A serotonergic system in the brain of the Antarctic fish, Trematomus bernacchii

The immunohistochemical distribution of serotonin-containing nerve fibres and cells has been described in the brain of the Antarctic fish, Trematomus bernacchii. The largest serotonergic system was associated with the diencephalic and rhombencephalic ventricles. In particular, serotonin-positive cells have been found in the lateral recess and neuropile zone of the diencephalic ventricle, where we have identified the serotonergic portion of the paraventricular organ. Numerous serotonin cells were localized in the dorsal nucleus of the raphe, the dorsal tegmental nucleus and the central gray. Two large cell groups, arranged in a pair of well-defined columns and connecting the central gray with the dorsal reticular formation, were immunostained in the region of the trigeminal nuclei. In addition, few positive cells have been found in the preoptic area and the cerebellar valvula, and few serotonergic nerve fibres, probably belonging to the lateral lemniscus, have been identified. The distribution of serotonin elements in the brain of T. bernacchii has been compared with that described in other fish, where it showed some modifications in the immunoreactive pattern. Finally, the lack of a serotonergic system at the level of the reticular superior formation has been reported; however, it was not possible to rule out a phylogenetic or environmental explanation.     

Neuronal Basis of Innate Olfactory Attraction to Ethanol in Drosophila

The decision to move towards a mating partner or a food source is essential for life. The mechanisms underlying these behaviors are not well understood. Here, we investigated the role of octopamine – the invertebrate analogue of noradrenaline – in innate olfactory attraction to ethanol. We confirmed that preference is caused via an olfactory stimulus by dissecting the function of the olfactory co-receptor Orco (formally known as OR83b). Orco function is not required for ethanol recognition per se, however it plays a role in context dependent recognition of ethanol. Odor-evoked ethanol preference requires the function of Tbh (Tyramine β hydroxalyse), the rate-limiting enzyme of octopamine synthesis. In addition, neuronal activity in a subset of octopaminergic neurons is necessary for olfactory ethanol preference. Notably, a specific neuronal activation pattern of tyraminergic/octopaminergic neurons elicit preference and is therefore sufficient to induce preference. In contrast, dopamine dependent increase in locomotor activity is not sufficient for olfactory ethanol preference. Consistent with the role of noradrenaline in mammalian drug induced rewards, we provide evidence that in adult Drosophila the octopaminergic neurotransmitter functions as a reinforcer and that the molecular dissection of the innate attraction to ethanol uncovers the basic properties of a response selection system.     

Plasmid-coded degradation of ethylbenzene and 1-phenylethanol in Pseudomonas fluorescens

Abstract Pseudomonas fluorescens EB carries genes for the catabolism of ethylbenzene and 1-phenylethanol on a plasmid. The size of the plasmid as measured by analysis of agarose electrophoresis gels after restriction endonuclease hydrolysis, was 253–267 kb. By treatment with Mitomycin C, mutants of EB strain were obtained bearing a plasmid which had undergone an extensive deletion of about 80 kb. These mutants have lost the ability to grow on ethylbenzene and 1-phenylethanol as well as to synthesize meta-cleavage enzymes.     

Ethanol Administration in the Rat Decreases Prostacyclin Production by Isolated Brain Microvessels

The effects of short- and long-term ethanol administration to rats on basal levels and formation of prostacyclin (PGI2) measured as 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), and on lipid class content and fatty acid composition of isolated brain microvessels (BMV) were studied. After acute treatment (2 h, at the peak of plasma ethanol concentration) basal 6-keto-PGF1 alpha levels in BMV and release on incubation were reduced to 50% of control values. After chronic administration (15 days), PGI2 release was reduced to about 40% of control values, without changes in basal levels. Total lipid, phospholipid, and cholesterol levels in BMV, measured after prolonged administration of alcohol, were not modified. Also, only minor changes in the fatty acid composition of individual phospholipid classes were detected. The observed reduction of PGI2 synthesis in BMV thus could not be related to changes of the fatty acid precursor pool in the preparation. Precursor release and/or the biosynthetic pathways may be affected by ethanol administration.     

Gas exchange studies in two Portuguese grapevine cultivars

Gas exchange characteristics of leaves of Vitis vinifera L. cvs Tinta Amarela and Periquita, two grapevine cultivars grown in distinct climatic regions of Portugal, were studied under natural and controlled conditions. Daily time courses of gas exchange were measured on both a hot, sunny day and a cooler, partly cloudy day. Responses of net photosynthesis to irradiance and internal partial pressure of CO₂, were also obtained. A strong correlation between net photosynthesis (P_N) and leaf conductance (g_s) was found during the diurnal time courses of gas exchange, as well as a relatively constant internal partial pressure of CO₂ (P_i), even under non-steady-state conditions. On the cloudless day, both P_N and g_s were lower in the afternoon than in the morning, despite similar conditions of leaf temperature, air to leaf water vapor deficit and irradiance. The response curves of net photosynthesis to internal CO₂ showed linearity up to p_i values of 50 Pa, possibly indicating a substantial excess of photosynthetic capacity. When measured at low partial pressures of O₂ (1 kPa), P_N became inhibited at high CO₂ levels. Inhibition of P_N at high CO₂ was absent under normal levels of O₂ (21 kPa). Significant differences in gas exchange characteristics were found between the two cultivars, with T. Amarela having higher rates under similar measurement conditions. In particular, the superior performance of T. Amarela at high temperatures may represent adaptation to the warmer conditions at its place of origin.     

Ultrastructural cytochemical and autoradiographic demonstration of nonspecific esterase(s) in guinea pig basophils

We used ultrastructural autoradiographic and cytochemical methods to localize esterase activities in unstimulated guinea pig basophils and in basophils undergoing degranulation or recovery from degranulation. We used tritium-labeled diisopropylfluorophosphate (DFP) as a probe for serine enzymes and localized this probe by ultrastructural autoradiography to cytoplasmic granules of immature or mature unstimulated basophils, as well as to granules released by degranulating basophils. Ultrastructural cytochemistry using alpha naphthyl acetate (ANA) as substrate localized nonspecific esterase activity to extruded granules, either within the interiors of degranulation sacs or within granules completely separated from degranulating basophils. Extruded granules retained their esterase activity for as long as 24 hr after antigen-induced degranulation. The plasma membranes of unstimulated or degranulating basophils, as well as of basophils recovering from degranulation, displayed prominent cell surface ANA esterase ectoenzyme activity. Lipid bodies, organelles present in the cytoplasm of both control and recovering basophils, were also alpha naphthyl acetate esterase (ANAE)-positive. Thus, cytochemical and autoradiographic techniques localized esterase and/or [3H]-DFP-binding activities to cytoplasmic granules, lipid bodies, and cell surface of basophils, and these enzyme activities persisted during both degranulation and recovery from degranulation.     

Stimulation of arachidonic acid metabolism by CCl4 in isolated rat hepatocytes

Arachidonic acid metabolism was evaluated in isolated rat hepatocytes after CCl4 exposure. CCl4 induced dose-dependently the synthesis and release of prostacyclin (PGI2) and thromboxane (TXB2). Treatment with prostaglandin E2 (PGE2) 30 min after exposure to CCl4, significantly reduced the cell damage as well as the release of TXB2 from the cells.     

Transport of l(-)malic acid and other dicarboxylic acids in the yeast Candida sphaerica

Summary dl-Malic acid grown cells of Candida sphaerica (anamorph of Kluyveromyces marxianus) formed a saturable transport system that mediated accumulative transport of l(-)malic acid with the following kinetic parameters at pH 5.0: V _max, 0.44 nmol l(-)malate·s^-1 per milligram dry weight; K _m ,0.1 mM l(-)malate. Initial uptake of the acid was accompanied by disappearance of extracellular protons, the rates of which followed Michaelis-Menten kinetics as a function of the acid concentration. Variation with extracellular pH of the K _m values, calculated either as the concentrations of anions or of undissociated acid, pointed to anions as the transported form. Furthermore, accumulated free acid suffered rapid efflux after the addition of the protonophore carbonylcyanide-M-chlorophenyl-hydrazone (CCCP). These results suggested that the transport system was a dicarboxylate-proton symporter. The system was inducible and was subject to glucose repression. Succinic, fumaric, -ketoglutaric, oxaloacetic and d-malic acid, but not maleic, malonic, oxalic nor l(+)-tartaric acid, apparently used the same transport system since they acted as competitive inhibitors of l(-)malic acid transport and induced proton movements that followed Michaelis-Menten kinetics. Experiments with glucose-repressed cells showed that undissociated dicarboxylic acid (measured with labelled succinic acid) entered the cells slowly by simple diffusion. The permeability of the cells for undissociated acid increased exponentially with pH, the diffusion constant increasing 100-fold between pH 3.5 and 6.0.     

Dietary n-9, n-6, and n-3 fatty acids modify linoleic acid more than arachidonic acid levels in plasma and platelet lipids and minimally affect platelet thromboxane formation in the rabbit

We have studied the effects of semisynthetic diets containing 5% by weight (12% of the energy) of either olive oil (70% oleic acid, OA) or corn oil (58% linoleic acid), or fish oil (Max EPA, containing about 30% eicosapentaenoic, EPA C 20:5 n-3, plus docosahexaenoic, DHA C 22:6 n-3, acids, and less than 2% linoleic acid), fed to male rabbits for a period of five weeks, on plasma and platelet fatty acids and platelet thromboxane formation. Aim of the study was to quantitate the absolute changes of n-6 and n-3 fatty acid levels in plasma and platelet lipid pools after dietary manipulations and to correlate the effects on eicosanoid-precursor fatty acids with those on platelet thromboxane formation. The major differences were found when comparing the group fed fish oil and depleted linoleic acid vs the other groups. The accumulation of n-3 fatty acids in various lipid classes was associated with modifications in the distribution of linoleic acid and arachidonic acid in different lipid pools. In platelets maximal incorporation of n-3 fatty acids occurred in phosphatidyl ethanolamine, which also participated in most of the total arachidonic acid reduction occurring in platelets, and linoleic acid, more than archidonic acid, was replaced by n-3 fatty acids in various phospholipids. The archidonic acid content of phosphatidyl choline was unaffected and that of phosphatidyl inositol only marginally reduced. Thromboxane formation by thrombin stimulated platelets did not differ among the three groups, and this may be related to the minimal changes of arachidonic acid in phosphatidyl choline and phosphatidyl inositol.     

Unilateral reduction mammaplasty: sculpturing the breast from the undersurface

Various traditional mammaplasty techniques have been suggested for unilateral breast reduction, and an inverted-T incision is still the most popular approach. However, unilaterally performed traditional techniques can rarely provide long-lasting symmetry because the operated and the unoperated breasts react differently to aging, weight changes, and pregnancy. Considerable residual scarring, interference with clinical and mammographic evaluation, and limited versatility are all major drawbacks of traditional procedures. We have performed unilateral mammaplasties on 47 patients with various types of congenital and acquired asymmetries, reducing and sculpturing the breast from the undersurface by means of minimal incisions, always avoiding horizontal scarring in the inframammary crease. Through a vertical infra-areolar incision, the breast is completely detached from the underlying pectoralis fascia and hooked up, thus completely exposing the undersurface of the mammary cone. The breast can thereafter be reshaped according to the size and shape of the contralateral breast by means of a discoid resection and/or selective sectoral removal of excessive subcutaneous tissues; modifications of the basic discoid resection can increase anterior projection of the new breast mound and can change the inclination of the anteroposterior breast axis on the anterior chest wall both on the horizontal and vertical planes. The results show that if criteria for patient selection are carefully respected, the procedure can provide long-lasting symmetry with minimal residual scarring and fully preserve the breast anatomy, function, and vascularization.