8-iso-prostaglandin F2alpha as a marker of tissue oxidative damage in bovine retained placenta

Retention of foetal membranes (RFM) in cows is supposed to be associated with the imbalance between production and neutralisation of reactive oxygen species (ROS). The consequence of uncontrolled ROS increase is oxidative damage to tissues, cells, and macromolecules. 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha) is considered as a marker of oxidative tissue damage. The aim of the study was to investigate whether the concentrations of 8-iso-PGF2alpha, in caruncles and cotyledons from the bovine placenta differ between retained and properly released foetal membranes. Placentomes were collected immediately after either spontaneous delivery at term via the vagina or caesarean section before as well as at term through the incision and divided into six groups consisting of eight cows each as follows: A-preterm caesarean section without RFM, B-preterm caesarean section with RFM, C-term caesarean section without RFM, D-term caesarean section with RFM, E-term spontaneous delivery without RFM, F-term spontaneous delivery with RFM. The concentrations of free and total 8-iso-PGF2alpha, were determined in caruncles as well as cotyledons by enzyme immunoassay and expressed in picogram per gram of wet weight of tissue. The concentrations of free and total 8-iso-PGF2alpha were lower (P < 0.05) in cotyledons than in caruncles in all groups examined, as well as they were higher (P < 0.05) in retained than in released placenta. The concentrations of both parameters were lower (P < 0.05) in term spontaneous delivery groups than in term caesarean section groups. The results indicate that oxidative tissue damage, which may be the result of ROS imbalance, appears during RFM. However, the dynamics of this damage requires further elucidation.     

Characterization of Paracoccidioides brasiliensis atypical isolates by random amplified polymorphic DNA analysis

Two atypical Paracoccidioides brasiliensis strains (yeast form at room temperature) have been isolated from chronically infected patients living in Brazil. Different random primers were used to characterize these isolates and compare them to typical strains. The RAPD patterns allowed the differentiation of all the selected isolates. Their genetic distance ranged from 5% to 80% of non-shared bands depending on the strains and the primer used. The RAPD data were used to build a Wagner phenogram, which showed two major branched with more than 56% of genetic distance separating them. No significant difference was observed between the atypical isolates and the others suggesting that specific genes are involved in the dimorphism phenomenon.     

Effect of melatonin on hyperlipidemic nephropathy under constant light exposure

Studies have shown anti-hyperlipidemic actions of melatonin, with pharmacological doses inducing changes in cholesterol levels. This study was designed to evaluate the effect of melatonin on adriamycin-induced (25mg/kg b.w., i.p.) hyperlipidemia under constant light exposure. Melatonin was injected i.p. (1,000 microg/kg b.w./day). Triglycerides, total cholesterol, high-density lipoprotein cholesterol, light-density lipoprotein cholesterol, non-proteic nitrogen compounds (urea and creatinine levels), total protein in serum, proteins eliminated in the urine and melatonin levels in serum and kidney were determined. Results show a decrease in melatonin levels induced by both adriamycin and constant light. Likewise, adriamycin induced significant increases in triglycerides, total cholesterol and light-density lipoprotein cholesterol, and lowered high-density lipoprotein cholesterol levels. Constant light exposure also prompted an increase in LDL-c levels and a decrease in HDL-c values, and intensified the effects of adriamycin on these two lipoproteins. All changes induced by adriamycin and constant light were reverted toward normality by melatonin administration.     

Effects of diazepam and stress on lung inflammatory response in OVA-sensitized rats

The influence of stress and diazepam treatment on airway inflammation was investigated in ovalbumin (OVA)-sensitized rats. Animals were injected with OVA plus aluminum hydroxide intraperitoneally (day 0) and boosted with OVA subcutaneously (day 7). From the first to 13th day after sensitization, rats were treated with diazepam, and 1 h later they were placed in a shuttle box where they received 50 mild escapable foot shocks/day preceded by a sound signal (S). Response during the warning (S) canceled shock delivery and terminated the S. On day 14, rats were submitted to a single session of 50 inescapable foot shocks preceded by S and then were challenged with OVA. High levels of stress were detected in shocked animals, manifested as ultrasonic vocalizations. Morphometric analysis of stressed animals revealed a significant increase in both edema and lymphomononucleated cells in airways compared with controls. Diazepam treatment reduced edema in stressed and nonstressed rats. No differences were found in polymorphonucleated cell infiltration. Diazepam treatment reduced lymphomononucleated cell infiltration in stressed animals. These data suggest that stress and diazepam treatment play relevant roles in edema and lymphomononucleated airway inflammation in OVA-sensitized rats.     

Prevalence and microdiversity of Alteromonas macleodii-like microorganisms in different oceanic regions

The presence, prevalence and variability of microorganisms related to the species Alteromonas macleodii, a well known culturable gamma-Proteobacterium, has been studied in different seawater samples from diverse geographical locations, in both the Northern and Southern hemispheres, and tested with two molecular techniques (rRNA hybridization and gene cloning and sequencing). Results show that A. macleodii-like microorganisms are present in high proportions in North Atlantic and, especially, Mediterranean waters, being higher at deep samples and particle-associated fractions, in agreement with previous findings. In contrast, Southern samples (all from very cold areas near Antarctica) presented no significant hybridization signals. The analysis of the ribosomal ITS (16S-23S internal transcribed spacers) revealed that A. macleodii-like microorganisms from Mediterranean, North Atlantic, Caribbean and Red Sea waters differed in both size and sequence, mostly depending on their geographical origin, with Mediterranean and North Atlantic clones clustering into two main groups whereas Caribbean and Red Sea clones appeared separated.     

A description of Cinclotaenia georgievi n. sp. (Cestoda: Dilepididae), a tapeworm from the dipper Cinclus cinclus (L.) (Passeriformes: Cinclidae)

Cinclotaenia sp., described originally by Georgiev & Genov (1985) from the dipper Cinclus cinclus (L.) in Bulgaria, has recently been identified from the same host in the Carpathian Mountains in the Slovak Republic. This tapeworm is considered to be a new species, which is named C. georgievi n. sp. It is characterised by: a scolex armed with 23-27 (predominantly 24-26) hooks in two rows; hooks 30.5-36 microm long, with a blade 10-13.5 microm long and resembling in shape the diorchoid hooks of hymenolepidids; irregularly alternating genital pores with simple genital atria; a slightly conical cirrus armed by small spines of up to 3 microm in length; 24-51 testes posterior to a bi-alate, branched ovary; a gravid uterus filled with egg packets; and eggs with filaments. C. georgievi n. sp. differs from the closely-related C. tarnogradskii (Dinnik, 1927) in the slightly higher number of rostellar hooks, which have longer blades, and a larger cirrus.     

Photosystem II solubilizes as a monomer by mild detergent treatment of unstacked thylakoid membranes*

We studied the aggregation state of Photosystem II in stacked and unstacked thylakoid membranes from spinach after a quick and mild solubilization with the non-ionic detergent n-dodecyl-α,D-maltoside, followed by analysis by diode-array-assisted gel filtration chromatography and electron microscopy. The results suggest that Photosystem II (PS II) isolates either as a paired, appressed membrane fragment or as a dimeric PS II-LHC II supercomplex upon mild solubilization of stacked thylakoid membranes or PS II grana membranes, but predominantly as a core monomer upon mild solubilization of unstacked thylakoid membranes. Analysis of paired grana membrane fragments reveals that the number of PS II dimers is strongly reduced in single membranes at the margins of the grana membrane fragments. We suggest that unstacking of thylakoid membranes results in a spontaneous disintegration of the PS II-LHC II supercomplexes into separated PS II core monomers and peripheral light-harvesting complexes. This revised version was published online in June 2006 with corrections to the Cover Date.