bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mate discrimination by females in the burying beetle Nicrophorus orbicollis: the influence of male size on attractiveness to females
Authors: Beeler Andria E. , Rauter Claudia M. , Moore Allen J. 
Published: March 2003

Summary1. Female burying beetles behave differently towards males of different sizes, avoiding mating with large males that are not defending resources but mating with small males regardless of the presence of resources. Females of the burying beetle Nicrophorus orbicollis were therefore examined to determine whether they discriminate among males using only pheromonal signals. The influence of female size on its own mate choice was also examined.2. Females do use male pheromonal signals to discriminate among males and these signals do appear to convey information about male body size to females. Overall, females were more likely to be attracted to larger males than to smaller males.3. Female choice of a male was influenced by both the female's own body size and the size of the female relative to the size of the two males available to it.4. While there is an overall mating advantage for larger males, resulting from female preferences based on odour cues, smaller males are also attractive to some females under some circumstances.5. It is argued that there are different costs and benefits of mating with different sized males, leading to the evolution of context‐dependent mate choice for females and the need to be able to discriminate males of different sizes from a distance.
Autoantibodies directed against phospholipids or human β2‐glycoprotein 1 in HIV‐seropositive patients: relationship with endothelial activation and antimalonic dialdehyde antibodies
Authors: Constans  , Guérin  , Couchouron  , Seigneur  , Ryman  , Blann  , Amiral  , Amara  , Peuchant  , Moreau  , Pellegrin  , Pellegrin  , Fleury  , Leng  , Conri  
Published: March 2003

BackgroundWe investigated the possible role of antiphospholipid (APA) and anti‐human β2‐glycoprotein I (β2‐GPI) antibodies (Ab) in thrombosis and atherosclerosis in human immunodeficiency (HIV)‐positive patients, in whom they seem to be more frequent.MethodsWe measured APA and anti‐β2‐GPI Ab in 58 HIV‐positive patients together with markers of disease progression, circulating β2‐GPI, plasma lipids, biological markers of endothelial activation and integrity (plasma thrombomodulin, von Willebrand factor, vascular cell adhesion molecule 1) and with antimalonic dialdehyde antibodies (anti‐MDA Ab).ResultsWe found a 41% frequency of IgG APA in the HIV‐positive patients. APA IgMs were rarely positive (7%), and anti‐β2‐GPI IgGs were positive in 3.4% patients. There was no correlation between APA or anti‐β2‐GPI Ab and the presence of opportunistic infections. Although plasma thrombomodulin, von Willebrand factor and vascular cell adhesion molecule 1 were significantly increased in the HIV‐positive patients, APA was correlated only with vascular cell adhesion molecule 1, suggesting that APAs are correlated with endothelial activation but not with vascular endothelial lesions. A correlation between APA and anti‐MDA IgG was demonstrated using multivariate analysis (r = 0.542,  P < 0.0001), suggesting a relationship between the targets of these antibodies. Finally, IgG APAs are frequent in HIV infection but are not correlated with biological markers of endothelial injury.ConclusionOur results do not support a role for APA or anti‐β2‐GPI in HIV‐associated silent vascular endothelial damage. However, the role of these autoantibodies in clinically relevant thrombotic events should be investigated in HIV‐positive patients.
Apo E isoforms, insulin output and plasma lipid levels in essential hypertension
Authors: Dembińska‐Kieć  , Kawecka‐Jaszcz  , Kwaśniak  , Guevara  , Pankiewicz  , Malczewska‐Malec  , Iwanejko  , Hartwich  , Zdzienicka  , Stochmal  , Leszczyńska‐Goľˇląbek  
Published: March 2003

BackgroundThe association between apo E isoforms and insulin output during the oral glucose test (OGTT) in 60 non‐diabetic, non‐obese patients with essential hypertension and in control subjects (non‐obese, non‐diabetic normotensive subjects) was estimated.MethodsAccording to low or high insulin output during OGTT, the subjects were divided into the following groups: normotensive subjects with low (NLI) and high (NHI) and hypertensive subjects with low (HLI) and high (HHI) insulin output.ResultsThe apo E 4/2 phenotype was detected in 32% of hypertensive subjects but not in control subjects. The frequency of apo E 3/2 phenotype in hypertensive subjects was 5% and in normotensive subjects 15%. An increased frequency of phenotype apo E 4/3 was noticed both in HHI (46%) and in NHI (50%) compared with HLI (22%) and NLI (17%) groups.ConclusionThe results suggest that the determination of phenotypes apo E and insulin output may contribute to an early detection of individuals at high risk of hypertension development.
The effects of IGF‐I and IGF‐II on proliferation and differentiation of human osteoblasts and interactions with growth hormone
Authors: Langdahl  , Kassem  , Møller  , Eriksen  
Published: March 2003

BackgroundWe have previously shown that growth hormone (GH) consistently stimulates proliferation of human osteoblasts in vitro. In rat osteoblasts, GH augments the effects of insulin‐like growth factor (IGF) I on cell proliferation and differentiation. We therefore investigated the effects of IGF‐I and ‐II alone and in combination with GH on human osteoblasts in vitro.MethodsHuman osteoblast‐like cells (HOB) were established from trabecular explants (n = 18) and human marrow stromal cells (HMS) from marrow aspiration (n= 21). The cell cultures were stimulated with IGF‐I or IGF‐II (1, 10 or 100 ng mL−1) alone, in combination with hGH (100 ng mL−1) or after prestimulation with hGH.ResultsIGF‐I alone, in combination with hGH and after pretreatment with hGH, increased proliferation of HOB and HMS by 49–190% (P < 0.05–0.01). IGF‐II alone, in combination with hGH and after pretreatment with hGH increased proliferation of HOB by 57–158% (P < 0.01). In HMS only IGF‐II in combination with hGH and after prestimulation with hGH increased proliferation. IGF‐I alone and in combination with hGH decreased alkaline phosphatase (AP) in both cell types. IGF‐II did not affect AP in HOB, but increased AP in HMS, this effect was abolished by hGH. In HOB, collagen production (PICP) was increased by IGF‐II but unaffected by IGF‐I. In HMS, PICP was decreased by IGF‐I and ‐II but increased by hGH. Co‐stimulation further increased PICP.ConclusionIGF‐I and ‐II exerted proliferative effects on both HOB and HMS. Co‐stimulation with GH exhibited synergism in enhancing the proliferative response. In HMS prestimulation improved the proliferative response significantly. The effects of the IGFs on differentiation are more complex and dependent on cell maturation and of the IGF used.
Decreased urinary apolipoprotein (a) excretion in patients with impaired renal function
Authors: Kostner  , Clodi  , Bodlaj  , Watschinger  , Hörl  , Derfler  , Huber  
Published: March 2003

BackgroundPlasma lipoprotein (a) [Lp(a)] levels are elevated in patients with kidney disease and are strongly associated with premature cardiovascular disease and stroke.MethodsAs the kidney is suggested to play an important role in apolipoprotein (a) [apo(a)] catabolism and as apo(a) fragments appear in urine, we determined plasma Lp(a) levels and urinary apo(a) excretion in relation to kidney function in a large cohort of renal patients. A total of 368 renal patients with normal or different degrees of impaired renal function and 163 healthy control subjects matched for age and sex were investigated. Plasma Lp(a) and urinary apo(a) were analysed immunochemically.ResultsRenal patients were found to have significantly elevated total cholesterol and low‐density lipoprotein (LDL)‐C values but lower high‐density lipoprotein (HDL)‐C values than control subjects. Plasma Lp(a) values were significantly higher only in patients with creatinine clearance < 70 mL min−1. There was a significant correlation between urinary apo(a) and plasma Lp(a) in patients and control subjects. Urinary apo(a) excretion was significantly lower in patients than in control subjects and showed no correlation with urinary protein excretion.ConclusionAlthough it is unlikely that impaired renal excretion of apo(a) fragments largely contributes to increased plasma Lp(a) levels in patients suffering from impaired kidney function, these data suggest that urinary apo(a) excretion is significantly decreased in renal patients and that this might contribute to increased plasma Lp(a) levels in this patient group.
Gelatinases in drug‐induced toxic epidermal necrolysis
Authors: Paquet  , Nusgens  , Piérard  , Lapière  
Published: March 2003

BackgroundThe matrix metalloproteinases (MMPs) MMP2 and MMP9 play a significant role in epidermal detachment, inflammation and re‐epithelialization. We have evaluated their activity in toxic epidermal necrolysis (TEN).DesignThe level and pattern of activity of MMP2 and MMP9 were investigated by measuring the degradation of 3H‐labelled gelatin and by zymography in blister fluid from six TEN patients and compared the results with three other blistering conditions: bullous pemphigoid (n = 6), second‐degree burn (n = 13) or suction blister (n = 3).ResultsA higher amount of MMP2 was found in TEN blister fluid with the constant presence of a significantly larger proportion of the activated forms of MMP2, a particular feature of TEN, than the other blistering diseases studied.ConclusionThis study emphasizes the potential role of MMP2 in the specific inflammatory reaction and reparation process in TEN skin.
Adenine nucleotides modulate epithelial wound healing in vitro
Authors: Dignass  , Becker  , Spiegler  , Goebell  
Published: March 2003

BackgroundAdenine nucleotides have been demonstrated to enhance structural and functional regeneration in experimental renal injury in rats. The mechanisms of adenine nucleotide action have not been elucidated. The aim of this study was to characterize the effects of adenine nucleotides on intestinal epithelial wound healing in vitro.MethodsThe effects of adenine nucleotides on cell migration, cell proliferation and cell adhesion were studied in the non‐transformed small intestinal epithelial cell line IEC‐6 using an in vitro wounding model, a colorimetric BrdU assay and a hexosaminidase adhesion assay.ResultsThe adenine nucleotides ADP and ATP were found to significantly stimulate epithelial cell restitution (migration) in vitro. Stimulation of epithelial restitution averaged 42% for ADP and 57% for ATP. In addition, adenine nucleotides inhibited the proliferation of rat small intestinal epithelial cells, averaging 56% for ADP and 74% for ATP. Enhancement of intestinal epithelial restitution and inhibition of epithelial cell proliferation by adenine nucleotides were mediated through transforming growth factor (TGF)‐β‐independent pathways.ConclusionThese findings suggest that adenine nucleotides exert functional effects on intestinal epithelial cell populations and may play a role in the morphogenesis of the gastrointestinal tract and its remodeling after injury.
Direct evidence for an increase in thrombopoiesis after liver transplantation
Authors: Stiegler  , Stohlawetz  , Peck‐Radosavljevic  , Jilma  , Pidlich  , Wichlas  , Höcker  , Panzer  
Published: March 2003

BackgroundIn advanced liver cirrhosis, thrombocytopenia results from ‘hypersplenism’ due to increased platelet sequestration and platelet ‘pooling’ in the enlarged spleen and/or from reduced platelet production in the bone marrow. We sought to differentiate between these two mechanisms by studying thrombopoiesis before and after orthotopic liver transplantation by the determination of reticulated platelets, direct indicators for the thrombopoietic activity in the bone marrow.MethodsReticulated platelets, peripheral platelet counts, mean platelet volumes and platelet‐reactive antibodies were determined in 15 patients suffering from advanced liver cirrhosis before and during an observation period of 14 days after orthotopic liver transplantation (OLT). Thrombopoietin levels of ten patients were determined before transplantation and consecutively for 14 days after surgery.ResultsAll patients except one were thrombocytopenic before transplantation (median count 94 × 109 L−1, range 69–114 × 109 L−1). Although levels of reticulated platelets rose 2 days after surgery from baseline values of 1.0% (range 0.2–1.6%) to peak values of 4.6% (range 1.7–17.9%, P < 0.05) on day 6, platelet counts declined during the first 5 days after transplantation. When peripheral platelet counts increased to the normal range (median day 11, range day 8–33), reticulated platelets were again at pretransplant levels. Thrombopoietin levels before OLT were within the normal range (< 85 pg mL−1). On day 5 post surgery, a maximum increase of 5.8‐fold (range 2.2‐ to 28‐fold) over baseline values was observed. Mean platelet volume did not show any significant deviation from the baseline values and platelet antibodies could not be detected during the observation period.ConclusionOur findings provide direct evidence for an increase in de novo platelet production after orthotopic liver transplantation. As the elevation of reticulated platelets precedes platelet recovery, it could serve as an early indicator to predict thrombopoiesis as a result of reconstituted liver function.
Coexistent thyroiditis is associated with lower tumour stage in thyroid carcinoma
Authors: Schäffler  , Palitzsch  , Seiffarth  , Höhne  , Riedhammer  , Hofstädter  , Schölmerich  , Rüschoff  
Published: March 2003

BackgroundMicrosatellite instability (MSI) is a new mechanism described in carcinogenesis of several tumours and seems to predispose for cancer in some chronic inflammatory diseases. As thyroiditis is thought to be both the cause and the consequence of thyroid carcinoma, it was the aim of this retrospective study to investigate the epidemiology and the influence of a coexistent thyroiditis on prognosis and clinicopathological parameters in an iodine‐deficient area.MethodsThe grade of lymphocytic infiltration (LI) of 153 thyroid carcinomas was determined in paraffin‐embedded tissues: G0 = no LI, G1 = peritumoral LI, G2 = peritumoral LI with follicle, G3 = diffuse LI. A non‐radioactive PCR‐based screening method was used for detection of MSI.ResultsTwenty‐seven (17.7%) out of 153 carcinomas were accompanied by thyroiditis (G1, 16; G2, 5; G3, 6). Ten cases fulfilled the criteria necessary for diagnosing Hashimoto's thyroiditis. Nine out of 10 (90%) Hashimoto's cases and 16 out of 17 (94%) other thyroiditis cases were associated with a significantly (χ2 < 0.01) lower pT stage (pT1, pT2) than cases without thyroiditis. No statistical association was found by comparing multifocality or sclerosing variants with the grade of lymphocytic infiltration. MSI was detected neither in patients with severe inflammation nor in the absence of thyroiditis.ConclusionsMSI does not seem to play a role in the pathogenesis of thyroid carcinoma. Coexistent thyroiditis is associated with a lower pT stage and thus could be an indicator of a better prognosis.
Influence of residual insulin secretion and duration of diabetes mellitus on the control of luteinizing hormone secretion in women
Authors: Volpi  , Chiodera  , Gramellini  , Capretti  , Caffarri  , Speroni  , Vescovi  , Coiro  
Published: March 2003

BackgroundThe aim of the present study was to establish whether the persistence of residual beta‐cell activity after long‐term diabetes mellitus (DM) exerts a protective role on luteinizing hormone (LH) secretion.MethodsThe LH responses to stimulation with gonadotropin‐releasing hormone (Gn‐RH) (100 μg in an i.v. bolus) or naloxone (4 mg injected in an i.v. bolus, followed by the constant infusion of 8 mg in 2 h) were measured in C‐peptide‐positive (CpP) and C‐peptide‐negative (CpN) normally menstruating women with short‐term (group 1 < 3 years, CpP n = 11, CpN n = 11) or long‐term (group 2 > 10 years, CpP n = 11, CpN n = 11) DM and in age‐matched normal control subjects (n = 11).ResultsGn‐RH induced significant increments in LH secretion in all groups. Significant LH responses to naloxone were observed in all groups, except in group 2 CpN patients. However, the LH response to either Gn‐RH or naloxone was significantly lower in group 1 CpN, group 2 CpP and group 2 CpN patients than in the normal control subjects. Furthermore, the LH response was significantly lower in group 2 CpP than in group 1 CpP patients and in group 2 CpN than in group 1 CpN subjects.ConclusionsThese results indicate a role for both deficiency in residual endogenous insulin secretion and duration of diabetes in the derangement of LH secretory control. The data suggest that the protective role exerted by residual beta‐cell activity on LH secretion during the early years of DM diminishes with time elapsed after the onset of diabetes mellitus.
Derangement of mucosal barrier function by bacteria colonizing the rat colonic mucosa
Authors: García‐Lafuente  , Antolín  , Guarner  , Crespo  , Salas  , Forcada  , Malagelada  
Published: March 2003

BackgroundInteraction between gut flora and the intestinal barrier may involve changes in permeability.MethodsRats with a colonic segment excluded from faecal transit were surgically prepared. Matched groups were either kept on luminal antibiotics to prevent colonization of the segment or recolonized with mixed rat flora. Permeability to low‐dose trinitrobenzenesulphonic acid (TNBS) or trinitrophenol (TNP), and mucosal injury by the compounds at a high dose were tested in antibiotic and recolonized rats (the compounds differ in water solubility but share a common antigenic domain).ResultsLumen to blood clearance of the hydrophilic probe (TNBS) was faster in recolonized than in antibiotic rats. The hydrophobic compound TNP was absorbed at faster rates than TNBS, but there was no difference between antibiotic and recolonized rats. Instillation of TNBS at a high dose induced mucosal release of inflammatory mediators and tissue myeloperoxidase accumulation in recolonized rats but not in antibiotic rats. Large necrotic lesions with submucosal involvement after TNBS were only observed in recolonized rats. In contrast, TNP induced mucosal inflammation and large lesions with submucosal necrosis both in recolonized and in antibiotic rats.ConclusionColonizing bacteria may increase intestinal permeability to hydrophilic compounds and render the mucosa susceptible to injury.
Management of renal cell carcinoma in von Hippel–Lindau disease
Authors: Hes  , Slootweg  , Van Vroonhoven  , Hené  , Feldberg  , Zewald  , Ploos van Amstel  , Höppener  , Pearson  , Lips  
Published: March 2003

BackgroundAn evaluation of nephron‐sparing surgery (NSS) or radical nephrectomy (RN) for treating renal cell carcinoma (RCC) in patients with von Hippel–Lindau disease (VHL) was carried out.MethodsBetween 1976 and 1997, 10 patients with RCC from four VHL families, of whom seven were from one family, were studied by clinical and histopathological examination. Before 1991, three patients were treated using RN, and thereafter five patients were treated using NSS. Two patients were not operated on.ResultsRCCs in our patients showed a slow growth rate (on average 0.3 cm year−1), and asymptomatic patients presented with tumours of low‐grade malignancy. In all patients, tumours were surrounded by a fibrous pseudocapsule. In 5 out of 17 tumours, pseudocapsular invasion was observed, and three of these five tumours broke through the pseudocapsule. To date, these patients have not shown a less favourable outcome than those without pseudocapsular involvement by tumour growth. Multicentricity of RCC was relatively low (4.6 lesions per kidney). In two of the three RN patients, only a single satellite lesion, in the direct vicinity of a RCC, was found in one kidney. Six tumours (1.8–5.5 cm) were enucleated by NSS. During a mean follow‐up of 30 months, renal function in these patients was well preserved.ConclusionsIn our patients, RCCs grew slowly, were of low grade, had a dense fibrous pseudocapsule and were thus good candidates for NSS.
The sensitivity of the lactulose/rhamnose gut permeability test
Authors: Van Nieuwenhoven M. A. , Geerling B. J. , Deutz N. E. P. , Brouns F. , Brummer R.‐J. M. 
Published: March 2003

BackgroundThe lactulose/rhamnose (L/R) intestinal permeability test is widely used. However, different quantities and proportions of lactulose and rhamnose are used. The aim of this study was to determine whether a low dosage of lactulose is able to discriminate between normal and increased permeability.Materials and methodsTwo groups of 10 healthy subjects were studied. In group 1, three different iso‐osmolar test solutions were administered on 3 days. The solutions consisted of 10 g of L with 1 g of R, 5 g of L with 0.5 g of R and 1 g of L with 0.1 g of R in 65 mL of water. Group 2 ingested these solutions 1 h after ingestion of 750 mg of chenodeoxycholeic acid (CDCA), which is known to increase permeability. The urinary L/R ratio was determined using high‐performance liquid chromatography. Data are presented as medians (range).ResultsIn group 1, no differences were observed between the three solutions. In Group 2, there was a significant difference (P = 0.045) between the three solutions. The L/R ratios were 0.0079 (0.0024–0.0152) (1L to 0.1R), 0.0138 (0.0066–0.0192) (5L to 0.5R) and 0.0144 (0.0074–0.0374) (10L to 1R). The L/R ratio differed significantly between Groups 1 and 2 (P < 0.001) using the 5L to 0.5R and 10L to 1R solutions respectively.ConclusionIf the permeability is increased, the urinary L/R ratio depends on the quantity of lactulose and rhamnose administered in equal proportion. 5L to 0.5R is sufficient to discriminate between a normal and a moderately increased permeability.
In vivo kinetics of human apolipoprotein A‐I variants in rabbits
Authors: Saku  , Von Eckardstein  , Zhang  , Liu  , Jimi  , Ou  , Ohta  , Assmann  , Arakawa  
Published: March 2003

BackgroundGenetic variants of human apolipoprotein (apo) A‐I, the major protein component of high‐density lipoprotein (HDL), with a single amino acid substitution have been reported, and some of these result in very low plasma HDL‐cholesterol (C) levels. Examining the kinetics of radiolabelled apolipoprotein is a straightforward technique for determining its metabolism in vivo. In this study, we investigated the in vivo kinetics of several human apo A‐I variants, which we had identified previously, in rabbits.Materials and methodsApo A‐I variants from heterozygous carriers of Lys‐107→0, Lys‐107→Met, Pro‐3→Arg, Pro‐4→Arg, Pro‐165→Arg and Glu‐198→Lys and the corresponding normal apo A‐I were purified and then radioiodinated with 131I and 125I. A kinetic study of apo A‐I variants was performed in normolipidaemic rabbits after simultaneous injection of the two isotopes that had been incorporated into HDL. The fractional catabolic rate (FCR) was calculated from the radioactive decay curve.ResultsAcidic mature (negatively charged) apo A‐I variants caused by a single amino acid substitution (Lys‐107→0, and Lys‐107→Met) were catabolized faster (FCR, 1.931 ± 0.539 per day vs. 1.636 ± 0.460 per day, P ≤ 0.01 using the Wilcoxon signed‐rank test) and basic mature (positively charged) apo A‐I variants (Pro‐3→Arg, Pro‐4→Arg, Pro‐165→Arg and Glu‐198→Lys) were catabolized more slowly (FCR 1.470 ± 0.380 per day vs. 1.654 ± 0.430 per day, P ≤ 0.01) than the corresponding normal mature apo A‐I in vivo in rabbits. In addition, an inverse linear relationship was observed between the deviation in the FCR of variant human apo A‐I from that of normal human apo A‐I and the number of electric charges that the apo A‐I variant carried (r = –0.90, k = –0.188, P = 0.0003), as assessed by a linear regression analysis, suggesting that the electric charge of apo A‐I variants may determine, at least in part, its in vivo kinetics in rabbits.ConclusionsGenetic variants of apo A‐I with a single amino acid substitution show abnormal kinetics, and the electric charge of a apo A‐I variant could contribute to determining its kinetics in vivo in this xenologous model.