Effect of heavy metals on stem anatomical characteristics of Trapa natans L. from Skadar Lake (Montenegro)

This study aimed to analyze stem anatomical characteristics of Trapa natans from five Skadar Lake locations (L1 - Milovića bay, L2 – inflow of the Morača river, L3 - Kamenik, L4 - Grmožur, L5 - Lipovik) with different concentrations of Cu, Mn, Zn, Co and Pb, during the summer period of the year 2012. Cross sections of stem were made using cryotechnic procedure. For all analyzed quantitative anatomical parameters, the minimum values at the location L2 were recorded, with the presence of maximum content for all investigated metals in stem of Trapa natans. On the other hand, except for cobalt, at the location L4 the minimum concentration for all investigated metals were recorded. Plants collected from this location have the largest average values of the most measured anatomical parameters. The results of Discriminant Analysis showed that plants from different location could be clearly classified into three groups according to their stem quantitative anatomical characteristics which corresponds with heavy metals content. Our research also showed that there is no statistically significant correlation between the content of most investigated metals (Co, Cu, Pb and Zn) and the values of anatomical parameters. Statistically significant negative correlation was found between Mn content in stem and values of two anatomical characters (stem cross-sectional area and Mn content, r = - 0.88; p < 0.05; number of hypodermal cell layers and Mn content, r = - 0.90; p < 0.05).

Physiological and Ultrastructural Alterations Linked to Intrinsic Mastication Inferiority of Segment Membranes in Satsuma Mandarin (Citrus unshiu Marc.) Fruits

Chewing texture is important for fresh citrus fruits, and the mastication trait of a segment directly determines chewing texture. Roughing disorder impairs the quality of Satsuma mandarin fruits, and it is typically correlated with intrinsic mastication inferiority (IMI). This study explored the role of segment membranes (SMs) in IMI. Similar to IMI in roughing-disordered fruits, segment shear force significantly enhanced relative to controls (CK); cell layers and cell wall thickness increased also in inferior masticating SMs. The ‘Miyamoto Wase’ cultivar exhibited larger segment shear force and more SM cell layers than ‘Juxiangzao’. In SMs, vessel cells could be divided into outside layers where segments adjoin and inside layers where juice sacs grow from. The inside vessel cell layers in the inferior masticating SMs were denser. Vessels with a length of 200 to 300 μm and a diameter of 5 to 15 μm predominated in SMs. The average vessel diameter enlarged by 13% to 16.5% in inferior masticating SMs, depending on cultivars. Furthermore, there was a decrease in vessels with a diameter <5 μm and an increase in vessels >10 μm in the inferior masticating SMs. Between phenotypes, protopectin increased significantly throughout development of inferior masticating SMs, while water-soluble pectin increased during the later stages of development. In one inferior masticating SM sample, protopectin and water-soluble pectin levels were higher in the inner-ring area than those in the outer-ring area. Correspondingly, expression of CuPME21 which is involved in pectin hydrolysis was consistently upregulated in the inferior masticating SMs throughout fruit development. The findings in this work provide novel insights into citrus SM structure and its IMI.

Increasing the efficiency of hyperthermic intraperitoneal chemotherapy (HIPEC) by a combination with a photosensitive drug in pediatric rhabdomyosarcoma

Background: Cytoreductive surgery (CRS) in combination with hyperthermic intraperitoneal chemotherapy (HIPEC) is an option in advanced peritoneal sarcomatosis. Nevertheless, CRS and HIPEC are not successful in all patients. An enhancement of HIPEC using photodynamic therapy might be beneficial. Therefore, a combination of the photosensitizer Hypericin (HYP) with HIPEC was evaluated in an animal model. Procedure: An established HIPEC animal model for rhabdomyosarcoma (NOD/LtSz-scid IL2Rγnullmice, n=80) was used. All groups received HYP (100 µg/200 µl) intraperitoneally with and without cisplatin-based (30 or 60 mg/m2) HIPEC (37 or 42 °C, for 60 min) (five groups, each n=16). Tumor dissemination was documented visually and by using HYP-based fluorescence guidance. HYP-based photodynamic therapy (PDT) of the tumor was performed. Finally, tissue samples were evaluated regarding proliferation (Ki-67) and apoptosis (TUNEL). Results: HYP uptake even in smallest tumor nodes (< 1 mm) was found. HYP-based fluorescence guidance allowed a better tumor detection in comparison to visual inspection. Immunohistochemistry revealed HYP penetration across the tumor surface. HYP-based PDT without HIPEC induced marginal apoptotic effects at the tumor surface. Combining HYP with HIPEC revealed cisplatin concentration dependent decrease in proliferation capacity and induction of apoptosis across determined cell layers of the tumor surfaces. Conclusion: HYP as fluorescent photosensitizer offers an intraoperative diagnostic advantage detecting intraperitoneal tumor dissemination. The combination of HYP and cisplatin-based HIPEC was feasible in vivo showing enhanced effects on tumor proliferation and apoptosis induction across the tumor surface. Further studies combining HYP and HIPEC will follow to establish a clinical application.

Biocompatibility of Platinum Nanoparticles in Brain ex vivo Models in Physiological and Pathological Conditions

Platinum nanoparticles (PtNPs) have unique physico-chemical properties that led to their use in many branches of medicine. Recently, PtNPs gathered growing interest as delivery vectors for drugs, biosensors and as surface coating on chronically implanted biomedical devices for improving electrochemical properties. However, there are contradictory statements about their biocompatibility and impact on target organs such as the brain tissue, where these NPs are finding many applications. Furthermore, many of the reported studies are conducted in homeostasis conditions and, consequently, neglect the impact of the pathologic conditions on the tissue response. To expand our knowledge on the effects of PtNPs on neuronal and glial cells, we investigated the acute effects of monodisperse sodium citrate-coated PtNPs on rat organotypic hippocampal cultures in physiological or neuronal excitotoxic conditions induced by kainic acid (KA). The cellular responses of the PtNPs were evaluated through cytotoxic assays and confocal microscopy analysis. To mimic a pathologic scenario, 7-day organotypic hippocampal cultures were exposed to KA for 24 h. Subsequently, PtNPs were added to each slice. We show that incubation of the slices with PtNPs for 24 h, does not severely impact cell viability in normal conditions, with no significant differences when comparing the dentate gyrus (DG), as well as CA3 and CA1 pyramidal cell layers. Such effects are not exacerbated in KA-treated slices, where the presence of PtNPs does not cause additional neuronal propidium iodide (PI) uptake in CA3 and CA1 pyramidal cell layers. However, PtNPs cause microglial cell activation and morphological alterations in CA3 and DG regions indicating the establishment of an inflammatory reaction. Morphological analysis revealed that microglia acquire activated ameboid morphology with loss of ramifications, as a result of their response to PtNPs contact. Surprisingly, this effect is not increased in pathological conditions. Taken together, these results show that PtNPs cause microglia alterations in short-term studies. Additionally, there is no worsening of the tissue response in a neuropathological induced scenario. This work highlights the need of further research to allow for the safe use of PtNPs. Also, it supports the demand of the development of novel and more biocompatible NPs to be applied in the brain.

Programmed Degradation of Pericarp Cells in Wheat Grains Depends on Autophagy

Wheat is one of the most important food crops in the world, with development of the grains directly determining yield and quality. Understanding grain development and the underlying regulatory mechanisms is therefore essential in improving the yield and quality of wheat. In this study, the developmental characteristics of the pericarp was examined in developing wheat grains of the new variety Jimai 70. As a result, pericarp thickness was found to be thinnest in grains at the top of the spike, followed by those in the middle and thickest at the bottom. Moreover, this difference corresponded to the number of cell layers in the pericarp, which decreased as a result of programmed cell death (PCD). A number of autophagy-related genes (ATGs) are involved in the process of PCD in the pericarp, and in this study, an increase in ATG8-PE expression was observed followed by the appearance of autophagy structures. Meanwhile, following interference of the key autophagy gene ATG8, PCD was inhibited and the thickness of the pericarp increased, resulting in small premature grains. These findings suggest that autophagy and PCD coexist in the pericarp during early development of wheat grains, with both processes increasing from the bottom to the top of the spike. Moreover, PCD was also found to rely on ATG8-mediated autophagy. The results of this study therefore provide a theoretical basis for in-depth studies of the regulatory mechanisms of wheat grain development.

The SlHB8 Acts as a Negative Regulator in Stem Development and Lignin Biosynthesis

The stem is an important organ in supporting plant body, transporting nutrients and communicating signals for plant growing. However, studies on the regulation of stem development in tomato are rather limited. In our study, we demonstrated that SlHB8 negatively regulated tomato stem development. SlHB8 belongs to homeo domain-leucine zipper Class III gene family transcription factors and expressed in all the organs examined including root, stem, leaves, flower, and fruit. Among these tissues, SlHB8 showed stable high expression level during tomato stem development. Overexpression of SlHB8 gene decreased stem diameter with inhibited xylem width and xylem cell layers, while loss of function of SlHB8gene increased the stem diameter and xylem width. The contents of lignin were decreased both in leaves and stems of SlHB8 overexpression plants. RNA-seq analysis on the stems of wild type and SlHB8 transgenic plants showed that the 116 DEGs (differential expressed genes) with reversible expression profiles in SlHB8-ox and SlHB8-cr plants were significantly enriched in the phenylpropanoid biosynthesis pathway and plant-pathogen pathway which were related to lignin biosynthesis and disease resistance. Meanwhile, the key genes involved in the lignin biosynthesis pathway such as SlCCR (cinnamoyl-CoA reductase), SlCYP73A14/C4H (cinnamate 4-hydroxylase), SlC3H (coumarate 3-hydroxylase) and SlCAD (cinnamoyl alcohol dehydrogenase) were down-regulated in both stem and leaves of SlHB8 overexpression plants, indicating a negative regulatory role of SlHB8 in the lignin biosynthesis and stem development.

Congenital orbital teratoma: a case report with preservation of the globe and 18 years of follow-up

Background Congenital orbital teratomas are extremely rare, usually benign neoplasms, comprised of cells originating from all three germ cell layers. Clinically the tumor appears solid, most of the times is intraconal and presents as a rapidly growing mass leading to a massive unilateral axial proptosis, chemosis, exposure keratopathy, markedly distended eyelids and often, loss of vision. To prevent these complications, tumor excision usually involves enucleation or even orbital exenteration. Case presentation We report a case of a 1-day old infant who presented with dramatic proptosis at birth due to a true congenital orbital teratoma. We describe the clinical findings, the preoperative neuroimaging, the surgical management which included complete tumor resection with preservation of the globe to allow for optimal orbital growth, the histopathological evaluation, and the clinical course during 18 years of follow up. Conclusion Every effort to salvage the globe should be made to achieve the best possible orbito-facial development. Furthermore, the value of prompt surgical management with a less invasive transconjunctival globe sparing procedure can be appreciated in our case.

Rice with Multilayer Aleurone: A Larger Sink for Multiple Micronutrients

Diet-related noncommunicable diseases impose a heavy burden on human health worldwide. Rice is a good target for diet-related disease prevention strategies because it is widely consumed. Liu et al. (Proc Natl Acad Sci USA 115(44):11327–11332, 2018. https://doi.org/10.1073/pnas.1806304115) demonstrated that increasing the number of cell layers and thickness of putative aleurone in ta2-1 (thick aleurone 2-1) mutant rice enhances simultaneously the content of multiple micronutrients. However, the increases of aleurone-associated nutrients were not proportional to the increases in the aleurone thickness. In this study, first, cytohistological analyses and transmission electron microscopy demonstrated that the multilayer in ta2-1 exhibited aleurone cell structural features. Second, we detected an increase in insoluble fibre and insoluble bound-phenolic compounds, a shift in aleurone-specific neutral non-starch polysaccharide profile, enhancement of phytate and minerals such as iron, zinc, potassium, magnesium, sulphur, and manganese, enrichment of triacylglycerol and phosphatidylcholine but slight reduction in free fatty acid, and an increase in oleic fatty acid composition. These findings support our hypothesis that the expanded aleurone-like layers in ta2-1 maintained some of the distinctive aleurone features and composition. We provide perspectives to achieve even greater filling of this expanded micronutrient sink to provide a means for multiple micronutrient enhancements in rice.