A Minimal Threshold of c-di-GMP Is Essential for Fruiting Body Formation and Sporulation in Myxococcus xanthus

Generally, the second messenger bis-(3’-5’)-cyclic dimeric GMP (c-di-GMP) regulates the switch between motile and sessile lifestyles in bacteria. Here, we show that c-di-GMP is an essential regulator of multicellular development in the social bacterium Myxococcus xanthus. In response to starvation, M. xanthus initiates a developmental program that culminates in formation of spore-filled fruiting bodies. We show that c-di-GMP accumulates at elevated levels during development and that this increase is essential for completion of development whereas excess c-di-GMP does not interfere with development. MXAN3735 (renamed DmxB) is identified as a diguanylate cyclase that only functions during development and is responsible for this increased c-di-GMP accumulation. DmxB synthesis is induced in response to starvation, thereby restricting DmxB activity to development. DmxB is essential for development and functions downstream of the Dif chemosensory system to stimulate exopolysaccharide accumulation by inducing transcription of a subset of the genes encoding proteins involved in exopolysaccharide synthesis. The developmental defects in the dmxB mutant are non-cell autonomous and rescued by co-development with a strain proficient in exopolysaccharide synthesis, suggesting reduced exopolysaccharide accumulation as the causative defect in this mutant. The NtrC-like transcriptional regulator EpsI/Nla24, which is required for exopolysaccharide accumulation, is identified as a c-diGMP receptor, and thus a putative target for DmxB generated c-di-GMP. Because DmxB can be—at least partially—functionally replaced by a heterologous diguanylate cyclase, these results altogether suggest a model in which a minimum threshold level of c-di-GMP is essential for the successful completion of multicellular development in M. xanthus

Status Report and Beam Time Request for Experiment AD-4

Summary of current status and plans for October 200

Pilot study: Improving attention bias modification of alcohol cues through concealed gaze-contingent feedback in alcohol dependence.

In an attempt to improve attention bias modification (ABM), we tested whether an attentional training protocol which featured monetary operant conditioning of eye-gaze to avoid alcohol stimuli in alcohol-dependent patients could reduce attention, craving and relapse to alcohol. We employed a pilot randomized control trial (RCT) with 21 detoxified alcohol dependent patients (48.9 ± 10 years of age, 9 male) from an inpatient and outpatient treatment centre. The novel concealed operant conditioning paradigm provided monetary reinforcements or punishments respective to eye-gaze patterns towards neutral or towards alcohol stimuli along with an 80% probability of a to-be-detected probe appearing following neutral stimuli (ET-ABM group). Patients in the control-group received random monetary feedback and a 50/50 ABM contingency. We compared AB on trained and untrained stimuli and addiction severity measures of obsessive thoughts and desires to alcohol following training. We further assessed addiction severity and relapse outcome at a 3-month follow-up. Results indicate that this attentional retraining only worked for the trained stimuli and did not generalize to untrained stimuli or to addiction severity measures or relapse outcome. Potential explanations for lack of generalization include the low sample size and imbalances on important prognostic variables between the active-group and control-group. We discuss progress and challenges for further research on cognitive training using gaze-contingent feedback

Long-term functional outcomes and the patient perspective following altered fractionation with concomitant boost for oropharyngeal cancer

With no long-term data available in published research to date, this study presents details of the swallowing outcomes as well as barriers to and facilitators of oral intake and weight maintenance at 2 years after altered fractionation radiotherapy with concomitant boost (AFRT-CB). Twelve patients with T1-T3 oropharyngeal cancer who received AFRT-CB were assessed at baseline, 6 months, and 2 years post-treatment for levels of dysphagia and salivary toxicity, food and fluid tolerance, functional swallowing outcomes, patient-reported function, and weight. At 2 years, participants were also interviewed to explore barriers and facilitators of oral intake. Outcomes were significantly worse at 2 years when compared to baseline for late toxicity, functional swallowing, and patient-rated physical aspects of swallowing. Most patients (83%) tolerated a full diet pretreatment, but the rate fell to 42% (remainder tolerated soft diets) at 2 years. Multiple barriers to oral intake that impacted on activity and participation levels were identified. Participants lost 11 kg from baseline to 2 years, which was not regained between 6 months and 2 years. Global, social, and emotional domains of patient-reported function returned to pretreatment levels. At 2 years post AFRT-CB, worsening salivary and dysphagia toxicity, declining functional swallowing, and multiple reported ongoing barriers to oral intake had a negative impact on participants' activity and participation levels relating to eating. These ongoing deficits contributed to significant deterioration in physical swallowing functioning determined by the MDADI. In contrast, patients perceived their broader functioning had improved at 2 years, suggesting long-term adjustment to ongoing swallowing deficits

The site of embolization related to infarct size, oedema and clinical outcome in a rat stroke model - further translational stroke research

<p>Abstract</p> <p>Background and purpose</p> <p>Reliable models are essential for translational stroke research to study the pathophysiology of ischaemic stroke in an effort to find therapies that may ultimately reduce oedema, infarction and mortality in the clinic. The purpose of this study was to investigate the relation between the site of arterial embolization and the subsequent oedema, infarction and clinical outcome in a rat embolic stroke model.</p> <p>Methods</p> <p>Thirty-six male Sprague-Dawley rats were thromboembolized into the internal carotid artery. The site of occlusion was demonstrated by arteriography. Following histological preparation and evaluation, the size of the hemispheres and the infarcts were measured by quantitative histology and planimetry. Another parallel stroke model study was subsequently examined to investigate if the conclusions from the first study could be applied to the second study.</p> <p>Results</p> <p>The median size of the infarct was 40% of the ipsilateral hemisphere in both the 19 animals with occlusion localised to the intracranial part of the internal carotid artery and in the 11 animals where the main trunk of the middle cerebral artery was occluded. In 5 animals, occlusion of the extracranial part of the internal carotid artery resulted in significantly smaller infarcts compared to other groups (p < 0.01). Another independent study re-confirmed these results. Furthermore, significant correlations (R > 0.76, p < 0.0001) were found between 1) cortical, subcortical, and total infarct volumes, 2) oedema in percent of the left hemisphere, 3) clinical score before termination and 4) postoperative weight loss.</p> <p>Conclusions</p> <p>Distal occlusions of the intracranial part of the internal carotid or middle cerebral arteries resulted in comparable large sized infarctions and oedema. This indicates that investigators do not need a similar number of such occlusions in each experimental group. Contrary to observations in the clinic, distal internal carotid artery occlusions did not result in worse outcome than middle cerebral stem occlusions, but this finding may be explained by the controlled emboli size in this experimental stroke model.</p

Caseload midwifery as organisational change:the interplay between professional and organisational projects in Denmark

BACKGROUND: The large obstetric units typical of industrialised countries have come under criticism for fragmented and depersonalised care and heavy bureaucracy. Interest in midwife-led continuity models of care is growing, but knowledge about the accompanying processes of organisational change is scarce. This study focuses on midwives’ role in introducing and developing caseload midwifery. Sociological studies of midwifery and organisational studies of professional groups were used to capture the strong interests of midwives in caseload midwifery and their key role together with management in negotiating organisational change. METHODS: We studied three hospitals in Denmark as arenas for negotiating the introduction and development of caseload midwifery and the processes, interests and resources involved. A qualitative multi-case design was used and the selection of hospitals aimed at maximising variance. Ten individual and 14 group interviews were conducted in spring 2013. Staff were represented by caseload midwives, ward midwives, obstetricians and health visitors, management by chief midwives and their deputies. Participants were recruited to maximise the diversity of experience. The data analysis adopted a thematic approach, using within- and across-case analysis. RESULTS: The analysis revealed a highly interdependent interplay between organisational and professional projects in the change processes involved in the introduction and development of caseload midwifery. This was reflected in three ways: first, in the key role of negotiations in all phases; second, in midwives’ and management’s engagement in both types of projects (as evident from their interests and resources); and third in a high capacity for resolving tensions between the two projects. The ward midwives’ role as a third party in organisational change further complicated the process. CONCLUSIONS: For managers tasked with the introduction and development of caseload midwifery, our study underscores the importance of understanding the complexity of the underlying change processes and of activating midwives’ and managers’ interests and resources in addressing the challenges. Further studies of female-dominated professions such as midwifery should offer good opportunities for detailed analysis of the deep-seated interdependence of professional and organisational projects and for identifying the key dimensions of this interdependence

Teriparatide seems to improve recovery after pertrochanteric hip fracture : Comparison with risedronate in a randomized, controlled trial

To compare the effects on fracture recovery of 26 wks' therapy with an oral antiresorptive (risedronate: RIS 35 mg QW) or a bone forming drug (teriparatide: TPTD 20 ug QD) started within 2 wks after osteosynthesis in a pertrochanteric hip fracture in patients with low bone mass. Methods: 224 patients were randomized to study drug and an oral/injectable placebo plus calcium/vitD3 in an osteoporosis trial. The primary outcome was bone mineral density which will be reported elsewhere. We report secondary (Timed Up-and-Go [TUG] test, hip pain, SF-36, safety) and exploratory (radiography) endpoints. Efficacy analyses of the TUG test, patient-rated health status, and hip pain 100 mm Visual Analog Scale were performed with a Mixed-effects Model for Repeated Measures. Results: Mean age was 77 years and 77% were female. The teriparatide group completed the TUG test in a shorter time (LS means 5.7, 4.4, 3.1, and 3.1 seconds less at 6, 12, 18, and 24 wks; overall difference p = 0.021) and reported less hip pain during the test (LS means 8.7, 10.6, 11.9, and 10.2 mm differences at 6, 12, 18, and 26 wks; overall difference p = 0.032). No significant between-group differences in SF-36, Charnley hip pain score, ability to walk or walking aids during follow-up. No patient was radiographically healed at 6 wks, and 90% were healed at 12 wks in both groups. Implant failure (TPTD:7, RIS:8), loss of reduction (TPTD:2, RIS:4) or non-union (0 cases) showed no significant differences. Mild hypercalcemia and hyperuricemia were more frequent with teriparatide. Conclusions: Patients treated with teriparatide reported less hip pain and shorter time to complete the TUG test than RIS between 6-26 wks. These outcomes were secondary

An Integrated Disease/Pharmacokinetic/Pharmacodynamic Model Suggests Improved Interleukin-21 Regimens Validated Prospectively for Mouse Solid Cancers

Interleukin (IL)-21 is an attractive antitumor agent with potent immunomodulatory functions. Yet thus far, the cytokine has yielded only partial responses in solid cancer patients, and conditions for beneficial IL-21 immunotherapy remain elusive. The current work aims to identify clinically-relevant IL-21 regimens with enhanced efficacy, based on mathematical modeling of long-term antitumor responses. For this purpose, pharmacokinetic (PK) and pharmacodynamic (PD) data were acquired from a preclinical study applying systemic IL-21 therapy in murine solid cancers. We developed an integrated disease/PK/PD model for the IL-21 anticancer response, and calibrated it using selected “training” data. The accuracy of the model was verified retrospectively under diverse IL-21 treatment settings, by comparing its predictions to independent “validation” data in melanoma and renal cell carcinoma-challenged mice (R2>0.90). Simulations of the verified model surfaced important therapeutic insights: (1) Fractionating the standard daily regimen (50 µg/dose) into a twice daily schedule (25 µg/dose) is advantageous, yielding a significantly lower tumor mass (45% decrease); (2) A low-dose (12 µg/day) regimen exerts a response similar to that obtained under the 50 µg/day treatment, suggestive of an equally efficacious dose with potentially reduced toxicity. Subsequent experiments in melanoma-bearing mice corroborated both of these predictions with high precision (R2>0.89), thus validating the model also prospectively in vivo. Thus, the confirmed PK/PD model rationalizes IL-21 therapy, and pinpoints improved clinically-feasible treatment schedules. Our analysis demonstrates the value of employing mathematical modeling and in silico-guided design of solid tumor immunotherapy in the clinic