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Biomedical subjects

A Takeuchi

Publications and source records attributed to A Takeuchi.

At least 55 records · Page 3Linked to original sources

Chemical restraint by medetomidine-ketamine and its cardiopulmonary effects in pigs.

Chemical restraint induced by medetomidine-ketamine (M-K) combination was evaluated compared with that by xylazine-ketamine (X-K) in pigs. The duration of restraint by M-K was 49.4 +/- 13.5 min (mean +/- SD) and longer than that by X-K (34.6 +/- 17.2 min), but the difference was not significant. The effect of X-K was not stable, since one of five pigs was restrained only for 6 min. Both combinations produced muscle relaxation. The duration of muscle relaxation in M-K was 43.6 +/- 12.7 min and was significantly longer than that in X-K (21.0 +/- 14.0 min). M-K combination had a slightly stimulative effect on the cardiovascular system, but scarcely changed the respiratory parameters. This limited effect on cardiopulmonary system was an advantage of M-K combination for chemical restraint in pigs. These results indicated that M-K combination is suitable for chemical restraint with prolonged muscle relaxation and has limited cardiopulmonary effects in pigs.

Anesthetics

Pharmacological activity of the C-terminal and N-terminal domains of secretory leukoprotease inhibitor in vitro.

1. In order to characterize the physiological functions of the domain structure of secretory leukoprotease inhibitor (SLPI), the biological capacities of half-length SLPIs, (Ser1-Pro54)SLPI and (Asn55-Ala107)SLPI, were investigated and compared with those of full-length SLPI. 2. The activities of these inhibitors against several serine proteases were determined using synthetic chromogenic substrates. The inhibitory capacity of the C-terminal domain, (Asn55-Ala107)SLPI, was as strong as that of full-length SLPI against human neutrophil elastase (NE), cathepsin G and chymotrypsin. It possessed less trypsin inhibitory activity than intact SLPI. For the N-terminal domain of SLPI, (Ser1-Pro54)SLPI, no inhibitory activity could be detected against the serine proteases tested in this study. 3. The inhibitory activity of (Asn55-Ala107)SLPI against the proteolysis of the natural substrates elastin and collagen by NE was comparable with that of full-SLPI (elastin, IC50 = 907 +/- 31 nM for SLPI, 767 +/- 33 nM for (Asn55-Ala107)SLPI; collagen, IC50 = 862 +/- 36 nM for SLPI, 727 +/- 47 nM for (Asn55-Ala107)SLPI). 4. The binding affinities of full- and half-length SLPIs for heparin were measured by affinity column chromatography. Full-length SLPI showed high affinity for heparin while the binding capacities of both half-length SLPIs were lower. (Concentration of NaCl for elution, 0.45 M for SLPI, 0.24 M for (Ser1-Pro54)SLPI, 0.27 M for (Asn55-Ala107)SLPI). 5. The effects of full-SLPI and (Asn55-Ala107)SLPI on blood coagulation were measured using the activated partial thromboplastin time (APTT). Full-length SLPI prolonged clotting time dose dependently(1.25, 2.5 and 5.0 microM), whereas (Asn55-AlalO7)SLPI had no effect even at the highest concentration.6. In conclusion, the C-terminal domain of SLPI is a promising candidate for the treatment of inflammatory diseases in which participation of neutrophil proteases has been suggested.

Animals

Periodic high extracellular glucose enhances production of collagens III and IV by mesangial cells.

We examined the effects of periodic changes in extracellular glucose concentration on matrix production and proliferation using three groups of cultured rat mesangial cells (MCs): 1) MCs in medium with continuous 5 mM glucose (CL), 2) MCs in medium alternating daily between 5 and 25 mM glucose (PH), and 3) MCs in medium with continuous 25 mM glucose (CH). MCs cultured in PH for 10 days produced 329 and 110% more type III collagen protein than MCs cultured in CL and CH, respectively. MCs cultured in PH induced 31 and 14% more type IV collagen than MCs cultured in CL and CH, respectively. Extracellular glucose concentration had no effect on the amount of type I collagen produced. MCs cultured in PH or CH for 5 days also expressed increased levels of type I, III, and IV collagen mRNA compared with MCs cultured in CL. MCs cultured in PH for 8-10 days also produced significantly more DNA than MCs in CL or CH. These data suggest that the temporal pattern of exposure to high extracellular glucose plays a role in regulating matrix formation and cellular proliferation by MCs. Furthermore, periodic elevations of extracellular glucose had a greater stimulatory effect on collagen production than a sustained elevation. These results suggest that decreasing the variability of blood glucose concentration may decrease the adverse effect of elevated glucose levels on MC matrix production and the progression of diabetic glomerulopathy.

Analysis of Variance

Effects of yohimbine and desipramine on adrenal catecholamine release in response to splanchnic nerve stimulation in anesthetized dogs.

The effects of yohimbine and desipramine on adrenal catecholamine (CA) release in response to splanchnic nerve stimulation (SNS) were examined in anesthetized dogs. SNS and 3 Hz produced frequency-dependent increases in epinephrine (EPI) and norepinephrine (NE) output determined from adrenal venous blood. Yohimbine (30 and 100 micrograms/kg, i.v.), a selective alpha 2-adrenoceptor antagonist, enhanced the SNS-induced increases in both EPI and NE output. Desipramine (100 and 300 micrograms/kg, i.v.), an amine pump inhibitor, enhanced the SNS-induced increases in NE output, whereas no enhancement of EPI output was produced. After desipramine treatment, yohimbine further enhanced the SNS-induced increases in EPI and NE output. After yohimbine treatment, desipramine further enhanced the SNS-induced increase in NE output. These results suggest that the release of adrenal CA in response to SNS is inhibited by alpha 2-adrenoceptors, and that released NE, rather than EPI, is predominantly taken up into the dog adrenal medullary cells.

Adrenal Glands

Cloning of canine osteosarcoma cells.

Six clonal cells were established from a canine osteosarcoma cell line (POS) by a limiting dilution method using feeder cells. Whereas histology of mass developed in nude mice by transplantation of POS cells revealed various cell types, clonal cells were morphologically consistent in size and shape. Doubling time of clonal cells ranged from 30 +/- 1.4 to 54 +/- 1.3 hr and alkaline phosphatase activity ranged from 0.040 +/- 0.001 to 2.61 +/- 0.435 mumol/min/mg protein depending on the cell types. When transplanted into nude mice, each clonal cell type formed following four histological types; osteoblastic, chondroblastic, fibroblastic, and undifferentiated types. Since each histological feature was found simultaneously in the primary tumor, osteosarcoma tissue might be a complex of various types of cells having different characteristics. Therefore, POS clonal cells may be useful as a potential tool for the studies of differentiation, phenotypic expression, and a new therapeutic modality of osteosarcoma.

Alkaline Phosphatase

The antitumor activity of the DNA fraction from Mycobacterium bovis BCG (MY-1) for glioblastoma.

The antitumor activity of the DNA fraction extracted from Mycobacterium bovis BCG (MY-1) for glioblastoma was investigated in the experimentally produced brain tumor in rats. The tumor-bearing rats were given intralesional injection of 1 mg of MY-1 twice a week for three weeks, and were sacrificed for comparison with those of control rats. The main macroscopic features of the tumors treated with serial injections of MY-1 were cystic and destructive structures, which were histologically characterized by multiple microcysts containing macrophages. Furthermore, infiltration of leukocytes as well as the perivascular cuffing in the marginal area was observed. These findings suggested that the serial injections of MY-1 into the brain tumor have the therapeutic potential for glioblastoma.

Animals

Cardiopulmonary effects of medetomidine, medetomidine-midazolam and medetomidine-midazolam-atipamezole in dogs.

Cardiopulmonary effects of medetomidine (20 micrograms/kg)-midazolam (0.3 mg) (Me-Mi) were compared with those of medetomidine alone (80 micrograms/kg) (Me80) in dogs. The intramuscular administration of this combination caused bradycardia and transient mild pressor response. Heart rate decreased soon after the administration and remained significantly below the baseline value with average values of 50-70 beats/min. Blood pressure increased to its maximum within 5 to 10 min then decreased gradually. Cardiac index decreased corresponding the decrease in heart rate. However these changes were less profound than those of Me80 indicating significantly higher values in cardiac index and lower values in systemic vascular resistance. Effects on the respiratory function were slight. The reduction of the dose of medetomidine to one-fourth in Me-Mi was effective to reduce the adverse effect of medetomidine, especially in peripheral vasoconstriction. Atipamezole effectively reversed cardiopulmonary effects induced by medetomidine-midazolam. Heart rate and cardiac index increased and systemic vascular resistance decreased significantly after administration of atipamezole. The possible use of an antagonist as a reversal agent might enhance the value and availability of medtomidine-midazolam as a chemical restraint agent in dogs.

Adrenergic alpha-Antagonists

[Identification and analysis of immune cells infiltrating into the glomerulus and interstitium in lupus nephritis].

This study was performed to investigate the role of cell-mediated immunity in lupus nephritis (LN). Frozen sections from 38 patients with LN were examined by indirect immunoalkaline-phosphatase labeling using monoclonal antibodies to identify the immune cells infiltrating into the interstitium and glomerulus. 14 patients showed minor glomerular abnormality (MGA), 9 had mesangial LN (MesLN), 12 had diffuse proliferative LN (DPLN) and 3 had membranous LN (MLN). Monocyte/macrophage and helper/inducer T cells infiltrated in the interstitium predominantly, but intraglomerular infiltration of these cells was rare. Monocyte/macrophage and suppressor/cytotoxic T cell levels were significantly higher (p < 0.05) in the interstitium in DPLN patients and monocyte/macrophage level was significantly higher (p < 0.05) in MesLN patients than in MGA patients. In the interstitium, serum creatinine level was highly correlated with infiltrations of suppressor/cytotoxic T cell, monocyte/macrophage (p < 0.01), pan T cell and total leucocyte (p < 0.05). Clinical activity score was correlated with suppressor/cytotoxic T cell (p < 0.001), monocyte/macrophage and pan T cell (p < 0.01). These results suggest that suppressor/cytotoxic T cell and and monocyte/macrophage may play an important role in the progression of lupus nephritis.

Antibodies, Monoclonal

Cytochalasin D reversibly weakens retinal adhesiveness.

This study asks whether retinal adhesiveness is affected by cytochalasin D, a drug that is known to alter the apical morphology of the retinal pigment epithelium (RPE). Cytochalasin D was injected intravitreally in Dutch rabbits and retinal adhesiveness measured 0.5 to 72 h later by two methods: in vitro peeling of the retina from retinal pigment epithelium to observe the amount of adherent pigment, and in vivo measurement of the pressure needed to achieve retinal separation. Electroretinograms were recorded, and RPE apical morphology was examined by scanning electron microscopy. The injection of 60 microM cytochalasin D caused in vitro retinal adhesiveness to fall within 3 h to 10% of normal although the electroretinogram (a, b, and c-waves) remained normal. Smaller doses of cytochalasin D had a lesser effect. The RPE apical surface at 3 h showed large bullet-like microvilli, swollen cone sheaths, and an absence of filamentous microvilli. The severity of these changes was dose-related. At 72 h after cytochalasin D, retinal adhesiveness had largely recovered, and RPE apical morphology appeared normal again. Thus, cytochalasin D weakens retinal adhesiveness acutely but reversibly, and both the initial effect and recovery correlate with changes in RPE microvillar morphology. This suggests that actin microfilaments may be involved in mechanisms of retinal adhesion.

Adhesiveness

[Clinicopathological studies of anti-HCV P1P4 core antibody].

Anti-P1P4 core antibody, derived from a Japanese hepatitis C virus clone, was evaluated clinicopathologically in serum samples from 40 blood donors positive for anti-HCV antibody by 2nd generation assay and in 37 patients with HCV chronic hepatitis treated with interferon. The presence of anti-P1P4 antibody was highly correlated with the presence of HCV-RNA in the blood donors. In the patients with chronic hepatitis, more than a 50% reduction in P1P4 antibody titer after interferon therapy suggested the disappearance of HCV-RNA from the blood. Thus, anti-P1P4 antibody was useful in evaluating the virological effects of interferon therapy. However, clinically and pathologically, the titer of P1P4 antibody did not indicate the grade of liver inflammation.

Hepacivirus

Effects of dietary vitamin D intake on plasma levels of parathyroid hormone and vitamin D metabolites in healthy Japanese.

To clarify the nutritional status of vitamin D in Japanese, effects of dietary intake of vitamin D on plasma levels of intact and highly sensitive parathyroid hormone (I-PTH and HS-PTH), 25-hydroxyvitamin D (25-OH-D), 1,25-dihydroxyvitamin D (1,25(OH)2D), calcium (Ca) and phosphorus (P(i)) in 79 healthy Japanese were investigated. The plasma levels of 25-OH-D in men were significantly higher than those in women, whereas those of HS-PTH in men were significantly lower than those in women. The levels of 25-OH-D in men were generally higher than those in women. Significant correlations were observed between the dietary vitamin D intake and the plasma 25-OH-D or HS-PTH levels. Correlations between the plasma 25-OH-D levels and the plasma HS-PTH levels were also significant. These results suggest that dietary intake of sufficient amounts of vitamin D is effective for improving the vitamin D nutritional status through normalizing PTH levels.

Adult

[A case of Behçet's disease with severe esophageal stenosis treated with esophageal bujie].

A 50-year-old woman who had been suffering from Behçet's disease came to our clinic. The patient developed recurrent oral aphthae, genital ulcers, and folliculitis when she was 25-year-old. In 1971 the diagnosis is of Behçet's disease was made and oral prednisolone was started. In 1976 oral and labial aphthae became worse, and after healing of these aphthae, adhesion of oral angle developed. At that time plastic surgery for adhesion was made. In 1990 the patient felt difficulty in opening the mouth again and operation for mouth was performed. In 1991 the patient was admitted to our hospital for the third time because of recurrent oral aphthae, vomitting, and dysphagia. Upper gastrointestinal series and endoscopic examination revealed that there was severe stenosis in the middle portion of esophagus. Above that lesion, dilatation of esophagus with retention of barium was observed. Forty mg/day of prednisolone with liquid meal was started, and operation for stenosis of the esophagus using bujie was performed twice. After that operation, the patient was able to take solid meals. Esophageal ulceration with Behçet's disease treated with prednisolone was reported and discussed with the review of the literture.

Behcet Syndrome

Albumin movement out of the subretinal space after experimental retinal detachment.

PURPOSE: The subretinal fluid of serous retinal detachments contains protein, but little is known about its origin and fate. The authors designed experiments to study the rate and route of albumin movement out of the subretinal space. METHODS: Experimental retinal detachments were made in Dutch rabbits by injecting Hanks' balanced salt solution containing serum levels (approximately 30 mg/ml) of fluorescein isothiocyanate (FITC) albumin into the subretinal space through a micropipette. Subretinal, vitreous, and serum fluid samples were withdrawn 0 to 4 hours later through a similar micropipette and were analyzed for osmolality, FITC albumin content (by fluorophotometry) and FITC+native albumin content (by gel electrophoresis). Sodium iodate was injected intravenously in some rabbits to damage the retinal pigment epithelium (RPE). RESULTS: Albumin injected into the subretinal fluid diffused steadily into the vitreous, and its concentration decreased by approximately 5% per hour. This rate was unaffected by RPE damage. Albumin did not move into the bloodstream unless the RPE was damaged with sodium iodate, and then it crossed the RPE at approximately 25% of the rate at which it moved into the vitreous. Subretinal fluid osmolality remained within the range of 293 to 294 mOsm/kg despite protein movement and the continual absorption of fluid from the detachments. CONCLUSIONS: These results show that albumin in the subretinal space diffuses readily into the vitreous, and subretinal osmolality changes are rapidly equilibrated with the vitreous. Albumin does not cross normal RPE, and it crosses iodate-damaged RPE more slowly than it crosses retina. Thus, there must be a constant supply of albumin if high subretinal concentrations are to be sustained in clinical serous detachments.

Animals

[Quantitative analysis of individual renal function using 99mTc-DMSA scintigram--comparison with 131I-OIH renogram].

99mTc-2,3-di-mercapto-succinic acid (DMSA) is able to be used for the quantitative analysis of individual renal function by calculating the uptake ratio. The purpose of this study is to assess the clinical feasibility of DMSA uptake ratio as compared with 131I-ortho-iodo-hippuran (OIH) renogram pattern. Two hundred eleven cases (191 patients, 1 to 87 years old) with renal disorders and 4 normal volunteers (27.8 +/- 2.4 years old) were studied. Just prior to the DMSA study in the same day, OIH renogram was carried out. They were divided into 6 types by OIH renogram patterns. In 24 cases of normal renogram pattern and normal blood data who were defined as the normal group and 4 normal volunteers, DMSA uptake ratio showed negative correlation with increasing age (r = 0.61, p < 0.05). Patients of the severe impaired functioning and the non functioning patterns showed significantly decreased DMSA uptake ratios as compared with the normal pattern. There was also a significant difference in DMSA uptake between impaired functioning patterns. Compensative hemi-hypertrophy kidneys showed significantly higher DMSA uptake ratios than those of atrophic kidneys. The possibility of the quantitative analysis of the functional compensation was presumed. In conclusion, quantitative analysis of individual renal function using DMSA uptake ratio is considered to be useful to evaluate the renal functional reserve.

Adolescent

Model of rate-dependent property in myocardial tissues as a useful algorithm for the PC-based arrhythmia generator.

Two mathematical models were presented as an arrhythmia generator. One was the so-called modulated parasystole model. The other was a model of the rate-dependent property of atrioventricular nodal conduction represented by the atrioventricular recovery curve (AVRC). Both models were mathematically formulated as a nonlinear first-order difference equation, and implemented on a personal computer (PC) as an arrhythmia simulator. It was utilized for evaluating the diagnostic performance of computerized ECG analyzers.

Algorithms

Computer-assisted instruction of arrhythmia for MS-windows.

1. INTRODUCTION. Training in the diagnosis of arrhythmias is an important part of the curriculum for medical students, postgraduates, and paramedical staff. Although several CAI for arrhythmia have been developed [1-3], we could not get CAI software for arrhythmia for the MS-Windows environment. In this report, we present a newly-developed computer-assisted reference system for arrhythmia that functions in the Windows environment. 2. DESCRIPTION OF THE SYSTEM. The system consists of a program and two data files. An MS-Windows program (ECG9405.EXE, 180kB) was compiled using Borland's C++ v.3.1. A binary file (ECPAT.BAS 33kB) includes data of normal and abnormal wave segments of ECG: P wave, PQ interval segment, and QRs complex with/without T wave. A mother file (ECG9405.sys, 57kB) includes 85 data sets to generate ECG waveforms of arrhythmia. Each data set contains a sequence of wave form numbers, the text for questions and answers, and the commands strings. There are five major commands: 1) to create a new window as "wave window"; 2) to make electrocardiogram data; 3) to plot the data on the window; 4) to create a "dialog box" for questions and explanations; and 5) to check the answers. he program gets a data set from the data according to the user's choice. The program then interprets the data set and executes the commands. The wave segment data are plotted in a "wave window" at every 10 milliseconds; this is controlled by the MS-Windows' timer. The timer interval can be changed by selecting the speed button. The ECG waveforms are displayed on a window just like an ordinary ECG monitor with beat sound. Many windows can be created by the user and many ECG waves simultaneously plotted on CRT. 3. USAGE OF THE SYSTEM. The "main window" has a menu that has three items corresponding to the training course: BASIC, TRY, and TEST. Thirty-five types of arrythmias are listed in the "list box" of the windows in BASIC course e.g., sinus arrhythmia, atrial flutter, atrial premature contraction, ventricular extrasystole, ventricular flutter, etc. If the user selects one of them on the list by double clicking, some textual explanations of the wave are described in a dialog box. Ten multiple choice questions are displayed in the dialog box in course of learning TRY and TEST; the answers to these are requested. In the TEST course, the system offers random access to each arrhythmia. he user can send the pictorial ECG data in the window to other graphics programs through a clip board. 4. DISCUSSION. It was successfully used in a lecture of electrocardiogram for medical students. They seem to be interested in this system because of its simple usage and the dynamic drawing of ECG waves on CRT. Multiple computer-based medical resources can be run on MS-Windows. The system is able to run simultaneously with other programs, such as an electronic reference system [4]. The system may be obtained from the authors upon request.

Arrhythmias, Cardiac

Inhibition by omega-conotoxin GVIA of adrenal catecholamine release in response to endogenous and exogenous acetylcholine.

Effects of the N-type voltage-dependent Ca2+ channel (VDCC) blocker, omega-conotoxin GVIA, and the L-type VDCC blockers, nifedipine and verapamil, on adrenal catecholamine release were examined in anesthetized dogs. These blockers were infused into the adrenal gland through the phrenicoabdominal artery. Splanchnic nerve stimulation at 1 and 3 Hz produced frequency-dependent increases in epinephrine and norepinephrine output determined from adrenal venous blood. Infusion of omega-conotoxin GVIA (0.4 micrograms/min) significantly inhibited the splanchnic nerve stimulation-evoked increases in epinephrine and norepinephrine output. Furthermore, increases in epinephrine and norepinephrine output induced by intraarterial injection of acetylcholine (3 micrograms) into the adrenal gland also were inhibited by omega-conotoxin GVIA (0.4 micrograms/min). Further inhibition of splanchnic nerve stimulation- or exogenous acetylcholine-induced increases in catecholamine output was observed even after the cessation of omega-conotoxin GVIA infusion. Neither nifedipine (1 microgram/min) nor verapamil (10 micrograms/min) affected the splanchnic nerve stimulation-evoked increases in catecholamine output, whereas they inhibited the exogenous acetylcholine-evoked catecholamine release. These results suggest that N-type VDCCs located in adrenal medullary cells may contribute to the release of adrenal catecholamines in response to endogenous and exogenous acetylcholine in the dog.

Acetylcholine

Purification and characterization of a human erythrocyte-derived growth factor with a wide target cell spectrum.

A cell extract from human erythrocytes promoted the growth of a wide variety of cell types, namely human and mouse myeloid cells, human and mouse T cells, human B cells, human melanoma cells, mouse transformed fibroblast cells, mouse mastocytoma cells, human lung fibroblast cells, and mouse bone marrow fibroblast/stroma-like cells. The growth-promoting activity was acid- and heat-labile and sensitive to proteases, indicating the proteinaceous nature of the molecule. The activity was also lost upon exposure to 2-mercaptoethanol. The novel growth-promoting factor, termed basic growth factor because of its fundamental effect and a wide target cell spectrum, was purified by sequential anion-exchange, hydrophobic, gel filtration, hydroxylapatite, and reverse-phase high performance liquid chromatographies. The purified factor has an apparent molecular mass of 53 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing and nonreducing conditions. The factor migrated at 270 kDa on native gradient polyacrylamide gel electrophoresis. Therefore, the factor consists of a homopolymer of a single polypeptide chain. The purified factor promoted the growth of the same cell types as the cell extract, except for bone marrow cells.

Amino Acids