Non-contact luminescence lifetime cryothermometry for macromolecular crystallography

Temperature is a very important parameter when aiming to minimize radiation damage to biological samples during experiments that utilize intense ionizing radiation. A novel technique for remote, non-contact, in situ monitoring of the protein crystal temperature has been developed for the new I23 beamline at the Diamond Light Source, a facility dedicated to macromolecular crystallography (MX) with long-wavelength X-rays. The temperature is derived from the temperature-dependent decay time constant of luminescence from a minuscule scintillation sensor (<0.05 mm3) located in very close proximity to the sample under test. In this work the underlying principle of cryogenic luminescence lifetime thermometry is presented, the features of the detection method and the choice of temperature sensor are discussed, and it is demonstrated how the temperature monitoring system was integrated within the viewing system of the endstation used for the visualization of protein crystals. The thermometry system was characterized using a Bi4Ge3O12 crystal scintillator that exhibits good responsivity of the decay time constant as a function of temperature over a wide range (8-270 K). The scintillation sensor was calibrated and the uncertainty of the temperature measurements over the primary operation temperature range of the beamline (30-150 K) was assessed to be ±1.6 K. It has been shown that the temperature of the sample holder, measured using the luminescence sensor, agrees well with the expected value. The technique was applied to characterize the thermal performance of different sample mounts that have been used in MX experiments at the I23 beamline. The thickness of the mount is shown to have the greatest impact upon the temperature distribution across the sample mount. Altogether, these tests and findings demonstrate the usefulness of the thermometry system in highlighting the challenges that remain to be addressed for the in-vacuum MX experiment to become a reliable and indispensable tool for structural biology.

Effects of scFOS on the composition of fecal microbiota and anxiety in patients with irritable bowel syndrome: a randomized, double blind, placebo controlled study

BACKGROUND

Short-chain fructooligosaccharides (scFOS) have beneficial effects in subjects with minor digestive complaints, but the potential mechanisms involved have not been elucidated. The aim of the study was to evaluate changes in rectal sensitivity related to the clinical effects of scFOS in a selected group of patients with irritable bowel syndrome (IBS) and rectal hypersensitivity.

METHODS

In 79 IBS patients (defined by Rome III criteria) with rectal hypersensitivity (defined as discomfort threshold ≤44 g) a parallel, placebo-controlled, randomized, and double-blind study was performed to assess the effects of dietary supplementation (5 g d^-1 ) with scFOS vs placebo for 4 weeks on rectal sensitivity (primary outcome: tolerance to increasing wall tension applied by a tensostat), clinical outcomes (IBS, anxiety/depression and quality of life scores) and composition of fecal microbiota.

KEY RESULTS

Rectal discomfort threshold, and IBS and quality of life scores, significantly improved during treatment, but in a similar manner in both scFOS and placebo groups; a post-hoc analysis showed that the effect of scFOS on rectal sensitivity was more pronounced in constipation-predominant-IBS patients (P=.051 vs placebo). Contrary with placebo, scFOS significantly reduced anxiety scores and increased fecal Bifidobacteria (P<.05 for both) without modifying other bacterial groups.

CONCLUSIONS & INTERFENCES

The effect of scFOS on anxiety may be related to modulation of the gut microbiota; demonstration of effects of scFOS on rectal sensitivity may require higher doses and may depend on the IBS subgroup.

Building Bridges for Innovation in Ageing: Synergies between Action Groups of the EIP on AHA

The Strategic Implementation Plan of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) proposed six Action Groups. After almost three years of activity, many achievements have been obtained through commitments or collaborative work of the Action Groups. However, they have often worked in silos and, consequently, synergies between Action Groups have been proposed to strengthen the triple win of the EIP on AHA. The paper presents the methodology and current status of the Task Force on EIP on AHA synergies. Synergies are in line with the Action Groups' new Renovated Action Plan (2016-2018) to ensure that their future objectives are coherent and fully connected. The outcomes and impact of synergies are using the Monitoring and Assessment Framework for the EIP on AHA (MAFEIP). Eight proposals for synergies have been approved by the Task Force: Five cross-cutting synergies which can be used for all current and future synergies as they consider overarching domains (appropriate polypharmacy, citizen empowerment, teaching and coaching on AHA, deployment of synergies to EU regions, Responsible Research and Innovation), and three cross-cutting synergies focussing on current Action Group activities (falls, frailty, integrated care and chronic respiratory diseases).

Prognosis of Accidental Hypothermia in the Urban Setting

Our goal was to study the outcome and factors affecting outcome in patients with accidental hypothermia in the urban setting. A retrospective cohort study was done on patients admitted to the emergency department with accidental hypothermia (core temperature less than 35°C) from 1991 to 1998. Patients received general intensive care (fluid replacement, mechanical ventilation, cardiopulmonary resuscitation) and were rewarmed actively by intravenous application of warmed fluids, warmed air, pleural lavage, or cardiopulmonary bypass as indicated. Rewarming was successful in 76 of 80 patients (95%) and hospital mortality was 34%. Survivors differed significantly from nonsurvivors with respect to demographic data (indoor finding, homelessness, alcohol abuse, chronic psychiatric disorder, presumed acute alcohol or drug intoxication), findings on admission [severity of hypothermia, systolic blood pressure, heart rate, multiple organ failure (MOF) score, hypothermia outcome score (HOS), BUN, creatinine, CPK, bilirubin, AST, platelet count], but not with respect to therapeutic modalities (mechanical ventilation, volume replacement, pleural lavage, mechanical ventilation, vasopressors, cardiopulmonary bypass). Rewarming time in nonsurvivors, however, was significantly longer. In logistic regression analysis only indoor occurrence, BUN, and platelet count proved to be independent predictors of in-hospital mortality. Survival of patients found outdoors was significantly higher than that of patients found indoors (p < 0.0001). Our study demonstrates that although rewarming and resuscitation are highly effective, accidental urban hypothermia is a condition with a significant in-hospital mortality. There were only a few independent indicators of unfavorable outcome, of which indoor occurrence was by far the most important. Therefore indoor occurrence of hypothermia has to be acknowledged as a risk factor of poor outcome in accidental urban hypothermia.

A multicentre comparative prospective blinded analysis of EUS and MRI for screening of pancreatic cancer in high-risk individuals

OBJECTIVE

Endoscopic ultrasonography (EUS) and MRI are promising tests to detect precursors and early-stage pancreatic ductal adenocarcinoma (PDAC) in high-risk individuals (HRIs). It is unclear which screening technique is to be preferred. We aimed to compare the efficacy of EUS and MRI in their ability to detect clinically relevant lesions in HRI.

DESIGN

Multicentre prospective study. The results of 139 asymptomatic HRI (>10-fold increased risk) undergoing first-time screening by EUS and MRI are described. Clinically relevant lesions were defined as solid lesions, main duct intraductal papillary mucinous neoplasms and cysts ≥10 mm. Results were compared in a blinded, independent fashion.

RESULTS

Two solid lesions (mean size 9 mm) and nine cysts ≥10 mm (mean size 17 mm) were detected in nine HRI (6%). Both solid lesions were detected by EUS only and proved to be a stage I PDAC and a multifocal pancreatic intraepithelial neoplasia 2. Of the nine cysts ≥10 mm, six were detected by both imaging techniques and three were detected by MRI only. The agreement between EUS and MRI for the detection of clinically relevant lesions was 55%. Of these clinically relevant lesions detected by both techniques, there was a good agreement for location and size.

CONCLUSIONS

EUS and/or MRI detected clinically relevant pancreatic lesions in 6% of HRI. Both imaging techniques were complementary rather than interchangeable: contrary to EUS, MRI was found to be very sensitive for the detection of cystic lesions of any size; MRI, however, might have some important limitations with regard to the timely detection of solid lesions.

Diagnostic Imaging in Fracture of Lumbar Vertebral Ring Apophyses

The findings at plain radiography, myelography, CT, and MR imaging in 3 cases of fracture of the lumbar vertebral ring apophysis are presented. Familiarity with this entity is important in evaluating low back pain in children and young adults. Conventional radiographs and/or MR imaging may suggest ring apophysis fracture; CT will confirm and classify the diagnosis.

MR Imaging in Advanced Abdominal Pregnancy

Abdominal pregnancy is a rare but life-threatening condition. The preoperative diagnosis may be difficult. When there is a suspicion of abdominal pregnancy and ultrasonographic findings are equivocal or inconclusive, MR imaging should be performed. We report a case of an abdominal pregnancy of 28 weeks' gestation diagnosed by MR.

Adrenoleukodystrophy

Purpose:

Adrenoleukodystrophy is a hereditary, usually X-linked recessive disorder, characterized by progressive demyelination of cerebral white matter and adrenal insufficiency.

Material and Methods and Results:

We report the case of a 14-year-old boy, presenting the typical changes in CT and MR with almost symmetrical changes in the white matter only, with no mass effect and a rim of enhancement. Adrenoleukodystrophy may resemble tumour but shows no mass effect.

Discussion and Conclusion:

We discuss the differential diagnoses and underline the importance of the characteristic appearance of this disease. Adrenoleukodystrophy is diagnosed by serum analysis.