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1.
Violence Against Women ; : 10778012231209011, 2023 Oct 25.
Article in English | MEDLINE | ID: mdl-37880954

ABSTRACT

The public condemnation of high-profile men accused of gendered violence in 2017 resulted in an upsurge of women labelling past experiences as sexual harassment. This study used Q methodology to explore understandings of sexual harassment in the UK. Forty participants sorted 62 statements into quasi-normal grids which were factor analyzed (by person). Eight factors were identified which were titled: Sex Not Sexism, Sexualized Discriminations, Victim Voice, Sameness and Difference, Power/Sex, Repeated Power Abuse, Personal Boundaries, and Masculinity and Heterosexism. Taken together, they signal that feminist efforts to articulate the experience of sexual harassment have gained ground during this period.

2.
Protist ; 174(1): 125927, 2023 02.
Article in English | MEDLINE | ID: mdl-36565615

ABSTRACT

Bioassays using cultures of the toxic haptophyte Prymnesium parvum and the ciliate Cyclidium sp. as prey were conducted to test the effect of pH (range = 6.5 - 8.5), salinity (range = 1.50 - 7.50‰), and a combination of pH and salinity on the toxicity of P. parvum. pH had a significant effect on P. parvum toxicity. Toxicity was rapidly (within 24 hr) induced by increasing pH of the medium, or reduced by lowering pH. Conversely, lowering salinity reduced toxicity, albeit less effectively compared to pH, and P. parvum cells remained toxic at the lowest values tested (1.50‰ at pH 7.5). An additional effect between pH and salinity was also observed: low salinity combined with low pH led to not only decreased toxicity, but also resulted in lower P. parvum growth rates. Such effects of pH and salinity on P. parvum growth and toxicity provide insight into the environmental factors supporting community dominance and toxic blooms of the alga.


Subject(s)
Chrysophyta , Haptophyta , Salinity , Hydrogen-Ion Concentration
3.
Behav Sci Law ; 40(3): 452-466, 2022 May.
Article in English | MEDLINE | ID: mdl-35460096

ABSTRACT

The current Scottish verdict system includes three verdicts: 'guilty', 'not guilty' and 'not proven'. The Scottish Government are currently reviewing the utility of the not proven verdict. Proponents of the not proven verdict suggest that it directs jurors to their true role of determining whether the prosecution's case has, or has not, been 'proven'. Reformists suggest a move to a system similar to England and Wales, with only guilty and not guilty verdicts. However, legal professionals have indicated a preference for an alternative system of proven and not proven. The aim of the current study was to test the effects of a proven and not proven system on verdicts given, when compared to alternative verdict systems (specifically, the current Scottish and Anglo-American verdict systems). 227 mock jurors watched a staged murder trial, filmed in a real-life courtroom, with legal professionals questioning witnesses and a judge giving legal direction. Jurors were significantly more likely to convict in a guilty and not guilty verdict system than either a proven and not proven or a guilty, not guilty and not proven verdict system. Future research should replicate this study with a focus on the impact of the not proven verdict in sexual offences.


Subject(s)
Criminal Law , Judicial Role , Decision Making , Homicide , Humans , Mass Media , Scotland
4.
Med Sci Law ; 61(4): 256-265, 2021 Oct.
Article in English | MEDLINE | ID: mdl-33596724

ABSTRACT

The unique Scottish legal system stands apart from the better-known Anglo-American legal system, with variations relating to jury size (15 vs. 12), the number of verdicts available (3 vs. 2) and majority size (simple majority vs. unanimous). At present, only a handful of investigations have explored the effects of the Scottish 'not proven' verdict on jurors, and only a single study has explored the combined impact of the unique elements of the Scottish legal system on juror and jury decision making. The current study is the first to investigate the views of Scottish legal professionals on the three-verdict system, 15-person jury and simple majority verdict system. The aim of the study is to inform public and political debate, involve legal stakeholders in policy changes and decision making and compare legal professionals' views with findings from previously conducted juror studies. Seventy-eight legal professionals took part in an online survey which asked for ratings and open responses on their attitudes to the Scottish (a) three-verdict system, (b) 15-person jury and (c) simple majority system. The results highlighted strong positive attitudes towards the 'not proven' verdict (particularly in a binary-verdict system of proven and not proven), 15-person juries and both the simple and qualified majority verdict systems. There was minimal support for reform towards an Anglo-American system. Instead, the reforms preferred by the legal professionals would be to require a qualified majority of 12/15 jurors, and to use a binary-verdict system of proven and not proven.


Subject(s)
Decision Making , Judicial Role , Jurisprudence , Adult , Aged , Attitude , Female , Humans , Lawyers/psychology , Male , Middle Aged , Scotland , Surveys and Questionnaires
5.
Front Psychol ; 10: 1962, 2019.
Article in English | MEDLINE | ID: mdl-31555168

ABSTRACT

An eyewitness can contribute to a police investigation both by creating a composite image of the face of the perpetrator and by attempting to identify them during an identification procedure. This raises the potential issue that creating a composite of a perpetrator might then interfere with the subsequent identification of that perpetrator. Previous research exploring this issue has tended to use older feature-based composite systems, but the introduction of new holistic composite systems is an important development as they were designed to be a better match for human cognition and are likely to interact with memory in a different way. This issue was explored in the current experiment. Participants were randomly assigned to a feature-based composite construction condition (using E-FIT), a holistic-based composite construction condition (using EFIT-V) or a control condition. An ecologically valid delay between seeing a staged crime, creating the composite, and completing the identification task was employed to better match conditions in real investigations. The results showed that neither type of composite construction had an effect on participants' accuracy on a subsequent identification task. This suggests that facial composite systems, including holistic systems, may not negatively impact subsequent eyewitness identification evidence.

6.
Injury ; 48(9): 2010-2016, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28625562

ABSTRACT

BACKGROUND: Trauma courses have been shown to improve clinical knowledge and patient outcomes. However, little is known about the individual drivers of change in practice amongst course participants in their home clinic environment. METHODS: Front-line healthcare workers participated in a two-day Primary Trauma Care (PTC) course. Immediately after the course participants completed an evaluation survey on intended change in the management of trauma patients. Six months after the course, participants completed a survey on actual changes that had occurred. RESULTS: A total of 451 participants were sampled, with 321 responding at 6 months, from 40 courses across East, Central and Southern Africa. The most commonly reported intended change was the adoption of an ABCDE/systematic approach (53%). Six months after the course, 92.7% of respondents reported that they had made changes in their management, with adoption of an ABCDE/systematic approach (50.0%) remaining most common. 77% of participants reported an improvement in departmental trauma management, 26% reported an increase in staffing, 29% an increase in equipment and 68% of participants had gone on to train other healthcare workers in PTC. CONCLUSION: The findings suggest that PTC courses not only improve individual management of trauma patients but also but is also associated with beneficial effects for participants' host institutions with regards to staffing, equipment and training.


Subject(s)
Clinical Competence/standards , Education, Medical, Continuing/organization & administration , Health Personnel/standards , Quality of Health Care/standards , Traumatology/education , Africa , Attitude of Health Personnel , Evaluation Studies as Topic , Health Resources , Humans , Program Development , Quality Improvement , Traumatology/standards
7.
Sci Adv ; 2(1): e1500837, 2016 Jan.
Article in English | MEDLINE | ID: mdl-27152323

ABSTRACT

In condensed matter systems, strong optical excitations can induce phonon-driven processes that alter their mechanical properties. We report on a new phenomenon where a massive electronic excitation induces a collective change in the bond character that leads to transient lattice contraction. Single large van der Waals clusters were isochorically heated to a nanoplasma state with an intense 10-fs x-ray (pump) pulse. The structural evolution of the nanoplasma was probed with a second intense x-ray (probe) pulse, showing systematic contraction stemming from electron delocalization during the solid-to-plasma transition. These findings are relevant for any material in extreme conditions ranging from the time evolution of warm or hot dense matter to ultrafast imaging with intense x-ray pulses or, more generally, any situation that involves a condensed matter-to-plasma transition.


Subject(s)
Models, Theoretical
8.
9.
Clin Med (Lond) ; 15(4): 337-43, 2015 Aug.
Article in English | MEDLINE | ID: mdl-26407382

ABSTRACT

Recent court cases in England and Wales have refocused attention on patients' decision-making capacity to consent. Little is known about the prevalence of incapacity across specialities but decision-making capacity is likely to be overestimated by clinicians. The aim of this systematic review is to estimate the prevalence of incapacity to consent to treatment or admission in different medical and psychiatric settings, and compare the two. We conducted an electronic search following PRISMA principles and included 35 studies in psychiatric and 23 studies in medical settings. The 58 included studies revealed 70 data sets across all settings. For psychiatric settings the weighted average proportion of patients with incapacity was 45% (95% confidence interval (CI) 39-51%). For medical settings, the weighted average proportion of patients with incapacity was 34% (95% CI 25-44%). The two groups are not significantly different from each other in terms of the proportion of incapacity (p=0.92). A considerable number of medical and psychiatric patients lack capacity to make treatment and assessment decisions. Clinicians should be more alert to the possibility that their patients may lack decision-making capacity. Assessment of capacity should be frequent using the appropriate legal frameworks to act in the best interest of patients.


Subject(s)
Informed Consent , Mental Competency/psychology , Mental Disorders/epidemiology , Decision Making , England/epidemiology , Humans , Mental Disorders/psychology , Prevalence , Wales/epidemiology
10.
Asian J Psychiatr ; 13: 52-5, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25466779

ABSTRACT

BACKGROUND: Patient and visitor violence (PVV) towards staff is common across health settings. It has negative effects on staff and treatment provision. Little data is available from the developing world. AIMS: To examine the prevalence of PVV in India and make comparisons with the existing data. METHODS: We administered an abbreviated version of the Survey of Violence Experienced by Staff (SOVES-A) in English in Mysore on medical and psychiatric wards. RESULTS: 249 staff participated. 16% of staff in psychiatric wards were subjected to some form of PVV in the past 4 weeks which is lower than in the developed world. 57% of staff on medical wards experienced PVV which is similar to the developed world. Patients and Visitors were almost equal sources of this violence. Verbal abuse was more common than threats and physical assaults. Training in aggression management may be a protective factor. CONCLUSION: PVV is a significant problem in India, especially on medical wards. Aggression management training may be a way to reduce the prevalence of PVV.


Subject(s)
Aggression/psychology , Family/psychology , Inpatients/psychology , Psychiatric Department, Hospital , Violence/statistics & numerical data , Workplace/psychology , Attitude of Health Personnel , Humans , Violence/psychology
11.
Eur J Emerg Med ; 22(5): 370-3, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25405462

ABSTRACT

The aim of this study was to investigate why nonurgent patients present to the Emergency Department (ED) despite availability of alternative services; also to assess impact of the UK Choose Well Campaign. A convenience sample of nonurgent ED attenders was surveyed in North Wales, UK. More than half of patients sought advice from friends, family, carer or GP before attending ED. Of the one-third of patients who had not tried an alternative service before presenting to ED, reasons given included patients thinking that they might need a radiograph (46%), believing that GP would be unable to help (29%) or stating that GP was not available (19%). Twenty per cent of patients reported they would have changed their decision about attending ED if they had known more about alternatives. Only 12% were aware of Choose Well. Analysis suggests that though Choose Well effectively provides information on alternatives, it does not translate into more appropriate attendance.


Subject(s)
Emergency Service, Hospital/statistics & numerical data , Health Services Accessibility/statistics & numerical data , Health Services Misuse/statistics & numerical data , Patient Preference/statistics & numerical data , Adult , Age Factors , Aged , Confidence Intervals , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Primary Health Care/statistics & numerical data , Risk Factors , Sex Factors , Surveys and Questionnaires , United Kingdom , Young Adult
12.
BMC Health Serv Res ; 14: 3, 2014 Jan 03.
Article in English | MEDLINE | ID: mdl-24387663

ABSTRACT

BACKGROUND: The duration between first symptom and a cancer diagnosis is important because, if shortened, may lead to earlier stage diagnosis and improved cancer outcomes. We have previously developed a tool to measure this duration in newly-diagnosed patients. In this two-phase study, we aimed further improve our tool and to conduct a trial comparing levels of anxiety between two modes of delivery: self-completed versus researcher-administered. METHODS: In phase 1, ten patients completed the modified tool and participated in cognitive debrief interviews. In phase 2, we undertook a Randomised Controlled Trial (RCT) of the revised tool (Cancer Symptom Interval Measure (C-SIM)) in three hospitals for 11 different cancers. Respondents were invited to provide either exact or estimated dates of first noticing symptoms and presenting them to primary care. The primary outcome was anxiety related to delivery mode, with completeness of recording as a secondary outcome. Dates from a subset of patients were compared with GP records. RESULTS: After analysis of phase 1 interviews, the wording and format were improved. In phase 2, 201 patients were randomised (93 self-complete and 108 researcher-complete). Anxiety scores were significantly lower in the researcher-completed group, with a mean rank of 83.5; compared with the self-completed group, with a mean rank of 104.0 (Mann-Whitney U = 3152, p = 0.007). Completeness of data was significantly better in the researcher-completed group, with no statistically significant difference in time taken to complete the tool between the two groups. When comparing the dates in the patient questionnaires with those in the GP records, there was evidence in the records of a consultation on the same date or within a proscribed time window for 32/37 (86%) consultations; for estimated dates there was evidence for 23/37 consultations (62%). CONCLUSIONS: We have developed and tested a tool for collecting patient-reported data relating to appraisal intervals, help-seeking intervals, and diagnostic intervals in the cancer diagnostic pathway for 11 separate cancers, and provided evidence of its acceptability, feasibility and validity. This is a useful tool to use in descriptive and epidemiological studies of cancer diagnostic journeys, and causes less anxiety if administered by a researcher.


Subject(s)
Neoplasms/diagnosis , Anxiety/etiology , Anxiety/psychology , Critical Pathways , Early Diagnosis , Humans , Interviews as Topic , Neoplasms/psychology , Reproducibility of Results , Surveys and Questionnaires , Time Factors
13.
Clin Med (Lond) ; 13(6): 543-6, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24298096

ABSTRACT

Patient and visitor violence adversely affects staff and organisations; however, there are few UK data about patient and visitor violence on medical wards. Therefore, we conducted a cross-sectional study using a validated tool (Survey of Violence Experienced by Staff) in six medical wards in three North Wales district general hospitals to assess the prevalence of violence against healthcare staff. A total of 158 staff responded (12 men, 144 women, two not stated). We found that, within the previous 4 weeks, 83% of staff had experienced verbal aggression, 50% had been threatened and 63% had been physically assaulted. Of those assaulted, 56% sustained an injury, with three requiring medical assessment or treatment. Length of experience in the workplace correlated negatively with verbal abuse, but not with threats or assaults. Direct patient contact positively correlated with more overall incidents. There was no correlation between training in aggression management and the experience of incidents. Healthcare support workers and nurses reported a higher prevalence of patient and visitor violence compared with other groups of health worker.


Subject(s)
Attitude of Health Personnel , Hospitals, General , Medical Staff, Hospital/statistics & numerical data , Professional-Patient Relations , Violence/statistics & numerical data , Visitors to Patients/psychology , Workplace/standards , Adolescent , Adult , Cross-Sectional Studies , Female , Humans , Inpatients , Male , Middle Aged , Prevalence , Risk Factors , Surveys and Questionnaires , United Kingdom , Violence/prevention & control , Young Adult
14.
Emerg Med J ; 29(1): 40-2, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21233485

ABSTRACT

BACKGROUND: Non-ST elevation acute coronary syndromes (NSTEACS) confer a broad range of risk of adverse outcomes following presentation to an emergency department. This study compares the Thrombolysis in Myocardial Infarction (TIMI) risk scoring system with the used but untested, Cheshire, Merseyside and North Wales Cardiac Network (CMNW) NSTEACS risk stratification system in predicting the adverse outcomes of re-admission to hospital with either a NSTEACS or death at 30 days post presentation. METHOD: Once a diagnosis of NSTEACS was made, patients were risk scored, then case notes were retrieved 30 days later. Primary adverse outcome of death and secondary adverse outcome of NSTEACS at 30 days was analysed using a ROC curve. RESULTS: 104 patients were included in the study diagnosed as having NSTEACS. Of these patients, 11 (11%) were initially diagnosed as having unstable angina (UA) (troponin I negative, <0.07), 43 (41%) non-ST elevation myocardial infarction Group 1 (troponin I 0.07-0.49) and 50 (48%) had non-ST elevation myocardial infarction Group 2 (troponin I ≥0.50). For death at 30 days, the CMNW risk c-statistic is 0.845 (95% CI 0.728 to 0.962, asymptotic significance 0.02) and TIMI 0.670 (CI 0.493 to 0.847, asymptotic significance 0.25). NSTEACS at 30 days (including NSTEMI and UA), the CMNW risk c-statistic is 0.466 (95% CI 0.345 to 0.586, asymptotic significance 0.616), TIMI 0.418 (CI 0.281 to 0.555, asymptotic significance 0.231). CONCLUSIONS: The CMNW score categorised more patients as higher risk, who suffered death at 30 days than the TIMI score.


Subject(s)
Acute Coronary Syndrome/diagnosis , Risk Assessment/methods , Acute Coronary Syndrome/blood , Acute Coronary Syndrome/mortality , Acute Coronary Syndrome/physiopathology , Adult , Aged , Aged, 80 and over , Angina, Unstable/diagnosis , Biomarkers/blood , Electrocardiography , Emergency Service, Hospital , Female , Humans , Male , Middle Aged , Myocardial Infarction/diagnosis , Patient Readmission/statistics & numerical data , Predictive Value of Tests , Prospective Studies , ROC Curve , Recurrence , Risk Factors , Troponin I/blood
15.
Bioorg Med Chem Lett ; 21(18): 5164-70, 2011 Sep 15.
Article in English | MEDLINE | ID: mdl-21835615

ABSTRACT

The proteolytic enzyme ß-secretase (BACE1) plays a central role in the synthesis of the pathogenic ß-amyloid in Alzheimer's disease. SAR studies of the S2' region of the BACE1 ligand binding pocket with pyrazolyl and thienyl P2' side chains are reported. These analogs exhibit low nanomolar potency for BACE1, and demonstrate >50- to 100-fold selectivity for the structurally related aspartyl proteases BACE2 and cathepsin D. Small groups attached at the nitrogen of the P2' pyrazolyl moiety, together with the P3 pyrimidine nucleus projecting into the S3 region of the binding pocket, are critical components to ligand's potency and selectivity. P2' thiophene side chain analogs are highly potent BACE1 inhibitors with excellent selectivity against cathepsin D, but only modest selectivity against BACE2. The cell-based activity of these new analogs tracked well with their increased molecular binding with EC(50) values of 0.07-0.2 µM in the ELISA assay for the most potent analogs.


Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Aspartic Acid Endopeptidases/antagonists & inhibitors , Enzyme Inhibitors/pharmacology , Hydantoins/pharmacology , Pyrazoles/chemistry , Thiophenes/chemistry , Amyloid Precursor Protein Secretases/metabolism , Aspartic Acid Endopeptidases/metabolism , Crystallography, X-Ray , Dose-Response Relationship, Drug , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Humans , Hydantoins/chemical synthesis , Hydantoins/chemistry , Models, Molecular , Molecular Structure , Stereoisomerism , Structure-Activity Relationship
16.
Int J Geriatr Psychiatry ; 26(4): 331-40, 2011 Apr.
Article in English | MEDLINE | ID: mdl-20973096

ABSTRACT

OBJECTIVE: Earlier reviews and meta-analyses have consistently concluded that psychological treatment of depression is effective in older adults. We conducted a systematic review randomised controlled trials of group psychotherapy to present the best available evidence in relation to its effectiveness in older adults with depressive disorders. METHODS: Electronic databases were searched to identify randomised controlled trials. Selected studies were quality assessed and data extracted by two reviewers. RESULTS: Six trials met the inclusion criteria. The trials included in the review examined group interventions based on the cognitive behavioural therapy (CBT) model with active therapeutic interventions or waiting list controls. Group psychotherapy is an effective intervention in older adults with depression in comparison to waiting list controls, the overall effect size is very modest (MD = -3.92, 95%CI: -6.18, -1.67). The reported benefits of group intervention in comparison to other active interventions did not reach statistical significance. The benefits of group psychotherapy were maintained at follow-up. The quality of the studies varied and studies were heterogeneous. CONCLUSIONS: Although quality of many studies was not optimal, the results of this meta analysis support the results of earlier meta analyses. Group cognitive behavioural therapy is effective in older adults with depression.


Subject(s)
Depressive Disorder/therapy , Psychotherapy, Group/standards , Aged , Cognitive Behavioral Therapy/standards , Female , Humans , Male , Middle Aged , Psychiatric Status Rating Scales , Randomized Controlled Trials as Topic
17.
Bioorg Med Chem Lett ; 20(22): 6597-605, 2010 Nov 15.
Article in English | MEDLINE | ID: mdl-20880704

ABSTRACT

The identification of small molecule aminohydantoins as potent and selective human ß-secretase inhibitors is reported. These analogs exhibit good brain permeability (40-70%), low nanomolar potency for BACE1, and demonstrate >100-fold selectivity for the structurally related aspartyl proteases cathepsin D, renin and pepsin. Alkyl and alkoxy groups at the meta-position of the P1 phenyl, which extend toward the S3 region of the enzyme, have contributed to the ligand's reduced affinity for the efflux transporter protein P-gp, and decreased topological polar surface area, thus resulting in enhanced brain permeability. A fluorine substitution at the para-position of the P1 phenyl has contributed to 100-fold decrease of CYP3A4 inhibition and enhancement of compound metabolic stability. The plasma and brain protein binding properties of these new analogs are affected by substitutions at the P1 phenyl moiety. Higher compound protein binding was observed in the brain than in the plasma. Two structurally diverse potent BACE1 inhibitors (84 and 89) reduced 30% plasma Aß40 in the Tg2576 mice in vivo model at 30 mg/kg p.o..


Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Brain/metabolism , Enzyme Inhibitors/chemical synthesis , Hydantoins/chemical synthesis , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Humans , Hydantoins/chemistry , Hydantoins/pharmacology , Permeability
18.
Health Informatics J ; 16(1): 58-62, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20413413

ABSTRACT

Communication with patients is vital in their management, and the NHS plan to copy clinic letters to patients was published in 2004. This study aims to determine whether patients are satisfied with their current communication or prefer alternative modes, overall and between different specialty clinics. A questionnaire was given to outpatients attending clinics in November to December 2006. A total of 483 patients returned the questionnaire, giving a 95 per cent response rate. Overall, 85 per cent of patients were satisfied with the current method of communication, and a significant number did want a copy of GP letters. Trend analysis suggests that, as the number of clinic visits increased, requests for copies of letters decreased (p = 0.02). Paediatric and psychiatric patients were more likely to want letters than medical and surgical patients (p = 0.003). Thus communication needs may differ between departments. Opt-in letter copy systems seem preferable.


Subject(s)
Copying Processes , Correspondence as Topic , Patient Access to Records , Patient Satisfaction/statistics & numerical data , Adolescent , Adult , Aged , Communication , Female , General Practitioners , Hospital Departments , Hospitals, District , Hospitals, General , Humans , Male , Middle Aged , Physician-Patient Relations , Surveys and Questionnaires , Young Adult
19.
Bioorg Med Chem Lett ; 20(7): 2068-73, 2010 Apr 01.
Article in English | MEDLINE | ID: mdl-20223661

ABSTRACT

The proteolytic enzyme beta-secretase (BACE1) plays a central role in the synthesis of the pathogenic beta-amyloid in Alzheimer's disease. Recently, we reported small molecule acylguanidines as potent BACE1 inhibitors. However, many of these acylguanidines have a high polar surface area (e.g. as measured by the topological polar surface area or TPSA), which is unfavorable for crossing the blood-brain barrier. Herein, we describe the identification of the 2-aminopyridine moiety as a bioisosteric replacement of the acylguanidine moiety, which resulted in inhibitors with lower TPSA values and superior brain penetration. X-ray crystallographic studies indicated that the 2-aminopyridine moiety interacts directly with the catalytic aspartic acids Asp32 and Asp228 via a hydrogen-bonding network.


Subject(s)
Alzheimer Disease/drug therapy , Aminopyridines/chemistry , Aminopyridines/pharmacokinetics , Amyloid Precursor Protein Secretases/antagonists & inhibitors , Amyloid Precursor Protein Secretases/metabolism , Aspartic Acid Endopeptidases/antagonists & inhibitors , Aspartic Acid Endopeptidases/metabolism , Brain/metabolism , Alzheimer Disease/enzymology , Aminopyridines/pharmacology , Amyloid Precursor Protein Secretases/chemistry , Aspartic Acid Endopeptidases/chemistry , Crystallography, X-Ray , Humans , Models, Molecular , Structure-Activity Relationship
20.
Bioorg Med Chem ; 18(2): 630-9, 2010 Jan 15.
Article in English | MEDLINE | ID: mdl-20045648

ABSTRACT

The identification of highly selective small molecule di-substituted pyridinyl aminohydantoins as beta-secretase inhibitors is reported. The more potent and selective analogs demonstrate low nanomolar potency for the BACE1 enzyme as measured in a FRET assay, and exhibit comparable activity in a cell-based (ELISA) assay. In addition, these pyridine-aminohydantoins are highly selectivity (>500x) against the other structurally related aspartyl proteases BACE2, cathepsin D, pepsin and renin. Our design strategy followed a traditional SAR approach and was supported by molecular modeling studies based on the previously reported aminohydantoin 3a. We have taken advantage of the amino acid difference between the BACE1 and BACE2 at the S2' pocket (BACE1 Pro(70) changed to BACE2 Lys(86)) to build ligands with >500-fold selectivity against BACE2. The addition of large substituents on the targeted ligand at the vicinity of this aberration has generated a steric conflict between the ligand and these two proteins, thus impacting the ligand's affinity and selectivity. These ligands have also shown an exceptional selectivity against cathepsin D (>5000-fold) as well as the other aspartyl proteases mentioned. One of the more potent compounds (S)-39 displayed an IC(50) value for BACE1 of 10nM, and exhibited cellular activity with an EC(50) value of 130nM in the ELISA assay.


Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Aspartic Acid Endopeptidases/antagonists & inhibitors , Hydantoins/pharmacology , Pyridines/pharmacology , Crystallography, X-Ray , Humans , Hydantoins/chemical synthesis , Hydantoins/chemistry , Ligands , Models, Molecular , Molecular Structure , Molecular Weight , Pyridines/chemical synthesis , Pyridines/chemistry , Stereoisomerism , Structure-Activity Relationship
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