Bioactive Compounds in Wild Asteraceae Edible Plants Consumed in the Mediterranean Diet

Plant Foods for Human Nutrition - Three wild edible plant species belonging to the Asteraceae family, Crepis vesicaria L. (s.l.), Sonchus asper (L.) Hill s.l., and Sonchus oleraceus L., usually...     

Ultrastructure of immature and mature human oocytes after cryotop vitrification

In vitro maturation of vitrified immature germinal vesicle (GV) oocytes is a promising fertility preservation option. We analyzed the ultrastructure of human GV oocytes after Cryotop vitrification (GVv) and compared it with fresh GV (GVc), fresh mature metaphase II (MIIc) and Cryotop-vitrified mature (MIIv) oocytes. By phase contrast microscopy and light microscopy, the oolemmal and cytoplasmic organization of fresh and vitrified oocytes did not show significant changes. GVv oocytes showed significant ultrastructural alterations of the microvilli in 40% of the samples; small vacuoles and occasional large/isolated vacuoles were abnormally present in the ooplasm periphery of 50% of samples. The ultrastructure of nuclei and mitochondria-vesicle (MV) complexes, as well as the distribution and characteristics of cortical granules (CGs), were comparable with those of GVc oocytes. MIIv oocytes showed an abnormal ultrastructure of microvilli in 30% of the samples and isolated large vacuoles in 70% of the samples. MV complexes were normal, but mitochondria-smooth endoplasmic reticulum aggregates appeared to be of reduced size. CGs were normally located under the oolemma but presented abnormalities in distribution and matrix electron density. In conclusion, Cryotop vitrification preserved main oocyte characteristics in the GV and MII stages, even if peculiar ultrastructural alterations appeared in both stages. This study also showed that the GV stage appears more suitable for vitrification than the MII stage, as indicated by the good ultrastructural preservation of important structures that are present only in immature oocytes, like the nucleus and migrating CGs.     

Evaluation of a portable lactate analyzer (Lactate Scout) in dogs

BACKGROUND: Measurement of blood lactate concentration has become a common practice in canine medicine. However, the accuracy of portable lactate monitors has not been reported in dogs. OBJECTIVES: The aim of this study was to evaluate the accuracy and precision of a portable analyzer (Lactate-Scout) in measuring canine blood lactate concentration. METHODS: A preliminary study was performed to assess the effects of sample storage time and temperature on plasma lactate concentration. Blood samples obtained from 6 canine patients at our hospital were divided into 8 aliquots and stored at 4 degrees C and 20 degrees C; plasma lactate was measured in duplicate with a spectrophotometric system (Konelab) at 0, 30, 60, 120, and 240 minutes after the blood collection. Values were compared with those obtained immediately after blood collection. Lactate values obtained by the portable method also were compared with those obtained by the reference spectrophotometric analyzer on blood samples collected from 48 additional canine patients. RESULTS: There was no significant effect of storage time (P = .89) or temperature (P = .51) on plasma lactate levels. The correlation between lactate values measured with the Lactate-Scout and the Konelab method was r = .98 (slope = .81, 95% confidence interval = .73-.87; intercept = .20, 95% confidence interval = .13-.31). The level of agreement between the 2 methods was generally good for mean lactate concentrations <5 mmol/L. However, at higher lactate concentrations (5 of 48 samples), the values recorded by the Lactate-Scout analyzer were lower than those measured by the Konelab method. CONCLUSION: The Lactate-Scout analyzer is reliably comparable to a reference method for measuring whole blood lactate concentration in dogs; however, caution should be used when interpreting lactate values of 5 mmol/L and higher.     

Stomatal regulation and xylem cavitation in Clementine (Citrus clementina Hort) under drought conditions

Summary

In many trees species, a strong relationship exists between stomatal closure and the onset of cavitation in xylem vessels. This relationship was investigated in a Citrus species. Young potted ‘Clementine’ (Citrus clementina Hort ‘Clementine’) grafted on ‘Carrizo Citrange’ (Citrus sinensis × Poncirus trifoliata) or ‘Trifoliate Orange’ (Poncirus trifoliata Raf), and grown under greenhouse conditions, were submitted to periods of drought by withholding irrigation. Pre-dawn water potential, leaf stomatal conductance, plant transpiration, the degree of xylem embolism, and xylem vulnerability curves were measured. Transpiration and stomatal conductance were reduced to a minimum value when the pre-dawn water potential reached -1 MPa. This value corresponded to the threshold pressure below which cavitation was induced. Higher intensities of water stress provoked more cavitation, but the degree of xylem embolism, as measured by percentage loss of conductivity, always remained below 50%. ‘Clementine’ is therefore vulnerable to embolism, but early stomatal regulation prevents the occurrence of embolism. Under severe water stress, ‘Clementine’ is able to maintain functional xylem vessels, which probably enhances its survival during periods of intense drought, and favours its recovery. This suggests that xylem cavitation is a key process in understanding the response of Citrus to drought and, hence, is a promising criterion by which to screen for more drought-tolerant genotypes.     

Differentially-regulated defence genes in Malus domestica during phytoplasma infection and recovery

To improve knowledge about plant/phytoplasma interactions and, in particular, about the ‘recovery’ phenomenon in previously-infected plants, we investigated and compared expression levels of several defence-related genes (four pathogenesis-related proteins and three jasmonate-pathway marker enzymes) in apple plants showing different states of health: vigorous (healthy), phytoplasma-infected, and recovered. Real Time-PCR analyses demonstrated that genes are differentially expressed in apple leaf tissue according to the plants’ state of health. Malus domestica Pathogenesis-Related protein (MdPR) 1, MdPR 2 and MdPR 5 were significantly induced in leaves of diseased and symptomatic plants compared to leaves of those plants that were healthy or recovered. On the other hand, levels of all the jasmonate (JA)-pathway marker genes that we selected for this study, were up-regulated in the leaves of recovered plants compared to the diseased ones. In conclusion, our study demonstrated that two different sets of defence genes are involved in the interactions between apple plants and ‘Candidatus Phytoplasma mali’ (‘Ca. P. mali’) and that these genes are differentially expressed during phytoplasma infection or recovery.     

Simple confirmatory method for the determination of erythromycin residues in trout: a fast liquid-liquid extraction followed by liquid chromatography-tandem mass spectrometry

In recent years, erythromycin has received considerable attention for its therapeutic efficacy against some bacterial kidney diseases in aquaculture and, therefore, suitable and sensitive analytical methods to monitor erythromycin residues in fish are required. A fast sample treatment followed by an LC-ESI-MS/MS method is described for the purification, identification, and quantification of erythromycin A residues in fish. After two extractions with acetonitrile, samples were defatted with n-hexane, filtered, and analyzed by tandem mass spectrometry. Three characteristic transition reactions (m/z 734 --> 716, 734 --> 576, and 734 --> 558) in multiple reaction monitoring were tested for the determination and confirmation of erythromycin A. The method was in-house validated through the determination of precision, accuracy, specificity, stability, calibration curve, decision limit (CCalpha), and detection capability (CCbeta), in accordance with European Commission Decision 657/2002. The coefficients of variation ranged from 1.8 to 9.4% and from 7.5 to 10.9% for intra- and interday repeatability, respectively. Recovery data were also satisfactory, with values varying from 85 to 97%. The method was specific, stable, and robust enough for the required purposes. The calibration curve showed a good linearity in the whole range of the tested concentrations (0-1000 microg kg(-1)) with a correlation coefficient (r2) equal to 0.9956. CCalpha and CCbeta were found to be 220 and 238 microg kg(-1), respectively.     

Bacterial Exopolysaccharides from Extreme Marine Habitats: Production,Characterization and Biological Activities

Many marine bacteria produce exopolysaccharides (EPS) as a strategy for growth, adhering to solid surfaces, and to survive adverse conditions. There is growing interest in isolating new EPS producing bacteria from marine environments, particularly from extreme marine environments such as deep-sea hydrothermal vents characterized by high pressure and temperature and heavy metal presence. Marine EPS-producing microorganisms have been also isolated from several extreme niches such as the cold marine environments typically of Arctic and Antarctic sea ice, characterized by low temperature and low nutrient concentration, and the hypersaline marine environment found in a wide variety of aquatic and terrestrial ecosystems such as salt lakes and salterns. Most of their EPSs are heteropolysaccharides containing three or four different monosaccharides arranged in groups of 10 or less to form the repeating units. These polymers are often linear with an average molecular weight ranging from 1 × 10⁵ to 3 × 10⁵ Da. Some EPS are neutral macromolecules, but the majority of them are polyanionic for the presence of uronic acids or ketal-linked pyruvate or inorganic residues such as phosphate or sulfate. EPSs, forming a layer surrounding the cell, provide an effective protection against high or low temperature and salinity, or against possible predators. By examining their structure and chemical-physical characteristics it is possible to gain insight into their commercial application, and they are employed in several industries. Indeed EPSs produced by microorganisms from extreme habitats show biotechnological promise ranging from pharmaceutical industries, for their immunomodulatory and antiviral effects, bone regeneration and cicatrizing capacity, to food-processing industries for their peculiar gelling and thickening properties. Moreover, some EPSs are employed as biosurfactants and in detoxification mechanisms of petrochemical oil-polluted areas. The aim of this paper is to give an overview of current knowledge on EPSs produced by marine bacteria including symbiotic marine EPS-producing bacteria isolated from some marine annelid worms that live in extreme niches.     

Pattern of variation for seed size traits and molecular markers in Italian germplasm of Phaseolus coccineus L.

Variation in Italian germplasm of Phaseolus coccineus L. was assessed for seed traits and molecular markers. A total of 130 seeds and seedlings, five for each of 21 Italian landraces, an Italian commercial cultivar and four Mesoamerican landraces of P. coccineus, were analysed using seven selected PCR markers: three RAPDs, two ISSRs and two ETs. Seed weight of the Mesoamerican landraces was ≤1 g, whereas that of the Italian landraces varied from 1 g to 2.5 g and was related to their origin. Oval shape was more frequent, with round shape observed only in Mesoamerican landraces. Three seed coat colours were observed: white, violet mottled or spotted black and buff spotted brown, also this trait was related to the origin. The level of polymorphism detected by molecular markers was low but with significant discriminant power. ISSRs were the most effective markers prone to unravel molecular polymorphism. The within accession component of variation exceeded that among accessions, as expected for an allogamous species. However correct classification of the individuals was achieved performing either discriminant analysis of the seed phenotypic traits or cluster analysis of seedling similarity measure based on the whole banding patterns obtained by the three marker types. Our data suggest that the Italian farmers, starting with ancestral Mesoamerican runner bean introductions in Europe, bred their own landraces through selection for seed size and seed coat colour, but occasional gene flow maintained variability within landraces bred by different farmers in the same Italian Region. Selection favored molecular and seed trait uniformity within several landraces making them suitable for certification.     

Validation of 2 techniques for electrocardiographic recording in dogs and cats

BACKGROUND: Standard electrocardiographic (ECG) recording in the dog and cat is commonly performed in right lateral recumbency, by connecting the ECG leads to the skin of the patient via metallic alligator clips. The jaws of the alligator clips are usually filed or flattened to reduce their uncomfortable pressure on the patient's skin. However, filed and flattened alligator clips can occasionally lose their grip to the skin, causing lead detachment during standard ECG recording. HYPOTHESIS: The aim of the study was to validate two novel ECG recording techniques ("gel" and "pads"). ANIMALS: Six-lead standard ECG recording was obtained from 42 dogs and 40 cats using the standard technique, as well as the two novel methods. METHODS: Measurements were taken of the amplitude and duration of P waves and QRS complexes, duration of PQ and QT intervals, and mean electrical axis (MEA). In each recording, five representative complexes were measured, and the results were averaged for each parameter. RESULTS: A good quality ECG recording was obtained with all the three different techniques, although a degree of wandering trace was observed in one third of cats with the "pads" technique. Bland-Altman analysis showed good agreement between the ECG values recorded with the two novel techniques and those recorded with the standard traditional technique. Furthermore, the observed differences were not clinically relevant, except for the R wave amplitude recorded with the "pads" method in cats (-0.35 to 0.37 mV). CONCLUSIONS AND CLINICAL IMPORTANCE: In conclusion, this study supports the reliability and clinical validity of the "gel" and "pads" techniques for ECG recording both in the dog and the cat, with some limitations for the "pads" technique in cats.