bluuebunny/crossref_metadata_2025 huggingface dataset:
Proximal and distal gut hormone secretion in slow transit constipation
Authors: Penning  , Delemarre  , Bemelman  , Biemond  , Lamers  , Masclee
Published: March 2003

Background

It has been suggested that slow transit constipation might be part of a pan‐enteric disorder. Gastrointestinal peptides are involved in regulation of motility.

Design

In the present study we have evaluated whether plasma levels of proximal and distal gut hormones in the fasting state, and for 120 min after a solid meal in 29 patients with slow transit constipation are different from those obtained from 29 healthy controls. Plasma levels of the gut hormones cholecystokinin, gastrin, pancreatic polypeptide, motilin, neurotensin and peptide YY were determined using sensitive radioimmunoassays. In the patient group, oro‐caecal transit time was determined by means of the hydrogen breath test on a separate test day. The results of transit were related with postprandial hormone secretion.

Results

Fasting plasma levels of cholecystokinin and pancreatic polypeptide were significantly (P < 0.05) increased in constipated patients. Postprandially, secretion of pancreatic polypeptide and cholecystokinin was significantly (P < 0.05) increased in the patients, while secretion of peptide YY was significantly (P < 0.05) reduced. Plasma motilin levels were not different between patients and controls. Altered postprandial hormone secretion was mainly observed in constipated patients with prolonged oro‐caecal transit time.

Conclusions

In patients with slow transit constipation, fasting and postprandial secretion of proximal gut hormones apart from motilin is increased and of distal gut hormones decreased, especially in those with severely delayed intestinal transit.
Effects of nitroglycerine on cerebral blood flow velocity, quantitative electroencephalogram and cognitive performance
Authors: Siepmann  , Kirch
Published: March 2003

Background

Despite the widespread use of nitroglycerine, little is known of its cerebral haemodynamic effects. The present study was undertaken to evaluate the effects of nitroglycerine on cerebral circulation and cognitive function in normal volunteers.

Design

Twelve healthy male volunteers (age 25 ± 3 years; mean ± SD) received continuous intravenous infusions of nitroglycerine at 1 mg h−1 and 2 mg h−1 rates as well as placebo (0.9% saline) under randomized, double‐blind cross‐over conditions on three different occasions. A 10‐min quantitative EEG (qEEG) was recorded before, during and repeatedly after infusion. Blood flow velocity in the left arteria cerebri media (MCA) was measured simultaneously by means of transcranial Doppler sonography. Cognitive performance was assessed with a computerized test battery.

Results

Administration of nitroglycerine caused a significant reduction of mean blood flow velocity in the left MCA. In parallel a significant increase of absolute power density < 4 Hz was noted. The latter effect was dose dependent. Cognitive functions, such as attention and memory, were not altered.

Conclusions

The decrease in cerebral blood flow velocity in the left MCA may be due to vasodilatation and/or reduction in perfusion. The concomitant increase of slow wave power in the qEEG may indicate an impairment of brain function.
Corticotropin‐releasing hormone binding to the syncytiotrophoblast membranes
Authors: Saeed B. , Fawcett M. , Self C.
Published: March 2003

The human placenta secretes large amounts of corticotropin‐releasing hormone (CRH) which was thought to exert a paracrine action in the placenta. We have recently characterized high‐affinity binding sites for CRH in the human placenta. However, our studies utilized whole placental membranes, which did not identify the site of binding of CRH in the plasma membrane.

In this study we investigated the characteristics of CRH binding to purified mother‐facing, brush border membranes (BBM) and fetus‐facing, basal plasma membranes (BPM) of the syncytiotrophoblast. The two membranes were separated by a series of differential and density‐gradient centrifugations. The purity of the membranes was determined by measuring alkaline phosphatase, as a marker of BBM and Na+/K+ATPase as a marker of BPM.

Each membrane showed specific and high‐affinity binding. Scatchard analysis revealed a high‐affinity binding site for CRH with Kd of 1·0 ± 0·15 and 1·3 ± 0·176 for BBM and BPM, respectively. The maximal number of binding sites was significantly different (P < 0·01) in the two plasma membranes: Bmax of 79 ± 6·4 fmol/mg protein for BBM and 23 ± 3·9 fmol/mg protein for BPM.

Both the mother‐facing and fetus‐facing membranes of the syncytiotrophoblast contain binding proteins for CRH, with significantly more binding sites on the mother‐facing membranes. The functional consequences of CRH binding could be different for the two polar membranes due to differential localization of second messenger systems between the two membrane types. It is proposed that partial purification of BBM and BPM provides a better system to study CRH action in the placenta, than whole placental membrane preparations.
Hepatic phenylalanine metabolism measured by the [13C]phenylalanine breath test
Authors: Kobayashi T. , Kubota K. , Imamura H. , Hasegawa K. , Inoue Y. , Takayama T. , Makuuchi M.
Published: March 2003

Background The amino acid clearance test including phenylalanine is known to reflect liver functional reserve, which correlates with surgical outcome; however, the procedure is not clinically useful because of its laborious and time‐consuming nature. This study evaluates whether phenylalanine oxidation capacity measured by a breath test could reflect liver functional reserve.

Design We determined phenylalanine oxidation capacity in 42 subjects using the l‐[1‐13C]phenylalanine breath test (PBT). The 13CO2 breath enrichment was measured at 10‐min intervals for 120 min after oral administration of 100 mg of

l‐[1‐13C]phenylalanine. Subjects were divided into the following three groups according to their plasma retention rate of indocyanine green at 15 min (ICG R15): Group I (ICG R15 < 10%), Group II (ICG R15 10–20%), and Group III (ICG R15 > 20%). First, we determined the parameters of the phenylalanine oxidation capacity that differentiated these groups and then, using these parameters, we compared the PBT with the ICG clearance test, Child–Pugh classification score and standard liver blood tests.

Results The %13C dose h−1 at 30 min and cumulative excretion at 80 min were significantly different among the three groups (P < 0·05). These two parameters significantly correlated with the ICG R15, Child–Pugh classification score (P < 0·0001) and results of standard liver blood tests (P < 0·05).

Conclusions Phenylalanine oxidation capacity measured by the PBT was reduced according to the severity of liver injury assessed by the ICG clearance test, Child–Pugh classification, and standard liver blood tests. These results indicate that the PBT can be used as a noninvasive method to determine liver functional reserve.
The cryoglobulins: an overview
Authors: Dammacco F. , Sansonno D. , Piccoli C. , Tucci F. A. , Racanelli V.
Published: March 2003

Cryoglobulins are cold‐precipitable immunoglobulins associated with a number of infectious, autoimmune and neoplastic disorders. Their appearance along with rheumatoid factor (RF) can be considered a normal event in the clearance of immune complexes and rarely produces any symptoms. The association between hepatitis C virus (HCV) and mixed cryoglobulinemia (MC) has been rendered evident since the recognition of serological markers of HCV infection. There is thus every reason to suppose that direct or indirect involvement of B cells on the part of the HCV results in their persistent stimulation, clonal expansion and release of molecules with RF activity. The formation of RF/IgG immune complexes is the key pathogenetic mechanism. The close correlation between HCV infection and MC also throws new light on the interpretation of autoimmune phenomena in the course of viral infection and on the close link between autoimmune diseases and lymphoproliferative disorders. The higher risk of non‐Hodgkin's lymphoma (NHL) displayed by HCV positive subjects, especially in the Mediterranean basin, suggests that the HCV's chronic lymphoproliferative drive may progress towards frank lymphoid neoplasia. The presence of MC does not represent an in situ or ‘occult’ NHL, because recent evidences indicate that none of the clones interpreted as predominant displays the molecular features of a true neoplastic process. The cryoglobulinemic syndrome is probably the consequence of pathogenic noxae that act upon the immune system of a host in which regulation of the peripheral T cell response appears to be in some way altered.
Fatty acid binding protein 2 and insulin resistance
Authors: Chiu K. C. , Chuang L.‐M. , Chu A. , Yoon C.
Published: March 2003

Background An A54T polymorphism of the fatty acid binding protein 2 (FABP2) gene was found to be associated with insulin resistance in nondiabetic Pima Indians.

Design This is a cross‐sectional study to examine the role of this polymorphism in insulin resistance in 71 healthy and normotensive Caucasian subjects with normal glucose tolerance. Insulin sensitivity (%S, ISIM, ISIS) and beta‐cell function (%B, dI/dG, 1stPHS, 2ndPHS) were estimated based on published models. Their genotypes were determined using a polymerase chain reaction‐restriction fragment length polymorphism assay. The relationship between genotypes and phenotypes was examined.

Results After genotyping, we identified 34 AA, 32 AT and five TT subjects. The TT subjects were pooled together with the AT subjects during the analysis due to their low number. No difference was noted in gender distribution, clinical features, or fasting lipid profile between the two genotypic groups (AA vs. AT/TT). The AT/TT group had lower %S and ISIS than the AA group (P = 0·0118 and P = 0·0170, respectively). The difference in ISIM was marginal (P = 0·0544). However, no difference was noted in beta‐cell function between the two groups. Multivariate analysis revealed that this polymorphism was an independent but modest determinant for %S (P = 0·0149), ISIM (P = 0·0489) and ISIS (P = 0·0175). It independently contributed 6·04% (95% CI, 0·02–20·53%), 4·28% (95% CI, 0·08–17·63%) and 4·94% (95% CI, 0·01–18·75%) of the variation of %S, ISIM and ISIS, respectively.

Conclusions We demonstrated that the A54T polymorphism at the FABP2 locus is a risk factor for insulin resistance in a Caucasian population.
Comparison of angiotensin II receptor antagonists
Authors: Kirch W. , Horn B. , Schweizer J.
Published: March 2003

Nonpeptide orally active angiotensin II type 1 (AT1) receptor antagonists are the most specific means presently available to block the renin‐angiotensin enzymatic cascade. Six of these drugs have already been licensed in Europe and in the United States for the treatment of high blood pressure, and additional candidates are in the pipeline. The World Health Organisation has also recently endorsed their use for this condition. Inasmuch as AT1 receptor antagonists have proven themselves the equals of angiotensin converting enzyme inhibitors with respect to antihypertensive efficacy, but demonstrated better safety profiles, this class of drugs may be considered to be a qualitative improvement in the treatment of essential hypertension. Interestingly, the six agents now on the market diverge considerably with respect to their pharmacokinetic and pharmacodynamic properties, although it is not certain whether such differences are clinically relevant. A considerable number of large, multicentre trials are in progress to ascertain the possible longer‐term organoprotective effects of these substances on cardiovascular morbidity and mortality. Because of their noteworthy safety record to date, and simple once‐a‐day dosage regimen, AT1 receptor antagonists have the potential to improve compliance in patients with chronic hypertension.
Apolipoprotein E polymorphism and lithogenic factors in gallbladder bile
Authors: Fischer S. , Dolu M. H. , Zündt B. , Meyer G. , Geisler S. , Jüngst D.
Published: March 2003

Background Associations between the polymorphism of apolipoprotein E, which plays an important role in cholesterol metabolism and cholesterol gallstone formation, have been reported recently. Patients with the apo E4 isoform showed increased numbers and cholesterol contents of their stones, a higher frequency of cholesterol crystals in bile, increased susceptibility to gallstone fragmentation by extracorporeal shock‐wave lithotripsy and an increase in recurrence rate after dissolution. A recent study, however, showed that fast cholesterol crystallization in bile is associated with multiple stones but not with apo E4. Therefore the mechanism for an increased risk of gallstone formation in patients with the apo E4 isoform still remains under debate.

Design To clarify this issue we investigated 37 patients with gallstones (10 with the apo E4 allele and 27 without the allele). Gallbladder biles were examined for total cholesterol and other lipids, cholesterol saturation index, crystal observation time, crystal mass, total protein and mucin. Moreover, number of gallstones and cholesterol in gallstones was compared in both groups.

Results The crystal observation time (2·5 vs. 2·0 days, median) and the cholesterol saturation index (1·34 ± 0·45 vs. 1·43 ± 0·74) did not differ significantly between the apo E4 and the non apo E4 group. Total biliary lipids (11·6 ± 3·8 vs. 9·3 ± 3·9 g 100 mL−1, P = 0·126) and total biliary cholesterol (21·8 ± 9·7 vs. 15·7 ± 7 mmol L−1, P = 0·067) tended to be elevated in the apo E4 group. Crystal mass (3·60 ± 4·10 vs. 2·38 ± 2·70 mmol L−1), biliary total protein (8·6 ± 3·5 vs. 8·3 ± 6·6 mg mL−1) and mucin (0·55 ± 0·38 vs. 0·66 ± 0·67 mg mL−1), number (solitary/multiple) of gallstones and cholesterol in gallstones were not different in both groups of patients.

Conclusions In comparison to the non apo E4 patients the apo E4 group showed a trend to elevated biliary cholesterol whereas crystal observation time, cholesterol saturation index, crystal mass, number of gallstones, cholesterol content of gallstones and total protein and mucin were not different. These findings do not suggest an association of the apo E isoform and the formation of cholesterol gallstones
d‐penicillamine reduces serum oxidative stress in Alzheimer’s disease patients
Authors: Squitti R. , Rossini P. M. , Cassetta E. , Moffa F. , Pasqualetti P. , Cortesi M. , Colloca A. , Rossi L. , Finazzi‐Agro′ A.
Published: March 2003

Abstract Background  Several lines of evidence address the emerging role for copper in Alzheimer’s disease (AD) for sustaining oxidative mechanisms. Studies indicate that peripheral markers of oxidative stress in AD patients could be informative about the pathophysiology of this brain condition. Here, we present a pilot study examining the efficacy of the copper‐chelating agent d‐penicillamine in reducing oxidative stress in AD patients.

Design  Serum levels of copper sampled in AD patients and healthy controls indicate a copper homeostasis imbalance in AD. On this basis, 34 AD patients were enrolled in a 6‐month, double‐blind, placebo‐controlled trial with the copper d‐penicillamine‐chelating agent. Nine patients for each group completed the trial. Oxidative stress, trace metals and clinical parameters were evaluated.

Results  At the start of the study (t0) total peroxides and copper serum content of AD patients were higher (P < 0·0001, P < 0·0001, respectively) and antioxidants were lower (P < 0·05) than in healthy controls. Copper and peroxides were correlated in the AD population (Pearson’s r = 0·61, P < 0·001). After treatment with d‐penicillamine, the extent of oxidative stress (P < 0·05) was decreased, but no difference was observed in the rate of cognitive decline.

Conclusion  Data from this pilot study suggest that copper could play a role in the production of peroxides in AD, and that d‐penicillamine has an effect in reducing oxidative damage, however, results are still inconclusive in terms of drug efficacy on the clinical progression of AD. Studies with larger cohorts are needed to elucidate the real effectiveness of d‐penicillamine treatment in AD.
Microcirculatory effects of KATP channel blockade by sulphonylurea derivatives in humans
Authors: Abbink E. J. , Wollersheim H. , Netten P. M. , Russel F. G. M. , Lutterman J. A. , Smits P.
Published: March 2003

Background Recent investigations have shown that glibenclamide inhibits the opening of vascular ATP‐sensitive potassium channels during ischemia. This observation may implicate cardiovascular effects of sulphonylurea derivatives when used under conditions of ischemia in patients with Type 2 diabetes mellitus. In addition to resistance arteries, the (pre) capillary vessels also contain ATP‐dependent potassium channels. Closure of these channels by sulphonylurea derivatives might affect the development of microvascular disease in Type 2 diabetes mellitus. Therefore, we investigated the microcirculatory effects of sulphonylurea derivatives in Type 2 diabetic patients as compared with healthy volunteers.

Materials and methods Arteriovenous blood flow (skin temperature and laser Doppler flux) and capillary blood cell velocity were measured before and during infusion of four doses of glibenclamide (0·1, 0·3, 1·0 and 3·0 µg min−1 dL−1) into the brachial artery of 14 Type 2 diabetic patients and 13 healthy controls. The experiments included appropriate time control studies.

Results Both skin temperature and laser Doppler flux decreased in response to glibenclamide in healthy volunteers (−7 ± 2%, P < 0·0005 and −31 ± 11%, P = 0·001, respectively), but did not change in Type 2 diabetic patients (1 ± 3%, P = 0·29 and 4 ± 14%, P = 0·97). However, capillary blood cell velocity decreased in Type 2 diabetic patients (−38 ± 18%, P = 0·04), but did not change in healthy volunteers (−1 ± 11%, P = 0·28).

Conclusions The results of the present study indicate that glibenclamide indeed affects microvascular blood flow. Glibenclamide may induce redistribution of the microvascular skin flow from nutritive flow to arteriovenous shunt flow in Type 2 diabetic patients. Therefore, closure of ATP‐dependent potassium channels by glibenclamide possibly plays a role in the development of microangiopathy in Type 2 diabetic patients.
Depletion of non specific esterase activity in the colonic mucosa of patients with ulcerative colitis
Authors: Kolios G. , Valatas V. , Psilopoulos D. , Petraki K. , Kouroumalis E.
Published: March 2003

Background Non specific esterases (NSE) are a group of cellular carboxylesterases, enzyme markers of monocytes/macrophages, whose tissue distribution in the human body and changes in various disease states have not been adequately studied. We investigate the presence and localization of NSE, in the normal and inflamed human colonic mucosa.

Design NSE were studied histochemically and biochemically using α‐naphthyl acetate as the substrate, in the colonic mucosa from 67 patients with colitis of various aetiologies and 10 normal controls. In addition, esterase activity was studied biochemically in serum from colitic patients and normal controls.

Results Histochemical study of the colonic tissue demonstrated that NSE were localised in the epithelial brush border, the goblet cells of the glands and a macrophage population of the lamina propria in the colonic mucosa of normal controls and patients with non specific colitis. In active ulcerative colitis, esterase depletion and esterase negative macrophages were identified in parallel with goblet cell disappearance. Gradual reappearance of esterase activity was found after successful treatment. Biochemical study of NSE activity showed that serum and colonic tissue esterase levels were greatly (P < 0·001) reduced in active ulcerative colitis compared to the normal controls or non specific colitis patients and they were increased after successful treatment. Despite this increase, the esterase activity in the colonic tissue from ulcerative colitis patients after treatment was significantly reduced compared to the normal controls. Interestingly, the enzyme levels from non‐inflamed areas of the bowel of patients with ulcerative colitis were also significantly (P < 0·01) decreased compared to the normal controls.

Conclusions These data suggest that esterase reduction in ulcerative colitis is not a simple result of the inflammatory process but rather it precedes its development. This enzyme depletion might have an important pathogenetic implication in the inflammatory process.
Relationship of genetic variation in genes encoding apolipoprotein A‐IV, scavenger receptor BI, HMG‐CoA reductase, CETP and apolipoprotein E with cholesterol metabolism and the response to plant stanol ester consumption
Authors: Plat J. , Mensink R. P.
Published: March 2003

Background Differences in genetic constitution may affect cholesterol metabolism and responses to diet. Identification of common variations in genes related to dietary responsiveness is therefore an attractive goal to be able to prescribe individually tailored diets for the treatment of dyslipidaemia.

Materials and methods We have examined relationships between serum lipids and lipoproteins, cholesterol‐standardized campesterol and lathosterol concentrations with genetic variation, and the presence of a gene–diet interaction between plant stanol ester consumption. Candidate genes were apolipoprotein A‐IV (apoA‐IV), scavenger receptor‐BI (SR‐BI), cholesterol ester transfer protein (CETP), 3‐hydroxy‐3‐methylglutaryl‐coenzyme A (HMG‐CoA) reductase, and apolipoprotein E (apoE). These relations were examined in 112 nonhypercholesterolaemic subjects, of whom 70 consumed 3·8–4·0 g plant stanol esters a day for 8 weeks.

Results At baseline, high‐density lipoprotein (HDL) concentrations of 1·56 ± 0·36 mmol L−1 in SR‐BI‐2 allele carriers tended to be lower compared to the 1·72 ± 0·42 mmol L−1 in SR‐BI‐1/1 subjects (P = 0·069). Cholesterol standardized lathosterol concentrations were also lower in the SR‐BI‐2 allele carriers (P = 0·002). Furthermore, low‐density lipoprotein (LDL) cholesterol concentrations in apoE2 subjects, were lower compared to the LDL cholesterol concentration in apoE3 group (P = 0·002) and apoE4 subjects (P < 0·001). No significant differences between the polymorphisms and dietary responsiveness to plant stanol ester consumption could be found, which indicates that it is unlikely that one of the single polymorphisms analysed in this study is a major factor in explaining the variation in serum LDL cholesterol responses.

Conclusion These findings suggest that all subjects who want to lower their cholesterol concentration, will benefit from plant stanol ester consumption, irrespective of their apoA‐IV, SR‐BI, HMG‐CoA reductase, CETP, or apoE genotype.
Molecular causes of colon cancer
Authors: Oving Irma M. , Clevers Hans C.
Published: March 2003

Cells in a developing embryo communicate with each other through a limited number of intercellular signalling pathways, of which the Wnt signalling pathway is one. Little is known about the function of Wnt signalling beyond that in embryogenesis. However, recent insights into the molecular etiology of colon cancer have implied a central role for the Wnt signalling pathway. The malignant transformation of colorectal epithelium is well defined, leading to adenoma and sequentially carcinoma formation. Several genes that regulate the Wnt pathway are mutated in cancer of the human colon and other organs. All of these mutations lead to the inappropriate activation of the pathway, which instructs the cell to divide unrestrictedly. These insights now allow the Wnt pathway to be exploited as a new target for drug development in colon cancer.
Interactions of human immunodeficiency virus‐1 proteins with neurons: possible role in the development of human immunodeficiency virus‐1‐associated dementia
Authors: Van De Bovenkamp M. , Nottet H. S. L. M. , Pereira C. F.
Published: March 2003

Human immunodeficiency virus‐1 (HIV‐1)‐associated dementia is a severe neurological complication of HIV‐1 infection that affects 15–20% of the patients in the late stages of acquired immunodeficiency syndrome. HIV‐1‐associated dementia is most probably a consequence of HIV‐1 infection of the brain rather than of an opportunistic pathogen. The exact mechanism by which the virus causes this disorder, however, is not completely understood. A number of HIV‐1 proteins have been shown to be released from HIV‐1‐infected cells and/or to be present in the extracellular milieu in the HIV‐1‐infected brain. Moreover, these proteins have been shown to posses neurotoxic and/or neuromodulatory features in vitro. This review describes the possible direct interactions of the HIV‐1 proteins gp120, gp41, vpr, tat, rev, vpu and nef with neurons, which might play a role in the development of HIV‐1‐associated dementia in vivo.
Effect of fluticasone on the elastase:antielastase profile of the normal lung
Authors: Kamal A. M. , Corrigan C. J. , Tetley T. D. , Alaghband‐Zadeh J. , Smith S. F.
Published: March 2003

Background Excessive elastolytic activity contributes to the pathogenesis of several inflammatory respiratory diseases. The effect of glucocorticoids, which are potent anti‐inflammatory agents, on the elastase:antielastase balance of the human respiratory tract is unclear, as studies on patients and in vitro have yielded inconsistent results.

Design To clarify this, bronchoalveolar lavage and lavage fluids from the upper and central airways were collected from 10 healthy, nonsmoking volunteers before and after a 2‐week course of inhaled fluticasone propionate (2 × 500 µg day−1). Concentrations of two neutrophil elastase inhibitors, α‐1‐proteinase inhibitor (PI) and secretory leukoproteinase inhibitor (SLPI), as well as neutrophil elastase (NE) activity and NE inhibitory capacity (NEIC) were quantified in all lavage fluids.

Results Concentrations of SLPI were highest in the proximal airways and decreased distally. Neutrophil elastase inhibitory capacity activity followed the same gradient and correlated positively and consistently with SLPI, suggesting that this inhibitor makes an important contribution to the regulation of elastolytic activity in the healthy human respiratory tract. Inhaled fluticasone propionate had no effect on any component of the elastase:antielastase balance at any level of the respiratory tract, even though circulating cortisol levels were reduced in all subjects, confirming subject compliance and adequate pulmonary delivery of the drug.

Conclusion This lack of action in the respiratory tract may contribute to the ineffectiveness of inhaled glucocorticoids in respiratory conditions characterised by excessive elastolytic activity.
Inflammatory imbalance between IL‐10 and TNFα in unstable angina potential plaque stabilizing effects of IL‐10
Authors: Wæhre T. , Halvorsen B. , Damås J. K. , Yndestad A. , Brosstad F. , Gullestad L. , Kjekshus J. , Frøland S. S. , Aukrust P.
Published: March 2003

Background The pathogenesis of atherosclerosis and acute coronary syndromes involves inflammation and immunological mechanisms. We hypothesized that patients with unstable angina may have an imbalance between inflammatory and anti‐inflammatory cytokines.

Design Plasma levels of tumour necrosis factor (TNF)α and interleukin (IL)‐10 were analyzed in 44 patients with stable angina, 29 patients with unstable angina and 20 controls. mRNA levels of these cytokines were analyzed in peripheral blood mononuclear cells (PBMC). We also studied the in vitro effects of IL‐10 in PBMC from unstable angina patients.

Results Our main findings were: (1) the angina patients and particularly those with unstable disease had significantly raised TNFα in comparison with the controls, both at the protein and mRNA level; (2) in contrast, the levels of IL‐10 were not different in the angina patients in comparison with the healthy controls, resulting in a markedly enhanced TNFα:IL‐10 ratio, particularly in the unstable angina patients; (3) while exogenously added IL‐10 markedly inhibited the release of TNFα, IL‐8 and tissue factor as well as impairing the gelatinolytic activity and mRNA production of matrix metalloproteinase‐9, it enhanced the tissue inhibitor of this metalloproteinase (i.e. TIMP‐1) in PBMC from the unstable angina patients.

Conclusion Patients with unstable angina appear to have an imbalance between TNFα and IL‐10, possibly favouring inflammatory net effects. IL‐10 may have beneficial effects on mechanisms that are important in plaque rupture and thrombus formation.
Airway surface liquid recovered by lavage with perfluorocarbon liquid in cats
Authors: Southern K. W. , Funkhouser W. K. , Kazachkova I. , Godfrey V. L. , Fordham L. A. , Gatzy J. T. , Barker P. M.
Published: March 2003

Background Airway surface liquid (ASL) is difficult to sample. Lavage with an immiscible perfluorocarbon (PFC) liquid to recover ASL was evaluated in cats.

Materials and Methods Six wild‐type cats underwent bronchoscopic lavage with a PFC (perfluorohexane), with the bronchoscope wedged in the feline equivalent of the right lower lobe. Two cats (control animals) were lavaged with a saline vehicle only. Four procedures were performed on each animal at 2–3‐week intervals. Ionic composition of ASL was determined by flame photometry.

Results Cats lavaged with PFC showed significantly more acute respiratory distress than those lavaged with saline (respiratory rate following procedure: PFC, 47 ± 5 min−1 vs. saline, 27 ± 2 min−1, P < 0·05; O2 saturation: PFC 80 ± 1% vs. saline, 91 ± 1%, P < 0·01). The PFC group also had clinical evidence of chronic respiratory compromise (mean respiratory rate before next anaesthetic; PFC, 37 ± 2 min−1 vs. saline, 20 ± 3 min−1, P < 0·01). The PFC‐lavaged lungs demonstrated persistent radiographic changes and histological evidence of small airways obstruction with distal alveolar damage. Six PFC lavages yielded ASL samples (> 100 µL) which were sufficient for analysis. Mean (± SEM) ionic concentrations in these samples were Na+ 157·4 ± 14·5 mmol L−1, Cl− 150·5 ± 16·8 mmol L−1 and K+ 10·1 ± 1·7 mmol L−1.

Conclusions Perfluorocarbon lavage can be used to collect unmodified ASL from the distal lung. However, repeated lavage with perfluorohexane was associated with significant pathological changes in this study.
The effect of lipoproteins on endothelial nitric oxide synthase is modulated by lipoperoxides
Authors: Lubrano V. , Vassalle C. , Blandizzi C. , Del Tacca M. , Palombo C. , L’Abbate A. , Baldi S. , Natali A.
Published: March 2003

Background and aim The effect of low‐density lipoproteins (LDLs) on endothelial nitric oxide synthase (eNOS) is debated. By coupling in vivo and in vitro experiments we evaluated the role of oxidized lipid substrates in the modulation of eNOS activity by LDLs.

Materials and methods Plasma lipids, nitrite/nitrates (NO2/NO3), and malondialdehyde (MDA) were measured in 14 controls, and in 13 patients with familial hypercholesterolemia (FH) before and after 12 weeks of treatment with atorvastatin (20 mg u.i.d.). Nitric oxide synthase in cell lysate and NO2/NO3 into the medium were measured in human microvascular (HMEC‐1) and umbilical vein (HUVEC) endothelial cells after 24 h of incubation with increasing concentrations of mildly oxidized LDLs with and without atorvastatin and in HMEC‐1 with and without vitamin C. In HMEC‐1, NO2/NO3 was also determined after exposure to more intensively oxidized LDLs.

Results At baseline, plasma NO2/NO3 (56 ± 7 vs. 35 ± 3 µM) and MDA (5·6 ± 0·7 vs. 2·9 ± 0·3 µM), were significantly (P < 0·02 for both) higher in the FH patients. In the whole study group, NO2/NO3 was more strongly correlated with plasma MDA (Rho = 0·70) than LDL‐cholesterol (Rho = 0·57). In the FH patients, atorvastatin induced a significant decline in plasma total and LDL‐cholesterol (−3·1 ± 0·5 and −2·9 ± 0·5 mM, respectively), NO2/NO3 (−35 ± 8 µM) and MDA (−3·4 ± 0·7 µM) (P < 0·001 for all). Changes in plasma NO2/NO3 were related to the concomitant changes in plasma MDA (Rho = 0·79, P < 0·006) and not to changes in LDL‐cholesterol. In HMEC‐1 and in HUVEC, mildly oxidized LDLs stimulated both e‐NOS and NO2/NO3 accumulation; the effect on e‐NOS was potentiated by vitamin C in HMEC‐1. Atorvastatin had no effect in HMEC‐1 while it stimulated eNOS but not NO2/NO3 in HUVEC. The accumulation of NO2/NO3 in HMEC exposed to increasing concentrations of more intensively oxidized‐LDLs showed a nonlinear dose–response curve.

Conclusions In uncomplicated patients with FH, plasma NO2/NO3 concentrations are elevated; the cross‐sectional data, intervention study and in vitro experiments indicate that oxidized lipids exert a tonic stimulatory action on e‐NOS and NO2/NO3 generation not mediated through superoxide anion formation. Atorvastatin amplify this eNOS response in HUVEC, but not in HMEC, and this effect is not associated with a parallel increased NO2/NO3 generation.
Early endothelial dysfunction following renal mass reduction in rats
Authors: Benchetrit S. , Green J. , Katz D. , Bernheim J. , Rathaus M.
Published: March 2003

Background Endothelial dysfunction has been previously described in severely hypertensive rats with renal mass reduction (RMR) receiving large dietary Na loads. Because hypertension and Na loading reduce endothelium‐dependent vasodilation, the effect of renal failure per se is unclear.

Methods Responses to acetylcholine in noradrenaline‐contracted isolated perfused mesenteric arteries were studied. Vessels were obtained from RMR rats kept on a normal diet, 3 and 10 days after surgery, and the results were compared with those from sham‐operated rats (SN). The role of three putative mediators of endothelium‐dependent vasodilation was assessed using: L‐NAME (10−4 mol L−1); indomethacin (INDO, 10−5 mol L−1); and a mixture of charybdotoxin and apamin (C/A, both 10−7 mol L−1), inhibitors of Ca‐activated K‐channels to mediate the effects of endothelium‐derived hyperpolarizing factor (EDHF).

Results Response to acetylcholine but not that to nitroprusside (endothelium‐ independent) was decreased in RMR. L‐NAME reduced further acetylcholine relaxations in SN but not in RMR. By contrary, INDO decreased acetylcholine vasodilation in RMR but had no effect in SN. C/A had similar effects in the SN and RMR rats. The levels of 6‐keto prostaglandin F1α were elevated in the urine of the RMR rats and were perfusate from the RMR vessels.

Conclusion Endothelial dysfunction occurs early after RMR, even when systolic blood pressure is only minimally elevated and Na intake is normal. This alteration may be because of decreased availability of nitric oxide, partially compensated by increased prostacyclin production.
Effects of adrenaline and potassium on QTc interval and QT dispersion in man
Authors: Lee S. , Harris N. D. , Robinson R. T. , Yeoh L. , Macdonald I. A. , Heller S. R.
Published: March 2003

Background Hypoglycaemia alters cardiac repolarization acutely, with increases in rate‐corrected QT (QTc) interval and QT dispersion (QTd) on the electrocardiogram (ECG); such changes are related to the counterregulatory sympatho‐adrenal response. Adrenaline produces both QTc lengthening and a fall in plasma potassium (K+) when infused into healthy volunteers. Hypokalaemia prolongs cardiac repolarization independently however, and therefore our aim was to determine whether adrenaline‐induced repolarization changes are mediated directly or through lowered plasma K+.

Materials and methods Ten healthy males were studied on two occasions. At both visits they received similar l‐adrenaline infusions but on one occasion potassium was also administered; infusion rates were adjusted to maintain circulating K+ at baseline. The QTc interval, QTd, peripheral physiological responses and plasma adrenaline and potassium concentrations were measured during both visits.

Results The QTc interval and QTd increased both with and without potassium clamping. Without K+ replacement, mean (SE) QTc lengthened from 378 (5) ms to a final maximum value of 433 (10) ms, and QTd increased from 36 (5) ms to 69 (8) ms (both P < 0·001). During K+ replacement, QTc duration at baseline and study end was 385 (7) ms and 423 (11) ms, respectively (P < 0·001), and QTd 38 was (4) ms and 63 (5) ms (P = 0·001).

Conclusions These data suggest that disturbed cardiac repolarization as a result of increases in circulating adrenaline occurs independently of extracellular potassium. A direct effect of adrenaline upon the myocardium appears the most likely mechanism.
Distributions of HLA‐DRB1/DQB1 alleles and haplotypes in the North‐eastern Thai population: indicative of a distinct Thai population with Chinese admixtures in the Central Thais
Authors: Romphruk A. V. , Puapairoj C. , Romphruk A. , Barasrux S. , Leelayuwat Y. Urwijitaroon*† & C.
Published: March 2003

The phenotype and gene frequencies of HLA class II alleles were studied in the North‐eastern Thai population. Blood samples were collected from 100 unrelated healthy North‐eastern Thais. The HLA‐DRB1 and DQB1 genes were typed using the polymerase chain reaction – sequence specific primer (PCR‐SSP) and polymerase chain reaction – sequence specific oligonucleotide probe (PCR‐SSO) techniques. Twenty‐six HLA‐DRB1 and 11 DQB1 alleles were found in this population. DRB1*1202, 1502, 0405 and DQB1*0502/0504, 0301/0304 alleles were commonly found. Linkage disequilibrium analysis suggested the existence of 13 DR‐DQ haplotypes. The DRB1*1502‐DQB1*0501 haplotype was the most common. The DRB1*1106‐DQB1*0301/0304 haplotype was found only in North‐eastern Thais and not in other Thai populations. Comparative analysis of the HLA‐DR/DQ alleles revealed differences in the distributions of these alleles amongst different ethnic groups. Interestingly, the distributions of HLA class II alleles in Central Thai, North‐eastern Thai and Southern Chinese populations are similar. However, it appears that the distribution in the Central Thais is a mixture of those in Southern Chinese and North‐eastern Thais, suggesting the existence of Thai–Chinese admixtures in the Central Thai population. This study provides basic information for further studies of the MHC in anthropology, organ transplantation and disease susceptibility in the North‐eastern Thai population.
Polymorphism of HLA‐A, ‐B, ‐DRB1, ‐DQA1 and ‐DQB1 haplotypes in a Croatian population
Authors: Grubic Z. , Z unec R. , C ec uk‐Jelic ic E. , Kerhin‐Brkljac ic V. , Kas telan A.
Published: March 2003

We describe for the first time extended haplotypes in a Croatian population. The present study gives the HLA‐A, ‐B, ‐DRB1, ‐DQA1 and ‐DQB1 allele and haplotype frequencies in 105 families with at least two offspring. All individuals were studied by conventional serology for HLA class I antigens (A and B), while class II alleles (DRB1, DQA1, DQB1) were typed using the PCR–SSOP method. HLA genotyping was performed by segregation in all 105 families. For extended haplotype analysis, 420 independent parental haplotypes were included. Fourteen HLA‐A, 18 HLA‐B, 28 DRB1, 9 DQA1 and 11 DQB1 alleles were found in the studied population. Most of the DRB1 alleles in our population had an exclusive association with one specific DQA1‐DQB1 combination. This strong linkage disequilibrium within the HLA class II region is often extended to the HLA‐B locus. A total of 10 HLA‐A, ‐B, ‐DRB1, ‐DQA1, ‐DQB1 haplotypes were observed with a frequency ≤ 1.0%. The three most frequent haplotypes were HLA‐A1, B8, DRB1*0301, DQA1*0501, DQB1*0201; HLA‐A3, B7, DRB1*1501, DQA1*0102, DQB1*0602 and HLA‐A24, B44, DRB1*0701, DQA1*0201, DQB1*02. These results should provide a useful reference for further anthropological studies, transplantation studies, and studies of associations between HLA and diseases.
The effect of geographic origin on the frequency of HLA antigens and their association with ageing
Authors: Izaks G. J. , Remarque E. J. , Schreuder G. M. T. , Westendorp R. G. J. , Ligthart G. J.
Published: March 2003

The association between HLA antigens and ageing is not clear. Ageing in women was associated with B40 and DR5 in a recent study, but other studies yielded conflicting results. In none of the studies, however, did the young and elderly samples originate from the same homogeneous population. Homogeneity is dependent on geographic origin. The aim of this study was to investigate whether differences in geographic origin between age groups could explain the age‐associated differences in the frequencies of B40 and DR5. The authors used the new design of a ‘birth‐place‐restricted comparison’ in which the origin of all subjects was ascertained. The total study population comprised 1010 young women aged 25–40 years and 660 elderly women aged 85 years and older. The ‘birth‐place‐restricted comparison’ included 66 young and 285 elderly women from one geographic area (Leiden, the Netherlands). Men were not included because ageing in men was not associated with HLA antigens in a recent study. In the total population, the frequency of B40 in young women of different origin varied between 16 and 28%, and the frequency of DR5 between 11 and 23%. Similar differences were observed in the elderly women. In the ‘birth‐place‐restricted comparison’, the frequency of B40 was 15% in the young women and 11% in the elderly women (difference 4%, 95% confidence interval, −5 to 13%). The frequency of DR5 was 20% in the young women, and 28% in the elderly women (difference 8%, 95% confidence interval, −4 to 19%). Thus, marked differences in HLA antigen frequency were found between populations of various geographic origins. Definition and ascertainment of the target population are therefore necessary in genetic studies of ageing. In such a ‘birth‐place‐restricted comparison’, the authors confirmed that ageing in women was negatively associated with HLA‐B40 and positively associated with HLA‐DR5.
Common polymorphisms and alternative splicing in the ILT3 gene are not associated with atopy
Authors: Heinzmann A. , Blattmann S. , Forster J. , Kuehr J. , Deichmann K. A.
Published: March 2003

Recently, a linkage of the chromosomal region 19q13.4 with bronchial asthma has been demonstrated. This region harbours the so‐called leucocyte receptor cluster with the gene for immunoglobulin‐like‐transcript 3 (ILT3) as a member. ILT3 represents an inhibitory receptor bearing three immunoreceptor tyrosine inhibitory motifs (ITIM). The protein mediates downregulation of cell activation through recruitment of different SH2‐containing protein tyrosine phosphatases. With regard to the negative immunoregulatory function particularly on B‐cells, ILT3 represents a candidate gene for atopy and asthma. The aim of this study was to screen for common polymorphisms in the gene coding for ILT3 and to test for association with the atopic phenotype. Using single‐stranded conformal polymorphism‐analysis and direct genomic sequencing seven polymorphisms, three mutations, a common deletion of 7 bp in the third intron and evidence for further alternative splicing of the ILT3 gene were found. Although no association was found with atopy phenotypes, it might prove useful to test for association with bronchial asthma.
A novel locus affecting serum levels of IgG2a maps to the murine H2 region
Authors: Matthews V. B. , Christiansen F. T. , Price P.
Published: March 2003

The effects of genes in the murine H2 region on basal immunoglobulin levels were investigated and ratios of IgG1/IgG2a were calculated, as low ratios indicate a Th1 cytokine mileu. H2b mice with B10 or BALB genetic backgrounds had higher levels of IgG2a than H2k and H2d congenic strains, and hence had low IgG1/IgG2a ratios. B10 (H2b) mice generally had high levels of IgG2b, IgG3, IgA and IgM, but this outcome was more variable. The high IgG2a phenotype was denoted Igis1 (Immunoglobulin isotype‐1) and mapped telomeric of IEβ using B10.A(4R) mice (high IgG2a) and B10.A(3R) and B10.A(5R) mice (low IgG2a). Further mapping in B10.A(2R), B10.A(1R) and B10.A(18R) mice placed Igis1 in the 27kb region between G7c and G7e.
CD154 polymorphism in Spanish populations. Differences in the allelic distribution between Canary Islanders and Peninsulars
Authors: Citores M. J. , Pérez‐Aciego P. , Rodríguez‐Gallego C. , Contreras‐Martín B. , García‐Laorden I. , Durántez A.
Published: March 2003

The CD154 gene contains a dinucleotide repeat (CA)n in the 3′ untranslated region. Allelic distribution in Spanish populations from two areas with different genetic background, the Canary Islands and Peninsula, are described. Seven alleles with different allelic distribution between the two groups, were found. This represents a highly polymorphic marker, useful for genetic studies on a critical molecule in immunity.
Cattle MHC genes DOA and DOB: sequence polymorphisms and assignments to the class IIb region
Authors: Gelhaus A. , Förster B.
Published: March 2003

In a study of the genetic polymorphism of the second exons of the cattle DOA and DOB genes, two and four allelic variants were detected, respectively. In the predicted amino acid sequence, the DOA polymorphism corresponded to variation at the respective residue position, whereas the nucleotide substitutions in the DOB gene were non‐informative. PCR‐RFLP assays were developed for DOA and DOB typing, and both loci were genetically mapped to the BoLA class IIb region by linkage analysis in the International Bovine Reference Panel. The single nucleotide polymorphisms detected in the BoLA‐DOA and ‐DOB genes enable these loci to be used as markers in genetic trait analyses.
Molecular cloning of four lambda light chain cDNAs from the Australian brushtail possum Trichosurus vulpecula
Authors: Belov K. , Harrison G. A. , Miller R. D. , Cooper D. W.
Published: March 2003

A brushtail possum mesenteric lymph node cDNA library was screened with a grey short‐tail opossum Cλ probe and four immunoglobulin lambda cDNAs were isolated. Two of the isolated clones (L5 and L10) contained identical framework 4 regions and constant regions (but different variable regions), suggesting that the possum lambda locus is organized as multiple J‐C pairs — a feature seen in the opossum and placental mammals. The cloning of the lambda light chain cDNAs signifies the completion of the basic molecular characterization of the brushtail possum immunoglobulin repertoire. The availability of this sequence data will allow extensive analysis of the immune response of the brushtail possum at the molecular level, as well as the development of specific immunological reagents for detection of immunoglobulin molecules at the protein level.
Structural basis of allotypes of ecto‐nucleotide pyrophosphatase/phosphodiesterase (plasma cell membrane glycoprotein PC‐1) in the mouse and rat, and analysis of allele‐specific xenogeneic antibodies
Authors: Banakh I. , Sali A. , Dubljevic V. , Grobben B. , Slegers H. , Goding J. W.
Published: March 2003

Ecto‐nucleotide pyrophosphatase/phosphodiesterases (E‐NPPs) have been implicated in bone calcification, type II diabetes, control of purinergic signalling and tumour invasion. The gene for the plasma cell membrane glycoprotein PC‐1 in the mouse (Enpp1) has been known since 1970 to exist in two allelic forms, but their structural basis was heretofore unknown. We show that the Enpp1a and Enpp1b alleles differ by only two amino acids, at positions 650 and 679 in the C‐terminal nuclease‐like domain. Histidine 650 but not arginine 679 forms an essential part of the Enpp1a epitope recognized by monoclonal antibody IR‐518. Sequences of LEW and LOU rats and the rat glioma cell line C6 differ from that of the mouse by about 60 amino acids. The LOU and C6 cell line sequences differ by only three amino acids, but differ from the LEW sequence by 10 amino acids. All three rat strains possess the mouse Enpp1b allele at positions 650 and 679. Despite numerous other differences from the mouse, rats immunized with Enpp1a mouse cells have generated monoclonal antibodies specific for the Enpp1a allele, suggesting that amino acids 650 and 679 may be particularly immunogenic. The cytoplasmic tails of the mouse and rat are highly conserved, but are significantly different from human cytoplasmic tails.