Quantitative evaluation of experimental choroidal neovascularization by confocal scanning laser ophthalmoscopy: fluorescein angiogram parallels heparan sulfate proteoglycan expression

The objective of the present study was to develop a quantitative method to evaluate laser-induced choroidal neovascularization (CNV) in a rat model using Heidelberg Retina Angiograph 2 (HRA2) imaging. The expression of two heparan sulfate proteoglycans (HSPG) related to inflammation and angiogenesis was also investigated. CNV lesions were induced with argon laser in 21 heterozygous Zucker rats and after three weeks a fluorescein angiogram and autofluorescence exams were performed using HRA2. The area and greatest linear dimension were measured by two observers not aware of the protocol. Bland-Altman plots showed agreement between the observers, suggesting that the technique was reproducible. After fluorescein angiogram, HSPG (perlecan and syndecan-4) were analyzed by real-time RT-PCR and immunohistochemistry. There was a significant increase in the expression of perlecan and syndecan-4 (P < 0.0001) in retinas bearing CNV lesions compared to control retinas. The expression of these two HSPG increased with increasing CNV area. Immunohistochemistry demonstrated that the rat retina damaged with laser shots presented increased expression of perlecan and syndecan-4. Moreover, we observed that the overexpression occurred in the outer layer of the retina, which is related to choroidal damage. It was possible to develop a standardized quantitative method to evaluate CNV in a rat model using HRA2. In addition, we presented data indicating that the expression of HSPG parallels the area of CNV lesion. The understanding of these events offers opportunities for studies of new therapeutic interventions targeting these HSPG.

Dermatan sulfate reduces monocyte chemoattractant protein 1 and TGF-β production, as well as macrophage recruitment and myofibroblast accumulation in mice with unilateral ureteral obstruction

Selectins play an essential role in most inflammatory reactions, mediating the initial leukocyte-rolling event on activated endothelium. Heparin and dermatan sulfate (DS) bind and block P- and L-selectin function in vitro. Recently, we reported that subcutaneous administration of DS inhibits colon inflammation in rats by reducing macrophage and T-cell recruitment and macrophage activation. In the present study, we examined the effect of porcine intestinal mucosa DS on renal inflammation and fibrosis in mice after unilateral ureteral obstruction (UUO). Twenty-four adult male Swiss mice weighing 20-25 g were divided into 4 groups: group C (N = 6) was not subjected to any surgical manipulation; group SH (N = 6) was subjected to surgical manipulation but without ureter ligation; group UUO (N = 6) was subjected to unilateral ureteral obstruction and received no treatment; group UUO plus DS (N = 6) was subjected to UUO and received DS (4 mg/kg) subcutaneously daily for 14 days. An immunoblot study was also performed for TGF-β. Collagen (stained area ~3700 µm²), MCP-1 (stained area ~1700 µm²), TGF-β (stained area ~13% of total area), macrophage (number of cells ~40), and myofibroblast (stained area ~1900 µm²) levels were significantly (P < 0.05) higher in the UUO group compared to control. DS treatment significantly (P < 0.05) reduced the content of collagen (stained area ~700 µm²), MCP-1 (stained area ~160 µm²) and TGF-β (stained area ~5% of total area), in addition to myofibroblast (stained area ~190 µm²) and macrophage (number of cells ~32) accumulation in the obstructed kidney. Overall, these results indicate that DS attenuates kidney inflammation by reducing macrophage recruitment, myofibroblast population and fibrosis in mice submitted to UUO.

Correlation between sodium and potassium excretion in 24- and 12-h urine samples

Low-sodium and high-potassium diets have been recommended as an adjunct to prevention and treatment of hypertension. Analysis of these nutrients in 24-h urine has been considered the reference method to estimate daily intake of these minerals. However, 24-h urine collection is difficult in epidemiological studies, since urine must be collected and stored in job environments. Therefore, strategies for shorter durations of urine collection at home have been proposed. We have previously reported that collecting urine during a 12-h period (overnight) is more feasible and that creatinine clearance correlated strongly with that detected in 24-h samples. In the present study, we collected urine for 24 h divided into two 12-h periods (from 7:00 am to 7:00 pm and from 7:00 pm to 7:00 am next day). A sample of 109 apparently healthy volunteers aged 30 to 74 years of both genders working in a University institution was investigated. Subjects with previous myocardial infarction, stroke, renal insufficiency, and pregnant women were not included. Significant (P < 0.001) Spearman correlation coefficients (r s) were found between the total amount of sodium and potassium excreted in the urine collected at night and in the 24-h period (r s = 0.76 and 0.74, respectively). Additionally, the 12-h sodium and potassium excretions (means ± SD, 95% confidence interval) corresponded to 47.3 ± 11.2%, 95%CI = 45.3-49.3, and 39.3 ± 4.6%, 95%CI = 37.3-41.3, respectively, of the 24-h excretion of these ions. Therefore, these findings support the assumption that 12-h urine collected at night can be used as a reliable tool to estimate 24-h intake/excretion of sodium and potassium.

Evaluation of cardiovascular toxicity of carbon nanotubes functionalized with sodium hyaluronate in oral regenerative medicine

It has been demonstrated that carbon nanotubes (CNTs) associated with sodium hyaluronate (HY-CNTs) accelerate bone repair in the tooth sockets of rats. Before clinical application of HY-CNTs, it is important to assess their biocompatibility. Moreover, cardiac toxicity may be caused by the translocation of these particles to the blood stream. The aim of this study was to evaluate possible changes in cardiovascular function in male Wistar rats whose tooth sockets were treated with either CNTs or HY-CNTs (100 μg/mL, 0.1 mL). Blood pressure and heart rate were monitored in conscious rats 7 days after treatment. Cardiac function was evaluated using the Langendorff perfusion technique. The data showed no changes in blood pressure or heart rate in rats treated with either CNTs or HY-CNTs, and no significant changes in cardiac function were found in any of the groups. To confirm these findings, experiments were conducted in rats injected intraperitoneally with a high concentration of either CNTs or HY-CNTs (0.75 mg/kg). The same parameters were analyzed and similar results were observed. The results obtained 7 days following injection indicate that the administration of low concentrations of CNTs or HY-CNTs directly into tooth sockets did not cause any significant change in cardiovascular function in the rats. The present findings support the possibility of using these biocomposites in humans.

Dexamethasone and sodium carboxymethyl cellulose prevent postoperative intraperitoneal adhesions in rats

We aimed to evaluate the effects of the barrier agent sodium carboxymethyl cellulose (SCMC) with and without dexamethasone for the prevention of postoperative adhesion formation in a rat model of postoperative peritoneal adhesion. A total of 160 three-month old male and female Wistar rats underwent a laparotomy, and adhesions were induced by ileocecal abrasion. Rats were randomly assigned to 4 groups (n=40 each): group A, untreated; group B, treated with SCMC only; group C1, treated with SCMC + 3 mg dexamethasone, and group C2, treated with SCMC + 8 mg dexamethasone. After 12 days, adhesion formation and histopathological changes were compared. In groups A, B, C1, and C2, the mortality rates were 10, 5, 5, and 5%, respectively. In groups C1 and C2, the adhesions were filmy and easy to dissect and were milder compared with those in groups A and B. The total adhesion score in group C1 (3.38±0.49) was significantly lower than that of group B (6.01±0.57; P<0.01) or group A (8.01±0.67; P<0.05). There was no significant difference in adhesion formation between groups C1 and C2. Compared with groups A and B, groups C1 and C2 exhibited milder histopathological changes. SCMC in combination with dexamethasone can prevent adhesion formation and is a better barrier agent than SCMC alone. The safety and feasibility of SCMC in combination with dexamethasone to prevent adhesion formation after abdominal surgery warrants further clinical study.

Single-walled carbon nanotubes functionalized with sodium hyaluronate enhance bone mineralization

The aim of this study was to evaluate the effects of sodium hyaluronate (HY), single-walled carbon nanotubes (SWCNTs) and HY-functionalized SWCNTs (HY-SWCNTs) on the behavior of primary osteoblasts, as well as to investigate the deposition of inorganic crystals on titanium surfaces coated with these biocomposites. Primary osteoblasts were obtained from the calvarial bones of male newborn Wistar rats (5 rats for each cell extraction). We assessed cell viability using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay and by double-staining with propidium iodide and Hoechst. We also assessed the formation of mineralized bone nodules by von Kossa staining, the mRNA expression of bone repair proteins, and the deposition of inorganic crystals on titanium surfaces coated with HY, SWCNTs, or HY-SWCNTs. The results showed that treatment with these biocomposites did not alter the viability of primary osteoblasts. Furthermore, deposition of mineralized bone nodules was significantly increased by cells treated with HY and HY-SWCNTs. This can be partly explained by an increase in the mRNA expression of type I and III collagen, osteocalcin, and bone morphogenetic proteins 2 and 4. Additionally, the titanium surface treated with HY-SWCNTs showed a significant increase in the deposition of inorganic crystals. Thus, our data indicate that HY, SWCNTs, and HY-SWCNTs are potentially useful for the development of new strategies for bone tissue engineering.

Partial purification and characterization of a bacteriocin produced by Enterococcus faecium 130 isolated from mozzarella cheese

Lactic acid bacteria are important in foods as potential probiotics and also due to the ability to produce antimicrobial compounds that can contribute for biopreservation. In this work, the bacteriocin produced by the food isolate Enterococcus faecium 130 was partially purified and characterized. The compound was active against Gram-positive bacteria, including Listeria monocytogenes. It was produced after 4 days of storage at a broad temperature range (4 to 37 °C); it was stable at pH ranging from 2 to 10 with no loss of activity after heating at 100 °C for 15 minutes. Bacteriocin was partially purified by the adsorption-desorption technique, and the analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed a molecular mass of 3.5 to 6.5 kDa. These data encourage studies on application of this bacteriocin in food systems as an additional hurdle to microbial growth.

The effect of sodium reduction and the use of herbs and spices on the quality and safety of bologna sausage

In this study, the replacement of 50% NaCl by KCl in Bologna sausage with the addition of herbs and spice blends (coriander, onion, white pepper, cardamom, and Jamaican pepper) was evaluated. The formulations tested showed a significant reduction in the sodium content with no major alterations in the emulsion stability, texture, and microbiological characteristics. The use of 50% KCl caused a reduction in the sensory quality leading to a significant decrease in the consumers' purchase intention. The formulations with the addition of herbs and spice blends presented better results in the sensory evaluation indicating that this strategy can reduce the negative effects resulting from the use of KCl.

A fast and efficient method for the study of caffeine levels in energy drinks using micellar electrokinetic chromatography (MEKC)

Energy drinks are becoming popular in Brazil and in the world due to their stimulant properties. Caffeine is present in energy drinks with the aim of stimulating the central nervous system and intensifying brain activity. On the other hand, the ingestion of high doses of caffeine can cause undesirable symptoms such as anxiety and tachycardia. Therefore, it is necessary to monitor the caffeine content added to energy drinks to guarantee that the levels in the final product are in accordance with the labeling and within the legislation limits. The goal of this work was to validate a fast, efficient, and low-cost method for the determination of caffeine in energy drinks by micellar electrokinetic chromatography (MEKC). A total of seven brands were analyzed, each in three lots. The electrolyte was prepared with 50 mmol.L-1 of sodium dodecyl sulfate (SDS) and 10 mmol.L-1 of sodium carbonate (pH 11.0). The mean concentration of caffeine ranged from 122.8 to 318.6 mg.L-1. None of the brands had caffeine levels above the maximum limit. Considering the interval of confidence (95%), 72% of the samples had less caffeine than the amount informed on the product label.

Raw-appearing Restructured fish models made with Sodium alginate or Microbial transglutaminase and effect of chilled storage

Restructuring by adding Sodium Alginate or Microbial Transglutaminase (MTGase) using cold gelation technology make it possible to obtain many different raw products from minced and/or chopped fish muscle that are suitable for being used as the basis of new restructured products with different physicochemical properties and even different compositions. Special consideration must be given to their shelf-life and the changes that may take place during chilling, both in visual appearance and physicochemical properties. After chilled storage, the restructured models made with different muscular particle size and composition at low temperature (5 °C), it was observed that microbial growth limited the shelf-life to 7-14 days. Mechanical properties increased (p < 0.05) during that time, and higher values were observed in samples elaborated by joining small muscle particle size than in those elaborated by homogenization. There was no clear increase in the cooking yield and purge loss, and no significant colour change (p > 0.05) was detected during storage.

Physicochemical and microbiological parameters of dried salted pork meat with different sodium chloride levels

The objective of this study was to evaluate the physicochemical and microbiological parameters of pork meat submitted to dry salting. Sodium chloride (NaCl) was added at levels of 0%, 2.5%, 5%, 7.5% or 10% by the meat weight. Dry salting technique was used, which consists of rubbing the sodium chloride manually, followed by a rest period. The data were submitted to analysis of variance using a completely randomized experimental design. The means were compared by Duncan test at 5%. The salting process reduced (P < 0.05) humidity and water activity, and it increased (P < 0.05) ash, chloride, palmitic acid, and water holding capacity levels compared to those of the control. Luminosity (L*) was lower (P < 0.05) in the control, and a* color was more intense in samples with 2.5% NaCl. Cooking loss was lower (P < 0.05) in the samples salted with 5% and 10% NaCl, and similarity was observed between the levels 0 and 7.5% salt. The treatments with levels 0% and 2.5% NaCl had higher mesophilic counts. The other microbiological parameters were within limits established by law. Therefore, salting with 5% NaCl can be used in pork meat in order to maintain the physicochemical and microbiological characteristics of the final product.

Evaluation of quality factors of bovine and chicken meat marinated with reduced sodium content

In many industrialized countries, including Brazil, sodium intake exceeds the nutritional recommendations. Excessive consumption is associated with hypertension and premature death by cardiovascular diseases. The industry's challenge is to produce products with reduced sodium that are similar to regular products in texture and flavor and consistent with consumers' dietary habits. The present study aimed at substituting 25 and 50% NaCl for KCl in marinated beef and chicken meat with the addition of aromatic herbs and spices. The following microbiological analyses were carried out: macronutrient, chemical composition, and sensorial analysis. The meats showed a reduction in NaCl contents without any changes in their physical and chemical characteristics, and the products´ quality and microbiological safety were maintained. Beef and chicken tenderness was maintained for both treatments. Furthermore, the use of 50% KCl did not cause any changes in the products' sensory quality, and the overall acceptance of both types of meat was maintained. Results showed that a reduction by 50% in the NaCl contents of marinated meat products with a combination of herbs and spices is possible. Future applications in other meat products and sausages are highly promising.

Effect of high and low molecular weight glutenin subunits, and subunits of gliadin on physicochemical parameters of different wheat genotypes

Identification of functional properties of wheat flour by specific tests allows genotypes with appropriate characteristics to be selected for specific industrial uses. The objective of wheat breeding programs is to improve the quality of germplasm bank in order to be able to develop wheat with suitable gluten strength and extensibility for bread making. The aim of this study was to evaluate 16 wheat genotypes by correlating both glutenin subunits of high and low molecular weight and gliadin subunits with the physicochemical characteristics of the grain. Protein content, sedimentation volume, sedimentation index, and falling number values were analyzed after the grains were milled. Hectoliter weight and mass of 1000 seeds were also determined. The glutenin and gliadin subunits were separated using polyacrylamide gel in the presence of sodium dodecyl sulfate. The data were evaluated using variance analysis, Pearson's correlation, principal component analysis, and cluster analysis. The IPR 85, IPR Catuara TM, T 091015, and T 091069 genotypes stood out from the others, which indicate their possibly superior grain quality with higher sedimentation volume, higher sedimentation index, and higher mass of 1000 seeds; these genotypes possessed the subunits 1 (Glu-A1), 5 + 10 (Glu-D1), c (Glu-A3), and b (Glu-B3), with exception of T 091069 genotype that possessed the g allele instead of b in the Glu-B3.

Effects of micronized sodium chloride on the sensory profile and consumer acceptance of turkey ham with reduced sodium content

The impact of sodium chloride reduction and its substitution for micronized salt on consumer acceptance of turkey ham was investigated. Five formulations - F1 (control - 2.0% NaCl), F2 (1.7% NaCl), F3 (1.4% NaCl), F4 (1.7% micronized NaCl), and F5 (1.4% micronized NaCl) - were evaluated with respect to sodium chloride content and by consumers using a nine-point hedonic scale for overall acceptability and CATA (check-all-that-apply) using 24 sensory descriptors. Trained panelists characterized the products using the flash profiling technique. Reductions in the salt content by up to 30% did not affect the overall acceptability of the samples by the consumers. However, the consumers characterized the formulations with lower salt content as "less salty and less seasoned" in comparison to the contents in the control. Products containing 1.7% NaCl were considered very similar to the control. The results obtained indicate that it is possible to reduce NaCl content by 30% without affecting consumer acceptance of the product. The use of micronized salt did not affect the sensory characteristics when compared with those of formulations containing the same level of sodium chloride indicating that micronized salt does not influence perception of salt.

Evaluation of some residual bioactivities of microencapsulated Phaseolus lunatus protein fraction with carboxymethylated flamboyant (Delonix regia) gum/sodium alginate

Recent studies have shown the beneficial effect of peptides, an unexploited source could be Phaseolus lunatus being an important raw material for those functional products in order to improve their utilization. In addition to improve the beneficial effect of bioactive peptides the microencapsulation could be a way to protect the peptides against the environment to which they are exposed. P. lunatus protein fraction (<10 kDa of weight) was encapsulated using a blend of carboxymethylated flamboyant gum (CFG) and sodium alginate (SA) at different concentrations of CaCl2 and hardening times. After in vitro digestion of microcapsules the residual activity, in the intestinal system, both inhibition of agiotensin-converting enzyme (I-ACE) and antioxidant activity obtained were in a range of 0.019-0.136 mg/mL and 570.64-813.54 mM of TEAC respectively. The microencapsulation employed CFG/SA blends could be used controlled delivery of peptide fractions with potential use as a nutraceutical or therapeutic agents.