367 research outputs found
A new hammer to crack an old nut : interspecific competitive resource capture by plants is regulated by nutrient supply, not climate
Peer reviewedPublisher PD
Relevance of biomarkers across different neurodegenerative
Background: The panel of fluid- and imaging-based biomarkers available for neurodegenerative disease research is
growing and has the potential to close important gaps in research and the clinic. With this growth and increasing use,
appropriate implementation and interpretation are paramount. Various biomarkers feature nuanced differences in
strengths, limitations, and biases that must be considered when investigating disease etiology and clinical utility. For
example, neuropathological investigations of Alzheimer’s disease pathogenesis can fall in disagreement with conclusions
reached by biomarker-based investigations. Considering the varied strengths, limitations, and biases of different research
methodologies and approaches may help harmonize disciplines within the neurodegenerative disease field.
Purpose of review: Along with separate review articles covering fluid and imaging biomarkers in this issue of Alzheimer’s
Research and Therapy, we present the result of a discussion from the 2019 Biomarkers in Neurodegenerative Diseases
course at the University College London. Here, we discuss themes of biomarker use in neurodegenerative disease
research, commenting on appropriate use, interpretation, and considerations for implementation across different
neurodegenerative diseases. We also draw attention to areas where biomarker use can be combined with other
disciplines to understand issues of pathophysiology and etiology underlying dementia. Lastly, we highlight novel
modalities that have been proposed in the landscape of neurodegenerative disease research and care
Supplier-induced demand for psychiatric admissions in Northern New England
The development of hospital service areas (HSAs) using small area analysis has been useful in examining variation in medical and surgical care; however, the techniques of small area analysis are underdeveloped in understanding psychiatric admission rates. We sought to develop these techniques in order to understand the relationship between psychiatric bed supply and admission rates in Northern New England. Our primary hypotheses were that there would be substantial variation in psychiatric admission across geographic settings and that bed availability would be positively correlated with admission rates, reflecting a supplier-induced demand phenomenon. Our secondary hypothesis was that the construction of psychiatric HSAs (PHSAs) would yield more meaningful results than the use of existing general medical hospital service areas
Is visual estimation of passive range of motion in the pediatric lower limb valid and reliable
<p>Abstract</p> <p>Background</p> <p>Visual estimation (VE) is an essential tool for evaluation of range of motion. Few papers discussed its validity in children orthopedics' practice. The purpose of our study was to assess validity and reliability of VE for passive range of motions (PROMs) of children's lower limbs.</p> <p>Methods</p> <p>Fifty typically developing children (100 lower limbs) were examined. Visual estimations for PROMs of hip (flexion, adduction, abduction, internal and external rotations), knee (flexion and popliteal angle) and ankle (dorsiflexion and plantarflexion) were made by a pediatric orthopaedic surgeon (POS) and a 5<sup>th </sup>year resident in orthopaedics. A last year medical student did goniometric measurements. Three weeks later, same measurements were performed to assess reliability of visual estimation for each examiner.</p> <p>Results</p> <p>Visual estimations of the POS were highly reliable for hip flexion, hip rotations and popliteal angle (ρ<sub>c </sub>≥ 0.8). Reliability was good for hip abduction, knee flexion, ankle dorsiflexion and plantarflexion (ρ<sub>c </sub>≥ 0.7) but poor for hip adduction (ρ<sub>c </sub>= 0.5). Reproducibility for all PROMs was verified. Resident's VE showed high reliability (ρ<sub>c </sub>≥ 0.8) for hip flexion and popliteal angle. Good correlation was found for hip rotations and knee flexion (ρ<sub>c </sub>≥ 0.7). Poor results were obtained for ankle PROMs (ρ<sub>c </sub>< 0.6) as well as hip adduction and abduction, the results of which not being reproducible. Influence of experience was clearly demonstrated for PROMs of hip rotations, adduction and abduction as well as ankle plantarflexion.</p> <p>Conclusion</p> <p>Accuracy of VE of passive hip flexion and knee PROMs is high regardless of the examiner's experience. Same accuracy can be found for hip rotations and abduction whenever VE is performed by an experienced examiner. Goniometric evaluation is recommended for passive hip adduction and for ankle PROMs.</p
Serum and cerebrospinal fluid biomarker profiles in acute SARS-CoV-2-associated neurological syndromes
Preliminary pathological and biomarker data suggest that SARS-CoV-2 infection can damage the nervous system. To understand what, where and how damage occurs, we collected serum and CSF from patients with COVID-19 and characterized neurological syndromes involving the PNS and CNS (n = 34). We measured biomarkers of neuronal damage and neuroinflammation, and compared these with non-neurological control groups, which included patients with (n = 94) and without (n = 24) COVID-19. We detected increased concentrations of neurofilament light, a dynamic biomarker of neuronal damage, in the CSF of those with CNS inflammation (encephalitis and acute disseminated encephalomyelitis) [14 800 pg/ml (400, 32 400)], compared to those with encephalopathy [1410 pg/ml (756, 1446)], peripheral syndromes (Guillain–Barré syndrome) [740 pg/ml (507, 881)] and controls [872 pg/ml (654, 1200)]. Serum neurofilament light levels were elevated across patients hospitalized with COVID-19, irrespective of neurological manifestations. There was not the usual close correlation between CSF and serum neurofilament light, suggesting serum neurofilament light elevation in the non-neurological patients may reflect peripheral nerve damage in response to severe illness. We did not find significantly elevated levels of serum neurofilament light in community cases of COVID-19 arguing against significant neurological damage. Glial fibrillary acidic protein, a marker of astrocytic activation, was not elevated in the CSF or serum of any group, suggesting astrocytic activation is not a major mediator of neuronal damage in COVID-19
Exploring Doctor–Patient Communication in Immigrant Australians with Type 2 Diabetes: A Qualitative Study
OBJECTIVE: The study explored the perceptions of Australian immigrants about their interactions with doctors regarding the diagnosis, treatment, and management of type 2 diabetes mellitus. RESEARCH DESIGN AND METHODS: In-depth interviews were conducted with 30 men and women from Greek, Indian, Chinese, and Pacific Island backgrounds living in Melbourne, Australia, to elicit their perceptions of the management of diabetes and its impact. Participants were recruited through a convenience sample of general practitioners and community organizations providing support to people living with diabetes. Topics discussed included initial reaction to diagnosis, patient—health care provider communication, and the influence of message framing on the perception of the quality of the doctor–patient relationship. Transcripts were coded and analyzed by both authors. RESULTS: Numerous issues facilitate or inhibit constructive and positive relationships between doctors and patients with type 2 diabetes. Patients reported difficulty in absorbing all the information provided to them at early consultations, and experienced difficulty comprehending the practical aspects of management. Styles of communication and discourses of normalization and catastrophe influenced participants’ responses. CONCLUSION: Doctors face a complex task in encouraging behavioral change and adherence and establishing and maintaining a supportive relationship with patients. The timing and technical complexity of communication about diabetes, its management, and the prevention of complications require further attention
Quality assurance in psychiatry: quality indicators and guideline implementation
In many occasions, routine mental health care does not correspond to the standards that the medical profession itself puts forward. Hope exists to improve the outcome of severe mental illness by improving the quality of mental health care and by implementing evidence-based consensus guidelines. Adherence to guideline recommendations should reduce costly complications and unnecessary procedures. To measure the quality of mental health care and disease outcome reliably and validly, quality indicators have to be available. These indicators of process and outcome quality should be easily measurable with routine data, should have a strong evidence base, and should be able to describe quality aspects across all sectors over the whole disease course. Measurement-based quality improvement will not be successful when it results in overwhelming documentation reducing the time for clinicians for active treatment interventions. To overcome difficulties in the implementation guidelines and to reduce guideline non-adherence, guideline implementation and quality assurance should be embedded in a complex programme consisting of multifaceted interventions using specific psychological methods for implementation, consultation by experts, and reimbursement of documentation efforts. There are a number of challenges to select appropriate quality indicators in order to allow a fair comparison across different approaches of care. Carefully used, the use of quality indicators and improved guideline adherence can address suboptimal clinical outcomes, reduce practice variations, and narrow the gap between optimal and routine care
Adenyl cyclases and cAMP in plant signaling - past and present
In lower eukaryotes and animals 3'-5'-cyclic adenosine monophosphate (cAMP) and adenyl cyclases (ACs), enzymes that catalyse the formation of cAMP from ATP, have long been established as key components and second messengers in many signaling pathways. In contrast, in plants, both the presence and biological role of cAMP have been a matter of ongoing debate and some controversy. Here we shall focus firstly on the discovery of cellular cAMP in plants and evidence for a role of this second messenger in plant signal transduction. Secondly, we shall review current evidence of plant ACs, analyse aspects of their domain organisations and the biological roles of candidate molecules. In addition, we shall assess different approaches based on search motifs consisting of functionally assigned amino acids in the catalytic centre of annotated and/or experimentally tested nucleotide cyclases that can contribute to the identification of novel candidate molecules with AC activity such as F-box and TIR proteins
Transitioning from cerebrospinal fluid to blood tests to facilitate diagnosis and disease monitoring in Alzheimer's disease
AbstractAlzheimer’s disease (AD) is increasingly prevalent worldwide, and disease-modifying treatments may soon be at hand; hence, now, more than ever, there is a need to develop techniques that allow earlier and more secure diagnosis. Current biomarker-based guidelines for AD diagnosis, which have replaced the historical symptom-based guidelines, rely heavily on neuroimaging and cerebrospinal fluid (CSF) sampling. While these have greatly improved the diagnostic accuracy of AD pathophysiology, they are less practical for application in primary care, population-based and epidemiological settings, or where resources are limited. In contrast, blood is a more accessible and cost-effective source of biomarkers in AD. In this review paper, using the recently proposed amyloid, tau and neurodegeneration [AT(N)] criteria as a framework towards a biological definition of AD, we discuss recent advances in biofluid-based biomarkers, with a particular emphasis on those with potential to be translated into blood-based biomarkers. We provide an overview of the research conducted both in CSF and in blood to draw conclusions on biomarkers that show promise. Given the evidence collated in this review, plasma neurofilament light chain (N) and phosphorylated tau (p-tau; T) show particular potential for translation into clinical practice. However, p-tau requires more comparisons to be conducted between its various epitopes before conclusions can be made as to which one most robustly differentiates AD from non-AD dementias. Plasma amyloid beta (A) would prove invaluable as an early screening modality, but it requires very precise tests and robust pre-analytical protocols.</div
Candidate high myopia loci on chromosomes 18p and 12q do not play a major role in susceptibility to common myopia
BACKGROUND: To determine whether previously reported loci predisposing to nonsyndromic high myopia show linkage to common myopia in pedigrees from two ethnic groups: Ashkenazi Jewish and Amish. We hypothesized that these high myopia loci might exhibit allelic heterogeneity and be responsible for moderate /mild or common myopia. METHODS: Cycloplegic and manifest refraction were performed on 38 Jewish and 40 Amish families. Individuals with at least -1.00 D in each meridian of both eyes were classified as myopic. Genomic DNA was genotyped with 12 markers on chromosomes 12q21-23 and 18p11.3. Parametric and nonparametric linkage analyses were conducted to determine whether susceptibility alleles at these loci are important in families with less severe, clinical forms of myopia. RESULTS: There was no strong evidence of linkage of common myopia to these candidate regions: all two-point and multipoint heterogeneity LOD scores were < 1.0 and non-parametric linkage p-values were > 0.01. However, one Amish family showed slight evidence of linkage (LOD>1.0) on 12q; another 3 Amish families each gave LOD >1.0 on 18p; and 3 Jewish families each gave LOD >1.0 on 12q. CONCLUSIONS: Significant evidence of linkage (LOD> 3) of myopia was not found on chromosome 18p or 12q loci in these families. These results suggest that these loci do not play a major role in the causation of common myopia in our families studied
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