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Biomedical subjects

A Takeuchi

Publications and source records attributed to A Takeuchi.

At least 199 records · Page 11Linked to original sources

Increased 1,25-(OH)2D2 concentration in a patient with malignancy-associated hypercalcemia receiving intravenous hyperalimentation inadvertently supplemented with vitamin D2.

A 55-year-old patient with hypercalcemic crisis due to gastric carcinoma with bone marrow metastasis was treated with bisphosphonate (pamidronate) and calcitonin. Urinary excretion of parathyroid hormone-related protein (PTHrP) was increased. When normocalcemia had been attained, intravenous hyperalimentation was started, in which 1,000 U vitamin D2 was inadvertently supplemented on days 5-18, On days 15-18, hypercalcemia rapidly recurred, accompanied by markedly increased serum levels of 25-OHD2 (9.1 ng/dl) and 1,25-(OH)2D2 (161 pg/ml). This clinical course suggests that PTHrP, like PTH, stimulated 1 alpha-hydroxylase activity and produced excessive 1,25-(OH)2D2. Vitamin D should not be administered to patients with malignancy-associated hypercalcemia, particularly that due to PTHrP-producing tumors.

Calcitriol↗

Development of neoglycoproteins conjugated with natural oligosaccharides through carboxyl residues of proteins and its application to recombinant human interleukin 1.

In order to develop glycosylated cytokines, neoglycoproteins were synthesized utilizing naturally occurring oligosaccharides. High mannose type oligosaccharide-asparagine (Asn)s, containing Man8GN2-Asn, Man7GN2-Asn and Man6GN2-Asn, were obtained from quail ovalbumin and were coupled to bovine serum albumin (BSA) by carbodiimide-mediated coupling. Major reaction occurred between amino residues of oligosaccharide-Asns and carboxyl residues of BSA. Approximately one molecules of oligosaccharides-Asns were coupled to per molecule of BSA with 50% yield of glycosylation. Among the oligosaccharides, Man6GN2-Asn appeared to be conjugated predominantly. While this strategy was applied to recombinant human interleukin 1 alpha (IL-1 alpha), three molecules of oligosaccharide-Asns were introduced into per molecule of IL-1 with 10% yield of glycosylation.

Animals↗

[Risk factors and therapeutic methods for sternal wound infection following cardiac surgery].

In a study of 1040 patients undergoing cardiac surgery at The Osaka Medical College Hospital from 1984 through 1991, we analyzed the correlation between a variety of preoperative and operative parameters and the risk of postoperative sternal wound infection, as well as the efficacy of various therapeutic method for this condition. Sternal infection or mediastinitis developed after cardiac surgery in 31 patients (3.0%). As the risk factors for wound infections, age, diabetes mellitus, reexploration, duration of cardiopulmonary bypass and use of bilateral internal thoracic artery grafting were listed. Application of pectoral muscle flaps significantly led to shorten a duration between diagnosis of infection and hospital discharge, and increased survival rate, than the other treating methods such as debridement or irrigation. We conclude that bilateral internal thoracic artery grafts should not be used in the cases with diabetes, and closure with pectoral muscle flaps is effective for sternal infection and mediastinitis.

Coronary Artery Bypass↗

[The effect of Ryanodine for the myocardial protection in the working heart model of rabbit].

The purpose of this paper is to evaluate the effects of Ryanodine for myocardial protection. Twenty-four rabbits were studied using the working heart model divided four groups. The first is control group with no Ryanodine, the second is 10(-9) M, the third is 10(-8) M and the last one is 10(-7) M Ryanodine with GIK cardioplegic solution respectively. The hemodynamics was studied and the elemental concentrations (Ca, Mg, K, Na, Cl) of myocardial cell was measured using X-ray microanalysis. The results showed that intracellular Ca accumulation was dose-dependently suppressed with Ryanodine during reperfusion and also Ryanodine was significantly effective to maintain the hemodynamics during same one.

Animals↗

[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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗

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↗