310 research outputs found
Light and electron microscopical studies of the infection of Vitis spp. by Plasmopara viticola, the downy mildew pathogen
The infection of the susceptible grapevine species, Vitis vinifera L., and the resistant species, V. riparia MICHX., by the downy mildew pathogen, Plasmopara viticola, has been studied by light and electron microscopy. The infection cycle and ultrastructural features of the disease are described in detail and compared with those of other hast-pathogen interactions.
Licht- und elektronenmikroskopische Untersuchungen über die Infektion von Vitis spp. durch Plasmopara viticola, den Erreger des Falschen Rebenmehltaues
Die Infektion der anfälligen Europäerrebe (Vitis vinifera L.) und einer resistenten Wildart (V. riparia MICHX.) durch den Erreger des Falschen Mehltaus (Plasmopara viticola) wurde mittels Licht- und Elektronenmikroskopie untersucht. Der Infektionsablauf und die ultrastrukturellen Besonderheiten der Krankheit werden eingehend beschrieben und mit dem Erscheinungsbild anderer Wirt-Parasit-Beziehungen verglichen
Reviewing Guidelines on Diabetic Retinopathy Screening in Children and Adolescents with Type 1 Diabetes: Is there consistency amongst practitioners?
Diabetic retinopathy (DR) is a common eye disease and a leading cause of visual impairment in patients with Type 1 diabetes (T1DM). Retinopathy screening for T1DM varies according to the age of disease onset and diabetes duration. Retinal screening varies from standard fundal examination to more advanced methods of screening. An online survey was conducted in February 2014. The purpose of this survey was to assess the frequency and methods of eye examinations routinely performed in children and adolescents with T1DM. Data on local practices were collected from a group of optometrists and ophthalmologists in the London-Middlesex area. One hundred and one surveys were e-mailed out and the response rate was 37.6%. Results indicated that different screening methods vary according to individual practices. These results may have an impact on the findings of retinopathy in this population. A review of utilized screening methods and comparisons to established guidelines will be highlighted
Titration-based screening for evaluation of natural product extracts: identification of an aspulvinone family of luciferase inhibitors
The chemical diversity of nature has tremendous potential for discovery of new molecular probes and medicinal agents. However, sensitivity of HTS assays to interfering components of crude extracts derived from plants, macro- and microorganisms has curtailed their use in lead discovery efforts. Here we describe a process for leveraging the concentration-response curves (CRCs) obtained from quantitative HTS to improve the initial selection of “actives” from a library of partially fractionated natural product extracts derived from marine actinomycetes and fungi. By using pharmacological activity, the first-pass CRC paradigm aims to improve the probability that labor-intensive subsequent steps of re-culturing, extraction and bioassay-guided isolation of active component(s) target the most promising strains and growth conditions. We illustrate how this process identified a family of fungal metabolites as potent inhibitors of firefly luciferase, subsequently resolved in molecular detail by x-ray crystallography
Does implementation matter if comprehension is lacking? A qualitative investigation into perceptions of advance care planning in people with cancer
Purpose: While advance care planning holds promise, uptake is variable and it is unclear how well people engage with or comprehend advance care planning. The objective of this study was to explore how people with cancer comprehended Advance Care Plans and examine how accurately advance care planning documentation represented patient wishes.
Methods: This study used a qualitative descriptive design. Data collection comprised interviews and an examination of participants’ existing advance care planning documentation. Participants included those who had any diagnosis of cancer with an advance care plan recorded: Refusal of Treatment Certificate; Statement of Choices; and/or Enduring Power of Attorney (Medical Treatment) at one cancer treatment centre.
Results: Fourteen participants were involved in the study. Twelve participants were female (86%). The mean age was 77 (range: 61-91) and participants had completed their advance care planning documentation between 8 and 72 weeks prior to the interview (mean 33 weeks). Three themes were evident from the data: Incomplete advance care planning understanding and confidence; Limited congruence for attitude and documentation; Advance care planning can enable peace of mind. Complete advance care planning understanding was unusual; most participants demonstrated partial comprehension of their own advance care plan, and some indicated very limited understanding. Participants’ attitudes and their written document congruence was limited, but advance care planning was seen as helpful.
Conclusions: This study highlighted advance care planning was not a completely accurate representation of patient wishes. There is opportunity to improve how patients comprehend their own advance care planning documentation
Human peritoneal mesothelial cells display phagocytic and antigen-presenting functions to contribute to intraperitoneal immunity
Mesothelial cells lining the peritoneal cavity are strategically positioned to respond to and counter intraperitoneal infections, cancer cells, and other challenges. We have investigated human peritoneal mesothelial cells (HPMCs) for phagocytic activity, expression of surface MHC Class II and accessory molecules involved in antigen presentation, and the ability to present recall antigens to T cells. Phagocytosis of dextran, latex beads and Escherichia coli was observed by flow cytometry, and internalization was visualised using confocal and electron microscopy. Flow cytometry and/or cellular ELISA showed constitutive expression of ICAM-I, LFA-3, and B7-1, but not B7-2 or MHC II. Interferon-gamma induced MHC II and ICAM-1 expression in a dose- and time-dependent manner. Importantly, HPMCs induced autologous CD3+ T lymphocyte proliferation (3H-incorporation) after pulse with recall antigen. HPMCs equipped with phagocytic and antigen-presenting machinery are anticipated to have an integral role in intraperitoneal immune surveillance
Structure–activity relationship of ipglycermide binding to phosphoglycerate mutases
Catalysis of human phosphoglycerate mutase is dependent on a 2,3-bisphosphoglycerate cofactor (dPGM), whereas the nonhomologous isozyme in many parasitic species is cofactor independent (iPGM). This mechanistic and phylogenetic diversity offers an opportunity for selective pharmacologic targeting of glycolysis in disease-causing organisms. We previously discovered ipglycermide, a potent inhibitor of iPGM, from a large combinatorial cyclic peptide library. To fully delineate the ipglycermide pharmacophore, herein we construct a detailed structure–activity relationship using 280 substituted ipglycermide analogs. Binding affinities of these analogs to immobilized Caenorhabditis elegans iPGM, measured as fold enrichment relative to the index residue by deep sequencing of an mRNA display library, illuminated the significance of each amino acid to the pharmacophore. Using cocrystal structures and binding kinetics, we show that the high affinity of ipglycermide for iPGM orthologs, from Brugia malayi, Onchocerca volvulus, Dirofilaria immitis, and Escherichia coli, is achieved by a codependence between (1) the off-rate mediated by the macrocycle Cys14 thiolate coordination to an active-site Zn2+ in the iPGM phosphatase domain and (2) shape complementarity surrounding the macrocyclic core at the phosphotransferase–phosphatase domain interface. Our results show that the high-affinity binding of ipglycermide to iPGMs freezes these structurally dynamic enzymes into an inactive, stable complex
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Obsessive Compulsive Treatment Efficacy Trial (OCTET) comparing the clinical and cost effectiveness of self-managed therapies: study protocol for a randomised controlled trial
Background: UK National Institute of Health and Clinical Excellence guidelines for obsessive compulsive disorder (OCD) specify recommendations for the treatment and management of OCD using a stepped care approach. Steps three to six of this model recommend treatment options for people with OCD that range from low-intensity guided self-help (GSH) to more intensive psychological and pharmacological interventions. Cognitive behavioural therapy (CBT), including exposure and response prevention, is the recommended psychological treatment. However, whilst there is some preliminary evidence that self-managed therapy packages for OCD can be effective, a more robust evidence base of their clinical and cost effectiveness and acceptability is required.
Methods/Design: Our proposed study will test two different self-help treatments for OCD: 1) computerised CBT (cCBT) using OCFighter, an internet-delivered OCD treatment package; and 2) GSH using a book. Both treatments will be accompanied by email or telephone support from a mental health professional. We will evaluate the effectiveness, cost and patient and health professional acceptability of the treatments.
Discussion: This study will provide more robust evidence of efficacy, cost effectiveness and acceptability of self-help treatments for OCD. If cCBT and/or GSH prove effective, it will provide additional, more accessible treatment options for people with OCD
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Low-intensity cognitive-behaviour therapy interventions for obsessive-compulsive disorder compared to waiting list for therapist-led cognitive-behaviour therapy: 3-arm randomised controlled trial of clinical effectiveness
Background Obsessive-compulsive disorder (OCD) is prevalent and without adequate treatment usually follows a chronic course. “High-intensity” cognitive-behaviour therapy (CBT) from a specialist therapist is current “best practice.” However, access is difficult because of limited numbers of therapists and because of the disabling effects of OCD symptoms. There is a potential role for “low-intensity” interventions as part of a stepped care model. Low-intensity interventions (written or web-based materials with limited therapist support) can be provided remotely, which has the potential to increase access. However, current evidence concerning low-intensity interventions is insufficient. We aimed to determine the clinical effectiveness of 2 forms of low-intensity CBT prior to high-intensity CBT, in adults meeting the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria for OCD. Methods and findings This study was approved by the National Research Ethics Service Committee North West–Lancaster (reference number 11/NW/0276). All participants provided informed consent to take part in the trial. We conducted a 3-arm, multicentre randomised controlled trial in primary- and secondary-care United Kingdom mental health services. All patients were on a waiting list for therapist-led CBT (treatment as usual). Four hundred and seventy-three eligible patients were recruited and randomised. Patients had a median age of 33 years, and 60% were female. The majority were experiencing severe OCD. Patients received 1 of 2 low-intensity interventions: computerised CBT (cCBT; web-based CBT materials and limited telephone support) through “OCFighter” or guided self-help (written CBT materials with limited telephone or face-to-face support). Primary comparisons concerned OCD symptoms, measured using the Yale-Brown Obsessive Compulsive Scale–Observer-Rated (Y-BOCS-OR) at 3, 6, and 12 months. Secondary outcomes included health-related quality of life, depression, anxiety, and functioning. At 3 months, guided self-help demonstrated modest benefits over the waiting list in reducing OCD symptoms (adjusted mean difference = −1.91, 95% CI −3.27 to −0.55). These effects did not reach a prespecified level of “clinically significant benefit.” cCBT did not demonstrate significant benefit (adjusted mean difference = −0.71, 95% CI −2.12 to 0.70). At 12 months, neither guided self-help nor cCBT led to differences in OCD symptoms. Early access to low-intensity interventions led to significant reductions in uptake of high-intensity CBT over 12 months; 86% of the patients allocated to the waiting list for high-intensity CBT started treatment by the end of the trial, compared to 62% in supported cCBT and 57% in guided self-help. These reductions did not compromise longer-term patient outcomes. Data suggested small differences in satisfaction at 3 months, with patients more satisfied with guided self-help than supported cCBT. A significant issue in the interpretation of the results concerns the level of access to high-intensity CBT before the primary outcome assessment. Conclusions We have demonstrated that providing low-intensity interventions does not lead to clinically significant benefits but may reduce uptake of therapist-led CBT
HIV Risk among MSM in Senegal: A Qualitative Rapid Assessment of the Impact of Enforcing Laws That Criminalize Same Sex Practices
Men who have sex with men (MSM) are at high risk for HIV in Senegal, with a prevalence of 21.5%. In December 2008, nine male HIV prevention workers were imprisoned for “acts against nature” prohibited by Senegalese law. This qualitative study assessed the impact of these arrests on HIV prevention efforts. A purposive sample of MSM in six regions of Senegal was recruited by network referral. 26 in-depth interviews (IDIs) and 6 focus group discussions (FGDs) were conducted in July–August 2009. 14 key informants were also interviewed. All participants reported pervasive fear and hiding among MSM as a result of the December 2008 arrests and publicity. Service providers suspended HIV prevention work with MSM out of fear for their own safety. Those who continued to provide services noticed a sharp decline in MSM participation. An effective response to the HIV epidemic in Senegal should include active work to decrease enforcement of this law
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