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Biomedical subjects

K Takayanagi

Publications and source records attributed to K Takayanagi.

At least 163 records · Page 9Linked to original sources
PubMed1980

Nocturnal angina pectoris. Comparison between angina with ST segment elevation and depression documented by continuous orthogonal ECG recording.

In 30 patients with nocturnal angina, the night-time ECGs were continuously recorded, and the time and duration of attack, cyclic character of attacks, the relation of chest pain to ischemic ECG changes and arrhythmias during attack were compared between 18 cases with ST elevation and 12 cases with ST depression during attack. In cases with ST elevation, 1) attacks occurred between 2:00 and 8:00 a.m., being most frequent between 4:00 and 5:00 a.m. 2) the duration of attack measured from the duration of ischemic ECG changes was less than 5 min in 88% of the attacks, 3) the attack often recurred with intervals less than 30 min and ECG changes were often unaccompanied bt chest pain, 4) the attack was complicated with various kinds of arrhythmias. These features were in marked contrast to the cases with ST depression, in which attacks were evenly distributed over the night-time, of longer duration, sporadic in occurrence and far less complicated with arrhythmias. These data suggest that the difference of mechanisms causing attacks between both groups.

Adult↗
PubMed1979

Apparent suppression of ventricular parasystole by cardiac pacing.

Complete disappearance of ventricular parasystolic beats by cardiac pacing with the rates of near multiples of the parasystolic rate was observed in 2 patients with ventricular parasystole. This finding represents a clinical counterpart of recently demonstrated experimental and mathematical models of electrotonic modulation of the parasystolic discharge.

Adolescent↗
PubMed1978

Three cases of sinoatrial block induced by anticonvulsants.

Diphenylhydantoin (DPH) and Carbamazepine have been widely used as anticonvulsants and known to have antiarrhythmic properties. Previous reports have shown that arrhythmias such as sinus bradycardia and atrioventricular block can be induced by these agents. In this paper, sinoatrial block (SA block) induced by these agents which were used as anticonvulsants in 3 aged patients is reported. Thre patients, 2 women and 1 man, were over 60 years old. In 2 cases, administration of DPH for recurrent epileptic seizures was followed by SA block. After withdrawal of DPH, SA block disappeared, but resumption of DPH resulted in SA block again. In 1 of these 2 patients, overdrive suppression test revealed normal sinus node recovery time. In the third patient, in addition to DPH which was administered for epileptic seizures, Carbamazepine was given for shoulder pain, then SA block occurred. Withdrawal of these agents restored normal sinus rhythm and combined administration of these 2 agents again induced SA block. Autopsy revealed decreased conduction cells in the sinus node.

Aged↗
PubMed1978

Sinoatrial response to premature atrial stimulation during atrial pacing in aged patients with and without sinus node dysfunction.

Sinus node function was analysed in 15 aged patients, including 8 with sick sinus syndrome and 7 without apparent sinus node dysfunction, by rapid artial pacing and premature atrial stimulation during sinus rhythm and 5 beats of atrial pacing. Three patterns of sinoatrial response were identified by premature atrial stimulation during atrial pacing. Type I response (3 cases) represented approximately constant return cycles and type II (2 cases) represented a markedly prolonged return cycles following premature stimulation. Type III response was characterized by a progressive shortening of return cycles as the prematurity of atrial extrastimuli was increased. Underlying mechanisms responsible for these responses were discussed in relation to the sinus node automaticity and sinoatrial conduction.

Aged↗
PubMed1971

Enhancement of germination rate of aged seeds by ethylene.

Naturally and artificially aged seeds of rape, Brassica napus L., produced less ethylene than freshly harvested seed during the early stage of germination. With freshly harvested seeds one peak of ethylene production was observed during germination, which coincided with the emergence and elongation of root and cotyledon, accompanied by splitting of the seed coat. Application of exogenous ethylene was effective in accelerating germination in aged seeds but did not significantly improve the percentage of germination. Ethylene as a hormone was considered to serve as a stimulator of germination and growth. One of the factors causing seed aging might be the degeneration of an ethylene-producing system in the seed. Exogenous ethylene may be effective only for the seeds in which the ethylene-producing system is weakened but the following responding systems are still functional.

Journal Article↗
PubMedDate not supplied

Postoperative changes over time in size of anterior capsulorrhexis in phacoemulsification/aspiration.

In the present study, we attempted to determine the extent to which an anterior capsulorrhexis carried out during cataract surgery contracts postoperatively. The size of the continuous curvilinear capsulorrhexis (CCC) was measured at the end of surgery and at the final follow-up examination in 52 eyes of 40 patients who underwent phacoemulsification/aspiration and implantation of an intraocular lens (IOL) with 6-mm optics. Images obtained by video during surgery and by slit-lamp microscopy were used to determine the CCC size with reference to the optics of the IOL. The average CCC size was 5.0 mm at the end of surgery; it contracted to 4.4 mm by the final postoperative examination. The contraction of the anterior capsule progressed rapidly in the first 50 days following surgery and then gradually thereafter. The extent of contraction was greater in older patients. The smaller the CCC size immediately after surgery, the more rapidly it contracted. The size of the capsulorrhexis contracted an average of 22% following cataract surgery. The contraction rate tended to be higher in older patients. The results suggest that the capsulorrhexis carried out in cataract surgery for elderly patients should be sufficiently large, but not larger than the optics size of the IOL.

Aged↗
PubMedDate not supplied

A mechanism of ischemic preconditioning during percutaneous transluminal coronary angioplasty.

Manifestation of ischemic preconditioning and its mechanisms during percutaneous transluminal coronary angioplasty (PTCA) was evaluated. Twenty-two patients with angina pectoris, who had one-vessel coronary artery disease of the proximal left anterior descending artery but without visual collateral circulation, underwent elective PTCA performed by balloon inflations of 90 s, repeated three times or more. Changes in standard 12-lead electrocardiogram, hemodynamics and oxygen saturation of the great cardiac vein by a fiber-optic catheter were analyzed. Anginal chest pain occurred in 21 patients (95%) during the first balloon inflation, and in only 9 patients (41%) during the third inflation. In comparison with the first inflation, the third produced less shifts in ST junction (p < 0.01) and peak T (p < 0.01), which were measured and averaged by 4 chest leads from V2 to V5. The heart rate-blood pressure product during the third inflation was equivalent to that during the first. The great cardiac vein oxygen saturation decreased equally during the first and third inflations. However, the ratio of the saturation at reactive hyperemia after balloon deflation to baseline was higher (p < 0.01) in the third than in the first inflation. The adenosine content of the great cardiac vein measured in 11 patients just prior to balloon deflation was also higher (p < 0.05) in the third inflation than the value in the first. Repeated coronary artery occlusion during PTCA could cause ischemic preconditioning, which may be derived from mechanisms common to accelerated reactive hyperemia, for example an increase in intrinsic adenosine levels.

Adenosine↗
PubMedDate not supplied

The role of the Maternal and Child Health Handbook system in reducing perinatal mortality in Japan.

OBJECTIVE: The purpose of this paper is to demonstrate the direct and indirect roles of the Maternal and Child Health (MCH) Handbook in promoting overall improvement in maternal health and child care and to attempt to clarify the relationship between the use of the MCH Handbook and the reduced perinatal mortality in Japan. Another important objective is to propose possible future applications of the MCH Handbook, especially with respect to the networking function of providing client-care provider feedback, and the exchange of health data between the authorities and relevant medical societies. RESULTS: Japan has achieved a decline in neonatal mortality in the 30-year period from 1960 to 1990, from 17.0 to 2.6 per 1,000 live births. There is a correlation between the ratio of the number of Handbooks distributed and the actual number of births and the perinatal mortality. CONCLUSIONS: The wide use of the MCH Handbook system seems to have played an important role in bringing about this reduction and in maintaining the figure as one of the lowest in the world. The reduction of perinatal mortality through the use of the MCH Handbook in this country suggests a similar possibility for application in other nations. The Handbook could aid in the early recognition of high-risk pregnancy and thus reduce inappropriate use of medical resources. The system, with the establishment of a feedback system between the client and the authorities via the care provider, may improve health care in such areas as maternal mortality, toxemia of pregnancy, and diabetes mellitus.

Adult↗
PubMedDate not supplied

Preventable trauma deaths: evaluation by peer review and a guide for quality improvement. Emergency Medical Study Group for Quality.

BACKGROUND: The trauma-injury severity-score (TRISS) methodology was developed in the United States to calculate the probability of survival for trauma patients presenting for emergency care. OBJECTIVE: We assessed the utility of using the TRISS methodology to identify preventable trauma deaths and compared the results to peer review using explicit standards. METHODS: Explicit peer review standards were developed by a focus group. The validity of these standards was evaluated by comparing the results of peer review performed by two independent expert panels. All trauma cases admitted to 10 centers in Japan between April 1, 1994, and March 31, 1996, were evaluated using the TRISS methodology. Cases with an expected probability of survival of more than 0.5 were considered preventable. These cases were subjected to peer review. Patients who were dead on arrival were excluded from analysis. RESULTS: Of 3,125 patients who were not dead on arrival, the TRISS methodology identified 2,525 as having a probability of survival greater than 0.5. In this group, 189 patients died; thus, 25.3% of all deaths were considered preventable by the TRISS method. Peer review found that only 11.2% of the deaths were preventable; thus, only 46.6% of preventable deaths identified by TRISS were confirmed by peer review. Agreement between the two expert peer review panels was very good (kappa = 0.62). CONCLUSION: TRISS can be used as a screening tool to identify potentially preventable trauma deaths. Peer review is appropriate to confirm preventability and to identify potential medical errors.

Data Collection↗
PubMedDate not supplied

The cost of burn care and implications for efficient care.

OBJECTIVE: To clarify the social issues and problems associated with burn care in Japan, based on a cost analysis of acute burn care. METHODS: A retrospective review was undertaken of 71 patients admitted with burns at Nippon Medical School between January 1 and December 31, 1997. A cost analysis was performed for three major burn patients with a burn surface area (BSA) of 70% to 80% and three minor burn patients with a BSA of 20% to 30%. A questionnaire was administered to both burn patients and medical providers in all 127 emergency centers to help improve long-term quality of life (QOL). RESULTS: 80% of burn patients were under age 70. In the major burn cases, the amount of reimbursement according to the government-regulated fee schedule was much less than the cost of treatment. The ratio of the cost of both medication and materials to total cost of treatment was higher for patients with major burns. Patients responding to the survey acknowledged being generally happy despite suffering from psychological and financial problems. A total of 413 medical providers from 63 institutions responded to the survey regarding improving long-term QOL. CONCLUSIONS: Acute burn care is a costly service. The goal of burn care should shift from saving lives to allowing for a productive return to society. Quality improvement, outcome measurement, and technology assessment combined with health economics research for burn care should be carried out in Japan.

Adolescent↗