The specificity of the effect of 2,4-D and NAA of the growth,micromorphology, and occurrence of starch in long-termNicotiana tabacum L. Cell strains

The characteristic micromorphology of the tobaoco cell strains, or its cyclic changes in the course of the subcultivation interval can be affected by auxin composition of the medium,i.e. by the application of either 2,4-D alone, or NAA, or their combination. On omitting one of the auxins, the over-all growth of the cultures is not substantially affeoted; however, the participation of various oell types, as well as the occurrenoe of starch grains are altered. The presenoe of 2,4-D alone results in an inhibition of starch occurrence, NAA alone causes a stimulation. There is no causal dependence of the occurrence or absence of starch grains on the stimulation of elongation (volume) growth, or, on the contrary, on cell division.     

External mass transfer in a biological film reactor

A method for calculating the mass transfer coefficient in a biological film system, under turbulent flow conditions, is presented. It is experimentally found that fluid velocity has a positive effect on the rate of substrate utilization when the system is operated in other than the kinetic regime. A correlation is developed which indicates a dependence of the mass transfer coefficient on the fluid velocity raised to the 0.7 power.     

Alcohol:NAD oxidoreductase in brain of rats from a colony fed dilute ethanol for many generations.

—Alcohol:NAD oxidoreductase (EC 1.1.1.1) was studied in brain cortex, hypothalamus, cerebellum and midbrain of adult and immature rats, and in the whole encephalon of neonatal rats. The rats used in this study were (i) from a colony which has been given 12% (v/v) aqueous ethanol as the only fluid for 54 generations (‘E.F.’ rats); (ii) rats removed from this colony after the forty-eighth generation and thereafter fed water instead of the alcohol solution (‘E.F./H₂O’ rats); and (iii) normal rats. Enzyme activity in the 20,000 g supernatant of tissue homogenates was measured by the method of Raskin and Sokoloff. Activity was found to be highest in neonatal rat brain and to decrease as the age increased. Activity in the hypothalamus of adult E.F. rats was significantly higher than that found in the same region of adult E.F./H₂O rats. Immature rat cerebellum alcohol:NAD oxidoreductase activity was higher both in ‘E.F.’ and ‘E.F./H₂O’ suggesting a possible genetic change be involved in this CNS region. It may be concluded that, with the exception of neonatal rats, ethanol consumption induces an increase in rat CNS alcohol :NAD oxidoreductase activity.     

Social grooming between squirrel monkeys and uakaris in a seminatural environment

Young squirrel monkeys (Saimiri sciureus) were reported grooming an adult female uakari (Cacajao calvus rubicundus) on four different occasions. Furthermore, the uakari was noted grooming two squirrel monkeys in separate instances. These observations took place in a seminatural rainforest (The Monkey Jungle; Goulds, Florida, U.S.A.) where provisions are provided. Some possible hypostheses tendered to account for this unusual behavior included (a) the unaverted interaction of food-seeking and fur-cleaning behavior, and (b) the compatibility of play-curiosity activities by squirrel monkeys with the uakaris' need for social contact.     

Nomenclatural adjustments in some European monocotyledons

New nomenclatural combinations are validated for fifteen taxa belonging to the generaDanthonia, Stipa, Lolium, Phippsia, Elymus, Schoenoplectus andAllium.     

Physiology of pepper fruit and the metabolism of antioxidants: chloroplasts,mitochondria and peroxisomes

Background and Aims Pepper (Capsicum annuum) contains high levels of antioxidants, such as vitamins A and C and flavonoids. However, information on the role of these beneficial compounds in the physiology of pepper fruit remains scarce. Recent studies have shown that antioxidants in ripe pepper fruit play a key role in responses to temperature changes, and the redox state at the time of harvest affects the nutritional value for human consumption. In this paper, the role of antioxidant metabolism of pepper fruit during ripening and in the response to low temperature is addressed, paying particular attention to ascorbate, NADPH and the superoxide dismutase enzymatic system. The participation of chloroplasts, mitochondria and peroxisomes in the ripening process is also investigated.Scope and Results Important changes occur at a subcellular level during ripening of pepper fruit. Chloroplasts turn into chromoplasts, with drastic conversion of their metabolism, and the role of the ascorbate–glutathione cycle is essential. In mitochondria from red fruits, higher ascorbate peroxidase (APX) and Mn-SOD activities are involved in avoiding the accumulation of reactive oxygen species in these organelles during ripening. Peroxisomes, whose antioxidant capacity at fruit ripening is substantially affected, display an atypical metabolic pattern during this physiological stage. In spite of these differences observed in the antioxidative metabolism of mitochondria and peroxisomes, proteomic analysis of these organelles, carried out by 2-D electrophoresis and MALDI-TOF/TOF and provided here for the first time, reveals no changes between the antioxidant metabolism from immature (green) and ripe (red) fruits.Conclusions Taken together, the results show that investigation of molecular and enzymatic antioxidants from cell compartments, especially chloroplasts, mitochondria and peroxisomes, is a useful tool to study the physiology of pepper fruit, particularly in the context of expanding their shelf-life after harvest and in maintaining their nutritional value.     

Porcine reproductive and respiratory syndrome (PRRS) virus in wild boar and Iberian pigs in south-central Spain

Porcine reproductive and respiratory syndrome (PRRS) is a swine infectious disease causing major economic problems on the intensive pig industry. This virus has been reported worldwide in domestic pigs and there is evidence of PRRS virus (PRRSV) infection in wild boar (Sus scrofa). Nonetheless, the epidemiological role of wild boar and extensively kept domestic pigs remains unclear. The aim of this study was to determine the occurrence of PRRS in wild boar and Iberian pigs in the dehesa ecosystem of the Castile-La Mancha region of Spain, which boasts one of the most important free-roaming porcine livestock and hunting industries in the country. Using geo-spatial analysis of literature data, we first explored the relationship between domestic pig density and PRRS occurrence in wild boar in Europe. Results revealed that PRRS occurrence in wild boar may be influenced, albeit not significantly, by domestic pig density. Next, we analyzed sera from 294 wild boar and 80 Iberian pigs by indirect enzyme-linked immunosorbent assay for PRRSV antibodies. The sera and 27 wild boar tissue samples were analyzed by two real-time RT-PCR assays, targeting the most conserved genes of the PRRSV genome, ORF1 and ORF7. Seven wild boar (2.4 %) and one Iberian pig (1.3 %) were seropositive, while none of the animals tested positive for PRRSV by RT-PCR. Our results confirm the limited spread of PRRSV in free-roaming Iberian pigs and wild boar living in mutual contact. Further studies would be necessary to address whether this low seroprevalence found in these animals reflects transmission from intensively kept pigs or the independent circulation of specific strains in free-roaming pigs.     

Advanced glycation end-products disrupt human endothelial cells redox homeostasis: new insights into reactive oxygen species production

Advanced glycation end-products (AGEs) trigger multiple metabolic disorders in the vessel wall that may in turn lead to endothelial dysfunction. The molecular mechanisms by which AGEs generate these effects are not completely understood. Oxidative stress plays a key role in the development of deleterious effects that occur in endothelium during diabetes. Our main objectives were to further understand how AGEs contribute to reactive oxygen species (ROS) overproduction in endothelial cells and to evaluate the protective effect of an antioxidant plant extract. The human endothelial cell line EA.hy926 was treated with native or modified bovine serum albumin (respectively BSA and BSA-AGEs). To monitor free radicals formation, we used H₂DCF-DA, dihydroethidium (DHE), DAF-FM-DA and MitoSOX Red dyes. To investigate potential sources of ROS, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and mitochondrial inhibitors were used. The regulation of different types of ROS by the polyphenol-rich extract from the medicinal plant Doratoxylon apetalum was also studied for a therapeutic perspective. BSA-AGEs exhibited not only less antioxidant properties than BSA, but also pro-oxidant effects. The degree of albumin glycoxidation directly influenced oxidative stress through a possible communication between NADPH oxidase and mitochondria. D. apetalum significantly decreased intracellular hydrogen peroxide and superoxide anions mainly detected by H₂DCF-DA and DHE respectively. Our results suggest that BSA-AGEs promote a marked oxidative stress mediated at least by NADPH oxidase and mitochondria. D. apetalum plant extract appeared to be an effective antioxidant compound to protect endothelial cells.