413 research outputs found
Brain energetics plays a key role in the coordination of electrophysiology, metabolism and hemodynamics: evidence from an integrated computational model
The energetic needs of brain cells at rest and during elevated neuronal activation has been the topic of many investigations where mathematical models have played a significant role providing a context for the interpretation of experimental findings. A recently proposed mathematical model, comprising a double feedback between cellular metabolism and electrophysiology, sheds light on the interconnections between the electrophysiological details associated with changes in the frequency of neuronal firing and the corresponding metabolic activity. We propose a new extended mathematical model comprising a three-way feedback connecting metabolism, electrophysiology and hemodynamics. Upon specifying the time intervals of higher neuronal activation, the model generates a potassium based signal leading to the concomitant increase in cerebral blood flow with associated vasodilation and metabolic changes needed to sustain the increased energy demand. The predictions of the model are in good qualitative and quantitative agreement with experimental findings reported in the literature, even predicting a slow after-hyperpolarization of a duration of approximately 16 s matching experimental observations.The work of Daniela Calvetti was partly support by NSF grants DMS-1522334 and NIH grant 1U01 GM111251-01. The work of Erkki Somersalo was partly support by NSF grants DMS 1714617 and NIH grant 1U01GM111251-01
Testosterone deficiency causes penile fibrosis and organic erectile dysfunction in aging men. Evaluating association among Age, TDS and ED.
INTRODUCTION: We studied the possible correlation between age, testosterone deficiency, cavernosal fibrosis and erectile dysfunction (ED). METHODS: 47 patients with ED were enrolled between September 2010 and October 2011. IIEF-EF score, NPTR test using the Rigiscan method, total and free testosterone levels, and cavernosum biopsy were carried out on all patients. Patients aged 65 or over were defined as Old Age (OA) while patients under 65 were defined Young age (YA). The strength of the relationships found was estimated by Odds Ratio. RESULTS: 74% of patients with values of over 52% collagen fibers in the corpora cavernosa were found to have organic ED. A significant difference was found in age, percentage of collagen fibers, testosterone levels between patients with Positive Rigiscan (PR) and Negative Rigiscan (NR). Hypotestosteronaemia increased the risk of ED with PR (OR: 21.4, 95% CI: 20.2-22.6) and in both young age patients (OR: 4.3, 95% CI: 2.4-6.2) and old age patients (OR: 15.5, 95% CI: 13.4-17.6). Moreover cavernosal fibrosis increased the risk of ED with PR in both young age patients (OR: 8.2, 95% CI: 6.4-10.0 and old age patients (OR: 24.6, 95% CI: 20.8-28.4). CONCLUSIONS: This study demonstrates a strong association among age, testosterone deficiency, cavernosal fibrosis and ED with PR. Age, testosterone deficiency and cavernosal fibrosis are potentially correctable factors of cavernosal fibrosis and organic ED. Further, prospective studies are needed to evaluate if testosterone treatment, alone or in association with PDE5 inhibitors, may lower the risk of cavernosal fibrosis or decrease the severity the fibrosis in ED patients
Precision medicine and machine learning towards the prediction of the outcome of potential celiac disease
Potential Celiac Patients (PCD) bear the Celiac Disease (CD) genetic predisposition, a significant production of antihuman transglutaminase antibodies, but no morphological changes in the small bowel mucosa. A minority of patients (17%) showed clinical symptoms and need a gluten free diet at time of diagnosis, while the majority progress over several years (up to a decade) without any clinical problem neither a progression of the small intestine mucosal damage even when they continued to assume gluten in their diet. Recently we developed a traditional multivariate approach to predict the natural history, on the base of the information at enrolment (time 0) by a discriminant analysis model. Still, the traditional multivariate model requires stringent assumptions that may not be answered in the clinical setting. Starting from a follow-up dataset available for PCD, we propose the application of Machine Learning (ML) methodologies to extend the analysis on available clinical data and to detect most influent features predicting the outcome. These features, collected at time of diagnosis, should be capable to classify patients who will develop duodenal atrophy from those who will remain potential. Four ML methods were adopted to select features predictive of the outcome; the feature selection procedure was indeed capable to reduce the number of overall features from 85 to 19. ML methodologies (Random Forests, Extremely Randomized Trees, and Boosted Trees, Logistic Regression) were adopted, obtaining high values of accuracy: all report an accuracy above 75%. The specificity score was always more than 75% also, with two of the considered methods over 98%, while the best performance of sensitivity was 60%. The best model, optimized Boosted Trees, was able to classify PCD starting from the selected 19 features with an accuracy of 0.80, sensitivity of 0.58 and specificity of 0.84. Finally, with this work, we are able to categorize PCD patients that can more likely develop overt CD using ML. ML techniques appear to be an innovative approach to predict the outcome of PCD, since they provide a step forward in the direction of precision medicine aimed to customize healthcare, medical therapies, decisions, and practices tailoring the clinical management of PCD children
Control of a Programmed Cell Death Pathway in Pseudomonas aeruginosa by an Antiterminator
In Pseudomonas aeruginosa the alp system encodes a programmed cell death pathway that is switched on in a subset of cells in response to DNA damage and is linked to the virulence of the organism. Here we show that the central regulator of this pathway, AlpA, exerts its effects by acting as an antiterminator rather than a transcription activator. In particular, we present evidence that AlpA positively regulates the alpBCDE cell lysis genes, as well as genes in a second newly identified target locus, by recognizing specific DNA sites within the promoter, then binding RNA polymerase directly and allowing it to bypass intrinsic terminators positioned downstream. AlpA thus functions in a mechanistically unusual manner to control the expression of virulence genes in this opportunistic pathogen
Merkel cell polyomavirus (MCPyV) in the context of Immunosuppression. Genetic analysis of noncoding control region (NCCR) variability among a HIV-1-positive population
Background: Since limited data are available about the prevalence of Merkel cell polyomavirus (MCPyV) and the genetic variability of its noncoding control region (NCCR) in the context of immunosuppression, this study aimed to investigate the distribution of MCPyV in anatomical sites other than the skin and the behavior of NCCR among an HIV-1-positive population. Methods: Urine, plasma, and rectal swabs specimens from a cohort of 66 HIV-1-positive patients were collected and subjected to quantitative real-time polymerase chain reaction (qPCR) for MCPyV DNA detection. MCPyV-positive samples were amplified by nested PCR targeting the NCCR, and NCCRs alignment was carried out to evaluate the occurrence of mutations and to identify putative binding sites for cellular factors. Results: MCPyV DNA was detected in 10/66 urine, in 7/66 plasma, and in 23/66 rectal samples, with a median value of 5 Ă— 102 copies/mL, 1.5 Ă— 102 copies/mL, and 2.3 Ă— 103 copies/mL, respectively. NCCR sequence analysis revealed a high degree of homology with the MCC350 reference strain in urine, whereas transitions, transversions, and single or double deletions were observed in plasma and rectal swabs. In these latter samples, representative GTT and GTTGA insertions were also observed. Search for putative binding sites of cellular transcription factors showed that in several strains, deletions, insertions, or single base substitutions altered the NCCR canonical configuration. Conclusions: Sequencing analysis revealed the presence of numerous mutations in the NCCR, including insertions and deletions. Whether these mutations may have an impact on the pathogenic features of the virus remains to be determined. qPCR measured on average a low viral load in the specimens analyzed, with the exception of those with the GTTGA insertion
Noncanonical Fungal Autophagy Inhibits Inflammation in Response to IFN-Îł via DAPK1
Defects in a form of noncanonical autophagy, known as LC3-associated phagocytosis (LAP), lead to increased inflammatory pathology during fungal infection. Although LAP contributes to fungal degradation, the molecular mechanisms underlying LAP-mediated modulation of inflammation are unknown. We describe a mechanism by which inflammation is regulated during LAP through the death-associated protein kinase 1 (DAPK1). The ATF6/C/EBP-β/DAPK1 axis activated by IFN-γ not only mediates LAP to Aspergillus fumigatus but also concomitantly inhibits Nod-like receptor protein 3 (NLRP3) activation and restrains pathogenic inflammation. In mouse models and patient samples of chronic granulomatous disease, which exhibit defective autophagy and increased inflammasome activity, IFN-γ restores reduced DAPK1 activity and dampens fungal growth. Additionally, in a cohort of hematopoietic stem cell-transplanted patients, a genetic DAPK1 deficiency is associated with increased inflammation and heightened aspergillosis susceptibility. Thus, DAPK1 is a potential drugable player in regulating the inflammatory response during fungal clearance initiated by IFN-γ
Lower urinary tract symptoms and mental health during COVID-19 pandemic
Objective: Coronaviruses (CoVs) are a group of RNA viruses involved in several human diseases affecting respiratory, enteric, hepatic, and neurological systems. COVID-19 was identified in 2020 and was named SARS-CoV-2. To limit worldwide contagion, many countries instituted a lockdown, which conducted to disruption of routine life. In fact, pandemic was associated with several stresses among population, such as loss of employment, deaths of family members, friends, or colleagues, financial insecurity, and isolation. This led to long-lasting psychosocial effects as anxiety and depression, increasing the prevalence of stress and traumarelated disorders in the population. The aim of this study was to investigate the correlation between lower urinary tracts symptoms (LUTS) and stress/depressive symptoms during COVID-19 pandemic. Materials and methods: An anonymous cross-sectional webbased survey (comprehending anthropometric data, education level, occupation status, smoking and alcohol habits, current therapies, quarantine and COVID-19 infection status) was conducted from March to May 2020 in Italy. LUTS were examined through National Institute of Health-Chronic Prostatitis Symptom Index (NIH-CPSI) and Genitourinary Pain Index (GUPI). Hamilton Depression Rating Scale (HDRS) was utilized to evaluate depressive and anxiety symptoms. Non-parametric Kruskal-Wallis H Test was used for statistical analysis. Results: A total of 356 out of 461 subjects fully completed the survey, with a response rate of 77.2%. Data showed that subjects involved in economic difficulties, quarantine measures or with increased HDRS reported a significative statistic worsened urinary symptoms (H(3) = 11.731, p = 0.008), quality of life, (H(3) = 10.301, p = 0.016), total NIH-CPSI/GUPI score (H(3) = 42.150, p = 0.000), and quality of life (H(3) = 48.638, p = 0.000). Conclusions: COVID-19 pandemic provoked several alterations in everyday life. Although general lockdown, quarantine and social distancing have been necessary to prevent virus spreading, this had long term effects on all population in terms of mental and physical health. NIH-CPSI and GUPI scores increased linearly with stress and anxiety levels measured at HDRS, confirming worse LUTS in subjects who suffered anxiety and stress from COVID-19 pandemic
Infections in patients with lymphoproliferative diseases treated with targeted agents: SEIFEM multicentric retrospective study
We describe the opportunistic infections occurring in 362 patients with lymphoproliferative disorders treated with ibrutinib and idelalisib in clinical practice. Overall, 108 of 362 patients (29·8%) developed infections, for a total of 152 events. Clinically defined infections (CDI) were 49·3% (75/152) and microbiologically defined infections (MDI) were 50·7% (77/152). Among 250 patients treated with ibrutinib, 28·8% (72/250) experienced one or more infections, for a total of 104 episodes. MDI were 49% (51/104). Bacterial infections were 66·7% (34/51), viral 19·6% (10/51) and invasive fungal diseases (IFD) 13·7% (7/51). Among the 112 patients treated with idelalisib, 32·1% (36/112) experienced one or more infections, for a total of 48 episodes. MDI were 54·2% (26/48). Bacterial infections were 34·6% (9/26), viral 61·5% (16/26) and IFD 3·8% (1/26). With ibrutinib, the rate of bacterial infections was significantly higher compared to idelalisib (66·7% vs. 34·6%; P = 0·007), while viral infections were most frequent in idelalisib (61·5% vs. 19·6%; P < 0·001). Although a higher rate of IFD was observed in patients treated with ibrutinib, the difference was not statistically significant (13·7% vs. 3·8% respectively; P = 0·18). Bacteria are the most frequent infections with ibrutinib, while viruses are most frequently involved with idelalisib
Beyond appearance: An unusual manifestation of isolated oral secondary syphilis
Syphilis is a sexually acquired chronic infection caused by Treponema pallidum and is characterized by a variety of clinical manifestations. The secondary stage of the disease results from the hematogenous and lymphatic dissemination of treponemes after a few weeks or months, and it is characterized by recurrent activity of the disease, with muco-cutaneous as well as systemic manifestations. Mucosal lesions range from small, superficial ulcers that resemble painless aphthae to large gray plaques, and they are generally associated with systemic manifestations of the disease. The exclusive asymptomatic oral localization not associated with general manifestations is uncommon but may actually be unrecognized and under-reported. We report a case of isolated oral manifestation as the unique presentation of secondary syphilis
Rewritable nanoscale oxide photodetector
Nanophotonic devices seek to generate, guide, and/or detect light using
structures whose nanoscale dimensions are closely tied to their functionality.
Semiconducting nanowires, grown with tailored optoelectronic properties, have
been successfully placed into devices for a variety of applications. However,
the integration of photonic nanostructures with electronic circuitry has always
been one of the most challenging aspects of device development. Here we report
the development of rewritable nanoscale photodetectors created at the interface
between LaAlO3 and SrTiO3. Nanowire junctions with characteristic dimensions
2-3 nm are created using a reversible AFM writing technique. These nanoscale
devices exhibit a remarkably high gain for their size, in part because of the
large electric fields produced in the gap region. The photoconductive response
is gate-tunable and spans the visible-to-near-infrared regime. The ability to
integrate rewritable nanoscale photodetectors with nanowires and transistors in
a single materials platform foreshadows new families of integrated
optoelectronic devices and applications.Comment: 5 pages, 5 figures. Supplementary Information 7 pages, 9 figure
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