A covalent fragment-based strategy targeting a novel cysteine to inhibit activity of mutant EGFR kinase

Several generations of ATP-competitive anti-cancer drugs that inhibit the activity of the intracellular kinase domain of the epidermal growth factor receptor (EGFR) have been developed over the past twenty years. The first-generation of drugs such as gefitinib bind reversibly and were followed by a second-generation such as dacomitinib that harbor an acrylamide moiety that forms a covalent bond with C797 in the ATP binding pocket. Resistance emerges through mutation of the T790 gatekeeper residue to methionine, which introduces steric hindrance to drug binding and increases the Km for ATP. A third generation of drugs, such as osimertinib were developed which were effective against T790M EGFR in which an acrylamide moiety forms a covalent bond with C797, although resistance has emerged by mutation to S797. A fragment-based screen to identify new starting points for an EGFR inhibitor serendipitously identified a fragment that reacted with C775, a previously unexploited residue in the ATP binding pocket for a covalent inhibitor to target. A number of acrylamide containing fragments were identified that selectively reacted with C775. One of these acrylamides was optimized to a highly selective inhibitor with sub-1 μM activity, that is active against T790M, C797S mutant EGFR independent of ATP concentration, providing a potential new strategy for pan-EGFR mutant inhibition.

PAC-FragmentDEL - photoactivated covalent capture of DNA-encoded fragments for hit discovery

We describe a novel approach for screening fragments against a protein that combines the sensitivity of DNA-encoded library technology with the ability of fragments to explore what will bind. Each of the members of the library consists of a fragment which is linked to a photoactivatable diazirine moiety. Split and pool synthesis combines each fragment with a set of linkers with the version of the library reported here containing some 70k different compounds, each with an individual DNA code. Incubation of the library with a protein sample is followed by photoactivation, washing and subsequent PCR and sequencing which allows the individual fragment hits to be identified. We illustrate how the approach allows successful hit fragment identification using only microgram quantities of material for two targets. PAK4 is a kinase for which conventional fragment screening has generated many advance leads. The as yet undrugged target, 2-epimerase, presents a more challenging active site for identification of hit compounds. In both cases, PAC-FragmentDEL identified fragments validated as hits by ligand-observed NMR measurements and crystal structure determination of off-DNA sample binding to the proteins.

A genome guided evaluation of the Lab4 probiotic consortium

In this study, we present the draft genome sequences of the Lab4 probiotic consortium using whole genome sequencing. Draft genome sequences were retrieved and deposited for each of the organisms; PRJNA559984 for B. bifidum CUL20, PRJNA482335 for Lactobacillus acidophilus CUL60, PRJNA482434 for Lactobacillus acid. Probiogenomic in silico analyses confirmed existing taxonomies and identified the presence putative gene sequences that were functionally related to the performance of each organism during in vitro assessments of bile and acid tolerability, adherence to enterocytes and susceptibility to antibiotics. Predictions of genomic stability identified no significant risk of horizontal gene transfer in any of the Lab4 strains and the absence of both antibiotic resistance and virulence genes. These observations were supported by the outcomes of acute phase and repeat dose tolerability studies in Wistar rats where challenge with high doses of Lab4 did not result in any mortalities, clinical/histopathological abnormalities nor indications of systemic toxicity. Detection of increased numbers of lactobacilli and bifidobacteria in the faeces of supplemented rats implied an ability to survive transit through the gastrointestinal tract and/or impact upon the intestinal microbiota composition. In summary, this study provides in silico, in vitro and in vivo support for probiotic functionality and the safety of the Lab4 consortium.

Computerized Tailored Interventions to Enhance Prevention and Screening for Hepatitis C Virus Among People Who Inject Drugs: Protocol for a Randomized Pilot Study

Background

Hepatitis C virus (HCV) infection is a growing problem among people who inject drugs. Strategies to reduce disease transmission (eg, syringe exchange programs) and facilitate HCV screening and linkage are available but are under-utilized in many communities affected by injection drug use. Novel approaches to increasing the use of these strategies are needed.

Objective

The goals of this project are to (1) develop and pilot test a computerized tailored intervention for increasing HCV screening and decreasing risky drug use behavior among people who inject drugs and (2) determine the feasibility of disseminating such an intervention using peer-based referrals in the setting of a community-based syringe exchange program.

Methods

This 2-arm, randomized pilot study is being conducted in a large-volume, multisite syringe exchange program in southern Wisconsin. A social network–based strategy was used to recruit a total of 235 adults who reported past-month injection of opioids, cocaine, or methamphetamine. Network recruiters were identified among clients requesting services from the syringe exchange program and were enlisted to refer eligible peers to the study. All participants completed a computer-adapted questionnaire eliciting information about risk behaviors and their knowledge, attitudes, and prior experiences related to HCV screening. Subjects were then randomly assigned to receive usual care, consisting of standard counseling by syringe exchange staff, or the Hep-Net intervention, which provides algorithm-based, real-time tailored feedback and recommendations for behavior change in the style of motivational interviewing. Changes in drug use behaviors and attitudes will be assessed during a second session between 90 and 180 days after the baseline visit. Frequency of repeat HCV testing and HCV incidence will be assessed through a database search 1 year after study completion.

Results

Recruitment for this study was completed in April 2015. Follow-up of enrolled participants is expected to continue until March 2016. Network recruiters were enrolled who referred a total of 195 eligible peers (overall N=235). At baseline, the median age was 34 years; 41.3% (97/235) were non-white; and 86.4% (203/235) reported predominantly injecting heroin. Most participants (161/234, 68.8%) reported sharing injection equipment in the past and of these, 30.4% (49/161) had never been tested for HCV.

Conclusions

This study will provide preliminary evidence to determine whether incorporating computerized behavioral interventions into existing prevention services at syringe exchange programs can lead to adoption of healthier behaviors.

Trial Registration

ClinicalTrials.gov NCT02474043; https://clinicaltrials.gov/ct2/show/NCT02474043 (Archived by WebCite at http://www.webcitation.org/6dbjUQG7J)

A practical approach to glare assessment for train cabs

The assessment of glare is a key consideration in the design of a railway driver's cab. However, unlike assessment of other factors, such as forward visibility, there are no standardised approaches for performing assessments of glare. This paper describes an approach for assessing the impact of glare in a full size mock-up of a railway cab. While it is unrealistic to evaluate every possible lighting condition that may potentially occur in the vehicle cab in service, a pragmatic and practical approach is taken to provide a good level of indicative information about the cab design's likely glare performance. This involves assessing internal light sources, such as internal lights and illuminated controls, and simulating external light sources (e.g. the sun, other trains' headlights) by illuminating the cab mock up windscreen, side and door windows with a single light source manually located in a sequence of discrete positions and orientations and assessing the resulting glare impacts. The paper describes a structured process for assessing and recording the impact of glare and recommending mitigations.

Essential thioredoxin-dependent peroxiredoxin system from Helicobacter pylori: genetic and kinetic characterization

Helicobacter pylori, an oxygen-sensitive microaerophile, contains an alkyl hydroperoxide reductase homologue (AhpC, HP1563) that is more closely related to 2-Cys peroxiredoxins of higher organisms than to most other eubacterial AhpC proteins. Allelic replacement mutagenesis revealed ahpC to be essential, suggesting a critical role for AhpC in defending H. pylori against oxygen toxicity. Characterization of the ahpC promoter region divulged two putative regulatory elements and identified the transcription initiation site, which was mapped to 96 and 94 bp upstream of the initiation codon. No homologue of ahpF, which encodes the dedicated AhpC reductase in most eubacteria, was found in the H. pylori genome. Instead, homologues of Escherichia coli thioredoxin (Trx) reductase (TrxR, HP0825) and Trx (Trx1, HP0824) formed a reductase system for H. pylori AhpC. A second Trx homologue (Trx2, HP1458) was identified but was incapable of AhpC reduction, although Trx2 exhibited disulfide reductase activity with other substrates [insulin and 5,5'-dithiobis(2-nitrobenzoic acid)]. AhpC interactions with each substrate, Trx1 and hydroperoxide, were bimolecular and nonsaturable (infinite V(max) and K(m) values) but rapid enough (at 1 x 10(5) to 2 x 10(5) M(-1) s(-1)) to suggest an important role for AhpC in cellular peroxide metabolism. AhpC also exhibited a wide specificity for hydroperoxide substrates, which, taken together with the above results, suggests a minimal binding site for hydroperoxides composed of little more than the cysteinyl (Cys49) active site. H. pylori AhpC was not reduced by Salmonella typhimurium AhpF and was slightly more active with E. coli TrxR and Trx1 than was S. typhimurium AhpC, demonstrating the specialized catalytic properties of this peroxiredoxin.

An analysis of the readability and cultural sensitivity of information on the National Cancer Institute's Web site: CancerNet

PURPOSE/OBJECTIVES

To ascertain the level of reading skills required by lay people who access patient-related cancer information through CancerNet, the Web site of the National Cancer Institute (NCI), and to assess the cultural sensitivity of the information targeted to certain ethnic groups.

DESIGN

Descriptive study, repeated measures.

SETTING

NCI's CancerNet Web site (http://cancernet.nci.nih.gov).

SAMPLE

A convenience sample of 49 documents from the CancerNet Web site was analyzed.

METHODS

The readability of each document was analyzed using the Flesch-Kincaid readability formula. Using Bloch's Ethnic/Cultural Assessment Tool as a guide, a content analysis of the ethnic-related documents was performed to determine the cultural sensitivity of the information.

MAIN RESEARCH VARIABLES

Readability and cultural sensitivity of the written cancer information.

FINDINGS

The overall mean reading level was 12th grade. Little variation existed in the cultural content of the information even though several ethnic groups were targeted.

CONCLUSION

Information on CancerNet needs to be modified to meet the information needs of people with low reading skills and to make the information more culturally sensitive for various ethnic groups.

IMPLICATIONS FOR NURSING PRACTICE

Finding successful methods for educating patients and families is a primary responsibility of oncology nurses. Information can play a vital role in helping patients to engage in self-care behavior. Therefore, nurses must be knowledgeable about the readability, usefulness, and cultural-sensitivity of information on cancer Web sites so that they can guide patients to appropriate Internet resources.

Theories for practitioners: two frameworks for studying consumer health information-seeking behavior

Consumer health information studies in library and information science (LIS) are typically not grounded within a theoretical framework. This article explains the importance of theory to LIS research in general, and the specific value of using theories from other disciplines to study consumers' health information-seeking behavior. The argument is supported with two examples: Miller's psychological theory of blunting and monitoring behavior and Granovetter's sociological theory of the strength of weak ties. These theories can be applied by practitioner-researchers to investigate a variety of research problems.

Novel glycineB antagonists show neuroprotective activity in vivo

The degeneration or dysfunction of cholinergic neurons within the basal forebrain of patients with Alzheimer's disease (AD) may be related to the vulnerability of these cells to endogenous glutamate (Beal, 1995; Greenamyre and Young, 1989). The administration of drugs that attenuate the toxic actions of glutamate in the early stages of the disease might significantly delay its rate of progression. Two approaches to neuroprotection from endogenous glutamatergic function were investigated and found to be effective: blockade of voltage-dependent, NMDA-type glutamate receptor channels and antagonism of an NMDA-receptor related glycineB modulatory site.

Neuroprotection by novel antagonists at the NMDA receptor channel and glycineB sites

Glutamate may act via an N-methyl-D-Aspartate (NMDA)-sensitive receptor site to destroy cholinergic neurons within the nucleus basalis magnocellularis in age-associated neurodegenerative diseases. Multiple interesting properties of the NMDA receptor are relevant to its excitotoxic actions, e.g., glutamate is ineffective unless a glycine (gly) modulatory site is also occupied. Thus, the antagonism of glutamate receptor-related toxicity by blockade of either the NMDA-sensitive recognition site or the gly binding site may therefore have therapeutic applications. The current study investigated the ability of four novel noncompetitive antagonists at these two sites: one NMDA open channel antagonist (MRZ 2/579: 1-amino-1,3,3,5,5-pentamethyl-cyclohexane hydrochloride), and three glyB receptor antagonists (MRZ 2/570: 8-bromo-4-hydroxy-1-oxo-1,2-dihydropyridaziono [4,5-beta] quinoline-5-oxide choline salt; MRZ 2/57: 8-fluoro-4-hydroxy-1-oxo-1,2-dihydropyridaziono [4,5-beta] quinoline-5-oxide choline; MRZ 2/576: 8-chloro-4-hydroxy-1-oxo-1,2-dihydropyridaziono [4,5-beta] quinoline-5-oxide choline) administered acutely, to provide neuroprotection from a NMDA receptor agonist within the nucleus basalis magnocellularis of young rats. Injection of NMDA into the nucleus basalis magnocellularis significantly decreased cortical choline acetyltransferase activity. Acute administration (i.p.) of MRZ 2/579, 2/570, 2/571 and 2/576 provided significant neuroprotection from NMDA.

Sense making in multiple sclerosis: the information needs of people during an acute exacerbation

Chronic illness has been described as a major disruption in one's everyday life. Studies have shown that people seek and use information to help them cope with their disease. Using the micro-moment time-line interview technique, this study focused on the information needs of people with multiple sclerosis (MS) who had recently experienced an exacerbation of their disease. The results revealed gaps in people's knowledge about physical symptoms they were experiencing, emotions they felt, and drugs. Various sources of and barriers to obtaining information were identified. The results suggest that health professionals need to be aware of the continuing need for relevant, current, and specific information to help people with MS retain their independence and to empower them to make informed decisions.

The effects of selective cholinergic basal forebrain lesions and aging upon expectancy in the rat

The effects of selective cholinergic cell loss within the basal forebrain (BF) were determined using a task that requires shifting of attention between two visual stimuli. Discriminability between two stimuli and response bias were determined in young and old F-344 rats given BF injections of IgG-192 saporin (100 ng). The lesion reduced ChAT activity in the frontal and parietal cortices, hippocampus, and olfactory bulbs. The lesion did not significantly alter Na+/K(+)-ATPase activity in cortex, hippocampus, or olfactory bulbs, or endogenous levels of neuropeptide Y and neurokinin B within the BF. The BF lesions impaired both stimulus discriminability and response bias in young and old rats. The BF lesions had a significantly greater effect upon stimulus discriminability and response bias in aged rats, compared to young rats, only when the stimulus duration was very brief, i.e., when the task was most difficult to solve. At longer stimulus durations, aging and lesions showed no interaction. The results suggest that the selective loss of cholinergic cells in the BF, but not normal aging, impairs the ability to discriminate between independent sensory stimuli. The loss of these cells confers a response bias in simple operant tasks involving motor responses to reward-related visual stimuli.

A new method for studying patient information needs and information-seeking patterns

Studies on information needs and information-seeking patterns of patients focus on people who seek information and rarely attempt to explain the behavior of people who do not want information. Strategies for coping with stress may yield insight into information-seeking patterns. A study of information preferences of women with multiple sclerosis was based on a theory of information seeking that states that "monitors" cope by actively seeking information, whereas "blunters" reject information. Results revealed that both monitors and blunters wanted information but differed in what they wanted and when they wanted it. This study contributes to the development of a methodology for studying information-seeking patterns.

Physician-patient communication from the perspective of library and information science

The physician-patient communication process has received little attention from library and information science (LIS) professionals. A limited review of other literature on this topic was undertaken to gain some understanding of the information exchange from an LIS perspective. The authors were interested in four issues, including how information is defined; how information-seeking behavior is portrayed; what barriers to information exist in the exchange process; and what role, if any, information plays in health outcomes. Studies have been conducted by researchers in various disciplines who have defined communication as a giving and seeking activity between the physician and the patient. Barriers to good communication, erected by either party or by both, prevent the participants from experiencing a satisfactory encounter. Because information can play a role in health outcomes, various strategies have been tried to improve the communication process. These studies provide a better understanding of the physician-patient encounter and suggest new areas of patient-centered research for LIS professionals.

Comparing two views of the landscape: Aboriginal traditional ecological knowledge and modern scientific knowledge

The potential for combining Aboriginal ecological knowledge and scientific knowledge to enhance understanding of the environment is explored. Results of a fauna survey jointly undertaken at Ulug National Park by Australian National Parks and Wildlife Service, CSIRO and Aboriginal members of Mutitjulu Community provide the basis for discussion. Examination of comparative habitat classifications, recognition of faunal habitat preferences and knowledge of the effects of drought and fire suggest that information from Aboriginal people can enhance, and in some instances provide an alternative perspective to, the knowledge currently held by scientists. The scientific community will benefit by accepting Aboriginal ecological knowledge on an equal basis to scientific research. The importance of involving Aboriginal people through all aspects of the research and ensuring that they maintain control over the usage of their traditional knowledge is stressed.

Computer searching of the medical literature. An evaluation of MEDLINE searching systems

Although clinicians can now search the medical literature electronically from the clinic, bedside, or operating suite, little is known about the performance characteristics of online information services. Fourteen access routes to the MEDLINE database of journal literature were compared for retrieval quantity and quality, user and online search time, and cost for randomly ordered, standardized searches on common clinical problems. All routes produced the articles we judged to be the most definitive on the clinical problem. However, routes differed significantly (p less than 0.01) for the same searches with respect to online time (range, 5.15 to 18.72 minutes), total search time (8.37 to 20.55 minutes), cost (US $3.38 to $11.62), and proportion of articles relevant to the topic (98% to 75%). "User friendliness" aside, our results showed that the higher the cost, the worse the product. Clinicians should consider these major differences when deciding which search system to use.

Hybrid electrooptical power cepstrum analyzer

The power cepstrum (power spectrum of the log of the power spectrum) of a signal in a multipath environment provides information on echo amplitudes and delay times. An electrooptical power cepstrum analyzer, which displays this information in real time, is described. The basic system approach is to use optics to provide the power spectrums and electronics to provide the logarithm function. The design and experimental results of a working system are presented.

Progressive retinopathy with improved control in diabetic dwarfism (Mauriac's syndrome)

We report four children aged 11-18 1/2 yr first seen 7-14 yr after the diagnosis of insulin-dependent diabetes. At presentation, all had marked short stature, two had hepatomegaly, and the older three had delayed adolescence. They had been severely underinsulinized. Initial funduscopy demonstrated only occasion microaneurysms in two children and a single intraretinal hemorrhage in another. The youngest was normal. Improved control required large increases in insulin dosage. Growth rate improved significantly and hepatomegaly regressed. Puberty progressed rapidly in two older patients with poor final height. Paradoxically, with improved control, retinopathy progressed rapidly with appearance of multiple microaneurysms, nerve fiber layer infarctions, intraretinal microangiopathic changes, hemorrhages, exudates, and macular edema in all the patients and severe proliferation changes in three. One child with proliferative retinopathy in both eyes developed vitreous hemorrhage and blindness in one eye. Two required panretinal photocoagulation with no further progression of their retinopathy. These rapidly progressive retinal changes remain unexplained. We advise caution when correcting metabolic derangements of diabetic patients who have been poorly controlled for a prolonged period.