bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasma and urinary leukotrienes in sickle cell disease: possible role in the inflammatory process
Authors: IBE B. O. , KURANTSIN‐MILLS J. , RAJ J. USHA , LESSIN L. S.
Published: March 2008

Abstract. Sickle cell (HbSS) disease is associated with rheological and inflammatory stresses within the microcirculation. In order to determine the role of leukotrienes in the inflammatory processes in HbSS patients, we analysed plasma and urine levels of leukotrienes (LT); LTB4, LTC4, LTD4, and LTE4 as indicators of their in vivo metabolism. Plasma and urine level samples of 15 HbSS patients in steady‐state and age‐matched healthy, homozygous (HbAA) controls were extracted for leukotrienes and quantitated by HPLC. Control plasma level of leukotrienes (mean ± SEM, ng ml‐1) were: LTB4, 8·95 ± 0·26; LTC4, 7·24 ± 0·21; LTD4, 11·42 ± 0·40; and LTE4, 14·51 ± 0·50. Corresponding values for HbSS patients were: LTB4, 6·15 ± 0·42; LTC4, 13·61 ± 1·45; LTD4, 6·44 ± 0·51 and LTE4, 4·97 ± 0·37. The differences were significant at P < 0·05. Urine levels (mean ± SEM, ng mmol‐1 creatinine), for controls were: LTB4, 10·60 ± 0·35; LTC4, 360·0 ± 9·82. Values for HbSS urine were: LTB4, 27·50 ± 3·33; LTC4, 356·0 ± 17·87; LTD4, 69·90 ± 14·51. LTD4 was not detected in control urine. These results suggest that sickle cell patients may exhibit impaired ability to catabolize LTC4 in plasma during steady state conditions. This altered metabolism may contribute to the persistent stress of the microcirculation, and is probably related to the abnormal microvascular rheology of sickle blood cells.
Effect on collagen metabolism of thrombolytic therapy with tissue‐plasminogen activator. A randomized, placebo‐controlled study
Authors: HØST N. B. , STOLTENBERG M. B. , JENSEN L. T. , LARSEN O. G. , AURUP P.
Published: March 2008

Abstract. This paper assesses alterations in collagen metabolism following thrombolytic therapy of acute myocardial infarction with tissue‐plasminogen activator. Sequential serum measurements of the amino‐terminal propeptide of type III procollagen (S‐PIIINP) and the carboxyterminal propeptide of type I collagen (S‐PICP) in patients suspected of acute myocardial infarction randomized to tissue‐plasminogen activator or placebo were used. S‐PIIINP increased at 3h in patients with acute myocardial infarction treated with tissue‐plasminogen activator (P < 0.05). S‐PIIINP was higher in patients treated with tissue‐plasminogen activator compared with placebo‐treated patients at 3 and 6 h (P < 0.05). S‐PICP decreased independently of therapy and diagnosis. Tissue‐plasminogen activator, therefore, induces breakdown of collagen, some of which is located in the wall of atheromatous arteries. Vascular patency following thrombolytic therapy may partly be mediated by breakdown of thrombogenic collagen in the vessel wall. The findings may suggest a role for S‐PIIINP as a non‐invasive indicator of the risk of reocclusion.
Activation of the respiratory burst in eosinophil leucocytes—a transduction sequence decoupled from cytosolic Ca2+ rise
Authors: WYMANN M. P. , KERNEN P. , VON TSCHARNER V. , TAI P.‐C. , SPRY C. J. , BAGGIOLINI M.
Published: March 2008

Abstract. The activation of the respiratory burst by complement factor 5a (C5a), platelet‐activating factor (PAF), formyl‐Met‐Leu‐Phe (fMLP) and neutrophil‐activating peptide IL‐8 was explored in eosinophils from patients with the hypereosinophilic syndrome. The amplitude of the response increased with increasing concentrations of C5a and PAF, but the time for its induction was unaffected by the amount of stimulus applied. Respiratory burst activity resulting from phorbol 12‐myristate, 13‐acetate (PMA)‐mediated activation of protein kinase C (PKC) produced longer onset times, which shortened with increasing PMA concentrations. Total inhibition of the C5a‐ and PMA‐mediated burst could be achieved with the PKC inhibitor staurosporine at concentrations of 100 and 5 nM, respectively. Calcium depletion abolished agonist‐induced rises in cytosolic free calcium ([Ca2+]i) and respiratory burst activity, but not PMA‐mediated NADPH‐oxidase activation. While PMA reduced elevations in [Ca2+]i, it restored the burst response to agonists in Ca2+‐depleted eosinophils. These results agree with the agonist‐induced activation of the NADPH‐oxidase via PKC, but suggest a parallel, Ca2+‐, phospholipase C‐ and PKC‐independent signal transduction pathway. Data obtained with B. pertussis toxin showed that the respiratory burst in eosinophils is blocked by ADP‐ribosylation of Gi‐proteins, but that in the presence of PMA portions of the agonist response could be recovered.
Membrane glycoprotein modifications of G6PD deficient red blood cells
Authors: HORN S. , BASHAN N. , PELEG N. , GOPAS J.
Published: March 2008

Abstract. In this study, the composition and the role of membrane glycoproteins in phagocytosis were determined in G6PD deficient RBCs. G6PD deficient RBCs were recognized and significantly phagocytosed by murine macrophages, without pre‐exposure to oxidants in vivo. Phagocytosis was partially (60%) inhibited by incubating macrophages with either galactose or mannose, or by incubating RBCs with β‐galactosidase, indicating the involvement of lectin‐like receptors in the recognition of G6PD deficient RBCs. Membrane glycoproteins on G6PD deficient cells were detected by binding of Con A to both intact RBCs and to purified membrane proteins. The results demonstrated modifications in the glycoprotein pattern of G6PD deficient RBCs compared to untreated controls. These included reduction in the amounts of several high molecular weight glycoproteins and appearance of lower molecular weight bands. These results suggest that G6PD deficient RBCs undergo glycoprotein modifications, which may lead to premature removal from circulation, even in non‐acute hemolysis.
Cholesterol biosynthesis in dermal fibroblasts from patients with metabolic disorders of peroxisomal origin
Authors: MALLE E. , OETTL K. , SATTLER W. , HOEFLER G. , KOSTNER G. M.
Published: March 2008

Abstract. As peroxisomes possess some of the integral enzymes for cholesterol biosynthesis, the role of these organelles in cholesterol formation was studied in dermal fibroblasts with three types of peroxisomal defect: group I, characterized by the absence of intact peroxisomes (neonatal adrenoleukodystrophy, cere‐brohepatorenal syndrome of Zellweger); group II, showing impaired activity of a single peroxisomal enzyme (X‐linked adrenoleukodystrophy, adrenomye‐loneuropathy); and group III, defective in more than one peroxisomal enzyme (rhizomelic chondrodysplasia punctata). Cells were incubated with three different radioactive precursors, namely [14C]‐octanoate, [14C]‐acetate, and [3H]‐mevalonate, and incorporation of these radiolabels into cholesterol was determined. All fibroblasts with peroxisomal defects were able to form cholesterol at concentrations comparable or higher than those in controls dependent on the radioactive substrate. Binding properties (KD and bmax values) of LDL to fibroblasts with peroxisomal defects and downregulation of intracellular cholesterol biosynthesis were similar to those found in fibroblasts from normolipidaemic controls, but different to those observed in LDL‐receptor negative fibroblasts. As our studies revealed that cholesterol biosynthesis is not impaired in fibroblasts from patients with metabolic disorders of peroxisomal origin, we conclude that peroxisomes play little or no role in the pathway of cholesterol synthesis beyond mevalonate. In earlier steps of the cholesterol synthesis pathway, peroxisomal and mitochondrial defects in parallel may alter cholesterol synthesis indirectly.
Assessment of interferon cardiotoxicity with quantitative radionuclide angiocardiography
Authors: SARTORI M. , ANDORNO S. , TERRA G. LA , POZZOLI G. , RUDONI M. , SACCHETTI G. M. , INGLESE E. , AGLIETTA M.
Published: March 2008

Abstract. Three different types of cardiovascular sequelae attributed to interferon therapy have been reported: arrhythmia, ischaemic heart disease and cardiomyopathy. We evaluated the left ventricular ejection fraction (LVEF) during alpha interferon therapy (3 MU administered subcutaneously three times a week for 6 months) in 11 patients with chronic viral hepatitis. LVEF was within the normal range in all patients (mean value ± SD 64.6 ± 10.7%) before interferon was started, but decreased after 1 month of therapy (mean value± SD 59.7 ± 8.3%) (P= 0.015). An LVEF reduction of more than 10% was observed in five of the 11 patients. Three months after therapy was stopped, nine of the 11 patients showed an LVEF close to the pre‐treatment level (mean value ± SD 62.1 ± 8.3%). In our patients with chronic C hepatitis, low subcutaneous doses of interferon alpha often decreased the LVEF. It is not clear whether this finding is due to the direct effect of interferon on cardiac cells, or to the peripheral vascular effects of the drug. As LVEF reduction could be critical in patients with previously reduced myocardial contractility, our results further highlight the need for careful cardiac analysis before starting interferon therapy.
Characterization of putrescine transport across the intestinal epithelium: study using isolated brush border and basolateral membrane vesicles of the enterocyte
Authors: MILOVIC V. , STEIN J. , PIIPER A. , GERHARD R. , ZEUZEM S. , CASPARY W. F.
Published: March 2008

Abstract. Putrescine transport was investigated in isolated brush border and basolateral membrane vesicles prepared from the rabbit enterocyte. Brush border vesicles were oriented right‐side‐out and basolateral vesicles inside‐out, forming a model representing uptake and extrusion across the intestinal epithelium. Putrescine transport across both membranes was initially rapid, and 66% of the equilibrium uptake was achieved within the first minute. According to osmo‐plots and measurements at 4d̀C, 20% of total incorporation presented binding to the membrane. In order to estimate actual uptake into the vesicles, Km was calculated from the differences in putrescine incorporation at 37d̀C and 4d̀C, and was 12.7 μmol L‐1 for brush border uptake and 38.2 μmol L‐1 for basolateral extrusion. Putrescine uptake into brush border and basolateral membrane vesicles was not enhanced in the presence of an Na+ gradient. When Na+ was substituted with an uncharged solute, mannitol, putrescine incorporation was increased, indicating that putrescine uptake is not Na+‐dependent and that cations might interfere with the carrier. Paraquat and methylglyoxal‐bis(guanylhydrazone), known to share the polyamine transport system, inhibited putrescine incorporation in both membrane vesicle preparations. Basolateral carrier showed significantly higher sensitivity to cations. We conclude that putrescine uptake across the apical membrane and extrusion across the basolateral membrane of the enterocyte are mediated by two different and independent carriers which differ in their electrical properties.
Human neutrophil and plasma endopeptidase 24.11: quantification and respective roles in atrial natriuretic peptide hydrolysis
Authors: NORTIER J. , PAUWELS S. , PREZ E. DE , DESCHODT‐LANCKMAN M.
Published: March 2008

Abstract. Neutral endopeptidase 24.11 activities were quantified on human peripheral blood cell preparations (reflecting the enzyme concentration on the surface of neutrophils) and in the corresponding diluted plasmas by a spectrofluorimetric assay. Despite statistically identical values in both compartments, enzymatic activity towards atrial natriuretic peptide was not comparable. Indeed, incubation of the radiolabelled peptide in whole blood resulted in the thiorphan‐sensitive production of the labelled metabolites Phe‐Arg‐Tyr and the Cys‐Phe bond‐cleaved peptide. A similar degradation pattern was observed for blood cells but not for plasma, providing evidence for the exclusive involvement of neutrophil endopeptidase in this peptide inactivation. In search for plasma component(s) susceptible to inhibit enzymatic activity, we observed that in the presence of α2‐macroglobulin at the physiological concentration of 3.5 mg mL‐1, endopeptidase activity decreased from 100% to 51.2±8.9% (P=0.002). Our data suggest that this protein could play a role in the endogenous inhibition of plasma endopeptidase activity.
Relationship of actin filament assembly to clearance of fibrinogen gold, GPIIb‐IIIa complexes on spread platelets
Authors: WHITE J. G. , BURRIS S. , II C. M. SMITH
Published: March 2008

Abstract. The present study has evaluated the influence of high concentrations of cytochalasins B and E on the detergent‐resistant actin levels in fully spread platelets by PAGE gel electrophoresis, and the effects of the two inhibitors of new actin filament assembly on translocation of fibrinogen gold (Fgn/Au) labelled GPIIb‐IIIa receptors on the surface‐activated cells. Concentrations of 10‐ 4m and 10‐5 m cytochalasin B and E reduced detergent‐resistant actin in fully spread platelets to levels present in resting discoid platelets in suspension. Despite reduction of actin filaments to levels in resting cells, cytochalasin B did not prevent translocation of Fgn/Au from platelet margins into channels of the open canalicular system (OCS). Similar concentrations of cytochalasin E completely blocked translocation of receptor‐ligand complexes and produced a patching phenomenon not observed in previous studies. Rinsing of the spread cells to remove cytochalasin, followed by incubation of the treated platelets in Hank's buffered salt solution (HBSS) restored levels of detergent‐resistant actin to those found in untreated, spread platelets. Resting grids of 10 5 m cytochalasin E‐treated platelets on drops of HBSS for 15min restored their ability to clear FGN/Au linked to GPIIb‐IIIa from exposed surfaces to the OCS, but 10‐4 m cytochalasin E‐treated cells remained anergic after incubation on drops of HBSS. Thus a fully assembled cytoplasmic actin filament cytoskeleton does not appear to be essential for translocating receptor‐ligand complexes on the platelet surface to the OCS, nor does its presence guarantee that the ability to clear GPIIb‐IIIa receptors will be restored.
Differentiation‐induced production of ASP in human adipocytes
Authors: CIANFLONE K. , MASLOWSKA M.
Published: March 2008

Abstract. Acylation Stimulating Protein (ASP) is a human plasma protein that stimulates both triacylgly‐cerol synthesis and glucose transport. ASP is identical to C3 adesArg and is generated by the interaction of factor B, complement C3 and adipsin. We have demonstrated that mature fat cells express messages for factors B, complement C3 and adipsin; that human pre‐adipocytes, when cultured under differentiating conditions to produce adipocytes, generate ASP in the culture medium; and that human adipocytes also become more responsive to ASP as they differentiate. The aim of this study, therefore, was to examine the temporal production of ASP during adipocyte differentiation in relation to other adipose specific factors involved in lipogenesis. The results demonstrate that (i) there was little ASP production by differentiating adipocytes over the first 7 days, with a marked increase in ASP thereafter (up to sixfold); (ii) this increase was paralleled by large increases in the message level of factor B and complement C3 and moderate increases in adipsin message; (iii) increases in lipoprotein lipase (LPL) message and glycerol‐3‐phosphate dehydrogenase (GPDH) activity (both key enzymes for substrate supply for triacylglycerol synthesis) occurred earlier than the increase in ASP; and (iv) in spite of the increase in LPL and GPDH, triacylglycerol synthetic capacity only markedly increases following the increase in ASP production in adipocytes. Although the present study cannot be interpreted as showing causality with respect to triacylglycerol synthesis, it does point to an important role for ASP in human adipose tissue physiology.
Platelet activation and interaction with leucocytes in patients with sepsis or multiple organ failure
Authors: GAWAZ M. , FATEH‐MOGHADAM S. , PILZ G. , GURLAND H.‐J. , WERDAN K.
Published: March 2008

Abstract. This study focuses on the role of platelet membrane glycoproteins and platelet‐leucocyte adhesion in patients with sepsis and multiple organ failure (MOF). Specifically, the study raises the following issues: (1) the influence of sepsis and MOF on platelet activation as assessed by surface expression of platelet membrane glycoproteins GPIIb‐IIIa and thrombospondin; and (2) the effect of sepsis and MOF on platelet adhesion to circulating leucocytes. In addition, platelet activation and platelet‐leucocyte adhesion are evaluated according to clinical outcome. Forty‐five patients with suspected sepsis or MOF were evaluated by intensive care scoring systems (APACHE II and Elebute) to assess severity of disease. Flow cytometric techniques were used to examine platelet membrane expression of various adhesion molecules on circulating platelets and the appearance of platelet specific antigen (CD41) on leucocytes as an index of platelet‐leucocyte adhesion. The results were compared with severity of disease and according to outcome in patients. Twenty‐eight patients of the total study population were septic and 17 were non‐septic. Twenty‐two of the 28 septic patients suffered from severe MOF (APACHE II ≥20) whereas in six septic patients MOF was absent. Eleven of the non‐septic group suffered from moderate MOF whereas in six, severe MOF was present. In septic patients fibrinogen receptor activity on platelets was significantly above normal values (P< 0.001). When MOF was present, thrombospondin surface expression on circulating platelets also increased significantly (P<0.05). Concomitantly, platelet‐leucocyte adhesion was increased in sepsis (P<0.05) and decreased in patients with MOF (P<0.05). Significant lower levels of circulating platelet‐leucocyte aggregates occurred in non‐survivors (P<0.05). We conclude that sepsis is associated with increased surface expression of platelet adhesion molecules and an increased occurrence of circulating platelet‐leucocyte aggregates. The decrease in circulating platelet‐leucocyte aggregates in MOF might result from enhanced peripheral sequestration. An increased platelet leucocyte adhesion and sequestration might account for development of MOF in the course of sepsis.
Effect of isosorbide‐5‐mononitrate on plasma and urine levels of cyclic GMP in relation to exercise in coronary patients compared with control subjects
Authors: BERRAZUETA J. R. , SALAS E. , RIESTRA A. , OCHOTECO A. , AMADO J. A. , POVEDA J. J.
Published: March 2008

Abstract. Nitric oxide (NO) and atrial natriuretic peptide (ANP) relax vascular smooth muscle increasing levels of cyclic guanosine 3′: 5′ monophosphate (cGMP). Nitrovasodilators act as exogenous nitric oxide donors. The aim of this study was to ascertain the response of cGMP to exercise without medication and after the administration of 20 mg of isosorbide‐5‐mononitrate (IS‐5‐MN) in coronary patients (n= 8) and healthy control subjects (n= 9). A third group of 10 normal volunteers was studied to test plasma cGMP response to second exercise test without IS‐5‐MN administration. Plasma cGMP increased significantly in both patients (P<0.02) and controls (P<0.01) after the first ergometry. After IS‐5‐MN administration, plasma cGMP did not increase either before or after exercise. In normal volunteers without IS‐5‐MN plasma cGMP increased significantly after first (P < 0.004) and second (P < 0.0008) exercise test. In conclusion, plasma cGMP increases during exercise. Administration of IS‐5‐MN does not raise plasma cGMP and neither does performance of further exercise after its administration.
Platelet size and left ventricular hypertrophy in hypertensive patients over 50 years of age
Authors: SCUTERI A. , CACCIAFESTA M. , PROPRIS A. M. DE , BERNARDO M. G. DI , RECCHI D. , CELLI V. , MARIGLIANO V.
Published: March 2008

Abstract. Both mean platelet volume (MPV) and left ventricular hypertrophy have been described as associated with increased risk for vascular events. Seventy‐six hypertensive patients (37 M and 39 F) over 50 years of age were studied. They were divided into subgroups according to the presence of left ventricular hypertrophy (LVH = LV mass index >125 gm‐2, when LV mass was assessed by M‐mode echocardiography according to Penn's Convention). MPV was 3% higher in hypertensive patients with LVH compared with those without LVH (P>0.05) and it was associated with the occurrence of LVH (chi‐square = 8.44, P= 0.042). MPV significantly correlated with left ventricular mass index (r= 0.298, P= 0.004) and interventricular septum thickness (r= 0.231, P= 0.022). Both correlations remained significant after adjustment for age, blood pressure and glycaemia. MPV seemed to be associated with increased left ventricular mass and interventricular septum thickness in middle‐aged to elderly hypertensive patients.
Decreased affinity of low density lipoprotein (LDL) particles for LDL receptors in patients with cholesteryl ester transfer protein deficiency
Authors: SAKAI N. , YAMASHITA S. , HIRANO K. I. , ISHIGAMI M. , ARAI T. , KOBAYASHI K. , FUNAHASHI T. , MATSUZAWA Y.
Published: March 2008

Abstract. We have reported that the disorder of lipoprotein metabolism in hyperalphalipoproteinae‐mic patients with a deficiency of cholesteryl ester transfer protein (CETP) is characterized by the poly‐disperse low density lipoprotein (LDL) particles and the accumulation of cholesteryl ester (CE) in high density lipoprotein (HDL) particles, forming cholesterol‐induced HDL (HDLc)‐like particles. In the present study we have investigated the interaction of these abnormal LDL with LDL receptors of normal human fibroblasts. Since the ultracentrifugally separated LDL fraction (1.019 < d < 1.063 gmL‐1) from the CETP‐deficient patients contained HDLc‐like particles, these particles were removed by anti‐apolipoprotein (apo) A‐I immunoaffinity column chromatography. The lipoproteins eluted in the unbound fraction of this column did not contain apo A‐I, so this fraction was considered to be authentic LDL. The authentic LDL of the patients were deficient in CE and rich in triglycerides and apo B. The authentic LDL itself showed polydispersity, ranging in size from 23 nm to 30 nm. The affinity of these abnormal LDL particles for LDL receptors was analysed by a competitive assay in which cold LDL from the patients or control compete with 125I‐labelled LDL for fibroblast LDL receptors. The concentration of LDL particles at which 50% of 125I‐labelled normal LDL was replaced was two to three times higher for the patients than for the normal control. Therefore, the affinity of patient LDL was thought to be reduced compared to that of control LDL. These results demonstrate that CETP may play an important role in making LDL particles homogeneous and rich in CE. This modulation of LDL by CETP may enhance the affinity of LDL for LDL receptors to deliver cholesterol to peripheral tissues.
Detectable levels of pyridinoline are present in synovial fluid from various patients with knee effusion: preliminary results*
Authors: RICARD‐BLUM S. , CHEVALIER X. , GRIMAUD J. A. , LARGET‐PIET B. , UEBELHART D.
Published: March 2008

Abstract. There is a major interest for using biochemical markers of bone metabolism as a non‐invasive tool for diagnostic purposes in the field of bone and joint diseases. Based upon the fact that the pyridinium crosslinks of collagen are markers of bone and cartilage degradation, this study was designed to assess the presence of pyridinoline in synovial fluid samples originating from various arthritic and non‐arthritic knee joints. Using a sample pooling method, significant levels of pyridinoline could be measured in synovial fluid by high performance liquid chromatography. Pyridinoline levels ranged from 19.3 ± 5.8 pmol mL‐1 (mean ± SD) in osteoarthritic knee joints up to 32.4 ± 14.6 pmol mL‐1 in rheumatoid arthritis joints. Pyridinoline levels in synovial fluid were not significantly correlated to disease duration and synovial fluid cell count, but were correlated to erythrocyte sedimentation rate in osteoarthritic patients (r= 0.99, P= 0.002). This study demonstrates that synovial fluid originating from knee effusion contains significant levels of pyridinoline which can be quantified by high performance liquid chromatography and could, therefore, be a tool to investigate the metabolism of a single joint.
Failure of complete suppression of endogenous glucose production by euglycaemic hyperinsulinaemia in normal humans
Authors: NEELY R. D. G. , HARPER R. , ROONEY D. P. , ENNIS C. N. , BELL P. M. , TRIMBLE E. R.
Published: March 2008

Abstract. In normal subjects, endogenous glucose production (EGP) is usually assumed to be completely suppressed during euglycaemic clamp studies performed at high insulin levels (>100 mU L‐1). However, this assumption is based on non‐steady‐state tracer measurements of EGP which are prone to negative errors. We have used purified [6‐3 H]glucose in an optimal tracer infusion protocol to assess the suppression of EGP during 4 h euglycaemic clamps in eight normal men. An insulin infusion rate of 5 mU kg‐1 min‐1 was chosen to achieve supraphysiological (> 500 mU L‐1) plasma insulin concentrations. Using a labelled exogenous glucose infusion, plasma glucose (mean ± SEM 5.3 ± 0.1 mmol L‐1) and glucose specific activities (mean 100 ± 3% of basal) were maintained constant from 80 to 240 min. During hyperinsulinaemia, isotopically determined glucose appearance rates (Ra) were greater than glucose infusion rates (GIR) throughout the euglycaemic clamp period (P <0.001) and EGP (Ra‐GIR) was always greater than zero. In seven of the eight subjects studied EGP was partly suppressed but showed a wide variation (EGP 5 to 91% of basal at 80–120 min and 12 to 87% of basal at 200–240 min) while in one subject EGP rose above basal (by 72% at 80–120 min and 49% at 200–240 min). We conclude that EGP is not completely suppressed during euglycaemic clamps at high insulin levels.
Effect of thyroid replacement therapy on the stature of Colombian children with minimal thyroid dysfunction
Authors: HERNÁNDEZ‐CASSIS C. , CURE‐CURE C. , LÓPEZ‐JARAMILLO P.
Published: March 2008

Abstract. The effect of thyroid replacement therapy (TRT) was evaluated in 372 children with minimal thyroid dysfunction (MTD; augmented TSH response to TRH, deficient iodine consumption, goiter, short stature and retarded bone age), by comparison of pre‐with post‐observation height in periods of 6 months with and without TRT alternated. A significant (P <0.05) height recovery was observed when children received TRT; however, during the period without TRT they showed a negative height recovery. Additionally, we followed 51 children with MTD who were observed from Tanner I until final height. The group with L‐thyroxine (n= 43) during all follow‐up (97 months) showed an important recovery in height (SDS‐H = 1.67 ± 0.93 vs. 1.08 ± 0.74) which when compared with the untreated group (n= 8; 114 months; SDS‐H = ‐1.50 ± 0.83 vs. ‐1.93 ± 0.33) was significant (P < 0.001).
Improved metabolic control in patients with non‐insulin‐dependent diabetes mellitus is associated with a slower accumulation of glycation products in collagen*
Authors: SALMELA P. I. , OIKARINEN A. I. , UKKOLA O. , KARJALAINEN A. , LINNALUOTO M. , PUUKKA R. , RYHÄNEN L.
Published: March 2008

Abstract. Twenty‐one patients with non‐insulin‐dependent diabetes in poor metabolic control were subjected to intensified therapy, in most cases with insulin, to investigate whether it is possible to slow down the accumulation of advanced glycosylation end products of collagen by improving glycaemic control. Fasting and mean daily blood glucose, serum fructo‐samine and glycohaemoglobin levels, as well as glycation of collagen were measured before and after 1.5 years of intensified therapy. All these parameters except for fructosamine correlated significantly with fasting blood glucose and glycohaemoglobin when measured before the insulin therapy was started, when the patients had had poor but stable metabolic control for a long period of time. After 1.5 years of intensified therapy the level of glycation of collagen did not significantly correlate with the fasting blood glucose or glycohaemoglobin levels, suggesting that the non‐enzymatic glycosylation of collagen reflects a longer period of metabolic control of diabetes than the glycohaemoglobin level. Intensified treatment improved previously poor metabolic control in patients with non‐insulin‐dependent diabetes, and this improvement was reflected in a decrease in fasting and mean daily blood glucose levels, serum fructosamine and glycohaemoglobin concentrations, and in the level of early products of glycation of collagen. The average content of advanced glycosylation end products of collagen, assayed in terms of collagen‐linked fluorescence did not decrease. However, they accumulated more slowly in the patient tercile with the greatest decrease in the level of fasting blood glucose than in the tercile with the smallest decrease, and even a decrease in fluorescence was observed in the patients with the greatest improvement in the metabolic control. Our findings suggest that the improvement of metabolic control in non‐insulin‐dependent diabetes is reflected in a slower accumulation of advanced glycosylation end products in collagen. If the slower accumulation of advanced glycosylation end products in collagen is translated into a slower development of the long‐term complications of diabetes remains to be studied.
Reverse transcription‐polymerase chain reaction detection of collagen transcripts in healing human wounds
Authors: HOPKINSON I. , EVANS W. , CHANT D. , HISCOX S. , BERRY D. , HARDING K.
Published: March 2008

Abstract.The aim of this study was to analyse the expression of CO11A1, C011A2 and CO13A1 in 6 mm diameter punch biopsies obtained from human wounds. Total RNA was isolated from biopsies taken fromSacrococcygeal pilonidalsinus excision cavities at weekly intervals between surgery and clinical closure. cDNAs were generated from the RNA using reverse transcriptase and polymerase chain reaction (PCR) amplifications performed with oligonucleotide primer pairs specific for regions of the CO11A1, CO11A2 and C013A1 genes. The expression of these three genes was demonstrated throughout the course of healing on 36 biopsies taken from nine patients between surgery and clinical closure. Amplification bands demonstrated on cDNAs generated from 6 mm diameter biopsies were comparable in intensity and specificity with those generated from 50 mg excised scar tissue and cultured fibroblasts. The RT‐PCR technique described here allows the rapid ‘routine’ detection of specific gene expression in 6 mm biopsies obtained from healing wounds.
Prolonged activation of the branched‐chain α‐keto acid dehydrogenase complex in muscle of zymosan treated rats
Authors: ROOYACKERS O. E. , SENDEN J. M. G. , SOETERS P. B. , SARIS W. H. M. , WAGENMAKERS A. J. M.
Published: March 2008

Abstract. Whole‐body oxidation rates of branched chain amino acids (BCAA) are increased during catabolic diseases. A significant role for muscle in this feature has been suggested and, therefore, activities of the rate limiting enzyme in the degrada‐tive pathway of the BCAA in muscle were investigated in a catabolic rat model (intraperitoneal zymosan injection). Both actual and total activities of the branched chain α‐keto acid dehydrogenase complex (BC‐complex) were measured in skeletal muscle of zymosan treated rats and compared with values measured in pair fed and ad libitum fed controls. The actual activity and the percentage of the enzyme in the active form were increased 2 and 6 days after the zymosan challenge. Total activity of the BC‐complex and the activities of mitochondrial marker enzymes were reduced 2 days after zymosan treatment. We conclude that zymosan treatment leads to (1) a reduction of the mitochondrial content in skeletal muscle and (2) a prolonged activation of the BC‐complex in muscle which may explain enhanced oxidation of BCAA during catabolic diseases.
The effect of starvation on leucine, alanine and glucose metabolism in obese subjects
Authors: UMPLEBY A. M. , SCOBIE I. N. , BOROUJERDI M. A. , SÖNKSEN P. H.
Published: March 2008

Abstract. The relationship between changes in ketone concentrations and leucine metabolism (seven obese subjects), glucose and alanine metabolism (seven obese subjects) was investigated using radioisotopic techniques after 12 h, 60 h and 2 weeks starvation. Leucine metabolism was also measured in five lean subjects after 12 h and 60 h starvation. In the obese subjects leucine concentration increased after 60 h starvation and leucine metabolic clearance rate, glucose and alanine concentration decreased (P < 0.05). Glucose and alanine production rate (Ra) decreased after 2 weeks (P < 0.05) but there was no change in leucine Ra after 60 h or 2 weeks. In the lean subjects leucine concentration, production rate and oxidation rate were increased after 60 h (P < 0.005, P < 0.05, P < 0.05). Ketone concentration was inversely related to alanine Ra (r=—0.51, P < 0.02) but was not related to measurements of protein metabolism in the obese subjects. This study demonstrates that the effect of short‐term starvation on protein metabolism differs in lean and obese subjects. The decrease in glucose Ra during long‐term starvation may be in part due to a decreased supply of alanine for gluco‐neogenesis.
Cellular mechanisms underlying the increased duodenal iron absorption in rats in response to phenylhydrazine‐induced haemolytic anaemia
Authors: O'RIORDAN D. K. , SHARP P. , SYKES R. M. , SRAI S. K. , EPSTEIN O. , DEBNAM E. S.
Published: March 2008

Abstract. Haemolytic anaemia induced by phenylhy‐drazine (PZ) promotes iron absorption across rat small intestine. This present study investigates the role of the brush border potential difference (Vm) and mucosal reducing activity in the response. In addition, quantitative autoradiography was used to assess PZ‐induced changes in the villus localization of brush border iron uptake. Iron transfer from duodenum to blood was increased significantly 5 days after treatment with PZ. Autoradiography showed that most brush border iron uptake occurred at the upper villus region and the maximal rate was increased fourfold by PZ. Duodenal villus length was increased in PZ‐treated rats. PZ treatment did not influence mucosal reducing activity but Vm, measured using duodenal sheets, increased from ‐50 to ‐57mV {P < 0.001) and this was due to a reduced brush border sodium permeability. Thus, an expanded absorptive surface and an enhanced electrical driving force for iron uptake across the duodenal brush border are important adaptations for increased iron absorption in PZ‐induced haemolytic anaemia.
Red blood cell cation transports in uraemic anaemia: evidence for an increased K/CI co‐transport activity. Effects of dialysis and erythropoietin treatment*
Authors: FRANCESCHI L. DE , OLIVIERI O. , GIRELLI D. , LUPO A. , BERNICH P. , CORROCHER R.
Published: March 2008

Abstract. This study examines the role of uraemia and the effect of different dialysis treatments on red cell cation transport. We evaluated the main cation transport systems in erythrocytes of non‐dialysed end‐stage renal disease (ESRD) subjects, of patients undergoing haemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD), as well as the changes induced by human recombinant erythropoietin (r‐HuEPO) administration. In uraemic undialysed and dialysed patients, we observed an increase in K/Cl co‐transport activity and in shrinkage‐induced amiloride‐sensitive (HMA‐sensitive) Na efflux (Na/H exchange) and a decrease in Na/K pump and Na/K/Cl co‐transport activity, while Na/Li exchange was increased only in dialysed patients. In uraemic erythrocytes, we showed for the first time an increased K/Cl co‐transport activity, which was cell age independent. Generally, the different method of dialysis (CAPD or HD) did not modify the cation transport abnormalities observed. During the treatment with r‐HuEPO, all the systems, with the exception of the Na/K pump and Na/K/Cl co‐transport, increased their activities following the increase of circulating young red cells. The changes produced under r‐HuEPO administration were transient and cation transports returned to the baseline values within 100 days of treatment, indicating a primary and prominent pathogenetic role of uraemia in modulating the red cell membrane cation transport activities.
Free amino acid concentrations in normal and abnormal third trimester placental villi
Authors: MORRIS N. H. , BURSTON D. , RAMSAY B. , SOORANNA S. R.
Published: March 2008

Abstract. Homogenates of placental villi were obtained from normotensive pregnancies and from pregnancies complicated by pre‐eclampsia and growth retardation. The homogenates were analysed for free amino acid concentrations using high performance liquid chromatography (HPLC). The study shows that there are significantly higher concentrations of two essential amino acids, L‐arginine and phenylala‐nine (P<0.05), in the growth‐retarded group compared to the term normotensive and pre‐eclamptic groups. There are significantly higher concentrations of the non‐essential amino acids: glutamic acid in the growth retarded group compared to the normotensive group, and of tyrosine in the growth‐retarded group compared to the pre‐eclamptic group. However, there is no increase in the glycine/valine ratio, a characteristic marker for kwashiorkor or a reduction in total protein concentration in the pre‐eclamptic or growth‐retarded groups. These findings suggest that there may be abnormalities in placental metabolism, amino acid transfer across the basal membrane into the fetal circulation, and also fetoplacental perfusion in pregnancies complicated by pre‐eclampsia and growth retardation.
Omega‐3 fatty acids suppress the enhanced production of 5‐Iipoxygenase products from polymorph neutrophil granulocytes in cystic fibrosis
Authors: KEICHER U. , KOLETZKO B. , REINHARDT D.
Published: March 2008

Abstract. Pulmonary damage in cystic br osis (CF) is associated with chronic inflammation mediated in part by proinflammatory 5‐lipoxygenase products (5‐LOP, leukotrienes and 5‐hydroxyeicosatetraenoic acid) from polymorph neutrophil granulocytes (PMN). The authors studied 5‐LOP formation of PMN from CF patients and in vitro effects of added eicosapentae‐noic acid (EPA) and fish oil. Circulating PMN were isolated from 10 CF patients without acute infections and 10 control persons of the same age (4–20 years). Total 5‐LOP liberation from PMN of CF patients was significantly increased over controls after incubation with the calcium ionophore A23 (1 μmol L‐1) without arachidonic acid (AA) (380 ±24 vs. 294±28pmol mL‐1) and with 10μmolL‐1 AA (1303±104 vs. 1015 ± 104 pmolmL‐1), and there were nonsignificant trends to high values after incubation with 5μmolL‐1 platelet activating factor (PAF, 134% of controls) and 1 μmol L‐1 formyl‐methionyl‐leucyl‐phenylalanine (FMLP, 125%). The addition of 100 mu;g mL‐1 fish oil to PMN of CF patients challenged with A23 completely suppressed synthesis of proinflammatory 5‐LOP of the 4‐series, while inactive 5‐LOP metabolites of the 5‐series were produced. Added EPA (10 μ molL‐1) also suppressed 4‐series 5‐LOP and significantly reduced leukotriene B4 concentration by 48% from 39.9 ±3.2 to 20.6 ± 11.4 pmol L‐1 again with a concomittant increase of inactive 5‐series metabolites. The authors conclude that the turnover of endogenous and exogenous AA is enhanced in CF, possibly due to stimulated phospho‐lipase A2 activity. The relatively small effect of the receptor dependent stimuli PAF and FMLP may be caused by a down‐regulation of PMN receptors in CF. Supplementation of long‐chain ω‐3‐fatty acids may be beneficial for reducing excessive inflammation in CF patients and should be further evaluated.
Progression of coronary artery disease in non‐dilated sites in the months following balloon angioplasty: time‐dependent relation with restenosis
Authors: BENCHIMOL D. , DARTIGUES J. F. , BENCHIMOL H. , BORDIER P. , DUPLÄA C. , COUFFINHAL T. , BONNET J.
Published: March 2008

Abstract. There is scant information on the progression of coronary artery disease in non‐dilated sites in the months following percutaneous trans‐luminal coronary angioplasty (PTCA) or on its relationship with restenosis. To assess the incidence of this progression and its relationship with restenosis at various times after PTCA, the authors selected 371 consecutive patients who had undergone a first successful PTCA for angina on native coronaries followed by a repeat angiographic study. The angio‐grams were analysed by a computer‐assisted method; progression was defined as a 20% decrease in diameter and restenosis as a 30% decrease in diameter or a return to > 50% stenosis. The relationship between progression and restenosis was analysed in the whole population and then, using the Mantel‐Haenszel chi‐square test, in two subgroups: patients with a stable clinical state, who were restudied routinely and those whose worsened state had prompted repeat angiogra‐phy. The relationship was assessed at different times between angioplasty and the repeat angiography. Progression was observed in 80 patients (22%) and restenosis in 155 patients (42%). There was a highly significant relationship between progression and restenosis in the total population (χ2= 26.4, odds ratio = 3.9 and P < 0.0003) and in the group of patients that were routinely restudied (χ2= 31.6, odds ratio = 5.3 and P < 0.0001), but not in the group of patients in whom restudy was performed because of clinical worsening (χ2= 0.13, odds ratio = 1.5 and P= NS). With respect to the length of follow‐up, in the total population the relationship was significant only at 6 and 7 months (P < 0.0001), and in the group receiving a routine restudy only at 4–5 and 6–7 months (P < 0.0001). Progression in non‐dilated sites appeared to be strongly and transiently linked with restenosis, suggesting that PTCA may enhance both restenosis and progression over a short period.
OKT3‐induced nephrotoxicity is associated with release of group II secretory phospholipase A2
Authors: WEVER P. C. , ROEST R. W. , WOLBINK‐KAMP A. M. , WOLBINK G. J. , WEENING J. J. , HACK C. E. , BERGE R. J. M. TEN
Published: March 2008

Abstract. Administration of the murine IgG2a CD3 monoclonal antibody OKT3 exerts a transient nephro‐toxic effect. Increased levels of group II secretory phospholipase A2 (sPLA2‐II) might account for this nephrotoxicity as sPLA2‐II induces the biosynthesis of prostaglandins, vasoactive lipid mediators that influence glomerular haemodynamics and renal function. Furthermore, extracellular phospholipases seem to be involved in proximal tubular cell injury. We studied plasma sPLA2‐II levels in relation to circulating creatinine, tumour necrosis factor α, interleukin 6 and C‐reactive protein levels in 15 renal allograft recipients receiving rejection treatment with OKT3. As a control group, we studied 15 renal allograft recipients receiving rejection treatment with methyl‐prednisolone. A maximal fourfold increase in sPLA2‐II levels was observed 48 h after the first OKT3 administration, preceded by increased tumour necrosis factor α and interleukin 6 levels and accompanied by increased C‐reactive protein levels. Creatinine levels reached a maximal increase 72 h after initiation of treatment. During methylprednisolone treatment no increase in any of the studied parameters was observed. Thus, administration of OKT3 induces increased sPLA2‐II levels, presumably via generation of cytokines. We hypothesize that sPLA2‐II may contribute to the nephrotoxic effect of OKT3 by inducing vasoconstrictive prostaglandins and renal tubular cell injury.
Effects of glyceryl trinitrate on the pyloric motor response to intraduodenal triglyceride infusion in humans
Authors: SUN W. M. , DORAN S. , LINGENFELSER TH. , HEBBARD G. S. , MORLEY J. E. , DENT J. , HOROWITZ M.
Published: March 2008

Abstract. The retardation of gastric emptying induced by infusion of triglyceride into the small intestine is associated with suppression of antral pressure waves and stimulation of basal pyloric tone in combination with phasic pressure waves localized to the pylorus. The role of nitric oxide (NO) mechanisms in the control of pyloric motility was evaluated in 12 healthy male subjects (21–43 years), using the NO donor glyceryl trinitrate (GTN). Antropyloric pressures were measured with a manometric assembly incorporating nine sideholes, spanning the antrum and proximal duodenum, and a pyloric sleeve sensor. On separate days, an intraduodenal triglyceride infusion (10% intralipid at l mL min‐1) was started during antral phase I activity and continued for 60 min. On one of the days GTN (600 μg) was given sublingually 20 min after start of the triglyceride infusion. The tonic pyloric motor response to triglyceride [5.6 (SEM 0.8.) vs. 2.7 (1.3) mmHg, P <0.001] and both the number [3.2 (0.2) vs. 2.2 (0.2) min‐1, P <0.05] and amplitude [40 (4) vs. 27 (5) mmHg, P <0.05] of phasic isolated pyloric pressure waves were reduced by GTN. These observations suggest that NO mechanisms are involved in the regulation of pyloric motor activity in humans.
Decrease in lipoprotein(a) after renal transplantation is related to the glucocorticoid dose
Authors: AHSEN N. VON , HELMHOLD M. , EISENHAUER T. , ARMSTRONG V. W. , OELLERICH M.
Published: March 2008

Abstract. Serum lipoprotein(a) [Lp(a)] concentrations and apolipoprotein(a) phenotypes were determined in 46 patients with end‐stage renal disease both before as well as 1 week and 1, 3 and 6 months after renal transplantation. Immunosuppressive therapy consisted of cyclosporin A, prednisone and azathioprine. Before transplantation median Lp(a) levels did not differ between the patients and a healthy control group. A highly significant decrease (P<0.001) in Lp(a) levels was observed in both male and female patients 1 week after transplantation. This marked reduction in Lp(a) occurred at a time when patients were receiving the highest doses of corticosteroids. As steroid doses were gradually tapered. Lp(a) concentrations subsequently increased, although at 6 months levels were still significantly reduced (P<0.01) in women. No significant correlation was observed between Lp(a) and whole‐blood cyclosporin levels, nor was there any correlation with the azathioprine dose. The reduction in Lp(a) concentrations was seen for all apo(a) phenotypes observed in the study.