Expression of inducible nitric oxide synthase in macrophages inversely correlates with parasitism of lymphoid tissues in dogs with visceral leishmaniasis     

Fran?oise P Sanches  Thaise Y Tomokane  Vania LR Da Matta  Mary Marcondes  Carlos EP Corbett  Márcia D Laurenti 《Acta veterinaria Scandinavica》2014,56(1)

Background

There are only a few studies reporting the role of nitric oxide metabolites for controlling macrophage intracellular parasitism, and these are controversial. Therefore, the present study aimed to evaluate the expression of inducible nitric oxide synthase (iNOS) in the lymph nodes and spleen of dogs affected by visceral leishmaniasis through immunohistochemistry and to determine its correlation with tissue parasite burden and serum interferon (IFN)-γ levels. Twenty-eight dogs were selected and assigned to one of two groups, symptomatic (n = 18) and asymptomatic (n = 10), according to clinical status and laboratory evaluation. A negative control group (n = 6) from a non-endemic region for visceral leishmaniasis was included as well.

Results

Parasite density (amastigotes/mm²) was similar between clinical groups in the lymph nodes (P = 0.2401) and spleen (P = 0.8869). The density of iNOS⁺ cells was higher in infected dogs compared to controls (P < 0.05), without a significant difference in lymph node (P = 0.3257) and spleen (P = 0.5940) densities between symptomatic and asymptomatic dogs. A positive correlation was found between the number of iNOS⁺ cells in lymph nodes and interferon-γ levels (r = 0.3776; P = 0.0303), and there was a negative correlation between parasites and iNOS⁺ cell densities both in lymph nodes (r = −0.5341; P = 0.0034) and spleen (r = −0.4669; P = 0.0329).

Conclusion

The negative correlation observed between tissue parasitism and the expression of iNOS may be a reflection of NO acting on the control of parasites.  相似文献   

Diversity of non‐structural carbohydrates in grasses (Poaceae) from Brazil     

M. G. Moraes  N. J. Chatterton  P. A. Harrison  T. S. Filgueiras  R. C. L. Figueiredo‐Ribeiro 《Grass and Forage Science》2013,68(1):165-177

Non‐structural carbohydrates (NSC) are the primary energy available for growth and dry‐mass production in forage grasses. They are also associated with tolerance to environmental stresses, including drought. Soluble carbohydrates, especially fructans of temperate forage grasses, have been extensively studied; however, little is known about NSC of tropical grasses. These plants are abundant in the Cerrado, a savanna‐like vegetation with a definite seasonality in rainfall distribution. Such an environment presents an ideal condition for the occurrence of fructans. However, the present analysis of carbohydrates in aerial parts of twenty‐four tropical grass species, mainly from the Panicoideae subfamily in the Cerrado, shows a distinctively different NSC profile when compared with temperate grasses. Free glucose and starch are common NSC found in most plant organs. However, free fructose and sucrose‐based oligosaccharides were only found in very low amounts. Sucrose was detected in higher amounts only in stems. A linear series of malto‐oligosaccharides was found in leaf blades, sheaths and stems of most of the Cerrado grasses, except for those from the Andropogoneae tribe. These results indicate a diversity of regulatory pathways of NSC metabolism in tropical forage grasses from the Cerrado.  相似文献   

Pathogenesis of reproductive failure induced by Trypanosoma vivax in experimentally infected pregnant ewes     

Taciana MF Silva  Roberio G Olinda  Carla MF Rodrigues  Ant?nio CL Camara  Francisco C Lopes  Wesley AC Coelho  Múcio FB Ribeiro  Carlos IA Freitas  Marta MG Teixeira  Jael S Batista 《Veterinary research》2013,44(1):1

The present study was aimed at investigating the effect of experimental infection by Trypanosoma vivax in different stages of pregnancy, determining the pathogenesis of reproductive failure, and confirming transplacental transmission. We used 12 pregnant ewes distributed into four experimental groups: G1, was formed by three ewes infected with T. vivax in the first third of pregnancy (30 days); G2 comprised three infected ewes in the final third of pregnancy (100 days); G3 and G4 were composed of three non-infected ewes with the same gestational period, respectively. Each ewe of G1 and G2 was inoculated with 1.25 × 10⁵ tripomastigotes. Clinical examination, determination of parasitemia, serum biochemistry (albumin, total protein, glucose, cholesterol, and urea), packed cell volume (PCV), serum progesterone, and pathological examination were performed. Placenta, amniotic fluid, blood and tissues from the fetuses and stillbirths were submitted to PCR. Two ewes of G1 (Ewe 1 and 3) presented severe infection and died in the 34^th and 35^th days post-infection (dpi), respectively; but both fetuses were recovered during necropsy. In G2, Ewe 5 aborted two fetuses on the 130^th day (30 dpi) of pregnancy; and Ewe 6 aborted one fetus in the 140^th day (40 dpi) of gestation. Ewes 2 and 4 delivered two weak lambs that died five days after birth. Factors possibly involved with the reproductive failure included high parasitemia, fever, low PCV, body score, serum glucose, total protein, cholesterol, and progesterone. Hepatitis, pericarditis, and encephalitis were observed in the aborted fetuses. The presence of T. vivax DNA in the placenta, amniotic fluid, blood, and tissues from the fetuses confirms the transplacental transmission of the parasite. Histological lesion in the fetuses and placenta also suggest the involvement of the parasite in the etiopathogenesis of reproductive failure in ewes.  相似文献   

Extracts of Peels and Seeds of Five Varieties of Brazilian Jabuticaba Present High Capacity to Deactivate Reactive Species of Oxygen and Nitrogen     

Paludo  Michelly Cristiane  de Oliveira  Luciana Fontes  Hermosín-Gutiérrez  Isidro  Ballus  Cristiano Augusto  Ribeiro  Alessandra Braga  de Oliveira  Silvia Borges Pimentel  Godoy  Helena Teixeira 《Plant foods for human nutrition (Dordrecht, Netherlands)》2019,74(1):135-140

Plant Foods for Human Nutrition - Jabuticaba has a high concentration of phenolic compounds, which have a significant antioxidant capacity. Methodologies have been developed to evaluate the ability...  相似文献   

Effect of Freeze-Dried Red Beet (Beta vulgaris L.) Leaf Supplementation on Biochemical and Anthropometrical Parameters in Overweight and Obese Individuals: a Pilot Study     

de Castro  Ana Paula Ribeiro Barcelos  da Cunha  Diogo Thimoteo  Antunes  Adriane Elisabete Costa  Corona  Ligiana Pires  Bezerra  Rosângela Maria Neves 《Plant foods for human nutrition (Dordrecht, Netherlands)》2019,74(2):232-234

Plant Foods for Human Nutrition - Obesity is an important public health concern and is directly related with chronic noncommunicable diseases that affect the health of millions of people around the...  相似文献   

Correlation between the pattern volatiles and the overall aroma of wild edible mushrooms     

de Pinho PG  Ribeiro B  Gonçalves RF  Baptista P  Valentão P  Seabra RM  Andrade PB 《Journal of agricultural and food chemistry》2008,56(5):1704-1712

  相似文献   

Yerba Maté (Ilex paraguariensis) aqueous extract decreases intestinal SGLT1 gene expression but does not affect other biochemical parameters in alloxan-diabetic Wistar rats     

Oliveira DM  Freitas HS  Souza MF  Arçari DP  Ribeiro ML  Carvalho PO  Bastos DH 《Journal of agricultural and food chemistry》2008,56(22):10527-10532

Yerba maté (Ilex paraguariensis) is rich in polyphenols, especially chlorogenic acids. Evidence suggests that dietary polyphenols could play a role in glucose absorption and metabolism. The aim of this study was to evaluate the antidiabetic properties of yerba maté extract in alloxan-induced diabetic Wistar rats. Animals (n = 41) were divided in four groups: nondiabetic control (NDC, n = 10), nondiabetic yerba maté (NDY, n = 10), diabetic control (DC, n = 11), and diabetic yerba maté (DY, n = 10). The intervention consisted in the administration of yerba maté extract in a 1 g extract/kg body weight dose for 28 days; controls received saline solution only. There were no significant differences in serum glucose, insulin, and hepatic glucose-6-phosphatase activity between the groups that ingested yerba maté extract (NDY and DY) and the controls (NDC and DC). However, the intestinal SGLT1 gene expression was significantly lower in animals that received yerba maté both in upper (p = 0.007) and middle (p < 0.001) small intestine. These results indicate that bioactive compounds present in yerba maté might be capable of interfering in glucose absorption, by decreasing SGLT1 expression.  相似文献   

Assessment and up-scaling of CO₂ exchange by patches of the herbaceous vegetation mosaic in a Portuguese cork oak woodland     

Yue-Lin Li  J. Tenhunen  H. Mirzaei  M.Z. Hussain  L. Siebicke  T. Foken  D. Otieno  M. Schmidt  N. Ribeiro  L. Aires  C. Pio  J. Banza  J. Pereira 《Agricultural and Forest Meteorology》2008,148(8-9):1318-1331

Long-term eddy covariance measurements over a montado oak woodland in southern Portugal have documented a vulnerability to predicted decreases in springtime rainfall, since water availability during spring limits annual CO₂ gain, the growth of fodder for animals, and the production of cork by Quercus suber. The current study examined CO₂ exchange of three different herbaceous vegetation components distributed over montado landscapes and within the footprint of long-term landscape eddy covariance monitoring studies. Simultaneous measurements with eddy covariance at two sites and with manually operated chambers at multiple locations revealed that slow drainage of shallow basins, the onset of drying at higher sites and a high release of CO₂ below tree canopies significantly influenced the overall course of montado ecosystem gas exchange during the spring.Hyperbolic light response models were employed to up-scale and compare herbaceous gas exchange with landscape net ecosystem CO₂ flux. The up-scaling demonstrates the importance of the herbaceous understory in determining annual carbon balance of the montado and suggests a relatively small additional CO₂ uptake by the tree canopies and boles, i.e., by the aboveground tree compartment, during springtime. Annual flux totals obtained during the extremely dry year 2005 and a normal precipitation year 2006 for the oak woodland and a nearby grassland were essentially the same, indicating that both ecosystems similarly exploit available resources. Based on comparisons with additional temperate grasslands, we can visualize the montado herbaceous cover as a typical European grassland canopy, but where temperature fluctuations in winter control uptake, and where total production depends on springtime rainfall as it controls phenological events and eventually dieback of the vegetation. On the other hand, tree canopies remain active longer during late spring and early summer, modifying the montado response from that of grassland. Uncertainties in flux estimates via both chamber and eddy covariance methodologies currently prevent a full understanding of vegetation/atmosphere coupling, of the recycling of CO₂ between the understory communities and trees, and of relationships between exchange rates of individual components of the vegetation mosaic and overall carbon and water balances in montado landscapes.  相似文献   

Microbial HemG‐type protoporphyrinogen IX oxidase enzymes for biotechnology applications in plant herbicide tolerance traits     

Clayton T Larue  Joel E Ream  Xuefeng Zhou  Farhard Moshiri  Arlene Howe  Michael Goley  Oscar C Sparks  Steven T Voss  Erin Hall  Christine Ellis  Janice Weihe  Qungang Qi  Daniela Ribeiro  Xiaoping Wei  Shirley Guo  Artem G Evdokimov  Marguerite J Varagona  James K Roberts 《Pest management science》2020,76(3):1031-1038

  相似文献   

Uncertainty assessment of soya bean yield gaps using DSSAT‐CSM‐CROPGRO‐Soybean calibrated by cultivar maturity groups     

Wilson Wagner Ribeiro Teixeira  Rafael Battisti  Paulo Cesar Sentelhas  Milton Ferreira de Moraes  Adilson de Oliveira Junior 《Journal of Agronomy and Crop Science》2019,205(5):533-544

Soya bean yield gap can be caused by different factors resulting in uncertainties when the objective is to use such information for farm decision‐making and reference yield determination. Thus, this study aimed to quantify the soya bean yield gap for four sites, located in Southern and Midwestern Brazil, as well as the uncertainties of that related to cultivars, sowing dates, soil types and reference yields. The crop simulation model DSSAT‐CSM‐CROPGRO‐Soybean was calibrated for cultivars with similar maturity groups, based on the data obtained from the best farmers at the county level. The yield gap by water deficit (YG_WD) was obtained through the difference between potential and attainable yields, and that one caused by sub‐optimum crop management (YG_CM) by subtracting actual yield of each county, obtained from official statistics between 1989/90 and 2014/15 growing seasons, from the estimated attainable yield. The yield was simulated using four sowing dates, three soil types and two soya bean maturity groups by county. The reference yield uncertainty was quantified using yield reference from crop model and regional winners of the soya bean yield context, conducted by CESB (Brazilian Soybean Strategic Committee), for the growing seasons from 2013/14 to 2015/16. The crop model showed a good agreement between measured and simulated crop development and growth using calibration by maturity group, with low root mean square error (347 kg/ha). Southern sites had a mean YG_WD of 1,047 kg/ha, while in the Midwest, it was lower than 100 kg/ha. The YG_CM was 1,067, 528, 984 and 848 kg/ha, respectively, for Castro, PR, Mamborê, PR, Montividiu, GO and Primavera do Leste, MT, representing the opportunity for yield gain when having the best farmers as reference. The maturity groups, sowing dates and soil types showed to be an important source of uncertainty for yield gap determination, being recommended to investigate the farms in detail for an appropriate quantification. The reference yield showed expressive uncertainties, with some farmers presenting conditions to increase their soya bean yields by more than 3,000 kg/ha, when considering as reference the yields obtained by the winners’ farmers. These results show that uncertainties must be reduced when assessing farm yield gaps, in order to ensure that expected rate of soya bean yield growth could be reached by adopting the same technologies from CESB winners and best farmers in the county as a reference.  相似文献