Copper thiocyanato complexes and cocaine – a case of ‘black cocaine’

The chemical composition of a black powder confiscated by German customs was elucidated. Black powders are occasionally used as a ‘transporter’ for cocaine and are obviously especially designed to cloak the presence of the drug. The material consisting of cocaine, copper, iron, thiocyanate, and graphite was approached by analytical tools and chemical modelling. Graphite is added to the material probably with the intention of masking the typical infrared (IR) fingerprints of cocaine and can be clearly detected by powder X‐ray diffraction (XRD) and Raman spectroscopy. Cu²⁺ and NCS^? ions, when carefully reacted with cocaine hydrochloride, form the novel compound (CocH)₂[Cu(NCS)₄] (CocH⁺ = protonated cocaine), which has been characterised by single crystal XRD, IR, NMR, UV/Vis absorption and EPR spectroscopy. Based on some further experiments the assumed composition of the original black powder is discussed. Copyright © 2014 John Wiley & Sons, Ltd.     

In-vitro tomography and non-destructive imaging at depth of pharmaceutical solid dosage forms

Tomographic imaging techniques offer new prospects for a better understanding of the quality, performance and release mechanisms of pharmaceutical solid dosage forms. It is only over the last fifteen years that tomography has been applied for the in-vitro characterisation of dosage forms. This review aims to introduce the concept of tomography in a pharmaceutical context, and describes the current state-of-the-art of the four most promising techniques: X-ray computed microtomography, magnetic resonance imaging, terahertz imaging and optical coherence tomography. The basic working principles of the techniques are introduced and the current pharmaceutical applications of the technologies are discussed, together with a comparison of their specific strengths and weaknesses. Possible future developments in these fields are also discussed.     

Sinecatechins, a defined green tea extract, in the treatment of external anogenital warts: a randomized controlled trial

OBJECTIVE: To estimate the clinical efficacy of topical sinecatechins, a defined green tea extract, in the treatment of external genital and perianal warts. METHODS: This was a randomized, double-blind, vehicle-controlled trial involving 502 male and female patients aged 18 years and older, with 2-30 anogenital warts ranging from 12 to 600 mm(2) total wart area. Patients applied sinecatechins ointment 15% or 10% or vehicle (placebo) three times daily for a maximum of 16 weeks or until complete clearance of all warts, followed by a 12-week treatment-free follow-up to assess recurrence. RESULTS: Complete clearance of all baseline and newly occurring warts was obtained in 57.2% and 56.3% of patients treated with sinecatechins ointment 15% and 10%, respectively, compared with 33.7% for vehicle (both P<.001). Significance was observed at weeks 4 and 6 and all subsequent visits. Numbers needed to treat were 4.3 and 4.4. Partial clearance rates of at least 50% were reported for 78.4% and 74.0% of patients in the sinecatechins ointment 15% and 10% groups compared with 51.5% of vehicle patients. During follow-up, recurrence of any wart was observed in 6.5%, 8.3%, and 8.8% in the sinecatechins ointment 15% group, sinecatechins ointment 10% group, and vehicle patients, respectively. A total of 3.7%, 8.3%, and 0.0% developed new warts, respectively. A total of 87.7% and 87.3% of patients in the sinecatechins ointment 15% and 10% groups, and 72.1% of vehicle patients experienced application site reactions; 49.2%, 46.2%, and 65.4% of those, respectively, were mild or moderate. CONCLUSION: Topical sinecatechins ointments 15% and 10% are effective and well-tolerated in the treatment of anogenital warts. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00449982. LEVEL OF EVIDENCE: I.     

Adrenalinhyperglykämie beim Hungerödem

Journal of Molecular Medicine - Bei 36 Hunge kranken wurde nach Ausschwemmung der Ödeme der Blutzuckerspiegel nach einer subcutanen Adrenalininjektion untersucht. Die Art des Zuckeranstieges...     

Structural conservation among variants of the SARS-CoV-2 spike postfusion bundle

Variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) challenge currently available COVID-19 vaccines and monoclonal antibody therapies due to structural and dynamic changes of the viral spike glycoprotein (S). The heptad repeat 1 (HR1) and heptad repeat 2 (HR2) domains of S drive virus–host membrane fusion by assembly into a six-helix bundle, resulting in delivery of viral RNA into the host cell. We surveyed mutations of currently reported SARS-CoV-2 variants and selected eight mutations, including Q954H, N969K, and L981F from the Omicron variant, in the postfusion HR1HR2 bundle for functional and structural studies. We designed a molecular scaffold to determine cryogenic electron microscopy (cryo-EM) structures of HR1HR2 at 2.2–3.8 Å resolution by linking the trimeric N termini of four HR1 fragments to four trimeric C termini of the Dps4 dodecamer from Nostoc punctiforme. This molecular scaffold enables efficient sample preparation and structure determination of the HR1HR2 bundle and its mutants by single-particle cryo-EM. Our structure of the wild-type HR1HR2 bundle resolves uncertainties in previously determined structures. The mutant structures reveal side-chain positions of the mutations and their primarily local effects on the interactions between HR1 and HR2. These mutations do not alter the global architecture of the postfusion HR1HR2 bundle, suggesting that the interfaces between HR1 and HR2 are good targets for developing antiviral inhibitors that should be efficacious against all known variants of SARS-CoV-2 to date. We also note that this work paves the way for similar studies in more distantly related viruses.

Three previously unknown beta-coronaviruses have emerged in the first two decades of this century: severe acute respiratory syndrome coronavirus (SARS-CoV) in 2003, Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in late 2019 (1). The most recent outbreak of SARS-CoV-2 that causes coronavirus disease 2019 (COVID-19) has claimed about 6 million lives in 2 y, and several variants of concern have emerged around the globe despite the relatively low mutation rate of coronaviruses (2). Some of these variants pose a challenge to currently available vaccines (3–6), likely due to structural changes of the target of these vaccines (7–11). Hence, there is an urgent need for new antiviral therapeutics (12) that target regions of viruses with conserved structural features that are less likely to be affected by mutations.SARS-CoV, MERS-CoV, and SARS-CoV-2 are enveloped viruses that rely on membrane fusion to deliver RNA to the host cell (13). In each case, the process of viral membrane fusion (14, 15) is mediated by the trimeric viral spike glycoprotein (S) that is cleaved into S1 and S2 subunits by multiple host proteases upon infection (16) (Fig. 1A). S1 recognizes the human angiotensin-converting enzyme 2 (ACE2) receptor and dissociates from S2. Subsequently, S2 undergoes substantial conformational changes that drive membrane remodeling. Similar to other enveloped viruses (14, 15), this process likely proceeds via an intermediate extended state that pulls together the two membranes via the transmembrane domain and fusion peptide of the S2 subunit (17). Two heptad repeat regions, HR1 and HR2, distant from each other in the prefusion S, drive membrane fusion by assembly into a six-helix bundle (18). This HR1HR2 bundle formation is thought to provide the energy for membrane fusion and is therefore a target for therapeutics, as exemplified by peptide inhibitors that disrupt infection by the HIV-1 (19, 20), SARS-CoV (21), MERS-CoV (22), SARS-CoV-2 (23–25), human parainfluenza virus 3 (26), and respiratory syncytial virus (26).Open in a separate windowFig. 1.Mutations of interest in the HR1HR2 bundle of SARS-CoV-2 variants. (A) Schematic diagram of the domain structures of the SARS-CoV-2 spike protein. The N and C termini are labeled on the left and right, respectively. FP, fusion peptide; HR1, heptad repeat 1; HR2, heptad repeat 2; TM, transmembrane region. (B) Locations of the five selected point mutations of SARS-CoV-2 variants (black spheres) and the three mutations of the SARS-CoV-2 Omicron variant (purple spheres) indicated in the crystal structure of the HR1HR2 bundle (PDB ID code 6lxt). Two HR2 residues, R1185 and N1187, that may be affected by the selected mutations are shown as red spheres. The HR1 and HR2 fragments are colored as light blue and light red, respectively. (C) Effects on fusion activity of these mutations. The fusion activity is shown as a percentage (Left)/fold change (Right) relative to that of the wild type (Materials and Methods). The Omicron construct used here for the fusion assay has three mutations—Q954H, N969K, and L981F—in the HR1 portion of the HR1HR2 bundle, but not other mutations from different regions of the spike found in the Omicron variant. *P < 0.05, **P < 0.01, ***P < 0.001, by a Student’s t test.Despite the established value of inhibitors targeting formation of the HR1HR2 bundle, the structural plasticity of this bundle upon mutation is largely unknown. Comparison with distantly related viruses suggests that the overall architecture is maintained despite vast differences in primary sequence (SI Appendix, Fig. S1). To what degree does the structure of the HR1HR2 bundle change upon mutation? To address this question, we surveyed mutations of all currently known variants (including Omicron) of SARS-CoV-2 S in the postfusion HR1HR2 bundle, selected eight mutations of potential interest, and investigated their effects on structure and function.Structural characterization of the HR1HR2 bundle has proven surprisingly challenging. To date, two successful approaches for determining structures of the HR1HR2 bundle have been employed. First, several HR1HR2 structures with the HR1 and HR2 domains synthetically linked were determined by X-ray crystallography (2.9 Å, Protein Data Bank [PDB] ID code 6lxt; 1.5 Å, PDB ID code 6m1v) (23, 25). Second, a sample of postfusion S2 was generated from a recombinant source (mammalian HEK-293F cells) expressing full-length S; as such, multiple states of S undergoing spontaneous transition from the prefusion to the postfusion state were present in the sample and the postfusion structure was determined by single-particle cryogenic electron microscopy (cryo-EM) (3.0 Å, PDB ID code 6xra) (18). Although the structures of the postfusion HR1HR2 bundle are similar, there are differences between these structures and the local resolution is quite variable or limited. More importantly, neither approach is particularly suited for efficient structure determination of multiple mutants at high resolution. Therefore, we decided to develop a platform for using single-particle cryo-EM to efficiently determine structures of HR1HR2 bundles at atomic resolution.The postfusion HR1HR2 bundle of SARS-CoV-2 is a 115 × 25 × 25 Å bundle consisting of six helices (PDB ID code 6lxt) (23). Its molecular weight is 40 kDa, close to the theoretical minimum size needed to achieve a reconstruction with near-atomic resolution by cryo-EM (27). To our knowledge, it has not yet been possible to determine structures of individual proteins <50 kDa to high resolution, with exception in the case of multimers (28, 29) or small RNA molecules (30). In addition, efforts extending the resolution limit of cryo-EM have largely focused on globular proteins (28, 29, 31, 32), perhaps because fibrous samples are more flexible, more susceptible to the issue of preferred orientation, and require thicker ice to bury the entire particle—all of which inevitably increase noise in the already extremely low-contrast and hard-to-align images. To overcome the size limit of single-particle cryo-EM, two strategies have been employed to increase the effective mass of the target protein, e.g. using antibodies/nanobodies/legobodies (33, 34) and molecular scaffolds (35–38). Since developing antibodies/nanobodies/legobodies can be time-consuming we resorted to the molecular scaffold approach. We first attempted to use existing scaffolds but were unable to engineer a linkage ensuring proper HR1HR2 bundle formation. We therefore designed a scaffold to efficiently determine structures of the postfusion HR1HR2 bundle and its mutants to near-atomic resolution by single-particle cryo-EM.Our high-resolution wild-type structure of the HR1HR2 bundle resolves uncertainties in some side-chain positions present in prior structures. Our HR1HR2 structures of SARS-CoV-2 variants reveal an overall architecture that is highly conserved, with only side-chain rearrangement for five point mutations and, for the Omicron variant containing three mutations in HR1, a slight shift of the HR2 backbone in a nonhelical region that interacts with HR1. These results suggest that interactions between HR1 and HR2 are excellent targets for disruption by broadly efficacious antiviral inhibitors. Moreover, our approach can be directly used to study the binding of potential HR2-based peptide inhibitors and adapted to study the postfusion bundles of other coronaviruses or other structurally similar viruses.     

Experimental radiofrequency ablation near the portal and the hepatic veins in pigs: differences in efficacy of a monopolar ablation system

BACKGROUND: We sought to compare the efficacy of a monopolar radiofrequency ablation system in vivo near the portal vein and the hepatic veins in porcine liver. MATERIALS AND METHODS: Radiofrequency ablation of healthy livers near the portal vein and the hepatic veins was performed in 10 pigs with a multitined expandable electrode. Volumes and diameters of zones of ablation were assessed by magnetic resonance imaging. RESULTS: Volumes (16.0 +/- 5.5 mL, P = 0.001) and diameters (4.0 +/- 0.7 cm, 3.3 +/- 0.7 cm, 3.0 +/- 0.6 cm, P 相似文献