Biomedical subjects

K Ota

Publications and source records attributed to K Ota.

At least 325 records · Page 18Linked to original sources

PubMed1992

Relationship between plasma levels of hyaluronic acid and amyloid-associated osteoarthropathy in chronic hemodialysis patients.

Plasma levels of hyaluronic acid (HA) and acute-phase reactants were determined in chronic hemodialysis patients with or without carpal tunnel syndrome (CTS) and/or shoulder pain, which are characteristic symptoms of amyloid-associated osteoarthropathy. While levels of acute-phase reactants tended to be higher in the patients with CTS and/or shoulder pain than in patients without these symptoms, the difference was not significant. However, plasma levels of HA were significantly higher in the patients with these symptoms. Analysis of plasma levels of HA in age-matched patients also demonstrated a significant correlation between elevated levels of HA and the presence of CTS and/or shoulder pain. Among the patients with CTS and/or shoulder pain, those patients with bone cysts in the carpal bone or humeral head had significantly higher plasma levels of HA than patients without bone cysts. Thus, there appears to be a relationship between elevated plasma HA and amyloid-associated osteoarthropathy in chronic hemodialysis patients that is more specific than any correlation with levels of acute-phase reactants.

Acute-Phase Proteins↗

PubMed1992

Serum concentrations of magnesium and parathyroid hormone in randomly selected hospital in-patients and out-patients, and in in-patients with dementia.

The relationship between hypomagnesaemia and the secretion of parathyroid hormone was studied. Serum parathyroid hormone (PTH) concentrations were measured in 63 randomly selected patients and 54 hospitalized demented patients using carboxyl-terminal PTH53-84 (h-PTH53-84), mid-region PTH44-68 (m-PTH44-68) and intact PTH1-84 kits. Both groups of patients were further subdivided into those with near normal serum magnesium concentrations (1.7 - 3.2 mEq/l) and those with hypomagnesaemia (1.2 - 1.6 mEq/l). Serum h-PTH53-84, m-PTH44-68 and PTH1-84 concentrations in both the randomly selected and the demented patients with hypomagnesaemia were significantly lower than those in the groups with near normal serum magnesium concentrations. The results suggest that parathyroid hormone secretion was inhibited in randomly selected patients and dementia patients with hypomagnesaemia.

Aged↗

PubMed1992

Clinical appraisal of vinpocetine for the removal of intractable tumoral calcinosis in haemodialysis patients with renal failure.

Previous studies have shown that vinpocetine [14-ethoxycarbonyl-(3 alpha, 16 alpha-ethyl)-14,15-eburnamenine] scavenges minerals and/or metals in the soft tissues of rabbits with artificially induced arteriosclerosis. The present study was carried out to determine whether or not vinpocetine would bring about the removal of intractable tumoral calcinosis in haemodialysis patients with renal failure. After administration of 15 mg/day vinpocetine for 3-12 months in haemodialysis patients with X-ray evidence of tumoral calcinosis, calcinosis was completely eliminated in all eight cases. Serum alkaline phosphatase and bone osteocalcin concentrations tended to decrease after treatment with vinpocetine compared with before treatment. Vinpocetine thus appears to be an effective scavenger of tumoral calcinosis in haemodialysis patients with renal failure without any side-effects during treatment.

Adult↗

PubMed1992

Effects of nicergoline on calcium and magnesium deposition in the central nervous system tissues of rats maintained on low-calcium diets.

Reduction of calcium intake leads to the mobilization of calcium and magnesium from the bone pool and to calcium deposition in the soft tissues, especially in the central nervous system (CNS). The effects of 10 alpha-methoxy-1,6-dimethylergoline-8 beta-methanol 5-bromonicotinate (nicergoline), an ameliorator of cerebral circulation and metabolism, on the deposition of calcium and magnesium in the CNS, heart, liver, kidney, muscle, abdominal aorta and bones were studied in rats maintained on standard and low-calcium diets. Rats were fed the following diets for 90 days: standard calcium (12.5 g/kg); standard calcium with 60 mg/kg nicergoline; low-calcium (30 mg/kg); and low-calcium with 60 mg/kg nicergoline. The presence of nicergoline did not affect blood chemistry but magnesium concentrations in the liver were significantly (P < 0.05) higher in rats fed standard diet with nicergoline. Magnesium concentrations in the occipital cortex, pons, cerebellum, liver, kidney, muscle and femur of nicergoline-treated rats fed low-calcium diet were significantly (P < 0.01-0.05) higher compared with those in the corresponding controls, whereas the calcium concentrations in the femur of nicergoline-treated rats fed both standard and low-calcium diets were significantly (P < 0.05) higher than those in the corresponding controls. In general, nicergoline tended to preserve the calcium content in the bone of rats fed a standard diet. Nicergoline may be implicated in calcium metabolism in rats fed low-calcium diets and may activate cerebral metabolism through the maintenance of magnesium concentrations in the CNS and soft tissues.

Animals↗

PubMed1992

Involvement of the gastric vagal nerve in the suppression of pulsatile luteinizing hormone release during acute fasting in rats.

Acute fasting has been shown to impair gonadotropin secretion in an estrogen-dependent manner in rats. The present study examined whether the vagus nerves have some role in the suppression of pulsatile LH release after 48-h fasting in ovariectomized estradiol-treated rats by performing complete subdiaphragmatic cutting of the nerves or selective sectioning of its branches (gastric, hepatic, or celiac) after the first hour of a 3-h blood sampling period. Vagotomy, alone, did not cause any changes in LH release in the unfasted animals. However, complete and gastric vagotomies restored pulsatile LH release that was suppressed before the nerves were cut in fasted animals. Neither hepatic nor celiac vagotomy restored pulsatile LH release, which remained suppressed throughout the sampling period in fasted animals. These results suggest that some mechanism involving the afferent vagal nerves, particularly the gastric vagus, has a major role in the suppression of pulsatile LH release during acute fasting in ovariectomized estradiol-primed rats.

Animals↗

PubMed1992

Prolongation of tetracaine spinal anesthesia by oral clonidine.

The effects of oral clonidine on the duration of isobaric tetracaine spinal anesthesia were studied in 30 patients undergoing urologic procedures. All patients received 15 mg of tetracaine intrathecally in isobaric saline solution. Group 1 (n = 10) received 0.25 mg of oral triazolam; group 2 (n = 10) received 0.15 mg of oral clonidine; and group 3 (n = 10) received 0.25 mg of oral triazolam and 0.75 mg of intrathecal phenylephrine. In group 1, the times for two- and four-segment regression of the level of analgesia to pin-prick were 80 +/- 17 and 123 +/- 22 min, respectively (mean +/- SD). The corresponding values of those measurements were 170 +/- 27 and 273 +/- 48 min in group 2 and 175 +/- 34 and 273 +/- 68 min in group 3. All the regression times in groups 2 and 3 were significantly longer than those in group 1. Regression times were not different between groups 2 and 3. The authors conclude that prolongation of tetracaine sensory analgesia may be produced by premedication with 0.15 mg of oral clonidine. The prolongation is similar to that produced by intrathecal phenylephrine.

Administration, Oral↗

PubMed1992

Impaired water diuresis in a patient with pseudo-Bartter syndrome.

A 32-year-old man was diagnosed as having pseudo-Bartter syndrome due to surreptitious habitual vomiting and to maldigestion related to decayed teeth. His chief complaints were muscle pain and weakness. In this case, metabolic alkalosis, hypokalemia, hypochloremia, increased plasma renin activity and aldosterone levels were noticed with marked decreases in urinary chloride excretion. Creatinine clearance (GFR) and renal plasma flow (RPF) were also decreased. Blood pressure was normal, but the pressor response to angiotensin II was attenuated. Before treatment with 0.9% saline infusion, plasma vasopressin (AVP) was not suppressed sufficiently by lowering the plasma osmolality (Posm) with an oral water load (WL), but it normally responded to a rise in Posm due to hypertonic saline infusion. Moreover, plasma AVP was normally suppressed by WL after the replenishment of saline. Plasma atrial natriuretic peptide (ANP) was low before WL, but increased normally in response to WL. However, inconsistent with the normal response in this case, decreases in plasma AVP failed to dilute urinary osmolality and to increase urine flow, irrespective of the levels of plasma ANP. These results indicate that chronic inanition due to surreptitious vomiting causes impaired renal diluting ability through decreases in GFR and RPF, irrespective of the levels of plasma AVP and ANP.

Adult↗

PubMed1992

Plasma vasopressin and atrial natriuretic hormone levels in hypopituitarism with and without hydrocortisone treatments: responses to an acute water load.

To assess whether arginine vasopressin and atrial natriuretic hormone participate in impaired urinary dilution and excretion in glucocorticoid deficiency secondary to hypopituitarism, an acute oral water load of 20 ml.kg-1 BW was undertaken in the absence and presence of an oral hydrocortisone (60 mg) treatment in patients with ACTH deficiency (N = 7) and panhypopituitarism (N = 2). Plasma arginine vasopressin and atrial natriuretic hormone and renal water handling were simultaneously determined and compared with those in similarly water-loaded normal subjects. Plasma arginine vasopressin did not fall in response to decreased blood osmolality after an acute water load in the absence of hydrocortisone; plasma atrial natriuretic hormone did not change despite blood volume expansion; and impairment in urinary dilution and excretion remained. On the other hand, in the presence of hydrocortisone, plasma arginine vasopressin fell in response to a decrease in plasma osmolality and plasma atrial natriuretic hormone increased, thereby restoring urinary dilution and excretion. These results demonstrate that the impaired arginine vasopressin response to acute water loading play an essential role in deranged renal water and electrolyte handling in the state of glucocorticoid deficiency; the impaired release of atrial natriuretic hormone also may affect these disorders.

Adult↗

PubMed1992

Mechanism of proteinuria in nephrotic syndrome.

We developed a "tissue negative staining method" to observe the molecular-level ultrastructure in situ in any portion of the ultrathin sections routinely prepared for electron microscopy. This method was used in electron microscopy of the glomerular basement membranes (GBM). The GBM in patients with nephrotic syndrome was discovered to possess a tunnel structure, designated as "nephrotic tunnel", with lumen large enough to allow free passage of protein molecules. This tunnel seemed to be involved in the etiology of nephrotic syndrome. This new method appears to be applicable to a variety of purposes in biological studies.

Animals↗

PubMed1992

Modified hemoglobin solution as possible perfusate relevant to organ transplantation.

A modified hemoglobin solution ( - conjugate solution, PHP solution) has very interesting characteristics such as oxygen-carrying property without corpuscular components. Experimental use of the PHP solution has shown promising possibilities as a perfusate relevant to organ transplantations. 1) Elongation of warm ischemic time in canine kidneys: Dogs survived even with the unilateral kidneys which had been exposed up to 4.5 hour warm ischemia and, thereafter, perfused with the PHP solution. 2) Elongation of perfusion preservation period of canine livers: Dogs survived with the transplanted livers which had been perfused for 48 hours with the PHP solution. 3) Successful perfusion of rat small intestine: Lewis rat intestines perfused and preserved for 12 hours with the PHP solution showed a higher survival rate compared with those with Collins or UW solution. 4) Removal of antibodies: By exchange transfusion with a total of 30-60 ml of the PHP solution, a Lewis rat hematocrit lowered to 5% while IgG went down to nil from 8970 mg/dl, IgA to 28 mg/dl from 118 mg/dl and IgM to 190 mg/dl from 897 mg/dl. This technique is expected to be applicable for removal of the naturally existing antibodies in xenotransplantation.

Animals↗

PubMed1992

Evaluation of a pyridoxylated hemoglobin polyoxyethylene conjugate solution as a perfusate for small intestine preservation.

A new type of artificial blood, pyridoxylated hemoglobin-polyoxyethylene conjugate (PHP) solution, (developed by PHP research group of the department of health and welfare of Japan, and produced by Ajinomoto Co., Inc. Tokyo) as an oxygen-carrying component, has been recently devised using hemoglobin obtained from hemolyzed human erythrocytes. Recently, the studies using this solution as a preservation solution were performed in some instances. To examine the mechanism of improved viability using this solution as a preservation solution, we developed a model of orthotopic small intestine transplantation (OIT) in the rat. As a baseline study, we compared parameters of viability of the grafts preserved in Collins and UW solution to those preserved in PHP solution including a survival rate, a serum level total protein and albumin, and a change in body weight after transplantation. In our study, the simple hypothermia storage together with intestinal perfusion preservation with PHP solution was performed. Animals were divided into 6, 12, and 24 hr preservation groups. All of the rats survived after 6 hr preservation following transplantation. However, in 12 hr storage, five of six rats in PHP solution preservation survived and recovery in body weight after grafting was better than those with Collins and UW solution. We conclude that the PHP solution is, therefore, considered to possibly be a more suitable perfusate for small intestine preservation than Collins and UW solution.

Adenosine↗

PubMed1992

[The distribution and localization of alpha 1-adrenoceptor agonist on the bladder and urethra of female rats].

The distribution of selective alpha 1-adrenoceptor agonist 1-(2',5'-dimethoxyphenyl)-2-glycinamidoethanol hydrochloride, midodrine, and its active metabolite 1-(2',5'-dimethoxyphenyl)-2-aminoethanol, DMAE, was evaluated on bladder and urethra of 8-weeks and 52-weeks old female rats. Prior to the intravenous injection of 14C-labeled midodrine and DMAE, bilateral ureters were ligated to prevent drug uptake from the urinary tract. In 8-weeks rats, 14C-midodrine activity was significantly (p less than 0.01) higher in the bladder than in the femoral muscle, which served as a control for drug distribution. Similarly, higher uptake of 14C-DMAE was observed in the bladder than in the femoral muscle (p less than 0.01) and the urethra (p less than 0.05). In 52-weeks rats, there was no significant difference of midodrine uptake among these tissues. However, significantly higher uptake of 14C-DMAE was observed in the urethra than in the femoral muscle (p less than 0.05). Compared with midodrine, the concentration of DMAE was significantly increased in the bladder of 8-weeks rat and in the urethra of 52-weeks rats (respectively, p less than 0.05). In autoradiogram, the grains corresponding to midodrine and DMAE were diffusely distributed on the smooth muscles of bladder (mainly bladder neck and trigone) and urethra. The grains were also recognized on the vessels and perivascular areas of these tissues. These findings support that midodrine and DMAE could be effective for stress incontinence, because these drugs are known to bind specifically to alpha 1-adrenoceptor.

Adrenergic alpha-Agonists↗

PubMed1992

Experimental and clinical studies on dysregulation of magnesium metabolism and the aetiopathogenesis of multiple sclerosis.

The proposed aetiologies of multiple sclerosis (MS) have included immunological mechanisms, genetic factors, virus infection and direct or indirect action of minerals and/or metals. The processes of these aetiologies have implicated magnesium. Magnesium and zinc have been shown to be decreased in central nervous system (CNS) tissues of MS patients, especially tissues such as white matter where pathological changes have been observed. The calcium content of white matter has also been found to be decreased in MS patients. The interactions of minerals and/or metals such as calcium, magnesium, aluminium and zinc have also been evaluated in CNS tissues of experimental animal models. These data suggest that these elements are regulated by pooling of minerals and/or metals in bones. Biological actions of magnesium may affect the maintenance and function of nerve cells as well as the proliferation and synthesis of lymphocytes. A magnesium deficit may induce dysfunction of nerve cells or lymphocytes directly and/or indirectly, and thus magnesium depletion may be implicated in the aetiology of MS. The action of zinc helps to prevent virus infection, and zinc deficiency in CNS tissues of MS patients may also be relevant to its aetiology. Magnesium interacts with other minerals and/or metals such as calcium, zinc and aluminium in biological systems, affecting the immune system and influencing the content of these elements in CNS tissues. Because of these interactions, a magnesium deficit could also be a risk factor in the aetiology of MS.

Humans↗

PubMed1992

The effect of thyroid hormone on generation of free radicals by neutrophils and alveolar macrophages.

We have sometimes observed the case of bronchial asthma accompanied by hyperthyroidism. But the pathophysiological mechanisms of both diseases remain obscure. In this study, we have shown that thyroid hormone directly stimulated the generation of superoxide anion by neutrophils and alveolar macrophages. In addition, neutrophils incubated with thyroid hormone became activated and generated greater amount of superoxide anion in response to f-met-leu-phe (fMLP) and phorbol myristate acetate (PMA). Our study suggests, for the first time, that reactive oxygen species may play one of the most important roles in exacerbating asthma in hyperthyroid patients.

Adult↗

PubMed1992

[Clinical evaluation of ondansetron (injection of a single intravenous dose) against nausea and emesis associated with anti-cancer drugs--dose-finding study in patients receiving cisplatin].

We examined anti-emetic effects, safety and the optimal dose of Ondansetron Injection given in a single intravenous dose in patients receiving a single high dose of cisplatin in randomized controlled comparative study using telephone registration. Ondansetron was injected intravenously in a single dose of 4 mg, 8 mg or 12 mg, at 15 minutes before administration of cisplatin. Nausea and emesis were observed for 24 hours after administration of cisplatin. Efficacy rate of inhibitory effects on nausea and emesis were 76% (19/25 cases) in the 4 mg dose group, 57% (12/21 cases) in the 8 mg dose group and 83% (20/24 cases) in the 12 mg dose group, without a statistically significant difference among 3 dose groups. Hence, it was estimated that the low dose of 4 mg was adequate to exert satisfactory anti-emetic effects. No clear relationship between onset time of the initial emetic episode and plasma concentrations of Ondansetron was found in 16 cases of the 4 mg dose group, 11 cases in the 8 mg dose group and 15 cases in the 12 mg dose group. Side effects observed during this study period were headache and diarrhea in 1 case in the 12 mg dose group. Both symptoms were mild and resolved without treatment. No abnormal findings attributable to Ondansetron were observed in clinical laboratory test. From the above, it was considered that Ondansetron given by a single intravenous injection was highly effective to inhibit nausea and emesis induced by cisplatin, and was highly safe. As to the dose, 4 mg once daily was considered to be adequate for prophylaxis of cisplatin-induced nausea and emesis.

Adult↗

PubMed1992

[Examination of anti-emetic effect, safety and usefulness of single oral dose of ondansetron tablet in nausea and emesis induced by anti-cancer drugs--dose-finding study of ondansetron tablet in patients receiving non-platinum anti-cancer drugs].

Inhibitory effects on acute nausea and emesis, safety and usefulness of a single oral dose of Ondansetron tablet were evaluated in 3 different dose levels for comparison by telephone registration system, in patients receiving non-platinum anti-cancer drugs. A single dose of ondansetron at 4 mg, 8 mg or 12 mg was given orally at 2 hrs before the initial administration of anti-cancer drugs. The patients were observed for 24 hours after administration of anti-cancer drugs, for occurrence of nausea and emesis. Efficacy rates of inhibitory effects on nausea and emesis were 83.3% (10/12 cases) in 4 mg dose group, 78.6% (11/14 cases) in 8 mg dose group and 84.6% (11/13 cases) in 12 mg dose group, without statistically significant difference. Side effects were observed in 3 cases (headache, cold feeling and trembling in limbs, sleepiness) in 12 mg dose group, but these symptoms were not severe and disappeared after several hours or several days. No abnormality in clinical laboratory findings attributable to Ondansetron was observed. From the above, it was considered that Ondansetron was a clinically useful anti-emetic for nausea and emesis induced by non-platinum anti-cancer drugs and that 4 mg once daily was the optimal dose.

Administration, Oral↗

PubMed1992

[Anti-emetic effect and safety of consecutive use of ondansetron injection in cisplatin-induced nausea and emesis].

Anti-emetic effect, safety and clinical usefulness of Ondansetron injection given in the dose of 4 mg once daily by intravenous administration for 3-5 consecutive days were examined in patients receiving a high single dose (not less than 50 mg/m2 or over 75 mg/body) and lower multiple doses (over 15-20 mg/m2 once daily, for 3-5 consecutive days) of cisplatin. Efficacy rates of inhibitory effects on nausea and emesis in patients receiving the high single dose of cisplatin were 76% on the 1st day, 67% on the 2nd day and 78% on the 3rd day, the average being 71% (86/121 cases) for the 3 days. Those in patients receiving lower multiple doses of cisplatin were 83% on the 1st day, 78% on the 2nd day, 61% on the 3rd day, 65% on the 4th day and 57% on the 5th day, the average being 72% (13/18 cases) for the 3-5 days. Side effects were observed in 15 cases out of 207 (1st course, 182 cases; 2nd course, 21 cases; 3rd course, 4 cases), and major symptoms were headache and fever. Also, abnormalities in clinical laboratory findings attributable to Ondansetron were observed in 13 cases, mainly consisting of elevation of the hepatic function values. From the above, Ondansetron injection which showed sufficient anti-emetic effects on acute emesis and delayed emesis induced by a high single dose or lower multiple doses of cisplatin with its once daily intravenous dose given for 3-5 consecutive days, were considered a safe and clinically useful anti-emetic.

Aged↗

PubMed1992

[Examination of anti-emetic effect and safety of multiple intravenous doses of ondansetron in patients receiving nonplatinum anti-cancer drugs].

Anti-emetic effects, safety and usefulness of Ondansetron given intravenously at 4 mg once daily for consecutive 3-5 days were investigated against nausea and emesis induced by non-platinum anticancer drugs. Efficacy rates in control of nausea and emesis were 59% (20/34 cases) and 68% (23/34 cases), respectively. The efficacy rate for inhibition of nausea and emesis, calculated based on the control of nausea and emesis, was 68% (23/34 cases). Adverse events (headache and constipation) were observed in 1 case and abnormal change in clinical laboratory findings (increase in eosinophil count) in another case. Out of 42 cases in which safety was evaluated, 41 (98%) cases were assessed as "no problem in safety." However, one case with side effect was assessed as a "Minor problem in safety." From the above, it was confirmed that Ondansetron injection exerted excellent inhibitory effects against nausea and emesis induced by non-platinum anti-cancer drugs, and this drug was a highly safe and useful anti-emetic.

Adolescent↗