Guar gum effects on food intake,blood serum lipids and glucose levels of Wistar rats

The effects of guar gum derived from the endosperm of Cyamopsis tetragonoloba (75% soluble fiber, 7.6% insoluble fiber, 2.16% crude protein, 0.78% total lipids, 0.54% ash and 9.55% moisture) on food intake, levels of blood serum cholesterol, triacylglycerols, glucose and LDL and HDL-cholesterol were studied. The effects of guar gum on indices of protein absorption and utilization were also investigated. Diets containing 0%, 10% and 20% (w/w) guar gum or 10% and 20% cellulose powder (reference) were fed to normal rats for 60 days. The rats fed the guar gum diets showed significantly (p 0.05) lower levels of blood serum cholesterol, triacylglycerols, reduced food intake and body weight gain. Furthermore, a concomitant increase in HDL-cholesterol with a substantial elevation of the HDL/LDL cholesterol ratio were noted. Guar gum decreased blood serum glucose only during the first month of the experiment, and no changes in the indices of protein absorption and utilization were found. The guar gum caused a 10% increase in the small intestine length and a 25% retardation in the intestinal transit. The results of this research suggested that guar gum could potentially be effective in the treatment of hypercholesterolemia and obesity in humans.     

Carbon stocks in a 50‑year‑old Eucalyptus camaldulensis stand in Sicily,Italy

Eucalyptus stands in semi?arid areas may contribute to enhance carbon (C) stocks in both biomass and soil. However, the limited information available is mainly focused on short?rotation plantations. In this study, the above? and below?ground C pools in five 50?year?old Eucalyptus camaldulensis Dehnh. stands planted on Miocenic evaporitic deposits in Sicily, Italy, with a xeric and thermic pedoclimate, were measured. Above?ground biomass was determined by partitioning and weighing branches, stem and leaves. Below?ground C pools included the determination of litter, root biomass, and soil organic and inorganic C. In terms of the above?ground biomass, the E. camaldulensis stand accumulated on average 116?Mg ha?1 corresponding to 55?Mg C ha?1. Below?ground biomass consisted mainly of larger roots, followed by fine and medium roots (33?Mg ha?1 corresponding to 14?Mg C ha?1). Litter accumulation on the soil surface accounted for 13?Mg ha?1 corresponding to 5?Mg C ha?1. The amount of C stored in soil was 554?Mg C ha?1, of which 75% was in organic form. Although E. camaldulensis is planted extensively throughout the Southern Hemisphere and tropics where it is managed over short rotations (c. 2–4 years), the results obtained from this study make this species important in terms of future afforestation planning for longer rotations due to its potential to sequester C, particularly in the below?ground components.     

Effect of host allelic dosage on Triticum aestivum–Puccinia recondita specific interaction

Allelic dosage changes in host-pathogen interactions (Triticum aestivum–Puccinia recondita) explain different situations where resistance or susceptibility is observed. Remarkably, the prediction of an interaction change (from compatible to incompatible) by increasing single host allelic dosage is confirmed. Cases of more lasting resistance could also be explained on the basis of these dosage effects. In addition a parallel between specific and nonspecific resistance is established pointing out their basic differences in expression with respect to allelic dosage effects. These situations, together with new possibilities for breeding arising from this knowledge, are discussed.     

Relationship between grain yield and grain nitrogen concentration in winter triticale

Summary Ten hexaploid winter triticale lines were grown for two cropping periods at three locations in western Switzerland. Averaged across the six environments, the differences between lines were statistically significant (P=0.05) for grain yield, above-ground biomass, N uptake, grain N yield, nitrogen harvest index, grain N concentration and straw N concentration. There were significant line x environment interactions for all traits. Grain yield and grain N concentration were inversely related (r=–0.74^**). Diagrams in which grain yields were plotted against grain N concentration were used to identify lines with a consistently unusual combination of grain yield and grain N concentration. Despite comparable grain yields, Line 3 had a high grain N concentration, while that of Line 7 was low. Line 3 was superior to Line 7 in both N uptake and N harvest index. Averaged across environments and lines, the N harvest index was 0.73 which corresponds to N harvest indices reported for bread wheat in the same region. We considered the feasibility of developing triticale lines which would outperform the best recent ones in N uptake and partitioning. However, we doubted that this would bring about a marked increase in grain N concentration, because, in the long run, the expected genetic progress in grain yield will lead to a dilution of grain protein by grain carbohydrate increments.Abbreviations GNC grain N concentration - GNY grain N yield - GY grain yield - HI above-ground dry matter harvest index - NHI nitrogen harvest index - SNC straw N concentration - TB total above-ground biomass - TPN total plant N     

Tritrichomonas foetus infection in cats with diarrhoea in a rescue colony in Italy

Faecal samples from 74 cats with chronic large bowel diarrhoea that were living in a rescue colony in Italy, were submitted for assessment of Tritrichomonas foetus by direct microscopy of faecal smears (n=20) and T foetus-specific culture (n=74), with confirmation by polymerase chain reaction (n=1). Twenty-four of the cats (32%) were found to be infected with T foetus. The infected cats were predominantly over a year of age (67%) and were all neutered non-pedigree domestic cats.     

Milk yield and composition of lactating Comisana ewes fed total mixed rations containing nitrogen sources with different ruminal degradability

The objective of this study was to examine the effects of pelleted total mixed rations (PTMR) containing two crude protein (CP) levels and N sources with different ruminal degradability on milk yield and composition of lactating ewes. The experiment, which lasted 14 weeks, was conducted during the spring and summer of 2007 and used 80 multiparous Comisana ewes in mid-lactation, reared in permanent stabling. A 2 × 2 factorial design was used, with ewes receiving two levels of CP (low 15.5% CP and high 17.5% CP) and two type of N sources with different rumen degradable protein (low and high) for each dietary treatment: (1) high-degradable protein diet (17.5% CP) composed by soybean meal, sunflower meal and urea (HPHD), (2) low-degradable protein diet (17.5% CP) included only corn gluten meal (HPLD), (3) high-degradable protein diet (15.5% CP) composed by soybean meal, sunflower meal and urea (LPHD), and (4) low-degradable protein diet (15.5% CP) included only corn gluten meal (LPLD). In order to evaluate in vivo digestibility of PTMRs, four adult rams were placed in metabolic cages and their individual faeces and urine were collected. In the performance trial, ewe milk yield was recorded daily and Individual milk samples were analysed weekly for milk composition and to determine milk renneting parameters. The 17.5% CP diets led to better nutrient apparent digestibility coefficients and had positive effects on milk production than the 15.5% CP diets. Similar results were obtained for corn gluten meal diets, compared to diets containing soybean meal, sunflower meal and urea. Data showed that corn gluten meal diets have had a positive effects on milk fat (P < 0.05), but not on milk protein, lactose and renneting parameters. All ewes gained weight during the experimental period, but the body weight change was not significant among treatments. Our findings indicate that an increase in rumen undegradable protein (RUP) content does not negatively affect nutrient digestibility of sheep rations and milk yield and composition.     

Influence of drought on tree rings and tracheid features of Pinus nigra and Pinus sylvestris in a mesic Mediterranean forest

We investigated the influence of climate on the ring width and xylem anatomy of two co-occurring pines (Pinus nigra Arn. and P. sylvestris L.) in the mountains of east-central Spain in order to test their utility for dendroclimatic reconstructions. We developed chronologies of ring width, mean lumen diameter and mean cell-wall thickness (in the earlywood, latewood, and the total annual ring) and the number of cells between 1960 and 2006. Drought, expressed as the standardized precipitation-evapotranspiration index (SPEI), was the main climatic driver of tree radial growth, although trees were also sensitive to temperature (negative effect in previous autumn and current summer) and precipitation (with a general positive effect). P. sylvestris response was stronger to climate of the current year, whereas the effect of previous-year climate was more important for P. nigra. Warm and dry summers reduced ring width, tracheid lumen, and wall thickness in both species, whereas warm winter-spring temperatures had the opposite effect, primarily for P. sylvestris. Previous-year or early-season conditions mainly affected earlywood features, whereas latewood was more responsive to summer climate. Overall, climate appeared to be a stronger limiting factor for P. sylvestris. During periods of drought, cell-wall thickness was reduced while lumen width increased in the latewood of P. sylvestris. This could compromise its hydraulic safety against drought-induced cavitation as our site was close to the southern and dry edge of the species distribution area. Our results suggest that anatomical variables record different and stronger climate information than ring width variables, especially in P. sylvestris. Reconstruction models for SPEI at the 3-month scale were developed for July–August and September–October using principal components regression. The best models included anatomical and width variables of both pine species suggesting that tracheid chronologies can be useful for drought reconstructions especially at mesic sites or with species that encode a mixed drought and temperature-precipitation signal.     

Cassava common mosaic virus infection causes alterations in chloroplast ultrastructure,function, and carbohydrate metabolism of cassava plants

Cassava common mosaic virus (CsCMV) is a potexvirus that causes systemic infections in cassava plants, leading to chlorotic mosaic and producing significant yield losses. To date, the physiological alterations and the mechanism underlying biotic stress during the cassava–CsCMV compatible interaction remains unknown. In this study, we found that CsCMV infection adversely modified chloroplast structure and had functional effects on chloroplasts in source leaves during the course of viral infection. Extrusion of the chloroplast membrane with amoeboid-shaped appearance and disorganized grana stacks were observed in infected mesophyll cells. These alterations were associated with up to 35% reduction of relative chlorophyll content, and a decline of CO₂ fixation (13.5% and 24.2% at 90 and 210 days after planting, respectively). The effects of CsCMV infection on the performance index on absorption basis dropped up to 37%. The analysis of chlorophyll a fluorescence showed a progressive loss of both oxygen evolving complex activity and “connectivity” within the tripartite system (core antenna-LHCII-reaction centre). Here, we report the latter phenomenon for the first time in a viral infection. The oxidative stress process was observed in CsCMV-infected plants (20.8% reduction of antioxidant capacity with respect to noninfected plants). Other effects of the pathogen included reduction of starch and maltose content in source leaves, and a significant increase (24.7%) of the sucrose:starch ratio, which indicates an altered pattern of carbon allocation. Our results suggest that CsCMV induces chloroplast distortion associated with progressive chloroplast function loss and diversion of carbon flux in source leaf tissue, leading to the loss of cassava tuber yield.     

Flow cytometric analysis of colonic and small intestinal mucosal lymphocytes obtained by endoscopic biopsy in the healthy dog

Flow cytometric analysis of the lymphocyte population of the gut could provide useful information on the immune cells present in the gut that would not be easily obtained in tissue sections. However, little is known of the normal lymphocyte population in the canine gut as determined by flow cytometry, which allows for simultaneous staining of multiple cell surface antigens and identification of specific lymphocytic subsets. Therefore, intraepithelial lymphocytes were obtained from biopsies of the healthy canine proximal small intestine and colon taken with an endoscope, and flow cytometric analysis was used to characterize the lymphocyte subsets present. Endoscopic biopsy of the intestine is a minimally invasive technique commonly used for diagnostic purposes. Although CD3+ lymphocytes were the most abundant subset in both colon and small intestine, CD3+/CD8- lymphocytes predominated in the proximal small intestine, whereas CD3+/CD8+ lymphocytes did in the colon. Canine CD8+ intraepithelial lymphocytes were predominantly CD8alphabeta+ in both small intestine and colon. CD4+ intraepithelial lymphocytes were always much less numerous than CD8+ intraepithelial lymphocytes. As in man, a majority of intraepithelial lymphocytes expressed the T-cell receptor, TCRalphabeta, but TCRgammadelta was expressed by a third of intraepithelial T-cells in the proximal small intestine, and approximately 15% of those in the colon. Very few CD21+ lymphocytes were detected in samples of healthy canine colon and small intestinal intraepithelial cells. We have showed that canine intraepithelial lymphocytes are regionally specialized, and that those from the small intestine are unique in comparison to those of other species such as man and rodents due to the large numbers of CD3+/CD8- intraepithelial lymphocytes. This study provides a baseline for comparison with intraepithelial lymphocytes obtained from canine patients with intestinal disease.