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Biomedical subjects

T Tamura

Publications and source records attributed to T Tamura.

At least 991 records · Page 55Linked to original sources
PubMed1989

AV nodal reentrant tachycardia with Mahaim fiber conduction.

Paroxysmal tachycardia with widened QRS complexes was found in a 46-year-old woman. In sinus rhythm, the patient had electrocardiographic evidence of type B preexcitation with a left bundle branch block pattern. The resting PR interval (160 msec) and A-H interval (100 msec) were within normal limits, but the H-V interval (10 msec) was abnormally short. Programmed atrial extrastimuli at progressively shorter coupling intervals resulted in sudden prolongation of the A-H interval from 120 msec to 250 msec, and the His bundle activities became incorporated just after initiation of the QRS complexes. The QRS morphology was changed but the change was minimal, and atrial echo beats or sustained tachycardia with wide and preexcited QRS complexes were elicited. It is postulated that the site of reentry is within the AV node with preexcitation occurring as the result of conduction in an anomalous nodoventricular pathway.

Cardiac Pacing, Artificial↗
PubMed1989

Different cross-linked types of collagen implanted in rat palatal gingiva.

Collagen membrane preparations were manufactured with the aim of enhancing wound healing following periodontal surgery. After crosslinking by various processing methods (with ultraviolet and hexamethylenediisocyanate) and to various extents, two types of collagen (atelocollagen and tendon collagen) were implanted into a dissection site within palatal gingival tissue. The time course of healing responses was investigated histologically. Collagen implantation was found to accelerate fibrous connective tissue attachment to the root surface and inhibit apical migration of the junctional epithelium. Cross-linked atelocollagen was superior in biocompatibility to the other collagen membranes studied.

Animals↗
PubMed1989

Subgingival administration of tetracycline on a collagen film.

The purpose of this study was to evaluate the duration of therapeutic effect after administration of the collagen film immobilized tetracycline (TC film). TC film or tetracycline non-immobilized placebo film was applied one time to the periodontal pocket (greater than or equal to 4 mm) of five periodontitis patients (20 teeth). The clinical and microbiological effects are summarized as follows: The group that received TC film continued to show significantly low values for bleeding upon probing the pocket depth for 3 and 4 weeks, respectively, after administration, but there was no significant difference in the plaque index or gingival index when compared with the group that received a placebo film. In the TC film group, the density of microorganisms and the proportion of motile rods and spirochetes were also significantly decreased 3 weeks after administration. These findings suggest that topically administered TC film remains both clinically and bacteriologically effective for 2 to 3 weeks.

Administration, Topical↗
PubMed1989

Application of a local drug delivery system to periodontal therapy: I. Development of collagen preparations with immobilized tetracycline.

For the purpose of applying a local drug delivery system to periodontal therapy, atelocollagen preparations with immobilized tetracycline (TC) were prepared by modifying the form of the collagen, the concentration of the immobilized TC, and the time of the cross-link process with glutaraldehyde. The course of the TC release from the collagen preparations into an aqueous solution was determined in relation to time. The preparations were also inserted into periodontal pockets, and the amount of TC remaining in the pocket was determined daily. The results obtained were as follows: 1) The degree of drug release could be controlled to some extent by adjusting the TC concentration and the time of the cross-link process; and 2) an amount of TC exceeding the effective dose in the gingival crevicular fluid was present in the periodontal pocket even 10 days after the insertion of TC fixed in the cross-linked processed collagen film in the periodontal pockets.

Bacteria↗
PubMed1989

[Recording of the temperature distribution on a bed and its application to the assessment of body movement].

In order to assess body movements during sleep, a system which records the temperature on a bed was developed. The system consists of 16 temperature sensors and a data logger with a memory card (RAM card). The 15 temperature sensors were arranged in line with a separation of 6 cm on a flat cable which was placed between the bed sheet and the mattress in such a manner that it crossed the bed at the level of the breast. 15 temperatures on the bed and the room temperature were stored in a RAM card at interval from 30 seconds to 30 minutes. The memory card can store 504 successive data. The stored data were transferred into a micro computer. It was shown that posture changes and the body movements during sleep, could be recognised from the changes in the temperature profile, and these changes were well visualized by a three-dimensional display of the successive temperature profile on the bed.

Body Temperature↗
PubMed1989

[Assessment of sensing parameters in the rate responsive cardiac pacemaker].

Rate responsive cardiac pacemakers in which pacing rate is adjusted by hemodynamic and metabolic demands have been developed in recent years. Although different parameters such as body activity, QT interval, respiration rate, body temperature are used to presume metabolic demand, it is suspected that no single parameter can provide accurate estimate of metabolic demand, and hence rate responsive pacemaker by combined parameters is proposed. This study is aimed to investigate physiological parameters during exercise so as to obtain reliable pacing control algorithm. Twenty healthy volunteers were assessed by a traded treadmill exercise according to the Bruce protocol, and hart rate, QT interval, body temperatures (forehead deep body temperature, rectal, tympanic, oral and axillary temperatures) and respiration rate were monitored. The results showed that correlation coefficient between heart rate and QT interval was 0.979, and that between hart rate and respiration rate was 0.969. Hysteresis was observed when these parameters were plotted against hart rate through a whole exercise protocol.

Body Temperature↗
PubMed1989

[Chronic neutrophilic leukemia associated with monoclonal gammopathy (IgA, kappa type)].

A 62-year-old woman with chronic neutrophilic leukemia (CNL) is described. She presented in February 1988 for evaluation of leukocytosis of 3 years' duration with no complaint. Physical examination was normal. The leukocyte count was 20,100/microliters with 70% segmented neutrophils and 12% band forms. A myelogram showed marked myeloid hyperplasia and plasmacytosis (5.9%). Neutrophil alkaline phosphatase score, serum lysozyme and vitamin B12 levels were elevated. Cytogenetic analysis of the marrow aspirate showed normal karyotype, with no Philadelphia chromosome. Total serum protein (TP) was 7.5 g/dl with increased beta-globulin (23.5%), identified as monoclonal IgA kappa (3.3 g/dl) on immunoelectrophoresis. No activity of G-CSF was detected in the serum. A retrospective study revealed that the beta-globulin level was normal (6.3%, TP 6.9 g/dl) in 1980 and that it was slightly increased (11.6%, TP 7.0 g/dl) without leukocytosis (5,900/microliter) in 1981. In 1985, when leukocytosis obviously existed (9,900/microliter), the percentage of beta-globulin was increased to 17.5% (TP 7.2 g/dl). The possibility that monoclonal gammopathy preceded the leukocytosis must be admitted. On the basis of our observation, it is assumed that CNL and monoclonal gammopathy may be blood dyscrasias derived from a common precursor cell or that the immunological abnormality associated with monoclonal gammopathy may be implicated in the development of CNL.

Female↗
PubMed1989

Phase II study of carboplatin in non-small cell lung cancer.

Forty four patients with advanced non-small cell lung cancer (NSCLC) were treated with carboplatin (CBDCA; cis-diammine-1, 1-cyclobutane dicarboxylate platinum II) at a dose of 400-450 mg/m2 intravenously every four weeks in a phase II study. Forty three patients were evaluated for response and toxicity. Two patients achieved responses resulting in an overall response rate of 4.7% (95% confidence limits: 0.6-15.8%); one of these had not been treated previously and the other had been treated previously with vinblastine. The durations of their responses were 5 and 7 months, respectively. The response rate in 28 previously untreated patients was 3.6% (1/28; 95% confidence limits: 0.1-18.3%). Myelosuppression was the most commonly found toxicity, and thrombocytopenia especially was dose-limiting. Thrombocytopenia (less than 75,000/mm3) was observed in 12 patients (28%). Leukopenia (less than 3,000/mm3) was observed in 14 patients (33%). No serious infection or bleeding occurred, however. Treatment with 400-450 mg CBDCA/m2 was well tolerated in the good risk patients in this study. Mild to moderate emesis was observed in 28 patients (65%). No renal toxicity, neurotoxicity or ototoxicity was seen. It was demonstrated that CBDCA had little efficacy in NSCLC at the dose and schedule given in the present study.

Adult↗
PubMed1989

Prognostic factors in small cell lung cancer: multivariate analysis in the National Cancer Center Hospital (Japan).

Consecutive series involving 172 patients with small cell lung cancer were analyzed retrospectively using eight pretreatment and two treatment-related prognostic factors in respect of their influence on survival. All the patients received chemotherapy with or without chest irradiation, according to phase II or phase III trial protocols of the National Cancer Center Hospital, Tokyo, from 1970 to 1987. The influence on survival of the various factors was investigated using univariate methods and Cox's proportional hazards model. In patients who survived for more than one year, a performance status of 0-1, limited disease, an age greater than 60 years, the absence of liver metastasis, radiotherapy to primary site and response to chemotherapy were determined by univariate analysis to be favorable prognostic factors. By multivariate analysis, performance status (P = 0.005), age (P = 0.026) and response to induction chemotherapy (P = 0.0001) proved to be valuable prognostic survival factors. The extent of disease which had been considered one of the most significant prognostic factors, was shown not to be a significant independent variable by multivariate analysis. Staging procedures may influence the prognostic analysis. Although classifying the limited or extensive stage of disease is still recommended, the current staging system lacks stringency and may not, in fact, reflect the tumor burden accurately. A simpler and meaningful staging system needs to adopted universally in order to continue the build-up of data for comparison from all institutions.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

Effects of the tumor promoter, phorbol 12-myristate, 13-acetate, on the epidermal adenylate cyclase system: evidence for adenylate cyclase-regulation by protein kinase C.

Exposure of pig epidermal sheets to the protein kinase C (PKC) activator, phorbol 12-myristate, 13-acetate (PMA) resulted in an increase in forskolin-induced cyclic AMP accumulation in the epidermis. Cholera toxin-induced cyclic AMP accumulation was moderately increased by PMA treatment, but this was not statistically significant. On the other hand, receptor-mediated adenylate cyclase responses (beta-adrenergic-, prostaglandin E-, adenosine-, and histamine (H2)-adenylate cyclase responses) were significantly decreased. These PMA-induced effects on the epidermal adenylate cyclase system were mimicked by 1-oleoyl-2-acetyl-glycerol, a membrane-permeable synthetic diacylglycerol, and by the non-phorbol PKC activator, mezerein. 4-O-methyl PMA, a very weak PKC activator, had no effect on adenylate cyclase responses of the epidermis. The addition of the PKC inhibitor, H-7 (1-(5-isoquinoline-sulfonyl)-2-methyl piperazine dihydrochloride), to the incubation medium significantly inhibited the effect of PMA on forskolin-induced cyclic AMP accumulation. Furthermore, following H-7 treatment, the epidermal receptor-adenylate cyclase responses were significantly increased. These results indicate that PKC modulates epidermal adenylate cyclase responses resulting in an increase in forskolin-induced cyclic AMP accumulation and a decrease in receptor-adenylate cyclase responses of the epidermis.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1989

[New quantitative method for non-invasive monitoring of tissue blood oxygenation by near infrared spectrophotometry].

The near infrared absorption spectra was measured with the transmitted light through rat brain under the various condition. The absorbance changes below 780 nm were attributable to hemoglobin (Hb) in the brain tissue, whereas those above 780 nm were associated with both Hb and cytochrome oxidase. To eliminate possible interference from cyt. oxidase, two wavelengths, 750 nm and 780 nm, were used to measure Hb oxygenation in the tissue. The absorbance changes in human blood cell suspensions were measured with changes in hematocrit values in the optical cuvette. At two wavelengths 750 nm and 780 nm, there was a linear relationship between absorbance changes and hematocrit values. Through these in vitro studies, the following equation (1) and (2) were obtained to monitor quantitatively the changes of oxy-Hb content (delta Hb O2) and total-Hb content (delta Hb Vol.) in the living tissue. These are (1) delta Hb O2 = -1.15 delta A 750 + 1.39 delta A 780, (2) delta Hb Vol. = -0.29 delta A 750 + 0.59 delta A 780. The studies using these equations showed that the oxy-Hb content in the brain was decreased as the O2 concentration in inspired gas was lowered with a half of Hb deoxygenated at 7% O2. The reliability of these equations was examined under the various conditions in situ such as CO2 inhalation, intravenous injection of Ca2+-blocker nicardipine, hemorrhage and retransfusion. These results confirmed that these equations derived from in vitro studies, were successfully applied to the in situ measurements of the oxygenation state of Hb in the living tissues.

Animals↗
PubMed1989

[Effects of fentanyl on left ventricular diastolic function].

Effects of fentanyl on left ventricular diastolic function were investigated in chronically instrumented dogs. An electromagnetic mitral flow probe was placed in the left atrium and a micromanometer was placed in the left atrium as well as in the left ventricle to measure ventricular pressure (LVP), left atrial pressure (LAP), derivative of left ventricular pressure (dp/dt), mitral flow (MIF) and ECG in conscious resting dogs. Following induction of anesthesia with thiopental (15-20 mg.kg-1) and vecuronium (0.1 mg.kg-1), fentanyl (10, 50 and 100 mcg.kg-1) was administered at 30 min intervals. The direct measurement of phasic MIF was used to obtain a set of diastolic indices: peak rapid filling period (PRFR), filling volume (FV), FV due to atrial contraction (FV-A), isovolumic relaxation period (IVRP) and diastolic filling period (DFP). Each diastolic index during conscious resting state was compared with that obtained during fentanyl anesthesia using paired t-test. There were no significant changes in those diastolic indices under fentanyl (10, 50 and 100 mcg.kg-1) anesthesia except PRFR and dp/dt under fentanyl 10 mcg.kg-1 which decreased. Although heart rate decreased about 50% under fentanyl, IVRP and PRFR did not increase significantly, but DFP (P less than 0.05) and FV (P less than 0.01) increased significantly. DFP correlated well with RR interval under conscious resting state under fentanyl anesthesia (r = 0.992 and r = 0.967). This study suggests that in the absence of surgical stress, fentanyl does not impair left ventricular diastolic function.

Animals↗
PubMed1989

[Coronary artery spasm under thoracic epidural anesthesia].

Three paroxysmal episodes of ST-segment elevation in lead II of ECG were observed during bullectomy and chest closing under epidural anesthesia supplemented with enflurane in compressed air in a patient who had history of variant angina with 50% obstruction of right coronary artery. The first and the third episodes were followed by ventricular tachycardia, complete A-V block and hypotension. These attacks were preceded by decreases in heart rate and blood pressure. It was suspected that coronary artery spasm developed with increased vagal tone under thoracic epidural block. The first and the second attacks were successfully treated with intravenous injection of nitroglycerin and lidocaine. The third attack needed additional treatments which included intravenous administrations of atropine, epinephrine, isoproterenol and phenylephrine and direct heart massage through the thoracic incision. Postoperative serial examinations of ECG showed inverted T in lead V1-V4, and serum enzymes (GOT, GPT, LDH, CPK, CPK-MB) were elevated. However ratio of CPK-MB to total CPK was only 1.5%. The patient was discharged two weeks after the operation with normal ECG and serum enzymes. It is speculated that coronary artery spasm was induced by hypotension and vagal stimulation under epidural anesthesia which blocks cardiac sympathetic nerves.

Aged↗
PubMed1989

[A case of hypereosinophilic syndrome associated with eosinophilic endocarditis].

A 66-year-old woman, who had had bronchial asthma, was admitted to our hospital because she suffered from fever, productive cough, wheezing, dyspnea, and chest pressure sensation. Her chest X-ray showed migrating infiltration and marked cardiomegaly. Her ECG at the admission revealed abnormal Q wave and T wave inversion, though that of 3 years before had been almost normal. Hematology showed leukocytosis and eosinophilia of 8,000/mm3 without abnormal cells. All immunological tests were negative and the specific cause of the eosinophilia was unknown. 2 weeks after admission, she complained of severe chest pain suddenly and her ECG showed ST elevation on V1-4 and serum CPK level was elevated to 290 IU/l. By the thrombolytic agent and anticoagulant therapy, her symptom was lightened immediately. 2 months later, we made her cardiac catheterization and myocardial biopsy. Her LVG showed a small aneurysm of the apex, though her CAG was normal finding. The biopsy revealed moderate fibrosis and cellular infiltration including a few eosinophils. We thought that eosinophilic endocarditis had existed first, and secondary embolism continued led to the small infarction. The hypereosinophilia was spontaneously normalized 2 months after admission, but the patient complained of myalgia and sensory disturbance of extremities. The biopsy of quadriceps muscle could prove neither infiltration of eosinophils nor vasculitis. But we diagnosed mononeuritis multiplex due to hypereosinophilia. Judging from various symptoms and laboratory findings, this case was included to the hypereosinophilic syndrome. We also thought allergic granulomatosis and angitis as one of the differential diagnoses, but histologically vasculitis was not proved. In this case, eosinophilia was disappeared without using corticosteroids.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗