bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of medium‐ and long‐chain triglyceride infusion on lipoprotein and hepatic lipase in healthy subjects
Authors: NORDENSTRÖM J. , NEESER G. , OLIVECRONA T. , WAHREN J. 
Published: March 2008

Abstract. Plasma lipolytic activity and hydrolysis of intravenous fat were studied in six healthy subjects during infusion of a long‐chain triglyceride (LCT) fat emulsion (Intralipid 20%) or of a medium‐chain triglyceride (MCT)/LCT emulsion (Lipofundin MCT 20%).The fat emulsions were infused continuously at a rate of 0·17 g triglyceride kg‐1 body weight (BW) h‐1 for 6 h in random order at 7‐day intervals. A continuous infusion of glucose (0·18 g kg‐1 BW h‐1) was administered for a period of 7h and was started 1h before the lipid infusion.Infusions of both types of fat increased plasma triglyceride (TG), free fatty acid (FFA) and lipoprotein lipase (LPL) levels and steady‐state values were present during the 3rd to 5th h of infusion. MCT/LCT infusion resulted in higher plasma levels at steady‐state of TG (3·63±0·45 [SEM] vs 2·73±0·45 mmol l‐1; P < 0·05), FFA (1·05±0·08 vs 0·54±0·04 mmol l‐1; P < 0·01) and LPL (4·6±0·6 vs 2·6±0·5 mU m l‐1; P < 0·05) in comparison with LCT administration. There was a positive correlation between plasma LPL activity and TG concentration (r=0·77; P< 0·001) when data for the two infusions were combined.Although the same amount of fat was infused on a weight basis, the molar infusion rate was 40% higher with MCT/LCT than with LCT infusion, due to differences in molecular weights (634 vs 885 Da). The increments in molar TG levels of both groups were comparable with differences in molar infusion rates, indicating that MCT/LCT and LCT fat were cleared at similar rates.After 5h of lipid infusion 50 IU of heparin kg‐1 BW was injected as a bolus dose to release endothelial lipases into the circulating blood. LPL activity increased approximately 90 times and reached 343·38 mU ml‐1 during MCT/LCT and 226·22 mU ml‐1 during LCT infusion (P < 0·01).It is concluded that the interaction between plasma TG and LPL activity is reciprocal. LPL activity is an important factor for regulating TG turnover and plasma TG affects LPL activity. On a molar basis, the two types (LCT and LCT/MCT) of fat emulsion were cleared at comparable rates.
Lipoproteins of human peripheral lymph. Apolipoprotein AI‐containing lipoprotein with alpha‐2 electrophoretic mobility
Authors: REICHL D. , HATHAWAY C. B. , STERCHI J. M. , MILLER N. E. 
Published: March 2008

Abstract. Evidence from diverse sources has implicated a central role of apolipoprotein AI (apo AI), the most abundant protein of plasma high‐density lipoproteins, in the transport of cholesterol from peripheral tissues to the liver (reverse cholesterol transport). Particles containing only apo AI appear to be more effective as cholesterol acceptors in tissue culture than do particles which also contain apo AII The apo AI‐containing lipoproteins of plasma have been extensively studied, but there is less information on those in tissue fluids, to which most peripheral cells are exposed. In the present study the heterogeneity of apo AI‐containing particles in human peripheral lymph, collected from the dorsum of the foot, has been examined by starch block electrophoresis, exclusion chromatography and immunoelectrophoresis.The apo AI‐containing particles of lymph were found to be more variable in both electrophoretic mobility and size than those of plasma from the same subjects. Of particular interest was a subpopulation which migrated on electrophoresis with the same mobility as alpha‐2‐macroglobulin. This fraction accounted for approximately 7% (range: 4–12%; n= 5) of lymph apo AI, contained no immunodetectable apo AII, and by exclusion chromatography was composed of particles the size of, or smaller than, albumin. Such physicochemical properties suggest that these alpha‐2 migrating particles may function as the principal primary acceptors of cell cholesterol in the extracellular matrix of human peripheral tissues. By isoelectric focusing, lymph apo AI was found to contain a higher proportion of more negatively charged isoforms than the apo AI of plasma.
Decreased insulin secretory capacity and normal pancreatic B‐cell glucose sensitivity in non‐obese patients with NIDDM
Authors: HAEFTEN T. W. VAN , MAARSCHALKERWEERD W. W. A. VAN , GERICH J. E. , VEEN E. A. VAN DER 
Published: March 2008

Abstract. We investigated the dose‐response characteristics of glucose‐induced insulin release and the influence of hyperglycaemia on arginine‐induced insulin secretion in eight non‐obese subjects with NIDDM and in eight non‐diabetic volunteers. Plasma C‐peptide levels, achieved during 60 min hyperglycaemic clamps with and without the infusion of a primed continuous infusion of arginine (infusion rate 15 mg kg‐1 min‐1) during the last 30 min, were analysed with a modified Michaelis‐Menten equation. The insulin secretory capacity (Vmax) for glucose‐stimulated insulin release snowed a trend towards a negative correlation with the fasting blood glucose in the NIDDM subjects (r=0.68, P=0.6); it was lower than the Vmax of non‐diabetic controls (2.2±0.2 vs 4.2±0.4 nmol 1‐1 respectively; P<0.001). The ED50 (half maximal stimulating blood glucose concentration) of the second‐phase glucose‐stimulated insulin release (determined from the plasma C‐peptide levels at 60 min) was not significantly different from the ED50 of the controls (11.9±0.8 vs 13.3±1.9 mmol 1‐1 respectively; P>0.2).Combined glucose‐arginine stimulation significantly increased insulin release. The Vmax for both phases were significantly lower in NIDDM patients than in controls (2.3±0.2 vs 5.0±0.9 and 3.8±0.5 vs 8.5±0.9 nmol 1‐1 respectively; P<0.01). In both NIDDM patients and controls, the ED50 of the influence of glucose on first‐phase arginine‐induced insulin release was significantly lower than the ED50 for the second phase (8.2±0.8 vs 10.5±1.1 mmol 1‐1 (NIDDM) and 9.4±1.4 vs 11.6±0.9 mmol 1‐1 (non‐diabetic subjects) respectively; P<0.02). No differences in ED50 were seen between the two groups.In NIDDM patients, the fasting blood glucose level was negatively correlated with the Vmax of the second phase of glucose‐arginine‐induced insulin release (r=‐0.70, P=0.05).We conclude that (1) insulin secretory capacity is reduced in NIDDM both for stimulation with glucose and with arginine; (2) the B‐cell glucose sensitivity is normal in patients with NIDDM.
Increased removal of remnants of triglyceride‐rich lipoproteins on a diet rich in polyunsaturated fatty acids
Authors: DEMACKER P. N. M. , REIJNEN I. G. M. , KATAN M. B. , STUYT P. M. J. , STALENHOEF A. F. H. 
Published: March 2008

Abstract. We studied the effect of two diets, one rich in polyunsaturated and the other in saturated fatty acids, on the postprandial processing of exogenous and endogenous triglyceride‐rich lipoproteins (chylomicrons, very‐low‐density lipoproteins, and their remnants).For this purpose, 12 normolipidaemic young volunteers were fed, in a cross‐over design of 9 days on each diet, either a diet rich in saturated fat (21% of their daily energy intake from saturated fat, 12% from monounsaturated fat, and 3% from polyunsaturated fat) or a diet rich in polyunsaturated fat (10% saturated fat, 9% monounsaturated fat, and 18% polyunsaturated fat) (P/S ratios 0.14 and 1.8, respectively). On the last day of each dietary period blood samples were drawn six times over a 24‐h period for determination, by densitometric scanning of SDS gels, of the diurnal pattern of apoprotein B‐48 and B‐100 in the d<1.019 g ml‐1fractions, as estimates for the processing of chylomicrons and very‐low‐density lipoproteins.In addition to the usual decrease in the fasting and diurnal concentrations of total serum cholesterol and of cholesterol in the low‐density lipoprotein fractions (between 15 and 21%), the diet rich in polyunsaturated fat resulted in 43% lower daily concentrations of chylomicrons and their remnants. This was due to differences in the clearance rate of chylomicrons and their remnants, rather than to differences in the absorption rate of exogenous fat. In addition, the concentrations of very low density lipoproteins and their remnants during the day were 20% lower on the diet rich in polyunsaturated fat.As remnants, especially those from intestinal origin, are considered to be atherogenic, our observations provide an additional explanation why atherosclerosis is reduced on diets with a relatively high ratio of polyunsaturated to saturated fat.
Late‐onset congenital adrenal hyperplasia in women with hirsutism
Authors: ARNAOUT M. A. 
Published: March 2008

Abstract. Hirsutism in women is a clinical manifestation of excessive production of androgens. The source of the excess androgen may be either the ovaries or the adrenal glands, or increased peripheral conversion of weak androgenic hormones to more potent androgens. Late‐onset (non‐classic) congenital adrenal hyperplasia is a cause of hirsutism in adult women, but its frequency and the patterns of abnormalities in adrenal hormone secretion are not well understood. The frequency of non‐classical adrenal hyperplasia due to deficiencies of 3β‐hydroxy‐Δ5‐steroid dehydrogenase, 21‐hydroxylase, and 11β‐hydroxylase among 65 women with hirsutism were determined. All enzyme defects were identified by comparing the patients' hormonal responses to 0.25 mg intravenous bolus of α1–24‐ACTH with those of age‐matched normal women. The hormones measured in plasma during the ACTH stimulation tests were progesterone, 17‐hydroxypregnenolone, 17‐hydroxyprogesterone, DHEA‐sulfate, androstenedione, testosterone, 11‐deoxycortisol, and cortisol. Similarly these hormones were measured after overnight 1 mg oral dexamethasone.Twelve women (18.5%) had 3β‐hydroxy‐Δ5‐steroid dehydrogenase deficiency, 24 (37%) 21‐hydroxylase deficiency, and 14 (21.5%) 1 lβ‐hydroxylase deficiency. Women with 21‐hydroxylase deficiency also had evidence of a partial deficiency in 11β‐hydroxylase activity (12 of the 24 patients). Similarly, most (11 of the 14) of the women with 11β‐hydroxylase deficiency also had evidence of a deficiency in 3β‐hydroxy‐δ5‐steroid dehydrogenase activity. Among the 15 patients with no adrenal biosynthetic defect, eight had high plasma androgen concentrations, and seven had normal concentrations. Elevated basal levels of hormones were not predictive of the individual response to ACTH. Polycystic ovary syndrome was present in all four groups, with an incidence of 35% in the adrenal biosynthetic defect groups. Paternal consanguinity, whether first degree or second degree, was present in 50% of patients with adrenal biosynthetic defect groups as compared to 20% in patients with no adrenal biosynthetic defects (P < 0.02).In conclusion, a substantial proportion (77%) of women with hirsutism had defects in adrenal steroidogenesis, revealed by ACTH stimulation test, that are indicative of non‐classical congenital adrenal hyperplasia. Measurements of basal steroid levels are not helpful in differentiating among the causes of increased androgen production in women with hirsutism. Secondary adrenal biosynthetic defects were frequent in these women and were probably caused by intraadrenal androgen excess rather than by dual inherited enzymatic deficiencies.
In vitro immune modulation of polymorphonuclear leukocyte adhesiveness by sodium fluoride
Authors: GÓMEZ‐UBRIC J. L. , LIÉBANA J. , GUTIÉRREZ J. , CASTILLO A. 
Published: March 2008

Abstract. We investigated the influence of sodium fluoride on polymorphonuclear leukocyte (PMN) adhesiveness in a healthy subject with low serum levels of fluoride. The PMN were separated from venous blood, and the percentages of adhered and unadhered cells were determined in vitro in plastic culture plates. The cells were cultured with five different fluoride concentrations ranging from 6.25 10‐2μM to 4.0 μM in the presence and absence of autologous serum.PMN adhesiveness in both the presence and in the absence of autologous serum was 98.5%; the addition of fluoride had no effect on the results in the absence of serum. However, in the presence of autologous serum, PMN adhesiveness decreased significantly with the addition of fluoride (P < 0.05) from 0.5 μM. The decrease was smaller (1.1%) at a concentration of 0.125 μM, and larger at 12 times this concentration of fluoride (52.7%). We conclude that sodium fluoride reduces PMN adhesiveness in a dose‐dependent manner. The effect is not direct, but should be modulated by a seric factor.
Can urinary pyridinium crosslinks and urinary oestrogens predict bone mass and rate of bone loss after the menopause?
Authors: MOLE P. A. , WALKINSHAW M. H. , ROBINS S. P. , PATERSON C. R. 
Published: March 2008

Abstract. We measured urinary pyridinoline and deoxy‐pyridinoline by high performance liquid chromatography, and urinary oestrogens by radio‐immunoassay, in 68 healthy postmenopausal women to evaluate these assays for the prediction soon after the menopause of the risk of developing osteoporotic fractures in later life. Change in forearm bone mineral content was assessed by single photon absorptiometry over 4 years.Although there was no significant correlation between the pyridinium crosslinks and urinary oestrogens, we found that up to 58% of the variation in the rate of loss of bone mineral content in women soon after the menopause could be explained by pyridinoline and oestradiol glucuronide assays together with body mass index. Measurement of the urinary pyridinium crosslinks and oestradiol glucuronide may make a significant contribution to a biochemical screening procedure for future osteoporotic fracture.
Postprandial control of gallbladder contraction and exocrine pancreatic secretion in man
Authors: BEGLINGER C. , HILDEBRAND P. , ADLER G. , WERTH B. , LUO H. , DELCO F. , GYR K. 
Published: March 2008

Abstract. To explore the interactions between chole‐cystokinin (CCK) and the cholinergic system, we compared the effect of cholinergic or peptidergic CCK blockade on gallbladder contraction and pancreatic enzyme secretion using atropine and loxiglumide (a specific CCK antagonist) as pharmacological tools. Gallbladder contraction was measured by sonography and pancreatic secretion by a marker perfusion and aspiration technique. Graded doses of exogenous CCK8 induced dose‐dependent contractions of the gallbladder and increasing enzyme outputs. Loxiglumide (10 mg kg‐1 h‐1) abolished the gallbladder response and prevented an increase in pancreatic enzyme secretion to CCK8. Atropine (5 μg kg‐1 h‐1), however, only reduced gallbladder contraction and enzyme output to CCK8.Gallbladder volumes decreased maximally to 12±4% after oral food, whereas enzyme output and plasma CCK levels increased 6‐ to 8‐fold. Loxiglumide completely abolished gallbladder contraction and inhibited enzyme secretion by 30%. Atropine caused a small reduction in gallbladder volumes, but essentially blocked postprandial enzyme secretion.The results indicate that CCK is the major regulator of gallbladder contraction with the cholinergic system modulating the response, while the exocrine pancreas is crucially dependent on a cholinergic background with CCK modulating the secretory response.
The human renal 25‐hydroxyvitamin D3‐1α‐hydroxylase: properties studied by isotope‐dilution mass spectrometry
Authors: HAGENFELDT Y. , BERLIN T. 
Published: March 2008

Abstract. The renal 25‐hydroxyvitamin D3‐α‐hy‐droxylase activity has been measured in normal human kidney cortex, using a highly specific assay based on isotope‐dilution mass spectrometry. The cortex was obtained from kidneys removed due to renal tumours.The subcellular distribution of 25‐hydroxyvitamin D3‐1α‐hydroxylase activity was studied. Enzyme activity was only observed in the mitochondrial fraction. Mitochondria from non‐tumourous kidney cortex had a Vmaxof 0.17 ±0.02 pmol min‐1 mg‐1 protein and the apparent Km was in the range 14 μmol l‐1.There was a tendency to a higher 25‐hydroxyvitamin D3‐1α‐hydroxylase activity in preparations from male kidney (0.21±0.03 pmol min‐1 mg‐1 protein) than female (0.12±0.02, P<0.05).A significant inverse correlation between serum phosphate and 25‐hydroxyvitamin D3‐1α‐hydroxylase activity was found. No correlation was observed between enzyme activity and serum levels of 1,25‐dihydroxyvitamin D (total and free index), PTH, total calcium or ionized calcium.The results indicate that there is a sex difference in human 25‐hydroxyvitamin D3‐1α‐hydroxylase activity similar to the one observed in laboratory animals. Furthermore, the data support the hypothesis that serum phosphate is a major regulator of 1,25‐dihy‐droxyvitamin D3 production in man.
Bone mass of spine and forearm in osteoporosis and in German normals: influences of sex, age and anthropometric parameters
Authors: WÜSTER C. , DUCKECK G. , UGUREL A. , LOJEN M. , MINNE H. W. , ZIEGLER R. 
Published: March 2008

Abstract. We measured forearm bone mineral density (BMD) using single photon absorptiometry (SPA) and bone mineral content (BMC) and BMD of lumbar spine by dual photon absorptiometry (DPA). The population consisted of 463 bone healthy subjects, 346 females and 117 males aged 20–85 years. Any underlying bone disease or other diseases known to affect bone mass were excluded by physical examination, thoracic and lumbar radiographs and laboratory screening. Patients with osteoarthritis of lumbar spine were excluded as well as patients taking drugs known to affect bone mass. All bone mass values declined with age. Body height also declined with age by 1.2 cm and 1.8 cm per 10 years (— 0.7% and — 1 %) in females and males respectively. Main effects of age, body height, ‐surface, ‐weight and ‐mass index on bone mass were calculated using multiple regression models. In males and females lumbar BMC measured in gHA depended primarily on body height and secondarily on age. Spinal BMD as measured in g cm‐2 was primarily dependent on age and then on height. In females forearm BMD depended primarily on age and then on body surface, in males on body surface only.Using receiver operating characteristic (ROC) analysis the ROC area increased from 0.81–0.85 (n.s.) including body height into spinal BMD values leading to a higher sensitivity of measurements of spinal bone mass in recognizing 58 patients with spinal postmeno‐pausal osteoporosis. Including body surface into forearm BMD measurements ROC area increased from 0.66–0.69 (P=0.055).We conclude from these data that measurements of bone mass not only depend on age and sex, but on body height and surface. These anthropometric parameters and their changes over decades have to be taken into account when examining any effects on bone mass in cross‐sectional studies. Including these parameters into bone mass values may lead to higher sensitivity of the method.
Renal reserve filtration capacity in growth hormone deficient subjects
Authors: DULLAART R. P. F. , MEIJER S. , MARBACH P. , SLUITER W. J. 
Published: March 2008

Abstract. In normal subjects, the glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) acutely increase in response to infusion of amino acids and to low doses of dopamine. It is uncertain whether circulatory growth hormone (GH) is a permissive factor for these stimulatory effects. GFR and ERPF (constant infusion technique using 125I‐iothalamate and 131I‐hippuran, respectively) were measured before and during the infusion of dopamine and amino acids in 8 GH deficient subjects. The clearance study was repeated during concomitant administration of octreotide to investigate whether this somatostatin analogue would modify the amino acid and dopamine‐induced renal haemodynamic changes. Dopamine increased baseline GFR from 89± 3 (mean±SEM, n= 8) to 102 ± 4 ml min‐1 1.73 m‐2 and ERPF from 352± 19 to 476± 26 ml min‐1 1.73 m‐2, P<0.001 for both. During amino acid infusion GFR and ERPF increased to 108±3 and 415±23 ml min‐1 1.73 m‐2, respectively, P< 0.001 for both. Octreotide did not significantly decrease baseline and dopamine‐stimu‐lated renal haemodynamics but lowered the amino acid‐stimulated GFR (98±4 ml min‐1 1.73 m‐2, P<0.05) and ERPF (381± 18 ml min‐1 1.73 m‐2, P<0.05). Basal plasma glucagon concentrations were not suppressed by octreotide, whereas the amino acid‐induced increments in plasma glucagon were partially inhibited.It is concluded that GH is not a necessary factor for the stimulatory effects of amino acids and dopamine on renal haemodynamics. The renal reserve filtration capacity in GH deficiency was at least as large as previously documented in normal subjects. It is likely that there is a functional antagonism between the effects of amino acids and octreotide on renal haemodynamics in GH deficiency.
Colchicine analogues: Effect on amyloidogenesis in a murine model and, in vitro, on polymorphonuclear leukocytes
Authors: WOLACH B. , GOTFRIED M. , JEDEIKIN A. , LISHNER M. , BROSSI A. , RAVID M. 
Published: March 2008

Abstract. Colchicine has been used in diverse clinical settings such as gout, familial Mediterranean fever, liver cirrhosis, Behcet's disease and pericarditis. It also has an antimitotic potential hitherto unexplored due to its narrow therapeutic toxic ratio.The aim of the present study was to compare the effectiveness and the toxicity of colchicine and three analogues: thiocolchicine, 2,3 dimethyl‐colchicine and 3‐dimethylthiocolchicine in the blockage of amyloid synthesis in a murine model.3‐demethylthiocolchicine was equipotent to colchicine in the blockage of casein induced amyloidogenesis. However, it was markedly less toxic (LD50 11.3 mg kg‐1 vs. 1.6 mg kg‐1). Thiocolchicine was toxic (LD50 1.0 mg kg‐1) and 2,3 didemethyl‐colchicine was far less effective.The effect of 3‐dimethylthiocolchicine on polymorphonuclear leukocytes was then compared to colchicine. The effect of this analogue on inhibition of chemotaxis was equivalent to that of colchicine whereas the latter was superior to the analogue in the suppression of phagocytosis (by a ratio of 2:1) and in the inhibition of bactericidal activity (by a ratio of 10:1).Since in therapeutic concentrations the only detectable effect of colchicine on PMNs is inhibition of chemotaxis, our data may point to 3‐demethylthiocolchicine as an optional, perhaps superior alternative to colchicine for some of its therapeutic indications.