The role of positively charged amino acids and electrostatic interactions in the complex of U1A protein and U1 hairpin II RNA

Previous kinetic investigations of the N-terminal RNA recognition motif (RRM) domain of spliceosomal protein U1A, interacting with its RNA target U1 hairpin II, provided experimental evidence for a ‘lure and lock’ model of binding in which electrostatic interactions first guide the RNA to the protein, and close range interactions then lock the two molecules together. To further investigate the ‘lure’ step, here we examined the electrostatic roles of two sets of positively charged amino acids in U1A that do not make hydrogen bonds to the RNA: Lys20, Lys22 and Lys23 close to the RNA-binding site, and Arg7, Lys60 and Arg70, located on ‘top’ of the RRM domain, away from the RNA. Surface plasmon resonance-based kinetic studies, supplemented with salt dependence experiments and molecular dynamics simulation, indicate that Lys20 predominantly plays a role in association, while nearby residues Lys22 and Lys23 appear to be at least as important for complex stability. In contrast, kinetic analyses of residues away from the RNA indicate that they have a minimal effect on association and stability. Thus, well-positioned positively charged residues can be important for both initial complex formation and complex maintenance, illustrating the multiple roles of electrostatic interactions in protein–RNA complexes

Vasemman aivopuoliskon aivoinfarktin sairastaneiden tutkimushenkilöiden kielellisen ymmärtämisen ja kielellisen työmuistin kuntoutuminen vuoden seurannassa

Aivoinfarkti aiheuttaa suurelle osalle sairastuneista erilaisia elämänlaatua heikentäviä vajaatoimintoja ja haittoja, muun muassa kognitiivisten toimintojen vaikeuksia. Nämä vaikeudet aiheuttavat sekä kansantaloudellista kuormitusta että heikentävät sairastuneiden henkilöiden elämänlaatua. Tämän tutkimuksen tavoitteena oli tarkastella miten vasemman aivopuoliskon aivoinfarktin sairastaneiden tutkimushenkilöiden kielellinen ymmärtäminen, kielellinen työmuisti ja neurologiset yleisoireet kuntoutuvat vuoden seurannan aikana. Lisäksi tarkasteltiin, onko akuuttivaiheessa todetulla afasialla, iällä, sukupuolella tai koulutuksen pituudella merkitystä kuntoutumisprosessissa ja ovatko kielellisen ymmärtämisen taidot, kielellinen työmuisti tai neurologinen status yhteydessä toisiinsa. Tutkimukseen osallistui 36 vasemman aivopuoliskon aivoinfarktin sairastanutta tutkimushenkilöä, joille tehtiin samat tutkimukset kymmenen päivän sisällä sairastumisesta sekä kuuden ja 12 kuukauden jälkeen sairastumisesta. Tutkimuksissa heidän kielellistä ymmärtämistään mitattiin WAB-testin (Western Aphasia Battery) ymmärtämisen tehtävillä ja esittämällä kyllä/ei-kysymyksiä juuri kerrotusta kertomuksesta. Kielellistä työmuistia mitattiin saman kuullun kertomuksen mieleen palauttamistehtävällä (toistokerrontatehtävä), ja neurologista statusta arvioitiin NIHSS-mittarilla (National Institutes of Health Stroke Scale). Koko aineistossa tutkimushenkilöiden kielellinen ymmärtäminen ja kielellinen työmuisti palautuivat sekä neurologiset yleisoireet lievittyivät akuuttivaiheen ja kuuden kuukauden välillä. Kuuden kuukauden jälkeen ei enää havaittu tilastollisesti merkitseviä muutoksia. Korkea ikä, vähäiset koulutusvuodet ja akuuttivaiheessa todettu afasia olivat yhteydessä siihen, että kielellisessä työmuistissa ei havaittu muutosta seurannan aikana. Yksittäisten taustamuuttujien vaikutuksista kuntoutumisprosessissa ei kuitenkaan voi tehdä yleistäviä johtopäätöksiä, sillä taustamuuttujat olivat kietoutuneet toisiinsa. Hyvät kielellisen ymmärtämisen taidot olivat yhteydessä kielellisen työmuistin toimivuuteen, ja kielellisen ymmärtämisen taidot akuuttivaiheessa myös ennustivat kielellisen työmuistin toimivuutta puolen vuoden päässä sairastumisesta. Lievät neurologiset yleisoireet olivat yhteydessä hyviin kielellisen ymmärtämisen taitoihin WAB-testistöllä mitattuna, mutta kielellisen työmuistin toimivuuteen ne eivät sen sijaan olleet yhteydessä seurannan missään vaiheessa. Tämä tutkimus osoitti, että vaikka kielellisen ymmärtämisen taidot kuntoutuvat vuoden seurannan aikana, kielellisen työmuistin taidot pysyvät joissain ryhmissä akuuttivaiheen tasolla. Kielellisen työmuistin tarkastelun tulisikin olla tärkeä puheterapeuttinen väline lievien kielellisten vaikeuksien arvioinnissa. Kognitiivisten toimintojen yhteys, joka myös tuli tutkimuksessa esille, osoittaa puheterapeutin ja neuropsykologin yhteistyön merkityksen. Jatkossa olisi kiinnostavaa tarkastella, miten aivoinfarktikuntoutujat ymmärtävät ja muistavat yksittäisiä kertomuksia laajempia kokonaisuuksia. Tällöin voitaisiin paremmin huomioida muun muassa tarkkaavaisuuden ja väsymisen merkitys

Clinical categories of patients and encounter rates in primary health care – a three-year study in defined populations

BACKGROUND: The objective was to estimate the proportion of inhabitants with a diagnosis-registered encounter with a general practitioner, and to elucidate annual variations of clinical categories of patients in terms of their individual comorbidity. METHODS: A three-year retrospective study of encounter data from electronic patient records, with an annual-based application of the Johns Hopkins Adjusted Clinical Groups (ACG) system. Data were retrieved from every patient with a diagnosis-registered encounter with a GP during the period 2001–2003 at 13 publicly managed primary health care centres in Blekinge county, southeastern Sweden, with about 150000 inhabitants. Main outcome measures: Proportions of inhabitants with a diagnosis-registered encounter, and ranges of the annual proportions of categories of patients according to ACGs. RESULTS: The proportion of inhabitants with a diagnosis-registered encounter ranged from about 64.0% to 90.6% for the primary health care centres, and averaged about 76.5% for all inhabitants. In a three-year perspective the average range of categories of patients was about 0.4% on the county level, and about 0.9% on the primary health care centre level. About one third of the patients each year had a constellation of two or more types of morbidity. CONCLUSION: About three fourths of all inhabitants had one or more diagnosis-registered encounters with a general practitioner during the three-year period. The annual variation of categories of patients according to ACGs was small on both the county and the primary health care centre level. The ACG system seems useful for demonstrating and predicting various aspects of clinical categories of patients in Swedish primary health care

Results of a diagnostic imaging audit in a randomised clinical trial in rectal cancer highlight the importance of careful planning and quality control

BACKGROUND: Magnetic resonance (MR) imaging is the modality used for baseline assessment of locally advanced rectal cancer (LARC) and restaging after neoadjuvant treatment. The overall audited quality of MR imaging in large multicentre trials on rectal cancer is so far not routinely reported.MATERIALS AND METHODS: We collected MR images obtained within the Rectal Cancer And Pre-operative Induction Therapy Followed by Dedicated Operation (RAPIDO) trial and performed an audit of the technical features of image acquisition. The required MR sequences and slice thickness stated in the RAPIDO protocol were used as a reference.RESULTS: Out of 920 participants of the RAPIDO study, MR investigations of 668 and 623 patients in the baseline and restaging setting, respectively, were collected. Of these, 304/668 (45.5%) and 328/623 (52.6%) MR images, respectively, fulfilled the technical quality criteria. The main reason for non-compliance was exceeding slice thickness 238/668, 35.6% in the baseline setting and 162/623, 26.0% in the restaging setting. In 166/668, 24.9% and 168/623, 27.0% MR images in the baseline and restaging setting, respectively, one or more of the required pulse sequences were missing.CONCLUSION: Altogether, 49.0% of the MR images obtained within the RAPIDO trial fulfilled the image acquisition criteria required in the study protocol. High-quality MR imaging should be expected for the appropriate initial treatment and response evaluation of patients with LARC, and efforts should be made to maximise the quality of imaging in clinical trials and in clinical practice.CRITICAL RELEVANCE STATEMENT: This audit highlights the importance of adherence to MR image acquisition criteria for rectal cancer, both in multicentre trials and in daily clinical practice. High-resolution images allow correct staging, treatment stratification and evaluation of response to neoadjuvant treatment.KEY POINTS: - Complying to MR acquisition guidelines in multicentre trials is challenging. - Neglection on MR acquisition criteria leads to poor staging and treatment. - MR acquisition guidelines should be followed in trials and clinical practice. - Researchers should consider mandatory audits prior to study initiation.</p

Results of a diagnostic imaging audit in a randomised clinical trial in rectal cancer highlight the importance of careful planning and quality control

BACKGROUND: Magnetic resonance (MR) imaging is the modality used for baseline assessment of locally advanced rectal cancer (LARC) and restaging after neoadjuvant treatment. The overall audited quality of MR imaging in large multicentre trials on rectal cancer is so far not routinely reported.MATERIALS AND METHODS: We collected MR images obtained within the Rectal Cancer And Pre-operative Induction Therapy Followed by Dedicated Operation (RAPIDO) trial and performed an audit of the technical features of image acquisition. The required MR sequences and slice thickness stated in the RAPIDO protocol were used as a reference.RESULTS: Out of 920 participants of the RAPIDO study, MR investigations of 668 and 623 patients in the baseline and restaging setting, respectively, were collected. Of these, 304/668 (45.5%) and 328/623 (52.6%) MR images, respectively, fulfilled the technical quality criteria. The main reason for non-compliance was exceeding slice thickness 238/668, 35.6% in the baseline setting and 162/623, 26.0% in the restaging setting. In 166/668, 24.9% and 168/623, 27.0% MR images in the baseline and restaging setting, respectively, one or more of the required pulse sequences were missing.CONCLUSION: Altogether, 49.0% of the MR images obtained within the RAPIDO trial fulfilled the image acquisition criteria required in the study protocol. High-quality MR imaging should be expected for the appropriate initial treatment and response evaluation of patients with LARC, and efforts should be made to maximise the quality of imaging in clinical trials and in clinical practice.CRITICAL RELEVANCE STATEMENT: This audit highlights the importance of adherence to MR image acquisition criteria for rectal cancer, both in multicentre trials and in daily clinical practice. High-resolution images allow correct staging, treatment stratification and evaluation of response to neoadjuvant treatment.KEY POINTS: - Complying to MR acquisition guidelines in multicentre trials is challenging. - Neglection on MR acquisition criteria leads to poor staging and treatment. - MR acquisition guidelines should be followed in trials and clinical practice. - Researchers should consider mandatory audits prior to study initiation.</p

Back to the future:re-establishing guinea pig in vivo asthma models

Research using animal models of asthma is currently dominated by mouse models. This has been driven by the comprehensive knowledge on inflammatory and immune reactions in mice, as well as tools to produce genetically modified mice. Many of the identified therapeutic targets influencing airway hyper-responsiveness and inflammation in mouse models, have however been disappointing when tested clinically in asthma. It is therefore a great need for new animal models that more closely resemble human asthma. The guinea pig has for decades been used in asthma research and a comprehensive table of different protocols for asthma models is presented. The studies have primarily been focused on the pharmacological aspects of the disease, where the guinea pig undoubtedly is superior to mice. Further reasons are the anatomical and physiological similarities between human and guinea pig airways compared with that of the mouse, especially with respect to airway branching, neurophysiology, pulmonary circulation and smooth muscle distribution, as well as mast cell localization and mediator secretion. Lack of reagents and specific molecular tools to study inflammatory and immunological reactions in the guinea pig has however greatly diminished its use in asthma research. The aim in this position paper is to review and summarize what we know about different aspects of the use of guinea pig in vivo models for asthma research. The associated aim is to highlight the unmet needs that have to be addressed in the future

Results of a diagnostic imaging audit in a randomised clinical trial in rectal cancer highlight the importance of careful planning and quality control

BACKGROUND: Magnetic resonance (MR) imaging is the modality used for baseline assessment of locally advanced rectal cancer (LARC) and restaging after neoadjuvant treatment. The overall audited quality of MR imaging in large multicentre trials on rectal cancer is so far not routinely reported.MATERIALS AND METHODS: We collected MR images obtained within the Rectal Cancer And Pre-operative Induction Therapy Followed by Dedicated Operation (RAPIDO) trial and performed an audit of the technical features of image acquisition. The required MR sequences and slice thickness stated in the RAPIDO protocol were used as a reference.RESULTS: Out of 920 participants of the RAPIDO study, MR investigations of 668 and 623 patients in the baseline and restaging setting, respectively, were collected. Of these, 304/668 (45.5%) and 328/623 (52.6%) MR images, respectively, fulfilled the technical quality criteria. The main reason for non-compliance was exceeding slice thickness 238/668, 35.6% in the baseline setting and 162/623, 26.0% in the restaging setting. In 166/668, 24.9% and 168/623, 27.0% MR images in the baseline and restaging setting, respectively, one or more of the required pulse sequences were missing.CONCLUSION: Altogether, 49.0% of the MR images obtained within the RAPIDO trial fulfilled the image acquisition criteria required in the study protocol. High-quality MR imaging should be expected for the appropriate initial treatment and response evaluation of patients with LARC, and efforts should be made to maximise the quality of imaging in clinical trials and in clinical practice.CRITICAL RELEVANCE STATEMENT: This audit highlights the importance of adherence to MR image acquisition criteria for rectal cancer, both in multicentre trials and in daily clinical practice. High-resolution images allow correct staging, treatment stratification and evaluation of response to neoadjuvant treatment.KEY POINTS: - Complying to MR acquisition guidelines in multicentre trials is challenging. - Neglection on MR acquisition criteria leads to poor staging and treatment. - MR acquisition guidelines should be followed in trials and clinical practice. - Researchers should consider mandatory audits prior to study initiation.</p

The importance of comorbidity in analysing patient costs in Swedish primary care

BACKGROUND: The objective was to explore the usefulness of the morbidity risk adjustment system Adjusted Clinical Groups(® )(ACG), in comparison with age and gender, in explaining and estimating patient costs on an individual level in Swedish primary health care. Data were retrieved from two primary health care centres in southeastern Sweden. METHODS: A cross-sectional observational study. Data from electronic patient registers from the two centres were retrieved for 2001 and 2002, and patients were grouped into ACGs, expressing the individual combination of diagnoses and thus the comorbidity. Costs per patient were calculated for both years in both centres. Cost data from one centre were used to create ACG weights. These weights were then applied to patients at the other centre. Correlations between individual patient costs, age, gender and ACG weights were studied. Multiple linear regression analyses were performed in order to explain and estimate patient costs. RESULTS: The variation in individual patient costs was substantial within age groups as well as within ACG weight groups. About 37.7% of the individual patient costs could be explained by ACG weights, and age and gender added about 0.8%. The individual patient costs in 2001 estimated 22.0% of patient costs in 2002, whereas ACG weights estimated 14.3%. CONCLUSION: ACGs was an important factor in explaining and estimating individual patient costs in primary health care. Costs were explained to only a minor extent by age and gender. However, the usefulness of the ACG system appears to be sensitive to the accuracy of classification and coding of diagnoses by physicians