Transcription factor condensates and signaling driven transcription

Transcription Factor (TF) condensates are a heterogenous mix of RNA, DNA, and multiple co-factor proteins capable of modulating the transcriptional response of the cell. The dynamic nature and the spatial location of TF-condensates in the 3D nuclear space is believed to provide a fast response, which is on the same pace as the signaling cascade and yet ever-so-specific in the crowded environment of the nucleus. However, the current understanding of how TF-condensates can achieve these feet so quickly and efficiently is still unclear. In this review, we draw parallels with other protein condensates and share our speculations on how the nucleus uses these TF-condensates to achieve high transcriptional specificity and fidelity. We discuss the various constituents of TF-condensates, their properties, and the known and unknown functions of TF-condensates with a particular focus on steroid signaling-induced transcriptional programs.

The effect of recreational cannabis legalization and commercialization on substance use, mental health, and injury: a systematic review

OBJECTIVE

To determine the effect of recreational cannabis legalization (RCL) and/or recreational cannabis commercialization (RCC) on emergency department (ED) visits, hospitalizations, and deaths due to substance use, injury, and mental health among those aged 11 years and older.

METHODS

A systematic review of six electronic databases up to February 1, 2023. Original, peer-reviewed articles with interrupted time series or before and after designs were included. Four independent reviewers screened articles and assessed risk of bias. Outcomes with 'critical' risk of bias were excluded. Protocol registered on PROSPERO (# CRD42021265183).

RESULTS

After screening and risk of bias assessment, 29 studies were included which examined ED visits or hospitalizations for cannabis use or alcohol (N = 10), opioid mortality (N = 3), motor vehicle fatalities or injury (N = 11), and intentional injury/mental health (N = 5). Rates or number of cannabis-related hospitalizations increased after RCL in Canada and the USA. Immediate increases in rates of cannabis-related ED visits were found after both RCL and RCC in Canada. Rates of traffic fatalities increased after RCL and RCC in certain jurisdictions in the USA.

CONCLUSIONS

RCL was associated with increased rates of cannabis-related hospitalizations. RCL and/or RCC was associated with increased rates of cannabis-related ED visits, consistently shown across sex and age groups. The effect on fatal motor vehicle incidents was mixed, with observed increases found after RCL and/or RCC. The effect of RCL or RCC on opioids, alcohol, intentional injury, and mental health is not clear. These results inform population health initiatives and international jurisdictions considering RCL implementation.

Nosocomial or not? A combined epidemiological and genomic investigation to understand hospital-acquired COVID-19 infection on an elderly care ward

Background

COVID-19 has the potential to cause outbreaks in hospitals. Given the comorbid and elderly cohort of patients hospitalized, hospital-acquired COVID-19 infection is often fatal. Pathogen genome sequencing is becoming increasingly important in infection prevention and control (IPC).

Aim

To inform the understanding of in-hospital SARS-CoV-2 transmission in order to improve IPC practices and to inform the future development of virological testing for IPC.

Methods

Patients detected COVID-19 positive by polymerase chain reaction on Ward A in April and May 2020 were included with contact tracing to identify other potential cases. Genome sequencing was undertaken for a subgroup of cases. Epidemiological, genomic, and cluster analyses were performed to describe the epidemiology and to identify factors contributing to the outbreak.

Findings

Fourteen cases were identified on Ward A. Contact tracing identified 16 further patient cases; in addition, eight healthcare workers (HCWs) were identified as being COVID-19 positive through a round of asymptomatic testing. Genome sequencing of 16 of these cases identified viral genomes differing by two single nucleotide polymorphisms or fewer, with further cluster analysis identifying two groups of infection (a five-person group and a six-person group).

Conclusion

Despite the temporal relationship of cases, genome sequencing identified that not all cases shared transmission events. However, 11 samples were found to be closely related and these likely represented in-hospital transmission. This included three HCWs, thereby confirming transmission between patients and HCWs.

How do you develop systems leadership in public health? Insights from a scoping study

OBJECTIVES

Systems leadership is widely acknowledged to be needed to address the many 'wicked issues' challenging public health systems. However, there is a lack of evidence on how to develop public health professionals into effective systems leaders. This study scoped the possibilities for developing the systems leadership capacity of public health specialists in England.

STUDY DESIGN

This was a mixed-methods qualitative scoping study design.

METHODS

The study involved three stages. In the first, a rapid literature review mapped key documents in three relevant areas: systems leadership theory and practice, the changing context of public health in the UK, and training and development for UK public health professionals. In the second, 29 stakeholders were consulted to understand the context and needs for systems leadership development in public health. A third phase involved stakeholders codesigning a potential development framework for the project commissioners.

RESULTS

Four main themes were identified: the nature and purpose of systems leadership; development needs and opportunities for public health specialists; the enabling environment; and wider contextual factors impacting public health.

CONCLUSIONS

Key principles of, and a framework for, a systems leadership development approach are identified, which could be applied to any public health system.

A rare variant of African ancestry activates 8q24 lncRNA hub by modulating cancer associated enhancer

Genetic variation at the 8q24 locus is linked with the greater susceptibility to prostate cancer in men of African ancestry. One such African ancestry specific rare variant, rs72725854 (A>G/T) (~6% allele frequency) has been associated with a ~2-fold increase in prostate cancer risk. However, the functional relevance of this variant is unknown. Here we show that the variant rs72725854 is present in a prostate cancer-specific enhancer at 8q24 locus. Chromatin-conformation capture and dCas9 mediated enhancer blocking establish a direct regulatory link between this enhancer and lncRNAs PCAT1, PRNCR1 and PVT1. The risk allele (‘T’) is associated with higher expression of PCAT1, PVT1 and c-myc in prostate tumors. Further, enhancer with the risk allele gains response to androgen stimulation by recruiting the transcription factor SPDEF whereas, non-risk alleles remain non-responsive. Elevated expression of these lncRNAs and c-myc in risk allele carriers may explain their greater susceptibility to prostate cancer.

Genetic variants on chromosome 8q24 are associated with prostate cancer risk in men of African ancestry. Here the authors show that one of these variants, rs72725854 alters the enhancer activity in its region, which upon androgen stimulation, activates multiple oncogenic lncRNAs and c-myc.

Ligand dependent gene regulation by transient ERα clustered enhancers

Unliganded Estrogen receptor alpha (ERα) has been implicated in ligand-dependent gene regulation. Upon ligand exposure, ERα binds to several EREs relatively proximal to the pre-marked, unliganded ERα-bound sites and affects transient but robust gene expression. However, the underlying mechanisms are not fully understood. Here we demonstrate that upon ligand stimulation, persistent sites interact extensively, via chromatin looping, with the proximal transiently ERα-bound sites, forming Ligand Dependent ERα Enhancer Cluster in 3D (LDEC). The E2-target genes are regulated by these clustered enhancers but not by the H3K27Ac super-enhancers. Further, CRISPR-based deletion of TFF1 persistent site disrupts the formation of its LDEC resulting in the loss of E2-dependent expression of TFF1 and its neighboring genes within the same TAD. The LDEC overlap with nuclear ERα condensates that coalesce in a ligand and persistent site dependent manner. Furthermore, formation of clustered enhancers, as well as condensates, coincide with the active phase of signaling and their later disappearance results in the loss of gene expression even though persistent sites remain bound by ERα. Our results establish, at TFF1 and NRIP1 locus, a direct link between ERα condensates, ERα enhancer clusters, and transient, but robust, gene expression in a ligand-dependent fashion.

Genomic sequence analysis reveals diversity of Australian Xanthomonas species associated with bacterial leaf spot of tomato, capsicum and chilli

Background

The genetic diversity in Australian populations of Xanthomonas species associated with bacterial leaf spot in tomato, capsicum and chilli were compared to worldwide bacterial populations. The aim of this study was to confirm the identities of these Australian Xanthomonas species and classify them in comparison to overseas isolates. Analysis of whole genome sequence allows for the investigation of bacterial population structure, pathogenicity and gene exchange, resulting in better management strategies and biosecurity.

Results

Phylogenetic analysis of the core genome alignments and SNP data grouped strains in distinct clades. Patterns observed in average nucleotide identity, pan genome structure, effector and carbohydrate active enzyme profiles reflected the whole genome phylogeny and highlight taxonomic issues in X. perforans and X. euvesicatoria. Circular sequences with similarity to previously characterised plasmids were identified, and plasmids of similar sizes were isolated. Potential false positive and false negative plasmid assemblies were discussed. Effector patterns that may influence virulence on host plant species were analysed in pathogenic and non-pathogenic xanthomonads.

Conclusions

The phylogeny presented here confirmed X. vesicatoria, X. arboricola, X. euvesicatoria and X. perforans and a clade of an uncharacterised Xanthomonas species shown to be genetically distinct from all other strains of this study. The taxonomic status of X. perforans and X. euvesicatoria as one species is discussed in relation to whole genome phylogeny and phenotypic traits. The patterns evident in enzyme and plasmid profiles indicate worldwide exchange of genetic material with the potential to introduce new virulence elements into local bacterial populations.

Electronic supplementary material

The online version of this article (10.1186/s12864-019-5600-x) contains supplementary material, which is available to authorized users.

Abstract P6-13-01: MRI breast cancer screening compared to mammography in women with a familial risk: A multicenter randomized controlled trial

Background: Screening guidelines for women with a family history of breast cancer without a known causative gene mutation differ per country. No randomized controlled trial has been performed to assess the optimal screening strategy for these women.

Methods: In twelve centers, 1355 women aged 30–55 years with a cumulative lifetime risk of ≥20% without a BRCA1/2 mutation were randomized into two arms. From January 2011 until December 2017, women in the MRI-arm received yearly MRI-screening, clinical breast examination (CBE), and mammography every other year; and in the Mx-arm yearly mammography and CBE. Outcomes were number and stage of detected breast cancers, sensitivity, specificity and positive predictive value, and stratified by screening round and by mammographic density.

Results: After on average 4.3 screening rounds per woman, in the MRI-arm (N=675) compared to the Mx-arm (N=680) more breast cancers were detected (41 versus 14, p<0.001), invasive cancers were smaller (median size 8 versus 17 mm, p=0.006) and less often node positive (20% versus 71.4%, p=0.019)(Table). In the MRI-arm, sensitivity was slightly higher (95.1% versus 92.9%, p=1), and specificity significantly lower (82% versus 90.1%, p<0.001), compared to the Mx-arm. After two rounds, specificity improved for both modalities (87.1% for MRI; 93.0% for Mx; p<0.001) and no ≥T2 tumors or interval cancers occurred in the MRI-arm. All tumors ≥T2 were in the two highest density categories. MRI detected more small invasive tumors than Mx across all density categories.

Conclusions: In real-life practice the MRI-arm detected more, relevantly smaller, and far more often node negative tumors, and also at low density in women with a familial risk for breast cancer.

Table 1Characteristics of participating women at baseline and of the detected breast cancers, according to study armParticipantsMRI-arm n=675Mx-arm n=680MRI-arm vs. Mx-arm p-valueMean age yr ± SD44.6 ± 6.244.7 ± 6.3 Premenopausal512 (76%)505 (74%) Previous Mx ≤ 2 yr536 (79 %)542 (80%) Previous Mx > 2 years ago23 ( 3%)29 ( 4%) Previous MRI ≤ 2 years ago62 ( 9%)81 (12%) Previous MRI > 2 years ago91 (14%)89 (13%) BI-RADS density category*   I (entirely fat)88 (13%)92 (14%) II (scattered densities)248 (37%)229 (34%) III (heterogeneously dense)238 (35%)243 (36%) IV (extremely dense)98 (15%)102 (15%) Mean age at cancer detection49,6 ± 7.049,8 ± 4,70.74No cancer – no. (%)634 (94%)666 (98%) Invasive breast cancers – no. (%)25 (4%)7 (1%)<0.001 (noBC/inv BC/DCIS)DCIS – no. (%)16 (2%)7 (1%) Median size of invasive cancers8 mm17 mm0.006T1a/b15 (60%)1 (14%) T1c7 (28%)4 (57%)0.078 (T1a-b/T1c/≥ T2)≥ T23 (12%)2 (29%) Node pos5 (20%)5 (71%)0.019 (N+/-)Node negative20 (80%)2 (29%) DCIS grade 15 (31%)2 (29%) DCIS grade 28 (50%)4 (57%)1 (dcis gr1,2,3)DCIS grade 33 (19%)1 (14%) *Determined by radiologists, according to the fourth ACR BI-RADS edition

Citation Format: Tilanus-Linthorst MM, Saadatmand S, Geuzinge AH, Rutgers EJ, Mann R, de Roy van Zuidewijn DB, Zonderland HM, Tollenaar RA, Lobbes MB, Ausems MG, van 't Riet M, Hooning MJ, Mares-Engelbert I, Luiten EJ, Heijnsdijk EA, Verhoef C, Karssemeijer N, Oosterwijk JC, Obdeijn I-M, de Koning HJ. MRI breast cancer screening compared to mammography in women with a familial risk: A multicenter randomized controlled trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-13-01.

An unusual complication of nasolabial flap reconstruction

Squamous cell carcinoma is the most common carcinoma in the oral cavity. Resection of these cancers often requires reconstruction. Nasolabial flaps are a robust and reliable local flap that provide a satisfactory outcome. We report two cases where an epidermoid cyst developed within the scar of the nasolabial flap and review the literature.

Quantification of Random Pore Structures of Porous Adsorbents

The structure of pore spaces in typical catalyst particles could often be described as being “not so much fabricated as thrown together”. Thus whilst for certain materials, such as zeolites, the microstructures are well defined and have a precise geometry, most materials when used in typical particulate form are at least partly composed of chaotically configured pore spaces. These random pore structures can be important in determining an adsorbent's performance, so it is necessary to define them quantitatively.

A heirarchy of approaches based upon developments from simple stochastic pore networks is described. A stochastic pore network is one in which simple pore segments form interconnecting networks within which pores can be either randomly or partly randomly distributed. Such stochastic networks can be characterised by mercury porosimetry and low-temperature gas adsorption. Interconnectivity and randomness affect the degree of hysteresis for both these techniques. For 3-D random pattern stochastic networks, it is possible to interpret sectioned SEM images using ‘random’ slices of particles subject to low melting point alloy visual porosimetry in order to arrive at measures of random pore structure. This ‘image analysis’ approach is being extended to 3-D image reconstruction of SEM sections using fractal surfaces in conjunction with randomly tortuous pores.

Association of previous injury and speed with running style and stride-to-stride fluctuations

Running-related injuries remain problematic among recreational runners. We evaluated the association between having sustained a recent running-related injury and speed, and the strike index (a measure of footstrike pattern, SI) and spatiotemporal parameters of running. Forty-four previously injured and 46 previously uninjured runners underwent treadmill running at 80%, 90%, 100%, 110%, and 120% of their preferred running speed. Participants wore a pressure insole device to measure SI, temporal parameters, and stride length (S(length)) and stride frequency (S(frequency)) over 2-min intervals. Coefficient of variation and detrended fluctuation analysis provided information on stride-to-stride variability and correlative patterns. Linear mixed models were used to compare differences between groups and changes with speed. Previously injured runners displayed significantly higher stride-to-stride correlations of SI than controls (P = 0.046). As speed increased, SI, contact time (T(contact)), stride time (T(stride)), and duty factor (DF) decreased (P < 0.001), whereas flight time (T(flight)), S(length), and S(frequency) increased (P < 0.001). Stride-to-stride variability decreased significantly for SI, T(contact), T(flight), and DF (P ≤ 0.005), as did correlative patterns for T(contact), T(stride), DF, S(length), and S(frequency) (P ≤ 0.044). Previous running-related injury was associated with less stride-to-stride randomness of footstrike pattern. Overall, runners became more pronounced rearfoot strikers as running speed increased.

The inferior turbinate flap: a novel technique for prosthetic preparation of a total rhinectomy defect

For total rhinectomy defects, the decision to proceed with a prosthetic versus surgical reconstruction is multifactorial, taking into account patient risk factors, availability of donor tissues, the need for tumor surveillance, and personal preferences. When a prosthetic approach is chosen, the reconstructive surgeon is tasked with preparing the defect to maximize prosthetic retention and prevent ulcerations. Stable bone coverage is critical to achieve this aim. Although skin grafting has been described previously for bone coverage, the periosteum is often stripped. We present a novel use of the inferior turbinate flap for preparation of rhinectomy defects that can be utilized regardless of the presence or absence of the periosteum and provides a more durable coverage than skin grafts.

Signatures of the Z = 82 shell closure in α-decay process

In recent experiments at the velocity filter Separator for Heavy Ion reaction Products (SHIP) (GSI, Darmstadt), an extended and improved set of α-decay data for more than 20 of the most neutron-deficient isotopes in the region from lead to thorium was obtained. The combined analysis of this newly available α-decay data, of which the (186)Po decay is reported here, allowed us for the first time to clearly show that crossing the Z = 82 shell to higher proton numbers strongly accelerates the α decay. From the experimental data, the α-particle formation probabilities are deduced following the Universal Decay Law approach. The formation probabilities are discussed in the framework of the pairing force acting among the protons and the neutrons forming the α particle. A striking resemblance between the phenomenological pairing gap deduced from experimental binding energies and the formation probabilities is noted. These findings support the conjecture that both the N = 126 and Z = 82 shell closures strongly influence the α-formation probability.

[Quality criteria for health promotion and primary prevention measures in association with obesity in children and adolescents. A BZgA-coordinated expert consensus]

On behalf of the Federal Ministry of Health, a working group coordinated by the Federal Center for Health Education (BZgA) compiled quality criteria for health promotion and primary prevention measures in association with obesity in children and adolescents that are applicable both to population-wide and to target group-specific measures. The criteria are intended to support the planning of new measures and the conceptual improvement of existing measures. Additional elements are the assessment of programs for financing purposes and the rendering of accounts to funding agencies, as well as the acquisition of further knowledge. The criteria, thus, address not only project developers and providers, but also multipliers who implement measures, as well as funding agencies, who can use the criteria as a basis for assessing the measures. The structure of the quality criteria is geared to the fundamental structure of the Public Health Action Cycle. In addition, resource orientation, participation and, above all, organizational development are important aspects associated with quality that have not been given adequate consideration to date. The quality criteria are applicable to all situation-based and behavioral prevention measures, and also development processes that focus on promoting the health and normal weight development of children and adolescents.

Methods to identify postnatal depression in primary care: an integrated evidence synthesis and value of information analysis

OBJECTIVES

To provide an overview of methods to identify postnatal depression (PND) in primary care and to assess their validity, acceptability, clinical effectiveness and cost-effectiveness, to model estimates of cost, to assess whether any method meets UK National Screening Committee (NSC) criteria and to identify areas for future research.

DATA SOURCES

Searches of 20 electronic databases (including MEDLINE, CINAHL, PsycINFO, EMBASE, CENTRAL, DARE and CDSR), forward citation searching, personal communication with authors and searching of reference lists.

REVIEW METHODS

A generalised linear mixed model approach to the bivariate meta-analysis was undertaken for the validation review with quality assessment using QUADAS. Within the acceptability review, a textual narrative approach was employed to synthesise qualitative and quantitative research evidence. For the clinical and cost-effectiveness reviews methods outlined by the Centre for Reviews and Dissemination and the Cochrane Collaboration were followed. Probabilistic models were developed to estimate the costs associated with different identification strategies.

RESULTS

The Edinburgh Postnatal Depression Scale (EPDS) was the most frequently explored instrument across all of the reviews. In terms of test performance, postnatally the EPDS performed reasonably well: sensitivity ranged from 0.60 (specificity 0.97) to 0.96 (specificity 0.45) for major depression only; from 0.31 (specificity 0.99) to 0.91 (specificity 0.67) for major or minor depression; and from 0.38 (specificity 0.99) to 0.86 (specificity 0.87) for any psychiatric disorder. Evidence from the acceptability review indicated that, in the majority of studies, the EPDS was acceptable to women and health-care professionals when women were forewarned of the process, when the EPDS was administered in the home, with due attention to training, with empathetic skills of the health visitor and due consideration to positive responses to question 10 about self-harm. Suggestive evidence from the clinical effectiveness review indicated that use of the EPDS, compared with usual care, may lead to reductions in the number of women with depression scores above a threshold. In the absence of existing cost-effectiveness studies of PND identification strategies, a decision-analytic model was developed. The results of the base-case analysis suggested that use of formal identification strategies did not appear to represent value for money, based on conventional thresholds of cost-effectiveness used in the NHS. However, the scenarios considered demonstrated that this conclusion was primarily driven by the costs of false positives assumed in the base-case model.

CONCLUSIONS

In light of the results of our evidence synthesis and decision modelling we revisited the examination of PND screening against five of the NSC criteria. We found that the accepted criteria for a PND screening programme were not currently met. The evidence suggested that there is a simple, safe, precise and validated screening test, in principle a suitable cut-off level could be defined and that the test is acceptable to the population. Evidence surrounding clinical and cost-effectiveness of methods to identify PND is lacking. Further research should aim to identify the optimal identification strategy, in terms of key psychometric properties for postnatal populations. In particular, research comparing the performance of the Whooley and help questions, the EPDS and a generic depression measure would be informative. It would also be informative to identify the natural history of PND over time and to identify the clinical effectiveness of the most valid and acceptable method to identify postnatal depression. Further research within a randomised controlled trial would provide robust estimates of the clinical effectiveness.

Hypoglycaemia in Type 2 diabetes

The primary cause of hypoglycaemia in Type 2 diabetes is diabetes medication-in particular, those which raise insulin levels independently of blood glucose, such as sulphonylureas (SUs) and exogenous insulin. The risk of hypoglycaemia is increased in older patients, those with longer diabetes duration, lesser insulin reserve and perhaps in the drive for strict glycaemic control. Differing definitions, data collection methods, drug type/regimen and patient populations make comparing rates of hypoglycaemia difficult. It is clear that patients taking insulin have the highest rates of self-reported severe hypoglycaemia (25% in patients who have been taking insulin for > 5 years). SUs are associated with significantly lower rates of severe hypoglycaemia. However, large numbers of patients take SUs in the UK, and it is estimated that each year > 5000 patients will experience a severe event caused by their SU therapy which will require emergency intervention. Hypoglycaemia has substantial clinical impact, in terms of mortality, morbidity and quality of life. The cost implications of severe episodes-both direct hospital costs and indirect costs-are considerable: it is estimated that each hospital admission for severe hypoglycaemia costs around pound1000. Hypoglycaemia and fear of hypoglycaemia limit the ability of current diabetes medications to achieve and maintain optimal levels of glycaemic control. Newer therapies, which focus on the incretin axis, may carry a lower risk of hypoglycaemia. Their use, and more prudent use of older therapies with low risk of hypoglycaemia, may help patients achieve improved glucose control for longer, and reduce the risk of diabetic complications.

Breast tumor characteristics of BRCA1 and BRCA2 gene mutation carriers on MRI

The appearance of malignant lesions in BRCA1 and BRCA2 mutation carriers (BRCA-MCs) on mammography and magnetic resonance imaging (MRI) was evaluated. Thus, 29 BRCA-MCs with breast cancer were retrospectively evaluated and the results compared with an age, tumor size and tumor type matched control group of 29 sporadic breast cancer cases. Detection rates on both modalities were evaluated. Tumors were analyzed on morphology, density (mammography), enhancement pattern and kinetics (MRI). Overall detection was significantly better with MRI than with mammography (55/58 vs 44/57, P = 0.021). On mammography, lesions in the BRCA-MC group were significantly more described as rounded (12//19 vs 3/13, P = 0.036) and with sharp margins (9/19 vs 1/13, P = 0.024). On MRI lesions in the BRCA-MC group were significantly more described as rounded (16/27 vs 7/28, P = 0.010), with sharp margins (20/27 vs 7/28, P < 0.001) and with rim enhancement (7/27 vs 1/28, P = 0.025). No significant difference was found for enhancement kinetics (P = 0.667). Malignant lesions in BRCA-MC frequently have morphological characteristics commonly seen in benign lesions, like a rounded shape or sharp margins. This applies for both mammography and MRI. However the possibility of MRI to evaluate the enhancement pattern and kinetics enables the detection of characteristics suggestive for a malignancy.

Driving behavior under the influence of cannabis or cocaine

OBJECTIVE

The purpose of this study is first to describe perceptions of driving under the influence of cannabis or cocaine among clients in treatment and, second, to assess whether these perceptions are related to the frequency of driving under the influence of cannabis or cocaine.

METHODS

A questionnaire was administered to clients in treatment for abuse of either cocaine or cannabis, many of whom also had a problem with alcohol; additional groups of clients consisted of those in smoking cessation and gambling programs (N = 1021). Open-ended and close-ended questions were used to assess self-reported effects of cannabis or cocaine on driving and frequency of driving under the influence of cannabis, cocaine, or alcohol.

RESULTS

Two dimensions of driving behavior under the influence of cocaine or cannabis were found in both qualitative and quantitative analyses: 1) physical effects and 2) reckless styles of driving. Common physical effects for both drugs were heightened nervousness, greater alertness, and poorer concentration. In terms of driving behavior, cautious or normal driving was commonly reported for cannabis, whereas reckless or reduced driving ability was frequently reported for cocaine. When comparing negative physical effects and reckless style of driving with frequency of driving under the influence of cannabis or cocaine, increased negative physical effects from cannabis were inversely related to frequency of driving under the influence of cannabis (p = .001), but other relationships were not significant.

CONCLUSIONS

The findings indicate that both cannabis and cocaine have detrimental but different effects on driving. The negative physical effects of cannabis may reduce the likelihood of driving under the influence of cannabis.

Peptide binding at the GLP-1 receptor

The receptor for GLP-1 [glucagon-like peptide-1-(7-36)-amide] is a member of the 'Family B' of GPCRs (G-protein-coupled receptors) comprising an extracellular N-terminal domain containing six conserved cysteine residues (the N-domain) and a core domain (or J-domain) comprising the seven transmembrane helices and interconnecting loop regions. According to the two-domain model for peptide binding, the N-domain is primarily responsible for providing most of the peptide binding energy, whereas the core domain is responsible for binding the N-terminal region of the peptide agonists and transmitting the signal to the intracellular G-protein. Two interesting differences between the binding properties of two GLP-1 receptor agonists, GLP-1 and EX-4 (exendin-4), can be observed. First, while GLP-1 requires its full length to maintain high affinity, the eight N-terminal residues of EX-4 can be removed with little reduction in affinity. Secondly, EX-4 (but not GLP-1) can bind to the fully isolated N-domain of the receptor with an affinity matching that of the full-length receptor. In order to better understand these differences, we have studied the interaction between combinations of full-length or truncated ligands with full-length or truncated receptors.