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71.
Caryedon serratus is found in different agro-ecological and agro-climatic zones, and its damage to groundnuts can vary up to an 80% quantitative loss of yield. This study seeks to demonstrate the effects of different agro-ecological refer to so as to very quickly process the content zones and the presence or absence of groundnut cultivation on the structure and genetic distribution of C. serratus in West Africa. Portions of the cytochrome b and 28S ribosomal genes of C. serratus were sequenced, using samples from four countries that represent different agro-ecological and agro-climatic sub-regions of West Africa. The results showed 37 haplotypes for the cytochrome b and 7 haplotypes for the 28S ribosomal gene. Although genetic diversity was different between agro-ecological zones tests show no significant differences in structuring according to agro-ecological zone. These tests, as well as the phylogenetic relationships that our results imply, indicate that there is a genetic differentiation between individuals from groundnut culturing areas compared to those from areas where the cultivation of groundnuts is absent or low.  相似文献   
72.

Background  

Enterococci rank among the leading causes of nosocomial infections. The failure to identify pathogen-specific genes in Enterococcus faecalis has led to a hypothesis where the virulence of different strains may be linked to strain-specific genes, and where the combined endeavor of the different gene-sets result in the ability to cause infection. Population structure studies by multilocus sequence typing have defined distinct clonal complexes (CC) of E. faecalis enriched in hospitalized patients (CC2, CC9, CC28 and CC40).  相似文献   
73.

Introduction

Chronic inflammation is a profound systemic modification of the cellular microenvironment which could affect survival, repair and maintenance of muscle stem cells. The aim of this study was to define the role of chronic inflammation on the regenerative potential of satellite cells in human muscle.

Methods

As a model for chronic inflammation, 11 patients suffering from rheumatoid arthritis (RA) were included together with 16 patients with osteoarthritis (OA) as controls. The mean age of both groups was 64 years, with more females in the RA group compared to the OA group. During elective knee replacement surgery, a muscle biopsy was taken from the distal musculus vastus medialis. Cell populations from four RA and eight OA patients were used for extensive phenotyping because these cell populations showed no spontaneous differentiation and myogenic purity greater than 75% after explantation.

Results

After mononuclear cell explantation, myogenic purity, viability, proliferation index, number of colonies, myogenic colonies, growth speed, maximum number of population doublings and fusion index were not different between RA and OA patients. Furthermore, the expression of proteins involved in replicative and stress-induced premature senescence and apoptosis, including p16, p21, p53, hTERT and cleaved caspase-3, was not different between RA and OA patients. Mean telomere length was shorter in the RA group compared to the OA group.

Conclusions

In the present study we found evidence that chronic inflammation in RA does not affect the in vitro regenerative potential of human satellite cells. Identification of mechanisms influencing muscle regeneration by modulation of its microenvironment may, therefore, be more appropriate.  相似文献   
74.
Vascular endothelial growth factor A (VEGFA) is among the most-significant stimulators of angiogenesis. Its effect on cardiovascular diseases and on the variation of related risk factors such as lipid parameters is considered important, although as yet unclear. Recently, we identified four common variants (rs6921438, rs4416670, rs6993770, and rs10738760) that explain up to 50% of the heritability of plasma VEGFA levels. In the present study, we aimed at assessing the contribution of these variants to the variation of blood lipid levels (including apoE, triglycerides, total cholesterol, low- and high-density lipoprotein cholesterol levels (LDL-C and HDL-C)] in healthy subjects. The effect of these single-nucleotide polymorphisms (SNPs) on lipid levels was assessed using linear regression in discovery and replication samples (n = 1,006 and n = 1,145; respectively), followed by a meta-analysis. Their gene×gene and gene×environment interactions were also assessed. SNP rs6921438 was associated with HDL-C (β = −0.08 mmol/l, Poverall = 1.2 × 10−7) and LDL-C (β = 0.13 mmol/l, Poverall = 1.5 × 10−4). We also identified a significant association between the interaction rs4416670×hypertension and apoE variation (Poverall = 1.7 × 10−5). Therefore, our present study shows a common genetic regulation between VEGFA and cholesterol homeostasis molecules. The SNP rs6921438 is in linkage disequilibrium with variants located in an enhancer- and promoter-associated histone mark region and could have a regulatory effect in the expression of surrounding genes, including VEGFA.  相似文献   
75.

Introduction

There are growing concerns about the emergence of resistance to artemisinin-based combination therapies (ACTs). Since the widespread adoption of ACTs, there has been a decrease in the systematic surveillance of antimalarial drug resistance in many malaria-endemic countries. The aim of this work was to test whether data on travellers returning from Africa with malaria could serve as an additional surveillance system of local information sources for the emergence of drug resistance in endemic-countries.

Methodology

Data were collected from travellers with symptomatic Plasmodium falciparum malaria returning from Senegal (n = 1,993), Mali (n = 2,372), Cote d’Ivoire (n = 4,778) or Cameroon (n = 3,272) and recorded in the French Malaria Reference Centre during the period 1996–2011. Temporal trends of the proportion of parasite isolates that carried the mutant genotype, pfcrt 76T, a marker of resistance to chloroquine (CQ) and pfdhfr 108N, a marker of resistance to pyrimethamine, were compared for travellers and within-country surveys that were identified through a literature review in PubMed. The in vitro response to CQ was also compared between these two groups for parasites from Senegal.

Results

The trends in the proportion of parasites that carried pfcrt 76T, and pfdhfr 108N, were compared for parasites from travellers and patients within-country using the slopes of the curves over time; no significant differences in the trends were found for any of the 4 countries. These results were supported by in vitro analysis of parasites from the field in Senegal and travellers returning to France, where the trends were also not significantly different.

Conclusion

The results have not shown different trends in resistance between parasites derived from travellers or from parasites within-country. This work highlights the value of an international database of drug responses in travellers as an additional tool to assess the emergence of drug resistance in endemic areas where information is limited.  相似文献   
76.
The influence of salinity on life-history traits was tested using two adjoining West African estuaries: the Gambia with a 'normal' salinity gradient (salinity always <40 and decreasing from the mouth upstream) and the Sine Saloum (Senegal) with an inverse gradient (from 35 at the estuary mouth up to >130 in the upper reaches). The breeding seasons and subsequent fork length ( L F) at first maturity ( L F50) were estimated for different fish species reproducing both in the Sine Saloum and in the Gambia River estuaries using a database built from experimental fish samplings between 1990 and 2003 with a purse seine (30 locations in the Sine Saloum and 44 in the Gambia). The database contained 30 553 individuals belonging to 60 different species among which only 20 species reproduced in both estuaries. The breeding seasons peaked just before, or at the beginning of the rainy season (June to July), and there were almost no sexually mature fishes at the beginning of the dry season (November to December). Patterns of differences between L F50 of the two estuaries did not follow a general trend (positive or negative), but varied in the same way for females and males of a given species. The L F50 was only systematically reduced with increasing salinity in species living in high-salinity waters (>70). For species living below 70, differences in sizes at first maturity between the two estuaries did not show any clear relationship with salinity. The smallest mature individual found in an environment was a good indicator of the size at first maturity reached in a particular ecosystem because the trend of the species differences between the two ecosystems generally followed that of the differences in size at maturity.  相似文献   
77.
This study presents the ultrastructure of the mature spermatozoon of Opechona bacillaris, a digenean belonging to the family Lepocreadiidae. The sperm cell of O. bacillaris exhibits the general pattern described in most of the Lepocreadioidea: two axonemes of the 9 + ‘1’ pattern of the Trepaxonemata, mitochondria, a cortical mitochondrion, a nucleus, electron‐dense material in the anterior extremity of the spermatozoon, external ornamentation of the plasma membrane with associated spinelike bodies, and granules of glycogen. However, particularities of O. bacillaris are the simultaneous presence in the anterior extremity of the spermatozoon of the electron‐dense material, a mitochondrion, and the absence of cortical microtubules. In the Lepocreadiidae, we describe for the first time in O. bacillaris spinelike bodies associated with the external ornamentation of the plasma membrane and two mitochondria. The first mitochondrion is moniliform and composed of a mitochondrial cord with joined mitochondrial bulges. The second mitochondrion shows a regular form. The posterior tip of the spermatozoon has only singlets to owing to the disorganization of the second axoneme and granules of glycogen as occurs in Hypocreadium caputvadum, the other studied species of the family Lepocreadiidae.  相似文献   
78.
Aphids (Homoptera: Aphididae) are sap-sucking insect pests that feed on several plants of agronomical importance. Entomopathogenic fungi are valuable tools for potential aphid control. As part of a selection process, laboratory bioassays were carried with five different concentrations of Aspergillus clavatus (Desmazières), Aspergillus flavus (Link) and Metarhizium anisopliae ((Metschnikoff) Sorokin) spores against the pea aphid, Acyrthosiphon pisum (Harris). Aspergillus isolates induced higher mortalities than M. anisopliae, which is a well-known entomopathogen in the literature. Lethal concentrations (LC50 and LC90) were 1.23 × 103 and 1.34 × 107 spores/ml for A. flavus, 4.95 × 102 and 5.65 × 107 spores/ml for A. clavatus, and 3.67 × 103 and 9.71 × 107 spores/ml for M. anisopliae 5 days after treatment. Mycelia development and sporulation on adult cadavers were observed 48 h after incubation. The intrinsic growth rate of A. pisum decreased with increased spore concentration for all fungal strains, suggesting an increase in pathogen fitness related to a consumption of host resources. In conclusion, Aspergillus species could be useful in aphid control as pest control agents despite their saprophytic lifestyle. This is also to our knowledge the first report of A. clavatus and A. flavus strains pathogenic to aphids.  相似文献   
79.

Introduction

Depression is frequent in ankylosing spondylitis (AS) patients. However, epidemiological data about the potential increase in risk are lacking. This study compares the rate of doctor-diagnosed depression in a well defined cohort of AS patients to the general population seeking care.

Methods

The Skåne Healthcare Register comprises healthcare data of each resident in Region Skåne, Sweden (population 1.2 million), including ICD-10 diagnoses. Using physician coded consultation data from years 1999 to 2011, we calculated depression consultation rates for all AS patients. We obtained standardized depression-rate ratios by dividing the observed depression rate in AS patients by the expected rate based on the corresponding age- and sex-specific rates of depression in the general population seeking care. A ratio >1 equals a higher rate of depression among AS patients.

Results

The AS cohort consisted of 1738 subjects (65% men) with a mean age of 54 years. The reference population consisted of 967,012 subjects. During the 13-year observation period 10% (n = 172) of the AS cohort had a doctor-diagnosed depression compared to 6% (n = 105) to be expected. The standardized estimate of depression-rate ratio was 1.81 (95% confidence interval 1.44 to 2.24) in women men and 1.49 (1.20 to 1.89) in men.

Conclusions

The rate of doctor-diagnosed depression is increased about 80% in female and 50% in male AS patients. Future challenges are to timely identify and treat the AS patients who suffer from depression.  相似文献   
80.
Circulating monocyte sub-sets have recently emerged as mediators of divergent immune functions during infectious disease but their role in helminth infection has not been investigated. In this study we evaluated whether ‘classical’ (CD14brightCD16), ‘intermediate’ (CD14brightCD16+), and ‘non-classical’ (CD14dimCD16+) monocyte sub-sets from peripheral blood mononuclear cells varied in both abundance and ability to bind antigenic material amongst individuals living in a region of Northern Senegal which is co-endemic for Schistosoma mansoni and S. haematobium. Monocyte recognition of excretory/secretory (E/S) products released by skin-invasive cercariae, or eggs, of S. mansoni was assessed by flow cytometry and compared between S. mansoni mono-infected, S. mansoni and S. haematobium co-infected, and uninfected participants. Each of the three monocyte sub-sets in the different infection groups bound schistosome E/S material. However, ‘intermediate’ CD14brightCD16+ monocytes had a significantly enhanced ability to bind cercarial and egg E/S. Moreover, this elevation of ligand binding was particularly evident in co-infected participants. This is the first demonstration of modulated parasite pattern recognition in CD14brightCD16+ intermediate monocytes during helminth infection, which may have functional consequences for the ability of infected individuals to respond immunologically to infection.  相似文献   
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