bluuebunny/crossref_metadata_2025 huggingface dataset:
LEPR gene polymorphisms: associations with overweight, fat mass and response to diet in women
Authors: Mammès O. , Aubert R. , Betoulle D. , Péan F. , Herbeth B. , Visvikis S. , Siest G. , Fumeron F.
Published: March 2003

Background In humans, a mutation of the leptin receptor gene (LEPR) leads to a rare obese syndrome of mendelian inheritance. However, obesity in humans results from interactions between genes and environment, mainly nutritional factors. Variations at the LEPR locus could be involved in the regulation of body weight.

Design Genetic variations at the LEPR locus were screened in a selection of 30 French overweight subjects by Single Strand Conformation Polymorphism (SSCP) analysis, then an association study between genotypes and obesity phenotypes was performed in 179 French overweight patients recruited from the Nutrition Department of Bichat Hospital in Paris who were prescribed a low calorie diet and in 387 unrelated volunteers (98 overweight, 289 normal weight) drawn from the Stanislas Family Study in Nancy.

Results Two new genetic variants were found: T + 70 → C (exon 1) and Asp (A) 96 Asp (G) (exon 4). In Nancy, the T + 70 → C polymorphism was associated with fat mass adjusted for BMI in women (P = 0·025). The genotype and allele frequencies of the Ser (T) 343 Ser (C) polymorphism (exon 9) were significantly different between normal and overweight women, with the T allele being more frequent in the overweight group (T frequency in Nancy, 0·82; in Nancy + Paris, 0·79) than in the normal weight group (0·69; P = 0·017 vs. Nancy overweight, P = 0·003 vs. Nancy + Paris overweight). In women from Nancy, fat mass adjusted for BMI was significantly associated with this polymorphism (P = 0·01). The overweight women carrying the C allele of this polymorphism lost more weight in response to low calorie diet than the non carriers (P = 0·006).

Conclusions In women, genetic variations at the LEPR gene level are associated with overweight and fat mass in a cross sectional study and with response to low calorie diet in an intervention study. These results indicate that variations at the leptin receptor locus are associated with common obesity phenotypes and are a part of the polygenic influences on the response to nutritional environment.
Protein adducts in type I and type II fibre predominant muscles of the ethanol‐fed rat: preferential localisation in the sarcolemmal and subsarcolemmal region
Authors: Worrall S. , Niemela O. , Parkkila S. , Peters T. J. , Preedy V. R.
Published: March 2003

Background Chronic alcoholic myopathy is characterised by reduced muscle strength and structural changes including a decrease in the diameter of Type II (glycolytic, fast‐twitch, anaerobic) fibres. In contrast, the Type I fibres (oxidative, slow‐twitch, aerobic) are relatively protected. It is possible that adduct formation with reactive metabolites of ethanol may be a contributory process.

Materials and Methods We analysed skeletal muscles from rats fed nutritional‐complete liquid diets containing ethanol as 35% of total dietary energy; control rats were fed the same diet in which ethanol was replaced by isocaloric glucose. Reduced‐acetaldehyde, unreduced‐acetaldehyde, malondialdehyde, malondialdehyde‐acetaldehyde and α‐hydroxyethyl protein‐adducts in both soleus and plantaris were analysed by ELISA or immunohistochemistry with comparative studies in liver.

Results After 6 weeks, the weights of the plantaris, but not the soleus, were decreased. ELISA analyses for protein adducts showed increased amounts of unreduced‐acetaldehyde adducts in soleus (P < 0·025) and plantaris (P < 0·025). Reduced‐acetaldehyde, malondialdehyde, malondialdehyde‐acetaldehyde and α‐hydroxyethyl protein‐adducts in both soleus and plantaris muscles from ethanol‐fed rats were not significantly different from their pair‐fed controls (P > 0·05). In contrast, liver from ethanol‐fed rats showed significantly higher levels of unreduced‐acetaldehyde (P < 0·025), reduced‐acetaldehyde (P < 0·01), malondialdehyde (P < 0·01), malondialdehyde‐acetaldehyde (P < 0·025) and α‐hydroxyethyl radical (P < 0·01) protein adducts compared to pair‐fed controls. Immuno‐histochemical analysis using an antiserum reacting with both reduced‐ and unreduced‐acetaldehyde adducts showed adducts were increased in soleus (P < 0·05) and plantaris (P < 0·025), confirming ELISA analysis. Adducts were located within the sarcolemmal (i.e. muscle membrane) and subsarcolemmal regions.

Conclusion This is the first report of adduct formation in myopathic skeletal muscle due to chronic alcohol ingestion and suggests a role for acetaldehyde in the aetiology of alcoholic myopathy.
Butyrate and the cytokine‐induced α1‐proteinase inhibitor release in intestinal epithelial cells
Authors: Faust D. , Hormann S. , Friedrich‐Sander M. , Milovic V. , Stein J.
Published: March 2003

Background α1‐proteinase inhibitor (α1‐PI), an anti‐inflammatory protein thought to play a role in the intestinal inflammation, is synthesised by and released from the intestinal epithelial cells. IL‐1β is a key proinflammatory cytokine in the abnormal immune response that occurs in inflammatory bowel disease. Butyrate is a normal luminal constituent in the colon, known to be of benefit in preventing inflammatory bowel disease. Direct modes of action of butyrate in intestinal inflammation have been poorly studied so far. The aim of this study was to investigate the effects of butyrate on cytokine‐mediated α1‐PI release in intestinal epithelial cells.

Methods Differentiated Caco‐2 cells were incubated with IL‐1β in the presence or absence of 2 mM butyrate. α1‐PI expression in the cells was evaluated by Western blot analysis and α1‐PI release by ELISA.

Results Treatment with butyrate alone had no effect on α1‐PI expression in differentiated Caco‐2 cells. However, treatment of the cells with 2 mM butyrate significantly reduced the α1‐PI level in IL‐1β‐treated cells. In the cell culture medium, the presence of butyrate impaired the IL‐1β‐induced α1‐PI release to 17–35%. The treatment induced no change in the number of detached cells or the percentage of viable cells.

Conclusion Our data show that butyrate inhibits α1‐PI release from Caco‐2 colonocytes treated with IL‐1β. It is therefore likely that anti‐inflammatory actions of butyrate occur via a mechanism that does not involve direct regulation of cytokine‐induced anti‐inflammatory protein expression in intestinal epithelial cells.
Dietary epoxy fatty acids are absorbed in healthy women
Authors: Wilson R. , Fernie C. E. , Scrimgeour C. M. , Lyall K. , Smyth L. , Riemersma R. A.
Published: March 2003

Background Epoxy fats in the diet may adversely affect human health. There are no data on the absorption of these fats in humans.

Methods Triglycerides were synthesized containing two U‐13C‐labelled monoepoxy or diepoxy stearic acid molecules. Apparently healthy women consumed a standardized fatty meal (30 g fat) containing either 20 mg monoepoxy or 25 mg diepoxy fat (n = 6 and n = 7, respectively). Plasma lipid [U‐13C]monoepoxy and diepoxy stearate concentrations were determined (0–24 h) by gas chromatography‐mass spectrometry.

Results Plasma triglycerides increased from 1·05 ± 0·12 to 1·83 ± 0·13 mmol L−1 (n = 6) and from 1·10 ± 0·19 to 1·41 ± 0·27 mmol L−1 (n = 7) (both P < 0·001). Plasma [U‐13C]monoepoxy and diepoxy stearate levels increased to 0·18 ± 0·07 µmol L−1 (n = 6) and to 0·08 ± 0·03 µmol L−1 (n = 7), respectively. Monoepoxy triglyceride was better absorbed than diepoxy triglyceride: 17 ± 4 vs. 8 ± 1% of dose (determined from area under curve (plasma 13C) normalized to that of absorbed triglycerides (plasma 12C); P < 0·02 after log transformation). The absorption of monoepoxy‐ and diepoxy‐labelled triglycerides was related to that of normal triglycerides (r = 0·80, P < 0·05 and r = 0·91, P < 0·001, respectively).

Conclusions Monoepoxy fats are better absorbed than diepoxy fats in women (17 ± 4 vs. 8 ± 1% of dose, P = 0·02). This difference in absorption is important when considering the relative toxicity of epoxidized material in the food chain.
Addition of glucose to a fatty meal delays chylomicrons and suppresses VLDL in healthy subjects
Authors: Westphal S. , Leodolter A. , Kahl S. , Dierkes J. , Malfertheiner P. , Luley C.
Published: March 2003

Background Postprandial lipemia has been shown in a number of studies to be associated with atherosclerosis. However, the test meals used in these studies were heterogeneous particularly in their carbohydrate content, which may be important for the resulting lipemia and which makes comparison between different studies difficult. We studied the effect of 75 g glucose added to a fatty meal on various lipoproteins and on gastric emptying.

Materials and methods Fourteen healthy young volunteers were studied in the fasting state and until 7 h postprandially. In a crossover design, each subject received an oral fat load (1 g fat kg−1 body weight) with or without 75 g glucose. Triacylglycerol (TG) and free fatty acids (FFA) were then measured in whole blood and lipoproteins were separated off by ultracentrifuging. Gastric emptying was determined by the 13C breath test.

Results The addition of 75 g glucose to a fatty meal had two different effects. Gastric emptying was delayed by about 2 h and the chylomicron response was consequently postponed. In addition, the postprandial increase in VLDL triacylglycerol was reduced by 40%, which may be due to the pronounced FFA depression during the glucose‐induced rise in insulin.

Conclusions 75 g glucose added to an oral fat load causes a delay of the chylomicron response and a marked suppression of the postprandial increase in VLDL.
Impaired estrogen‐induced negative feedback on gonadotropin secretion in patients with gonadotropin‐secreting and nonfunctioning pituitary adenomas
Authors: Lania A. , Gangi E. , Romoli R. , Losa M. , Travaglini P. , Meringolo D. , Ambrosi B. , Faglia G. , Beck‐Peccoz P. , Spada A.
Published: March 2003

Background Several in vitro studies suggest that gonadotropin‐secreting pituitary adenomas (Gn‐omas) and non functioning pituitary adenomas (NFPA) originate from gonadotroph cells. Patients with Gn‐oma and NFPA frequently show abnormal gonadotropin response to TRH. The aim of the study was to investigate whether the estrogen‐induced negative feedback is operating in either patients with Gn‐oma or NFPA.

Materials and methods Serum gonadotropin levels were evaluated at 24 h after ethinylestradiol administration (1 mg per os; EE2 test) in seven patients with a diagnosis of Gn‐oma, based on the presence of high follicle‐stimulating hormone (FSH) and/or lutenising hormone (LH) levels with normal or high levels of sex steroids, in 22 patients with NFPA with normal or low levels of gonadotropin and sex steroids, and 30 sex‐ and age‐matched healthy subjects. A normal response to EE2 test was arbitrarily defined as a serum LH and FSH decrease of at least 40 and 30% below basal levels.

Results Among patients with Gn‐oma, only one had a normal FSH inhibition and another, a normal LH inhibition. Among the 22 patients with NFPA, the EE2 test caused a normal FSH or LH reduction in 10 and 15, respectively, while a normal reduction of both FSH and LH was observed in nine.

Conclusions The study demonstrates that estrogen‐induced negative feedback of gonadotropin secretion is disrupted in almost all patients with Gn‐oma and in half of those with NFPA. This defective feedback is reminiscent of the resistance to thyroid hormones and glucocorticoids observed in patients with thyroid‐stimulating hormone‐ (TSH‐) and adrenocorticotropic hormone‐ (ACTH‐)secreting adenomas, respectively.
Factorial study of the effects of atorvastatin and fish oil on dyslipidaemia in visceral obesity
Authors: Chan D. C. , Watts G. F. , Mori T. A. , Barrett P. H. R. , Beilin L. J. , Redgrave T. G.
Published: March 2003

Background  Dyslipidaemia may account for increased risk of cardiovascular disease in central obesity. Pharmacotherapy is often indicated in these patients, but the optimal approach remains unclear. We investigated the effects of atorvastatin and fish oil on plasma lipid and lipoprotein levels, including remnant‐like particle‐cholesterol and apolipoprotein C‐III, in dyslipidaemic men with visceral obesity.

Methods  We carried out a 6‐week randomized, placebo‐controlled, 2 × 2 factorial intervention study of atorvastatin (40 mg day−1) and fish oil (4 g day−1) on plasma lipids and lipoproteins in 52 obese men (age 53  1 years, BMI 33·7  0·55 kg m−2) with dyslipidaemia and insulin resistance. Treatment effects were analysed by general linear modelling.

Results  Atorvastatin had significant main effects in decreasing triglycerides (−0·38  0·02 mmol L−1, P = 0·002), total cholesterol (−1·89  0·17 mmol L−1, P = 0·001), LDL‐cholesterol (−1·78  0·14 mmol L−1, P = 0·001), remnant‐like particle‐cholesterol (−0·08  0·04 mmol L−1, P = 0·035), apolipoprotein B (−49  4 mg dL−1, P = 0·001), apolipoprotein C‐III (−12·6  6·1 mg L−1, P = 0·044) and in increasing HDL‐cholesterol (+0·10  0·04 mmol L−1, P = 0·007). Fish oil had significant main effects in decreasing triglycerides (−0·38  0·11 mmol L−1, P = 0·002) and in increasing HDL‐cholesterol (+0·07  0·04 mmol L−1, P = 0·041). There were no significant changes in weight or insulin resistance during the study.

Conclusions  Atorvastatin and fish oil have independent and additive effects in correcting dyslipidaemia in viscerally obese men. Improvement in abnormalities in remnant lipoproteins may occur only with use of atorvastatin. Combination treatment with statin and fish oil may, however, offer an optimal therapeutic approach for globally correcting dyslipidaemia in obesity.
Heritability of left atrial size in the Tecumseh population
Authors: Palatini P. , Amerena J. , Nesbitt S. , Valentini M. , Majahalme S. , Krause L. , Tikhonoff V. , Julius S.
Published: March 2003

Background  Little is known about the determinants of atrial size, and no study has analyzed whether genetic factors are involved in the pathogenesis of LA enlargement.

Materials and methods We studied the heritability of echocardiographic left atrial size in 290 parents from the Tecumseh Blood Pressure Study and 251 children from the Tecumseh Offspring Study. All data from the parents and children were obtained at the same field office in Tecumseh, USA. Left atrial dimension was determined echocardiographically in accordance with American Society of Echocardiography guidelines with the use of leading‐edge‐to‐leading‐edge measurements of the maximal distance between the posterior aortic root wall and the posterior left atrial wall at end systole.

Results For correlation between the left atrial dimensions of the parents and their offspring, several models were generated to adjust the atrial dimensions in both groups for an increasing number of clinical variables. After removing the effect of age, gender, height, weight, skinfold thickness, and systolic blood pressure, parent–child correlation for left atrial size was 0·19 (P = 0·007). Further adjustment for left ventricular mass and for measuring left ventricular diastolic function increased the correlation to 0·25 (P = 0·001).

Conclusions  The present data indicate that heredity can explain a small but definite proportion of the variance in left atrial dimension.
Lipid peroxidation and antioxidant status in professional American football players during competition
Authors: Schippinger G. , Wonisch W. , Abuja P. M. , Fankhauser F. , Winklhofer‐Roob B. M. , Halwachs G.
Published: March 2003

Background Oxidative stress occurs during strenuous physical exercise, perhaps as a result of increased consumption of oxygen.

Materials and methods In this study, different markers of oxidative stress were determined in eight national league American football players. Before (March) and at three time‐points during the competition season (May, June, July) serum total peroxide concentrations, autoantibody titres against oxidized low‐density lipoprotein (oLab), and lag time of reactive oxygen species‐induced degradation of the fluorophore 1‐palmitoyl‐2‐((2‐(4‐(6‐phenyl‐trans‐1,3,5‐hexatrienyl)phenyl)ethyl)‐carbonyl)‐sn‐glycero‐3‐phosphocholine (DPHPC) were measured along with serum ascorbate, α‐ and γ‐tocopherol, and β‐carotene concentrations.

Results Before the competition season, serum antioxidant concentrations were within the lower normal range; ascorbate concentrations increased significantly during the competition period (P < 0·05). Serum peroxide concentrations were within the normal range and increased significantly during the competition period (P < 0·05); in four of the eight subjects the increase was several times the baseline values, while four athletes did not show any increase. The oLab titres increased significantly at the mid‐competition period time‐point (P < 0·01), but levelled off thereafter.

Discussion Given that it could not be predicted from the baseline oxidative stress and antioxidant status which subject would respond to strenuous exercise with an increase in oxidative stress status, it is concluded that oxidative stress should be monitored in all athletes.
Procoagulant and inflammatory response of virus‐infected monocytes
Authors: Bouwman J. J. M. , Visseren F. L. J. , Bosch M. C. , Bouter K. P. , Diepersloot R. J. A.
Published: March 2003

Background Monocytes play a prominent role in inflammation, coagulation and atherosclerosis by their ability to produce tissue factor (TF) and cytokines. The aim of the present study was to establish whether virus‐infected monocytes initiate coagulation. In addition, the production of cytokines by monocytes may accelerate the chronic process of atherosclerosis and may contribute to coronary syndromes by eliciting plaque instability.

Materials and methods Monocytes were isolated by Vacutainer®, BD Biosciences, Alphen aan den Rijn, Netherlands and subsequent magnetic cell sorting (MACS®, Milteny Biotec, Bergish Gladbach, Germany). Coagulation times in normal pooled plasma and Factor VII‐deficient plasma were measured after infection with cytomegalovirus (CMV), Chlamydia pneumoniae (Cp) and influenza A\H1N1. Anti‐TF antibodies were added to neutralize TF expressed on monocytes. Interleukins (IL) 6, 8 and 10 were measured in the supernatants.

Results Chlamydia pneumoniae‐ and CMV‐infected monocytes decreased the clotting time by 60%, and influenza‐infected monocytes by 19%, as compared to uninfected monocytes. Procoagulant activity was absent when Factor VII‐deficient plasma or anti‐TF antibodies were used. Monocytes produced both IL‐6 and IL‐8 after infection with CMV (317 pg mL−1 and 250 pg mL−1) or Cp (733 pg mL−1 and 268 pg mL−1). Similar results were obtained for influenza virus‐infected monocytes, but the levels of both cytokines were 3–5‐fold higher (1797 pg mL−1 and 725 pg mL−1). Interleukin‐10 was not produced by infected monocytes.

Conclusion The procoagulant activity of virus‐infected monocytes is TF‐dependent. Although influenza infection did not generate a significant reduction in clotting time, the pronounced expression of IL‐6 and IL‐8 may induce local and/or systemic inflammatory reactions, which may be associated with plaque rupture and atherosclerosis. The lack of production of the anti‐inflammatory cytokine IL‐10 may even accelerate these processes.
Selectin‐P and interleukin‐8 plasma levels in coronary heart disease patients
Authors: Romuk E. , Skrzep‐Poloczek B. , Wojciechowska C. , Tomasik A. , Birkner E. , Wodniecki J. , Gabrylewicz B. , Ochala A. , Tendera M.
Published: March 2003

Background  Alterations of the immune system are now believed to play crucial role in the pathogenesis of atherosclerosis. The aim of this study was analysis of soluble forms of selectin‐P and interleukin‐8 levels in patients with different form of coronary heart disease. Materials and methods: In the study took part 18 patients with stable coronary heart disease, 20 patients with unstable coronary heart disease and 15 healthy persons from control group. Soluble selectin‐P and interleukin‐8 levels were measured in EDTA plasma with the use of enzyme immunoassay ELISA.

Results The level of soluble selectin‐P was significantly higher in unstable coronary heart disease patients in comparison to the stable coronary heart disease patients (P ≤ 0·01) and nonsignificantly higher in comparison to the control group. The level of interleukin‐8 were significantly higher in unstable coronary heart disease patients in comparison to the stable coronary heart disease patients (P ≤ 0·01) and in comparison to the control group (P ≤ 0·02). Conclusion: Our findings suggest that soluble form of selectin‐P and interleukin‐8 may be useful clinical predictors of unstable coronary heart disease. The assessment of the risk for the development of coronary heart disease requires further serial investigation.
Effect of Sildenafil on hypertensive lower oesophageal sphincter
Authors: Bortolotti M. , Pandolfo N. , Giovannini M. , Mari C. , Miglioli M.
Published: March 2003

Background Sildenafil relaxes the muscle cells of the penis arterioles by inhibiting phosphodiesterase‐type 5 (PD‐5), inactivating the nitric oxide‐stimulated cyclic guanosine monophosphate. We investigated whether this effect of Sildenafil is also displayed on the muscles of the hypertensive lower oesophageal sphincter (LES).

Methods In 14 patients with symptomatic hypertensive LES, oesophageal motility was recorded by means of a low‐compliance manometric system with five manometric ports for the oesophageal body and a sleeve for the sphincter. After a basal period of 60 min a tablet of Sildenafil 50 mg (group A; seven patients) or one of placebo (group B; seven patients) ground and dissolved in 20 cc of water was infused in the stomach, randomly and in double‐blind manner. Recording continued for a further 60 min. Sphincter tone and pressure wave amplitude were measured each minute and the values averaged for each 5‐min period for the post‐infusion period of 60 min. The values of the whole post infusion period, the lowest values among the 5‐min periods (nadir values) and the values of the last 5‐min periods were compared with the basal values in each group, and those of group A were compared with the corresponding values of group B.

Results Sphincter tone and wave amplitude showed after Sildenafil a significant decrease comparable that of the basal period and the placebo. The inhibitory effect reached its maximum 10 min after the infusion and lasted approximately 1 h.

Conclusions Sildenafil inhibits the lower oesophageal sphincter tone and pressure wave amplitude of patients with symptomatic hypertensive LES. These findings suggest a clinical application of PD‐5 inhibitors in the treatment of spastic oesophageal motor disorders.
Influence of atherosclerosis on age‐related changes in renal size and function
Authors: Bax L. , Van Der Graaf Y. , Rabelink A. J. , Algra A. , Beutler J. J. , Mali for the Smart Study Group W. P. Th. M.
Published: March 2003

Background Renal size and function reflect the health of the kidney. These parameters are associated with age, gender and body weight. The kidneys are also influenced by micro‐ and macrovascular diseases. Atherosclerotic markers and risk factors may influence the age‐related changes of renal size and function.

Methods Data of 1056 patients who entered the SMART‐study (Second Manifestations of ARTerial disease) were used to assess the effect of atherosclerosis on the relationship between age and renal size and function and to study the effect of atherosclerosis on renal size and function. Patients who were newly referred to the hospital with manifestations of vascular disease were screened for asymptomatic atherosclerosis with noninvasive tests. The carotid intima‐media thickness (IMT) and albuminuria were used as estimates for the atherosclerotic burden. Renal size was defined as the mean pole‐to‐pole length of both kidneys measured by ultrasonography. Renal function was represented by serum creatinine.

Results Intima‐media thickness was a significant effect modifier of the age‐renal size relationship (P = 0·041). The increase of serum creatinine with age was more pronounced in the highest tertile of IMT (P = 0·048). Renal size decreased equally with age in patients with and without hypertension or diabetes mellitus (DM). The same held true for the age‐renal function relationship. Albuminuria and DM were independent predictors of renal size and function.

Conclusion Atherosclerosis accelerates the decrease of renal size and the increase of serum creatinine with age. Renal size and function are determined by albuminuria and DM.
Lactose intolerance: analysis of underlying factors
Authors: Vonk R. J. , Priebe M. G. , Koetse H. A. , Stellaard F. , Lenoir‐Wijnkoop I. , Antoine J.‐M. , Zhong Y. , Huang C.‐Y.
Published: March 2003

Background We studied the degree of lactose digestion and orocecal transit time (OCTT) as possible causes for the variability of symptoms of lactose intolerance (LI) in a sample of a population with genetically determined low lactase activity.

Methods Lactose digestion index (LDI) was measured by the recently developed 13C‐lactose/2H‐glucose test. The OCTT was determined using the breath hydrogen test. Based on a 6‐h symptom score (SSC) after a challenge dose of 25 g of lactose the subjects were divided into a tolerant group (T: n= 15; SSC = 0) and an intolerant group (IT: n= 28; SSC 1–40). The intolerant group was subdivided according to the severity of symptoms: group ITa (n = 17; mild symptoms without diarrhoea) and group ITb (n = 11; with diarrhoea).

Results The LDI was lower in the intolerant group (0·34 ± 0·14) (mean ± SD) than in the tolerant group (0·47 ± 0·14) (P = 0·008). The OCTT of group IT (60, 30–90 min) (median, quartiles) was significantly shorter than that of group T (105, 60–120 min) (P = 0·003) and was positively correlated with the LDI (P = 0·050). In groups ITa and ITb the OCTT (60, 30–90 min; 60, 26–83 min) and LDI (0·30 ± 0·14; 0·39 ± 0·14) were similar.

Conclusions Lactose digestion capacity, which is determined by small intestinal lactase activity as well as by OCTT, affects the occurrence of lactose intolerance. However, the major difference in intolerance symptoms is caused by differences in the colonic processing of maldigested lactose.
Transcapillary insulin transfer in human skeletal muscle
Authors: Herkner H. , Klein N. , Joukhadar C. , Lackner E. , Langenberger H. , Frossard M. , Bieglmayer C. , Wagner O. , Roden M. , Müller M.
Published: March 2003

Background Transcapillary insulin transfer is considered a rate‐limiting step in insulin action at supraphysiological insulin concentrations. However, it remains unclear whether this concept also applies for physiological conditions.

Materials and methods In the present study we set out to characterize transcapillary insulin transfer by measuring insulin concentrations in plasma and interstitial space fluid of skeletal muscle during an oral glucose tolerance test and euglycaemic hyperinsulinaemic clamp conditions, respectively. For this purpose we employed in vivo microdialysis of skeletal muscle in conjunction with an ultrasensitive insulin assay in eight healthy lean male volunteers (aged 25 ± 1 years).

Results Insulin concentrations at baseline were 48 ± 8 pmol L−1 in plasma and 19 ± 4 pmol L−1 in the interstitium (P = 0·002). The mean interstitium to plasma ratio at baseline was 0·48 ± 0·09 pmol L−1. During the oral glucose tolerance test the interstitium to plasma ratio remained unchanged (0·43 ± 0·12, P = NS vs. baseline), but was significantly reduced during euglycaemic hyperinsulinaemic clamp conditions at steady‐state hyperinsulinaemia (0·12 ± 0·01, P = 0·01 vs. baseline).

Conclusion In summary there is a substantial transcapillary insulin gradient in healthy human skeletal muscle under baseline and glucose‐stimulated conditions. Our findings support the hypothesis of a saturable transcapillary insulin transport representing a partly rate‐limiting step for insulin action.
The evolution of β‐cell dysfunction and insulin resistance in type 2 diabetes
Authors: Bergman R. N. , Finegood D. T. , Kahn S. E.
Published: March 2003

Insulin resistance and β‐cell dysfunction have important roles in the pathogenesis and evolution of type 2 diabetes. The development of precise methods to measure these factors has helped us to define the relationship between them and evidence is reviewed that changes in insulin sensitivity are compensated by inverse changes in β‐cell responsiveness such that the product of insulin sensitivity and insulin secretion (the disposition index) remains constant. While the disposition index promises to be a useful tool to predict individuals at high risk of developing type 2 diabetes, other factors that contribute to β‐cell dysfunction and mark disease onset and progression include impairments in proinsulin processing and insulin secretion, decreased β‐cell mass and islet amyloid deposition. Emerging data indicate that anti‐diabetic agents, such as the thiazolidinediones that simultaneously target insulin resistance and β‐cell dysfunction, may have a beneficial impact on disease onset and progression. Several landmark clinical studies are underway to investigate if their initial promise is supported by data from large‐scale trials.
Molecular characterization of immunoglobulin G4 gene isoallotypes
Authors: Brusco A. , Saviozzi S. , Cinque F. , DeMarchi M. , Boccazzi C. , De Lange G. , Van Leeuwen A. M. , Carbonara A. O.
Published: March 2003

The molecular bases of classical serological immunoglobulin allotypes are progressively uncovered through detailed characterization of the relevant genes. Here we describe two isoallotypic determinants of the G4 gene. In the first, Leu 309, as in G1 and G3, is changed to Val, as in G2; studies on myeloma proteins have long assigned the immunologically defined nG4 m(a)/(b) to the same position. The two molecular variants, here called IGHG4*L309 and IGHG4*V309, are allelic in IGHC haplotypes with a single G4 gene, but can be found together in cis in G4‐duplicated haplotypes. A second isoallotypic variant was found at codon 409, where either Arg, as in G1 and G3, or Lys, as in G2, can be found. Both isoallotypes are associated with several ‘silent isoallotypic’ substitutions dispersed through the hinge, CH2 and CH3 domains. This suggests segmental gene conversion as the common mechanism of origin.
Mitochondrial DNA polymorphism in the Vietnamese population
Authors: Ivanova R. , Astrinidis A. , Lepage V. , Djoulah S. , Wijnen E. , Vu‐Trieu A. N. , Hors J. , Charron D.
Published: March 2003

The mitochondrial DNA variation was screened in a sample of 50 unrelated individuals of the Vietnamese population originating from Hanoi. A combination of long and standard PCR and restriction endonuclease digests with the enzymes HpaI, BamHI, HaeII, MspI, AvaII and HincII were used to reveal mtDNA variation. Twenty enzyme morphs were detected, three of which (HaeII‐13Viet, MspI‐19Viet and MspI‐20Viet) are new and are produced by a single mutational event in already known enzyme morphs. Ten already known and four new mitotypes [93Viet (1‐1‐2‐4‐1), 94Viet (2‐1‐13Viet‐1‐1), 95Viet (2‐1‐13Viet‐19Viet‐1) and 96Viet (1‐1‐2–20Viet‐12)] were found in the Vietnamese population. The 9‐bp deletion occurring in the COII/tRNALys region of the mitochondrial genome was also analysed and 10 samples were found to have this deletion. The comparison of the Vietnamese with other East Asian populations showed a close genetic relationship of the population under investigation with other Orientals. However, the Vietnamese population can be differentiated by the significantly higher frequency of the enzyme morph HincII‐5 and by seven new markers. These results strongly support the hypothesis of a dual ethnic origin of the Vietnamese population from the Chinese and Thai–Indonesian populations based on HLA markers and linguistic evidence.
Common polymorphisms in the CTLA‐4 and CD28 genes at 2q33 are not associated with asthma or atopy
Authors: Heinzmann A. , Plesnar C. , Kuehr J. , Forster J. , Deichmann K. A.
Published: March 2003

Recently, genetic linkage of the chromosomal region 2q33 with asthma has been shown. The genes coding for CD28 and CTLA‐4 have been localized to this chromosomal region. CD28 and CTLA‐4 have been shown to be involved as an important costimulatory signal in the regulation of allergic inflammation and TH2 cytokine production, and thus both genes are good candidate genes for asthma and atopy.

Two common polymorphisms in the CTLA‐4 gene and one polymorphism in the CD28 gene found by single‐strand conformation polymorphisms (SSCP) analysis and direct genomic sequencing were tested for association with asthma and atopy phenotypes in a population of 260 largely atopic children and young adults. No association was found between any of the three polymorphisms and asthma or atopy phenotypes. The newly described common CD28 polymorphism is situated in the third intron of the gene. We conclude that neither gene is likely to exert a major influence on the development of asthma or atopy in our population. However, it might prove useful to test for association of these polymorphisms with asthma in populations recruited through asthmatic but not necessarily atopic individuals.
A study of Gm allotypes and immunoglobulin heavy gamma IGHG genes in Berbers, Arabs and sub‐Saharan Africans from Jerba Island, Tunisia
Authors: Yacoubi Loveslati B. , Sanchez‐Mazas A. , Ennafaa H. , Marrakchi R. , Dugoujon J.‐M. , Lefranc M.‐P. , Ben Ammar Elgaaied A.
Published: March 2003

The Gm polymorphism of human IgG immunoglobulins was investigated in three different ethnic groups — Arabs, Berbers and ‘dark‐skinned people’— on Jerba Island, Tunisia. The genetic relationships among these groups and several populations from North Africa, sub‐Saharan Africa, west Asia and Europe were analysed by principal coordinate analysis, Fst significance testing, and analysis of molecular variance based on haplotype frequencies. The results revealed a non‐significant genetic differentiation between Arabs and Berbers from Jerba. However, the Jerbian population of sub‐Saharan African origin was close to Ethiopians. Gene flow among the three Jerbian populations, as well as an East African origin of the dark‐skinned individuals, is proposed to account for the observed genetic pattern. However, the genetic diversity observed among the different Tunisian populations did not show any significant correlation with either geographic or linguistic differentiation. A preliminary analysis of the restriction fragment length polymorphism of the IGHG genes in Arabs and Berbers from Jerba confirmed the close genetic relationship between the two populations. However, it also indicated a lower level of genetic diversity in the Berbers, which may be explained by more rapid genetic drift due to longer isolation on the island.
HLA DMA and DMB show no association with rheumatoid arthritis in US Caucasians
Authors: Moxley G. , Han J.
Published: March 2003

HLA DM is a heterodimeric molecule functioning in normal antigen presentation; it is encoded by adjacent HLA‐region loci, HLA DMA and DMB, located between DP and DQ. Some previous studies have suggested that HLA susceptibility to rheumatoid arthritis (RA) is associated with certain DMA and DMB alleles. Our aim was to examine whether this association is also present in US Caucasians. We studied 288 US Caucasian subjects with rheumatoid arthritis and 263 US Caucasian control subjects. DMA and DMB typing was achieved by PCR amplification followed by sequence‐specific oligonucleotide hybridization and by PCR–restriction fragment length polymorphism. There was no frequency difference for DMA alleles or DMB alleles between RA and control subjects, indicating no association. Neither was a difference apparent when data were analysed in subgroups based on shared‐epitope DRB1, on the rheumatoid factor test, on radiographic changes of RA, or on sex. DRB1‐DQB1‐DMB analyses for linkage disequilibrium showed that the DRB1*0401‐DQB1*0301 haplotype had the DMB*0103 allele more often than DMB*0101 (estimated haplotype frequencies 0.08 and 0.039 in RA, respectively). In contrast, the DRB1*0401‐DQB1*0302 haplotype usually had the DMB*0101 allele (haplotype frequency 0.084 compared to 0.01 for DMB*0103). Thus, neither HLA DMA nor DMB was associated with RA in this population, and not all shared‐epitope‐bearing haplotypes had the same DMB allele distribution.
Prevalence of human leukocyte antigen (HLA) DRB1 alleles in Kuwaiti children with juvenile rheumatoid arthritis
Authors: Alsaeid K. , Haider M. Z. , Kamal H. , Srivastva B. S. , Ayoub E. M.
Published: March 2003

The prevalence of human leukocyte antigen (HLA) DR alleles has been determined in 69 Kuwaiti Arab children with juvenile rheumatoid arthritis (JRA) and compared to that in 212 ethnically matched normal healthy controls using a PCR–sequence specific primers (PCR‐SSP) method. A very high incidence of DR3 was detected in JRA patients compared to the controls (P < 0.0001, RR = 2.235). The high incidence of HLA‐DR3 in JRA patients was accounted for mainly by an excess of DRB1*0307 (P < 0.05, RR = 3.072) and DRB1*0308 (P < 0.009, RR = 2.663) compared to the controls. Moreover, DR3 was more prevalent when patients with ANA‐positive JRA were analysed separately; 73% compared to 58% for the whole JRA patient group. The frequency of DR1 was also higher in the JRA group compared to controls (P = 0.019, RR = 3.585). Although the incidence of some alleles was higher in the control group (DR13 and DR7), none reached a statistically significant level. All the patients with iridocyclitis had either a DR1 or DR3 allele, except for one child. The frequency of DRB1*03 was found to be much higher in the polyarticular subtype of Kuwaiti JRA cases compared to the oligoarticular subgroup and the controls. Also, a non‐significant increase in the frequency of the DRB1*04, *11 and *15 alleles was detected in the polyarticular subtype of the Kuwaiti JRA cases compared to the controls.
CD45 exon 4 point mutation does not confer susceptibility to type 1 diabetes mellitus or Graves’ disease
Authors: Wood J. P. , Bieda K. , Segni M. , Herwig J. , Krause M. , Usadel K. H. , Badenhoop K.
Published: March 2003

A point mutation in the leukocyte common antigen (CD45, C → G77, exon 4) was investigated in patients with type 1 diabetes (IDDM), patients with Graves’ disease and controls. The distribution did not differ significantly between patients and controls. This CD45 variant does not therefore confer susceptibility to either IDDM or Graves’ disease.
A BAC contig of approximately 400 kb contains the classical class I major histocompatibility complex (MHC) genes of cattle
Authors: Di Palma F. , Archibald S. D. , Young J. R. , Ellis S. A.
Published: March 2003

A cattle BAC library derived from an MHC homozygous animal was screened for MHC class I genes. This revealed at least nine class I‐related genes in a contig spanning ~400 kb, and several additional genes on other clones. The three classical class I genes expressed on this haplotype (A14) were shown to be distributed over a region at most 212 kb apart.
HLA class I polymorphism in a Moroccan population from Casablanca
Authors: Choukri F. , Chakib A. , Himmich H. , Raissi H. , Caillat‐Zucman S.
Published: March 2003

We have studied the distribution of HLA‐A and ‐B alleles and haplotypes by sequence‐specific primer amplification in a sample of 100 unrelated healthy individuals belonging to both Berber and Arabic‐speaking groups from the region of Casablanca in Morocco. Among the 17 HLA‐A and 23 HLA‐B alleles observed, the most frequent were HLA‐A2 (21%), ‐A1 (11%), ‐A3 (10%), ‐B44 (11.4%), ‐B50 (9.9%), ‐B5(8.5%) and ‐B35 (6.5%). Six two‐locus haplotypes were observed with a frequency above 5%: A2‐B50 (9.6%), A23‐B44 (7.4%), A2‐B15 (6.4%), A68‐B39 (5.3%), A1‐B51 (5.3%) and A68‐B44 (4.3%). Our data confirm that, on the basis of genetic distances, the majority of present‐day North Africans from Morocco are closely related to Berbers and also to Iberians. They cluster apart from Middle‐Eastern Mediterranean populations, and show greater genetic distances to Eastern and other Mediterranean populations. This study will serve as a reference for further anthropological studies, as well as studies of HLA and disease associations.
HLA‐DPB1 allelic frequency of the Pumi ethnic group in south‐west China and evolutionary relationship of Pumi with other populations
Authors: Liu Z.‐H. , Lin J. , Pan D. , Chen W. , Tao H. , Xu A.
Published: March 2003

A sequencing‐based typing of the HLA‐DPB1 gene was carried out in 51 unrelated healthy individuals from the Yunnan Pumi ethnic minority. A total of 18 DPB1 alleles, in which DPB1*0501 (52.0%) and DPB1*0402 (15.7%) greatly predominated, were found, of which alleles DPB1*20011, 2201, 3601, 3701, 3801, 4901, 5001 and 8001 were recorded for the first time in the Chinese population. This may be because the typing methods used in previous genotyping of Chinese populations were of lower sensitivity than that used in our study. A dendrogram constructed by the maximum likelihood method showed that the Pumi ethnic minority belongs to the Asian/Australasian cluster and has the closest relationship to Trobriander, implying an unusual relationship between Australasian and South China populations. However, the Yi ethnic minority, which also comes from the ancient Qiang, did not show a very close relationship with the Pumi. This is probably because the Pumi were historically assimilated by local south‐west China populations.
Nucleotide sequence of the upstream regulatory region of BoLA–DRB†
Authors: Ripoli M. V. , Díaz S. , Peral‐García P. , Giovambattista G.
Published: March 2003

The sequence of the proximal upstream regulatory region (URR) of the bovine DRB genes was amplified using oligonucleotide primers designed from the consensus among DRB sequences from different species. The obtained DNA sequence was 234 bp long and composed of highly conserved sequence motifs, showing the same organization as the HLA‐DRB, H2‐IAb, H2‐IEb and ELA‐DRB genes.
Steroid‐sensitive nephrotic syndrome and vascular endothelial growth factor gene polymorphisms
Authors: Holt R. C. L. , Ralph S. A. , Webb N. J. A. , Watson C. J. , Clark A. G. B. , Mathieson P. W. , Brenchley P. E. C.
Published: March 2003

Genetic polymorphisms have been recognized as important determinants of gene expression. Three common single nucleotide polymorphisms have been identified in the promoter and 5′ untranslated region of the vascular endothelial growth factor (VEGF) gene: −460 C → T, −141 A → C and +405 G → C. As VEGF has been postulated to play a role in the pathogenesis of childhood steroid‐sensitive nephrotic syndrome (SSNS), this study tested the hypothesis that VEGF genotype may be associated with susceptibility to SSNS. We examined the genotype frequencies of these polymorphisms in a total of 116 children with SSNS and 150 control subjects, using polymerase chain reaction–restriction fragment length polymorphism analysis (PCR‐RFLP). There were no statistically significant differences in any of the genotype frequencies between SSNS patients and controls. We conclude that VEGF −460, −141 and +405 genotypes are not associated with susceptibility to childhood SSNS.
Genotyping for cytokine polymorphisms: allele frequencies in the Italian population
Authors: Uboldi de Capei M. , Dametto E. , Fasano M. E. , Rendine S. , Curtoni E. S.
Published: March 2003

It has been demonstrated that many cytokine genes [e.g. tumour necrosis factor α (TNF‐α) and interleukin 10 (IL‐10)] show polymorphisms which may affect gene transcription, causing individual variations in cytokine production. The majority of polymorphisms described are single nucleotide polymorphisms (SNPs). In 140 healthy Italian subjects, the allelic and genotype frequencies were determined for the cytokine genes IL‐1α (T/C −889), IL‐1α (C/T −511, T/C +3962), IL‐12 (C/A −1188), interferon (IFN)‐γ (A/T UTR 5644), transforming growth factor (TGF)‐α (C/T codon 10, G/C codon 25), TNF‐α (G/A −308, G/A −238), IL‐2 (T/G −330, G/T +166), IL‐4 (T/G −1098, T/C −590, T/C −33), IL‐6 (G/C −174, G/A nt565), IL‐10 (G/A −1082, C/T −819, C/A −592), IL‐1R (C/T pst11970), IL‐1RA (T/C mspa111100) and IL‐4RA (G/A +1902). All typings were performed with PCR‐SSP assays. Allele and genotype frequencies and linkage disequilibria were calculated and compared with those of other populations.
Modelling the concentration or dilution of saline soil‐water systems
Authors: Rieu M. , Vaz R. , Cabrera F. , Moreno F.
Published: March 2003

For the survey of saline and alkali soils sampling soil solution in situ is difficult. An alternative is to take soil samples, analyse their extracts and then calculate the chemical composition of the soil solution. A model (EXPRESO) has been designed to calculate both the chemical speciation of electrolyte solution and the exchange equilibrium with an adsorbed phase during simulated dilution and concentration. EXPRESO was validated using reclaimed saline soil samples. Results demonstrated that EXPRESO is a thermodynamically coherent and mass conservative model that allows the calculation of the chemical composition of both the soil solution and the exchange complex over a large range of soil water content (0.250–5 kg water kg–1 soil). EXPRESO enables the estimation of the chemical composition of the in situ soil solution, giving a comprehensive picture of the soil status under different field conditions.

Modélisation de la concentration ou de la dilution des systèmes eau‐sols salés Résumé
Mineral formation in micaceous Mediterranean Red soils of Sierra Nevada, Granada, Spain
Authors: MARTÍN‐GARCÍA  , DELGADO  , PÁRRAGA  , BECH  , DELGADO
Published: March 2003

We investigated the processes of mineral formation in three Alfisol profiles of Sierra Nevada (southern Spain), with special emphasis on the little‐studied process of mica inheritance, particularly as regards its quantitative aspects. X‐ray diffraction, conventional and high resolution transmission electron microscopy, selected‐area electron diffraction, and geochemical analysis of the soil solution were used, and the granulometric fractions gravel, coarse sand, fine sand, silt and clay were studied, as was unaltered parent rock. Most interesting was inheritance of dioctahedral mica (illites) with small crystallochemical changes. The transition of mica from parent rock to clay was characterized by small crystallochemical changes affecting their structural formulae, reduction of the 2M1 polytype content, decrease in crystallite size, increase in crystal defects, and other changes in particle morphology. We propose the term ‘pedocrystallochemical evolution’ for the transition. The changes reverse the processes that take place in micas when rocks are formed by sedimentation, diagenesis and metamorphism. The kaolinite in the soils is a result of neoformation, and acts as the equilibrium phase within the chemical system. Reddening seems to have been caused by both inheritance and neoformation of iron oxides (haematite + goethite).