Nitric oxide of the supraoptic nucleus influences the salivary secretion, sodium renal excretion, urinary volume and arterial blood pressure induced by pilocarpine

Male Holtzman rats weighting 200-250 g were anesthetized with zoletil 50 mg/Kg (tiletamine chloridrate 125.0 mg and zolazepan chloridrate 125.0 mg) into quadriceps muscle and stainless steel cannulas were implanted into their supraoptic nucleus (SON). We investigated the effects of the injection into the supraoptic nucleus (SON) of FK 409, a nitric oxide donor, and N(W-)nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor (NOS), on the salivary secretion, arterial blood pressure, sodium excretion and urinary volume induced by pilocarpine, which was injected into SON. The drugs were injected in 0.5 mul volume over 30-60 s. Controls was injected with a similar volume of 0.15 M NaCl. FK 409 and L-NAME were injected at doses of 20 mug/0.5 mul and 40 mug/0.5 mul. respectively. The amount of saliva secretion was studied over a five-minute period after injection of pilocarpine into SON. Injection of pilocarpine (10, 20, 40, 80, 160 mug/mul) into SON produced a dose-dependent increase in salivary secretion. L-NAME was injected into SON prior to the injection of pilocarpine into SON, producing an increase in salivary secretion due to the effect of pilocarpine. FK 409 injected into SON attenuating the increase in salivary secretion induced by pilocarpine. Mean arterial pressure (MAP) increase after injections of pilocarpine into the SON. L-NAME injected into the SON prior to injection of pilocarpine into SON increased the MAP. FK 409 injected into the SON prior to pilocarpine attenuated the effect of pilocarpine on MAP. Pilocarpine (0.5 mumol/0.5 mul) injected into the SON induced an increase in sodium and urinary excretion. L-NAME injected prior to pilocarpine into the SON increased the urinary sodium excretion and urinary volume induced by pilocarpine. FK 409 injected prior to pilocarpine into the SON decreased the sodium excretion and urinary volume induced by pilocarpine. All these roles of pilocarpine depend on the release of nitric oxide into the SON. In summary the present results show: a) SON is involved in pilocarpine-induced salivation; b) that mechanism involves increase in MAP, sodium excretion and urinary volume. (C) 2003 Elsevier B.V. All rights reserved.

Red blood cells from the South American rattlesnake (Crotalus durissus terrificus) regulate volume incompletely following osmotic shrinkage and swelling in vitro

The ability of rattlesnake (Crotalus durissus terrificus) red blood cells to volume regulate in vitro has been investigated. Blood was drawn through a catheter inserted in the dorsal aorta and equilibrated to gas mixtures of different composition. Cells shrunken osmotically by increasing the extracellular osmolarity from approximate to 291 mosm l(-1) (n = 3) to approximate to 632 mosm l(-1) (calculated) only partially regulated their volume back towards the original volume either at pH 7.51 +/- 0.05 (mean +/- S.D., n = 5) or pH 7.20 +/- 0.06 (mean +/- S.D., n = 3), There was no improvement of the regulatory volume increase at low haemoglobin oxygen saturation. The limited volume restoration was inhibited by separate additions of amiloride (10(-4) M) or DIDS (10(-4) M) suggesting involvement of the Na+/H+ and Cl-/HCO3- exchangers. Cells that were swollen osmotically by an approximate to 30% dilution of the extracellular medium also exhibited a limited ability to recover their volume. Therefore, these cells show little ability to volume regulate when exposed to in vitro conditions that shrink or swell the cell. (C) 2000 Elsevier B.V. All rights reserved.

Fractal character of the SAXS correlation volume in poly(ethylene glycol)/silica hybrid wet gels

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

Effect of the temperature on the TMOS sono-hydrolysis and a study of the structure of the resulting aged sonogels

The effect of temperature on the oxalic acid catalyzed sono-hydrolysis of tetramethoxysilane (TMOS) was studied by means of a heat flux calorimetric method. The activation energy of the process was measured as (24.5 +/- 0.8) kJ/mol in the temperature range between 10 and 50 degreesC. The structural characteristics of the resulting sonogels, after long period of aging in saturated conditions, were studied by means of small angle X-ray scattering. The structure can be described as formed by similar to2.7 nm mean size mass fractal-like aggregates (clusters) of primary silica particles of similar to0.3 nm mean size, all imbibed in a liquid phase. The average mass fractal dimension of the clusters was found to be 2.58. The primary particle density was estimated as 2.23 g/cm(3), in good agreement with the value frequently quoted for fused silica. The volume fraction of the clusters, in the saturated sonogels was estimated as about 28%. The moment in which the meniscus of the liquid phase penetrates into the clusters under rapid evaporation process has been detected by an inflection in the first derivative of the curve of weight loss in a simple thermogravimetric test. (C) 2003 Elsevier B.V. All rights reserved.

Influence from the free volume on the photoinduced birefringence in azocompound-containing polymers

The photoinduced birefringence is analyzed in a guest-host azobenzene-containing polymer in the temperature range from 20 to 330 K. An anomalous behavior arises in the low-temperature range, suggesting strong influence from the free volume for the chromophores in the polymer. This influence is so strong that quenched samples have a photoinduced signal ca. 5 times greater than the annealed ones at room temperature. An extended free volume model is presented based on two assumptions about thermal fluctuations in the cavities and their size distribution. This model, which is an extension of the model by Mita et al., can explain the main features of the photoinduced birefringence as a function of time, temperature, and initial free volume state. To account for the influence of free volume on the photoorientation, the detailed reorientation model by Sekkat's was used. We show that Sekkat's model leads to an exponential behavior at small orientation regimes, which simplifies the mathematical treatment and allows the mean free volume to be obtained from the data fitting.

REDUCTION OF URINE VOLUME AMELIORATES ADRIAMYCIN-INDUCED NEPHROPATHY

1. Adriamycin, a commonly used antineoplastic antibiotic, induces glomerular lesions in rats, resulting in persistent proteinuria and glomerulosclerosis.2. The effect of urine volume on the progression of adriamycin-induced nephropathy was studied in 70 male Wistar rats (180-200 g) observed for 30 weeks and separated into 4 groups: healthy control group (HCG, N = 10) inoculated iv with 1 ml of saline, and nephrotic groups inoculated iv with a single dose of adriamycin of 3 mg/kg body weight. The nephrotic rats were separated into 3 groups (N = 20): nephrotic control group (NCG) receiving only adriamycin; dehydrated nephrotic group (DNG) water deprived for 36 h within each 48-h period, and furosemide nephrotic group (FNG) treated with 12 mg/dl furosemide, and 0.9 g/dl NaCl in the drinking water.3. The 30-week survival rates of the DNG (100%) and HCG (100%) were significantly higher than those of the NCG (85%) and FNG (55%).4. The proteinuria observed in the HCG (range, 7.38 +/- 0.7 to 13.6 +/- 1.27 mg/24 h) was significantly lower than that observed for all the nephrotic groups throughout the experiment. The DNG presented significantly less proteinuria (range, 42.71 +/- 6.83 to 140.10 +/- 19.22 mg/24 h) than the NCG (range, 35.32 +/- 7.64 to 250.00 +/- 25.91 mg/24 h) from week 10 on. There was no significant difference between the mean 24-h proteinuria of the NCG (range, 35.32 +/- 7.64 to 250.00 +/- 25.91 mg/24 h) and the FNG (range, 35.82 +/- 7.91 to 221.54 +/- 26.74).5. The mean frequency of damaged glomeruli was 0.3% +/- 0.3 for HCG, 42% +/- 6% for CNG, 40.8% +/- 8% for DNG, and 47% +/- 14% for FNG. The median value of the tubulointerstitial lesion, evaluated by a semiquantitative method, was 0 in HCG, 10 in CNG, 8.5 in DNG and 9.5 in FNG(P<0.05 for all groups compared to HCG).6. The data indicate that reduction of urine volume has a protective effect on adriamycin-induced nephropathy.

Peridural com ropivacaina a 1%: Experiencia com volume proporcional a estatura

Background and Objectives - Ropivacaine - a local amino amide anesthetic agent - is a plain S enantiomer which makes it a potent and low toxicity drug. The aim of our study was to evaluate 1% ropivacaine for epidural block in lower doses than those described in the literature. Methods - Thirty-eight patients, physical status ASA I and II, aged 15 to 70 years, weighing 50 to 100 kg were selected. Premedication consisted of 15 mg oral midazolam given 60 min before anesthesia induction. In the OR, after standard monitoring a catheter was inserted intravenously to administer 10 ml.kg-1 Ringers lactate solution. Epidural puncture was performed with the patient in the sitting position and 1% ropivacaine was administered in a volume corresponding to 10% of patient's height in centimeters. With the patient in the supine position, motor blockade intensity, temperature sensitivity and sensory block extension at 1, 3, 5, 7, 10, 15, 20, 30 minutes after drug injection were evaluated. Blood pressure, heart rate and adverse side effects during the course of anesthesia and in the post-anesthetic period were also observed. In the recovery room patients were followed-up until motor blockade intensity temperature sensitivity and sensory block had returned to level L2. Results - Mean values were 41.4 years of age, 68.8 kg of body weight and 165 cm height. Upper thermal blockade level was T4 and upper sensory block level was T6. Most patients showed motor block level 1 (Bromage scale) after 30 minutes of observation. Motor block mean duration was 254 minutes and temperature sensitivity 426 minutes. Only three patients had complications: two cases of hypotension and one of bradycardia. Conclusions - In the volumes used in this study, ropivacaine produced adequate analgesia and a less intense lower limb motor block which, however, was sufficient to allow for surgical procedures with low incidence of side-effects.

Estudo comparativo dos efeitos hemodinâmicos e ventilatórios da ventilação controlada a volume ou a pressão, em cães submetidos ao pneumoperitônio

BACKGROUND AND OBJECTIVES: Pressure controlled ventilation (PCV) is available in anesthesia machines, but there are no studies on its use during CO 2 pneumoperitoneum (CPP). This study aimed at evaluating pressure-controlled ventilation and hemodynamic and ventilatory changes during CPP, as compared to conventional volume controlled ventilation (VCV). METHODS: This study involved 16 dogs anesthetized with thiopental, fentanyl and pancuronium, which were randomly assigned to two groups: VC - volume controlled ventilation (n=8) and PC - pressure controlled ventilation (n=8). Hemodynamic and ventilatory parameters were monitored and recorded in 4 moments: M1 (before CPP), M2 (30 minutes after CPP = 10 mmHg), M3 (30 minutes after CPP=15 mmHg) and M4 (30 minutes after deflation). RESULTS: With CPP, there has been significant increase in tidal volume in PC group; there has been increase in airway pressures (peak and plateau), decrease in compliance with increase in CPP pressure, increase in heart rate, maintenance of mean blood pressure with higher values in the VC group in all stages; there was also increase in right atrium pressure with significant decrease after deflation, decrease in arterial pH with minor variations in PC group, greater arterial pCO 2 stability in PC group, and no significant changes in arterial pO 2. CONCLUSIONS: There were some differences in hemodynamic and ventilatory data between both ventilation control modes (VC and PC). It is possible to use pressure controlled ventilation during CPP, but the anesthesiologist must monitor and take a close look at alveolar ventilation, adjusting inspiratory pressure to ensure proper CO 2 elimination and oxygenation. © Sociedade Brasileira de Anestesiologia, 2005.

Efeitos determinados pelo pneumoperitônio sobre a hemodinâmica e função renais de cães ventilados com volume e pressão controlados

Pós-graduação em Anestesiologia - FMB

Mineralogia da argila e atributos físicos de um argissolo em curvaturas de relevo

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

Influência do volume do preparo oclusal para inlays e do material restaurador na distribuição de tensão e resistência à fratura de pré-molares

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Pulverização conjugada à fertilização para controle de Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae) em diferentes híbridos de milho, em função do volume de calda e ponta de pulverização

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Comparação entre um modelo teórico e o real, no investimento em construção de estradas de uso florestal, relacionado com o volume de madeira transportado

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Alterações em latossolo vermelho e na cultura da soja em função de sistemas de preparo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação dos efeitos da expansão rápida da maxila no volume aéreo nasal, por meio da tomografia computadorizada de feixe cônico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)