Effect of caloric restriction on myenteric neuroplasticity in the rat duodenum during aging

The objective of this study was to evaluate the effects of caloric restriction (CR) on myenteric neurons in the duodenum of Wistar rats during aging. Thirty rats were divided into three groups: the C group (six-month-old animals that were fed a normal diet from weaning until six months of age), the SR group (18-month-old animals that were fed a normal diet from weaning until 18 months of age) and the CR group (18-month-old animals that were fed a 30% CR diet after six months of age). After 12 months, the animals were euthanized. Whole-mount preparations of the duodenums were either stained with Giemsa or underwent NADPH-diaphorase histochemistry to determine the general myenteric neuron population and the nitrergic neuron subpopulation (NADPH-d +), respectively. The NADPH-d-negative (NADPH-d -) neuron population was estimated based on the difference between the Giemsa-stained and NADPH-d + neurons. The neurons were counted, and the cell body areas were measured. Aging was associated with neuronal loss in the SR group, which was minimized by caloric restriction in the CR group. The density (mm(2)) of the Giemsa-stained neurons was higher in the SR group (79.09 +/- 6.25) than in the CR (92.37 +/- 11.6) and C (111.68 +/- 15.26) groups. The density of the NADPH-d + neurons was higher in the SR group (44.90 +/- 5.88) than in the C (35.75 +/- 1.6) and RC (39.14 +/- 7.02) groups. The density of NADPH-d - neurons was higher in the CR (49.73 +/- 12.08) and C (75.64 +/- 17.05) groups than in the SR group (33.82 +/- 4.5). In the C group, 32% and 68% of the Giemsa-stained myenteric neurons were NADPH-d + or NADPH-d -, respectively. With aging (SR group), the percentage of nitrergic neurons (56.77%) increased, whereas the percentage of NADPH-d - neurons (43.22%) decreased. In the CR group, the change in the percentage of nitrergic (42.37%) and NADPH-d - (57.62%) neurons was lower. As NADPH-d - neurons will be mostly cholinergic neurons, CR appears to reduce the loss of cholinergic neurons during aging. The cell body dimensions (mu m(2)) were not altered by aging or CR. Thus. CR had a protective effect on myenteric neurons during aging. (C) 2012 Elsevier B.V. All rights reserved.

Long-term effect of prolactin treatment on glucose-induced insulin secretion in cultured neonatal rat islets

Insulin secretion and 45SCa2+ uptake and efflux were studied in neonatal rat islets maintained in culture for 7 or 19 days in the absence or presence of prolactin (PRL). Insulin secretion in response to glucose (G), leucine (Leu), arginine (Arg) and carbachol (Cch) was augmented after 7 and 19 days in culture, compared to basal secretion (G 2.8 mM), in both PRL- treated and control islets. However, the increase in insulin secretion induced by the above secretagogues was higher in islets cultured in the presence of PRL for 19 days. In PRL-treated islets, the 45Ca2+ content after a 5 min incubation in the presence of G, Leu, Arg and Cch was significantly higher than the control only in islets cultured for 19 days. Except with Arg, the 45Ca2+ uptake in PRL-treated islets after a 90 min incubation was also significantly higher than the control only in islets cultured for 19 days. Finally, Leu-induced alterations in the 45Ca2+ efflux were higher in PRL-treated than in control islets cultured for 7 or 19 days. In the absence of external Ca2+, the reduction in 45Ca2+ efflux induced by glucose was also significantly higher in PRL-treated than in control islets. This effect was slightly potentiated after 19 days in culture. These data further support the hypothesis that PRL treatment enhances maturation of the secretory mechanism in neonatal islets. This effect can be potentiated even more if the treatment is prolonged.

A preliminary report on the effect of laser therapy on the healing of cutaneous surgical wounds as a consequence of an inversely proportional relationship between wavelength and intensity: Histological study in rats

Objective: The objective of the present investigation was to assess the histological effects of different wavelengths and intensities on the healing process of cutaneous wounds. Background Data: Tissue repair is a dynamic interactive process which involves mediators, cells and extra-cellular matrix. Several reports on the use of laser therapy have shown that the healing process is positively affected when the correct parameters are used. Methods: Eighteen standardized wounds were surgically created on the dorsum of male and female Wistar rats, which were subsequently divided into two experimental groups according to wavelength used λ.670 or λ685 nm) for lasertherapy (LLLT). Each group was divided into three subgroups of three animals according to the intensity of the applied irradiation (2,15, or 25 mW). Twelve animals were used as entreated controls and were not irradiated. The irradiation was carried out during seven consecutive days. The animals were sacrificed eight days after surgery. The specimens were removed, kept in 4% formaldehyde for 24 h, routinely prepared to wax, stained with H&E, and analyzed under light microscopy. Results: For both groups, light microscopy showed a substitution repair process; however, when LLLT was used, a positive biomodulatory effect was detectable, chiefly associated with shorter wavelength and low intensity. Conclusions: The results of the present study indicate that LLLT improved cutaneous wound repair and that the effect is a result of an inversely proportional relationship between wavelength and intensity, with treatment more effective when combining higher intensity with short wavelength or lower intensity with higher wavelength.

The effect of adhesive systems on the pullout strength of a fiberglass-reinforced composite post system in bovine teeth

Purpose: To evaluate the pullout strength of a glass fiber-reinforced composite post (glass FRC) cemented with three different adhesive systems and one resin cement. The null hypothesis was that pullout strengths yielded by the adhesive systems are similar. Materials and Methods: Thirty bovine teeth were selected. The size of the specimens was standardized at 16 mm by sectioning off the coronal portion and part of the root. The specimens were divided into three groups, according to the adhesive system, which were applied following the manufacturers' instructions: G1, ScotchBond Multi-Purpose Plus; G2, Single Bond; G3, Tyrian SPE/One-Step Plus. The glass FRCs (Reforpost) were etched with 37% H3PO4 for 1 min and silanized (Porcelain Primer). Thereafter, they were cemented with the dual resin cement En-Force. The specimens were stored for 24 h, attached to an adapted device, and submitted to the pullout test in a universal testing machine (1 mm/min). The data were submitted to the one-way ANOVA and Tukey's test (α = 0.05). Results: G1 (30.2 ± 5.8 Kgf) displayed the highest pullout strength (p < 0.001) when compared to G2 (18.6 ± 5.8 Kgf) and G3 (14.3 ± 5.8 Kgf), which were statistically similar. Analysis of the specimens revealed that all failures occurred between the adhesive system and the root dentin (pullout of the post cement), regardless of group. Conclusion: The multiple-bottle, total-etch adhesive system provided higher pullout strength of the glass FRC when compared to the single-bottle, total-etch, and single-step self-etching adhesive systems. The null hypothesis was rejected (p < 0.001).

Effect of air humidity on the egg viability of predatory mites (Acari: Phytoseiidae, Stigmaeidae) common on rubber trees in Brazil

Rubber pest mites, Calacarus heveae and Tenuipalpus heveae, reach economic damage levels at the end of the rainy season and the beginning of the dry season in Brazil. Therefore, low humidity adaptation might be an important characteristic for predatory mites to successfully control pest organisms. This study determined the effect of the relative humidity (RH) levels of 30-100% on the hatching of larvae of Amblyseius acalyphus, Euseius citrifolius, Iphiseiodes zuluagai, Metaseiulus camelliae, Agistemus floridanus and Zetzellia malvinae at 25 ± 0.5°C. These predatory mites are common on rubber trees in the state of São Paulo and might be used for introduction in the major rubber tree production regions in the state of Mato Grosso. At 70% RH or higher, viability was 70% or higher for all species, indicating that their performance might be higher during the rainy season than during the dry season. Eggs of E. citrifolius and M. camelliae presented higher viability at the lower relative humidity levels than those of other species, indicating that these species might have higher chance to persist in the dry season. It is suggested that M. camelliae should be further evaluated for introduction in the state of Mato Grosso, considering that this mite is not yet present in that area. © Springer 2006.

Effect of fiber surface on flexural strength in carbon fabric reinforced epoxy composites

The effect of carbon fiber surface characteristics on flexural properties of structural composites is studied in this work. Two types of intermediate modulus carbon fibers were used: T800HB and IM7. Results revealed that higher mechanical properties are linked with higher interfacial adhesion. Morphologies and chemical compositions of commercial carbon fibers (CF) were characterized by Fourier Transformed Infra Red (FTIR) and Scanning Electronic Microscopy (SEM). Comparing the results, the T800HB apparently has more roughness, since the IM7 seems to be recovered for a polymeric film. On other hand, the IM7 one shows higher interactivity with epoxy resin system Cycom 890 RTM. Composites produced with Resin Transfer Molding (RTM) were tested on a flexural trial. Interfacial adhesion difference was showed with SEM and Dynamic Mechanical Analyses (DMA), justifying the higher flexural behavior of composites made with IM7 fibers. © 2013 Elsevier B.V. All rights reserved.

Effect of sodium trimetaphosphate on hydroxyapatite solubility: An in vitro study

This study evaluated the effect of different concentrations of sodium trimetaphosphate (TMP) with and without fluoride (F) on the concentration of calcium (Ca), phosphorus (P) and F in hydroxyapatite (HA). Synthetic HA powder (0.15 g) was suspended (n=6) in solutions (75 mL) of TMP at 0%, 0.1%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 2.0%, 4.0%, 6.0%, 8.0% and 10% concentrations in the presence and absence of 100 ppm F and subjected to a pH-cycling process. The precipitates were filtrated, dried at 70° C for 24 h and ground onto a fine powder. The concentrations of F (KOH (CaF2) and HCl (FA) soluble), Ca (Arsenazo III), and P (molybdate method) in HA were determined. The Ca P, and Ca/P ratio data were subjected to Tukey's test and the F data were subjected to Student-Newman-Keuls test (p<0.05). The addition of TMP to the samples reduced F deposition to 98% (p<0.001). The groups containing 100 ppm F and 0.4% or 0.6% TMP exhibited a higher Ca concentration than the group containing only 100 ppm F (p<0.05). Furthermore, the HA treated with 0.2% and 0.4% TMP and 100 ppm F showed a higher Ca/P ratio than the other groups (p<0.001). In conclusion, TMP at 0.2%, 0.4% and 0.6% concentrations combined with F seemed to be able to precipitate HA with low solubility. However, especially at high concentrations, TMP interferes with F deposition on HA.

Effect of physical training on metabolic and bone profile in weaning rats

Introduction: The practice of moderate-intensity exercise can reduce the risk of infections and improve metabolic aspects of the person. Objective: To investigate the effects of aerobic physical training on endocrine and metabolic aspects, bone and immune systems. Methods: Twenty Wistar rats were divided in two groups: sedentary (SG) and trained group (TG). Training program consisted in swimming, 6 weeks, supporting a workload corresponding to 5% of body weight. At the end of the experiment, were performed counting total and differential leukocyte count and hematocrit. After training period, were analyzed glucose, total protein, triglycerides, cholesterol, liver and muscle samples for the determination of the levels of glycogen, and determination of the tibia length and bone area. All dependent variables were analyzed by one-way analysis of variance (ANOVA) and a significance level of P < 0.05 was used for all comparisons. Results: Hematocrit (%) analyzed showed a significant difference, with higher values ffor TG (54.63 ± 1.41) than for the SG (49.5 ± 1.65). The total leukocyte count was not significantly different, as there was no difference in the differential count. Total cholesterol showed significant decrease in TG (TG = 68.27 ± 13.71 mg/dL; SG = 94.44 ± 28.09), the total protein levels also showed significant reduction (TG = 7.3 ± 0.40 g/dL; SG = 7.74 ± 0.36 g/dL) glucose levels and triglyceride showed no significant differences. The bone length showed significant difference (TG = 40±0.14 mm; SG = 42.10 ± 0.12mm). Tibial area showed a lower value for TG (1.53 ± 0.12cm2) than for SG (1.67 ± 0.18cm2); however, the difference was not statistically significant. Conclusion: It can be concluded that aerobic exercise training is able to produce some unique physiological changes in young rats. There is also the need to prescribe exercises that meet the particular maturational stage of development.

Effect of follicular fluid supplementation during in vitro maturation on total cell number in bovine blastocysts produced in vitro

This study evaluated the influence of follicular fluid (FF) added to the maturation medium on the quality of bovine embryos produced in vitro. In the first experiment, oocytes were matured in media containing five different FF concentrations with different maturation times and classified according to meiotic progression and migration of cortical granules. In the second experiment, oocytes matured in the same media were fertilized at three different maturation times; thereafter, cleavage and blastocyst rates were evaluated. In the third experiment, oocytes were matured in media containing three different FF concentrations at two different maturation times, and embryo quality, inferred by the ratio of inner cell mass and trophectoderm cells compared with total cell number, was evaluated. Higher FF concentration (75 - 100% FF) slowed meiotic progression and CG migration (control - 78.13% vs. treated - 52.58% and control - 52.7% vs. treated - 11.59%, respectively, at 24 h of maturation). Also, FF at concentration of 75% or 100% had a negative influence on cleavage and blastocyst rates (control - 90.13% vs. treated - 82.64% and control - 35.73% vs. treated - 11.57%, respectively, at 24 h of maturation). The 50% FF resulted in embryos with increased inner cell mass numbers (control - 29.91 vs. treated - 35.49, at 24 h of maturation) and total cell numbers (control - 109.53 vs. treated - 120.67, at 26 h of maturation). Even though higher concentration of FF added to the maturation medium reduced embryonic development rates, in lower concentrations, FF slowed the meiotic progression and migration of CG and contributed to increases in inner cell mass number. Thus, FF added to the maturation medium enhances the number of cells in bovine embryos produced in vitro, especially for inner cell mass.

Effect of tank colour on larval performance of the Amazon River prawn Macrobrachium amazonicum

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of exercise on the maternal outcome in pregnancy of spontaneously hypertensive rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

EFFECT OF FOOD SHORTAGE ON GROWTH, ENERGETIC RESERVES MOBILIZATION, AND WATER QUALITY IN JUVENILES OF THE REDCLAW CRAYFISH, CHERAX QUADRICARINATUS, REARED IN GROUPS

The aim of this study is to analyze the impact of food shortage on growth performance, by means of energetic reserves (proteins, glycogen and lipids) mobilization and hepatopancreas cells analysis in C. quadricarinatus juveniles maintained in groups, as well as the effect on culture water quality. Two experiments were performed, each of them with two feeding regimes during 45 days. The Control feeding regime, in which crayfish were fed daily (once a day) throughout the experimental period (DF), and the Cyclic feeding regime, in which juveniles were fed for 2 or 4 days (once a day) followed by 2 or 4 days of food deprivation (2F/2D and 4F/4D, respectively) in repeated cycles. Cyclic feeding influenced growth, biochemical composition from hepatopancreas and muscle, and water quality. Juveniles cyclically fed were unable to maintain a normal growth trajectory during 45 days. Apparent feed conversion ratio, apparent protein efficiency ratio, hepatosomatic index and relative pleon mass were similar in cyclic and daily fed animals and no structural damage was found in the hepatopancreas of juveniles subjected to cyclic feeding. The novelty of this study was the significant accumulation of proteins in pleonal muscle in both cyclic feeding regimes (approx. 18%) suggesting that the storage of this constitutive material during food shortage may be an adaptation for a compensatory growth when food becomes abundant again. The cyclic feeding regimes had a positive effect on water quality decreasing inorganic nitrogen concentration. This was due to the reduction in the amount of animal excretes and feces in the group that received approx. 50% less feed. Additionally, water pH was higher in cyclic feeding tanks, as a result of lower organic matter decomposition and consequent release of CO2. Accordingly, total ammonia in the water was significantly lower for the cyclic feeding regimes compared to their respective controls. This study suggests that the protocol of cyclic feeding could be applied at least 45 days in 1 g juveniles maintained in group conditions, without affecting the energetic reserves and hepatopancreas structure, emphasizing the high tolerance of this species to food restriction.

Effect of mechanical cycling on screw torque in external hexagon implants with and without platform switching

This in vitro study evaluated the effect of mechanical cycling on the torque of retaining screw in external hexagon implants with platform switching (PS), regular platform (RP) and wide platform (WP). A total of 30 specimens were equally divided into 3 groups: PS, PR and WP. Each specimen was prepared with implants: 3.75 x 10 mm for RP group and 5.0x10 mm for PS and WP groups and its respective abutment with 32 Ncm torque. All groups were subjected to 106 cycles with 100 N (corresponding to about 40 months of chewing). The results were obtained with the reverse torque of each specimen and data were evaluated using ANOVA and Tukey test (p<0.05). The PS group showed statistically significant difference in screw removal torque (30.06±5.42) compared with RP (23.75±2.76) and WP (21.32±3.53) (p<0.05) groups; the RP and WP groups showed no statistically significant difference between them. It was concluded that the PS group showed higher reverse torque value, suggesting lower susceptibility of the abutment screw loosening.

Effect of oral infections on serum creatinine levels in diabetic rats

Aim: The aim of this study was to evaluate the relationship between pulpal and/or periodontal disease and serum creatinine levels in a rat model of diabetes mellitus. Methods: Eighty male rats (Rattus norvegicus albinus, Wistar) were divided into the following 8 groups compris-ing 10 animals each: normal (G1), with pulpal disease (G2), with periodontal disease (G3), with both pulpal and periodontal disease (G4), diabetic (G5), diabetic with pulpal disease (G6), diabetic with periodontal disease (G7), and diabetic with both pulpal and periodontal disease (G8). Diabetes was induced by injecting streptozotocin, pul-pal disease were induced by exposing pulpal tissue to the oral environment, and periodontal disease was induced by periodontal ligature. After 30 days, blood was collected by cardiac puncture and the animals were killed. The maxillae were processed for histopathology. Serum creatinine levels were measured by the enzymatic method. The total assessed values were statistically analyzed by analysis of variance and Tukey’s test (p < 0.05). Results: Serum creatinine levels were significantly higher in diabetic rats than that in all normoglycemic rats (p < 0.05). The presence of pulpal and periodontal disease increased the serum creatinine levels in normoglycemic and diabetic rats, but there was no statistical difference between the groups (p > 0.05). Conclusions: We found that the serum creatinine level was higher in diabetic rats and may be related to the pres-ence of oral infections. Clinical significance: Changes in serum creatinine level may be related to the presence of oral infections and diabetes.

Effect of N-acetylcysteine on pulmonary cell death in a controlled hemorrhagic shock model in rats

PURPOSE: To evaluate the effect of N-acetylcysteine (NAC) combined with fluid resuscitation on pulmonary cell death in rats induced with controlled hemorrhagic shock (HS). METHODS: Two arteries (MAP calculation and exsanguination) and one vein (treatments) were catheterized in 22 anesthetized rats. Two groups of male albino rats were induced with controlled HS at 35mmHg MAP for 60 min. After this period, the RL group was resuscitated with Ringer's lactate and the RL+NAC group was resuscitated with Ringer's lactate combined with 150mg/Kg NAC. The control group animals were cannulated only. The animals were euthanized after 120 min of fluid resuscitation. Lung tissue samples were collected to evaluate the following: histopathology, TUNEL and imunohistochemical expression of caspase 3. RESULTS: RL showed a greater number of cells stained by TUNEL than RL + NAC, but there was no change in caspase 3 expression in any group. CONCLUSION: N-acetylcysteine associate to fluid resuscitation, after hemorrhagic shock, decreased cell death attenuating lung injury.