Novel synthesis of 2-fluoroestradiol from 19-nortestosterone: biomimetic oxidative defluorination to 2-hydroxyestradiol

A new, short synthetic route to 2-fluoroestradiol from 19-nortestosterone is described which gives the target compound in an approximately 25% overall yield. Oxidative defluorination of 2-fluoroestradiol to 2-hydroxyestradiol via treatment with Frémy's salt/iodide ion is reported. This process is regarded as biomimetic with respect to cytochrome P-450-dependent oxidative defluorination.     

Effects of the pathogenic Vibrio tapetis on defence factors of susceptible and non-susceptible bivalve species: I. Haemocyte changes following in vitro challenge

In microbial infections, the interaction between microorganisms and phagocytic cells is a crucial determinant in the outcome of the disease process. We used flow cytometry to study the in vitro interactions between Vibrio tapetis, the bacterium responsible for Brown Ring Disease (BRD) in the Manila clam Ruditapes philippinarum, and haemocytes from three bivalve species: the Manila clam (susceptible to BRD), the hard clam Mercenaria mercenaria and the eastern oyster Crassostrea virginica (both non-susceptible to BRD). Results demonstrated that V. tapetis cells and extracellular products elicit major changes in the haemocytes of R. philippinarum, including decreased viability and phagocytic activity, and altered size and internal structure. V. tapetis was able to kill haemocytes from M. mercenaria and C. virginica but to a far lesser extent than those of R. philippinarum. These results suggest that disease resistance is not solely dependent on a host activity against the pathogen, but is also a function and magnitude of the injury to the host cell by a given pathogen.     

Effects of antisense oligodeoxynucleotides targeting CCR3 on the airway response to antigen in rats

Asthma is characterized by airway hyperresponsiveness (AHR) and inflammation, consisting predominantly of eosinophils within the airway lumen and walls. Eosinophil recruitment to the airways is mediated mainly by eotaxin and other chemokines that bind to the CC-chemokine receptor-3 (CCR3), which is highly expressed on eosinophils. This study assessed whether topical inhibition of CCR3 mRNA expression by phosphorothioate antisense oligodeoxynucleotides (AS-ODNs) modifies pulmonary eosinophilia and AHR in an antigen-induced allergic asthma model in Brown Norway (BN) rats. Results show that specific inhibition of CCR3 expression in the lungs by an AS-ODN (AS4) reduced total eosinophil infiltration and the percentage of eosinophils into the airways of ovalbumin challenged rats. Moreover, reduction in CCR3 mRNA levels was correlated with a decrease in CCR3 protein in lung tissue. In addition, AS4 treatment had no effect on circulating eosinophils or on eosinophils in the bone marrow. Finally, AHR was significantly decreased in AS4-treated rats when compared with rats treated with a mismatch AS-ODN. In conclusion, inhibition of the expression of CCR3 decreased pulmonary eosinophilia and reduced AHR after antigen challenge in rats. Topical inhibition of CCR3 expression, using an AS-ODN, could represent a novel approach for the treatment of asthma.     

Comparative growth and survival of juvenile hard clams,Mercenaria mercenaria,fed commercially available diets

Hobbyist and researchers often use commercially available phytoplankton concentrates to maintain filter feeding organisms held in their ornamental or experimental tanks. This study investigated the nutritional value of 10 products available commercially for juvenile hard clams, Mercenaria mercenaria. Growth and mortality rates in clams fed these products were compared with those found in clams fed fresh cultures of the microalgae Isochrysis galbana, which is considered an industry standard for supporting growth of juvenile bivalves. Our results show a clear difference in feed nutritional value between non‐living and living commercial diets, and among commercial diets advertised as containing live algae. Overall, results showed that juvenile hard clams fed fresh cultures of I. galbana displayed the best growth and lowest mortality rates, followed by those fed the commercial diet DT's Live Marine Phytoplankton. Growth and mortality rates in unfed controls were similar to those found in clams fed commercial non‐living algae mixes or diets advertised as containing live algae (Phyto‐Feast Live product). Results also showed that the nutritional value of fresh algae (I. galbana) cultures is lost rapidly when cultures are maintained at 4°C, suggesting that algae present in some commercial diets may lose their nutritional value during processing or refrigerated storage. The commercial blend, DT's Live Marine Phytoplankton, seems to represent a good substitute to lab grown algae for clams held in ornamental or experimental aquariums. Zoo Biol 0:1–13, 2006. © 2006 Wiley‐Liss, Inc.     

Mitochondrial apoptosis is dispensable for NLRP3 inflammasome activation but non‐apoptotic caspase‐8 is required for inflammasome priming

A current paradigm proposes that mitochondrial damage is a critical determinant of NLRP3 inflammasome activation. Here, we genetically assess whether mitochondrial signalling represents a unified mechanism to explain how NLRP3 is activated by divergent stimuli. Neither co‐deletion of the essential executioners of mitochondrial apoptosis BAK and BAX, nor removal of the mitochondrial permeability transition pore component cyclophilin D, nor loss of the mitophagy regulator Parkin, nor deficiency in MAVS affects NLRP3 inflammasome function. In contrast, caspase‐8, a caspase essential for death‐receptor‐mediated apoptosis, is required for efficient Toll‐like‐receptor‐induced inflammasome priming and cytokine production. Collectively, these results demonstrate that mitochondrial apoptosis is not required for NLRP3 activation, and highlight an important non‐apoptotic role for caspase‐8 in regulating inflammasome activation and pro‐inflammatory cytokine levels.     

Effect of certain cultural practices on susceptibility of potato tubers to soft rot disease caused by Erwinia carotovora pv. carotovora

Erwinia soft rot causes destructive and serious damage to many vegetable crops including potato in the field, transit and storage periods. The effect of certain cultural practices on the susceptibility of potato tubers to soft rot bacteria was studied and the results of this work can be summarised in the following: potato tubers harvested on 1 May first exhibited the highest disease incidence compared with those harvested on 15 May or 30 May. Harvesting on 15 June resulted in the lowest disease infection. The application of high levels of nitrogen fertiliser as urea (46.5%), ammonium nitrate (31%) and ammonium sulphate (20.5%) resulted in an increase of the susceptibility of potato tubers to bacterial soft rot disease. In contrast, the addition of phosphorous as superphosphate (15.5%) fertiliser caused the reverse effect. The addition of potassium as potassium sulphate (48%) alone at any of the tested levels showed no effect. The susceptibility of potato tubers to bacterial soft rotting disease was increased by increasing storage periods at 4°C for 1, 2, 3 and 4 months. Spraying copper sulphate exhibited the highest decrease in soft rot incidence disease followed by manganese, zinc and iron. However, spraying of boron increased susceptibility to the disease. Potato tubers obtained from plants sprayed with copper and stored for different periods showed the lowest susceptibility to disease incidence. Tuber sprayed with zinc, iron, manganese and finally boron came next.     

Some kinetic studies on ribonucleosides degradation by extracts of penicillium citrinum

Cell-free extracts of 3–4 days old mats of nitrate-grown Penicillium citrinum catalyze the hydrolytic cleavage of the N-glycosidic bonds of inosine, guanosine and adenosine optimally at pH 4, 0.1 M citrate buffer. The same extracts catalyze the hydrolytic deamination of cytidine at a maximum rate in 0.08 M Tris-acetate buffer pH 6.5, 40°C and 50°C were the most suitable degrees for purine nucleoside hydrolysis and cytidine deamination, respectively. The incubation of the extracts at 60°C, in the absence of cytidine caused a loss in the deaminating activity, while freezing and thawing had no effect on both activities. The deaminating activity seems to be cytidine specific as neither cytosine, adenine, adenosine nor guanosine could be deaminated. Uridine competively inhibited this activity, while ammonia had no effect. The apparent K_m value of this enzyme for cytidine was 1.57×10^?3M and its K_i value for uridine was 7.8×10^?3M. The apparent K_m values of the N-glycosidic bond cleaving enzyme for inosine, guanosine and adenosine were 13.3, 14.2 and 20×10^?3 M, respectively.