Cellulose synthase-like CslF genes mediate the synthesis of cell wall (1,3;1,4)-beta-D-glucans

A characteristic feature of grasses and commercially important cereals is the presence of (1,3;1,4)-beta-d-glucans in their cell walls. We have used comparative genomics to link a major quantitative trait locus for (1,3;1,4)-beta-d-glucan content in barley grain to a cluster of cellulose synthase-like CslF genes in rice. After insertion of rice CslF genes into Arabidopsis, we detected (1,3;1,4)-beta-d-glucan in walls of transgenic plants using specific monoclonal antibodies and enzymatic analysis. Because wild-type Arabidopsis does not contain CslF genes or have (1,3;1,4)-beta-d-glucans in its walls, these experiments provide direct, gain-of-function evidence for the participation of rice CslF genes in (1,3;1,4)-beta-d-glucan biosynthesis.     

Parasite density and impaired biochemical/hematological status are associated with severe clinical aspects of canine visceral leishmaniasis

We have performed a detailed investigation in 40 dogs naturally infected with Leishmania infantum (syn. chagasi), subdivided into three groups: asymptomatic (AD = 12), oligosymptomatic (OD = 12) and symptomatic (SD = 16), based on their clinical features. Twenty non-infected dogs (CD) were included as control group. Serological analysis, performed by IFAT and ELISA, demonstrated higher antibodies titers in SD in comparison to the AD. A positive correlation was found between parasite density in the spleen and skin smears as well as the bone marrow parasitism with clinical status of the infection. We observed that the progression of the disease from asymptomatic to symptomatic clinical form was accompanied by intense parasitism in the bone marrow. It is likely that this led to the impaired biochemical/hematological status observed. Finally, we believe that the follow-up of these parameters could be a relevant approach to be used as markers during therapeutic and vaccine evaluations.     

Histopathological and immunohistochemical findings in lymphoid tissues of the endangered Iberian lynx (Lynx pardinus)

The Iberian lynx (Lynx pardinus) is the most threatened wild feline in the world. Little is known about the diseases and pathology that affect this animal. The aim of this study was to evaluate the histopathological status of the peripheral lymphoid tissues and thymus of Iberian lynxes necropsied between 1998 and 2003. Seventeen animals including females (n=8) and males (n=9), age range of 10 months to 16 years, with different causes of death were histopathologically and immunohistochemically (anti-CD3, CD79, MAC387, CD68) studied. Feline immunosuppressive virus laboratorial tests were negative. Five individuals presented neoplasia and/or tuberculosis. All animals presented some degree of both B and T cells depletion in peripheral lymphoid tissues and follicular hyalinosis in the center of depleted follicles. A viral origin of the lymphoid depletion is postulated although other causes (inbreeding, stress, toxic) are not ruled out. The loss of the effectiveness of the immune system increases the vulnerability of the critically endangered Iberian lynx to pathogens.     

Acute effect of tea, wine, beer, and polyphenols on ecto-alkaline phosphatase activity in human vascular smooth muscle cells

Alkaline phosphatase (ALP) is an ecto-enzyme widely distributed across species. It modulates a series of transmembranar transport systems, has an important role in bone mineralization, and can also be involved in vascular calcification. Polyphenol-rich diets seem to have protective effects on human health, namely, in the prevention of cardiovascular diseases. We aimed to investigate the effects of polyphenols and polyphenol-rich beverages upon membranar alkaline phosphatase (ecto-ALP) activity in intact human vascular smooth muscle cells (AALTR). The ecto-ALP activity was determined at pH 7.8, with p-nitrophenyl phosphate as the substrate, by absorbance spectrophotometry at 410 nm. Cell viability was assessed by the lactate dehydrogenase (LDH) method, and the polyphenol content of beverages was assessed using the Folin-Ciocalteu reagent. All polyphenols tested inhibited ecto-ALP activity, in a concentration-dependent way. Teas, wines, and beers also inhibited ecto-ALP activity, largely according to their polyphenol content. All tested compounds and beverages improved or did not change AALTR cell viability. Stout beer was an exception to the described behavior. Although more studies must be done, the inhibition of AALTR ecto-ALP activity by polyphenolic compounds and polyphenol-containing beverages may contribute to their cardiovascular protective effects.     

Modeling the secondary shelf life of ground roasted coffee

This work was addressed to study the secondary shelf life of ground roasted coffee. To this purpose, fresh dark-roasted ground coffee samples were equilibrated at increasing water activity (aw) values up to 0.44 and stored at 30 degrees C for up to 1 month. To simulate home storage conditions, the headspace atmosphere was periodically perturbed by opening for a short time and then closing the packaging. The changes of some chemical and physicochemical indexes of coffee staling were studied, and sensory analysis was carried out to determine the end point of coffee acceptability. The results showed that the volatile compounds in the headspace are representative indexes of the quality depletion of roasted ground coffee during home usage. The sensory and instrumental results were used to develop a mathematical model allowing to simply and quickly calculate the secondary shelf life of coffee on the basis of its aw value at a given temperature.     

New constituents of sweet Capsicum annuum L. fruits and evaluation of their biological activity

Four new acyclic diterpene glycosides named capsianosides (1-4), together with 12 known compounds, were isolated from the fresh sweet pepper fruits of Capsicum annuum L., a plant used as a vegetable food, spice, and external medicine. The chemical structures of new natural compounds, as well as their absolute configurations, were established by means of spectroscopic data including infrared, high-resolution mass spectrometry, and one- and two-dimensional nuclear magnetic resonance and by chemical derivatization. The known capsidiol (11) showed bacteriostatic properties in vitro against Helicobacter pylori with a minimum inhibitory concentration (MIC) of 200 microg/mL when compared with the commercial drug metronidazole (MIC, 250 microg/mL). Some purified components were also tested for their antioxidant activities.     

Chronic eosinophilic leukemia in a cat: cytochemical and immunophenotypical features

A 3-year-old, male, domestic shorthaired cat was presented with a 3-day history of anorexia and depression. The cat was moderately dehydrated, had pale, slightly icteric, mucous membranes, oral ulcerations, and mild hepatosplenomegaly. A feline leukemia virus (FeLV) antigen test was positive. CBC results obtained at initial presentation included severe normocytic, normochromic, nonregenerative anemia, severe thrombocytopenia, and marked leukocytosis (>100,000/microL) with 77% eosinophils. After 15 days of treatment with prednisone and doxycycline, the cat had persistent severe nonregenerative anemia (HCT 3.4%), thrombocytopenia (28,000/microL), and extreme eosinophilia (total eosinophils, 123.1 x 10(3)/microL; segmented 103.0 x 10(3)/microL; immature 20.1 X 10(3)/microL). Cytologic examination of aspirates from bone marrow, liver, lymph nodes, and spleen revealed a predominance of mature and immature eosinophils, many with dysplastic changes. The M:E ratio was 96.4. On histopathologic examination, multiple organs were infiltrated by eosinophilic granulocytes. Neoplastic cells in blood and bone marrow stained positive for alkaline phosphatase and were negative for myeloperoxidase, chloroacetate esterase, and alpha-naphthyl acetate esterase. On flow cytometric analysis of peripheral blood, the neoplastic cells were positive for CD11b and CD14. These findings were consistent with chronic eosinophilic leukemia. To our knowledge, this is the first report of chronic eosinophilic leukemia in a cat associated with naturally acquired FeLV infection, in which flow cytometry was used to characterize the neoplastic cells.     

Diversity of the infracommunities of strongylid nematodes in the ventral colon of Equus caballus from Rio de Janeiro state, Brazil

Nematodes from the ventral colon of 31 adult horses, 24 males and 9 females, in the metropolitan region of the state of Rio de Janeiro were analysed. There were 53,444 (86.4%) adults of the total recovered strongylid nematodes. They belonged to 21 species of Cyathostominae and seven of Strongylinae. Larval forms made up 13.6% (8407) of the total recovered, and 49% of the strongylid nematodes were observed in ventral colon. The most prevalent and abundant species were Cyathostomum tetracanthum, Cylicocyclus nassatus, Cylicostephanus minutus, Cylicostephanus longibursatus, Cylicostephanus leptostomus, Cylicostephanus calicatus and Cylicostephanus goldi, corresponding to 93.2% of the total adult population; these species were classified as central species, except C. goldi; and other species were classified as secondary (n = 8) and satellite (n = 14). The low Green's aggregation index, presented to central species, indicated high dispersion because they were found in a greater number of infracommunities and were proven by the greater prevalence. Only 12.1% of the horses were uninfected or infected by a single species; the other infections were multiple, ranging from 3 to 23 species.     

Allelopathic effects of Araucaria angustifolia needle extracts in the growth of Lactuca sativa seeds

Araucaria forest, named due to the high abundance of Araucaria angustifolia, occurs mainly in the southern Brazilian highlands, and the abundance of A. angustifolia in the forest is a current forest issue. The present study aimed at evaluating a potential allelopathic effect of A. angustifolia needle extracts that could mediate plant successional dynamics in the Araucaria forests. Senescent araucaria needles from A. angustifolia were evaluated for their allelopathic potential on Lactuca sativa through an in vitro study. The effect was evaluated by determining the germination of seeds, length of seedling and germination rate. The allelopathic potential of the A. angustifolia was confirmed for the highest doses tested (187.5 and 250?mg of the extracts). The potential allelochemical compounds identified were ent-kaurene and phyllocladene. In conclusion, A. angustifolia showed a potential allelophatic effect that may play an important role in successional dynamics of Araucaria forests.     

Examination of the failure behavior of wood with a short crack in the radial–longitudinal system by single-edge-notched bending test

The failure behavior of wood with a short crack was examined by conducting the single-edge-notched bending tests of a radial-longitudinal system on Agathis specimens. In the test, the mode I critical stress intensity factor was measured, and its validity was checked by the result from double cantilever beam testing method. The mode I critical stress intensity factor decreased when the crack length approached zero. With crack length correction, a constant critical stress intensity factor was obtained over a wide range of crack length including crack-free specimen.