MicroRNA MIR396 regulates the switch between stem cells and transit-amplifying cells in arabidopsis roots

To ensure an adequate organ mass, the daughters of stem cells progress through a transit-amplifying phase displaying rapid cell division cycles before differentiating. Here, we show that Arabidopsis thaliana microRNA miR396 regulates the transition of root stem cells into transit-amplifying cells by interacting with GROWTH-REGULATING FACTORs (GRFs). The GRFs are expressed in transit-amplifying cells but are excluded from the stem cells through inhibition by miR396. Inactivation of the GRFs increases the meristem size and induces periclinal formative divisions in transit-amplifying cells. The GRFs repress PLETHORA (PLT) genes, regulating their spatial expression gradient. Conversely, PLT activates MIR396 in the stem cells to repress the GRFs. We identified a pathway regulated by GRF transcription factors that represses stem cell-promoting genes in actively proliferating cells, which is essential for the progression of the cell cycle and the orientation of the cell division plane. If unchecked, the expression of the GRFs in the stem cell niche suppresses formative cell divisions and distorts the organization of the quiescent center. We propose that the interactions identified here between miR396 and GRF and PLT transcription factors are necessary to establish the boundary between the stem cell niche and the transit-amplifying region.Fil: Rodriguez Virasoro, Ramiro Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Ercoli, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Debernardi, Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Breakfield, Natalie W.. University of Duke; Estados UnidosFil: Mecchia, Martin Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Sabatini, Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Cools, Toon. University of Ghent; BélgicaFil: De Veylder, Lieven. University of Ghent; BélgicaFil: Benfey, Philip N.. University of Duke; Estados UnidosFil: Palatnik, Javier Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; Argentin

Assessment of sars-cov-2 infection through rapid serology testing in the homeless population in the city of rome, Italy. Preliminary results

Background: The development of COVID-19 pandemic has affected all segments of the population; however, it had a significant impact on vulnerable subjects, such as in people experiencing homelessness. The aim of this study was to evaluate the prevalence of COVID-19 spread in homeless persons in the city of Rome, Italy. Design and Methods: Patients included in the study underwent a clinical evaluation and rapid antibody analysis on capillary blood for the presence of immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies to SARS-CoV-2 virus. Symptomatic patients were not included in the screening and immediately referred to local hospitals for further evaluation. Results: One-hundred seventy-three patients of both sexes were tested for SARS-CoV-2 infection through rapid serological test. Age range was 10-80 years; people came from 35 different countries of origin and 4 continents. Test results were negative for most patients (170-98.2%); two patients had positive IgM (1.2%) and one patient had positive IgG (0.6%). Conclusions: Our study is the first to evaluate the prevalence of SARS-CoV-2 infection in people experiencing homelessness in the city of Rome, Italy. Most patients were negative for COVID-19, although several factors may have had an impact on this result, such as the exclusion of symptomatic patients, the limited sensitivity of rapid serological tests in the initial stage of infection and the prevention measures adopted in these populations. Larger studies on fragile populations are needed to prevent and intercept new clusters of infection in the upcoming months

SARS-CoV-2 infection prevalence in people experiencing homelessness

Objective: People experiencing homelessness have peculiar characteristics that make them more vulnerable to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) transmission and to more serious forms of Coronavirus Disease 19 (COVID-19). The aim of this study was to evaluate the prevalence of SARS-CoV-2 infection in the homeless population assisted by the primary care services of the Eleemosynaria Apostolica, Vatican City. Patients and methods: Persons experiencing homelessness and the volunteers assisting them were tested for COVID-19 through PCR and antigen rapid test between October 1st, 2020, and June 5th, 2021, in the clinical facilities of the Eleemosynaria Apostolica. Results: A total of 1665 subjects from 96 different countries in five continents were included in the study; age range was 1-90 years. Overall, 2315 COVID-19 tests through nasopharyngeal swab were performed; 1052 Polymerase Chain Reaction (PCR) tests and 1263 antigen rapid tests. Nearly 40% of the subjects underwent both tests (n=650, 39.04%), 402 were tested with PCR test only (24.14%) and 613 with antigen test only (36.8%). PCR tests were negative in 966 cases and positive in 86 (8.17%), while antigen tests were negative in 1205 cases and positive in 58 (4.59%). The number of positive cases varied over time, with a drastic increase during the winter months of 2020 and a progressive decrease over 2021. Among positive cases, 24.41% were symptomatic; symptoms included fever, breathing difficulties, anosmia/hyposmia, cough, headache, and diarrhea. Conclusions: This study reported an overall prevalence of SARS-CoV-2 infection in our sample slightly above 8%. Additional data on viral genome through sequencing of SARS-CoV-2 in positive cases are of utmost importance to help identify variants and implement specific infection control measures

Thickness in Entorhinal and Subicular Cortex Predicts Episodic Memory Decline in Mild Cognitive Impairment

Identifying subjects with mild cognitive impairment (MCI) most likely to decline in cognition over time is a major focus in Alzheimer's disease (AD) research. Neuroimaging biomarkers that predict decline would have great potential for increasing the efficacy of early intervention. In this study, we used high-resolution MRI, combined with a cortical unfolding technique to increase visibility of the convoluted medial temporal lobe (MTL), to assess whether gray matter thickness in subjects with MCI correlated to decline in cognition over two years. We found that thickness in the entorhinal (ERC) and subicular (Sub) cortices of MCI subjects at initial assessment correlated to change in memory encoding over two years (ERC: r = 0.34; P = .003) and Sub (r = 0.26; P = .011) but not delayed recall performance. Our findings suggest that aspects of memory performance may be differentially affected in the early stages of AD. Given the MTL's involvement in early stages of neurodegeneration in AD, clarifying the relationship of these brain regions and the link to resultant cognitive decline is critical in understanding disease progression

A randomized controlled trial of Kundalini yoga in mild cognitive impairment

Background: Global population aging will result in increasing rates of cognitive decline and dementia. Thus, effective, low-cost, and low side-effect interventions for the treatment and prevention of cognitive decline are urgently needed. Our study is the first to investigate the effects of Kundalini yoga (KY) training on mild cognitive impairment (MCI). Methods: Older participants (≥55 years of age) with MCI were randomized to either a 12-week KY intervention or memory enhancement training (MET; gold-standard, active control). Cognitive (i.e. memory and executive functioning) and mood (i.e. depression, apathy, and resilience) assessments were administered at baseline, 12 weeks and 24 weeks. Results: At baseline, 81 participants had no significant baseline group differences in clinical or demographic characteristics. At 12 weeks and 24 weeks, both KY and MET groups showed significant improvement in memory; however, only KY showed significant improvement in executive functioning. Only the KY group showed significant improvement in depressive symptoms and resilience at week 12. Conclusion: KY group showed short- and long-term improvements in executive functioning as compared to MET, and broader effects on depressed mood and resilience. This observation should be confirmed in future clinical trials of yoga intervention for treatment and prevention of cognitive decline (NCT01983930).Harris A. Eyre, Prabha Siddarth, Bianca Acevedo, Kathleen Van Dyk, Pattharee Paholpak, Linda Ercoli, Natalie St. Cyr, Hongyu Yang, Dharma S. Khalsa and Helen Lavretsk

Prognostic significance of a comprehensive histologic evaluation of reticulin fibrosis, collagen deposition and osteosclerosis in primary myelofibrosis patients.

AimsTo evaluate whether a comprehensive histological evaluation of reticulin fibrosis, collagen deposition and osteosclerosis in bone marrow trephine biopsies (BMBs) of primary myelofibrosis (PMF) patients may have prognostic implications. Methods and resultsReticulin fibrosis, collagen deposition and osteosclerosis were graded from 0 to 3 in a series of 122 baseline BMBs. Then, we assigned to each case a comprehensive score [reticulin, collagen, osteosclerosis (RCO) score, ranging from 0 to 9] that allowed us to distinguish two groups of patients, with low-grade (RCO score 0-4) and high-grade (RCO score 5-9) stromal changes. Of 122 patients, 88 displayed a low-grade and 34 a high-grade RCO score. The latter was associated more frequently with anaemia, thrombocytopenia, peripheral blood blasts and increased lactate dehydrogenase levels. The RCO score was correlated strictly with overall mortality (P = 0.013) and International Prognostic Scoring System (IPSS) risk categories, and was able to discriminate the overall survival of both low- and high-grade patients (log-rank test: P < 0.001). Moreover, it proved to be more accurate than the European Consensus on Grading of Bone Marrow Fibrosis (ECGMF grade) in identifying high-risk patients with poor prognosis. Finally, a combined analysis of RCO scores and IPSS risk categories in an integrated clinical-pathological evaluation was able to increase the positive predictive value (PPV) for mortality in high-risk patients. ConclusionThe comprehensive RCO score, obtained by histological evaluation of reticulin fibrosis, collagen deposition and osteosclerosis was prognostically significant and more accurate than ECGMF grade in identifying high-risk patients and improved PPV when applied in addition to IPSS

Changes in neural connectivity and memory following a yoga intervention for older adults: a pilot study

Background: No study has explored the effect of yoga on cognitive decline and resting-state functional connectivity. Objectives: This study explored the relationship between performance on memory tests and resting-state functional connectivity before and after a yoga intervention versus active control for subjects with mild cognitive impairment (MCI). Methods: Participants ( ≥ 55 y) with MCI were randomized to receive a yoga intervention or active “gold-standard” control (i.e., memory enhancement training (MET)) for 12 weeks. Resting-state functional magnetic resonance imaging was used to map correlations between brain networks and memory performance changes over time. Default mode networks (DMN), language and superior parietal networks were chosen as networks of interest to analyze the association with changes in verbal and visuospatial memory performance. Results: Fourteen yoga and 11 MET participants completed the study. The yoga group demonstrated a statistically significant improvement in depression and visuospatial memory. We observed improved verbal memory performance correlated with increased connectivity between the DMN and frontal medial cortex, pregenual anterior cingulate cortex, right middle frontal cortex, posterior cingulate cortex, and left lateral occipital cortex. Improved verbal memory performance positively correlated with increased connectivity between the language processing network and the left inferior frontal gyrus. Improved visuospatial memory performance correlated inversely with connectivity between the superior parietal network and the medial parietal cortex. Conclusion:Yoga may be as effective as MET in improving functional connectivity in relation to verbal memory performance. These findings should be confirmed in larger prospective studies.Harris A. Eyre, Bianca Acevedo, Hongyu Yang, Prabha Siddarth, Kathleen Van Dyk, Linda Ercoli, Amber M. Leaver, Natalie St. Cyr, Katherine Narr, Bernhard T. Baune, Dharma S. Khalsa and Helen Lavretsk