Habitat requirements, short-term population dynamics and coexistence of native and invasive Impatiens species: a field study

The genus Impatiens (Balsaminaceae) includes three widespread species in the Czech Republic, central Europe: the native I. noli-tangere, and two invasive species, I. parviflora and I. glandulifera, differing in the dynamics of invasion. They all occur in similar habitats and share basic life-history characteristics, which make them a suitable model for studying species traits associated with invasiveness. In this study we investigated differences in habitat requirements of these Impatiens species, their coexistence and short-term population dynamics in the field. We established 84 1 × 1 m permanent plots in five localities where all three species co-occurred. In each plot vascular plant species were determined, their cover estimated and all individuals of Impatiens species counted. Site characteristics including tree canopy cover, soil moisture, nitrogen and carbon content, and slope were measured directly. Nutrients, light, humidity and soil reaction were estimated using Ellenberg indicator values. The presence of I. noli-tangere was strongly correlated with high soil moisture, that of I. parviflora with high tree canopy cover and low soil moisture. Impatiens glandulifera exhibited a unimodal response to tree canopy cover, avoiding both very shaded and fully open sites. The current-year abundances of all species were negatively related to those of congeneric species. These results suggest that the coexistence of Impatiens species in the same habitat is due to microsite differentiation. Further spread of I. glandulifera to new habitats, and reduction of the native I. noli-tangere niche, can be expected in areas where the latter species co-occurs with competitively strong invasive congeners.     

Gold(I)-Triphenylphosphine Complexes with Hypoxanthine-Derived Ligands: In Vitro Evaluations of Anticancer and Anti-Inflammatory Activities

A series of gold(I) complexes involving triphenylphosphine (PPh₃) and one N-donor ligand derived from deprotonated mono- or disubstituted hypoxanthine (HL_n) of the general composition [Au(L_n)(PPh₃)] (1–9) is reported. The complexes were thoroughly characterized, including multinuclear high resolution NMR spectroscopy as well as single crystal X-ray analysis (for complexes 1 and 3). The complexes were screened for their in vitro cytotoxicity against human cancer cell lines MCF7 (breast carcinoma), HOS (osteosarcoma) and THP-1 (monocytic leukaemia), which identified the complexes 4–6 as the most promising representatives, who antiproliferative activity was further tested against A549 (lung adenocarcinoma), G-361 (melanoma), HeLa (cervical cancer), A2780 (ovarian carcinoma), A2780R (ovarian carcinoma resistant to cisplatin), 22Rv1 (prostate cancer) cell lines. Complexes 4–6 showed a significantly higher in vitro anticancer effect against the employed cancer cells, except for G-361, as compared with the commercially used anticancer drug cisplatin, with IC₅₀ ≈ 1–30 µM. Anti-inflammatory activity was evaluated in vitro by the assessment of the ability of the complexes to modulate secretion of the pro-inflammatory cytokines, i.e. tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), in the lipopolysaccharide-activated macrophage-like THP-1 cell model. The results of this study identified the complexes as auspicious anti-inflammatory agents with similar or better activity as compared with the clinically applied gold-based antiarthritic drug Auranofin. In an effort to explore the possible mechanisms responsible for the biological effect, the products of interactions of selected complexes with sulfur-containing biomolecules (L-cysteine and reduced glutathione) were studied by means of the mass-spectrometry study.     

Thiosulfate production from cystine by the keratinolytic prokaryote Streptomyces fradiae

In cultures of Streptomyces fradiae on wool as the only source of nutrition inorganic thiosulfate (in amounts up to 0.5 mg of Na₂S₂O₃·5 H₂O/ml) was formed as the final product of metabolization of sulfur from cystine of keratin proteins. The presence of thiosulfate was proved by qualitative tests and thin-layer chromatography and estimated quantitatively by spectrophotometry, titrimetry, and capillary isotachophoresis. Metabolization of organic sulfur to thiosulfate excreted into the medium is a process not yet described in microorganisms.     

Selective enzymic esterification of free fatty acids with n-butanol under microwave irradiation and under classical heating

Selective enzymic esterification of free fatty acids, obtained from blackcurrant oil by chemical saponification, with n-butanol using four immobilized lipases under microwave irradiation and under classical heating was studied. A positive effect of microwave irradiation on chemical yields of the products of the enzymic reactions and specificity of lipases were observed in comparison with a controlled heating in an incubator equipped with shaking (classical heating) applied during the identical enzyme-mediated processes. The maximum quantity of -linolenic acid (30%) was obtained with Lipozyme used as biocatalyst of the reaction under microwave irradiation. The maximum quantity of butyl -linolenate (20%) was obtained by a Pseudomonas cepacia lipase catalyzed esterification under classical heating.     

Coordination conjugates of therapeutic proteins with drug carriers: a new approach for versatile advanced drug delivery

We present here a general system for the coordination attachment of therapeutic proteins to a drug delivery system and its application in combined therapy. Proof of concept is demonstrated by the synthesis and testing of the targeted drug delivery system for cytostatics, which is based on a combination of the drug carrier Zn-porphyrin-cyclodextrin conjugates and their supramolecular coordination complexes with immunoglobulins. This system can be as readily used for a variety of therapeutic and targeting proteins including PAs, MAs, lectins, and HSA. Moreover, it allows combined photodynamic therapy, cell targeted chemotherapy and immunotherapy. When tested in a mouse model with human C32 carcinoma, the therapeutic superiority of the coordination assembly nanosystem was shown in comparison with the efficacy of building blocks used for the construction of the system.     

Expression of HLA-DR antigens on tumour cells does not contribute to skin reactivity to autologous cholesteryl hemisuccinate (CHS)-treated tumour cells in patients with metastatic melanoma

Summary Skin tests with autologous cholesteryl hemisuccinate (CHS)-treated and untreated cells were performed in ten metastatic melanoma patients. In the majority of cases evident reaction was noted with CHS-treated cells (9/10) while the reaction with untreated cells was mostly negative (7/10). Tumour cell suspensions used for skin tests were characterized for reactivity with monoclonal antibody TAL 1B5 detecting the HLA-DR alpha chain. There were no differences between CHS-treated and untreated cells with respect to HLA-DR expression and no correlation was found between grade of skin reaction to CHS-treated cells and the proportion of HLA-DR positive cells in the injected cell sample.     

Production and cleavage of a fusion protein of porcine trypsinogen and enhanced green fluorescent protein (EGFP) in <Emphasis Type="Italic">Pichia pastoris</Emphasis>

Pharmaceutical grade trypsin is in ever-increasing demand for medical and industrial applications. Improving the efficiency of existing biotechnological manufacturing processes is therefore paramount. When produced biotechnologically, trypsinogen—the inactive precursor of trypsin—is advantageous, since active trypsin would impair cell viability. To study factors affecting cell physiology and the production of trypsinogen in fed-batch cultures, we built a fusion protein of porcine trypsinogen and enhanced green fluorescent protein (EGFP) in Pichia pastoris. The experiments were performed with two different pH values (5.0 and 5.9) and two constant specific growth rates (0.02 and 0.04 1/h), maintained using exponential addition of methanol. All the productivity data presented rely on an active determination of trypsin obtained by proteolysis of the trypsinogen produced. The pH of the medium did not affect cell growth, but significantly influenced specific production of trypsinogen: A 1.7-fold higher concentration of trypsinogen was achieved at pH 5.9 (64 mg/L at 0.02 1/h) compared to pH 5.0. EGFP was primarily used to facilitate detection of intracellular protein over the biosynthetic time course. Using flow cytometry with fluorescence detection, cell disruption was avoided, and protein extraction and purification prior to analysis were unnecessary. However, Western blot and SDS-PAGE showed that cleavage of EGFP-trypsinogen fusion protein occurred, probably caused by Pichia-endogenous proteases. The fluorescence analysis did therefore not accurately represent the actual trypsinogen concentration. However, we gained new experimentally-relevant insights, which can be used to avoid misinterpretation of tracking and quantifying as well as online-monitoring of proteins with the frequently used fluorescent tags.