Carbosilane dendrimers are a non-viral delivery system for antisense oligonucleotides: characterization of dendriplexes.

The success of gene therapy depends on the development of suitable carriers, and because of their architecture dendrimers are promising tools for gene delivery. This research concerns the use of second generation carbosilane dendrimers as carriers for anti-HIV oligodeoxynucleotides (ODNs). The aim was to characterize complexes formed by positively charged dendrimers and negatively charged oligonucleotides using a fluorescence method, laser Doppler electrophoresis, dynamic light scattering (DLS), atomic force microscopy (AFM), transmission electron microscopy (TEM) and molecular modeling.

Characterization of complexes formed by polypropylene imine dendrimers and anti-HIV oligonucleotides.

Current anti-HIV therapies are capable of controlling viral infection but do not represent a definitive cure. They rely on the administration of antiretroviral nucleoside analogues, either alone or in combination with vectors. Dendrimers are branched, synthetic polymers with layered architectures, promising non-viral vectors in gene therapy.

The effects of the anthocyanin-rich extract from red cabbage leaves on Allium cepa L. root tip cell ultrastructure.

The effect of exogenously applied 250 μM anthocyanin-rich (ATH-rich) extract from red cabbage leaves on the ultrastructure of Allium cepa root meristematic cells was investigated. The tested extract slightly affected mitochondria, endoplasmic reticulum (ER), Golgi apparatus and vacuoles. In the presence of ATH, 62% of mitochondria converted to condensed type.

Use of polyamidoamine dendrimers to engineer BDNF-producing human mesenchymal stem cells.

We report the use of polyamidoamine (PAMAM-NH(2)) dendrimers along with other non-viral vehicles for the in vitro transfection of human bone marrow mesenchymal stem cells (hMSCs) and for engineering MSCs to secrete brain-derived neurotrophic factor (BDNF). Different generations of cationic polyamidoamine dendrimers (generations 3-6) were tested on HEK 293T cells. hMSCs were then transfected with PAMAM-NH(2) G4 dendrimers and Lipofectamine 2000, which elicited the expression of GFP reporter in around 6 and 20% of the cells, respectively.

Effects of anthocyanin-rich extract from red cabbage leaves on meristematic cells of Allium cepa L. roots treated with heavy metals.

The incubation of Allium cepa L. roots in Pb(NO3)2, Cd(NO3)(2)x4H2O or Cr(NO3)(3)x9H2O solution at the concentration of 100 microM lowered the mitotic index (MI) value in meristem by 58%, 39%, 48%, respectively. The proportion of mitotic phases (mainly prophases and telophases) in MI value was also changed.

Effects of N,N-bis(3-aminopropyl)dodecylamine on antioxidant enzyme activities, mitochondrial morphology and metabolism in Aspergillus niger.

The activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSP) as well as of succinate dehydrogenase (SDG), NADH dehydrogenase (NDG) and fumarate hydratase (FHT) were examined in relation to mitochondrial ultrastructure changes in Aspergillus niger exposed to N,N-bis(3-aminopropyl)dodecylamine (Apd) that was shown to exhibit fungicidal activity. There was a progressive increase in SOD, CAT and GSP activities 1 and 4 h after 0.05 and 0.

Localization of selenium deposits in meristematic cells of Allium sativum L. roots treated with selenium salts.

Ultrastructural analysis of garlic roots treated for 24 h with sodium selenate or sodium selenite at the concentrations 80, 160, 320 microM revealed the presence of selenium deposits in meristematic cells. They appeared as small and large granules or aggregates of electron-dense material. Many small granules were localised in plastids but some in mitochondria, endoplasmic reticulum as well as in Golgi apparatus, nucleus and cytoplasm.

White yellow virescent pattern in winter rye: inheritance, plant growth, and ultrastructure of plastids.

Inbred lines from different varieties of cultivated plants characterized by a white yellow irregular pattern on the leaves obtained after selection in the inbred generation (S3) of winter rye (Secale cereale L.) were the object of the present studies. The feature of a white yellow irregular pattern in all lines was monomeric and recessive.

Effect of Spumol K on the ultrastructure of Aspergillus niger strains sensitive or resistant to toxic compounds of beet molasses.

Aspergillus niger strains sensitive and resistant to toxic compounds of beet molasses grown in the presence of Spumol K were the object of the present studies. The antifoamer used diminished the number of mitochondria in both groups of strains and caused the reduction of their cristae in the sensitive ones. The disturbances in the ultrastructure of nucleus and mitochondria appeared mostly in sensitive strains.

Effect of calcium on RNA content in meristematic cells of pea (Pisum sativum L.) roots treated with toxic metals.

RNA content in nucleolus, nucleus and cytoplasm in meristematic cells of pea roots growing for 144 h in the presence of calcium and/or toxic metals (Cd2+, Cr3+, Pb2+) was examined using cytophotometric procedures, after staining with gallocyanine. The effect of treatment with tested metals was twofold: on the one hand, it considerably reduced RNA content in the nucleolus, on the other it enhanced RNA level in the nucleus and most visibly in the cytoplasm, resulting in the increase in total amount of RNA in cells of pea roots. The presence of calcium in metal solutions in different ways affected RNA content in meristematic cells of pea.

Effect of Spumol K on cell wall of Aspergillus niger strains characterized by different tolerance to toxic compounds of beet molasses.

Cell walls in the mycelium of Aspergillus niger strains sensitive or resistant to toxic molasses compounds growing in the presence of Spumol K were the object of the present studies. Although the inhibitory effect of Spumol K on the cell wall was noticed in studied mycelia the sensitive strains reacted more strongly. In sensitive strains in Spumol K presence lower content of cell wall was accomplished by higher amount of proteins but lower of lipids as well as structural polymers i.

Cell wall analysis in Aspergillus niger strains characterized by different tolerance to toxic compounds of beet molasses.

Aspergillus niger strains, sensitive or resistant to toxic compounds of beet molasses, were the object of the present studies. Between the studied strains differences existed in the cell wall dry mass and wall components content, chitin synthesis, activity of enzymes involved in cell wall synthesis, and in the wall ultrastructure. Higher content of proteins and lipids but lower of glucan and chitin; less or lack of fibrillar components, thinner cell wall as well as lower level of glucanase and chitinase, diminished [3H] glucosamine incorporation into cytoplasm and cell wall characterized the sensitive strains of A.

Changes in dehydrogenases activity, number and ultrastructure of mitochondria in Aspergillus niger mycelium growing on molasses media.

Effects of toxic molasses compounds and of the antifoamer (Spumol BJ) on dehydrogenases activity, on the number and ultrastructure of mitochondria in A. niger mycelium of two strains characterized by different tolerance to toxic agents, were observed. In spite of significantly higher dehydrogenases activity in the intolerant strain (R-16) mycelia developing both on productive molasses in the presence of the defoamer and on non-productive molasses are characterized by marked reduction in the activity of these enzymes.

The effect of calcium on DNA synthesis in pea (Pisus sativus L.) roots after treatment with heavy metals.

Cortex cells of the meristematic (1 mm) and differentiated (7 mm) zones of Pisus sativus L. roots after 144 h culture in distilled water (control), Ca2+ (10(-3) M) and/or Cd2+, Cr3+, Pb2+ solutions (10(-4) M, each) were subject of the present studies. Reductions in the number of nuclei incorporating 3H thymidine was observed in meristem in the presence of Cd2+ and in differentiated zone in Pb2+ treated roots.

Changes in development and ultrastructure of Aspergillus niger mycelium, strain with increased tolerance to toxic substances from beet molasses.

Effects of a defoamer and toxic molasses compounds on development and ultrastructure of A. niger mycelium, strain Z, characterized by high tolerance to these substances and producing citric acid in surface fermentation on proper molasses media with 70% yield were presented. Spumol BJ in concentration of 5 microliters/100 cm3 as well as toxic molasses compounds stimulated the process of swelling and germinating of conidia.

Changes in development and ultrastructure of Aspergillus niger mycelium in the presence of toxic substances from molasses in citric acid fermentation medium.

Effects of a surface-active agent (Spumol BJ) and toxic molasses compounds on development and ultrastructure of Aspergillus niger strain R-16 mycelium producing citric acid in surface fermentation on molasses medium with 80% yield are presented. Microscopic observations showed that Spumol BJ in concentration of 5 microliters/100 cm3 as well as toxic molasses compounds stimulated the process of swelling and germinating of conidia. Giant conidia unable to germinate, appeared along with typical ones.

Calcium influence on the dry mass content and surface area of nuclei and cytoplasm during differentiation of cortex cells in pea (Pisum sativum L.) roots treated with heavy metals.

The effect of Ca addition to Cd, Cr and Pb solutions on the nuclear and cytoplasmic dry mass content and its concentration as well as on these organelles dimensions were studied in cortex cells of pea roots. Ca alone, at the concentration 10(-8)M brought about a decrease (in comparison to water) in the dry mass content of nuclei and its concentration, but the increment was almost twice in the dry mass content of cytoplasm; however, it has no significant effect on its concentration. Ca ions addition does not change the surface area of nuclei except the 1st and 5th mm segments but causes a doubling of the area occupied by cytoplasm.

Heavy metal action on the dry mass content and surface area of nuclei and cytoplasm during differentiation of cortex cells in pea (Pisum sativum L.) roots.

The cortex cells of pea roots (Pisum sativum L.) grown for 144 h in the presence of cadmium, chromium and lead at the concentration 10(-4) M were the object of the present studies. Applied metals reduced dry mass content and concentration of nuclei in meristematic and differentiation zones.

Effect of low temperature on the nucleolus of larkspur (Delphinium Ajacis L.) meiocytes.

In comparison with stage specific modifications of nucleolus in the early stages of meiotic prophase in Delphinium Ajacis meiocytes, the effect of low temperature is described. On the contrary to control leptotene nucleolus, exhibiting intermingled fibrillar and granular components, cold induced a disappearance of fibrillar material from these organelles. Disappearance of fibrillar material was accompanied by marked diminishment of 3H-uridine incorporation.