Practical and Simple Systems for Food Intake Studies on Phloem-Sucking Insects.

Studies of insect feeding behavior are useful in different areas of entomology such as plant resistance, biology, and insecticide efficacy. For chewing insects, this kind of technique is well established, but for sap-sucking insects, especially tiny ones such as whiteflies, aphids, and psyllids, these tests can be laborious. Manipulation is difficult and can damage the plant, affecting the results. We describe here three types of cages for tests with small insects, one for seedlings in pots, a second for larger plants or plants in the field, and a third for caging insects on part of a leaf. These cages have been useful for different types of studies in addition to feeding behavior and can facilitate research with small phytophagous sucking insects.

Rheology and soft tribology of thickened dispersions aiming the development of oropharyngeal dysphagia-oriented products.

Dysphagia is a swallowing disorder that mainly affects elderly but can be minimized by thickening of liquid foods. Flaxseed gum (FG) was studied as a potential alternative thickener for dysphagia patients in comparison to commercial thickeners based on xanthan gum (XG) and modified starch (MS). Rheological and tribological responses of biopolymer-based thickening solutions (0.75-3% w/w) incorporated in different food matrices (water, orange-flavoured soy juice and skim milk) were recorded and correlated. In general, the increase in gums concentration led to increases in viscosity, viscoelastic properties and lubricating capacity. An opposite behavior was observed for the MS-based products, since an increase in concentration led to a lower increase in viscosity and viscoelastic properties but caused a decrease in the lubricating capacity. These results indicated that associating tribology to rheology is crucial to further define formulations with pleasant swallowing characteristics.

The Enemy is Outside: Releasing the Parasitoid Tamarixia radiata (Hymenoptera: Eulophidae) in External Sources of HLB Inocula to Control the Asian Citrus Psyllid Diaphorina citri (Hemiptera: Liviidae).

Huanglongbing (HLB), the most destructive citrus disease worldwide, was first recorded in Brazil in 2004, and since then, more than 50 million trees identified with this disease have been eliminated. The disease is managed mainly by controlling the psyllid vector Diaphorina citri Kuwayama, 1908 (Hemiptera: Liviidae). Although the presence of the insect in commercial citrus groves is low, HLB infection rates increase in areas bordering the groves. The disease is transmitted by psyllids from host citrus plants in areas outside the managed groves, such as abandoned or organic groves and residential trees, and from orange jasmine plants in urban settings. In order to provide information to support HLB control, this study evaluated the biotic and abiotic variables that affect the dynamics of D. citri populations after releases of the parasitoid wasp Tamarixia radiata (Waterston, 1922) (Hymenoptera: Eulophidae) in external sources of HLB inocula. The study was divided into two parts. After releasing the parasitoids in non-commercial areas, we determined the following: (a) the variables that significantly affected the number of nymphs collected on shoots in the same non-commercial area; (b) the variables that significantly affected the number of adult psyllids collected in a neighboring commercial citrus area. Our results indicated that the number of nymphs in external areas was affected only by the host plant and rainfall. However, periodic parasitoid releases significantly reduced the number of adult psyllids collected in the commercial area. The results indicate that the release of parasitoids in external sources of inocula has the potential to maximize actions for D. citri control, contributing to the reduction of psyllid populations in commercial areas. Consequently, this strategy may help to manage the disease infection without an increase in insecticide use.

Effect of extraction temperature on rheological behavior and antioxidant capacity of flaxseed gum.

Soluble flaxseed gum (SFG) extracted at different temperatures (25, 40, and 60 °C) was analyzed in relation to the yield, polysaccharides and phenolics composition, surface charge, color, and rheological properties. The yield of SFG extract increased as the extraction temperature increased. The SFG xylan was the main component regardless the extraction temperature, but a reduction of substituents on the xylose chain was observed when increasing the extraction temperature. The phenolic compounds were also affected by the extraction temperature, influencing the antioxidant capacity of the gum. For all the extraction temperatures, SFG aqueous solutions showed a shear time-independent and shear-thinning behavior. Furthermore, oscillatory measurements showed a prevailing viscous character, but the decrease of the extraction temperature resulted in an increase of both G' and G". Therefore, SFG extracted at low extraction temperatures showed higher viscous and elastic properties, while high extraction temperatures increased the antioxidant activity.

Energy and protein requirements for growth of Holstein × Gyr heifers.

There is little information regarding the nutritional requirements for dairy heifers, leading the majority of nutrient requirement systems to consider dairy heifers to be similar to beef heifers. Therefore, we evaluated the muscle protein metabolism and physical and chemical body composition of growing Holstein × Gyr heifers and estimated the energy and protein requirements. We performed a comparative slaughter experiment with 20 Holstein × Gyr heifers at an initial body weight of 218 ± 36.5 kg and an average age of 12 ± 1.0 months. Four heifers were designated as the reference group, and the 16 remaining heifers were fed ad libitum. The 16 heifers were distributed using a completely randomized design in a 2 × 2 factorial arrangement with two roughages (corn silage or sugarcane) and two concentrate levels (30 or 50%) for 112 days. Greater (p < 0.05) values for fractional rates of muscle protein synthesis, degradation and accretion were observed for heifers that were fed 50% concentrate. The following equations were obtained to estimate the net energy for gain (NEg ) and net protein for gain (NPg ): NEg (Mcal/day) = 0.0685 × EBW0.75  × EBWG1.095 and NPg (g/day) = 203.8 × EBWG - 14.80 × RE, respectively, in which EBW is the empty body weight, EBWG is the empty body weight gain and RE is the retained energy. We concluded that increased rates of protein turnover are achieved when a greater quality diet is provided. In the future, these results can be used to calculate the nutritional requirements for growth of Holstein × Gyr heifers after equation validation rather than using the recommendations provided by other systems, which use values developed from beef heifers, to determine the nutritional requirements of dairy cattle.

Urinary MCP-1 and RBP: independent predictors of renal outcome in macroalbuminuric diabetic nephropathy.

BACKGROUND: Albuminuria has been considered a sine qua non condition for the diagnosis of diabetic nephropathy (DN) and has been widely used as a surrogate outcome of chronic kidney disease (CKD). However, recent data suggest that albuminuria may fail as a biomarker in a subset of patients, and the search for novel markers is intense. METHODS: We analyzed the role of urinary RBP and of serum and urinary cytokines (TGF-beta, MCP-1 and VEGF) as predictors of the risk of dialysis, doubling of serum creatinine or death (primary outcome, PO) in 56 type 2 diabetic patients with macroalbuminuric DN. RESULTS: Mean follow-up time was 30.7±10 months. Urinary RBP and MCP-1 were significantly higher in patients presenting the PO, whereas no difference was shown for TGF-ß or VEGF. In the Cox regression, urinary RBP, MCP-1 and VEGF were positively associated and serum VEGF was inversely related to the risk of the PO. However, after adjustments for creatinine clearance, proteinuria, and blood pressure only urinary RBP (OR 11.6; 95% CI 2.7-49.2, p=0.001 for log RBP) and urinary MCP-1 (OR 11.0; 95% CI 1.6-76.4, p=0.02 for log MCP-1) remained as significant independent predictors of the PO. CONCLUSION: Urinary RBP and MCP-1 are independently related to the risk of CKD progression in patients with macroalbuminuric DN. Whether these biomarkers have a role in the setting of normoalbuminuria and microalbuminuria in DN should be further investigated.

Atividade antimicrobiana de extratos etanólicos de Peperomia pellucida e Portulaca pilosa / Antimicrobial activity of ethanol extracts of Peperomia pellucida and Portulaca pilosa

As plantas utilizadas na medicina tradicional estão sendo cada vez mais estudadas por serem possíveis fontes de substâncias com atividades antimicrobianas. Dentre elas, destacando-se a Peperomia pellucida (erva-de-jabuti) e a Portulaca pilosa (amor-crescido), utilizadas comumente na Amazônia. A P. pellucida é utilizada, popularmente, em casos de hemorragia, como curativo para feridas, dores abdominais, abscessos, acne, furúnculos, cólicas, problemas renais, hipertensão e colesterol, enquanto a P. pilosa é utilizada como hepato-protetor, antidiarreico, diurético, para queimaduras, erisipelas e ferimentos. Neste trabalho, foram realizadas a abordagem fitoquímica e a atividade antimicrobiana in vitro desses dois materiais vegetais. A prospecção fitoquímica revelou a presença de açúcares redutores, fenóis e taninos, esteroides e triterpenoides, glicosídios cardíacos e carotenoides no extrato etanólico seco (EES) de P. pillosa, e a presença de proteínas e aminoácidos, fenóis e taninos, flavonoides, esteroides e triterpenoides, azulenos, carotenoides, depsídios e depsidonas no EES de P. pellucida. Para avaliação da atividade antimicrobiana dos extratos etanólicos brutos, foi empregado o método de disco difusão em ágar, nas concentrações de 500; 250; 125 e 62,5 µg/mL. Os extratos testados que apresentaram atividade antimicrobiana na avaliação preliminar foram submetidos à determinação da concentração inibitória mínima (CIM) pela técnica de microdiluição em caldo. O extrato de P. pellucida possui atividade antimicrobiana frente a S. aureus e P. aeruginosa, e o de P. pilosa contra Pseudomonas aeruginosa.

Plants used in traditional medicine are under increasing scrutiny as possible sources of substances with antimicrobial activity. In this article we focus on Peperomia pellucida (erva-de-jabuti) and Portulaca pilosa (amor crescido), both commonly used in the Amazon. P. pellucida is popularly used as a wound dressing, to stop bleeding, and in cases of abdominal pain and cramps, abscesses, acne, boils, kidney problems, hypertension and raised cholesterol, and P. pilosa as a hepato-protective, antidiarrheal and diuretic and for burns, erysipelas and injuries. In this study, we investigated the phytochemistry and antimicrobial activity of extracts of these two plant materials. Phytochemical screening revealed the presence of reducing sugars, phenols and tannins, steroids and terpenoids, cardiac glycosides and carotenoids in the dried ethanol extract (DEE) of P. pilosa and of proteins and amino acids, phenols and tannins, flavonoids, steroids and triterpenoids, azulenes, carotenoids, depsides and depsidones in the P. pellucida DEE. The antimicrobial activity of the ethanol extracts was assayed by the agar disc diffusion method, at concentrations of 500, 250, 125 and 62.5µg/mL. The plant extracts that showed antimicrobial activity in the preliminary assessment were subjected to the broth microdilution test to determine the minimum inhibitory concentration (MIC). The P. pellucida extract had antimicrobial activity against S. aureus and P. aeruginosa and that of P. pilosa against P. aeruginosa.

Bacteroides fragilis induce necrosis on mice peritoneal macrophages: In vitro and in vivo assays.

Bacteroides fragilis is an anaerobic bacteria component of human intestinal microbiota and agent of infections. In the host B. fragilis interacts with macrophages, which produces toxic radicals like NO. The interaction of activated mice peritoneal macrophages with four strains of B. fragilis was evaluated on this study. Previously was shown that such strains could cause metabolic and morphologic alterations related to macrophage death. In this work propidium iodide staining showed the strains inducing macrophage necrosis in that the labeling was evident. Besides nitroblue tetrazolium test showed that B. fragilis stimulates macrophage to produce oxygen radicals. In vivo assays performed in BalbC mice have results similar to those for in vitro tests as well as scanning electron microscopy, which showed the same surface pore-like structures observed in vitro before. The results revealed that B. fragilis strains studied lead to macrophage death by a process similar to necrosis.

Statin monotherapy attenuates renal injury in a salt-sensitive hypertension model of renal disease.

BACKGROUND: Several salutary biological effects of statins have been described. We sought to investigate more closely the anti-inflammatory and antiproliferative effects of simvastatin (SIMV) in a model of hypertension and progressive renal disease, as well as its effects on the cyclin-cdk inhibitors p21 and p27. METHODS: Munich-Wistar rats received the nitric oxide (NO) synthase inhibitor L-NAME (25 mg/kg/day p.o.) for 20 days accompanied by a high-salt diet (HS, 3% Na) and then were kept on HS for 60 days. Animals were then divided into two groups: vehicle (VH) or SIMV 2 mg/kg/day p.o. Albuminuria and tail-cuff pressure were determined at 30 and 60 days. RT-PCR was done to assess renal expression of TGF-beta1, collagen I and III, fibronectin, p27, p21 and monocyte chemoattractant protein-1 (MCP-1). Renal protein expression was assessed by Western blot (proliferating cell nuclear antigen (PCNA)) and immunostaining (macrophage, lymphocyte, PCNA). RESULTS: SIMV did not prevent the development of severe hypertension or albuminuria. SIMV-treated animals had less severe renal interstitial inflammation and cell proliferation. MCP-1 expression was significantly diminished in the SIMV-treated animals (55.4 +/- 7.3 vs. 84.4 +/- 8.2 OD, p = 0.02). mRNA renal expression for p27 and TGF-beta did not change between groups, but p21 mRNA renal expression, highly induced in this model, significantly decreased with SIMV treatment (31.6 +/- 6.6 vs. 50.2 +/- 5.8 OD, p < 0.05). The interstitial fibrosis score significantly decreased with SIMV (2.46 +/- 0.40 vs. 4.07 +/- 0.38%, p < 0.01), which was confirmed by a decrease in renal collagen I and fibronectin expression. Serum cholesterol level did not change with SIMV. CONCLUSION: SIMV attenuated interstitial fibrosis associated with this model of hypertensive renal disease. The mechanism involved MCP-1 downregulation. SIMV treatment was also associated with a p21 downregulation in the kidney, which might be involved in the protection of renal scarring.

Evaluation of the cariogenic potential of cassava flours from the Amazonian region.

Cassava flour is the main dietary carbohydrate source in the Amazonian region. The cariogenic potentials of the two main kinds of cassava flour - 'seca' and 'd'água' - were evaluated in vivo and in vitro. A sweet made from a regional fruit (cupuaçú) and a species of local fish (tambaqui) were used as positive and negative controls, respectively. For in vivo evaluation of dental plaque acidogenicity, the study had a crossover design, in four legs, with 19 volunteers in four treatment groups. Dental plaque pH was determined by the microtouch method before and for 60 min after food consumption. For in vitro evaluation, stimulated saliva of each volunteer was incubated with the food and pH variation was determined over 4 h. Carbohydrates were chemically determined in the flours and the majority was found to be water-insoluble. In vivo, plaque pH decreased significantly after the consumption of the sweet (p < 0.05), increased after the fish (p < 0.05), but did not change after intake of the flours (p > 0.05). In vitro, the flours were slowly fermented by bacteria present in saliva. The in vivo and in vitro findings suggest that, in the form that the main cassava flours from the Amazonian region of Brazil are customarily eaten, they may be considered to have no or very low cariogenicity.

Evaluation of the Cariogenic Potential of Cassava Flours from the Amazonian Region / Avaliação do potencial cariogênico da farinha de Cassava da região amazônica

Cassava flour is the main dietary carbohydrate source in the Amazonian region. The cariogenic potentials of the two main kinds of cassava flour - `seca` and `d`água` - were evaluated in vivo and in vitro. A sweet made from a regional fruit (cupua;ú) and a species of local fish (tambaqui) were used as positive and negative controls, respectively. For in vivo evaluation of dental plaque acidogenicity, the study had a crossover design, in four legs, with 19 volunteers in four treatment groups. Dental plaque pH was determined by the microtouch method before and for 60 min after food consumption. For in vitro evaluation, stimulated saliva of each volunteer was incubated with the food and pH variation was determined over 4 h. Carbohydrates were chemically determined in the flours and the majority was found to be water-insoluble. In vivo, plaque pH decreased significantly after the consumption of the sweet (p < 0.05), increased after the fish (p < 0.05), but did not change after intake of the flours (p > 0.05). In vitro, the flours were slowly fermented by bacteria present in saliva. The in vivo and in vitro findings suggest that, in the form that the main cassava flours from the Amazonian region of Brazil are customarily eaten, they may be considered to have no or very low cariogenicity

Antimicrobial resistance of strains of the Bacteroides fragilis group isolated from the intestinal tract of children and adults in Brazil.

The results of this study show that there is a high frequency of resistant species in the Bacteroides fragilis group in the intestinal tract of children and adults in Brazil. B. fragilis was not studied. Of the 73 strains examined, B. distasonis was the most resistant species to penicillin, cefoxitin, cefotaxime and clindamycin. High rates of multiresistance were found, most commonly to penicillin and clindamycin (18 of 36 strains). High levels of beta-lactamase production were detected in isolates showing high resistance to penicillin and multiresistance to the cephamycins, suggesting a widespread dissemination of such resistance.

Cyclosporine-induced interstitial fibrosis and arteriolar TGF-beta expression with preserved renal blood flow.

BACKGROUND: Cyclosporine A (CsA)-induced chronic nephrotoxicity is characterized by interstitial fibrosis and afferent arteriole hyalinosis. CsA lesion has been linked to maintained renal vasoconstriction and narrowing of the afferent arteriole lumen diameter, leading to preglomerular ischemia. We investigated the role of renal hemodynamics in CsA-induced transforming growth factor (TGF-beta) expression and interstitial fibrosis. METHODS: Groups of rats fed a low salt diet were given CsA 5 mg/kg/day (CsA) or the vehicle (olive oil, [VH]) s.c. and had the renal blood flow (RBF), glomerular filtration rate (GFR), mean arterial pressure, renal vascular resistance, renal histologic changes, and immunohistochemical features for macrophages and TGF-beta evaluated after 1, 2, and 8 weeks of treatment. RESULTS: At week 1, despite normal renal hemodynamics and MAP, there was a significant macrophage interstitial influx in CsA-treated rats (70+/-16 vs. 29+/-4 cells+/0.5 mm2, in CsA vs. VH, P=0.02) that was progressive with treatment (80+/-13 vs. 32+/-8 cells+/0.5 mm2, P=0.016 and 197+/-36 vs. 23+/-3 cells+/0.5 mm2, P=0.0002, CsA vs. VH at 2 and 8 weeks, respectively). After 2 weeks of treatment, CsA animals developed a significant interstitial fibrosis, with preserved RBF, even when it was assessed 2 hr after CsA injection. There was a significant increase in the immunostaining for TGF-beta in the juxtaglomerular arterioles in CsA-treated rats (48.6+/-3.8 vs. 35.1+/-1.1%, CsA vs. VH at 2 weeks, P<0.05 and 59.0+/-3.2 vs. 37.0+/-2.1%, CsA vs. VH at 8 weeks, P=0.0001). A significant and progressive GFR decrease followed the renal structural injury of CsA treatment. Arteriolar and glomerular anatomic injury were not found throughout the study. CONCLUSIONS: Low CsA doses might generate interstitial fibrosis without any decrease in RBF or structural arteriolar lesion evidence, possibly through early macrophage influx and increased TGF-beta expression. It clearly seems that CsA-induced ischemia and tubulointerstitial injury may occur independently, suggesting that chronic CsA nephrotoxicity may be very hard to prevent or even not be preventable at all.