Microcomputer-aided insulin dose determination in intensified conventional insulin therapy.
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Biomedical subjects
Publications and source records attributed to N Kugai.
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Extract of exocrine pancreatic cancer associated with humoral hypercalcemia of malignancy was examined for biological activities of PTH-like factor and transforming growth factor (TGFA and TGFB), both of which are possible causes of hypercalcemia. The crude extract had both PTH-like and TGF activities. On Bio Gel P-60 column chromatography, PTH-like and TGFA activities were eluted at around 10 kD, whereas TGFB activity was eluted at around void fractions, 10 kD and 6 kD. Liver extract, used as a control material, exhibited only TGFB activity at around 6 kD. CM-cellulose column chromatography of 10 kD fractions resulted in a subtle distinction between PTH-like activity and TGF activities. Further fractionation of the peak with PTH-like activity on reverse-phase high performance liquid chromatography separated PTH-like activity distinctly from TGFB activity. TGFA activity was lost through the procedure. It was concluded that the exocrine pancreatic cancer associated with hypercalcemia produced not only PTH-like activity but also TGFA and TGFB activities. Several chromatographic analyses suggested that PTH-like activity and at least TGFB activity stem from distinct molecules and that the PTH-like factor has no significant TGFB activity intrinsically.
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A woman with exocrine pancreatic cancer presented a syndrome of humoral hypercalcemia of malignancy (HHM). Either urea extract or acid/ethanol extract of the tumor showed a dose-dependent activity to elevate cyclic adenosine monophosphate (AMP) level in rat bone cells in primary culture. When each population obtained by the sequential digestion of rat fetal calvaria was cultured individually and cyclic AMP responses to parathyroid hormone (PTH), calcitonin, and tumor extract were examined, tumor extract-sensitive cells showed a similar distribution to PTH-sensitive cells. Tumor extract and PTH, but not calcitonin, increased cyclic AMP in osteogenic cell line MC 3T3-E1. PTH receptor-mediated increase of cyclic AMP was indicated by an antagonistic action of PTH analogue, (3-34) hPTH, on increase of cyclic AMP in MC 3T3-E1 elicited by tumor extract. Human breast cancer derived cell line MCF-7 had calcitonin-sensitive adenylate cyclase, but neither PTH nor tumor extract increased cyclic AMP in the cells. On Bio-Gel P-60 column, the activity to stimulate bone cell cyclic AMP was eluted as a single peak at the molecular size between 6.5 K and 12.4 K. It was concluded that pancreatic cancer, although rather exceptional as a cause of HHM, produced a factor very similar to that reported in representative HHM tumors of human and animal models.
To clarify the mechanism for the impaired mineral metabolism in Cushing's syndrome, the clinical features, biochemical parameters before and after oral calcium load, and vitamin D metabolism were compared between two groups of patients of endogenous Cushing's syndrome (17 cases) with and without osteopenia. The patients with osteopenia [OP (+): 7 cases, all female] were older (42.7 +/- 8.3 y. o.) and had a longer duration (117 +/- 75 M) of the syndrome than those without osteopenia [OP (-): 33.8 +/- 8.9 y. o., 36 +/- 25 M]. OP (-) showed a blunted hypercalciuria after oral calcium load (63.7 +/- 20.4 to 90.9 +/- 36.1 mg/g X Cr), while OP (+) had higher levels of urinary excretion of calcium (fasting: 120.4 +/- 37.5, and after oral calcium load: 235.6 +/- 72.6 mg/g X Cr), of cyclic AMP (7.6 +/- 1.1 nmol/dl X GF), and of plasma 1.25(OH)2D (76.6 +/- 34.0 pg/ml) than OP (-) (u-cAMP: 3.2 +/- 2.0 nmol/dl X GF, 1,25(OH)2D: 27.9 +/- 16.3 pg/ml). These results indicate that 1) elderly female patients with Cushing's syndrome of long duration are susceptible to OP, 2) during the early phases of the syndrome, reduced intestinal calcium absorption with sustained calciuria (probably through the inhibition of calcium reabsorptive effect of PTH by glucocorticoid) induces negative calcium balance, leading to 3) a development of secondary hyperparathyroidism which stimulates 1,25(OH)2D synthesis. Thus, the mechanism involving bone resorption stimulated by excess PTH along with the direct inhibition of bone formation by glucocorticoid seems to play an important role in a progressive development of OP in Cushing's syndrome.
Statistical analysis of relationship between free thyroxine (FT4) and thyroxine (T4) in patients with Graves' disease has revealed that serum FT4 values correlated well with serum T4 values at variable thyroid states before and during treatment with anti-thyroid drugs. However, the ratio of FT4 concentration to T4 concentration at hyperthyroid state was more than twice as large as the ratio at euthyroid and hypothyroid states. These findings are considered to denote the elevation of per cent of FT4 to T4 (% FT4) in thyrotoxicosis. Nevertheless, thyroxine-binding globulin (TBG) concentrations in hyperthyroid patients were slightly, but significantly lower by 7.3% than those in normal euthyroid volunteers. These results indicate the minimal contribution of the slight decrease in TBG concentrations to the marked elevation of %FT4 in patients with thyrotoxicosis.
The role of extracellular calcium in hormone-induced glycogenolysis was examined in a rat liver perfusion system by manipulating the perfusate calcium concentration and by using calcium antagonistic drugs. When the perfusate contained 1 mM CaCl2, 5 microM phenylephrine, 20 nM vasopressin, and 10 nM angiotensin II caused a persistent increase in glucose output and phosphorylase activity as well as a transient increase in 45Ca efflux from 45Ca preloaded liver. Verapamil hydrochloride (20-100 microM) inhibited the activation of glucose output by these hormones in a dose-dependent manner. This inhibitory effect was also associated with the inhibition of hormone-induced activation of phosphorylase and 45Ca efflux. In the absence of CaCl2 in the perfusate, the glycogenolytic effect of phenylephrine and its inhibition by verapamil were obtained equally as in the presence of CaCl2. However, the effects of vasopressin and angiotensin II were markedly attenuated and were not inhibited any further by verapamil. The substitution of diltiazem hydrochloride for verapamil produced essentially identical results. Cyclic AMP concentrations in the tissue did not change under any of these test conditions. The results indicate that the glycogenolytic effect of alpha-adrenergic agonists depends on intracellular calcium but those of vasopressin and angiotensin II on extracellular calcium, and support the concept that calcium antagonistic drugs inhibit the glycogenolytic effects of calcium-dependent hormones at least by inhibiting the mobilization of calcium ion from cellular pools.
The role of extracellular calcium in the glycogenolytic effects of calcium-dependent hormones was examined in a rat liver perfusion system. Decreasing the perfusate CaCl2 concentration resulted in a concentration-dependent inhibition of glucose output by maximal concentrations of vasopressin (20 nM) and angiotensin II (10 nM), but not of glucagon (1.4 nM), cyclic AMP (100 microM), dibutyryl cyclic AMP (10 microM) or phenylephrine (5 microM). However, the effect of phenylephrine was inhibited when livers were perfused with CaCl2-free perfusate containing 0.5 mM EGTA in a duration-dependent manner. These effects were exerted through the inhibition of the maximal response of each hormone, and were associated with a parallel decrease in phosphorylase activation but not with changes in tissue cyclic AMP concentrations. When livers were preloaded with 45Ca for 45 min and then washed for either 15 min or 45 min, these hormones elicited a rapid and transient 45Ca efflux regardless of the perfusate calcium concentration. The sequential perfusion of two hormones resulted in the loss of 45Ca efflux by the second hormone. These results suggest that the glycogenolytic effects of vasopressin and angiotensin II depend on the extracellular calcium and that of phenylephrine primarily on the cellular calcium. It was also demonstrated that these calcium-dependent hormones mobilize calcium from the same pools. However, the mobilization of cellular calcium does not necessarily correlate directly with the glycogenolytic actions of vasopressin and angiotensin II.
A 59-year-old Japanese farmer with asymptomatic fasting hypoglycemia and with exaggerated hypoglycemic episodes induced by insulin and oral hypoglycemic agent administered for his postprandial hyperglycemia was diagnosed as glycogen storage disease type I. This diagnosis was suggested by unresponsiveness of blood glucose level to glucagon and confirmed by 13% normal level of glucose 6-phosphatase activity in liver biopsy specimen and by the presence of PAS positive amylase digestable glycogen in liver specimen. This case was associated with an incomplete type of Fanconi syndrome characterized by hyperphosphaturic hypophosphatemia, partial aminoaciduria, mild proteinuria and hyperuricosuric normouricemia in spite of the lactic acidemia due to glycogen storage disease type I. The etiology for the absence of hypoglycemia and other typical manifestations of glycogen storage disease type I was studied. The glucose production from glycogen by lysosomal alpha 1,4-glucosidase especially at prolonged fasting and the presence of postprandial hyperglycemia by insulin deficiency are regarded as responsible for keeping this patient free from typical manifestations of glycogen storage disease type I.
To study the effects of various vitamin D preparations on PTH secretion, serum calcium and urinary excretion of cAMP were monitored in conscious perfused rats, and the influences of a bolus iv injection of the preparations on these parameters were examined. Three hours after the administration of 0.25 microgram/kg (0.6 nmol/kg) of 1 alpha, 24(R)-dihydroxycholecalciferol [1 alpha, 24(OH)2D3], the urinary excretion of cAMP decreased to a level compatible with that of parathyroidectomized (PTX) rats (50% of initial value; p less than 0.05) with no change in the concentration of serum calcium (total and ionized). In PTX rats supplemented with bovine PTH (1 U/h), the vitamin D preparation showed no significant effects either on the urinary excretion of cAMP or on serum calcium. These effects were rather specific for active vitamin D preparations, i.e. 1 alpha, 25(OH)2D3 (0.25 micrograms/kg) and 1 alpha OHD3 (1.25-6.25 micrograms/kg). However, 24,25(OH)2D3 (up to 25 micrograms/kg) had no significant effect on these parameters. These results suggest that, in rats, active vitamin D preparations specifically inhibit PTH secretion without causing a significant increase in the serum calcium concentration, reflecting a direct feedback mechanism between active vitamin D metabolite and the parathyroid glands.
In an attempt to elucidate the role of Ca2+ flux in the initial events of hepatic glycogenolysis, extracellular Ca2+ concentration was manipulated in rat liver perfused with Ca2+ antagonistic drugs. After the liver had been perfused with a buffer containing verapamil and 1 mM CaCl2, either the addition of ethyleneglycol-bis-(beta-aminoethyl ether)-N,N'-tetraacetic acid to the perfusate or the replacement of the perfusate with Ca2+-free buffer caused a rapid increase in glucose output as well as 45Ca2+ efflux. Substitution of diltiazem, but not 5-20 mM LaCl2, for verapamil also stimulated glucose output and 45Ca2+ efflux. However, when Ca+-free buffer was used throughout the experiment, any modes of verapamil or diltiazem perfusion were without significant effects on glucose output or Ca2+ efflux. The increases in glucose output and 45Ca2+ efflux were not affected by either 20 microM phentolamine or 300 microM ouabain, but they were inhibited significantly by 10-100 microM trifluoperazine. These results indicate that rapid decline in the extracellular Ca2+ concentration in verapamil- or diltiazem-perfused liver initiates the change in Ca2+ equilibrium on or across plasma membrane and activates glycogenolysis through a Ca2+-dependent mechanism.
A male patient with recurring episodes of hypoglycemic attacks was diagnosed as having isolated ACTH deficiency as well as renal glycosuria and ichthyosis vulgaris. In addition, he had facial diplegia and abducens palsy consistent with Moebius syndrome, muscle atrophy with proximal dominancy, high arched palate, hammer toes, and mental retardation. There was electrophysiological evidence of peripheral neuropathy. Muscle biopsy of the deltoid showed mild myofiber atrophy with occasional cylindrical laminated bodies. The association of these disorders has never been reported and it could be coincidental. However, considering the high rate of association of isolated hypogonadotropic hypogonadism and Moebius syndrome with peripheral neuropathy, the present case may indicate a causal relationship between isolated ACTH deficiency and Moebius syndrome, reflecting the disorders in the organ systems derived from a common ectoderm.
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The glycogenolytic effect of catecholamine has been proposed to be mediated by calcium ions mobilized mainly from mitochondria. In this study, the contribution of mitochondria as a source of the mobilized calcium was evaluated by use of perfused rat livers. Phenylephrine-induced efflux of 45Ca from 45Ca preloaded liver was abrupt and transient, and almost ceased within 5 min. The perfusion with 5 microM phenylephrine for 5 min caused a significant decline in the content of 45Ca retained in the liver homogenate; control, 0.97 +/- 0.11 nmol of 45Ca/mg protein (mean +/- SEM) and phenylephrine, 0.41 +/- 0.08 nmol of 45Ca/mg protein (P less than 0.01), when calculated from the specific radioactivity of calcium in the perfusate used for loading perfusion. The contents of 45Ca in mitochondria isolated subsequently from the homogenate were 0.43 +/- 0.07 nmol/mg protein in controls and 0.22 +/- 0.03 nmol/mg protein (p less than 0.05) when phenylephrine was administered. Taking into consideration that mitochondrial protein is a fraction of homogenate protein, it is obvious that the decline in mitochondrial 45Ca represents only a small portion of the total reduction of radioactivity in the homogenate. In a series of experiments in which various perfusion periods were employed for 45Ca loading and for washing-out, it was found that phenylephrine induced 45Ca efflux also from a pool with a calcium turnover rate slower than that if mitochondria. These results suggest that alpha-adrenergic stimulation enhances release of calcium not only from mitochondria but also from other compartments with a slower turnover rate. The probability of plasma membrane is proposed as the other source of calcium released in response to alpha-adrenergic stimulation.
The effect of PTH given as a bolus on renal handling of phosphate in rats was studied by a perfusion balance study method. In vitamin D-fed rats, iv PTH as a bolus (10 USP units) elicited a phosphaturic response and an increase in urinary cAMP, whether or not the rats were thyroparathyroidectomized. When given to thyroparathyroidectomized rats receiving continuous infusion of PTH (2.5 USP units/h) for 16 h, PTH led to a paradoxical decline of phosphate clearance in spite of an increase in urinary cAMP. Vitamin D-deficient intact rats also showed this paradoxical response. Vitamin D-deficient thyroparathyroidectomized rats showed an ordinary phosphaturic response. When PTH had been supplied continuously (2.5 USP units/h) to these rats, the PTH bolus again produced the paradoxical response. Phosphate supplementation did not restore the phosphaturic response. (Bu)2cAMP infusion reproduced the paradoxical effect in vitamin D-fed, thyroparathyroidectomized rats receiving continuous infusion of PTH. These data indicate that a long-lasting excess of circulating PTH alters the nature of the response of the kidney to an iv bolus of PTH, so that PTH leads to a paradoxical decline of phosphate clearance, and that the mechanism responsible for the paradox may lie in a step (or steps) subsequent to cAMP production.
A TSH- and FSH-screening pituitary adenoma was demonstrated in a 23-yr-old man who presented with bitemporal hemianopsia, but without clinical or laboratory evidences of hyper- or hypothyroidism or hypogonadism. Basal TSH (29-45 microunits/ml) and FSH (44-63 mIU/ml) were moderately elevated. GH and ACTH secretion were impaired, and basal PRL and testosterone were normal. TRH and LRH elicited a significant increase in TSH and FSH, respectively. The plasma glycoprotein alpha-subunit concentration was normal, and its response to simultaneous administration of TRH and LRH was low. Plasma TSH was not suppressed completely by exogenous T3. After operation and radiotherapy, elevated TSH and FSH as well as failure of T3 to suppress TSH were corrected. No significant changes in thyroid hormone concentration in the blood were detected in spite of the reduction of TSH. TSH and FSH concentrations in the tumor extract were lower than those in normal pituitaries. Histologically, the tumor was very vascular and consisted mostly of a single type of cell. The tumor cells were positively stained for FSH beta-subunit by immunohistochemical study, but for none of other pituitary hormones or subunits examined. Electron microscopic examination revealed relatively abundant single type secretory granules of high electron density. It is possible that the tumor simultaneously secreted TSH and FSH, the former possibly being immunologically active, but biologically inactive.
The effects of trifluoperazine on the activation of glycogenolysis by various hormones were studied in perfused rat liver. Trifluoperazine significantly inhibited glycogenolytic effect of phenylephrine and angiotensin II by lowering maximal response, and that of vasopressin by shifting the dose-response curve to the right, while alpha-antagonist phentolamine was inhibitory only to phenylephrine. Phosphorylase activation of phenylephrine was inhibited by trifluoperazine in parallel with glycogenolytic response. The increase in 45Ca2+ efflux induced by phenylephrine, angiotensin II, and vasopressin was also inhibited by the agent. These inhibitory effects of trifluoperazine were not related to the change in tissue cyclic AMP or cyclic GMP levels. On the other hand, neither the glycogenolytic effect of glucagon, cyclic AMP, and N6,O2-dibutyryl cyclic AMP nor phosphorylase activation by glucagon was affected by trifluoperazine. Thus, trifluoperazine specifically inhibits the activation of glycogenolysis by Ca2+-dependent hormones.
Cerebrotendinous xanthomatosis (CTX) is a rare familiar disease characterized by tendon xanthomas, cataracts, cerebellar ataxia, dementia and an elevated serum cholestanol level. In this paper, a 50-year-old man with typical signs and symptoms of CTX is described. Serum cholestanol and chelesterol concentrations were 17.9-28.6 micrograms/ml and 109-153 mg/dl, respectively. The determination of non-sulfated bile acid concentration in the serum assayed by mass fragmentography disclosed an abnormal profile. The concentration of cholic acid (0.30-0.52 microgram/ml) was higher than normal, while those of chenodeoxycholic acid, ursodeoxycholic acid, deoxycholic acid and lithocholic acid were extremely low or undetectable. Administration of ursodeoxycholic acid (300 mg per day, orally) for 2 weeks resulted in a marked reduction of serum cholic acid concentration. However, serum cholestanol levels remained unchanged.