Sozioökonomischer Vergleich der niedersächsischen und schleswig-holsteinischen Fischereiwirtschaft

In der "Ökosystemforschung niedersächsisches Wattenmeer" wird in einem Teilprojekt seit Januar 1993 "Die sozioökonomische Entwicklung der Fischerei im niedersächsischen Wattenmeer und ihr Bezug zu Naturschutzforderungen" untersucht. Im Rahmen dieses Projektes wurde am 19.05.1994 auf dem 4. Wissenschaftlichen Symposium der Ökosystemforschung Wattenmeer in Husum ein Vortrag gehalten, dessen Kurzfassung im folgenden wiedergegeben wird

Enhanced chloroplastic generation of H_{2}O_{2} in stress-resistant Thellungiella salsuginea in comparison to Arabidopsis thaliana

In order to find some basis of salinity resistance in the chloroplastic metabolism, a halophytic Thellungiella salsuginea was compared with glycophytic Arabidopsis thaliana. In control T.s. plants the increased ratios of chlorophyll a/b and of fluorescence emission at 77 K (F_{730}/F_{685}) were documented, in comparison to A.t.. This was accompanied by a higher YII and lower NPQ (non-photochemical quenching) values, and by a more active PSI (photosystem I). Another prominent feature of the photosynthetic electron transport (PET) in T.s. was the intensive production of H_2O_2 from PQ (plastoquinone) pool. Salinity treatment (0.15 and 0.30 M NaCl for A.t. and T.s., respectively) led to a decrease in ratios of chl a/b and F_{730}/F_{685}. In A.t., a salinity-driven enhancement of YII and NPQ was found, in association with the stimulation of H_2O_2 production from PQ pool. In contrast, in salinity-treated T.s., these variables were similar as in controls. The intensive H_2O_2 generation was accompanied by a high activity of PTOX (plastid terminal oxidase), whilst inhibition of this enzyme led to an increased H_2O_2 formation. It is hypothesized, that the intensive H_2O_2 generation from PQ pool might be an important element of stress preparedness in Thellungiella plants. In control T.s. plants, a higher activation state of carboxylase ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) was also documented in concert with the attachment of Rubisco activase (RCA) to the thylakoid membranes. It is supposed, that a closer contact of RCA with PSI in T.s. enables a more efficient Rubisco activation than in A.t

Evaluation of the In vitro cytotoxic activity of caffeic acid derivatives and liposomal formulation against pancreatic cancer cell lines

Pancreatic cancer belongs to the most aggressive group of cancers, with very poor prognosis. Therefore, there is an important need to find more potent drugs that could deliver an improved therapeutic approach. In the current study we searched for selective and effective caffeic acid derivatives. For this purpose, we analyzed twelve compounds and evaluated their in vitro cytotoxic activity against two human pancreatic cancer cell lines, along with a control, normal fibroblast cell line, by the classic MTT assay. Six out of twelve tested caffeic acid derivatives showed a desirable effect. To improve the therapeutic efficacy of such active compounds, we developed a formulation where caffeic acid derivative (7) was encapsulated into liposomes composed of soybean phosphatidylcholine and DSPE-PEG2000. Subsequently, we analyzed the properties of this formulation in terms of basic physical parameters (such as size, zeta potential, stability at 4 °C and morphology), hemolytic and cytotoxic activity and cellular uptake. Overall, the liposomal formulation was found to be stable, non-hemolytic and had activity against pancreatic cancer cells (IC50 19.44 µM and 24.3 µM, towards AsPC1 and BxPC3 cells, respectively) with less toxicity against normal fibroblasts. This could represent a promising alternative to currently available treatment options

Synthesis and antiplasmodial activity of novel bioinspired imidazolidinedione derivatives

Malaria is an enormous threat to public health, due to the emergence of Plasmodium falciparum resistance to widely-used antimalarials, such as chloroquine (CQ). Current antimalarial drugs are aromatic heterocyclic derivatives, most often containing a basic component with an added alkyl chain in their chemical structure. While these drugs are effective, they have many side effects. This paper presents the synthesis and preliminary physicochemical characterisation of novel bioinspired imidazolidinedione derivatives, where the imidazolidinedione core was linked via the alkylene chain and the basic piperazine component to the bicyclic system. These compounds were tested against the asexual stages of two strains of P. falciparum—the chloroquine-sensitive (D10) and chloroquine-resistant (W2) strains. In parallel, in vitro cytotoxicity was investigated on a human keratinocyte cell line, as well as their hemolytic activity. The results demonstrated that the antiplasmodial effects were stronger against the W2 strain (IC50 between 2424.15–5648.07 ng/mL (4.98–11.95 µM)), compared to the D10 strain (6202.00–9659.70 ng/mL (12.75–19.85 µM)). These molecules were also non-hemolytic to human erythrocytes at a concentration active towards the parasite, but with low toxicity to mammalian cell line. The synthetized derivatives, possessing enhanced antimalarial activity against the CQ-resistant strain of P. falciparum, appear to be interesting antimalarial drug candidates

Azacarbazole n-3 and n-6 polyunsaturated fatty acids ethyl esters nanoemulsion with enhanced efficacy against Plasmodium falciparum

Alternative therapies are necessary for the treatment of malaria due to emerging drug resistance. However, many promising antimalarial compounds have poor water solubility and suffer from the lack of suitable delivery systems, which seriously limits their activity. To address this problem, we synthesized a series of azacarbazoles that were evaluated for antimalarial activity against D10 (chloroquine-sensitive) and W2 (chloroquine-resistant) strains of P. falciparum. The most active compound, 9H-3-azacarbazole (3), was encapsulated in a novel o/w nanoemulsion consisting of ethyl esters of polyunsaturated fatty acids n-3 and n-6 obtained from flax oil as the oil phase, Smix (Tween 80 and Transcutol HP) and water. This formulation was further analyzed using transmission electron microscopy, dynamic light scattering and in vitro and in vivo studies. It was shown that droplets of the 3-loaded nanosystem were spherical, with satisfactory stability, without cytotoxicity towards fibroblasts and intestinal cell lines at concentrations corresponding to twice the IC50 for P. falciparum. Moreover, the nanoemulsion with this type of oil phase was internalized by Caco-2 cells. Additionally, pharmacokinetics demonstrated rapid absorption of compound 3 (tmax = 5.0 min) after intragastric administration of 3-encapsulated nanoemulsion at a dose of 0.02 mg/kg in mice, with penetration of compound 3 to deep compartments. The 3-encapsulated nanoemulsion was found to be 2.8 and 4.2 times more effective in inhibiting the D10 and W2 strains of the parasite, respectively, compared to non-encapsulated 3. Our findings support a role for novel o/w nanoemulsions as delivery vehicles for antimalarial drugs

Chicken Anti-Campylobacter Vaccine – Comparison of Various Carriers and Routes of Immunization

Campylobacter spp, especially the species Campylobacter jejuni, are important human enteropathogens responsible for millions of cases of gastro-intestinal disease worldwide every year. C. jejuni is a zoonotic pathogen, and poultry meat that has been contaminated by microorganisms is recognized as a key source of human infections. Although numerous strategies have been developed and experimentally checked to generate chicken vaccines, the results have so far had limited success. In this study, we explored the potential use of non-live carriers of Campylobacter antigen to combat Campylobacter in poultry. First, we assessed the effectiveness of immunization with orally or subcutaneously delivered GEM (Gram-positive Enhancer Matrix) particles carrying two Campylobacter antigens: CjaA and CjaD. These two immunization routes using GEMs as the vector did not protect against Campylobacter colonization. Thus, we next assessed the efficacy of in ovo immunization using various delivery systems: GEM particles and liposomes. The hybrid protein CjaAD, which is CjaA presenting CjaD epitopes on its surface, was employed as a model antigen. We found that CjaAD administered in ovo at embryonic development day 18 by both delivery systems resulted in significant levels of protection after challenge with a heterologous Campylobacter jejuni strain. In practice, in ovo chicken vaccination is used by the poultry industry to protect birds against several viral diseases. Our work showed that this means of delivery is also efficacious with respect to commensal bacteria such as Campylobacter. In this study, we evaluated the protection after one dose of vaccine given in ovo. We speculate that the level of protection may be increased by a post-hatch booster of orally delivered antigens