Antimicrobial effects of Photodynamic Therapy to gram negative bacteria envelope revealed by Cryo-electron tomography

Cryo-electron tomography (cryo-ET) is an emerging technology that enables thin samples, including small intact prokaryotic cells, to be imaged in three dimensions in a near-native 'frozenhydrated' state to a resolution sufficient to recognize very large macromolecular complexes in situ. This methodology has been fundamental to provide information about cellular ultrastructure. This study used cryo-ET to evaluate the photodynamic effect on the viability and envelope architecture of a Gram-negative bacteria. Bacterial suspension of E. coli minicells were submitted to photodynamic treatment with methylene blue solution (100μM) and a 100mW low power diode laser emitting at 660nm with 6 and 18J of energy. As a control group, a suspension of minicells were submitted to 462 IU/mL penicillin G for 60 min at 30 °C, to compare the damage in cell wall structure. After treatment bacteria were immediately plunge-frozen across EM grids and standard cryo-ET tilt series were collected, 3D images reconstructions were calculated and recorded. The imagens showed detachment of the bacterial cell walls and mesosome-like structures. In addition, some sites showed interrupted stretches in both inner and outer membranes and cell wall degradation, indicating bacterial envelope damage. Cryo-electron tomography revealed that the effects of photodynamic therapy on Gram negative bacteria was based on damage to the outer membrane, cell wall and inner membrane and occurs in an energy-dependent manner

He-Ne Laser Effects on Blood Microcirculation During Wound Healing: A Method of In Vivo Study Through Laser Doppler Flowmetry

Background and Objectives: Low-intensity laser therapy (LILT) is widely used for wound healing promotion and its mechanism of action may be due to an enhancement of blood supply. The aim of this study was to evaluate blood flow alterations in a wound healing model, using laser Doppler flowmetry (LDF) associated with a normalized perfusion parameter. Study Design/Materials and Methods: An injury was provoked in 15 rats and blood flow was measured periodically over a period of 21 days. Control groups were established to evaluate LDF and He-Ne laser effects on microcirculation. A 1 J/cm 2 dose was utilized, with 6 mW/ cm 2 irradiance. Results: The results demonstrated flow alterations provoked by lesion, and inflammatory response (P < 0.05). There were no statistical differences between groups. Conclusions: The results did not show a significant sustained effect on microcirculation with this He-Ne dose

Photobiomodulation reduces the cytokine storm syndrome associated with Covid-19 in the zebrafish model

Although the exact mechanism of the pathogenesis of COVID-19 is not fully understood, oxidative stress and the release of pro-inflammatory cytokines have been highlighted as playing a vital role in the pathogenesis of the disease. In this sense, alternative treatments are needed to reduce the inflammation caused by COVID-19. Therefore, this study aimed to investigate the potential effect of red PBM as an attractive therapy to downregulate the cytokine storm caused by COVID-19 from a zebrafish model. RT-PCR analyses and protein-protein interaction prediction among SARS-CoV-2 and Danio rerio proteins showed that rSpike was responsible for generating systemic inflammatory processes with significantly increased pro-inflammatory (il1b, il6, tnfa, and nfkbiab), oxidative stress (romo1) and energy metabolism (slc2a1a, coa1) mRNA markers, with a pattern like those observed in COVID-19 cases in humans. On the other hand, PBM treatment decreased the mRNA levels of these pro-inflammatory and oxidative stress markers compared with rSpike in various tissues, promoting an anti-inflammatory response. Conversely, PBM promotes cellular and tissue repair of injured tissues and significantly increases the survival rate of rSpike-inoculated individuals. Additionally, metabolomics analysis showed that the most impacted metabolic pathways between PBM and the rSpike-treated groups were related to steroid metabolism, immune system, and lipids metabolism. Together, our findings suggest that the inflammatory process is an incisive feature of COVID-19, and red PBM can be used as a novel therapeutic agent for COVID-19 by regulating the inflammatory response. Nevertheless, the need for more clinical trials remains, and there is a significant gap to overcome before clinical trials.publishedVersio

Effects of maxillary skeletal expansion on respiratory function and sport performance in a para-athlete - A case report

Made available in DSpace on 2019-09-12T16:53:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2019The aim of this case report was to demonstrate the effects of the Maxillary Skeletal Expander (MSE) used to orthopedically correct a maxillary constriction, on the respiratory functions and swimming performance of a Para-athlete. Cone-beam computed tomography (CBCT) images taken before and after MSE activation were used to demonstrate the disarticulation of midpalatal suture, and the changes involved in dental and nasomaxillary structures, nasal cavity and pharyngeal airway. Respiratory tests included: maximum inspiratory and expiratory pressure, oral peak expiratory flow and inspiratory nasal flow. The 6-min-walk and heart rate recovery tests were also performed. Patient's swimming performances during national swimming competitions were compared. CBCT images showed that palatal expansion was 5.91 mm at the suture, and that nasal and pharyngeal airways increased in volume by 31%. All respiratory indices improved after MSE activation. The 6-min walk test and heart rate recovery test performance also improved after the maxillary expansion. Patient's swimming performance in all category were anemic prior to the treatment, but performance improved considerably after the expansion, particularly the 100 m-Backstroke modality. MSE treatment had a significant positive impact in respiratory functions and sport performance. (C) 2019 Elsevier Ltd. All rights reserved.[Garcez, Aguinaldo S.] Sao Leopoldo Mandic Inst & Res Ctr, Dept Microbiol, Campinas, SP, Brazil[Suzuki, Selly S.; Storto, Camilla J.] Sao Leopoldo Mandic Inst & Res Ctr, Dept Postgrad Orthodont, Campinas, SP, Brazil[Cusmanich, Karla G.] Universidade de Taubaté (Unitau), Dept Grad Phys Therapy[Elkenawy, Islam; Moon, Won] Univ Calif Los Angeles, Sch Dent, Sect Orthodont, Los Angeles, CA 90024 US

Effects of photobiomodulation on SOFAT, A T-cell-derived Cytokine, may explain accelerated orthodontic tooth movement

Orthodontic tooth movement is based on mechanical forces inducing bone remodeling, and several methods have been proposed to increase tooth movement, including photobiomodulation. This study evaluated, in an animal model, the effects of photobiomodulation on SOFATa secreted osteoclastogenic factor of activated T cells and RANK-L during tooth movement. The results showed that tooth displacement, RANK-L and SOFAT levels were significantly greater compared to Control group. SOFAT may play an important role in bone remodeling during orthodontic movement, possibly increasing the osteoclast cells at the compression area and bone remodeling activity943604610FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2013/06079-

Antimicrobial mechanisms behind photodynamic effect in the presence of hydrogen peroxide

This study describes the use of methylene blue (MB) plus light (photodynamic inactivation, PDI) in the presence of hydrogen peroxide (H(2)O(2)) to kill Staphylococcus aureus, Escherichia coli, and Candida albicans. When H(2)O(2) was added to MB plus light there was an increased antimicrobial effect, which could be due to a change in the type of ROS generated or increased microbial uptake of MB. To clarify the mechanism, the production of ROS was investigated in the presence and absence of H(2)O(2). It was observed that ROS production was almost inhibited by the presence of H(2)O(2) when cells were not present. In addition, experiments using different sequence combinations of MB and H(2)O(2) were performed and MB optical properties inside the cell were analyzed. Spectroscopy experiments suggested that the amount of MB was higher inside the cells when H(2)O(2) was used before or simultaneously with PDI, and ROS formation inside C. albicans cells confirmed that ROS production is higher in the presence of H(2)O(2). Moreover enzymatic reduction of MB by E. coli during photosensitizer uptake to the photochemically inactive leucoMB could be reversed by the oxidative effects of hydrogen peroxide, increasing ROS formation inside the microorganism. Therefore, the combination of a photosensitizer such as MB and H(2)O(2) is an interesting approach to improve PDI efficiency.FAPESP[05/51598-7]FAPESP[05/00253-0]CNPqUS NIH[R01AI050875]AFOSR US Air Force[FA9550-04-1-0079