bluuebunny/crossref_metadata_2025 huggingface dataset:
Food sources of nutrients in the diet of Spanish children: the Four Provinces Study
Authors: Royo-Bordonada M. A. , Gorgojo L. , de Oya M. , Garcés C. , Rodríguez-Artalejo F. , Rubio R. , del Barrio J. L. , Martín-Moreno J. M.
Published: February 2003

The aim of the present study was to assess the principal food sources of energy and nutrients among Spanish children. We used a cross-sectional study design, based on results obtained from a food-frequency questionnaire. The sample included 1112 children, aged 6–7 years, from Cadiz, Madrid, Orense and Murcia, Spain. Children were selected through random cluster-sampling in schools. We analysed the percentage contributed by each food item to total energy and nutrient intake. The most important food sources were: white bread in the case of carbohydrate (13·4 %); olive oil in the case of total lipids (18·3 %) and monounsaturated fatty acids (29·2 %); whole milk in the case of protein (10·2 %) and saturated fatty acids (14·9 %); chips (French fried potatoes) in the case of polyunsaturated fatty acids (30·4 %). The greatest proportion of Na, consumed in excess, came from salt added to meals. Ham ranked second as a source of saturated fats. Fruits and green leafy vegetables proved to have great relevance as sources of fibre and vitamins, though with regard to the latter, it was observed that fortified foods (breakfast cereals, dairy products, fruit juices, etc.) had come to play a relevant role in many cases. In conclusion, the nutritional profile of Spanish school-aged children aged 6–7 years could be improved by nutritional policies targeted at limiting their consumption of ham (cured or cooked) and of salt added to meals, replacing whole milk with semi-skimmed milk, encouraging the consumption of products rich in complex carbohydrates already present in children's diets (bread, pasta, rice) and promoting less fatty ways of cooking food.
Effect of feed intake on amino acid transfers across the ovine hindquarters
Authors: Hoskin S. O. , Savary-Auzeloux I. C. , Calder A. G. , Zuur G. , Lobley G. E.
Published: February 2003

Responses in variables of amino acid (AA) metabolism across peripheral tissues to feed intake were studied in six sheep (mean live weight 32 kg) prepared with arterio–venous catheters across the hindquarters. Four intakes (0·5, 1·0, 1·5 and 2·5 × maintenance energy) were offered over 2-week periods to each sheep in a Latin square design with two animals replicated. Animals were infused intravenously with a mixture of U-13C-labelled AA for 10 h and integrated blood samples withdrawn from the aorta and vena cava hourly between 5 and 9 h of infusion. Biopsy samples were also taken from skin andm. vastus lateralis. Data from both essential (histidine, isoleucine, leucine, lysine, phenylalanine, threonine) and nonessential (glycine, proline, serine, tyrosine) AA were modelled to give rates of inward and outward transport, protein synthesis and degradation, plus the fraction of total vascular inflow that exchanged with the hindquarter tissues. Rates of inward transport varied more than 10-fold between AA. For all essential AA (plus serine), inward transport increased with food intake (P<0·04). There were corresponding increases in AA efflux (P<0·05) from the tissues for threonine and the branched-chain AA. Protein synthesis rates estimated from the kinetics of these AA also increased with intake (P<0·02). Rates of inward transport greatly exceeded the amount of AA necessary to support protein retention, but were more similar to rates of protein synthesis. Nutritional or other strategies to enhance AA transport into peripheral tissues are unlikely to increase anabolic responses.
Casein and whey exert different effects on plasma amino acid profiles, gastrointestinal hormone secretion and appetite
Authors: Hall W. L. , Millward D. J. , Long S. J. , Morgan L. M.
Published: February 2003

Protein, generally agreed to be the most satiating macronutrient, may differ in its effects on appetite depending on the protein source and variation in digestion and absorption. We investigated the effects of two milk protein types, casein and whey, on food intake and subjective ratings of hunger and fullness, and on postprandial metabolite and gastrointestinal hormone responses. Two studies were undertaken. The first study showed that energy intake from a buffet meal ad libitum was significantly less 90 min after a 1700 kJ liquid preload containing 48 g whey, compared with an equivalent casein preload (P<0·05). In the second study, the same whey preload led to a 28 % increase in postprandial plasma amino acid concentrations over 3 h compared with casein (incremental area under the curve (iAUC), P<0·05). Plasma cholecystokinin (CCK) was increased by 60 % (iAUC, P<0·005), glucagon-like peptide (GLP)-1 by 65 % (iAUC, P<0·05) and glucose-dependent insulinotropic polypeptide by 36 % (iAUC, P<0·01) following the whey preload compared with the casein. Gastric emptying was influenced by protein type as evidenced by differing plasma paracetamol profiles with the two preloads. Greater subjective satiety followed the whey test meal (P<0·05). These results implicate post-absorptive increases in plasma amino acids together with both CCK and GLP-1 as potential mediators of the increased satiety response to whey and emphasise the importance of considering the impact of protein type on the appetite response to a mixed meal.
Effects of ornithine α-ketoglutarate on insulin secretion in rat pancreatic islets: implication of nitric oxide synthase and glutamine synthetase pathways
Authors: Schneid Christina , Darquy Sylviane , Cynober Luc , Reach Gérard , De Bandt Jean-Pascal
Published: February 2003

Ornithine α-ketoglutarate (OKG) administration in human subjects elicits insulin secretion. We investigated whether this action was related to an effect of OKG on islets of Langerhans, and addressed the underlying mechanisms of action. For this purpose the influence of OKG on insulin secretion was measured in isolated rat islets of Langerhans under two different conditions. In incubated islets, OKG (0·25 to 2·5 mmol/l) significantly and dose-relatedly increased insulin secretion (1·7- to 4·2-fold;P<0·05v.basal). To study the kinetics of OKG-stimulated insulin secretion, perifusion experiments were performed, which showed that OKG affected insulin secretion in both initial and later phases. Experiments using α-ketoglutarate (α-KG) (1 mmol/l) or ornithine (Orn) (2 mmol/l) alone, in concentrations equal to that of OKG, showed that the OKG-induced insulin secretion could not be obtained by either component alone, suggesting that an α-KG–Orn interaction is mandatory for the insulin-secreting effect to occur. Since data obtainedin vivosuggest that effects of OKG may depend on the synthesis of NO, glutamine and/or polyamines, three metabolic pathways potentially involved in insulin secretion, we then evaluated their contribution by means of their respective inhibitors: α-NG-nitroarginine methyl ester (l-NAME), methionine sulfoximine (MSO) and difluoromethylornithine (DFMO). Both l-NAME and MSO were able significantly to reduce OKG-induced insulin secretion (30 and 40 % respectively;P<0·05), while DFMO was ineffective. Thus OKG is an effective stimulator of insulin secretion, requiring the joint presence of both Orn and α-KG, and acting mainly via the synthesis of NO and glutamine. A better understanding of OKG insulino-secretory properties and its mechanisms of action are a prerequisite for its use in insulin-compromised situations.
Glucose transporters (GLUT and SGLT): expanded families of sugar transport proteins
Authors: Wood I. Stuart , Trayhurn Paul
Published: February 2003

The number of known glucose transporters has expanded considerably over the past 2 years. At least three, and up to six, Na+-dependent glucose transporters (SGLT1–SGLT6; gene name SLC5A) have been identified. Similarly, thirteen members of the family of facilitative sugar transporters (GLUT1–GLUT12 and HMIT; gene name SLC2A) are now recognised. These various transporters exhibit different substrate specificities, kinetic properties and tissue expression profiles. The number of distinct gene products, together with the presence of several different transporters in certain tissues and cells (for example, GLUT1, GLUT4, GLUT5, GLUT8, GLUT12 and HMIT in white adipose tissue), indicates that glucose delivery into cells is a process of considerable complexity.
Fate of genetically modified maize DNA in the oral cavity and rumen of sheep
Authors: Duggan Paula S. , Chambers Philip A. , Heritage John , Forbes J. Michael
Published: February 2003

The polymerase chain reaction (PCR) technique was used to investigate the fate of a transgene in the rumen of sheep fed silage and maize grains from an insect-resistant maize line. A 1914-bp DNA fragment containing the entire coding region of the syntheticcryIA(b) gene was still amplifiable from rumen fluid sampled 5 h after feeding maize grains. The same target sequence, however, could not be amplified from rumen fluid sampled from sheep fed silage prepared from the genetically modified maize line. PCR amplification of a shorter (211-bp), yet still highly specific, target sequence was possible with rumen fluid sampled up to 3 and 24 h after feeding silage and maize grains, respectively. These findings indicate that intact transgenes from silage are unlikely to survive significantly in the rumen since a DNA sequence 211-bp long is very unlikely to transmit genetic information. By contrast, DNA in maize grains persists for a significant time and may, therefore, provide a source of transforming DNA in the rumen. In addition, we have examined the biological activity of plasmid DNA that had previously been exposed to the ovine oral cavity. Plasmid extracted from saliva sampled after incubation for 8 min was still capable of transforming competentEscherichia colito kanamycin resistance, implying that DNA released from the diet within the mouth may retain sufficient biological activity for the transformation of competent oral bacteria.
The combined effects of garlic oil and fish oil on the hepatic antioxidant and drug-metabolizing enzymes of rats
Authors: Chen Haw-Wen , Tsai Chia-Wen , Yang Jaw-Ji , Liu Cheng-Tze , Kuo Wei-Wen , Lii Chong-Kuei
Published: February 2003

This present study was designed to investigate the combined modulatory effect of garlic oil (GO) and fish oil (FO) on the antioxidant and drug metabolism systems. Rats were fed either a low-maize oil (MO) diet (50 g MO/kg), high-MO diet (235 g MO/kg) or high-FO diet (205 g FO+30 g MO/kg) and received different doses of GO (0–200 mg/kg body weight) three times per week for 6 weeks. Fatty acid analysis showed that 20: 5n−3 and 22: 6n−3 were incorporated into serum lipid at the expense of 18: 2n−6 and 20: 4n−6 in rats fed the high-FO diet. GO dose-dependently increased hepatic glutathioneS-transferase (GST), glutathione reductase, superoxide dismutase (SOD) and ethoxyresorufinO-deethylase (EROD) activities, but decreased glutathione peroxidase andN-nitrosodimethylamine demethylase (NDMAD) activities (P<0·05). With the exception of glutathione peroxidase, the activities of glutathione reductase, SOD, GST, EROD and NDMAD were modulated by the dietary fat. The high-FO group had greater SOD and EROD activity than either MO-fed group; it also had greater NDMAD activity than the low-MO group (P<0·05). GST activity was higher in rats fed high-FO or high-MO diets than rats fed the low-MO diet. Change in erythromycin demethylase activity, however, was not caused by either dietary fat or GO. Immunoblot assay showed that GO dose-dependently enhanced the protein level of the Ya, Yb1, Yc isoenzymes of GST and cytochrome P450 (CYP) 1A1 and 3A1, but GO suppressed CYP2E1 expression. Regardless of the dosage of GO, the high-FO diet increased CYP1A1, CYP3A1 and CYP2E1 levels compared with the high- and low-MO diets. Accompanying the changes observed in immunoblots, CYP1A1 and CYP3A1 mRNA levels were increased by GO in a dose-dependent manner and also increased additively in combination with FO feeding. These present results indicate that co-administration of GO and FO modulates the antioxidant and drug-metabolizing capacity of animals and that the effect of GO and FO on drug-metabolizing enzymes is additive.
The effect of various vitamin E derivatives on the urokinase-plasminogen activator system of ovine macrophages and neutrophils
Authors: Politis I. , Voudouri A. , Bizelis I. , Zervas G.
Published: February 2003

The effect of vitamin E derivatives on the urokinase-plasminogen activator (u-PA) system of resting and phorbol myristate acetate (PMA)-activated ovine macrophages and neutrophils were investigated. Blood monocyte–macrophages and neutrophils were isolated from twenty-four animals. Macrophages or neutrophils were culturedin vitrofor 3 or 24 h with or without various vitamin E derivatives: free α-tocopherol (α-T), α-tocopheryl acetate (α-TA), or α-tocopheryl succinate (α-TS). Following incubation, cells were stimulated with 80 μM-PMA. Total cell-associated u-PA, membrane-bound u-PA and free u-PA binding sites were determined before and after stimulation with PMA. Results showed that none of the vitamin E derivatives had any effect (P>0·05) on the u-PA system of resting monocyte–macrophages or neutrophils. In contrast, α-TS, but not α-TA or α-T, increased (P<0·01) total cell-associated u-PA and membrane-bound u-PA of PMA-stimulated macrophages and neutrophils. α-TS had no effect (P>0·05) on total u-PA and membrane-bound u-PA activities of macrophages and neutrophils cultured in the presence of 4-phorbol 12,13 didecanoate, a phorbol ester that does not activate protein kinase (PK) C. Addition of H7 (1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride), which is a potent inhibitor of both PK A and C, completely abolished the effect of α-TS on total cell-associated u-PA and membrane-bound u-PA of PMA-activated macrophages and neutrophils. Addition of HA1004 (N-(2-quanidinoethyl)-5-isoquinoline sulfonamide hydrochloride), which is a potent PK A but a weak PK C inhibitor, had no effect (P>0·05) on total cell-associated u-PA and membrane-bound u-PA of PMA-activated macrophages and neutrophils cultured in the presence of α-TS. Thus, PK C modulates the effect of α-TS on the u-PA system of ovine macrophages and neutrophils.
Dietary rhubarb (Rheum rhaponticum) stalk fibre does not lower plasma cholesterol levels in diabetic rats
Authors: Cheema Sukhinder Kaur , Goel Vinti , Basu Tapan K. , Agellon Luis B.
Published: February 2003

Rhubarb (Rheum rhapontiam) stalk fibre was previously shown to be hypolipidaemic under clinical and experimental conditions. The present study was undertaken to investigate whether rhubarb stalk fibre has a hypolipidaemic effect under diabetic conditions. Two models of diabetic rats were used: streptozotocin-induced diabetic rats, and diabetes-prone BB (BBdp) rats. The plasma cholesterol and triacylglycerol concentrations were elevated after the onset of diabetes in BBdp rats, but not in sterptozotocin-induced diabetic rats. The rhubarb-fibre diet had no effect on the plasma cholesterol or triacylglycerol concentrations of diabetic rats. The hypolipidaemic effect of rhubarb stalk fibre has been suggested to be due to the bile-acid-binding capacity of rhubarb fibre, which in turn up regulates cholesterol 7α-hydroxylase (cyp7a) activity. cyp7a is the first and the rate-limiting enzyme in the breakdown of cholesterol to bile acids. We measured the cyp7a activity and mRNA levels in control and diabetic rats fed rhubarb- and cellulose-fibre diets. The cyp7a activity and mRNA abundance were increased in both diabetic rat models, indicating that bile acid synthesis is enhanced in diabetes. Feeding a diet enriched with rhubarb fibre caused a slight but significant increase (P<0·05) in cyp7a enzyme activity in BBdp rats, but no change in cyp7a mRNA abundance was detected. These results suggest that although a rhubarb-fibre-enriched diet increased cyp7a activity in BBdp rats, there was no apparent therapeutic benefit in terms of lowering plasma cholesterol concentrations.
A randomised four-intervention crossover study investigating the effect of carbohydrates on daytime profiles of insulin, glucose, non-esterified fatty acids and triacylglycerols in middle-aged men
Authors: Brynes Audrey E. , Edwards C. Mark , Ghatei Mohammed A. , Dornhorst Anne , Morgan Linda M. , Bloom Stephen R. , Frost Gary S.
Published: February 2003

Postprandial concentrations of glucose, insulin and triacylglycerols (TG) correlate to risk for CHD. Carbohydrates affect many metabolites that could have a potential effect on cardiovascular risk factors. The objective of the present study was to examine, using a randomised prospective study, the acute (day 1) and ad libitum medium-term (day 24) effects of four diets: a high-fat diet (HIGH-FAT; 50 % fat, >34 % monounsaturated fatty acids); a low-glycaemic index (GI) diet (LOW-GI; high-carbohydrate, low-GI); a high-sucrose diet (SUCROSE; high carbohydrate increase of 90 g sucrose/d); a high-GI diet (HIGH-GI; high-carbohydrate, high-GI). Daytime profiles (8 h) (breakfast, lunch and tea) of lipid and carbohydrate metabolism were completed during day 1 and day 24. Seventeen middle-aged men with one or more cardiac risk factors completed the study. There was no change from day 1 or between diets in fasting glucose, lipids or homeostatic assessment model (HOMA) on day 24. The HIGH-FAT compared with the three high-carbohydrate diets was associated with lower postprandial insulin and glucose but higher postprandial TG and non-esterified fatty acids (NEFA). There was a significant increase in the 6 h (15.00 hours) TG concentration (day 1, 2·6 (SEM 0·3) MMOL/L v. DAY 24, 3·3 (sem 0·3) mmol/l; P<0·01) on the SUCROSE diet. Postprandial HOMA (i.e. incremental area under the curve (IAUC) glucose (mmol/l per min)×IAUC insulin/22·5 (mU/l per min)) median changes from day 1 to day 24 were −61, −43, −20 and +31 % for the HIGH-FAT, LOW-GI, SUCROSE and HIGH-GI diets respectively. The HIGH-GI percentage change was significantly different from the other three diets (P<0·001). Despite being advised to maintain an identical energy intake there was a significant weight change (−0·27 (sem 0·3) kg; P<0·02) on the LOW-GI diet compared with the SUCROSE diet (+0·84 (sem 0·3) kg). In conclusion the HIGH-FAT diet had a beneficial effect on postprandial glucose and insulin over time but it was associated with higher postprandial concentrations of TG and NEFA. Conversely the HIGH-GI diet appeared to increase postprandial insulin resistance over the study period.
Demographic and lifestyle characteristics of functional food consumers and dietary supplement users
Authors: de Jong Nynke , Ocké Marga C. , Branderhorst Hester A. C. , Friele Roland
Published: February 2003

Functional foods and/or supplements may be used in the context of a healthy lifestyle or as a means to compensate for an unhealthy lifestyle. Adverse long-term and/or cumulative effects of functional food or supplement intake are of public health concern; it is therefore important to identify functional food and supplement users. The present study compared Dutch functional food and supplement consumers with non-consumers with regard to demographic and lifestyle factors. The consumption of the most common functional foods and supplements in 2000 was studied (yoghurt with extra lactic acid bacteria, cholesterol-lowering margarine, lemonade and sweets with extra vitamins and minerals, milk and margarine with extra Ca, Ca tablets, multivitamin and mineral supplements, and Echinacea supplements). Data were obtained from self-administered questionnaires filled in by a consumer panel, aged 19–91 years (response rate 76 %, n 1183), representative of the Dutch population. The number of daily consumers of functional foods or supplements appeared to be relatively low (daily use of multivitamin and mineral supplements, 20 %; all other products, 3–9 %). Explanatory variables depended on the type of product; but gender, age, education, and vegetable intake were significant factors in the logistic regression model. Consumption of cholesterol-lowering margarines was more likely to be reported by individuals with a poorer subjective health (odds ratio 2·62 (95 % CI 1·15, 6·05)) and by smokers (odds ratio 2·93 (95 % CI 1·34, 6·40)). In conclusion, determinants of functional food or supplement use depended on the type of product, so generalisation of consumer characteristics over different foods is not legitimate. In addition to research on lifestyle factors, surveys about consumers' attitudes, norms and knowledge regarding functional foods in relation to actual dietary patterns and health risk profiles are necessary.
Heterologous transmission with Dictyocaulus capreolus from roe deer (Capreolus capreolus) to cattle (Bos taurus)
Authors: Divina B.P. , Höglund J.
Published: February 2003

Eight Swedish Red Breed cattle, about 2 months old, were experimentally infected with a Swedish isolate of Dictyocaulus viviparus (Dviv-Se) from cattle and D. capreolus from roe deer. The aims were to determine whether the roe deer lungworm is infective to cattle or if it can induce seroconversion in cattle against D. viviparus as measured with an ELISA. Four calves which were given 500 Dviv-Se infective larvae (L3) each by larval dosing for two successive days developed patent infection between days 23 and 25 post-inoculation (PI). Larval output varied among the calves and during the patent period. However, maximum recovery occurred between 28 and 56 days PI with peak shedding on day 37 PI. Shedding ceased at day 58 PI and adult worms were recovered from one calf at necropsy (day 67 PI). No immature worms were recovered from the lungs at necropsy. Seroconversion was detected on days 35–42 PI. One Dviv-Se infected calf became seronegative on day 67 PI whereas the other calves still remained seropositive during this period. Prepatency and patency periods of D. viviparus and serological findings in this study basically conform to previous studies. Each calf that was infected with 400 L3 of D. capreolus for two successive days, and about 800 L3 of the same species about 8 weeks later, did not develop to patency based on faecal and post-mortem examinations. Consequently, under the conditions of this study, D. capreolus was not infective to cattle. Two of the four calves that were infected with L3 from roe deer were challenged with L3 cultured from faeces of the Dviv-Se-infected calves. This infection did not develop to patency. Whether this was due to cross-protection as a result of the prior priming with L3 from roe deer is not clear. However, if it is so, it opens up the possibility of using D. capreolus L3 for preventing bovine dictyocauliasis.
In vitro culture of tetrathyridia of Mesocestoides corti using a gel based diphasic medium
Authors: Chernin J. , Thompson D. , Swaine D.
Published: February 2003

Tetrathyridia of Mesocestoides corti were cultured in vitro in a diphasic medium consisting of a liquid medium (CMRL Sigma) and a thixotropic nutrient gel (Oxoid). Tests demonstrated that a 50% medium/gel mixture produced optimum conditions for the survival and development of tetrathyridia. Established anthelminthic drugs were inoculated into the gel which demonstrated that this system can be used for preliminary anthelminthic drug screening. The development and survival of the tetrathyridia were influenced by the addition of pepsin, trypsin and liver peptone to the culture media. The development and maturation of proglottids were observed in addition to asexual reproduction by the process of budding. Tetrathyridia maintained in vitro and reinfected into both mouse and rat hosts retained their viability.
The presence of predators modifies the larval development of Fasciola hepatica in surviving Lymnaea truncatula
Authors: Rondelaud D. , Vignoles P. , Dreyfuss G.
Published: February 2003

Experimental infections of Lymnaea truncatula with Fasciola hepatica were performed to study the consequences of the presence of predators (sciomyzid larvae or zonitid snails) on the characteristics of larval F. hepatica development in surviving snails. Controls consisted of infected snails that were not subjected to predators. Compared to controls, the survival rate at day 30 post-exposure, the duration of cercarial shedding, and the number of cercariae shed by surviving snails were significantly lower when predators were present in snail breeding boxes, whatever the type of predator used. In contrast, the prevalences of Fasciola infections in snails, and the length of time between exposure and the onset of cercarial shedding showed no significant variation. The progressive development of a stress reaction in surviving snails against predators during the first 30 days of experimental exposure to F. hepatica would influence snail survival during the cercarial shedding period and, consequently, the number of cercariae shed by the snails.
Immunoglobulins anti-Anisakis simplex in patients with gastrointestinal diseases
Authors: Gutiérrez R. , Cuéllar C.
Published: February 2003

The nematode Anisakis simplex causes anisakidiasis, a disease that often mimics other gastrointestinal diseases. Patients with digestive haemorrhaging, Crohn's disease, digestive cancer and appendicitis were analysed for antibodies to A. simplex. Antibody detection was carried out by enzyme-linked immunosorbent assay (ELISA) and immunoblotting using crude extract (CE) antigen and excretory-secretory (ES) products. Total immunoglobulin (Igs), IgG, IgM, IgA and IgE were studied. The highest percentage was obtained when Igs were tested against CE antigen. A higher percentage of positivity was observed with the appendicitis group. The Crohn's disease group showed the highest levels of IgG against the ES antigen. Using immunoblotting, 24% and 48% of sera from patients with symptoms of Crohn's disease and digestive haemorrhaging, respectively, showed a positive immunorecognition pattern of CE antigen. The prevalence of detectable antibodies against A. simplex is higher in patients with digestive disorders than in the healthy population. A linear correlation was observed between prothrombin activity and Igs-CE, IgA-CE and IgA-ES but not between IgE-CE and the other immunoglobulin levels. Specific IgA is associated with a higher activity index of Crohn's disease. Specific antibodies were observed against A. simplex in patients with appendicitis and gastrointestinal cancer, indicating a higher rate of positivity for IgA.
Ultrastructural aspects of the oesophageal and reproductive systems of the equine parasite Strongylus vulgaris
Authors: Mobarak M.S. , Ryan M.F.
Published: February 2003

The ultrastructure of the dorsal oesophageal gland ampulla and its relationship with the oesophagus, oesophageal ultrastructure, and control mechanisms in oesophageal activity were studied. Terminal ducts of the sub-ventral glands open through the oesophageal crown at the base of the buccal cavity. The terminal duct of the dorsal oesophageal gland running through the dorsal gutter opens to the exterior at the rim ‘groove’ of the buccal capsule. The posterior oesophageal region is clavate and the cuticle of the lumen folds to form outlet valves, ‘valvulae’. An inconspicuous oesophago-intestinal valve (three lobes) connects oesophagus and intestine and is visualized in the open and shut position. In the female reproductive tract, with the exception of the uterus, the cells lie on a thick, irregular (convoluted) basal lamina. The apical plasma membrane of the uterus, and seminal receptacle, extend into the lumen by microvilli-like projections with which spermatozoa make intimate contact. The lumen of the uterus is filled with oocytes, fertilized and unfertilized. Testicular cells have two parts linked by a rachis. Spermatocytes are elongated with a large nucleus, distinct nuclear membrane, and many granules. The apical membrane of the rachis forms long microvilli-like projections with balloon-like tips. The amoeboid spermatozoa contain membrane specializations, a nucleus devoid of a membrane, and are enclosed by a pseudopodial-like extension.
Molecular cloning and characterization of a novel protein ofTrichinella pseudospiralisexcretory–secretory products
Authors: Nagano I. , Wu Z. , Nakada T. , Boonmars T. , Takahashi Y.
Published: February 2003

A novel excretory–secretory (ES) protein ofTrichinella pseudospiraliswas produced. A cDNA library was constructed from mRNA of muscle larvae at 30 days post infection (p.i.) and immunoscreened with the antibody against ES products. A clone, designated Tp22-3, contained a cDNA transcript of 815 bp in length with a single open reading frame which encoded 244-amino acids (28407 Da in the estimated molecular mass). A database search revealed that no sequences had a homology to this predicted protein. The recombinant protein was produced in anEscherichia coliexpression system. Stage specific expression of this protein was suggested from the following experiments. An antibody against the recombinant protein could stain proteins migrating at about 28 kDa (which is the expected size from the sequence) on Western blotting of crude extracts or ES products from 30 days p.i. muscle larvae, but failed to stain any proteins in crude extracts from newborn larvae or 15 days p.i. muscle larvae. The antibody reacted to the stichocytes of larvae at 30 days p.i., but did not react to 15 days p.i. muscle larvae. The production of an mRNA transcript for Tp22-3 gene was restricted largely to the 30 days p.i. muscle larvae and adult worms.
Local variation in endoparasite intensities of bank voles (Clethrionomys glareolus) from ecologically similar sites: morphometric and endocrine correlates
Authors: Barnard C.J. , Behnke J.M. , Bajer A. , Bray D. , Race T. , Frake K. , Osmond J. , Dinmore J. , Sinski E.
Published: February 2003

Much interest has centred recently on the role of adaptive trade-offs between the immune system and other components of life history in determining resistance and parasite intensities among hosts. Steroid hormones, particularly glucocorticoids and sex steroids, provide a plausible mechanism for mediating such trade-offs. A basic assumption behind the hypothesis, however, is that steroid activity will generally correlate with reduced resistance and thus greater parasite intensities. Here, we present some findings from a field study of bank voles (Clethrionomys glareolus) in which we have looked at associations between parasite intensities, anatomical and morphometric measures relating to endocrine function and life history variation in three local populations inhabiting similar but mutually isolated woodland habitats. In general, sites with greater parasite intensities were those in which male C. glareolus had significantly larger adrenal glands, testes and seminal vesicles for their age and body size. Females also showed a site difference in adrenal gland weight. Some aspects of site-related parasite intensity were associated with asymmetry in adrenal gland weight and hind foot length, which may have reflected developmental effects on glucocorticoid activity.
Toxic effects of cadmium and zinc on the transmission of Echinoparyphium recurvatum cercariae
Authors: Morley N.J. , Crane M. , Lewis J.W.
Published: February 2003

The toxicity of cadmium, zinc and Cd/Zn mixtures to the transmission of Echinoparyphium recurvatum (Digenea: Echinostomatidae) cercariae into the snail second intermediate hosts was investigated at concentrations ranging from 100 μg l-1 to 10 000 μg l-1 in both soft and hard water. A differential response in the infectivity of metal-exposed cercariae into Lymnaea peregra and Physa fontinalis was demonstrated which was dependent on the snail species being infected. Exposure of L. peregra, P. fontinalis, and L. stagnalis to heavy metals caused a differing susceptibility to E. recurvatum cercariae depending on the snail species being exposed. The mechanism and effects of metal toxicity, together with the importance of the parasite/host strain on cercarial transmission are discussed.
Parameters of intestinal inflammation in mice given graded infections of the nematode Trichinella spiralis
Authors: Dehlawi M.S. , Wakelin D.
Published: February 2003

Four parameters of the intestinal inflammatory response (numbers of mucosal mast cells (MMC) and Paneth cells, villus:crypt ratios and mitotic figures) were measured in mice exposed to varying doses of infective larvae of Trichinella spiralis.The aim of the experiments was to determine whether generation of these components of inflammation required a threshold level of infection and whether, once triggered, inflammation became pan-mucosal. Near maximal MMC and Paneth cell responses were elicited even with infections as low as 35 larvae; changes in villus:crypt ratios and in mitotic indices also occurred at this level of infection, but were progressively greater with increasing levels of infection. In all infected mice, including those infected with 35 larvae, MMC and Paneth cell responses extended over most of the small intestine. These data are interpreted as showing: (i) that the intestinal mucosa is highly responsive to T. spiralis infection; (ii) that once triggered, components of the inflammatory response are amplified by T cell-dependent mechanisms, becoming pan-mucosal; and (iii) that MMC and Paneth cell responses, which require cell division and differentiation, become maximal at a lower infection threshold than changes in the villus:crypt ratio or in mitotic indices, which directly reflect increased rates of division in crypt cells.
Changes in the expression of cytochrome P450 isozymes and related carcinogen metabolizing enzyme activities in Schistosoma mansoni-infected mice
Authors: Sheweita S.A. , Mubark J. , Doenhoff M.J. , Mostafa M.H. , Margison G.P. , O'Connor P.J. , Elder R.H.
Published: February 2003

Mixed-function oxidase enzymes metabolize most xenobiotic agents. Western blotting was used to investigate the effect of Schistosoma mansoni infection on the expression of various cytochrome P450 (CYP) isozymes and specific enzyme assays to study related metabolic functions in mouse liver microsomes. Male BK-TO mice were infected with 200 cercariae per mouse and their livers were assayed at 6, 15, 30 and 45 days post-infection (p.i.) and compared with appropriately matched controls. The expression of each of the CYP isozymes (1A1, 2B1/2, 2C6, and 4A) was either unaffected or transiently increased up to 30 days post-infection. By 45 days, a significant loss of signal was observed, particularly for CYP 1A1 and 2B1/2 where no signal could be detected. Evidence supporting these findings was obtained from enzyme assays specific for particular CYP isozymes. The activity of ethoxyresorufin O-deethylase (CYP 1A1) was reduced by 97% and that of pentoxyresorufin O-depentylase (CYP 2B1/2) by 96% at 45 days p.i. Similarly, the activity of ethoxycoumarin hydroxylase was progressively reduced over the period under study. It is believed that N-nitrosamines are activated principally by N-nitrosodimethylamine N-demethylase I which was significantly increased at both 30 and 45 days p.i. To further investigate metabolic competency following S. mansoni infection, the in vitro binding of benzo(a)pyrene metabolites to DNA was measured, using isolated liver microsomes to activate benzo(a)pyrene. Benzo(a)pyrene-DNA adduct formation was markedly increased at 6, 15 and 30 days with a maximum at 15 days, but decreased at 45 days p.i. It was concluded that S. mansoni infection changes the expression of different CYP isozymes and also the activity of phase I drug-metabolizing enzymes at different periods of infection and may thus change the liver's capacity to activate or detoxify many endogenous and exogenous compounds. Such alterations may also change the therapeutic actions of drugs that are primarily metabolized by the P450 system, when administered to patients with schistosomiasis.
Trace element levels in the liver of rats with acute and chronic fascioliasis and after treatment with zinc-copper hydroxochloride mixed crystals
Authors: Tsocheva-Gaitandjieva N.T. , Gabrashanska M.P. , Tepavitcharova S.
Published: February 2003

Quantities of trace elements including copper, zinc, cobalt, manganese and iron were investigated in the liver tissue of rats at the acute or chronic stages of fascioliasis following treatment with zinc-copper hydroxochloride mixed crystals. Oral dosing (with food) of zinc–copper mixed crystals to healthy rats increased zinc and copper levels in the liver and decreased the iron content compared with controls. Manganese and cobalt levels did not change significantly. Significant reductions in all trace elements except manganese occurred in the liver of rats with acute or chronic fascioliasis. Manganese levels were slightly increased in rats at the acute stage and slightly decreased in rats at the chronic stage of fascioliasis. The application of mixed zinc–copper crystals at the acute or chronic stages of fascioliasis lead to a restoration of zinc and copper levels and a slight reduction in the iron levels in liver tissue of rats. The beneficial effects of applied salts were more apparent in rats chronically infected with Fasciola hepatica.
Effect of Echinococcus multilocularis on the origin of acetyl-CoA entering the tricarboxylic acid cycle in host liver
Authors: Kepron C. , Novak M. , Blackburn B.J.
Published: February 2003

Carbon-13 nuclear magnetic resonance (NMR) spectroscopy was employed to investigate alterations in hepatic carbohydrate metabolism in Meriones unguiculatus infected with Echinococcus multilocularis. Following portal vein injections of an equimolar mixture of ]#x005B;1,2-13C2]acetate and [3-13C]lactate, perchloric acid extracts of the livers were prepared and NMR spectra obtained. Isotopomer analysis using glutamate resonances in these spectra showed that the relative contributions of endogenous and exogenous substrates to the acetyl-CoA entering the tricarboxylic acid cycle differed significantly between infected and control groups. The mole fraction of acetyl-CoA that was derived from endogenous, unlabelled sources (FU) was 0.50±0.10 in controls compared to 0.34±0.04 in infected animals. However, the fraction of acetyl-CoA derived from [3-13C]lactate (FLL) was larger in livers of infected animals than those from controls with values of 0.27±0.04 and 0.18±0.04, respectively. Similarly, the fraction of acetyl-CoA derived from [1,2-13C2]acetate (FLA) was larger in livers of infected animals compared to those in controls; the fractions were 0.38±0.01 and 0.32±0.07, respectively. The ratio of FLA:FLL was significantly smaller in the infected group with a value of 1.42±0.18 compared to 1.74±0.09 for the controls. These results indicate that alveolar hydatid disease has a pronounced effect on the partitioning of substrates within the pathways of carbohydrate metabolism in the host liver.
First report of Elaphostrongylus cervi in Spanish red deer Cervus elaphus hispanicus
Authors: F. Valcárcel F. , García Romero C.
Published: February 2003

Elaphostrongylus cervi Cameron, 1931 was identified in six Cervus elaphus hispanicus sampled in Cuenca, central Spain. A total of 23 adult worms were found in the central nervous system with a mean of 3.8. Although E. cervi is reported to be widespread in cervids, this is the first time it has been recorded in Spanish red deer.
Epidemiology of Toxascaris leonina infection post-weaning within a colony of dogs
Authors: Fisher M.A. , Murphy M.G. , Siedek E.M.
Published: February 2003

This communication reports incidental observations on Toxascaris leonina infections in a beagle breeding colony. Regular faecal monitoring demonstrated that T. leonina was endemic in the adult dam population within this colony. Small numbers of T. leonina eggs were also detected in the faeces of weaned pups from eight weeks of age possibly produced by a patent infection. This would mean a pre-patent period for T. leonina of 56 days or less. Worm counts on 10 pups showed that 60% of pups had acquired a T. leonina infection by 12 weeks of age. Since prenatal and lactogenic transmission do not occur and as the pups were kept in an environment which reduced chances of infection with T. leonina and there was no apparent source of paratenic hosts, the source of infection must have been embryonated T. leonina eggs from the whelping environment. These observations on T. leonina demonstrate that, if pups are exposed to an infected environment, patent infections may be seen in a younger age group than is normally associated with T. leonina infections.
Immunolocalization of a putative cuticular collagen protein in several developmental stages of Meloidogynearenaria, Globodera pallida and G. rostochiensis
Authors: Abrantes I.M. de O. , Curtis R.H.C.
Published: February 2003

The monoclonal antibody IACR-CCNj.3d has previously been used to isolate a gene (gp-col-8) with strong similarity to cuticular collagen from a mixed stage Globodera pallida cDNA expression library. The antibody has also been shown to label specifically the amphidial canal of pre-parasitic second stage juveniles (J2) of several plant nematode species without any reactivity on the cuticular surface, indicating that this protein is either not present or is inaccessible on the cuticular surface. This paper investigates the cross-reactivity of Mab IACR-CCNj.3d with Meloidogyne arenaria and the localization of the putative collagen protein on the cuticular surface of parasitic stages in planta and on the cuticular surface of juveniles inside eggs. The antigen was shown to be present in all developmental stages of the two species of potato cyst nematodes and M. arenaria. The antibody bound strongly to the amphidial canal and hypodermis of pre-parasitic J2 and adult females. The antigen was present on the cuticular surface of the sausage-shaped J2 in planta and of first stage juveniles (J1) inside the eggs. The presence of collagen on the surface of the cuticle of moulting stages of plant parasitic nematodes has been observed for the first time. It is clear that this protein has a role in the construction of the cuticle of the first stage juveniles and parasitic second stage juveniles, during moulting inside the eggs and in the root tissue, respectively.
Effects of recombinant bovine interferon γ on Strongyloides papillosus infection in calves
Authors: Nakamura Y. , Syouji T. , Onodera T. , Kawashima K. , Inumaru S. , Yokomizo Y.
Published: February 2003

The effects of interferon (IFN) γ on the course of infection with Strongyloides papillosus in calves were investigated. Calves (N=7 each) were inoculated with recombinant bovine IFNγ or control solution daily from day 0 to day 15 following S. papillosus infection. Treatment with IFNγ induced an increase in faecal egg output in the peak stage of infection. The IFNγ-treated animals harboured more worms, especially more immature worms, in the small intestine than control animals at necropsy on day 17, with no decreases in intestinal mucosal mast cells. Both animal groups had similar small numbers of intestinal worms at necropsy on day 26. All control animals developed peripheral blood eosinophilia on day 7, while five of seven IFNγ-treated animals did not. Serum α1-acid glycoprotein concentrations increased on day 7 in both animal groups, with higher values in control animals than in IFNγ-treated animals. Control animals mounted a predominant IgG1 response to S. papillosus from day 10, while IFNγ-treated animals did from day 22. These data suggested that IFNγ inhibited some host protective responses to S. papillosus migrating larvae, resulting in an improvement of worm survival after a period when protective responses should be activated during the early stage of infection. The effects of IFNγ on intestinal worm expulsion should be confirmed by further experiments.
Failure to infect laboratory rodent hosts with human isolates of Rodentolepis (= Hymenolepis) nana
Authors: Macnish M.G. , Morgan U.M. , Behnke J.M. , Thompson R.C.A.
Published: February 2003

Confusion exists over the species status and host-specificity of the tapeworm Rodentolepis (= Hymenolepis) nana. It has been described as one species, R. nana, found in both humans and rodents. Others have identified a subspecies; R. nana var. fraterna, describing it as morphologically identical to the human form but only found in rodents. The species present in Australian communities has never been identified with certainty. Fifty one human isolates of Rodentolepis (= Hymenolepis) nana were orally inoculated into Swiss Q, BALB/c, A/J, CBA/CAH and nude (hypothymic) BALB/c mice, Fischer 344 and Wistar rats and specific pathogen free (SPF) hamsters. Twenty four human isolates of R. nana were cross-tested in flour beetles, Tribolium confusum. No adult worms were obtained from mice, rats or hamsters, even when immunosuppressed with cortisone acetate. Only one of the 24 samples developed to the cysticercoid stage in T. confusum; however, when inoculated into laboratory mice the cysticercoids failed to develop into adult worms. The large sample size used in this study, and the range of techniques employed for extraction and preparation of eggs provide a comprehensive test of the hypothesis that the human strain of R. nana is essentially non-infective to rodents.
Neurotropic behaviour of Trichobilharzia regenti in ducks and mice
Authors: Hrádková K. , Horák P.
Published: February 2003

The bird nasal schistosome Trichobilharzia regenti is a new agent of cercarial dermatitis. Cercariae are able to penetrate the skin of birds and mammals including man. The parasite then attacks the central nervous system. The present study has shown that schistosomula avoid penetration of blood capillaries and enter the peripheral nerves of the legs of mice and ducks as early as 1 day post-infection (p.i.) and 1.5 days p.i., respectively. These peripheral nerves are used as a route to the spinal cord. In the specific host (duck) schistosomula were found in the spinal cord from 2 days p.i. until 15 days p.i. and in the brain from 12 days p.i. until 18 days p.i. In non-specific hosts (mice; inbred strains BALB/c, hr/hr, SCID) living schistosomula were found in the spinal cord from 2 days p.i. until 21 or 24 days p.i. (depending on the mouse strain) and in the brain of two (BALB/c, SCID) of three inbred strains from 3 days p.i. until 24 days p.i. No correlation was found between the infection dose and clinical status of the experimental hosts. A high affinity of schistosomula for the peripheral nerves was also proved in vitro, suggesting a new type of migratory behaviour in schistosomatids.
Egg production by metacercariae of Microphallus papillorobustus: a reproductive insurance?
Authors: Wang C.L. , Thomas F.
Published: February 2003

This study aimed to determine whether metacercariae of Microphallus papillorobustus (Trematoda: Microphallidae) produce eggs by self-fertilization when their intermediate host, the gammarid Gammarus insensibilis, dies before being eaten by predatory definitive hosts. Such a mechanism would allow the parasite to reproduce even if transmission fails. The percentage of metacercariae that produced eggs and the mean number of eggs were significantly higher in metacercariae placed in a Ringer's solution compared with those in salt water or metacercariae remaining inside the dead gammarid. The lack of egg production in metacercariae removed from dead gammarids in the field supported the idea that self-fertilization is not, for this parasite, a mechanism of reproductive insurance when establishment in the definitive hosts fails.