bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of gemfibrozil on peripheral atherosclerosis and platelet activation in a pig model of hyperlipidemia
Authors: Royo T. , Alfón J. , Berrozpe M. , Badimon L.
Published: March 2003

Background

Gemfibrozil has been shown to have beneficial effects in the primary and secondary prevention of atherosclerosis. However, a platelet pro‐activating effect induced by the drug has been reported.

Material and methods

We analysed the effect of hyperlipidemia and its treatment with gemfibrozil on platelet‐fibrinogen binding and the development of early fibrinogen‐rich vascular lesions in a porcine model of atherosclerosis. Polyclonal antibodies were raised against purified pig fibrinogen and intact platelets. Two groups of animals were fed a cholesterol/saturated fat‐enriched diet for 50 days; one group was treated with gemfibrozil and the other with placebo.

Results

The hyperlipidemic diet induced a significant increase in total cholesterol; this was prevented by gemfibrozil (P < 0.05). The increase in platelet‐fibrinogen binding induced by hypercholesterolemia was mildly reduced in the gemfibrozil treated animals. Histological analysis of aortic vascular wall (abdominal aorta at the iliac bifurcation) from hyperlipidemic animals showed early lesions with fibrinogen infiltration; the lesions were reduced in the fibrate‐treated animals.

Conclusions

Gemfibrozil delayed the development of peripheral atherosclerotic plaque, normalised the impaired lipid profile induced by the hyperlipidemic diet and did not show a functionally detectable platelet pro‐activating effect able to increase platelet‐fibrinogen binding.
Phospholipid composition in late infantile neuronal ceroid lipofuscinosis
Authors: Granier L.‐A. , Langley K. , Leray C. , Sarlieve L. L.
Published: March 2003

Neuronal ceroid lipofuscinosis (NCL) is a relatively common group of inherited neurodegenerative disorders characterised by the accumulation of autofluorescent lipopigments (ceroid) similar to lipofuscin. Because of this property, studies have concentrated on fatty acid metabolism and lipid peroxidation.

In the present study, the fatty acid composition of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) and the molecular species compositions of diacylglycerophosphocholine (diacyl GPC), diacylglycerophosphoethanolamine (diacyl GPE) and alkenylacyl GPE (plasmalogens) were investigated in cultured skin fibroblasts from three patients with a confirmed diagnosis of the late infantile form of the disease (LINCL, CLN2) and three healthy age‐matched controls.

Relatively minor differences in the fatty acid compositions of PC and PE were observed between patients and controls. However, dimethyl acetals of plasmalogens were found to be 40% higher in the patients compared to in the controls. Control and LINCL fibroblasts displayed only slight differences in the molecular compositions of diacyl GPE and diacyl GPC. In contrast, compared with normal cells, LINCL fibroblasts had higher levels of alkenylacyl GPE species containing both 18 : 1 and polyunsaturated fatty acids, but lower levels of species with 16 : 0 or 18 : 0 in the sn‐1 position.

The molecular composition of PC and PE subclasses in skin fibroblasts of healthy subjects and patients suffering from LINCL is here described for the first time. While few differences are noticeable in the fatty acid composition of PC and PE and the molecular species distribution of diacylGPC and diacylGPE, the alkenylacyl GPE (or ethanolamine plasmalogens) were found to differ significantly between patients and healthy controls.
Intracrinology and the local enzymatic control of hormone distribution and metabolism: dehydroepiandrosterone does not just act as a prohormone for androgens and estrogens
Authors: Kühn‐Velten W. N.
Published: March 2003

The study of subcellular environments for the interaction of biomolecules and observations of certain features of hormone actions have nourished the concept of ‘intracrinology’, which describes hormone actions within a singular cell, in contrast to the well‐described autocrine, paracrine and endocrine fashion. Synthesis and metabolism of DHEA make it a likely candidate for intracrine actions in target tissues. Recent experimental findings are reviewed in this context.
Molecular cues for the development of adrenal chromaffin cells and their preganglionic innervation
Authors: Schober A. , Krieglstein K. , Unsicker K.
Published: March 2003

Based on recent evidence from in vitro and gene knockout/insertion studies, this short review summarizes the molecular scenario underlying the development of adrenal chromaffin cells and their preganglionic innervation. During migration of neural crest cells from the dorsal surface of the neural tube to their destinations in the sympathetic primordia and adrenal glands, precursors of the so‐called sympathoadrenal (SA) cell lineage are exposed to signals from the notochord and ventral neural tube probably including the protein, Sonic hedgehog. These, and signals in the region of the dorsal aorta (members of the family of bone morphogentic proteins), where SA progenitor cells subsequently assemble, are essential for the induction of the adrenergic phenotype. SA progenitor cells subsequently differentiate into paravertebral and prevertebral sympathetic neurones, intra‐ and extra‐adrenal chromaffin cells and intermediate SIF (small intensely fluorescent) cells. Based on in vitro studies with isolated SA and chromaffin progenitor cells, glucocortiocids have been claimed as essential for suppressing neuronal commitment and for channelling SA cells towards the chromaffin phenotype. However, mice deficient for a functional glucocorticoid receptor possess the full complement of adrenal chromaffin cells at birth, suggesting that signals other than glucocorticoid hormones may be important in triggering chromaffin cell differentiation. The cholinergic neurones that are preganglionic to adrenal chromaffin cells have their cell bodies located in the intermediolateral column (IML) of the spinal cord. For their normal development, these neurones require signals from the adrenal medulla, which include neurotrophin‐4, a major neurotrophic factor of adrenal chromaffin cells. Taken together, these data provide a more complete picture of molecular signalling in the development of one of the most important neuroendocrine tissues in vertebrates.
Elevated apolipoprotein B‐48 and remnant‐like particle–cholesterol in heterozygous familial hypercholesterolaemia
Authors: Dane‐Stewart C. A. , Watts G. F. , Mamo J. C. L. , Dimmitt S. B. , Barrett P. H. R. , Redgrave T. G.
Published: March 2003

Apolipoprotein B‐48 (apoB‐48) is a marker of triglyceride‐rich lipoprotein (TRL) remnants of intestinal origin. Chylomicron remnants are causally related to atherosclerosis. We have shown previously that fasting plasma apoB‐48 may predict postprandial lipaemia. Remnant‐like particle–cholesterol (RLP‐C) may also reflect TRL remnants. We aimed to determine whether subjects with heterozygous familial hypercholesterolaemia (FH) had an accumulation of remnants of intestinal origin, as reflected by fasting plasma apoB‐48 and RLP‐C levels.

The fasting plasma concentrations of apoB‐48 and RLP‐C were measured in 15 subjects with heterozygous FH and 15 age‐ and sex‐matched, normolipidaemic subjects. ApoB‐48 was determined using SDS‐PAGE and a western blotting/enhanced chemi‐luminescence technique. RLP‐C was measured using an immuno‐separation assay. Serum apolipoprotein B‐100 (apoB‐100) levels were measured using immmunonephelometry; lipids were assayed enzymatically.

Compared with controls, FH subjects had significantly elevated plasma concentrations of apoB‐48 (29·3 median, 16·7–45·1 mg L−1 range vs. 12·8, 7·3–28·6; P < 0·001) and RLP‐C (16·2, 1·5–114·3 mg dL−1 vs. 8·5, 5·0–13·5; P = 0·003), as well as serum total apoB‐100 (1·9, 1·3–2·6 g L−1 vs. 1·0, 0·3–1·3; P < 0·001), LDL‐cholesterol (8·1, 4·6–10·4 mmol L−1 vs. 3·5, 2·4–4·4; P < 0·001) and triglyceride (1·5, 0·6–5·6 mmol L−1 vs. 1·0, 0·4–1·8; P = 0·018). There was no significant difference in HDL cholesterol.

The findings suggest that patients with heterozygous FH have elevated plasma concentrations of TRL remnants, including those of intestinal origin. This may be a consequence of decreased clearance of these particles by the LDL‐receptor.
Low frequency of p53 and ras mutations in bile of patients with hepato‐biliary disease: a prospective study in more than 100 patients
Authors: Müller P. , Ostwald C. , Püschel K. , Brinkmann B. , Plath F. , Kröger J. , Barten M. , Nizze H. , Schareck W. D. , Hauenstein K. , Liebe S. , Löhr J. M.
Published: March 2003

The diagnosis of biliary disease, namely malignant disorders, is frequently hampered by the inconclusive cytology. We investigated prospectively the frequency of molecular changes in p53 and ras compared with cytology in patients with primary or secondary hepato‐biliary disease.

We investigated 118 consecutive patients, aged 24–89 with the following clincal diagnoses: choledocho/cholecystolithiasis (28), cholangiocellular carcinoma (21), gall bladder tumor (8), liver metastasis (3), autoimmune disease (8), chronic pancreatitis (16), pancreatic carcinoma (11), papillary disease (4), hepatic cirrhosis (6), cholangitis (2), anomalies (2), and normal (9). Bile was aspirated during routine endoscopic retrograde cholangio pancreatography (ERCP) or percutaneous transhepatic cholangiography (PTC). DNA was prepared freshly from a native aliquot. p53 mutations were detected by polymerase chain reaction (PCR) for exons 5 through 8 followed by TGGE. PCR for ras mutations was performed as RFLP–PCR with sequencing.

In four cases, mutations in p53 could be found in exons 6 and 7. Twenty‐two samples showed ras mutations; ras mutations were found in choledocholithiasis (4/28), bile duct (5/21), gall bladder (3/8) and pancreatic (1/11) carcinoma, liver metastasis (3/3), ulcerative colitis (2/3), PSC (1/2), and chronic pancreatitis (1/16). Cytology was clearly positive in seven cases, suspicious in three other, inconclusive in six, and negative in the rest. The molecular analysis resulted in a sensitivity of 33% and specificity of 87%, respectively, for the diagnosis of a malignant condition.

PCR for p53 and ras mutations may aid the diagnosis of primary and secondary (metastatic) hepatobiliary disease if a malignant condition of the bile ducts and the liver is suspected and cytology is inconclusive or negative. However, the incidence of p53 and ras mutations in bile seems less frequent than in other malignant conditions of the gastrointestinal tract and the pancreas and lower than in tissue, leaving a poor sensitiviy and specificity. Nevertheless, the presence of a p53 and/or ras mutation per se supports a clinical suspicion of malignancy, even when the conventional cytology is negative or inconclusive.
Phospholipase C activity of Helicobacter pylori is not associated with the presence of the cagA gene
Authors: Bode G. , Barth R. , Song Q. , Adler G.
Published: March 2003

Background Knowledge about the possible role of phospholipase C (PLC) activity of microbial pathogens in the development of disease is increasing. Recently attention has focused on investigating PLC activity elaborated by Helicobacter pylori, but the role of this enzyme in H. pylori pathogenesis is still unknown. The aim of this study was to correlate PLC‐activity of H. pylori on the basis of the cagA status with the clinical diagnosis of the patients.

Materials and methods Helicobacter pylori was isolated from patients with gastritis (G; n = 38), duodenal ulcer (DU; n = 15), gastric ulcer (GU; n = 11) and gastric cancer (GC; n = 12). Polymerase chain reaction primers DZ3/R009 which amplified a 1350‐bp fragment were used to detect the cagA gene. PLC activity was determined using p‐nitrophenylphosphorylcholine as substrate.

Results Of the strains, 60% were cagA+ and 40% were cagA−. All strains showed PLC activity (2·20 ± 0·91 U mg−1 protein). PLC activity showed no association with the cagA status: cagA+ (2·21 ± 1·03 U mg−1 protein), cagA− (2·18 ± 0·79 U mg−1 protein). Patients with GU had the highest PLC activity (2·77 ± 1·26 U mg−1 protein) and patients with GC had the lowest activity (1·8 ± 0·57 U mg−1 protein).

Conclusions Although PLC activity was present in all strains tested, it may only have pathological importance in patients with GU. However, the extent of PLC activity was independent of the presence of the cagA gene.
Bone turnover markers and sex hormones in men with idiopathic osteoporosis
Authors: Pietschmann P. , Kudlacek S. , Grisar J. , Spitzauer S. , Woloszczuk W. , Willvonseder R. , Peterlik M.
Published: March 2003

Background In contrast to osteoporosis in postmenopausal women, osteoporosis in men has received much less attention.

Patients and We determined various biochemical parameters of bone metabolism and sex hormones in 31 men with idiopathic osteoporosis and 35 age matched control subjects.

Results In the men with osteoporosis, a significantly increased urinary excretion of deoxypyridinoline (5·3 ± 0·2 vs. 4·6 ± 0·2 nmol mmol−1 creatinine; P = 0·033) in addition to increased serum levels of the c‐terminal telopeptide of type I collagen (2677 ± 230 vs. 2058 ± 153 pmol; P = 0·037) were found. While parameters of bone formation were not significantly different in the patients and controls, serum bone sialoprotein levels were significantly decreased in the patients (3·7 ± 0·8 vs. 12·4 ± 4·0 ng mL−1; P = 0·021). Moreover, in men with idiopathic osteoporosis, lower levels of estradiol (91·3 ± 5·8 vs. 114·6 ± 7·8 pmol L−1; P = 0·044), higher levels of sex hormone binding globulin (31·5 ± 3·1 vs. 24·2 ± 1·4 nmol L−1; P = 0·034) and a decreased free androgen index (42·6 ± 5·2 vs. 56·4 ± 5·9; P = 0·016) were seen. Serum estradiol levels correlated negatively with several parameters of bone resorption.

Conclusions In men with idiopathic osteoporosis, bone resorption is increased and exceeds bone formation. The excessive bone resorption seen in idiopathic male osteoporosis may be due to decreased estradiol levels and low levels of bioavailable testosterone.
Impaired nutritional status in common variable immunodeficiency patients correlates with reduced levels of serum IgA and of circulating CD4+ T lymphocytes
Authors: Muscaritoli M. , Fanfarillo F. , Luzi G. , Sirianni M. C. , Iebba F. , Laviano A. , Russo M. , Aiuti F. , Fanelli F. Rossi
Published: March 2003

Background Common variable immunodeficiency (CVI) is a primary defect of the immune system. Infections, persistent diarrhoea and malabsorption may result in malnutrition, which may in turn contribute to increased morbidity. In this paper, the prevalence of malnutrition in CVI was evaluated.

Patients and methods Forty CVI patients (20 male, 20 female, aged 17–75 years) underwent anthropometric measurements from which body mass index, arm fat and muscle area were calculated. Body mass index values < 18·5 and arm fat and muscle area values < 10th percentile were considered indicative of malnutrition. Patients were divided into four groups according to circulating CD4+ T cells (lower or greater than 300 µL−1) and serum immunoglobulin A (IgA) levels (detectable and undetectable).

Results Body mass index < 18·5, arm fat and muscle area < 10th percentile were observed in 23%, 58% and 44%, respectively, of patients. Lower values of body mass index, arm fat and muscle area were more frequent in patients with low CD4+ cells and undetectable IgA. Low arm fat values were more frequent in patients with diarrhoea (P = 0·03). Infectious episodes were more frequent in undetectable IgA than in detectable IgA patients (P = 0·04).

Conclusions Anthropometric measurements revealed an increased rate of malnutrition in CVI patients, particularly in those with low CD4+ and undetectable IgA, suggesting that selected CVI subjects could be considered for standard or specialized nutritional support.
Variation at the cholesteryl ester transfer protein gene in relation to plasma high density lipoproteins cholesterol levels and carotid intima‐media thickness
Authors: Kakko S. , Tamminen M. , Päivänsalo M. , Kauma H. , Rantala A. O. , Lilja M. , Reunanen A. , Kesäniemi Y. A. , Savolainen M. J.
Published: March 2003

Background Cholesteryl ester transfer protein (CETP) plays a major role in lipoprotein metabolism. We have screened the CETP gene for mutations and polymorphisms regulating high density lipoproteins cholesterol (HDL‐C) levels and the development of atherosclerosis, and found some polymorphisms (I405V and R451Q) to have minor effects.

Design The purpose of this study was to investigate the combined effect of the several polymorphisms of the CETP gene so far found on HDL‐C levels and carotid intima‐media thickness (IMT), and, in addition, to study whether the recently found functional polymorphism in the promoter region of the CETP gene (C to A, − 629 relative to the first transcribed nucleotide) explains the previous associations due to linkage disequilibrium. The genotypes were determined in a population sample of 481 men and women.

Results There were no significant differences in plasma CETP activity or carotid IMT between the genotypes of the promoter polymorphism. The women with the CC genotype of the promoter polymorphism had the lowest HDL‐C levels (P < 0·001), but no such difference was seen in men. Detected polymorphisms of the CETP gene explained about 8% of the variation in HDL‐C in women and about 7 and 10% of the variation in carotid IMT in women and men, respectively. The associations of the promoter, I405V and R451Q‐A373P polymorphisms with HDL‐C and carotid IMT seemed to be independent of each other. The associations with IMT were independent of total HDL‐C levels, suggesting that HDL subfractions may have more effect on IMT.

Conclusion The CETP gene locus was found to be polymorphic and its polymorphisms explained a reasonable proportion of the variation in the degree of carotid atherosclerosis.
Prevalence and risk of gingival enlargement in patients treated with anticonvulsant drugs
Authors: Brunet L. , Miranda J. , Roset P. , Berini L. , Farré M. , Mendieta C.
Published: March 2003

BackgroundPredictors of gingival enlargement in patients treated with anti‐epileptics have not been previously assessed. This study was conducted to determine, with the aid of two indices that score vertical and horizontal overgrowth, the prevalence and risk factors for gingival enlargement in patients treated with phenytoin and other anticonvulsant drugs.

Materials and MethodsA cross‐sectional study was conducted and data from 59 patients taking antiepileptics were compared with 98 controls. Gingival enlargement was evaluated with two indices to score vertical overgrowth [Gingival overgrowth index (GO] and horizontal overgrowth [Miranda‐Brunet index (MB)] . Gingival index, plaque index, and probing depth were also evaluated.

ResultsThe prevalence of gingival enlargement was significantly higher (P < 0·0001) for both indices in the anticonvulsants treated groups than in the control group. Gingival overgrowth was significantly higher for both indices in the phenytoin group than in the non phenytoin group. Among the possible risk factors, only the gingival index showed a significant association with gingival enlargement. For the MB index the risk of gingival enlargement (odds ratio) associated to phenytoin therapy and other anticonvulsants therapy were 52·6 (13·5–205) and 6·6 (1·5–28·2). Gingival index‐adjusted odds ratios for the same drugs were 5·7 (1·3–24·7) and 18·1 (2–158), respectively. The concordance between GO and MB indices in the control group and in the phenytoin‐group and non phenytoin‐group showed a Kappa value of 0·773 and 0·697, respectively.

ConclusionThis study reports significant differences in the prevalence and severity of gingival overgrowth in two groups of patients, one treated with phenytoin, and another treated with other anticonvulsants. Gingival inflammation is a significant risk factor for gingival enlargement in these patients.
Fcγ receptors in autoimmune diseases
Authors: Fossati G. , Bucknall R. C. , Edwards S. W.
Published: March 2003

Fcγ‐receptors (Fcγ‐R) recognise the Fc portion of IgG and thus form a link between humoral and cellular immunity. These receptors are expressed by a variety of immune cells, and they function in the binding of immune complexes or IgG‐opsonised particles, such as microbial pathogens. The are three major types of Fcγ‐R, namely Fcγ‐RI (CD64), Fcγ‐RII (CD32) and Fcγ‐RIII (CD16), and these differ in their ability to bind IgG and complexes. There are many isoforms of these receptors and a number of recently identified polymorphisms in their structure. This review describes the structure and function of these Fcγ‐Rs, and highlights how gene deficiencies and polymorphisms may contribute to the pathology of human diseases.
Dysregulation of monocyte oxidative burst in streptococcal endocarditis
Authors: Presterl E. , Rokita E. , Graninger W. , Hirschl A. M.
Published: March 2003

Background Streptococcal subacute endocarditis is characterized by low‐grade systemic inflammation. Although structural cardiac defects are pivotal, phagocytic cells, i.e. monocytes and neutrophils, are involved in the induction and the course of bacterial endocarditis. Decreased production of reactive oxygen metabolites was described in long‐lasting infections. We hypothesized that the oxidative burst of phagocytes induced by the infecting organism is defective in patients with streptococcal endocarditis.

Patients and methods The monocytes and neutrophils of 11 patients with streptococcal native valve endocarditis were challenged with the respective pathogens and two control streptococcal strains, and the oxidative burst was determined by fluorescence‐activated cell sorter analysis. These experiments were done before any antibiotic therapy was administered, and repeated at least 12 months after recovery. Eight volunteers served as healthy controls.

Results The monocyte response to the respective pathogens was decreased in the patient groups compared to the response to the control streptococci. After cure the monocyte response to the pathogens was not different to the response to the control strains. The monocyte response of the healthy volunteers did not show any differences between the patients' pathogens and the control strains. The neutrophil oxidative burst to the pathogens was similar to that to the control streptococci in both patient and the volunteer group.

Conclusion The decreased response of patient monocytes to the pathogens may contribute to the low‐grade inflammatory response and to the course of streptococcal endocarditis.
Matrix‐bound fibroblasts regulate angiogenesis by modulation of VE‐cadherin
Authors: Martin T. A. , Harding K. , Jiang W. G.
Published: March 2003

Background Vascular endothelial cadherin (VE‐cadherin/cadherin‐5) has previously been described as playing a specific role in angiogenesis due to its localisation at areas of intercellular contact, where it functions in maintenance of tubular architecture. Matrix‐bound fibroblasts have been show to produce a number of factors that are important in inducing angiogenesis and to promote tubule‐formation by human endothelial cells, an indicator of angiogenic potential.

Results Tubule formation stimulated by fibroblast‐derived growth factors can be prevented by the addition of monoclonal antibody to VE‐cadherin. In addition, fibroblasts‐derived growth factors are able to modulate the expression and hence the regulation of this endothelial cell specific cadherin.

Conclusions The change in VE‐cadherin expression of human endothelial cells by fibroblast‐derived growth factors may contribute to the regulation of angiogenesis.
Impact of genetic defects on atherosclerosis in patients suspected of familial hypercholesterolaemia
Authors: Descamps O. S. , Gilbeau J‐P. , Leysen X. , Van Leuven F. , Heller F. R.
Published: March 2003

Among patients with severe hypercholesterolaemia and a family history of early cardiovascular disease, we assessed whether patients with mutations of low‐density lipoprotein (LDL) receptor and apolipoprotein B genes related to familial hypercholesterolaemia (FH) have a different degree of atherosclerosis than those without such mutations.

In our lipid clinics, 273 patients were selected on the basis of a severe hypercholesterolaemia (cholesterol above 95th percentile) and a family history of early cardiovascular disease. By molecular genetic test, 122 patients were classified as FH. Atherosclerosis was evaluated by the ultrasonographic measurement of intima‐media thickness (IMT) in the carotid and femoral arteries.

Despite the fact that non‐FH individuals had a higher prevalence of obesity, hypertension, diabetes and hypertriglyceridaemia, FH individuals had significantly greater carotid and femoral IMT than non‐FH patients: difference between carotid and femoral IMT, respectively, 0·19 mm (95% CI, 0·08–0·29; P < 0·001) and 0·20 mm (95% CI, 0·09–0·35; P = 0·001), respectively. These differences remained statistically significant after adjustment for the various risk factors as well as in sub‐analysis restricted to the patients with LDL‐cholesterol between 240 and 300 mg dL−1 (range with similar distribution in the two groups). When classified according to the severity of their mutations, FH individuals with null LDL receptor allele tended to have thicker carotid IMT than FH individuals carrying the LDL receptor‐defective allele.

Among patients with severe hypercholesterolaemia and a family history of early cardiovascular disease, the presence of a genetically ascertained FH is associated with a higher degree of atherosclerosis. This suggests that molecular genetic identification of FH may be helpful to evaluate better the coronary heart disease risk in these patients.
Histidine induces lipolysis through sympathetic nerve in white adipose tissue
Authors: Yoshimatsu H. , Tsuda K. , Niijima A. , Tatsukawa M. , Chiba S. , Sakata T.
Published: March 2003

Background Hypothalamic neuronal histamine has been shown to increase lipolysis in white adipose tissue. The present study aimed to clarify whether peripheral loading with L‐histidine, a precursor of neuronal histamine, may affect lipid metabolism in adipose tissue.

Materials and methods The in vivo microdialysis study was used to assess lipolysis in rat epididymal adipose tissue by measuring the release of glycerol in response to administration of L‐histidine. In addition, electrophysiological measurements were performed to record changes in activity of sympathetic nerve innervating adipose tissue following histidine treatment.

Results Sequential administration of isoproterenol, a β‐adrenoceptor agonist, through the microdialysis cannula at concentrations of 10−8 to 10−6 M increased the glycerol concentration in the dialysate dose‐dependently (P < 0·05). Intraperitoneal administration of L‐histidine at a dosage of 0·35 mmol kg−1 also increased the glycerol concentration compared to that of phosphate buffered saline (P < 0·05). Concomitantly, the administration of histidine increased the serum concentration of free fatty acid compared to control treatment (P < 0·05). The accelerating effects of histidine on lipolysis were mimicked by the infusion of 102 nmol rat−1 L‐histamine into the third cerebroventricle (P < 0·05). Electrophysiological measurement demonstrated that administration of histidine at a dosage of 0·35 mmol kg−1 increased the activity of efferent sympathetic nerve, innervating adipose tissue more than the infusion of phosphate buffered saline (P < 0·05).

Conclusion The present results indicate that histidine accelerates lipolysis in white adipose tissue through activation of the sympathetic nerve. The regulation of lipolysis may therefore involve histamine neurons in the brain, probably through the conversion of L‐histidine to histamine in the hypothalamus.
Homocysteine and the stage of atherosclerotic disease: a study in patients suffering from clinically silent and clinically manifest atherosclerotic disease
Authors: Pasterkamp G. , Algra A. , Grobbee D. E. , De Jaegere P. P. T. , Banga J. D. , Van Der Graaf Y.
Published: March 2003

Background Elevated serum levels of homocysteine are considered a risk factor for cardiovascular disease. It has been suggested that homocysteine is a late stage predictor of adverse cardiovascular events, which might explain reported controversies in literature. The objective of the present study was to study the relationship between homocysteine levels and the stage of atherosclerotic disease.

Methods In a cross‐sectional study we compared the prevalence of hyperhomocysteinemia in high risk patients without silent or clinically overt atherosclerosis (group I, n= 196) with two patient groups: patients with clinically manifest atherosclerosis in the past or asymptomatic atherosclerosis (group II, n= 364) and patients who currently suffer from a clinically relevant manifestation of ischemic cardiovascular disease (group III, n= 967). In addition, we related homocysteine levels with a cumulative index of atherosclerotic disease (SMART‐score).

Results Homocysteine levels (µmol L−1) for the different groups were 13·5 ± 8·9 (group I), 13·7 ± 8·2 (group II) and 14·7 ± 7·7 (group III). After adjustment for age, body mass index, creatinine levels and current use of vitamins, no significant differences in the prevalence of hyperhomocysteinemia were observed, compared with the reference category. Linear regression analysis revealed a significant relationship between Smart score and homocysteine levels that remained after adjustment for potential confounders (Beta = 0·36 (0·14–0·59), P = 0·001).

Conclusion If homocysteine levels are associated with the presence and indicators of atherosclerotic plaque burden, then this relationship is apparently not affected by the stage of atherosclerotic disease.
LDL‐receptors expression in HIV‐infected patients: relations to antiretroviral therapy, hormonal status, and presence of lipodystrophy
Authors: Petit J. M. , Duong M. , Duvillard L. , Florentin E. , Portier H. , Lizard G. , Brun J. M. , Gambert P. , Verges B.
Published: March 2003

Background Abnormalities in lipid levels and lipodystrophy (LD) have been commonly reported after commencement of highly active antiretroviral therapy (HAART). A major mechanism by which plasma low‐density lipoprotein (LDL) cholesterol levels may be influenced is via the regulation of hepatic LDL receptor expression. The activity of LDL receptors is under hormonal control. Moreover, HIV infection and HAART are associated with important modifications of hormonal status. As the cause of these adverse reactions is unknown, the effects of HAART and lipodystrophy on LDL receptors were evaluated.

Materials and methods Thirty‐nine HIV treated patients (21 with a protease inhibitor (PI) containing regimen, 18 without PI use) and 22 control subjects were tested for insulin resistance (HOMA model assessment), lipid profile, serum concentration of dehydroepiandrosterone (DHEA) and LDL‐R expression. LDL‐R on mononuclear cells were quantified by flow cytrometry.

Results Among the 39 HIV infected patients, 14 patients had a lipodystrophy (LD). Patients with LD had significantly higher levels of triglyceride (TG) and insulin resistance compared to patients without LD. There was no significant difference in LDL‐R count between patients with or without PI use. In contrast, LDL‐R count was significantly lower in patients with LD compared with those without (8504 ± 3901 vs. 13 200 ± 4532, P = 0·001). There was no difference in LDL‐R count between patients without LD and control subjects. Patients with LD had lower levels of DHEA compared to patients without LD. In HIV‐infected patients, we found a significant correlation between LDL‐R expression and TG (r = −0·32; P = 0·04) and LDL cholesterol (r = −0·33; P = 0·04). In contrast, we did not observe a correlation between DHEA level and LDL‐R count or LDL cholesterol level.

Conclusions HIV‐lipodystrophy is associated with a lower expression of LDL‐R. This decreased expression of LDL‐R seems independent of DHEA or insulin secretion.
Effect of trefoil factors on the viscoelastic properties of mucus gels
Authors: Thim L. , Madsen F. , Poulsen S. S.
Published: March 2003

Background Trefoil peptides (TFFs) are expressed and secreted in a tissue‐specific manner in the gastrointestinal tract. Evidence of coexpression of trefoil peptides and mucins has been demonstrated in most mucus‐producing cells in the gastrointestinal tract. The expression of trefoil peptides is up‐regulated in gastric ulceration and colitis. It is believed that TFF peptides interact with mucin to increase viscosity but this has never been confirmed. The aims of the present study were to elucidate the direct effect of trefoil peptides on mucus gel formation.

Materials and methods The viscosity of mucin solutions was measured by means of a rotational rheometer after adding three mammalian trefoil peptides: TFF1, TFF2, and TFF3.

Results Adding TFF2 (0·3%) to the mucin solutions (8%) resulted in more than a factor 10 increase in viscosity and elasticity, and the mucin solution was transformed into a gel‐like structure with serpentine‐like complexes between the mucin and TFF2. The dimer form of TFF3 also increased viscosity but resulted in a spider's web‐like structure. The monomer forms of TFF1 and TFF3 had very little effect on the viscosity and elasticity of the mucin solutions.

Conclusions The addition of TFF2 to mucin solutions results in significantly increased viscosity and elasticity, under which the mucin solutions are transformed into a gel‐like state. The ability of some trefoil peptides to catalyse the formation of stable mucin complexes may be one of the ways by which these peptides exert their protective and healing functions.
Serum homocysteine, creatinine, and glucose as predictors of the severity and extent of coronary artery disease in asymptomatic members of high‐risk families
Authors: Pajunen P. , Syvänne M. , Nieminen M. S. , Kareinen A. , Viitanen L. , Lehto S. , Laakso M.
Published: March 2003

Background There has been no previous study to determine the severity and extent of coronary artery disease (CAD) in subjects with no diagnosis or symptoms of CAD at the time of the angiography.

Methods Fifty‐three subjects, who were siblings of patients with early onset CAD, underwent coronary angiography. Indices to describe per‐patient characteristics of CAD were calculated, based on computer‐aided quantitative coronary angiography. Clinical and laboratory characteristics were correlated to the angiographic parameters.

Results Serum total homocysteine (ρ = 0·29, P < 0·05) and creatinine (ρ = 0·47, P = 0·001) levels were related to the global atheroma burden index. The median of the atheroma burden index was two times higher in the top homocysteine quartile compared to the lowest quartile. The overall atheroma burden index correlated significantly with the fasting blood glucose level in all subjects. Diabetes, especially when albuminuria was present, was a powerful risk factor. In a multivariate analysis, only age and sex were independent predictors of atheroma burden.

Conclusions Serum homocysteine and creatinine concentrations, and diabetes with albuminuria were found to be markers of the severity and extent of CAD in subjects of high‐risk families without symptoms of CAD.
Long‐term sequelae of HFE deletion in C57BL/6 × 129/O1a mice, an animal model for hereditary haemochromatosis
Authors: Lebeau A. , Frank J. , Biesalski H. K. , Weiss G. , Srai S. K. S. , Simpson R. J. , McKie A. T. , Bahram S. , Gilfillan S. , Schümann K.
Published: March 2003

Background HFE knockout mice (C57BL/6 × 129/Ola strain) mimic the functional aberrations of human hereditary haemochromatosis (HH) in short‐term experiments. The present study investigates functional and morphological long‐term changes.

MethodsHFEo/o, HFE+/oand HFE+/+mice were maintained on iron‐rich and control diets for 2 weeks, 3, 12 and 18 months. Light microscopic tissue iron distribution, pathomorphological alterations, tissue iron content and oxidative stress were analysed in liver, pancreas, spleen, gastrointestinal tract, kidneys and myocardium. Additionally, duodenal59Fe absorption and59Fe whole body loss were measured.

ResultsIron distribution between organs and microscopic iron deposition in the tissues resembled the patterns described in HH. After 3 months of iron‐rich feeding duodenal59Fe absorption decreased to ∼15% of iron‐adequate controls but remained about twice as high in HFEo/oas in HFE+/+mice. Hepatic iron concentrations reached only half the values known to induce hepatic fibrosis in rats and humans, while whole body59Fe loss was about twice as high. Consequently no hepatic fibrosis developed, although massive hepatocellular iron deposition and indication for oxidative stress were observed.

ConclusionC57BL/6 × 129/O1a HFEo/omice mimic HH iron distribution and the regulation of intestinal iron absorption after long‐term feeding. However, characteristic morphological late changes in untreated HH are not modelled.
Short‐term cortisol infusion in the brachial artery, with and without inhibiting 11β‐hydroxysteroid dehydrogenase, does not alter forearm vascular resistance in normotensive and hypertensive subjects
Authors: Van Uum S. H. M. , Hermus A. R. M. M. , Sweep C. G. J. , Walker B. R. , Ross H. A. , De Leeuw P. W. , Lenders J. W. M.
Published: March 2003

Background Vascular tone is increased in primary hypertension, and glucocorticoids affect vascular tone. Local cortisol availability is modulated by activity of 11β‐hydroxysteroid dehydrogenase (11β‐HSD). As this activity may be decreased in patients with primary hypertension, vascular sensitivity to cortisol may be increased in these patients. We studied the acute effect of cortisol on forearm vascular resistance (FVR) by infusing cortisol directly into the brachial artery, both with and without inhibition of 11β‐HSD, in normotensive and hypertensive subjects.

Design Twenty normotensive volunteers and 20 patients with primary hypertension participated in the study. After a 10‐min infusion of vehicle (glucose 5%), cortisol was infused into the brachial artery in three stepwise increasing doses (3·5, 10·5 and 35 µg per 100 mL of forearm volume), each for 10 min. Next, the participants received placebo or 500 mg glycyrrhetinic acid (GA) orally, and 150 min later the same infusion schedule was repeated. Forearm vascular resistance was measured during the last 5 min of the infused vehicle and of each dose. Arterial and forearm venous plasma samples for measurement of cortisol and cortisone were taken at the end of the infusions of glucose 5% and the highest cortisol dose.

Results In both normotensive and hypertensive subjects, neither the infusion of cortisol nor the administration of GA changed FVR. Also 2 h after the cortisol infusion there remained no change in FVR in both the normotensive and hypertensive groups who received placebo. Following the infusion of the highest cortisol dose, total plasma cortisone levels in the venous plasma were decreased compared with levels in the arterial plasma (36 ± 3 and 49 ± 4 nmol L−1, respectively, P < 0·05). The protein‐bound venous cortisone was 37·1 ± 4·8 nmol L−1 during the vehicle compared with 23·9 ± 3·7 nmol L−1 during the cortisol infusion (P < 0·01), whereas the free cortisone level was not altered by the cortisol infusion.

Conclusions In both normotensive and hypertensive subjects, high‐dose cortisol infusion both with and without 11β‐HSD inhibition did not change FVR either immediately or after 2 h. We could not demonstrate in vivo 11β‐HSD activity in the forearm vascular tissues. When binding of cortisone to CBG is changed, e.g. during cortisol infusion, arterio‐venous changes in cortisone cannot reliably be used to assess (alterations in) local 11β‐HSD activity.
Transferrin toxin but not transferrin receptor immunotoxin is influenced by free transferrin and iron saturation
Authors: Gosselaar P. H. , Van‐Dijk A. J. G. , De‐Gast G. C. , Polito L. , Bolognesi A. , Vooijs W. C. , Verheul A. F. M. , Krouwer H. G. J. , Marx J. J. M.
Published: March 2003

Background  Cytotoxic agents can be targeted successfully to cancer cells. The efficacy of such novel and potent anticancer strategies may be influenced by variables of iron metabolism.

Methods  The in vitro cytotoxicity against glioma cells of transferrin (Tf)‐based targeted toxins was compared with that of α‐transferrin receptor (TfR)‐immunotoxin.

Results  Of four Tf‐based targeted toxins, Tf‐gelonin, Tf‐pokeweed antiviral protein, Tf‐momordin and Tf‐saporin, inhibitory concentration 50% values against glioma‐derived cell lines HS683 and U251, ranged from [4·8 ± 1·5] × 10−10 m for Tf‐saporin to [26·9 ± 15·3] × 10−10 m for Tf‐gelonin in [3H]‐leucine incorporation assays. Tf‐saporin and α‐TfR‐saporin‐immunotoxin had similar efficacy, even in the more quantitative clonogenic assay (4–5 log kill with 1 × 10−9 m) using the myeloma cell line RPMI 8226 and glioma cell line U251. However, on RPMI 8226, the efficacy of Tf‐saporin 1 × 10−9 m was reduced by 90% in the presence of 150 µg mL−1 (=20% of normal plasma value) competing diferric transferrin, whereas the efficacy of the corresponding immunotoxin was affected only marginally. In addition, the efficacy of Tf‐based conjugates will depend on their iron saturation state. Iron desaturation of Tf‐saporin was demonstrated by [59Fe]‐labelling, subsequent CM‐Sepharose chromatography and SDS‐PAGE. Desaturation led to virtually complete loss of affinity for the transferrin receptor, as determined by flow cytometry, which could be largely restored upon resaturation.

Conclusion  Transferrin‐based toxin conjugates are strongly influenced by the presence of free transferrin and the iron saturation state. The corresponding α‐transferrin receptor‐immunotoxin does not show these disadvantages, has similar efficacy and should be preferred for further experiments.
DNA typing for BoLA class I using sequence‐specific primers (PCR‐SSP)
Authors: Ellis S. A. , Staines K. A. , Stear M. J. , Hensen E. J. , Morrison W. I.
Published: March 2003

The analysis of cattle MHC (BoLA) class I gene expression is an essential component of studies on immune responses and susceptibility to disease. International BoLA workshops have generated data and reagents that allow discrimination of class I molecules at the haplotype level, but progress has been limited by difficulties encountered in defining single alleles. Our aim in this study was to develop a DNA‐based system for improved identification of expressed class I alleles, utilizing available cDNA sequences derived from cattle carrying a series of serologically defined class I specificities. This method has allowed more accurate typing of animals for expression of the class I genes present within a small number of haplotypes. The method has also reliably differentiated between allelic variants (identified by prior sequence analysis) and has split existing serological specificities. The data show that MHC class I genes in cattle are more polymorphic than demonstrated by serology and biochemical analysis.
Frequencies of platelet‐specific alloantigen systems 1–5 in three distinct ethnic groups in Brazil
Authors: Castro V. , Origa A. F. , Annichino‐Bizzacchi J. M. , Soares M. , Menezes R. C. , Gonçalves M. S. , Costa F. F. , Arruda V. R.
Published: March 2003

The human platelet antigen (HPA) systems are related to immune platelet disorders as well as to the development of occlusive vascular disease. Several distinct biallelic HPA systems are known, and a heterogeneous distribution of HPA alleles has been described among distinct ethnic groups. In this study we genotyped 320 carefully selected individuals from three distinct ethnic groups in Brazil (Caucasians, Blacks and Amazonian Indians) for the HPA‐1, ‐2, ‐3, ‐4 and ‐5 systems. A similar prevalence for all HPA alleles was found in Brazilians of Caucasian and Black descent. These data contrast with those reported for similar ethnic groups in other countries. Among the Amazonian Indians, no b allele of the HPA‐1, ‐4 and ‐5 systems was identified. The data presented here could be useful in the diagnosis of alloimmune platelet disease, in genetic counselling and in the development of screening programmes for HPA‐related diseases.
Polymorphism of LMP2, TAP1, LMP7 and TAP2 in Brazilian Amerindians and Caucasoids: implications for the evolution of allelic and haplotypic diversity
Authors: Rueda Faucz F. , Macagnan Probst C. , Petzl‐Erler M. L.
Published: March 2003

In the class II region of the major histocompatibility complex (MHC), four genes implicated in processing of MHC class I‐presented antigens have been described. Two of these (TAP1 and TAP2) code for endoplasmic reticulum membrane transporter proteins and the other two (LMP2 and LMP7) for proteasome subunits. These genes are polymorphic, although much less so than classical MHC class I and II genes. There is controversy concerning the possible functional implications of this variation. Population genetics is one of the means of investigating the evolutionary and functional significance of genetic polymorphisms; however, few populations have been analysed with respect to TAP and LMP diversity. We present here the polymorphism of TAP1, TAP2, LMP2 and LMP7 genes in the Kaingang and Guarani Amerindian tribes, and in the Caucasoid population of the Brazilian State of Paraná. Allele frequencies found in the Caucasoids were close to those described for similar populations. Amerindians had a somewhat more restricted polymorphism, and allele and haplotype frequencies differed greatly between the two tribes. Overall linkage disequilibrium (LD) between the four genes was low in the Caucasoids, but high in the Amerindians, for which significant LD was seen for all informative pairs of loci. Comparing results of this and previous studies we observed that, whenever significant LD occurs in non‐Amerindians, it tends to be similar in the different ethnic groups. While this might be interpreted as evidence of co‐evolution of genes in the TAP‐LMP region, the high haplotypic diversity in all populations and low LD in non‐Amerindians indicate absence of co‐evolution of the different genes. Distributions of allele and genotype frequencies are consistent with the hypothesis of selective neutrality. We conclude that genetic polymorphism of the human TAP and LMP genes and haplotypes is of little, if any, functional significance.
Identification of further DLA‐DRB1 and DQA1 alleles in the dog
Authors: Kennedy Lorna J. , Hall Laurence S. , Carter Stuart D. , Barnes Annette , Bell Susan , Bennett David , Ollier Bill , Thomson Wendy
Published: March 2003

Three novel DLA‐DRB1 alleles and one novel DQA1 allele have been identified in a panel of 367 dogs. These were suggested by unusual reaction patterns found in sequence specific oligonucleotide probing (SSOP) data. Four new alleles were confirmed using DNA cloning and sequencing.