Showing papers by "Universidade Federal de Santa Catarina published in 1995"

Short-term and long-term sick-leave in Sweden: relationships with social circumstances, working conditions and gender.

Abstract: The primary aim of the study was to analyse similarities and differences between repeated spells of short-term sick-leave (more than 3 spells of less than 7 days' duration in a 12-month period) and...

Involvement of B1 and B2 receptors in bradykinin-induced rat paw oedema.

Abstract: 1 The mechanisms involved in bradykinin (BK)-induced oedema in the rat paw as well as the interactions between BK and several inflammatory mediators, have been investigated. 2 Intraplantar injection of BK (1 nmol/paw) in rats pretreated with captopril (5 mg kg−1, s.c.) caused a small amount of oedema formation (0.17 ± 0.05 ml). Des-Arg9-BK (DABK, a selective B1 receptor agonist) up to 300 nmol/paw caused minimal oedema (0.03 ± 0.01 ml). 3 Co-administration of prostaglandin E2 (PGE2), prostaglandin I2 (PGI2), calcitonin gene-related peptide (CGRP), 5-hydroxytryptamine (5-HT), substance P (SP) or platelet activating factor (PAF) (1 pmol–1 nmol/paw) with BK (1 nmol/paw) dose-dependently potentiated BK-induced paw oedema. The rank order of potency (mean ED50, pmol/paw) for this effect was: SP (8.1) > PAF (13.7) > PGI2 (20.5) > 5-HT (23.8) > CGRP (25.7) > PGE2 (52.0). Co-administration of BK with the various inflammatory mediators resulted in maximal paw oedemas (ml) of: PGE2 (0.71 ± 0.02); PGI2 (0.66 ± 0.02); 5-HT (0.65 ± 0.01); SP (0.63 ± 0.05); CGRP (0.60 ± 0.05) and PAF (0.47 ± 0.02) ml. Histamine (up to 1 nmol/paw) was ineffective in potentiating the response to BK. 4 Hoe 140 or NPC 17731 (two selective B2 receptor antagonists, 0.1–3 nmol/paw) produced dose-dependent inhibition of paw oedema potentiation induced by co-injection of BK with other mediators with the following mean ID50s (nmol/paw): Hoe 140–1.4; 1.3; 1.5 and 1.1 and NPC 17731–1.0; 1.0; 0.9 and 0.7; in the presence of PGE2, PGI2, CGRP and SP, respectively. The selective B1 receptor antagonist des-Arg9 [Leu8]-BK (DALBK, up to 300 nmol/paw) had no effect. 5 Daily intraplantar injections of BK (10 nmol/paw) once a day for 7 consecutive days caused a progressive and complete desensitization of the paw oedema, which was specific for BK, since paw oedema induced by PAF, PGE2, SP or histamine was not affected. In addition, the oedema caused by BK in the paw desensitized to the peptide was almost completely reversed if BK was co-injected with PGE2, PGI2 or SP (1 nmol/paw). Injection of PGE2 or SP (10 nmol/paw) together with the first BK injection (10 nmol/paw), partially prevented BK-induced desensitization. 6 When animals were completely desensitized to BK, DABK (100 nmol/paw) caused paw oedema (0.25 ± 0.03 ml) which was consistently blocked by the B1 receptor antagonist, DALBK (100 nmol/paw). 7 Treatment of animals with dexamethasone (0.5 mg kg−1, s.c., 24 h previously) antagonized paw oedema induced by DABK (100 nmol/paw) in desensitized paws, but not that induced by BK (3 nmol/ paw) in naive paws. The steroid also prevented the recovery of oedema seen after co-injection of BK with PGE2 or PGI2 (1 nmol/paw) in desensitized paws. 8 These results suggest that both B1 and B2 receptors are involved in BK-induced rat paw oedema. The B2 receptors are constitutive, but induction of expression of B1 receptors seems to occur only after complete desensitization of the paw to BK. In addition, very low doses of inflammatory mediators markedly potentiate BK-induced paw oedema and can attenuate BK-induced paw oedema desensitization. Such mechanisms may be relevant for the manifestation of acute and chronic inflammatory processes.

New Developments in Generalized Information Measures

Abstract: Publisher Summary The concept of Shannon's (1948) entropy is the central concept of information theory. Sometimes this measure is referred to as the “measure of uncertainty.” The entropy of a random variable is defined in terms of its probability distribution and can be shown to be a good measure of randomness or uncertainty. This chapter discusses new developments in generalized information measures. The entropy of a random variable is defined in terms of its probability distribution and can be shown as a good measure of randomness or uncertainty. In the past, researchers' interest tended toward one- and two-scalar parametric generalizations of the measures. The unified ( r , s )-measures are divided in two parts: (1) unified ( r , s )-information measures and (2) M-dimensional unified (r, s)-divergence measures. The measure H ( P ) is the Shannon's entropy and the measure H ( P | Q ) is the inaccuracy. The arithmetic-geometric mean divergence measure and its unified ( r , s )-generalizations are also presented in this chapter.

Analysis of the mechanisms underlying the antinociceptive effect of the extracts of plants from the genus Phyllanthus

Abstract: 1. 1. We examine some of the mechanisms underlying the analgesic effects of the hydroalcoholic extracts (HE) of Phyllanthus urinaria and P. niruri against formalin-induced nociception in mice. In addition, we also investigate the action of both HEs against capsaicin-mediated pain. 2. 2. Both prazosin and yohimbine (0.15 mg/kg, i.p.) induced a marked inhibition of the analgesic effect caused by phenylephrine (10 mg/kg, i.p.) and clonidine (0.1 mg/kg, i.p.), respectively, but had no effect on the antinociceptive action caused by HE of P. urinaria (10 mg/kg, i.p.) or P. niruri (30 mg/kg, i.p.). 3. 3. NG-nitro- l -arginine ( l -NOARG, 75 mg/kg, i.p.) caused marked analgesic effect against the second phase of formalin-induced pain. Treatment of animals with l -arginine (600 mg/kg) completely antagonized the antinociceptive effect of l -NOARG but had no significant effect against the HE of P. urinaria (10 mg/kg, i.p.) or P. niruri (30 mg/kg, i.p.) analgesic properties. 4. 4. The antinociceptive effects caused by the HEs of P. urinaria (10 mg/kg, i.p.) and P. niruri (30 mg/kg, i.p.) were unaffected by methysergide (5 mg/kg, i.p.), p-chloro-phenylalanine-methyl-ester (100 mg/kg, i.p., once a day for 4 consecutive days) or after previous adrenalectomy of animals. 5. 5. The HE of P. urinaria and P. niruri given either intraperitoneally (1–30 mg/kg) or orally (25–200 mg/kg) caused marked and dose-related inhibition of capsaicin-induced pain with ID50 of 2.1 and 6.1 mg/kg given intraperitoneally and 39 and 35 mg/kg given orally, respectively.

Antinociceptive properties of steroids isolated from Phyllanthus corcovadensis in mice.

Abstract: The antinociceptive actions of the steroid compounds isolated from the leaves, stems, and roots of P. corcovadensis have been investigated in mice. Stigmasterol, stigmasterol acetate, beta-sitosterol, and aspirin (3-100 mk/kg, i.p.) inhibited, in a dose-related manner, acetic acid-induced abdominal constriction in mice with ID50s of 16, 11, 9, and 24 mg/kg, respectively. In the formalin test, stigmasterol and stigmasterol acetate (10-100 mg/kg, i.p.) caused graded inhibition of both the neurogenic (first phase) and inflammatory phases (second phase) of formalin-induced pain. However, both compounds were more effective in relation of the second phase of the formalin test with ID50 values of 26 and 41 mg/kg, respectively. Furthermore, both steroids failed to affect the edematogenic response of the formalin test. Given orally, stigmasterol and stigmasterol acetate (50-200 mg/kg) also exhibited significant though less potent analgesic action against both acetic acid- and formalin-induced nociception in mice. In addition, stigmasterol (up to 100 mg/kg, i.p.), in contrast to morphine (10 mg/kg, s.c.), had no analgesic effect in either tail-flick or hot-plate models. These findings suggest that stigmasterol and beta-sitosterol may account, at least in part, for the antinociceptive actions reported previously for the hydroalcoholic extract of Phyllanthus corcovadensis.

Relationships between microflora and caecal fermentation in rabbits before and after weaning

Abstract: Some microbiological and biochemical parameters of caecal content were studied in 15- to 49-d-old rabbits that were slaughtered sequentially. The ammonia level did not differ before weaning (11.5 mmol/L on average) (P = 0.41) or after weaning (7.4 mmol/L on average) (P = 0.19) but decreased by 40% (P < 0.001) between days 29 and 32. The level of pH decreased linearly (P < 0.001) throughout the period studied. The Escherichia coli counts decreased up to weaning (P < 0.001) and was then not significantly affected by age (P = 0.12). The total volatile fatty acid (VFA) concentration increased between days 15 (8.2 mmol/L) and 25 (33.9 mmol/L) (P < 0.05) and then levelled off below 40 mmol/L. Molar proportions in propionate and in branched-chain fatty acid (BCFA) and valeric acid were high at day 15 but decreased when the animals began to eat solid feed. The C3/C4 ratio reversed at weaning (3.8 on day 15 and 0.5 on day 49) whereas the acetic acid proportion was not affected by age (P = 0.19). High counts of anaerobic microflora were found between 15 and 22 d of age (10(11) bacteria/g of caecal content, on average) and did not change significantly according to the age (at about 10(10) bacteria/g), from day 29 until the end of the experiment (P = 0.29). Amylolytic flora had a similar evolution at a slightly lower level. In contrast, under our breeding conditions cellulolytic microflora slowly colonized the caecum and remained at a low level. The discriminant analysis revealed relationships between ages, intestinal microflora and fermentation parameter; the colibacilli flora was associated with mother-fed animals and amylolytic flora which was linked to BCFA and valeric acid, while the cellulolytic flora was associated with animals older than 4 weeks and linked to the production of C2, C3, C4 and ammonia.

Nonvital tooth bleaching: guidelines for the clinician.

Abstract: The combination of intracoronal and extracoronal bleaching represents a conservative treatment to restore esthetics to darkened or stained nonvital teeth. Notwithstanding the eventual risks and difficulties accompanying such technique, nonvital teeth often can be successfully lightened. This article presents a few guidelines for bleaching nonvital teeth as well as a clinical case to illustrate the indications and clinical protocol for the technique.

An explicit physical model for the long-channel MOS transistor including small-signal parameters

Abstract: This paper presents a long-channel MOSFET model wherein the drain current, total charges and small-signal parameters for quasi-static operation are very simple functions of the inversion charge densities at the channel boundaries The inversion charge densities, in turn, are formulated as explicit continuous functions of the terminal voltages, with continuous first order derivatives, resulting in an explicit MOSFET model valid in the whole inversion region Physical properties, such as the symmetry of the transistor with respect to source and drain are carefully observed in order to achieve a proper prediction of the device behavior The proposed model contains only the classical parameters of the MOSFET theory

Seroprevalence of HIV, HTLV-I/II and other perinatally-transmitted pathogens in Salvador, Bahia.

Abstract: Generation of epidemiological data on perinatally-transmitted infections is a fundamental tool for the formulation of health policies. In Brazil, this information is scarce, particularly in Northeast, the poorest region of the country. In order to gain some insights of the problem we studied the seroprevalence of some perinatally-transmitted infections in 1,024 low income pregnant women in Salvador, Bahia. The prevalences were as follow: HIV-1 (0.10%), HTLV-I/II (0.88%), T.cruzi (2.34%). T.pallidum (3.91%), rubella virus (77.44%). T.gondii IgM (2.87%) and IgG (69.34%), HBs Ag (0.6%) and anti-HBs (7.62%). Rubella virus and T.gondii IgG antibodies were present in more than two thirds of pregnant women but antibodies against other pathogens were present at much lower rates. We found that the prevalence of HTLV-I/II was nine times higher than that found for HIV-1. In some cases such as T.cruzi and hepatitis B infection there was a decrease in the prevalence over the years. On the other hand, there was an increase in the seroprevalence of T.gondii infection. Our data strongly recommend mandatory screening tests for HTLV-I/II, T.gondii (IgM), T.pallidum and rubella virus in prenatal routine for pregnant women in Salvador. Screening test for T.cruzi, hepatitis and HIV-1 is recommended whenever risk factors associated with these infections are suspected. However in areas with high prevalence for these infections, the mandatory screening test in prenatal care should be considered.

T3 affects cerebellar astrocyte proliferation, GFAP and fibronectin organization

Abstract: Thyroid hormone T 3 and conditioned medium from cerebellar T 3 -treated astrocytes induced proliferation in astroglial cells. In addition, T 3 treatment promoted alterations in the organization of cytoskeleton (GFAP) and extracellular matrix (fibronectin) in these cerebellar astrocytes in culture. GFAP filaments that normally spread in the cytoplasm of astrocytes became organized around the cell nucleus. Fibronectin that had a punctate distribution on control cell surface, became diffused in T 3 -treated astrocytes. This hormone also induced growth factor(s) secretion by astrocytes. These results suggest that T 3 may be an important regulator of astrocyte growth and differentiation

Expression of B1 kinin receptors mediating paw edema and formalin-induced nociception. Modulation by glucocorticoids.

Abstract: La bradykinine (BK) et la Tyr 8 -BK ont induit un oedeme graduel dans des pattes de rats avec une EC 50 de 1,9 et 1,1 nmol/patte, alors que la des-Arg 9 -BK (DABK, jusqu'a 300 nmol/patte) a eu tres peu d'effet. La Tyr 8 -BK, mais pas la DABK, a aussi provoque une augmentation dose-dependante de l'oedeme dans des pattes de souris avec une EC 50 de 1,3 nmol/patte. Les antagonistes des recepteurs B 2 (HOE-140 ou NPC 17731, 30 nmol/patte), mais pas l'antgoniste B 1 des-Arg 9 [Leu 8 ]BK (DALBK, 100 nmol/patte), se sont opposes a la reponse a la Tyr 8 -BK (10 nmol/patte) dans les pattes des rats. Des injections intraplantaires quotidiennes de Tyr 8 -BK (10 nmol/patte) pendant 7 jours ont cause une desensibilisation (D) progressive de l'oedeme chez des rats Wistar surrenalectomises et operes de maniere factice. La DABK (100 nmol/patte) a induit un oedeme marque dans les pattes D des rats des deux groupes, alors que la DALBK (100 nmol/patte) ou le dexamethasone (0,5 mg/kg, s.c.) l'ont inhibe. L'injection systemique de lipopolysaccharide (10 μg/souris, 24 h plus tot) a potentialise les premiere et deuxieme phases de la douleur induite par la formaline, mais elle n'a pas eu d'effet sur l'oedeme des pattes. La co-injection de DABK (2-22 nmol/patte) et de faibles doses de formaline chez les souris traitees au lipopolysaccharide, qui n'a eu aucun effet sur les animaux naifs, a potentialise de maniere dose-dependante les deux phases de la douleur induite par formaline, mais n'a pas eu d'effet sur l'oedeme. La DALBK s'est opposee a ces effets avec des ED 50 de 21,9 (premiere phase) et de 64,1 nmol/patte (deuxieme phase). Ainsi, la D des recepteurs B 2 et un traitement systemique au LPS induisent une regulation positive sensible aux glucocorticoides des recepteurs B 1 produisant un oedeme dans les pattes des rats ainsi qu'une nociception induitge par la formalisme chez les souris. Ces resultats suggerent que la regulation positive des recepteurs B 1 pourrait jouer des roles importants dans le controle des processus inflammatoires et l'hyperalgesie.

Thyroid hormone and conditioned medium effects on astroglial cells from hypothyroid and normal rat brain : factor secretion, cell differentiation, and proliferation

Abstract: The effects of triiodothyronine (T3)on cell morphology were examined in cerebral hemisphere and cerebellar astrocyte cultures obtained from normal and hypothyroid neonatal rats. T3-treatment induced morphological changes in astrocytes from cerebral hemispheres. This morphological effect was produced earlier if astrocytes were treated with conditioned medium obtained from cerebral hemisphere astrocyte cultures previously exposed to 50 nM T3. T3 or conditioned medium-treatment produced faster morphological changes in hypothyroid rat cerebral hemisphere astrocyte monolayers. Cerebellar astrocytes from normal brain did not respond to thyroid hormone with morphological changes, but proliferated after T3-treatment. However, hypothyroid cerebellar astrocyte cultures exhibited morphological changes, differently than normal cells. We verified that T3 may induce astrocyte secretion of factor(s) that promotes morphological differentiation in cerebral hemisphere astroglial cultures and stimulates the proliferation of cerebellar astrocytes. Astrocytes obtained from hypothyroid animals were more sensitive to secreted factors than normal cells. These results emphasize the heterogeneity and the importance of glial cells to normal brain development and open new questions about thyroid hormone therapy in hypothyroidism. © 1995 Wiley-Liss, Inc.

Application of Arbuscular Mycorrhizal Fungi (AMF) in Orchard and Ornamental Plants

Abstract: Technology has brought a great increase in world agricultural production in the last decades, by improving productivity and by making possible the incorporation of areas until then considered marginal. These benefits have essentially come from the increase in the quantity of grains, oilseeds and feeds for animal production. However, in the last years, urbanization and changes in eating habits have caused a shift towards the consumption of fresh fruits and vegetables. This has been followed by a growing commercialization of ornamental plants. These products come from a labour- and capital-intensive activity, where chemical input plays an essential role, but also brings up a set of problems linked with the degradation of the natural environment and resource base. The aim of this chapter is to present new developments in the potential use of biological tools such as the arbuscular mycorrhizal fungi (AMF), which should ensure adequate levels of food production with a satisfactory reduction of chemical fertilizer and pesticides, in the context of the technologies needed for sustainable agriculture. The potential of AMF as biofertilizers and bioprotectors to enhance crop production is well recognized, but not well exploited because of the current agronomic practices, with their implications for the environment. In order to clarify some of these points, we will first briefly review some aspects of arbuscular mycorrhiza biology, ecology, and the methods used to study them. Readers can refer to other sections of this volume, where many of these topics are more extensively discussed.

Discussion: On the Very Real Distinction Between Fuzzy and Statistical Methods

Abstract: In this discussion we review the main remarks of Laviolette, Seaman, Barrett, and Woodall. First, we examine how the subjectivist view of probability faces the task of modeling human reasoning according to a cognitive viewpoint. We then investigate the nature of the fuzzy and probabilistic controllers analyzed by the authors, refuting the hypothesis of similarity. We show that, due to the different theoretical basis, the representativeness of the fuzzy controller overcomes the probabilistic controller in resembling the expert's knowledge. We also review the authors'comparison between the fuzzy and probabilistic approaches to monitor multinomial processes, emphasizing biases and misconceptions in the authors' analysis.

Enzymatic resolution of alcohols via lipases immobilized in microemulsion-based gels

Abstract: Lipases immobilized in microemulsion-based gel (MBG) were used in the resolution of racemic alcohols, in a new, convenient method of catalysis in organic solvents which employs small amounts of the enzyme.

An improved high power factor and low cost three-phase rectifier

Abstract: A new method to improve the power factor of three-phase rectifiers is introduced in this paper. The main features of the proposed circuit are low cost, small size, high efficiency and simplicity. The power factor improvement is achieved with three bidirectional active switches rated at a small fraction of the total processed power, and gated at the line frequency. Principle of operation and design procedure, with practical examples are also presented. The theoretical analysis was validated with experimental results from a laboratory prototype rated at 6.4 kW and connected to the 220 V, 60 Hz AC system. The same circuit was also used in another prototype rated at 12 kW, with similar results. >

On the solvatochromic reversal of merocyanine dyes. Part 1. The UV–VIS spectroscopic behaviour of vinylogous γ-pyridones

Abstract: A theoretical approach is described to rationalize and predict the solvatochromic behaviour of vinylogous γ-pyridones. The theoretical curves obtained are shown to reproduce the experimental UV–VIS spectroscopic behaviour of dyes 1, 2, 3 and 5. The model reconciles previous conflicting reports on the solvatochromism of these and related dyes.

Do paradigma etiológico ao paradigma da reação social: mudança e permanência de paradigmas criminológicos na ciência e no senso comum

Abstract: Neste artigo abordamos, numa perspectiva sincrônica antes que diacrônica (histórica), a mudança do paradigma etiológico para o paradigma da reação social que a Criminologia experimenta desde a década de sessenta de nosso século, situando a desconstrução epistemológica que o novo paradigma operou em relação ao tradicional e a permanência deste, para além desta desconstrução, pela sua importante funcionalidade (não declarada) como ciência do controle sócio-penal. Muitas razões justificam, pensamos, a atenção aqui dedicada ao tema. Mas ao invés de explicitá-las o que ensejaria basicamente um outro artigo deixamos que o leitor extraia suas próprias conclusões.

Comparison of experimental losses among six different topologies for a 1.6 kW boost converter, using IGBTs

Abstract: This paper presents a comparative analysis of experimental losses between a new ZCS-PWM boost converter and five different boost topologies, using IGBTs, rated at 1.6 kW and operating at 20 kHz. The advantages of the new ZCS-PWM technique employing IGBTs are presented. This new ZCS operation can reduce the average total power dissipation in the devices, practically by half, when compared with the hard-switching method. This new ZCS-PWM boost converter is suitable for high power applications using IGBTs in power factor correction. The principle of operation, experimental results, and comparative analysis of the new ZCS-PWM boost converter are also provided. >

On the Complexity of Linear Programming

Abstract: In this paper we show a simple treatment of the complexity of Linear Programming. We describe the short step primal-dual path following algorithm and show that it solves the linear programming problem in 0 (foL) iterations, each one with a bound of O(n3 ) arithmetic computations.