Can treatment with chondroitin and glucosamine sulphate prevent changes in the articular disc caused by temporomandibular joint osteoarthritis?

BACKGROUND: Chondroitin and glucosamine sulphates (CGS) are considered structure-modifying drugs and have been studied in the prevention, delay or reversal of structural morphological changes in joints caused by osteoarthritis. OBJECTIVE: The aim of the present study was to investigate the action of CGS on the progression of chemically induced osteoarthritis in the temporomandibular joint (TMJ) of rabbits by evaluating the serum levels of tumour necrosis factor (TNF-α) and collagen in the articular discs. MATERIALS AND METHODS: A sample of 36 male rabbits was divided into three groups: control (CG), osteoarthritis (OG) and treatment (TG). The disease was induced by intra-articular injection of sodium monoiodoacetate (10 mg/mL) in the OG and TG groups bilaterally. After 10 days, the TG animals received subcutaneous injection of chondroitin sulphates and glucosamine (7.5 mg/kg) and the OG and CG received saline solution (50 µL). Euthanasia times were subdivided into 40 and 100 days. Collagen quantification was performed by biochemical and histological analysis and for the quantification of serum levels of TNF-α, an enzyme immunoassay was used. RESULTS: The TG showed an increase in the collagen area of the articular disc when compared to the CG and the OG. The increase collagen concentration in the discs did not show a statistically significant difference between the groups. Post-treatment TNF-α levels were significantly lower in TG compared to OG. CONCLUSIONS: The results indicate that CGS treatment delayed the degeneration of the collagen in the TMJ articular disc and reduced serum TNF-α levels, indicating a preventive effect on OA progression.

Effect of glycosaminoglycans on the structure and composition of articular cartilage and bone of broilers.

This study aimed to assess the influence of glycosaminoglycan (chondroitin and glucosamine sulfates) supplementation in the diet of broilers on the expression of matrix metallopeptidase 9 (MMP-9) and metallopeptidase inhibitor 2 (TIMP-2) genes, the synthesis of proteoglycans, collagen type II and chondrocytes, bone and cartilage macroscopy, bone mineral densitometry, bone breaking strength and mineral profile. A completely randomized design was carried out in a 3 × 3 factorial scheme (3 levels of chondroitin sulfate: 0.00, 0.05, and 0.10%; and 3 levels of glucosamine sulfate: 0.00, 0.15, and 0.30%), totaling 9 treatments. At 21 and 42 d of age, broilers were slaughtered, and tibias and femurs were collected for evaluation. There was an interaction (P < 0.05) of sulfates for the expression of MMP-9 and its inhibitor TIMP-2 in femur articular cartilage, as well as for the number of chondrocytes, collagen type II and proteoglycans in tibia articular cartilage, bone and cartilage macroscopy and mineral profile (P < 0.05), with better results obtained with the inclusion of chondroitin and/or glucosamine sulfates in the feed. In conclusion, chondroitin and glucosamine sulfates can be used in broiler diets in order to favor the development of the structure of the locomotor system (bones and joints), thus preventing locomotion problems.

Regulation of Tau protein phosphorylation by glucosamine-induced O-GlcNAcylation as a neuroprotective mechanism in a brain ischemia-reperfusion model.

Purpose:Tau hyperphosphorylation is a modification frequently observed after brain ischemia which has been related to the aggregation of this protein, with subsequent cytoskeletal damage, and cellular toxicity. The present study tests the hypothesis of using glucosamine, an agent that increases protein O-GlcNAcylation, to decrease the levels of phosphorylation in Tau during ischemia-reperfusion.Material and methods: Transient focal ischemia was artificially induced in male Wistar rats by occlusion of the middle cerebral artery (MCAO) with an intraluminal monofilament. A single dose of intraperitoneal glucosamine of 200 mg/kg diluted in normal saline (SSN) was administered 60 min before ischemia. Histological brain sections were processed using indirect immunofluorescence with primary antibodies (anti-O-GlcNAc and anti pTau-ser 396). The Image J software was used to calculate the immunofluorescence signal intensity.Results: The phosphorylation of Tau at the serine residue 396 had a significant decrease with the administration of glucosamine during ischemia-reperfusion compared with the administration of placebo.Conclusions: These results show that glucosamine can reduce the phosphorylation levels of Tau in rodents subjected to ischemia and cerebral reperfusion, which implies a neuroprotective role of glucosamine.

Effects of oral treatment with chondroitin sulfate and glucosamine in an experimental model of metacarpophalangeal osteoarthritis in horses.

BACKGROUND: Combined chondroitin sulfate (CS) and glucosamine (GlcN) has been widely used in oral formulations to prevent and treat osteoarthritis. CS is effective for controlling pain in osteoarthritic patients, whereas GlcN can stimulate glycosaminoglycan synthesis, thus reducing extracellular matrix degradation. Although several studies have been published on this topic, the effectiveness of treatment with oral CS and GlcN remains uncertain. The objective of this study was to analyze the progression of experimentally induced osteoarthritis in horses and verify the effectiveness of an oral compound based on CS and GlcN to treat and/or modulate this disease. The study analyzed the metacarpophalangeal joint of the left thoracic limb of 16 horses divided into two groups, with eight horses treated with CS and GlcN in the treated group (GT) and eight untreated horses in the control group (GC). Chondral lesions were induced through arthroscopy, which was defined as time-point zero (T0). Physical, ultrasonographic, and radiographic examinations and synovial fluid biomarkers measurements were performed on days 0, 30, 60, 90, and 120. At the end of the experiment (T4), arthroscopy was performed again to macroscopically evaluate the joints and collect material for microscopic analysis. RESULTS: Significant differences were observed between groups in some evaluated parameters, such as visual lameness assessment, synovial concentrations of prostaglandin E2, and ultrasound examination. However, the GT still presented slightly improved results for joint flexion angle, analysis of lameness using sensors, and histopathological analysis of chondral repair tissue, however, without the statistical significance (p>0.05). CONCLUSIONS: The treatment was considered effective in the clinical modulation of experimental osteoarthritis, with improvement of some parameters in the GT. However, this type of treatment may not be entirely effective to change the catabolic process in articular cartilage and the progressive induced chondral damage.

O-GlcNAc impairs endothelial function in uterine arteries from virgin but not pregnant rats: The role of GSK3ß.

Increased O-Linked ß-N-acetylglucosamine (O-GlcNAc) is observed in several pathologies, and unbalanced O-GlcNAcylation levels favor endothelial dysfunction. Whether augmented O-GlcNAc impacts the uterine artery (UA) function and how it affects the UA during pregnancy remains to be elucidated. We hypothesized that glucosamine treatment increases O-GlcNAc, leading to uterine artery dysfunction and this effect is prevented by pregnancy. Pregnant (P) and non-pregnant (NP) Wistar rats were treated with glucosamine (300 mg/kg; i.p.) for 21 days. Concentration response-curves (CRC) to acetylcholine (in the presence or absence of L-NAME) and sodium nitroprusside were performed in UAs. In NP rats, glucosamine treatment increased O-GlcNAc expression in UAs accompanied by decreased endothelium-dependent relaxation, which was abolished by L-NAME. Endothelial nitric oxide synthase (eNOS) activity and total Akt expression were decreased by glucosamine-treatment in NP rats. Further, NP rats treated with glucosamine displayed increased glycogen synthase kinase 3 beta (GSK3ß) activation and O-GlcNAc-transferase (OGT) expression in the UA. P rats treated with glucosamine displayed decreased O-GlcNAc in UAs and it was accompanied by improved relaxation to acetylcholine, whereas eNOS and GSK3ß activity and total Akt and OGT expression were unchanged. Sodium nitroprusside-induced relaxation was not changed in all groups, indicating that glucosamine treatment led to endothelial dysfunction in NP rats. The underlying mechanism is, at least in part, dependent on Akt/GSK3ß/OGT modulation. We speculate that during pregnancy, hormonal alterations play a protective role in preventing O-GlcNAcylation-induced endothelial dysfunction in the UAs.

DNase increases the efficacy of antimicrobial photodynamic therapy on Candida albicans biofilms.

Antimicrobial Photodynamic Therapy (aPDT) has been proposed as a means to treat Candida infections. However, microorganisms in biofilms are less susceptible to aPDT than planktonic cultures, possibly because the matrix limits the penetration of the photosensitizer. Therefore, the goals here were: (1) to target biofilm matrix components of a fluconazole-susceptible (S) and a fluconazole-resistant (R) C. albicans (Ca) strains using the hydrolytic enzymes ß-glucanase and DNase individually or in combination; (2) to apply the best enzyme protocol in association with aPDT mediated by Photodithazine® (PDZ); (3) to verify under confocal microscope the penetration of PDZ in biofilms pre-treated or not with DNase at different periods of incubation. CaS and CaR 48h-old biofilms were incubated with the hydrolytic enzymes (5 min) and evaluated by cell viability, biomass, and matrix components. DNase showed the best outcomes by significantly reducing extracellular DNA (eDNA) and soluble proteins from the matrix of both strains; and water-soluble polysaccharides from CaR matrix. Subsequently, 48h-old biofilms were incubated with DNase for 5 min, followed by incubation with PDZ for 20 min and exposure to LED light (660 nm, 50 J/cm²). Controls were biofilms treated only with aPDT without DNase, PDZ only, PDZ + DNase, light only, light + DNase, and biofilm without treatment. Pre-treatment with DNase allowed PDZ penetration into deeper biofilm layers, and the aPDT effect was enhanced, showing a significant reduction of the cell viability (p = 0.000) and eDNA amounts (p ≤ 0.047). DNase affected the matrix composition improving the penetration of the photosensitizer, thereby, improving the effectiveness of subsequent aPDT.

Chondroitin sulfate and glucosamine sulfate associated to photobiomodulation prevents degenerative morphological changes in an experimental model of osteoarthritis in rats.

The aim of this study was to compare the effects of combined treatment with chondroitin sulfate and glucosamine sulfate (CS/Gl) and photobiomodulation (PBM) on the degenerative process related to osteoarthritis (OA) in the articular cartilage in rats. Forty male Wistar rats were randomly divided into four groups: OA control group (CG); OA animals submitted to PBM treatment (PBM); OA animals submitted to CS/Gl treatment (CS/Gl); OA submitted to CS/GS associated with PBM treatments (GS/Gl + PBM). The CS/Gl started 48 h after the surgery, and they were performed for 29 consecutive days. Moreover, PBM was performed after the CS/Gl administration on the left joint. Morphological characteristics and immunoexpression of interleukin 10 (IL-10) and 1 beta (IL-1ß) and collagen type II (Col II) of the articular cartilage were evaluated. The results showed that all treated groups (CS/Gl and PBM) presented attenuation signs of degenerative process (measured by histopathological analysis) and lower density chondrocytes [PBM (p = 0.0017); CS/Gl (p = 0.0153) and CS/Gl + PBM (p = 0.002)]. Additionally, CS/Gl [associated (p = 0.0089) or not with PBM (p = 0.0059)] showed significative lower values for OARSI grade evaluation. Furthermore, CS/GS + PBM decreased IL-1ß protein expression (p = 0.0359) and increased IL-10 (p = 0.028) and Col II imunoexpression (p = 0.0204) compared to CG. This study showed that CS/Gl associated with PBM was effective in modulating inflammatory process and preventing the articular tissue degradation in the knees OA rats.

Photodithazine photodynamic effect on viability of 9L/lacZ gliosarcoma cell line.

Even with the advances of conventional treatment techniques, the nervous system cancer prognosis is still not favorable to the patient which makes alternative therapies needed to be studied. Photodynamic therapy (PDT) is presented as a promising therapy, which employs a photosensitive (PS) agent, light wavelength suitable for the PS agent, and molecular oxygen, producing reactive oxygen species in order to induce cell death. The aim of this study is to observe the PDT action in gliosarcoma cell using a chlorin (Photodithazine, PDZ). The experiments were done with 9L/lacZ lineage cells, grown in a DMEM medium supplemented with 10% fetal bovine serum and 1% penicillin/streptomycin solution and put in a culture chamber at 37 °C with an atmosphere of 5% CO2. The PS agent used was the PDZ to an LED light source device (Biopdi/IRRAD-LED 660) in the 660-nm region. The location of the PS agent was analyzed by fluorescence microscopy, and cell viability was analyzed by MTT assay (mitochondrial activity), exclusion by trypan blue (cell viability), and morphological examination through an optical microscope (Leica MD 2500). In the analysis of the experiments with PDZ, there was 100% cell death at different concentrations and clear morphological differences in groups with and without treatment. Furthermore, it was observed that the photodithazine has been focused on all nuclear and cytoplasmic extension; however, it cannot be said for sure whether the location is in the inside core region or on the plasma membrane. In general, the PDZ showed a promising photosensitive agent in PDT for the use of gliosarcoma.

Treatment of Oral Candidiasis Using Photodithazine®- Mediated Photodynamic Therapy In Vivo.

This study evaluated the effectiveness of antimicrobial photodynamic therapy (aPDT) in the treatment of oral candidiasis in a murine model using Photodithazine® (PDZ). This model of oral candidiasis was developed to allow the monitoring of the infection and the establishment of the aPDT treatment. Six-week-old female mice were immunosuppressed and inoculated with C. albicans to induce oral candidiasis. PDZ-mediated aPDT and nystatin treatment were carried out for 5 consecutive days with one application per day. The macroscopic evaluation of oral lesions was performed. After each treatment, the tongue was swabbed to recover C. albicans cells. Viable colonies were quantified and the number of CFU/ml determined. The animals were sacrificed 24 hours and 7 days after treatment and the tongues were surgically removed for histological analysis and analysis of inflammatory cytokines expression (IL-1, TNF-α and IL-6) by RT-qPCR. Data were analyzed by two-way ANOVA. PDZ-mediated aPDT was as effective as Nystatin (NYS group) in the inactivation of C. albicans, reducing 3 and 3.2 logs10 respectively, 24 h after treatment (p<0.05). Animals underwent PDZ-mediated aPDT showed complete remission of oral lesions, while animals treated with NYS presented partial remission of oral lesions in both periods assessed. Histological evaluation revealed mild inflammatory infiltrate in the groups treated with aPDT and NYS in both periods assessed. The aPDT induced the TNF-α expression when compared with the control (P-L-) (p<0.05), 24 h and 7 days after treatment. In summary, the murine model developed here was able to mimic the infection and PDZ-mediated aPDT was effective to treat mice with oral candidiasis.

Photodynamic inactivation of a multispecies biofilm using Photodithazine(®) and LED light after one and three successive applications.

In this investigation, the effectiveness of successive applications of antimicrobial photodynamic inactivation (API) mediated by Photodithazine(®) (PDZ) and LED light was evaluated against a multispecies biofilm formed by Candida albicans, Candida glabrata, and Streptococcus mutans on denture base acrylic resin. Standard cell suspensions (bacteria and yeast) were inoculated on acrylic resin samples, and the biofilm was grown for 48 h (37 °C/75 rpm). API was performed by the administration of PDZ (175 and 200 mg/L) and exposure to 37.5 J/cm(2) of LED light (660 nm). Additional samples were treated with PDZ or LED light only. Untreated control samples were not submitted to light or PDZ. The conditions described were applied once or in three consecutive applications for all groups. Cell viability was determined by colony counts (CFU/mL), metabolic activity, total biomass, and confocal laser scanning microscopy (CLSM). Data were analyzed by a nonparametric two-way ANOVA and Tukey tests (α = 0.05). The results obtained demonstrated a significant effect (p < 0.05) of number of applications and treatment groups for CFU/mL, and S. mutans showed the highest susceptibility to API. The metabolic activity of the multispecies biofilm was significantly reduced (p < 0.05) after API for both numbers of applications, which were also significantly different (p < 0.05) between them. The total biomass of the biofilm was significantly different (p < 0.05) only between groups submitted to one and three API applications. CLSM showed a visual increase of dead cells after API. API-mediated PDZ was effective in reducing the cell viability of multispecies biofilm. Three consecutive applications of API were more effective for reducing the cell viability and the total biomass of multispecies biofilm.

Análise das propriedades físico-químicas da glucosamina sulfato comercial, uma matéria- prima utilizada em formulações farmacêuticas / Physicochemical properties analysis of commercial glucosamine sulfate, a raw material used in pharmaceutical formulations

Introdução: A qualidade dos produtos em farmácias de manipulação é determinada pela Agência Nacional de Vigilância Sanitária (ANVISA), mas os métodos descritos podem não ser adequados para analisar seus aspectos físico-químicos. Objetivo: Comparar aspectos físico-químicos da glucosamina sulfato de dois diferentes fornecedores com análises realizadas na farmácia de manipulação. Métodos: As características organolépticas, pH, solubilidade e densidade da glucosamina (n=50) dos fornecedores foram analisadas conforme descrito na Farmacopeia Brasileira e Compêndio Oficial e comparados aos laudos técnicos dos produtos adquiridos. Usaram-se os testes de Kolmogorov-Smirnov, coeficiente de correlação intraclasse (CCI) e Bland-Altman. Resultados: A análise de CCIevidenciou baixa reprodutibilidade para o teste de pH e densidade, e a análise de Bland-Altman demonstrou que os fornecedores subestimavam ou superestimavam os valores de pH e densidade em relação à farmácia. Conclusão: Os aspectos físico-químicos estão adequados conforme orientações da Anvisa, mas novas técnicas mais sensíveis devem ser utilizadas para garantir a qualidade da glucosamina nas formulações.

Introduction: The raw materials quality in the manipulation pharmacies are determined by Brazilian Health Surveillance Agency (ANVISA), but the protocols described may not be appropriate to analyze their physicochemical properties. Objective: To compare the physicochemical properties of glucosamine sulfate from two different suppliers with results obtained in the manipulation pharmacy. Methods: The organoleptic characteristics, pH, solubility and density of glucosamine samples (n=50) were analyzed according to the Brazilian Pharmacopoeia and Official Compendium and compared the technical reports of the suppliers. The results were analyzed by the Kolmogorov-Smirnov test, intraclass correlation coefficient (CCI) and Bland-Altman. Results: CCI analyses showed low reproducibility for pH and density test in the samples tested. In addition, Bland-Altman analysis indicated pH values and density of suppliers were underestimated or overestimated compared to the pharmacy. Conclusion: Physicochemical properties of glucosamine are appropriate according to Anvisa specifications, but new more sensitive techniques should be employed to ensure the glucosamine quality in the formulations.

Apoptosis-associated genes related to photodynamic therapy in breast carcinomas.

The aim of this study was to find the apoptosis molecular markers involved in the cell death that might be related to photodynamic therapy (PDT) mechanisms in breast cancer. The mammary tumors were induced in 25 Sprague-Dawley female rats by a single, oral gavage of 7,12-dimethylbenz(a)anthracene (DMBA; 70 mg/kg body weight). Animals were divided into four groups: G1 (normal, without DMBA), G2 (control, without PDT treatment), G3 (euthanized 48 h after PDT), and G4 (euthanized 24 h after PDT). For PDT experiments, the photosensitizer used was Photodithazine, and 100 J/cm of light at a fluence rate of 100 mW/cm was delivered to treat lesions. A sample of each animal was investigated by quantitative real-time PCR using Rat Apoptosis RT2 Profiler™ PCR Array platform. The results showed 20 genes with differential expression between PDT and control groups. A significant upregulation was observed for pro-apoptotic genes CASP4, CASP12, CIDEA, GADD45A, and FAS and downregulation of anti-apoptotic genes MAPK8IP1, TNFRSF11B, and NAIP2 in PDT-treated tumors. These results indicate that these genes are more directly involved in cell apoptosis induced by PDT.

Photodynamic therapy in Pythium insidiosum - an in vitro study of the correlation of sensitizer localization and cell death.

Pythiosis is an infectious disease caused by Pythium insidiosum, a fungus-like organism. Due to the lack of ergosterol on its cell membrane, antibiotic therapy is ineffective. The conventional treatment is surgery, but lesion recurrence is frequent, requiring several resections or limb amputation. Photodynamic therapy uses photo-activation of drugs and has the potential to be an attractive alternative option. The in vitro PDT response on the growing of Pythium insidiosum culture was investigated using three distinct photosensitizers: methylene blue, Photogem, and Photodithazine. The photosensitizer distribution in cell structures and the PDT response for incubation times of 30, 60, and 120 minutes were evaluated. Methylene blue did not penetrate in the pathogen's cell and consequently there was no PDT inactivation. Photogem showed heterogenous distribution in the hyphal structure with small concentration inside the cells. Porphyrin-PDT response was heterogenous, death and live cells were observed in the treated culture. After 48 hours, hyphae regrowth was observed. Photodithazine showed more homogenous distribution inside the cell and with the specific intracellular localization dependent on incubation time. Photodithazine first accumulates in intracellular vacuoles, and at incubation times of one hour, it is located at all cell membranes. Higher inhibition of the growing rates was achieved with Photodithazine -PDT, over 98%. Our results showed that the photosensitizers that cross more efficiently the Pythium insidiosum membranes are able to cause extensive damage to the organism under illumination and therefore, are the best options for clinical treatment.

Glucosamine and chondroitin sulfate association increases tibial epiphyseal growth plate proliferation and bone formation in ovariectomized rats.

OBJECTIVE: The growth plate consists of organized hyaline cartilage and serves as a scaffold for endochondral ossification, a process that mediates longitudinal bone growth. Based on evidence showing that the oral administration of glucosamine sulfate (GS) and/or chondroitin sulfate (CS) is clinically valuable for the treatment of compromised articular cartilage, the current study evaluated the effects of these molecules on the tibial epiphyseal growth plate in female rats. METHOD: The animals were divided into two control groups, including vehicle treatment for 45 days (GC45) and 60 days (GC60) and six ovariectomized (OVX) groups, including vehicle treatment for 45 days (GV45), GS for 45 days (GE45GS), GS+CS for 45 days (GE45GS+CS), vehicle for 60 days (GV60), GS for 60 days (GE60GS) and GS+CS for 60 days (GE60GS+CS). At the end of treatment, the tibias were dissected, decalcified and processed for paraffin embedding. Morphological and morphometric methods were employed for analyzing the distal tibial growth plates using picrosirius red staining and the samples were processed for histochemical hyaluronan detection. Morphometric analyses were performed using the 6.0ProPlus® Image system. RESULTS: Notably, after 60 days of treatment, the number of proliferative chondrocytes increased two-fold, the percentage of remaining cartilage increased four-fold and the percentage of trabecular bone increased three-fold in comparison to the control animals. CONCLUSION: GS and CS treatment drugs led to marked cellular proliferation of the growth plate and bone formation, showing that drug targeting of the tibial epiphyseal growth plate promoted longitudinal bone growth.

Glucosamine and chondroitin sulfate association increases tibial epiphyseal growth plate proliferation and bone formation in ovariectomized rats

OBJECTIVE: The growth plate consists of organized hyaline cartilage and serves as a scaffold for endochondral ossification, a process that mediates longitudinal bone growth. Based on evidence showing that the oral administration of glucosamine sulfate (GS) and/or chondroitin sulfate (CS) is clinically valuable for the treatment of compromised articular cartilage, the current study evaluated the effects of these molecules on the tibial epiphyseal growth plate in female rats. METHOD: The animals were divided into two control groups, including vehicle treatment for 45 days (GC45) and 60 days (GC60) and six ovariectomized (OVX) groups, including vehicle treatment for 45 days (GV45), GS for 45 days (GE45GS), GS+CS for 45 days (GE45GS+CS), vehicle for 60 days (GV60), GS for 60 days (GE60GS) and GS+CS for 60 days (GE60GS+CS). At the end of treatment, the tibias were dissected, decalcified and processed for paraffin embedding. Morphological and morphometric methods were employed for analyzing the distal tibial growth plates using picrosirius red staining and the samples were processed for histochemical hyaluronan detection. Morphometric analyses were performed using the 6.0ProPlus¯ Image system. RESULTS: Notably, after 60 days of treatment, the number of proliferative chondrocytes increased two-fold, the percentage of remaining cartilage increased ...

Photodynamic inactivation of clinical isolates of Candida using Photodithazine®.

This study evaluated the photodynamic inactivation (PDI) mediated by Photodithazine(®) (PDZ) against 15 clinical isolates of Candida albicans, Candida glabrata and Candida tropicalis. Each isolate, in planktonic and biofilm form, was exposed to PDI by assessing a range of PDZ concentrations and light emitting diode fluences. Cell survival of the planktonic suspensions was determined by colony forming units (CFU ml(-1)). The antifungal effects of PDI against biofilms were evaluated by CFU ml(-1) and metabolic assay. Data were analyzed by non-parametric tests (α = 0.05). Regardless of the species, PDI promoted a significant viability reduction of planktonic yeasts. The highest reduction in cell viability of the biofilms was equivalent to 0.9 log10 (CFU ml(-1)) for C. albicans, while 1.4 and 1.5 log10 reductions were obtained for C. tropicalis and C. glabrata, respectively. PDI reduced the metabolic activity of biofilms by 62.1, 76.0, and 76.9% for C. albicans, C. tropicalis, and C. glabrata, respectively. PDZ-mediated PDI promoted significant reduction in the viability of Candida isolates.

Safety assessment of oral photodynamic therapy in rats.

Photodynamic therapy (PDT) is based on the synergism of a photosensitive drug (a photosensitizer) and visible light to destroy target cells (e.g., malignant, premalignant, or bacterial cells). The aim of this study was to investigate the response of normal rat tongue mucosa to PDT following the topical application of hematoporphyrin derivative (Photogem®), Photodithazine®, methylene blue (MB), and poly(lactic-co-glycolic acid) (PLGA) nanoparticles loaded with MB. One hundred and thirty three rats were randomly divided in various groups: the PDT groups were treated with the photosensitizers for 10 min followed by exposure to red light. Those in control groups received neither photosensitizer nor light, and they were subjected to light exposure alone or to photosensitizer alone. Fluorescent signals were obtained from tongue tissue immediately after the topical application of photosensitizers and 24 h following PDT. Histological changes were evaluated at baseline and at 1, 3, 7, and 15 days post-PDT treatment. Fluorescence was detected immediately after the application of the photosensitizers, but not 24 h following PDT. Histology revealed intact mucosa in all experimental groups at all evaluation time points. The results suggest that there is a therapeutic window where PDT with Photogem®, Photodithazine®, MB, and MB-loaded PLGA nanoparticles could safely target oral pathogenic bacteria without damaging normal oral tissue.

Agglutinating activity and structural characterization of scalarin, the major egg protein of the snail Pomacea scalaris (d'Orbigny, 1832).

Apple snail perivitellins are emerging as ecologically important reproductive proteins. To elucidate if the protective functions of the egg proteins of Pomacea canaliculata (Caenogastropoda, Ampullariidae), involved in embryo defenses, are present in other Pomacea species we studied scalarin (PsSC), the major perivitellin of Pomacea scalaris. Using small angle X-ray scattering, fluorescence and absorption spectroscopy and biochemical methods, we analyzed PsSC structural stability, agglutinating activity, sugar specificity and protease resistance. PsSC aggluttinated rabbit, and, to a lesser extent, human B and A erythrocytes independently of divalent metals Ca(2+) and Mg(2+) were strongly inhibited by galactosamine and glucosamine. The protein was structurally stable between pH 2.0 to 10.0, though agglutination occurred only between pH 4.0 to 8.0 (maximum activity at pH 7.0). The agglutinating activity was conserved up to 60 °C and completely lost above 80 °C, in agreement with the structural thermal stability of the protein (up to 60 °C). PsSC was able to withstand in vitro gastrointestinal digestion, and showed no trypsin inhibition activity. The presence of lectin activity has been reported in eggs of other Pomacea snails, but here we link for the first time, this activity to an apple snail multifunctional perivitellin. This novel role for a snail egg storage protein is different from closely related P.canaliculata defensive proteins.

In vitro oxidant effects of D-glucosamine reduce adhesión and biofilm formation of Staphylococcus epidermidis.

Staphylococcus epidermidis is a common pathogen in medical device-associated infections. Its major pathogenic factor is the ability to form adherent biofilms. In this work, three S. epidermidis strains isolated from infected catheters were chosen with the objective of investigating the effect of D-glucosamine (D-Glu) on reactive oxygen species (ROS) production, adhesion and biofilm formation. The chemiluminescence and nitroblue tetrazolium reduction assays were used to determine ROS production by planktonic S. epidermidis and the microtiter plate assay to quantify in vitro biofilm formation. D-Glu generated a dose-dependent increase in ROS in planktonic cells with maximum stimuli at a concentration of 0.05 mM, and reduced adhesion and biofilm formation. On the other hand, glucose showed an antioxidative stress action and promoted biofilm adhesion and growth. This study suggests a potential application of D-Glu against infections associated with indwelling medical devices, since the oxidative stress caused by this hexosamine in planktonic S. epidermidis contributed to reducing biofilm formation.

In vitro oxidant effects of D-glucosamine reduce adhesión and biofilm formation of Staphylococcus epidermidis / Los efectos oxidantes de la D-glucosamina in vitro reducen la adhesión y formación de biofilms de Staphylococcus epidermidis

Staphylococcus epidermidis is a common pathogen in medical device-associated infections. Its major pathogenic factor is the ability to form adherent biofilms. In this work, three S. epidermidis strains isolated from infected catheters were chosen with the objective of investigating the effect of D-glucosamine (D-Glu) on reactive oxygen species (ROS) production, adhesion and biofilm formation. The chemiluminescence and nitroblue tetrazolium reduction assays were used to determine ROS production by planktonic S. epidermidis and the microtiter plate assay to quantify in vitro biofilm formation. D-Glu generated a dose-dependent increase in ROS in planktonic cells with maximum stimuli at a concentration of 0.05 mM, and reduced adhesion and biofilm formation. On the other hand, glucose showed an antioxidative stress action and promoted biofilm adhesion and growth. This study suggests a potential application of D-Glu against infections associated with indwelling medical devices, since the oxidative stress caused by this hexosamine in planktonic S. epidermidis contributed to reducing biofilm formation.(AU)

Staphylococcus epidermidis es un patógeno común en infecciones asociadas a dispositivos médicos. Su factor de patogenicidad más importante es la capacidad para formar biofilms. Se trabajó con tres cepas de S. epidermidis aisladas de catéteres, con las que se efectuaron ensayos de quimioluminiscencia y de reducción de azul de nitrotetrazolio, para determinar la producción de especies reactivas del oxígeno (ERO) en S. epidermidis planctónico, y ensayos dirigidos a cuantificar la formación de biofilm in vitro, empleando placas multipocillos. La D-glucosamina generó un aumento dependiente de la dosis en la producción de ERO en las células planctónicas, con un estímulo máximo a una concentración de 0,05 mM. Este aumento condμlo a la reducción de la adhesión y de la formación de biofilm. La adición de glucosa, en cambio, mostró un efecto anti estrés oxidativo y promovió la adhesión y el crecimiento de biofilm. Este estudio sugiere una posible aplicación de la D-glucosamina contra las infecciones asociadas a dispositivos médicos, ya que el estrés oxidativo provocado por esta hexosamina contribuyó a una menor formación de biofilm.(AU)