Long pepper (Piper longum) derived carbon dots as fluorescent sensing probe for sensitive detection of Sudan I

In this piece of work, microwave-assisted conversion of a natural precursor in to high-valued nano-scale material was carried out by a completely greener method. The fluorescent carbon dots prepared, designated as long pepper derived carbon dots (LPCDs), have been thoroughly characterized to explore the physical and chemical properties. The system exhibits excitation dependent emission behavior and from the optimal studies the excitation and emission wavelength of the system was found to be 330 nm and 455 nm respectively. On account of the superior fluorescent behavior of the LPCDs, it was successfully employed as a fluorescent sensing probe to detect Sudan I with good level of selectivity and sensitivity. This carcinogenic dye extensively used as food adulterant can impart several health issues. Food product safety is of high concern, therefore a simple facile and economical analytical method was proposed based on the fluorescence of LPCDs for this dye detection with satisfactory statistical parameters. A linear relationship was maintained in the range of 0 to 27.27 μM Sudan I with limit of detection of 0.92 μM. The quenching mechanism was studied and finally attributed to Förster resonance energy transfer (FRET) mechanism. In addition, the probe was effectively implemented for Sudan I detection in commercial chili powder samples with good level of recovery parameters.

Microwave-assisted green synthesis of carbon dots derived from wild lemon (Citrus pennivesiculata) leaves as a fluorescent probe for tetracycline sensing in water

Herein, we report an eco-friendly biomass based completely greener microwave assisted synthesis of carbon dots from wild lemon leaves having superior photo-luminescent properties with moderately good quantum yield. The carbon dots synthesized (LLCDs) were characterized by high resolution transmission electron microscopy, fluorescent, UV-vis absorption, Fourier transform infrared and Raman spectroscopic techniques. The quenching of native fluorescence of LLCDs observed with tetracycline antibiotic was made use to make it as a fluorescent probe. Tetracycline is widely used as a drug to treat various bacterial infections and as a growth promoter in variety of farming fields like aquaculture and feedstock's. The excessive usage of this antibiotic in farming fields caused severe water pollution and micro level detection of tetracycline in water system is highly demanded for the protection of health and environment. Based on the selective interaction of tetracycline with LLCDs, a simple and cost effective analytical method was proposed to detect tetracycline in water with satisfactory parameters. The limit of detection is 0.42 µM with a linear range of 0 to 27. 27 µM. The mechanism of quenching was investigated through various experiments and finally accredited to static quenching. Furthermore, the same method has been practically applied for tetracycline detection in natural water resources with acceptable recoveries ranging from 95.56 % to 101.93 %.

Cortical excitability changes as a marker of cognitive impairment in Parkinson's disease

Cognitive impairment of different severity with eventual progression to dementia in Parkinson's disease (PD) appears during the course of the disease. In this study, transcranial magnetic stimulation (TMS) was used to assess cortical excitability changes in PD patients with varying cognitive impairment. We aimed to identify the TMS parameters that could serve as a non-invasive marker of cognitive impairment in patients with PD. Consecutive PD patients were recruited in the study. Detailed neuropsychological assessment was carried out to identify PD without cognitive impairment (PD-nC), PD with mild cognitive impairment (PD-MCI) and PD with dementia (PDD). Twenty patients of PDD (2 females and 18 males), 20 PD-MCI (4 females and 16 males), 18 PD-nC (5 females, 13 males) and 18 healthy controls (4 females, and 14 males) were included in the study. All the participants underwent TMS with recording of resting motor threshold, central motor conduction time, silent period, short interval intracortical inhibition (SICI) and intracortical facilitation (ICF). All the groups were age matched. The SICI was present in all; however, significantly greater inhibition was noted in PDD (Mean±SD; 0.11±0.08) followed by PD-MCI (0.31±0.17), PD-nC (0.49±0.26) and controls (0.61±0.23; p<0.001). The ICF was significantly reduced in PDD (Mean±SD; 0.15±0.18), PD-MCI (0.55±0.31), PD-nC (0.96±0.59), when compared to healthy controls (1.81±0.83; p<0.001). Patients with PD-nC, PD-MCI and PDD had graded reduction in ICF and increasing intracortical inhibition as the disease progressed from PD-nC through PD-MCI to PDD. This suggests progressive overactivity of GABAergic transmission, glutaminergic deficiency with consequent reduction of cholinergic transmission leading to dementia.

Understanding the virulence of the entero-aggregative E. coli O104:H4

O104:H4 is a new strain of E. coli that has caused an outbreak in Germany. It was isolated from patients with bloody diarrhoea and Haemolytic Uremic Syndrome (HUS). BGI (www.genomics.cn) sequenced and assembled this new strain. It was reported to show resistance to a number of drugs that are toxic to other E. coli and causes serious complications during infections, which ultimately lead to death. Multi-drug resistance and high virulence of this strain is thought to be acquired from different sources, by horizontal gene transfer. A total of 38 prophage elements were detected from the new strain by using three computational tools viz., DRAD, Prophage Finder and PHAST. Analysis on these prophage elements shows a number of virulence proteins like Shiga toxin and multi-drug resistance protein encoding genes. The high virulence of the strain could be attributed by the prophage elements acquired from its micro environment.

Mast cell density in oral submucous fibrosis: a possible role in pathogenesis

OBJECTIVE

Oral submucous fibrosis (OSMF) is a premalignant condition of oral cavity characterized by inflammation and progressive mucosal fibrosis. It has questionable pathogenesis. Mast cells (MC) have been associated with variety of inflammatory and fibrotic conditions, but little is known about their role in OSMF. Mast cells have been studied in normal gingiva, chronic inflammatory gingivitis, desquamative gingivitis, lichen planus, OSMF and oral cancer. Mast cells exhibit phenotypic plasticity. There is variation in the mast cell mediators with the change in the microenvironment, which makes the study of this cell in various diseases interesting.

STUDY DESIGN

A retrospective study was conducted to find possible correlation between MC in 25 cases of OSF, 10 cases of oral squamous cell carcinoma (OSCC) and 10 cases of normal buccal mucosa by means of acidified toluidine blue staining method.

RESULTS

The density of MC increased with disease progression. The densities of MC were significantly higher in OSMF than in normal buccal mucosa (p=0.001). The average numbers of MCs per square millimeter were 25, 49.50, 53.25 & 55.25 respectively.

CONCLUSION

The results suggest that MC have a definite role in initiation and progression of OSMF.

Molecular modeling and docking studies of glutamate racemase in Vibrio vulnificus CMCP6

Identification of novel drug targets in silico in Vibrio vulnificus is important as it is one of the emerging pathogenic microorganisms. Glutamate racemase, an important constituent of bacterial cell wall is chosen for structure prediction using homology modeling. With the aid of tools and software like MODELLER and Swiss-PdbViewer, the 3D structure is predicted and the final model is refined by energy minimization. The quality of the refined model is assessed using PROCHECK. The interaction between the predicted structure of glutamate racemase and its potential inhibitors namely L-serine O-sulfate, (2R,4R)-2-amino-4-(2-benzo[b]thienyl)methyl pentanedioic acid, aziridino glutamate, exiguaquinol, gamma-2 naphthylmethyl-D-glutamate and D-glutamine is analysed in silico by Autodock. The results indicate that certain residues like Aspl3, Tyr45, Gly46, Asn78, Thr79, Cys185, His187 are highly conserved across the active site stretches of different bacterial species and may possibly assume precedence over the other residues for inhibitory action. This study provides an insight into the structure of glutamate racemase in V. vulnificus and also gives an idea about potential sites responsible for inhibitory action that could further be substantiated by experimental investigations.

Quality of life in Wilson's disease

BACKGROUND

Assessment of Quality of life (QoL) is fast assuming significance as the measure of health in many disorders.

AIM

To correlate clinical severity and QoL in patients with Wilson's disease (WD).

MATERIALS AND METHODS

We evaluated patients of WD on regular follow up for at least two years and aged over 18 years using Neurological Symptom Score (NSS) for clinical severity and WHO-BREF for QoL at a university teaching hospital. Patients with inability to respond to the questionnaire due to behavioral problems, low IQ or other disease related factors were excluded. These 30 patients (M:F:: 23:7) had a mean age of 27.97 +/- 11.16 years at evaluation and the mean duration of treatment of 9.2 +/- 6.4 years.

RESULTS

All four domains of WHO-QoL-BREF viz., Physical, Psychological, Social and Environmental correlated well with each other (p < 0.01). The NSS correlated inversely with the physical domain (p < 0.02), while the duration of treatment had a positive correlation with the physical domain (p < 0.01). None of the other features of QoL showed any significant correlation with age, NSS or duration of treatment.

CONCLUSION

QoL is complementary to formal neurological assessment and should be routinely incorporated in the evaluation of outcome of patients with WD and other chronic neurological disorders.

In vitro generation of superoxide anion by the hemocytes ofMacrobrachium rosenbergii: possible mechanism and pathways

The hemocytes from the giant freshwater prawn Macrobrachium rosenbergii were examined for their ability to generate superoxide anion (O(2) (-)) in vitro upon exposure to various components derived from microbial cell wall components. Among the test molecules, laminarin (a polymer of beta-1, 3 glucans), mannan and LPS from five different bacterial species produced a differential response in terms of stimulated O(2) (-) production in prawn hemocytes, suggesting the ability of the hemocytes to differentiate non-self. This response was almost completely inhibited by superoxide dismutase (SOD) suggesting SOD-inhibitable O(2) (-) generation by prawn hemocytes. Phorbol 12-myristate 13-acetate (PMA) and Ca ionophore led to enhanced O(2) (-) generation by the hemocytes and this suggests the possible role of protein kinase C and Ca(2+) ions in such generation. Cytochemical analysis using nitroblue tetrazolium (NBT)-staining revealed the importance of granular hemocytes in O(2) (-) generation in these prawns. Inhibition of O(2) (-) generation by inhibitors of NADPH-oxidase and phenoloxidase pathways clearly reveal the involvement of two different pathways in non-self stimulated O(2) (-) generation by the prawn hemocytes. These findings demonstrate the importance of O(2) (-) generation and role of possible pathways in hemocyte mediated cellular immune response of a crustacean.

Practical Synthesis of Triaryl- and Triheteroarylmethanes by Reaction of Aldehydes and Activated Arenes Promoted by Gold(III) Chloride

[reaction: see text] Electron-rich arenes condense efficiently with various aldehydes under the influence of AuCl3, thus opening up a practical route to triarylmethanes, which have important applications. The mild conditions employed are especially noteworthy.