998 resultados para Transdutor de 5 a 10 MHz
Resumo:
The metabolic effects of carbohydrate supplementation in mice have not been extensively studied. In rats, glucose- and fructose-rich diets induce hypertriacylglycerolemia. In the present study, we compared the metabolic responses to two monosaccharide supplementations in two murine models. Adult male Wistar rats (N = 80) and C57BL/6 mice (N = 60), after 3 weeks on a standardized diet, were submitted to dietary supplementation by gavage with glucose (G) or fructose (F) solutions (500 g/L), 8 g/kg body weight for 21 days. Glycemia was significantly higher in rats after fructose treatment (F: 7.9 vs 9.3 mM) and in mice (G: 6.5 vs 10 and F: 6.6 vs 8.9 mM) after both carbohydrate treatments. Triacylglycerolemia increased significantly 1.5 times in rats after G or F supplementation. Total cholesterol did not change with G treatment in rats, but did decrease after F supplementation (1.5 vs 1.4 mM, P < 0.05). Both supplementations in rats induced insulin resistance, as suggested by the higher Homeostasis Model Assessment Index. In contrast, mice showed significant decreases in triacylglycerol (G: 1.8 vs 1.4 and F: 1.9 vs 1.4 mM, P < 0.01) and total cholesterol levels (G and F: 2.7 vs 2.5 mM, P < 0.05) after both monosaccharide supplementations. Wistar rats and C57BL/6 mice, although belonging to the same family (Muridae), presented opposite responses to glucose and fructose supplementation regarding serum triacylglycerol, free fatty acids, and insulin levels after monosaccharide treatment. Thus, while Wistar rats developed features of plurimetabolic syndrome, C57BL/6 mice presented changes in serum biochemical profile considered to be healthier for the cardiovascular system.
Resumo:
We showed that guaraná (Paullinia cupana Mart var. sorbilis) had a chemopreventive effect on mouse hepatocarcinogenesis and reduced diethylnitrosamine-induced DNA damage. In the present experiment, we evaluated the effects of guaraná in an experimental metastasis model. Cultured B16/F10 melanoma cells (5 x 10(5) cells/animal) were injected into the tail vein of mice on the 7th day of guaraná treatment (2.0 mg P. cupana/g body weight, per gavage) and the animals were treated with guaraná daily up to 14 days until euthanasia (total treatment time: 21 days). Lung sections were obtained for morphometric analysis, apoptotic bodies were counted to calculate the apoptotic index and proliferating cell nuclear antigen-positive cells were counted to determine the proliferation index. Guaraná-treated (GUA) animals presented a 68.6% reduction in tumor burden area compared to control (CO) animals which were not treated with guaraná (CO: 0.84 ± 0.26, N = 6; GUA: 0.27 ± 0.24, N = 6; P = 0.0043), a 57.9% reduction in tumor proliferation index (CO: 23.75 ± 20.54, N = 6; GUA: 9.99 ± 3.93, N = 6; P = 0.026) and a 4.85-fold increase in apoptotic index (CO: 66.95 ± 22.95, N = 6; GUA: 324.37 ± 266.74 AB/mm², N = 6; P = 0.0152). In this mouse model, guaraná treatment decreased proliferation and increased apoptosis of tumor cells, consequently reducing the tumor burden area. We are currently investigating the molecular pathways of the effects of guaraná in cultured melanoma cells, regarding principally the cell cycle inhibitors and cyclins.
Resumo:
The use of positive end-expiratory pressure (PEEP) or lung recruitment maneuvers (RM) to improve oxygenation in acute respiratory distress syndrome (ARDS) is used but it may reduce cardiac output (CO). Intermittent PEEP may avoid these complications. Our objective was to determine if variable PEEP compared with constant PEEP is capable of maintaining arterial oxygenation and minimizing hemodynamic alterations with or without RM. Eighteen dogs with ARDS induced by oleic acid were randomized into three equal groups: group 1, low variable PEEP; group 2, high variable PEEP, and group 3, RM + high variable PEEP. All groups were submitted to constant PEEP, followed by variable PEEP (PEEP was increased from 5 to 10 cmH2O in group 1, and from 5 to 18 cmH2O in the other two groups). PaO2 was higher in group 3 (356.2 ± 65.4 mmHg) than in group 1 (92.7 ± 29.7 mmHg) and group 2 (228.5 ± 72.4 mmHg), P < 0.05. PaO2 was maintained during variable PEEP except in group 2 (318.5 ± 82.9 at constant PEEP to 228.5 ± 72.4 at variable PEEP). There was a reduction in CO in group 3 after RM (3.9 ± 1.1 before to 2.7 ± 0.5 L·min-1·(m2)-1 after; P < 0.05), but there was not any difference between constant and variable PEEP periods (2.7 ± 0.5 and 2.4 ± 0.7 L·min-1·(m2)-1; P > 0.05. Variable PEEP is able to maintain PaO2 when performed in combination with RM in dogs with ARDS. After RM, CO was reduced and there was no relevant difference between the variable and constant PEEP periods.
Resumo:
Pueraria mirifica is a Thai phytoestrogen-rich herb traditionally used for the treatment of menopausal symptoms. Pueraria lobata is also a phytoestrogen-rich herb traditionally used in Japan, Korea and China for the treatment of hypertension and alcoholism. We evaluated the mutagenic and antimutagenic activity of the two plant extracts using the Ames test preincubation method plus or minus the rat liver mixture S9 for metabolic activation using Salmonella typhimurium strains TA98 and TA100 as indicator strains. The cytotoxicity of the two extracts to the two S. typhimurium indicators was evaluated before the mutagenic and antimutagenic tests. Both extracts at a final concentration of 2.5, 5, 10, or 20 mg/plate exhibited only mild cytotoxic effects. The plant extracts at the concentrations of 2.5, 5 and 10 mg/plate in the presence and absence of the S9 mixture were negative in the mutagenic Ames test. In contrast, both extracts were positive in the antimutagenic Ames test towards either one or both of the tested mutagens 2-(2-furyl)-3-(5-nitro-2-furyl)-acrylamide and benzo(a)pyrene. The absence of mutagenic and the presence of anti-mutagenic activities of the two plant extracts were confirmed in rec-assays and further supported by a micronucleus test where both plant extracts at doses up to 300 mg/kg body weight (equivalent to 16 g/kg body weight plant tuberous powder) failed to exhibit significant micronucleus formation in rats. The tests confirmed the non-mutagenic but reasonably antimutagenic activities of the two plant extracts, supporting their current use as safe dietary supplements and cosmetics.
Resumo:
Both epidural and general anesthesia can impair thermoregulatory mechanisms during surgery. However, there is lack of information about the effects of different methods of anesthesia on newborn temperature. The purpose of this study was to determine whether there are differences in newborn rectal temperature related to type of anesthesia. Sixty-three pregnant women were randomly assigned to receive general or epidural anesthesia. Maternal core temperature was measured three times with a rectal probe just before anesthesia, at the beginning of surgery and at delivery. In addition, umbilical vein blood was sampled for pH. The rectal temperatures of the babies were recorded immediately after delivery, and Apgar scores were determined 1, 5, and 10 min after birth. The duration of anesthesia and the volume of intravenous fluid given during the procedure (833 ± 144 vs 420 ± 215 mL) were significantly higher in the epidural group than in the general anesthesia group (P < 0.0001). Maternal rectal temperatures were not different in both groups at all measurements. In contrast, newborn rectal temperatures were lower in the epidural anesthesia group than in the general anesthesia group (37.4 ± 0.3 vs 37.6 ± 0.3°C; P < 0.05) immediately after birth. Furthermore, the umbilical vein pH value (7.31 ± 0.05 vs 7.33 ± 0.01; P < 0.05) and Apgar scores at the 1st-min measurement (8.0 ± 0.9 vs 8.5 ± 0.7; P < 0.05) were lower in the epidural anesthesia group than in the general anesthesia group. Since epidural anesthesia requires more iv fluid infusion and a longer time for cesarean section, it involves a risk of a mild temperature reduction for the baby which, however, did not reach the limits of hypothermia.
Resumo:
In the present study, we evaluated 42 wrists using the semi-quantitative scales power Doppler ultrasound (PDUS) and gray scale ultrasound (GSUS) with scores ranging from 0 to 3 and correlated the results with clinical, laboratory and radiographic data. Twenty-one patients (17 women and 4 men) with rheumatoid arthritis according to criteria of the American College of Rheumatology were enrolled in the study from September 2008 to July 2009 at Universidade Estadual de Campinas (UNICAMP). The average disease duration was 14 months. The patients were 66.6% Caucasians and 33.3% non-Caucasians, with a mean age of 42 and 41 years, respectively. A dorsal longitudinal scan was performed by ultrasound on the radiocarpal and midcarpal joints using GE LOGIQ XP-linear ultrasound and a high frequency (8-10 MHz) transducer. All patients were X-rayed, and the Larsen score was determined for the joints, with grades ranging from 0 to V. This study showed significant correlations between clinical, sonographic and laboratory data: GSUS and swollen right wrist (r = 0.546), GSUS of right wrist and swelling of left wrist (r = 0.511), PDUS of right wrist and pain in left wrist (r = 0.436), PDUS of right wrist and C-reactive protein (r = 0.466). Ultrasound can be considered a useful tool in the diagnosis of synovitis in early rheumatoid arthritis mainly when the anti-cyclic citrullinated peptide and rheumatoid factor are negative, and can lead to an early change in the therapeutic decision.
Resumo:
Vaccination with xenogeneic and syngeneic endothelial cells is effective for inhibiting tumor growth. Nontoxic diphtheria toxin (CRM197), as an immunogen or as a speciʂ57;c inhibitor of heparin-binding EGF-like growth factor, has shown promising antitumor activity. Therefore, immunization with or administration of viable human umbilical vein endothelial cells (HUVECs) combined with CRM197 could have an enhanced antitumor effect. Six-week-old C57BL/6J male mice were vaccinated with viable HUVECs, 1 x 10(6) viable HUVECs combined with 100 56;g CRM197, or 100 56;g CRM197 alone by ip injections once a week for 4 consecutive weeks. RM-1 cells (5 x 10(5)) were inoculated by sc injection as a preventive procedure. During the therapeutic procedure, 6-week-old male C57BL/6J mice were challenged with 1 x 10(5) RM-1 cells, then injected sc with 1 x 10(6) viable HUVECs, 1 x 10(6) viable HUVECs + 100 56;g CRM197, and 100 56;g CRM197 alone twice a week for 4 consecutive weeks. Tumor volume and life span were monitored. We also investigated the effects of immunization with HUVECs on the aortic arch wall and on wound healing. Vaccination with or administration of viable HUVECs+CRM197 enhanced the inhibition of RM-1 prostatic carcinoma by 24 and 29%, respectively, and prolonged the life span for 3 and 4 days, respectively, compared with those of only vaccination or administration with viable HUVECs of tumor-bearing C57BL/6J mice. Furthermore, HUVEC immunization caused some damage to the aortic arch wall but did not have remarkable effects on the rate of wound healing; the wounds healed in approximately 13 days. Treatment with CRM197 in combination with viable HUVECs resulted in a marked enhancement of the antitumor effect in the preventive or therapeutic treatment for prostatic carcinoma in vivo, suggesting a novel combination for anti-cancer therapy.
Resumo:
Statins are among the most prescribed drugs in recent clinical practice. They are also known for their pleiotropic actions, which are independent of their lipid-lowering properties. The effect of lovastatin was investigated against carrageenan-induced paw edema in male Wistar rats (200-250 g) and on leukocyte migration, as measured by carrageenan-induced peritonitis in male Swiss mice (20-25 g), which are models of acute inflammation. Lovastatin (administered 1 h prior to carrageenan), at oral doses of 2, 5, and 10 mg/kg, markedly attenuated paw edema formation in rats at the 4th hour after carrageenan injection (25, 43, and 37% inhibition, respectively). Inhibitions of 20, 45 and 80% were observed in the leukocyte migration, as evaluated by carrageenan-induced peritonitis in mice with lovastatin doses of 0.5, 1 and 5 mg/kg, as compared to controls. Furthermore, lovastatin (administered 1 h before initiation) reduced the nociceptive effect of the formalin test in mice, at both phases, at doses of 2, 5, and 10 mg/kg: first phase (51, 65, and 70%, respectively) and second phase (73, 57, and 66% inhibition of licking time, respectively). The anti-nociceptive activity of lovastatin was inhibited by naloxone (3 mg/kg, sc). Lovastatin (0.01, 0.1, and 1 µg/mL) inhibited by 23, 79, and 86%, respectively, the release of myeloperoxidase from human neutrophils. Leukocyte (predominantly neutrophils) infiltration was almost completely reduced by lovastatin treatment, as observed in the model of acute paw edema with hematoxylin and eosin staining. In addition, lovastatin decreased the number of cells expressing tumor necrosis factor-^5; (TNF-^5;) and the inducible form of nitric oxide synthase (iNOS) activity. Therefore, the alterations in leukocyte activity and cytokine release could contribute to the anti-inflammatory activity of lovastatin.