactic activity of RCF-CM was well correlated with HGF content. These results show that the RCF secrete an HGF-like factor, and suggest that such a factor derived from periodontal fibroblasts might play a role in epithelial apical migration in periodontitis.

Cell Line↗
PubMed2000

Profiles of cytokine expression in radicular cyst-lining epithelium examined by RT-PCR.

Levels of messenger RNA (mRNA) extracted from five samples of radicular cyst-lining epithelium were analyzed for cytokines, growth factors and epithelial cell growth-related receptors by RT-PCR. All five samples expressed IL-1alpha, -1beta, IL-6, IL-8, IL-11, TGF-beta1, PDGF-A and aFGF, and receptors for EGF (c-erbB), KGF, HGF (c-met) and IL-6. Some of the specimens expressed MIP-1alpha, RANTES, GM-CSF, M-CSF, TNF-alpha, PDGF-B and bFGF, but no expression of IL-2, IL-4, IFN-gamma, IGF-I, EGF and KGF was detected. These results indicate that radicular cyst-lining epithelium, which is considered to be identical to the cell rests of Malassez, may play a role in periodontal pocket formation or apical cyst formation by interaction with surrounding connective tissue or hematopoietic cells through the expression of various cytokines.

Cytokines↗
PubMed2000

Extracorporeal shock wave lithotripsy: elimination of densely calcified gallstones and gallstones with calcified rims.

OBJECTIVE: Until now, radiopaque gallstones have been excluded from extracorporeal shock wave lithotripsy (ESWL), because these stones in vivo are less sensitive to the forces that cause disintegration. In Japan there is a higher percentage of patients with radiopaque gallstones than in Western countries. Our purpose in working with patients in Japan was to warrant extensive indication of ESWL to radiopaque gallstones, especially densely calcified stones. DESIGN/METHODS: Retrospective analysis of clinical data. Patients were classified by computed tomography (CT) of stones. Group A consisted of 78 patients whose gallstones were densely calcified (CT attenuation values in Hounsfield units (HU), 473 +/- 323). Group B consisted of 22 patients whose stones had a calcified rim (CT attenuation values, 357 +/- 244). Ninety-eight patients received adjuvant dissolution therapy with ursodeoxycholic acid. Other recommendations, such as a glass of milk at night, were not given to the patients. SETTING: One university hospital and one general hospital. PATIENTS: One hundred consecutive Japanese patients with radiopaque stones in contractile gallbladder (CT attenuation values, > 150 HU, 447 +/- 310, mean +/- SD) were the subjects. With respect to the efficacy of ESWL, a degree of calcification for stones and its relationship with the rates of stone fragmentation and disappearance were assessed. Fragmentation to less than 3 mm in stone diameter was the aim, without limit of shock wave discharges and sessions. RESULTS: After ESWL sessions stones were fragmented successfully in 74 of the 100 patients (57 of the 78 patients in Group A, and 17 of the 22 patients in Group B). The mean number of discharges per patient was 10,435 +/- 8,726. The mean number of discharges for successful stone fragmentation of Group A (9,839 +/- 8,187) was not significantly different from that of Group B (11,376 +/- 6,344). One year after lithotripsy, 60 of the 100 patients were free of stones (45 in Group A, and 15 in Group B). CONCLUSION: It appears that patients with either densely calcified gallstones, or those in whom the stones have a calcified rim, are both suitable candidates for lithotripsy.

Adult↗
PubMed2000

Restoration of prehension with the double free muscle technique following complete avulsion of the brachial plexus. Indications and long-term results.

BACKGROUND: Recent interest in reconstruction of the upper limb following brachial plexus injuries has focused on the restoration of prehension following complete avulsion of the brachial plexus. METHODS: Double free muscle transfer was performed in patients who had complete avulsion of the brachial plexus. After initial exploration of the brachial plexus and (if possible) repair of the fifth cervical nerve root, the first free muscle, used to restore elbow flexion and finger extension, is transferred and reinnervated by the spinal accessory nerve. The second free muscle, transferred to restore finger flexion, is reinnervated by the fifth and sixth intercostal nerves. The motor branch of the triceps brachii is reinnervated by the third and fourth intercostal nerves to restore elbow extension. Hand sensibility is restored by suturing of the sensory rami of the intercostal nerves to the median nerve or the ulnar nerve component of the medial cord. Secondary reconstructive procedures, such as arthrodesis of the carpometacarpal joint of the thumb, shoulder arthrodesis, and tenolysis of the transferred muscle and the distal tendons, may be required to improve the functional outcome. RESULTS: The early results were evaluated in thirty-two patients who had had reconstruction with use of the double free muscle procedure. Twenty-six of these patients were followed for at least twenty-four months (mean duration, thirty-nine months) after the second free muscle transfer, and they were assessed with regard to the long-term outcome as well. Satisfactory (excellent or good) elbow flexion was restored in twenty-five (96 percent) of the twenty-six patients and satisfactory prehension (more than 30 degrees of total active motion of the fingers), in seventeen (65 percent). Fourteen patients (54 percent) could position the hand in space, negating simultaneous flexion of the elbow, while moving the fingers at least 30 degrees and could use the reconstructed hand for activities requiring the use of two hands, such as holding a bottle while opening a cap and lifting a heavy object. The results were analyzed to identify factors affecting the outcome. CONCLUSIONS: The double free muscle procedure can provide reliable and useful prehensile function for patients with complete avulsion of the brachial plexus.

Accessory Nerve↗
PubMed2000

[Hypertension and altered cardiovascular variability associated with obstructive sleep apnea].

In the past 5 years several epidemiologic studies have demonstrated that sleep-related breathing disorders are an independent risk factor for hypertension, probably resulting from a combination of repetitive episodes of hypoxia, hypercapnea, arousals, and a striking surge in sympathetic excitation, and altered baroreflex control during sleep. Obstructive sleep apnea (OSA) may lead to the cardiac arrhythmias and myocardial ischemia and it is a possible risk factor for stroke. We confirmed that nasal CPAP has been shown to lower blood pressure in some hypertensive OSA patients. Early recognition and treatment of sleep-apnea may improve cardiovascular function.

Baroreflex↗
PubMed2000

[Hyperuricaemia].

Explore the source record for details and available documents.

Antihypertensive Agents↗
PubMed2000

The cosmos and CHAT, prompting blood pressure and heart rate monitoring for Dérer's week.

BACKGROUND: The effects of natural environmental factors upon health, documented in Minnesota, support the proposition of Bratislava's champions of the cosmos and of the biological week, gauged via circaseptan rhythms by the late Ladislav Dérer, whose "macro-rhythm" lasted "most frequently about 6 days". MAIN PURPOSE: To introduce 7-day monitoring of blood pressure and heart rate into routine practice. STARTING POINTS AND METHODS: Cosinor analysis on 7-day series determines (conventionally ignored) consistent blood pressure overswinging, i.e., circadian hyper-amplitude-tension (CHAT), a disease risk syndrome, whether it is associated with a normal average blood pressure or a high blood pressure. RESULTS: Summary of information understandable by the general population on the dynamics of blood pressure. CONCLUSIONS AND MEANING FOR PRACTICE AND THEORY: Space weather reports may prompt preventive measures. Caution dictates in any event monitoring blood pressure and heart rate for 7 days to attempt to prevent strokes, rather than to ignore the greatest yet detectable risk of catastrophic vascular disease, CHAT, a risk greater than old age or high blood pressure. (Tab. 1, Fig. 3, Ref. 31.)

Blood Pressure Monitoring, Ambulatory↗
PubMed2000

[A Warthin's tumor showing extensive necrosis].

Warthin's tumors are one of the most easily recognizable tumors using light microscopy. However, histopathological diagnosis is difficult in a few cases when characteristic cystic cavities with papillary walling and underlying lymphoid stroma are obscured by reactive changes. We describe a case of an extirpated Warthin's tumor of the right parotid gland which demonstrated extensive necrosis, squamous metaplasia and xanthomatous inflammation. No characteristic structure for this tumor was noticed in a section of an initially sampled specimen. As a result, a destroyed fistula was suspected. An additional sampling was performed to confirm the diagnosis and the sampled specimen fortunately demonstrated the diagnostic structure of a Warthin's tumor excluding malignancy. An awareness of the morphological variation seen in this tumor should lead to additional sampling of specimens, thereby preventing erroneous interpretation.

Adenolymphoma↗
PubMed1999

Highly-sensitive micellar electrokinetic chromatographic analysis of dioxin-related compounds using on-line concentration.

An application study of an on-line concentration technique of neutral analytes for micellar electrokinetic chromatography (MEKC) was carried out in environmental analysis to enhance the UV detection sensitivity. Several dioxins and related compounds, such as dibenzofuran, dibenzo-p-dioxin, 2,3- and 2,7-dichlorodibenzo-p-dioxins, and 2,3,7-trichlorodibenzo-p-dioxin, were used as test solutes. For a highly sensitive separation and detection, cyclodextrin-modified MEKC (CD-MEKC) under acidic conditions was employed as a separation mode and stacking using reverse migrating micelles and a water plug (SRW) as an on-line concentration technique. Almost a 200-fold gain in detection sensitivity was obtained for the model compounds in SRW-CD-MEKC compared to that in normal CD-MEKC without on-line concentration and the limit of detection was found to be around 0.1 ppm for each solute.

Chromatography, Micellar Electrokinetic Capillary↗
PubMed1999

Further characterization of the type 3 ryanodine receptor (RyR3) purified from rabbit diaphragm.

We characterized type 3 ryanodine receptor (RyR3) purified from rabbit diaphragm by immunoaffinity chromatography using a specific antibody. The purified receptor was free from 12-kDa FK506-binding protein, although it retained the ability to bind 12-kDa FK506-binding protein. Negatively stained images of RyR3 show a characteristic rectangular structure that was indistinguishable from RyR1. The location of the D2 segment, which exists uniquely in the RyR1 isoform, was determined as the region around domain 9 close to the corner of the square-shaped assembly, with use of D2-directed antibody as a probe. The RyR3 homotetramer had a single class of high affinity [3H]ryanodine-binding sites with a stoichiometry of 1 mol/mol. In planar lipid bilayers, RyR3 displayed cation channel activity that was modulated by several ligands including Ca2+, Mg2+, caffeine, and ATP, which is consistent with [3H]ryanodine binding activity. RyR3 showed a slightly larger unit conductance and a longer mean open time than RyR1. Whereas RyR1 showed two classes of channel activity with distinct open probabilities (Po), RyR3 displayed a homogeneous and steeply Ca2+-dependent activity with Po approximately 1. RyR3 was more steeply affected in the channel activity by sulfhydryl-oxidizing and -reducing reagents than RyR1, suggesting that the channel activity of RyR3 may be transformed more precipitously by the redox state. This is also a likely explanation for the difference in the Ca2+ dependence of RyR3 between [3H]ryanodine binding and channel activity.

Animals↗
PubMed1999

Determinants of collateral development in patients with acute myocardial infarction.

BACKGROUND: The presence or absence of collateral circulation to the infarct-related coronary artery in acute myocardial infarction (AMI) significantly impacts on infarct size and resulting left ventricular function. However, the determinants of collateral development have not been clarified. HYPOTHESIS: The purpose of this study was to elucidate the determinants of collateral development in humans. METHODS: The study group consisted of 248 patients (178 men, 70 women; mean age 63 years) undergoing coronary angiography within 12 h after the onset of a first AMI. All patients exhibited complete occlusion of the infarct-related artery. The extent of collateral circulation to the area perfused by the infarct-related artery was graded as none, or poorly or well developed, depending on the degree of opacification of the occluded coronary artery on the contralateral injection of contrast. RESULTS: Well-developed collateral circulation was observed in 92 of the 248 patients (37.1%). The prevalence of well-developed collaterals was 57% in patients with a history of angina pectoris prior to AMI, which was significantly (p < 0.0001) higher than the 26% in those without a history of angina. Multivariate stepwise logistic regression analysis was then applied to identify predictors of collateral development. Possible determinants of collateral development were long-standing preinfarction angina, severity of coronary artery disease, age, gender, and coronary risk factors (hypertension, diabetes, hypercholesterolemia, smoking). This analysis revealed that only the presence of a history of angina pectoris prior to AMI was a significant predictor of collateral development (p < 0.0001). CONCLUSIONS: A history of angina pectoris prior to AMI is a clinical marker for coronary stenoses. Since severe coronary stenoses can provide stimuli that lead to collateral development, it is reasonable that a history of angina would also be a clinical marker for collateral vessels.

Age Factors↗
PubMed1999

Simple and reproducible model of rat spinal cord injury induced by a controlled cortical impact device.

Consistently reproducible experimental trauma was inflicted on the rat spinal cord (L3-L4) employing a controlled cortical impact device. The spinal cord was injured with one of three sizes of chips; thick (3 mm diameter), medium (2 mm diameter), thin (1 mm diameter). Each chip was applied at 1, 2 and 3 mm deformation depths. The correlations of the magnitude of the primary trauma were examined histopathologically. It was found that the extent and intensity of the trauma could be changed by altering the depth of deformation and the chip diameter at a fixed velocity of 4.6 m per sec. The injury caused by the 2 mm diameter chip at 0.5 mm-deformation damaged one to two segments of the perifocal spinal cord. In the surviving animals, the histological changes could be classified as primary, secondary, and late phase changes, and finally the lesion became a cavity. This study reports the application of a controlled cortical impact device to morphological research on a spinal cord injury. We found that the injury by the 2 mm chip at 0.5 mm deformation was the most advantageous and reproducible model for further investigations.

Animals↗