Patients' perspectives about the role of primary healthcare providers in long-term opioid therapy: a qualitative study in Dutch primary care.

BACKGROUND: Over the past decade, long-term use of prescription opioids for chronic non-cancer pain has risen globally despite the associated risks. Most opioid users receive their first prescription in primary care. AIM: To investigate the perspective of patients who are long-term opioid users in primary care regarding the role of healthcare providers (HCPs) in their prolonged opioid use. DESIGN AND SETTING: Semi-structured interviews in Dutch primary care. METHOD: We recruited patients who were long-term users of opioids for chronic non-cancer pain from seven community pharmacies in the Netherlands. In-depth, semi-structured interviews focused on patients' experiences with long-term opioid use, access to opioids, and the guidance of their HCPs (primarily their GPs and pharmacists). A directed content analysis was conducted on the transcribed interviews using NVivo. RESULTS: Participants (n = 25) described ways in which HCPs impacted their long-term use of opioids. These encompassed the initiation of treatment, chronic use of opioids, and discontinuation of treatment. Participants stressed the need for risk counselling during initial prescribing, ongoing medication evaluations including tapering conversations, and more support from their HCP during a tapering attempt. CONCLUSION: Patients' perspectives illustrate the important role of HCPs across the spectrum of opioid use - from initiation to tapering. The results of this study underscore the importance of clear risk counselling starting at initial prescribing, repeated medication assessments throughout treatment, addressing tapering at regular intervals, and strong support during tapering. These insights carry significant implications for clinical practice, emphasising the importance of informed and patient-centred care when it comes to opioid use for chronic non-cancer pain management.

Activity of the Enterococcus faecalis EIIA(gnt) PTS component and its strong interaction with EIIB(gnt).

Eubacteria can import and simultaneously phosphorylate a range of different carbohydrates by means of sugar specific phosphoenolpyruvate (PEP) dependent sugar phosphotransferase systems (PTSs). Here, we report the biochemical characterization of the gluconate specific PTS component EIIA(gnt) from Enterococcus faecalis and its unexpectedly strong complex with EIIB(gnt). We analyze the activity of the complex regarding phosphoryl transfer using kinetic measurements and demonstrate by mutagenesis that His-9 of EIIA(gnt) is essential for this process and represents most likely the phosphoryl group carrier of EIIA(gnt). With a combination of isothermal titration calorimetry (ITC), analytical ultracentrifugation (AUC), native gel electrophoresis and chemical crosslinking experiments we show that EIIA(gnt) and EIIB(gnt) form a strong 2:2 heterotetrameric complex, which seems to be destabilized upon phosphorylation of EIIB(gnt).

Structure of the Enterococcus faecalis EIIA(gnt) PTS component.

In Eubacteria, the utilization of a number of extracellular carbohydrates is mediated by sugar specific phosphoenolepyruvate (PEP) dependent sugar phosphotransferase systems (PTSs), which simultaneously import und phosphorylate their target sugars. Here, we report the crystal structure of the EIIA(gnt) component of the so far little investigated Enterococcus faecalis gluconate specific PTS. The crystal structure shows a tightly interacting dimer of EIIA(gnt) which is structurally similar to the related EIIA(man) from Escherichia coli. Homology modeling of E. faecalis HPr, EIIB(man) and their complexes with EIIA(man) suggests that despite moderate sequence identity between EIIA(man) and EIIA(gnt), the active sites closely match the situation observed in the E. coli system with His-9 of EIIA(gnt) being the likely phosphoryl group carrier. We therefore propose that the phosphoryl transfer reactions involving EIIA(gnt) proceed according to a mechanism analog to the one described for E. coli EIIA(man).

Long-term oral lacosamide in painful diabetic neuropathy: a two-year open-label extension trial.

OBJECTIVES: This open-label follow-on trial aimed to investigate long-term safety and efficacy of lacosamide in patients with painful diabetic neuropathy. METHODS: After 1-week baseline period, lacosamide 100mg/day was started. Each week, based on pain and safety assessments, doses were escalated by 100mg/day to an optimal level, up to a maximum of 400mg/day. Patients then entered the 20-week maintenance period (dose adjusted as needed). Thereafter, patients could opt to continue lacosamide up to about 2.5 years (extension period). RESULTS: Of the 69 enrolled patients, 47 (68%) completed the 20-week maintenance period and elected to continue into the extension period; 37/69 (54%) patients were in the extension period for more than one year and 34/69 (49%) continued until study termination. The modal lacosamide dose in most patients (54%) was 400mg/day. Headache, upper respiratory tract infection, arthralgia, sinusitis, nasopharyngitis, and back pain were the most frequently reported adverse events (10% of patients). Significant reductions from baseline in Likert pain scores began during dose titration and were sustained throughout the study. Significant improvements were also seen in Neuropathic Pain Scale, Quality of Life scores, and Patient's Global Impression of Change assessment. Of 34 patients at study termination, 32 (90%) elected to continue with lacosamide treatment in another long-term open-label trial (NCT00235443). CONCLUSION: The long-term safety profile and sustained efficacy of lacosamide observed in this trial support its continued development for treatment of painful diabetic neuropathy.

Lacosamide in painful diabetic peripheral neuropathy: a phase 2 double-blind placebo-controlled study.

BACKGROUND: Peripheral diabetic neuropathy affects between 20% and 45% of patients with diabetes. OBJECTIVE: To ascertain the effect of lacosamide on pain associated with peripheral diabetic neuropathy. METHODS: One hundred nineteen patients with a 1 to 5-year history of pain attributed to diabetic neuropathy and a score of > or =4 on the Likert pain scale entered the multicenter, randomized, double-blind, placebo-controlled trial. Lacosamide (N=60) titrated from 100 to 400 mg/d or maximum tolerated dose and placebo (N=59) were the trial interventions. Primary efficacy criterion was change in pain score on the 11-point Likert pain scale. Secondary assessments included Short-Form McGill Pain and Short-Form-36 Quality of Life Questionnaires, sleep/activity interference, pain intensity, Patient and Clinical Global Impression of Change, and Profile of Mood. Patients receiving at least 1 dose of medication underwent safety evaluation. RESULTS: Ninety-four patients (lacosamide 46; placebo 48) completed the trial. Lacosamide had significantly (P=0.039) better pain relief versus placebo (primary outcome). Improvements were also seen in secondary outcome measures. Adverse events occurred in 52 lacosamide and 44 placebo patients. Common adverse events, occurring in > or =5% of patients, were headache (lacosamide 18%, placebo 22%), dizziness (lacosamide 15%, placebo 8%), and nausea (lacosamide 12%, placebo 7%). Five lacosamide and 3 placebo patients withdrew for adverse events. DISCUSSION: Lacosamide seems to attenuate pain in diabetic neuropathy in doses up to 400 mg/d and improves quality of life issues.

Structure of the full-length enzyme I of the phosphoenolpyruvate-dependent sugar phosphotransferase system.

Enzyme I (EI) is the phosphoenolpyruvate (PEP)-protein phosphotransferase at the entry point of the PEP-dependent sugar phosphotransferase system, which catalyzes carbohydrate uptake into bacterial cells. In the first step of this pathway EI phosphorylates the heat-stable phospho carrier protein at His-15 using PEP as a phosphoryl donor in a reaction that requires EI dimerization and autophosphorylation at His-190. The structure of the full-length protein from Staphylococcus carnosus at 2.5A reveals an extensive interaction surface between two molecules in adjacent asymmetric units. Structural comparison with related domains indicates that this surface represents the biochemically relevant contact area of dimeric EI. Each monomer has an extended configuration with the phosphohistidine and heat-stable phospho carrier protein-binding domains clearly separated from the C-terminal dimerization and PEP-binding region. The large distance of more than 35A between the active site His-190 and the PEP binding site suggests that large conformational changes must occur during the process of autophosphorylation, as has been proposed for the structurally related enzyme pyruvate phosphate dikinase. Our structure for the first time offers a framework to analyze a large amount of research in the context of the full-length model.

Solution structure of the active-centre mutant I14A of the histidine-containing phosphocarrier protein from Staphylococcus carnosus.

High-pressure NMR experiments performed on the histidine-containing phosphocarrier protein (HPr) from Staphylococcus carnosus have shown that residue Ile14, which is located in the active-centre loop, exhibits a peculiarly small pressure response. In contrast, the rest of the loop shows strong pressure effects as is expected for typical protein interaction sites. To elucidate the structural role of this residue, the mutant protein HPr(I14A), in which Ile14 is replaced by Ala, was produced and studied by solution NMR spectroscopy. On the basis of 1406 structural restraints including 20 directly detected hydrogen bonds, 49 1H(N)-15N, and 25 1H(N)-1Halpha residual dipolar couplings, a well resolved three-dimensional structure could be determined. The overall fold of the protein is not influenced by the mutation but characteristic conformational changes are introduced into the active-centre loop. They lead to a displacement of the ring system of His15 and a distortion of the N-terminus of the first helix, which supports the histidine ring. In addition, the C-terminal helix is bent because the side chain of Leu86 located at the end of this helix partly fills the hydrophobic cavity created by the mutation. Xenon, which is known to occupy hydrophobic cavities, causes a partial reversal of the mutation-induced structural effects. The observed structural changes explain the reduced phosphocarrier activity of the mutant and agree well with the earlier suggestion that Ile14 represents an anchoring point stabilizing the active-centre loop in its correct conformation.

High-resolution structure of the histidine-containing phosphocarrier protein (HPr) from Staphylococcus aureus and characterization of its interaction with the bifunctional HPr kinase/phosphorylase.

A high-resolution structure of the histidine-containing phosphocarrier protein (HPr) from Staphylococcus aureus was obtained by heteronuclear multidimensional nuclear magnetic resonance (NMR) spectroscopy on the basis of 1,766 structural restraints. Twenty-three hydrogen bonds in HPr could be directly detected by polarization transfer from the amide nitrogen to the carbonyl carbon involved in the hydrogen bond. Differential line broadening was used to characterize the interaction of HPr with the HPr kinase/phosphorylase (HPrK/P) of Staphylococcus xylosus, which is responsible for phosphorylation-dephosphorylation of the hydroxyl group of the regulatory serine residue at position 46. The dissociation constant Kd was determined to be 0.10 +/- 0.02 mM at 303 K from the NMR data, assuming independent binding. The data are consistent with a stoichiometry of 1 HPr molecule per HPrK/P monomer in solution. Using transversal relaxation optimized spectroscopy-heteronuclear single quantum correlation, we mapped the interaction site of the two proteins in the 330-kDa complex. As expected, it covers the region around Ser46 and the small helix b following this residue. In addition, HPrK/P also binds to the second phosphorylation site of HPr at position 15. This interaction may be essential for the recognition of the phosphorylation state of His15 and the phosphorylation-dependent regulation of the kinase/phosphorylase activity. In accordance with this observation, the recently published X-ray structure of the HPr/HPrK core protein complex from Lactobacillus casei shows interactions with the two phosphorylation sites. However, the NMR data also suggest differences for the full-length protein from S. xylosus: there are no indications for an interaction with the residues preceding the regulatory Ser46 residue (Thr41 to Lys45) in the protein of S. xylosus. In contrast, it seems to interact with the C-terminal helix of HPr in solution, an interaction which is not observed for the complex of HPr with the core of HPrK/P of L. casei in crystals.

NMR-spectroscopic mapping of an engineered cavity in the I14A mutant of HPr from Staphylococcus carnosus using xenon.

The interaction between the histidine-containing phosphocarrier protein HPr and xenon atoms in solution is studied in the present paper. Wild-type HPr as well as the exchange mutant I14A have been studied. Specific binding of xenon into an engineered cavity created via the exchange of amino acid residue I14 by alanine could be shown using 1H-15N heteronuclear single-quantum coherence (HSQC) spectroscopy. Xenon binding results in pronounced changes of the 1H and 15N chemical shifts of amide groups close to the cavity. In addition to this observation which allows the NMR-spectroscopic mapping of such cavities, we have shown that the entire molecule is slightly rearranged as a result of xenon binding. In contrast, wild-type HPr only exhibits minor chemical shift changes due to the nonspecific interactions with the xenon atoms in solution.

Structure of the full-length HPr kinase/phosphatase from Staphylococcus xylosus at 1.95 A resolution: Mimicking the product/substrate of the phospho transfer reactions.

The histidine containing phospho carrier protein (HPr) kinase/phosphatase is involved in carbon catabolite repression, mainly in Gram-positive bacteria. It is a bifunctional enzyme that phosphorylates Ser-46-HPr in an ATP-dependent reaction and dephosphorylates P-Ser-46-HPr. X-ray analysis of the full-length crystalline enzyme from Staphylococcus xylosus at a resolution of 1.95 A shows the enzyme to consist of two clearly separated domains that are assembled in a hexameric structure resembling a three-bladed propeller. The N-terminal domain has a betaalphabeta fold similar to a segment from enzyme I of the sugar phosphotransferase system and to the uridyl-binding portion of MurF; it is structurally organized in three dimeric modules exposed to form the propeller blades. Two unexpected phosphate ions associated with highly conserved residues were found in the N-terminal dimeric interface. The C-terminal kinase domain is similar to that of the Lactobacillus casei enzyme and is assembled in six copies to form the compact central hub of the propeller. Beyond previously reported similarity with adenylate kinase, we suggest evolutionary relationship with phosphoenolpyruvate carboxykinase. In addition to a phosphate ion in the phosphate-binding loop of the kinase domain, we have identified a second phosphate-binding site that, by comparison with adenylate kinases, we believe accommodates a product/substrate phosphate, normally covalently linked to Ser-46 of HPr. Thus, we propose that our structure represents a product/substrate mimic of the kinase/phosphatase reaction.

Establishment and characterization of an atypical cell line from a patient with Wiskott-Aldrich-Syndrome and bone marrow allografting

Se aislaron blastos atípicos de la sangre periférica de un niño con síndrome de Wiskott-Aldrich y autotransplante de médula ósea. Las células fueron inmunotipificadas como monoblastos y crecieron en cultivo tisular en doble tiempo de 3 a 4 días. Las células aisladas originalmente y los cultivos iniciales, contenían antígenos tanto del virus herpes humano-6 (HHV-6) como del virus herpes humano-7 (HHV-7) y ácido desoxirribonucleico (ADN). Lo que disminuyó con la desdiferenciación celular en los cultivos subsecuentes. Los sobrenadantes de los cultivos celulares contenían cantidades moderadas de interleucina-6 (IL-6) y marcados niveles de factor estimulante de colonias-granulocito-monocítico (GM-CSF). Se discutió el caso desde el punto de vista de una posible co-patogénesis viral

Apoptosis y proliferación celular en infecciones por el virus Herpes humano 6 (HHV-6). Mecanismos de regulación a través de interacciones de p53, bcl-2, ras y p21WAF / Apoptosis and celular proliferation in human herpes virus 6 (HHV-6) infection. Mechanism as of regulation by interactions of p53, bcl2, ras and p21WAF

Se analizaron inmunohistológicamente líneas de cultivo celular infectadas con el HHV-6: HSB2-células T inmaduras y HDLM2-células de Hodgkin, así como ganglios linfáticos de pacientes con enfermedad de Hodgkin y linfadenitis de Kikuchi-Fujimoto (LKF) en relación a la expresión de los productos oncógenos/antioncógenos p53, bcl-2, ras y p21WAF. Se comprobó la proliferación celular inmunohistológicamente mediante anticuerpos contra PCNa (antígeno nuclear de proliferación celular) y la apoptosis se investigó en cortes finos de tejido ganglionar, analizando el ADN fragmentado con marcación final in situ. La LKF mostró alta incidencia de focos de células muertas (linfadenitis histiocítica necrozante), mientras que en la enfermedad de Hodgkin se observó proliferación celular. Con las técnicas utilizadas no se logró mostrar diferencias significativas en la expresión de ADN viral no de antígenos en las líneas celulares, ni en las biopsias de enfermedad de Hodgkin y de LKF. Las células HDLM2 con mejor viabilidad posterior a la infección con HHV-6 y un grado de apoptosis inferior, mostraron una expresión de p53 y de PCNA mucho menor que las células HSB2. Las biopsias de LKF no expresaron p53; ras se observó en menores células que en la enfermedad de Hodgkin y la positividad de PCNA fue tres veces mayor en enfermedad de Hodgkin en comparación con LKf. Sin embargo el bcl-2 se observó con mayor frecuencia en LKF que en enfermedad de Hodgkin. Los resultados no son de fácil interpretación; los datos sugieren la implicación de otros factores exógenos (por ejemplo, citoquinas y factores de crecimiento) en el mecanismo regulatorio de la proliferación celular y de la apoptosis, ambas inducidas probablemente por virus

Prevalencia del virus humano herpes 7 en donadores de sangre mexicanos / Prevalence of human herpes viruz 7 in Mexican blood donors

El herpes virus humano 7 (HHV-7) fue aislado recientemente de las células CD4 de individuos sanos; actualmente se realizan estudios de suposible asociación con enfermedades de humanos. Se estudiaron 200 muestras de sangre de candidatos a donadores asintomáticos del banco de sangre del Hospital General de México, utilizando la prueba de inmunofluorescencia indirecta (IFA) en células SupT1 infectadas con el HHV-7 en la Universidad de Colonia, Alemania. El 83.5 por ciento de las muestras fueron de varones y el 16.5 por ciento de mujeres; provenían de 12 diferentes estados de la república mexicana con predominio del Distrito Federal (60.5 por ciento) y del Estado de México (28 por ciento) con edad promedio de 29.2 años. El HHV-7 fue detectado en el 98.5 por ciento de los casos a diferentes titulaciones; el 84.5 por ciento presentó títulos elevados (ò 1:80). El 1 por ciento resultó positivo a hepatitis B, el 2 por ciento a sífilis, y el 0.5 por ciento a brucella. Todos fueron negativos a hepatitis C así como al VIH. La elevada prevalencia de HHV-7 deberá aclararse en investigaciones futuras que permitan determinar la posible asociación de títulos altos con infección activa, así como el significado de ésta en relación a enfermedad