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Vitro Response (vitro + response)
Selected AbstractsIn vitro response to Candida albicans in cultures of whole human blood from young and aged donorsFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 2 2007Celia Murciano Abstract Invasive infections with opportunistic fungi, such as Candida albicans, have become an increasing problem in aged adults in recent years. This work investigates the influence of human ageing on C. albicans recognition by toll-like receptors (TLRs), essential components of the innate immune system, using a cohort of 96 young (15,42 years) and aged (>70 years) human volunteers. No significant differences between aged and young donors were observed on (1) cell surface TLR2, TLR6 and TLR4 expression on lymphocytes, monocytes and granulocytes, (2) production of cytokines [IL-8, IL-1,, IL-6, IL-10, tumour necrosis factor (TNF)-, and IL-12p70] and prostaglandin E2 (PGE2) by whole human blood in response to C. albicans and (3) fungicidal activity of whole blood. A statistically significant higher titre of natural anti- C. albicans antibodies was found in plasma of volunteers between 80 and 95 years old when compared with other age groups, probably as a consequence of the increased levels of serum Ig that has been described in elderly subjects. Therefore, the results indicate that the increased susceptibility to C. albicans infections in the elderly is not a consequence of defects in TLRs expression or signalling, nor of an impaired fungicidal activity of blood. [source] Fungicide Effectiveness during the Various Developmental Stages of Peronophythora litchii In VitroJOURNAL OF PHYTOPATHOLOGY, Issue 7-8 2009Hancheng Wang Abstract Litchi downy blight caused by Peronophythora litchii is one of the most destructive diseases suffered by litchi in China. This study has evaluated the activities of the fungicides dimethomorph (DMM), azoxystrobin (AZB), famoxadone (FMD), metalaxyl (MTL), cymoxanil (CYX) and mancozeb (MCB) on the mycelial growth, sporulation, zoospores release, and germination of sporangia as well as of cystospores of P. litchii. Dimethomorph and MTL inhibited mycelial growth more effectively than the other fungicides tested. Mycelial growth was affected less by MCB, and only weakly by AZB, FMD and CYX. Sporangia production was more strongly reduced by DMM and MTL than by AZB, FMD, CYX or MCB. Zoospore release from the sporangia was most sensitive to AZB and FMD, less sensitive to MCB and insensitive to DMM, MTL and CYX. Direct germination of sporangia of P. litchii was the most strongly inhibited by AZB and FMD, followed by DMM and MCB, whilst the sensitivity of this life stage to MTL and CYX was relatively low. Germination of encysted zoospores of P. litchii was the most sensitive to AZB and FMD, followed by DMM. Mancozeb was moderately active, while MTL and CYX did not inhibit this development stage. This is the first report on the in vitro response of the litchi pathogen, P. litchii, to fungicides. These findings can be valuable tools in setting up efficient disease management programmes to control litchi downy blight. [source] Investigating the Effects of High-Dose Phenylephrine in the Management of Prolonged Ischaemic PriapismTHE JOURNAL OF SEXUAL MEDICINE, Issue 9 2008Asif Muneer BSc(Hons), FRCS(Urol) ABSTRACT Introduction., Acute priapism can be managed by corporal blood aspirations and the instillation of , adrenergic agonists such as phenylephrine if patients present early. Following prolonged ischaemic priapism, this regimen is often unsuccessful, and the use of phenylephrine is limited due to systemic cardiovascular side effects. Aim., To investigate the effects of high-dose phenylephrine on human corpus cavernosal smooth muscle obtained from patients presenting with refractory ischaemic priapism. Methods., Strips of corpus cavernosum were obtained from six patients presenting with prolonged ischaemic priapism (duration 60,240 hours), where detumescence was refractory to conventional doses of phenylephrine. The smooth muscle contractile response to high doses of phenylephrine were then compared with that of normal control corpus cavernosum obtained from four patients undergoing a penectomy for penile cancer. The tissue was then analyzed using TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling) to assess its viability. Main Outcome Measures., The in vitro response to high-dose phenylephrine of corpus cavernosum smooth muscle obtained from patients with refractory priapism compared with normal human corpus cavernosum. Results., Corporal blood gas analysis confirmed hypoxia (pO2 1.5,2.3 kPa), acidosis (pH 6.9,7.1), and glucopenia (0,0.3 mmol/L) in all six patients confirming the ischaemic nature of the priapism. Application of high doses of phenylephrine produced a marked muscle contraction in the control tissue, but there was no contractile response at all in any of the priapism patients. Analysis with TUNEL indicated widespread smooth muscle cell apoptosis in all the priapism tissue. Conclusions., This study has shown that patients with ischaemic priapism that fails to respond to conventional doses of an ,-agonist are unlikely to benefit from continual or high-dose phenylephrine administration, as there is usually widespread apoptosis of the cavernosal smooth muscle preventing further contraction. Muneer A, Minhas S, Freeman A, Kumar P, and Ralph DJ. Investigating the effects of high-dose phenylephrine in the management of prolonged ischaemic priapism. J Sex Med 2008;5:2152,2159. [source] Influence of biofilm formation in the susceptibility of Pseudomonas aeruginosa from Brazilian patients with cystic fibrosisAPMIS, Issue 8 2010ALEX GUERRA FERREIRA Ferreira AG, Leão RS, Carvalho-Assef APD, Folescu TW, Barth AL, Marques EA. Influence of biofilm formation in the susceptibility of Pseudomonas aeruginosa from Brazilian patients with cystic fibrosis. APMIS 2010; 118: 606,12. Biofilms play a key role in the occurrence of lung infections by Pseudomonas aeruginosa in patients with cystic fibrosis (CF). In this study, we examined 40 isolates of P. aeruginosa from CF patients according to their capacity to form biofilm. We also compared their in vitro response to antimicrobials according to different modes of growth (planktonic vs biofilm) and performed molecular typing. All isolates proved capable of forming biofilm. However, there was no difference in biofilm development according to the mucoid and nonmucoid phenotypes and among isolates obtained at different periods of the chronic infection. All isolates tested for antimicrobial susceptibility in the biofilm state (BIC) were consistently more resistant to antibiotics than the same isolate tested in the planktonic state. The molecular typing indicates a considerable clonal diversity among isolates. We identified five patients harboring the same strain over different periods. These strains, however, displayed different levels of biofilm formation and BIC values for antibiotics tested. The results of the present study demonstrate that there is a marked difference in the susceptibility profile according to the mode of growth of CF P. aeruginosa, as cells tested in the biofilm state proved consistently more resistant to antibiotics. [source] Prognostic relevance of in vitro response to cell stimulation via surface IgD in binet stage a CLLBRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2010Fortunato Morabito First page of article [source] Contrasting in vitro effects for the combination of fludarabine, cytosine arabinoside (Ara-C) and granulocyte colony-stimulating factor (FLAG) compared with daunorubicin and Ara-C in P-glycoprotein-positive and P-glycoprotein-negative acute myeloblastic leukaemiaBRITISH JOURNAL OF HAEMATOLOGY, Issue 2 2000Y. Higashi It has been suggested that the FLAG remission induction regimen comprising fludarabine (F-ara), cytosine arabinoside (Ara-C) and granulocyte colony-stimulating factor (G-CSF) may be capable of overcoming P-glycoprotein (P-gp)-related multidrug resistance (MDR) in patients with acute myeloblastic leukaemia (AML). We have investigated the in vitro response of P-gp-positive and -negative AML clones to FLAG and compared this with their response to treatment with Ara-C and daunorubicin (DNR). Twenty-four cryopreserved samples from patients with AML were studied using a flow cytometric technique for the enumeration of viable (7-amino actinomycin D negative) cells. Samples consisted of 12 P-gp-positive and 12 P-gp-negative cases, as measured by the MRK16 antibody. The results were analysed by calculating the comparative drug resistance (CDR), i.e. the percentage cell death caused by Ara-C + DNR subtracted from the percentage cell death, caused by FLAG after 48 h incubation in suspension culture. P-gp-positive clones were shown to have a significantly higher CDR than P-gp-negative clones (P = 0·001). Furthermore, a significant positive correlation (r2 = 0·40, P < 0·01) was found between P-gp protein expression and CDR. However, P-gp function, measured using cyclosporin modulation of rhodamine 123 (R123) uptake, was not associated with the CDR, demonstrating that there are other properties of P-gp, besides its role in drug efflux, that modulate the responsiveness of AML blasts to chemotherapy. These results are consistent with a potential benefit for FLAG in P-gp-positive AML, but not P-gp-negative AML, compared with standard anthracycline and Ara-C therapy. [source] Prediction of in vitro response to interferon-, in renal cell carcinoma cell linesCANCER SCIENCE, Issue 4 2007Toru Shimazui We analyzed the correlation between interferon-, (IFN,) response and gene expression profiles to predict IFN, sensitivity and identified key molecules regulating the IFN, response in renal cell carcinoma (RCC) cell lines. To classify eight RCC cell lines of the SKRC series into three subgroups according to IFN, sensitivity, that is, sensitive, resistant and intermediate group, responses to IFN, (300,3000 IU/mL) were quantified by WST-1 assay. Microarray, followed by supervised hierarchical clustering analysis, was applied to selected genes according to IFN, sensitivity. In order to find alteration of expression profiles induced by IFN,, sequential microarray analyses were performed at 3, 6, and 12 h after IFN, treatment of RCC cell lines and mRNA expression level was confirmed using quantitative real time polymerase chain reaction. According to the sequential microarray analysis between IFN,-sensitive and -resistant line, seven genes were selected as candidates for IFN,-sensitivity-related genes in RCC cell lines. Among these seven genes, we further developed a model to predict tumor inhibition with four genes, that is, adipose differentiation-related protein, microphthalmia associated transcription factor, mitochondrial tumor suppressor 1, and troponin T1 using multiple linear regression analysis (coefficient = 0.948, P = 0.0291) and validated the model using other RCC cell lines including six primary cultured RCC cells. The expression levels of the combined selected genes may provide predictive information on the IFN, response in RCC. Furthermore, the IFN, response to RCC might be modulated by regulation of the expression level of these molecules. (Cancer Sci 2007; 98: 529,534) [source] Phospholipid profile of rat testis, its unique high level of monolysocardiolipin and its lipolytic capabilities in vitro.CELL BIOCHEMISTRY AND FUNCTION, Issue 4 2008A chromatographic analysis Abstract The phospholipid profiles of testes and heart of 1-, 3-, and 6-month-old rats and their in vitro response to the endogenous phospholipases at pH 7.4 and 38°C for 60,min were analyzed by TLC technology and densitometry. A noticeable high level of monolysocardiolipin (MLCL) was shown in rat testes of all samples analyzed (1-, 3-, and 6-month-old), both control and incubated. In contrast, rat heart control samples revealed a high level of CL and no MLCL was detected. MLCL was only produced subsequent to in vitro incubation of whole tissue homogenate at pH 7.4 and 38°C for 60,min, with concurrent reduction of CL. Alkenyl phosphatidyl ethanolamine (PE) was the major plasmalogen of rat testes. Following in vitro incubation, (a) a very low level of lyso PE plasmalogen was produced only in 3- and 6-month-old rat testes, (b) ceramide was also produced in all testes analyzed with concurrent reduction of sphingomyelin indicating the action of sphingomyelinase. These data clearly illustrate, for the first time, the presence of high levels of MLCL in all rat testes studied which probably is related to the physiological activity in vivo and requires further investigation. Copyright © 2008 John Wiley & Sons, Ltd. [source] Studies on the endogenous phospholipids of chick embryo myocardium and their in vitro hydrolysis by endogenous phospholipases during embryogenesisCELL BIOCHEMISTRY AND FUNCTION, Issue 5 2007Fatma M. Helmy Abstract The phospholipid profiles of the myocardium (from 10- and 18-day old chick embryos and 13-day old chick) and their in vitro response to the endogenous lipolytic enzymes (mainly of the phospholipase group) at pH 7.4 and 38°C for 60,min were analyzed by TLC technology and densitometry. Cardiolipin (CL) was shown to be one of the major phospholipids of the chick embryo myocardium and its concentration increased as the chick embryo advanced in development. Monolysocardiolipin (MLCL) was produced subsequent to in vitro incubation of whole tissue homogenates in all myocardia studied as well as a concurrent reduction in CL. This deacylation of CL increased in magnitude as the chick embryo advanced in development indicating its age relatedness. The level of phosphatidyl ethanolamine (PE) plasmalogen was also high in all myocardia studied. Lyso alkenyl PE (LPE) was produced subsequent to in vitro incubation and its level increased as the chick embryo advanced in development, indicating PLA2 action on the sn-2 fatty acid of PE. Phosphatidyl choline (PC) plasmalogen was also present in the chick embryo myocardium and its level increased gradually as the chick embryo advanced in development. In contrast, yolk-sac membrane contains very minute amounts of CL and PE. No PC was detected and no LPE was formed following in vitro incubation. The yolk of the unfertilized chicken egg has no CL and has very minute amounts of PE, no PC and no lysophospholipids were detected following in vitro incubation in all samples analyzed. Copyright © 2007 John Wiley & Sons, Ltd. [source] On the differential lipolytic capabilities of rat spleen and cardiac muscle.CELL BIOCHEMISTRY AND FUNCTION, Issue 2 2007An in vitro incubation in conjunction with chromatographic, densitometric analysis Abstract The phospholipid profiles of newborn, young adult and aged rat heart and spleen and their in vitro response to endogenous phospholipases at pH 7.4 and 38°C for 60,min were analysed by thin layer chromatography (TLC) technology and densitometry measurement. The noticeable high level of cardiolipin (CL) and its preferential deacylation, as detected by the formation of monolysocardiolipin (MLCL) and concurrent reduction of CL level were the most prevalent lipolytic events of rat cardiac muscle (newborn, young adult and aged) but the least prevalent in rat spleen. The level of ethanolamine plasmalogen (PE) was high in both the rat spleen and cardiac muscle (newborn, young adult and aged). Following in vitro incubation, the reduction in the level of PE and the high level of lyso alkenyl PE produced were most conspicuous in rat spleen (newborn, young adult and aged) and noticeably less in rat cardiac muscle. These data clearly illustrate the differential response of the endogenous substrates (phospholipids) to the endogenous phospholipases of these two tissues, and probably are related to their physiological activities in vivo. Copyright © 2006 John Wiley & Sons, Ltd. [source] The in vitro response of human retinal endothelial cells to cytokines and other chemically active agents is altered by coculture with vitreous-derived hyalocytesACTA OPHTHALMOLOGICA, Issue 3 2010Naoki Tojo Abstract. Background:, Ocular angiogenesis is regulated by polypeptides including cytokines, which are known to affect vascular endothelial cells. We have reported that hyalocytes interact with vascular endothelial cells, and some cytokines affect these interactions. Aims:, To determine the effect of various chemically active agents on the viability of endothelial cells alone and cocultured with hyalocytes. Methods:, The viability of human retinal endothelial cells (HRECs) was determined after exposure to IL-1,, IL-1,, IL-6, TNF, and VEGF using the MTT assay. These results were compared to the viability when the HRECs were cocultured with porcine hyalocytes that had been exposed to different types of cytokines. The effects of bevacizumab, fenofibrate and dexamethasone on the viability of HRECs in coculture with hyalocytes were also assessed. Results:, Ten micrograms/millilitre of bevacizumab decreased the percentage of living HRECs stimulated by VEGF without hyalocytes, but with the hyalocytes, 100 ,g/ml of bevacizumab was required to decrease the percentage of viable HRECs stimulated by VEGF. Fenofibrate, at 5 ,g/ml, decreased the viability of HRECs stimulated by IL-1, and VEGF without hyalocytes but could not decrease the viability of HRECs cocultured with hyalocytes. Dexamethasone, at 50 ,g/ml, decreased the viability of HRECs stimulated by IL-1,, IL-1,, IL-6 and VEGF without hyalocytes but could not decrease the viability of HRECs cocultured. Conclusions:, Coculturing HRECs with vitreous-derived hyalocytes depressed the effects of cytokines, bevacizumab, fenofibrate and dexamethasone. This suggests that the vitreal hyalocytes may play a role in pathogenic endothelial cell proliferation in vivo. Future studies to better understand this pathobiology should utilize coculture systems of HRECs and vitreal hyalocytes. [source] The effect of tamsulosin on the response of the rabbit bladder to partial outlet obstructionNEUROUROLOGY AND URODYNAMICS, Issue 1 2006Robert M. Levin Abstract Aim To determine if tamsulosin treatment prevents or decreases the incidence and severity of outlet obstruction-induced bladder dysfunction in rabbits. Materials and Methods Male New Zealand White rabbits were treated with tamsulosin or vehicle for 4 weeks with treatments initiated 1 week prior to sham or obstruction surgery. Cystometry was done on anesthetized rabbits 21 days after surgery. The bladders were then removed, weighed, and prepared for in vitro whole bladder studies. Responses to 32 Hz field stimulation (FS), carbachol, phenylephrine, and KCl were measured. Results Obstruction resulted in a significant increase in bladder weight, which was unchanged by tamsulosin treatment and a significant increase in micturition pressure in the vehicle-treated group but not in the tamsulosin-treated group. Compliance was significantly decreased in both obstructed groups. The vehicle-treated obstructed rabbits had a very sharp increase in intravesical pressure as the bladder reached capacity; this was not seen in the tamsulosin-treated obstructed rabbits. Tamsulosin did not change the pattern of modifications in contractile responses induced by bladder outlet obstruction. Conclusions In vitro responses of vehicle and tamsulosin-treated obstructed rabbit groups in this study were similar. A greater micturition pressure was found for the vehicle-treated obstructed group than for the tamsulosin-treated obstructed group, which was probably due to decreased urethral resistance in the latter. On a functional basis, the higher compliance at capacity and decreased micturition pressure in the tamsulosin-treated obstructed group would be considered beneficial for bladder function. Neurourol. Urodynam. © 2005 Wiley-Liss, Inc. [source] Control of Toxoplasma gondii infection by athymic LEW- Whnrnu ratsPARASITE IMMUNOLOGY, Issue 6-7 2008J. C. SEPULVEDA-ARIAS SUMMARY In immunocompetent rats and humans infection with Toxoplasma gondii remains mostly without overt clinical symptoms, but can be fatal, if the T-cell response is impaired. For a better understanding of the lack of control of T. gondii infection under immunosuppressed conditions, congenitally athymic rats were used as the experimental model. Whereas athymic F344- Whnrnu (F344 nude) rats die from a generalized infection during the first 3 weeks after peritoneal inoculation with 106 tachyzoites of T. gondii strain NTE, LEW- Whnrnu (LEW nude) rats and euthymic LEW rats infected with a 10-fold higher number of parasites developed chronic infection. To identify underlying mechanisms of LEW rats resistance to T. gondii infection and to investigate a possible contribution of residual T-cells to LEW- Whnrnu rat resistance, we characterized the immune response of LEW rats by determination of cellularity and composition of lymphocyte population, antigen-specific IgG2b response as well as assays of antigen-specific proliferation and production of IL-2, IFN-, and TNF-,. As only euthymic LEW rats developed production of antigen-specific IgG and cellular in vitro responses, these results strongly suggest that the genetic background of LEW rats permits a control of the infection independent of an adaptive immune response. [source] Ex vivo Inhibition of NF-,B Signaling in Alloreactive T-cells Prevents Graft-Versus-Host DiseaseAMERICAN JOURNAL OF TRANSPLANTATION, Issue 3 2009M. J. O'Shaughnessy The ex vivo induction of alloantigen-specific hyporesponsiveness by costimulatory pathway blockade or exposure to immunoregulatory cytokines has been shown to inhibit proliferation, IL-2 production, and the graft-versus-host disease (GVHD) capacity of adoptively transferred T-cells. We hypothesized that inhibition of the intracellular NF-,B pathway in alloreactive T-cells, which is critical for T-cell activation events including IL-2 transcription, could lead to alloantigen hyporesponsiveness and loss of GVHD capacity. We demonstrate that treatment of mixed lymphocyte reaction (MLR) cultures with PS1145, a potent inhibitor of NF-,B activation, can induce T-cell hyporesponsiveness to alloantigen in primary and secondary responses while preserving in vitro responses to potent mitogenic stimulation. GVHD lethality in recipients of ex vivo PS1145-treated cells was profoundly inhibited. Parking of control or PS1145-treated MLR cells in syngeneic Rag,/, recipients resulted in intact contact hypersensitivity (CHS) responses. However, GVHD lethality capacity also was restored, suggesting that lymphopenic expansion uncoupled alloantigen hyporesponsiveness. These results indicate that the NF-,B pathway is a critical regulator of alloresponses and provide a novel small molecule inhibitor based approach that is effective in preventing early posttransplant GVHD lethality but that also permits donor T-cell responses to recover after a period of lymphopenic expansion. [source] | |||||||||||||