bluuebunny/crossref_metadata_2025 huggingface dataset:
What influences the timing of the introduction of solid food to infants?
Authors: Alder Elizabeth M. , Williams Fiona L. R. , Anderson Annie S. , Forsyth Stewart , Florey Charles du V. , van der Velde Patricia
Published: October 2004

The aim of the present study was to assess the factors which may influence the timing of the introduction of solid food to infants. The design was a prospective cohort study by interview and postal questionnaire. Primiparous women (n 541) aged between 16 and 40 years were approached in the Forth Park Maternity Hospital, Fife, Scotland. Of these, 526 women agreed to participate and seventy-eight were used as subjects in the pilot study. At 12 weeks we interviewed 338 women of the study sample. The postal questionnaire was returned by 286 of 448 volunteers. At 12 weeks 133 of 338 mothers said that they had introduced solids. Those that said that they had introduced solids early (>12 weeks) were compared with those who had introduced solids late (<12 weeks) by bivariate and multiple regression analysis. Psychosocial factors influencing the decision were measured with the main outcome measure being the time of introduction of solid food. The early introduction of solids was found to be associated with: the opinions of the infant's maternal grandmother; living in a deprived area; personal disagreement with the advice to wait until the baby was 4 months; lack of encouragement from friends to wait until the baby was 4 months; being in receipt of free samples of manufactured food. Answers to open-ended questions indicated that the early introduction appeared to be influenced by the mothers' perceptions of the baby's needs. Some of the factors influencing a woman's decision to introduce solids are amenable to change, and these could be targeted in educational interventions.
The effect of six different C18 fatty acids on body fat and energy metabolism in mice
Authors: Javadi M. , Everts H. , Hovenier R. , Kocsis S. , Lankhorst Æ. , Lemmens A. G. , Schonewille J. Th. , Terpstra A. H. M. , Beynen A. C.
Published: October 2004

We studied the effects of five high-fat semi-purified diets varying at a 4 % (w/w) level in either stearic, oleic, linoleic, α-linolenic, or γ-linolenic acid on body fat and energy metabolism in BALB/c mice. A diet containing caprylic, capric, lauric, and myristic acid was used as a reference diet and a diet with 4 % conjugated linoleic acid (CLA) was used as a positive control as it is known to effectively lower body fat in mice. The diets were fed for 35 d. Body fat was significantly lower in the CLA group than in the other groups but was not significantly different among the non-CLA groups. Among the non-CLA groups, the linoleic acid group tended to have the highest and the α-linolenic acid group the lowest proportion of body fat. In energy-balance studies, the percentage of energy intake that was stored in the body was significantly lower in the CLA group compared with the other dietary groups. The percentage of energy intake eliminated in excreta was highest in the stearic acid group followed by the γ-linolenic acid group. These results were reflected in apparent fat digestibility, which was lowest in the stearic acid group. The percentage of energy intake expended as heat was highest in the CLA-fed mice. The results of the present study suggest that body fat and energy accretion in mice fed diets containing different C18 fatty acids is by far the lowest with CLA and that linoleic acid produced the highest fat intake and energy accretion.
Soyabean protein hydrolysate prevents the development of hypertension in spontaneously hypertensive rats
Authors: Yang Hsin-Yi , Yang Suh-Ching , Chen Jiun-Rong , Tzeng Ya-Hui , Han Bor-Cheng
Published: October 2004

The aim of the present study was to investigate the anti-hypertensive and angiotensin-converting enzyme (ACE) inhibition effects of soyabean protein hydrolysate in spontaneously hypertensive rats (SHR). Soyabean protein hydrolysate was prepared by peptic hydrolysis and was added into the feed of SHR (0 % for the S0 group, 0·5 % for the S1 group, and 1 % for the S2 group) for 12 weeks. Systolic blood pressure and mean blood pressure of the S1 (164·3 (sem 4·7); 128·0 (sem 5·0) mmHg) and S2 (156·8 (sem 1·6); 120·8 (sem 3·4) mmHg) groups were significantly lower than those of the S0 group (199·4 (sem 5·2); 158·3 (sem 7·0) mmHg) at the end of the study. In the analysis of ACE activity, plasma and heart ACE activities of the S1 and S2 groups were significantly lower than those of the S0 group, and there were no significant differences in aorta, kidney, and lung ACE activities among all SHR. Soyabean protein hydrolysate had no significant effect on plasma lipids, electrolytes, or on left ventricular wall or aorta wall thickness. The results suggest that the long-term administration of soyabean protein hydrolysate might retard the development of hypertension in SHR by its inhibitory effect on ACEin vivo.
Different effects of whole milk and a fermented milk with the same fat and lactose content on gastric emptying and postprandial lipaemia, but not on glycaemic response and appetite
Authors: Sanggaard K. M. , Holst J. J. , Rehfeld J. F. , Sandström B. , Raben A. , Tholstrup T.
Published: October 2004

Longitudinal studies indicate that milk and fermented milk products lower basal plasma cholesterol concentrations, despite their high content of saturated fat, and therefore have favourable health effects. However, there have been few studies on the postprandial effects of milk products. The present study compared the effect of whole milk with a fermented milk, A-38, on postprandial carbohydrate and lipid metabolism, gastric emptying and appetite. Eight healthy young men participated. On the two test days, they arrived fasting for collection of baseline values before consuming the meals, which for a 75 kg subject consisted of 1·4 litre milk or fermented milk, plus 165 mg [13C]acetate (for later determination of gastric emptying by a [13C]acetate breath test). Lactose (15 g) was added to the A-38 meal to equalize the lactose content. Postprandially the A-38 meal resulted in a slower gastric emptying rate than milk (P>0·001). Furthermore, the A-38 meal resulted in a greater increase and a quicker decrease of the triacylglycerol content in all lipoprotein fractions (LDL-fraction,P>0·05; other fractions,P>0·001) and of the gastrointestinal hormones (cholecystokinin and peptide YY,P>0·05; gastric inhibitory polypeptide and glucagon-like polypeptide-1,P>0·001). There were no significant differences in appetite sensations (measured by visual analogue scale) or in the glucose and insulin response (P<0·10). The slower emptying rate of the liquid phase after the A-38 meal is probably due to the higher viscosity of A-38. The lower and more prolonged triacylglycerol response after the milk meal might be caused by coagulation of milk in the stomach.
Thetrans-10,cis-12 isomer of conjugated linoleic acid reduces hepatic triacylglycerol content without affecting lipogenic enzymes in hamsters
Authors: Zabala Amaia , Churruca Itziar , Macarulla M. Teresa , Rodríguez Víctor M. , Fernández-Quintela Alfredo , Martínez J. Alfredo , Portillo María P.
Published: October 2004

Conjugated linoleic acid (CLA) refers to the positional and geometric dienoic isomers of linoleic acid. The dietary intake of CLA has been associated with changes in lipid metabolism. The aim of the present work was to assess the effects of the two main isomers of CLA on sterol regulatory element binding protein (SREBP)-1a and SREBP-1c mRNA levels, as well as on mRNA levels and the activities of several lipogenic enzymes in liver. For this purpose hamsters were fed an atherogenic diet supplemented with 5 g linoleic acid,cis-9,trans-11 ortrans-10,cis-12 CLA/kg diet for 6 weeks. Thetrans-10,cis-12 isomer intake produced significantly greater liver weight, but also significantly decreased liver fat accumulation. No changes in mRNA levels of SREBP-1a, SREBP-1c and lipogenic enzymes, or in the activities of these enzymes, were observed. There was no effect of feedingcis-9,trans-11 CLA. These results suggest that increased fat accumulation in liver does not occur on the basis of liver enlargement produced by feeding thetrans-10,cis-12 isomer of CLA in hamsters. The reduction in hepatic triacylglycerol content induced by this isomer was not attributable to changes in lipogenesis.
Prenatal exposure to a maternal low-protein diet programmes a preference for high-fat foods in the young adult rat
Authors: Bellinger Leanne , Lilley Christina , Langley-Evans Simon C.
Published: October 2004

Nutrient restriction in pregnancy has been shown to programme adult obesity. Modulation of feeding behaviour may provide a mechanism through which obesity may be programmed. Pregnant Wistar rats were fed either a control diet or a low-protein (LP) diet throughout gestation. Their offspring were allocated to a self-selected-diet protocol to assess appetite and food preferences at 12 and at 30 weeks of age. Self-selection of high-fat, high-protein or high-carbohydrate foods by 12-week-old rats indicated that the prenatal environment influenced feeding behaviour. Both male and female offspring of LP-fed mothers consumed significantly more of the high-fat (P>0·001) and significantly less (P>0·02) of the high-carbohydrate food than the control animals. Female, but not male, offspring of LP-fed rats failed to adjust food intake to maintain a constant energy intake and had higher fat (P>0·005) and energy intakes (P>0·05) than control female rats. At 30 weeks of age there were no differences in the pattern of food selection between the two groups of animals. Male offspring of LP-fed rats had significantly more gonadal fat than control animals (P>0·05), but analysis of total body fat content indicated that there was no significant difference in overall adiposity. The present study suggests that in young adults at least, early life exposure to undernutrition determines a preference for fatty foods. Maternal nutrition may thus promote changes in systems that are involved in control of appetite or the perception of palatability.
Inulin-type fructans modulate gastrointestinal peptides involved in appetite regulation (glucagon-like peptide-1 and ghrelin) in rats
Authors: Cani Patrice D. , Dewever Cédric , Delzenne Nathalie M.
Published: October 2004

The hypothesis tested in the present study is that dietary fructans are able to modulate gastrointestinal peptides involved in the control of food intake, namely glucagon-like peptide (GLP)-1 (7-36) amide and ghrelin. After 3 weeks of treatment with a standard diet (control) or the same diet enriched with 100 g fructans varying in their degrees of polymerization (oligofructose (OFS), Synergy 1 (Syn) or long chain inulin)/kg, male Wistar rats were deprived of food for 8 h before sample collection. Dietary energy intake throughout the experiment was significantly lower (P>0·05) in fructans-fed rats than in control rats, leading to a significant decrease (P>0·01) in epidydimal fat mass at the end of the treatment in OFS- and Syn-treated rats. GLP-1 (7-36) amide concentration in portal vein serum was higher in OFS- and Syn-fed than in control rats. Both GLP-1 (7-36) amide concentration and proglucagon mRNA concentrations were significantly greater (P>0·05) in the proximal colonic mucosa of fructans-fed ratsv.controls. Normally active ghrelin concentration in plasma increases during food deprivation and rapidly falls during a meal. In the present study, after 8 h of food deprivation, active ghrelin in the plasma remained significantly lower (P>0·05) in OFS and Syn-fed than in control rats. These results are in accordance with the modifications of dietary intake and fat-mass development in short-chain fructans-treated rats and demonstrate the potential modulation of GLP-1 (7-36) amide and ghrelin by fermentable fibres such as fructans, which are rapidly and extensively fermented in the proximal part of the colon.
Effects of one single bout of low-intensity exercise on postprandial lipaemia in type 2 diabetic men
Authors: Dalgaard Marian , Thomsen Claus , Hermansen Kjeld
Published: October 2004

Fighting type 2 diabetes and its high risk of CVD, lifestyle intervention with diet and exercise is of uttermost importance. Epidemiological studies strongly suggest an inverse association between increased physical activity, moderate alcohol drinking and the incidence of both type 2 diabetes and CVD. However, alcohol is known to increase postprandial lipaemia, a risk marker of CVD, and exercise to reduce postprandial lipaemia in healthy individuals. The aim of the present study was to investigate how type 2 diabetic men respond, in the postprandial period, to a single exercise session feasible to perform on a daily basis for type 2 diabetic men. The twelve participants ingested a test meal containing 100 g butter, 50 g carbohydrate, together with 40 g alcohol, at each meal test, imitating a social meal situation. Two protocols included exercise sessions with 40 min at 40 % VO2max, one where they exercised 3·5 h after, and another the afternoon before the test meal. One protocol was without any exercise. No significant effect of low-intensity exercise on postprandial lipaemia following a fat-rich meal with alcohol was seen in the middle-aged type 2 diabetic men.
Heat shock protein synthesis over time in infective Trichinella spiralis larvae raised in suboptimal culture conditions
Authors: Martinez J. , Perez-Serrano J. , Bernadina W.E. , Rincon I. , Rodriguez-Caabeiro F.
Published: October 2004

Changes in the viability, infectivity and heat shock protein (Hsp) levels are reported in Trichinella spiralis first stage larvae (L1) stored in 199 medium for up to seven days at 37°C. These conditions induce stress that the larvae, eventually, cannot overcome. After three days of storage, the infectivity and viability were unchanged, although higher Hsp70 levels were observed. After this time, larvae gradually lost viability and infectivity, coinciding with a decrease in Hsp70 and Hsp90 and an increase in actin (a housekeeping protein). In addition, a possibly inducible heat shock protein, Hsp90i, appeared as constitutive Hsp90 disappeared. No significant changes in Hsp60 levels were detected at any time. These results suggest that heat shock proteins initially try to maintain homeostasis, but on failing, may be involved in cell death.
The helminth community of the wood mouse, Apodemus sylvaticus, in the Sierra Espuña, Murcia, Spain
Authors: Fuentes M.V. , Sáez S. , Trelis M. , Galán-Puchades M.T. , Esteban J.G.
Published: October 2004

The helminth community of the wood mouse, Apodemus sylvaticus, in the Sierra Espuña was characterized after a complete analysis of its helminth community component and infracommunity structure relative to host age, sex and year of capture. The helminth community comprised 13 species: one trematode, four cestodes and eight nematodes. The cestode Pseudocatenotaenia matovi and the nematode Syphacia frederici were the most prevalent and abundant helminth species, respectively. Sixty four percent of mice analysed presented helminths with a direct cycle and 42% presented helminths with an indirect cycle. The helminth community presents a low diversity with infracommunities usually made up of only one or two helminth species. Host age and year of capture seem to play a major role in determining species richness and helminth diversity, but not in determining the abundance of helminths. Host sex does not seem to affect the infection rate nor the diversity. Further studies on more samples of wood mice and other small mammal species in this regional park are needed to explore any possible interactions between helminth communities in the host populations.
Natural infection of the gerbil Meriones lybicus with the metacestode of Taenia endothoracicus in Arak, central Iran
Authors: Mowlavi G.R. , Kia E.B. , Mobedi I.
Published: October 2004

Polycephalic larvae of Taenia endothoracicus were found from naturally infected gerbils Meriones lybicus in a rural area of Arak, central Iran. A large cyst containing 19 protoscolices was located in the peritoneum, attached to the large omentum. The characteristics of the protoscolices and rostellar hooks confirmed the identification of these larvae as T. endothoracicus.
Epidemiology of cerebrospinal Elaphostrongylus cervi infection in red deer in central Spain
Authors: Valcárcel F. , Corchero J. , Olmeda A.S. , García Romero C.
Published: October 2004

Elaphostrongylus cervi produces a subclinical cerebrospinal disease in many wild and domestic ruminants from Europe, North America and New Zealand and has recently been described in Spain. To determine some aspects of its epidemiology, 121 red deer (Cervus elaphus) from central Spain were sampled during 2000. The prevalence (7%) and mean worm burden (3.8 worms per brain) were similar to the values previously recorded in other European areas. The infection was only detected in young deer during the winter. The estimation of larval production in the faeces was not a reliable method of diagnosing E. cervi infection.
Utilization of brown trout Salmo trutta by Acanthocephalus clavula in an Irish lake: is this evidence of a host shift?
Authors: Byrne C.J. , Holland C.V. , Walsh E. , Mulligan C. , Kennedy C.R. , Poole W.R.
Published: October 2004

The population biology of the fish acanthocephalan Acanthocephalus clavula was described from 161 wild brown trout, Salmo trutta sampled over a two-year period in Clogher Lake in the west of Ireland. Overall prevalence of the parasite was 86% and the mean abundance was 53 worms per fish. Despite the presence of large numbers of worms in the trout very few females (2%) attained full reproductive maturity. This suggests that trout is an accidental host. A sample of yellow eels, Anguilla anguilla was examined at a different time from the same lake. The prevalence of A. clavula was 97% and the average abundance was 8 worms per fish. In contrast to the situation in trout, the proportion of female worms attaining full reproductive maturity was 61% fulfilling the expected characteristic of a preferred definitive host. The possible explanations for the very high abundance of A. clavula in trout are discussed and include the influence of fluctuations in host populations, host diet and the absence of a potential competitor.
Effects of snail size on encystment of Echinostoma caproni in juvenile Biomphalaria glabrata (NMRI strain) and observations on the survival of infected snails
Authors: Schneck J.L. , Fried B.
Published: October 2004

The effects of snail size on encystment of Echinostoma caproni cercariae in neonatal and juvenile Biomphalaria glabrata (NMRI strain) snails were studied. Encystment in neonatal (0.7–1.1 mm shell diameter) and juvenile (2–3 mm shell diameter) snails was compared 24 h post-infection (PI) following individual exposure of snails of each size to 1, 5, 10, 25 and 50 cercariae. Significantly more cysts were recovered from juveniles exposed to 1, 5, 10 and 50 cercariae than from neonatals with comparable exposure. Size of B. glabrata was a major factor in determining cyst burden in this planorbid. Survival of infected versus uninfected neonatals and juveniles was also examined for 7 days. Neonatals exposed to 10 cercariae showed a significant decrease in survival at 3, 6 and 7 days PI when compared to the uninfected controls. There was no significant decrease in the survival of juveniles exposed to 10 cercariae compared to uninfected controls at any time point. Snail size was a factor in mortality associated with echinostome cercarial penetration and encystment.
Intestinal anisakiasis in Italy: case report
Authors: Moschella C.M. , Mattiucci S. , Mingazzini P. , De Angelis G. , Assenza M. , Lombardo F. , Monaco S. , Paggi L. , Modini C.
Published: October 2004

A case of intestinal anisakiasis caused by Anisakis sp. larva type I in a woman from Italy who consumed raw marinated anchovies, is reported. The diagnosis was based on the morphological features characteristic of anisakid larval stages, which were readily recognized in a large granuloma removed after emergency surgical treatment.
Schistosoma bovis in western Uganda
Authors: Stothard J.R. , Lockyer A.E. , Kabatereine N.B. , Tukahebwa E.M. , Kazibwe F. , Rollinson D. , Fenwick A.
Published: October 2004

During routine parasitological surveillance and monitoring activities within a National Control Programme for control of human schistosomiasis in Uganda, it was noted that cattle grazing in a water meadow immediately adjacent to Tonya primary school, where the prevalence of intestinal schistosomiasis in children was in excess of 90%, were unusually emaciated. To test the hypothesis that there may have been an anthropozoonotic focus of Schistosoma mansoni within the local herd, a young female heifer, clearly emaciated and c. 8 months old, was slaughtered from which schistosome worms were later recovered by dissection. As female worms inspected by microscopy were not gravid, morphological identification proved inconclusive but analysis of cytochome oxidase subunit I (COI) and small subunit (SSU) ribosomal DNA sequences from these worms identified them as Schistosoma bovis Sonsino, 1876. This is the first substantiated report of S. bovis from Lake Albert, western Uganda. Further epidemiological surveys are needed to clarify the extent of bovine schistosomiasis within this region, particularly so since this lakeside plain has been earmarked as a future game reserve.
Lack of evidence for co-speciation in a parasitic nematode of grey kangaroos
Authors: Chilton N.B. , Morris G.M. , Beveridge I. , Coulson G.
Published: October 2004

Multilocus enzyme electrophoresis was used to compare specimens of the parasitic nematode Cloacina obtusa from the stomach of the eastern grey kangaroo, Macropus giganteus and the western grey kangaroo, M. fuliginosus. Allelic variation among nematodes was detected at 17 (85%) of 20 loci, but there was only a single fixed genetic difference (at the locus for isocitrate dehydrogenase, IDH) between C. obtusa from M. fuliginosus and those from M. giganteus in areas where each host occurred in allopatry. However, this fixed difference was not apparent within the zone of host sympatry. Although electrophoretic data indicate genetic divergence among allopatric populations of C. obtusa in the two host species, the magnitude of the electrophoretic difference (5%) between these populations does not refute the hypothesis that C. obtusa represents a single species. The ’usual’ situation for parasitic helminths of grey kangaroos is that pairs of parasite species occur in the two host species. This situation differs for C. obtusa, where there has been a lack of speciation following a speciation event in its macropodid marsupial hosts. This finding suggests that a speciation event in the host does not necessarily lead to a speciation event for all its parasites and further highlights our lack of understanding of which processes drive speciation in parasites.
Epidemiology of alveolar echinococcosis in southern Cantal, Auvergne region, France
Authors: Magnaval J.-F. , Boucher C. , Morassin B. , Raoul F. , Raoul F. , Duranton C. , Jacquiet P. , Giraudoux P. , Vuitton D.A. , Piarroux R.
Published: October 2004

Alveolar echinococcosis (AE) is a helminth zoonosis which is encountered only in the northern hemisphere. In central France, the Auvergne region represents the most western and southern extension of this helminthiasis. In 1999, a human case of AE was diagnosed in the southern part of the Cantal department, where AE was supposed absent, and an epidemiological survey was subsequently carried out. The transmission of the zoonosis in the sylvatic and peridomestic definitive hosts was studied, as well as that in the rodent and human intermediate hosts. Eleven red foxes (Vulpes vulpes) were shot, and 50 fox faecal deposits were collected. Twelve farm dogs had their faeces taken by rectal touch, and four were checked after arecoline purgation. Optical detection of Echinococcus multilocularis worms was achieved on fox intestines after scraping, and also on dog stools after arecoline therapy. Coproantigen ELISA assay was performed for the 11 scraping products, for the 50 fox faeces, and for the 12 dog faecal samples. No adult AE agent was observed by microscopy, and the ELISA assay yielded positive results in one of 11 fox intestines, one of 50 fox faeces, and 2 of 12 dog faecal samples. Twenty-five small mammals were trapped, of which 19 were Arvicola terrestris water voles. One rodent liver exhibited a hepatic lesion consistent with AE. An epidemiological questionnaire was completed in 85 human volunteers, who were also serologically tested for AE. Only one (the case's husband) exhibited a Western-blotting pattern indicative of a low-grade AE infection. The results of this preliminary study suggested a slow AE extension to the south of Cantal department from the northern focus.
Association of ABCA1 with Syntaxin 13 and Flotillin-1 and Enhanced Phagocytosis in Tangier Cells
Authors: Bared Salim Maa , Buechler Christa , Boettcher Alfred , Dayoub Rania , Sigruener Alexander , Grandl Margot , Rudolph Christian , Dada Ashraf , Schmitz Gerd
Published: October 2004

The ATP-binding cassette transporter A1 (ABCA1) facilitates the cellular release of cholesterol and choline-phospholipids to apolipoprotein A-I (apoA-I) and several studies indicate that vesicular transport is associated with ABCA1 function. Syntaxins play a major role in vesicular fusion and have also been demonstrated to interact with members of the ABC-transporter family. Therefore, we focused on the identification of syntaxins that directly interact with ABCA1. The expression of syntaxins and ABCA1 in cultured human monocytes during M-CSF differentiation and cholesterol loading was investigated and syntaxins 3, 6, and 13 were found induced in foam cells together with ABCA1. Immunoprecipitation experiments revealed a direct association of syntaxin 13 and full-length ABCA1, whereas syntaxin 3 and 6 failed to interact with ABCA1. The colocalization of ABCA1 and syntaxin 13 was also shown by immunofluorescence microscopy. Silencing of syntaxin 13 by small interfering RNA (siRNA) led to reduced ABCA1 protein levels and hence to a significant decrease in apoA-I–dependent choline-phospholipid efflux. ABCA1 is localized in Lubrol WX–insoluble raft microdomains in macrophages and syntaxin 13 and flotillin-1 were also detected in these detergent resistant microdomains along with ABCA1. Syntaxin 13, flotillin-1, and ABCA1 were identified as phagosomal proteins, indicating the involvement of the phagosomal compartment in ABCA1-mediated lipid efflux. In addition, the uptake of latex phagobeads by fibroblasts with mutated ABCA1 was enhanced when compared with control cells and the recombinant expression of functional ABCA1 normalized the phagocytosis rate in Tangier fibroblasts. It is concluded that ABCA1 forms a complex with syntaxin 13 and flotillin-1, residing at the plasma membrane and in phagosomes that are partially located in raft microdomains.
The Na+/H+Exchanger Regulatory Factor Stabilizes Epidermal Growth Factor Receptors at the Cell Surface
Authors: Lazar Cheri S. , Cresson Catherine M. , Lauffenburger Douglas A. , Gill Gordon N.
Published: October 2004

Ligand binding to cell surface receptors initiates both signal transduction and endocytosis. Although signaling may continue within the endocytic compartment, down-regulation is the major mechanism that controls the concentration of cell surface receptors, their ability to receive environmental signals, and the ultimate strength of biological signaling. Internalization, recycling, and trafficking of receptor tyrosine kinases (RTKs) within the endosome compartment are each regulated to control the overall process of down-regulation. We have identified the Na+/H+exchanger regulatory factor (NHERF) as an important molecular component that stabilizes epidermal growth factor receptors (EGFRs) at the cell surface to restrict receptor down-regulation. The NH2-terminal PDZ domain (PDZ 1) of NHERF specifically binds to an internal peptide motif located within the COOH-terminal regulatory domain of EGFR. Expression of NHERF slows the rate of EGF-induced receptor degradation. A point mutation that abolishes the PDZ 1 recognition sequence of EGFR enhances the rate of ligand-induced endocytosis and down-regulation of EGFR. Similarly, expression of a dominant negative mutant of NHERF enhances EGF-induced receptor down-regulation. In contrast to β-adrenergic receptors where NHERF enhances recycling of internalized receptors, NHERF stabilizes EGFR at the cell surface and slows the rate of endocytosis without affecting recycling. Although the mechanisms differ, for both RTKs and G protein-coupled receptors, the overall effect of NHERF is to enhance the fraction of receptors present at the cell surface.
Regulation of the Vasopressin V2 Receptor by Vasopressin in Polarized Renal Collecting Duct Cells
Authors: Robben J.H. , Knoers N.V.A.M. , Deen P.M.T.
Published: October 2004

Binding of arginine-vasopressin (AVP) to its V2 receptor (V2R) in the basolateral membrane of principal cells induces Aquaporin-2–mediated water reabsorption in the kidney. To study the regulation of the V2R by dDAVP in a proper model, a polarized renal cell line stably-expressing V2R-GFP was generated. Labeled AVP-binding studies revealed an equal basolateral vs. apical membrane distribution for V2R-GFP and endogenous V2R. In these cells, GFP-V2R was expressed in its mature form and localized for 75% in the basolateral membrane and for 25% to late endosomes/lysosomes. dDAVP caused a dose- and time-dependent internalization of V2R-GFP, which was completed within 1 h with 100 nM dDAVP, was prevented by coincubation with a V2R antagonist, and which reduced its half-life from 11.5 to 2.8 h. Semiquantification of the V2R-GFP colocalization with E-cadherin (basolateral membrane), early endosomal antigen-1 (EEA-1) and lysosome-associated membrane protein-2 (LAMP-2) in time revealed that most dDAVP-bound V2R was internalized via early endosomes to late endosomes/lysosomes, where it was degraded. The dDAVP-internalized V2R did not recycle to the basolateral membrane. In conclusion, we established the itinerary of the V2R in a polarized cell model that likely resembles the in vivo V2R localization and regulation by AVP to a great extent.
Regulation of Epidermal Growth Factor Receptor Degradation by Heterotrimeric Gαs Protein
Authors: Zheng Bin , Lavoie Christine , Tang Ting-Dong , Ma Phuong , Meerloo Timo , Beas Anthony , Farquhar Marilyn G.
Published: October 2004

Heterotrimeric G proteins have been implicated in the regulation of membrane trafficking, but the mechanisms involved are not well understood. Here, we report that overexpression of the stimulatory G protein subunit (Gαs) promotes ligand-dependent degradation of epidermal growth factor (EGF) receptors and Texas Red EGF, and knock-down of Gαs expression by RNA interference (RNAi) delays receptor degradation. We also show that Gαs and its GTPase activating protein (GAP), RGS-PX1, interact with hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs), a critical component of the endosomal sorting machinery. Gαs coimmunoprecipitates with Hrs and binds Hrs in pull-down assays. By immunofluorescence, exogenously expressed Gαs colocalizes with myc-Hrs and GFP-RGS-PX1 on early endosomes, and expression of either Hrs or RGS-PX1 increases the localization of Gαs on endosomes. Furthermore, knock-down of both Hrs and Gαs by double RNAi causes greater inhibition of EGF receptor degradation than knock-down of either protein alone, suggesting that Gαs and Hrs have cooperative effects on regulating EGF receptor degradation. These observations define a novel regulatory role for Gαs in EGF receptor degradation and provide mechanistic insights into the function of Gαs in endocytic sorting.
Plk1 Regulates Activation of the Anaphase Promoting Complex by Phosphorylating and Triggering SCFβTrCP-dependent Destruction of the APC Inhibitor Emi1
Authors: Hansen David V. , Loktev Alexander V. , Ban Kenneth H. , Jackson Peter K.
Published: October 2004

Progression through mitosis requires activation of cyclin B/Cdk1 and its downstream targets, including Polo-like kinase and the anaphase-promoting complex (APC), the ubiquitin ligase directing degradation of cyclins A and B. Recent evidence shows that APC activation requires destruction of the APC inhibitor Emi1. In prophase, phosphorylation of Emi1 generates a D-pS-G-X-X-pS degron to recruit the SCFβTrCPubiquitin ligase, causing Emi1 destruction and allowing progression beyond prometaphase, but the kinases directing this phosphorylation remain undefined. We show here that the polo-like kinase Plk1 is strictly required for Emi1 destruction and that overexpression of Plk1 is sufficient to trigger Emi1 destruction. Plk1 stimulates Emi1 phosphorylation, βTrCP binding, and ubiquitination in vitro and cyclin B/Cdk1 enhances these effects. Plk1 binds to Emi1 in mitosis and the two proteins colocalize on the mitotic spindle poles, suggesting that Plk1 may spatially control Emi1 destruction. These data support the hypothesis that Plk1 activates the APC by directing the SCF-dependent destruction of Emi1 in prophase.
Vaccines that facilitate antigen entry into dendritic cells
Authors: Gamvrellis Anita , Leong David , Hanley Jennifer C , Xiang Sue D , Mottram Patricia , Plebanski Magdalena
Published: October 2004

Although vaccines have been highly successful in preventing and treating many infectious diseases (including smallpox, polio and diphtheria) diseases prevalent in the developing world such as malaria and HIV, that suppress the host immune system, require new, multiple strategies that will be defined by our growing understanding of specific immune activation. The definition of adjuvants, previously thought of as any substance that enhanced the immunogenicity of antigen, could now include soluble mediators and antigenic carriers that interact with surface molecules present on DC (e.g. LPS, Flt3L, heat shock protein) particulate antigens which are taken up by mechanisms available to APC but not other cell types (e.g. immunostimulatory complexes, latex, polystyrene particles) and viral/bacterial vectors that infect antigen presenting cells (e.g. vaccinia, lentivirus, adenovirus). These approaches, summarized herein, have shown potential in vaccinating against disease in animal models, and in some cases in humans. Of these, particle‐antigen conjugates provide rapid formulation of the vaccine, easy storage and wide application, with both carrier and adjuvant functions that activate DC. Combined vaccines of the future could use adjuvants such as virus‐like particles and particles targeted towards a predominant cellular type or immune response, with target cell activation enhanced by growth factors or maturation signals prior to, or during immunization. Collectively, these new additions to adjuvant technology provide opportunities for more specific immune regulation than previously available.
Tumour susceptibility to innate and adaptive immunotherapy changes during tumour maturation
Authors: Stewart Trina J , Fernando Germain JP , Frazer Ian H , Leggatt Graham R
Published: October 2004

Immunotherapy of tumours using T cells expanded in vitro has met with mixed clinical success suggesting that a greater understanding of tumour/T‐cell interaction is required. We used a HPV16E7 oncoprotein‐based mouse tumour model to study this further. In this study, we demonstrate that a HPV16E7 tumour passes through at least three stages of immune susceptibility over time. At the earliest time point, infusion of intravenous immune cells fails to control tumour growth although the same cells given subcutaneously at the tumour site are effective. In a second stage, the tumour becomes resistant to subcutaneous infusion of cells but is now susceptible to both adjuvant activated and HPV16E7‐specific immune cells transferred intravenously. In the last phase, the tumour is susceptible to intravenous transfer of HPV16E7‐specific cells, but not adjuvant‐activated immune cells. The requirement for IFN‐γ and perforin also changes with each stage of tumour development. Our data suggest that effective adoptive T‐cell therapy of tumour will need to be matched with the stage of tumour development.
Interaction of soluble CD163 with activated T lymphocytes involves its association with non‐muscle myosin heavy chain type A
Authors: Timmermann Meike , Buck Friedrich , Sorg Clemens , Högger Petra
Published: October 2004

CD163 is a monocyte/macrophage‐specific scavenger receptor that undergoes ectodomain shedding upon an inflammatory stimulus. Soluble CD163 (sCD163) actively inhibits lymphocyte proliferation, but to date exactly how it interacts with these cells has remained elusive. We screened T lymphocytes and endothelial cells for proteins binding to sCD163. In both cell types a high affinity binding protein was detected. Partial sequencing of the protein revealed sequence identity to a non‐muscle myosin heavy chain type A. Employing labelled sCD163 we found little specific binding of sCD163 to the extracellular domains of T lymphocytes and human umbilical vein endothelial cells (HUVEC). In activated T lymphocytes we demonstrated specific binding of sCD163 to intracellular structures as well as the presence of the native protein within the cell after co‐incubation with purified sCD163. Furthermore, we developed a novel ELISA for highly specific detection of sCD163−myosin complexes. These complexes were present in activated T lymphocytes after incubation with shed sCD163. Co‐localization of sCD163 and cellular myosin in T lymphocytes was further confirmed by fluorescence microscopy. Our results suggest that sCD163 associates with cellular myosin, thereby possibly modulating the cells’ response to an inflammatory stimulus.
Development of a nasal vaccine for chronic hepatitis B infection that uses the ability of hepatitis B core antigen to stimulate a strong Th1 response against hepatitis B surface antigen
Authors: Aguilar JC , Lobaina Y , Muzio V , García D , Pentón E , Iglesias E , Pichardo D , Urquiza D , Rodríguez D , Silva D , Petrovsky N , Guillén G
Published: October 2004

There are estimated to be 350 million chronic carriers of hepatitis B infection worldwide. Patients with chronic hepatitis B are at risk of liver cirrhosis with associated mortality because of hepatocellular carcinoma and other complications. An important goal, therefore, is the development of an effective therapeutic vaccine against chronic hepatitis B virus (HBV). A major barrier to the development of such a vaccine is the impaired immune response to HBV antigens observed in the T cells of affected patients. One strategy to overcome these barriers is to activate mucosal T cells through the use of nasal vaccination because this may overcome the systemic immune downregulation that results from HBV infection. In addition, it may be beneficial to present additional HBV epitopes beyond those contained in the traditional hepatitis B surface antigen (HbsAg) vaccine, for example, by using the hepatitis B core antigen (HBcAg). This is advantageous because HBcAg has a unique ability to act as a potent Th1 adjuvant to HbsAg, while also serving as an immunogenic target. In this study we describe the effect of coadministration of HBsAg and HBcAg as part of a strategy to develop a more potent and effective HBV therapeutic vaccine.
Liposome‐stabilized oil‐in‐water emulsions as adjuvants: Increased emulsion stability promotes induction of cytotoxic T lymphocytes against an HIV envelope antigen
Authors: Richards Roberta L , Rao Mangala , Vancott Thomas C , Matyas Gary R , Birx Deborah L , Alving Carl R
Published: October 2004

Protective or therapeutic immunity against HIV infection is currently believed to require both antibody and CTL responses against the envelope protein. In the present study, the adjuvant activity of a unique oil‐in‐water emulsion, in which liposomes containing lipid A (LA) and encapsulated antigen served as the emulsifying agent, was examined in mice using oligomeric gp140 (ogp140) derived from the HIV‐1 envelope as the antigen. Emulsions rendered either highly stable or unstable by altering the ratio of liposomes to oil were used to examine the effect of stability of the emulsion on adjuvant activity. Stable and unstable emulsions had similar potencies for inducing both IgG antibodies to ogp140 and antigen‐specific T‐lymphocyte proliferation. Stable emulsions, but not unstable emulsions, induced antigen‐specific CTL responses, possibly because of the depot effect of the stable emulsions. Furthermore, stable emulsions induced lower IgG2a/IgG1 ratios than the unstable emulsions. We conclude that stable liposomal oil‐in‐water emulsions provide an effective means of obtaining both antibody and CTL responses against an HIV envelope antigen.
Aluminium compounds for use in vaccines
Authors: Lindblad Erik B
Published: October 2004

Aluminium adjuvants are the most widely used adjuvants in both human and veterinary vaccines. These adjuvants have been used in practical vaccination for more than 60 years and are generally recognized as safe and as stimulators of Th2 immunity. The present review gives a short introduction to the pioneering research at the start of the use of aluminium compounds as adjuvants, including references on the chemistry of these compounds. Analytical methods for identifying the most commonly used aluminium compounds, such as boehmite and aluminium hydroxyphosphate, are mentioned. Emphasis is placed on the important factors for antigen adsorption and on the latest work using gene‐deficient mice in the research of the mechanism of aluminium adjuvants in terms of cytokine and T‐cell subset stimulation. Key references on the ability of aluminium adjuvants to stimulate IgE and also in vivo clearing of aluminium adjuvants are discussed. Furthermore, the review addresses the issue of local reactions in the context of injection route and local tissue disturbance. Possible new applications of aluminium adjuvants in, for example, combined aluminium‐adsorbed protein and DNA oligonucleotide vaccines as well as the possible use of aluminium adjuvants in combination with IL‐12 to stimulate Th1‐type immune responses are mentioned.
The Advantages of Designing Adaptive Business Agents Using Reputation Modeling Compared to the Approach of Recursive Modeling
Authors: Tran Thomas , Cohen Robin
Published: October 2004

Adaptive business agents operate in electronic marketplaces, learning from past experiences to make effective decisions on behalf of their users. How best to design these agents is an open question. In this article, we present an approach for the design of adaptive business agents that uses a combination of reinforcement learning and reputation modeling. In particular, we take into account the fact that multiple selling agents may offer the same good with different qualities, and that selling agents may alter the quality of their goods. We also consider the possibility of dishonest agents in the marketplace. Our buying agents exploit the reputation of selling agents to avoid interaction with the disreputable ones, and therefore to reduce the risk of purchasing low value goods. We then experimentally compare the performance of our agents with those designed using a recursive modeling approach. We are able to show that agents designed according to our algorithms achieve better performance in terms of satisfaction and computational time and as such are well suited for the design of electronic marketplaces.
Modeling Agent Negotiation Via Fuzzy Constraints in E‐Business
Authors: Lai K. Robert , Lin Menq‐Wen
Published: October 2004

In e‐business, disputes between two or more parties arise for various reasons and involve different issues. Thus, resolution of these disputes frequently relies on some form of negotiation. This article presents a general problem‐solving framework for modeling multi‐issue multilateral agent negotiation using fuzzy constraints in e‐business. Fuzzy constraints are thus used not only to define each agent's demands involving human concepts, but also to represent the relationships among agents. A concession strategy, based on fuzzy constraint‐based problem‐solving, is proposed to relax demands, and a trade‐off strategy is presented to evaluate existing alternatives. This approach provides a systematic method for reaching an agreement that benefits all agents with a high satisfaction degree of constraints. Meanwhile, by applying the method, agents can move toward an agreement more quickly, because their search focuses only on the feasible solution space. An example application to negotiate an insurance policy among agents is provided to demonstrate the usefulness and effectiveness of the proposed framework.
Negotiation Agents that Make Prudent Compromises and are Slightly Flexible in Reaching Consensus
Authors: Sim Kwang Mong
Published: October 2004

The contribution of this work is designing and developingenhanced market‐driven agentswith the flexibility to (1) respond to changing market conditions, and (2) raise and relax trade aspirations. Previous theoretical analyses have shown that market‐driven agents (MDAs) make prudent compromises by reacting to changing market situations by taking into account factors such as competition, deadlines, and trading options. This work augments the design of anMDAwith three fuzzy decision controllers that guide the agent in (i) relaxing trade aspiration in face of intense negotiation pressure, and (ii) raising trade aspiration in extremely favorable markets. Results from extensive simulations conducted using an implemented testbed suggest that when compared toMDAs, agents in this work achieved (1) higher success rates in reaching deals, (2) higher average utilities, and (3) higher expected utility.
Negotiating Exchanges of P3p‐Labeled Information for Compensation
Authors: Buffett Scott , Jia Keping , Liu Sandy , Spencer Bruce , Wang Fang
Published: October 2004

We consider private information a commodity, of value to both the information holder and the information seeker. Hence, a customer can be enticed to trade his/her private information with a business in exchange for compensation. In this article, we propose to apply utility theory to allow each participant to express the value they place on each private datum and, separately, on combinations of data. The PrivacyPact protocol transmits messages that comprise possible exchanges. Each participant is prevented from making offers that necessarily have lower utility for the other partner than previous ones. The protocol is complete in that if an exchange exists that is acceptable to both, it will be found as long as neither partner exits the negotiation early. While the space of possible offers grows exponentially on the number of negotiable items, experimentation with simple strategies indicates that negotiations can converge relatively quickly.
Growth hormone (GH)‐induced reconstitution of CD8+ CD28+ T lymphocytes in a rare case of severe lymphopenia associated with Juvenile Haemochromatosis and Turner's syndrome
Authors: Porto Graça , Cruz Eugénia , Miranda Helena Pessegueiro , Porto Beatriz , Vasconcelos José Carlos , Lacerda Rosa , Roetto Antonella , Daraio Filomena , Bacelar Conceição
Published: October 2004

This paper describes a rare case of Turner's syndrome associated with Juvenile Haemochromatosis and severe lymphopenia, followed‐up for a period of 5 years. Because of the indication for treatment with growth hormone (GH), this case was observed as a model to analyse the effects of GH on growth, iron mobilization and lymphocyte reconstitution. For this purpose, a serial study of the T lymphocyte subpopulations CD4+, CD8+, CD8+ CD28+ and CD8+ CD28‐ was performed by immunophenotyping during the follow‐up period. Besides the impact of both phlebotomy treatment and GH on the rapid growth and mobilization of 20·8 g of iron in 136 weeks, the most relevant observation was the finding of a significant expansion of CD8+ T lymphocytes expressing the costimulatory marker CD28 in the setting of the severe lymphopenia. These findings constitute new clinical evidence supporting the notion that the GH/IGF‐1 system has an important role on the maintenance of T cell homeostasis in vivo, and that GH may be regarded as a putative therapeutic agent in T lymphocyte reconstitution.