Strecker-type degradation of phenylalanine by methyl 9,10-epoxy-13-oxo-11-octadecenoate and methyl 12,13-epoxy-9-oxo-11-octadecenoate

The reaction of methyl 9,10-epoxy-13-oxo-11(E)-octadecenoate, methyl 12,13-epoxy-9-oxo-11(E)-octadecenoate, 4,5(E)-epoxy-2(E)-heptenal, and 4,5(E)-epoxy-2(E)-decenal with phenylalanine in acetonitrile-water (2:1, 1:1, and 1:2) at 80 degrees C and at different pHs and carbonyl compound/amino acid ratios was investigated both to determine if epoxyoxoene fatty esters were able to produce the Strecker-type degradation of the amino acid and to study the relative ability of oxidized long-chain fatty esters and short chain aldehydes with identical functional systems to degrade amino acids. The studied epoxyoxoene fatty esters degraded phenylalanine to phenylacetaldehyde. The mechanism of the reaction was analogous to that described for epoxyalkenals and is suggested to be produced through the corresponding imine, which is then decarboxylated and hydrolyzed. This reaction also produced a conjugated hydroxylamine, which was the origin of the long-chain pyridine-containing fatty ester isolated in the reaction and characterized as methyl 8-(6-pentylpyridin-2-yl)octanoate. Epoxyoxoene fatty esters and epoxyalkenals exhibited a similar reactivity for producing phenylacetaldehyde, therefore suggesting that nonvolatile lipid oxidation products, which are produced to a greater extent than volatile products, should be considered for determining the overall contribution of lipids to Strecker degradation of amino acids produced during nonenzymatic browning. In addition, the obtained data confirm that, analogously to carbohydrates, lipid oxidation products are also able to produce the Strecker degradation of amino acids.     

Strecker type degradation of phenylalanine by 4-hydroxy-2-nonenal in model systems

The reaction of 4-hydroxy-2-nonenal, an oxidative stress product, with phenylalanine in acetonitrile-water (2:1, 1:1, and 1:2) at 37, 60, and 80 degrees C was investigated to determine whether 4-hydroxy-2-alkenals degrade amino acids, analogously to 4,5-epoxy-2-alkenals, and to compare the reactivities of both hydroxyalkenals and epoxyalkenals for production of Strecker aldehydes. In addition to the formation of N-substituted 2-pentylpyrrole and 2-pentylfuran, the studied hydroxyalkenal also degraded phenylalanine to phenylacetaldehyde with a reaction yield of 17%. The reaction mechanism is suggested to be produced through the corresponding imine, which is then decarboxylated and hydrolyzed. This reaction also produced a conjugated amine, which both may be one of the origins of the produced 2-pentyl-1H-pyrrole and may contribute to the development of browning in these reactions. 4-Hydroxy-2-nonenal and 4,5-epoxy-2-decenal degraded phenylalanine in an analogous extent, which is likely a consequence of the similarity of the degradation mechanisms involved. These results suggest that different lipid oxidation products are able to degrade amino acids; therefore, the Strecker type degradation of amino acids produced by oxidized lipids may be quantitatively significant in foods.     

Nutrient concentrations of peach‐tree leaves under deficit irrigation

The effect of different deficit‐irrigation treatments on the dynamics of mineral nutrients in leaves of peach trees growing under Mediterranean conditions was studied. Treatments consisted of a control, continuous deficit irrigation, regulated deficit irrigation, and partial root drying. The dynamics of nutrients were unchanged by the water deficits, though the amount absorbed was slightly modified. The advantages of deficit‐irrigation strategies with regard to water‐use efficiency were accompanied by the absence of any harmful effect on leaf mineral nutrition.     

Variability of hair coat and skin traits as related to adaptation in Criollo Limonero cattle

The variation in hair coat and skin histology traits of Criollo Limonero cattle was analyzed using 213 Criollo Limonero females. Skin biopsies were obtained from slick-haired (N = 16) and normal-haired (N = 14) animals. Measured traits included hair length (HL), color coat (CC), number of hair follicles per square centimeter (NHF), sweat glands per square centimeter (NSG), sweat glands size (SGS), sebaceous glands per square centimeter (NSBG), blood vessels per square centimeter (NBV), and thickness of epidermis (TE). Hair length differed (P < 0.001) between slick- and normal-haired animals (4.9 ± 0.12 vs 10.9 ± 0.20, respectively). Differences (P < 0.01) in CC (Bayo = 144/67.6% vs Red = 69/32.4%) and HL (slick-haired = 199/93.4% vs normal-haired = 14/6.5%) were found. Distribution of slick- and normal-haired animals differed (P < 0.01) between bayo-coated and red-coated (139/62.2% vs 9/4.2%; respectively). Most (P < 0.05) red-coated animals belonged to a single family. No differences (P > 0.05) were found between slick-haired and normal-haired animals in NHF (637 ± 164 vs 587 ± 144, respectively), NSG (556 ± 134 vs 481 ± 118, respectively), NSBG (408 ± 87 vs 366 ± 77, respectively), NBV (1628 ± 393 vs 1541 ± 346, respectively), and TE (1.24 ± 0.14 vs 1.32 ± 0.12, respectively). However, SGS was greater (P < 0.01) in slick-haired than normal-haired animals. In conclusion, Criollo Limonero cattle are predominantly bayo-coated, slick-haired, with a reduced number of hair follicles relative to Zebu cattle, sweat and sebaceous glands in proportion to hair follicle numbers, and with a high blood flow irrigating the skin. There is a sub-group of red-coated animals with yellow or cream skin, thicker epidermis, and with a higher frequency of normal-haired animals. It appears that the slick hair gene has been favored by natural selection in this breed.     

Soil Contamination in Dumps on the Karstic Areas from the Plateaus (Southeast of Madrid, Spain)

After over 10 years of accumulation of residues in the studied dumps near Madrid, it has been registered low or moderate heavy metals concentrations on the surrounding area. Only occasionally, some rubbish dumps contain significant quantities of Cu, Ni, Zn and Pb. The concentration levels of Pb, Ni, Zn and Cu are safe when they are compared with the surrounding areas levels of heavy metals. The aim of this paper is the analysis of pollutants existing around in the dumps located at the sides of the plateaus of the central valley of the Tajo River (provinces of Madrid and Toledo, Spain). The high karstification rate of the upper layer of these tablelands and the existence of numerous dumps on them (even on their slopes) make these areas vulnerable to heavy metal pollution. However, after several years of use, the concentration of pollutants only reaches moderate values in the studied areas. Dumping materials were collected at four rubbish dumps. The mineralogical composition of the materials were analysed by XRD. Sequential extraction procedure was applied for speciation of the metal forms in the collected samples. Concentrations of Zn, Pb, Ni, Cu, Cr and Cd in extracts were determined by AAS. The studied samples showed high carbonate concentration. Contamination processes are combined there with weathering processes. Heavy metals concentration in control samples (gypsum, limestones, red soils and colluviums) were compared with samples of the studied dump in order to evaluate the pollution level. Concentrations of Zn, Pb, Ni and Cu were variable. The contamination was elevated for samples in depth in relation with weathering process of heavy metals.     

Degradation of ochratoxin a by Brevibacterium species

The ability to degrade ochratoxin A was studied in different bacteria with a well-known capacity to transform aromatic compounds. Strains belonging to Rhodococcus, Pseudomonas, and Brevibacterium genera were grown in liquid synthetic culture medium containing ochratoxin A. Brevibacterium spp. strains showed 100% degradation of ochratoxin A. Ochratoxin α was detected and identified by high-performance liquid chromatography-mass spectrometry (HPLC-MS) as a degradation product in the cell-free supernatants. The degradation of ochratoxin A is of public concern for food and environmental safety, because it could contribute to the development of new biological ochratoxin A detoxification systems in foodstuffs. In this study, the degradation of ochratoxin A by bacteria belonging to the food chain was demonstrated for the first time.     

Rate of apoptosis in feline mammary tumors is not predictive of postsurgical survival.

Invasion, cell proliferation and apoptosis are important biological features of neoplasia, bearing prognostic importance. Histological stage, mitotic index, and apoptotic index have been assessed in 33 feline malignant mammary tumors. Histological stage (P < 0.01) and mitotic index (P < 0.001) had a significant association with prognosis in univariate analysis. Apoptotic index did not correlate with survival (P = 0.44), and histological stage (P = 0.48) did not correlate with mitotic index (P = 0.39). In feline malignant mammary tumors the apoptotic index seems unable to predict survival and lacks any correlation with proliferation assessed as mitotic index. A possible explanation for the lack of correlation between apoptotic index and survival may be due to the rapid acquisition of pathways of apoptosis resistance in feline mammary tumors or to rapid hormone receptors loss.     

Prognostic value of histologic stage and proliferative activity in canine malignant mammary tumors.

The aim of this study was to investigate the correlation between the histologic invasiveness (histologic stage) and various cell proliferation activity assays (quantity of argyrophil proteins associated with nucleolar organizer regions [AgNORs], mitotic activity, MIB1 [Ki67] immunohistochemical detection) for predicting the biologic behavior of malignant canine mammary tumors. Sixty specimens from malignant canine mammary tumors with no distant metastases (M0) at surgery were selected, and follow-up data were collected over a 2-year period. The histologic invasiveness was graded by histologic stage (stage 0 = tumors without stromal invasion; stage I = tumors with stromal invasion; stage II = tumors with neoplastic emboli in vessels), and the proliferative indices were expressed as MIB1 index (the percentage of nuclear area immunohistochemically stained by MIB1 antibody), mitotic index (the number of mitoses per 1,000 neoplastic cells), and AgNOR index (the ratio between mean AgNOR area of tumor cells and the mean AgNOR area of fibroblasts/lymphocytes). The measures of proliferative activity were compared among groups with different histologic stages, and the influence of different prognostic variables (histologic stage, AgNOR index, mitotic index, MIB1 index) on survival time was evaluated. A significant difference in the proliferation patterns was recorded between the different histologic stages for the mitotic index (P = 0.0006) and MIB1 index (0.0013). Among the different parameters considered, histologic stage (P < 0.05), AgNOR index (P = 0.0291), and MIB1 index (P = 0.014) revealed a significant association with prognosis in univariate analysis. AgNOR index for 1-year survival and histologic stage for 2-year survival were the most significant parameters influencing survival, as determined by multiple nonlinear logistic regression.     

Osteitis deformans (Paget's disease) in a Burmese python (Python molurus bivittatus)--a case report

Osteitis deformans (Paget's disease of bone) is a chronic focal disorder of bone remodelling characterized by an initial increase in osteoclast-mediated bone resorption, with subsequent compensatory increase in new bone formation, resulting in a disorganized mosaic of woven and lamellar bone. In the Burmese python (Python molurus bivittatus) of this report, multifocal gross swellings involving the proximal third of the vertebral spine were observed and associated with anorexia, a relative inability to move or to fully extend the body, and to strike at prey. Serum biochemistry revealed elevated alkaline-phosphatase activity. Radiographic changes (irregular bone proliferation along the vertebral margins), computed tomography scan results (abnormal mineral density), and histopathological features (generalized thickening of the bony trabeculae at the expense of the intertrabecular spaces and irregular patches of lamellar bone with a characteristic "mosaic" pattern) indicated osteitis deformans.     

Endophytic bacteria from selenium-supplemented wheat plants could be useful for plant-growth promotion,biofortification and Gaeumannomyces graminis biocontrol in wheat production

In this study, we isolated putative plant-growth-promoting endophytic bacteria from selenium-supplemented wheat grown under field conditions. These bacterial strains belonged to Bacillus, Paenibacillus, Klebsiella, and Acinetobacter genera and showed genetic similarly with rhizospheric bacteria isolated in the same Andisol soil and with other endophytic strains previously reported. Strains isolated from selenium-supplemented wheat were highly tolerant to elevated selenium concentration (ranged from 60 to 180 mM), and showed potential plant-growth-promoting capabilities (auxin and siderophore production, phytate mineralization, and tricalcium phosphate solubilization). In addition, some strains like Acinetobacter sp. (strain E6.2), Bacillus sp. (strain E8.1), Bacillus sp., and Klebsiella sp. (strains E5 and E1) inhibited the growth of Gaeumannomyces graminis mycelia in vitro at 100, 50, and 30 %, respectively. These endophytic microorganisms would be useful for dual purposes: selenium biofortification of wheat plants and control of G. graminis, the principal soil-borne pathogen in volcanic soils from southern Chile.