Kinetics of adsorption and desorption of aflatoxin B1 by viable and nonviable bacteria

The reactions involved in the binding (adsorption) and release (desorption) of aflatoxin B1 (AFB1) to and from the surface of bacteria were investigated. Viable and heat-killed Lactobacillus rhamnosus GG, L. rhamnosus LC-705, and Propionibacterium freudenreichii subsp. shermanii JS were incubated in phosphate-buffered saline containing variable concentrations (0.0017 to 13.3 microg/ml) of AFB1. The relationship between the bacterial surface hydrophobicity and the AFB1 adsorption affinity was also investigated. A linear relationship was observed between the specific rate of AFB1 adsorption and the AFB1 concentration for all bacteria. The nature of desorption of adsorbed AFB1 was investigated by repetitive aqueous washes. A linear relationship was observed between the natural log value of the concentration of AFB1 adsorbed and the number of washes for all bacteria studied. The desorption constants were strain-dependent and were lower for heat-killed bacteria than for viable bacteria. Heat treatment appears to alter the surface properties of the bacteria rather than expose new adsorption sites. No correlation was found between the hydrophobicity and the AFB1 adsorption affinity.     

Physician and patient communication training in primary care: Effects on participation and satisfaction.

[Correction Notice: An erratum for this article was reported in Vol 28(2) of Health Psychology (see record 2009-03297-015). There was a typographical error in the text on page 521, in the first sentence of the first full paragraph. The corrected sentence is provided in the erratum.] Objective: To assess the effects of a communication skills training program for physicians and patients. Design: A randomized experiment to improve physician communication skills was assessed 1 and 6 months after a training intervention; patient training to be active participants was assessed after 1 month. Across three primary medical care settings, 156 physicians treating 2,196 patients were randomly assigned to control group or one of three conditions (physician, patient, or both trained). Main Outcome Measures: Patient satisfaction and perceptions of choice, decision-making, information, and lifestyle counseling; physicians' satisfaction and stress; and global ratings of the communication process. Results: The following significant (p     

“Physician and patient communication training in primary care: Effects on participation and satisfaction”: Correction.

Reports an error in "Physician and patient communication training in primary care: Effects on participation and satisfaction" by Kelly B. Haskard, Summer L. Williams, M. Robin DiMatteo, Robert Rosenthal, Maysel Kemp White and Michael G. Goldstein (Health Psychology, 2008[Sep], Vol 27[5], 513-522). There was a typographical error in the text on page 521, in the first sentence of the first full paragraph. The corrected sentence is provided in the erratum. (The following abstract of the original article appeared in record 2008-13168-002.) Objective: To assess the effects of a communication skills training program for physicians and patients. Design: A randomized experiment to improve physician communication skills was assessed 1 and 6 months after a training intervention; patient training to be active participants was assessed after 1 month. Across three primary medical care settings, 156 physicians treating 2,196 patients were randomly assigned to control group or one of three conditions (physician, patient, or both trained). Main Outcome Measures: Patient satisfaction and perceptions of choice, decision-making, information, and lifestyle counseling; physicians' satisfaction and stress; and global ratings of the communication process. Results: The following significant (p     

Endothelial activation in monosodium urate monohydrate crystal-induced inflammation: in vitro and in vivo studies on the roles of tumor necrosis factor alpha and interleukin-1

OBJECTIVE: There is relatively little direct evidence for the roles of interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF alpha) in activating endothelium in vivo. The aim of this study was to use in vitro and in vivo models to investigate the contribution of these cytokines to both E-selectin expression and the recruitment of polymorphonuclear cells (PMN) in monosodium urate monohydrate (MSU) crystal-induced inflammation. METHODS: MSU crystals were incubated with freshly isolated mononuclear cells, after which the harvested supernatants were tested for their ability to induce E-selectin expression during coculture with human umbilical vein endothelial cells. Subsequent experiments were performed with the addition of neutralizing anticytokine antibodies/antisera. The role of TNF alpha was then studied in an MSU crystal-induced monarthritis model, in the presence or absence of anti-TNF alpha (5 mg/kg intravenously). 99mtechnetium (99mTc)-labeled PMN cells and (111)indium (111In)-labeled anti-E-selectin monoclonal antibody (MAb) 1.2B6 were intravenously administered 4 hours after intraarticular injection to quantify PMN recruitment and E-selectin expression in inflamed joints. RESULTS: MSU crystals were a potent stimulus for IL-1 and TNF alpha production by monocytes in vitro, and these cytokines fully accounted for MSU crystal-stimulated, monocyte-mediated endothelial activation. In the MSU crystal-induced monarthritis model, TNF alpha blockade was very effective in suppressing both E-selectin expression and PMN emigration into the inflamed joints, as judged by gamma-camera image analysis and postmortem tissue counting following the intravenous injection of 99mTc-PMN and 111In-anti-E-selectin MAb. CONCLUSION: IL-1 and TNF alpha appear to be the only factors released by monocytes following incubation with MSU crystals, which induce E-selectin expression in vitro. Anti-TNF alpha is effective in suppressing endothelial activation and PMN recruitment in vivo E-selectin imaging can be used to assess the endothelial response to therapy and may prove useful for clinical studies.     

Expression of vascular cell adhesion molecule-1 by vascular endothelial cells in immune and nonimmune inflammatory reactions in the skin

Expression of VCAM-1 was compared with that of E-selectin in cytokine-induced lesions and in delayed-type hypersensitivity reactions to tuberculin purified protein derivative (PPD) in pig skin. Lumenally expressed Ags were quantified by measuring localization in skin of i.v. injected (111)In-mAb 10.2C7 (anti-vascular cell adhesion molecule-1 (anti-VCAM-1), (125)I-mAb 1.2B6 (anti-E-selectin), and (99m)Tc-MOPC21 (control IgG1). Anti-VCAM-1 mAb uptake was greater following intradermal (i.d.) injection of TNF-alpha than following injection of IL-1, while the two cytokines induced similar uptake of anti-E-selectin. In immunologically naive pigs there was no detectable increase in anti-VCAM-1 after i.d. injection of PPD, although anti-E-selectin uptake was increased at 3 and 6 h. In contrast, i.d. injection of PPD in sensitized pigs led to increased uptake of both anti-VCAM-1 and anti-E-selectin at 6, 8, 24, and 48 h, each of which was significantly greater than the uptake of control IgG1 into the same lesions (each p < 0.01). Anti-TNF-alpha mAb abolished the increased uptake of anti-VCAM-1 3 and 8 h following i.d. injection of PPD in sensitized pigs and significantly inhibited uptake at 24 h (p = 0.0025), but did not significantly reduce uptake of anti-E-selectin. We conclude that in this delayed-type hypersensitivity model 1) E-selectin expression by endothelial cells follows sequential Ag nonspecific and immune-specific phases, 2) increased VCAM-1 expression by endothelial cells is only seen in sensitized animals, and 3) expression of VCAM-1 appears to be relatively more dependent on TNF-alpha than E-selectin. Differential expression of E-selectin and VCAM-1 may influence the leukocytic infiltrate during the course of nonspecific and immune-specific inflammatory reactions.     

Selective in vitro binding of dietary mutagens, individually or in combination, by lactic acid bacteria.

Specific strains of lactic acid bacteria possessing antimutagenic properties are suggested to remove mutagenic contaminants of foods through binding and an investigation of their substrate specificity is required. The ability of Lactobacillus rhamnosus strains GG and LC-705 in viable and non-viable (heat- and acid-treated) forms to remove both dietary mutagens and other aromatic dietary substrates from solution was studied using HPLC. Overall, removal increased in the order: caffeine = vitamin B12 =folic acid < ochratoxin A < aflatoxin B1 = PhIP (2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine) < Trp-P-1 (3-amino-1, 4-dimethyl-5H-pyrido[4,3-b]indole) (p < 0.05). Aflatoxin B1, Trp-P-1 and PhIP were removed in high amounts (77-95%) and ochratoxin A was removed in moderate amounts (36-76%). By contrast, only minimal amounts of caffeine, vitamin B12 andfolic acid were removed (9-28%). The significant removal of selected mutagens, but not other substrates, suggests these strains may be useful for dietary detoxification. Since exposure to multiple mutagens is likely, the removal of aflatoxin B1 and Trp-P-1 from a mixture of these substrates was also investigated. Removal of AFB1 significantly increased (p < 0.05) in the presence of Trp-P-1, while removal of Trp-P-1 significantly decreased (p < 0.05) in the presence of AFB1. Overall, no significant differences in removal were found between bacterial strains or between viable, heat- and acid-treated bacteria.     

Aflatoxin B1 binding by dairy strains of lactic acid bacteria and bifidobacteria.

Various food commodities including dairy products may be contaminated with aflatoxins, which, even in small quantities, have detrimental effects on human and animal health. Several microorganisms have been reported to bind or degrade aflatoxins in foods and feeds. This study assessed the binding of aflatoxin B1 (AFB1) from contaminated solution by 20 strains of lactic acid bacteria and bifidobacteria. The selected strains are used in the food industry and comprised 12 Lactobacillus, five Bifidobacterium, and three Lactococcus strains. Bacteria and AFB1 were incubated (24 h, +37 degrees C) and the amount of unbound AFB1 was quantitated by HPLC. Between 5.6 and 59.7% AFB1 was bound from solution by these strains. Two Lactobacillus amylovorus strains and one Lactobacillus rhamnosus strain removed more than 50% AFB1 and were selected for further study. Bacterial binding of AFB1 by these strains was rapid, and more than 50% AFB1 was bound throughout a 72-h incubation period. Binding was reversible, and AFB1 was released by repeated aqueous washes. These findings further support the ability of specific strains of lactic acid bacteria to bind selected dietary contaminants.     

Targeting endothelium for gene therapy via receptors up-regulated during angiogenesis and inflammation

Endothelial cells are an attractive target for gene therapy because they are intimately involved in disease processes associated with inflammation and angiogenesis and because endothelial cells are readily accessible to gene therapy vectors via the circulation. Furthermore, specific receptors are up-regulated during angiogenesis or during inflammation. Therefore it should be possible to target the specific populations of endothelial cells involved in each of these disease processes. We have utilized two bispecific antibodies to target entry of an adenovirus vector into endothelial cells expressing a receptor up-regulated during angiogenesis (alpha v integrins) and a receptor up-regulated during inflammation (E-selectin). Both bispecific antibodies contain the anti-FLAG M2 mAb, which binds to a FLAG epitope genetically incorporated into the penton base protein of the vector, AdFLAG. The anti-alpha v-integrin x anti-FLAG bsAb was able to direct binding and entry of AdFLAG into endothelial cells via alpha v integrins. Likewise, the anti-E-selectin x anti-FLAG bsAb was able to direct binding and entry of AdFLAG into tumor-necrosis-factor(TNF)-activated endothelial cells via E-selectin. Endothelial cells not activated with TNF were not efficiently transduced by the AdFLAG/E-selectin bsAb complex. These results demonstrate that bispecific antibodies can be successfully used to target adenovirus to endothelially expressed receptors that are up-regulated during angiogenesis or inflammation.     

The inhibitory effect of tenidap on leukocyte-endothelial cell adhesion

Treatment of symptomatic unilateral vocal cord paralysis is most frequently surgical. Medialization of the vocal cord using Teflon injection has proved effective; however, studies have shown this technique to produce stiffness of the vocal fold with loss of the "mucosal wave" and concomitantly poor vocal function. As well, overcorrection may occur and is not reversible. Isshiki type 1 medialization thyroplasty has been shown to produce a substantial improvement in vocal quality, as well as preserve the mucosal wave. A number of problems encountered during the performance of Isshiki type 1 thyroplasty has led us to modify the original technique. We have developed a new implant that allows for precise, easily adjustable control of vocal cord medialization. To evaluate the degree of vocal cord medialization afforded by this implant, larynges of fresh male and female cadavers were used as an experimental model. In both larynges, vocal cord medialization was shown to occur in a predictable fashion for the anterior, middle, and posterior segments, as well as in the functionally important inter-arytenoid region. We believe the use of this implant in medialization thyroplasty will allow precise, atraumatic medialization of the paralyzed vocal cord. This greater control over positioning and ease of adjustment should contribute to enhanced vocal quality.