Impact of Biofilms on Surface Properties of Polymethyl Methacrylate (PMMA) Resins.

Poly(methyl methacrylate) (PMMA) resins are widely used in medical and dental applications. Their susceptibility to bacterial biofilm formation poses significant challenges related to material degradation and infection risk. This study investigated the effects of Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) biofilms on PMMA resin surface properties over a 45-day period at 35°C. The study examined various parameters including biofilm adhesion, morphology, surface roughness, hydrophobicity, solid fraction, and zeta potential. PMMA resin specimens were inoculated with bacteria and incubated for 45 days. Biofilm adhesion was visually assessed, while surface characterization was conducted using scanning electron microscopy (SEM), atomic force microscopy (AFM), roughness analysis, contact angle measurements, solid fraction determination, and zeta potential analysis. The P. aeruginosa and S. aureus isolates were selected based on their biofilm-positive characteristics, which were further confirmed using Congo red and biofilm formation assays through crystal violet staining and spectrophotometric analysis. The results demonstrated robust biofilm adhesion on PMMA surfaces. SEM and AFM imaging revealed textured surfaces with elevated structures and depressions within the biofilm matrix. Biofilm-exposed resins exhibited significantly increased roughness (Ra = 164.5 nm, Rq = 169.5 nm) and hydrophobicity (mean angle = 85.5°-90.5°) compared to control samples (Ra = 38-50 nm, angle = 55°). Solid fraction measurements indicated a denser biofilm matrix on exposed resins (0.908) compared to controls (0.65). Additionally, zeta potential values were more negative for biofilm-exposed resins (mean = -84.2 mV) than controls (-45.0 mV). These findings underscore the substantial alterations in PMMA resin surface properties induced by bacterial biofilms, emphasizing the critical need for strategies to prevent biofilm formation and mitigate associated risks in healthcare settings. Future research should focus on developing anti-biofilm coatings or treatments to preserve the integrity and functionality of PMMA materials.

Navigating the threat of African swine fever: a comprehensive review.

African swine fever (ASF) is caused by Asfivirus and has become one of the most important diseases of swine in recent years. ASF was an endemic disease of the sub-Saharan Africa but later spread to various parts of the world. The infection in ticks and wild swine, alongside global pork trade, drives its spread and persistence. Once introduced to an area, the disease is difficult to eliminate due to sylvatic, domestic, and tick-swine transmission cycles. Because of the existence of various modes of transmission of the ASF virus, biosecurity measures have not been very successful. The line of treatment is not of much use and the outcome of this disease is usually fatal. The prognosis or the recovery of the animal depends on the virulence of the strain involved. Development of vaccines has been attempted but to date has not been very successful. This review focuses on the basic context of ASF, the challenges associated with it, and the options that might be available to prevent its occurrence which includes the different vaccine development strategies tried and tested till now.

Evaluation of the Impact of Irradiance Lamps and Storage Media on Elution of TEGDMA from Dental Composites.

OBJECTIVES: The aim of this study was to evaluate and compare the effect of irradiance light and storage media on the elution of triethylene glycol dimethacrylate (TEGDMA) from conventional Filtek Z350XT 3M ESPE and two bulk-fill composites Shofu Beautifil-Bulk and Filtek Bulk fill flowable 3M ESPE using high-performance liquid chromatography (HPLC). MATERIALS AND METHODS: Shofu Beautifil-Bulk, Filtek Bulk fill flowable 3M ESPE, and Filtek Z350XT 3M ESPE were the three types of composites used in this study. Disk shaped samples of 4-mm thickness and 10-mm diameter were fabricated using a stainless steel mold and were polymerized using light emitting diode (LED) and quartz tungsten halogen (QTH) lamps. After polymerization, the samples were immersed in ethanol, artificial saliva with betel quid extract, and distilled water for 1, 7, and 30 days, respectively. The elution of monomer TEGDMA was evaluated using HPLC. STATISTICAL ANALYSIS: To evaluate the mean concentration difference, mixed way analysis of variance (ANOVA) was applied. Between different light, materials, and within the time duration, Tukey's post hoc test was used. A p value of 0.05 was considered significant. RESULTS: During the first day of storage, a significant amount of monomer TEGDMA elution was seen in all the materials. The highest values observed to be in the disks cured with QTH lamp. However, the highest elution was seen when the disks were immersed in ethanol/water solution. While the most stable medium was distilled water, artificial saliva with betel nut extract also had a significant effect on the elution of TEGDMA. The highest value obtained was of Filtek Bulk fill flowable 3M ESPE after 30 days of immersion in both LED and QTH cured disks. CONCLUSION: Filtek Bulk fill flowable 3M ESPE shows better properties in relation to the release of monomer TEGDMA as it releases less amount of monomer in the storage media. The release of monomer was highest in ethanol as compared to artificial saliva and distilled water with the passage of time.

Silicon nanoparticles: A promising approach for control of Pseudomonas aeruginosa biofilms.

Objectives: The current study aimed to investigate the control and treatment of biofilm-producing isolates of Pseudomonas aeruginosa using silicon nanoparticles (SiNPs). Materials and Methods: Biofilm-producing isolates of P. aeruginosa were recovered from various food samples and identified through fluorescent green colony formation on selective and differential media, as well as the amplification of oprI and oprL genes. Tube methods, Congo-red agar method, and scanning electron microscopy (SEM) were used to study biofilm phenotypes. The effect of SiNPs was evaluated by broth dilution assay. Results: The biofilm assay revealed that these isolates formed biofilms on glass surfaces within 72 hr of incubation. Scanning electron micrographs showed that the biofilm communities were composed of multicellular clusters of P. aeruginosa encased in matrix material. However, these isolates were unable to form biofilms on SiNPs-coated surfaces. The results showed that the planktonic isolates of P. aeruginosa were comparatively sensitive to the antibacterial properties of SiNPs, with minimum inhibitory concentration (MIC) ranging from 100 to 200 µg/ml. Contrarily, the biofilms were found to be 500 times more tolerant to the highest concentration of SiNPs (MIC of 500 µg/ml) and were more resistant. Under static conditions, the sedimentation of SiNPs resulted in their ineffectiveness. However, under shaking conditions, the biofilms were effectively dispersed and the cells were lysed. The results showed that SiNPs were effective against both the planktonic and the metabolically inactive forms of P. aeruginosa. Conclusion: This study suggests that SiNPs could be a useful tool for preventing the formation of biofilms and removing pre-existing biofilms.

Post COVID-19 AA amyloidosis of the kidneys with rapidly progressive renal failure.

Coronavirus disease 2019 (COVID-19) pandemic has taken the world by a storm, posing a gruelling challenge to the medical fraternity globally. Besides its very high infectivityinfectivity, significant organ dysfunction occurs in critically ill COVID-19 patients, leading to severe morbidity and mortality. Pulmonary involvement is the leading cause of death in these patients to be followed by the cardiovascular involvement. Kidney involvement due to COVID-19 is becoming more discernible with AKI adversely affecting the outcome. Besides AKI, a few cases of collapsing FSGS in genetically vulnerable patients and thrombotic microangiopathies have been reported as well. We report a case of AA amyloidosis of the kidney with a rapidly progressive renal failure and congestive heart failure with preserved left ventricular functions, which complicated a moderate COVID-19 pneumonia providing some clues to a possible association of this novel virus disease with this complication, which needs to be confirmed in future studies.

In vitro anticancer activities of Withania coagulans against HeLa, MCF-7, RD, RG2, and INS-1 cancer cells and phytochemical analysis.

BACKGROUND: The Pakistani Salt Range has a rich floral diversity including Withania coagulans from the Solanaceae family. METHODS: The crude methanolic extracts of the root, leaf, leaf stalk, and fruit of this plant were screened for their cytotoxic activity against human (HeLa, MCF-7, RD) and rat (RG2 and INS-1) cancer cell lines at 20 µg/mL and compared to methotrexate. The IC50 values indicated that leaf stalk and fruit extracts exert an 80% or higher cytotoxic activity against all cell lines at 24 hours. RESULTS: The leaf stalk extract showed the highest cytotoxic efficacy against all tested cell lines, with IC50 values ranging from 0.96 ± 0.01 µg/mL to 4.73 ± 0.05 µg/mL followed by the fruit extract with IC50 values of 0.69 ± 0.01-6.69 ± 0.06 µg/mL after 48-72 hours incubation. The leaf stalk and seed extracts were analyzed for polyphenols and flavonoids using RP-HPLC. The total flavonoid content (TFC) was calculated for all tested samples, and the highest TFC was recorded for the root extract (394.34 ± 1.26 µg/g). The total phenolic content (TPC) was found in the seed extract (307.86 ± 9.42 µg/g) of W. coagulans. The highest contents of myricetin (358.46 ± 2.91 µg/g) were noted in the leaf extract, and highest quercetin was recorded in the seed extract (21.43 ± 0.13 µg/g). The highest gallic acid concentration (83.62 ± 0.71 µg/g) was recorded in leaf stalk extract and p-hydroxybenzoic acid in the seed extract (157.46 ± 1.43 µg/g). CONCLUSION: The present study gives a scientific insight and comparative analysis of various plant parts in this medicinally important plant species from the Salt Range of Pakistan against both human and rat cancer cells.

Enhancement of memory function by antioxidant potential of Nigella sativa L. oil in restrained rats.

Stress is a vulnerable state to cellular homeostasis which leads to oxidative damage via free radical generation. The acute stress induces alteration in antioxidant enzyme activities to an extent which produce oxidative stress and causes certain pathological conditions. The use of Nigella sativa L. oil (NSO) in folk medicine has increased throughout the world for the prevention or treatment of various ailments because of potent antioxidant properties. In the present study, potential therapeutic effects of NSO on memory in both unrestrained and 2h restrained rats were observed. Shortterm memory (STM) and long-term memory (LTM) were assessed by elevated plus maze (EPM) and Morris water maze (MWM) respectively. The present study also demonstrated the effect of NSO on lipid peroxidation (LPO) and activities of antioxidant enzymes (superoxide dismutase, catalase and glutathione peroxidase) along with the activity of acetyl cholinesterase (AChE). The results obtained from the present study showed that 2h restraint stress significantly enhanced both short-term memory (p<0.01) and long-term memory (p<0.05) in rats. Pretreatment with NSO at a dose of 0.2ml/kg/day also significantly improved STM (p<0.05) in restrained rats and LTM (p<0.01) in unrestrained rats. This study also showed significantly decreased (p<0.01) LPO and significantly increased (p<0.01) endogenous antioxidant enzymes activity in NSO treated restrained rats. Similarly significant decreased (p<0.01) AChE activity was also observed in NSO treated unrestrained and 2h restrained rats. Therefore, current findings suggested that repeated administration of NSO may exert memory enhancing effects against restrained stress and it can be used for therapeutic purpose because of having fewer side effects.

Ectopic Expression of Plant RNA Chaperone Offering Multiple Stress Tolerance in E. coli.

Members of the plant glycine-rich RNA-binding proteins (GR-RBPs) family have been reported in flowering, development, circadian rhythms, biotic and abiotic stresses. Particularly, GR-RBPs are reported to function as RNA chaperones, promoting growth and acclimation during cold shock. It is indispensable to further question the efficacy and mechanism of GR-RBPs under various environmental strains. Monitoring the expression of stress-regulated proteins under stress conditions has been a beneficial strategy to study their functional roles. In an effort to elucidate the NtGR-RBP1 function, stress markers such as salinity, drought, low temperature and heat stresses were studied. The NtGR-RBP1 gene was expressed in E. coli followed by the exposure to stress conditions. Recombinant E. coli expressing NtGR-RBP1 were more tolerant to stresses, e.g., salinity, drought, cold and heat shock. Recombinants exhibited higher growth rates compared to control in spot assays. The tolerance was further confirmed by monitoring the growth in liquid culture assays. Cells expressing NtGR-RBP1 under salt (500 mM NaCl), drought (20% PEG), cold (4 and 20 °C) and heat stresses (50 °C) had enhanced growing ability and better endurance. Our study supports the notion that the protective role of NtGR-RBP1 may contribute to growth and survival during diverse environmental stresses.

The broad spectrum 2-oxoglutarate oxygenase inhibitor N-oxalylglycine is present in rhubarb and spinach leaves.

2-Oxoglutarate (2OG) and ferrous iron dependent oxygenases are involved in many biological processes in organisms ranging from humans (where some are therapeutic targets) to plants. These enzymes are of significant biomedicinal interest because of their roles in hypoxic signaling and epigenetic regulation. Synthetic N-oxalylglycine (NOG) has been identified as a broad-spectrum 2OG oxygenase inhibitor and is currently widely used in studies on the hypoxic response and chromatin modifications in animals. We report the identification of NOG as a natural product present in Rheum rhabarbarum (rhubarb) and Spinach oleracea (spinach) leaves; NOG was not observed in Escherchia coli or human embryonic kidney cells (HEK 293T). The finding presents the possibility that NOG plays a natural role in regulating gene expression by inhibiting 2OG dependent oxygenases. This has significance because tricarboxylic acid cycle (TCA) intermediate inhibition of 2OG dependent oxygenases has attracted major interest in cancer research.

Longipetalosides A-C, new steroidal saponins from Tribulus longipetalus.

Longipetalosides A-C (1-3); three new furostane steroidal saponins together with (25S)-5α-furastan-3ß,22,26-triol (4) and gitogenin (5) were isolated from the methanolic extract of the whole plant of Tribulus longipetalus. The structures of these compounds (1-5) were established by using 1D ((1)H, (13)C) and 2D NMR (HMQC, HMBC, COSY, NOESY) spectroscopy, and mass spectrometry (ESIMS, HRESIMS), and in comparison with literature data reported for related compounds. Compounds 1-5 were evaluated for their inhibitory activities against enzymes α-glucosidase, lipoxygenase, acetylcholinesterase, and butyrylcholinesterase. Only the compounds 4 and 5 were found as the inhibitors of enzyme α-glucosidase with IC50 values of 33.5±0.22 and 37.2±0.18µM, respectively.

Isolation of natural compounds from Phlomis stewartii showing α-glucosidase inhibitory activity.

Stewartiiside (1), a phenylethanoid glycoside and three 28-nortriterpenoids: stewertiisins A-C [(17R)-19(18→17)-abeo-3α,18ß,23,24-tetrahydroxy-28-norolean-12-ene, 2; (17R)-19(18→17)-abeo-2α,16ß,18ß,23,24-pentahydroxy-28-norolean-12-en-3-one, 3; (17R)-19(18→17)-abeo-2α,3α,23,24-tetrahydroxy-28-noroleane-11,13-diene, 4] together with eight known compounds: lunariifolioside (5), notohamosin A (6), phlomispentanol (7), isorhamnetin 3-(6-p-coumaroyl)-ß-D-glucopyranoside (8), tiliroside (9), caffeic acid (10), p-hydrxybenzoic acid (11) and oleanolic acid (12) were isolated from the ethyl acetate soluble fraction of the methanolic extract of whole plant of Phlomis stewartii. The structures of these isolates (1-12) were elucidated by the combination of 1D ((1)H and (13)C NMR), 2D (HMQC, HMBC COSY, NOESY) NMR spectroscopy and mass spectrometry (EIMS, HREIMS, FABMS, HRFABMS) and in comparison with literature data of related compounds. All the isolates (1-12) showed α-glucosidase inhibitory activity with IC50 values ranging between 14.5 and 355.4 µM, whereas, compounds 1, 5, 9 and 10 showed promising α-glucosidase inhibitory activity with IC50 values below 30 µM.

New lipoxygenase inhibitory sphingolipids from Chrozophora plicata.

Two new sphingolipids plicatin A [(2S,3S,4R)-2-{[(2R)-2-hydroxyoctdecanoyl]amino}hexaeicosane-1,3,4-triol (1)] and plicatin B [(2S,3S,4R,10E)-2-{[(2R)-2-hydroxyoctdecanoyl]amino}tricont-10-ene-1,3,4-triol (2)], together with 4-hydroxybenzaldehyde, scopoletin, uracil, and dl-threonolactone were isolated from the methanolic extract of the whole plant of Chrozophora plicata. The structures of these compounds were established using 1D ((1)H, (13)C) and 2D NMR (HMQC, HMBC, and COSY) spectroscopy and mass spectrometry (EI-MS and HR-EI-MS) and in comparison with the reported data in the literature. Compounds 1 and 2 showed inhibitory potential against enzyme lipoxygenase with IC50 values 195.1 and 102.3 µM, respectively.

Cholinesterase inhibitory constituents from Ficus bengalensis.

Bengalensinone (22ß-hydroxylup-12,20-dien-3-one; 1), a new lupane triterpene, and benganoic acid (2), a new apocarotenoid, together with lupanyl acetate, 3-acetoxy-9(11),12-ursandiene, stigmasterol, alpinumisoflavone, 4-hydroxyacetophenone, 4-hydroxybenzoic acid, 4-hydroxymellein, and p-coumeric acid were isolated from the methanolic extract of the aerial roots of Ficus bengalensis. The structures of these compounds were established by the combination of 1D NMR (¹H and ¹³C NMR) and 2D NMR (HMQC, HMBC, and COSY) analyses, and mass spectrometry (EI-MS and HR-EI-MS), and in comparison with literature data of the related compounds. Compounds 1 and 2 displayed inhibitory potential against enzyme cholinesterase in a concentration-dependent manner with IC50 values 194.5 and 154.5 µM for acetylcholinesterase and 224.9 and 120.0 µM for butyrycholinesterase, respectively.