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Biomedical subjects

K Nonaka

Publications and source records attributed to K Nonaka.

At least 217 records · Page 12Linked to original sources

Effects of the intravenous administration of magnesium sulfate on corrected serum calcium level and nephrogenous cyclic AMP excretion in normal human subjects.

The effect of intravenous magnesium sulfate infusion on corrected serum calcium level and parathyroid function assessed by determination of nephrogenous cAMP (NcAMP) excretion were studied in normal human subjects. Significant hypermagnesemia induced by the magnesium sulfate infusion for 120 minutes was accompanied by a gradual and progressive decrease in the corrected serum calcium level. NcAMP excretion fell rapidly, reaching a nadir between 60 and 120 minutes after the infusion began, and after that rose above the baseline excretion. Urinary calcium excretion gradually increased, reaching a peak between 120 and 180 minutes after the infusion began and then gradually decreased. Since magnesium was given as the sulfate, it is not clear whether these changes were attributable to magnesium or sulfate or both. As a control study, we performed intravenous sodium sulfate infusion. The sodium sulfate infusion caused slight hypocalcemia, slight hypercalciuria, and a significant increase in NcAMP excretion. These findings indicate that the hypocalcemia and the hypercalciuria caused by the magnesium sulfate infusion is mainly due to the effect of magnesium, and that the decrease in NcAMP excretion during the infusion is due to the effect of magnesium alone. We conclude that the hypocalcemia caused by the magnesium sulfate infusion is mainly due to the renal calcium loss, and that the inhibition of parathyroid function caused by hypermagnesemia may be only partially involved in the early phase of this hypocalcemia.

Adult↗

Ultrastructural and immunocytochemical aspects of lymphocytic submandibulitis in the non-obese diabetic (NOD) mouse.

The submandibular glands of female non-obese diabetic (NOD) mice (22-26 weeks of age) were studied by light and electron microscopy. Mononuclear cells consisting mostly of lymphocytes were recognized in and among the acini and secretory ducts. Some parts of the secretory ducts and mucous acini surrounded by lymphocytes showed destructive changes. In the secretory ducts lymphocytes invaded the duct epithelial lining and the duct lumen was occluded by these cells. The duct epithelial cells in such lesions were extremely distorted and tonofilament bundles running in various directions were present in the cytoplasm. Lymphocytes were in close contact with the duct epithelial cells. In the mucous acini some acinar cells, which appeared to be compressed by the infiltrating lymphocytes, showed degenerative changes. Immunocytochemical study revealed that both T- and B-lymphocytes were involved, T-lymphocytes tending to occupy the center of the infiltrate, while B-lymphocytes occupied the periphery. Although autoantibody against duct epithelial cells was identified, damage to duct epithelial cells was not correlated with the presence of this antibody. The morphological changes in the submandibular gland of the NOD mouse are very similar to those reported in the salivary gland of patients with Sjögren's syndrome.

Animals↗

Influence of endogenous hyperinsulinism on high density lipoprotein2 level in type 2 (non-insulin-dependent) diabetes mellitus and impaired glucose tolerance.

We determined the insulin response to an oral glucose ingestion and levels of serum lipoproteins in 25 untreated patients with type 2 diabetes mellitus, in 26 subjects with impaired glucose tolerance (IGT), and in 35 non-diabetic control subjects. The three groups had similar compositions with respect to age and sex distribution. The levels of VLDL triglyceride in the subjects with type 2 diabetes or IGT were higher than those in controls. Serum HDL- and HDL2 cholesterol were significantly decreased in type 2 diabetics, and the subjects with IGT showed a similar tendency. Serum apolipoprotein A-II levels were lower in the male subjects with type 2 diabetes or IGT than in controls. Insulin response, i.e., sum of immunoreactive insulin (IRI) levels at basal, 30, 60, 90 and 120 min after a 75-g oral glucose load, negatively correlated to HDL- and HDL2 cholesterol levels (r = -0.396, P less than 0.05; r = -0.482, P less than 0.001, respectively), and positively correlated to VLDL triglyceride values (r = 0.485, P less than 0.001) in the male subjects with type 2 diabetes or IGT. In the female subjects, fasting plasma IRI values significantly correlated to HDL cholesterol (r = -0.496, P less than 0.05). There was a significant negative correlation between the concentrations of HDL2 cholesterol and VLDL triglyceride. These data show that lipoprotein metabolism, not only in type 2 diabetics, but also in IGT tends to show changes such as decreased HDL2 cholesterol and increased VLDL triglyceride levels, and which might be related to the hypersecretion of endogenous insulin.

Adult↗

Elevated antibody-dependent cell-mediated cytotoxicity and its inhibition by nicotinamide in the diabetic NOD mouse.

Antibody-dependent cell-mediated cytotoxicity (ADCC) by splenic mononuclear cells was measured in female non-obese diabetic (NOD) mice and age-matched ICR mice. No significant difference in ADCC activities was observed between the two groups when all the NOD mice were pre-diabetic. ADCC activities in diabetic NOD mice were significantly higher than those in age-matched ICR mice (P less than 0.001). Nicotinamide, known to prevent the diabetes of the NOD mouse, strongly inhibited ADCC by the mononuclear cells from diabetic NOD mice. Kinetic studies revealed that the inhibition was non-competitive.

Animals↗

Renal hypouricaemia in a patient with 48,XXYY syndrome.

Studies on hypouricaemia observed in a patient with 48,XXYY syndrome revealed an abnormality in renal urate handling. His renal urate clearance was abnormally increased. Inosine administration and provocative tests using probenecid and pyrazinamide identified an isolated renal tubular abnormality with increased urate secretion. Since the serum urate in his brother with a normal sex chromosome constitution was also low, the association of renal hypouricaemia and 48,XXYY syndrome in this patient is probably coincidental. Although the brother was not investigated, these siblings may be a previously unreported case of familial hypouricaemia due to isolated renal hypersecretion.

Adult↗

Increased plasma uric acid after exercise in muscle phosphofructokinase deficiency.

Type VII glycogenosis (muscle phosphofructokinase deficiency) is attended by hyperuricemia and hyperuricosuria. In one patient, we found that exercise on a bicycle ergometer increased plasma uric acid, inosine, and hypoxanthine levels. Forearm exercise also markedly increased venous inosine, hypoxanthine, and ammonia in the exercising arm of two patients. Exaggerated release of precursors for uric acid synthesis from exercising muscle may be related to the hyperuricemia.

Adult↗

Hypercalcemia in glucocorticoid withdrawal.

We found severe hypercalcemia in the course of hydrocortisone withdrawal in a patient who had undergone unilateral adrenalectomy to resect a cortisol-hypersecreting adenoma. Serum calcium gradually but progressively increased after unilateral adrenalectomy. Severe hypercalcemia developed on the 77th postoperative day (the 15th day after discontinuing hydrocortisone replacement). The serum concentration of calcium, PTH, 25(OH)D, and 1,25(OH)2D were 8.0 mEq/l, less than 100 pg/ml, 10.1 ng/ml and 29.6 pg/ml, respectively. This hypercalcemia was accompanied by marked urinary hydroxyproline excretion and less calcium excretion in the urine than the prevailing level of serum calcium. Serum concentrations of 25(OH)D, 1,25(OH)2D and PTH were not elevated during the severe hypercalcemia. We concluded that the hypercalcemia in this patient was due in part to enhanced bone resorption and increased renal tubular reabsorption of calcium as a result of glucocorticoid withdrawal, but not to the elevation of serum PTH or serum 25(OH)D and serum 1,25(OH)2D.

Adenoma↗

Aclarubicin in the treatment of elderly patients with acute nonlymphocytic leukemia.

Thirteen previously untreated patients aged 70 and above with acute nonlymphocytic leukemia were treated with aclarubicin (ACR) alone. Among 10 cases (3, acute myelocytic leukemia; 4, acute myelomonocytic leukemia; 2, acute monocytic leukemia; and one, acute erythroleukemia) in which an evaluation was possible, 5 cases (3, acute myelomonocytic leukemia; and 2, acute monocytic leukemia) obtained complete remission (CR). The CR rate was 83% in 6 patients with acute myelomonocytic leukemia or acute monocytic leukemia. The median CR duration and survival was 7.5 and 10 + months, respectively. Although side effects of the drug on digestive system such as nausea, vomiting and anorexia were observed in all patients, they were controllable by conventional treatments. The results suggest that ACR is effective for the clinical management of elderly patients with acute nonlymphocytic leukemia, especially those with acute myelomonocytic leukemia or acute monocytic leukemia.

Aclarubicin↗

Demonstration of islet cell surface antibodies in sera of New Zealand black mice and inhibitory effect on insulin release.

Islet cell surface antibodies (ICSAs) in sera of New Zealand Black (NZB) and New Zealand White (NZW) mice were detected by the indirect immunofluorescence method with cultured Balb/c mouse islet cells as antigens. Circulating ICSAs appeared in NZB mice from age 20 wk; at 30 wk, 73% of male mice and 88% of female mice had detectable ICSAs. The ICSAs were significantly absorbed with mouse islet cells but hardly absorbed with spleen cells or liver powder. The ICSAs also bound with islet cells of ICR mice, Sprague-Dawley rats, and NZB mice. NZB mice showed glucose intolerance especially at ages 10 and 30 wk. Although plasma glucose levels tended to be higher in NZB mice with strongly positive ICSAs, pancreatic insulin content was not reduced, and insulitis was rarely observed in the pancreases. On the other hand, 30-wk-old NZW mice had normal or mildly impaired glucose tolerance and only weak, if any, ICSAs. The ICSA-positive serum of NZB mice significantly suppressed glucose-induced insulin release by cultured islet cells. The ICSAs may be responsible, at least in part, for glucose intolerance in NZB mice after age 20 wk through the inhibitory effect on insulin secretion.

Age Factors↗

[Low-dose 4N-behenoyl-1-beta-D-arabinofuranosylcytosine (BHAC) in the treatment of atypical leukemia].

Four cases of hypoplastic leukemia, one of acute myelocytic leukemia (M2) and one of RAEB-t were treated with a low-dose 4N-behenoyl-1-beta-D-arabinofuranosylcytosine (LD-BHAC) regimen, in which 50 mg BHAC was administered daily intravenously by one-hour drip infusion for 14 days. Among the 6 cases, three (2 hypoplastic leukemia and one M2) obtained complete remission and one (hypoplastic leukemia), partial remission. Response rates were 66.6% of all cases, and 75% of cases of hypoplastic leukemia. During treatment, cytopenia was observed in all cases and a decrease in bone marrow nucleated cell counts was recognized in the aged M2 patient with remission. Although side effects of the drug on the digestive system such as anorexia and nausea were observed in some cases, they were all controllable by conventional treatments. The serum concentration of ara-C was measured in 4 cases. The peak level of serum ara-C concentration, 3.62-18.9 ng/ml (mean: 11.74 ng/ml), was observed at the time of cessation of infusion of BHAC, and an ara-C level of 2.75-4.89 ng/ml (mean: 3.54 ng/ml) was still present in the blood 6 hours after the cessation of infusion. It was concluded that LD-BHAC was useful in the clinical management of atypical leukemia and acute myelocytic leukemia in the aged.

Adult↗

Hyperphosphatemia as a detectable laboratory manifestation of glucocorticoid withdrawal syndrome.

We found hyperphosphatemia in five patients who had undergone unilateral adrenalectomy (ADX) for resection of cortisol-producing adenomas. The mean (+/- SEM) serum inorganic phosphorus level, theoretical renal phosphorus threshold and percent tubular phosphorus reabsorption rose from the preoperative level of 3.3 +/- 0.2 mg/dl, 2.6 +/- 0.2 mg/dl and 82.1 +/- 0.6%, to 6.0 +/- 0.2 mg/gl, 7.4 +/- 0.4 mg/dl and 95.9 +/- 1.0%, respectively, after ADX (P less than 0.001, P less than 0.001, P less than 0.001). Urinary phosphorus excretion decreased from 549 +/- 40 to 294 +/- 108 mg/day after ADX (P less than 0.05). Changes in serum calcium, serum sodium, serum potassium, serum chloride and creatinine clearance were not significant after ADX. Hyperphosphatemia may be the only abnormality found in serum electrolytes in glucocorticoid deficiency. It thus seems that hyperphosphatemia may be regarded as one of the clinical manifestations of the glucocorticoid withdrawal syndrome.

Adenoma↗

[A case of Isaac's syndrome--continuous muscle fiber activity syndrome].

A 34-year-old woman noted difficulty of gait initiation, then dilated finger opening and hyperhidrosis appeared. Her stature was a muscular habitus, and muscle stiffness and myokymia were found in all muscles of the extremities. Her stiffness persisted during sleep. Her calf muscles were large and a contracture was noticed in ankle joints. There was no evidence of wasting and weakness. A remarkable delay in voluntary relaxation of the contracted muscles without percussion myotonia was recognized. Tendon reflexes of lower extremities were absent. Laboratory examination revealed elevation of CPK, LDH, myoglobulin, aldolase and basal metabolic rate (BMR). An extraband of CPK isoenzyme between MB and MM fraction was observed. The thin layer gel filtration technique and immunofixation technique showed that this extraband was complexes of CPK and IgA, and light chain of the CPK linked IgA was lambda type. All other laboratory tests were normal for the following: urinalysis, ESR, a blood count, liver function, kidney function, glucose, rheumatoid factor, CRP, thyroid function, parathyroid function, serum electrolytes, ECG, EEG, cranial CT, without slight elevation of IgA, and CSF protein. In needle EMG and surface EMG spontaneous discharges were recorded at rest. These discharges consist of normal motor unit potentials, doublets, and triplets in needle EMG. The discharges were markedly reduced after the median nerve block with xylocaine. In needle EMG, myotonic discharge was not observed. Nerve conduction velocities were within normal ranges. According to these data, she was diagnosed as having Issacs' syndrome (continuous muscle fiber activity syndrome). Carbamazepine, 200 mg daily was administrated and showed a dramatic reversal of the symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Morphological aspects on pancreatic islets of non-obese diabetic (NOD) mice.

The pancreatic islets of female non-obese diabetic (NOD) mice (a model of insulin-dependent diabetes mellitus), have been examined by both light and electron microscopy. At about the age of 2 weeks, mononuclear cells began to infiltrate in or near the islets and some of these cells were in contact with the islet cells. Following this degeneration of islet B-cells took place, the process occurring in two ways. In many cells numerous secretory granules with extremely dense cores occupied the cytoplasm. Other cells, however, were filled with low-density secretory granules and the nuclei of these cells became pycnotic. After degeneration of B-cells, the islets were effaced by numerous mononuclear cells. With the onset of the diabetic state these mononuclear cells gradually disappeared, and thereafter small islets remained. By electron microscopy, retrovirus-like particles were observed in cisternae of the rough endoplasmic reticulum in islet B-cells at all stages. With an anti-retrovirus serum (goat anti-KiMSV-NIHxeno serum), positive immunofluorescence was observed in some pancreatic islet cells of NOD mice aged 1 day and 4, 6, 8, 9, 10 and 14 weeks. It is suggested that these virus particles may be intimately related to the inflammatory reaction occurring in the islets and to the development of diabetes mellitus.

Animals↗

A case of cerebral infarction showing periodic lateralized epileptiform discharges.

This is a report about the case of a 37-year-old female with left temporal damage due to a cerebral infarction and showing periodic lateralized epileptiform discharges (PLEDs). A hypsarhythmia-like pattern was observed a week after the onset. A repeat tracing of EEGs taken two weeks after the onset clarified the presence of PLEDs, consisting of a lateralized slow spike discharge in a rhythmic fashion at a frequency of every 1.6 seconds. PLEDs disappeared two months after the onset, and EEG activity normalized three months after the onset. But, her regressive behavior, crying before her doctor, which was considered to be due to a personality change, persisted for some years.

Adult↗

Excess purine degradation in exercising muscles of patients with glycogen storage disease types V and VII.

To investigate purine catabolism in exercising muscles of patients with muscle glycogen storage disease, we performed ischemic forearm exercise tests and quantitated metabolites appearing in cubital venous blood. Two patients with glycogen storage disease type V and three with glycogen storage disease type VII participated in this study. Basal lactate concentrations lowered in every patient with glycogen storage disease type V or type VII. Two patients with glycogen storage disease type VII, who had markedly elevated concentrations of serum uric acid (14.3 and 11.9 mg/dl, respectively), showed high basal concentrations of ammonia (118 and 79 mumol/liter, respectively; 23 +/- 4 mumol/liter in healthy controls) and of hypoxanthine (23.4 and 20.4 mumol/liter, respectively; 2.0 +/- 0.4 mumol/liter in healthy controls). Other patients showed near normal measurements of these metabolites. After forearm exercise, ammonia, inosine, and hypoxanthine levels increased greatly in every patient studied, in contrast with the lack of increase in lactate levels. The incremental area under the concentration curves for venous ammonia was 13-fold greater in the glycogen storage disease group than in controls (1,120 +/- 182 vs. 83 +/- 26 mumol X min/liter). The incremental areas of inosine and hypoxanthine were also greater in the glycogen storage disease group (29.2 +/- 7.2 vs. 0.4 +/- 0.1 and 134.6 +/- 23.1 vs. 14.9 +/- 3.2 mumol X min/liter, respectively). The incremental areas of ammonia in controls and in glycogen storage disease patients strongly correlated with those of hypoxanthine (r = 0.984, n = 11, P less than 0.005). These findings indicated that excess purine degradation occurred in the exercising muscles of patients with glycogen storage disease types V and VII, and suggested that the ATP pool in the exercising muscles may be deranged because of defective glycogenolysis or glycolysis.

Adult↗

Monocyte chemiluminescence and macrophage precursors in the aged.

Age-related alterations in the host defense system have been vigorously investigated because of increased susceptibility to infection and neoplasms in the aged. Although monocyte-macrophages form a major part of the cellular defense against microorganisms, the majority of investigations has been limited to neutrophils and lymphocytes. The present study, designed to determine the influence of age on mononuclear phagocytes, revealed no significant decrease in the absolute number of blood monocytes, but did reveal a tendency for the chemiluminescence of blood monocytes to decrease (p less than 0.10) and a significant decrease in the numbers of macrophage precursors (p less than 0.05) in the aged (over 70 year old), in comparison with controls (under 40 years old). On the basis of these findings, functional alterations of monocyte-macrophages seem to participate in the increased susceptibility to infection in the aged.

Adult↗

Nicotinamide prevents lymphocytic infiltration in submandibular glands but not the appearance of anti-salivary duct antibodies in non-obese diabetic (NOD) mice.

Previously we have shown that nicotinamide prevents spontaneously occurring diabetes associated with insulitis in non-obese diabetic (NOD) mice. In this study we injected nicotinamide (0.5 mg/g) or saline (0.01 ml/g) into female NOD mice daily during a period between 4 and 16 weeks of age. At the end of the treatment, periductal and perivascular lymphocytic infiltration in submandibular glands was observed in 91% of saline-injected control mice and 36% of nicotinamide-injected mice (P less than 0.01). No significant difference was observed in the prevalence of anti-salivary duct antibodies or antinuclear antibodies between the nicotinamide group and the saline group. Nicotinamide may alter cell-mediated, but not humoral, immunity to salivary gland cells, resulting in the prevention of submandibulitis.

Animals↗