In-silico molecular docking and molecular dynamic simulation of γ-elemene and caryophyllene identified from the essential oil of Kaempferia galanga L. against biofilm forming proteins, CrtM and SarA of Staphylococcus aureus.

Medicinal plants play an important role as antimicrobials by inhibiting various key targets of diverse microorganisms. A major antimicrobial component of plants is its essential oil, which are increasingly being studied for their antimicrobial properties as well as for their potential role in the inhibition of biofilm formation. In the present study, essential oil from Kaempferia galanga L was isolated resulting in the identification of eleven compounds. Of these, two of the compounds, γ-elemene and caryophyllene were found to dock with the target proteins, CrtM and SarA of Staphylococcus aureus, which are essential for the formation of biofilm. γ-elemene demonstrated the best binding affinity with CrtM with binding energy of -8.1 kcal/mol whereas caryophyllene and its derivative isocaryophyllene showed the best binding with SarA with binding energy -6.1 kcal/mol. ADMET study of the compounds also revealed that the compounds are non-toxic and can be used as probable compounds for inhibition of biofilms. Molecular dynamic simulation studies revealed high affinity of binding and stability of the molecules with their targets. PCA analysis helped in identifying the principal motions occurring within a trajectory that are essential in inducing conformational changes.Communicated by Ramaswamy H. Sarma.

Correction: A highly sensitive triazole-based perfectly water soluble novel bis-Schiff base reversible fluorescent-colorimetric chemosensor for fast detection of Pb2+ ions.

[This corrects the article DOI: 10.1039/D3RA06185J.].

A highly sensitive triazole-based perfectly water soluble novel bis-Schiff base reversible fluorescent-colorimetric chemosensor for fast detection of Pb2+ ions.

A reversible fluorescent-colorimetric azino bis-Schiff base receptor for the detection of Pb2+ in aqueous medium has been developed for the first time. Receptor L exhibits an excellent selective and rapid fluorescent-colorimetric response towards Pb2+. The sensitivity of the fluorescent-based assay (0.53 nM) and colorimetric assay (1.0 nM) for Pb2+ is sufficiently good in comparison to previously reported literature. From 1H NMR data, Job plot measurement and the ESI-MS spectrum, a 1 : 2 stoichiometric complexation between L and Pb2+ has been established. Receptor L shows a remarkable detection ability in a wide pH range of 4-8 and it has been successfully utilised in the determination of Pb2+ in aqueous solution of bovine serum albumin protein and in real samples. The geometry of L has been optimized by both DFT studies and NMR, FTIR and mass spectra. Moreover, we have studied molecular docking of the probe L.

Synthesis, Crystal Structure, DFT and Fluorescence Quenching Study of Novel syringe aldehyde-derived hydrazinyl-imidazole Based Schiff base Chemosensor.

In this study, we report a new syringe aldehyde-derived hydrazinyl-imidazole based fluorescent sensor (L) for sensitive detection of different inorganic quenchers (halide ions, bicarbonate ion, sulphide ion and transition metal ions). The chromophore (L) was obtained in good yield by the 1:1 condensation reaction of 2-hydrazino-4,5-dihydroimidazole hydrobromide and 4-hydroxy-3,5-dimethoxy benzaldehyde. L exhibited strong fluorescence in the visible region (around 380 nm) and its interaction with different quenchers was studied in details via fluorescence technique. For the halide ions series, its sensitivity is higher for NaF (Climit = 4 × 10- 4 M) than for NaCl while the fluorescence quenching occurred mainly through a dynamic process. Similar considerations were observed for HCO3- and S2- quencher too, when static and dynamic quenching take place simultaneously. Regarding transition metal ions, at a fixed ion concentration (4 × 10- 6 M), best performance was achieved for Cu2+ and Fe2+ (fluorescence intensity was reduced by 79% and 84.9% respectively), while for other metal ions, the sensor performance was evaluated and found to be very less (< 40%). Thus, minimum detection limits (10- 6 - 10- 5 M range) recommended the use of such derivatives as highly sensitive sensors capable to monitor delicate changes in varied environments.

A quinazolin-based Schiff-base chemosensor for colorimetric detection of Ni2+ and Zn2+ ions and 'turn-on' fluorometric detection of Zn2+ ion.

Herein, we have reported a novel quinazolin-based Schiff base chemosensor (E)-2-benzamido-N'-(1-(pyridin-2-yl)ethylidene)benzohydrazide (L). L has been designed, synthesised and characterised by 1H-NMR, IR spectroscopy, ESI-MS spectrometry and theoretical studies. The receptor showed appreciable colorimetric λ max shift for both Ni2+ and Zn2+ ions and fluorometric "turn on" response in presence of only Zn2+ ion. The Jobs plot analysis revealed that receptor forms 2 : 1 complex with both the ions Ni2+ and Zn2+, further confirmed by ESI-MS analysis. The single crystal structure of L-Ni2+ complex (1) has also been determined. The colorimetric detection limits were calculated to 7.9 nM and 7.5 nM respectively for Ni2+ and Zn2+ in methanol-Tris-HCl buffer medium (10 mM, pH 7.2, 1 : 1 v/v). The chemosensor L can be applied for the recovery of contaminated water samples.

Urine collection devices to reduce contamination in urine samples for diagnosis of uncomplicated UTI: a single-blind randomised controlled trial in primary care.

BACKGROUND: Urine collection devices (UCDs) are being marketed and used in clinical settings to reduce urine sample contamination, despite inadequate supporting evidence. AIM: To determine whether UCDs, compared with standardised instructions for urine sample collection, reduce the proportion of contaminated samples. DESIGN AND SETTING: Single-blind randomised controlled trial in general practices in England and Wales. METHOD: Women aged ≥18 years presenting with symptoms attributable to urinary tract infection (UTI) were randomised (1:1:1) to use either a Peezy UCD or a Whiz Midstream UCD, or were given standardised verbal instructions (SVI) for midstream sample collection. The primary outcome was the proportion of urine samples reported as contaminated by microbiology laboratory analysis. RESULTS: A total of 1264 women (Peezy UCD: n = 424; Whiz Midstream UCD: n = 421; SVI: n = 419) were randomised between October 2016 and August 2018. Ninety women were excluded from the primary analysis as a result of ineligibility or lack of primary outcome data, leaving 1174 (Peezy UCD: n = 381; Whiz Midstream UCD: n = 390; SVI: n = 403) for intention-to-treat analysis. The proportion of contaminated samples was 26.5% with the Peezy UCD, 28.2% with the Whiz Midstream UCD, and 29.0% with SVI (relative risk: Peezy UCD versus SVI = 0.91, 95% CI = 0.76 to 1.09, P = 0.32; Whiz Midstream UCD versus SVI = 0.98, 95% CI = 0.97 to 1.20, P = 0.82). There were 100 (25.3%) device failures with the Peezy UCD and 35 (8.8%) with the Whiz Midstream UCD; the proportion of contaminated samples was similar after device failure samples were excluded. CONCLUSION: Neither the Peezy UCD nor the Whiz Midstream UCD reduced urine sample contamination when used by women presenting to primary care with suspected UTI. Their use cannot be recommended for this purpose in this setting.

Impact of a single eGFR and eGFR-estimating equation on chronic kidney disease reclassification: a cohort study in primary care.

BACKGROUND: Chronic kidney disease (CKD) is diagnosed using the estimated glomerular filtration rate (eGFR) and the urinary albumin:creatinine ratio (ACR). The eGFR is calculated from serum creatinine levels using the Modification of Diet in Renal Disease (MDRD) or Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations. AIM: To compare the performance of one versus two eGFR/ACR measurements, and the impact of equation choice, on CKD diagnosis and classification. DESIGN AND SETTING: Cohort study in primary care in the Thames Valley region of the UK. METHOD: Data were from 485 participants aged >60 years in the Oxford Renal Cohort Study with at least two eGFR tests. The proportion of study participants diagnosed and classified into different CKD stages using one and two positive tests were compared. Prevalence of CKD diagnosis and classification by CKD stage were compared when eGFR was calculated using MDRD and CKD-EPI equations. RESULTS: Participants included in the analysis had a mean age of 72.1 (±6.8) years and 57.0% were female. Use of a single screening test overestimated the proportion of people with CKD by around 25% no matter which equation was used, compared with the use of two tests. The mean eGFR was 1.4 ml/min/1.73 m2 (95% CI = 1.1 to 1.6) higher using the CKD-EPI equation compared with the MDRD equation. More patients were diagnosed with CKD when using the MDRD equation, compared with the CKD-EPI equation, once (64% versus 63%, respectively) and twice (39% versus 38%, respectively), and 16 individuals, all of who had CKD stages 2 or 3A with MDRD, were reclassified as having a normal urinary ACR when using the CKD-EPI equation. CONCLUSION: Current guidance to use two eGFR measures to diagnose CKD remains appropriate in an older primary care population to avoid overdiagnosis. A change from MDRD to CKD-EPI equation could result in one in 12 patients with a CKD diagnosis with MDRD no longer having a diagnosis of CKD.

Is vascular endothelial growth factor a useful biomarker in giant cell arteritis?

OBJECTIVES: To assess the performance of circulating vascular endothelial growth factor (VEGF) levels as a tool for diagnosing giant cell arteritis (GCA) in a cohort of patients referred for assessment of suspected GCA. METHODS: We selected 298 patients recruited to the multicentre study Temporal Artery Biopsy versus Ultrasound in diagnosis of suspected GCA (TABUL). In a random subset of 26 biopsy-proven GCA cases and 26 controls, serum from weeks 0, 2 and 26 was analysed for VEGF concentration using ELISA. VEGF concentration at week 0 was used to generate a receiver-operating characteristic curve and thereby identify a cut-off for an abnormal result which was used to analyse the full patient cohort. Sections of paraffin-embedded temporal artery were stained by immunohistochemistry for VEGF. RESULTS: The mean (95% CI) VEGF concentration at week 0 was 873 pg/mL (631 to 1110) in 26 patients versus 476 pg/mL (328 to 625) in 26 controls (p=0.017). This difference was not observed at any other time point. The optimal cut-off of 713 pg/mL was applied to the whole patient cohort (n=298), yielding sensitivity of 32% and specificity of 85%. This was not improved by combination with any clinical parameters. When patients with biopsy-proven GCA were compared with controls, sensitivity was 58% and specificity remained 85%. Sections of biopsy from biopsy-positive GCA showed intense staining in the adventitia which was not seen in controls. CONCLUSIONS: Serum VEGF concentration predicts biopsy positivity but is not useful for differentiating clinical cases of GCA from controls. Further studies into VEGF as a prognostic marker and therapeutic target are warranted. TRIAL REGISTRATION NUMBER: NCT00974883; Post-results.