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Biomedical subjects

N Ikeda

Publications and source records attributed to N Ikeda.

At least 271 records · Page 15Linked to original sources
PubMed1989

Forensic usefulness of the silicone rubber cast of the cardiac vessels.

Adequate examination of the coronary arteries at forensic autopsy is often difficult. No matter whether the arteries are opened longitudinally or transversely, each method has its disadvantages. A technique making silicone rubber casts of the cardiac vessels providing simultaneous angiography is described. The method allows the three-dimensional precise assessment of stenotic lesions of the coronary arteries. It is concluded that the method examined could be useful for the forensic problems.

Adolescent↗
PubMed1989

Adriamycin-lipiodol suspension for i.a. chemotherapy of hepatocellular carcinoma.

Physicochemical properties of two types of adriamycin preparation, suspensions and emulsions prepared for i.a. chemotherapy of hepatocellular carcinoma, were investigated. A suspension was prepared by dispersing adriamycin directly into the lipid contrast medium, Lipiodol, whereas an emulsion was obtained by emulsifying an aqueous solution of adriamycin into Lipiodol. The dispersibility of the drug in each preparation was examined microscopically. The chemical stability of and drug release from the preparation were determined by high-performance liquid chromatography and spectrophotometry, respectively. The suspension was then given to ten patients with primary hepatocellular carcinoma. The suspension maintained good dispersibility without coagulation of drug particles, whereas coalescence of aqueous droplets and the resultant phase separation occurred 4 h after preparation of the emulsion. Both preparations maintained the initial drug content for at least 1 week at room temperature. The release of adriamycin was more prolonged in the suspension than in the emulsion. After i.a. administration of the suspension, a selective accumulation of Lipiodol in the tumor and decrease in serum alpha-fetoprotein (AFP) levels were found in most patients. A significant amount of adriamycin was still detected in hepatic specimens resected from two patients 1 and 2 months after treatment. These findings suggest that the adriamycin-Lipiodol suspension may be a useful preparation for targeting chemotherapy to hepatocellular carcinoma.

Adult↗
PubMed1989

Immunotherapy using Freund's adjuvant and recombinant interleukin-2 combined with transarterial chemoembolization for hepatocellular carcinoma.

A new immunotherapy for hepatocellular carcinoma (HCC) using Freund's adjuvant and recombinant interleukin-2 (IL-2) combined with conventional transarterial chemoembolization therapy was performed. In 16 patients with HCC and one patient with metastatic liver cancer receiving this therapy, decrease and suppression of reelevation of alpha-fetoprotein after therapy was observed. Disappearance of tumor thrombi of HCC in the main portal vein was observed in a patient, and decrease of carcinoembryonic antigen was also observed in a patient with metastatic liver cancer. The present therapy using Freund's adjuvant and IL-2 is likely to open a new avenue for the treatment of patients with advanced liver cancer.

Aclarubicin↗
PubMed1989

A computer-based model of parasystolic activity modulated by ventricular activation in the open-chest dog.

The modulated parasystole hypothesis proposed by Moe has been suggested as a common mechanism of a wide variety of arrhythmias. To represent the arrhythmic patterns defined by the model as an actual ECG trace, a "hybrid" experimental system was devised. The system consisted of the intact canine heart connected to a microcomputer that operated as the modulated parasystolic pacemaker. An intrinsic cycle length of the "ectopic" pacemaker was modulated by the phase-dependent effect of the activity of the intact heart in situ. Discharges in the "ectopic" pacemaker were transmitted to the right ventricle. The result was that the theoretically defined patterns of the ectopic activity were represented as real ECG traces. Some published examples of intermittent parasystole that had been attributed to other complex mechanisms were accurately reproduced when the estimated phase response curves were set in the "ectopic" pacemaker. A wide variety of clinical eCG tracings of ventricular arrhythmias may be reproduced by this hybrid experimental model.

Animals↗
PubMed1989

The dynamics of progesterone output in perifused granulosa layer of the Japanese quail (Coturnix coturnix japonica): response to adenosine 3',5'-cyclic monophosphate and aminoglutethimide.

A perifusion system has been developed in which the rates of progesterone output of quail granulosa layer in response to steroidogenic stimuli, can be measured under dynamic condition. In response to a continuous perifusion for 8 h with dibutyryl cyclic AMP (dbcAMP), there was a gradual increase in the rate of progesterone output, which reached a plateau at 4-5 h of perifusion. When progesterone output was inhibited by aminoglutethimide, a reversible inhibitor of the cholesterol side chain cleavage reaction, dbcAMP caused the accumulation of cholesterol in mitochondria. The rate of progesterone output after the release of inhibition was much faster when the tissue had been stimulated with dbcAMP during the inhibition. This indicates that dbcAMP stimulates progesterone production by increasing the steroidogenic cholesterol in mitochondria. However, the resumption of progesterone output after the release of inhibition was not observed unless the tissue was again stimulated with dbcAMP. This indicates that the mitochondrial cholesterol is not readily available for the cholesterol side chain cleavage enzyme, and there is another step of stimulation of dbcAMP for progesterone output of quail granulosa layer.

Aminoglutethimide↗
PubMed1989

Sudden infant death from atelectasis due to amniotic fluid aspiration.

An infant girl, whose hands showed lobster-claw deformity, was found dead in her bed at 17 days of age. Macroscopic and microscopic examination of the lungs showed fatal atelectasis. The alveolar spaces were filled with fluid, epithelial cells, and squamous debris. These were the constituents of amniotic fluid aspirated before birth. The present case suggested that some sudden unexpected deaths in early infancy are delayed deaths caused by amniotic fluid aspiration.

Amniotic Fluid↗
PubMed1989

An unusual shotgun slug injury.

A fatal case with an unusual shotgun slug injury caused by an accidental discharge of a shotgun used in hunting bear is reported. The slug is old-fashioned, and is no longer on the market. Some old hunters, however, still possess such shotgun slugs, and the possibility of their use must be borne in mind.

Accidents↗
PubMed1989

Reentrant arrhythmias generated by a computer-based model of the modulated parasystole in an open-chest dog.

It has been demonstrated that parasystolic activity of a linear Purkinje bundle can be converted into a form of reentry, termed reflections, as a function of changes in electrotonic interactions between two active segments separated by an inexcitable gap. In this study, we attempted to reproduce arrhythmic patterns based upon the reflection mechanism by utilizing a hybrid experimental model of modulated parasystole. The experimental system consisted of the intact heart of a dog connected to a computer, which operated as an ectopic focus. The "ectopic" discharges were shifted by the phase-dependent effects of the input ventricular activation of the heart and were transmitted to the ventricle with a conduction delay in the circuit. A high level of the electrotonic influence was incorporated in the "ectopic" focus by programming a phase response curve with dominant acceleratory phase. The focus was repeatedly captured and reset by the ventricular activation over a wide range of basic heart rates. This preparation produced heart rate-dependent changes in arrhythmias defined by the reflection model. Appropriate conduction delays in the simulated exit pathway allowed the focus to be captured by the activity that it initiated. This process of reciprocation generated a ventricular tachycardia, which could be either induced or terminated by a timed premature beat. Thus, arrhythmias of reentrant type, including reciprocating tachycardia, can be produced by a computer-based model of the modulated parasystole.

Animals↗
PubMed1989

[Evaluation of the effectiveness of ion exchange on strengthening of dental porcelain].

This study evaluated the effectiveness of ion exchange on strengthening of porcelain used in metal ceramic. The paste for ion exchange was painted directly on the porcelain surface, dried, and heated at 450 degrees C in the porcelain furnace. The bending strength of porcelain test samples (6.5 x 1.5 x 20 mm), the compressive strength of porcelain-fused-to-metal (PFM) crowns, which were cemented on the metal dies of upper central incisor by an adhesive luting resin 'Panavia EX', and the color change of porcelain test samples (phi 10 x 4 mm) were measured before and after ion exchange. The conclusions were: 1. It was confirmed by X-ray analysis that the compressive stress layer generated by ion exchange for 30 minutes was 150-200 microns in thickness. However, further elongation of time of ion exchange elicited no significant argumentation in the strength. 2. 34 or 57 percent increase of the mean compressive strength of PFM crowns was observed after ion exchange for 30 minutes when the load was applied in the direction of 45 degrees lingually to the tooth long axis or of the tooth long axis, respectively. 3. No significant decrease was found when parts of the incisal edge or the lingual surface of PFM crowns which were strengthened by ion exchange for 30 minutes were reduced by 200 microns. 4. There was so slight difference in the color of dental porcelain before and after ion exchange that the influence seemed to be negligible in its clinical application.

Dental Porcelain↗
PubMed1989

Detection of orosomucoid 1 phenotypes in semen and semen stains.

Orosomucoid 1 phenotypes were detected in seminal plasma by isoelectric focusing and immunoprinting. The orosomucoid 1 phenotypes in seminal plasma correlated with the types found in the corresponding serum specimens. Semen stains stored for ten days could be typed for orosomucoid 1. The present work revealed that orosomucoid 1 is a useful genetic marker for the medicolegal grouping of semen stains.

Alleles↗
PubMed1989

Sudden unexpected death from a superior mesenteric venous thrombosis after a gastrectomy.

Reported are the autopsy findings of a 55-year-old man who died unexpectedly 20 h after a subtotal gastrectomy of an early gastric cancer. The cause of his death was a superior mesenteric venous thrombosis, involving his small bowel which manifested a marked vascular engorgement. The entire small bowel mesentery was thickened and edematous, and hemorrhagic infarctions were scattered near the bowel. Many fresh thrombi could be identified in the superior mesenteric veins. This case is described, together with the legal aspects of medical malpractice.

Death, Sudden↗
PubMed1988

A delayed drowning death with histological findings of shock.

A delayed drowning death case with histological findings of shock was described. The person was sustained by continuous positive-pressure respiration and died 2 days after resuscitation from drowning. The histological findings were intravascular microthrombi, hyaline bodies and fibrin thrombi in the brain, multiple megakaryocytes in the pulmonary capillaries, hyaline membranes of the lung, multiple small hyaline bodies in the liver sinusoids, and erosion of the mucous membrane of the stomach as well as histological findings of shock kidney. Drowning and systemic hypotension during resuscitation seemed to cause irreversible oxygen debt of the organs and the tissues to lead to shock.

Adolescent↗
PubMed1988

A personal computer-based arrhythmia generator based on mathematical models of cardiac arrhythmia.

A personal computer-based arrhythmia generator has been developed based upon mathematical models of modulated parasystole and the related equations. A system of nonlinear difference equations is used to generate the time series of RR intervals of ECG that contain normal as well as ectopic QRS waves. The ECG waveform is synthesized according to the computed RR interval and the type of QRS wave and output via DA converter in a real-time base. Various types of ECGs with ventricular ectopic beats and those with very long periods were generated by selecting values for a small number of model parameters. This method requires neither large RAM nor external memory for storing a library of arrhythmic ECGs. The theory, hardware design, software implementation on a personal computer, and experimental reconstruction of clinical ECGs based on the model are discussed.

Arrhythmias, Cardiac↗
PubMed1988

Malignant pericardial effusion in endometrial adenocarcinoma.

A case of endometrial adenocarcinoma in a 62-year-old woman with malignant pericardial effusion is presented. The patient underwent a total abdominal hysterectomy, bilateral salpingo-oophorectomy, pelvic node dissection, and paraaortic node biopsy. Postoperatively, she was placed on a combination chemotherapy regimen of cisplatin, doxorubicin, and cyclophosphamide. The patient developed cardiac tamponade during the course of chemotherapy. Although we first suspected cardiotoxic effect of doxorubicin, cytologic examination revealed adenocarcinoma cells in the pericardial fluid. A review of the literature revealed no other cases of cardiac metastasis from endometrial carcinoma diagnosed during life.

Adenocarcinoma, Papillary↗
PubMed1988

Cellular electrophysiologic responses of isolated neonatal and adult cardiac fibers to d-sotalol.

The short-term cellular electrophysiologic actions of d-sotalol on isolated neonatal and adult canine ventricular myocardium and Purkinje fibers were evaluated using standard microelectrode techniques. d-Sotalol, 10(-6) to 10(-4)M, had no effects on action potential amplitude, maximal diastolic potential or action potential upstroke velocity (Vmax) in any neonatal or adult preparation. In five adult myocardial preparations, d-sotalol produced concentration-dependent increases in action potential duration at 50% (APD50) and 90% (APD90) repolarization and effective refractory period. In six neonatal myocardial preparations, d-sotalol produced a biphasic response; APD50, APD90 and effective refractory period decreased at 10(-6) and 10(-5)M. At 10(-4)M, these values increased significantly but to a lesser extent compared with values in adults. In seven adult Purkinje fibers, d-Sotalol significantly increased APD50, APD90 and effective refractory period in a concentration-dependent manner. All six neonatal Purkinje fibers responded in a biphasic manner, with values for APD50, APD90 and effective refractory period being less than control at 10(-6)M and near control values at 10(-5)M. At 10(-4)M, these variables were significantly increased, but to a lesser extent than in adult preparations. Our data confirm the typical class III effects of d-sotalol in adult cardiac tissues. The shortening of repolarization and refractoriness at lower drug concentrations in developing cardiac tissues may relate to age-dependent differences in cellular ionic function and basic electrophysiology.

Action Potentials↗
PubMed1988

Molecular cloning of complementary DNA encoding one of the human pancreatic protease E isozymes.

We have cloned a DNA from a human pancreatic cDNA library using a cloned rat pancreatic elastase 1 cDNA as a probe, and determined its nucleotide sequence. This cDNA contains a coding region of 810 nucleotides which encodes a 270-amino-acid protein. The deduced amino acid sequence shows less than 60% homologies with rat and porcine pancreatic elastase 1, although its substrate binding region is homologous with those of the above elastases 1. When this deduced amino acid sequence was compared with known amino acid sequences of pancreatic proteases other than elastases, it was found to contain an amino acid sequence which was highly homologous with the N-terminal amino acid sequence of porcine pancreatic protease E. We also purified human pancreatic protease E isozymes from human pancreatic juice, and determined their N-terminal amino acid sequences. One of the isozymes does not hydrolyze elastin but does hydrolyze a synthetic substrate. Endoglycosidase F digests glycoside bonds of the isozyme. These results suggest that the cDNA cloned by us corresponded to one of the human protease E isozymes.

Amino Acid Sequence↗