Solution structure of a calmodulin-binding domain in the carboxy-terminal region of HIV type 1 gp160

The cytosolic domain of human immunodeficiency virus gp160 glycoprotein contains two calmodulin-binding regions. The role of these domains in modulating intracellular calmodulin signaling is of considerable interest in unraveling the mechanism whereby calmodulin regulates Fas-mediated apoptosis in HIV-infected cells. In this investigation we have employed 2D-NMR spectroscopy to determine the solution structure of the 30-residue calmodulin-binding domain corresponding to residues 826-855 of gp160. In solution, the gp160 (826-855) peptide exhibits a high degree of segmental flexibility. Within its conformational manifold, we have detected two separate flexible amphipathic helices involving residues 826-841 and 846-855 connected by a highly flexible type-II beta-turn at Pro-843 and Arg-844. The observed NOE pattern as well as the observation of long-range NOE contacts between the side chains of His-841 and Ile-846 are compatible with the presence of this turn in the conformational manifold of this peptide. This investigation focusing on the properties of the free peptide in solution paves the way for extending the investigations on the interaction of calmodulin with HIV-1 gp160.     

Endoscopic ultrasound： It＇s accuracy in evaluating mediastinal lymphadenopathy？ A meta-analysis and systematic review

AIM：To evaluate the accuracy of endoscopic ultrasound （EUS）, EUS-fine needle aspiration （FNA） in evaluating mediastinal lymphadenopathy.
METHODS：Only EUS and EUS-FNA studies confirmed by surgery or with appropriate follow-up were selected. Articles were searched in Medline, Pubmed, and Cochrane control trial registry. Only studies from which a 2 × 2 table could be constructed for true positive, false negative, false positive and true negative values were included. Two reviewers independently searched and extracted data. The differences were resolved by mutual agreement. Meta-analysis for the accuracy of EUS was analyzed by calculating pooled estimates of sensitivity, specificity, likelihood ratios, and diagnostic odds ratios. Pooling was conducted by both Mantel-Haenszel method （fixed effects model） and DerSimonian Laird method （random effects model）. The heterogeneity of studies was tested using Cochran＇s Q test based upon inverse variance weights.
RESULTS：Data was extracted from 76 studies （n = 9310） which met the inclusion criteria. Of these, 44 studies used EUS alone and 32 studies used EUS-FNA. FNA improved the sensitivity of EUS from 84.7% （95% CI：82.9-86.4） to 88.0% （95% CI：85.8-90.0）. With FNA, the specificity of EUS improved from 84.6% （95% CI：83.2-85.9） to 96.4% （95% CI：95.3-97.4）. The P forchi-squared heterogeneity for all the pooled accuracy estimates was 〉 0.10.
CONCLUSION：EUS is highly sensitive and specific for the evaluation of mediastinal lymphadenopathy and FNA substantially improves this. EUS with FNA should be the diagnostic test of choice for evaluating mediastinal lymphadenopathy.     

Influence of selective fluorination on the biological activity and proteolytic stability of glucagon-like peptide-1

The relative simplicity and high specificity of peptide therapeutics has fueled recent interest. However, peptide and protein drugs generally require injection and suffer from low metabolic stability. We report here the design, synthesis, and characterization of fluorinated analogues of the gut hormone peptide, GLP-1. Overall, fluorinated GLP-1 analogues displayed higher proteolytic stability with simultaneous retention of biological activity (efficacy). Fluorinated amino acids are useful for engineering peptide drug candidates and probing ligand-receptor interactions.     

Screening of Chemical Penetration Enhancers for Transdermal Drug Delivery Using Electrical Resistance of Skin

Purpose  A novel technique is presented for identifying potential chemical penetration enhancers (CPEs) based on changes in the electrical resistance of skin. Methods  Specifically, a multi-well resistance chamber was designed and constructed to facilitate more rapid determination of the effect of CPEs on skin resistance. The experimental setup was validated using nicotine and decanol on porcine skin in vitro. The multi-well resistance chambers were capable of operating at 37°C in order to simulate the physiological temperature of the human body. Further, the utility of the multi-well resistance chamber technique was validated using standard Franz diffusion cells. Electrical resistance measurements were used to evaluate the potency of seven new potential CPEs, identified using virtual screening algorithms. From the resistance measurements, the chemicals 1-dodecyl-2-pyrrolidinone (P), menthone (M) and R(+)-3-amino-1-hydroxy-2-pyrrolidinone (C) were identified as the better penetration enhancers among the seven tested. Further, traditional permeation experiments were performed in Franz diffusion cells to confirm our findings. Results  The permeation test results indicated that, of the three CPEs deemed potentially viable using the newly-developed resistance screening technique, both P and M increased the permeation of the test drug (melatonin) through skin in 48 h. Conclusion  In summary, this resistance technique can be used to effectively pre-evaluate potential CPEs, thereby reducing the time required to conduct the permeability studies.     

Continuous counter current extraction, isolation and determination of solanesol in Nicotiana tobacum L. by non-aqueous reversed phase high performance liquid chromatography

A method of continuous counter current extraction in a large-scale production of solanesol from tobacco leaves was developed. The crude extract containing 15-20% solanesol was subjected to a series of steps, viz., saponification, solvent recrystallization and column chromatography. The pure material was characterized by FT-IR, ESI-MS, 1H NMR and 13C NMR spectrometry. The analysis was carried out by a simple and rapid non-aqueous reversed-phase high performance liquid chromatographic method on a Hypersil BDS C18 column (250 mm x 4.6mm, particle size 5 microm) with isopropyl alcohol-methanol (60:40, v/v) as mobile phase and detection at 215 nm. The product purity was between 95 and 98% (w/w) as determined by HPLC.     

Assessment of tissue redox status using metabolic responsive contrast agents and magnetic resonance imaging

Regulation of tissue redox status is important to maintain normal physiological conditions in the living body. Disruption of redox homoeostasis may lead to oxidative stress and can induce many pathological conditions such as cancer, neurological disorders and ageing. Therefore, imaging of tissue redox status could have clinical applications. Redox imaging employing magnetic resonance imaging (MRI) with nitroxides as cell-permeable redox-sensitive contrast agents has been used for non-invasive monitoring of tissue redox status in animal models. The redox imaging applications of nitroxide electron paramagnetic resonance imaging (EPRI) and MRI are reviewed here, with a focus on application of tumour redox status monitoring. While particular emphasis has been placed on differences in the redox status in tumours compared to selected normal tissues, the technique possesses the potential to have broad applications to the study of other disease states, inflammatory processes and other circumstances where oxidative stress is implicated.     

Use of Clinical Decision Support to Increase Influenza Vaccination: Multi-year Evolution of the System

Despite recognition that clinical decision support (CDS) can improve patient care, there has been poor penetration of this technology into healthcare settings. We used CDS to increase inpatient influenza vaccination during implementation of an electronic medical record, in which pharmacy and nursing transactions increasingly became electronic. Over three influenza seasons we evaluated standing orders, provider reminders, and pre-selected physician orders. A pre-intervention cross-sectional survey showed that most patients (95%) met criteria for vaccination. During our intervention, physicians were increasingly likely to accept pre-selected vaccination orders, Year 1 (47%), Year 2 (77%), Year 3 (83%); however vaccine administration by nurses was suboptimal. As electronic medical record functionality improved, patient receipt of vaccine increased dramatically, Year 1 [0/36; 0%], Year 2 [8/66; 12%], Year 3 [286/805; 36%]. Successful use of clinical decision support to increase inpatient influenza vaccination only occurred after initiation of CPOE for all medications and integration of an electronic medication administration record. Also, since most patients met criteria for influenza vaccination, complicated logic to identify high-risk patients was unnecessary.     

Biological activities of curcumin and its analogues (Congeners) made by man and Mother Nature

Curcumin, a yellow pigment present in the Indian spice turmeric (associated with curry powder), has been linked with suppression of inflammation; angiogenesis; tumorigenesis; diabetes; diseases of the cardiovascular, pulmonary, and neurological systems, of skin, and of liver; loss of bone and muscle; depression; chronic fatigue; and neuropathic pain. The utility of curcumin is limited by its color, lack of water solubility, and relatively low in vivo bioavailability. Because of the multiple therapeutic activities attributed to curcumin, however, there is an intense search for a “super curcumin” without these problems. Multiple approaches are being sought to overcome these limitations. These include discovery of natural curcumin analogues from turmeric; discovery of natural curcumin analogues made by Mother Nature; synthesis of “man-made” curcumin analogues; reformulation of curcumin with various oils and with inhibitors of metabolism (e.g., piperine); development of liposomal and nanoparticle formulations of curcumin; conjugation of curcumin prodrugs; and linking curcumin with polyethylene glycol. Curcumin is a homodimer of feruloylmethane containing a methoxy group and a hydroxyl group, a heptadiene with two Michael acceptors, and an α,β-diketone. Structural homologues involving modification of all these groups are being considered. This review focuses on the status of all these approaches in generating a “super curcumin.”.