Biofilm-forming microorganisms causing hospital-acquired infections from intravenous catheter: A systematic review.

The high prevalence of nosocomial infections is related to the use of medical insertion devices such as central venous catheters (CVCs). Most of the microorganisms causing nosocomial infections are biofilm producers, this characteristic allows them to adhere to abiotic surfaces and cause initial catheter infections that can lead to bloodstream infections. Our main goal in this systematic review was to evaluate the prevalence of biofilm among CVC-related infections, particularly among Intensive Care Unit (ICU) patients, in the studies applying different in vitro and in vivo methodologies. All studies reporting clinical isolates from patients with catheter-related nosocomial infections and biofilm evaluation published up to 24 June 2022 in the PubMed and Scopus databases were included. Twenty-five studies met the eligibility criteria and were included in this systematic review for analysis. Different methodologies were applied in the assessment of biofilm-forming microorganisms including in vitro assays, catheter-infected in vitro, and in vivo mouse models. The present study showed that between 59 and 100% of clinical isolates were able to form biofilms, and the prevalence rate of biofilm formation varied significantly between studies from different countries and regions. Among the clinical isolates collected in our study set, a wide variety of microorganisms including Gram-positive strains, Gram-negative strains, and Candida albicans were found. Many authors studied resistance mechanisms and genes related to biofilm development and surface adherence properties. In some cases, the studies also evaluated biofilm inhibition assays using various kinds of catheter coatings.

Ziziphus abyssinica root bark extract ameliorates paracetamol-induced liver toxicity in rats possibly via the attenuation of oxidative stress.

Ziziphus abyssinica root bark is widely used in folk medicine to manage liver diseases, particularly, jaundice but its effect on paracetamol-induced liver toxicity (PILT) has not yet been validated. This study explored the ameliorative effect of ethanolic root bark extract of Ziziphus abyssinica (ZAE) against PILT in rats. The flavonoid and phenolic content of ZAE was evaluated using Folin-Ciocalteau and aluminium trichloride colorimetric methods, respectively. Antioxidant activity of ZAE was determined in vitro by evaluating its ferrous reducing antioxidant capacity (FRAC) as well as DPPH and nitic oxide (NO) radicals scavenging activities. Sprague-Dawley rats were assigned to six groups (n = 6) and administered with normal saline (10 mL/kg, p.o.), N-acetylcysteine (50 mg/kg, i.p.) and ZAE (30, 100, and 300 mg/kg, p.o.) respectively for seven days after which they received paracetamol (PCM, 3000 mg/kg, p.o.). Animals were sacrificed 48 h after paracetamol administration under light anaesthesia and assessed for liver toxicity and oxidative stress. Total flavonoid and phenolic contents of ZAE were 1313.425 µg/mL quercetin equivalence and 268.31 µg/mL gallic acid equivalence respectively. ZAE exhibited marked FRAC as well as DPPH and NO radical scavenging activities with IC50s of 80.41 ± 1.56, 67.56 ± 1.11 and 7.11 ± 1.48 µg/mL respectively. ZAE and N-acetylcysteine significantly (p < 0.05) reduced the paracetamol-mediated elevation of serum total bilirubin, proteins and activity of liver enzymes (AST, ALP, and ALT). Similarly, ZAE increased hepatic glutathione, total thiols and catalase activity of the paracetamol intoxicated rats. Morphological changes associated with the paracetamol hepatotoxicity were also ameliorated by ZAE. Overall, the hepatoprotective effect of ZAE may be related to its antioxidant property.

PP2A is activated by cytochrome c upon formation of a diffuse encounter complex with SET/TAF-Iß.

Intrinsic protein flexibility is of overwhelming relevance for intermolecular recognition and adaptability of highly dynamic ensemble of complexes, and the phenomenon is essential for the understanding of numerous biological processes. These conformational ensembles-encounter complexes-lack a unique organization, which prevents the determination of well-defined high resolution structures. This is the case for complexes involving the oncoprotein SET/template-activating factor-Iß (SET/TAF-Iß), a histone chaperone whose functions and interactions are significantly affected by its intrinsic structural plasticity. Besides its role in chromatin remodeling, SET/TAF-Iß is an inhibitor of protein phosphatase 2A (PP2A), which is a key phosphatase counteracting transcription and signaling events controlling the activity of DNA damage response (DDR) mediators. During DDR, SET/TAF-Iß is sequestered by cytochrome c (Cc) upon migration of the hemeprotein from mitochondria to the cell nucleus. Here, we report that the nuclear SET/TAF-Iß:Cc polyconformational ensemble is able to activate PP2A. In particular, the N-end folded, globular region of SET/TAF-Iß (a.k.a. SET/TAF-Iß ΔC)-which exhibits an unexpected, intrinsically highly dynamic behavior-is sufficient to be recognized by Cc in a diffuse encounter manner. Cc-mediated blocking of PP2A inhibition is deciphered using an integrated structural and computational approach, combining small-angle X-ray scattering, electron paramagnetic resonance, nuclear magnetic resonance, calorimetry and molecular dynamics simulations.

Inhibition of Porphyromonas gingivalis peptidyl arginine deiminase, a virulence factor, by antioxidant-rich Cratoxylum cochinchinense: In vitro and in silico evaluation.

Porphyromonas gingivalis, the cause of periodontitis, is also linked to many systemic disorders due to its citrullination capability from a unique peptidyl arginine deiminase (PPAD). Protein citrullination is able to trigger an autoimmune response, increasing the severity of rheumatoid arthritis. The main objective of this study is to evaluate the inhibitory activity of Cratoxylym cochinchinense leaves extract towards the PPAD in vitro and in silico. Methanolic extract of Cratoxylum cochinchinense (CCM) was tested for total phenolic and flavonoid contents along with antioxidative assays. Inhibition of PPAD activities was conducted thereafter using recombinant PPAD in cell lysate. Phytocompounds postulated present in the CCM such as mangiferin, vismiaquinone A, δ-tocotrienol and α-tocotrienol and canophyllol were used as ligands in a simulated docking study against PPAD. Results obtained indicated high antioxidant potential in CCM while recording abundant phenolic (129.0 ± 2.5495 mg GA/g crude extract) and flavonoid (159.0 ± 2.1529 mg QE/g crude extract) contents. A dose-dependent inhibition of PPAD was observed when CCM was evaluated at various concentrations. CCM at 1 mg/mL exhibited citrulline concentration of 24.37 ± 3.25 mM which was 5 times lower than the negative control (114.23 ± 3.31 mM). Molecular docking simulation revealed that mangiferin and vismiaquinone A engaged in H-bonding and pi-pi interactions with important active site residues (Asp130, Arg152, Arg154 and Trp127) of PPAD and could be the potential phytochemicals that accounted for the inhibitory activities observed in the methanolic leaves extract. As such, CCM could be further explored for its therapeutic properties not only for periodontitis, but also for other systemic diseases like rheumatoid arthritis.

DNA damage by Withanone as a potential cause of liver toxicity observed for herbal products of Withania somnifera (Ashwagandha).

Withania somnifera, commonly known as Ashwagandha, is a medicinal plant used for thousands of years for various remedies. Extracts of Ashwagandha contain more than 200 metabolites, with withanone (win) being one of the major ones responsible for many of its medicinal properties. Recently, several cases of liver toxicity resulting from commercially available Ashwagandha products have been reported. The first report of Ashwagandha-related liver damage was from Japan, which was quickly resolved after drug-withdrawal. Later, similar cases of liver toxicity due to Ashwagandha consumption were reported from the USA and Iceland. Towards understanding the liver toxicity of Ashwagandha extracts, we studied win, a representative withanolide having toxicophores or structural alerts that are commonly associated with adverse drug reactions. We found that win can form non-labile adducts with the nucleosides dG, dA, and dC. Using various biochemical assays, we showed that win forms adducts in DNA and interfere with its biological property. Win also forms adducts with amines and this process is reversible. Based on the data presented here we concluded that win is detoxified by GSH but under limiting GSH levels it can cause DNA damage. The work presented here provides a potential mechanism for the reported Ashwagandha-mediated liver damage.

Association of Angiotensin-Converting Enzyme gene polymorphism in Pakistani women with the atypical steroidogenesis in Polycystic ovarian syndrome: A case-control study.

BACKGROUND: Polymorphism in the angiotensin-converting enzyme gene (ACE) is responsible for elevated ACE concentrations in plasma. High ACE levels induce insulin resistance and hyperandrogenism, which are the main attributes of polycystic ovary syndrome (PCOS). Therefore, it was hypothesized that I/D polymorphism plays a role in the pathogenesis of PCOS. OBJECTIVE: A case-control study was designed to investigate the association of I/D polymorphism of the ACE gene with PCOS in Pakistani women of reproductive age. METHODS: ACE I/D polymorphism was assessed in 252 women of age group 16-40 years. For genotypic analysis, PCR amplification of genomic DNA was carried out. Statistical analysis was performed to interpret the results using SPSS software. RESULTS: Our study showed that PCOS women were more likely to have a high body mass index and waist circumferences. Most PCOS patients had menstrual irregularities 99.3%, hirsutism 75.2% and cysts in ovaries 66.6%, along with other hyperandrogenic conditions (P-value = 0.001). The genotypic and allelic frequencies were significantly different between patients and controls. There was a significant association of three genotypes with the ratio of LH: FSH among PCOS patients (P = 0.05). Anthropometric characters, comorbidities, clinical symptoms, and PCOS conditions showed no statistical significance with ACE polymorphism. CONCLUSIONS: ACE I/D polymorphism was not found associated with clinical conditions of PCOS in women of reproductive age. However, it was associated with atypical steroidogenesis. So, it indicates that ACE I/D polymorphism aggravates the pathogenesis of PCOS.

Artemisia judaica L. diminishes diabetes-induced reproductive dysfunction in male rats via activation of Nrf2/HO-1-mediated antioxidant responses.

Diabetes mellitus is a well-known danger element for the progression of male reproductive dysfunctions. Available evidence supports oxidative stress to be the underlying mechanism for the manifestation of testicular dysfunctions during diabetes, and this relation represents an attractive target to antagonize these complications. Artemisia judaica L. is known to have antidiabetic and antioxidant characteristics. The possible protective effect of Artemisia judaica against diabetes-induced testicular disorders was not explored. In this investigation, we planned to estimate the possible protective effect of Artemisia judaica extract against diabetes-induced testicular disorders in male rats. The blood levels of insulin, glucose, glycosylated hemoglobin, testosterone, luteinizing hormone and follicle stimulating hormone were evaluated in rats after 12 weeks of Artemisia judaica treatment. Further, oxidative stress markers were determined in their testicular tissue. Epididymal fluid and testicular histological changes were also assessed. Expression of proliferating cell nuclear antigen has been evaluated in testis. Testicular mRNA expression of nuclear factor erythroid 2-related factor 2 and heme oxygenase-1 as the significant transcription factors in controlling antioxidant system were evaluated by real-time polymerase chain reaction. Artemisia judaica extracts have the ability to ameliorate the elevation in the serum glucose and blood glycosylated hemoglobin and the reduction in insulin, testosterone, follicle stimulating hormone and luteinizing hormone caused by streptozotocin-induced diabetes. It induced a significant recovery of the testicular oxidative stress markers, sperm characteristics and improved histopathological findings of the testes. Treatment with Artemisia judaica extracts led to an increase in proliferating cell nuclear antigen protein expression. Reduction of testicular oxidative stress potential in streptozotocin-treated groups was confirmed by upregulation of nuclear factor erythroid 2-related factor 2 and heme oxygenase-1.

Increased Afterload Augments Sunitinib-Induced Cardiotoxicity in an Engineered Cardiac Microtissue Model.

Sunitinib, a multitargeted oral tyrosine kinase inhibitor, used widely to treat solid tumors, results in hypertension in up to 47% and left ventricular dysfunction in up to 19% of treated individuals. The relative contribution of afterload toward inducing cardiac dysfunction with sunitinib treatment remains unknown. We created a preclinical model of sunitinib cardiotoxicity using engineered microtissues that exhibited cardiomyocyte death, decreases in force generation, and spontaneous beating at clinically relevant doses. Simulated increases in afterload augmented sunitinib cardiotoxicity in both rat and human microtissues, which suggest that antihypertensive therapy may be a strategy to prevent left ventricular dysfunction in patients treated with sunitinib.

28-day inhalation toxicity of 3-methoxybutyl chloroformate in rats.

The 28-day repeated inhalation study was applied for hazard assessment of 3-methoxybutyl chloroformate (3-MBCF) in Sprague Dawley rats. Groups of five rats per sex were exposed 6 h/day, 5 days per week for 4 weeks to test substance concentration (ranging from 3 to 12 ppm) using a whole-body exposure system. At the terminal sacrifice, following blood collection and gross pathological examination, organ weights were determined and fixed organs were examined. The micronucleus test was performed using bone marrow cells. Exposure of 3-MBCF induced mortality at concentrations above 6 ppm. Decreases in body weight and food intake, hematologic alterations, organ weight changes, and gross and microscopic findings were seen even at the lowest concentrations of 3 ppm. Histopathology revealed principal test substance exposure correlated with lesions in the respiratory tract in both male and female rats above 3 ppm. Groups of male rats exposed above 6 ppm show microscopic lesions in spleens, livers, testes and epididymides; however, the micronucleated polychromatic erythrocytes frequency in bone marrow cells was not changed. Based on histopathology of the respiratory tract and other organs, the no observed adverse effect level (NOAEL) of 3-MBCF in the present study was less than 3 ppm.

Flame retardant tris(1,3-dichloro-2-propyl)phosphate (TDCPP) toxicity is attenuated by N-acetylcysteine in human kidney cells.

Prolonged exposure to the flame retardants found in many household products and building materials is associated with adverse developmental, reproductive, and carcinogenic consequences. While these compounds have been studied in numerous epidemiological and animal models, less is known about the effects of flame retardant exposure on cell function. This study evaluated the toxicity of the commonly used fire retardant tris(1,3-dichloro-2-propyl)phosphate (TDCPP) in cell line derived from the kidney, a major tissue target of organohalogen toxicity. TDCPP inhibited cell growth at lower concentrations (IC50 27 µM), while cell viability and toxicity were affected at higher concentrations (IC50 171 µM and 168 µM, respectively). TDCPP inhibited protein synthesis and caused cell cycle arrest, but only at higher concentrations. Additionally, the antioxidant N-acetylcysteine (NAC) reduced cell toxicity in cells treated with TDCPP, suggesting that exposure to TDCPP increased oxidative stress in the cells. In summary, these data show that low concentrations of TDCPP result in cytostasis in a kidney cell line, whereas higher concentrations induce cell toxicity. Furthermore, TDCPP toxicity can be attenuated by NAC, suggesting that antioxidants may be effective countermeasures to some organohalogen exposures.

Amino-functionalized poloxamer 407 with both mucoadhesive and thermosensitive properties: preparation, characterization and application in a vaginal drug delivery system.

Lack of mucoadhesive properties is the major drawback to poloxamer 407 (F127)-based in situ hydrogels for mucosal administration. The objective of the present study was to construct a novel mucoadhesive and thermosensitive in situ hydrogel drug delivery system based on an amino-functionalized poloxamer for vaginal administration. First, amino-functionalized poloxamer 407 (F127-NH2) was synthesized and characterized with respect to its micellization behavior and interaction with mucin. Then using acetate gossypol (AG) as model drug, AG-loaded F127-NH2-based in situ hydrogels (NFGs) were evaluated with respect to rheology, drug release, ex vivo vaginal mucosal adhesion, in vivo intravaginal retention and local irritation after vaginal administration to healthy female mice. The results show that F127-NH2 is capable of forming a thermosensitive in situ hydrogel with sustained drug release properties. An interaction between positively charged F127-NH2 and negatively charged mucin was revealed by changes in the particle size and zeta potential of mucin particles as well as an increase in the complex modulus of NFG caused by mucin. Ex vivo and in vivo fluorescence imaging and quantitative analysis of the amount of AG remaining in mouse vaginal lavage all demonstrated greater intravaginal retention of NFG than that of an unmodified F127-based in situ hydrogel. In conclusion, amino group functionalization confers valuable mucoadhesive properties on poloxamer 407.

Mitochondrial involvement in memory impairment induced by scopolamine in rats.

OBJECTIVE: Scopolamine (SCO) administration to rats induces molecular features of AD and other dementias, including impaired cognition, increased oxidative stress, and imbalanced cholinergic transmission. Although mitochondrial dysfunction is involved in different types of dementias, its role in cognitive impairment induced by SCO has not been well elucidated. The aim of this work was to evaluate the in vivo effect of SCO on different brain mitochondrial parameters in rats to explore its neurotoxic mechanisms of action. METHODS: Saline (Control) or SCO (1 mg/kg) was administered intraperitoneally 30 min prior to neurobehavioral and biochemical evaluations. Novel object recognition and Y-maze paradigms were used to evaluate the impact on memory, while redox profiles in different brain regions and the acetylcholinesterase (AChE) activity of the whole brain were assessed to elucidate the amnesic mechanism of SCO. Finally, the effects of SCO on brain mitochondria were evaluated both ex vivo and in vitro, the latter to determine whether SCO could directly interfere with mitochondrial function. RESULTS: SCO administration induced memory deficit, increased oxidative stress, and increased AChE activities in the hippocampus and prefrontal cortex. Isolated brain mitochondria from rats administered with SCO were more vulnerable to mitochondrial swelling, membrane potential dissipation, H2O2 generation and calcium efflux, all likely resulting from oxidative damage. The in vitro mitochondrial assays suggest that SCO did not affect the organelle function directly. CONCLUSION: In conclusion, the present results indicate that SCO induced cognitive dysfunction and oxidative stress may involve brain mitochondrial impairment, an important target for new neuroprotective compounds against AD and other dementias.

ST-elevation myocardial infarction risk in the very elderly.

BACKGROUND: Despite the high incidence and mortality of ST-segment elevation myocardial infarction (STEMI) among the very elderly, risk markers for this condition remain poorly defined. This study was designed to identify independent markers of STEMI among individuals carefully selected for being healthy or manifesting STEMI in < 24 h. METHODS: We enrolled participants aged 80 years or older of whom 50 were STEMI patients and 207 had never manifested cardiovascular diseases. Blood tests, medical and psychological evaluations were obtained at study admission. Odds Ratio (OR) and attributed risk (AR) were obtained by multivariate regression models using STEMI as dependent variable. RESULTS: Low glomerular filtration rate (GFR) [OR:4.41 (1.78-10.95); p = 0.001], reduced levels of HDL-C [OR:10.70 (3.88-29.46); p = 0.001], male gender [OR:12.08 (5.82-25.08); p = 0.001], moderate to severe depressive symptoms [OR:10.00 (2.82-35.50); p = 0.001], prior smoking [OR:2.00 (1.05-3.80); p = 0.034] and current smoking [OR:6.58 (1.99-21.70); p = 0.002] were significantly associated with STEMI. No association was found between STEMI and age, diabetes, hypertension, mild depressive symptoms, triglyceride or LDL-C. CONCLUSIONS: This is the first case-control study carried out with very elderlies to assess STEMI risk. Our findings indicate that reduced HDL-C, GFR, male gender, smoking habits and moderate to severe depressive symptoms are markers of STEMI in this age group. GENERAL SIGNIFICANCE: In Individuals aged 80 or more years, a greater attention must be paid to low HDL-C and GFR at the expense of conventional STEMI risk factors for younger adults such as diabetes mellitus, hypertension and high LDL-C or triglyceride.

Development and implementation of an HPLC-ECD method for analysis of vitamin C in plasma using single column and automatic alternating dual column regeneration.

OBJECTIVES: Vitamin C (l-ascorbic acid) is a water-soluble micronutrient necessary for human life. Inadequate intake can lead to the fatal disease scurvy. Measurement of vitamin C is used to assess nutritional status and to monitor supplementation. The goal of this study was to develop a chromatographic method for the quantitation of vitamin C in human plasma. DESIGN AND METHODS: Samples were prepared by protein precipitation, addition of internal standard, and reduction with dithiothreitol. Separation of ascorbic acid was accomplished by isocratic elution on a reverse-phase column; concentration was determined by coulometry. The method was validated through studies of assay linearity, sensitivity, imprecision, accuracy, analytical specificity, and carryover. RESULTS: The new assay was developed using a single pump/single analytical column HPLC system. Results correlated well with our previously used spectrophotometric method. The analytical measurement range was 1.0-2500 µmol/L. The injection-to-injection time was 13 min. Subsequently, to increase method throughput and shorten turnaround time, a dual LC pump system with a 2-position/10-port switching valve capable of performing automatic alternating column regeneration was validated and implemented. The injection-to-injection time was reduced 2-fold to 6 min. The method was linear to 5000 µmol/L; limit of quantification was 1.9 µmol/L. Total imprecision was less than 5%. CONCLUSIONS: We have developed a robust method suitable for routine clinical measurement of vitamin C in plasma specimens. The method incorporates a simplified sample preparation and a stable, non-endogenous internal standard to specifically quantify vitamin C. Faster throughput was achieved by employing an automatic alternating column regeneration system.

Oxidative stress and cell damage in a model of precancerous lesions and advanced hepatocellular carcinoma in rats.

Hepatocellular carcinoma (HCC) is the third most frequent cause of cancer deaths throughout the world. This study was aimed to analyze oxidative stress and cell damage in a multistage model of liver carcinogenesis induced by diethylnitrosamine (DEN) in rats. Male Wistar rats weighing 145-150 g were divided into three groups: control, precancerous lesions (PL) (which received 100 mg DEN once a week every 6 weeks up to 28 weeks), and advanced HCC (50 mg DEN once/twice per week up to 19 weeks). Lipid peroxidation (TBARS), superoxide dismutase (SOD) activity, and expression of transforming growth factor-1 beta (TGF)-1ß, endothelial and inducible nitric oxide syntahese (eNOS, iNOS), NADPH quinone oxireductase (NQO)-1, nuclear factor erythroid 2-related factor (NrF)2, kelch-like ECH-associated protein (Keap)1 and heat shock protein (HSP)70 were measured. TBARS concentration was augmented in the PL and advanced HCC groups. SOD activity, TGF-1ß and Nrf2 expression were higher in animals with precancerous lesions. In advanced HCC, expression of NQO1 and iNOS increased while there was a decrease in HPS70 expression. Data obtained provide evidence for the differential activation of proteins involved in oxidative stress and cell damage during progression of carcinogenesis in an animal model of HCC.

Mammalian safety of Decaleside II in the laboratory mouse.

Decaleside II, a novel trisaccharide isolated from the edible roots of Decalepis hamiltonii, belongs to a new class of natural insecticides. We have evaluated the mammalian safety of Decaleside II in the laboratory mouse. Our results on acute and sub acute toxicity study suggest that Decaleside II is not toxic to the laboratory mice as there were no symptoms of toxicity or mortality up to 2400 mg/kg bw. Haematological profile was unaltered and serum profiles of enzymes were not significantly affected. The lack of toxicity of Decaleside is attributed to the 1,4 α linkage of the sugars which are easily hydrolyzed by the digestive enzymes such as glucosidases. The selective toxicity to insects and mammalian safety of Decaleside II makes them highly suitable for use as novel grain protectants of natural origin.