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Biomedical subjects

K Kodama

Publications and source records attributed to K Kodama.

At least 487 records · Page 27Linked to original sources
PubMed1989

Influence of high and low wall shear rates on the inhibition of factor Xa and thrombin at surfaces coated with immobilized heparin.

The thromboresistant function of a surface with end-point attached heparin is based upon interaction among the immobilized heparin, antithrombin, and at least factor Xa or thrombin. Heparinized arteriovenous shunts were implanted in dogs. By compressing a segment of the shunt, high and low wall shear rate regions were obtained in each shunt. After removal, the tubings were tested for their factor Xa and thrombin inhibitory capacity. It was found that on a molar basis, the factor Xa and thrombin inhibitory capacity were similar in low wall shear rate segments. In high wall shear rate segments, the thrombin inhibitory capacity was decreased, thus indicating that the AT-mediated inhibition of the serine protease is dependent on the wall shear rate.

Animals↗
PubMed1989

Urinary lactic dehydrogenase isoenzyme analysis in children with spinal lesions.

In 48 children with spinal lesions and micturition problems urinary lactic dehydrogenase (LDH) isoenzymes were analyzed. They had higher total LDH activities (716.8 +/- 1,050.2 nkat/I), isoenzymes V percents (22.2 +/- 13.0%) and isoenzyme V activities (203.4 +/- 308.4 nkat/I) than those of healthy children (150.0 +/- 83.4 nkat/I, 1.9 +/- 1.0%, 5.0 +/- 3.3 nkat/I). Many subjects had an isoenzyme V-dominant LDH isoenzyme pattern. Among 48 subjects the patients with pyuria, bacteriuria or abnormal pyelograms had markedly high total LDH activities, isoenzyme V percents and isoenzyme V activities. The rise in LDH isoenzyme V levels may reflect the renal damage in the patients with neurogenic bladders.

Adolescent↗
PubMed1989

Effects of antiserum against alpha-rat atrial natriuretic polypeptide in spontaneously hypertensive rats.

To clarify the physiological role of endogenous atrial natriuretic polypeptide (ANP), we investigated the effects of specific rabbit antiserum against alpha-rat ANP (alpha-rANP) on hemodynamics, diuresis, and natriuresis in spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). Intravenous administration of anti-alpha-rANP antiserum caused an obvious rise of mean blood pressure and cardiac output in both SHR and WKY compared with rats administered with normal rabbit serum. Although there was no significant difference in increments of mean blood pressure between SHR and WKY, the increment of cardiac output in SHR was significantly higher than that in WKY. On the other hand, significant reductions in urine output and urinary sodium and potassium excretion lasted for approximately 20 min after administration of the antiserum in both SHR and WKY compared with rats administered with normal rabbit serum. There was no significant difference in these initial maximal decrements between SHR and WKY. These results indicate that endogenous ANP has an important physiological role in the regulation of hemodynamics and water-electrolyte balance in both SHR and WKY. The greater increment of cardiac output in SHR in response to the antiserum suggests that endogenous ANP in SHR may have a stronger cardiosuppressive action that it does in WKY.

Animals↗
PubMed1989

Proximal communication between the glossopharyngeal and facial nerves.

The facial nerve branch termed Ramus communicans cum nervo glossopharyngeo in the current Nomina anatomica was investigated in 245 Japanese, especially as regards the frequency and pertinence as an approved definition. The communication was found in only 18.8%. It runs, if present, either medially, laterally or through the digastric posterior muscle. Teasing examination reveals that it always originates from the ninth nerve instead of the seventh and that it is destined to the back of the pinna. Its terminal bundle leaves the seventh nerve somewhat distally than the posterior auricular nerve in many examples, but the communication is likely to represent the auricular branch of the ninth nerve. As an offshoot of the seventh nerve, it is ill-defined, and should be affiliated to the ninth nerve in the Nomina anatomica. If it pierces the digastric muscle, half examples certainly give additional innervation to this muscle, but the fundamental disposition of the communication itself is not affected.

Facial Nerve↗
PubMed1989

Visualization of subendocardial myocardial ischemia with myocardial contrast echocardiography in humans.

Previous studies indicate the degree of myocardial echo contrast enhancement may be related to regional myocardial perfusion. In this study, myocardial contrast echocardiography was used to characterize changes in the transmural myocardial blood flow distribution that were provoked by rapid atrial pacing in 11 patients with one-vessel coronary artery disease. Ten patients without coronary artery disease served as controls. Myocardial contrast echocardiography was performed by intracoronary injection of 2 ml hand-agitated amidotrizoate sodium meglumine (Urografin-76) and by imaging a short-axis view of the left ventricle with two-dimensional echocardiography before and during injection of the contrast agent. The two-dimensional echocardiographic images at end diastole, before and after injection of the contrast agent, were digitized off-line into a 512 x 512 pixel matrix with 256 gray levels/pixel to quantify the degree of the enhancement of the peak gray level after injection. Transmural myocardial blood flow distribution was evaluated by measuring the ratio of the enhanced gray level in the endocardial half (endo) to that in the epicardial half (epi) (endo:epi gray level ratio) in the anteroseptal, posterolateral, and inferior segments before and just after rapid atrial pacing in each patient. In patients without coronary artery disease, there were no differences in the endo:epi gray level ratio between any of the three segments both before and after pacing. Mean values of the three segments were 0.95 +/- 0.08 before pacing and 0.90 +/- 0.13 after pacing, respectively. In contrast, in patients with coronary artery disease, the endo:epi gray level ratio for the segment supplied with stenotic coronary artery decreased after pacing (0.40 +/- 0.21 vs. 0.93 +/- 0.18, p less than 0.01), probably reflecting subendocardial myocardial ischemia, whereas that for the segment supplied with nonstenotic coronary artery remained unchanged (0.88 +/- 0.20 vs. 0.99 +/- 0.23, NS). Thus, changes in transmural myocardial blood flow distribution with rapid pacing, which may be due to transient subendocardial ischemia, are visualized with myocardial contrast echocardiography.

Adult↗
PubMed1989

Comparative histology of the tympanic membrane and its relationship to cholesteatoma.

The purpose of this study was to determine whether anatomic differences in the tympanic membranes of various species could explain differences in the propensity to form aural cholesteatomas and retraction pockets. Tympanic membranes from humans, dogs, cats, rabbits, guinea pigs, rats, gerbils, and mice were examined histologically. The pars flaccida and pars tensa varied greatly among the species studied. The guinea pig's pars flaccida was very small and had a thin lamina propria. In contrast, the lamina propria of the rabbit and cat pars flaccida were thick. The amount of collagen, elastin, mast cells, and macrophages varied widely. The human and gerbilline tympanic membranes were anatomically dissimilar; for example, the human pars flaccida and pars tensa contained more and denser collagen than did those of the gerbil. The presence of macrophages or mast cells did not correlate with the propensity to develop cholesteatomas. Therefore, anatomic differences among these species do not explain why some develop aural cholesteatomas and others do not.

Animals↗
PubMed1989

Preliminary clinical experience with intermittent coronary sinus occlusion in combination with thrombolytic therapy in acute myocardial infarction.

Previous experimental studies have clarified the effectiveness of intermittent coronary sinus occlusion or ICSO. We evaluated the clinical feasibility, safety and effectiveness of ICSO in the patients with acute myocardial infarction (AMI) who were treated with concomitant thrombolytic therapy. Implementation of ICSO was obtained in 76% of the eligible patients. Twelve patients with evolving anteroseptal infarction treated with ICSO + thrombolysis were compared with 12 patients with anterior AMI treated with thrombolysis alone. Baseline characteristics were comparable between the two groups. Adverse effects of ICSO on hemodynamics, hematologic parameters and ventricular arrhythmias were not detected. Enzymatic infarct size, myocardial lactate metabolism in the acute phase, and left ventricular wall motion and Tl-201 perfusion defect at follow-up in ICSO group were slightly improved compared with controls.

Adult↗
PubMed1989

Impact of a family history of hypertension on blood pressure levels during early and late adolescence.

The aim of this study was to examine the impact of a family history of hypertension (FHH) on blood pressure levels in Japanese rural adolescents. The study population consisted of 458 and 553 subjects, aged 13 and 16 years, respectively. Particular attention was focussed on subjects with a FHH (13 years old, n = 38; 16 years old, n = 46) and those without a FHH (13 years old, n = 83; 16 years old, n = 97). Significant associations were found between FHH and systolic blood pressure for boys and girls at 16 years old and diastolic blood pressure for girls at 16 years old. The impact of a FHH on blood pressure mainly affected systolic blood pressure in late adolescence (16 years of age). In early adolescence (13 years of age), different physical maturation status may have masked the real impact of a FHH on blood pressure.

Adolescent↗
PubMed1989

[A comparative study of human placenta hydrolysate (Laennec) by intravenous or subcutaneous injection on liver regeneration after partial hepatectomy in normal and CCl4-induced cirrhosis rats].

The effect of human placenta hydrolysate (Laennec) on residual liver regeneration after about 70% partial hepatectomy (PH) in normal and CCl4-induced cirrhosis rats was examined. Both intravenous or subcutaneous injections of Laennec increased the regeneration rate of the residual liver after PH in normal rats. Intravenous injection of Laennec inhibited the decrease of liver total protein, and it decreased the level of serum transaminase (GOT, GPT). The regeneration rate of the residual liver after PH in CCl4-induced cirrhosis (CCl4-PH) rats increased by intravenous or subcutaneous injection of Laennec. Laennec also inhibited the increase of serum GOT caused by CCl4-PH. In the pathological examination of the regenerating liver, intravenous injection of Laennec minimized the pathological changes caused by PH or CCl4-PH such as vacuolation and necrosis in the hepatocytes. The enhancement of cytoplasma regeneration in hepatocytes was noticed by intravenous injection of Laennec, but that by subcutaneous Laennec was slight. Intravenous injection of Laennec also minimized the lipid deposition in liver caused by CCl4-PH. Laennec had no effect on the pseudolobule formation caused by CCl4. Thus, the effect of intravenous injection of Laennec on the liver regeneration in PH rats was much more potent than that by the subcutaneous injection.

Animals↗
PubMed1989

Characterization of a parvovirus isolated from the diarrheic feces of a pig.

A small DNA virus was isolated from the feces of a sow with diarrhea and identified as a parvovirus on the basis of its properties. The virus replicated preferentially in cell cultures of swine origin, including primary porcine thyroid gland and kidney cell cultures in which the cytopathic effect developed. The virus agglutinated erythrocytes of guinea pig, mouse and human group O but not these of chicken. The growth of the virus was inhibited by 5-iodo-2'-deoxyuridine. The virus was resistant to ether and heating at 56 degrees C for 30 min and stable at pH 3.0. The buoyant density of the infectious particles was 1.40 g/ml in CsCl density gradient, and the virions were 27 nm in diameter by electron microscopy. The viral protein seemed to be separated into four polypeptides with molecular weights of 81k, 70k, 66k and 62k daltons respectively. Cross serum neutralization test demonstrated that the virus was antigenically different from porcine parvovirus as well as bovine and canine parvoviruses. These findings and the survey on neutralizing antibody distribution indicated indirectly that another parvovirus which could be antigenically distinguished from well-known porcine parvovirus had been widespread among swine in Japan.

Animals↗
PubMed1989

Fosfonochlorin, a new antibiotic with spheroplast forming activity.

A new antibiotic, fosfonochlorin, was found in the culture filtrate of four strains of fungi freshly isolated from soil samples. These strains were identified as Fusarium avenaceum, Fusarium oxysporum, Fusarium tricinctum and Talaromyces flavus. Fosfonochlorin was a low molecular weight antibiotic (MW 158), soluble in water and methanol, but insoluble in acetone, ethyl acetate and chloroform. It was named after its possession of phosphorus and chlorine atoms, each one molar in its structure. The structure was determined as chloroacetylphosphonic acid mainly by the 1H NMR and mass spectrometric analyses. It was moderately active against some species of Gram-negative bacteria and its synergistic effect with glucose-6-phosphate was observed on Staphylococcus aureus and Escherichia coli. Spheroplast formation of the susceptible organisms with this antibiotic suggested that it might inhibit their cell wall synthesis.

Anti-Bacterial Agents↗
PubMed1989

[Evaluation of function of human collateral coronary arteries using myocardial contrast echocardiography].

The morphology of collateral vessels can be imaged by coronary angiography, but no method has been available for evaluating their function. This is a report of the use of regional myocardial perfusion to visualize collateral flow by means of myocardial contrast echocardiography in 28 patients with old myocardial infarction. Myocardial contrast echocardiography was accomplished by the intracoronary injection of two ml agitated amidotrizoate sodium meglumine. Short-axis images of the left ventricle were recorded on video tape. Those images were digitized off-line into a 512 x 512 pixel matrix. Using coronary angiography, the morphology and function of the collateral vessels were evaluated, then classified as poor, moderate or good. Myocardial perfusion was evaluated using the enhanced gray level after contrast injection, and the level was compared with the morphology and degree of collateral development. The enhanced gray level was evaluated arbitrarily as 3 +/- 2 U (mean +/- S.D.) in the "poor" group; 13 +/- 6 U in the "moderate" group; and 20 +/- 11 U in the "good" group (p less than 0.01 vs the "poor" group; NS vs the "moderate" group). Regional myocardial perfusion via the collateral vessels was generally proportional to the morphology. However, there were a few discrepancies between these two parameters.

Aged↗
PubMed1989

[Role of O6-methylguanine-DNA methyltransferase in repair of DNA damaged by alkylating agents].

Some human tumor cell lines show the Mer- (Mex-) phenotype characterized by defects in repair of O6-methylguanine. Since the Mer- cells are deficient in O6-methylguanine-DNA methyltransferase activity, we examined whether introduction of the cloned bacterial gene, ada, encoding methyltransferase would make Mer- cells resistant to alkylating agents. When a DNA fragment carrying the ada gene of Escherichia coli on pSV2 neo vector was introduced into HeLa Mer- cells, transformants which are resistant to alkylating agents were obtained. The cells produced a large amount of methyltransferase enzyme. By expressing foreign genes in E. coli cells, it may be possible to clone DNA repair genes of various organisms. In this manner, we cloned the Bacillus subtilis gene that encodes a constitutive O6-methylguanine-DNA methyltransferase. Based on the nucleotide sequence of the gene, it was deduced that the protein comprises 165 amino acids and that the molecular weight is about 18,800. In principle, this method is applicable for cloning of cDNA for methyltransferase from higher organisms. The sequence homology evidenced in the present experiments also provides a useful tool for screening the gene or cDNA for methyltransferase. We developed a new vector which can replicate autonomously in EB-transformed lymphoblasts as well as in fibroblast cell lines such as HeLa. We found that the cloned ada gene on the vector is effective for increasing survival rates of Mer- cells treated with alkylating agents. This system can be used for cloning cDNA for human methyltransferase.

Alkylating Agents↗
PubMed1989

[Measurement of blood flow of saphenous vein graft with Doppler catheter].

We investigated the measurement of blood flow of saphenous vein graft by Doppler Catheter. Under operation of femoro-popliteal bypass graftings (3 cases with 5 grafts of arteriosclerosis obliterans) with reversed saphenous vein grafts, blood flow of saphenous vein graft was measured. At the same time, blood flow of saphenous vein graft was measured by electromagnetic flowmeter. And the values obtained by Doppler Catheter (y) and those obtained by electromagnetic flowmeter (x) were compared. As a result, a good corelationship (y = 0.752 x -14.9, r = 0.836, p = 0, n = 20) was obtained. In conclusion, we suggest that the values of saphenous vein graft can be measured by Doppler Catheter. We actually measured the blood flow of saphenous vein graft with CABG. The measurement was thought to be possible.

Arteriosclerosis Obliterans↗
PubMed1989

[Three cases of successful early operations of post-infarction ventricular septal perforation].

We reviewed three cases who underwent early operations for post-infarction ventricular septal perforation. Three patients were 56-year-old male, 66-year-old female, and 62-year-old female. These three cases had sustained antero-septal infarction with perforation. The periods to operations were 11 days, 86 hours, and 76 hours from the onsets of myocardial infarction. And 70 hours, 51 hours, and 42 hours from the onset of postinfarction ventricular septal perforation. Operations were performed after cardiac standstill using cold potassium cardioplegia and topical cooling. At first ventricular infarctectomy was performed and a large Teflon patch was used to create the septum after resection of the necrotic septum, and then resulting defect in the right and left ventricles was closed with Teflon strips and interrupted mattress sutures, incorporating the patch in the repair. Postoperative clinical courses were not smooth, but all the cases were going well. So we believed to get good results for early operations of post-infarction ventricular septal perforation, unless operative chances were lost.

Aged↗
PubMed1989

[Noninvasive evaluation of changes in stroke volume and left ventricular filling dynamics. Produced by atrioventricular interval manipulation].

To evaluate the effects of atrioventricular pacing interval on hemodynamics, we studied the changes in stroke volume and left ventricular filling dynamics in fourteen consecutive patients with implanted atrioventricular pacemakers using a Doppler echocardiographic technique. Twelve patients had sick sinus syndrome and 2 had complete atrioventricular block. Stroke volume was determined as the time-velocity integral of the pulsed Doppler recordings at the aortic annulus multiplied by the area of the aortic annulus obtained by 2-dimensional echocardiography. Left ventricular filling velocity was measured at the mitral annulus by the pulsed Doppler technique to provide the time-velocity integral of rapid filling (TVI-R) and that of atrial filling (TVI-A). No significant change in stroke volume was noted during the atrioventricular interval manipulation. TVI-R was greater with short atrioventricular intervals than that with the long atrioventricular intervals. On the contrary, TVI-A was greater with long atrioventricular intervals than that with short atrioventricular intervals. These results suggested that there is a compensatory mechanism in the left ventricular filling dynamics to keep the stroke volume constant despite the change in the atrioventricular interval. However, in patients with high atrial filling to rapid filling ratio (A/R), the stroke volume varied with change of atrioventricular interval, suggesting that the compensatory mechanism was not sufficient in such patients. We conclude that Doppler echocardiography is a useful, noninvasive technique to assess the changes in the hemodynamics produced by atrioventricular interval manipulation in patients with implanted atrioventricular pacemakers.

Adult↗