Attracted Diffusion-Limited Aggregation

In this paper, we present results of extensive Monte Carlo simulations of diffusion-limited aggregation (DLA) with a seed placed on an attractive plane as a simple model in connection with the electrical double layers. We compute the fractal dimension of the aggregated patterns as a function of the attraction strength \alpha. For the patterns grown in both two and three dimensions, the fractal dimension shows a significant dependence on the attraction strength for small values of \alpha, and approaches to that of the ordinary two-dimensional (2D) DLA in the limit of large \alpha. For non-attracting case with \alpha=1, our results in three dimensions reproduce the patterns of 3D ordinary DLA, while in two dimensions our model leads to formation of a compact cluster with dimension two. For intermediate \alpha, the 3D clusters have quasi-2D structure with a fractal dimension very close to that of the ordinary 2D-DLA. This allows one to control morphology of a growing cluster by tuning a single external parameter \alpha.Comment: 6 pages, 6 figures, to appear in Phys. Rev. E (2012

Mediterranean diet, physical activity and gut microbiome composition: A cross-sectional study among healthy young italian adults

Background. This cross-sectional study aimed to explore the microbial composition of the gut and its possible association with the Mediterranean diet (MD) after adjusting for demographic and anthropometric characteristics in a sample of healthy young Italian adults. Methods. Gut microbiota, demographic information, and data on adherence to MD and physical activity (PA) habits were collected in a sample of 140 university students (48.6% males, mean age 22.5 ± 2.9) with a mean body mass index (BMI) of 22.4 ± 2.8 kg/m2 (15.2–33.8) and a mean PA level of 3006.2 ± 2973.6 metabolic equivalent (MET)-minutes/week (148–21,090). Results. A high prevalence of Firmicutes and Bacteroidetes was found in all the fecal samples. Significant dissimilarities in the microbiota composition were found on the basis of MD adherence and PA levels (p = 0.001). At the genus level, Streptococcus and Dorea were highly abundant in overweight/obese individuals, Ruminococcus and Oscillospira in participants with lower adherence to MD, and Lachnobacterium in subjects with low levels of PA (p = 0.001). A significantly higher abundance of Paraprevotella was shown by individuals with lower BMI, lower MD adherence, and lower PA levels (p = 0.001). Conclusions. This study contributes to the characterization of the gut microbiome of healthy humans. The findings suggest the role of diet and PA in determining gut microbiota variability

T-cell depleted HLA-haploidentical HSCT in a child with neuromyelitis optica

Neuromyelitis optica is an immune-mediated disease characterized by a relapsing course, resulting in progressive disability. In children, given the long life expectancy, a disease-modifying treatment could be particularly desirable. Unfortunately, the currently available treatment strategies with this potential are scarce. Very limited data are available about the use of allogeneic hematopoietic stem cell transplantation (HSCT) for autoimmune neurological diseases. In this report, we present a pediatric case successfully treated with allogeneic HSCT from an HLA-haploidentical donor, after ex vivo TCR/CD19-depletion of the graft. To the best of our knowledge, this is the first case of a pediatric patient to benefit from such a treatment

A Staphylococcus aureus coinfection on a COVID-19 pneumonia in a breast cancer patient

Introduction: Coronavirus disease 19 (COVID-19), due to severe acute respiratory syndrome-coronavirus 2 (SARS-CoV2), comprises a broad spectrum of clinical presentation ranging from flu-like syndrome to organ failure. The risk of coinfections is high and responsible for a worse prognosis, mainly in the case of bacterial involvement and in the presence of particular comorbidity. We present the clinical, laboratory, radiologic characteristic along with therapeutic management of a patient with COVID-19 and Staphylococcus aureus coinfection. Case Presentation: A 55-year-old Caucasian woman was admitted to our hospital due to a two-day history of fever and acute dyspnea with severe respiratory failure worsened after the administration of atezolizumab and nab-paclitaxel. Her medical history comprehended a triple negative, BRCA1-related, PD-L1 positive right breast cancer with multiple bone metastasis, causing bone marrow infiltration-related severe pancytopenia. Her physical examination revealed scattered wheezes, rales, and bilateral dry crackles in the middle and lower lung fields and lower limb paresis. The body mass index was 30 kg/m2 and arterial blood gas evaluation revealed a stage III acute respiratory distress syndrome. Microbiological specimens revealed a Staphylococcus aureus positivity from endotracheal aspirate. The chest computed tomography (CT) scan showed the presence of large areas of parenchymal consolidation and aerial broncho-gram, bilateral “ground glass” areas reaching the highest extension on the upper and middle zones. The high clinical and radiological suspicion of COVID-19 along with the negative result of nasopharyngeal specimen make necessary an endotracheal aspirate resulting positive for SARS-CoV2. Patient started an antimicrobial treatment and lopinavir-ritonavir plus hydroxy-chloroquine but, unfortunately, died five days after hospital admission. Conclusion: The high risk of mortality of our patient was due to viral-bacterial coinfection, advanced cancer status with active immunotherapy. This case highlights the need for a prompt clinical, laboratory, and radiological evaluation to allow a correct diagnosis and start a specific therapy

Active surveillance cultures and procalcitonin in combination with clinical data to guide empirical antimicrobial therapy in hospitalized medical patients with sepsis

Objective: The prevalence of colonization with multidrug-resistant organisms (MDRO) has increased over the last decade, reaching levels as high as 23% in certain patient populations. Active surveillance cultures (ASC) represent a valuable tool to identify patients colonized with MDRO to apply preventive measures, reduce transmission, and guide empiric antimicrobial therapy. There is a paucity of data evaluating the impact of admission ASCs to predict future infection. The aim of this study was to evaluate the concordance between ASCs results and the development of clinical infection by the same microorganism identified in the surveillance swab (“swab-related infection”), in hospitalized septic patients, and to evaluate the presence of specific risk factors associated with the development of a swab-related infection. Methods: All adults admitted to the Diagnostic and Therapeutic Medicine Department of the University Hospital Campus Bio-Medico of Rome with a diagnosis of infection or any other medical reason with admission surveillance swabs (rectal or nasal) between January 2018 and February 2021 were included in the study. A retrospective chart review was conducted to identify patients that developed infections with concordant MDROs identified on ASC, and the risk factors for swab-related infection. Secondary outcomes were need of intensive care unit transfer, length of stay, sepsis or septic shock development, and all-cause mortality. Results: A total of 528 patients were included in the study, of which 97 (18.3%) had a positive surveillance swab. Among patients with positive surveillance swabs, 18 (18.5%) developed an infection with the same microorganism recovered from the swab, 57 (58.8%) developed an infection with a different microorganism than that recovered from the surveillance swab, and 22 (22.7%) did not develop an infection during hospitalization. The number of colonized sites, an interventional procedure within the previous 3 months, a Systemic Inflammatory Response Syndrome (SIRS) score ≥ 2, and a quick Sequential Organ Failure Assessment (q-SOFA) score ≥ 2 were associated with a significantly higher risk of developing a swab-related infection. SIRS and q-SOFA scores ≥ 2 and procalcitonin ≥ 0.43 ng/ml help for identifying patients with a swab-related infection. Conclusion: Patients with positive surveillance swabs were at increased risk for development of infections by the same MDRO identified in surveillance swabs (swab-related infection). This study is the first to show that the positivity of surveillance swabs, in combination with anamnestic data, PCT values, and SIRS or q-SOFA scores, serves as a valuable tool to help clinicians predict patients at higher risk for swab-related infection development and guide the administration of appropriate empiric antimicrobial therapy in septic patients

Can physical activity influence human gut microbiota composition independently of diet? A systematic review

Evidence suggests that physical activity (PA) influences the human gut microbiota composition, but its role is unclear because of dietary interference. The aim of this review is to clarify this issue from this new perspective in healthy individuals. Articles analyzing intestinal microbiota from fecal samples by 16S rRNA amplicon sequencing were selected by searching the electronic databases PubMed, Scopus, and Web of Science until December 2020. For each study, methodological quality was assessed, and results about microbiota biodiversity indices, phylum and genus composition, and information on PA and diet were considered. From 997 potentially relevant articles, 10 met the inclusion criteria and were analyzed. Five studies involved athletes, three were performed on active people classified on the basis of habitual PA level, and two among sedentary subjects undergoing exercise interventions. The majority of the studies reported higher variability and prevalence of the phylum Firmicutes (genera Ruminococcaceae or Fecalibacteria) in active compared to inactive individuals, especially in athletes. The assessment of diet as a possible confounder of PA/exercise effects was completed only in four studies. They reported a similar abundance of Lachnospiraceae, Paraprevotellaceae, Ruminococcaceae, and Veillonellaceae, which are involved in metabolic, protective, structural, and histological functions. Further studies are needed to confirm these findings

Sedentary behaviors and physical activity of Italian undergraduate students during lockdown at the time of COVID−19 pandemic

Background: From March to May 2020, lockdown measures were adopted in Italy to contain the epidemic of the novel Coronavirus. People were forced to restrict their movement and social contacts, therefore having a higher risk of inactivity. This study, carried out among Italian undergraduates, explored their sedentary and physical activities (PA) during the lockdown with respect to their previous habits. Methods: An electronic questionnaire was administered once to students attending three Italian universities after the end of lockdown. Results: A total of 1430 students (mean age 22.9 ± 3.5 years, 65.5% females) completed the questionnaire. All the sedentary behaviors increased significantly, and all the physical activities decreased significantly during the lockdown. Time spent using electronic devices showed the highest increase (+52.4 min/day), and walking the greatest decrease (−365.5 min/week). Being younger than 22 years old, female, and previously active, attending the universities of Naples and Rome and having at least one graduate parent were associated with the achievement of recommended levels of PA even during the lockdown. Conclusions: This study highlights the reduction of PA among Italian undergraduates in the course of home-confinement due to the CoViD-19 pandemic. The practice of adequate PA during the lockdown was mainly associated with the previous adoption of an active lifestyle. Promoting active lifestyles during the non-pandemic period may have had positive effects also in case of lockdown