bluuebunny/crossref_metadata_2025 huggingface dataset:
Potential aetiological factors concerning the development of osteonecrosis of the femoral head
Authors: Zalavras CH. , Dailiana  , Elisaf  , Bairaktari  , Vlachogiannopoulos  , Katsaraki  , Malizos
Published: March 2003

Background

The aetiology and pathogenesis of non‐traumatic osteonecrosis (ON) of the femoral head have not been fully elucidated. The present study was conducted to evaluate the possible correlation of relevant haematological and biochemical factors with the development of ON.

Patients and methods

Our investigation consisted of measurement of haematological indices and assessment of the biochemical and lipid profile of a study population of 68 patients with non‐traumatic ON of the femoral head and 36 healthy controls. The disease was considered idiopathic in 17 and secondary in 51 patients.

Results

There were no statistically significant differences in the parameters measured among the idiopathic ON, secondary ON and control groups, except for globulins α1, α2 and β, which were significantly increased in both patient groups, and apolipoprotein B (Apo B), which was increased in patients with idiopathic disease compared with the control group. Both patient groups presented increased von Willebrand factor (VWF) and lipoprotein (a) [Lp(a)] levels and decreased protein C and S concentrations, but without statistical significance. However, both patient groups exhibited a greater proportion of abnormal values of any of these parameters, in 58.9% of the idiopathic and in 62.7% of the secondary ON patients, compared with 8.3% of the controls.

Conclusion

Our study underlines the potential association of abnormal values of protein C, protein S, VWF and Lp(a) with ON. To our knowledge this is the first reported association of VWF with the disease. The majority of both idiopathic and secondary ON patients in our series exhibits a thrombotic potential that adds further support to the postulation that intravascular coagulation is a major pathogenetic mechanism leading to the disease.
Localization and characterization of antigen‐presenting dendritic cells in the gastric mucosa of murine and human autoimmune gastritis
Authors: Ninomiya  , Matsui  , Akbar  , Murakami  , Onji
Published: March 2003

Background

Activated CD4+ T cells and inflammatory cytokines are implicated in the pathogenesis of experimental autoimmune gastritis. However, there is a paucity of information about the cells that induce them. Antigen‐presenting dendritic cells (DCs) play a cardinal role in the formation and survival of activated lymphocytes.

Materials and methods

Autoimmune gastritis was induced in neonatal BALB/c mice by thymectomy. DCs were detected in situ in the gastric mucosa from thymectomized mice and in patients with autoimmune gastritis, by immunohistochemistry and immunoelectron microscopy. The expression of MHC class II and CD86 antigens on DCs in the gastric mucosa and spleen was evaluated in dual‐colour flow cytometry.

Results

DCs were detected in the gastric mucosa of mice with autoimmune gastritis, and the number of DCs increased as the levels of gastritis became more severe as time passed following thymectomy. Flow cytometric analyses revealed that more than 60% of the DCs in the gastric mucosa had a mature phenotype (expressed MHC class II and/or CD86 antigens) both at 4 and 16 weeks after thymectomy. Activated and mature DCs were localized in the gastric mucosa from patients with autoimmune gastritis.

Conclusions

This is the first report on the localization and phenotypes of DCs in the gastric mucosa of autoimmune gastritis. The presence of mature DCs in the gastric mucosa of murine and human autoimmune gastritis, in spite of their absence in the gastric mucosa of normal mice, suggests that mature DCs play a role in the pathogenesis of autoimmune gastritis.
Late diagnosis of Kawasaki disease is associated with haptoglobin phenotype
Authors: Lee  , Hwang  , King  , Chen  , Chiou  , Yang  , Huang
Published: March 2003

Background

Kawasaki disease (KD) is an acute febrile illness characterized by multiple clinical and biochemical features of inflammation and the most common complications of coronary artery abnormality (CAA). Haptoglobin (Hp) is an acute‐phase protein whose phenotype is known to be involved in coronary artery diseases. In this paper, we report the investigation of the association of Hp phenotype with the formation of CAA in KD.

Patients and methods

Forty‐seven consecutive patients with clinically diagnosed KD were admitted. Sera were taken before therapy of intravenous immunoglobulins (IVIG) plus aspirin, and levels of serum proteins were measured by a rate immunonephelometer. The echocardiographic criteria for coronary artery abnormality were evaluated during acute or subacute stages. Hp phenotyping was performed by Western immunoblotting.

Results

Duration of fever at diagnosis of KD was significantly different between patients with Hp 2–2 (6.4 ± 1.2 days, n = 25) and with Hp1 allele (Hp 2–1 plus Hp 1–1; 8.8 ± 3.5 days, n = 22). In contrast, serum levels of Hp between KD patients with Hp2–2 and with Hp1 allele (297 ± 121 mg dL−1 vs. 330 ± 101 mg dL−1, respectively) was not significantly different. On the other hand, no patients with Hp 2–2 (0/25) were recognized as having KD in subacute stage. However, 5 out of 20 patients with Hp 2–1 were recognized in subacute stage, and their incidence of CAA was 80.0% (4/5).

Conclusions

Patients with Hp 2–1 have patterns of delayed or incomplete presentation of clinical symptoms. Therefore, the late diagnosis of KD is associated with haptoglobin phenotype.
Pre‐eclampsia‐induced alterations in IGF‐I of human umbilical cord
Authors: Bańkowski  , Pałka  , Jaworski
Published: March 2003

Background

Extracellular matrix (ECM)‐components serve as a storage site to concentrate and stabilise growth factors in the vicinity of cells. Human umbilical cord (UC) tissues contain significant amounts of IGF‐I and IGF‐binding proteins (BPs). IGF‐I is known as a stimulator of collagen and sulphated glycosaminoglycans (GAGs) biosynthesis. Pre‐eclampsia, the most common pregnancy associated syndrome, is accompanied by an accumulation of collagen and sulphated glycosaminoglycans in the UC. One may expect that IGF‐I and BPs play an important role in such a remodelling of the UC tissue. For this reason it was decided to evaluate the alterations in amounts of IGF‐I and BPs in UC serum and in the UC arterial wall of newborns delivered by mothers with pre‐eclampsia.

Materials and methods

Studies were performed on the UCs of 12 control and 12 investigated newborns, delivered by mothers with pre‐eclampsia (edema, proteinuria > 500 mg l−1, arterial pressure: systolic > 140 mmHg, diastolic > 100 mmHg). Radioimmunological techniques were employed to determine IGF‐I and IGF‐BPs (BP‐1 and BP‐3).

Results

It was found that pre‐eclampsia is associated with an increase of IGF‐I concentration in the UC serum and with simultaneous decrease of its content in the umbilical cord artery (UCA). The decrease of IGF‐I content in the UCA wall was accompanied by an increase of BP‐3 and BP‐1 in this tissue. The increase in BPs content in the UCA wall was not associated with an enhancement of IGF binding by extracts from the homogenates of arterial wall. Heparin drastically decreased the binding of IGF‐I by BP‐3.

Conclusions

Pre‐eclampsia is associated with an increase of IGF‐I‐concentration in the umbilical cord blood and an elevation of BPs contents in the UCA wall. Despite a high concentration of binding proteins, IGF‐I is not accumulated in this tissue. High amounts of sulphated GAGs in the UCA wall may be a factor that prevents the binding of IGF‐I by BPs. Free IGF‐I can easily bind to cell receptors and stimulate the cells to produce collagen and sulphated GAGs in the arterial wall.
Role of macrophage activation in the pathogenesis of Alzheimer's disease and human immunodeficiency virus type 1‐associated dementia
Authors: Smits  , Boven  , Pereira  , Verhoef  , Nottet
Published: March 2003

The structure and function of neurons are changed not only during development of the central nervous system but also in certain neurological disorders, such as Alzheimer's disease and human immunodeficiency virus type 1 (HIV‐1) ‐associated dementia. Immunological activation and altered production of neurotoxins and neurotrophins by brain macrophages are thought to play an important role in neuronal structure and function. This review describes the clinical and pathological features of both Alzheimer's disease and HIV‐1‐associated dementia and tries to interpret the role of the macrophage and astrocytes therein. The consequences of activation of macrophages by amyloid‐β in Alzheimer's disease and HIV infection of macrophages in HIV‐1‐associated dementia and the similarities between these diseases will be discussed. Although the neuropathology of Alzheimer's disease and HIV‐1‐associated dementia differs, Alzheimer's disease is a cortical dementia and HIV‐1‐associated dementia is a subcortical dementia, the process of macrophage activation and the resulting pathways leading to neurotoxicity seem very similar. In both Alzheimer's disease and HIV‐1‐associated dementia, interaction of macrophages and astrocytes appear to play an important role.
Insulin activates p38 mitogen‐activated protein (MAP) kinase via a MAP kinase kinase (MKK) 3/MKK 6 pathway in vascular smooth muscle cells
Authors: Igarashi  , Yamaguchi  , Hirata  , Daimon  , Tominaga  , Kato
Published: March 2003

Background

Induction of stress‐activated mitogen‐activated protein (MAP) kinases such as p38 could be important for the development of cardiovascular diseases since p38 MAP kinase activation stimulates apoptosis, cell growth, prostanoid formation and other cellular dysfunctions when induced by oxidants, hyperosmolarity, or pro‐inflammatory cytokines. On the other hand, insulin resistance is one of the most important factors promoting atherogenesis, including cardiovascular diseases, but it is not clear how these different factors transmit their signals intracellularly at the cytosolic and nuclear levels. In this study, we investigated the effect of insulin on p38 mitogen‐activated protein (MAP) kinase activation in cultured rat vascular smooth muscle cells (VSMC).

Materials and methods

VSMC were obtained from the aortas of male Wistar rats by the media explant technique. After being stimulated by insulin with SB‐203580, PD‐98059, or GF109203X, the cells were solubilized and the expressions of MAP kinases, MAP kinase kinases and p70 S6 kinase were examined by immunoblot analysis. The amount of DNA synthesis was measured by [3H]thymidine incorporation.

Results

Insulin activated p38 MAP kinase phosphorylation in a dose‐dependent manner, and the phosphorylation was specifically inhibited by SB‐203580, a p38 MAP kinase‐specific inhibitor, but not by PD‐98059, a specific inhibitor of upstream kinase (MEK), of extracellular signal‐regulated kinase (ERK), or GF209203X, a protein kinase C‐specific inhibitor. Insulin also activated MAP kinase kinase (MKK) 3/MKK 6 phosphorylation, the upstream kinase of p38 MAP kinase, but neither stress‐activated protein kinase (SAPK)/ERK kinase (SEK1/MKK4) nor SAPK/c‐jun NH2‐terminal protein kinase. Surprisingly, phosphorylation of p70 S6 kinase and an increase of DNA synthesis by insulin were suppressed dose dependently by SB‐203580.

Conclusion

These results have established that insulin activates the p38 MAP kinase cascade via an MKK 3/6 pathway in rat VSMC, independently of a MEK–ERK cascade, and partly regulates cell growth.
Differential expression of human α‐ and β‐defensins mRNA in gastrointestinal epithelia
Authors: Frye  , Bargon  , Lembcke  , F. Wagner  , Gropp
Published: March 2003

Background

While defensins have received great attention for their role in bronchial innate immune defence, little is known about the expression levels of the four human epithelial defensins (HD5, HD6, hBD1 and hBD2) in the digestive tract. In this study we quantified the α‐ and β‐defensins mRNA in biopsies obtained from the gastrointestinal mucosa and identified the cells expressing the β‐defensin hBD1 mRNA in ileal mucosa.

Material and methods

Biopsies from human stomach (corpus and antrum), duodenum, jejunum, ileum and colon were analysed for their expression of α‐ and β‐defensins. The mRNA of defensins was quantified by semiquantitative reverse transcription–polymerase chain reaction. Cells expressing β‐defensin hBD1 mRNA were identified by in situ hybridization with 35S‐labelled RNA probes in tissue sections of human ileum.

Results

The hBD1 mRNA was expressed at low levels with little variability throughout the gastrointestinal tract and was detected in all epithelial cells of ileal mucosa. HD5 and HD6 mRNA expression was restricted to the intestine and displayed high interindividual variability. The highest expression levels were observed in jejunum and ileum. Biopsies obtained from duodenum displayed low levels or no expression of HD5 and HD6. The expression level increased considerably in a biopsy obtained from a patient with acute coeliac sprue. In contrast, low levels were observed in a biopsy from a patient with coeliac sprue in remission.

Conclusions

The expression levels of hBD1, HD5 and HD6 throughout the gastrointestinal tract are tissue and peptide specific and these defensins are expressed with high interindividual variability.
Mechanisms of HIV‐1 to escape from the host immune surveillance
Authors: Kamp  , Berk  , T. Visser  , Nottet
Published: March 2003

Since the beginning of the acquired immune deficiency syndrome (AIDS) pandemic in 1981, research on human immunodeficiency virus (HIV) has been focused on mechanisms by which the virus escapes from immune surveillance. Several human leucocyte antigen haplotypes have been shown to be associated with rapid disease progression or resistance to disease progression. In addition, HIV is able to down‐regulate major histocompatibility complex type I (MHC‐I) on the surface of the host cell. For this down‐regulation HIV seems to use three different mechanisms mediated by three different viral proteins. The viral Tat protein represses transcription of the MHC‐I, Vpu retains nascent MHC‐I chains in the endoplasmic reticulum and Nef mediates selective internalization of MHC‐I molecules from the plasma membrane. The last mechanism also provides protection to natural killer cells that attack cells with little or no MHC‐I on the cell surface. Together these mechanisms provide a very efficient escape from the host immune system.
Effects of phospholipase A2, free fatty acids and 2‐lysolecithin on the crystallization of cholesterol in gallbladder bile
Authors: Schöne  , Jüngst  , Meyer  , Hernandez‐Richter  , Fischer
Published: March 2003

Background

Phospholipase A2 (PLA2) and its enzymatic products free fatty acids (FFAs) and 2‐lysolecithin are physiological constituents of bile. Their role in the crystallization of cholesterol in gallbladder bile of patients with cholesterol gallstones is still controversial.

Design

To clarify this issue we evaluated the activity of PLA2 and the concentration and pattern of FFAs in the gallbladder bile of cholesterol stone patients. We furthermore added PLA2, FFAs and 2‐lysolecithin to isotropic gallbladder bile, determined the crystal observation time (COT) and counted the cholesterol crystals in a crystal growth assay for up to 21 days.

Results

A PLA2 activity of 1.8 ± 1.2 U L−1 and total FFA concentrations of 1.32 ± 0.71 mmol L−1 were determined. After incubation of bile for 24 h at 37 °C total FFAs increased to 2.72 ± 1.29 mmol L−1 (P < 0.005). Biliary saturated and unsaturated FFAs were found in equal proportions before and after incubation, pointing to an additional presence of lipases other than PLA2. A COT of 1 day was observed in all gallbladder biles and increased to 1.7 ± 0.5 days after addition of 5 U L−1 of PLA2 (P < 0.01). An even higher COT of 2.5 ± 0.8 days was seen after addition of 5 mmol L−1 of a ‘biliary’ mixture of FFAs (P < 0.005) but the COT remained unchanged after addition of 5 mmol L−1 of 2‐lysolecithin. However, in the crystal growth assay in gallbladder bile addition of 5 U L−1 of PLA2, of 5 mmol L−1 of ‘biliary’ FFAs and of 5 mmol L−1 of 2‐lysolecithin decreased significantly the number of cholesterol crystals formed during follow‐up.

Conclusion

An elevated activity of PLA2 in gallbladder bile may counteract the formation of cholesterol crystals through increased formation of FFAs and 2‐lysolecithin. However, regarding the comparatively low activity of PLA2 in gallbladder bile PLA2 seems to be of only minor pathophysiological importance in the formation of cholesterol gallstones.
A 4‐trifluoromethyl derivative of salicylate, triflusal, stimulates nitric oxide production by human neutrophils: role in platelet function
Authors: De Miguel  , Jiménez  , Montón  , Farré  , Del Mar Arriero  , Rodríguez‐Feo  , García‐Cañete  , Rico  , Gómez  , Núñez  , Casado  , Farré
Published: March 2003

Background

The thrombotic process is a multicellular phenomenon in which not only platelets but also neutrophils are involved. Recent in vitro studies performed in our laboratory have demonstrated that triflusal, a 4‐trifluoromethyl derivative of salicylate, reduced platelet aggregation not only by inhibiting thromboxane A2 production but also by stimulating nitric oxide (NO) generation by neutrophils. The aim of the present study was to evaluate whether oral treatment of healthy volunteers with triflusal could modify the ability of their neutrophils to produce NO and to test the role of the NO released by neutrophils in the modulation of ADP‐induced platelet aggregation and α‐granule secretion.

Methods

The study was performed in 12 healthy volunteers who were orally treated with triflusal (600 mg day−1) for 5 days. Flow cytometric detection of platelet surface expression of P‐selectin was used as a measure of the ability of platelets to release the contents of their α‐granules.

Results

After treatment with triflusal, there was an increase in NO production by neutrophils and an increase in endothelial nitric oxide synthase (eNOS) protein expression in neutrophils. A potentiation of the inhibition of platelet aggregation by neutrophils was reversed by incubating neutrophils with both an l‐arginine antagonist, NG‐nitro‐
l‐arginine methyl ester (
l‐NAME) and an NO scavenger, 2‐(4‐carboxyphenyl)‐4,4,5,5 tetramethylimidazoline 1‐oxyl 3‐oxide (C‐PTIO). A slight decrease in P‐selectin surface expression on platelets was found which was not modified by the presence of neutrophils and therefore by the neutrophil‐derived NO. Exogenous NO released by sodium nitroprusside dose‐dependently inhibited both ADP‐stimulated α‐granule secretion and platelet aggregation. Therefore, platelet aggregation showed a greater sensitivity to be inhibited by exogenous NO than P‐selectin expression.

Conclusion

Oral treatment of healthy volunteers with triflusal stimulated NO production and eNOS protein expression in their neutrophils. After triflusal treatment, the neutrophils demonstrated a higher ability to prevent ADP‐induced platelet aggregation. However, the neutrophils and the endogenous NO generated by them failed to modify P‐selectin expression in ADP‐activated platelets.
Disordered calcium homeostasis of sepsis: association with calcitonin precursors
Authors: Müller  , Becker  , Kränzlin  , Schächinger  , Huber  , Nylèn  , Snider  , White  , Schmidt‐Gayk  , Zimmerli  , Ritz
Published: March 2003

Background

Hypocalcemia and increased serum levels of calcitonin precursors are common in critically ill patients, especially in those with sepsis. We investigated calcium homeostasis in such patients.

Patients and methods

Serum concentrations of total and ionized calcium and known factors influencing or reflecting calcium homeostasis were measured in 101 consecutive patients of a medical intensive care unit. Calcitonin precursor levels were determined using a highly sensitive radioimmunoassay.

Results

Critical illness per se was associated with decreased serum total and ionized calcium levels, which correlated with the severity of the underlying disease as measured by the APACHE II score. In addition, total and ionized hypocalcemia was more pronounced with increasing severity of infection (P < 0.02), and occurred in parallel with a marked increase of calcitonin precursors (P < 0.001). Mature calcitonin levels, however, remained normal. Changes of serum ionized calcium concentrations from admission to discharge correlated significantly with changes in the serum calcitonin precursor concentration (r2 = − 0.14, P < 0.001). Circulating vitamin D levels, parathyroid hormone levels and other markers reflecting calcium homeostasis did not correlate with the severity of infection.

Conclusions

In critically ill patients with sepsis, markedly elevated circulating calcitonin precursors might play a role in the development of the pronounced hypocalcemia. The specific calcitonin precursor(s) responsible for this effect and the pathophysiological mechanism remain to be elucidated.
Oxidative stress in symptom‐free HCV carriers: relation with ALT flare‐up
Authors: Vendemiale G. , Grattagliano I. , Portincasa P. , Serviddio G. , Palasciamo G. , Altomare E.
Published: March 2003

Background

The reason why some hepatitis C virus carriers with normal aminotransferase activity present, during time, an activation of the disease, is unknown. The aim of this study was to assess the oxidative balance in such patients and to evaluate its possible role on the severity of disease.

Materials and methods

Histology, glutathione and malondialdehyde were determined in the liver of 30 HCV‐RNA positive patients with persistently normal aminotransferase. Patients were followed‐up for 18 months with plasmatic determinations of aminotransferase, ferritin, glutathione, malondialdehyde, carbonyl and sulphydryl protein levels (every 2 months) and serum HCV‐RNA (every 3 months).

Results

Four subjects had normal histology, whereas the remaining 26 showed mild/moderate chronic hepatitis. Hepatic glutathione and malondialdehyde concentrations were normal in 16 patients and clearly altered in the other 14. The hepatic redox state did not correlate with histology whereas it correlated with plasmatic oxidative markers. During the study, aminotransferase flared up in 11 patients, 9 of these (82%) having at enrolment an altered hepatic oxidative balance. Patients with aminotransferase elevation showed increased blood indices of oxidative stress, which occurred earlier than aminotransferase flare‐ups. No oxidative stress was observed in the remaining subjects.

Discussion

This study suggests that symptom‐free HCV carriers with impaired redox state have a higher risk of aminotransferase flare‐up; therefore the impaired oxidative balance may have a prognostic significance on disease activity.
Molecular analysis of estrogen receptor alpha and beta in lupus patients
Authors: Kassi E. N. , Vlachoyiannopoulos P. G. , Moutsopoulos H. M. , Sekeris C. E. , Moutsatsou P.
Published: March 2003

Background In female patients with systemic lupus erythematosus (SLE), we identified estrogen receptor ERα, ERβ and ERα variant transcripts in peripheral blood mononuclear cells (PBMC). Exon 1 and 2 of ERα gene was subjected to mutation analysis to assess whether possible nucleotide alterations are linked to the disease.

Methods The whole coding sequence of ERα was analysed by reverse transcription polymerase chain reaction (RT‐PCR) and cDNA sequencing in PBMC prepared from 19 SLE patients and 12 healthy females. ERα exon 1 and exon 2 were subjected to mutation analysis using DNA isolated from whole blood of 21 SLE patients and 29 healthy females. The aminoterminal coding sequence of ERβ was also analysed by RT‐PCR.

Results Wild type ERα and ERα splicing variants with deletions in exons 2, 5 and 7 were detected both in healthy individuals and in SLE patients, with no qualitative difference in their expression among the two populations. In ERα exon 1, the polymorphisms identified codon 10 and codon 87, both in patients and in healthy individuals who were not associated with the disease. No other mutations were present in ERα exon 1 or ERα exon 2 in all subjects studied. ERβ was expressed in both populations.

Conclusion: PBMC of SLE patients express wild type ERα, ERβ and the same ERα variants as do healthy individuals. Genetic alterations in exon 1 and exon 2 of the ERα gene are not linked with SLE disease.
Effect of vitamin C on neutrophil function after high‐intensity exercise
Authors: Krause R. , Patruta S. , Daxböck F. , Fladerer P. , Biegelmayer C. , Wenisch C.
Published: March 2003

High‐intensity exercise leads to an increased risk of upper respiratory tract infections in athletes, which had been related to an exercise‐induced impairment of neutrophil function. In this study, several indices of neutrophil function were analysed before and after a biathlon and the effect of oral vitamin C on neutrophil function was determined.

Six athletes took 2 g vitamin C daily for 1 week prior to a biathlon and four athletes did not take any supplementation. Neutrophil phagocytosis was analysed by fluorescence microscopy and flow cytometry. Cytosolic calcium kinetics were assessed fluorometrically and neutrophil bactericidal ability was assessed by fluorescence microscopy. Reactive oxygen production was analysed by flow cytometry. Catecholamines were analysed by high‐performance liquid chromatography.

After high‐intensity exercise there were significant reductions in the number of phagocytosed Escherichia coli per neutrophil and in neutrophil bactericidal ability. There was a significant exercise‐dependent increase of catecholamines. There was no difference between the two groups of athletes.

These results do not support the concept that vitamin C supplementation corrects neutrophil dysfunction after strenuous exercise.
Idiopathic chronic constipation: tachykinins as cotransmitters in colonic contraction
Authors: Mitolo‐Chieppa D. , Mansi G. , Nacci C. , De Salvia M. A. , Montagnani M. , Potenza M. A. , Rinaldi R. , Lerro G. , Siro‐Brigiani G. , Mitolo C. I. , Rinaldi M. , Altomare D. F. , Memeo V.
Published: March 2003

Background Tachykinins (TKs) have been shown to be involved in the excitatory enteric motor pathway. This study aimed to examine the direct and nerve‐mediated effect of specific NK1, NK2 and NK3 receptor agonists and antagonists in colonic preparations from control subjects and patients with idiopathic chronic constipation (ICC).

Materials and methods Cumulative concentrations of Sar9Met(O2)11 substance P (selective NK1 receptor agonist), [Ala5,β‐Ala8]‐neurokinin A (4–10) (selective NK2 receptor agonist) and [MePhe7]‐neurokinin B (selective NK3 receptor agonist) were tested on colonic circular muscle strips to evaluate the direct drug effects. In addition, in the presence of atropine, the role of TKs in the off‐contraction that follows the typical inhibitory response evoked by low frequencies of electrical field stimulation (0·5–10 Hz, 20 V, 1 ms pulse trains lasting 1 min) was investigated.

Results In control preparations, the rank order of potency was: NK2 receptor‐selective agonist > NK3 receptor‐selective agonist > NK1 receptor‐selective agonist. The off‐contraction was found to be reduced by about 30–40% in colonic circular muscle from ICC patients with respect to controls. Incubation with the NK1 receptor agonist did not modify the off‐contraction measurements in either control or ICC preparations. Conversely, both NK2 and NK3 receptor agonists significantly (P < 0·01) increased the off‐contraction in ICC preparations only. This increased response was fully antagonized by MEN‐10627, a NK2 and NK3 receptor antagonist depending on the dose.

Conclusions We may conclude that ICC is hyporesponsive to TKs and that the contractile reflex to distension is greatly reduced in ICC disease, but can be restored by incubation with NK2 and NK3 receptor agonists.
Interferon‐γ in healthy subjects: selective modulation of inflammatory mediators
Authors: De Metz J. , Hack C. E. , Romijn J. A. , Levi M. , Out T. A. , Ten Berge I. J. M. , Sauerwein H. P.
Published: March 2003

Background It is suggested that interferon‐γ (IFN‐γ), like other cytokines, is a mediator in the host inflammatory response, which could be of importance in the pathophysiology of sepsis. The role of IFN‐γ in human host inflammatory responses, however, has not been studied.

Design In a placebo‐controlled trial we studied the acute effects of IFN‐γ administration on host inflammatory mediators in healthy men: i.e. the cytokine/chemokine cascade system, acute‐phase proteins, activation markers of the innate cellular immunity and coagulation/fibrinolysis parameters.

Results IFN‐γ increased plasma levels of interleukin‐6 (IL‐6), IL‐8 and IFN‐γ‐inducible protein‐10 (IP‐10) (P < 0·05), but did not affect plasma levels of other cytokines (IL‐4, IL‐10, tumour necrosis factor‐α, IL‐12p40/p70). Plasma concentrations of C‐reactive protein and secretory phospholipase A2 both increased (P < 0·05). Plasma levels of the leucocyte activation marker elastase‐α1–antitrypsin complexes increased after IFN‐γ administration (P < 0·05), IFN‐γ increased the percentage of high‐affinity Fcγ‐receptor (FcγRI) ‐positive neutrophils (P < 0·05), but did not affect the mean fluorescence intensity of FcγRI on neutrophils. Procoagulant and profibrinolytic effects of IFN‐γ were evidenced by increased plasma levels of prothrombin fragment F1 + F2, tissue‐plasminogen activator and plasmin‐α2–antiplasmin complexes (P < 0·05).

Conclusion We conclude that IFN‐γ selectively affects host inflammatory mediators in humans.
Effects of smoking on activation markers, Fas expression and apoptosis of peripheral blood lymphocytes
Authors: Bijl M. , Horst G. , Limburg P. C. , Kallenberg C. G. M.
Published: March 2003

Background Smoking influences numbers and function of peripheral blood lymphocytes (PBL) by a process that is badly understood. We conducted this study to evaluate whether the immune impairment of smoking might be related to changes in the expression or functionality of Fas, a cell surface molecule that plays a central role in immune homeostasis and cytotoxic activity.

Methods PBL from 10 smoking and 10 nonsmoking healthy volunteers were isolated. Flow cytometry was performed to measure the state of activation, Fas expression and apoptosis of PBL. Functionality of Fas was tested by assessing apoptosis after incubation of isolated lymphocytes with agonistic anti‐Fas antibodies in four smoking and four nonsmoking individuals.

Results Smoking was associated with an increase in the percentage of Fas‐expressing CD4+ T and B lymphocytes. A decrease in the percentage of activated (CD38+) B cells was observed. In vitro Fas‐induced apoptosis did not appear different between smokers and nonsmokers. No differences in the percentages of circulating apoptotic lymphocytes could be demonstrated between smoking and nonsmoking individuals.

Conclusion Smoking is associated with increased Fas expression on PBL in general, and on B cells in particular. This might render these cells more susceptible for apoptosis. As Fas is functionally intact this may also explain the reduced percentage of activated (CD38+) B cells found in smoking individuals. The latter may contribute to the reduced humoral immune response observed in smokers.
Peripheral blood T‐cell responses to pyruvate dehydrogenase complex in primary biliary cirrhosis: role of antigen‐presenting dendritic cells
Authors: Akbar S. M. F. , Yamamoto K. , Miyakawa H. , Ninomiya T. , Abe M. , Hiasa Y. , Masumoto T. , Horiike N. , Onji M.
Published: March 2003

Patients with primary biliary cirrhosis (PBC) are usually characterized by the presence of antibody to pyruvate dehydrogenase complex (PDC) in the sera and PDC‐specific T cells in the liver. However, most of the patients with PBC do not show peripheral blood T cells response to PDC. In this study, we re‐evaluated the peripheral blood T cell responses to PDC in PBC using antigen‐presenting dendritic cells (DCs).

Twenty‐four patients with PBC (AMA‐positive: 16; AMA‐negative: 8) and 13 normal controls were enrolled in the study. Peripheral blood mononuclear cells (PBMC) and highly enriched populations of T cells were stimulated with either only PDC or DCs plus PDC or PDC‐pulsed DC plus PDC. Antibodies to different components of PDC were estimated by an immunoblotting technique.

PBMC from only one out of ten AMA‐positive PBC patients proliferated when cultured with only PDC. However, peripheral blood T cells from ten out of ten AMA‐positive PBC patients and three out of ten AMA‐negative PBC patients, but none of the five normal controls showed PDC‐specific proliferation when cultured with PDC‐pulsed DCs. Two of these three AMA‐negative PBC patients, although negative for AMA, were positive for antibodies to other components of PDC.

PDC‐specific T cells are present in the peripheral blood from most of the patients with PBC. This is the first report on the effectiveness of antigen‐pulsed DCs for the elucidation of autoantigen‐specific immune response in human autoimmune diseases.
Lack of association between apolipoprotein E genoype and ischaemic stroke in a Scottish population
Authors: MacLeod M. J. , De Lange R. P. , Breen G. , Meiklejohn D. , Lemmon H. , St Clair D.
Published: March 2003

Background Apolipoprotein E ε4 allele has been associated with increased risk of coronary heart disease, and is also a major genetic susceptibility locus for Alzheimer's disease. Some studies have shown an association between apoE genotype and ischaemic stroke or outcome following stroke, while other studies have failed to do so.

Materials and methods Using PCR and the Taqman fluorescence system to detect polymorphisms we examined apoE genotype in 266 ischaemic stroke cases and in a control population.

Results We found no association between apoeE ε 4 allele distribution and ischaemic stroke, or with outcome following stroke as measured using the Rankin score.

Conclusion This study disagrees with a recent meta‐analysis, and suggests that further studies are required to clarify the exact relationship between apoE genotype and ischaemic stroke.
Gemfibrozil improves insulin sensitivity and flow‐mediated vasodilatation in type 2 diabetic patients
Authors: Avogaro A. , Miola M. , Favaro A. , Gottardo L. , Pacini G. , Manzato E. , Zambon S. , Sacerdoti D. , De Kreutzenberg S. , Piliego T. , Tiengo A. , Del Prato S.
Published: March 2003

Background Endothelial dysfunction is an early feature of atherosclerosis. The relationship between insulin action and hypertriglyceridaemia on endothelial function is still debated.

Materials and Methods This study was designed to determine the effect of a 3 month treatment with Gemfibrozil (GF) on flow‐mediated vasodilatation and insulin sensitivity. Ten type 2 diabetic patients were randomised in crossover, double blind fashion, either to GF, 600 mg b.i.d. or placebo, for 12 weeks. Lipid profile, low‐density lipoprotein (LDL) distribution and flotation properties, insulin action and flow‐mediated vasodilatation (FMD) by brachial artery ultrasound, were assessed.

Results GF decreased serum triglyceride (TG) concentration with an absolute difference of 1·79 ± 1·28 mmol L−1 (P < 0·0016) between active treatment and placebo, and significantly increased serum high‐density lipoprotein (HDL) cholesterol (P = 0·0233). No differences were observed in total, intermediate‐density lipoproteins (IDL), LDL cholesterol concentration and LDL peak buoyancy between treatments. GF also improved SI, an index of insulin action (P = 0·005). The FMD was 7 ± 3% in the baseline condition, 7 ± 2% during placebo and 14 ± 3% after GF (P < 0·006).

Conclusions GF treatment improves both insulin action and flow‐mediated vasodilatation in type 2 diabetic patients. The reduction of TG concentration allows the simultaneous correction of two important components of the metabolic syndrome.
Genetic polymorphisms and lipid response to dietary changes in humans
Authors: Weggemans R. M. , Zock P. L. , Ordovas J. M. , Ramos‐Galluzzi J. , Katan M. B.
Published: March 2003

Previous studies on the effects of genetic polymorphisms on the serum cholesterol response to dietary treatments were often inconsistent and frequently involved small numbers of subjects.

We studied the effect of 10 genetic polymorphisms on the responses of serum cholesterol to saturated and trans fat, cholesterol and the coffee diterpene, cafestol, as measured in 26 dietary trials performed over 20 years in 405 mostly normolipidaemic subjects.

Apoprotein A4 360‐2 allele attenuated the response of low‐density lipoprotein cholesterol to dietary cholesterol, but not in women. Subjects with the cholesteryl ester transfer protein TaqIb‐1 allele had −0·02 to −0·05 mmol L−1 smaller responses of high‐density lipoprotein cholesterol to diet than those with the 2/2 genotype. The effects of the other eight polymorphisms on cholesterol response were either inconsistent with results in previous studies or need to be replicated in other studies.

Apoprotein A4360 and cholesteryl ester transfer protein TaqIb polymorphisms may affect dietary responses. However, no one single genotype was a major determinant of a subject's lipid response to diet. Therefore, knowledge of these genotypes by themselves is of little use in the identification of subjects who may or may not benefit from dietary treatment.
Saturated triglycerides and fatty acids activate neutrophils depending on carbon chain‐length
Authors: Wanten G. J. A. , Janssen F. P. , Naber A. H. J.
Published: March 2003

Background Unsaturated fatty acids are known as neutrophil activators. In the present study we investigated whether saturated triglycerides and fatty acids may also contribute to the previously observed activation of neutrophils by nutritional lipid emulsions. Furthermore we tested the hypothesis that carbon‐chain length is of importance in this respect.

Materials and methods Neutrophils (1 × 106 mL−1) were isolated from the blood of nine volunteers. Chemiluminescence was used to evaluate neutrophil activation, characterized by the production of oxygen radicals by neutrophils during incubation with 1 mmol L−1 saturated fatty acid (6–20 carbon) or triglycerides (6–12 carbon fatty acid), dissolved in aqueous medium by preparing micelles with dipalmitoyl phosphatidylcholine (DPPC). Results were expressed as means ± SEMs of the overall luminescence signal relative to the signal of cells incubated in medium.

Results Similar to a positive control, the polyunsaturated fatty acid arachidonic acid (C20 : 4), the triglycerides tricaproin (TC6 : 0), tricaprylin (TC8 : 0) and trilaurin (TC12 : 0) as well as the fatty acids lauric acid (C12 : 0), palmitic acid (C16 : 0), stearic acid (C18 : 0) and arachidic acid (C20 : 0) all induced oxygen radical production in neutrophils, while the medium‐chain triglyceride tricaprin (TC10 : 0) and fatty acids caproic acid (C6 : 0), caprylic acid (C8 : 0) and capric acid (C10 : 0) exerted no clear effects, similar to negative controls (DPPC and glycerol).

Conclusions Besides their (poly)‐unsaturated counterparts, saturated triglycerides and fatty acids also activate neutrophils. Carbon chain‐length is pivotal in the interaction of fatty acids and triglycerides and cells of the immune system.
Oestrogen receptor gene variation is a determinant of coronary reactivity in healthy young men
Authors: Lehtimäki T. , Laaksonen R. , Mattila K. M. , Janatuinen T. , Vesalainen R. , Nuutila P. , Laakso J. , Jaakkola O. , Koivula T. , Knuuti J.
Published: March 2003

Background Oxidised low‐density lipoprotein (ox‐LDL) is a determinant of impaired coronary function and oestrogens inhibit its formation probably throughout genetically‐variable oestrogen receptor 1 (ESR1) in artery wall. We hypothesized that the ESR1 polymorphism might influence coronary function and reactivity as measured by positron emission tomography (PET), which allows the detection of coronary dysfunction before appearance of angiographic lesions.

Materials and methods Fifty‐one healthy young men (aged 35 ± 4 years), with normal or slightly‐elevated serum cholesterol, underwent PET with intravenous adenosine. ESR1 PvuII genotypes P/P, P/p, and p/p in addition to the plasma autoantibody titre against ox‐LDL, a marker of in vivo oxidation, were determined.

Results The ESR1 genotype persisted as the only significant predictor of adenosine stimulated coronary flow (P = 0·035) after adjustment for other coronary risk factors. Subjects with P/P genotype had 33·4 and 41·8% lower adenosine‐stimulated flow values than subjects with P/p and p/p genotypes (P = 0·030). Furthermore, plasma levels of ox‐LDL titre were on average 59 and 77% higher in subjects with P/P genotype than in subjects with P/p or p/p genotypes (P = 0·049).

Conclusions These tentative findings from our pilot study provide evidence that genetic variation in ESR1 may modify coronary reactivity and LDL oxidation and reflect differences in the early pathogenesis of coronary dysfunction in these healthy young men.
Amadori‐albumin correlates with microvascular complications and precedes nephropathy in type 1 diabetic patients
Authors: Schalkwijk C. G. , Chaturvedi N. , Twaafhoven H. , Van Hinsbergh V. W. M. , Stehouwer C. D. A. ,   the EUCLID Study Group
Published: March 2003

Background Amadori‐albumin, a major glycated protein, is involved in experimental hyperglycaemia‐induced microvascular complications, and is associated with advanced nephropathy in Type I diabetic patients in humans. Our aim was to assess the association of Amadori‐albumin with early nephropathy and with retinopathy in Type I diabetic patients and the involvement of chronic low‐degree inflammation therein.

Design and Methods Amadori‐albumin, the Amadori product of haemoglobin (HbA1c), C‐reactive protein, and fibrinogen levels were measured in the EUCLID study, a 2‐year randomised, double‐blind, placebo‐controlled trial of lisinopril in 447 Type I diabetic patients. Retinal photographs were taken in 341 patients at baseline and 294 at follow up.

Results Amadori‐albumin was positively associated with albumin the excretion rate and retinopathy status (P = 0·0001 and P = 0·02 for trend, respectively) and with the progression from normoalbuminuria to (micro)albuminuria (38·6 U mL−1 in nonprogressors, 44·3 U mL−1 in progressors; P = 0·02), but not with the development or progression of retinopathy during a 2‐year follow up. Amadori‐albumin levels at baseline were associated with C‐reactive protein and fibrinogen (P = 0·0007 and P = 0·0001, respectively). C‐reactive protein and fibrinogen were also associated with albumin excretion rates (P = 0·03 and P = 0·01, respectively) and retinopathy status (P = 0·02 and P = 0·0006, respectively). Adjustment for these inflammatory markers did not markedly attenuate the association between Amadori‐albumin and the albumin excretion rate, while adjustment for fibrinogen, but not C‐reactive protein, abolished the association between Amadori‐albumin and retinopathy. Lisinopril had no impact on the association between the levels of Amadori‐albumin and albumin excretion rates or retinopathy.

Conclusions Amadori‐albumin was associated with early nephropathy and with retinopathy in Type I diabetic patients and preceded an increase in albumin excretion rate, but not retinopathy. A chronic low‐degree inflammation does not appear to be involved in Amadori‐albumin‐associated microvascular complications in Type I diabetes.
Effects of combined treatment with pravastatin and ursodeoxycholic acid on hepatic cholesterol metabolism
Authors: Hillebrant C.‐G. , Nyberg B. , Gustafsson U. , Sahlin S. , Björkhem I. , Rudling M. , Einarsson C.
Published: March 2003

Background Treatment with ursodeoxycholic acid and also, to some degree, statins reduces cholesterol saturation of bile. The present study aimed [1] to study the effects of combined treatment with ursodeoxycholic acid and pravastatin on hepatic cholesterol metabolism and [2] to evaluate if the addition of pravastatin to ursodeoxycholic acid treatment has beneficial effects on the lipid composition of gallbladder bile in gallstone patients.

Materials and methods Nineteen patients with cholesterol gallstones were subjected to combined treatment with ursodeoxycholic acid (500 mg bid) and pravastatin (20 mg bid) for three weeks before cholecystectomy. Eleven patients received ursodeoxycholic acid only and 20 untreated gallstone patients served as controls. Gallbladder bile was collected, and for both the patients receiving combined treatment and the controls a liver biopsy was also obtained peroperatively.

Results The cholesterol saturation of bile averaged 59% in the patients on combined treatment, 60% in the ursodeoxycholic acid‐treated patients, and 130% in the untreated controls. In the patients receiving ursodeoxycholic acid, this bile salt constituted approximately 60% of all bile salts. The patients receiving combined treatment had reduced cholesterol synthesis, as reflected by a 45% reduction in serum lathosterol. The activity and the mRNA levels of cholesterol 7α‐hydroxylase and the mRNA levels for the low density lipoprotein‐receptor were not significantly affected.

Conclusions Pravastatin does not further reduce the cholesterol saturation of bile in gallstone patients treated with ursodeoxycholic acid, although hepatic cholesterol synthesis is inhibited. The study supports the important concept that de novo synthesized cholesterol is not particularly important for biliary cholesterol secretion in humans.
Ca2+ mobilization in saphenous vein smooth muscle cells derived from patients with primary varicosity
Authors: Schuller‐Petrovic S. , Stessel H. , Brunner F.
Published: March 2003

Background  Human primary varicosity is associated with ‘weakness’ of the vein wall. We investigated whether the reduced responsiveness of varicose veins to physiological vasoconstrictors might result from impaired Ca2+ mobilization in venous smooth muscle.

Materials and methods  The hypothesis was tested in cells derived from phenotypically different vein segments that were obtained from the inguinal saphenous vein (tissue with incompetent valves), the distal portion of the long saphenous vein just above the medial ankle (clinically healthy tissue), and from a tributary to the long saphenous vein just below the knee (incompetent and overtly varicose tissue). Saphenous vein from patients undergoing cardiac surgery served as control. Cytosolic free Ca2+ levels ([Ca2+]i) were determined with the fura‐2 method in cultured medial smooth muscle cells of third to sixth passage (21–23 measurements per tissue derived from five controls and seven patients).

Results  Angiotensin II (10 nmol L−1 to 10 µmol L−1) induced a significantly (P < 0·05) smaller rise in [Ca2+li response in cells derived from incompetent or varicose segments (∼70 nmol L−1) than in cells derived from clinically healthy vein (∼130 nmol L−1) or controls (∼170 nmol L−1). Likewise, the effect of endothelin‐1 (100 nmol L−1) on [Ca2+]i was considerably less in cells derived from segments with incompetent valves or from varicose vessel segments than in cells derived from control patients (P < 0·05). In organ baths, endothelium‐denuded strips of varicose vessels contracted significantly less in response to these agonists than clinically healthy segments from the same patient.

Conclusions  The reduced contractility of diseased human varicose veins in response to angiotensin II and endothelin‐1 involves impaired Ca2+ mobilization.