bluuebunny/crossref_metadata_2025_split huggingface dataset:
The pea aphid complex as a model of ecological speciation
Authors: JEAN PECCOUD , JEAN‐CHRISTOPHE SIMON 
Published: January 2010

1. Host‐specialised races of plant‐feeding insects are particularly informative models in the study of ecological speciation, that is, the evolution of reproductive isolation through divergent natural selection. However, within the enormous diversity of phytophagous insects, the mechanisms of ecological divergence have been elucidated in few host race systems.2. Here we review the literature covering speciation through host‐plant specialisation in a well‐studied model, the pea aphid complex,Acyrthosiphon pisum, which encompasses numerous biotypes that parasitise different legume host species worldwide.3. Published results are consistent with ecologically promoted reproductive isolation. Divergent host‐induced selection is pronounced across biotypes, and reflects genetic trade‐offs preventing the optimal use of multiple host plants. While these genetic trade‐offs may partly explain the unfitness of hybrids between biotypes, hybridisation occurring on plants is also limited by genetically‐based host preference, and by selection against migrants that chose unfavourable hosts. The continuum of genetic divergence displayed by 11 races and species of the pea aphid complex suggests that host races constitute an intermediate step in the speciation process, and that host specialisation may indeed lead to complete speciation. Uncertainties remain on the contribution of non‐ecological reproductive barriers to biotype divergence and on the physiological and molecular bases of host specialisation.
Speciation in fig wasps
Authors: COOK JAMES M. , SEGAR SIMON T. 
Published: January 2010

1. There are over 700 species of fig trees in the tropics and several thousand species of fig wasps are associated with their syconia (inflorescences). These wasps comprise a monophyletic family of fig pollinators and several diverse lineages of non‐pollinating wasps. The pollinator larvae gall fig flowers, while larvae of non‐pollinating species either initiate their own galls or parasitise the galls of other wasps.2. A single fig species has one to four pollinator species and also hosts up to 30 non‐pollinating wasp species. Most wasps show a high degree of host‐plant specificity and are known from only a single fig species. However, in some cases wasps may be shared across closely related fig species.3. There is impressive morphological co‐evolution between figs and fig wasps and this, combined with a high degree of partner specificity, led to the expectation that figs and pollinators have cospeciated extensively. Comparison of deep phylogenies supports long‐term codivergence of figs and pollinators, but also suggests that some host shifts have occurred.4. Phylogenies of more closely related species do not match perfectly and may even be incongruent, suggesting significant roles for processes other than strict cospeciation. Combined with recent evidence on host specificity patterns, this suggests that pollinator wasps may often speciate by host shifts between closely related figs, or by duplication (the wasp speciates but the fig doesn't). The frequencies and biological details of these different modes of speciation invite further study.5. Far less is known about speciation in non‐pollinating fig wasps. Some lineages have probably co‐evolved with figs and pollinators for most of the evolutionary history of the symbiosis, while others appear to be more recent colonisers. Many species appear to be highly host‐plant specific, but those that lay eggs through the fig wall without entering the syconium (the majority of species) may be subject to fewer constraints on host shifting than pollinators. There is evidence for substantial host shifting in at least one genus, but also evidence for ecological speciation on the same host plant by niche shifts in other cases.6. Finally, recent work has begun to address the issue of ‘community phylogeny’ and provided evidence for long‐term co‐divergence of multiple pollinating and non‐pollinating wasp lineages with their host figs.
Evolutionary aspects of ecological generalism with special reference to conservation biological control
Authors: EMELIANOV IGOR 
Published: January 2010

1. If ecological generalism is an evolving heritable trait, we need to study the underlying genetics in order to understand the nature of this fundamental phenomenon.2. I consider two alternatives. Under the Type I mechanism, ecological generalism is exclusively a population property. Under the Type II mechanism, generalism can vary among genotypes as well as among populations.3. The genetics underlying the Type I mechanism is straightforward, whereas Type II genetics is less so. I propose that a broad adaptive range of generalist genotypes can be a result of a pleiotropic modifier that, when expressed, renders fitness of the carrier relatively insensitive to environmental variance.4. A review of the theory and the data indicates that stable ecological generalism is more likely to occur under the Type II compared to the Type I mechanism. Type II generalism appears to be relatively more common and more compatible with patterns observed in the wild.5. Generalism of natural enemies is a key factor influencing the effectiveness of conservation biological control (CBC). I argue that natural enemies with Type II generalism are relatively more suitable for CBC applications, and spell out directions for further research.
The effects of an in utero exposure to 2,3,7,8‐tetrachloro‐dibenzo‐p‐dioxin on male reproductive function: identification of Ccl5 as a potential marker
Authors: Rebourcet D. , Odet F. , Vérot A. , Combe E. , Meugnier E. , Pesenti S. , Leduque P. , Déchaud H. , Magre S. , Le Magueresse‐Battistoni B. 
Published: January 2010

Summary2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) and dioxin‐like compounds are widely encountered toxic substances suspected of interfering with the endocrine systems of humans and wildlife, and of contributing to the loss of fertility. In this study, we determined the changes in testicular gene expression caused by in utero exposure to TCDD along with the intra‐testicular testosterone levels, epididymal sperm reserves, daily sperm production (DSP) and testis histology. To this purpose, female pregnant Sprague–Dawley rats orally received TCDD (10, 100 or 200 ng/kg body weight) or vehicle at embryonic day 15, and the offspring was killed throughout development. Hepatic Cyp1a1 gene expression was measured in the offspring to confirm the exposure to TCDD. The gross histology of the testes and intra‐testicular testosterone levels were normal among the studied groups. Sperm reserves were altered in 67‐day‐old rats of the TCDD‐200 group, but not in 145‐day‐old animals or in the other TCDD‐exposed groups. Nonetheless, fertility was not altered in males of the TCDD‐200 group, and the F2 males generated had normal sperm reserves and DSP. Microarray analysis permitted the identification of eight differentially expressed genes in the 4‐week‐old testes of the TCDD‐200 compared with that of the control group (cut‐off value ± 1.40), including the down‐regulated chemokine Ccl5/Rantes. Inhibition of Ccl5/Rantes gene expression was observed throughout development in the TCDD‐200 group, and at 67 and 145 days in the TCDD‐100 group (animals of younger ages were not examined). Ccl5/Rantes gene expression was mostly confined in Leydig cells. F2 males generated from males of the TCDD‐200 group had normal levels of Ccl5/Rantes in testis and Cyp1a1 in liver, which might indicate that Ccl5/Rantes is a marker of TCDD exposure in testis such as Cyp1a1 in liver. In conclusion, we demonstrated a decrease in Ccl5/Rantes RNA levels and a transitory decline in sperm reserves in the testes of rats of TCDD‐dosed dams.
Phthalate exposure and asthma in children
Authors: Bornehag C. G. , Nanberg E. 
Published: January 2010

SummaryDuring the last decades more than 100 000 new chemicals have been introduced to the environment. Many of these new chemicals and many common consumer products that include these have been shown to be toxic in animal studies and an increasing body of evidence suggests that they are also impacting human health. Among the suspect chemicals, the endocrine disrupting chemicals (EDCs) are of particular concern. One such chemical group is the phthalates, used in soft poly vinyl chloride (PVC) material and in a huge number of consumer products. During the same period of time that the prevalence of these modern chemicals has increased, there has been a remarkable increase in several chronic illnesses, including asthma and allergy in children. In this article we outline the scientific knowledge on phthalate exposure for asthma and airway diseases in children by examining epidemiological and experimental peer review data for potential explanatory mechanisms. Epidemiological data point to a possible correlation between phthalate exposure and asthma and airway diseases in children. Experimental studies present support for an adjuvant effect on basic mechanisms in allergic sensitization by several phthalates. Despite variations in the experimental design and reported result in the individual studies, a majority of published reports have identified adjuvant effects on Th2 differentiation, production of Th2 cytokines and enhanced levels of Th2 promoted immunoglobulins (mainly IgG1 but also IgE) in mice. A limited amount of data do also suggest phthalate‐induced enhancement of mast cell degranulation and eosinophilic infiltration which are important parts in the early inflammation phase. Thus, some of the early key mechanisms in the pathology of allergic asthma could possibly be targeted by phthalate exposure. But the important questions of clinical relevance of real life exposure and identification of molecular targets that can explain interactions largely remain to be answered.
Prospective association of low serum total testosterone levels with health care utilization and costs in a population‐based cohort of men
Authors: Haring R. , Baumeister S. E. , Völzke H. , Kohlmann T. , Marschall P. , Flessa S. , Nauck M. , Wallaschofski H. 
Published: January 2010

SummaryDespite the burgeoning interest in the field of andrology, no studies have specifically addressed the impact of serum testosterone levels on healthcare utilization and costs. We analysed data from the population‐based cohort Study of Health in Pomerania (SHIP), Germany, to assess the association of serum testosterone levels with self‐reported health care utilization and costs at baseline and at 5 years follow up. Study sample comprised 2023 men at baseline, of whom 1530 men were repeatedly examined. Low and high serum testosterone levels, defined according to the age‐specific 10th and 90th percentile, were compared with reference subjects with serum testosterone levels ≥10th −≤90th percentile. Two‐part econometric models were applied adjusting for socio‐economic and medical confounders.Cross‐sectional models revealed higher numbers of outpatient visits and higher costs for both, men with low (+19.1 and +19.9%, respectively) and high serum testosterone levels (+25.3 and +30.2%, respectively), whereas number of inpatient days and costs were not associated with serum testosterone levels. Adjustment for age, educational level, income, waist circumference, smoking status, physical activity and alcohol consumption did not considerably alter the results. Longitudinal models revealed a significant association of low serum testosterone levels with increased number of follow‐up outpatient visits (age‐adjusted: +28.6%) and costs (+38.0%) only. Low and high serum testosterone levels were associated with increased short‐term outpatient health care costs, whereas low serum testosterone levels appear to be predictive of long‐term outpatient health care costs. Cost‐effectiveness studies of available treatments are necessary to identify benefits for physicians, patients and health care system as a whole.
Temporal and anatomical sensitivities to the aryl hydrocarbon receptor agonist 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin leading to premature acyclicity with age in rats
Authors: Jablonska O. , Shi Z. , Valdez K. E. , Ting A. Y. , Petroff B. K. 
Published: January 2010

SummaryThe aryl hydrocarbon receptor (AhR) is a ligand‐activated transcription factor that mediates diverse dioxin toxicities. While the acute effects of activation of the AhR pathway by 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) have been a focus of past study, the role of this pathway in normal physiology and ageing is unclear. The purpose of this study was to identify the portion of the reproductive axis [ovary vs. hypothalamus and pituitary gland (H‐H axis)] and the stages of the reproductive lifespan (foetal and early post‐natal life vs. adolescence and adulthood) that are particularly sensitive to the effects of TCDD during female reproductive ageing. Adult pregnant Lewis rat dams were dosed with corn oil vehicle or TCDD (50 ng/kg‐week by gavage) on days 14 and 21 of gestation and post‐natal days 7 and 14 to provide in utero and lactational (IUL) exposure to pups. Female pups (n = 96) were weaned on post‐natal day 21 and dosed with TCDD or vehicle weekly. Half of the pups were used as donors for ovary transplantation while the remainder were recipients. Following ovary transplantation, rats (n = 6–8 per group) received weekly TCDD or vehicle again until sacrifice at 8 months of age. Beginning at vaginal opening, reproductive cycles were monitored by vaginal cytology for 10 days each month. Blood samples were collected at 22.00 h on proestrus to measure concentration of 17β‐oestradiol in serum. Real‐time PCR was used to determine differences in Cyp1a1, Cyp19a1, Cyp17a1, LH receptor (LHR), FoxA2 and FoxJ1 genes expression between control and remaining groups. IUL exposure of the H‐H axis plus adult exposure of the whole body to TCDD significantly delayed puberty in females rats. Data analysis revealed an accelerated onset of acyclicity by 5 months in all groups involving IUL exposure of the developing ovary to TCDD. 17β‐oestradiol was significantly decreased in animals receiving TCDD during IUL exposure of the H–H axis. CYP1a1 expression was markedly greater in the liver than in ovarian tissue and correlated with ongoing TCDD exposure. Aromatase, 17α‐hydroxylase and LHR gene expressions were largely unchanged (or occasionally elevated) by TCDD. FoxA2 and FoxJ1 mRNAs were similarly of limited value mechanistically, although FoxJ1 was much higher in TTT females (receiving TCDD as donor, recipient and adult). This study reveals a particular sensitivity of the developing ovary to TCDD leading to early loss of reproductive function with age.
Catalase can protect spermatozoa of FSH receptor knock‐out mice against oxidant‐induced DNA damage in vitro
Authors: Libman J. , Gabriel M. S. , Sairam M. R. , Zini A. 
Published: January 2010

SummaryThe aetiology of sperm DNA damage is likely multi‐factorial with abnormal compaction of nuclear DNA, abortive apoptosis and oxidative stress implicated as potential causes of DNA damage. The objective of this study was to evaluate DNA damage in spermatozoa from wild‐type (WT) and FSH receptor knock‐out (FORKO) mice, compare the relative susceptibility of spermatozoa from these animals to oxidative DNA damage, and examine the protective effect of the antioxidant catalase on sperm DNA damage. Epididymal spermatozoa from FORKO mice (n = 5) and WT controls (n = 5) were extracted and incubated with or without catalase. Sperm DNA damage was assessed immediately after epididymal extraction (time 0 control) and following 2‐h incubation at 37 °C. DNA damage was measured by the sperm chromatin structure assay and the results expressed as the %DNA fragmentation index or %DFI. Freshly retrieved epididymal spermatozoa from WT mice had a significantly lower mean (±SD) %DFI than that of FORKO mice (2.7 ± 1.8 vs. 6.4 ± 2.9%, p < 0.05). Prolonged (2‐h) incubation of FORKO mice spermatozoa resulted in a significant increase in %DFI compared with the time 0 control (17.9 ± 9.2% vs. 6.4 ± 2.9%, respectively, p < 0.05) and the addition of catalase protected these spermatozoa from DNA damage (9.8 ± 4.1 vs. 17.9 ± 9.2%, respectively, p < 0.05). However, incubation of WT mice spermatozoa did not increase %DFI significantly (5.8 ± 5.0 vs. 2.7 ± 1.8, respectively, p > 0.05) and the addition of catalase (vs. no catalase) did not result in a significant reduction in %DFI (5.8 ± 5.0 vs. 7.7 ± 6.5%, respectively, p > 0.05). These data indicate that catalase may protect sperm nuclear DNA from oxidative stress in vitro. The data also demonstrate the differential susceptibility of WT and FORKO mice spermatozoa to oxidative stress.
Relationships between growth and disease resistance in rainbow trout, Oncorhynchus mykiss (Walbaum)
Authors: Overturf K , LaPatra S , Towner R , Campbell N , Narum S 
Published: January 2010

AbstractRainbow trout from 23 families were evaluated for growth and resistance to the bacterial coldwater disease (BCWD) caused by Flavobacterium psychrophilum and infectious haematopoietic necrosis (IHN) caused by IHN virus. Average family weights were between 161 and 263 g with an average of 225 g at 213 days post‐fertilization with specific growth rates ranging from 2.37 to 2.88. Per cent survival of fish challenged with F. psychrophilum was between 18% and 100%, while for those challenged with IHNV, the range was between 12% and 93%. Significant positive correlations were found for end body weight and resistance to IHN (P < 0.05) and for early body weight and resistance to BCWD (P < 0.1). However, no significant correlations were detected between resistance to both pathogens or disease resistance and overall genetic diversity or diversity within the major histocompatibility locus.
Regulation of morphological differentiation in S. coelicolor by RNase III (AbsB) cleavage of mRNA encoding the AdpA transcription factor
Authors: Xu Weijing , Huang Jianqiang , Lin Richard , Shi Jing , Cohen Stanley N. 
Published: January 2010

SummaryRNase III family enzymes, which are perhaps the most widely conserved of all ribonucleases, are known primarily for their role in the processing and maturation of small RNAs. The RNase III gene of Streptomyces coelicolor, which was discovered initially as a global regulator of antibiotic production in this developmentally complex bacterial species and named absB (antibiotic biosynthesis gene B), has subsequently also been found to modulate the cellular abundance of multiple messenger RNAs implicated in morphological differentiation. We report here that regulation of differentiation‐related mRNAs by the S. coelicolor AbsB/RNase III enzyme occurs largely by ribonucleolytic cleavage of transcripts encoding the pleiotropic transcription factor, AdpA, and that AdpA and AbsB participate in a novel feedback‐control loop that reciprocally regulates the cellular levels of both proteins. Our results reveal a previously unsuspected mechanism for global ribonuclease‐mediated control of gene expression in streptomycetes.
Arsenic Stress in Plants
Authors: Panda S. K. , Upadhyay R. K. , Nath S. 
Published: January 2010

AbstractBeing a toxic metalloid and group I carcinogen, Arsenic (As) poses a threat to plants, especially to crops which are consumed by human beings, and sooner or later results in hyper/hypopigmentation and skin cancer. It is a well‐known fact that South‐East Asia is suffering from groundwater As contamination, and according to a recent report, the contamination has been found also in Hungary, Mexico, Argentina, Australia, United States, etc. Thus, As contamination has become a global problem. As is toxic even at low concentration because it has no known function as nutrients. Arsenite (III) and arsenate (V) are the main phytoavailable forms of inorganic arsenic. Being analogous to phosphate, As(V) is transported by a phosphate‐cotransport system in plants, whereas As(III) is transported through ‘OsNIP2.1’ (member of aquaporin superfamily) in rice. Besides, ‘AsSe1’ (As‐accumulation gene), ‘AsTol’ (As‐tolerance gene) and ‘OsACR2.1’ (an arsenate reductase gene) have also been identified. The production of phytochelatins (PCs), a metal‐binding thiol peptide, in response to As stress may hold a way of proper As tolerance in plants but still needs a thorough study. However, with the proper knowledge of arsenic speciation, transportation, accumulation, overexpression in crop plants may result in ways to develop arsenic tolerant transgenics.
Clinical relevance of single administration of prophylactic antimicrobial agents against febrile events after removal of ureteral stents for patients with urinary diversion or reconstruction
Authors: Hashimoto Jiro , Takahashi Satoshi , Kurimura Yuichiro , Takeyama Koh , Kunishima Yasuharu , Tsukamoto Taiji 
Published: January 2010

Objective:  To assess the efficacy of antimicrobial prophylaxis when removing ureteral stents after urinary diversion or reconstruction and to establish the most appropriate prophylactic protocol to prevent febrile events.Methods:  We retrospectively investigated the incidence of febrile events in the two studies. Study 1 consisted of 39 patients who received antimicrobial prophylaxis and 31 who did not. Study 2 included 48 patients who were given oral fluoroquinolone (FQ) and 27 who had intramuscular injection of an aminoglycoside (AG).Results:  In study 1, the incidence of febrile events was significantly lower in patients receiving antimicrobial prophylaxis (26.0%) than in those not receiving it (51.6%) (P = 0.025, χ2 test). In study 2 there was a 13% incidence of febrile events, which was much lower than the incidence found in study 1. The incidence of these events was similar between the two study groups, being 13% for those receiving FQ and 15% for those receiving AG.Conclusions:  Prophylactic administration of antimicrobials reduces the incidence of febrile events after removal of ureteral stents. Both FQ and the AG are equally effective in this setting.
Advances in the management of inflammatory bowel disease
Authors: Grimpen F. , Pavli P. 
Published: January 2010

AbstractOur understanding of inflammatory bowel diseases (IBD) is constantly evolving, and many new treatment options have emerged recently. This review critically examines the evidence for these new developments and aims to provide an overview for medical professionals involved in the care of patients with IBD. Proposed changes in the use of aminosalicylates, immunosuppressants and biological agents are described, and the evidence for several promising novel agents is reviewed.