Practicability and patients' subjective experiences of low-dose spinal anaesthesia using hyperbaric bupivacaine for transanal surgery

Purpose  The safety, effectiveness and long lasting post-operative analgesia make spinal anaesthesia in saddle block technique an “ideal” method for transanal surgery. To improve patient satisfaction and offer reliable operation conditions to surgeons, this study quantifies practicability and patients' subjective experiences with this technique. Methods  Within a 5-month period, 400 consecutive patients undergoing transanal surgery in saddle block technique were evaluated by a standardised questionnaire. Results  The success rate of spinal anaesthesia was 99.5%. Side effects occurred far less frequently as mentioned in the literature. The duration of the sensory block was about twice as long as the time until first mobilisation and micturition. Despite some negative experiences during the procedure, 92% of the investigated patients would choose a saddle block again. Conclusions  Both from reasons of practicability and from patients' view, spinal anaesthesia in saddle block technique can be thoroughly recommended for transanal surgery. Patients undergoing a stapler haemorrhoidectomy should receive additional opioids.     

Characterization of the humoral immune response of experimentally infected and vaccinated pigs to swine influenza viral proteins

Summary. The value of serologic tests for diagnosis of swine influenza virus (SIV) infection has been diminished by the emergence of new subtypes and by antigenic drift within subtype. The intensive use of vaccination also has complicated interpretation of serology results. Serologic assays are needed that can detect infection regardless of subtype or antigenic variation and that can differentiate antibody induced by infection from that induced by vaccination. In this study, the antibody responses to specific viral proteins in pigs infected by or vaccinated for SIV were characterized by Western immunoblot. Both IgM and IgG against hemagglutinin, nucleoprotein, NS1 and NS2 were detected in experimentally infected pigs by 7 days post inoculation (DPI). IgG against these proteins was still detectable at the end of the study (28 DPI). In contrast, IgG against neuraminidase and M1 was not detected until 14 DPI and no IgM against these proteins was detected. In vaccinated pigs, no antibody against NS1 was detected while antibody responses to other proteins were identical to those in exposed pigs. In conclusion, nucleoprotein may be a suitable antigen for use in a subtype-unrestricted serologic assay. NS1 protein may be suitable for a serologic assay that differentiates between infected and vaccinated pigs.     

Diffusion indices on magnetic resonance imaging and neuropsychological performance in amnestic mild cognitive impairment

Background

Magnetic resonance diffusion tensor imaging (DTI) shows promise in the early detection of microstructural pathophysiological changes in the brain.

Objectives

To measure microstructural differences in the brains of participants with amnestic mild cognitive impairment (MCI) compared with an age‐matched control group using an optimised DTI technique with fully automated image analysis tools and to investigate the correlation between diffusivity measurements and neuropsychological performance scores across groups.

Methods

34 participants (17 participants with MCI, 17 healthy elderly adults) underwent magnetic resonance imaging (MRI)‐based DTI. To control for the effects of anatomical variation, diffusion images of all participants were registered to standard anatomical space. Significant statistical differences in diffusivity measurements between the two groups were determined on a pixel‐by‐pixel basis using gaussian random field theory.

Results

Significantly raised mean diffusivity measurements (p<0.001) were observed in the left and right entorhinal cortices (BA28), posterior occipital–parietal cortex (BA18 and BA19), right parietal supramarginal gyrus (BA40) and right frontal precentral gyri (BA4 and BA6) in participants with MCI. With respect to fractional anisotropy, participants with MCI had significantly reduced measurements (p<0.001) in the limbic parahippocampal subgyral white matter, right thalamus and left posterior cingulate. Pearson''s correlation coefficients calculated across all participants showed significant correlations between neuropsychological assessment scores and regional measurements of mean diffusivity and fractional anisotropy.

Conclusions

DTI‐based diffusivity measures may offer a sensitive method of detecting subtle microstructural brain changes associated with preclinical Alzheimer''s disease.Substantial effort is currently being focused towards improving the diagnosis of early Alzheimer''s disease. The term mild cognitive impairment (MCI) is often used to describe the transitional stage between normal ageing and dementia. Owing to the heterogeneity of MCI, not all participants with MCI will have predementia Alzheimer''s disease.¹ Peterson et al² suggested the criteria for a subtype of MCI, so‐called amnestic MCI, which is presumed to present a typical prodrome of dementia in Alzheimer''s disease. People with amnestic MCI have a 10–15% annual conversion rate to Alzheimer''s disease compared with 1–2% in the normal elderly population.² Neuroimaging studies conducted on participants with MCI using magnetic resonance imaging (MRI) morphological analysis have consistently reported atrophic changes primarily in the medial temporal lobe and, to a lesser extent, in the thalamus and cingulate gyrus.^3,4,5 Furthermore, the degree of atrophy in temporal lobe structures correlates with performance on memory tasks³ and with density of neurofibrillar tangles at autopsy.⁶ These findings support the concept that MRI‐based neuroimaging studies together with neuropsychological assessment may enable identification of participants with MCI which may progress to Alzheimer''s disease, and evaluation of the efficacy of novel treatments.Recent studies using diffusion tensor magnetic resonance imaging (DTI) have shown microstructural changes in the hippocampus of participants with MCI that may not be apparent using standard anatomical imaging.^7,8,9 DTI measures the random motion of bulk water in cerebral tissue. When the random motion of water is restricted preferentially in one direction when compared with the orthogonal planes, such as occurs in white matter, diffusion is referred to as anisotropic; in contradistinction, bulk water motion in the cerebrospinal fluid is equal in all directions and is thus referred to as isotropic. Fractional anisotropy, a quantitative measurement of the degree of anisotropy, can be used to probe the integrity of white matter fibre tracts.¹⁰ The mean diffusivity is a quantitative measurement of the bulk mean motion of water considered in all directions and is used to interrogate pathological changes in cerebral tissue, such as ischaemia in patients with stroke.¹⁰ DTI studies in patients with MCI have shown raised mean diffusivity in the hippocampus and other temporal lobe regions, using manually traced regions of interest (ROI).^7,8,9 Although the precise neural correlates of altered mean diffusivity measurements are uncertain, increased mean diffusivity most likely results from loss of neurones, axons and dendrites, resulting in an increase in extracellular space and raised water diffusivity in these regions.⁷ It is unknown whether such microstructural changes, detectable by DTI, are due to amyloid or neurofibrillar tangle formation or some other neuropathological process in Alzheimer''s disease. However, the finding of a negative correlation between hippocampal diffusivity and volume in people with MCI indicates that both measurements are sensitive to early Alzheimer''s disease neuropathology.⁷ Using manually defined ROI analyses, a recent study has identified marked changes in volume, mean diffusivity and fractional anisotropy indices in the hippocampus in participants with MCI compared with age‐matched controls.⁹ Specifically, compared with volume measurements, raised left hippocampal mean diffusivity was found to be a strong independent predictor of poor verbal memory performance in both controls and participants with MCI.In this study, we investigated whether mean diffusivity and fractional anisotropy measurements differed between participants with MCI and age‐matched controls, using an optimised DTI protocol¹¹ and a fully automated voxel‐by‐voxel method of data analysis. This approach assesses the entire brain, rather than just one structure, and circumvents any operator‐introduced errors in the manual selection of ROI for analysis. In addition, we investigated the relationship between measurements of water diffusivity and performance on memory and other cognitive tasks across participants.     

Chapter 8: Touchstones of Validity: The Teachers' Rewards

To maximize the success of intergenerational programs (IGPs), it is necessary to understand older adults’ concerns related to these programs and the benefits they perceive from their involvement. However, there is a lack of research that examines the perceptions of racial minority older adults’ involved in IGPs and sociodemographic predictors of IGPs outcomes. This study examined older adults’ (n?=?195) perceptions of the Linking Intergenerational Networks in Communities (LINC) Project, an intergenerational program, in South Carolina, and explored whether outcomes varied by race. Findings suggest that older adults’ race and ethnicity were associated with a variety of perceived benefits and concerns in LINC.     

IL-2 induces in vivo suppression by CD4(+)CD25(+)Foxp3(+) regulatory T cells

Interleukin-2 (IL-2) treatment is currently used to enhance T cell-mediated immune responses against tumors or in viral infections. At the same time, IL-2 is essential for the peripheral homeostasis of CD4(+)CD25(+)Foxp3(+ )regulatory T cells (Treg). In our study, we show that IL-2 is also an important activator of Treg suppressive activity in vivo. IL-2 treatment induces Treg expansion as well as IL-10 production and increases their suppressive potential in vitro. Importantly, in vivo application of IL-2 via gene-gun vaccination using IL-2 encoding DNA plasmids (pIL-2) inhibited naive antigen-specific T cell proliferation as well as a Th1-induced delayed type hypersensitivity response. The suppressive effect can be transferred onto naive animals by Treg from IL-2-treated mice and the suppression depends on the synergistic action of IL-10 and TGF-beta. These data highlight that during therapeutic treatment with IL-2 the concomitant activation of Treg may indeed counteract the intended activation of cellular immunity.     

Postnatal lung and metabolic development in two marsupial and four eutherian species

Two marsupial species (Monodelphis domestica, Macropus eugenii) and four eutherian species (Mesocricetus auratus, Suncus murinus, Tupaia belangeri and Cavia aperea) were examined to compare and contrast the timing of lung and metabolic development during the postnatal maturation of the mammalian respiratory apparatus. Using light, scanning and transmission electron microscopy, the lung structural changes were correlated with indirect calorimetry to track the metabolic development. Marsupial and eutherian species followed the same pattern of mammalian lung development, but differed in the developmental pace. In the two newborn marsupial species, the lung parenchyma was at the early terminal sac stage, with large terminal air sacs, and the lung developed slowly. In contrast, the newborn eutherian species had more advanced lungs at the late terminal sac stage in altricial species (M. auratus, S. murinus) and at the alveolar stage in precocial species (T. belangeri, C. aperea). Postnatal lung development proceeded rapidly in eutherian species. The marsupial species had a low metabolic rate at birth and achieved adult metabolism late in postnatal development. In contrast, newborn eutherian species had high metabolic rates and reached adult metabolism during the first week of life. The time course of the metabolic development is thus tightly linked to the structural differentiation of the lungs and the timing of postnatal lung development. These differences in the neonatal lung structure and the timing of postnatal lung maturation between marsupial and eutherian species reflect their differing reproductive strategies.     

Toxin genes on pathogenicity islands: impact for microbial evolution

Toxin-specific genes are often located on mobile genetic elements such as phages, plasmids and pathogenicity islands (PAIs). The uropathogenic E. coli strain 536 carries two alpha-hemolysin gene clusters, which are part of the pathogenicity islands I536 and II536, respectively. Using different genetic techniques, two additional PAIs were identified in the genome of the E. coli strain 536, and it is likely that further PAIs are located on the genome of this strain. Pathogenicity islands are often associated with tRNA genes. In the case of the E. coli strain 536, the PAI-associated tRNA gene leuX, which encodes a minor leucyl-tRNA, affects the expression of various virulence traits including alpha-hemolysin production. The exact mode of action of the tRNA5Leu-dependent gene expression has to be identified in the future.     

Development of a student rating scale to evaluate teachers' competencies for facilitating reflective learning

Medical Education 2011: 45 : 155–165 Context Teaching students in reflection calls for specific teacher competencies. We developed and validated a rating scale focusing on Student perceptions of their Teachers’ competencies to Encourage Reflective Learning in small Groups (STERLinG). Methods We applied an iterative procedure to reduce an initial list of 241 items pertaining to teacher competencies to 47 items. Subsequently, we validated the instrument in two successive studies. In the first study, we invited 679 medical and speech and language therapy students to assess the teachers of their professional development groups with the STERLinG. Principal components analysis (PCA) with varimax rotation was used to investigate the internal structure of the instrument. In the second study, which involved 791 medical, dental, and speech and language therapy students, we performed a confirmatory factor analysis using the oblique multiple group (OMG) method to verify the original structure. Results In Study 1, 463 students (68%) completed the STERLinG. The PCA yielded three components: Supporting self‐insight; Creating a safe environment, and Encouraging self‐regulation. The final 36‐item instrument explained 44.3% of the variance and displayed high reliability with α‐values of 0.95 for the scale, and 0.91, 0.86 and 0.86 for the respective subscales. In Study 2, 501 students (63%) completed the STERLinG. The OMG confirmed the original structure of the STERLinG and explained 53.0% of the total variance with high α‐values of 0.96 for the scale, and 0.94, 0.90 and 0.90 for the respective subscales. Conclusions The STERLinG is a practical and valid tool for gathering student perceptions of their teachers’ competencies to facilitate reflective learning in small groups considering its stable structure, the correspondence of the STERLinG structure with educational theories and the coverage of important domains of reflection. In addition, our study may provide a theoretical framework for the practice of and research into reflective learning.     

Public Health,Hypertension, and the Emergency Department

Hypertension (HTN) is the most common cardiovascular disease worldwide and is associated with severe long-term morbidity when not treated appropriately. Despite this, blood pressure (BP) control remains suboptimal, particularly among underserved populations and those who rely on emergency departments (EDs) as a source of primary care. ED providers encounter patients with severely elevated BP daily, and yet adherence to minimal standards of BP reassessment and referral to outpatient medical care, as recommended by the American College of Emergency Physicians, is limited. Barriers such as provider knowledge deficits, resource constraints, and negative attitudes towards patients who utilize EDs for nonurgent complaints are compounded by perceptions of HTN as a condition that can only be addressed in a primary care setting to contribute to this. Efforts to reduce this gap must go beyond government mandates to address systemic issues including access to care and payment models to encourage health promotion. Additionally, individual physician behavior can be shifted through targeted education, financial incentives, and the accumulation of high-quality evidence to encourage more proactive approaches to the management of uncontrolled HTN in the ED.