Cardiopulmonary and isoflurane-sparing effects of epidural or intravenous infusion of dexmedetomidine in cats undergoing surgery with epidural lidocaine

Objective To compare the cardiorespiratory, anesthetic-sparing effects and quality of anesthetic recovery after epidural and constant rate intravenous (IV) infusion of dexmedetomidine (DEX) in cats given a low dose of epidural lidocaine under propofol-isoflurane anesthesia and submitted to elective ovariohysterectomy. Study design Randomized, blinded clinical trial. Animals Twenty-one adult female cats ( mean body weight: 3.1 +/- 0.4 kg). Methods Cats received DEX (4 mu g kg(-1), IM). Fifteen minutes later, anesthesia was induced with propofol and maintained with isoflurane. Cats were divided into three groups. In GI cats received epidural lidocaine (1 mg kg(-1), n = 7), in GII cats were given epidural lidocaine (1 mg kg(-1)) + DEX (4 mu g kg(-1), n = 7), and in GIII cats were given epidural lidocaine (1 mg kg(-1)) + IV constant rate infusion (CRI) of DEX (0.25 mu g kg(-1) minute(-1), n = 7). Variables evaluated included heart rate (HR), respiratory rate (f(R)), systemic arterial pressures, rectal temperature (RT), end-tidal CO(2), end-tidal isoflurane concentration (E`ISO), arterial blood gases, and muscle tone. Anesthetic recovery was compared among groups by evaluation of times to recovery, HR, f(R), RT, and degree of analgesia. A paired t-test was used to evaluate pre-medication variables and blood gases within groups. ANOVA was used to compare parametric data, whereas Friedman test was used to compare muscle relaxation. Results Epidural and CRI of DEX reduced HR during anesthesia maintenance. Mean +/- SD E/ISO ranged from 0.86 +/- 0.28% to 1.91 +/- 0.63% in GI, from 0.70 +/- 0.12% to 0.97 +/- 0.20% in GII, and from 0.69 +/- 0.12% to 1.17 +/- 0.25% in GIII. Cats in GII and GIII had longer recovery periods than in GI. Conclusions and clinical relevance Epidural and CRI of DEX significantly decreased isoflurane consumption and resulted in recovery of better quality and longer duration, despite bradycardia, without changes in systemic blood pressure.

Assessment of antimicrobial effect of Biosilicate (R) against anaerobic, microaerophilic and facultative anaerobic microorganisms

This study assessed the antimicrobial activity of a new bioactive glass-ceramic (Biosilicate (R)) against anaerobic, microaerophilic, and facultative anaerobic microorganisms. Evaluation of the antimicrobial activity was carried out by three methods, namely agar diffusion, direct contact, and minimal inhibitory concentration (MIC). For the agar diffusion technique, bio glass-ceramic activity was observed against various microorganisms, with inhibition haloes ranging from 9.0 +/- 1.0 to 22.3 +/- 2.1 mm. For the direct contact technique, Biosilicate (R) displayed activity against all the microorganisms, except for S. aureus. In the first 10 min of contact between the microorganisms and Biosilicate (R), there was a drastic reduction in the number of viable cells. Confirming the latter results, MIC showed that the Biosilicate (R) inhibited the growth of microorganisms, with variations between <= 2.5 and 20 mg/ml. The lowest MIC values (7.5 to <= 2.5 mg/ml) were obtained for oral microorganisms. In conclusion, Biosilicate (R) exhibits a wide spectrum of antimicrobial properties, including anaerobic bacteria.

Mate Tea Inhibits In Vitro Pancreatic Lipase Activity and Has Hypolipidemic Effect on High-fat Diet-induced Obese Mice

The inhibitory effects of mate tea (MT), a beverage produced with leaves from Ilex paraguariensis, in vitro lipase activity and on obesity in obese mice models were examined. For the in vitro experiment, porcine and human pancreatic lipase (PL) activities were determined by measuring the rate of release of oleic acid from hydrolysis of olive oil emulsified with taurocholate, phospholipids, gum arabic, or polyvinyl alcohol. For the in vivo experiments, animals were fed with a standard diet (SD, n = 10) or high-fat diet (HFD, n = 30) for 16 weeks. After the first 8 weeks on the HFD, the animals were treated with 1 and 2 g/kg of body weight of MT. The time course of the body weight and obesity-related biochemical parameters were evaluated. The results showed that MT inhibited both porcine and human PL (half-maximal inhibitory concentration = 1.5 mg MT/ml) and induced a strong inhibition of the porcine lipase activity in the hydrolysis of substrate emulsified with taurocholate + phosphatidylcholine (PC) (83 +/- 3.8%) or PC alone (62 +/- 4.3%). MT suppressed the increases in body weight (P < 0.05) and decreased the serum triglycerides and low-density lipoprotein (LDL)-cholesterol concentrations at both doses (from 190.3 +/- 5.7 to 135.0 +/- 8.9 mg/dl, from 189.1 +/- 7.3 to 129.3 +/- 17.6 mg/dl; P < 0.05, respectively) after they had been increased by the HFD. The liver lipid content was also decreased by the diet containing MT (from 132.6 +/- 3.9 to 95.6 +/- 6.1 mg/g of tissue; P < 0.05). These results suggest that MT could be a potentially therapeutic alternative in the treatment of obesity caused by a HFD.

Correlation Between Etest (R), Disk Diffusion, and Microdilution Methods for Antifungal Susceptibility Testing of Candida Species From Infection and Colonization

The correlation between the microdilution (MD), Etest (R) (ET), and disk diffusion (DD) methods was determined for amphotericin B, itraconazole and fluconazole. The minimal inhibitory concentration (MIC) of those antifungal agents was established for a total of 70 Candida spp. isolates from colonization and infection. The species distribution was: Candida albicans (n = 27), C. tropicalis (n = 17), C. glabrata (n = 16), C. parapsilosis (n = 8), and C. lusitaniae (n = 2). Non-Candida albicans Candida species showed higher MICs for the three antifungal agents when compared with C. albicans isolates. The overall concordance (based on the MIC value obtained within two dilutions) between the ET and the MD method was 83% for amphotericin B, 63% for itraconazole, and 64% for fluconazole. Considering the breakpoint, the agreement between the DD and MD methods was 71% for itraconazole and 67% for fluconazole. The DD zone diameters are highly reproducible and correlate well with the MD method, making agar-based methods a viable alternative to MD for susceptibility testing. However, data on agar-based tests for itraconazole and amphotericin B are yet scarce. Thus, further research must still be carded out to ensure the standardization to other antifungal agents. J. Clin. Lab. Anal. 23:324-330, 2009. (C) 2009 Wiley-Liss, Inc.

In Vitro and In Vivo Antiplasmodial Activities of Risedronate and Its Interference with Protein Prenylation in Plasmodium falciparum

The increasing resistance of malarial parasites to almost all available drugs calls for the identification of new compounds and the detection of novel targets. Here, we establish the antimalarial activities of risedronate, one of the most potent bisphosphonates clinically used to treat bone resorption diseases, against blood stages of Plasmodium falciparum (50% inhibitory concentration [IC(50)] of 20.3 +/- 1.0 mu M). We also suggest a mechanism of action for risedronate against the intraerythrocytic stage of P. falciparum and show that protein prenylation seems to be modulated directly by this drug. Risedronate inhibits the transfer of the farnesyl pyrophosphate group to parasite proteins, an effect not observed for the transfer of geranylgeranyl pyrophosphate. Our in vivo experiments further demonstrate that risedronate leads to an 88.9% inhibition of the rodent parasite Plasmodium berghei in mice on the seventh day of treatment; however, risedronate treatment did not result in a general increase of survival rates.

Synthesis, characterization, X-ray structure and in vitro anti mycobacterial and antitumoral activities of Ru(II) phosphine/diimine complexes containing the ""SpymMe(2)"" ligand, SpymMe(2)=4,6-dimethyl-2-mercaptopyrimidine

The reaction of cis-[RuCl2(dppb)(N-N)], dppb = 1,4-bis(diphenylphosphino)butane, complexes with the ligand HSpymMe(2), 4,6-dimethyl-2-mercaptopyrimidine, yielded the cationic complexes [Ru(SpymMe(2))(dppb)(N-N)]PF6, N-N = bipy (1) and Me-bipy (2), bipy = 2,2`-bipyridine and Me-bipy = 4,4`dimethyl-2,2`-bipyridine, which were characterized by spectroscopic and electrochemical techniques and X-ray crystallography and elemental analysis. Additionally, preliminary in vitro tests for antimycobacterial activity against Mycobacterium tuberculosis H37Rv ATCC 27264 and antitumor activity against the MDA-MB-231 human breast tumor cell line were carried out on the new complexes and also on the precursors cis-[RuCl2(dppb)(N-N)], N-N = bipy (3) and Me-bipy (4) and the free ligands dppb, bipy, Me-bipy and SpymMe(2). The minimal inhibitory concentration (MIC) of compounds needed to kill 90% of mycobacterial cells and the IC50 values for the antitumor activity were determined. Compounds 1-4 exhibited good in vitro activity against M. tuberculosis, with MIC values ranging between 0.78 and 6.25 mu g/mL, compared to the free ligands (MIC of 25 to >50 mu g/mL) and the drugs used to treat tuberculosis. Complexes I and 2 also showed promising antitumor activity, with IC50 values of 0.46 +/- 0.02 and 0.43 +/- 0.08 mu M, respectively, against MDA-MB-231 breast tumor cells. (C) 2008 Elsevier Inc. All rights reserved.

Isolation and characterization of four type 2 ribosome inactivating pulchellin isoforms from Abrus pulchellus seeds

Abrus pulchellus seeds contain at least seven closely related and highly toxic type 2 ribosome-inactivating pulchellins, each consisting of a toxic A-chain linked to a sugar binding B-chain. In the present study, four pulchellin isoforms (termed P I, P II, P III and P IV) were isolated by affinity, ion exchange and chromatofocusing chromatographies, and investigated with respect to toxicity and sugar binding specificity. Half maximal inhibitory concentration and median lethal dose values indicate that P I and P II have similar toxicities and that both are more toxic to cultured HeLa cells and mice than P III and P IV. Interestingly, the secondary structural characteristics and sugar binding properties of the respective pairs of isoforms correlate well with the two toxicity levels, in that P I/P II and P III/P IV form two specific subgroups. From the deduced amino acids sequences of the four isoforms, it is clear that the highest similarity within each subgroup is found to occur within domain 2 of the B-chains, suggesting that the disparity in toxicity levels might be attributed to subtle differences in B-chain-mediated cell surface interactions that precede and determine toxin uptake pathways.

Pt(II) and Ag(I) complexes with acesulfame: Crystal structure and a study of their antitumoral, antimicrobial and antiviral activities

Two new complexes of platinum(II) and silver(I) with acesulfame were synthesized. Acesulfame is in the anionic form acesulfamate (ace). The structures of both complexes were determined by X-ray crystallography. For K(2)[PtCl(2)(ace)(2)] the platinum atom is coordinated to two Cl(-) and two N-acesulfamate atoms forming a trans-square planar geometry. Each K(+) ion interacts with two oxygen atoms of the S(=O)(2) group of each acesulfamate. For the polymeric complex [Ag(ace)](n) the water molecule bridges between two crystallographic equivalent Agl atoms which are related each other by a twofold symmetry axis. Two Agl atoms, related to each other by a symmetry centre, make bond contact with two equivalent oxygen atoms. These bonds give rise to infinite chains along the unit cell diagonal in the ac plane. The in vitro cytotoxic analyses for the platinum complex using HeLa (human cervix cancer) cells show its low activity when compared to the vehicle-treated cells. The Ag(I) complex submitted to in vitro antimycobacterial tests, using the Microplate Alamar Blue (MABA) method, showed a good activity against Mycobacterium tuberculosis, responsible for tuberculosis, with a minimal inhibitory concentration (MIC) value of 11.6 mu M. The Ag(I) complex also presented a promising activity against Gram negative (Escherichia colt and Pseudomonas aeruginosa) and Gram positive (Enterococcus faecalis) microorganisms. The complex K(2)[PtCl(2)(ace)(2)] was also evaluated for antiviral properties against dengue virus type 2 (New Guinea C strain) in Vero cells and showed a good inhibition of dengue virus type 2 (New Guinea G strain) replication at 200 mu M, when compared to vehicle-treated cells. (C) 2010 Elsevier Inc. All rights reserved.

Antiprotozoan activity of Brazilian marine cnidarian extracts and of a modified steroid from the octocoral Carijoa riisei

In the present investigation, we have evaluated the antileishmanial and antitrypanosomal activity of methanolic crude extracts obtained from eight species of cnidarians and of a modified steroid isolated from the octocoral Carijoa riisei. The antileishmanial activity of cnidarians crude extracts showed 50% inhibitory concentration ( IC50) values in the concentration range between 2.8 and 93.3 mu g/mL. Trypomastigotes of Trypanosoma cruzi were less susceptible to the crude extracts, with IC50 values in the concentration range between 40.9 and 117.9 mu g/mL. The steroid (18-acetoxipregna-1,4,20-trien-3-one) displayed a strong antileishmanial activity, with an IC50 value of 5.5 mu g/mL against promastigotes and 16.88 mu g/mL against intracellular amastigotes. The steroid also displayed mammalian cytotoxicity (IC50 of 10.6 mu g/mL), but no hemolytic activity was observed at the highest concentration of 12.5 mu g/mL. The antileishmanial effect of the steroid in macrophages suggested other mechanism than macrophage activation, as no upregulation of nitric oxide was observed. The antitrypanosomal activity of the steroid resulted in an IC50 value of 50.5 mu g/mL. These results indicate the potential of cnidarian natural compounds as antileishmanial drug candidates.

Thiosemicarbazones, semicarbazones, dithiocarbazates and hydrazide/hydrazones: Anti-Mycobacterium tuberculosis activity and cytotoxicity

The aim of this study was to identify a candidate drug for the development of anti-tuberculosis therapy from previously synthesized compounds based on the thiosemicarbazones, semicarbazones, dithio-carbazates and hydrazide/hydrazones compounds. The minimal inhibitory concentration (MIC) of these compounds against Mycobacterium tuberculosis was determined. Their in vitro cytotoxicity to J774 cells (IC(50)) was determined to establish a selectivity index (SI) (SI = IC(50)/MIC). The best compounds were the thiosemicarbazones (2, 3 and 4) and the hydrazide/hydrazones (14, 15, 16 and 18). The results are comparable to or better than those of ""first line"" or ""second line"" drugs commonly used to treat TB, suggesting these compounds as anti-TB drug candidates. (C) 2010 Elsevier Masson SAS. All rights reserved.

Spatiotemporal patterns of macrophage migration inhibitory factor (Mif) expression in the mouse placenta

Background: Macrophage migration inhibitory factor (MIF) has special pro-inflammatory roles, affecting the functions of macrophages and lymphocytes and counter-regulating the effects of glucocorticoids on the immune response. The conspicuous expression of MIF during human implantation and early embryonic development also suggests this factor acts in reproductive functions. The overall goal of this study was to evaluate Mif expression by trophoblast and embryo placental cells during mouse pregnancy. Methods: Mif was immunolocalized at implantation sites on gestation days (gd) 7.5, 10.5, 13.5 and 17.5. Ectoplacental cones and fetal placentas dissected from the maternal tissues were used for Western blotting and qRT-PCR assays on the same gestation days. Results: During the post-implantation period (gd7.5), trophoblast giant cells showed strong Mif reactivity. In later placentation phases (gds 10.5-17.5), Mif appeared to be concentrated in the junctional zone and trophoblast giant cells. Mif protein expression increased significantly from gd7.5 to 10.5 (p = 0.005) and from gd7.5 to 13.5 (p = 0.03), remaining at high concentration as gestation proceeded. Higher mRNA expression was found on gd10.5 and was significantly different from gd13.5 (p = 0.048) and 17.5 (p = 0.009). Conclusions: The up-regulation of Mif on gd10.5 coincides with the stage in which the placenta assumes its three-layered organization (giant cells, spongiotrophoblast and labyrinth zones), fetal blood circulation begins and population of uNK cells reaches high proportions at the maternal counter part of the placenta, suggesting that Mif may play a role in either the placentation or in the adaptation of the differentiated placenta to the uterus or still in gestational immunomodulatory responses. Moreover, it reinforces the possibility of specific activities for Mif at the maternal fetal interface.

Inhibitory action of toxic compounds present in lignocellulosic hydrolysates on xylose to xylitol bioconversion by Candida guilliermondii

The inhibitory action of acetic acid, ferulic acid, and syringaldehyde on metabolism of Candida guilliermondii yeast during xylose to xylitol bioconversion was evaluated. Assays were performed in buffered and nonbuffered semidefined medium containing xylose as main sugar (80.0 g/l), supplemented or not with acetic acid (0.8-2.6 g/l), ferulic acid (0.2-0.6 g/l), and/or syringaldehyde (0.3-0.8 g/l), according to a 2(3) full factorial design. Since only individual effects of the variables were observed, assays were performed in a next step in semidefined medium containing different concentrations of each toxic compound individually, for better understanding of their maximum concentration that can be present in the fermentation medium without affecting yeast metabolism. It was concluded that acetic acid, ferulic acid, and syringaldehyde are compounds that may affect Candida guilliermondii metabolism (mainly cell growth) during bioconversion of xylose to xylitol. Such results are of interest and reveal that complete removal of toxic compounds from the fermentation medium is not necessary to obtain efficient conversion of xylose to xylitol by Candida guilliermondii. Fermentation in buffered medium was also considered as an alternative to overcome the inhibition caused by these toxic compounds, mainly by acetic acid.

Macrophage migration inhibitory factor is up-regulated in human first-trimester placenta stimulated by soluble antigen of Toxoplasma gondii, resulting in increased monocyte adhesion on villous explants

Considering the potential role of macrophage migration inhibitory factor (MIF) in the inflammation process in placenta when infected by pathogens, we investigated the production of this cytokine in chorionic villous explants obtained from human first-trimester placentas stimulated with soluble antigen from Toxoplasma gondii (STAg). Parallel cultures were performed with villous explants stimulated with STAB, interferon-gamma (IFN-gamma), or STAB plus IFN-gamma. To assess the role of placental MIF on monocyte adhesiveness to human trophoblast, explants were co-cultured with human myelomonocytic THP-1 cells in the presence or absence of supernatant from cultures treated with STAB (SPN), SPN plus anti-MIF antibodies, or recombinant MIF. A significantly higher concentration of MIF was produced and secreted by villous explants treated with STAB or STAB plus IFN-gamma after 24-hour culture. Addition of SPN or recombinant MIF was able to increase THP-1 adhesion, which was inhibited after treatment with anti-MIF antibodies. This phenomenon was associated with intercellular adhesion molecule expression by villous explants. Considering that the processes leading to vertical dissemination of T. gondii remain widely unknown, our results demonstrate that MIF production by human first-trimester placenta is up-regulated by parasite antigen and may play an essential role as an autocrine/paracrine mediator in placental infection by T. gondii.

SBTX, a new toxic protein distinct from soyatoxin and other toxic soybean [Glycine max] proteins, and its inhibitory effect on Cercospora sojina growth

SBTX, a novel toxin from soybean, was purified by ammonium sulfate fractionation followed by chromatographic steps DEAE-Cellulose, CM-Sepharose and Superdex 200 HR fast-protein liquid chromatography (FPLC). Lethality of SBTX to mice (LD50 5.6 mg/kg) was used as parameter in the purification steps. SBTX is a 44-kDa basic glycoprotein composed of two polypeptide chains (27 and 17 kDa) linked by a disulfide bond. The N-terminal sequences of the 44 and 27 kDa chains were identical (ADPTFGFTPLGLSEKANLQIMKAYD), differing from that of 17 kDa (PNPKVFFDMTIGGQSAGRIVMEEYA). SBTX contains high levels of Glx, Ala, Asx, Gly and Lys and showed maximum absorption at 280 nm, epsilon(1 cm) (1%) of 6.3, and fluorescence emission in the 290-450nm range upon excitation at 280nm. The secondary structure content was 35% alpha-helix, 13% beta-strand and beta-sheet, 27% beta-turn, 25% unordered, and 1% aromatic residues. Immunological assays showed that SBTX was related to other toxic proteins, such as soyatoxin and canatoxin, and cross-reacted weekly with soybean trypsin inhibitor and agglutinin, but it was devoid of protease-inhibitory and hemagglutinating activities. The inhibitory effect of SBTX on growth of Cercospora sojina, fungus causing frogeye leaf spot in soybeans, was observed at 50 mu g/ml, concentration 112 times lesser than that found to be lethal to mice. This effect on phytopathogenic fungus is a potential attribute for the development of transgenic plants with enhanced resistance to pathogens. (c) 2007 Elsevier Ltd. All rights reserved.