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Biomedical subjects

A Takeuchi

Publications and source records attributed to A Takeuchi.

At least 19 recordsLinked to original sources
PubMed1992

[Fundamental study of helical scanning CT--evaluation of spatial resolution in the longitudinal axis].

We evaluated spatial resolution in the longitudinal axis with helical scanning CT using a fourth-generation fast CT scanner. We made a phantom by stringing acrylic balls (65 mm phi x 8 and 9 mm phi x 6). The acquired images were processed by MPR and assessed visually to evaluate axis resolution. With the conventional scanning method, the partial volume effect varied with the starting position, but helical scanning was able to reconstruct high-resolution images using continuous raw data. During helical scanning, axis resolution varied depending on the slice width and sliding speed of the couch top. Even if the sliding speed was kept constant at 4 mm/sec, axis resolution was superior with a slice width of 2 mm than with one of 5 mm.

Microcomputers↗
PubMed1992

Cloning of the gene encoding a glycylprolyl aminopeptidase from Porphyromonas gingivalis.

A genomic library of Porphyromonas gingivalis 381 was constructed in the cosmid vector pHC79. A clone, pSN1, was identified by the expression of glycylprolyl-naphthylamide hydrolysing activity. The DNA insert contained within the cosmid pSN1 was subcloned into the plasmid vector pBR328 to create the recombinant plasmid pSN11 containing a 2.9 kb EcoRV insert. An Escherichia coli transformant containing pSN11 produced a protein having a molecular weight of 75 kDa. Southern-blot hybridization revealed that the 2.9 kb EcoRV DNA hybridized with an identical sized Eco RV DNA fragment in the chromosomal DNA of P. gingivalis 381.

Blotting, Southern↗
PubMed1992

Synthesis of lipopolysaccharide by Escherichia coli cells recovering from sublethal heat stress.

Escherichia coli cells exposed to a sublethal heat treatment at 55 degrees C for 15s synthesized lipopolysaccharide during their recovery period after heat stress. As chloramphenicol at least partly inhibited the synthesis of lipopolysaccharide, it is suggested that its synthesis might be in part due to the lipopolysaccharide-synthesizing enzymes produced de novo. The results obtained coincided with our previous finding that the permeability barrier function was repaired by heat-stressed cells.

Adaptation, Biological↗
PubMed1992

Enhancement by endothelin-1 of the release of catecholamines from the canine adrenal gland in response to splanchnic nerve stimulation.

1. The effect of endothelin-1 on the release of adrenal catecholamines was examined in anaesthetized dogs. 2. Splanchnic nerve stimulation (SNS) at 1 and 3 Hz was applied before and after the intravenous injection of endothelin-1. 3. Endothelin-1 (0.1 and 0.3 micrograms/kg) significantly enhanced the release of adrenal catecholamines induced by 3 Hz SNS, but did not affect basal release and the release of adrenal catecholamines induced by 1 Hz SNS. 4. Endothelin-1 produced a slight and short-lasting fall in arterial blood pressure and decreases in adrenal and renal blood flow rates. 5. These results indicate that endothelin-1 enhances the release of adrenal catecholamines from the canine adrenal gland in response to relatively high frequency SNS.

Adrenal Glands↗
PubMed1992

Nephrotoxicity of germanium compounds: report of a case and review of the literature.

A 55-year-old woman was admitted to our hospital, complaining of general malaise, muscular weakness, anorexia and weight loss. She had a history of ingesting of a certain germanium (Ge) compound over the preceding 19 months, with a total dose of 47 g as Ge element. She was found to have renal failure (blood urea nitrogen, 44 mg/dl; serum creatinine, 2.6 mg/dl) without abnormal findings in urinalysis, and muscular and nervous damage. Initially, polymyositis was diagnosed and prednisolone administered. However, no improvement was seen, and neuromuscular symptoms and signs steadily worsened, ending in death. Microscopic study of the kidney showed that lipofuscin granules increased in the cells of the thick ascending limb of Henle's loop to the distal convoluted tubule accompanying mild tubular atrophy and that some of the tubules of these segments had vacuolar degeneration or desquamation. No apparent glomerular and vascular changes were observed. High Ge content was found in serum, urine and various tissues, e.g., spleen, liver, kidney, adrenal gland and myocardium, while in controls Ge could not be detected in sera, urine or tissues. We also review case reports about Ge toxicity, and discuss the pathogenesis of renal failure induced by Ge compounds.

Acute Kidney Injury↗
PubMed1992

Effects of pulsing electromagnetic fields on the ligament healing in rabbits.

Effects of pulsing electromagnetic fields (PEMFs) on ligament healing were investigated using 80 rabbits. All animals received square resection (4 mm x 4 mm) of both patellar ligaments in full thickness at their center. They were divided into 4 groups of 20 rabbits each and stimulated with different electromagnetic intensity of 0 (control), 2, 10, and 50 gauss (G) for 6 hr daily. Pulse frequency and pulse width were 10 Hz and 25 microseconds, respectively. After PEMFs stimulations for 1, 2, 3 and 4 weeks, 5 animals of each group were euthanized and the regenerated tissue at the defective portion was investigated histologically and biomechanically. Histologically, the tissue stimulated by PEMFs showed an earlier increase in capillaries and fibroblasts and more matured, prominent longitudinal orientation of collagen fibers than those of control groups. Among the rabbits stimulated electromagnetically, those stimulated at 50 G revealed the earliest ligament healing. Tensile strength of regenerated ligament tissues of any PEMFs groups increased significantly at 1 and 2 weeks after operation, however, at 3 and 4 weeks after operation, there were no significant differences between groups. Among these values, those of 50 G group were the highest consistently during most of the experimental period. From the above results, PEMFs enhanced the earlier stage of ligament healings and 50 G gauss seemed to be the most effective among the 3 field intensities used. This promoting effect may potentiate the earlier recovery of the function after the ligament injury.

Animals↗
PubMed1992

Enhancing effect of butorphanol on medetomidine-induced sedation in pigs.

Enhancing effect of an opiate agonist-antagonist butorphanol (0.2 mg/kg) on sedation induced by medetomidine (80 micrograms/kg) was evaluated in pigs. Butorphanol significantly enhanced the depth of medetomidine-induced sedation and prolonged the duration of that assessed by posture score and spontaneous movement of pigs. The combination of medetomidine and butorphanol produced excellent muscle relaxation and moderate surface analgesia which was enough for procedures with mild pain in pigs.

Animals↗
PubMed1992

Antagonism of medetomidine sedation by atipamezole in pigs.

The efficacy of atipamezole as a medetomidine antagonist was evaluated in pigs. The atipamezole doses (intramuscularly) were 80, 160, 320 and 480 micrograms/kg of body weight, which were one, two, four and six times higher than the preceding medetomidine dose (80 micrograms/kg, intramuscularly). Atipamezole effectively reversed medetomidine-induced sedation, and the optimal action was seen at doses of 160 and 320 micrograms/kg. Recovery from sedation was quick and smooth, and adverse effects such as hyperactivity or tachycardia were minimal with either dose.

Adrenergic alpha-Agonists↗
PubMed1992

A balanced anesthesia with a combination of xylazine, ketamine and butorphanol and its antagonism by yohimbine in pigs.

The effects of intramuscular injections of xylazine (2 mg/kg)-ketamine (15 mg/kg) [X-K15], and xylazine (2 mg/kg)-ketamine (5 mg/kg)-butorphanol (0.22 mg/kg) [X-K5-B] were compared in atropinized (0.05 mg/kg) miniature pigs (pigs). Both combinations induced the anesthesia for more than 1 hr, however X-K5-B induced the more potent and well balanced anesthesia as compared with X-K15, although the amount of ketamine was reduced to one third. The duration of loss of pedal reflex, an indicator of surgical anesthesia, in X-K5-B (62 +/- 13 min) was significantly (P less than 0.05) longer than in X-K15 (28 +/- 19 min). In addition, X-K5-B was accompanied by loss of laryngeal reflex in all pigs. Recovery from anesthesia in X-K5-B was much smoother than in X-K15, and the administration of yohimbine (0.05 mg/kg) could rapidly and smoothly reverse the anesthesia induced by X-K5-B, although it was accompanied by a transient fall in blood pressure and tachycardia. The combination of xylazine, ketamine and butorphanol appears to be a relatively safe and widely available anesthesia for the period of one hour in pigs.

Acid-Base Equilibrium↗
PubMed1992

Evaluation of plasma erythropoietin levels in normal adult dogs by in vivo bioassay using concentrated plasma.

Measurement of plasma erythropoietin level in normal dogs by in vivo bioassay has been considered to be impossible so far. In the present study, we successfully determined it by using concentrated plasma 60 times which allowed the lower limit to 2.7 mU/ml. This normal plasma erythropoietin level was the first to be determined as an in vivo bioactivity and was 9.14 +/- 7.81 mU/ml in 75 normal adult dogs. This value was sufficiently reliable in terms of accuracy of determination and considered to be meaningful as the low level in vivo bioactivity that hasn't been known to date. Furthermore, erythropoietin levels in normal plasma were within a certain lower range and showed neither difference in plasma erythropoietin level between males and females or among breeds nor correlation between erythropoietin and hemoglobin level.

Animals↗
PubMed1992

Sedative effects of medetomidine in pigs.

Sedative effects of medetomidine, a potent selective and specific alpha 2-adrenoceptor agonist, were evaluated in pigs using 5 different doses (30, 50, 80, 100 and 150 micrograms/kg of body weight) and compared with those of xylazine (2 mg/kg). Atropine (25 micrograms/kg) was mixed with both drugs to prevent severe bradycardia. All drugs were administered intramuscularly. Medetomidine at a dosage of 30 micrograms/kg produced more potent sedation than xylazine. The depth of sedation induced by medetomidine was dose dependent within the range from 30 to 80 micrograms/kg. At 100 or 150 micrograms/kg, the depth of sedation was mostly the similar level to that at 80 micrograms/kg but the duration was prolonged. The degree of muscle relaxation produced by medetomidine also seemed to be dose dependent from 30 to 80 micrograms/kg and was stronger than that produced by xylazine. An increase in the duration of muscle relaxation was dose dependent up to 150 micrograms/kg. No analgesic effect was produced by xylazine, however moderate analgesia was obtained by medetomidine. There were no marked changes in heart rate and respiratory rate during the observation period in pigs of any groups, however mild hypothermia after the administration of both drugs was observed. From these results, medetomidine has a significant and dose-dependent sedative effects which are much more potent than that of xylazine, and a combination of 80 micrograms/kg of medetomidine and 25 micrograms/kg of atropine is suitable for sedation with lateral recumbency and moderate muscle relaxation without notable side effects in pigs.

Analgesia↗
PubMed1992

Detection of uremic peaks in dogs by anion exchange high performance liquid chromatography.

Sera of dogs with gentamicin-induced uremia were analyzed by high performance liquid chromatography system with strongly basic macroreticular anion exchange resin. Satisfactory separation of peaks was achieved with good reproducibility after deproteinization of sera with trichloroacetic acid at a final concentration of 3%, confirming that the system was suitable for qualitative analysis of uremic serum. The chromatograms showed that the number of peaks and the peak area had relation to concentrations of serum urea nitrogen or creatinine and severity of uremia. Four peaks were selected as suspected canine uremic peaks with high correlation to serum creatinine concentrations which were hardly influenced by extrarenal factors. The results suggested that these four fractions might contain uremic toxins.

Animals↗
PubMed1992

Metabolism of orally administered ergosterol and 7-dehydrocholesterol in rats and lack of evidence for their vitamin D biological activity.

Metabolism of orally administered ergosterol (Erg) and 7-dehydrocholesterol (7-DHC) in rats and their vitamin D biological activity were investigated. Most of orally administered Erg and 7-DHC were excreted in feces and the remaining sterols were absorbed through intestine. The absorbed sterols were not transported in skin as the intact forms but metabolized into brassicasterol and cholesterol, respectively, within 25 h. Neither increment of intestinal calcium absorption nor plasma calcium concentrations were observed by oral administration of Erg and 7-DHC to vitamin D-deficient rats. Therefore, we have concluded that orally administered Erg and 7-DHC have no vitamin D biological activity.

Administration, Oral↗
PubMed1992

[IgM HCV antibody in chronic hepatitis and liver cirrhosis].

To evaluate the role of IgM specific antibody in the diagnosis and monitoring of the patients with chronic hepatitis C, sera from 114 cases with chronic hepatitis C and liver cirrhosis were tested. IgM antibody to hepatitis C virus was detected in 40.0% of CAH, as compared with 21.4% of CIH, 17.4% of LC, 20.0% of LC with HCC. IgM antibody was also detectable in cases with high level of s-ALT. Patients with positive this antibody have high titer of IgG antibody to hepatitis C virus. In summary, testing for this antibody may be useful to evaluate the recurrence or disease activity and may also be helpful in IFN therapy.

Adult↗
PubMed1992

[Successful intrauterine digoxin therapy for fetal complete atrioventricular block with endocardial cushion defect: a case report].

We report herein a case of fetal complete atrioventricular block accompanied with endocardial cushion defect, successfully diagnosed and treated, in utero, with transplacental digitalization. A 23-year-old Japanese woman, at 20 weeks of gestation, was referred to the Maternity and Perinatal Care Unit of Kyushu University Hospital because of fetal continuous bradycardia. B-mode scanning and dual M-mode echocardiography revealed that the fetus had complete atrioventricular block with endocardial cushion defect with a ventricular rate of 60 beats per minute. At 23 weeks of gestation, it was found that the fractional shortenings (FSs) in both ventricles and the ventricular rate had decreased, with an increase in pericardial effusion. Thus, we diagnosed the fetus as having cardiac failure. Transplacental digoxin treatment was started and continued for 10 weeks, after which fetal pericardial effusion, as well as FSs ameliorated. The pregnancy was interrupted by cesarean section at 33 weeks of gestation due to a decrease in FSs with an accumulation of fetal ascites. A 1780g female infant was delivered and a pacemaker was implanted surgically, immediately after birth. She is alive and well at the time of writing.

Adult↗
PubMed1992

Quantitative measurement of regional cerebral blood flow using N-isopropyl-(iodine-123)p-iodoamphetamine and single-photon emission computed tomography.

We have developed a quantitative method of measuring regional cerebral blood flow (rCBF) by using N-isopropyl-(iodine-123)p-iodoamphetamine and single-photon emission computed tomography (SPECT). Twenty-five dynamic SPECT images (24 sec/scan) were collected immediately after tracer injection using a ring-type SPECT system and the accumulation curve (C(t)) was obtained. The time-activity curve corresponding to the arterial blood activity curve was used as B(t). The latter curve was calculated from the lung time-activity curve monitored during scanning and corrected by the actual activity obtained by one-point blood sampling 5 min after tracer injection. The octanol extraction ratio during scanning was considered to be constant and taken as the value measured 5 min after tracer injection (E). The uptake constant (K) per pixel was calculated by the least squares fitting method as the slope of the linear relationship in which C(t)/E x B(t) was plotted against E x integral of t(o)B(tau)d tau/E x B(t). Functional maps of rCBF values were obtained on a 64 x 64 matrix by calculating the uptake constant per pixel and the cross calibration factor (CF) between the SPECT system and a well counter (rCBF = K.CF x 100).

Adult↗
PubMed1992

[A case report of aorto-pulmonary window associated with atrial septal defect].

The patient was a one-year-old boy, who underwent surgery with a diagnosis of atrial septal defect (ASD). During operation, aorto-pulmonary window (A-P window) which had not been detected by the preoperative examinations, was found. Therefore, the A-P window was divided prior to closing ASD. The patient is in good condition six months after the operation. The causes of the inaccurate preoperative diagnosis were discussed.

Aortopulmonary Septal Defect↗