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Biomedical subjects

M Ohtani

Publications and source records attributed to M Ohtani.

At least 181 records · Page 10Linked to original sources
PubMed1990

Synthesis and in vitro activity of stereoisomers of a novel thromboxane receptor antagonist, (+-)-(5Z)-7-[3-endo-[(phenylsulfonyl)amino]bicyclo [2.2.1]hept-2-exo-yl]heptenoic acid.

Three stereoisomers of S-145 (1) with variations at the side-chain junctions were synthesized. Endo-cis isomer 10 and N-exo-trans isomer 18 were obtained via the common intermediate 5 having an endo-fused ring structure. Exo-cis isomer 28 was prepared via exo-fused azetidino compound 21. Inhibitory concentrations (IC50) of the sodium salts newly obtained for platelet aggregation were measured using washed rat platelets (WP) and human platelet-rich plasma (PRP). The IC50 values of these compounds for contraction of the rat aorta were also measured. Compound 1 of N-endo-trans structure and N-exo-trans isomer 18 exhibited more potent inhibitory activity than cis-isomers 10 and 28 against responses induced by TXA2-related substances for rat WP and rat thoracic aorta. However, these compounds exhibited almost comparable inhibitory activity for human PRP.

Animals↗
PubMed1990

The effect of left ventricular bypass on the right ventricular function: experimental analysis of the effects of ischemic injuries to the right ventricular free wall and interventricular septum.

The right ventricular (RV) function during left heart bypass (LHB) was examined in open-chest anesthetized mongrel dogs (average weight, 11.8 kg). The LHB was carried out by a left ventricle (LV) to femoral artery bypass using a centrifugal pump for 90 min, and the bypass flow was kept maximum to obtain almost complete decompression of the LV. The RV function was evaluated by hemodynamic parameters and pressure-dimension (sonomicrometry) relationship at pre-LHB (control) and 30, 60, and 90 min after LHB (LHB-30, LHB-60, and LHB-90). The materials were divided into three groups after LHB-30: intact heart (group 1, n = 5), RV free wall ischemia (group 2, n = 5), and interventricular septum (IVS) ischemia group (group 3, n = 8). No significant changes in mean right atrial pressure (mRAP), RV end-diastolic pressure (RVEDP), RV maximum derivative pressure, or RV fractional shortening (RVFS) were found between pre-LHB and post-LHB in groups 1 and 2. On the contrary, group 3 showed significant increases in mRAP and RVEDP, and a decrease in RVFS at LHB-90 compared to both pre-LHB and LHB-30. The RV end-systolic dimension (percentage of pre-LHB) showed significant increases at LHB-90 compared to LHB-30 in groups 2 and 3. These results indicate that the LHB itself does not depress the RV function in the intact heart and in the RV free wall ischemic heart, while the impairment of the IVS during LHB appears to lead to RV dysfunction.

Animals↗
PubMed1990

Hepatic neoplasms: detection with hepatoportal subtraction angiography--a new technique of DSA.

A new technique for hepatic intraarterial digital subtraction angiography (DSA)--hepatoportal subtraction angiography (HPSA)--that emphasizes the enhancement of tumors by suppressing liver parenchymal enhancement has been developed. The tumor detection sensitivity of HPSA was evaluated prospectively in comparison with that of conventional hepatic intraarterial DSA, unenhanced computed tomography (CT) or CT enhanced with iodine-containing contrast material (conventional CT), CT with iodized oil, and ultrasound (US). For 84 detected lesions of hepatoma, the sensitivity of HPSA was 92%, statistically superior to the 71% of hepatic intraarterial DSA (P less than .002), the 42% of US (P less than .001), and the 39% of conventional CT (P less than .001) and nearly the same as the 90% of CT with iodized oil. Among 33 lesions of metastasis, HPSA depicted 91%; conventional CT, 93%; US, 87%; and hepatic intraarterial DSA, 76%. HPSA was more sensitive than hepatic intraarterial DSA, but the difference was not statistically significant. Compared with hepatic intraarterial DSA, HPSA enabled detection of more faintly enhanced tumors, and this technique was considered useful for detecting small hypervascular hepatic tumors.

Adult↗
PubMed1990

A case of nonseminomatous testicular tumor with liver metastases, treated by intrahepatic arterial cisplatinum-diaminedichloride infusion.

We report a case of nonseminomatous testicular tumor with lymph node involvement and multiple lung and liver metastases. The patient was considered to have a poor prognosis. He received systemic chemotherapy and cytoreductive surgery. Postoperatively a residual metastatic tumor in the liver was treated by intrahepatic arterial cisplatinum-diaminedichloride infusion. Follow-up observation has revealed no evidence of recurrence for 30 months since the last treatment.

Adult↗
PubMed1990

[Clinical study of proton radiotherapy in urological cancers].

Therapy with proton beam is superior to that with photon beam in concentrating the dose within a lesion. Fifteen patients with urinary malignant tumors were treated by proton irradiation during the period from June, 1985 to March, 1989 at Particle Radiation Medical Center, University of Tsukuba. Four patients were with renal cell carcinoma, five with prostatic cancer and six with bladder cancer. Treatment results were assessed by change in tumor size either three or six months after the irradiation. In all the four cases with renal cell carcinoma, the tumor sizes were found to be unchanged without any enlargement. Of the five cases with prostatic cancer, two showed that the treatment was effective and the tumor sizes in the other three cases were found to be unchanged. In three of the six cases with bladder cancer the tumors disappeared while the treatment was found effective in two other and it did not cause any enlargement of the tumor in the remaining one. Although local control of the tumor was successful in all the cases, one patient with prostatic cancer and three with bladder cancer died of cancer. Various side effects, such as radiation cystitis, were observed. This prospective therapy is expected to replace the conventional photon therapy. However, some improvement is needed to make full use of the advantageous properties in dose distribution. Combination therapy with other general therapy is required for some cases.

Aged↗
PubMed1990

[Basic study of nephrotoxicity of antibiotics. I. Studies of the effects of antibiotics on nucleic acids and protein metabolism in rat kidneys].

In order to evaluate the nephrotoxicity by antibiotics, effects of these agents were investigated in terms of protein synthesis and nucleic acid metabolism in the kidneys of Wistar rats. Aminoglycoside antibiotics (streptomycin, kanamycin, gentamycin), tetracycline (doxytetracycline), chloramphenicol, and cephems (cephalothin, cephaloridine, ceftezol, latamoxef) were used. These antibiotics were given to the rats for 5 successive days. On the 6th day 14C-6-orotic acid and 14C-1-leucine were administered intraperitoneally. Incorporation rates of these tracers into ribonucleic acid and protein fraction in rat kidney ribosomes (polysomes) were measured. Another experiment was undertaken in vitro by separating the polysome fraction from the rat kidneys. In vitro acellular protein synthesis using these polysomes was established. Effects of antibiotics on the incorporation rates of 14C-1-leucine were examined. Marked reduction of incorporation of these tracers into nucleic acid and protein in vivo and in vitro was induced by aminoglycoside antibiotics. These facts suggest that aminoglycoside antibiotics develop nephrotoxicity by interfering with the metabolism of ribosomal RNA and protein.

Aminoglycosides↗
PubMed1990

[Guillain-Barré syndrome and disturbance in multiple organs associated with cytomegalovirus infection].

We presented a case of Guillain-Barré syndrome (GBS) associated with pneumonitis, liver, pancreatic and renal dysfunction, and encephalopathy, who showed an increase in anti-cytomegalovirus (CMV) antibody titer of the serum and cerebrospinal fluid (CSF). A 41-year-old male admitted to our hospital with complaints of gait disturbance and muscle weakness in the extremities. The symptoms appeared following common cold, and developed gradually. Neurological examination showed mild mental symptoms, bilateral abducens, facial and bulbar palsy. Muscle weakness was shown on the neck and four extremities. Bilateral hand tremor, glove and stocking type sensory disturbance, and dysautonomia were also presented. Examination of the CSF revealed albumin-cytologic dissociation, and the anti-CMV antibody titer of the serum and CSF increased significantly. The titer of anti-CMV IgG antibody was 1:6400 in the serum, and was 1:80 in the CSF. Immunological examination showed no immunodeficiency. The conduction velocity of the peripheral motor and sensory nerves was decreased. The coefficient variation (CV%) of the R-R interval was also decreased. P1 and P2 latency and central conduction time for a somatosensory evoked potential (SEP) were also elongated, and paroxysmal abnormality was present on electroencephalogram (EEG). Two days after admission, pneumonitis appeared, leading to respiratory insufficiency. He needed respirator because of bulbar and respiratory disturbance. The chest roentgenogram revealed a consolidation-like shadow in the right upper lung filed. Two weeks after admission, liver, pancreatic and renal dysfunction was noted by biochemical examination of the blood, urinalysis, and abdominal echography. Since 10 days after the onset of GBS, 70 mg/day prednisolone was administered.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Serum concentration of beta-carotene and intake frequency of green-yellow vegetables among healthy inhabitants of Japan.

Serum levels of beta-carotene were measured among healthy inhabitants (671 males and 948 females) of 2 towns in Japan to determine the association between the levels and intake frequency of green-yellow vegetables. Those individuals who consumed green-yellow vegetables frequently showed higher levels of serum beta-carotene than those who ate them less often. The influences of alcohol drinking, smoking, obesity and age on serum beta-carotene levels were similarly observed for the 2 areas. The factors listed above were used for adjustment, giving a significant association between intake frequency of green-yellow vegetables and serum beta-carotene level. The proportion of the subjects who rarely consumed green-yellow vegetables was larger among smokers than among non-smokers. There was a large difference in serum beta-carotene levels between the 2 towns, which could not be explained by alcohol drinking and smoking. Women showed statistically significantly higher serum beta-carotene levels than men.

Adult↗
PubMed1989

Evaluation of prostacyclin analogue OP-41483 as an adjunct to crystalloid cardioplegia in infants and children.

A chemically stable prostacyclin analogue (PGI2-A, carbacyclin, OP-41483) was evaluated as an adjunct to potassium cardioplegia in infants (n = 13) and children (n = 32), in whom the current potassium cardioplegia may be limited in its effects. PGI2-A was added in a dose of 300 micrograms/L to the potassium cardioplegic solution. Postoperatively, peak levels of the myocardial-specific isoenzyme of creatine kinase (MB-CK) were compared for the PGI2 group and a control group (n = 65). In patients 1 year of age or older (n = 32 and 49 for the PGI2 and control groups, respectively), the MB-CK level was significantly lower in the PGI2 group only when compared between the subgroups with an aortic cross-clamp time of 120 minutes or more (n = 9 and 10; MB-CK level, 35.2 +/- 15.6 vs 68.3 +/- 32.4 IU/L;p less than 0.05). In patients less than 1 year of age, in whom aortic cross-clamp times were generally less than 120 minutes, the MB-CK level was also lower in the PGI2-A group than in the control group (n = 13 and 16; MB-CK level, 33.6 +/- 14.3 vs 61.6 +/- 36.3 IU/L;p less than 0.05). Infants less than 6 months of age (n = 18) underwent ultrastructural assessment of left ventricular myocardial biopsy specimens, and the PGI2-A group showed better results in mitochondrial and intracellular edema scores. This clinical trial showed beneficial effects of PGI2-A used with crystalloid potassium cardioplegia in infants and children.

Adolescent↗
PubMed1989

Detection of S-methylfenitrothion, aminofenitrothion, aminofenitroxon and acetylaminofenitroxon in the urine of a fenitrothion intoxication case.

A 23-year-old male attempted suicide by ingesting approximately 50 ml of 5% fenitrothion emulsion, and vomited soon afterwards. He was admitted to a hospital about 3 h after ingestion. He recovered and was discharged from hospital 3 days after admission. The serum cholinesterase activity (normal range: 175-440 I.U.) was only 29 at 3 h, 32 at 1 day, 59 at 2 days and 75 at 3 days after ingestion. Fenitrothion and its metabolites in the body fluids were extracted by an Extrelut column extraction method, detected by a gas chromatograph equipped with either a hydrogen flame ionization detector or a flame photometric detector, and confirmed by a gas chromatograph-mass spectrometer. Fenitrothion concentration in the blood was 169.5 ng/g at 3 h after ingestion. The half life of blood fenitrothion concentration was found to be about 4.5 h. Fenitrothion metabolites, 3-methyl-4-nitrophenol, aminofenitrothion, aminofenitroxon, acetylaminofenitroxon and S-methylfenitrothion, were detected in the urine samples. All of them except S-methylfenitrothion were detected in the urine samples collected up to 62 h after ingestion. It would appear therefore that fenitrothion poisoning can be determined by detection and analysis of the metabolites in urine even if fenitrothion has not been detected in the blood.

Adult↗
PubMed1989

Analysis of acute and chronic heart failure in view of hepatic oxygen supply-demand relationship using hepatic venous oxygen saturation.

The adequacy of hepatic circulation in terms of oxygen supply-demand relation was assessed by measuring hepatic venous oxygen saturation (Shvo2) in patients. Among those with congenital cardiac lesions (n = 11), Shvo2 during the early postoperative period was markedly low as less than 20% in Fontan operation group (n = 5) with subsequent clinical findings of acute hepatic dysfunction. Significant correlations were found between Shvo2 values early after surgery and subsequent peak values in serum hepatic enzymes. Serum total bilirubin and prothrombin time started to deteriorate when Shvo2 became below 30%. Cardiac index, hepatic perfusion pressure and mixed venous oxygen saturation showed positive linear correlations with Shvo2, and central venous pressure (CVP) with an inverse relation. In chronic valvular disease (n = 28), those with NYHA class IV patients showed lower Shvo2 (average; 47.4%) at cardiac catheterization than the others (class-I; 66.4%, class-II; 63.9%, p less than 0.05). These results indicate that Shvo2 monitoring appears to be useful to assess the hepatic perfusion in terms of oxygen supply-demand relation in acute and chronic heart failure, and Shvo2 of 30% seems to be a critical level.

Adult↗
PubMed1989

[Studies on the urophonography (1)--Basic investigation with the model of lower urinary tract].

The purpose of this study is to ascertain whether the urinary (turbulent) flow really causes the sounds during micturition in humans. For this purpose the artificial bladder and urethra, which were made of silicon rubber (3M Co. Minnesota, U.S.A.), were used. The manometric device was attached to the bladder to measure the intravesical pressure. Outside the bladder neck a prostate like protrusion surrounding the urethra was made. A microphone was attached to this protrusion to detect the sound. A recording system was also adopted. The bladder was filled with 200 ml of sterile eater. By pressurising the artificial bladder at 100 cmH2O, the water passed through the urethra. During this artificial voiding the sound detection was undertaken. At the same time uroflowmetry was also performed. It was demonstrated that sound spikes were recorded whenever water in the artificial bladder passed through the artificial urethra.

Auscultation↗
PubMed1989

[Studies on the urophonography (2)--Clinical investigation on normal human subjects and patients with benign prostatic hypertrophy].

Recently we have developed an entirely new method of sonic detection of lower urinary tract disorders during micturition. The detection of these sounds was performed by a data catching and recording system, consisting of a detector, amplifier, and recorder. This procedure was designated as "urophonography" and its recording as "urophonogram". Twenty-five patients with BPH before and three months after suprapubic prostatectomy and 10 healthy male volunteers underwent urophonography. The urophonograms were classified into four types. Type 1 was characterized by its diamond shape, while Type 2 was characterized by its random sound spikes. Type 3 was a mixture of Types 1 and 2. Type 4 had only few sound spikes. Analysis of these urophonograms also revealed that the frequencies of these urethral sounds belonged to the range from 0.4 to 1.5 KHz. The amplitude (power) of the sounds was in the range of 40-60 dB. Healthy volunteers belonged to Type 4. BPH patients belonged to Types 1, 2 and 3 at equal frequency. Comparison of uroflowmetric parameters with urophonograms revealed that Type 3 patients with BPH showed a lesser degree of micturition disturbances, which was consistent with the weight of prostatic tumors surgically resected. Urophonography was undertaken before and after the treatment on these patients. It was clearly shown that the pattern of urophonograms shifted to normal (Type 4). It was considered that urophonograms were useful for urodynamic investigation.

Aged↗
PubMed1989

[Studies on the urophonography (3)--Clinical investigation on prostatic cancer].

Recently we have developed an entirely new method of sonic detection of lower urinary tract disorders during micturition. This procedure was designated as "urophonography" and its recording as "urophonogram". Sixteen patients with prostatic cancer before and three months after anti-androgenic therapy and ten healthy male volunteers underwent urophonography. The urophonograms were classified into four types. Type 1 was characterized by its diamond shape, while Type 2 was characterized by its random sound spikes. Type 3 was a mixture of Types 1 and 2. Type 4 had few sound spikes. Analysis of these urophonograms also revealed that the frequencies of these urethral sounds belonged to the range from 0.4 to 1.5 KHz. The amplitude (power) of the sounds was in the range of 40-60 dB. Healthy volunteers belonged to Type 4. Prostatic cancer patients belonged to Types 1, 2 and 3 at 18.8, 68.8, nad 12.4%, respectively. After the treatment the percentages of Types 1, 2, 3, and 4 changed to 18.8, 50.0, 0, and 31.2%, respectively. Comparison of uroflowmetric parameters with urophonograms showed that Type 2 patients showed a lesser degree of micturition disturbances, evidenced by these parameters. It was considered that urophonograms were useful as urodynamic investigation.

Aged↗