1,001 research outputs found
Photodynamic Therapy of Necrobiosis Lipoidica - A Multicenter Study of 18 Patients
Background: Necrobiosis lipoidica (NL) is a granulomatous skin disease of unknown origin, and no reliably effective treatment option exists to handle this often disfiguring disease. Recently, a patient with long-lasting NL was reported to be cured by topical photodynamic therapy (PDT). Objective: To evaluate the overall potential of PDT in the treatment of NL on the lower legs. Methods: Retrospective study of 18 patients (aged 16 - 62 years) from 3 European university departments of dermatology treated with PDT for NL. Methyl aminolevulinate or 5-aminolevulinic acid were used as topically applied photosensitizers. Illumination followed with red light-emitting diode light. Results: Complete response was seen in 1/18 patients after 9 PDT cycles, and partial response in 6/18 patients (2 - 14 PDT cycles) giving an overall response rate of 39% (7/18). Conclusion: Although almost 40% of the cases showed some degree of response, PDT cannot currently be recommended as first-line therapy of NL. Subpopulations of therapy-resistant NL patients may, however, benefit from PDT. Copyright (C) 2008 S. Karger AG, Base
Management of benign inverted sinonasal papilloma avoiding external approaches
Even though endoscopic removal of inverted papillomas has gained popularity, many studies advocate supplementary external approaches. The impact of including the current surgical staging system into the pre-operative clinical and radiological assessment has not been systematically evaluated. We present our experience with total endoscopic management of inverted papillomas and compare the accuracy of the pre-operative predicted extent of surgery, with the actually performed surgery. From 1997 to 2005 data from 51 patients with inverted papillomas were prospectively collected and subsequently reviewed. All have been operated on endoscopically without an external approach. The overall recurrence rate was 3.9 per cent. Pre-operative prediction of extent of surgery was accurate in 26 of 51 (51 per cent). The main reasons for the inaccurate pre-operative prediction were the variable sizes and locations of the inverted papilloma bases, particularly in the maxillary sinus and the frontal recess. Our results encourage us to recommend endoscopic management as the standard treatment of benign inverted papillomas
Hyperthermia induced by transient receptor potential vanilloid-1 (TRPV1) antagonists in human clinical trials: Insights from mathematical modeling and meta-analysis
Antagonists of the transient receptor potential vanilloid-1 (TRPV1) channel alter body temperature (Tb) in laboratory animals and humans: most cause hyperthermia; some produce hypothermia; and yet others have no effect. TRPV1 can be activated by capsaicin (CAP), protons (low pH), and heat. First-generation (polymodal) TRPV1 antagonists potently block all three TRPV1 activation modes. Second-generation (mode-selective) TRPV1 antagonists potently block channel activation by CAP, but exert different effects (e.g., potentiation, no effect, or low-potency inhibition) in the proton mode, heat mode, or both. Based on our earlier studies in rats, only one mode of TRPV1 activation - by protons - is involved in thermoregulatory responses to TRPV1 antagonists. In rats, compounds that potently block, potentiate, or have no effect on proton activation cause hyperthermia, hypothermia, or no effect on Tb, respectively. A Tb response occurs when a TRPV1 antagonist blocks (in case of hyperthermia) or potentiates (hypothermia) the tonic TRPV1 activation by protons somewhere in the trunk, perhaps in muscles, and - via the acido-antithermogenic and acido-antivasoconstrictor reflexes - modulates thermogenesis and skin vasoconstriction. In this work, we used a mathematical model to analyze Tb data from human clinical trials of TRPV1 antagonists. The analysis suggests that, in humans, the hyperthermic effect depends on the antagonist's potency to block TRPV1 activation not only by protons, but also by heat, while the CAP activation mode is uninvolved. Whereas in rats TRPV1 drives thermoeffectors by mediating pH signals from the trunk, but not Tb signals, our analysis suggests that TRPV1 mediates both pH and thermal signals driving thermoregulation in humans. Hence, in humans (but not in rats), TRPV1 is likely to serve as a thermosensor of the thermoregulation system. We also conducted a meta-analysis of Tb data from human trials and found that polymodal TRPV1 antagonists (ABT-102, AZD1386, and V116517) increase Tb, whereas the mode-selective blocker NEO6860 does not. Several strategies of harnessing the thermoregulatory effects of TRPV1 antagonists in humans are discussed
Clan Structure Analysis and Rapidity Gap Probability
Clan structure analysis in rapidity intervals is generalized from negative
binomial multiplicity distribution to the wide class of compound Poisson
distributions. The link of generalized clan structure analysis with correlation
functions is also established. These theoretical results are then applied to
minimum bias events and evidentiate new interesting features, which can be
inspiring and useful in order to discuss data on rapidity gap probability at
TEVATRON and HERA.Comment: (14 pages in Plain TeX plus 5 Postscript Figures, all compressed via
uufiles) DFTT 28/9
Non-steroidal anti-inflammatory drugs decrease the quality of pleurodesis after mechanical pleural abrasion
Objective: Non-steroidal anti-inflammatory drugs (NSAIDs) are often applied for pain management after thoracic surgery. Since these drugs diminish collagen deposition through inhibition of the prostaglandin synthesis, we investigated their effects on adhesion formation after endoscopic mechanical pleural abrasion, which is often applied in the therapy of pneumothorax. Methods: Mechanical pleural abrasion was performed unilaterally by the use of video-assisted thoracoscopic surgery technique in an established pig model. Ten animals (41.3±3.4 kg) were divided into a treatment group and a control group. In the treatment group, animals received 100 mg diclofenac (2 mg/kg body weight) orally daily for 3 weeks after surgery. At 3 weeks, all animals were sacrificed and efficacy of pleurodesis was macroscopically assessed by three independent reviewers blinded to the treatment of animals using a five-point severity pleurodesis score (from 0, no adhesions to 4, complete symphisis) and obliteration grade rating the distribution of adhesions (from 0, no adhesions to 4, adhesions in the whole chest). Microscopic evaluation was performed by two pathologists blinded to the study groups as well. A four-point score assessed the amount of collagen deposition (from 1, a few collagen fibers to 4, scar). Results: Gross observation showed more dense adhesions in control animals with a median pleurodesis score of 3.67±1.0 in comparison to 2±2.2 in the treatment group (P=0.01*, Mann-Whitney non-parametric test). Distribution of adhesions was comparable in both groups with a median obliteration score of 3.67±1.3. Histopathologic examination showed a higher amount of collagen deposition in the control group, suggesting more dense adhesions, whereas in the treatment group there was loose granulation tissue (score of 4.0±0.8 vs. 2.3±1.0 in the treatment group, P=0.06). The degree of inflammatory reaction was comparable in the two groups. Conclusions: Our results demonstrate that perioperative use of NSAIDs highly affects the quality of pleural adhesions obtained after mechanical abrasion in this pig model, which further suggests that these drugs should be avoided for pain management when a pleurodesis is performe
Needs and difficulties of food businesses in the substantiation of health and nutrition claims
The food industry has been struggling with existing guidance on how to prepare health claim dossiers. Hence the EU-funded project PATHWAY-27 seeks to provide a more tailored guidance.Within this project, robust guidelines for the food industry will be developed. The guidelines will be applicable to bioactives and bioactive enriched foods in general, to facilitate health claim documentation and dossiers.Based on a questionnaire, information on the needs and difficulties of the food industry in reaching the requirements established by the national and EU authorities (EFSA) was gathered. Particular emphasis was placed on scientific, economic, technical and technological barriers
11 beta-hydroxysteroid dehydrogenase type 1 regulates glucocorticoid-induced insulin resistance in skeletal muscle
OBJECTIVE: Glucocorticoid excess is characterized by increased adiposity, skeletal myopathy, and insulin resistance, but the precise molecular mechanisms are unknown. Within skeletal muscle, 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) converts cortisone (11-dehydrocorticosterone in rodents) to active cortisol (corticosterone in rodents). We aimed to determine the mechanisms underpinning glucocorticoid-induced insulin resistance in skeletal muscle and indentify how 11beta-HSD1 inhibitors improve insulin sensitivity. \ud
RESEARCH DESIGN AND METHODS: Rodent and human cell cultures, whole-tissue explants, and animal models were used to determine the impact of glucocorticoids and selective 11beta-HSD1 inhibition upon insulin signaling and action. \ud
RESULTS: Dexamethasone decreased insulin-stimulated glucose uptake, decreased IRS1 mRNA and protein expression, and increased inactivating pSer insulin receptor substrate (IRS)-1. 11beta-HSD1 activity and expression were observed in human and rodent myotubes and muscle explants. Activity was predominantly oxo-reductase, generating active glucocorticoid. A1 (selective 11beta-HSD1 inhibitor) abolished enzyme activity and blocked the increase in pSer IRS1 and reduction in total IRS1 protein after treatment with 11DHC but not corticosterone. In C57Bl6/J mice, the selective 11beta-HSD1 inhibitor, A2, decreased fasting blood glucose levels and improved insulin sensitivity. In KK mice treated with A2, skeletal muscle pSer IRS1 decreased and pThr Akt/PKB increased. In addition, A2 decreased both lipogenic and lipolytic gene expression.\ud
CONCLUSIONS: Prereceptor facilitation of glucocorticoid action via 11beta-HSD1 increases pSer IRS1 and may be crucial in mediating insulin resistance in skeletal muscle. Selective 11beta-HSD1 inhibition decreases pSer IRS1, increases pThr Akt/PKB, and decreases lipogenic and lipolytic gene expression that may represent an important mechanism underpinning their insulin-sensitizing action
Spatial vegetation patterns and neighborhood competition among woody plants in an East African savanna
The majority of research on savanna vegetation dynamics has focused on the coexistence of woody and herbaceous vegetation. Interactions among woody plants in savannas are relatively poorly understood. We present data from a 10-year longitudinal study of spatially explicit growth patterns of woody vegetation in an East African savanna following exclusion of large herbivores and in the absence of fire. We examined plant spatial patterns and quantified the degree of competition among woody individuals. Woody plants in this semi-arid savanna exhibit strongly clumped spatial distributions at scales of 1 - 5 m. However, analysis of woody plant growth rates relative to their conspecific and heterospecific neighbors revealed evidence for strong competitive interactions at neighborhood scales of up to 5 m for most woody plant species. Thus, woody plants were aggregated in clumps despite significantly decreased growth rates in close proximity to neighbors, indicating that the spatial distribution of woody plants in this region depends on dispersal and establishment processes rather than on competitive, density-dependent mortality. However, our documentation of suppressive effects of woody plants on neighbors also suggests a potentially important role for tree-tree competition in controlling vegetation structure and indicates that the balanced-competition hypothesis may contribute to well-known patterns in maximum tree cover across rainfall gradients in Africa
Direct presynaptic and indirect astrocyte-mediated mechanisms both contribute to endocannabinoid signaling in the pedunculopontine nucleus of mice
The pedunculopontine nucleus (PPN), a cholinergic nucleus of the reticular activating system, is known to be involved in the regulation of sleep and wakefulness. Endogenous and exogenous cannabinoids, by systemic or local administration to the pedunculopontine nucleus, can both influence sleep. We previously demonstrated that activation of astrocytes by cannabinoid type 1 (CB1) receptor agonists was able to modulate the membrane potential of PPN neurons, even in the presence of blockers of fast synaptic neurotransmission. In the present work, we provide evidence that synaptic inputs of PPN neurons are also affected by activation of presynaptic and astrocytic CB1 receptors. Using slice electrophysiology combined with calcium imaging, optogenetics and immunohistochemistry, we revealed a direct presynaptic inhibitory action on inhibitory postsynaptic currents, along with a mild increase of excitatory postsynaptic currents during CB1 receptor stimulation. Besides inhibition of excitatory and inhibitory neurotransmission through stimulation of presynaptic CB1 receptors, astrocyte- and mGluR-dependent tonic inhibition and excitation also developed. The mild stimulatory action of CB1 receptor activation on excitatory neurotransmission is the combination of astrocyte-dependent tonic excitation on excitatory neurons and the canonical presynaptic CB1 receptor activation and consequential inhibition of excitatory synaptic neurotransmission, whereas the astrocyte-dependent stimulatory action was not observed in inhibitory neurotransmission within the PPN. Our findings demonstrate that endocannabinoids act in the PPN via a dual pathway, consisting of a direct presynaptic and an indirect, astrocyte-mediated component, regulating synaptic strength and neuronal activity via independent mechanisms
Clinical usefulness of scoring systems to predict severe acute pancreatitis: A systematic review and meta-analysis with pre and post-test probability assessment
Background: Scoring systems for severe acute pancreatitis (SAP) prediction should be used in conjunction with pre-test probability to establish post-test probability of SAP, but data of this kind are lacking.Objective: To investigate the predictive value of commonly employed scoring systems and their usefulness in modifying the pre-test probability of SAP.Methods: Following PRISMA statement and MOOSE checklists after PROSPERO registration, PubMed was searched from inception until September 2022. Retrospective, prospective, cross-sectional studies or clinical trials on patients with acute pancreatitis defined as Revised Atlanta Criteria, reporting rate of SAP and using at least one score among Bedside Index for Severity in Acute Pancreatitis (BISAP), Acute Physiology and Chronic Health Examination (APACHE)-II, RANSON, and Systemic Inflammatory Response Syndrome (SIRS) with their sensitivity and specificity were included. Random effects model meta-analyses were performed. Pre-test probability and likelihood ratio (LR) were combined to estimate post-test probability on Fagan nomograms. Pooled severity rate was used as pre-test probability of SAP and pooled sensitivity and specificity to calculate LR and generate post-test probability. A priori hypotheses for heterogeneity were developed and sensitivity analyses planned.Results: 43 studies yielding 14,116 acute pancreatitis patients were included: 42 with BISAP, 30 with APACHE-II, 27 with Ranson, 8 with SIRS. Pooled pre-test probability of SAP ranged 16.6%-25.3%. The post-test probability of SAP with positive/negative score was 47%/6% for BISAP, 43%/5% for APACHE-II, 48%/5% for Ranson, 40%/12% for SIRS. In 18 studies comparing BISAP, APACHE-II, and Ranson in 6740 patients with pooled pre-test probability of SAP of 18.7%, post-test probability when scores were positive was 48% for BISAP, 46% for APACHE-II, 50% for Ranson. When scores were negative, post-test probability dropped to 7% for BISAP, 6% for Ranson, 5% for APACHE-II. Quality, design, and country of origin of the studies did not explain the observed high heterogeneity.Conclusions: The most commonly used scoring systems to predict SAP perform poorly and do not aid in decision-making
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