bluuebunny/crossref_metadata_2025 huggingface dataset:
Tumor necrosis factor alpha is associated with disease activity and the degree of anemia in patients with rheumatoid arthritis
Authors: VREUGDENHIL G. , LÖWENBERG B. , EIJK H. G. VAN , SWAAK A. J. G.
Published: March 2008

Abstract. To elucidate the role of tumor necrosis factor alpha (TNF) in determining anemia of chronic disease (ACD) in rheumatoid arthritis (RA), 24 patients were studied for disease parameters, TNF serum levels and bone marrow for erythroid colony growth and compared with six controls. Serum TNFα was highest in ACD and correlated well with RA disease parameters. Both TNF and other RA disease parameters correlated inversely with degree of anemia. BFUe counts were lower in ACD, correlated positively with Hb and negatively with erythrocyte sedimentation rate (ESR). TNF reduced whereas anti‐TNF upregulated in vitro erythroid colony counts. TNF production occurred in similar amounts in bone marrow cultures in the three groups. From these preliminary findings we conclude that ACD in RA correlates with by RA disease activity and that TNF may serve not only as an RA disease marker but also could be one of the factors mediating impaired erythropoiesis in ACD in active RA.
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.
Role of hepatitis C virus infection in German patients with fulminant and subacute hepatic failure
Authors: THEILMANN L. , SOLBACH C. , TOEX U. , MÜLLER H. M. , PFAFF E. , OTTO G. , GOESER T.
Published: March 2008

Abstract. To investigate the possible role of hepatitis C virus (HCV) in fulminant and subacute liver failure, we tested serum and liver of 13 patients undergoing orthotopic liver transplantation for the presence of HCV RNA. HCV RNA was detected in specimens from two out of eight patients negative for all viral markers with suspected hepatitis non‐A, non‐B infection and in one out of four patients with hepatitis B virus infection. Only in this patient replication of HCV could be demonstrated. We conclude, that fulminant and subacute hepatic failure is induced by hepatitis C virus only in few patients with hepatitis non‐A, non‐B.
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.
Thromboxane mediates glomerular haemodynamics in a model of chronic glomerular disease
Authors: THAISS F. , MIHATSCH M. J. , SCHOEPPE W. , STAHL R. A. K.
Published: March 2008

Abstract. In order to evaluate a possible haemodyna‐mic role of cyclooxygenase products in chronic renal disease, a model of chronic glomerular injury was induced in nephritic rats by unilateral nephrectomy and high dietary protein intake. Eight weeks after induction of an in situ immune complex glomerulo‐nephritis (ICGN), rats subjected to high protein (HP) intake (42% protein) and uninephrectomy revealed a significantly lower glomerular filtration rate (GFR; 485±53 μ1 min‐1 100 g‐1 body weight (BW)) compared with uninephrectomized rats with ICGN which were on low protein (LP) diet (6% protein) (825 ±155 μ1 min‐1 100 g‐1 BW) (P<0.01). The glomerular thromboxane B2 (TxB2) formation in uninephrectomized rats with ICGN on either LP or HP intake was not significantly different (HP: 473 ± 61; LP: 493 ± 63 pg mg‐1 min‐1), but was significantly higher when compared with non‐nephritic controls on either diet. Glomerular prostaglandin E2 (PGE2) production in rats on HP diet was higher compared with rats with LP intake (HP: 617 ± 67; LP: 351±76 pg mg‐1 min‐1) (P<0.01). The thromboxane receptor blocker daltro‐ban significantly elevated suppressed GFR in ICGN rats on HP diet (ICGN + vehicle: 426± 69; ICGN + daltro: 689 + 66 μ1 min‐1 100 g‐1 BW) (P<0.01). Thromboxane receptor blockade had no effect on glomerular haemodynamics in ICGN animals receiving LP diet (ICGN + vehicle: 771 ± 24; ICGN + daltro: 684+85 μ1 min‐1 100 g‐1 BW). The cyclooxygenase inhibitor indomethacin reduced the already compromised GFR in ICGN animals on HP diet (ICGN + vehicle: 533±54; ICGN + indo: 335±43 μl min‐1 100 g‐1BW) (P<0.05), but was without effect on GFR in nephritic rats on LP intake (ICGN + vehicle: 785±102; ICGN + indo: 633 ± 89 μl min‐1 100 g‐1 BW). These data demonstrate that eicosanoids modulate glomerular haemodynamics in a model of chronic glomerular disease induced by immune complex formation, uninephrectomy and HP intake.
Glucagon‐independent renal hyperaemia and hyperfiltration after an oral protein load in Child A liver cirrhosis
Authors: SANTO N. G. DE , ANASTASIO P. , LOGUERCIO C. , BLANCO C. DEL VECCHIO , CAPASSO G. , COPPOLA S. , BELLINI L. , SPAGNUOLO G. , FEDERICO P. , ALFIERI R. , LOMBARDI A. , POLICASTRO M. , PERRELLI A.
Published: March 2008

Abstract. The work was designed to study the effects of a meat meal on glomerular filtration rate (GFR), renal plasma flow (RPF), and plasma concentrations of glucagon, insulin, growth hormone, renin, aldoster‐one, total amino acids, and NH3 in healthy humans (H) as well as in patients with Child A liver cirrhosis (LC). The meat meal produced renal hyperaemia and hyperfiltration without changes in the filtration fraction. Fractional Na excretion in urine increased significantly after the meat meal only in LC. Hyperinsulinae‐mia and hyperglucagonaemia were seen at baseline in LC and were not affected by the meat meal, whereas in H glucagon concentration increased significantly over baseline within 30 min from the meat meal and insulin within 60 min. Growth hormone concentration was normal at baseline in LC and increased significantly 120–180 min after the meal, whereas it was not affected in H. Renin and aldosterone were stable in both H and LC. Plasma amino acid concentration began to increase 60 min after the meat meal, when hyperfiltration was present. The data indicate that in human Child A cirrhosis of the liver the renal haemodynamic response to a meat meal is independent of changes in glucagon.
Effect of endothelin‐1 in man: pretreatment with nifedipine, with indomethacin and with cyclosporine A
Authors: VIERHAPPER H. , WAGNER O. F. , NOWOTNY P. , WALDHÄUSL W.
Published: March 2008

Abstract. The rise in blood pressure following the intravenous administration of endothelin‐1 remained unchanged in healthy male volunteers pretreated with either the calcium‐channel antagonist nifedipine (10 mg orally), the cyclo‐oxygenase inhibitor indomethacin (150 mg day‐1 for three days) or the immunosup‐pressive agent cyclosporine (5 mg kg‐1 body weight for five days). Following administration of nifedipine the rise in plasma concentrations of endothelin‐1 during the infusion of the peptide was markedly higher (P <0.01) than during control experiments without nifedipine. It is concluded that, in healthy men, nifedipine, indomethacin and cyclosporine do not exert a major influence on the pressor action of endothelin‐1. However, nifedipine apparently influences the elimination of endothelin‐1 from the circulation in healthy men.
Somatostatin does not block the effect of vasoactive intestinal peptide on bile secretion in man
Authors: NYBERG B. , ANGELIN B. , EINARSSON K.
Published: March 2008

Abstract. The effects of intravenously administered somatostatin and vasoactive intestinal peptide (VIP) on bile secretion were studied in 10 patients with complete biliary fistulas. The two peptides were administered both separately and simultaneously. During the infusion of vasoactive intestinal peptide, bile secretion increased by 85%, whereas during somatostatin infusion it decreased by 40%. When the peptides were administered together, the VIP‐induced cholere‐tic effect was not reduced by somatostatin. Vasoactive intestinal peptide infusion increased bicarbonate concentration and output, whereas somatostatin had the opposite effect. The output of chloride also increased following vasoactive intestinal peptide infusion but decreased following somatostatin infusion. The concentration of chloride was unaffected by somatostatin whereas it was decreased by vasoactive intestinal peptide. The output of bile acids was unaffected by vasoactive intestinal peptide and decreased by somatostatin infusion, whereas total lipid concentration increased during somatostatin infusion and decreased when vasoactive intestinal peptide was added. It is concluded that, in man, somatostatin acts on the bile acid‐dependent canalicular bile secretion and also, to some extent, on the ductular secretion, whereas vasoactive intestinal peptide acts strictly at the ductular level. The effects of the two peptides on bile secretion are independent of each other.
Apolipoprotein C‐ll deficiency syndrome due to apo C‐IIHamburg: clinical and biochemical features and Hphl restriction enzyme polymorphism
Authors: BEIL F. U. , FOJO S. S. , BREWER H. B. , GRETEN H. , BEISIEGEL U.
Published: March 2008

Abstract. We have characterized the clinical and biochemical features of three siblings of a kindred with severe hypertriglyceridaemia due to apolipoprotein C‐II (apo C‐II) deficiency caused by the mutation described as apo C‐IIHumburg. The clinical syndrome is characterized by recurrent pancreatitis in two of three affected individuals, with discrete hepatosplenomegaly in all three patients and cholelithiasis in one. Eruptive xanthomas and lipemia retinalis were absent.

Plasma lipoproteins were characterized by fasting chylomicronaemia, reduced low density lipoproteins (LDL) and low high density lipoproteins (HDL). The marked hypertriglyceridaemia could be corrected promptly by infusion of normal plasma. Apolipoprotein C‐II (apo C‐II) levels in homozygotes were very low (0.01 mg dl‐1), and mean apo C‐II levels in heterozygotes were lower (2.08 pM 0.11 mg dl‐1) than in normal family members (3.38 pM 0.75 mg dl‐1). Lipoprotein lipase and hepatic triglyceride lipase activities in post‐heparin plasma were normal. Zonal ultracentrifugation revealed a marked increase in triglyceriderich lipoproteins and reduced LDL and HDL. LDL consisted of two fractions with higher hydrated density of the main fraction compared with normals with a trend to normalization on a fat‐free diet.

The molecular defect in the apo C‐II Hamburg gene has been previously identified as a donor splice site mutation in the second intron. This leads to abnormal splicing of the apo C‐II Hamburg mRNA and apo C‐II deficiency in plasma. The mutation causes the loss of an Hphl restriction enzyme site present in the normal apo C‐II gene. Digestion of polymerase chain reaction (PCR)‐amplified DNA of members of the Hamburg kindred with Hphl permitted the identification of non‐obligate heterozygote individuals which could not be recognized by either fasting triglyceride or apo C‐II plasma levels.
Plasma triglyceride and low density lipoprotein metabolism
Authors: CASLAKE M. J. , PACKARD C. J. , SERIES J. J. , YIP B. , DAGEN M. M. , SHEPHERD J.
Published: March 2008

Abstract. This study examines the relationship between plasma triglyceride and low density lipoprotein (LDL) levels by measuring the turnover of the native and 1,2 cyclohexanedione‐treated lipoprotein in 25 healthy adults. Plasma triglyceride showed a strong positive correlation with circulating LDL apoprotein (apo LDL) mass. In order to achieve a satisfactory fit to the kinetic data it was necessary to postulate the existence of two plasma apo LDL pools (A and B). When subjects were grouped in quintiles on the basis of circulating apo LDL mass, pool A predominated in those in the lowest quintile. The fractional catabolic rate (FCR) of apo LDL from this pool was high (FCR = 0.57 pM 0.06 pools day‐1). As plasma triglyceride and apo LDL mass rose, apoprotein accumulated in the more slowly metabolized pool B as a result of an increase in the rate of input of apo LDL into the latter. The fractional clearance rate of protein from this pool remained unchanged at 0.26 pM 0.04 pools day‐1. Synthesis of apo LDL into pool B correlated with plasma triglyceride (r= 0.553, P < 0.01), suggesting that the protein in this pool was derived from large, triglyceride‐rich very low density lipoprotein.
Erythrocytes with covalently bound fibrinogen as a cellular replacement for the treatment of thrombocytopenia
Authors: AGAM G. , LIVNE A. A.
Published: March 2008

Abstract. Thrombocytopenia in general, and autoimmune thrombocytopenia in particular, is a disease of high prevalence with a non‐satisfactory regime of treatment. The present study aimed to explore the feasibility of an alternative treatment, based on the rationale that autologous erythrocytes modified to bear covalently bound fibrinogen would participate passively in the aggregation of the remaining platelets, thus augmenting the haemostatic needs, while resisting the autoimmune reaction directed towards the platelets. Several procedures for the cross‐linking of fibrinogen to red blood cells (RBCs) were tested. Formaldehyde (33 μm) for 10 min at 23°C attached 58 fibrinogen molecules per erythrocyte. These erythrocytes were indistinguishable from untreated erythrocytes in the following properties: osmotic fragility, bound haemoglobin, sedimentation rate, acetylcholi‐nesterase activity, phagocytosis by macrophages, rosette formation with K562 cells. It is shown that RBCs cross‐linked with fibrinogen are capable of participating in the in vitro aggregation of platelets and are indeed effective in the in vivo process of arrest of bleeding in an animal model of autoimmune thrombocytopenia.
The characterization of a mutation of the 3‘ flanking sequence of the α1‐antitrypsin gene commonly associated with chronic obstructive airways disease
Authors: MORGAN K. , SCOBIE G. , KALSHEKER N.
Published: March 2008

Abstract. A restriction fragment length polymorphism (RFLP) of the 3′ flanking region of the α1‐antitrypsin (AAT) gene, detected with the restriction enzyme Taql, occurs in about 17% of patients with chronic obstructive airways disease (COAD). To characterize the mutation the sequence of this region of the normal AAT gene had to be determined. The sequence containing the site of the mutation was amplified by the polymerase chain reaction and the DNA was sequenced in six COAD patients. The mutation is a G to A transition and occurs in a region containing potential regulatory sequences corresponding to enhancer elements. It is as yet unclear if the mutation alters the expression of AAT.
Different immunologic properties of the globular NC1 domain of collagen type IV isolated from various human basement membranes
Authors: WEBER M. , PULLIG O.
Published: March 2008

Abstract. The C‐terminal globular domain NC1 of collagen IV, which carries the epitopes recognized by anti‐GBM antibodies in Goodpasture's syndrome, was isolated from human basement membranes (BM) of glomeruli (GBM‐NC1), tubules (TBM‐NC1), lung (ABM‐NC1), placenta (PBM‐NC1), and small intestine (IBM‐NC1). A11 NC1 hexamers were of globular size on electron microscopy. On SDS PAGE, the hexamers dissociated into monomeric and dimer‐sized subunits of similar molecular weights. The following monomer: dimer relationships were identified: GBM‐NC1, TBM‐NC1, and PBM‐NC1 = 1:3; ABM‐NC1 =1:4; and IBM‐NC1 = 1:32. On immunoblot, all dimers of the various NC1 globules showed binding of anti‐GBM antibodies. However, monomers stained differently, with three monomers demonstrable in GBM‐NC1 and no monomer staining in PBM‐NC1. In addition, studies with monoclonal antibodies showed that the C‐terminus of the alphal (IV) collagen chain was demonstrable in all different NC1 hexamers. In contrast, the alpha3(IV) chain, to which Goodpasture sera preferentially bind, showed a restricted distribution. One monomer and dimers were demonstrable in GBM‐NC1 and ABM‐NC1, only a weak dimer staining was seen in TBM‐NC1, while no evidence for alpha3(IV) was found in IBM‐NC1 and PBM‐NC1. Dissociation by 6 m guanidine‐HCl or treatment by acid increases the apparent number of accessible epitopes for anti‐GBM antibodies. In addition, dose‐response curves, which were obtained by incubation of increasing concentrations of NC1 with anti‐GBM antibody positive sera, indicated that for GBM‐NC1 and ABM‐NC1 the lowest NC1 protein concentrations were necessary to bind 50% of the antibodies. For tubular NC1, five‐fold higher NC1 concentrations were necessary to achieve the same effect. In contrast, for intestinal NC1, more than 30‐fold higher protein concentrations of the dissociated NC1 bound only 40% of anti‐GBM antibodies. PBM‐NC1 did not bind any antibodies, even at these high NC1 concentrations. We conclude, that the differences in the amount of accessible epitopes may possibly explain the preferential involvement of the lungs and the kidneys in the autoimmune Goodpasture's syndrome and that this distribution may be due mainly to a regional expression of the alpha3(IV) collagen chain.
Detection and localization of cytokine immunoreactivity in retro‐ocular connective tissue in Graves' opthalmopathy
Authors: HEUFELDER A. E. , BAHN R. S.
Published: March 2008

Abstract. Paracrine interactions between fibroblasts residing in the retro‐ocular space and infiltrating lymphocytes/macrophages are thought to be of central importance in the pathogenesis of Graves' opthalmopathy (GO). Although various roles have been suggested for interferon‐γ (IFNγ), tumour necrosis factor‐αTNFα) and interleukin‐lα (IL‐lα) in GO, their actual presence in Graves' retro‐ocular connective tissue has not been demonstrated. We examined surgical specimens obtained during orbital decompression from patients with severe GO (n= 6), and from normal individuals (n= 5), for the presence of IFNγ, TNFα and IL‐1α. We used immunohistochemical methods on frozen tissue sections and primary fibroblast cultures, and sodium dodecylsulfate polyacryl‐amide‐gel electrophoresis of tissue extracts and tissue culture supernatants. In addition, immunohistochemical staining of tissues for characterization of the mononuclear cell infiltrates was performed. Aggregates of mononuclear cells in retro‐ocular connective and fatty tissue were found in five of six GO tissue specimens, but in none of the control specimens. We detected immunoreactivity for the three cytokines (IFNγ, TNFα and IL‐lα) in the five GO tissue specimens that contained mononuclear cell aggregates. In addition, IL‐la immunoreactivity was demonstrable in primary and subsequent GO fibroblast cultures and in their supernatants. In contrast, no immunoreactivity for any of these cytokines was detected in tissue specimens, primary cultures or culture supernatants derived from normal individuals. The presence of mononuclear cell infiltrates and associated immunoreactivity for IFNγ, TNFα, IL‐1α in retro‐ocular connective tissue derived from patients with GO suggests that the previously demonstrated in vitro functions of these cytokines may indeed be operative in vivo. Our results further support the concept that IFNγ, TNFα and IL‐lα may play a role in the pathogenesis of GO.
Impaired G‐proteins and cyclic nucleotide phosphodiesterase activity in T‐lymphocytes from patients with sarcoidosis
Authors: NEMOZ G. , PRIGENT A. F. , ALOUI R. , CHARPIN G. , GORMAND F. , GALLET H. , DESBOS A. , BIOT N. , PERRIN‐FAYOLLE M. , LAGARDE M. , PACHECO Y.
Published: March 2008

Abstract. Among the various immune abnormalities which characterize active sarcoidosis, a low proliferative response of peripheral blood lymphocytes to mitogenic lectins has long been observed. Since membrane‐associated G‐proteins are very likely to be crucial elements in lectin signal transduction, we investigated the binding of 5′‐guanylylimidodiphosphate (GppNHp), a non hydrolyzable GTP analogue, to blood total lymphocyte membranes and to blood T‐lymphocyte membranes from patients with active sarcoidosis, and from healthy control subjects. GppNHp binding was markedly decreased in peripheral cells from patients with sarcoidosis as compared to controls, suggesting the occurence of a detect at the level of G‐protein(s). A further characterization of G‐proteins in these cells by means of ADP‐riboselabelling in the presence of bacterial toxins brought forward a significant decrease in the labelling of a 40 kDa protein, the major pertussis toxin substrate, in membranes from sarcoid patients, while the labelling of the major 44 kDa cholera toxin substrate proved to be unchanged with respect to control membranes. It is hypothesized that, in sarcoid lymphocytes, a detect in the negative control of adenylate cyclase mediated by the inhibitory G‐protein Gi, prevents the lowering of cAMP necessary to normal mitogenic response of blood lymphocytes to stimulation. cAMP degradation by the specialized enzyme phosphodiesterase constitutes another critical step in the control of cAMP levels. Both CAMP and cGMP phosphodiesterase activities were found decreased in blood total lymphocyte preparations from sarcoid patients. With purified T‐cells, although the mean cAMP and cGMP phosphodiesterase activities from sarcoid patients were found more markedly decreased with respect to healthy donors, only the decrease in cGMP phosphodiesterase was found statistically significant. The role these detects in cyclic nucleotide degradation potentially play in the disturbance of blood lymphocytes response associated with sarcoidosis is discussed
Suppression of lipolysis in normal man does not inhibit recovery from insuIin‐induced hypoglycaemia
Authors: NEWRICK P. G. , BRAATVEDT G. , STANSBIE D. , CORRALL R. J. M.
Published: March 2008

Abstract. Pharmacological suppression of lipolysis is being increasingly used in the treatment of diabetic hyperlipidaemia. Although theoretical hazard of such treatment is that recovery from hypoglycaemia might be impaired. Seven normal subjects were theretore studied on two occasions, following treatment with a single dose of either acipimox 250 mg or placebo. Hypoglycaemic recovery was unaffected, despite effective suppression of plasma non‐esterified fatty acid levels with acipimox. The results suggest that under these conditions activation of lipolysis may not be essential to recovery from hypoglycaemia.
Effect of jejunal infusion of different caloric loads on pancreatic enzyme secretion and gastro‐intestinal hormone response in man
Authors: PFEIFFER A. , VIDON N. , FEURLE G. E. , CHAYVIALLE J.‐A. , BERNIER J.‐J.
Published: March 2008

Abstract. It has recently been demonstrated that the infusion of a high caloric load (3.3 kcal min‐1≙ 14.0 kJ min ‐1) into human upper jejunum inhibited pancreatic enzyme and bile salt secretion. The aim of the present study was to investigate whether this phenomenon was mediated by gastrointestinal hormones which interfere with pancreatic secretion. In six healthy volunteers, jejunal infusion of 1.3 kcal min‐1 (5.5 kJ min‐1) did not modify secretion of lipase and chymotrypsin to any significant extent compared with saline infusion, but the rate of 3.3 kcal min‐1 (14.0 kJ min‐1) resulted in an inhibition. Somatostatin and pancreatic polypeptide, which are known to inhibit exocrine pancreatic secretion, remained unchanged during jejunal nutrient infusion. The inhibition of pancreatic enzyme secretion was observed in temporal relationship with an increase of the stimulators of pancreatic exocrine secretion such as secretin, neurotensin, and CCK. The existence of an hitherto undetined inhibitor and a feedback mechanism is postulated.
Effects of oral calcium supplementation on intestinal bile acids and cytolytic activity of fecal water in patients with adenomatous polyps of the colon
Authors: WELBERG J. W. M. , KLEIBEUKER J. H. , MEER R. VAN DER , KUIPERS F. , CATS A. , RIJSBERGEN H. VAN , TERMONT D. S. M. L. , EK W. BOERSMA‐VAN , VONK R. J. , MULDER N. H. , VRIES E. G. E. DE
Published: March 2008

Abstract. Calcium has been proposed to prevent colon cancer in subjects at risk for this tumour. This effect is supposed to be due at least in part to binding the bile acids to calcium, making them insoluble and harmless. To evaluate the effects of oral calcium supplementation on intestinal bile acids, 19 patients with adenomatous colonic polyps were supplemented with 35.5 mmol Ca2+daily for 12 weeks. Duodenal bile, 24‐h feces and 24‐h urine were collected betore and at the end of the 12‐week period. In duodenal bile proportional concentration of cholic acid increased (38 ± 4 vs. 51 ± 3%, P< 0.001), whereas that of chenodeoxycholic acid decreased (35 ± 3 vs. 25 ± 2%, P< 0.01). Total fecal bile acid excretion increased (950 ± 126 vs. 1218 ± 137 μmol 24 h‐1P<0.01), with proportional concentrations of the main primary and secondary bile acids remaining the same. Cytolytic activity of fecal water, measured by the degree of lysis of erythrocytes by the water, decreased (45 ± 8 vs. 30 ± 7%, P<0.05). Total excretion of calcium increased as expected from the supplementary dose. It is concluded that calcium supplementation markedly affects intestinal bile acids and lytic activity of fecal water and that, in view of similar results during 1‐week calcium supplementation in young healthy subjects, these effects remain constant over at least 3 months and occur both in healthy persons and in patients at increased risk for colon cancer.
Antimicrotubule agents induce polyploidization of human leukaemic cell lines with megakaryocytic features
Authors: LOO B. VAN DER , HONG Y. , HANCOCK V. , MARTIN J. F. , ERUSALIMSKY J. D.
Published: March 2008

Abstract. In most eukaryotic cells the regular alternation of chromosome reduplication and cell division is controlled by interdependent relationships which prevent progression to the next cell‐cycle phase unless the preceding phase has been completed. Megakaryo‐cytes become polyploid by allowing many rounds of DNA replication without completion of intervening mitoses. To assess the role of cell‐cycle dependencies in megakaryocytopoiesis we examined human cell lines which express megakaryocytic features for their ability to continue DNA synthesis and undergo polyploidization in the presence of mitotic poisons. Treatment of HEL cells with colcemid blocked cell division but not cellular DNA synthesis. DNA content distributions of cells treated with colcemid for 48 h showed a marked increase in the proportion of polyploid cells (57.6%± 9.9%, n= 16), an increase in cellular size and nuclear lobation. Identical effects were observed in HEL cells treated with colchicine, nocodazole or taxol but not with the inactive compound lumicolchicine. Induction of polyploidization by antimicrotubule agents was also observed in the megakaryoblastic cell lines MEG‐01, DAMI and UT‐7 but not in the T‐cell line MOLT‐4 or the promyelocytic cell line HL‐60. These results suggest that dependency of DNA replication on completion of the previous mitosis is suppressed in the megakaryocytic lineage.
Smoking and plasma lipoproteins in man: effects on low density lipoprotein cholesterol levels and high density lipoprotein subfraction distribution
Authors: FREEMAN D. J. , GRIFFIN B. A. , MURRAY E. , LINDSAY G. M. , GAFFNEY D. , PACKARD C. J. , SHEPHERD J.
Published: March 2008

Abstract. In a survey of a healthy population (n = 197), LDL cholesterol, plasma triglycerides and VLDL triglycerides were found to be substantially increased and plasma HDL cholesterol decreased in smokers. The lipid‐associated atherogenic risk in smokers as assessed by the LDL/HDL ratio was significantly higher [2.89 (SD 1.18, n= 63)] than in non‐smokers [2.38 (SD 0.98, n= 86) P < 0.01]. The lower HDL level found in smokers was explained by a lower HDL‐2 subfraction as determined by analytical ultracentrifugation. HDL 2b, 2a and 3a, measured by gradient gel electrophoresis, were all lower in the smokers but this was only significant for HDL 2a. Smoking had no effect on Lp(a) levels. HDL cholesterol and HDL‐2 were strongly negatively correlated whereas LDL cholesterol and LDL/HDL ratio were strongly positively correlated with the plasma triglyceride concentration. There was a small but significant reduction in plasma CETP activity [non‐smokers 49%t/μl (SD 17, n= 90), smokers 43%t/μl (SD 17, n= 66) P < 0.05] but CETP activity was not correlated with any measure of HDL in this population. Smoking was found to be an important independent contributor to the variation in plasma triglyceride, HDL, HDL‐2 and LDL/HDL ratio. After correcting for sex, age, BMI, alcohol consumption, oral contraceptive use and plasma triglycerides smoking was still found to be significantly associated with HDL and the LDL/HDL ratio. Upon adjustment for covariant factors the mean differences between smokers and non‐smokers for HDL cholesterol, HDL‐2 and LDL/HDL were 0.15 mM, 16 mg dl‐1 and 0.39 respectively. There appeared to be important sex differences in the influence of smoking on plasma lipoproteins. In women the main impact of smoking was on triglyceride levels and they in turn affected LDL and HDL. In contrast, in men, smoking had little impact on triglycerides and affected HDL more directly. We conclude that smoking cigarettes has an important effect on plasma lipoprotein metabolism through multiple mechanisms.
Effects of diet and the cholecystokinin antagonist; devazepide (L364, 718) on CCK mRNA, and tissue and plasma CCK concentrations
Authors: PLAYFORD R. J. , KING A. W. , DEPREZ P. H. , DE‐BELLEROCHE J. , FREEMAN T. C. , CALAM J.
Published: March 2008

Abstract. The mechanisms by which raw soya diets and CCK‐receptor antagonists increase postprandial plasma CCK concentrations are not fully understood. Therefore we examined the effects of different diets including raw soya, and the effect of the potent CCK antagonist devazepide in the fed and fasted state on CCK concentrations in plasma and in the duodenal mucosa and on the duodenal CCK: β‐tubulin mRNA ratio in rats. Diets which stimulated high plasma CCK levels, such as raw soya, also gave the highest CCK tissue and mRNA concentrations with a close correlation between plasma and tissue CCK concentrations within each group (r = 0.94, P= 0.018) and between tissue CCK concentrations and CCK: β‐tubulin mRNA ratios (r = 0.91, P = 0.030). Animals fed ad libitum and treated with devazepide (1 mg kg‐1) had higher CCK: β‐tubulin mRNA ratios, tissue CCK concentrations and plasma CCK concentrations than animals injected with vehicle. Fasted animals treated with devazepide for 28 h also had higher CCK mRNA:β‐tubulin mRNA ratios (1.86 ± 0.43 vs. 0.85 ± 0.15, P < 0.05), and higher tissue CCK concentrations (0.99 ± 0.09 vs. 0.69 ± 0.04, P < 0.01). However, despite these intracellular changes devazepide did not elevate plasma CCK concentrations in the fasted state. Therefore, devazepide increases tissue concentrations of CCK but requires an additional dietary stimulus to raise plasma concentrations. These findings indicate that devazepide produces a dissociation between synthesis and release of CCK in fasted animals.
House dust mite allergy: from T‐cell epitopes to immuno‐therapy
Authors: O'HEHIR R. E. , HOYNE G. F. , THOMAS W. R. , LAMB J. R.
Published: March 2008

Abstract. CD4+ T‐lymphocytes induce and regulate allergic inflammatory responses to common environmental aeroallergens derived from Dermatophagoides spp. (house dust mite, HDM), which cause clinical symptoms in approximately 10% of the population. Definition of the molecular structure of HDM proteins combined with the ability to isolate monoclonal populations of human CD4+ T‐cells representative of the ‘interleukin‐4 (IL‐4) dominant functional pheno‐type, which support immunoglobulin E (IgE) synthesis, has allowed T‐cell recognition of HDM to be examined in detail. The results of these investigations demonstrated extensive heterogeneity in both the antigen and HLA class II restriction specificity of the HDM reactive T‐cell repertoire. Furthermore, long‐lived clones of T‐cells with oligoclonality in T‐cell antigen receptor (TcR) usage, driven by chronic stimulation with HDM, have been identified in human peripheral blood. The presentation of specific peptides and superantigens under conditions that induce T‐cell non‐responsiveness has provided an in vitro model for analysing the mechanisms of CD4+ T‐cell targeted immunotherapy.’ It appears that the mechanisms underlying T‐cell anergy are accompanied by a transient downregulation of TcR and CD28 and mediated by a shift in the cytokine profile from that of the ‘IL‐4 dominant’ to the ‘interferon‐γ (IFN‐γ) dominant’ functional phenotype of CD4+ T‐cells. In parallel, using a murine model, it has been demonstrated that administration of an immunodominant peptide via the mucosal surfaces of the respiratory and alimentary tracts may tolerize an established response to intact HDM proteins. The potential application of these models in the development of novel approaches to immunotherapy is discussed.
A new method for the determination of the cytotoxicity of bile acids and aqueous phase of stool: the effect of calcium
Authors: MUNSTER I. P. VAN , TANGERMAN A. , HAAN A. F. J. DE , NAGENGAST F. M.
Published: March 2008

Abstract. Soluble secondary bile acids in the colon are supposed to be cytotoxic for normal colonic cells, resulting in an increased compensatory proliferation of colonic crypt cells, which is associated with an increased risk for colonic cancer. We developed a sensitive method to determine cytotoxicity of bile acids in the HT‐29 colon cancer cell line, using a tetrazolium‐based colorimetric assay. Only in vital cells, tetrazo‐lium‐salts are converted into formazan, which can be measured easily. Chenodeoxycholic acid and deoxy‐cholic acid (DCA) were cytotoxic in concentrations above 100 μM, which is in the physiological range for soluble DCA in faeces. Conjugation of bile acids diminished cytotoxicity 7–10 fold. In this concentration range, no effect of calcium or calciumphosphate was demonstrated, suggesting that the effect of calcium on colonic proliferation is not mediated by a precipitation of soluble bile acids in the large bowel. Finally, we could demonstrate a significant correlation between the cytotoxicity of the aqueous phase of faeces and the soluble DCA concentration.
Comparison of intestinal absorption of cholesterol with different plant sterols in man*
Authors: HEINEMANN T. , AXTMANN G. , BERGMANN K. VON
Published: March 2008

Abstract. Intestinal absorption of cholesterol, campes‐terol, campestanol, stigmasterol and sitosterol were measured in 10 healthy subjects by an intestinal perfusion technique over a 50 cm segment of the upper jejunum using sitostanol as non‐absorbable marker. Cholesterol absorption was highest and averaged 33%, whereas the absorption rate of sitosterol averaged 4.2% and of stigmasterol 4.8%. Higher absorption rates were found for campesterol (9.6%). Canipestanol, the 5a saturated derivative of campesterol, showed the highest absorption rate (12.5%) of all plant sterols. A positive correlation between the absorption rate of cholesterol and campesterol was established. In addition, there was a negative correlation between the ratio of sitosterol to cholesterol and the mass of cholesterol absorption. These results are in agreement with previous observations in animal studies, namely, that increasing the length of the side‐chain of cholesterol decreases the absorbability of the sterol. Surprisingly, campestanol, the 5α saturated derivate of campesterol, was shown to have higher absorbability compared with its unsaturated compound. This finding is in contrast to previous assumptions, that hydrogenisa‐tion of the nucleus double bond of a sterol causes a decrease of absorbability, as has been demonstrated for cholesterol/cholestanol and sitosterol/sitostanol.
Hepatitis C virus‐related autoimmunity in patients with porphyria cutanea tarda
Authors: FERRI C. , BAICCHI U. , CIVITA L. LA , GRECO F. , LONGOMBARDO G. , MAZZONI A. , CARECCIA G. , BOMBARDIERI S. , PASERO G. , ZIGNEGO A. L. , MANNS M. P.
Published: March 2008

Abstract. Hepatitis C virus (HCV) infection is frequently found in autoimmune hepatitis and mixed cryoglobulinaemia. In these conditions HCV could be responsible for immuno‐mediated organ alterations. The aim of this study was to evaluate the presence of immunological alterations in PCT patients, in which HCV infection has been frequently found. Twenty‐three PCT patients were evaluated for clinical and serological alterations, including: chronic hepatitis, other systemic symptoms, serum cryoglobulins and rheumatoid factor (RF), haemolytic complement, serum immunoglobulins, anti‐nuclear (ANA), anti‐smooth muscle (ASMA), anti‐liver‐kidney‐microso‐mal (anti‐LKMl), anti‐soluble‐liver‐antigen (SLA), anti‐mitochondrial (AMA), anti‐GOR antibodies, anti‐HCV and HCV RNA. Abnormal serum ALT were present in the majority of cases (20/23, 87%), while liver biopsy revealed a chronic persistent hepatitis or chronic active hepatitis in 15/20 (75%) PCT patients. In a high percentage of subjects (91%) the presence of anti‐HCV was detected by ELISA and RIBA II (Chiron, Emeryville CA, USA). In 17/22 (77%) cases the ongoing HCV replication in the serum was demonstrated by the detection of HCV genomes (polymerase chain reaction). The prevalence of both anti‐HCV and HCV RNA in PCT was significantly higher if compared to 22 systemic immunological diseases (P< 0.00l) and 47 healthy subjects (P<0.001). A possible HCV‐induced autoimmunity in PCT was suggested by the presence of the following immunological parameter alterations: anti‐GOR in 13/23 (57%), ANA in 4/23 (17%), ASMA in 18/23 (78%), anti‐LKMI in 1/23 (4%), RFin 23/23 (100%), mixed cryoglobulins in 4/23 (170/0), complement consumption in 10/23 (43%). The high prevalence of HCV infection and various immunological abnormalities suggest that HCV in combination with other factors (genetic, alcohol, etc.) could play a relevant role in the pathogenesis of hepatic and metabolic alterations of PCT.
Diabetes mellitus induces accelerated growth of aortic smooth muscle cells: association with overexpression of PDGF β‐receptors
Authors: KAWANO M. , KOSHIKAWA T. , KANZAKI T. , MORISAKI N. , SAITO Y. , YOSHIDA S.
Published: March 2008

Abstract. The mechanism of diabetic macroangio‐pathy was studied from the view point of phenotypic change of aortic smooth muscle cells (SMC). The growth rates of cultured SMC of diabetic rats or rabbits were higher than those of non‐diabetic animals (controls). This difference of the growth responses was observed specifically with platelet‐derived growth factor (PDGF). Of the three PDGF dimers, PDGF‐AB heterodimer (PDGF‐AB) and PDGF‐BB homodimer (PDGF‐BB) stimulated growth of diabetic SMC more than that of control SMC but PDGF‐A A homodimer (PDGF‐AA) did not. The binding of ′251‐PDGF to the diabetic SMC was greater than that to control SMC. This was due to increase in the number of cell surface receptors for PDGF. On in vitro culture, SMC from diabetic rats expressed more PDGF β‐receptor mRNA than SMC from non‐diabetic rats. Moreover, in vivo, the aortic media of diabetic rabbits expressed PDGF β‐receptor mRNA, but that from non‐diabetic rabbits did not. Thus diabetic SMC over‐react on PDGF stimulation through over‐expression of the PDGF P‐receptor gene. The significance of this fact in development of diabetic macroangiopathy is discussed.
Evaluation of the 13CO2 kinetics in humans after oral application of sodium bicarbonate as a model for breath testing
Authors: MEINEKE I. , MEY C. DE , EGGERS R. , BAUER F. E.
Published: March 2008

Abstract. The kinetics of 13CO2 have been investigated following oral administration at five doses between 12.5 and 100 mg of 13C labelled sodium bicarbonate to 10 healthy subjects in a randomized study. Sodium bicarbonate in this study served as a model compound for carbon dioxide/bicarbonate generated in breath tests. Exhalation of 13CO2 into breath was monitored by stable isotope ratio mass spectrometry. The kinetics of 13CO2 were characterized by an apparent terminal elimination half‐life of 1 h and a mean recovery of 0.630 of the dose administered. The kinetics were not dose‐dependent. These results were in agreement with the findings reported previously after iv. application of sodium bicarbonate.
Oncogene‐mediated propagation of tracheal epithelial cells from two cystic fibrosis fetuses with different mutations. Characterization of CFT‐1 and CFT‐2 cells in culture
Authors: LEMNAOUAR M. , CHASTRE E. , PAUL A. , MERGEY M. , VEISSIÈRE D. , CHERQUT G. , BARBRY P. , SIMON‐BOUY B. , FANEN P. , GESPACH C. , PICARD J.
Published: March 2008

Abstract. Primary tracheal epithelial cells obtained from two fetuses with cystic fibrosis (CF) were successfully transfected with a plasmid vector recombined with the large T oncogene of SV40. The resulting tracheal cells were propagated in culture for up to 25 passages and retained the mutations of the CF genes carried by the two fetuses, one heterozygous for the S549N and N1303K substitutions (CFT‐I cells), and the other homozygous for the most common deletion ΔF508 (CFT‐2 cells). The transfected cells: (a) expressed the SV40 large T oncogene, as determined by immunofluorescence and Northern blot analysis; (b) retained typical epithelial morphology, as assessed by the presence of microvilli, desmosomes, gap junctions, and cytokeratin expression; (c) were fully responsive to the cAMP‐stimulating agents isproterenol, forskolin and vasoactive intestinal peptide for cAMP production and PKA activation; (d) do not produce any tumour in the athymic nude mice; (e) were diploid and tetraploid with a normal chromosomal complement at early passages, and (f) exhibited the abnormal regulation of chloride conductance characteristic of CF.

These results indicate that CFT‐1 and CFT‐2 cells constitute a suitable model for: (a) comparison of the maturation and function of the CFTR protein mutated in the two nucleotide‐binding domains; (2) analysis of the biochemical defect in CF epithelial airway cells, (c) development of new therapeutic agents, and correction of the CF defect by gene replacement therapy in vitro.
Increased rates of cortisol production and urinary free cortisol excretion in elderly women 2 weeks after proximal femur fracture
Authors: BARTON R. N. , WEIJERS J. W. M. , HORAN M. A.
Published: March 2008

Abstract. Cortisol production rate and urinary free cortisol excretion have been measured in healthy elderly women and elderly women about two weeks after upper femur fracture. Plasma cortisol was determined mid‐morning, at the start of urine collection. All three variables were higher in the injured patients than in the control subjects. Urinary free cortisol excretion showed the greatest rise and was correlated with cortisol production rate in the patients. In the control subjects there was no correlation and nearly all the points fell below the regression line for the injured patients, indicating that urinary free cortisol excretion rose in relation to cortisol production rate after injury. Measurement of creatinine clearance showed that this was not due to an increased glomerular filtration rate, and a possible explanation is decreased metabolic clearance of cortisol. Plasma cortisol was not significantly correlated with either cortisol production rate or urinary free cortisol excretion.
Lipid synthesis and apolipoprotein gene expression in hepatocytes in primary culture from (puromycin‐induced) nephrotic rats
Authors: BOUSTANI S. EL , RIBEIRO A. , JANVIER B. , LORIETTE C. , BENSMAN R. , DRUET P. , CHAMBAZ J. , MANGENEY M.
Published: March 2008

Abstract. Primary culture of hepatocytes from puromycin aminonucleoside‐induced nephrotic rats were used to discriminate between the hepatic and extra‐hepatic contribution to the hyperlipidemia occurring in the nephrotic syndrome. De novo lipogenesis and utilization of exogenous fatty acids were not modified in nephrotic hepatocytes as compared to controls. In contrast 2.2 and 5.3‐fold more triacylglycerol and phospholipids were secreted respectively by nephrotic hepatocytes than by controls. Triacylglycerol overproduction was not associated with an increase either in apo B mRNA level or in ape B synthesis or secretion measured by [35S]‐methionine incorporation and immunoprecipitation. We also observed a significant increase in apo A1 and apo E synthesis and secretion by nephrotic hepatocytes. This increase was correlated with a greater amount of apo A1 and apo E mRNA than in controls. The overproduction of apo A1 and apo E by nephrotic hepatocytes might intervene in the clearance of plasma lipoproteins and the redistribution of plasma cholesterol.