By U. Thordir. MCP Hahnemann University.
Some of the interviews were conducted with both researchers present purchase 100 mg kamagra gold with amex erectile dysfunction treatment options, other interviews with just one researcher order 100 mg kamagra gold with visa erectile dysfunction treatment on nhs. In the main, interviews were recorded and transcribed. The researchers drew on a semistandard interview schedule comprising semistructured interview questions. These had to be adapted to the varying situations including, for example, the subject of the service redesign under scrutiny and the role and vantage point of the interviewee. The semistructured interview schedule was adapted accordingly. Appendix 4 shows a typical example of one such interview guideline. This issue may be freely reproduced for the purposes of private research and study and extracts (or indeed, the full report) may be included in professional journals 15 provided that suitable acknowledgement is made and the reproduction is not associated with any form of advertising. Applications for commercial reproduction should be addressed to: NIHR Journals Library, National Institute for Health Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK. PROJECT DESIGN AND METHODOLOGY Case study data analysis As mentioned, members of the research team worked in pairs for each main case study. These subteams undertook the first stage of each data analysis process. In this way a coherent narrative of the flow of events within each case could be constructed. This was combined with a descriptive account of the issues and challenges encountered by the actors involved. These first-level reports used a common framework: (1) context, (2) focus and narrative of the case, (3) clinical leadership themes emerging and (4) emerging ideas for cross-case comparisons. The first three sections of these initial draft reports were fed back to informants in the case studies concerned, as a way of validating the accuracy of the data collected and the descriptive interpretations made. Next, the first-level case reports were discussed, in turn, at a monthly series of research team meetings. From these discussions emerged ideas for explanatory concepts that could be applied to understand differences and similarities in the nature of clinical leadership across the cases. This process of discussion, conceptualisation and comparison between the cases led to the development of the conceptual framework for analysing the cases set out at the beginning of Chapter 4. This second-level analysis was carried out by two members of the research team, who were also the main authors of this report. That analysis brings together the descriptive summary of events with an explanatory analysis of the forms of clinical leadership and their relationship to the achievements and difficulties encountered in bringing about service innovation. The analyses are compared and discussed further in Chapter 5. TABLE 2 Interviews for the case studies Interviewee role Number of interviews GP chairpersons, clinical leads, other GPs 65 CCG accountable officers and other managers 36 Nurses 8 Lay members 7 Acute sector doctors and managers, mental health 25 Community health managers and nurses 10 NHSE, CQC, NHS Improvement, CSU and other agencies 10 LA representatives, councillors, chief executives and directors, public health 9 Voluntary sector 9 GP practice managers 7 Patient representatives 8 Ambulance service, paramedics 8 Total 202 16 NIHR Journals Library www. First, the responses to each of the questions were gathered together and the results presented as tables and charts. Second, a number of cross-tabulations were made in order to investigate whether or not occupants of different roles answered questions in particular ways. Third, comparisons were made between our data and the ratings of CCGs made separately by NHSE. These correlations produced some very interesting findings. A notable feature of the completed questionnaires were the free-form questions. As a result of the careful preparation of the questionnaires in conjunction with a range of informants from the scoping phase, respondents readily recognised the relevance of the issues being raised and were very keen to share their thoughts. In the next chapter, the statistical results stemming from the structured questions are presented and analysed along with the free-text responses.
Finally kamagra gold 100 mg on-line erectile dysfunction prevalence age, before this discussion is concluded kamagra gold 100mg discount erectile dysfunction causes n treatment, it is important to return to the issue of multiple definitions and understandings, which introduced this section. Other child outcomes Interviewees readily identified other outcomes that they believed to be appropriate and meaningful, and that should be considered when designing evaluations. These included measures of body structure and functioning, engagement in/achievement of activities, emotional well-being, quality of life, acceptance of impairment and engagement with interventions. Parent outcomes Outcomes for parents were also strongly emphasised. These were regarded as legitimate indicators of the impact of a therapy intervention. Objective 8: evidence gaps and issues of study design Objective 8 was: 8. Following this, we reported on the perceived challenges of evaluative research (see Chapter 9), some of which generated research questions/priorities themselves. It is important to stress the significant limitation regarding this aspect of the study that we were unable to secure the involvement of children and young people and, thus, their views on research priorities are absent. Views about the need for research Chapter 8 began by reporting widespread acceptance and agreement that the current evidence base on therapy interventions for children with neurodisability is very limited. These findings are not unique to the therapy professions investigated in this study, and have 64–66 been reported across a wide range of health-care professions. This issue may be freely reproduced for the purposes of private research and study and extracts (or indeed, the full report) may be included in professional journals 97 provided that suitable acknowledgement is made and the reproduction is not associated with any form of advertising. Applications for commercial reproduction should be addressed to: NIHR Journals Library, National Institute for Health Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK. DISCUSSION 61–63 report, the applicability of existing, higher-quality evidence (derived from studies not conducted in routine practice or clinical settings) was questioned. This lack of evidence was generally viewed as causing variability in practice and models of service delivery, and inequity of provision. Overall, therefore, there was strong support for research into therapies for children with neurodisability. However, this was sometimes tempered by concerns about whether or not it was possible to show that therapies make a difference. However, sometimes there was a concurrent rhetoric about the importance of clinical experience and professional autonomy within the clinical decision-making process. Research infrastructure within the therapy professions There was a strong consensus that, currently, the majority of therapy services could not be described as research engaged or research active. Furthermore, time for research is not routinely incorporated into roles; indeed, engaging in research may not be supported by service leads or managers. Opportunities to review and discuss research evidence (e. They appeared to be most likely to be located in services based in, or linked to, university hospitals. Instances of services actively seeking evidence to inform their practice and service development were, however, described to us. We also learned about a service (non-NHS) that had invested in research posts, which focused on both developing evidence-informed guidance and initiating primary research. Interviewees noted that, in the past, research had not been part of the training curriculum but that this has changed over the past decade. However, although more recently qualified therapists might have had some exposure to research and research methods during their training, there had been little opportunity to pursue this. That said, it was reported that within continuing professional development provision, there had been a growing focus on research. This description of the research infrastructure within the therapy professions aligns closely with findings 60–63 from other studies, carried out in England and other countries. Perceived challenges of designing and conducting evaluative research Study participants readily identified challenges with evaluating therapy interventions and a minority believed that these were insurmountable. Most regarded them as issues that may themselves need to be researched. The challenges identified included the heterogeneous nature of the population, the nature of therapy interventions, research design issues, the challenges associated with implementing evaluation studies and the requirements of funders. The main message arising from these debates was that evaluations of therapy interventions will require a range of study designs and methods, and a willingness on the part of funders to both invest in non-experimental designs and be cognisant, but accommodating, of the challenges of implementing experimental study designs when evaluating highly complex, non-pharmacological interventions. Thus, parents called for research that supported and informed integrated care, goals-focused approaches and empowering parents.
This can be done in the domain of neuroimag- levels of organization is the systems level cheap 100mg kamagra gold amex erectile dysfunction jacksonville fl, which includes ing by using currently available technology in an unprece- the motor purchase kamagra gold 100mg without a prescription erectile dysfunction and diet, sensory, and central neural systems. In the past two centuries, functional–structural central systems are included those related to cognitive func- correlations were derived mostly from experimental nonhu- tion, such as attention, memory, language, and executive man material, whereas anatomic–clinical correlations were function. Each system can be considered as a set of intercon- derived principally from human behavioral and, eventually, nected processors or centers constituted by nerve cells. With the tremendous develop- physical connections are composed of axons of different ment of magnetic resonance imaging (MRI) technol- lengths that can form fascicles as they run from origin to ogy—both structural and functional MRI (fMRI) and mag- destination. Within the neocortex, these connections are netic resonance spectroscopy (MRS)—the study of the selective and architectonic (1). Howcytoarchitecture, con- structure, function, and metabolism of the living human is nections, and function relate within the neocortex is a fun- an ongoing reality. This question addresses One of the latest advancements of MRI technology has basic organizational principles of the nervous system and been diffusion tensor imaging (DTI), a technique capable of aims to elucidate the mechanisms through which the cere- measuring the diffusivity of water molecules and rendering brum mediates behavior (2,3). Behavior, to a large extent visible the preferential orientation of their movement. On the other hand, within a strongly ori- ented tissue such as a white matter tract, water diffusion is Nikos Makris, G. Jenkins, not equal in all directions but is instead anisotropic, specifi- L. Wu, cally predominant along the direction of the tissue. Ken- nedy: Massachusetts General Hospital, Harvard Medical School, Boston, strongly parallel axonal arrangement within a fiber bundle Massachusetts. These connections can be categorized in three and orientation of a tissue, and because brain white matter principal classes—namely, associational, commissural, and can be characterized to a large extent by its orientation and projectional. Intrahemispheric associational corticocortical anisotropy, the detection of white matter fiber pathways has connectivity in particular is accomplished in general by (a) become feasible in the living brain. To delineate neuroanatomic connections exactly, ent lobes (10). A tract can be described at a morphologic white matter fiber tracts have been traced systematically in level in terms of a set of descriptors (i. Extensive research during the past two Morphologic Descriptors of a Fiber centuries in higher brain function (and aphasiology in par- Pathway ticular) has demonstrated the tight relationship between damage of commissural or associational fiber tracts and Conceptually, a white matter fiber pathway is a group of breakdown in cognitive human behavior (7–9). In the light axons that originate from a set of neuronal bodies and end of brain organization at a systems level in terms of architec- on one or more sets of target neurons. Moreover, the study of fiber tracts in vivo is However, in current MRI research, the term extreme periph- only beginning and is largely based on MRI techniques. First, DTI does not allowthe tional structure of the CNS. Even though the identification identification of this portion of a fiber pathway clearly and reconstruction of major fiber bundles has been accom- enough to justify the application of such specific terminol- plished with the use of DTI and computational techniques, ogy. Second, both the corticocortical associational and the the basic problems related to the biological sources of the commissural connections are generally bidirectional, mean- DTI signal remain to be clarified. Thus, to achieve a com- ing that within the stem of a tract fibers are running in prehensive understanding of the sensitivity and specificity both directions; thus, origins and terminations pertaining of the DTI technique, studies addressing both the gross and to the same fiber tract occur in adjacent locations. The dif- ultrastructural level of the white matter are necessary. Therefore, at a morpho- tion of the cerebrum, emphasizing the morphology and ar- logic level, a comprehensive delineation of a fiber pathway chitectonic structure of its pathways. Subsequently, we over- should include its stem, splay, and extreme periphery. A viewthe DTI technique and illustrate its use at an description of the extreme periphery of an association fiber ultrastructural and a gross neuroanatomic level. In this per- tract is related to a cortical field of origin or termination spective, we elaborate on three representative white matter (Fig. Additionally, we discuss the utility, potential, and limita- Architectonic Connections tions of the DTI technique in the context of its applications and its integration within a larger neurofunctional MRI The detailed characterization of a fiber pathway in terms examination. For this purpose, we present a case of amyotro- of its cytoarchitectonic correlates is a fundamental step for phic lateral sclerosis that we studied with MRI, DTI, MRS, the understanding of cerebral structural and functional or- and fMRI. These issues have been addressed at the architec- tonic level in experimental animals and in human postmor- OVERVIEW OF WHITE MATTER PATHWAYS tem material. In particular, cerebral cytoarchitecture has been described precisely in both the human and the experi- Anatomic Connections mental animal, such as the macaque.
Abnormalities in psychiatric disorders likely represent the However discount 100mg kamagra gold with amex erectile dysfunction jacksonville, such equilibrium binding conditions are achieved complex interaction of several neurotransmitter systems in for neither the tracer nor the displacer if each is injected the brain buy discount kamagra gold 100mg online erectile dysfunction uk. PET imaging has recently been used to examine as a bolus. Even under these conditions, the sensitivity of aspects of neurotransmitter interactions. For example, Dewy radioligand binding to endogenous dopamine levels is theo- and colleagues (44–46) have pioneered studies on interac- retically (at least based on the in vitro theories) independent tions among dopamine, GABA, and acetylcholine (ACh) of the affinity of the radioactively labeled ligand when both systems in striatum. GABA neurons in the striatum have the tracer and the displacer have achieved equilibrium bind- inhibitory effects on nigral dopamine neurons, nigral dopa- ing conditions. However, if either the radiotracer (as in the mine neurons have inhibitory effects on striatal ACh neu- bolus injection paradigm) or endogenous dopamine (as in rons, and striatal ACh neurons have facilitating effects on stimulant-induced release) changes dynamically over time, striatal GABA neurons. By estimating dopamine levels in the equilibrium condition is not achieved, and the apparent striatum as described above, Dewey and collaborators sensitivity of the radioligand to endogenous dopamine levels showed in human or anesthetized nonhuman primates that is determined by the kinetic properties of the radioligand the blockade of cholinergic transmission by benztropine 11 (34,35). Equilibrium conditions can be achieved for both (44) or scopolamine (45) decreased [ C]raclopride binding tracer and displacer in the dopamine depletion paradigm. The high-af- pine agonist) increased [ C]raclopride binding (decrease 123 finity D2 radioligand [ I]epidepride provides an instruc- in dopamine levels) (46). In addition, they showed that tive example of the differences seen in kinetic and equilib- a dopamine antagonist, N-methylspiroperidol, induced a rium studies. The kinetics of its uptake in brain are slow decrease in [N-11C-methyl]benztropine binding, indicating and do not show displacement by transiently increased do- an increase in ACh levels (44). However, Other interactions have also been studied with PET. In stable low levels of dopamine induced with AMPT show two human studies, an N-methyl-D-aspartate (NMDA) an- unmasking of D2 receptors (37). In two human studies with similar tech- niques, the binding of [11C]raclopride was decreased by In Vivo Confounding Factors stimulation of 5-hydroxytryptamine (5-HT) transmission Although the displacement of radioligand binding by neu- with fenfluramine (a 5-HT releaser) (49) or psilocybin (a rotransmitter can be simply described with in vitro tissue mixed 5-HT2A and 5-HT1A agonist) (50). However, these homogenates, several factors complicate the interpretation results are discordant with those of previous studies in ba- of in vivo experimental results. Key aspects of the by the receptor to guanyl nucleotide-binding proteins (38). For example, typical antipsychotic limitation of these studies is that no useful glutamatergic agents occupy 50% to 80% of striatal D2 receptors (54). PET probes have been developed to examine this important Thus, a new typical antipsychotic agent should show a rea- mediating neurotransmitter system. Furthermore, the link- sonably acceptable side effect profile when given at doses age of pharmacologic challenges can be difficult to interpret. With regard to dos- For example, if a disorder is associated with an abnormal ing interval, the drug may be retained in tissue much longer dopamine outcome measured with PET in response to a 5- than in plasma, and, therefore dosing intervals based on HT challenge, is the abnormal response caused by altered plasma pharmacokinetics may be too frequent. Such a situa- sensitivity of the dopamine or 5-HT system? This kinetics in brain combined with the evaluation of adverse simple assumption has been questioned by elaborate studies reactions in a small number of healthy subjects may provide by Tsukada et al. If targeted receptor occupancy [ -11C]methyldopa (L-[ -11C]DOPA), [11C] -CIT, and is achieved without causing adverse reactions, studies in pa- [11C]raclopride, respectively, in combination with microdi- tients are justified. If not, further studies may not be indi- alysis in conscious rhesus monkeys. Even in the absence of a target level for receptor change extracellular dopamine levels in the striatum but occupancy, it is reasonably safe to assume that doses associ- increased [11C]raclopride binding by decreasing its affinity ated with greater than 95% occupancy are unnecessarily at the dopamine D2 receptor (52) Furthermore, ketamine high, and that those with less than 10% occupancy are un- decreased [11C]raclopride binding in the striatum without likely to be efficacious. By measur- the pharmacokinetics of either the tracer or displacer and ing receptor occupancy with [11C]N-methylspiperone in changes in the synthesis and reuptake of neurotransmitters healthy human subjects, initially an appropriate amount of and affinity of receptor binding may complicate the experi- a single dose (57) and then an appropriate dose and dosing ment, the authors feel that challenges linked with radio- interval were determined (56). Further, a similar level of tracer imaging are likely to provide useful information to receptor occupancy was recently confirmed with allow a better understanding of the pathophysiology of neu- [11C]M100907 in a small number of patients with schizo- ropsychiatric disorders. Dopamine Transporter Imaging as a USE OF RADIOTRACER IMAGING IN Biological Marker in Parkinson Disease THERAPEUTIC DRUG DEVELOPMENT Imaging of a biological marker may provide information Radiotracer imaging can provide useful information about that is useful either for diagnosis or as a monitor of disease molecules that are either the direct target of or indirect progression. In Parkinson disease, the two most successful markers for the effects of therapeutic drugs. For example, imaging targets used as biological markers are measures of if both the tracer and therapeutic drug competitively bind dopamine synthesis with [18F]FDOPA and of dopamine to the same target, then imaging can provide direct informa- terminal innervation with ligands for dopamine transporter.
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