Floral abnormalities in field grown “Tigrina” plants from xHaynaldoticum sardoum Meletti et Onnis (Gramineae)

A ‘tigrina’ mutant stock of xHaynaldoticum sardoum Meletti et Onnis grown under field conditions produced high frequency spikes with abnormal stamens and pistils. The abnormalities occurred mostly in the stamens, which frequently changed to either pseudoovaries, or leaf-shaped structures or, in extreme cases, did not form at all. The developmental abnormalities of the stamens resulted in male sterility in the whole or in part of the spike. It is proposed that the “tigrina” status changes the physiology of the plant (e.g. photosynthetic activity) in such a way that it responds with floral abnormalities brought about by environmental conditions which permit normal flower development in control (non-mutant) plants.     

Anti-amnesic properties of (±)-PPCC, a novel sigma receptor ligand, on cognitive dysfunction induced by selective cholinergic lesion in rats

Previous studies have reported that selective sigma-1 agonists may improve cognitive abilities in experimental animals possibly via a cholinergic mechanism. However, the issue of a direct action on to sigma-1 receptors in memory-related brain areas has been much less investigated. The newly synthetised compound methyl(1 R ,2 S /1 S ,2 R )-2-[4-hydroxy-4-phenylpiperidin-1-yl)methyl]-1-(4-methylphenyl) cyclopropanecarboxylate [(±)-PPCC] has recently been shown to possess high affinity for the sigma-1 receptor where it specifically acts as an agonist. Here, the functional effects of (±)-PPCC were investigated in rat models of mild or severe cognitive dysfunction based on a sub-total (≤ 70–80%) or complete (≥ 90–95%) central cholinergic depletion induced by different doses of the selective immunotoxin 192 IgG-saporin injected intraventricularly. At 5–6 weeks post-surgery, the lesioned animals exhibited dose-dependent deficits in reference memory, as assessed using the Morris water maze task, whereas working memory abilities, evaluated using the radial arm water maze task, appeared equally impaired in the two dose groups. Daily treatment with (±)-PPCC significantly improved both reference and working memory performance in all lesioned animals but it did not affect intact or sham-lesioned subjects. In a separate test, treatment with (±)-PPCC reversed the learning deficits induced by the muscarinic receptor antagonist atropine sulphate in both control and mild-lesioned rats. The effect was blocked in lesioned, but not normal animals by pre-treatment with the sigma-1 antagonist N -[2-(3,4-dichlorophenyl)ethyl]- N -methyl-2-(dimethylamino)ethylamine. The results suggest that (±)-PPCC may efficiently ameliorate perturbed cognitive abilities, and that these anti-amnesic effects most probably occur via a direct interaction of the compound with sigma-1 receptors.     

Very-low-protein diets lead to reduced food intake and weight loss,linked to inhibition of hypothalamic mTOR signaling,in mice

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Maximizing and evaluating the impact of test-trace-isolate programs: A modeling study

BackgroundTest-trace-isolate programs are an essential part of coronavirus disease 2019 (COVID-19) control that offer a more targeted approach than many other nonpharmaceutical interventions. Effective use of such programs requires methods to estimate their current and anticipated impact.Methods and findingsWe present a mathematical modeling framework to evaluate the expected reductions in the reproductive number, R, from test-trace-isolate programs. This framework is implemented in a publicly available R package and an online application. We evaluated the effects of completeness in case detection and contact tracing and speed of isolation and quarantine using parameters consistent with COVID-19 transmission (R₀: 2.5, generation time: 6.5 days). We show that R is most sensitive to changes in the proportion of cases detected in almost all scenarios, and other metrics have a reduced impact when case detection levels are low (<30%). Although test-trace-isolate programs can contribute substantially to reducing R, exceptional performance across all metrics is needed to bring R below one through test-trace-isolate alone, highlighting the need for comprehensive control strategies. Results from this model also indicate that metrics used to evaluate performance of test-trace-isolate, such as the proportion of identified infections among traced contacts, may be misleading. While estimates of the impact of test-trace-isolate are sensitive to assumptions about COVID-19 natural history and adherence to isolation and quarantine, our qualitative findings are robust across numerous sensitivity analyses.ConclusionsEffective test-trace-isolate programs first need to be strong in the “test” component, as case detection underlies all other program activities. Even moderately effective test-trace-isolate programs are an important tool for controlling the COVID-19 pandemic and can alleviate the need for more restrictive social distancing measures.     

Endocytosis of the TCR/CD3 complex and the class-I major histocompatibility complex in a human T cell line.

We investigated the expression of the T cell receptor (TCR)/CD3 complex on a CD4-positive human T cell lymphoma cell line treated with phorbol myristate acetate (PMA) and/or CA2+ ionophore using fluorescence flow cytometry and fluorescence microscopic analysis. PMA induced a significant decrease in the expression of the CD3 complex on the cell membranes. Fluorescence microscopy confirmed that the down regulation is due to internalization of the antigens. Ca2+ ionophore treatment had no effect on the internalization of the CD3 complex. Double staining revealed that the vesicles containing the internalized CD3 complex and those containing intra-cytoplasmic class I major histocompatibility complex antigen had similar distribution in the PMA-stimulated cells, implying coexistence of these two antigens in a cytoplasmic perinuclear distribution.     

Early diagnosis and prompt treatment by surgery in Jorge Lobo's disease (Keloidal blastomycosis)

In 1931 the Brasilian doctor Jorge Lobo examined a patient from the Amazon Basin who had nodular confluent skin lesions over the lumbosacral region and encountered a new fungus pathogenic for man Paracoccidioides loboi. This classification was based on the morphological aspect of the parasite which was very similar to Paracoccidioides brasiliensis the causative agent of a systemic mycosis Paracoccidioidomycosis or South American Blastomycosis. Other authors use the name Loboa loboi. The final determination of the name must await cultivation of the fungus.     

Effects of pertussis toxin and indomethacin on murine lymphocytes in the bronchoalveolar lavage fluids

The total number of lymphocytes in the bronchoalveolar lavage (BAL) fluids significantly increased in mice injected intravenously with pertussis toxin (PT), while the absolute number of alveolar macrophages markedly decreased. This finding probably reflects the lymphocyte accumulation in interstitial spaces as we previously observed in mice injected with PT. In addition, indomethacin, at lower dosage (0.5 mg/kg) prevented peripheral lymphocytosis and lymphocyte accumulation in the alveolar spaces of the lungs of mice injected with PT. These results provide evidence that PT is responsible for lymphocyte accumulation together with a marked decrease of alveolar macrophages in the lungs of treated mice; moreover, indomethacin is effective in preventing bronchoalveolar changes caused by PT.