Objective: To study the perception of informed consent among various raters for thrombolysis in acute ischemic stroke patients receiving intravenous tissue plasminogen activator (IV-tPA). Methods: Twenty randomly selected videotaped telestroke consultations of acute stroke patients administered IV-tPA were retrospectively reviewed. Adequacy of informed consent was reviewed by five raters: a neurologist and emergency physician who routinely treat stroke, a medical risk management paralegal, a bioethicist, and a lay person. Raters assessed the quality of the informed consent presentation by the treating physician and the degree of understanding demonstrated by the patient/family authorizing consent. Factors associated with adequacy of consent were analyzed. Results: Consent was rated as adequately understood by the patient-family in 78.6% cases. Agreement between all five raters with regard to the patient-family understanding of consent was poor and also between the subgroups of non-physician and physician (all k < 0.20). Similarly, the quality of the physician consent process was poor for agreement between all five raters (k = 0.07) or between the subgroup of the three non-physician raters (k = −0.06) and fair between the two physician raters (k = 0.24). The legal reviewer and the bioethicist rated the physician consent process as being of lower quality than did the two physicians and the layperson. Conclusion: Despite high variability in the perception of informed consent among raters in this time-sensitive clinical situation, almost 80% of patients were rated by all reviewers as having adequate understanding of risks and benefits of tPA. This suggests the need for a standardized but brief tPA consent process that includes patient/family demonstration of understanding.

The purpose of this review is to present the preclinical, epidemiological and clinical data relevant to the association between β-blockers and breast cancer progression. Preclinical studies have shown that β-adrenergic receptor (β-AR) signalling can inhibit multiple cellular processes involved in breast cancer progression and metastasis, including extracellular matrix invasion, expression of inflammatory and chemotactic cytokines, angiogenesis and tumour immune responses. This has led to the hypothesis that the commonly prescribed class of β-AR antagonist drugs (β-blockers) may favourably impact cancer progression. A number of recent pharmacoepidemiological studies have examined the association between β-blocker exposure and breast cancer progression. The results from these studies have suggested a potential role for targeting the β-AR pathway in breast cancer patients. Larger observational studies are, however, required to confirm these results. Questions regarding the type of β-blocker, predictive biomarkers or tumour characteristics, appropriate treatment paradigms and, most importantly, efficacy must also be answered in randomized clinical studies before β-blockers can be considered a therapeutic option for patients with breast cancer.

Summary

Protein quality control (PQC) degradation systems protect the cell from the toxic accumulation of misfolded proteins. Because any protein can become misfolded, these systems must be able to distinguish abnormal proteins from normal ones, yet be capable of recognizing the wide variety of distinctly shaped misfolded proteins they are likely to encounter. How individual PQC degradation systems accomplish this remains an open question. Here we show that the yeast nuclear PQC ubiquitin ligase San1 directly recognizes its misfolded substrates via intrinsically disordered N- and C-terminal domains. These disordered domains are punctuated with small segments of order and high sequence conservation that serve as substrate-recognition sites San1 uses to target its different substrates. We propose that these substrate-recognition sites, interspersed among flexible, disordered regions, provide San1 an inherent plasticity that allows it to bind its many, differently shaped misfolded substrates.

Widely known for its role in adipogenesis and energy metabolism, PPARγ also plays a role in platelet function. To further understand functions of platelet-derived PPARγ, we produced rabbit polyclonal (PoAbs) and mouse monoclonal (MoAbs) antibodies against PPARγ 14mer/19mer peptide-immunogens. Unexpectedly, our work produced two key findings. First, MoAbs but not PoAbs produced against PPARγ peptide-immunogens displayed antigenic crossreactivity with highly conserved PPARα and PPARβ/δ. Similarly, Santa Cruz PoAb sc-7196 was monospecific for PPARγ while MoAb sc-7273 crossreacted with PPARα and PPARβ/δ. Second, immunized rabbits and mice exhibited unusual pathology including cachexia, excessive bleeding, and low platelet counts leading to thrombocytopenia. Spleens from immunized mice were fatty, hemorrhagic and friable. Although passive administration of anti-PPARγ PoAbs failed to induce experimental thrombocytopenia, megakaryocytopoiesis was induced 4–8–fold in mouse spleens. Similarly, marrow megakaryocytopoiesis was enhanced 1.8–4–fold in immunized rabbits. These peptide-immunogens are 100% conserved in human, rabbit and mouse; thus, immune-mediated platelet destruction via crossreactivity with platelet-derived PPARγ likely caused bleeding, thrombocytopenia, and compensatory megakaryocytopoiesis. Such overt pathology would cause significant problems for large-scale production of anti-PPARγ PoAbs. Furthermore, a major pitfall associated with MoAb production against closely related molecules is that monoclonicity does not guarantee monospecificity, an issue worth further scientific scrutiny.

The yeast nuclear protein quality control ubiquitin ligase San1 recognizes exposed hydrophobicity in its misfolded substrates. San1 recognition is triggered by exposure of as few as five contiguous hydrophobic residues, which defines the minimum window of hydrophobicity required for San1 targeting.

Protein quality control (PQC) degradation protects the cell by preventing the toxic accumulation of misfolded proteins. In eukaryotes, PQC degradation is primarily achieved by ubiquitin ligases that attach ubiquitin to misfolded proteins for proteasome degradation. To function effectively, PQC ubiquitin ligases must distinguish misfolded proteins from their normal counterparts by recognizing an attribute of structural abnormality commonly shared among misfolded proteins. However, the nature of the structurally abnormal feature recognized by most PQC ubiquitin ligases is unknown. Here we demonstrate that the yeast nuclear PQC ubiquitin ligase San1 recognizes exposed hydrophobicity in its substrates. San1 recognition is triggered by exposure of as few as five contiguous hydrophobic residues, which defines the minimum window of hydrophobicity required for San1 targeting. We also find that the exposed hydrophobicity recognized by San1 can cause aggregation and cellular toxicity, underscoring the fundamental protective role for San1-mediated PQC degradation of misfolded nuclear proteins.

Hepatitis C virus (HCV) infection causes significant morbidity, and efficient mouse models would greatly facilitate virus studies and the development of effective vaccines and new therapeutic agents. Entry factors, innate immunity, and host factors needed for viral replication represent the initial barriers that restrict HCV infection of mouse cells. Experiments in this paper consider early postentry steps of viral infection and investigate the roles of interferon regulatory factors (IRF-3 and IRF-9) and microRNA (miR-122) in promoting HCV replication in mouse embryo fibroblasts (MEFs) that contain viral subgenomic replicons. While wild-type murine fibroblasts are restricted for HCV RNA replication, deletion of IRF-3 alone can facilitate replicon activity in these cells. This effect is thought to be related to the inactivation of the type I interferon synthesis mediated by IRF-3. Additional deletion of IRF-9 to yield IRF-3−/− IRF-9−/− MEFs, which have blocked type I interferon signaling, did not increase HCV replication. Expression of liver-specific miR-122 in MEFs further stimulated the synthesis of HCV replicons in the rodent fibroblasts. The combined effects of miR-122 expression and deletion of IRF-3 produced a cooperative stimulation of HCV subgenome replication. miR-122 and IRF-3 are independent host factors that are capable of influencing HCV replication, and our findings could help to establish mouse models and other cell systems that support HCV growth and particle formation.

Background

A newly identified mechanism of smooth muscle relaxation is the interaction between the small heat shock protein 20 (HSP20) and 14-3-3 proteins. Focusing upon this class of interactions, we describe here a novel drug target screening approach for treating airflow obstruction in asthma.

Methods

Using a high-throughput fluorescence polarization (FP) assay, we screened a library of compounds that could act as small molecule modulators of HSP20 signals. We then applied two quantitative, cell-based biophysical methods to assess the functional efficacy of these molecules and rank-ordered their abilities to relax isolated human airway smooth muscle (ASM). Scaling up to the level of an intact tissue, we confirmed in a concentration-responsive manner the potency of the cell-based hit compounds.

Results

Among 58,019 compound tested, 268 compounds caused 20% or more reduction of the polarized emission in the FP assay. A small subset of these primary screen hits, belonging to two scaffolds, caused relaxation of isolated ASM cell in vitro and attenuated active force development of intact tissue ex vivo.

Conclusions

This staged biophysical screening paradigm provides proof-of-principle for high-throughput and cost-effective discovery of new small molecule therapeutic agents for obstructive lung diseases.

Protective humoral immune responses critically depend on the optimal differentiation of B cells into antibody secreting cells. Because of the important role of antibodies in fighting infections and in successful vaccination, it is imperative to identify mediators that control B cell differentiation. Activation of B cells through toll-like receptor 9 (TLR-9) by CpG-DNA induces plasma cell differentiation and antibody production. Herein, we examined the role of the PPARγ/RXRα pathway on human B cell differentiation. We demonstrated that activated B cells upregulate their expression of PPARγ. We also show that nanomolar levels of natural (15d-PGJ2) or synthetic (Rosiglitazone) PPARγ ligands enhanced B cell proliferation and significantly stimulated plasma cell differentiation and antibody production. Moreover, the addition of GW9662, a specific PPARγ antagonist, abolished these effects. RXR is the binding partner for PPARγ and is required to produce an active transcriptional complex. The simultaneous addition of nanomolar concentrations of the RXRα ligand (9-cis-RA) and PPARγ ligands to CpG-activated B cells resulted in additive effects on B cell proliferation, plasma cell differentiation and antibody production. Furthermore, PPARγ ligands alone or combined with 9-cis-RA enhanced CpG-induced expression of Cox-2 and the plasma cell transcription factor BLIMP-1. Induction of these important regulators of B cell differentiation provides a possible mechanism for the B cell enhancing effects of PPARγ ligands. These new findings indicate that low doses of PPARγ/RXRα ligands could be used as a new type of adjuvant to stimulate antibody production.

Several lines of evidence suggest that exploring the neurochemical basis of reward in invertebrate species may provide clues for the fundamental behavioral and neurobiology underpinnings of drug addiction. How the presence of drug-sensitive reward relates to a decrease in drug-seeking behavior and reinstatement of drug seeking behavior in invertebrate systems is not known. The present study of a conditioned place preference (CPP) paradigm in crayfish (Orconectes rusticus) explores morphine-induced reward, extinction and reinstatement. Repeated intra-circulatory infusions of 2.5μg/g, 5.0μg/g and 10.0μg/g doses of morphine over 5 days serve as a reward when paired with a distinct visual or tactile environment. Morphine-induced CPP was extinguished after repeated saline injections for 5 days in the previously morphine-paired compartment. After the previously established CPP had been eliminated during the extinction phase, morphine-experienced crayfish were challenged with 2.5 μg/g, 5.0 μg/g and 10.0 μg/g respectively. The priming injections of morphine reinstated CPP in all training doses, suggesting that morphine-induced CPP is unrelenting, and that with time, it can be reinstated by morphine following extinction in an invertebrate model just like in mammals. Together with other recent studies, this work demonstrates the advantage of using crayfish as an invertebrate animal model to investigate the basic biological processes that underline exposure to mammalian drugs of abuse.

The structure of the title compound, C18H10N2S3, consists of a central thio­phene ring and two terminal thia­zole rings. The two S atoms of the thia­zole rings are trans to the thio­phene S atom sulfur. The thia­zole rings are approximately coplanar with the thio­phene ring, with dihedral angles of 6.23 (11) and 4.81 (11)° between them. In the crystal, zigzag chains are formed along [010] by weak C—H⋯N inter­actions.

Coronary ostial stenosis is a rare but potentially serious sequela after aortic valve replacement. It occurs in the left main or right coronary artery after 1% to 5% of aortic valve replacement procedures. The clinical symptoms are usually severe and may appear from 1 to 6 months postoperatively. Although the typical treatment is coronary artery bypass grafting, patients have been successfully treated by means of percutaneous coronary intervention.

Herein, we present the cases of 2 patients in whom coronary ostial stenosis developed after aortic valve replacement. In the 1st case, a 72-year-old man underwent aortic valve replacement and bypass grafting of the saphenous vein to the left anterior descending coronary artery. Six months later, he experienced a non-ST-segment-elevation myocardial infarction. Coronary angiography revealed a critical stenosis of the right coronary artery ostium. In the 2nd case, a 78-year-old woman underwent aortic valve replacement and grafting of the saphenous vein to an occluded right coronary artery. Four months later, she experienced unstable angina. Coronary angiography showed a critical left main coronary artery ostial stenosis and occlusion of the right coronary artery venous graft. In each patient, we performed percutaneous coronary intervention and deployed a drug-eluting stent. Both patients were asymptomatic on 6-to 12-month follow-up. We attribute the coronary ostial stenosis to the selective ostial administration of cardioplegic solution during surgery. We conclude that retrograde administration of cardioplegic solution through the coronary sinus may reduce the incidence of postoperative coronary ostial stenosis, and that stenting may be an efficient treatment option.

In the title compound, C20H16N3O+·Br−·C2H6O, the phenol ring forms dihedral angles of 84.5 (1) and 89.3 (1)° with the benzimidazole system and the quinazoline benzene ring, respectively. The two N—H groups act as donors in hydrogen bonds with the bromide ion as acceptor, leading to infinite eight-membered chains along [100]. According to graph-set theory the descriptor on the binary level is C 2 1(8). O—H⋯O and O—H⋯Br hydrogen bonds also occur.

In the structure of the title compound, C20H16N4·CH4O, the aniline ring forms dihedral angles of 89.9 (2) and 85.4 (2)° with the benzimidazole and benzene rings, respectively. The orientation of the aniline ring is mainly determined by strong hydrogen bonds between the amino group and the non-fused quinazoline N atom. Inter­molecular hydrogen bonds of the N—H⋯N—H⋯N type along [010] and the N—H⋯O—H⋯N type along [100] are formed, resulting in C 2 2(4) and C 2 2(10) descriptors, respectively, on a binary level of graph-set analysis. There are C—H⋯π contacts with H⋯π distances of 2.44 Å; however, no π-stacking is observed.

In the structure of the title compound, C20H18N4O2, the N—H and C=O bonds are trans to each other and the amide O atoms are syn to the ortho amino N atom in the benzoyl rings. The amide groups form dihedral angles of 8.4 (2) and 13.8 (2)° with their respective benzoyl rings, and dihedral angles of 51.85 (16) and 51.19 (17)° with the phenyl­enediamine ring. In the crystal, a centrosymmetric dimer is formed by inter­molecular N—H⋯O hydrogen bonds, resulting in an R 2 2(14) descriptor on a unitary level of graph-set analysis, and three intramolecular N—H⋯O bonds also occur.

The unique capabilities of multiple collector inductively coupled mass spectrometry (MC-ICP-MS) for high precision isotope ratio measurements in light elements as Li, Mg, Ca, and Cu are reviewed in this paper. These elements have been intensively studied at the Geological Survey of Israel (GSI) and other laboratories over the past few years, and the methods used to obtain high precision isotope analyses are discussed in detail. The scientific study of isotopic fractionation of these elements is significant for achieving a better understanding of geochemical and biochemical processes in nature and the environment.

A 13 year old female patient presented to ENT OPD with chronic recurrent tonsillitis and underwent tonsillectomy. The histopathological examination revealed heterotopic cartilage in both the tonsils. The postoperative period was uneventful. The histopathologic finding of choristom of the tonsil is rare.

Debate continues over the effectiveness of screening by mammography in women below age 50. We report here on results of screening in the first 10 years of a randomised trial to study the effect on breast cancer mortality of invitation to annual mammography from age 40 to 41 compared to first invitation to the 3-yearly UK national programme at age 50–52. The trial is taking place in 23 NHS breast screening centres. Between 1991 and 1997, 160 921 women were randomised in the ratio 1 : 2 to intervention and control arms. Screening is by two views at first screen and single view subsequently; data on screening up to and including round five are now complete. Uptake of invitation to screening is between 68 and 70% at all but the latest screening rounds. Rates of referral for assessment are 4.6% at first screen and 3.4% at subsequent screens. Invasive cancer detection rates are 0.09% at first screen, and similar at rescreens until the sixth and later screens. There is little evidence of regular mammography in the trial control arm. The setting of this trial within the NHS breast screening programme should ensure applicability of results to a national programme.