Putting the cheshire cat together in amblyopia. Focus on "spatial resolution for feature binding is impaired in peripheral and amblyopic vision".
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Amblyopia↗
Biomedical subjects
Michael Morgan
Publications and source records attributed to Michael Morgan.
The role of mood states underlying sex differences in the perception and tolerance of pain.
While sex differences in pain reporting are frequently observed, the reasons underlying these differences remain unclear. The present study examined sex differences in self-report and physiological measures of pain threshold and tolerance following the administration of two laboratory pain-induction tasks. The primary study aim centered on determining whether repeated exposure to such tasks would yield sex differences in terms of pain threshold and tolerance. In addition, it was hypothesized that if such differences did exist, negative mood states might account for changes in pain ratings, threshold, and/or tolerance in subsequent exposure to noxious stimuli. Recruited from a convenience sample, 66 participants (44 female and 22 male) were exposed to both thermal and cold noxious stimuli at three separate times, while psychophysiological and self-report data were collected. Because women outnumbered men 2:1, Fisher z transformations were performed to determine whether the observed associations between mood states and pain ratings differed. We found stronger associations between fatigue and thermal-heat pain ratings for men at their first and third exposure to the pain task compared to women (z = 2.11, P < 0.05; z = 3.14, P < 0.001, respectively). Results indicated that women evidenced greater pain tolerance than men on both a behavioral and physiological level; however, they reported greater pain severity than men. Fatigue was also found to be particularly important to reports of pain severity in men and pain tolerance in response to noxious stimuli for women. Possible pathways in which mood states influenced these endpoints are discussed.
Adult↗
Progress toward the culture and transformation of chicken blastodermal cells.
Chicken blastodermal cells can be cultured for short periods of time and retain the ability to contribute to somatic and germline tissues when injected into gamma-irradiated stage X embryos. Such a method has yet to yield a germline transgenic bird, in part due to the low rate of transgene integration into the avian genome. In addition, the short culture period precludes the identification and expansion of those cells that carry an integrated transgene. In this study, two methods were developed that produced blastodermal cells isolated from stage X Barred Plymouth Rock embryos bearing an integrated transgene. Addition of chick embryo extract to the culture medium enabled expansion of single colonies for multiple passages. Southern blot analysis indicated that the transgenes had integrated as a single copy in most of the clones. Cells from passaged, transgenic embryo cells were injected into irradiated stage X White Leghorn embryos, producing hatched chicks that bore the donor cells in their somatic tissues. Transgene sequences were detected in sperm DNA; however, breeding of chimeras did not result in germline transmission of the transgene, indicating that the contribution of the transgenic cells to the germline was either nonexistent or very low.
Animals↗
Pulmonary rehabilitation for COPD.
Pulmonary rehabilitation is a therapeutic process, which entails taking a holistic approach to the welfare of the patient with chronic respiratory illness--most commonly chronic obstructive pulmonary disease (COPD). Pulmonary rehabilitation is considered essential throughout the lifetime management of patients with symptomatic chronic respiratory disease. It requires the coordinated action of a multidisciplinary healthcare team in order to deliver an individualised rehabilitation programme to best effect--incorporating multiple modalities, such as advice on smoking cessation, exercise training and patient self-management education, among others. As core components of pulmonary rehabilitation, exercise training and self-management education have been shown to be beneficial in improving health-related quality of life (HRQoL) in patients with chronic respiratory disease. Physical training can help to reduce the muscle de-conditioning that occurs when the activity of patients is restricted by their breathlessness and fatigue, and is often associated with an increase in patient HRQoL. HRQoL can also be improved by the use of self-management education, which is designed to provide the patient with the skills to manage the health consequences of their disease. In doing so, patients are better able to cope with disease symptoms, potentially leading to reduced healthcare costs. A great deal of research has been conducted to try and fully define which patients will benefit most from pulmonary rehabilitation. Although progress has been made, many questions remain as to the best means of delivering rehabilitation, particularly with respect to the optimum programme of physical training and patient self-management education.
Bronchodilator Agents↗
A novel somatic mutation of the 3beta-hydroxysteroid dehydrogenase gene in sporadic cutaneous verruciform xanthoma.
OBJECTIVE: To analyze the 3beta-hydroxysteroid dehydrogenase (NSDHL) gene in verruciform xanthoma (VX) to elucidate its potential role in the histogenesis of this lesion. DESIGN: DNA was extracted from paraffin-embedded tissue, followed by polymerase chain reaction amplification of exons 4 and 6 of the NSDHL gene. The polymerase chain reaction products were then directly sequenced and analyzed for the presence of somatic mutations. PATIENTS: Nine lesions of VX from 8 patients and 3 unrelated normal controls were evaluated. RESULTS: Two of 9 VXs (22%) demonstrated a novel somatic missense mutation in exon 6 of the NSDHL gene. The mutation was not present in the remaining 7 lesions of VX, nonlesional internal controls, and 3 unrelated normal controls. No mutation of exon 4 was found in any case. Mutations of exons 4 and 6 previously identified in CHILD syndrome were not seen in our cases. CONCLUSIONS: (1) A novel missense mutation (R199H) in exon 6 of the NSDHL gene was identified in a small subset of sporadic VXs. (2) Known CHILD syndrome mutations in exons 4 and 6 of the NSDHL gene do not contribute to the histogenesis of sporadic VXs.
3-Hydroxysteroid Dehydrogenases↗
Stimulus contrast and the Reichardt detector.
The direction of a drifting grating can become more easily identified when a stationary, flickering grating, with the same spatial and temporal frequencies, is added to it. This amplification has been accepted as evidence that motion perception depends on the product of visual signals elicited before and after a target changes position, as computed by a Reichardt detector. However, amplification is also consistent with a model in which direction identification depends on the product of detection probabilities before and after the position shift. In this paper, we compare the Reichardt detector with a model of Probability Multiplication. For 2-frame sequences, similar results are predicted by Probability Multiplication and a Reichardt model, in which the performance-limiting noise is early (i.e. it is added prior to signal multiplication). Many new and previously published results are consistent with these predictions. Other results are documented in which the amplification is too large to be consistent with Probability Multiplication. To explain these latter results, Reichardt detectors must have both early and late noises.
Discrimination, Psychological↗
Histological changes associated with mesotherapy for fat dissolution.
Mesotherapy is a form of medical therapy popular in Europe and South America. It is used for treating a variety of medical conditions, including the treatment of localized fat deposits and cellulite. Phosphatidylcholine/deoxycholate injections are a popular technique to treat localized fat accumulations and have recently become synonymous with mesotherapy, although their history and technique are distinct. To treat localized fat deposits, phosphatidylcholine (PC) and deoxycholate (DC) are utilized. To date, there have been no published histological studies that explain the mechanism of action of PC and DC.Method. In this study the authors have obtained skin biopsies from a patient who had undergone mesotherapy with PC and DC. Punch biopsies were taken at one and two weeks after the procedure.Results. Each of the biopsies taken at one and two weeks after treatment with PC and DC showed a normal epithelium and dermis, with a mixed septal and lobular panniculitis. The fat lobules were infiltrated by increased numbers of lymphocytes and, in particular, macrophages. The macrophages consisted of conventional forms, foam cells, and multinucleated fat-containing giant cells. The inflammation was associated with serous atrophy and microcyst formation.Conclusion. This study demonstrates that mesotherapy with PC and DC affects the subcutaneous fat. We theorize that the reduction of subcutaneous fat likely follows inflammatory-mediated necrosis and resorption.
Adipose Tissue↗
Excessive alcohol consumption and dependence on amphetamine are associated with parallel increases in subjective ratings of both 'wanting' and 'liking'.
AIM: One of the tenets of the incentive sensitization theory of drug addiction is that 'as drugs come to be wanted more and more, they often come to be liked less and less'. The aim of this study was to test whether this assumption holds true. Specifically, the study aimed to test the hypothesis that in non-clinical samples, dependence on amphetamines and excessive alcohol use are associated with increased 'wanting' but decreased 'liking' for the drug. DESIGN, SETTING AND PARTICIPANTS: In two studies, the Desires for Alcohol Questionnaire (DAQ) was administered to 380 recreational drinkers, and the Desires for Speed Questionnaire (DSQ) and the Leeds Dependence Questionnaire (LDQ) were administered to 174 amphetamine users. Scales were derived from the DAQ and DSQ representing craving, on one hand, and positive and negative reinforcement on the other hand. Craving and positive reinforcement were taken as measures of alcohol or amphetamine 'wanting' and 'liking', respectively. FINDINGS: Scores on all three DAQ scales increased monotonically as a function of the extent of alcohol consumption. Scores on all three DSQ scales increased monotonically as a function of dependence, as measured by the LDQ. 'Liking' for amphetamine was unrelated to time since the drug was last taken. (These data were not available for alcohol.) CONCLUSIONS: The finding that 'wanting' increased as a function of dependence on amphetamine or level of consumption in the case of alcohol is as predicted by the incentive sensitization theory, but the finding that 'liking' also increased as a function of dependence or excess is the opposite of the predicted effects While not refuting the incentive sensitization theory directly, the study questions the validity of one of the tenets of the theory.
Adolescent↗
Exponential modeling, washout curve reconstruction, and estimation of half-life of toluene and its metabolites.
Health risks from ostensible occupational and environmental toxicant exposure are difficult to quantify. Maximal use of limited biological measurements of xenobiotic or metabolite concentration in the body is therefore essential. Elimination rates of exhaled [2H8]toluene and urinary metabolites were analyzed from 33 exposures of males to 50 ppm [2H8]toluene for 2 h at rest. It was hypothesized that the shapes from our decay curves would be applicable to any occupational or environmental toluene exposure. Except for a rapid decline in toluene blood and breath levels in the 0-0.1 h period, this "curve reconstruction" method successfully fit data from published studies. Urinary hippuric acid concentrations were not well fit due to substantial background levels, whereas o-cresol levels were accurately described. Our approach was able to reconstruct data from studies where exposure duration ranged from 10 min to 7 h, and where activity level ranged from rest to 150 W (strenuous exercise). Using this approach, limited biological data following toluene exposure could be back-extrapolated to immediate postexposure concentrations, which in turn could be compared to biological indicators of exposure to determine risk.
Adult↗
Differential neural responses to overt and covert presentations of facial expressions of fear and disgust.
There is debate in cognitive neuroscience whether conscious versus unconscious processing represents a categorical or a quantitative distinction. The purpose of the study was to explore this matter using functional magnetic resonance imaging (fMRI). We first established objective thresholds of the critical temporal parameters for overt and covert presentations of fear and disgust. Next we applied these stimulus parameters in an fMRI experiment to determine whether non-consciously perceived (covert) facial expressions of fear and disgust show the same double dissociation (amygdala response to fear, insula to disgust) observed with consciously perceived (overt) stimuli. A backward masking paradigm was used. In the psychophysics experiment, the following parameters were established: 30-ms target duration for the covert condition, and 170-ms target duration for the overt condition. Results of the block-design fMRI study indicated substantial differences underlying the perception of fearful and disgusted facial expressions, with significant effects of both emotion and target duration. Findings for the overt condition (170 ms) confirm previous evidence of amygdala activation to fearful faces, and insula activation to disgusted faces, and a double dissociation between these two emotions. In the covert condition (30 ms), the amygdala was not activated to fear, nor was the insula activated to disgust. Overall, findings demonstrate significant differences between the neural responses to fear and to disgust, and between the covert presentations of these two emotions. These results therefore suggest distinct neural correlates of conscious and unconscious emotion perception.
Adult↗
Oral pemphigus vulgaris after anthrax vaccine administration: association or coincidence?
Pemphigus vulgaris is an autoimmune blistering disorder of the skin and mucous membranes. Numerous medications, ultraviolet light, and radiation have all been implicated in the etiology of the disease. We present a patient with pemphigus vulgaris whose disease developed after administration of anthrax vaccine. The histologic and immunofluorescence findings were characteristic of pemphigus vulgaris. Adverse systemic events associated with the anthrax vaccine consist primarily of flu-like symptoms. Previous cases of pemphigus vulgaris associated with anthrax vaccine administration have not been reported. Considering the recent deliberate outbreaks of anthrax and continued threats of bioterrorism, the potential exists for widespread administration of the anthrax vaccine. Accordingly, continued observation and documentation of true adverse events is needed.
Adult↗
The intraepidermal blistering conditions.
The intraepidermal vesiculobullous disorders constitute a wide variety of pathogenically unrelated disorders that share in common the formation of cleft or bullae formation within the epithelium. The etiologic, pathogenic, clinical and, in particular, the histopathologic attributes of the most important intraepidermal blistering conditions are described.
Biopsy↗
A summary of the workshop applying biomarkers to occupational health practice.
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Biomarkers↗
Paraganglioma-like dermal melanocytic tumor: a unique entity distinct from cellular blue nevus, clear cell sarcoma, and cutaneous melanoma.
We are reporting a previously undescribed primary dermal melanocytic tumor identified by reviewing all dermal melanocytic tumors referred in consultation that did not qualify histologically as a previously described entity. From these cases, 8 were remarkably similar. We termed them "paraganglioma-like dermal melanocytic tumor" (PDMT) based on their nested growth pattern. This term is used descriptively and does not imply any histogenetic or biologic similarity to true paraganglioma. PDMT is primarily a tumor of the extremities of adult females (18-53 years, mean 35 years; males 2; females 6) which present as a dermal nodule (range, 0.5-4.2 cm; mean, 1.4 cm) composed of nests of clear to amphophilic oval cells separated by delicate fibrous strands. Nuclear atypia was mild and mitotic activity low (1-4 mitoses/10 HPF). Melanin was not obvious on light microscopy. Tumors expressed S-100 protein (8 of 8), Melan-A (4 of 8), HMB-45 (8 of 8), and microphthalmia transcription factor (8 of 8) and lacked pancytokeratin (8 of 8) and smooth muscle actin (8 of 8). FISH analysis of 5 cases revealed an intact EWS gene locus, supporting absence of the clear cell sarcoma 12;22 translocation. Follow-up information in 8 patients (range, 35-92 months; mean, 54 months) indicated that all were alive without disease. PDMT comprises a clinically and pathologically unique subtype of dermal melanocytic tumors. Our study suggests a benign course, although a lesion of low malignant potential cannot be excluded.
Adolescent↗
Finishing and polishing of direct posterior resin restorations.
UNLABELLED: Direct composite resin materials have revolutionized the delivery of minimally invasive treatment in the posterior region. Contemporary resin formulations provide improved strength, wear resistance, and aesthetics. Microhybrid formulations have also been associated with enhanced polishability. Development of an optimal surface polish in turn reduces stain and plaque accumulation, minimizes wear, and enhances the appearance of the definitive restoration. This article presents a simplified technique and protocol for finishing and polishing composite resin materials following restoration of the posterior region. LEARNING OBJECTIVES: This article discusses techniques and a protocol for finishing and polishing posterior direct resin restorations. Upon reading this article, the reader should: Understand the clinical protocol necessary to create direct posterior resin restorations that require minimal finishing. Be able to select appropriate instrumentation for direct posterior resin finishing and polishing procedures. Understand the importance of correct finishing and polishing on plaque accumulation, stain resistance, and wear resistance.
Bicuspid↗
Oxidant stress is increased during treatment of human immunodeficiency virus infection.
Some diseases and environmental exposures, including those that are risk factors for atherosclerosis, are associated with increased oxidant stress. The objective of this cross-sectional, observational study was to determine whether oxidant stress is increased during human immunodeficiency virus type 1 (HIV-1) infection or its therapy. To quantify oxidant stress, plasma F2 isoprostane (F2-IsoP) concentrations were determined by gas chromatography/mass spectroscopy. A total of 120 subjects were enrolled during routine primary care visits. The median CD4+ T cell count was 341 cells/mm3, the median HIV-1 RNA level was 3.4 log10 copies/mL, and 74% of patients were receiving antiretroviral therapy. Plasma F2-IsoP concentrations were 12-149 pg/mL (median, 31 pg/mL). In univariate analysis, higher F2-IsoP concentrations were associated with lower log10 plasma HIV-1 RNA levels (P=.009) and with efavirenz use (P=.02). Both factors remained associated with plasma F2-IsoP concentrations in multivariate analysis. Oxidant stress associated with therapeutic control of viral replication may have important implications for long-term complications of antiretroviral therapy.
Adult↗
The Human Genome Project: lessons from large-scale biology.
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Access to Information↗
Enlarging pigmented patches on the hand.
This case illustrates the clinical and pathological features of Tinea nigra. Awareness of the characteristic features of this cutaneous infection, especially in areas where the organism is endemic, can ultimately lead clinicians to the appropriate diagnosis. If Tinea nigra should be considered in the differential diagnosis of palmoplantar pigmentation, potassium hydroxide (KOH) preparation may facilitate the diagnosis.
Administration, Topical↗