Acceptance and perceived barriers of implementing a guideline for managing low back in general practice

Background

There is considerable interest today in shared decision-making (SDM), defined as a decision-making process jointly shared by patients and their health care provider. However, the data show that SDM has not been broadly adopted yet. Consequently, the main goal of this proposal is to bring together the resources and the expertise needed to develop an interdisciplinary and international research team on the implementation of SDM in clinical practice using a theory-based dyadic perspective.

Methods

Participants include researchers from Canada, US, UK, and Netherlands, representing medicine, nursing, psychology, community health and epidemiology. In order to develop a collaborative research network that takes advantage of the expertise of the team members, the following research activities are planned: 1) establish networking and on-going communication through internet-based forum, conference calls, and a bi-weekly e-bulletin; 2) hold a two-day workshop with two key experts (one in theoretical underpinnings of behavioral change, and a second in dyadic data analysis), and invite all investigators to present their views on the challenges related to the implementation of SDM in clinical practices; 3) conduct a secondary analyses of existing dyadic datasets to ensure that discussion among team members is grounded in empirical data; 4) build capacity with involvement of graduate students in the workshop and online forum; and 5) elaborate a position paper and an international multi-site study protocol.

Discussion

This study protocol aims to inform researchers, educators, and clinicians interested in improving their understanding of effective strategies to implement shared decision-making in clinical practice using a theory-based dyadic perspective.     

Characterization of truncated forms of abnormal prion protein in Creutzfeldt-Jakob disease

In prion disease, the abnormal conformer of the cellular prion protein, PrP(Sc), deposits in fibrillar protein aggregates in brain and other organs. Limited exposure of PrP(Sc) to proteolytic digestion in vitro generates a core fragment of 19-21 kDa, named PrP27-30, which is also found in vivo. Recent evidence indicates that abnormal truncated fragments other than PrP27-30 may form in prion disease either in vivo or in vitro. We characterized a novel protease-resistant PrP fragment migrating 2-3 kDa faster than PrP27-30 in Creutzfeldt-Jakob disease (CJD) brains. The fragment has a size of about 18.5 kDa when associated with PrP27-30 type 1 (21 kDa) and of 17 kDa when associated with type 2 (19 kDa). Molecular mass and epitope mapping showed that the two fragments share the primary N-terminal sequence with PrP27-30 types 1 and 2, respectively, but lack a few amino acids at the very end of C terminus together with the glycosylphosphatidylinositol anchor. The amounts of the 18.5- or 17-kDa fragments and the previously described 13-kDa PrP(Sc) C-terminal fragment relatively to the PrP27-30 signal significantly differed among CJD subtypes. Furthermore, protease digestion of PrP(Sc) or PrP27-30 in partially denaturing conditions generated an additional truncated fragment of about 16 kDa only in typical sporadic CJD (i.e. MM1). These results show that the physicochemical heterogeneity of PrP(Sc) in CJD extends to abnormal truncated forms of the protein. The findings support the notion of distinct structural "conformers" of PrP(Sc) and indicate that the characterization of truncated PrP(Sc) forms may further improve molecular typing in CJD.     

Frequent Occurrence of Human-Associated Microsporidia in Fecal Droppings of Urban Pigeons in Amsterdam, The Netherlands

Human-associated microsporidia were frequently observed in fecal samples of 331 feral pigeons in Amsterdam, The Netherlands, obtained during high- and low-breeding periods. Thirty-six of 331 samples (11%) contained the human pathogens Enterocytozoon bieneusi (n = 18), Encephalitozoon hellem (n = 11), Encephalitozoon cuniculi (n = 6), and Encephalitozoon intestinalis (n = 1); 5 samples contained other microsporidia. Pigeon feces can be an important source of human microsporidian infection.     

Cellular Mechanisms of Interferon Production

Rabbit kidney cell cultures stimulated with either double-stranded polyinosinate-polycytidylate (poly I:poly C) or with ultraviolet-irradiated Newcastle disease virus (UV-NDV) produce two types of interferon response, designated "early" and "late," respectively. The early response is suppressed by inhibitors of RNA or protein synthesis and is therefore thought to represent de novo synthesis of interferon. Circumstantial evidence suggested that this interferon response is regulated by a translation control mechanism. Late interferon production with poly I:poly C only took place in the presence of inhibitors of RNA or protein synthesis. The late interferon is therefore likely to be derived by the activation of an interferon precursor. The stimulation of late poly I:poly C-induced interferon production by cycloheximide suggested the existence of a second, posttranslational level of control of interferon production. This posttranslation control seems to be activated by interferon. UV-NDV can probably suppress the synthesis of the posttranslation inhibitory protein, and therefore it stimulates a late interferon response in the absence of inhibitors of RNA or protein synthesis. It is postulated that both the translation and posttranslation inhibitor participate in the development of a cellular refractory state to repeated interferon stimulation. The picture of interferon which emerges from this study is one of a heterogenous class of proteins whose production is controlled by cellular repressors acting at various levels.     

Chemical congruence of the complex odoriferous secretions from Dufour's gland in three species of ants of the genus Formica

Forty-six volatile compounds were identified in the secretions from Dufour's gland of worker ants of the species Formica nigricans, F. rufa, and F. polyctena using combined gas chromatography-mass spectrometry and capillary gas chromatography. In both methods the natural volatile material has been driven off excised glands using a precolumn technique.The composition of the secretions from the three species are very similar but there are also some distinct differences, especially between F. nigricans on the one hand and F. rufa and F. polyctena on the other. Straight-chain, saturated hydrocarbons are the quantitatively dominating compounds, with undecane as the largest individual component, followed by tridecane, pentadecane, and heptadecane. Straight-chain, monounsaturated hydrocarbons and methyl-branched, saturated hydrocarbons are also present and a few straight-chain, doubly unsaturated hydrocarbons are present in trace amounts.In the region of lower volatility two isoprenoids identified as all-trans-geranylgeraniol and the corresponding acetate all-trans-geranylgeranyl acetate, have been found together with octadecyl acetate. The relative amounts between these compounds are the main difference between the secretions from the three species. Octadecyl acetate is thus present only in trace amounts in the secretion of F. nigricans.In addition to the compounds mentioned a few aliphatic acetates and alcohols present in small amounts have been identified.The secretions are thought to have many functions which are reflected in their complex composition. This is discussed in comparison with results from other formicine ants. The species specificity in the composition of the secretion from Dufour's gland and the taxonomic value of this specificity are also discussed.     

EVIDENCE FOR THE PARTICIPATION OF THE GOLGI APPARATUS IN THE INTRACELLULAR TRANSPORT OF NASCENT ALBUMIN IN THE LIVER CELL

A comparative biochemical and radioautographic in vivo study was performed to identify the site of synthesis and route of migration of albumin in the parenchymal liver cell after labeling with leucine-¹⁴C or leucine-³H via the portal vein. Free cytoplasmic ribosomes, membrane-bound ribosomes, rough- and smooth-surfaced microsomes, and Golgi membranes were isolated. The purity of the Golgi fraction was examined morphologically and biochemically. After administration of leucine-¹⁴C, labeled albumin was extracted, and the sequence of transport was followed from one fraction to the other. Approximately 2 min after the intravenous injection, bound ribosomes displayed a maximal rate of leucine-¹⁴C incorporation into albumin. 4 min later, a peak was reached for rough microsomes. Corresponding maximal activities for smooth microsomes were recorded at 15 min, and for the Golgi apparatus at ~20 min. The relative amount of albumin, calculated on a membrane protein basis, was higher in the Golgi fraction than in the microsomes. By radioautography the silver grains were preferentially localized over the rough-surfaced endoplasmic reticulum at the 5 min interval. Apparent activity in the Golgi zone was noted 9 min after the injection; at 15 and 20 min, the majority of the grains were found in this location. Many of the grains associated with the Golgi apparatus were located over Golgi vacuoles containing 300–800 A electron-opaque bodies. It is concluded that albumin is synthesized on bound ribosomes, subsequently is transferred to the cavities of rough-surfaced endoplasmic reticulum, and then undergoes migration to the smooth-surfaced endoplasmic reticulum and the Golgi apparatus. In the latter organelle, albumin can be expected to be segregated together with very low density lipoprotein in vacuoles known to move toward the sinusoidal portion of the cell and release their content to the blood.     

Methionine sulfoxides on PrPSc: a prion-specific covalent signature

Prion diseases are fatal neurodegenerative disorders believed to be transmitted by PrP (Sc), an aberrant form of the membrane protein PrP (C). In the absence of an established form-specific covalent difference, the infectious properties of PrP (Sc) were uniquely ascribed to the self-perpetuation properties of its aberrant fold. Previous sequencing of the PrP chain isolated from PrP(27-30) showed the oxidation of some methionine residues; however, at that time, these findings were ascribed to experimental limitations. Using the unique recognition properties of alphaPrP mAb IPC2, protein chemistry, and state of the art mass spectrometry, we now show that while a large fraction of the methionine residues in brain PrP (Sc) are present as methionine sulfoxides this modification could not be found on brain PrP (C) as well as on its recombinant models. In particular, the pattern of oxidation of M213 with respect to the glycosylation at N181 of PrP (Sc) differs both within and between species, adding another diversity factor to the structure of PrP (Sc) molecules. Our results pave the way for the production of prion-specific reagents in the form of antibodies against oxidized PrP chains which can serve in the development of both diagnostic and therapeutic strategies. In addition, we hypothesize that the accumulation of PrP (Sc) and thereafter the pathogenesis of prion disease may result from the poor degradation of oxidized aberrantly folded PrP.     

Human TLR8 senses UR/URR motifs in bacterial and mitochondrial RNA

Toll‐like receptor (TLR) 13 and TLR2 are the major sensors of Gram‐positive bacteria in mice. TLR13 recognizes Sa19, a specific 23S ribosomal (r) RNA‐derived fragment and bacterial modification of Sa19 ablates binding to TLR13, and to antibiotics such as erythromycin. Similarly, RNase A‐treated Staphylococcus aureus activate human peripheral blood mononuclear cells (PBMCs) only via TLR2, implying single‐stranded (ss) RNA as major stimulant. Here, we identify human TLR8 as functional TLR13 equivalent that promiscuously senses ssRNA. Accordingly, Sa19 and mitochondrial (mt) 16S rRNA sequence‐derived oligoribonucleotides (ORNs) stimulate PBMCs in a MyD88‐dependent manner. These ORNs, as well as S. aureus‐, Escherichia coli‐, and mt‐RNA, also activate differentiated human monocytoid THP‐1 cells, provided they express TLR8. Moreover, Unc93b1 ^−/−‐ and Tlr8 ^−/−‐THP‐1 cells are refractory, while endogenous and ectopically expressed TLR8 confers responsiveness in a UR/URR RNA ligand consensus motif‐dependent manner. If TLR8 function is inhibited by suppression of lysosomal function, antibiotic treatment efficiently blocks bacteria‐driven inflammatory responses in infected human whole blood cultures. Sepsis therapy might thus benefit from interfering with TLR8 function.