126 research outputs found
Mesenteric cyst in 11-year old girl: A technical note. Case report
AbstractWe report on a case of a mesenteric cyst occurred in an 11-year-old girl referred to our institution after a period of 2 months of recurrent abdominal pain. The girl underwent laparoscopic surgery after abdominal Ultrasound Scan (US) and Magnetic Resonance Imaging (MRI) demonstrated a voluminous cyst of about 18 cm Ă 10.7 cm Ă 5.8 cm, occupying principally left abdomen. The cyst's root extended into retroperitoneum (Losanoff type 3) so the majority was excised and the remaining was marsupialized with good results. Laparoscopic excision of the mesenteric cyst has been facilitated by rolling the isolated cyst progressively around a grasper obtaining a constant control of the structure: the âspaghetti maneuverâ. As confirmed by our experience, a mesenteric cyst can be easily and safely managed by laparoscopy, and the âspaghetti maneuverâ is a feasible and effective surgical tool to facilitate the excision
Evaluation of an ELISA method to detect Listeria monocytogenes in fresh-cut rocket
Leafy vegetables are consumed fresh after harvest with bland washes, not always efficient in removing pathogenic bacteria that may be attached to the external skin or surfaces. In this work, an optimized ELISA based method developed in our laboratory was used to detect the presence of Listeria monocytogenes in fresh-cut rocket leaves. From a certain quantity (5 g) of fresh rocket leaves contaminated with Listeria monocytogenes, bacteria were isolated and the pathogen was detected using an ELISA protocol. The preliminary results are promising in the use of antibody-antigen interaction to verify the presence of L. monocytogenes in the minimally processed vegetable distribution chain
Recommended from our members
Rocket science: a review of phytochemical & health-related research in Eruca & Diplotaxis species
Rocket species (Eruca spp. and Diplotaxis spp.) are becoming increasingly important leafy salad crops across the world. Numerous scientific research papers have been published in recent years surrounding the potential health benefits associated with phytochemicals contained in leaves, such as flavonoids and isothiocyanates. Other research of note has also been conducted into the unique taste and flavour properties of leaves, which can be hot, peppery, bitter, and sweet depending upon the genotype and phytochemical composition. While research into these aspects is increasing, some studies lack cohesion and in-depth knowledge of commercial breeding and cultivation practices that makes interpretation and application of results difficult. This review draws together all significant research findings in these crops over the last five years, and highlights areas that require further exploration and/or resolution. We also advise on experimental considerations for these species to allow for more meaningful utilisation of findings in the commercial sector
Validation of ELISA-based detection of L. monocytogenes and E. coli O157:H7 in fresh cut vegetables
Innovative diagnostic methods were developed for the detection and quantification of Listeria monocytogenes and Escherichia coli O157:H7 in
minimally processed fresh cut fruits and vegetables. The aim of the present study was to validate the technical efficiency of these methods and
evaluate their efficacy and viability for routine analysis. To this purpose, ready-to-eat fresh fruits and vegetables were collected throughout the
production chain. A multidisciplinary approach, including a newly developed ELISA method compared to ISO procedures, was applied to detect the
pathogenic bacteria after harvesting, processing and shelf-life. Results obtained exhibited the technical efficiency of the developed methods showing
similar sensitivity, specificity, negative predictive values and negative likelihood ratios
Gene expression analysis of rocket salad under pre-harvest and postharvest stresses : a transcriptomic resource for Diplotaxis tenuifolia
Diplotaxis tenuifolia L. is of important economic value in the fresh-cut industry for its nutraceutical and sensorial properties. However, information on the molecular mechanisms conferring tolerance of harvested leaves to pre- and postharvest stresses during processing and shelf-life have never been investigated. Here, we provide the first transcriptomic resource of rocket by de novo RNA sequencing assembly, functional annotation and stress-induced expression analysis of 33874 transcripts. Transcriptomic changes in leaves subjected to commercially-relevant pre-harvest (salinity, heat and nitrogen starvation) and postharvest stresses (cold, dehydration, dark, wounding) known to affect quality and shelf-life were analysed 24h after stress treatment, a timing relevant to subsequent processing of salad leaves. Transcription factors and genes involved in plant growth regulator signaling, autophagy, senescence and glucosinolate metabolism were the most affected by the stresses. Hundreds of genes with unknown function but uniquely expressed under stress were identified, providing candidates to investigate stress responses in rocket. Dehydration and wounding had the greatest effect on the transcriptome and different stresses elicited changes in the expression of genes related to overlapping groups of hormones. These data will allow development of approaches targeted at improving stress tolerance, quality and shelf-life of rocket with direct applications in the fresh-cut industries
Detection and enumeration of Listeria monocytogenes in fresh cut vegetables using MPN-Real-Time PCR
Listeria monocytogenes is a gram positive, rod shaped, pathogenic bacterium,
causative agent of a severe infection generally known as listeriosis. Packaging and
storage conditions of fresh cut vegetables may favour the growth of this
psychrotrophic pathogen leading to potential health threat. Detection and
enumeration of L. monocytogenes in concentrations up to 103 CFU/g, usually implies
use of the most-probable-number technique (MPN) which may take up to seven days
for verified identification of the pathogen. We developed a fast and reliable protocol
combining MPN with a Real-Time quantitative PCR (qPCR) approach. Samples of
fresh cut salads (25 g) purchased at local shops were spiked with 1 to 105 CFU/g of
L. monocytogenes. Samples were homogenized, and triplicate series of tubes
containing 10-5 to 10 g of food were incubated in Fraser broth at 30\ub0C for 48 h for
standard MPN analysis. After incubation, broth samples were taken from each tube
and DNA was extracted. DNA from enrichment tubes was used as template in a
qPCR assay targeting a 64 bp hlyA gene sequence of L. monocytogenes. Results of
this assay were than compared with those of standard MPN analysis and a complete
accordance was observed. Furthermore, we tested an enrichment free approach
using the same qPCR assay. Samples were prepared as described for MPN-qPCR
while DNA extraction was performed prior to enrichment of inoculated salads. This
approach allowed us to identify L. monocytogenes in samples spiked with 10-105
CFU/g. The whole process, including DNA extraction, required less than four hours,
thus providing a fast and reliable tool for detection of L. monocytogenes in fresh cut
vegetables
The maize fused leaves1 (fdl1) gene controls organ separation in the embryo and seedling shoot and promotes coleoptile opening
The fdl1-1 mutation, caused by an Enhancer/Suppressor mutator (En/Spm) element insertion located in the third exon
of the gene, identifies a novel gene encoding ZmMYB94, a transcription factor of the R2R3-MYB subfamily. The fdl1
gene was isolated through co-segregation analysis, whereas proof of gene identity was obtained using an RNAi strategy
that conferred less severe, but clearly recognizable specific mutant traits on seedlings.
Fdl1 is involved in the regulation of cuticle deposition in young seedlings as well as in the establishment of a
regular pattern of epicuticular wax deposition on the epidermis of young leaves. Lack of Fdl1 action also correlates
with developmental defects, such as delayed germination and seedling growth, abnormal coleoptile opening
and presence of curly leaves showing areas of fusion between the coleoptile and the first leaf or between
the first and the second leaf. The expression profile of ZmMYB94 mRNA\u2014determined by quantitative RT-PCR\u2014
overlaps the pattern of mutant phenotypic expression and is confined to a narrow developmental window. High
expression was observed in the embryo, in the seedling coleoptile and in the first two leaves, whereas RNA
level, as well as phenotypic defects, decreases at the third leaf stage. Interestingly several of the Arabidopsis
MYB genes most closely related to ZmMYB94 are also involved in the activation of cuticular wax biosynthesis,
suggesting deep conservation of regulatory processes related to cuticular wax deposition between monocots
and dicots
Effect of temperature and cut size on the volatile organic compound profile, and expression of Chorismate synthase in fresh-cut melon
The postharvest quality of fresh-cut melon is strongly affected by storage conditions to which it is subjected. During postharvest, fruit undergoes several stresses and its physiology is similar to that in senescent tissues. This affects both its biochemistry and the expression of genes involved in secondary metabolite biosynthesis. Volatile organic compounds (VOCs) have been used previously to assess quality of fresh cut melon as they reflect changes in flavor and also changes in overall metabolism. Chorismate synthase (CS) is a key enzyme in the shikimate pathway and catalyzes the formation of chorismate, which is the precursor of numerous aromatic compounds in plants. In this work the effects of different storage temperatures and cut-sizes were studied, with the aim of identifying effects on flavor through changes in VOCs, and molecular responses of the CmCS gene to different postharvest conditions. Melon (Cucumis melo L. 'Macigno') fruits were harvested at a fully ripened commercial stage, were washed in a chlorine water solution, and the mesocarp (pulp) was cut in cube-shaped portions; two sizes were chosen, 1Ă1 and 3Ă2 cm. Melon cubes were then stored at 20 or 4°C. VOCs were assessed in the 3Ă2 cut size at both temperatures and showed clear changes during storage. A subset of VOCs were shown to correlate negatively with storage time and temperature and from these, specific compounds can be identified that act as markers for an overall change in VOC profiles. CmCS was more affected by temperature, showing decreased levels of expression during storage at 20°C with respect to harvest and to cold storage. On the other hand, cut-size did not result in changes in its expression in 3Ă2 cut size
A complex interaction between pre-harvest and post-harvest factors determines fresh-cut melon quality and aroma
Melons are prized for their characteristic aroma, however, pre-harvest growth, stage of ripening at harvest, post-harvest processing and storage conditions lead to quality changes in fresh-cut fruit. We considered changes in metabolites and gene expression over 14 days storage to assess underlying mechanisms and identify potential quality markers. Overall, 99 volatile organic compounds (VOCs) were detected and VOC profiles discriminated between two melon seasons, cut-size, storage temperatures and storage time, although season affected their discriminatory power. Abundance of two VOCs fell rapidly and was not associated with cut size, indicating their use as markers for early changes post-processing. Non-acetate to acetate ester ratio differed between the seasons and correlated with changes in alcohol acyl-transferase (CmAAT1) gene expression. Furthermore, CmAAT1 expression clustered with two ester VOCs that may be potential new products of this enzyme. Season also strongly affected post-harvest sugar content, most likely attributable to meteorological differences during growth. Storage temperature and cut size affected expression of transcription factors ERF71, ERF106, and TINY, whose expression generally rose during storage, probably related to increased stress. Thus, although time Ă temperature of storage are key factors, pre-harvest conditions and fruit processing impact significantly gene expression and aroma loss post-harvest
Recommended from our members
The Eruca sativa genome and transcriptome: a targeted analysis of sulfur metabolism and glucosinolate biosynthesis pre and postharvest
Rocket (Eruca sativa) is a source of health-related metabolites called glucosinolates (GSLs) and isothiocyanates (ITCs) but little is known of the genetic and transcriptomic mechanisms responsible for regulating pre and postharvest accumulations. We present the first de novo reference genome assembly and annotation, with ontogenic and postharvest transcriptome data relating to sulfur assimilation, transport, and utilization. Diverse gene expression patterns related to sulfur metabolism, GSL biosynthesis, and glutathione biosynthesis are present between inbred lines of rocket. A clear pattern of differential expression determines GSL abundance and the formation of hydrolysis products. One breeding line sustained GSL accumulation and hydrolysis product formation throughout storage. Multiple copies of MYB28, SLIM1, SDI1 and ESM1 have increased and differential expression postharvest, and are associated with GSLs and hydrolysis product formation. Two glucosinolate transporter gene (GTR2) copies were found to be associated with increased GSL accumulations in leaves. Monosaccharides (which are essential for primary metabolism and GSL biosynthesis, and contribute to the taste of rocket) were also quantified in leaves, with glucose concentrations significantly correlated with the expression of numerous GSL-related genes. Significant negative correlations were observed between the expression of glutathione synthetase (GSH) genes and those involved in GSL metabolism. Breeding line âBâ showed increased GSH gene expression and low GSL content compared to two other lines where the opposite was observed. Co-expression analysis revealed senescence (SEN1) and oxidative stress-related (OXS3) genes have higher expression in line B, suggesting that postharvest deterioration is associated with low GSL concentrations
- âŠ