Reduction In Optical Density Research Articles

Preparation & characterization of polyvinyl alcohol/thymol blue composites gel and films for low radiation dosimetry

BackgroundExposure to low radiation has been indispensable due to it is necessity in radiography and it is induced potential effects in patients and radiology staff. Hence the measurement and detection became inevitable for radiation practitioners and the patients. The study aimed to present the synthesis of polyvinyl alcohol gel doped with Thymol Blue dye (PVA/TB) as gel and films for low radiation dosimetry. MethodThe polymer was prepared under controlled parameters (PVA 5%, temperature 80 °C, dopped with 0.01, 0.03, 0.05, 0.07, 0.09 mw of TB). The formed gel and films were irradiated with x-ray as: 0, 2, 4, 6, 8, 10 mGy. ResultsGel and films showed color quenching from yellow to light yellow as the radiation dose increased, as well as gradual significant (R2 = 0.97) reduction in optical density for all concentration (0.01, 0.02–0.09 mw of TB). The UV-spectroscope for (PVA/TB0.01mw) gel showed absorbance peaks at λ = 435, 326 and 279 nm, that decreased significantly (R2 = 0.97) as the radiation dose increases. And XRD for (PVA/TB0.01 mw) reveals the crystallinity of PVA at 2 thetas = 19.5° which increased to 40.5% at 10 mGy. FTIR revealed the chemical bonds with relevant intensities (CH (725.1–781 & 3030 cm−1), C – C (883.2 & 1170.6 cm−1), C – O (1063- 1096 cm−1), CH2 (1357.6 cm−1 wagging, 2879.2 cm−1 alkyl stretch), C = C (1623.8–1651.5 cm−1), C = O (1681.6–1683.6 cm−1), C – OH (3288 cm−1)) that decreased as the radiation dose increased and new radiogenic bonds at vibrational bands 1063–1096 cm−1 referring to C – O – C of Polysaccharide's pyranose and at 2125.1 cm−1 for C ≡ C alkenyl). ConclusionBoth forms of PVA/TB films and gel showed feasibility and applicability for radiation detection and measurement.

The addition of silicon nitride to PMMA bone cements reduces bacterial attachment while supporting preosteoblast viability

Injectable poly (methyl methacrylate) (PMMA) bone cements are widely used in orthopaedics to stabilize fractures and for implant fixation. However, bacterial attachment to bone cements leads to significant complications that can create a need for implant revision. Common attempts at reducing bacterial attachment are through the addition of antibiotics or antibacterial nanometals to the bone cements. However, clinical data is inconclusive on the effectiveness of antibiotic-loaded bone cements and a negative osteoblastic response has been reported for certain additive concentrations. There is therefore a need for an additive that can positively affect osteoblastic behaviour while inhibiting bacterial attachment. Silicon nitride (Si3N4) could be such an additive, with initial studies showing promise in achieving antipathogenic properties. The aim of this study was hence to investigate the possibility of creating a bone cement that can support osteoblast growth while reducing bacterial attachment by introducing silicon nitride powders into an injectable PMMA cement. To this end, commercially available bone cements were doped with 5%, 10% and 20% weight/weight (w/w) of Si3N4. Their mechanical properties were examined through compression testing and their radiopacity was evaluated through fluoroscopy imaging. The samples that fulfilled compressive strength requirements had their biological properties tested using Staphylococcus epidermidis bacteria for antibacterial properties and MC3T3-E1 preosteoblasts for the examination of cytotoxicity. Bone cements that were doped with up to 20% w/w Si3N4 were radiopaque (only 13% reduction in optical density compared to radiopaque controls) and retained their compressive strength (85.35 ± 2.1 MPa compared to 83.4 ± 1.9 MPa for the commercial cements), while significantly reducing bacterial attachment by more than 90% compared to commercial cements and achieving a similar level of preosteoblast metabolic activity. This study supports further evaluation of Si3N4 as an additive to injectable bone cements as a way to create mechanically stable, radiopaque, bacteriostatic bone cements that could improve osteointegration.

New bacteriophage-derived lysins, LysJ and LysF, with the potential to control Bacillus anthracis

Bacillus anthracis is an etiological agent of anthrax, a severe zoonotic disease that can be transmitted to people and cause high mortalities. Bacteriophages and their lytic enzymes, endolysins, have potential therapeutic value in treating infections caused by this bacterium as alternatives or complements to antibiotic therapy. They can also be used to identify and detect B. anthracis. Endolysins of two B. anthracis Wbetavirus phages, J5a and F16Ba which were described by us recently, differ significantly from the best-known B. anthracis phage endolysin PlyG from Wbetavirus genus bacteriophage Gamma and a few other Wbetavirus genus phages. They are larger than PlyG (351 vs. 233 amino acid residues), contain a signal peptide at their N-termini, and, by prediction, have a different fold of cell binding domain suggesting different structural basis of cell epitope recognition. We purified in a soluble form the modified versions of these endolysins, designated by us LysJ and LysF, respectively, and depleted of signal peptides. Both modified endolysins could lyse the B. anthracis cell wall in zymogram assays. Their activity against the living cells of B. anthracis and other species of Bacillus genus was tested by spotting on the layers of bacteria in soft agar and by assessing the reduction of optical density of bacterial suspensions. Both methods proved the effectiveness of LysJ and LysF in killing the anthrax bacilli, although the results obtained by each method differed. Additionally, the lytic efficiency of both proteins was different, which apparently correlates with differences in their amino acid sequence.Key points• LysJ and LysF are B. anthracis-targeting lysins differing from lysins studied so far• LysJ and LysF could be overproduced in E. coli in soluble and active forms• LysJ and LysF are active in killing cells of B. anthracis virulent strains

Light-degradable nanocomposite hydrogels for antibacterial wound dressing applications.

Skin injuries infected by bacteria can cause life-threatening human diseases if not treated properly. In this work, we developed a light-degradable nanocomposite hydrogel to achieve both controlled antibiotic delivery and hydrogel degradation using light as the sole stimulus. Specifically, we incorporated triclosan-loaded, poly(N-isopropylacrylamide)-based nanogels (TCS-NGs) that exhibited potent antibacterial efficacy, into a light-degradable poly (ethylene glycol) (PEG)-based hydrogel matrix via simple physical entrapment method. Upon exposure to 365 nm light, the hydrogel matrix could rapidly degrade, which subsequently released the entrapped TCS-NGs into the surrounding environment. Our results demonstrated that TCS-NGs released from light-degradable nanocomposite hydrogels still possessed remarkable antibacterial efficacy by inhibiting the growth of Staphylococcus aureus both in solution (a fivefold reduction in optical density compared to the blank control) and on bacteria-infected porcine skins (a fivefold reduction in colony-forming units compared to the blank control). Finally, using an alamarBlue assay on human dermal fibroblasts, we determined that each component of the nanocomposite hydrogel exhibited excellent biocompatibility (>90% cell viability) and would not cause significant cytotoxicity. Overall, the fabricated light-degradable nanocomposite hydrogels could serve as novel material for antibacterial wound dressing applications.

Evaluation of polymethyl-methacrylate and acetal denture base resins processed by two different techniques before and after nano-chlorohexidine surface treatment

BackgroundFlexible denture base polymers have gained popularity in modern dentistry however, their biofilm formation tendency, adversely affecting the oral tissue heath, remains a concern. Consequently, this study aimed to evaluate surface roughness and biofilm formation tendency of two types of denture base resins manufactured with two techniques before and after surface coating with chlorohexidine (CHX) NPs.Materials and methodsAcetal (AC) and Polymethyl-methacrylate (PMMA) resins manufactured by conventional and CAD/CAM methods were shaped into disk (10 X 10 X 1 mm). They were dipped for 8 h and 24 h in colloidal suspension prepared by mixing aqueous solution of CHX digluconate and hexa-metaphosphate (0.01 M). Surface roughness, optical density (OD) of microbial growth media and biofilm formation tendency were evaluated directly after coating. Elutes concentrations of released CHX were evaluated for 19 days using spectrophotometer. Three-way ANOVA and Tukey’s post-hoc statistical analysis were used to assess the outcomes.ResultsAC CAD/CAM groups showed statistically significant higher roughness before and after coating (54.703 ± 4.32 and 77.58 ± 6.07 nm, respectively). All groups showed significant reduction in OD and biofilm formation tendency after surface coating even after 19 days of CHX NPs release.ConclusionsBiofilm formation tendency was highly relevant to surface roughness of tested resins before coating. After CHX NPs coating all tested groups showed significant impact on microbial growth and reduction in biofilm formation tendency with no relation to surface roughness. Significant antimicrobial effect remained even after 19 days of NPs release and specimens storage.

Оценка зависимости скорости лизиса эритроцитов от количества микросфероцитов при наследственном сфероцитозе

INTRODUCTION: Hereditary spherocytosis (HS) is a disease, which belongs to congenital membranopathies and runs with hemolytic anemia of different severity. In patients with HS, morphologically transformed erythrocytes — microspherocytes — appear in blood in different quantities. Erythrocyte lysis rates in patients with HS are significantly higher than in individuals with no hematologic diseases in history, however, there are no studies demonstrating the relationship between the amount of microspherocytes and erythrocyte lysis rates. AIM: Was to establish correlation between erythrocyte lysis rates and the amount of microspherocytes in patients with HS. MATERIALS AND MATERIALS: Study material was venous blood of 15 patients with HS (the main group) and of 14 “healthy” individuals (control group). Venous blood was taken into test tubes with K3EDTA as an anticoagulant for calculation of morphometric parameters of erythrocytes, and into test tubes with Li-heparin for determination of erythrocyte lysis rates. Morphometric parameters of erythrocytes were calculated using VideoTesT-Morphologia hardware and software complex. For each erythrocyte, average surface area, average diameter, thickness and sphericity index were determined Erythrocyte lysis rate was determined with use of glycerol reagent (glycerol test) on Vitalon-400 semi-automatic biochemical analyzer, and was assessed by reduction of optical density of the incubation medium and expressed as the difference between the initial and final optical densities multiplied by 1 000 (standard units). Statistic data processing was carried out using parametric and non-parametric statistical methods, and Spearman correlation analysis was performed by Spearman method using Sigma-Plot 11.0 software. RESULTS: Erythrocyte lysis in glycerol test occurred faster in patients with HS than in “healthy” persons due to instability of membrane of microspherocytes which make a significant proportion of erythrocytes in peripheral blood of patients with HS. CONCLUSIONS: A proportional dependence was established between the amount of microspherocytes and increase in the rate of erythrocyte lysis, which indicates their instability typical of HS. This dependence permits to use the automated glycerol test with graphic record of erythrocyte lysis rate for detection of microspherocytes in blood of patients with HS, when morphometric hardware and software complex is not available in clinical diagnostic laboratories.

Effect of low-power diode laser on infected root canals.

This study evaluated the effect of photodynamic therapy (PDT) on infected root canals. Twenty-one human teeth were selected, and 18 were infected by E. faecalis for 60 days. The antimicrobial strategies tested were: G1. Root canal preparation (RCP) using Niquel-Titanium (NiTi) rotary instruments, 2.5% NaOCl, and final irrigation with 17% EDTA, followed by PDT with methylene blue photosensitizer and laser diode low power; G2. RCP using stainless steel files and the same irrigation and PDT protocols as G1; G3. Same RCP protocol as G1 without PDT; G4. Only irrigation with 2.5% NaOCl; G5. Same PDT protocol as G1 without RCP; G6. Negative control; G7. Positive control. Samples for microbiological tests were collected initially (S1), after RCP (S2), and after PDT (S3). Subsequently, the roots were sectioned and prepared for Scanning Electron Microscopy (SEM) analysis. Bacterial growth was analyzed according to the turbidity of the culture medium, followed by spectrophotometric optical density (nm). The effect of PDT on the dentinal structure was evaluated at magnifications 1,600X and 5,000X and described qualitatively. The Wilcoxon test was used for the comparisons from the same specimens, and the Mann-Whitney test was used to compare groups ((=5%). Bacteria were found in all experimental groups' microbiological samples (S1, S2 and S3). The optical density of culture media was lower in S2 than in S1 of G1, 2, 3, and 4 (p> 0.05). After PDT (S3) in G1 and 2, there was an additional reduction in optical density of the culture medium, respectively (p>0.05). In Group 5, the analysis of culture media at S2 revealed an increase in optical density compared to S1(p>0.05). In SEM images of G1, 2, and 5, dentin with melting and recrystallization areas were evidenced. After preparation of the root canal with the rotary system or manually associated with 2.5% NaOCl, PDT was not able to completely eliminate E. faecalis present in the root canal.

Comparison dose effects of vitamin C and zinc administration to inhibit klebsiella pneumoniae biofilms formation

Background: Klebsiella pneumoniae is a Gram-negative bacterium that form biofilm and causes various infections. Biofilms have important role in resistance to antibiotics. Alternative agents that can inhibit biofilms formation with minimal side effects is required. This study show effects of vitamin C and zinc to inhibit Klebsiella pneumoniae biofilms formation. Method: This experiment used clinically stored Klebsiella pneumoniae isolates using controls. Isolates other than control are exposed with vitamin C and zinc oral preparations with various doses invitro then Optical Density and percentage reduction in biofilm is calculated and compared. Results: Vitamin C and zinc had invitro-inhibiting effect on biofilms formation of Klebsiella pneumoniae at all doses. The differences in decrease of Optical Density biofilm from the doses used after statistical testing was significant (P < 0.05). The smallest Optical Density and the largest percentage of Optical Density reduction of biofilms is found in vitamin C 1000 mg and zinc 50 mg. Conclusion: There are differences in inhibition of biofilm formation Klebsiella pneumoniae in the administration of vitamin C and zinc, with higher dose of vitamin C and zinc, the inhibition of biofilms formation is greater.

Soot biodegradation by psychrotolerant bacterial consortia.

To probe the bioavailability of soot released into the atmosphere is pivotal to understanding their environmental impacts. Soot aerosol absorbs organic matter, creating a hot spot for biogeochemical transformation and the global carbon cycle. Soot primarily contains condensed aromatics chemically recalcitrant; however, oligotrophic microorganisms might use it as a nutritional source. This study investigated the influence of psychrotolerant bacterial consortia on soot. Significant increase in the bacterial biomass, reduction in water-insoluble organic carbon (OC) and elemental carbon (EC) in soot residues and increase in water-soluble OC in the filtrate signifies the use of soot as a carbon and nutritional source. The influence on morphology and composition of soot was reported using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy, and Energy Dispersive X-Ray analysis (EDX). The FTIR analysis showed significant variations in the pattern of soot spectra, suggesting degradation. Elemental analysis and EDX showed a reduction in carbon percentage. Besides, the reduction of optical density with incubation time signifies the OC and EC consumption. This study shows that soot can be a substrate and pivotal factor in the microbial food web. Nowadays, soot emission to the environment is growing; therefore, soot involvement in microbe-mediated processes should be closely focused.

Oxidative stress and metformin: An in-vitro study on serum and primary human granulosa cell cultures

Objective: To observe the effect of metformin on the oxidative stress (OS) levels and SIRT1 expression in primary human granulosa cell cultures from infertile females. Methods: This cross-sectional study was conducted from August 2017-July 2019 on ten infertile patients. After written informed consent, the follicular fluid of these subjects was collected for establishing primary human granulosa cell cultures (HGCs), to test the capacity of metformin to reduce OS. The cultured HGCs were divided into (i) control: HGCs without any treatment, (ii) test1: HGCs induced with H2O2 (metformin absent), and (iii) test2: HGCs treated with metformin after H2O2 induction. Baseline OS (control group) was estimated, it was induced and measured by an increase in optical density (OD) (test1 & test 2). Finally, test2 was incubated with metformin (1 ml of 100 mmol/l concentration) and it effect on the levels of OS were determined by Mishra OS assay. Effect of metformin modulating SIRT1 expression in OS-induced cells was analyzed using quantitative-PCR. Results: Age of female subjects was 32.04±2.29years and BMI was 27.61±2.15 kg/m2. Test (OS induced) samples gave an OD of 0.28 (0.16-0.40) while control HGC samples gave an OD; 0.153 (0.09-0.23). Test cells showed significant reduction in ODs after metformin treatment. The relative expression of SIRT1 in metformin untreated and treated cells was found to be 61.5% and 80%, respectively. Conclusion: Metformin was found to suppress OS in HGCs and increases the expression of SIRT1 in OS induced environment of primary cell cultures, suggesting a relationship between metformin, SIRT1 expression, and reduction of OS.

Preservation Potential of Galangal Water Extract on Tofu

Galangal (Alpinia galanga (L.) Willd.) has been long used for medicinal purposes. It showed promising effects on the food-spoilage microorganisms and is commonly used as spices in various cuisines. This study aimed to evaluate the microbial growth inhibitory activity and the preservation potential of galangal water extracts on tofu. The water extracts were prepared by infundation method in the concentrations of 5, 10, and 20%w/v. The phytochemical compounds in the extracts were screened as per standard methods. The tofu was preserved by immersion method for eight days under room temperature with an evaluation time point of two days. The microbial growth inhibitory activity was evaluated by indirect optical density (OD)-based enumeration, and the OD reduction by the extracts was calculated accordingly. The preservation potential was calculated from the changes of the physical characters on tofu evaluated by sensorial analysis. Galangal water extracts contained tannins and terpenoids. It concentration- dependently inhibited microbial growth on tofu, and the extract showed the best OD reduction at a concentration of 20%. It changed the color of tofu but maintained its texture. It also masked the odor of fresh tofu with the aromatic galangal scent. All three tested concentrations showed an equal preservation potential of 2 days. Our data suggested galangal water extract in the optimum concentration of 20% inhibited the microbial growth on tofu and potentially preserved it for two days. This moderate preservation effect might be attributable to its tannins and terpenoids content.

P–229 Oxidative stress and Metformin; an in-vitro study on serum and primary human granulosa cell cultures

Abstract Study question What is the effect of administration of Metformin on the oxidative stress (OS) levels in serum and primary human granulosa cell cultures of infertile females? Summary answer Metformin suppresses oxidative stress in serum and human granulosa cells and increases the expression of SIRT1 in OS induced environment. What is known already Oxidative stress (OS) is a resultant of mitochondrial dysfunction when it either fails to fight against the oxidants or the expression of the antioxidants is not sufficient. Cellular damage including DNA damage is a common resultant of oxidative stress. OS effects the oocyte maturation and moreover, the cleavage phase in the early embryonic stage. The raised levels of OS makers are hypothesized to compromise the nuclear maturation and the mitotic spindles of the maturing oocytes. Metformin seemed to decrease oxidative stress and improve insulin resistance, dyslipidaemia and endothelial dysfunction in PCOS patients Study design, size, duration This cross-sectional study was conducted from August 2017 – July 2019, at Aga Khan Hospital in collaboration with Australian Concept Infertility Medical Centre (ACIMC) on ten infertile patients undergoing egg retrieval after ethical approval from of Aga Khan Hospital (AKU-ERC–2018–0557–601). Participants/materials, setting, methods Serum samples were obtained and analysed. Follicular fluid of these subjects was collected for establishment of primary cell culture model of normal human granulosa cells (hGCs). Serum and hGC cultures were grouped as; a) control: treatment, b) Test1: H2O2 induced OS, and c) Test2: H2O2 induced OS treated with metformin. OS was estimated in all groups by Mishra method. The two Test groups were assessed for SIRT1 levels using quantitative PCR employing SIRT1 specific primers Main results and the role of chance With mean age of 32.04 ± 2.29 years the mean BMI was 27.61 ± 2.15 kg/m2. OS was induced and measured by an increase in optical density (OD) in hGC Test samples which showed 0.28 (0.16–0.40) OD when compared with control hGC samples 0.153 (0.09–0.23). There was a significant reduction in ODs after metformin treatment in the stress induced cells 0.182 (0.05–0.30). A similar pattern was observed in the serum samples in ODs; control: 0.105 (0.09–0.15), stress induced samples: 0.199 (0.19–0.20). and stress induced serum sample with metformin treatment: 0.1415 (0.06–0.18). The Ct values obtained to express the effect of metformin on SIRT1 levels, for OS induced (Test1) and OS induced metformin treated (Test2) cells were found to be 29.12 and 26.42, respectively. We also observed a significant (85%) difference in the fold change of SIRT1 expression between metformin treated and untreated cells. Limitations, reasons for caution Small sample size is the limitation of this study. The impact of metformin on cell cultures due to different causes of infertility could not be ascertained Wider implications of the findings: Metformin suppresses oxidative stress in serum and human granulosa cells and increases the expression of SIRT1 in OS induced environment, therefore, metformin may be considered as a treatment of oxidative stress in infertile patients. Randomized control trial with large sample size is recommended to confirm the cause and effect relationship. Trial registration number Not applicable

Morphological characteristics of Candida albicans, Candida krusei, Candida guilliermondii, and Candida glabrata biofilms, and response to farnesol.

Background and Aim:Different Candida species isolated in humans and animals have different types of parasite activity. The most pathogenic species is Candida albicans followed by Candida tropicalis. However, the effects of the morphology of Candida krusei, Candida guilliermondii, and Candida glabrata biofilms on the pathogenicity of these species have not been fully characterized. To the best of our knowledge, there is no literature on the effect of farnesol on rare Candida species. This study aimed to check the effect of different farnesol concentrations on the species C. krusei, C. guilliermondii, and C. glabrata compared with the strain C. albicans ATCC 10231, which has been widely studied, and is a strong producer of biofilms.Materials and Methods:We studied the morphological and densitometric parameters of biofilms produced by Candida species under the influence of the drug farnesol (Sigma-Aldrich, St. Louis, MO). We used a heart brain broth with the addition of 2% bovine blood serum in 96-well plates. To each well, we added 100 mL of C. albicans, C. krusei, C. guilliermondii, or C. glabrata culture, and 0.2-400 mM farnesol. The microliter plates were cultured with the lid closed at 37°C for 48 h. Then, the liquid was removed, and the wells were washed 3 times with 200 mL phosphate buffer solution (pH 7.3). Biofilm fixation was performed using 150 mL of 96% ethanol for 15 min. Then, the microliter plates were dried for 20 min at 37°C, a 0.5% solution of crystalline violet was added, and the plates were placed in an incubator at 37°C. After 5 min, the contents of the wells were removed, washed 3 times with 200 mL of phosphate buffer solution (pH 7.2), and dried. The dye was extracted by washing with 200 mL of 96% ethanol for 30 min. The results were obtained using a photometric analyzer of enzyme immunoassay reactions at an optical density (OD) wavelength of 450 nm.Results:All of Candida spp. strains tested were susceptible to farnesol at concentrations ranging from 0.8 to 400 mM for C. albicans, C. krusei, and C. guilliermondii, and 12.5 to 400 mM for C. glabrata.Conclusion:This study provides new insights into the use of farnesol against biofilms produced by Candida species, but further studies in vivo are necessary to evaluate the effectiveness of the reduction of OD. To the best of our knowledge, the antimicrobial activity of farnesol against C. krusei, C. guilliermondii, and C. glabrata has not been reported previously, although studies have confirmed the inhibitory effect of farnesol on the growth of different microorganisms.

Green synthesis, characterization applications of iron oxide nanoparticles for antialgal and wastewater bioremediation using three brown algae

This study aims at controlling excess nutrients, including nitrogen and phosphorus, and harmful algae that pollute the marine environment using biosynthesized iron oxide nanoparticles. Aqueous extracts of brown seaweeds named Petalonia fascia, Colpomenia sinuosa, and Padina pavonica were selected for iron oxide nanoparticles' biosynthesis. The extracts were used as reductants of ferric chloride, and dark brown colors due to Fe3O4-NPs biosynthesis were observed. Iron signals were recorded in EDX spectra. FTIR analyses showed that the three algae extracts contained proteins and lipids that have the ability to proceed dual functions of bioreduction and stabilization of Fe3O4-NPs, suggesting that proteins in P. fascia, C. sinuosa, and P. pavonica extracts reduced FeCl3, and the aromatic compounds stabilized the biogenic Fe3O4-NPs. The biosynthesized Fe3O4-NPs via P. pavonica had the best nitrogen reduction percentage, followed by C. sinuosa and P. fascia for both concentrations 2 and 4 µg mL−1. The best results of phosphorus removal and Chlorophyll a (Chl a) reduction percentages using the Fe3O4-NPs concentrations were 2 and 4 µg mL−1 with nanoparticles synthesized via P. fascia and P. pavonica, respectively. The highest reduction in optical density for both 2 and 4 µg mL−1 was achieved by the nanoparticles synthesized by P. fascia. Novelty Statement Application of nanoparticles using seaweeds extracts could be alternative safe bioremediation of wastewaters. Currently, iron oxide nanoparticles are used to reduce nitrogen and phosphorus and reduce the blooming of harmful algae; little information about this issue has been reported. Such study also presented the anti-algal impacts of Fe3O4-NPs by tracing optical density and Chl a concentrations in the examined real seawater samples. Modern biotechnology to develop phytoremediation and seaweeds to enhance these remediation methods can be adopted.

Macular pigment optical density after panretinal photocoagulation

ABSTRACT Clinical relevance Panretinal photocoagulation, an important treatment method in diabetic retinopathy, can affect macular pigment optical density, which has protective and antioxidant properties. As a result of this effect, the retina may become more sensitive to high‐energy visible light. Background The current study assesses the effect of panretinal photocoagulation treatment on macular pigment optical density, which has essential functions for the retina. Methods In this prospective clinical study, the colour perimetry method was used to measure macular pigment optical density. Thirty‐six eyes of 36 participants with severe non‐proliferative diabetic retinopathy without macular involvement were included in the study. Conventional panretinal photocoagulation treatments were applied at baseline, one month, two months, and at three months to the participants who clinically required this treatment. Macular pigment optical density and retinal thickness measurements were performed at baseline, months one, two, three and six. Results The mean macular pigment optical density reduction in the fovea over the six-months was 0.02 ± 0.02 logarithmic units (p < 0.001). Similarly, the pericentral areas declined by 0.04 ± 0.03 logarithmic units (p < 0.001). Mean central macular thickness and foveal thickness increased by 5.03 ± 5.02 μm and 2.78 (interquartile range 2–4) μm, respectively. In this study, correlation analysis shows that the laser energy applied was significantly and strongly correlated with reductions in macular pigment optical density (for the fovea and pericentral area respectively: r = −0.855, p < 0.001; r = −0.895, p < 0.001). Further, there were significant and strong correlations between the applied laser energy, and central macular thickness and fovea thickness (r = 0.751, p < 0.001; ρ = 0.718, p < 0.001, respectively). Conclusion Panretinal photocoagulation may potentially cause a decrease in macular pigment density in proportion to the laser energy applied.

The potential therapeutic role of PTR1 gene in non-healing anthroponotic cutaneous leishmaniasis due to Leishmania tropica.

BackgroundDrug resistance is a common phenomenon frequently observed in countries where leishmaniasis is endemic. Due to the production of the pteridine reductase enzyme (PTR1), drugs lose their efficacy, and consequently, the patient becomes unresponsive to treatment. This study aimed to compare the in vitro effect of meglumine antimoniate (MA) on non‐ healing Leishmania tropica isolates and on MA transfected non‐healing one to PTR1.MethodsTwo non‐healing and one healing isolates of L. tropica were collected from patients who received two courses or one cycle of intralesional MA along with biweekly liquid nitrogen cryotherapy or systemic treatment alone, respectively. After confirmation of L. tropica isolates by polymerase chain reaction (PCR), the recombinant plasmid pcDNA‐rPTR (antisense) was transfected via electroporation and cultured on M199. Isolates in form of promastigotes were treated with different concentrations of MA and read using an enzyme‐linked immunosorbent assay (ELISA) reader and the half inhibitory concentration (IC50) value was calculated. The amastigotes were grown in mouse macrophages and were similarly treated with various concentrations of MA. The culture glass slides were stained, and the mean number of intramacrophage amastigotes and infected macrophages were assessed in triplicate for both stages.ResultsAll three transfected isolates displayed a reduction in optical density compared with the promastigotes in respective isolates, although there was no significant difference between non‐healing and healing isolates. In contrast, in the clinical form (amastigotes), there was a significant difference between non‐healing and healing isolates (p < 0.05).ConclusionThe results indicated that the PTR1 gene reduced the efficacy of the drug, and its inhibition by antisense and could improve the treatment of non‐healing cases. These findings have future implications in the prophylactic and therapeutic modality of non‐ healing Leishmania isolates to drug.

Using autochthonous Bdellovibrio as a predatory bacterium for reduction of Gram-negative pathogenic bacteria in urban wastewater and reuse it.

Background and Objectives:The microbial contamination of wastewater is associated with health risks. The aim of this study was to use the autochthonous Bdellovibrio potential to prey Gram-negative pathogenic bacteria as a bio-control agent to treat urban wastewater.Materials and Methods:Thirty-six raw sewage samples were collected for isolation of Bdellovibrio. Double layer plaque assay was used for isolation and the isolates were identified by microscopic examination and molecular analysis. To evaluate the predatory potential for decrease number of Gram-negative pathogenic bacteria, plaque perdition assay, reduction in host cells viability by colony-forming unit (CFU) counting, reduction in optical density (OD) in co-cultures and assay of killing efficiency were carried out. Also, the raw wastewater was treated by Bdellovibrio then the reduction in CFU counting and reduction in OD was evaluated.Results:Four strains of Bdellovibrio were isolated and were registered in Gene Bank. Clear plaques were observed after 3–6 days of incubation for all prey cells. The CFU enumerations of all preys were decreased after 48 hrs in co-cultures and raw wastewater. Also, OD was decreased down to 0.2 nm after 48 hrs.Conclusion:These autochthonous Bdellovibrio strains are proposed to use for bio-control of Gram-negative pathogenic bacteria in wastewater and reuse it for irrigation in arid regions.

Laser-induced twisting of phosphorus functionalized thiazolotriazole as a way of cholinesterase activity change.

Herein, the synthesis, design, and the physicochemical characterization of phosphorus functionalized thiazolotriazole (PFT) compound are presented. The PFT tests on the biological activity revealed butyrylcholinesterase inhibition that was confirmed and explained with molecular docking studies. The pronounced reduction of optical density and biological activity was found as a result of irradiation of the PFT water solution with laser beam at wavelength 266nm. The observed phenomenon was explained on the base of molecular dynamics, docking, and density functional theory modeling by the formation of PFT conformers via laser-induced phosphonate group twisting. The reorganization of the PFT geometry was found to be a reason of butyrylcholinesterase inhibition mechanism change and the site-specificity loss. These results demonstrate that PFT combines photoswitching and bioactive properties in one molecule that makes it promising as a molecular basis for the further design of bioactive substances with photosensitive properties based on the mechanism of the phosphonate group phototwisting.

Ascorbic Acid Changes Growth of Food-Borne Pathogens in the Early Stage of Biofilm Formation.

Since bacterial biofilm may contribute to the secondary contamination of food during the manufacturing/processing stage there is a need for new methods allowing its effective eradication. Application of food additives such as vitamin C already used in food industry as antioxidant food industry antioxidants may be a promising solution. The aim of this research was evaluation of the impact of vitamin C (ascorbic acid), in a range of concentrations 2.50 µg mL−1–25.0 mg mL−1, on biofilms of Staphylococcus aureus, Escherichia coli, and Listeria monocytogenes strains isolated from food. The efficacy of ascorbic acid was assessed based on the reduction of optical density (λ = 595 nm). The greatest elimination of the biofilm was achieved at the concentration of vitamin C of 25.0 mg mL−1. The effect of the vitamin C on biofilm, however, was strain dependent. The concentration of 25.0 mg mL−1 reduced 93.4%, 74.9%, and 40.5% of E. coli, L. monocytogenes, and S. aureus number, respectively. For E. coli and S. aureus lower concentrations were ineffective. In turn, for L. monocytogenes the biofilm inhibition was observed even at the concentration of 0.25 mg mL−1. The addition of vitamin C may be helpful in the elimination of bacterial biofilms. Nonetheless, some concentrations can induce growth of the pathogens, posing risk for the consumers’ health.

EVALUATION OF IN VITRO HEPATIC TOXICITY OF LEAVES OF PTEROSPERMUM ACERIFOLIUM (L.) WILLD.

Objective: The objective of the study was to determine the in vitro hepatic toxicity profile of methanolic extract of leaves of Pterospermum acerifolium (L.) Willd. (MEPA) using a mammalian hepatic cell line (HepG2).&#x0D; Methods: To assess its in vitro hepatic toxicity, 3-(4,5-dimethylthiazol-2-yl)-2,5-2,5-diphenyltetrazolium bromide assay using MEPA at a concentration of 25 μg, 50 μg, 100 μg, 200 μg, and 300 μg was carried out. Sorafenib tosylate was used as the standard agent to assess cytotoxicity.&#x0D; Results: The inhibitory concentration 50 (IC50) value for HepG2 cell lines was determined after 24 h. Thereafter the cytotoxicity study was again performed with the ½ IC50, IC50, and 2IC50 doses of MEPA. Experimentally, the IC50 was found to be 150.42 μg/ml for HepG2 using MEPA. A dose-dependent cytotoxicity and reduction in optical density were also observed with incremental MEPA administration.&#x0D; Conclusion: The cytotoxic potential of MEPA was found to be much less than that of sorafenib tosylate. Thus, MEPA shows in vitro cytotoxicity in mammalian hepatic cells (HepG2) at a concentration as low as 100 μg.