338 research outputs found
On the Pairing Structure of the Vacuum induced by a Magnetic Field in 2+1-dimensional Dirac Field Theory
Using a sequence of Bogoliubov transformations, we obtain an exact expression
for the vacuum state of a Dirac field in 2+1 dimensions in presence of a
constant magnetic field. This expression reveals a peculiar two level pairing
structure for any value of the mass m greater than zero. This calculation
clarifies the nature of the condensate in the lowest Landau level whose
existence has been emphasized recently by a several authors.Comment: 10 pages, AMSLaTeX (with LaTe2e), no figures (to be published in
Phys. Lett. B
Evidence for Polymicrobic Flora Translocating in Peripheral Blood of HIV-Infected Patients with Poor Immune Response to Antiretroviral Therapy
In advanced HIV infection, the homeostatic balance between gastrointestinal indigenous bacteria and gut immunity fails and microbes are able to overcome the intestinal barrier and gain the systemic circulation. Because microbial translocation is not fully controlled by antiviral therapy and is associated with inefficient CD4+ reconstitution, we investigated the profile of translocating bacteria in peripheral blood of 44 HIV-infected patients starting therapy with advanced CD4+ T-lymphopenia and displaying poor CD4+ recovery on virologically suppressive HAART. According to CD4+ reconstitution at 12-months HAART, patients were considered Partial Immunological Responders, PIRs (CD4+âĽ250/Âľl, nâ=â29) and Immunological non Responders, INRs (CD4+<200/Âľl, nâ=â15)). We show that PIRs and INRs present similarly elevated plasma levels of lipopolysaccharide (LPS) and its ligand sCD14 that were not lowered by virologically suppressive therapy. Bacterial 16S rRNA gene amplification and sequencing resulted in a highly polymicrobic peripheral blood microbiota both prior and after 12-month HAART. Several differences in bacterial composition were shown between patients' groups, mainly the lack of probiotic Lactobacillaceae both prior and after therapy in INRs. Failure to control microbial translocation on HAART is associated with a polymicrobic flora circulating in peripheral blood that is not substantially modified by therapy
A Wnt1 regulated Frizzled-1/β-Catenin signaling pathway as a candidate regulatory circuit controlling mesencephalic dopaminergic neuron-astrocyte crosstalk: Therapeutical relevance for neuron survival and neuroprotection.
BACKGROUND: Dopamine-synthesizing (dopaminergic, DA) neurons in the ventral midbrain (VM) constitute a pivotal neuronal population controlling motor behaviors, cognitive and affective brain functions, which generation critically relies on the activation of Wingless-type MMTV integration site (Wnt)/β-catenin pathway in their progenitors. In Parkinson's disease, DA cell bodies within the substantia nigra pars compacta (SNpc) progressively degenerate, with causes and mechanisms poorly understood. Emerging evidence suggests that Wnt signaling via Frizzled (Fzd) receptors may play a role in different degenerative states, but little is known about Wnt signaling in the adult midbrain. Using in vitro and in vivo model systems of DA degeneration, along with functional studies in both intact and SN lesioned mice, we herein highlight an intrinsic Wnt1/Fzd-1/β-catenin tone critically contributing to the survival and protection of adult midbrain DA neurons. RESULTS: In vitro experiments identifie Fzd-1 receptor expression at a mRNA and protein levels in dopamine transporter (DAT) expressing neurons, and demonstrate the ability of exogenous Wnt1 to exert robust neuroprotective effects against Caspase-3 activation, the loss of tyrosine hydroxylase-positive (TH+) neurons and [3H] dopamine uptake induced by different DA-specific insults, including serum and growth factor deprivation, 6-hydroxydopamine and MPTP/MPP+. Co-culture of DA neurons with midbrain astrocytes phenocopies Wnt1 neuroprotective effects, whereas RNA interference-mediated knockdown of Wnt1 in midbrain astrocytes markedly reduces astrocyte-induced TH+ neuroprotection. Likewise, silencing β-catenin mRNA or knocking down Fzd-1 receptor expression in mesencephalic neurons counteract astrocyte-induced TH+ neuroprotection. In vivo experiments document Fzd-1 co-localization with TH+ neurons within the intact SNpc and blockade of Fzd/β-catenin signaling by unilateral infusion of a Fzd/β-catenin antagonist within the SN induces reactive astrocytosis and acutely inhibits TH+ neuron survival in ipsilateral SNpc, an effect efficiently prevented by pharmacological activation of β-catenin signaling within the SNpc. CONCLUSION: These results defining a novel Wnt1/Fzd-1/β-catenin astrocyte-DA autoprotective loop provide a new mechanistic inside into the regulation of pro-survival processes, with potentially relevant consequences for drug design or drug action in Parkinson's disease.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Fertility preservation in gynaecologic cancers
Due to substantial improvement in the diagnosis and treatment of gynaecologic cancers, a better understanding of patient care needs to be revised. We reviewed the literature related to fertility preservation strategies in gynaecological cancer and discussed current general management approaches. New technical modalities and patientsâ own desire for motherhood should be integral and paramount in the clinical evaluation to significantly contribute to preserving fertility in those women diagnosed with gynaecologic cancers during the reproductive years
Late aortic lymphocele and residual ovary syndrome after gynecological surgery
<p>Abstract</p> <p>Background</p> <p>Gynecological surgery, as radical hysterectomy or pelvic and aortic lymphadenectomy, accounts for more than 50% of iatrogenic injuries. In premenopausal women, an hysterectomy with ovarian sparing and concomitant lateral ovarian transposition is frequently performed. However, the fate of the retained ovary is complicated by the residual ovarian syndrome (ROS) and one of the most common postoperative complications of the lymphadenectomy procedure is the lymphocele, with an average incidence of 22â48.5%. The differential diagnosis of a postoperative fluid collection includes, in addition to a lymphocele, urinoma, hematoma, seroma or abscess and the computed tomography (CT) findings alone is not enough.</p> <p>Case presentation</p> <p>We describe a patient, affected by ROS concomitant with a asymptomatic lymphocele, initially confused with an aortic lymph nodes relapse, after abdominal radical hysterectomy. The patient was subjected to a surgical approach, included a diagnostic open laparoscopy and laparotomy with sovraombelico-pubic incision, wide opening of the pelvic peritoneum and retroperitoneum. Examination of the mass revealed, macroscopically, a ovary with multiloculated cystic masses filled with clear or yellow serous fluid and the layers were composed by flat or cuboidal mesothelial cells.</p> <p>Conclusion</p> <p>The tribute of this case illustrates the atypical appearance with uncertain aetiology after complex imaging. Gynecologist and radiologist should acquaint with the appearance of fluid collection (urinoma, lymphocele, seroma, hematoma, abscess) in gynecologic oncology follow-up to properly differentiated from tumor recurrence.</p
Syncope and Cannabis: hypervagotonia from chronic abuse? A case report and literature review
Background: Cannabis is the most consumed drug worldwide and number of users is increasing, particularly among youth. Moreover, cannabis potential therapeutic properties have renewed interest to make it available as a treatment for a variety of conditions. Albeit rarely, cannabis consumption has been associated with cardiovascular diseases such as arrhythmias, myocardial infarction (MI) and potentially sudden death. Case presentation: A 24-year-old woman presented to the emergency department sent by her cardiologist because of a recent finding of a 16 seconds asystole on the implantable loop recorder (ILR) she implanted 7 months before for recurrent syncopes. She declared that she is a heavy cannabis user (at least 5 cannabis-cigarette per day, not mixed up with tobacco, for no less than 12 years) and all syncopes occurred shortly after cannabis consumption. After a collective discussion with the heart team, syncope unit, electrophysiologists and toxicologist, we decided to implant a dual chamber pacemaker with a rate response algorithm due to the high risk of trauma of the syncopal episodes. 24 months follow-up period was uneventful. Conclusions: Cannabis cardiovascular effects are not well known and, although rare, among these we find ischemic episodes, tachyarrhythmias, symptomatic sinus bradycardia, sinus arrest, ventricular asystole and possibly death. Because of cannabis growing consumption both for medical and recreational purpose, cardiovascular diseases associated with cannabis use may become more and more frequent. In the light of the poor literature, we believe that cannabis may produce opposite adverse effects depending on the duration of the habit. Acute administration increases sympathetic tone and reduces parasympathetic tone; conversely, with chronic intake an opposite effect is observed: repetitive dosing decreases sympathetic activity and increases parasympathetic activity. Clinicians should be aware of the increased risk of cardiovascular complications associated with cannabis use and should investigate its consumption especially in young patients presenting with cardiac dysrhythmias
Microglia Polarization, Gene-Environment Interactions and Wnt/β-Catenin Signaling: Emerging Roles of Glia-Neuron and Glia-Stem/Neuroprogenitor Crosstalk for Dopaminergic Neurorestoration in Aged Parkinsonian Brain.
Neuroinflammatory processes are recognized key contributory factors in Parkinson's disease (PD) physiopathology. While the causes responsible for the progressive loss of midbrain dopaminergic (mDA) neuronal cell bodies in the subtantia nigra pars compacta are poorly understood, aging, genetics, environmental toxicity, and particularly inflammation, represent prominent etiological factors in PD development. Especially, reactive astrocytes, microglial cells, and infiltrating monocyte-derived macrophages play dual beneficial/harmful effects, via a panel of pro- or anti-inflammatory cytokines, chemokines, neurotrophic and neurogenic transcription factors. Notably, with age, microglia may adopt a potent neurotoxic, pro-inflammatory "primed" (M1) phenotype when challenged with inflammatory or neurotoxic stimuli that hamper brain's own restorative potential and inhibit endogenous neurorepair mechanisms. In the last decade we have provided evidence for a major role of microglial crosstalk with astrocytes, mDA neurons and neural stem progenitor cells (NSCs) in the MPTP- (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-) mouse model of PD, and identified Wnt/β-catenin signaling, a pivotal morphogen for mDA neurodevelopment, neuroprotection, and neuroinflammatory modulation, as a critical actor in glia-neuron and glia-NSCs crosstalk. With age however, Wnt signaling and glia-NSC-neuron crosstalk become dysfunctional with harmful consequences for mDA neuron plasticity and repair. These findings are of importance given the deregulation of Wnt signaling in PD and the emerging link between most PD related genes, Wnt signaling and inflammation. Especially, in light of the expanding field of microRNAs and inflammatory PD-related genes as modulators of microglial-proinflammatory status, uncovering the complex molecular circuitry linking PD and neuroinflammation will permit the identification of new druggable targets for the cure of the disease. Here we summarize recent findings unveiling major microglial inflammatory and oxidative stress pathways converging in the regulation of Wnt/β-catenin signaling, and reciprocally, the ability of Wnt signaling pathways to modulate microglial activation in PD. Unraveling the key factors and conditons promoting the switch of the proinflammatory M1 microglia status into a neuroprotective and regenerative M2 phenotype will have important consequences for neuroimmune interactions and neuronal outcome under inflammatory and/or neurodegenerative conditions
Less air pollution did not explain the decline in admissions for AMI during the first wave of COVID-19 pandemic in Sardinia, Italy
During the COVID-19 pandemic, hospitalizations for acute myocardial infarction (AMI) decreased worldwide. We compared the admissions for AMI in the four regional 24/7 cath lab during the national lockdown, the 8âweeks before the lockdown, the 8âweeks after the e lockdown, and the corresponding time period in 2019 and we analyzed the average level of pollution in the studies areas. A marked decline in AMI admissions was observed during the lockdown period in comparison with the 8âweeks before the lockdown (pâ<â0.0001) and a significant increase in the 8âweeks after the lockdown (pâ<â0.00001). No significant change in air pollutants density were highlighted. Since air pollution did not change substantially in our region, the environment factor cannot explain the decline in the number of admissions for AMI we recorded during the lockdown. Fear of contagion is the most plausible reason for the drop of hospitalizations during the lockdown period
The Happiness for Italy's Victory at the European Soccer Championships Costs a âHappy Heart Syndromeâ
Takotsubo syndrome (TTS) is usually caused by physical or emotional negative stressors. Sometimes positive emotions trigger a rare form of Takotsubo syndrome, called the âhappy heartâ syndrome. We discuss the management of a 52-year-old female with happy heart syndrome, the differences between these stress cardiomyopathies and the relationship with hyperthyroidism
Cost analysis of dalbavancin versus standard of care for the treatment of acute bacterial skin and skin structure infections (ABSSSIs) in two Italian hospitals
The study was presented at the 21st Conference of the National Society of Infectious Diseases and Tropical Medicine âCongresso Nazionale SocietĂ Italiana Malattie Infettive e Tropicaliâ, 20â23 November 2022, Rome, Italy (Poster PP259).OBJECTIVES: Thanks to its long half-life, dalbavancin qualifies as an optimal drug for saving costs. We aimed to assess the cost and effectiveness of dalbavancin versus the standard of care (SoC).
PATIENTS AND METHODS: Thanks to its long half-life, dalbavancin qualifies as an optimal drug for saving costs. We aimed to assess the cost and effectiveness of dalbavancin versus the standard of care (SoC).
RESULTS: One hundred and twenty-six of 228 (55.3%) patients received SoC, while 102/228 (44.7%) received dalbavancin. Twenty-seven of the 102 (26.5%) patients received dalbavancin as first-line treatment, 46 (45.1%) as second-line, and 29 (28.4%) as third- or higher-line treatment. Most patients received dalbavancin as monotherapy (62/102; 60.8%). Compared with SoC, dalbavancin was associated with a significant reduction of LOS (5âÂąâ7.47â
days for dalbavancin, 9.2âÂąâ5.59â
days for SoC; Pâ<â0.00001) and with lower mean direct medical costs (3470âÂąâ2768⏠for dalbavancin; 3493âÂąâ1901⏠for SoC; Pâ=â0.9401). LOS was also reduced for first-line dalbavancin, in comparison with second-, third- or higher-line groups, and for dalbavancin monotherapy versus combination therapy. Mean direct medical costs were significantly lower in first-line dalbavancin compared with higher lines, but no cost difference was observed between monotherapy and combination therapy.
CONCLUSIONS: Monotherapy with first-line dalbavancin was confirmed as a promising strategy for ABSSSIs in real-life settings, thanks to its property in reducing LOS and saving direct medical costs.https://www.ncbi.nlm.nih.gov/pmc/journals/4039School of Health Systems and Public Health (SHSPH
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