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Biomedical subjects

A Takeuchi

Publications and source records attributed to A Takeuchi.

At least 181 records · Page 10Linked to original sources
PubMed1994

[Multicenter prospective study of retinopathy of prematurity--IV. Comparison with the data from University of Miami].

We investigated the records of 360 cases of retinopathy of prematurity (ROP) in 12 institutions in Japan (we treated the severe progressive "plus" disease by coagulation therapy), and compared them with data from University of Miami (Ophthalmology 94: 620-629, 1987), as representative of the natural course of ROP without coagulation therapy in those days. The timing of the first examination and the first positive diagnosis were later at University of Miami than in Japan. The time of maximal severity of the disease and occurrence of regression were also later the University of Miami than in Japan. In Japan, the first examination was performed at 29 weeks of postconceptional age or at 3 weeks after birth. At the University of Miami, the first examination was performed at 32 weeks of postconceptional age. If the severe progressive "plus" disease is to be properly treated by photo-coagulation or cryotherapy, it is essential to commence fundus examination earlier.

Florida↗
PubMed1994

Novel growth promoting activity with a wide target cell spectrum is present in extracts of various cell types.

Cell extracts from a variety of cell lines, myeloid, T, B, mastocytoma, fibroblast, melanoma and breast carcinoma of human, mouse and guinea pig promoted the growth of a wide variety of cell types, namely human myeloid cells HL-60, human B cells Daudi, human melanoma cells A375-C6, mouse transformed-fibroblast cells L929, human myelomonocytic cells THP-1. Among them, the activities in extracts from U937, A375-C6 and Daudi were characterized because these extracts exhibited much more potent activity. These growth promoting activities were acid-labile, sensitive to 2-mercaptoethanol and to heat treatment at 50C or 70C for 5 min. The activities were also sensitive to proteases indicating the proteinous nature of these active entities. The molecular weight of activities from A375 and Daudi cells were estimated to be 100,000-150,000 daltons by gel filtration high performance liquid chromatography, while that from U937 cells was 60,000-70,000 daltons. The isoelectric point of these activities were 5.5-6.5.

Animals↗
PubMed1994

[Surgical treatment of infective endocarditis].

Since 1976, 37 patients have undergone valve replacement for infective endocarditis at our institute. Twenty patients required surgery during the active stage and 17 in the inactive stage. The former group consisted of 17 native and three prosthetic valve endocarditis, and all patients in the latter group had native valve endocarditis. Eighteen patients had AVRs, 15 had MVRs and four had DVRs. Congestive heart failure was the indication for surgery in 80% of the active and 100% of the inactive group. There were nine early deaths (45%) and one late death in the active group, and one early (6%) and one late death in the inactive group. Operative mortality in the active group, however, has recently been reduced to 30% for the 10 patients operated upon in the past two years. Two patients with active endocarditis were complicated by rupture of cerebral mycotic aneurysms postoperatively and resulted in one early and one late death, respectively. It is suggested that timely surgical intervention according to the hemodynamic state of the patients is essential in reducing early mortality in infective endocarditis. Attention should be paid to cerebral mycotic aneurysm as one of the problems affecting on postoperative mortality and morbidity.

Adult↗
PubMed1994

Immunohistochemical study of hepatocellular carcinoma-specific aldehyde dehydrogenase.

Tumor-associated aldehyde dehydrogenase (ALDH) was reported in cases of human hepatocellular carcinoma and animal hepatoma models. This ALDH isozyme is similar to ALDH3 which exists in the stomach and lung; however, the biochemical and clinical significance of this unique ALDH isozyme have not been established. Human tumor-associated ALDH was purified, and polyclonal antibodies prepared. Using these antibodies, specific development of tumor-associated ALDH was confirmed by immunohistochemical techniques. It was found that about 50% of hepatocellular carcinomas reacted with the antibody. This unique ALDH isozyme may be a novel tumor marker of hepatocellular carcinoma.

Aldehyde Dehydrogenase↗
PubMed1993

[Visualization of coronary arteries with helical scanning CT: diastolic reconstruction].

The purpose of this study was the visualization of coronary arteries by the diastolic reconstruction method with helical scanning (HES) CT. We chose diastolic phase images from the image data acquired with the HES technique using a continuous nutate-rotate fast CT scanner, because few motion artifacts are induced by cardiac pulsation during the slow filling diastolic phase. We assessed coronary diseases using this method based on HES-CT, and evaluated its clinical effectiveness. We also studied the clinical value of multiplanar reconstruction and three-dimensional surface reconstruction. The subjects consisted of 31 patients with coronary disease, aged 41-77 years. When a diastolic reconstruction HES-CT was employed, the average rate of visualization of the coronary arteries was 72%. An examination can be completed during a 30-second single breath-hold, permitting the acquisition of coronary artery images with excellent continuity. Calcified coronary arteries can be identified.

Adult↗
PubMed1993

Human myelomonocytic cell line THP-1 produces a novel growth-promoting factor with a wide target cell spectrum.

Conditioned medium from a human myelomonocytic cell line THP-1 promoted the growth of a wide variety of cell types, i.e., human and mouse myeloid cells (HL-60, U937, K562, and M1), mouse T-cells (EL-4), human B cells (Daudi and Raji), mouse mastocytoma cells (IC-2), human melanoma cells (A375-C6), mouse transformed fibroblast cells (L929), human lung fibroblast cells (TIG-1), and mouse bone marrow fibroblast/stromal-like cells. The growth-promoting activity was acid-labile. The activity was resistant to 50 degrees C for 5 min but completely lost in 5 min at 70 degrees C. The activity was resistant to treatment with trypsin but sensitive to chymotrypsin alpha, Pronase E, and proteinase K, indicating the proteinous nature of this activity. The activity was lost by dithiothreitol and 2-mercaptoethanol. Molecular weight (M(r) 50,000-70,000) was estimated by gel filtration-high performance liquid chromatography. After the sequential anion exchange, hydrophobic, and hydroxylapatite high performance liquid chromatography, the partially purified factor exhibited the same target cell spectrum as the conditioned medium.

Animals↗
PubMed1993

Liquid chromatography-mass spectrometry for the determination of medetomidine and other anaesthetics in plasma.

A liquid chromatographic-atmospheric pressure chemical ionization mass spectrometric method is presented for the simultaneous determination of medetomidine and other anaesthetic drugs in solutions and dog plasma. The drugs examined were flumazenil, butorphanol, atropine, ketamine, xylazine, medetomidine, atipamezole and midazolam. The separation was carried out on a reversed-phase column using methanol-0.1 M ammonium acetate (3:2) as eluent.

Anesthetics↗
PubMed1993

Surgical effects of trabeculotomy ab externo on adult eyes with primary open angle glaucoma and pseudoexfoliation syndrome.

OBJECTIVES: Retrospective and prospective studies examined the surgical effects in lowering intraocular pressure levels of trabeculotomy ab externo in adult eyes with either primary open angle glaucoma or pseudoexfoliation syndrome. We report the results of primary trabeculotomy as an intervention for glaucoma. PATIENTS: Included in the retrospective study were 357 eyes of 227 patients with primary open angle glaucoma and 82 eyes of 65 patients with pseudoexfoliation syndrome, each of which underwent trabeculotomy ab externo alone and none of which had a history of laser or surgical treatment for ocular disease. Included in the prospective study were 33 eyes of 22 patients with primary open angle glaucoma and 17 eyes of 15 patients (older than 40 years) with pseudoexfoliation syndrome. RESULTS: A life-table analysis for the retrospective study showed that the final success probability (mean +/- SE) at 5 years after surgery was 73.5% +/- 6.3% in eyes with pseudoexfoliation syndrome, which is significantly better than 58.0% +/- 3.1% in eyes with primary open angle glaucoma (P < .05). Also, the higher the preoperative intraocular pressure levels are, the less likely that the postoperative intraocular pressure levels will be brought under control (P < .01). Surgical outcome in the prospective study demonstrated success in 27 (79%) of 34 eyes after 3 years and in 16 (64%) of 25 eyes after 5 years, with medication. Complications included Descemet's membrane detachment (one eye), cyclodialysis (one eye), and decreased visual acuity due to progression of cataract (four eyes). CONCLUSION: The surgical results of trabeculotomy ab externo remain effective in controlling intraocular pressure levels for a long time in selected patients. It thus appears that trabeculotomy ab externo can be considered as an alternative choice of surgical treatment in some cases of glaucoma.

Adult↗
PubMed1993

Effects of nifedipine and Bay-K-8644 on the release of catecholamines from the dog adrenal gland in response to splanchnic nerve stimulation.

1. The effects of nifedipine and Bay-K-8644 on the release of adrenal catecholamines were examined in anaesthetized dogs. 2. Splanchnic nerve stimulation (SNS) at 1 and 3 Hz produced frequency-dependent increases in adrenaline (ADR) and noradrenaline (NA) output determined from adrenal venous blood. 3. Neither nifedipine (10 and 30 micrograms/kg, i.v.) nor Bay-K-8644 (10 and 30 micrograms/kg, i.v.) modified the SNS-induced increases in catecholamine output. Basal catecholamine output tended to be increased and decreased by nifedipine and Bay-K-8644, respectively. 4. Nifedipine produced significant decreases in arterial pressure and renal blood flow rate. Bay-K-8644 produced a significant increase in arterial pressure associated with a decrease in renal blood flow rate. 5. These results suggest that dihydropyridine-sensitive calcium channels do not play a major role in adrenal catecholamine release evoked by SNS.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1993

Isolation and identification of canine plasma components suspected as uremic toxins.

Suspected uremic substances contained in four fractions, which had been selected as the suspected canine uremic peaks in the previous study, were isolated by two stages of preparative liquid chromatography (PLC) from plasma of uremic dogs treated with the ligation of the ureter, and then their physicochemical properties were examined. The primary separation of the suspected uremic peaks were performed with the same anion exchange resin as used in the analytical HPLC in the previous study. Analytical reverse phase HPLC showed that three of 4 suspected uremic peaks almost consisted of single substances, but the other contained several substances. Main subfractions of these peaks were successfully isolated by the secondary stage reverse phase PLC. By means of thin layer chromatography, ultraviolet absorption spectrometry and proton-nuclear magnetic resonance spectroscopy, components of 4 main peaks were confirmed to be small molecules such as a pyridine derivative, uric acid, hippuric acid and kynurenic acid, respectively.

Animals↗
PubMed1993

Cardiopulmonary effects of a combination of medetomidine and butorphanol in atropinized pigs.

Cardiopulmonary effects of a combination of medetomidine and butorphanol were evaluated in atropinized pigs. This combination unchanged the cardiac output and significantly lowered the oxygen consumption compared with base-line values. Although some statistically significant changes were recorded, both medetomidine and butorphanol did not have a marked effect on the cardiopulmonary parameters in atropinized pigs. It was indicated that the administration of the combination of medetomidine and butorphanol is relatively safe in atropinized pigs.

Adrenergic alpha-Agonists↗
PubMed1993

Evaluation of phlebotomy-induced erythropoietin production in the dog.

Erythropoietin (EPO) production in dogs was studied by reducing red blood cells with phlebotomy. In this study, the hemoglobin reduction rate (delta %Hb) was newly taken into account as the regulating factor for EPO production, and its usefulness to estimate the stimulating intensity to EPO production was examined. As the result, plasma EPO was highly correlated with delta %Hb showing the importance related to regulation of EPO production, in the increasing plasma EPO by different degrees of phlebotomy, in the change of plasma EPO through the anemia progress and recovery period after severe phlebotomy, and in the initial variation of plasma EPO induced by chronic mild phlebotomy. On the other hand, increasing EPO production appeared at least within 6 hr after acute severe phlebotomy, which revealed significantly higher plasma level compared with the mild chronic phlebotomy, suggesting the effect of time leading to red blood cell reduction on EPO production response. Simultaneously, considering an in vivo EPO half life of 8.4 hr calculated from plasma EPO disappearance after bilateral nephrectomy, endogenous plasma EPO accumulation should be taken into consideration in rapidly increasing of delta %Hb.

Anemia↗
PubMed1993

Collagen production and maturation at the experimental ligament defect stimulated by pulsing electromagnetic fields in rabbits.

Eighty rabbits receiving the square resection (4 x 4 mm) of both patellar ligaments in full thickness at their center were divided into 4 groups, and each group (20 rabbits) were electromagnetically stimulated with different magnetic intensities, 0 (control group), 2, 10, or 50 gauss (G), for 6 hr daily. Pulse frequency and pulse width were 10 Hz and 25 microseconds, respectively. Five animals of each group were sacrificed weekly from 1st to 4th week after operation and the defect tissue was collected for biochemical and ultrastructural evaluations. Before sacrificing, the blood flow of the central portion of patellar defects were measured. Significant increases in blood flow at the defect were observed in 50 G group compared to those of other groups from 2 to 4 weeks after operation. The collagen content in PEMFs groups showed a significant increase compared to that of control group. Furthermore, those increases were higher according to the increase in magnetic intensity. Electronmicroscopically, massive developmental rough endoplasmic reticulum was seen in the fibroblasts at 2 weeks after operation in 50 G group compared to other groups, which suggests the more active collagen production in this group. These results suggest that PEMFs enhanced the blood flow and increased the fibroblasts at the defect. At the same time, PEMFs directly stimulated the collagen production from the fibroblasts, thus accelerate the healing process of the ligament.

Animals↗
PubMed1993

Evaluation of erythropoietin production in dogs with reduced functional renal tissue.

This study was designed to determine the quantity of functional renal tissue needed to maintain homeostasis of red blood cell production by evaluating the erythropoietin (EPO) production response to phlebotomic stimulation in the 1/2- and 1/4-kidney dogs surgically prepared. The results showed that the reduction in functional renal tissue caused a decrease in EPO production, which led to the delay in recovery from anemia. In the anemic progress stage, the plasma EPO level showed a transition proportional to the quantity of functional renal tissue immediately after the operation for tissue reduction. The 1/2-kidney dog group still kept such proportional relation even in the recovery stage. Thus, the half of the normal renal tissue was considered sufficiently contributory to EPO production needed to maintain homeostasis of red blood cell production. However, the 1/4-kidney dog group precipitously decreased in plasma EPO level in the recovery stage and fell into an extremely unfavorable anemia. This indicated that homeostatic maintenance in erythropoiesis would be impossible more below a quarter of normal renal tissue. These findings disclosed that reduction in functional renal tissue quantity would sensitively influence homeostatic maintenance of red blood cell production through the decrease in EPO production, even if it does not affect renal function concerned with urine production.

Anemia↗
PubMed1993

Comparison of sedative and analgesic/anesthetic effects induced by medetomidine, acepromazine, azaperone, droperidol and midazolam in laboratory pigs.

The sedative and analgesic/anesthetic effects of medetomidine, acepromazine, azaperone, droperidol and midazolam were compared in laboratory pigs. In these sedatives, medetomidine produced the most profound degree of sedation with greater drowsiness than was achieved by other sedatives tested. Medetomidine induced sedation accompanied with weak analgesia and muscle relaxation smoothly and quickly and depressed arousal reaction deeply as compared with other sedatives. Pigs given medetomidine were not aroused easily even by moderately rough stimulation for approximately 60 min after injection.

Acepromazine↗
PubMed1993

Sedative effect induced by a combination of medetomidine and midazolam in pigs.

Sedative and analgesic/anesthetic effects induced by a combination of medetomidine and midazolam were evaluated in pigs. This combination exerted a much more potent sedative effect than that induced by a medetomidine alone, even if the dose of medetomidine was reduced to one half, and even if the pigs were stimulated continuously during the induction phase. Pigs given this combination were induced to sedation smoothly and very quickly. During being sedated the arousal reaction induced by sensory stimuli were depressed profoundly and pigs could be placed in dorsal recumbency without any resistance. In addition, this combination produced moderate analgesic effect and apparent muscle relaxation. This potent effect induced by this combination seemed to be induced by a synergistic interaction between medetomidine and midazolam because the sedative effect achieved with this combination was much greater than that which could be expected from a simple additive response of both sedatives. This sedative combination may be a widely available and valuable for chemical restraint in pigs.

Analgesia↗
PubMed1993

Antagonistic effects of atipamezole and flumazenil on medetomidine-midazolam induced sedation in laboratory pigs.

Antagonistic effects of atipamezole (80, 160 and 240 micrograms/kg, im), and flumazenil (100 micrograms/kg, iv) or atipamezole (80 micrograms/kg) and flumazenil (100 micrograms/kg) on medetomidine-midazolam induced sedation were evaluated in laboratory pigs. Atipamezole at each dose effectively reversed sedation, and the arousal time, standing time and total recovery time were significantly shortened. The optimal action of atipamezole was seen at a dose of 160 micrograms/kg. At this dose recovery from the sedation was quick and smooth, and adverse effects such as hyperactivity or tachycardia were minimal. Flumazenil reversed sedation temporary, but the pigs went back to moderate sedation soon after arousal. The combination of atipamezole and flumazenil most effectively reversed the sedation, however atipamezole (160 micrograms/kg) alone was thought to be practically potent enough to antagonize sedation induced by medetomidine-midazolam in laboratory pigs.

Adrenergic alpha-Antagonists↗