Precipitation of minerals by 22 species of moderately halophilic bacteria in artificial marine salts media: Influence of salt concentration

Precipitation of minerals was shown by 22 species of moderately halophilic bacteria in both solid and liquid artificial marine salts media at different concentration and different Mg2+-to-Ca2+ ratio. Precipitation of minerals was observed for all the bacteria used. When salt concentration increased, the quantity and the size of bioliths decreased, the time required for precipitation being increased. The precipitated minerals were calcite, magnesian calcite, aragonite, dolomite, monohydrocalcite, hydromagnesite and struvite in variable proportions, depending on the bacterial species, the salinity and the physical state of the medium; the Mg content of the magnesian calcite also varied according to the same parameters. The precipitated minerals do not correspond exactly to those which could be precipitated inorganically according to the saturation indices. Scanning electron microscopy showed that the formation of the bioliths is initiated by grouping of calcified cells and that the dominant final morphologies were spherulitic with fibrous radiated interiors. It was demonstrated that moderately halophilic bacteria play an active role in the precipitation of carbonates and we hypothesize about this process of biomineralization.

Protective effects of a standard extract of Mangifera indica L. (VIMANG) against mouse ear edemas and its inhibition of eicosanoid production in J774 murine macrophages

A standard aqueous extract of Mangifera indica L., used in Cuba as antioxidant under the brand name VIMANG, was tested in vivo for its anti-inflammatory activity, using commonly accepted assays. The standard extract of M. indica, administered orally (50-200mg/kg body wt.), reduced ear edema induced by arachidonic acid (AA) and phorbol myristate acetate (PMA) in mice. In the PMA model, M. indica extract also reduced myeloperoxidase (MPO) activity. In vitro studies were performed using macrophage cell line J774 stimulated with pro-inflammatory stimuli lipopolysaccharide-interferon gamma (LPS-IFNgamma) or calcium ionophore A23187 to determine prostaglandin PGE(2) or leukotriene LTB(4) release, respectively. The extract inhibited the induction of PGE(2) and LTB(4) with IC(50) values of 21.7 and 26.0microg/ml, respectively. Mangiferin (a glucosylxanthone isolated from the extract) also inhibited these AA metabolites (PGE(2), IC(50) value=17.2microg/ml and LTB(4), IC(50) value=2.1microg/ml). These results represent an important contribution to the elucidation of the mechanism involved in the anti-inflammatory and anti-nociceptive effects reported for the standard extract of M. indica VIMANG.

Evaluation of the genotoxic potential of Mangifera indica L. extract (Vimang), a new natural product with antioxidant activity

Mangifera indica L. extract (Vimang) consists of a defined mixture of components (polyphenols, terpenoids, steroids, fatty acids and microelements). It contains a variety of polyphenols, phenolic esters, flavan-3-ols and a xanthone (mangiferin), as main component. This extract has antioxidant action, antitumor and immunemodulatory effects proved in experimental models in both in vitro and in vivo assays. The present study was performed to investigate the genotoxicity potential activity of Vimang assessed through different tests: Ames, Comet and micronucleus assays. Positive and negative controls were included in each experimental series. Histidine requiring mutants of Salmonella typhimurium TA1535, TA1537, TA1538, TA98, TA100 and TA102 strains for point-mutation tests and in vitro micronucleus assay in primary human lymphocytes with and without metabolic activation were performed. In addition, genotoxic effects were evaluated on blood peripheral lymphocytes of NMRI mice of both sexes, which were treated during 2 days with intraperitoneal doses of M. indica L. extract (50-150 mg/kg). The observed results permitted to affirm that Vimang (200-5,000 microg/plate) did not increase the frequency of reverse mutations in the Ames test in presence or not of metabolic activation. Results of Comet assay showed that the extract did not induce single strand breaks or alkali-labile sites on blood peripheral lymphocytes of treated animals compared with controls. On the other hand, the results of the micronucleus studies (in vitro and in vivo) showed Vimang induces cytotoxic activity, determined as cell viability or PCE/NCE ratio, but neither increased the frequency of micronucleated binucleate cells in culture of human lymphocytes nor in mice bone marrow cells under our experimental conditions. The positive control chemicals included in each experiment induced the expected changes. The present results indicate that M. indica L. extract showed evidences of light cytotoxic activity but did not induce a mutagenic or genotoxic effects in the battery of assays used.

Delays to treatment and out-of-pocket medical expenditure for tuberculosis patients, in an urban area of South America

Short delays to treatment are important for the control of tuberculosis (TB). National Tuberculosis Programmes provide free diagnosis and treatment for smear-positive patients, so that the patients' out-of-pocket medical expenditure could be almost nil. The factors associated with delays in starting treatment, and the pre-treatment out-of-pocket medical expenditure for TB patients, have now been investigated in the Bolivian city of Cochabamba. Bolivia is the Latin American country with the highest incidence of TB. It is covered by a national TB programme that provides free diagnosis and free treatment for smear-positive patients. Structured interviews with 144 smear-positive patients enrolled in this programme revealed median patient, provider and total delays of 3.6, 6.2 and 12.9 weeks, respectively. The total delays were longer for the female patients than for the male, and for patients who consulted private doctors than for the other patients. When the first healthcare provider was a doctor, the median provider delay was 4.9 weeks in the public sector but 7.2 weeks in the private. The median out-of-pocket medical expenditure per patient, which was U.S.$13.2 overall, was much higher for those who consulted a private doctor than for those who did not (U.S.$21.9 v. U.S.$5.4, respectively; P<0.001). It appears that interventions targeting doctors (in both the private and public sectors) are likely to have a larger impact on the shortening of delays in TB treatment than interventions targeting patients. They could also reduce unnecessary out-of-pocket expenditure.

Putative ClC-2 Chloride Channel Mediates Inward Rectification in Drosophila Retinal Photoreceptors

We report that Drosophila retinal photoreceptors express inwardly rectifying chloride channels that seem to be orthologous to mammalian ClC-2 inward rectifier channels. We measured inwardly rectifying Cl(-) currents in photoreceptor plasma membranes: Hyperpolarization under whole-cell tight-seal voltage clamp induced inward Cl(-) currents; and hyperpolarization of voltage-clamped inside-out patches excised from plasma membrane induced Cl(-) currents that have a unitary channel conductance of approximately 3.7 pS. The channel was inhibited by 1 mM: Zn(2+) and by 1 mM: 9-anthracene, but was insensitive to DIDS. Its anion permeability sequence is Cl(-) = SCN(-)> Br(-)>> I(-), characteristic of ClC-2 channels. Exogenous polyunsaturated fatty acid, linolenic acid, enhanced or activated the inward rectifier Cl(-) currents in both whole-cell and excised patch-clamp recordings. Using RT-PCR, we found expression in Drosophila retina of a ClC-2 gene orthologous to mammalian ClC-2 channels. Antibodies to rat ClC-2 channels labeled Drosophila photoreceptor plasma membranes and synaptic regions. Our results provide evidence that the inward rectification in Drosophila retinal photoreceptors is mediated by ClC-2-like channels in the non-transducing (extra-rhabdomeral) plasma membrane, and that this inward rectification can be modulated by polyunsaturated fatty acid.

Genetic and non-genetic effects on productive and reproductive traits of cows in dual-purpose herds in southeastern Mexico

Data on productive and reproductive performance of cows in dual-purpose herds were analyzed to determine the effect of some environmental and genetic factors on saleable milk yield (SMY), lactation length (LL), daily saleable milk per lactation (DMYL), calving interval (CI), and daily saleable milk per calving interval (MYCI) in dual-purpose herds in Yucatan, Mexico. Repeatabilities (re) for these traits were also estimated. Data were obtained from monthly visits to 162 herds from 1996 to 2000. The fixed factors studied were: region (central, eastern and southern), parity number (1 to 6), calving year (1996 to 2000) and calving season (dry, rainy and windy and rainy), genetic group (low- (< 0.50%), medium- (50%) and high- (> 50%) grade cows with European genes). About 2700 to 7700 cows were evaluated for each trait. All factors had significant effects (P < 0.05) on the traits except for region on CI and calving season on DMYL. The overall means for SMY, LL, DMYL, CI, and MYCI were: 1322.3 +/- 80.5 kg, 224.8 +/- 1.3 days, 5.8 +/- 0.1 kg, 555.1 +/- 16.5 days, and 3.0 +/- 0.1 kg, respectively. The re values for SMY, LL, DMYL, CI, and MYCI traits were: 0.19 +/- 0.03, 0.08 +/- 0.04, 0.16 +/- 0.04, 0.00 +/- 0.08, and 0.08 +/- 0.07, respectively. First parity cows had lower SMY, shorter LL, longer CI, and lower MYCI means than cows with more than one parity. Medium grade cows produced more SMY, DMYL and MYCI and had shorter CI than low- and high-grade cows. Therefore, under Yucatan conditions medium-grade cows should be exploited, and more attention should be given to first parity cows in order to improve the productivity in the herd. The relatively high re estimates for SMY and DMYL can be used to calculate most probable producing abilities, in order to identify which cows should be culled.

An Anacardiaceae preparation reduces the expression of inflammation-related genes in murine macrophages

This study investigated the effects of an aqueous extract of the stem bark of Mangifera indica L. (Anacardiaceae; Vimang), which contains a defined mixture of components including polyphenols (principally mangiferin, MA), triterpenes, phytosteroids, fatty acids and microelements, on expression of inflammation mediators in inflammatory murine macrophages after stimulation in vitro with lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma). In vitro treatment with Vimang at 4 microg/ml reduced levels of NOS-2 mRNA and NOS-2, while treatment at 40 microg/ml also reduced levels of COX-2 mRNA, COX-2, and prostaglandin E2 (PGE2). Results suggested that MA is involved in these effects. In vitro treatment with Vimang at 40 microg/ml also inhibited mRNA levels of the proinflammatory cytokines interleukin 1beta (IL-1beta), tumor necrosis factor alpha (TNF-alpha) and colony-stimulating factor (GM-CSF), but did not affect mRNA levels of IL-6 or tumor growth factor-beta (TGF-beta). Extracellular release of TNF-alpha by inflammatory macrophages was inhibited by in vitro treatment with Vimang at the same concentrations that showed inhibition of TNF-alpha mRNA levels. The inhibition of TNF-alpha production appears to be at least partially attributable to MA. Vimang at 4 microg/ml decreased mRNA levels of nuclear factor-kappaB (NF-kappaB) but did not affect expression of the NF-kappaB inhibitor (IkappaB). These data indicate that the potent anti-inflammatory effects of Vimang are due to selective modulation of the expression of inflammation-related genes, leading to attenuation of macrophage activation.

Collaboration between private pharmacies and national tuberculosis programme: an intervention in Bolivia

BACKGROUND

Public-private partnerships are felt to be necessary for tuberculosis (TB) control in some developing countries.

OBJECTIVES

To evaluate the potential of a collaboration between the National TB Programme (NTP) and private pharmacies in Bolivia, the country with the highest TB incidence in Latin America.

METHODS

We contacted the local Pharmacists' Association in the city of Cochabamba, and designed a two phase intervention. The objectives of the first phase were to decrease the availability of TB drugs in private pharmacies on a voluntary basis, and to improve referral of clients seeking TB drugs to the NTP. A survey of all pharmacies allowed for a before-after comparison with a baseline survey. The objectives of the second phase were to obtain referral of pharmacy clients with chronic cough for TB screening in the NTP. This phase was started in 70 pharmacies and evaluated after 2 months using the referral slips issued by the pharmacists.

RESULTS

The proportion of pharmacies selling TB drugs decreased (rifampicin: 23-11.5%; isoniazid: 16-3.1%; P<0.001) and the proportion of pharmacies referring to the NTP clients seeking TB drugs increased (22-58%; P<0.0001). In the second phase, 26 of 70 pharmacies (38%) referred a total of 41 clients for screening in the NTP (i.e. an average of 0.29 clients per pharmacy and per month); 11 of 41 (27%) were screened and three of 11 (27%) diagnosed with smear-positive TB.

CONCLUSION

The first phase of the intervention proved effective in reducing the availability of the main TB drugs in pharmacies, and in improving referral of clients seeking TB drugs. Key factors in this success were not specific to Bolivia, and collaboration between private pharmacies and public services appears possible in that respect. However, collaboration with pharmacies does not seem an efficient way to increase the number of patients screened for TB, and to shorten delays to TB diagnosis and treatment.

Orientation of Arabidopsis thaliana KAT1 channel in the plasma membrane

The Arabidopsis thaliana KAT1, an inward-rectifying potassium channel, shares molecular features with the Shaker family of outward rectifier K(+) channels. The KAT1 amino-acid sequence reveals the presence of a positively charged S4 and a segment containing the TXGYGD signature sequence in the pore (P) region. To test whether the inward-rectifying properties of KAT1 are due to reverse orientation in the membrane, such that the voltage sensor is oriented in the opposite direction of the electric field compared with the Shaker K(+) channel, we have inserted a flag epitope in the NH(2) terminus or the S3-S4 loop. The KAT1 and tagged constructs expressed functional channels in whole cells, Xenopus oocytes and COS-7. The electrophysiological properties of both tagged constructs were similar to those of the wild type. Immunofluorescence with an antibody against the flag epitope and an anti-C terminal KAT1 determined the membrane localization of these epitopes and the orientation of the KAT1 channel in the membrane. Our data confirm that KAT1 in eukaryotic cells has an orientation similar to the Shaker K(+) channel.

Tuberculosis control and the private health sector in Bolivia: a survey of pharmacies

BACKGROUND

Bolivia is a high tuberculosis (TB) incidence country with a large private for-profit health sector. TB drug sales in private pharmacies are not illegal.

OBJECTIVES

To measure the availability of TB drugs in private pharmacies, study vendors' attitudes, and explore the potential for collaboration between the public health sector and pharmacies.

METHODS

Simulated clients visited a random sample of 100 pharmacies in the city of Cochabamba, presenting with a prescription for four TB drugs. After the survey, contacts were made with the local Pharmacist's Association.

RESULTS

Twenty-five pharmacies sold at least one drug, 23 sold rifampicin and 16 sold isoniazid. Of 99 pharmacies unable to fill the whole prescription, 59 referred the client to another pharmacy, and 22 to the public services. Pharmacists said that rifampicin was often prescribed for non-TB indications, and that TB drug sales were of minimal contribution to their income. They agreed to stop selling the drugs and to refer clients seeking them to the public sector.

CONCLUSION

This study has documented a small market for TB drugs sales in private pharmacies and provided the opportunity to start collaboration with the pharmacists. Our results suggest that the private sector contributes little to managing TB in Bolivia.

Monoclonal antibodies against a 62 kDa proteinase of Trichomonas vaginalis decrease parasite cytoadherence to epithelial cells and confer protection in mice

Trichomonas vaginalis infects the epithelium of the genital tract. The mechanism by which it invades the tissue leading to the disease is not thoroughly understood. However, results of several studies seem to agree that parasite adhesion to epithelium cells is the initial step leading to infection in women. T. vaginalis is associated with high levels of proteolytic activity. The role of some of these proteinases in the development of infection has been demonstrated. The current study establishes the role of a 62 kDa excretion-secretion proteinase in parasite cytoadherence. Monoclonal antibodies (MAbs) against this enzyme were tested for their ability to inhibit this process. Three stable hybrid producers of IgG(1)class MAbs (4D8, 1A8, 3C11) against the 62 kDa proteinase were obtained. Two of them (4D8 and 1A8) showed parasite recognition by immunofluorescence. Parasite cytoadherence to a monolayer of HeLa cells was inhibited by the 4D8, 1A8 and 3C11 antibodies. MAb 4D8 administered 24 h before a challenge with T. vaginalis by the intraperitoneal route was able to protect the majority of mice. Nitric oxide levels in the serum of animals inoculated with MAb 4D8 and challenged with the parasite were significantly different from those recorded in mice treated with an unrelated MAb. These studies show that an appropriate antibody against 62 kDa proteinase can help the host resist a challenge by the intraperitoneal route with T. vaginalis.

Anthelminthic and antiallergic activities of Mangifera indica L. stem bark components Vimang and mangiferin

This study investigated the antiallergic and anthelmintic properties of Vimang (an aqueous extract of Mangifera indica family stem bark) and mangiferin (the major polyphenol present in Vimang) administered orally to mice experimentally infected with the nematode, Trichinella spiralis. Treatment with Vimang or mangiferin (500 or 50 mg per kg body weight per day, respectively) throughout the parasite life cycle led to a significant decline in the number of parasite larvae encysted in the musculature; however, neither treatment was effective against adults in the gut. Treatment with Vimang or mangiferin likewise led to a significant decline in serum levels of specific anti-Trichinella IgE, throughout the parasite life cycle. Finally, oral treatment of rats with Vimang or mangiferin, daily for 50 days, inhibited mast cell degranulation as evaluated by the passive cutaneous anaphylaxis test (sensitization with infected mouse serum with a high IgE titre, then stimulation with the cytosolic fraction of T. spiralis muscle larvae). Since IgE plays a key role in the pathogenesis of allergic diseases, these results suggest that Vimang and mangiferin may be useful in the treatment of diseases of this type.

[Utility of intra-access pressure]

Monitoring of vascular access is essential for clinical evaluation on hemodialysis patients, detects early disfunction of access, allows adequate dialysis and decreases the morbidity associated. Although is demonstrated that intra-access pressure (IAP) is a good method of screening to evaluate arterial-venous (AV) fistulas, its utility is uncommon because its measurement requires a complex system. We would like to validate the utility of IAP monitoring using a simplified measure of IAP and its relation with other methods of screening in detecting stenoses prior to thromboses of AV grafts. We studied 24 AV grafts of 24 patients during 18 months we measured arterial pressure, mean arterial pressure (MAP), dynamic venous pressure, IAP, Kt/v, URR, recirculation index (RI), access flow and color Doppler flow, dividing the patients in two groups, with stenoses or not, if IAP/MAP > 0.5 and stenoses > 0.50 by Doppler we performed arteriography and percutaneous transluminal angioplasty with stent if stenoses exits. The values of IAP, MAP, RI were higher significantly in the stenoses group with increase of vascular access in grafts were dilation by angioplasty was made. All stenoses detected with IAP were confirmed by Doppler and arteriography but one. We conclude that IAP is an early, useful, easy, effective method in detecting stenoses of AV grafts prior to thrombosis.

Mangifera indicaL. extract (Vimang) and mangiferin modulate mouse humoral immune responses

The present study investigated the effects of orally administered Vimang (an aqueous extract of Mangifera indica) and mangiferin (the major polyphenol present in Vimang) on mouse antibody responses induced by inoculation with spores of microsporidian parasites. Inoculation induced specific antibody production with an exponential timecourse, peaking after about one month. Vimang significantly inhibited this antibody production from about three weeks post-inoculation, and most markedly by four weeks post-inoculation; by contrast, mangiferin had no significant effect. Determination of Ig isotypes showed that the IgM to IgG switch began about four weeks post-inoculation, with IgG2a predominating. Vimang significantly inhibited IgG production, but had no effect on IgM. Mangiferin did no affect either IgM or IgG2a, but significantly enhanced production of IgG1 and IgG2b. Neither Vimang nor mangiferin enhanced specific antibody secretion by splenic plasma cells from mice inoculated with microsporidian spores, whether administered in vivo before serum extraction or in vitro to the culture medium. Inoculation with spores induced splenomegaly, which was significantly reduced by Vimang and significantly enhanced by mangiferin. These results suggest that components of Mangifera indica extracts may be of potential value for modulating the humoral response in different immunopathological disorders.

Is decreased HIV-1 infectivity of placental macrophages caused by high levels of beta-chemokines?

The objective of this study was to determine the effect of beta-chemokine secretion on HIV infection of placental macrophages (HF) as compared to monocyte-derived macrophages (MDM). For this purpose, we measured chemokine production in supematants of LPS stimulated and unstimulated HF and MDM. LPS stimulated cultures produced 3 to 10 times higher levels of MIP-1alpha, MIP-1beta and RANTES than unstimulated cultures. The level of MIP-1beta was the highest of the three chemokines secreted upon stimulation of HF cells. Cell cultures were inoculated with HIV-BaL, a R5 virus, and tested for p24 antigen and chemokine production at days 5 and 10 post-infection (P.I.). We did not find significant differences in the level of chemokines produced by HIV-1-infected and uninfected MDM and HF cells. However, significant differences were found in p24 antigen released by unstimulated and LPS stimulated cells. In contrast to HF cells, MDM cultures showed a significant inhibition of p24 antigen production when cells were stimulated with LPS prior to infection. HF cells were less susceptible to HIV-1 infection than MDM, and chemokines produced by HF cells did not result in further inhibition of HIV-1 infection. We found that in contrast to MDM, decreased susceptibility HF cells to HIV infection is not due to increased levels of chemokines, but to decreased HIV-1 coreceptor expression.

Modulation of rat macrophage function by the Mangifera indica L. extracts Vimang and mangiferin

Vimang is an aqueous extract of Mangiferia indica L., traditionally used in Cuba as an anti-inflammatory, analgesic and antioxidant. In the present study, we investigated the effects of Vimang and of mangiferin (a C-glucosylxanthone present in the extract) on rat macrophage functions including phagocytic activity and the respiratory burst. Both Vimang and mangiferin showed inhibitory effects on macrophage activity: (a) intraperitoneal doses of only 50-250 mg/kg markedly reduced the number of macrophages in peritoneal exudate following intraperitoneal injection of thioglycollate 5 days previously (though there was no significant effect on the proportion of macrophages in the peritoneal-exudate cell population); (b) in vitro concentrations of 0.1-100 microg/ml reduced the phagocytosis of yeasts cells by resident peritoneal and thioglycollate-elicited macrophages; (c) in vitro concentrations of 1-50 microg/ml reduced nitric oxide (NO) production by thioglycollate-elicited macrophages stimulated in vitro with lipopolysaccharide (LPS) and IFNgamma; and (d) in vitro concentrations of 1-50 microg/ml reduced the extracellular production of reactive oxygen species (ROS) by resident and thioglycollate-elicited macrophages stimulated in vitro with phorbol myristate acetate (PMA). These results suggest that components of Vimang, including the polyphenol mangiferin, have depressor effects on the phagocytic and ROS production activities of rat macrophages and, thus, that they may be of value in the treatment of diseases of immunopathological origin characterized by the hyperactivation of phagocytic cells such as certain autoimmune disorders.

[Comparison of three genotyping methods for the detection of HIV-1 resistance to antiretroviral drugs]

Highly active antiretroviral therapy has dramatically improved the life expectancy of human immunodeficiency virus (HIV)-infected patients, but mutations in the HIV-1 reverse transcriptase (RT) and protease (P) genes confer drug failure. Evaluation of drug resistance genotyping in HIV-1 has proven to be useful for the selection of drug combinations with maximum antiretroviral activity. The aim of this study was to evaluate the optimal procedure to determine the resistance profile in the laboratory. Plasma from 90 antiretroviral-treated patients was analyzed by reverse hybridization, which identifies the presence of wild-types or mutations at the 19 key codons for protease and RT regions, and was compared with two other methods of direct cDNA sequencing. A total of 408 mutations were detected by InnoLiPA HIV-1, (Line Probe Assay, Innogenetics, Belgium), 572 by TrueGene HIV-1 Genotyping System (Visible Genetics, Canada), and 721 by ViroSeq HIV-1 Genotyping System (Perkin Elmer/Applied Biosystems, California). Hybridization detected a significantly higher number of primary mutations which are associated with a high level of drug resistance (p <0.001). Hybridization also detected a higher number of mixtures of wild-type and mutant viruses. There was a good concordance among the three methods, although it was higher between the two sequencing methods. Sequencing determines a higher number of mutations, but hybridization better identifies primary mutations correlated with a high level of drug resistance. Hybridization is more suitable for detecting mixed populations and is easier to implement in clinical laboratories but does not eliminate the need for sequence analysis for detection of drug-resistant HIV.

Albumin-derived advanced glycation end-products trigger the disruption of the vascular endothelial cadherin complex in cultured human and murine endothelial cells

Endothelial cell (EC) junctions regulate in large part the integrity and barrier function of the vascular endothelium. Advanced glycation end-products (AGEs), the irreversibly formed reactive derivatives of non-enzymic glucose-protein condensation reactions, are strongly implicated in endothelial dysfunction that distinguishes diabetes- and aging-associated vascular complications. The aim of the present study was to determine whether AGEs affect EC lateral junction proteins, with particular regard to the vascular endothelial cadherin (VE-cadherin) complex. Our results indicate that AGE-modified BSA (AGE-BSA), a prototype of advanced glycated proteins, disrupts the VE-cadherin complex when administered to ECs. AGE-BSA, but not unmodified BSA, was found to induce decreases in the levels of VE-cadherin, beta-catenin and gamma-catenin in the complex and in total cell extracts, as well as a marked reduction in the amount of VE-cadherin present at the cell surface. In contrast, the level of platelet endothelial cell adhesion molecule-1 (PECAM-1), which is located at lateral junctions, was not altered. Supplementation of the cellular antioxidative defences abolished these effects. Finally, the loss of components of the VE-cadherin complex was correlated with increases in vascular permeability and in EC migration. These findings suggest that some of the AGE-induced biological effects on the endothelium could be mediated, at least in part, by the weakening of intercellular contacts caused by decreases in the amount of VE-cadherin present.