Dual colorimetric sensing of ascorbic acid and thyroxine using Ag–EGCG–CTAB via a DFT approach

In this work, a colorimetric approach for the detection of ascorbic acid (AA) and thyroxine (TH) was developed by synthesizing cost-effective silver nanoparticles (AgNPs) decorated with epigallocatechin gallate (EGCG) and CTAB. EGCG is the major bioactive chemical constituent that played a significant role in this study. The environment around the nanoparticle (NP) was controlled by adding CTAB surfactants. The synthesized NPs were characterized by different advanced techniques including XRD, XPS, SEM, and TEM. UV-visible spectra were thoroughly analyzed for sensing of AA and TH and the colour change of the solution can be visually monitored. The change in the localized surface plasmon resonance (LSPR) properties was used as an asset for the detection of AA and TH. A good linear relationship was obtained in both the sensing schemes with a limit of detection (LoD) of 0.67 μM and 0.33 μM for AA and TH respectively. Furthermore, the nanoparticles (NP) were implemented for real-sample analysis (pharmaceutical tablets). A cost-effective filter paper strip-based method coupled with smartphone scanning sensing was developed for the detection of AA. The interaction of AA and TH with the probe was depicted by a density functional theory (DFT) analysis. The synthesized NPs show tremendous selectivity towards AA and TH and excellent potential for practical applications.

In this work, a colorimetric approach for the detection of ascorbic acid and thyroxine was developed by synthesizing cost-effective silver nanoparticles (AgNPs) decorated with epigallocatechin gallate (EGCG) and CTAB.     

Pregnancy and Its Outcome in a Rare Case of Combined Protein C and Protein S Deficiency with Severe Adenomyosis

The Journal of Obstetrics and Gynecology of India -     

Unveiling of a smartphone-mediated ratiometric chemosensor towards the nanomolar level detection of lethal CN−: combined experimental and theoretical validation with the proposition of a molecular logic circuitry

A promising naphthalene-functionalized ratiometric chemosensor (E)-1-((naphthalen-5-yl) methylene)-2-(2,4-dinitrophenyl) hydrazine (DNMH) is unveiled in the present work. DNMH demonstrates brisk discernible colorimetric response from yellow to red in the presence of CN⁻, a lethal environmental contaminant, in a near-perfect aqueous medium with a LOD of 278 nM. The “key role marker” controlling the electrochemical and non-covalent H-bonding interaction between DNMH and CN⁻ is through the commendable role of acidic –NH functionalities. Kinetic studies reveal a pseudo second order reaction rate and the formation of an unprecedented photostable adduct. The negative value of ΔG as evaluated from ITC substantiates the spontaneity of the DNMH⋯CN⁻ interaction. The sensing mechanism was further reinforced with state-of-the-art theoretical investigations, namely DFT, TDDFT and Fukui indices (FIs). Moreover, the proposition of a reversible multi-component logic circuitry implementing Boolean functions in molecular electronics has also been triggered by the turn-over spectrophotometric response of the ditopic ions CN⁻ and Cd²⁺. The cytotoxicity of DNMH towards Bacillus thuringiensis and Escherichia coli is successfully investigated via the MTT assay. Impressively, “dip stick” and “easy to prepare” test paper device and silica gel-based solid-phase CN⁻ recognition validate the on-site analytical application of DNMH. Furthermore, the involvement of a synergistic approach between ‘chemistry beyond the molecule’ and ‘engineering’ via an exquisitely implemented smartphone-assisted colorimetric sensory prototype makes this work unprecedented among its congeners and introduces a new frontier in multitudinous material-based functional product development.

A ratiometric chemosensor (DNMH) is unveiled herein, demonstrating selective chromogenic response towards CN⁻, with a LOD of 278 nM. Consequently, molecular logic circuitry and a smartphone-based colorimetric sensory prototype has been explored.     

Cytokine levels in HIV infected and uninfected Indian women: Correlation with other STAs

Host immune status is an important determinant of disease progression. Infections in the genital tract may alter the immunity in the particular site and hence affect the production of local cytokines. We performed this study to determine whether HIV in association with cervical HPV and CT/GC infections influences the production of local cytokines. Cervical secretions from 100 women with or without HIV infection were collected for measuring IL-1β, -6, -10 and -12 concentrations by ELISA. Cervical HPV and CT/GC DNA were detected by HCII test. Significant elevations of IL-6 and IL-10 were observed in patients having HIV infection. Although cervical HPV infection increased the concentrations of both IL-6 and IL-1β but HPV induced abnormal cervical smear was associated only with increased IL-6 concentrations significantly. Double infection had marked relation with IL-6 and IL-10. CT/GC had no direct effect on any of these cytokines but in association with HIV and HPV, these bacterial pathogens elevated the concentrations of IL-6 significantly. Thus, our results suggest that the presence of HIV and other STAs in the genital tract can cause imbalance of local cytokine levels which in turn may facilitate other opportunistic infections.     

Therapeutic significance of elevated tissue transglutaminase expression in pancreatic cancer.

PURPOSE: Tissue transglutaminase (TG2) is a multifunctional protein that is implicated in development of drug resistance and metastasis. Therefore, we examined therapeutic targeting of TG2 for inhibiting growth and metastasis of in vivo growing pancreatic ductal adenocarcinoma (PDAC) in nude mice. EXPERIMENTAL DESIGN: We implanted Panc-28 pancreatic cancer cells to induce orthotopic PDAC tumors in nude mice and determined the efficacy of liposomal TG2 small interfering RNA (siRNA) either alone or in combination with gemcitabine. RESULTS: We show that down-regulation of endogenous TG2 by siRNA could effectively block the growth of PDAC. Moreover, down-regulation of TG2 significantly enhanced the therapeutic efficacy of gemcitabine against PDAC and inhibited metastatic spread of the disease. The antitumor activity was related to inhibition of proliferation, angiogenesis, and Akt phosphorylation. CONCLUSION: siRNA-mediated down-regulation of TG2 represents a promising therapeutic approach for improved treatment of PDAC.     

Impairment of stimulation by estrogen of insulin-activated nitric oxide synthase in human breast cancer

Nitric oxide (NO) is reported to have several important effects in the control of neoplasm. We have reported before the presence of an insulin-activated constitutive form of membrane-bound nitric oxide synthase (IANOS) in various cells. Since the insulin-induced NO synthesis by IANOS could have important consequences on the pathophysiology of neoplastic cells, the role of estrogen on the activity of IANOS in malignant and nonmalignant breast tissue as well as in erythrocytes in breast cancer patients was determined. It was found that the IANOS activity of nonmalignant breast tissue was maximally stimulated by 4-fold over the basal activity in the presence of physiologic amounts of estrogen (8-32 nM). The enzymic activity was, however, inhibited by estrogen both below and above this range when compared to appropriate controls. In contrast, both the basal IANOS activity and the stimulatory effect of estrogen was markedly impaired in malignant breast tissue and in erythrocytes in these patients. It was also noted that tamoxifen, a widely used nonsteroidal compound in breast cancer, mimicked estrogen both in the stimulation and in the inhibition of IANOS activity in both of the tissues. These results indicated the probable existence of a novel pathway for estrogen effect independent of nuclear receptor for the stimulation of IANOS activity that might have important consequences in breast cancer and suggested that some of the beneficial effects of tamoxifen could be related to its estrogen-mimicking effect on IANOS independent of hormone-responsive elements sequence in the DNA.     

Neuropathology of genetically engineered mice: consensus report and recommendations from an international forum

The Mouse Models of Cancer Consortium of the NCI sponsored a meeting of neuropathologists and veterinary pathologists in New York City in November of 2000. A rapidly growing number of genetically engineered mice (GEM) predisposed to tumors of the nervous system have led to a concomitant need for neuropathological evaluation and validation of these models. A panel of 13 pathologists reviewed material representing most of the available published and unpublished GEM models of medulloblastoma, primitive neuroectodermal tumor, astrocytoma, oligodendroglioma, mixed glioma, and tumors of the peripheral nerve. The GEM tumors were found to have many similarities and some distinct differences with respect to human disease. After review of the biology and pathology for all models presented, participants were split into groups reflective of clinical expertise in human pathology, tumor biology, neuroimaging, or treatment/intervention. Recommendations were made detailing an extensive and complete neuropathological characterization of animals. Importance was placed on including information on strains, tumor clonality, and examination for genetic mutation or altered gene expression characteristics of the corresponding human malignancy. Specific proposals were made to incorporate GEM models in emerging neuroradiological modalities. Recommendations were also made for preclinical validation of these models in cancer therapeutics, and for incorporation of surrogate markers of tumor burden to facilitate preclinical evaluation of new therapies.