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Biomedical subjects

K Yasuda

Publications and source records attributed to K Yasuda.

At least 685 records · Page 38Linked to original sources
PubMed1994

Measurement of iminodipeptides in the serum of patients with prolidase deficiency using liquid chromatography-mass spectrometry.

Iminodipeptides containing C-terminal proline or hydroxyproline were determined in sera from patients with prolidase deficiency, in their mother's serum, and in the sera of unrelated controls, using liquid chromatography-mass spectrometry with an atmospheric pressure ionization interface system. The separation was carried out on a reversed phase column using 1 g/l aqueous trifluoroacetic acid-methanol (75 + 25, by vol.). The quasi-molecular ions ([M + H])+ of various iminodipeptides containing C-terminal proline and hydroxyproline were observed in the sera of patients with prolidase deficiency, using selected ion monitoring. The quasi-molecular ions ([M + H])+ of iminodipeptides containing C-terminal proline were not observed in the sera of normal subjects or the patients' mother, but the latter did contain various iminodipeptides with C-terminal hydroxyproline. This method proved useful for the determination of iminodipeptides in the sera of patients with prolidase deficiency.

Chromatography, Liquid↗
PubMed1994

Simultaneous measurement of plasma 18-oxocortisol and 18-hydroxycortisol levels in normal man.

Plasma 18-oxocortisol (18-oxoF) and 18-hydroxycortisol (18-OH-F) were measured in 47 healthy subjects. Plasma 18-oxoF and 18-OH-F in the early morning were 0.827 +/- 0.04 nmol/l and 3.29 +/- 0.175 nmol/l, respectively. The plasma levels of both steroids correlated with each other and with cortisol, but not with aldosterone. Postural stimulation with or without furosemide administration increased 18-oxoF, 18-OH-F, aldosterone and plasma renin activity (PRA). Two hours after 2 mg of oral dexamethasone administration or after an overnight 2 mg of dexamethasone suppression cortisol, 18-oxoF and 18-OH-F decreased. Cortisol, aldosterone, 18-oxo-F and 18-OH-F increased after the intravenous administration of 250 micrograms of 1-24 ACTH. Changes in plasma 18-oxo-F and 18-OH-F levels correlated with PRA change during the posture studies and correlated with the change of ACTH during the dexamethasone studies. The ratios of post-/pre-test values of the postural stimulation and dexamethasone suppression in 18-oxoF and 18-OH-F were lower than that of aldosterone. Plasma 18-oxoF and 18-OH-F are more dependent on ACTH than on the renin-angiotensin system. The ratio of 18-OH-F/18-oxoF, which is between 4 and 5, remains constant during the various stimulation or suppression maneuvers.

Adrenocorticotropic Hormone↗
PubMed1994

Long term follow-up of Cushing's disease treated with reserpine and pituitary irradiation followed by subtotal adrenalectomy.

Subtotal adrenalectomy was given to 10 adult patients with Cushing's disease, concurrently with or following therapeutic regimen by long term reserpine administration and pituitary irradiation. In the present study, we describe long term follow-up results. Two patients died after the operation due to acute adrenal crisis and pneumonia, respectively. The other 8 patients achieved clinical and biochemical remissions and were followed for long term. Three patients relapsed 9, 14 or 17 years after achieving remission, two patients developed hypopituitarism 12 or 20 years after and one died of cerebral vascular accident at 64 years, 5 years after the remission. The remaining 2 patients maintained remission for 10 or 18 years, respectively. During the remission periods of 0.5 to 20 years with a mean of 10.1 +/- 6.7 years, 6 of 7 patients examined by 1 mg overnight dexamethasone test showed normal suppressibility of plasma cortisol. Provocative tests of plasma GH by l-arginine infusion and/or insulin-induced hypoglycemia were performed in 6 patients in the early remission period. All of 5 patients in the arginine infusion test and 3 of 5 in the insulin-induced hypoglycemia test showed normal responses. Furthermore, to facilitate prediction of long term response or failure to our therapeutic regimen, long term reserpine administration and pituitary irradiation, pretreatment clinical and biochemical characteristics were analyzed retrospectively in 3 divided groups; the present 10 patients treated with reserpine and pituitary irradiation followed by subtotal adrenalectomy, 11 patients achieving long term remission treated by our regimen alone, and 7 patients failed with our regimen alone. There were no significant factors predictive of response to our regimen. These findings suggest that subtotal adrenalectomy does not lead favorable outcome, however, reserpine administration shows usefulness to improve pituitary functions in treating Cushing's disease.

Adolescent↗
PubMed1994

Immunocytochemical investigation of rat gamma-glutamyl transpeptidase in chemically-induced hepatocarcinogenesis using monoclonal antibody.

An immunocytochemical study using a monoclonal antibody showed the presence of gamma-glutamyl transpeptidase (gamma-GTP) in the bile duct epithelium of the normal adult rat liver, while a slight immunoreactivity for gamma-GTP could be observed on the membranes of bile canaliculi (the membranes of hepatocytes facing the lumen of bile canaliculi). In hepatocarcinogenesis induced by 3'-methyl-4-dimethylaminoazobenzene, no immunoreactivity was detected in alpha-fetoprotein-positive cholangiolar "oval" cells, though it was detected on the membranes of bile canaliculi. In livers with hyperplastic nodules, gamma-GTP immunoreactivity was observed in clusters, with two different staining patterns. In one pattern, gamma-GTP was present not only on the membranes of bile canaliculi, but also on the membranes facing the Disse's space or the lateral cell surface of hepatocytes. In the other pattern, gamma-GTP immunoreactivity was seen on the membranes of the dilated bile canaliculi. In livers with developing hepatocellular carcinomas, the immunoreactivity was present on the membranes of irregularly dilated bile canaliculi in malignant cells.

Animals↗
PubMed1994

[On the localization of the binding site(s) of antibodies against TSH receptor using synthetic peptides].

In order to elucidate autoimmune B-cell recognition sites of human thyrotropin receptor (TSHR), nine overlapping synthetic peptides (residues 12-30, 24-44, 151-175, 171-195, 308-328, 324-344, 339-364, 359-380, and 375-399) were synthesized and biological activities of antibodies against each of the peptide were examined. It was shown that antibodies against TSHR 12-30, 24-44, 151-175, 171-195, 324-344, and 359-380 had thyroid stimulating antibody activity (TSAb), whereas antibodies against 339-364, 359-380, and 375-399 had thyroid stimulation blocking activity (TSBAb). From these results it was concluded that epitopes where TSH receptor antibodies with TSAb and TSBAb activities are bound are widely located in N-terminal, mid portion, and C-terminal regions.

Animals↗
PubMed1994

[Clinical results of selective cerebral perfusion during reconstruction of the transverse aortic arch].

Selective cerebral perfusion (SPC) has become a reliable method for brain protection during reconstruction of the transverse aortic arch. However, arterial cannulation technique for the branches of the aortic arch varies among groups, and the necessity of perfusion for the left subclavian artery is controversial. To avoid atheroembolism to the brain and malperfusion of the vertebral arterial system, we carefully selected the arterial cannulation technique according to the result of preoperative ultrasonographic and angiographic evaluation of the branches of the aortic arch, and decided the necessity of perfusion for the left subclavian artery according to the dominance of the two vertebral arteries and the result of pressure monitoring of all three branches. In this report, we analyzed our clinical results of selective cerebral perfusion on 22 consecutive patients, which was performed between April 1992 and December 1993. There were 14 atherosclerotic aneurysms and 8 aortic dissections. The flow rate for SCP was controlled by a single blood pump separate from that for systemic perfusion, with the mean value being 13.1 ml/kg/min. Mean of minimum left superficial temporal arterial pressure was 51 mmHg, mean duration of SCP was 134 minutes, and mean of the lowest esophageal temperature was 17.9 degrees C. Blood pH was regulated with alpha-stat strategy. Arterial cannula for SCP was inserted directly into the vessels through a stab wound in most cases. In three of four patients in whom dissection extended to the branches, a balloon catheter was introduced through the lumen of the aortic arch.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Use of Bullard intubating laryngoscope in emergency room].

A sixty-year-old male patient with caries of the cervical spine suffered from cardio-respiratory arrest outside the hospital. Laryngeal mask was inserted into his pharynx and he was brought to the emergency department of our hospital under CPR by emergency paramedical staffs. Endotracheal intubation was tried three times with a Macintosh laryngoscope but was unsuccessful. His neck was difficult to extend and his epiglottis was not visible at all (X-ray photograph showed the fusion and the significant backward protrusion of his cervical spine). EGTA and Combitube were tried but in vain. At last Bullard intubating laryngoscope with videocamera system was operated. An endotracheal tube was easily inserted into his trachea with it and effective cardiopulmonary resuscitation was managed under reliable airway maintenance. These facts indicate that Bullard intubating laryngoscope is valuable at the emergency department and it should be always available there.

Cardiopulmonary Resuscitation↗
PubMed1994

Molecular mechanisms of agonist-induced desensitization of the cloned mouse kappa opioid receptor.

Prolonged exposure of opioid receptors to agonists can cause desensitization, a cellular event linked to tolerance. Although evidence exists for mu and delta opioid receptor desensitization, much less information is available concerning the in vitro regulation of kappa opioid receptors because no cell lines exist that specifically express this class of opioid receptor. Recently we have cloned the mouse kappa opioid receptor. After expression in COS-7 cells, this protein exhibits the pharmacological specificity of a kappa 1 receptor and mediates agonist inhibition of cAMP formation. Continuous exposure of COS-7 cells expressing the kappa receptor to the agonist trans-(+/-)-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)-cyclohexyl]- benzeneacetamide methanesulfonate salt (U50,488) reduces the specific binding of the kappa-selective agonist [3H]U69,593. Furthermore, the potency of U50,488 to inhibit the binding of the opiate antagonist [3H]naloxone to the kappa receptor is reduced. However, total specific binding of [3H]naloxone is not altered, indicating that short-term (2-4 hr) agonist treatment of the kappa receptor reduces the affinity of the receptor for agonists but does not reduce the density of kappa receptors. The reduction in affinity of the kappa receptor for agonists is dependent on the time of agonist exposure and is reversible. The reduced affinity of the receptor for agonists is associated with kappa receptor desensitization, because kappa receptor-mediated inhibition of cAMP formation is lost in cells pretreated with U50,488. The desensitization of the kappa receptor is dependent on the time and concentration of agonist treatment, is blocked by the kappa-selective antagonist nor-binaltorphimine and is reversible.(ABSTRACT TRUNCATED AT 250 WORDS)

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1994

[Physiological diagnostic techniques of patients with vasculitis].

This article discusses physiological diagnostic methods in the intractable vasculitis, including Buerger's, Takayasu's and vasculo-Behçet disease. Clinical manifestations of these diseases depend on the lesions of the diseased arteries or veins such as obstruction of the extremities often occurring in Buerger's disease, the obstruction of aortic arch branches in Takayasu's disease and the deep vein thrombosis in vasculo-Behçet disease. Measurements of segmental blood pressure and flow allows a detection of peripheral vascular disease and non-invasive diagnostic techniques, such as the doppler ultrasonic techniques and strain-gauze plethysmography, permit accurate evaluation of arterial occlusive disease and estimation of its physiological significance. Noninvasive diagnostic techniques, together with clinical symptoms and physical examinations, make possible correct diagnosis and subsequently appropriate treatment.

Blood Pressure Determination↗
PubMed1994

1H-NMR analysis of nerve edema in the streptozotocin-induced diabetic rat.

To define the existence of intracellular hydration caused by metabolic derangements in the excised sciatic nerves of diabetic rats quantitatively, relaxation times (T1, T2) and fraction of intracellular water content were measured with 1H-nuclear magnetic resonance (NMR) spectroscopy in normal rats (control group, n = 10), streptozotocin (STZ)-induced (50 mg/kg, i.v.) diabetic rats (DM group, n = 10), STZ-induced diabetic rats treated with an aldose reductase inhibitor (ARI, Epalrestat, 100 mg/kg) (ARI group, n = 8), and STZ-induced diabetic rats treated with insulin (insulin group, n = 4). For selective measurement of intracellular relaxation times, the inversion recovery (IR) method for conventional T1 and Carr-Purcell-Meiboom-Gill method for T2 were used with an aqueous chemical shift reagent, 10 mmol/L dysprosium triethylenetetramine-N,N,N',N",N"',N"'-hexaacetic acid, resulting in distinct separation of intracellular (Schwann cell, axon, endothelial cell, and pericyte) and extracellular waters under the isotonic condition of the rat sciatic nerves. Furthermore, a new method of driven-equilibrium single-pulse observation of T1 (DESPOT) was used for rapid measurement of T1 for the purpose of clinical application on magnetic resonance imaging (MRI). T1 values measured by the DESPOT and IR methods were significantly correlated (p < 0.001). Total and intracellular water contents, sorbitol contents, and relaxation times of the sciatic nerve taken from the DM group were significantly elevated (p < 0.01), while myoinositol (p < 0.01) and extracellular water (p < 0.05) contents were significantly decreased as compared with the control group. Both insulin and ARI treatments significantly improved relaxation times as compared with those in the DM group (p < 0.05-0.01). Relaxation times correlated positively with total water (T1, p < 0.05-0.01; T2, p < 0.01), intracellular water (T1, p < 0.001; T2, p < 0.001), and sorbitol (T1, p < 0.001; T2, p < 0.001) contents of the excised nerve. Sorbitol content correlated positively with total and intracellular water contents (p < 0.01) but negatively with extracellular water content (p < 0.05). These findings indicated that sorbitol itself and/or secondary sodium accumulation caused by an increase in sorbitol may be a major contributor to the increase in intracellular hydration and prolonged relaxation times associated with hyperglycemia, which are reversible with insulin or ARI treatment. It was also suggested that rapid T1 measurement would provide new insights into the pathogenesis of human diabetic neuropathy as a non-invasive evaluation method on MRI.

Aldehyde Reductase↗
PubMed1994

[Candidate gene approach in Japanese NIDDM: liver/pancreatic beta cell type glucose transporter (GLUT2)].

The liver/pancreatic beta cell type glucose transporter (GLUT2) is expressed in the pancreatic beta cell, a glucose carrier with a low affinity for glucose but a high capacity for glucose transport. The expression of GLUT2 in the normal pancreatic islet is increased after exposure to high glucose, while it is decreased in model animal with non-insulin-dependent diabetes mellitus (NIDDM). In Pima Indians, to assess the genetic components of the acute insulin response (AIR) and NIDDM, polymorphic dinucleotide repeat regions in the GLUT2 gene were evaluated. Robust sib-pair linkage analyses suggest linkage between GLUT2 and AIR, but no linkage was observed with NIDDM. The coding region of the GLUT2 gene was screened for mutations using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis. A single base change was identified in exon 3 in -5% of the study population. Although this base change resulted in an amino acid substitution (Thr110-Ile110), no significant association was noted between AIR and the mutation. We also screened for mutations using PCR-SSCP analysis in Japanese subjects. A single base silent polymorphism (Phe497, TTT-TTC) was identified in exon 10. Significant association was noted between TTC type and NIDDM (N = 78), compared to normal controls (N = 80). These data suggest the possibility that GLUT2 is one of the candidate genes for NIDDM.

Diabetes Mellitus, Type 2↗
PubMed1994

[Effects of estrogen and progestin on platelet-activating factor acetylhydrolase].

Platelet-activating factor (PAF) is one of the potent proinflammatory agents and is associated with a number of human diseases, including asthma, endotoxin shock and cardiovascular diseases. Additionally, plasma PAF acetylhydrolase (PAF-AH) activity to inactivate PAF is regulated by hormones. In this study, we elucidated the effects of estrogen and progestin on plasma PAF-AH and also the effects of PAF on rat tissues to investigate the mechanisms involved in the thrombotic episode. Plasma PAF-AH activity in female adult rats treated with 17 alpha-ethynylestradiol (50 micrograms/kg, 5 days) was decreased by 50%. However, medroxyprogesterone (50 mg/kg, 5 days) increased the enzyme activity by 50%. When PAF (5 to 60 nmol/kg) was injected intravenously into non-treated female adult rats, 80% of the animals died at 20 nmol/kg of PAF. Macroscopic findings showed hemorrhage, hyperemia and congestion in the lungs and heart, and necrosis-like change in the gastrointestines. Microscopically, thrombus was observed in the lungs and heart. When PAF was administered to female adult rats pretreated with sex steroid hormones, the mortality of the rats with low plasma PAF-AH activity caused by estrogen was increased, but decreased in the animals with high enzyme activity caused by progestin. These findings suggest that the imbalance between PAF and plasma PAF-AH is one of the mechanisms involved in the thrombotic episode, and estrogen and progestin are related to the event by regulating the plasma PAF-AH activity.

Animals↗
PubMed1994

[Determination of serum vitamin B12 and folic acid by non boil (new standard) radioassay].

On purpose to study the radioassay of serum vitamin B12 and folic acid using non boil methods in with these two vitamins were released from their endogenous binding proteins with alkaline denaturation and separated the bound vitamins from the free ones with the magnetic iron particles coated these vitamin binders (purified hog intrinsic factor and beta-lactoglobulin from cow milk) were evaluated on precision and accuracy, compared with boil radioassay. 1. The reproducibilities of non boil method were 4.5 +/- 2.5% on vit. B12 and 3.5 +/- 0.2% on folate (n = 10), respectively. 2. The recovery test of the two serum vitamins with the use of cyanocobalamin and pteroylglutamic acid (J.P.) were finely showed the rations of 95.2-99.0% for vit. B12 and 101.0-108.0% for folic acid. And that of folic acid use of 5-methyl-tetrahydro-pteroylglutamic acid was showed the ratios of 101.0-104.0%. The values of folic acid measured by this method were found slightly higher than non boil method using conventional standard. 3. The correlation coefficient between non boil method and boil method were 0.987 and regression equation was showed y = 0.97x + 73.59 for vit. B12 (n = 75) and r = 0.932, y = 1.02x-0.08 (n = 78) for folic acid. 4. Normal range of serum total vit. B12 concentration was 210-920 (484 +/- 160 pg/ml, n = 259) and that of folic acid was 2.5-9.2 (5.2 +/- 1.4 ng/ml, n = 257), as well as boil method. 5. Accordingly it was considered that non boil (new standard) method was excellent for estimation of vitamin B12 and folic acid clinical status.

Female↗
PubMed1994

[A case of dissecting aortic aneurysm and presence of anti-Jr(a) antibody].

A 66-year-old woman was diagnosed as a DeBakey type II dissecting aortic aneurysm with angiography and CT. Antibody screening revealed circulating anti-Jr(a) antibody. Preoperatively, erythropoietin was administered twice a week. Over 24 days, a total of 1200 ml of her blood was removed and stored for autologous transfusion. The dissecting ascending aorta was replaced with the aid of cardiopulmonary bypass. The post operative course was uneventful. By using erythropoietin, pre-donated autologous blood, cell saver, aprotinin and transfusion of fresh autologous blood, it was possible to perform cardiovascular surgery on this patient who had an abnormal antibody. This patient is the first case of repair or dissecting aortic aneurysm with anti-Jr(a) antibody in Japan.

Aged↗
PubMed1994

[Acute dissection of the interatrial septum after re-replacement of the mitral valve--a case report].

A 64-year-old man who had received a Carpentier-Edward mitral valve replacement seven years earlier was seen with dyspnea on exertion. After re-replacement of the mitral valve with SJM prosthesis, the patient developed acute left-sided heart failure on the third postoperative day. Transesophageal echocardiography revealed abnormal lumen posterior to the left atrium with regurgitant flow from the left ventricle. Right and left atriotomy revealed dissection of the interatrial septum and after removal of the prosthesis, communication between the left ventricle and the dissected lumen was recognized. After closing the communicating orifice, SJM prosthesis was again sutured on the mitral annulus with sub-annular pledgets to reinforce the annular attachment. Excessive debridement of the annular tissue was thought to be a causative factor to develop the dissection of the interatrial septum after mitral valve replacement.

Acute Disease↗
PubMed1994

Pharmacological characterization of the cloned kappa-, delta-, and mu-opioid receptors.

Opioid drugs, such as morphine, and the endogenous opioid peptides, namely the enkephalins, endorphins, and dynorphins, exert a wide spectrum of physiological and behavioral effects, including effects on pain perception, mood, motor control, and autonomic functions. These effects are mediated via membrane-bound receptors, of which the best characterized are the kappa, delta, and mu receptors. The existence of these distinct types of opioid receptors has recently been confirmed by molecular cloning. In the present study, we have examined the pharmacological profiles of the cloned kappa, delta, and mu receptors using a battery of widely employed opioid agents. Our results suggest that the cloned kappa and mu receptors have pharmacological characteristics similar to those of the endogenously expressed kappa 1 and mu receptors, respectively. The cloned delta receptor displays a pharmacological profile consistent with that of a delta 2 receptor. Opioid agents with abuse potential possess high affinities for the mu receptor. The availability of the cloned receptors will facilitate the identification and development of more specific and selective compounds with greater therapeutic potential and fewer undesirable side effects.

Analgesics↗
PubMed1994

[Chemical structural analysis of steroids by NMR spectroscopy].

NMR is so convenient way to get stereochemical information of an organic compound that organic chemists have readily taken advantage of its spectra to investigate its stereochemistry by means of chemical shifts, coupling constants, nuclear Overhauser effect, etc. Especially in the steroid field, there have been reported many studies for determination of chemical structure and analysis of conformation. It is exemplified how NMR is in steroid chemistry.

Aldosterone↗