Search Results (3)

Cocoa tree genotypes (Theobroma cacao L.) were studied and characterized in terms of their morphoanatomical and physiological attributes in a non-stressful environment, as these attributes are of fundamental importance to understanding the plant’s relationship with the environment. Therefore, the objective of this study is to describe morphoanatomical and physiological patterns that can differentiate the seven cocoa genotypes, evaluated under the same conditions of temperature, humidity, and light. The genotypes remained in a greenhouse for 40 days, where sample collection procedures were carried out to analyze gas exchange parameters, such as net photosynthetic rate, stomatal conductance, and transpiration; growth parameters, such as dry weight, height, and leaf area; and the anatomy of leaves and stems via root, stem, and leaf dimensions and histochemistry. The cluster divided the genotypes into six groups. The Ipiranga-01, CCN-10, and PH-16 genotypes were grouped since they presented the highest means of anatomical variables and photosynthetic parameters. The PS-1319 genotype was segregated from the others for having the lowest physiological parameter values. CCN-51 and Cepec-2002 were grouped due to their similarity only in the internal concentration of CO₂, while Ipiranga-01, CCN-10, SJ-02, and PH-16 were grouped due to having higher physiological parameters and morphoanatomical variables. The results indicated an intergenotypic variation in physiological and morphoanatomical variables, serving as a basis for the six genotype groups. Full article

Astrocytes regulate important functions in the brain, and their dysregulation has been linked to the etiology of neurodegenerative diseases, such as Alzheimer’s disease (AD). The role of astroglia in human AD remains enigmatic, owing to the limitations of animal models, which, while recreating some pathological aspects of the disease, do not fully mirror its course. In addition, the recognition of major structural and functional differences between human and mouse astrocytes has also prompted research into human glial cells. In the current study, astrocytes were generated using human iPSCs from patients with sporadic Alzheimer’s disease (sAD), familial Alzheimer’s disease (fAD) and non-demented controls (NDC). All clones gained astrocyte-specific morphological and proteomic characteristics upon in vitro differentiation, without considerable inter-clonal variances. In comparison to NDC, AD astrocytes displayed aberrant calcium dynamics in response to glutamate. When exposed to monomeric and aggregated tau, AD astrocytes demonstrated hypertrophy and elevated GFAP expression, differential expression of select signaling and receptor proteins, and the enhanced production of metalloproteinases (MMPs). Moreover, astrocytic secretomes were able to degrade tau in both monomeric and pathologically aggregated forms, which was mediated by MMP-2 and -9. The capacity to neutralize tau varied considerably between clones, with fAD astrocytes having the lowest degradability relative to sAD and healthy astrocytes. Importantly, when compared to aggregated tau alone, astrocytic secretome pretreatment of tau differentially reduced its detrimental effects on neurons. Our results show crucial differences in sporadic and familial AD astrocytes and suggests that these cells may play distinctive roles in the pathogenesis of early and late onset Alzheimer’s disease. Full article

In the present exploratory study, we aim to elucidate the action of radon in vivo and to assess the possible health risks. Chromosome aberrations were analyzed in lymphocytes of two patients (P1, P2) undergoing radon spa therapy in Bad Steben (Germany). Both patients, suffering from painful chronic degenerative disorders of the spine and joints, received nine baths (1.2 kBq/L at 34 °C) over a 3-week period. Chromosome aberrations were analyzed before and 6, 12 and 30 weeks after the start of therapy using the high-resolution multiplex fluorescence in situ hybridization (mFISH) technique. For comparison, the lymphocytes from two healthy donors (HD1, HD2) were examined. P1 had a higher baseline aberration frequency than P2 and both healthy donors (5.3 ± 1.3 vs. 2.0 ± 0.8, 1.4 ± 0.3 and 1.1 ± 0.1 aberrations/100 analyzed metaphases, respectively). Complex aberrations, biomarkers of densely ionizing radiation, were found in P1, P2 and HD1. Neither the aberration frequency nor the fraction of complex aberrations increased after radon spa treatment, i.e., based on biological dosimetry, no increased health risk was found. It is worth noting that a detailed breakpoint analysis revealed potentially clonal aberrations in both patients. Altogether, our data show pronounced inter-individual differences with respect to the number and types of aberrations, complicating the risk analysis of low doses such as those received during radon therapy. Full article