bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of biomarkers of sub-clinical infection, nutrition and neonatal maturity to interpret plasma retinol in Nigerian neonates
Authors: Adelekan Delana A. , Northrop-Clewes Christine A. , Owa Joshua A. , Oyedeji Adesola O. , Owoeye Adedayo A. , Thurnham David I.
Published: August 2003

Using the World Health Organization criterion, the prevalence of sub-clinical vitamin A deficiency can be assessed using plasma retinol concentrations <0·7 μmol/l. However, plasma retinol can be depressed by infection; thus, the use of this criterion alone may overestimate deficiency. In the present study, we investigated the usefulness of the acute-phase proteins (APP) α1-antichymotrypsin (ACT) and α1-acid glycoprotein (AGP), plasma carotenoids and anthropometric and gestational indices to interpret plasma retinol in the blood of 192 apparently healthy Nigerian neonates collected randomly during days 1–20 postpartum. The mean weight (2·64 kg) and length (0·458 m) of the neonates and plasma concentrations (geometric mean, μmol/l) of retinol (0·54), α-carotene (0·072), ß-carotene (0·076) and lutein (0·080) were low. The prevalence of vitamin A deficiency was 72 %, indicating a severe public health problem. Babies who were of low birth weight (P<0·003) or premature and low birth weight (P<0·023) had significantly lower retinol concentrations than full-term normal weight babies. Thirty-two neonates had abnormal ACT and forty-four abnormal AGP concentrations. Positive correlations between retinol and ACT (r0·186,P=0·05) and AGP (r0·31,P=0·0001) during days 1–5 may be due to the increasing plasma retinol from maternal milk and a coincidental increasing capacity to synthesise APP. Subsequently, negative correlations between retinol and ACT (r−0·28,P=0·02) and AGP (r−0·29,P=0·018) from day 6 onwards reflected the continuing increase in plasma retinol, but no further increase in the APP. Overall, weight, ACT, lutein and age explained 30 % of the variance in retinol, but lutein was the most significant (r20·18,P<0·0001). Hence, the distribution of plasma retinol concentrations in this group of neonates was more strongly linked with nutrition (via the surrogate marker lutein) than infection.
Single oral doses of13C forms of pteroylmonoglutamic acid and 5-formyltetrahydrofolic acid elicit differences in short-term kinetics of labelled and unlabelled folates in plasma: potential problems in interpretation of folate bioavailability studies
Authors: Wright A. J. A. , Finglas P. M. , Dainty J. R. , Hart D. J. , Wolfe C. A. , Southon S. , Gregory J. F.
Published: August 2003

Single13C6-labelled doses of pteroylmonoglutamic acid (PteGlu; 634 nmol) or 5-formyltetrahydrofolic acid (431–569 nmol) were given to fasted adult volunteers, and the rise in total and13C-labelled plasma 5-methyltetrahydrofolic acid metabolite monitored over 8 h by HPLC and liquid chromatography–MS. The dose-adjusted area under the curve (AUC) for total (labelled plus unlabelled) plasma 5-methyltetrahydrofolic acid following a 5-formyltetrahydrofolic acid test dose was 155 % that obtained following a PteGlu test dose. Surprisingly, an average 60 and 40 % of the total plasma 5-methyltetrahydrofolic acid response to [13C6]PteGlu and [13C6]5-formyltetrahydrofolic acid, respectively, was unlabelled; an observation never before reported. Short-term kinetics of plasma [13C6]5-methyltetrahydrofolic acid showed a slower initial rate of increase in plasma concentration and longer time to peak following an oral dose of [13C6]PteGlu compared with that for an oral dose of [13C6]5-formyltetrahydrofolic acid, while the [13C6]5-methyltetrahydrofolic acid AUC for [13C6]5-formyltetrahydrofolic acid was 221 % that for [13C6]PteGlu. These data indicate that PteGlu and 5-formyltetrahydrofolic acid, which are thought to be well absorbed (about 90 %) at physiological doses, exhibit dramatically different rates and patterns of plasma response. A limitation in the rate of reduction of PteGlu before methylation could result in slower mucosal transfer of [13C6]5-methyltetrahydrofolic acid derived from [13C6]PteGlu into the plasma. This, when coupled with an observed similar plasma clearance rate for [13C6]5-methyltetrahydrofolic acid metabolite derived from either folate test dose, would yield a comparatively smaller AUC. These findings suggest potential problems in interpretation of absorption studies using unlabelled or labelled folates where the rate of increase, the maximum increase, or the AUC, of plasma folate is employed for test foods (mainly reduced folates)v. a ‘reference dose’ of PteGlu.
Effect of reduced maternal protein intake in pregnancy in the rat on the fatty acid composition of brain, liver, plasma, heart and lung phospholipids of the offspring after weaning
Authors: Burdge Graham C. , Delange Emmanuelle , Dubois Ludivine , Dunn Rebecca L. , Hanson Mark A. , Jackson Alan A. , Calder Philip C.
Published: August 2003

Reduced protein intake during pregnancy decreased maternal hepatic and plasma docosahexaenoic acid concentrations and impaired docosahexaenoic acid accumulation into fetal brain in the rat. The present study investigated whether restriction of maternal protein intake during pregnancy in the rat alters membrane phospholipid fatty acid composition in the offspring after weaning. Female rats (six per group) were mated and fed diets containing either 180 or 90 g protein/kg throughout pregnancy. Mothers were transferred to standard chow after delivery and the litters reduced to eight pups. Weaning was at 28 d and pups were killed 5 to 6 d later. Tissue weights or membrane total phosphatidylcholine (PC) and phosphatidylethanolamine (PE) concentrations in the offspring did not differ between dietary groups. There were significant differences between the 180 and 90 g/kg groups in liver, brain, lung and heart fatty acid composition that differed between tissues and phospholipid classes. For example, docosahexaenoic and arachidonic acid concentrations were 23 and 10 % lower respectively in hepatic PC, but not PE, in the 90 g/kg group. In brain, docosahexaenoic acid concentration was 17 % lower in PC, but not PE, while arachidonic acid content was 21 % greater in PE but unchanged in PC. The greatest differences were in unsaturated fatty acids, which suggests alterations to desaturase activities and/or the specificity of phospholipid biosynthesis. These results suggest that restricted maternal protein intake during pregnancy results in persistent alterations to membrane fatty acid content.
Effects of dietary macronutrient content on energy metabolism and uncoupling protein mRNA expression in broiler chickens
Authors: Collin Anne , Malheiros Ramon D. , Moraes Vera M. B. , Van As Pieter , Darras Veerle M. , Taouis Mohammed , Decuypere Eddy , Buyse Johan
Published: August 2003

The objective of the present study was to investigate the effects of dietary macronutrient ratio on energy metabolism and on skeletal muscle mRNA expression of avian uncoupling protein (UCP), thought to be implicated in thermogenesis in birds. Broiler chickens from 2 to 6 weeks of age received one of three isoenergetic diets containing different macronutrient ratios (low-lipid (LL) 30 v. 77 g lipid/kg; low-protein (LP) 125 v. 197 g crude protein (N×6·25)/kg; low-carbohydrate (LC) 440 v. 520 g carbohydrate/kg). LP chickens were characterised by significantly lower body weights and food intakes compared with LL and LC chickens (−47 and −38 % respectively) but similar heat production/kg metabolic body weight, as measured by indirect calorimetry, in the three groups. However, heat production/g food ingested was higher in animals receiving the LP diet (+41 %, P<0·05). These chickens also deposited 57 % less energy as protein (P<0·05) and 33 % more as fat. No significant differences in energy and N balances were detected between LL and LC chickens. The diets with the higher fat contents (i.e. the LP and LC diets) induced slightly but significantly higher relative expressions of avian UCP mRNA in gastrocnemius muscle, measured by reverse transcription–polymerase chain reaction, than the LL diet (88 and 90 v. 78 % glyceraldehyde-3-phosphate dehydrogenase respectively, P<0·05). Our present results are consistent with the recent view that UCP homologues could be involved in the regulation of lipid utilisation as fuel substrate and provide evidence that the macronutrient content of the diet regulates energy metabolism and especially protein and fat deposition.
Effects of dietary fat quantity and composition on fasting and postprandial levels of coagulation factor VII and serum choline-containing phospholipids
Authors: Schou Lindman Anja , Müller Hanne , Seljeflot Ingebjørg , Prydz Hans , Veierød Marit , Pedersen Jan I.
Published: August 2003

Dietary fat influences plasma levels of coagulation factor VII (FVII) and serum phospholipids (PL). It is, however, unknown if the fat-mediated changes in FVII are linked to PL. The present study aimed to investigate the effects of dietary fat on fasting and postprandial levels of activated FVII (FVIIa), FVII coagulant activity (FVIIc), FVII protein (FVIIag) and choline-containing PL (PC). In a randomized single-blinded crossover-designed study a high-fat diet (HSAFA), a low-fat diet (LSAFA), both rich in saturated fatty acids, and a high-fat diet rich in unsaturated fatty acids (HUFA) were consumed for 3 weeks. Twenty-five healthy females, in which postprandial responses were studied in a subset of twelve, were included. The HSAFA diet resulted in higher levels of fasting FVIIa and PC compared with the LSAFA and the HUFA diets (all comparisonsP≤0·01). The fasting PC levels after the LSAFA diet were also higher than after the HUFA diet (P<0·001). Postprandial levels of FVIIa and PC were highest on the HSAFA diet and different from LSAFA and HUFA (all comparisonsP≤0·05). Postprandial FVIIa was higher on the HUFA compared with the LSAFA diet (P<0·03), whereas the HUFA diet resulted in lower postprandial levels of PC than the LSAFA diet (P<0·001). Significant correlations between fasting levels of PC and FVIIc were found on all diets, whereas FVIIag was correlated to PC on the HSAFA and HUFA diet. The present results indicate that dietary fat, both quality and quantity, influences fasting and postprandial levels of FVIIa and PC. Although significant associations between fasting FVII and PC levels were found, our results do not support the assumption that postprandial FVII activation is linked to serum PC.
Ontogeny and nutritional manipulation of mitochondrial protein abundance in adipose tissue and the lungs of postnatal sheep
Authors: Mostyn A. , Wilson V. , Dandrea J. , Yakubu D. P. , Budge H. , Alves-Guerra M. C. , Pecqueur C. , Miroux B. , Symonds M. E. , Stephenson T.
Published: August 2003

The present study examined the ontogeny of mitochondrial protein abundance in adipose tissue and lungs over the first month of life in the sheep and the extent to which this may be altered by maternal undernutrition during the final month of gestation. The ontogeny of uncoupling protein (UCP), voltage-dependent anion channel (VDAC) and cytochromecabundance were determined in adipose tissue and lungs sampled from near-term fetuses and young sheep aged 4 h, 1, 7 and 30 d. In adipose tissue, the abundance of UCP1, VDAC and cytochromecall peaked at 1 d of age and then decreased by 30 d of age, at which stage the brown adipose tissue-specific UCP1 was no longer detectable but UCP2 was clearly abundant. For the lungs, however, UCP2 and VDAC abundance both peaked 7 d after birth and then decreased by 30 d of age. During postnatal development, therefore, a marked change in mitochondrial protein abundance occurs within both adipose tissue and lungs. Maternal nutrient restriction had no effect on lamb growth or tissue weights at 30 d of age but was associated with increased abundance of UCP2 and VDAC but not cytochromecin both adipose tissue and lungs. These mitochondrial adaptations within both adipose tissue and the lungs of offspring born to previously nutrient-restricted mothers may compromise adipose tissue and lung function during periods of environmental stress.
A potential protective mechanism of soya isoflavones against 7,12-dimethylbenz[a]anthracene tumour initiation
Authors: Yee Chan Ho , Leung Lai K.
Published: August 2003

Epidemiological studies indicate that Asian women have a lower breast cancer incidence compared with their counterparts in the West, and the difference has been related to soya consumption. Animal studies have suggested that soya may prevent dimethylbenz[a]anthracene (DMBA)-induced carcinogenesis in the breast. In the present study a cell culture model was developed to address the effect of soya isoflavones on the DMBA-induced DNA damage. DMBA is metabolized into a DNA-attacking moiety by two phase I cytochrome P450 (CYP) enzymes CYP1A1 and CYP1B1. DNA mutation caused by this genotoxic agent is a crucial step in cancer initiation. Substances that interfere with the CYP1 enzyme activities can affect the initiation. In the present study, genistein was found to be an effective inhibitor of recombinant human CYP1A1 and CYP1B1 with Ki of 15·35 and 0·68 μmol/l. The other soya isoflavone daidzein, on the other hand, did not demonstrate any significant inhibition of the enzyme activities. At the transcriptional level, DMBA induced the CYP1 enzyme expressions by stimulating the xenobiotic response element (XRE)-dependent transactivation pathway. When genistein (25 μmol/l) was co-administered with DMBA, the XRE-Luc activity the CYP1 mRNA abundances were significantly suppressed. The present study illustrated that the soya isoflavone genistein, but not daidzein, protected against DMBA genotoxicity.
The effect of retinyl palmitate added to iron-fortified maize porridge on erythrocyte incorporation of iron in African children with vitamin A deficiency
Authors: Davidsson Lena , Adou Pierre , Zeder Christophe , Walczyk Thomas , Hurrell Richard
Published: August 2003

Retinyl palmitate added to Fe-fortified maize bread has been reported to enhance Fe absorption in adult Venezuelan subjects but not in Western Europeans. It is not known to what extent these results were influenced by differences in vitamin A status of the study subjects. The objective of the present study was to evaluate the influence of retinyl palmitate added to Fe-fortified maize porridge on erythrocyte incorporation of Fe in children with vitamin A deficiency, before and after vitamin A supplementation. Erythrocyte incorporation of Fe-stable isotopes was measured 14 d after intake of maize porridge (2·0 mg Fe added as ferrous sulfate) with and without added retinyl palmitate (3·5 μmol; 3300 IU). The study was repeated 3 weeks after vitamin A supplementation (intake of a single dose of 210 μmol retinyl palmitate; ‘vitamin A capsule’). Vitamin A status was evaluated by the modified relative dose–response (MRDR) technique. Retinyl palmitate added to the test meal reduced the geometric mean erythrocyte incorporation of Fe at baseline from 4·0 to 2·6 % (P=0·008, n 13; paired t test). At 3 weeks after vitamin A supplementation, geometric mean erythrocyte incorporation was 1·9 and 2·3 % respectively from the test meal with and without added retinyl palmitate (P=0·283). Mean dehydroretinol:retinol molar ratios were 0·156 and 0·125 before and after intake of the single dose of 210 μmol retinyl palmitate; ‘vitamin A capsule’ (P=0·15). In conclusion, retinyl palmitate added to the labelled test meals significantly decreased erythrocyte incorporation of Fe in children with vitamin A deficiency at baseline but had no statistically significant effect 3 weeks after vitamin A supplementation. The difference in response to retinyl palmitate added to Fe-fortified maize porridge on erythrocyte incorporation of Fe before and after intake of the vitamin A capsule indicates, indirectly, changes in vitamin A status not measurable by the MRDR technique. The lack of conclusive data on the effect of retinyl palmitate on Fe absorption indicates the complexity of the interactions between vitamin A status, dietary vitamin A and Fe metabolism.
The rat as a model for pigs: comparative values for the digestibility of NSP and other macronutrients
Authors: Wisker Elisabeth , Bach Knudsen Knud Erik
Published: August 2003

The present investigation was undertaken to study whether conventional male Wistar rats could be used as a model for pigs with regard to total tract digestibilities of NSP and macronutrients and whether nebacitin-treated rats could be used as a model for small intestinal digestibility in pigs. Nineteen experimental diets prepared from different fractions of wheat and oats, and which all had been evaluated in experiments with ileal cannulated pigs, were used for the present study. There was a close relationship between the total tract digestibilities of organic matter in the two species. The same was the case with regard to the digestibility of total NSP and arabinoxylans, but the values were on average 6 % lower in rats than in pigs. On average, there were no significant differences between rats and pigs with regard to faecal protein digestibility. However, protein in oat-based diets was significantly better digested in the rat than the pig. The digestibility of fat was consistently higher in rats than in pigs, with the biggest difference being found in oat-based diets, in which most of the fat was locked in cell structures. For the wheat-based diets, in which a large proportion of the fat was present as added fat, there was a greater similarity between the two species. In nebacitin-treated rats the digestibility of organic matter, starch, protein and fat was negatively related to the dietary level of NSP, but this model could not be used to predict the small intestinal digestibility of NSP and macronutrients in ileal-cannulated pigs.
An adaptive metabolic demand model for protein and amino acid requirements
Authors: Millward D. J.
Published: August 2003

The shortcomings of the metabolic implications of the current protein requirements model are reviewed, and an alternative model, validated with [1-13C]leucine balance results in human adults, is presented and evaluated in the context of defining protein requirements. The model identifies metabolic demands for amino acids as comprising a small fixed component and a variable adaptive component that is relatively insensitive to acute food or protein intake, but which changes slowly with a sustained change in intake, enabling N equilibrium to be achieved. The model accounts for the apparent low efficiency of utilisation of animal proteins in N balance studies and enables more realistic efficiency values to be measured within an experimental framework that takes account of the adaptive metabolic demand. However, the complex relationship between the adaptive metabolic demand and habitual level and quality of protein intake prevents prediction of protein quality by amino acid scoring, which can markedly underestimate actual values. In contrast to the current model, for fully adapted individuals risk of deficiency (i.e. negative N balance after complete adaptation) will only start to increase when intakes fall below the range of the true minimum requirements, i.e. a value that is currently unknown, but likely to be between 0·40 and 0·50 g/kg per d at the lower end of the reported distribution of requirements. At intakes greater than this with additional metabolic demands varying directly with intake, deficiency is only likely as a short-term response to a change to a lower intake within the adaptive range. Thus, for adults satisfying energy needs on most mixed human diets, intakes will be within the adaptive range, and N equilibrium ceases to be a useful indicator of nutritional adequacy of protein. In the context of prescriptive dietary guidelines it may be expedient to retain current values until the benefits (and any risks) of protein intakes within the adaptive range can be quantified. However, from a diagnostic perspective, indicators other than N balance need to be identified, since maintenance of N balance can no longer be used as a surrogate of adequate protein-related health.
Modulation of liver fibrosis and pathophysiological changes in mice infected with Mesocestoides corti (M. vogae) after administration of glucan and liposomized glucan in combination with vitamin C
Authors: Ditteová G. , Velebný S. , Hrčkova G.
Published: August 2003

The effects of glucan and liposomized glucan, alone or co-administered with vitamin C, and empty liposomes on hepatic fibrosis in mice infected with Mesocestoides corti (M. vogae) tetrathyridia were studied. Preparations were administered every third day from day 7 to day 31 post-infection (p.i.), nine doses in total. Activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and cholesterol levels were measured in sera collected on days 11, 15, 21, 28, 32, 42, 50 and 65 p.i. Liver fibrosis was studied on the same days by measuring hydroxyproline concentration, which is considered a marker for collagen content. Larvicidal effects of the glucan and liposome preparations were estimated on day 65 p.i. in the liver and peritoneal cavity. Glucan formulations significantly enhanced collagen content, most prominently after administration of liposomized glucan in combination with vitamin C. Activities of both enzymes and cholesterol levels were slightly modified after administration of glucan alone. Liposomized glucan with vitamin C significantly increased ALT and AST activity and cholesterol levels up to days 28–32 p.i., after which they plateaued or declined. The most pronounced decrease was after administration of liposomized glucan and vitamin C. The same pattern of biochemical parameters in serum was observed after administration of empty liposomes, however, collagen content was not modified significantly. Larval counts in the liver and the peritoneal cavity were significantly reduced after treatment with either glucan formulation, but were unaffected following treatment with empty liposomes. In summary, intense fibrosis in the liver of mice treated with liposomized glucan and vitamin C did not result in the most extensive parenchymal cell injury but, rather in the highest efficacy of treatment. Liposomal lipids were probably utilized in the reparation of the damaged parenchymal cells, while glucan stimulated phagocytic cells.
Interactions between Schistosoma intercalatum (Zaire strain) and S. mansoni
Authors: Cosgrove C.L. , Southgate V.R.
Published: August 2003

Schistosoma mansoni and S. intercalatum, two schistosomes from different evolutionary lineages, are parasitic in humans and therefore able to co-infect the same host where they occur sympatrically in Africa. Previous studies of mating interactions between these species in mice, using the Lower Guinea strain of S. intercalatum, have demonstrated the competitive dominance of S. mansoni over S. intercalatum in terms of pairing ability, which is potentially an important mechanism restricting the distribution of S. intercalatum in Africa. The study presented here examines the mating interactions in mice between S. mansoni and the Zaire (Democratic Republic of Congo) strain of S. intercalatum, which differs from the Lower Guinea strain in many biological characteristics. Analysis of the data showed a preponderance of intraspecific pairs over interspecific, demonstrating a specific mate preference system for both species. Mating competition between these species and the ability of males of both species to effect a change of mate by pulling paired females away from their partners was indicated. Comparisons are made between the competitive mating abilities of both strains of S. intercalatum relative to those of S. mansoni, with the data suggesting that S. mansoni is competitively dominant to S. intercalatum (Zaire) in sequential infections but to a lesser extent than for S. intercalatum (Lower Guinea). Additional factors which may contribute to the confinement of S. intercalatum (Zaire) to the Democratic Republic of Congo are discussed.
Isoenzyme analysis of Schistosoma haematobium, S. intercalatum and their hybrids and occurrences of natural hybridization in Cameroon
Authors: Webster B.L. , Southgate V.R. , Tchuem Tchuenté L.-A.
Published: August 2003

Isoelectric focusing of glucose-6-phosphate dehydrogenase (G6PD) produced clearly identifiable profiles for S. haematobium and S. intercalatum and their hybrids. To provide a more detailed analysis of the interactions of S. haematobium and S. intercalatum in South West Cameroon over the last 12 years, G6PD analyses were carried out on individual schistosomes collected in Kumba in 1990, Loum in 1990, 1999 and 2000 and Barombi Mbo and Barombi Kotto in 1999. Studies were also carried out on the two parental species S. haematobium Barombi Mbo, S. intercalatum Edea and subsequent generations of hybrids resulting from laboratory crosses of the two parental species. The isoenzyme analysis demonstrated that the 1990 isolate from Kumba, was a recombinant of S. intercalatumxS. haematobium, and that 30% of individual schistosomes collected in 1990 in Loum were also recombinants. The remainder gave data indicative of S. haematobium. In 1999, 12.5% of individuals from Loum showed recombination and 10% in 2000. Results from the most recent parasitological survey in October 2000 showed the persistence of the recombinant population in addition to that of S. haematobium. There was also evidence of recombination having taken place in Barombi Kotto but not Barombi Mbo. This study demonstrates how the situation has changed over the last 12 years, and emphasizes the importance of assessing morphological, biological and molecular data together to gain a true picture of the rapidly evolving situation.
Embryogenesis and the first-stage larva of Thelazia lacrymalis
Authors: Dongus H. , Beelitz P. , Schöl H.
Published: August 2003

The female reproductive system of Thelazia lacrymalis (Nematoda: Thelaziidae) was investigated by light and scanning electron microscopy (SEM) with regard to the developmental stages and the stage deposited by the gravid nematode. Female T. lacrymalis have a didelphic and opisthodelphic type of reproductive system with paired ovaries, oviducts and uteri and a single vagina and vulva. Round and spindle-shaped primary oocytes are documented within the ovaries and oviducts, respectively. The distal part of each uterus provides a fertilization chamber filled with spermatozoa, followed by a sphincter-like part. Further anterior, the uteri broaden gradually containing dividing zygotes, small and large morulae, tadpole-stage embryos and horseshoe-shaped embryos which increase in length and become slimmer forming pretzel-stage embryos and larvae rolled up. The larvae stretch gradually and finally lie straight but still covered with their egg membrane in the vagina. The egg membrane encloses the whole larva and is enlarged at the pointed tail of the larva forming a bulb. At the SEM level, the first-stage larva is shown to have a terminal mouth and three hooks directed posteriorly and a striated cuticle. As morphologically identical larvae were also found in lavages of the conjunctival sac of horses infected with T. lacrymalis, this nematode species can be described as ovoviviparous.
Helminth parasites of the wild boar, Sus scrofa, in Luristan province, western Iran and their public health significance
Authors: Solaymani-Mohammadi S. , Mobedi I. , Rezaian M. , Massoud J. , Mohebali M. , Hooshyar H. , Ashrafi K. , Rokni M.B.
Published: August 2003

Seven helminth species were obtained from 12 wild boars (Sus scrofa) during a survey from 2000 to 2001 in Luristan province, western Iran. These species include the cestode larvae Cysticercus tenuicollis (25%), C. cellulosae (8.3%), the nematodes Metastrongylus apri (41.6%), M. pudendotectus (16.6%), M. salmi (8.3%), Trichuris suis (8.3%) and the acanthocephalan Macracanthorhynchus hirudinaceus (41.6%). No trematodes were found. Seven wild boars (58.3%) were identified as having at least one helminth species. A single infection was detected in 16.6% of cases, but a three species infection covered the highest rank (25%). All these helminths have been reported from other areas of Iran including the north, northeast and southwest, but not in Luristan. Among seven helminths identified, at least three species are transmissible to humans. The public health significance of these helminths is discussed.
Syphacia obvelata infections and reproduction of male domestic mice Mus musculus domesticus on a sub-Antarctic Island
Authors: Pisanu B. , Chapuis J.-L. , Périn R.
Published: August 2003

The reproductive activity of feral male mice on an island of the sub-Antarctic Kerguelen archipelago was influenced by biological factors depending on periods within the breeding season. After having controlled host reproductive activity indices for body size, i.e. age, and body condition effects, Syphacia obvelata prevalence did not vary with host reproductive status or age either during the beginning or the middle–end of the reproductive season. Considering the beginning of the breeding season, worm abundance was more pronounced in males the year following a strong winter crash of the population than in years when high over wintering survival occurred. During the middle–end of the breeding season, males with the highest reproductive status were more infected than males with a lower reproductive status in years when oldest individuals dominated the population. It is suggested that this situation was due to an endocrine related increased host susceptibility partly influenced by a change in the age structure of the population, and that an increase in worm transmission was not directly related to male activity concurrent with reproductive status, nor to population density.
The experimental production of Fasciola hepatica metacercariae from three aquatic populations of Galba truncatula
Authors: Vignoles P. , Favennec L. , Rondelaud D. , Dreyfuss G.
Published: August 2003

Laboratory investigations on three aquatic populations of Galba truncatula, originating from the Peruvian Altiplano and French Massif Central, were carried out during three successive snail generations to determine if these populations might be successfully used for the metacercarial production of Fasciola hepatica under experimental conditions. High numbers of surviving snails at day 30 post-exposure (>70%), high prevalences of F. hepatica infections (>60%), and prolonged productions of cercariae for a mean period of 35 to 47 days were observed in the three populations, whatever the snail generation. In the Peruvian population, metacercariae of F. hepatica significantly decreased in numbers from a mean of 251 in the parent snails to 124 per snail in the F2 generation, whereas no significant variation was observed in the two French populations. As these aquatic snails rarely emerged out of water, the use of these populations for the commercial production of F. hepatica metacercariae was of great interest, because the daily time spent watching the breeding boxes of snails was clearly shorter, thereby reducing the cost of producing metacercariae compared with using amphibious snails reared with romaine lettuce.
Effects of temperature on survival, infectivity and in vitro encystment of the cercariae of Echinostoma caproni
Authors: Fried B. , Ponder E.L.
Published: August 2003

The effects of temperature on survival, infectivity and in vitro encystment of Echinostoma caproni cercariae in artificial spring water (ASW) were studied. Effects of aging cercariae in ASW at various temperatures showed that at 23°C cercariae achieved 50% survival in 24 h, compared to 92 h at 12°C. Cercariae aged in ASW at 28 and 37.5°C showed 50% survival at 16 and 10 h, respectively. Cercariae aged at different temperatures for various times were used to infect juvenile Helisoma trivolvis (Colorado strain) snails maintained in ASW at 23°C. Index of infectivity was based on counting encysted metacercariae in the snails at 8 to 12 h post-infection. Cercariae aged at 23, 28 and 37.5°C showed 50% encystment at 6, 8 and 4 h, respectively. Cercariae aged at 4°C showed 50% encystment in 10 h and cercariae aged at 12°C showed 50% encystment beyond 16 h. Cercariae showed maximal longevity and infectivity in snails when aged at 12°C in ASW. For E. caproni, as in other digeneans, the infective period of cercariae is markedly shorter than the maximal life-span at any given temperature. Studies on in vitro encystment of E. caproni cercariae in Locke's solution:ASW (1:1) showed that encystment was optimal at 23°C (78% encystment) and that it declined to 44% at 28°C and became almost nil (0.02%) at 12 or 37.5°C.
Identities of two Paragonimus species from Sri Lanka inferred from molecular sequences
Authors: Iwagami M. , Rajapakse R.P.V.J. , Paranagama W. , Agatsuma T.
Published: August 2003

Metacercariae of Paragonimus spp. were obtained from field-collected freshwater crabs in Sri Lanka. Genomic DNA was extracted from single metacercariae. Two gene regions (partial mitochondrial cytochrome c oxidase subunit 1 (CO1) and the second internal transcribed spacer of the nuclear ribosomal gene repeat (ITS2)) were amplified using the polymerase chain reaction. Two differing sequences were obtained for each of these gene regions. Phylogenetic analyses placed the type 1 sequences as sister to a clade containing P. westermani and P. siamensis whereas the type 2 sequences were close to published sequences of P. siamensis from Thailand. The possible taxonomic status of these two types are discussed. This is the first report of molecular data about Paragonimus from Sri Lanka.
Host specificity and geographical distribution of Eubothrium in European salmonid fish
Authors: Scholz T. , Kuchta R. , Shinn A.P. , Šnábel V. , Hanzelová V.
Published: August 2003

The host specificity and distribution of Eubothrium crassum (Bloch, 1779) and Eubothrium salvelini (Schrank, 1790), morphologically fairly similar pseudophyllidean tapeworms parasitizing salmonid fish, were critically assessed on the basis of morphological and genetic evaluation of extensive material collected from different definitive hosts and geographical regions in Europe. Eubothrium crassum occurs in fish of the genera Salmo, i.e. salmon (S. salar – both freshwater and marine), sea trout (S. trutta trutta), brown trout (S. truttafario), and lake trout (S. truttalacustris), and also in Danubian salmon (Hucho hucho) and vendace (Coregonus albula). Eubothrium salvelini parasitizes Arctic char (Salvelinus alpinus) and brook trout (Salvelinus fontinalis) in Europe, and also whitefish (Coregonus wartmanni). Rainbow trout (Oncorhynchus mykiss), which is not a native European fish species, was found to be a suitable definitive host for both Eubothrium species, which may occur simultaneously in the same fish. Previous records of E. crassum in Arctic char and brook trout, and those of E. salvelini in fish of the genus Salmo were most probably misidentifications. Most studies of Eubothrium have involved salmonids from the northern part of Europe, with few records from southern and south-eastern Europe. This study also confirmed the reliability of the morphology of the apical disc for the discrimination of E. crassum and E. salvelini.
Local variation in helminth burdens of Egyptian spiny mice (Acomys cahirinus dimidiatus) from ecologically similar sites: relationships with hormone concentrations and social behaviour
Authors: Barnard C.J. , Sayed E. , Barnard L.E. , Behnke J.M. , Abdel Nabi I. , Sherif N. , Shutt A. , Zalat S.
Published: August 2003

Populations of Egyptian spiny mice (Acomys cahirinus dimidiatus) in a fragmented montane wadi system in the Sinai showed significant differences in the abundance of gut helminths. Differences in parasite load between populations were positively associated with measures of androgen activity but showed no significant relationship with glucocorticoid activity. Social discrimination tests with adult males from different wadis showed that those from sites with greater helminth abundance were less likely to investigate odours from other males and were less aggressive when subsequently interacting with the odour donors. Subjects showed markedly more investigation towards the odours of males from distant wadis compared with those from their own or immediately neighbouring wadi, but were less aggressive when confronted with odour donors from distant wadis. Despite this, there was a positive relationship between the amount of investigation towards distant male odour and subsequent aggression towards the male. While aggressiveness was positively associated with measures of androgen and glucocorticoid activity, no significant relationship emerged with individual helminth infection. Thus aggressiveness appeared to relate to overall local population levels of infection rather than individual challenge.
Local variation in helminth burdens of bank voles (Clethrionomys glareolus) from ecologically similar sites: temporal stability and relationships with hormone concentrations and social behaviour
Authors: Barnard C.J. , Kulis K. , Behnke J.M. , Bajer A. , Gromadzka-Ostrowska J. , Stachon M. , Sinski E.
Published: August 2003

Populations of bank voles (Clethrionomys glareolus) in a fragmented forest habitat in north-east Poland showed local differences in helminth infection intensity, morphometric measures and organ weights that were consistent with differences at the same locations two years previously. Although overall intensities of infection were lower than previously, and there were some differences in the relative intensities of individual helminth species, site differences remained significant and were consistent across replicated subsites. In keeping with site differences in helminth infection and adrenal gland weight and asymmetry, voles at site 1 (high intensity infection) had higher circulating concentrations of corticosterone than those at site 2 (low intensity infection). Since males were sampled outside the breeding season, and thus non-scrotal, testosterone levels were low and did not differ between sites. As previously, voles at site 1 also showed greater hind foot asymmetry. Dyadic interactions between males from the same and different sites in the laboratory showed that males from site 1 were significantly less aggressive, especially when confronted with intruder males from site 2. There was no relationship between aggressiveness and intensity of infection overall or at site 1, but a significant negative relationship emerged at site 2. Aggression thus appeared to be downregulated at the higher intensity site independently of individual levels of infection. Terminal corticosterone concentrations were greater at site 1 and lower among residents that initiated more aggression. While corticosterone concentrations rose over the period of testing, they did not correlate with the amount of aggression initiated or received.
Nitrogen oxides as environmental sensors for seeds
Authors: Giba Zlatko , Grubišić Dragoljub , Konjević Radomir
Published: August 2003

Nitrates have long been known to promote seed germination in many species, and various proposals have been made regarding the role of nitrates in this process. One hypothesis suggests a possible ecological role for nitrate, providing the seeds with a report of soil nitrogen status and the proximity of already established plants. However, nitrogen oxides (NO, NO2), which are present in the soil, also may be information carriers that indicate not only soil nitrate content, but also microbial activity and, therefore, soil quality. Because of annual variation of soil trace gas fluxes, seeds could be provided with information on seasonal and climate changes in their surroundings. Thus, nitrogen oxides would be the outer information carriers providing the seeds with integral data about many important factors required for successful germination and seedling establishment.
A quantitative analysis of seed responses to cycle-doses of fluctuating temperatures in relation to dormancy: Development of a thermal time model forPolygonum aviculareL. seeds
Authors: Batlla Diego , Verges Virginia , Luis Benech-Arnold Roberto
Published: August 2003

The sensitivity ofPolygonum aviculareL. seeds to the dormancy-breaking effect of cycle-doses of fluctuating temperature changes as seeds lose dormancy due to storage under stratification temperatures. Sensitivity changes during seed stratification were characterized by a decrease in the number of cycles required to saturate the germination response, and by a progressive loss of the requirement for temperature fluctuations for dormancy breakage in increasing fractions of the seed population. The rate of these changes was dependent on the temperature at which seeds were stored for stratification; lower storage temperatures produced higher rates of change than higher storage temperatures. Germination curves, obtained in response to the effect of fluctuating temperature cycle-doses for seeds stratified at variable temperatures and times of storage, were brought to a common stratification thermal time (Stt) scale by accumulating thermal time units under a threshold temperature for dormancy loss to occur. Results showed that those seeds that had accumulated similarSttunits during stratification under different storage temperatures presented a similar germination response. Therefore, response-curve functions were adjusted to germination data of exhumed seeds that had accumulated similarStt, obtaining a family of germination response curves in relation toSttaccumulation during storage. Based on these results, a simulation model was constructed relating dynamic changes in the parameters that determine germination response curves in relation toSttaccumulation. The model was tested against independent data, showing a good description of the dynamics of changes in the fraction of the seed population requiring temperature fluctuation for dormancy breakage as dormancy release progressed.
Cloning and characterization of aCOBRA-like gene expressedde novoduring maize germination
Authors: Cruz-García Felipe , Gómez Alberto , Zúñiga José Juan , Plasencia Javier , Vázquez-Ramos Jorge M.
Published: August 2003

The search for germination-specific genes has been a laborious and unrewarding task, since many of the genes expressed during germination are also expressed in embryogenesis or in other developmental stages. By using mRNA differential display of transcript populations from maize (Zea maysL.) embryo axes, germinated for different times with or without a previous osmopriming treatment, a 682 bp cDNA was isolated that was present only after 24 h germination, and absent during osmopriming or during early germination. Screening of a cDNA library using the 682 bp probe yielded a 1554 bp cDNA that contained an open reading frame coding for 436 amino acids. This gene, referred to asZmAA9-24, was expressed in root tissues, but was not detected in shoot or leaf tissues. Expression ofZmAA9-24occurred earlier during germination (by 15 h) if embryo axes were imbibed in the presence of cytokinins or if seeds were previously osmoprimed. The predicted protein sequence ofZmAA9-24is 39.6% identical to the product of the recently identifiedArabidopsisgeneCOBRA(54.5% in the central region), which appears to participate in the regulation of cell expansion, particularly in roots, and belongs to the glycosylphosphatidylinositol (GPI)-anchored protein family.ZmAA9-24expression might be regulated by both cell expansion and the cell cycle, processes that have a central role during seed germination.
Endo-β-mannanase activity is associated with the completion of embryogenesis in imbibed carrot (Daucus carota L.) seeds
Authors: Homrichhausen Tanja M. , Hewitt Jessica R. , Nonogaki Hiroyuki
Published: August 2003

Development of the rudimentary embryo in mature carrot (Daucus carota) seed during imbibition was characterized. The small embryo in the carrot seed, located in the micropylar region, elongated into the lateral part during imbibition and attained about two-thirds the length of the seed before radicle protrusion. Developing embryos excised from imbibed seeds were only capable of germinating in both water and Murashige–Skoog (MS) medium when they reached maximum size. The corrosion cavity into which the embryo grew enlarged concomitantly with endosperm degradation. The expression of endo-β-mannanase (EC 3.2.1.78), which is assumed to be involved in endosperm degradation, was characterized. A cDNA encoding an endo-β-mannanase was obtained by reverse transcription polymerase chain reaction (RT-PCR) using total RNA extracted from 24-h-imbibed carrot seeds. The full-length cDNA (DcMAN1) exhibited 64% deduced amino acid sequence identity with tomato (Lycopersicon esculentum) seed germination-associated mannanase (LeMAN2). DcMAN1 mRNA and endo-β-mannanase activity were first detected in the micropylar-half seed and then in the lateral-half seed. The timing of the appearance of DcMAN1 mRNA and endo-β-mannanase activity in the lateral-half seed corresponded with that of embryo development into this region. These results suggest that the expression of DcMAN1 and endo-β-mannanase activity in imbibed carrot seeds is associated with the enlargement of the corrosion cavity, which accompanies embryogenesis.
The heat-shock response of developing barley aleurone layers
Authors: Harju Melissa A. , deSouza Sunita , Brodl Mark R.
Published: August 2003

Aleurone layers of mature germinating barley (Hordeum vulgare, cv. Himalaya) grains respond to heat shock by synthesizing heat-shock proteins (HSPs) and by selectively suppressing the synthesis of proteins normally translated by endoplasmic reticulum (ER)-bound ribosomes. To determine if this also was the case during seed development, we investigated the synthesis of proteins translated by ER-bound ribosomes in heat-shocked aleurone layers isolated from developing barley grains. The optimal induction temperature for the heat shock response in developing aleurone layers was 37.5°C, and temperatures above 42°C inhibited translation. HSPs with apparent molecular masses of 71.1, 66.2, 57.8, 19.1 and 18.8 kDa were induced. Other studies have shown that, in gibberellic acid (GA)-induced aleurone layers from mature barley grains, these temperatures were 40°C and 45°C, respectively. Furthermore, in developing aleurone layers, mRNAs encoding proteins translated by ER-bound ribosomes (mRNAs for a lipid transfer protein and a putative amylase/protease inhibitor) remained stable during heat shock. The ER membranes themselves remained in stacks, but the lumen became distended with electron-dense material. Heat shock prevented the movement of proteins from the ER into the rest of the endomembrane pathway. In contrast, other studies show that in mature, GA-induced aleurone layers, heat shock dissociates ER stacks and blocks translation, but the processing of secretory proteins in the endomembrane pathway is not inhibited. The observation that the same tissue at different developmental stages may respond differently to heat shock indicates that components of the heat-shock response are developmentally regulated. This system provides an opportunity to better understand the nuances of the heat-shock response, especially the post-transcriptional gene regulatory mechanisms that occur.