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Biomedical subjects

H Takeuchi

Publications and source records attributed to H Takeuchi.

At least 829 records · Page 46Linked to original sources

Effects of glutamic acid analogues on identifiable giant neurones, sensitive to beta-hydroxy-L-glutamic acid, of an African giant snail (Achatina fulica Férussac).

The effects of the seven glutamic acid analogues, alpha-kainic acid, alpha-allo-kainic acid, domoic acid, erythro-L-tricholomic acid, DL-ibotenic acid, L-quisqualic acid and allo-gamma-hydroxy-L-glutamic acid were examined on six identifiable giant neurones of an African giant snail (Achatina fulica Férussac). The neurones studied were: PON (periodically oscillating neurone), d-RPLN (dorsal-right parietal large neurone), VIN (visceral intermittently firing neurone), RAPN (right anterior pallial neurone), FAN (frequently autoactive neurone) and v-RCDN (ventral-right cerebral distinct neurone). Of these, d-RPLN and RAPN were excited by the two isomers (erythro- and threo-) of beta-hydroxy-L-glutamic acid (L-BHGA), whereas PON, VIN, FAN and v-RCDN were inhibited. L-Glutamic acid (L-Glu) had virtually no effect on these neurones. alpha-Kainic acid and domoic acid showed marked excitatory effects, similar to those of L-BHGA, on d-RPLN and RAPN. Their effective potency quotients (EPQs), relative to the more effective isomer of L-BHGA were: 0.3 for both substances on d-RPLN, and 1 for alpha-kainic acid and 3-1 for domoic acid on RAPN. alpha-Kainic acid also had excitatory effects on FAN and v-RCDN (EPQ for both: 0.3), which were inhibited by L-BHGA but excited by gamma-aminobutyric acid (GABA). Erythro-L-tricholomic acid showed marked effects, similar to those of L-BHGA, on VIN (EPQ: 0.3) and RAPN (EPQ: 3-1), but produced weaker effects on PON and d-RPLN (EPQ: 0.1). DL-Ibotenic acid produced marked effects, similar to those of L-BHGA, on PON, VIN (EPQ for both: 1) and RAPN (EPQ: 1-0.3), but had weak effects on d-RPLN (EPQ: less than 0.1) and FAN (EPQ: 0.1). It had excitatory effects on v-RCDN (EPQ: 0.1). This neurone was inhibited by L-BHGA but excited by GABA. L-Quisqualic acid showed the same effects as L-BHGA on all of the neurones examined (EPQ range 30-0.1). It was the most potent of the compounds tested on RAPN (EPQ: 30-10), FAN (EPQ: 30) and v-RCDN (EPQ: 3). alpha-Allo-kainic acid and allo-gamma-hydroxy-L-glutamic acid had no obvious effect on any of the neurones examined. As described above, the responses of the neurones examined to these substances varied widely. However, L-quisqualic acid generally had effects on the neurones similar to those of L-BHGA; the L-BHGA-excited neurones were also excited by alpha-kainic acid and domoic acid.

Animals↗

Pharmacological characteristics of four giant neurons identified in the cerebral ganglia of an African giant snail (Achatina fulica Férussac).

Two giant neurons, d-RCDN (dorsal-right cerebral distinct neuron) and d-LCDN (dorsal left cerebral distinct neuron), with a diameter of about 100 microns, were found symmetrically on the dorsal surface of the cerebral ganglia of an African giant snail (Achatina fulica Férussac). They showed spontaneous spike discharges at a stable frequency. Two giant neurons, v-RCDN (ventral-right cerebral distinct neuron) and v-LCDN (ventral-left cerebral distinct neuron), (diameter, approx. 150 microns) were identified on the ventral surface of the same ganglia. No spontaneous spike discharges were evident. Both d-RCDN and d-LCDN were equally inhibited by dopamine, octopamine, 5-hydroxytryptamine and histamine. Acetylcholine sometimes showed inhibitory effects, but they were not so stable. No substance having excitatory effects on the neurons was found. Both v-RCDN and v-LCDN were equally excited by octopamine, 5-hydroxytryptamine, GABA and acetylcholine and inhibited by dopamine and beta-hydroxy-L-glutamic acid.

Acetylcholine↗

[A case of Werner's syndrome with neurogenic bladder].

The present report is Werner's-syndrome associated with a neurogenic bladder. The patient visited our clinic with the chief complaint of retention of urine and urinary tract infections. The diagnosis of Werner's syndrome was made because the patient had such clinical features as bird-like or "masked" face, short stature, graying of the hair in youth, cataracts in youth, skin changes like scleroderma principally on limbs, early menopause. After trans-urethral-resection of bladder neck and administration of distigmine bromide, her bladder function was improved, she could urinate by herself and she was free from urinary tract infections.

Adult↗

[Immunological analysis of mixed lymphocyte culture reaction inhibitory factor induced by donor specific blood transfusions in potential kidney transplant patients].

There is now overwhelming evidence that preoperative donor specific blood transfusions (DST) improve kidney graft survival remarkably. However, the exact mechanism is as yet unknown. In this study, we compared a DST group with a non-DST and investigate the mechanism of the beneficial effect of DST by using MLR, CML, and the MLR inhibition test. In the DST group, the severity of acute rejection and MLR reactivity was decreased after DST in most cases, but there was no such tendency in CML reaction. In the MLR inhibition test, the MLR serum inhibitory factor was induced in 70% of the cases (7 out of 10) received 3 times of DST. All of them were directed against recipient cell (auto-lymphocyte) and not to the blood donor cell and its activity was found in IgG fraction. The specificity to the stimulator cell was also found in 43% (3 out of 7). The results of MLR inhibition tests were well correlated with clinical findings and changes of MLR and CML. In positive cases of MLR inhibition tests, acute rejection occurred in 14% (1 out of 7), CML decreased in all (3 out of 3) and MLR decreased in 83% (5 out of 6) after DST. On the contrary, in negative cases, acute rejection occurred in 67% (2 out of 3), CML increased in all (3 out of 3) and MLR increased in 67% (2 out of 3). These results suggested that antibodies directed against recognition sites on auto-lymphocytes, so called anti-idiotypic antibodies, will be induced by 3 DST and play an important role in the prolongation of graft survival.

Adult↗

[Changing modality of the treatment in upper urinary tract calculi. Percutaneous nephrolithotripsy and transurethro-ureteral lithotripsy].

From March, 1984 to April, 1985, 70 cases of upper urinary tract calculi (73 renal units) were treated by percutaneous nephrolithotripsy or transurethro-ureteral lithotripsy, mainly utilizing ultrasonic lithotrite. While in the early period of treatment, two stage procedure of creation of nephrostomy tract and percutaneous nephrolithotripsy was performed for renal and upper or middle part of the ureteral calculi, one stage procedure, nephrostomy tract formation followed by ultrasonic nephrolithotripsy is commonly used in recent cases. During this period, conventional stone surgery was seen in 6 cases of pyelolithotomy and 2 of ureterolithotomy, while 52 cases of stone surgery were performed during the earlier period (from January, 1983 to February, 1984). Renal and upper or middle part of ureteral calculi were successfully removed in 49 out of 58 cases (84.5%). Most of the patients required 1 or 2 trials of percutaneous nephrolithotripsy. Middle or lower part of ureteral calculi were removed in transurethro-ureteral approach in 11 of the 12 cases. Hematuria and fever were most common complications after treatment and 3 patients required blood transfusion after 3 or 4 sessions of nephrolithotripsy. Percutaneous nephrolithotripsy and transurethro-ureteral lithotripsy are now widely used for treatment of upper urinary tract calculi, replacing the conventional surgical treatment. Moreover, very recently, extracorporeal shock wave lithotripsy is available in Japan. To the patients with renal calculi indicative of this treatment, both percutaneous nephrolithotripsy and extracorporeal shock wave lithotripsy are introduced and either way of treatment can be chosen by the patient himself.

Adult↗

[Two-dimensional echocardiographic measurement of the surgical aortic ring: its clinical significance in non-rheumatic regurgitation and in predicting the sizes of prosthetic valves].

The purpose of the present study was to determine the usefulness of two-dimensional echocardiographic measurements of the surgical aortic ring diameters (ARDs) in predicting correct sizes of the prosthetic valves and in determining the mechanisms of aortic regurgitation. Forty patients with aortic regurgitation who underwent prosthetic valve surgery, and 20 normal controls were selected for the study. The 40 patients consisted of 21 with rheumatic aortic regurgitation (RHD group), and 19 with non-rheumatic non-inflammatory aortic regurgitation (non-RHD group). Aortic regurgitation due to annuloaortic ectasia with or without the stigmata of Marfan's syndrome and bicuspid aortic valves were excluded from the non-RHD group. Echocardiographic estimates of the ARDs proved to be useful for predicting prosthetic valve sizes considering the good correlation between the echocardiographic and direct measurements (r = 0.814), despite a slight tendency to echocardiographic underestimation. The ARDs was 24.7 +/- 3 mm in the RHD group, 28.8 +/- 2.9 mm in the non-RHD group and 21.8 +/- 1.7 mm in the normal controls. The ARDs in the RHD group was significantly larger than that of the normal controls (p less than 0.001), and the ARDs of the non-RHD group was significantly larger than that of the RHD group (p less than 0.001). There were loose correlations between the ARDs and left ventricular end-diastolic dimension, and between the ARDs and left ventricular end-systolic dimension in the RHD group (r = 0.549 and r = 0.455, respectively), but there were no correlations between these two parameters in the non-RHD group. In four patients with aortic regurgitation in the non-RHD group, mitral regurgitation coexisted. Both the ARDs and the mitral ring dimension were markedly increased in these patients. It is concluded that in the non-RHD group, marked dilatation of the ARDs appears to be one of the cause of aortic regurgitation.

Adult↗

[Pulmonary regurgitation with special reference to the shape of the pulmonary valve ring: a pulsed Doppler and angiographic study].

Using pulsed Doppler echocardiography and cineangiography, the significance of pulmonic valve ring dimensions in the genesis of pulmonic regurgitation (PR) was studied in 40 patients, including 12 with valvular disease, 19 with coronary artery disease and nine with the normal heart. In nine of the 40 subjects, pulmonary hypertension (mean pulmonary artery pressure greater than or equal to 20 mmHg) was observed. The criterion for diagnosing PR was disturbed flow patterns recorded just below the pulmonic valve which spanned more than 40% of diastole, exceeding 1.5 KHz in peak frequency (corresponding to a flow velocity of about 50 cm/sec). Sagittal and transverse diameters of the pulmonic valve ring (PRDs, PRDt) at the upper edge of the pulmonary sinus, and the sagittal diameter of the pulmonary sinus (PSD) at the level of its maximal bulging were measured using pulmonary angiography. PR was detected in 15 subjects (37.5%). The prevalence of PR among three groups regardless of the absence or presence of pulmonary hypertension was not significantly different. The peak frequency of the regurgitant flow signals as well as the farthest point of the signals detected did not differ among the three groups irrespective of pulmonary hypertension. The ratio of the PRDs to the PRDt (PRDs/PRDt) was greater in patients with PR than in those without PR (p less than 0.001), but no correlation was established between PRDs/PRDt and mean pulmonary artery pressure. The PRDt index and PRDs index (normalized by body surface area) correlated well with the mean pulmonary artery pressure (r = 0.70, p less than 0.001 and r = 0.62, p less than 0.001, respectively). PSD also correlated with the mean pulmonary artery pressure (r = 0.49, p less than 0.01), whereas, PSD/PRDs correlated inversely with the mean pulmonary artery pressure (r = 0.40, p less than 0.01), indicating a relatively more prominent dilatation of the PRDs than of the PSD in cases with pulmonary hypertension. These results suggest that the etiology of PR in our series of patients was primarily attributable to the distortion of the pulmonic valve ring. The wide-spread concept that pulmonary hypertension dilates the pulmonic valve ring, leading to the development of PR, should be criticized.

Blood Pressure↗

[Clinical experience in renal transplantation].

In Shiga Prefecture, 378 chronic renal failure patients were registered at the end of 1981. In 1982, the Kidney Transplantation Group, composed of the department of Urology and the 1st division of Surgery, was organized in our hospital and 10 living related renal transplantations and 8 cadaver renal transplantations were performed between July 1982 and October 1984. As immunosuppressants, azathioprine, mizoribine, cyclosporine, prednisolone, methylprednisolone and ALG were used. Azathioprine was used mainly for living transplantation and cyclosporine mainly for cadaver transplantation. ALG was used only for the initial 3 living transplantations. Mizoribine was sometimes used in combination with azathioprine to reduce the dose of azathioprine and reduce its severe side effects. Seven episodes of acute rejection were experienced and all episodes were remitted by methylprednisolone pulse therapy. There were 20 major post-transplant complications in 13 recipients and among them 2 pulmonary infections were fetal (1 from aspergillus infection and 1 from cytomegalovirus infection). The 10 living related kidney transplantation recipients are all well and none have undergone hemodialysis. Three of the 8 cadaver renal transplantation are well without hemodialysis. One patient could not obtain diuresis. In addition to our experience of renal transplantation, the preoperative scheduled blood transfusion with combination of azathioprine administration, was briefly discussed.

Adolescent↗