Rooster testicular germ cells and epididymal sperm contain P450 aromatase

We recently found that cytochrome P450 aromatase (P450arom) is present in germ cells of the mammalian testis and is capable of converting androgens to estrogens in the male reproductive tract. The objective of the present study was to determine whether testicular germ cells and epididymal sperm of an avian species are also capable of synthesizing estrogen. P450arom was localized in the rooster testis and epididymal region by immunocytochemistry, using an antiserum generated against purified human placental cytochrome P450arom. Immunostaining was present in pachytene spermatocytes, round spermatids, elongated spermatids, flagella of late spermatids, and sperm in the epididymal region. A positive reaction was also found in nonciliated cells of the epididymal region. However, the absence of mRNA for P450arom in the epididymal region indicated that the immunoreactive protein present in the epididymal region is not synthesized in this region. The immunoreactive P450arom found in epididymal sperm was shown to be active through use of a 3H2O assay. On the basis of these data, we conclude that rooster testicular germ cells and epididymal sperm are sites for the synthesis of estrogen, a potential regulator or modulator of germinal epithelium in the testis and the epithelium of the epididymal region of the avian species.     

Loss of parathyroid hormone-stimulated 1,25-dihydroxyvitamin D3 production in aging does not involve protein kinase A or C pathways

Intestinal calcium absorption declines with aging as a result of decreased renal 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] biosynthesis. At least part of the decline in 1,25-(OH)2D3 may be due to acquired resistance to parathyroid hormone (PTH) stimulation of renal 25-hydroxyvitamin D1-hydroxylase (1-OHase) activity. To test whether aging rats can increase 1,25-(OH)2D3 production in response to PTH, male rats of the same litter were fed a normal Ca diet and were sacrificed at 175-225 g (young rats) or 3 months later at 350-425 g (aging rats). At sacrifice, basal serum 1,25-(OH)2D3 levels (88 +/- 16 versus 49 +/- 8 pg/ml, P < 0.05) and in vitro renal proximal tubule 1-OHase activity (178 +/- 15 versus 77 +/- 5 pmol/mg protein/5 minutes, n = 6, P < 0.001) were lower in aging animals. rPTH-(1-34) (10(-11) or 10(-7) M) increased in vitro 1,25-(OH)2D3 secretion by perifused renal proximal tubules from young but not aging rats. For young and aging rats, rPTH-(1-34) (10(-7) M) increased proximal tubule cAMP-dependent protein kinase (PKA) activity, and lower concentrations (10(-11) M) stimulated translocation of protein kinase C (PKC) activity from cytosolic to soluble membrane proximal tubule cell fractions. The results of this study show that PTH activation of 1,25-(OH)2D3 production may involve both signaling pathways, with the PKC pathway responsive to lower concentrations of the hormone. The acquired resistance to PTH stimulation of 1,25-(OH)2D3 production in aging appears not to involve the hormonal activation of PKA or PKC.     

Biodegradability of biodiesel fuel of animal and vegetable origin

One of the positive features of biofuel concerning environmental protection is its high biodegradability. Fuel is considered to be biodegradable if not less than 90% of it degrades within 21 days. The aim of this work was to determine the biodegradability of various kinds of fatty acid methyl esters and their mixtures with fossil diesel fuel in natural environments. It was determined that fatty acid methyl esters meet the requirements for biodegradability set by the EU. Of rapeseed oil fatty acid methyl esters (RME), 91.2% degraded within 21 days, compared to 94.2% of rapeseed oil fatty acid ethyl esters, 98.3% of linseed oil fatty acid methyl esters (LSME), 90% of tallow fatty acid methyl esters, and 92.5% of pork lard fatty acid methyl esters (LME), while the amount of degraded fossil diesel fuel reached only 57.3%. The biodegradability of multi‐component biofuels containing RME, LSME and LME is similar; the best is of a mixture of 70% RME, 6% LSME and 24% LME. It was determined that more than 90% of multi‐component biofuel and fossil diesel fuel mixtures degrade within 21 days when they contain 35% and more of multi‐component biofuel.     

Achillea millefolium L. s.l. herb extract: Antioxidant activity and effect on the rat heart mitochondrial functions

An extract of Achillea millefolium herb (YE) was investigated for antioxidant activity using chemical and biological assays. Qualitative and quantitative analysis of some major phenolics was carried out by HPLC. An on-line HPLC-DPPH assay showed that YE possesses significant antiradical activity which is due to the presence of active components amongst phenolic compounds. Furthermore, direct effects of YE and a mixture of its identified phenolic compounds (MPC) on isolated rat heart mitochondrial function were investigated. We found that YE in concentration-dependent manner induce a decrease in State 3 respiration rate without any changes in the integrity of inner mitochondrial membrane. Thus, pyruvate oxidation was affected only by the highest used YE concentrations; meanwhile succinate oxidation was reduced even at lower YE concentrations. MPC had no effect on mitochondrial State 3 respiration rate. Fluorimetric measurements demonstrated that YE at concentrations that had no effect on the State 3 respiration rate significantly decreased H₂O₂ production in mitochondria.     

Serial bit-stream analysis using quantum-dot cellular automata

Quasi-adiabatically switched quantum-dot cellular automata (QCA) devices present the opportunity to extend our efforts from the implementation of combinational logic devices to more useful sequential logic devices. One very important application of sequential logic is in the recognition of patterns in serial bit streams. This is important, for example, in Internet applications, where particular bit patterns are designated as "sentinel" characters that indicate a particular action should be taken. The foundation of a serial bit-stream analyzer is a shift register, which can be implemented very easily using quasi-adiabatically switched QCA devices. In addition to the shift register, the device will require a multiple-bit comparator, which has not yet been demonstrated in a QCA architecture. We will present a multiple-bit serial stream analyzer that combines the functions of the shift register and the comparator. This device will be analyzed first using behavioral and structural models developed specifically for this project, then its correct quasi-adiabatic behavior will be demonstrated using well established quantum mechanical models. We will show that the proposed device can be used to detect any arbitrary bit pattern appearing in a serial stream of data applied to its serial input. The bit pattern to be detected can be changed using device inputs, and a successful match will be indicated by asserting an output.     

Role of mitogen-activated protein kinases and c-Jun/AP-1 trans-activating activity in the regulation of protease mRNAs and the malignant phenotype in NIH 3T3 fibroblasts

Ras activates a multitude of downstream activities with roles in cellular proliferation, invasion and metastasis, differentiation, and programmed cell death. In this work we have evaluated the requirement of extracellular signal-regulated protein kinase (ERK), c-Jun NH2-terminal kinase kinase (JNKK), and c-Jun/AP-1 activities in transformation and extracellular matrix invasion of ras oncogene expressing NIH 3T3 fibroblasts by expressing stable mutant genes that constitutively inhibit these activities. Whereas the inhibition of ERK activity reverts the transformed and invasive phenotype, the inhibition of the JNK pathway and AP-1 trans-activating activities by JNKK[K129R] and c-Jun(TAM67) had no effect on the ability of the ras oncogene-expressing cells to grow in soft agar or invade Matrigel basement membrane. Thus an elevated JNK activity and/or c-Jun/AP-1 trans-activating activity are not absolute requirements for ras transformation or invasion through basement membrane, and the dependence on AP-1 activity for transformation is cell-specific. However, inhibition of JNK kinase (JNKK) in ras-transformed cells with normally elevated JNK activity switches the protease-dependent invasive phenotype from a urokinase plasminogen activator (uPA)-dependent to a cathepsin L (CL)-dependent invasive phenotype. Conversely, treatment of ras-transformed cells of low constitutive JNK activity with the JNK stimulator, anisomycin, converts the protease mRNA levels from those characteristic of a CL-dependent to a uPA-dependent phenotype. These protease phenotypes can be duplicated in untransformed NIH 3T3 cells that express platelet-derived growth factor receptors and m1 muscarinic receptors that selectively stimulate the ERK or JNK pathways, respectively. It is concluded that high ERK activity is required for both protease phenotypes, whereas the JNK pathway and c-Jun/AP-1 activity are not required for transformation but regulate a switch between uPA and CL protease phenotypes in both transformed and untransformed cells. In ras-transformed NIH 3T3 fibroblasts, the uPA- and CL-dependent protease phenotypes are redundant in their ability to invade through basement membrane.     

Environmental effect of rapeseed oil ethyl ester

Exhaust emission tests were conducted on rapeseed oil methyl ester (RME), rapeseed oil ethyl ester (REE) and fossil diesel fuel as well as on their mixtures. Results showed that when considering emissions of nitrogen oxides (NO_x), carbon monoxide (CO) and smoke density, rapeseed oil ethyl ester had less negative effect on the environment in comparison with that of rapeseed oil methyl ester. When fuelled with rapeseed oil ethyl ester, the emissions of NO_x showed an increase of 8.3% over those of fossil diesel fuel. When operated on 25–50% bio-ester mixed with fossil diesel fuel, NO_x emissions marginally decreased. When fuelled with pure rapeseed oil ethyl ester, HC emissions decreased by 53%, CO emissions by 7.2% and smoke density 72.6% when compared with emissions when fossil diesel fuel was used. Carbon dioxide (CO₂) emissions, which cause greenhouse effect, decreased by 782.87 g/kWh when rapeseed oil ethyl ester was used and by 782.26 g/kWh when rapeseed oil methyl ester was used instead of fossil diesel fuel. Rapeseed oil ethyl ester was more rapidly biodegradable in aqua environment when compared with rapeseed oil methyl ester and especially with fossil diesel fuel. During a standard 21 day period, 97.7% of rapeseed oil methyl ester, 98% of rapeseed oil ethyl ester and only 61.3% of fossil diesel fuel were biologically decomposed.