Tissue distribution of bupivacaine enantiomers in sheep

rac-Bupivacaine HCl was infused intravenously to constant arterial blood drug concentrations in sheep using a regimen of 4 mg/min for 15 min followed by 1 mg/min to 24 h. At 24 h, arterial blood was sampled, the animal was killed with a bolus of KCl solution, then rapidly dissected and samples were obtained from heart, brain, lung, kidney, liver, muscle, fat, gut, and rumen. Tissue:blood distribution coefficients for (+)-(R)-bupivacaine exceeded those of (?)-(S)-bupivacaine (P < 0.05) for heart, brain, lung, fat, gut, and rumen by an overall mean of 43%. Blood:plasma distribution coefficients of (?)-(S)-bupivacaine exceeded those of (+)-(R)-bupivacaine by a mean of 29% and this offset the tissue:blood distribution coefficients so that the previously significant enantioselective differences disappeared. It is concluded that although enantioselectivity of bupivacame distribution is shown by the measured tissue:blood distribution coefficients, it is not shown when tissue:plasma water distribution coefficients are calculated, suggesting that there is no intrinsic difference between the bupivacaine enantiomers in tissue affinity. Sheep given fatal intravenous bolus doses of rac-bupivacaine had significantly greater concentrations of (+)-(R)-bupivacaine than (?)-(S)-bupivacaine in brain (P = 0.028) and ventricle (P = 0.036); these could augment the greater myocardial toxicity of this enantiomer found in vitro. © 1993 Wiley-Liss, Inc.     

Competition between red kangaroos (Macropus rufus) and sheep (Ovis aries) in the arid rangelands of Australia

Abstract Competition between red kangaroos and sheep in the more arid areas of Australia was examined by means of a large-scale manipulative experiment incorporating two replicates of each of three treatments: sheep-only, kangaroo-only and a sheepAangaroo mixture. The study was conducted over two years during which time pasture conditions varied markedly. Competition was intermittent, occurring only during a period of climatically related food depletion (semi-drought). At this time there was a large increase in kangaroo densities due to an influx of kangaroos from neighbouring areas. Competition reduced live-weight in sheep but had no significant impact on wool production. This effect was linked to diet selection. Competition caused red kangaroos to favour paddocks destocked of sheep but had no detectable effect on the condition of kangaroos.     

Synthesis and secretion of the mouse whey acidic protein in transgenic sheep

The synthesis of foreign proteins can be targeted to the mammary gland of transgenic animals, thus permitting commercial purification of otherwise unavailable proteins from milk. Genetic regulatory elements from the mouse whey acidic protein (WAP) gene have been used successfully to direct expression of transgenes to the mammary gland of mice, goats and pigs. To extend the practical usefulness of WAP promoter-driven fusion genes and further characterize WAP expression in heterologous species, we introduced a 6.8 kb DNA fragment containing the genomic form of the mouse WAP gene into sheep zygotes. Two lines of transgenic sheep were produced. The transgene was expressed in mammary tissue of both lines and intact WAP was secreted into milk at concentrations estimated to range from 100 to 500 mg/litre. Ectopic WAP gene expression was found in salivary gland, spleen, liver, lung, heart muscle, kidney and bone marrow of one founder ewe. WAP RNA was not detected in skeletal muscle and intestine. These data suggest that unlike pigs, sheep may possess nuclear factors in a variety of tissues that interact with WAP regulatory sequences. Though the data presented are based on only two lines, these findings suggest WAP regulatory sequences may not be suitable as control elements for transgenes in sheep bioreactors.     

人细胞差异表达基因cDNA消减杂交体系的建立

为克隆肺腺癌分化相关基因, 采用诱导分化与消减杂交相结合的策略, 建立了全反式维甲酸(RA)诱导前后人肺腺癌细胞系的cDNA消减文库, 得到124个cDNA消减克隆. 经加减法杂交差异筛选、DNA和RNA印迹、cDNA全序列测定和生物学功能分析, 分离到3个在人肺腺癌细胞系分化过程中由RA激活而特异表达的新的cDNA序列这一策略和技术路线适用于分离细胞中呈过量表达或表达抑制基因的cDNA克隆, 并具有反映细胞分化过程中基因表达动态变化特征和相对简便适用的特点.     

A comparative study of the effects of iloprost and PGE1 on pulmonary arterial pressure and edema formation in the isolated perfused rat lung model

Isolated lungs from male Wistar rats (250–350 g) were perfused at a constant flow rate (10 ml/min, non -recirculating) with Krebs-Ringerbicarbonate buffer containing 4.5 % bovine serum albumin, and were ventilated at a positive pressure (60 breaths/min). Pulmonary arterial pressure and lung weight (as a measure of edema formation) were recorded continuously. After an equilibration period of 20 minutes the various test compounds were added to the perfusion fluid and experimental recording was continued for another 60 minutes.The effects of the stable PGI₂-mimetic, iloprost, of PGE₁, and of the biologically active PGE₁-metabolite, 13,14-dihydro-PGE,, were evaluated in this model (n=6). Iloprost showed slight, but not significant vasodilation; however, lung weight remained unchanged. PGE₁ and 13,14-dihydro-PGE₁ also caused slight vasodilation, but in contrast to iloprost these compounds induced distinct pulmonary edema. The lung weight gain was discernible at concentrations of 2.8 × 10^-6 mol/1 (significant at 2.8 × 10^-5 mol/l; p 0.05) and was accompanied by increases in the wet-weight to dry-weight ratios. These findings were duplicated in a second set of experiments (n = 6) from which the same results were obtained.The results indicate that at high concentrations PGE, (and 13,14-dihydro-PGE₁), but not iloprost, can induce pulmonary edema in rats probably by increasing the permeability of the pulmonary vasculature.     

The Nucleotide Sequence of Human Acylamino Acid-Releasing Enzyme

The nucleotide sequence of a cDNA coding for the human acylaminoacid-releasing enzyme (AARE, also known as acylpeptide hydrolase)[EC 3.4.19.1] subunit has been determined. The amino acid sequenceof human AARE subunit deduced from its cDNA nucleotide sequenceshowed a high degree of identity (91.5%) with both the correspondingproteins from the pig and the rat. The AARE cDNA shows 99.2%identity with a 3.3 kb cDNA transcribed from a locus (DNF15S2)on the short arm of human chromosome 3, whose deletion is associatedwith small cell lung cancer, taking into consideration thatthe sequence of the 3.3-kb cDNA previously reported was causedby misreading.     

Orientation of agents of wound myiasis to hosts and artificial stimuli in Hungary

Abstract. The orientation of adults of the myiasis species Wohlfahrtia magnified and Lucilia sericata to artificial visual stimuli (cloth targets) and olfactory stimuli ('swormlure-4', a potent screwworm attractant), was studied in sheep pastures near to Sarbogard in Hungary. Experiments with odour-baited cloth targets, enclosed in electrocuting grids, demonstrated that colour was an important factor influencing catches on targets: a black target caught most flies of both species, with other colours in the following order of effectiveness, blue > white > yellow. Wohlfahrtia magnified did not respond to swormlure-4 in the strong manner that L. sericata did. The sex ratios of W. magnifica caught on targets (67.2% males) and hand-netted from fence posts (68.8% males) were similar and biased towards males, whereas that of L. sericata on targets was strongly biased towards females (15.6% males), indicating a fundamental difference in the response of these two myiasis species towards the swormlure-baited targets. The orientation of these two species towards hosts was also recorded together with that of a third species, Phormia regina . Electric nets placed beside infested sheep caught significantly more flies of all three species than those placed beside uninfested sheep or in the absence of sheep. The sex ratio of W. magnified caught around infested sheep was the reverse of that on targets, with 68.5% females. Wohlfahrtia magnifica responded more strongly to healthy, uninfested sheep than did L. sericata and P. regina . The potential for use of targets both for population monitoring and control is discussed.     

Characterization of sheep hemopexin glycovariants

The hemopexin phenotype HpxB1 isolated from sheep serum, yields three major bands when subjected to starch gel and/or polyacrylamide gel electrophoresis which are here designated as subcomponents HpxB1-I, HpxB1-II and HpxB1-III. Electrospray mass spectrometric analysis of samples of the isolated subcomponents prepared by ion exchange chromatography showed that each was composed of three glycoproteins and that the major difference between the subcomponents was due to their constituent glycoproteins possessing different numbers of sialic acid residues. Combined analysis of the ESI-MS data and of the overall carbohydrate compositional data obtained by colorimetric procedures, leads to the composition of the glycan of each glycoprotein, and a combined methylation and 400 MHz H-NMR analysis of the alkaline cleaved glycans identified them as being of only the biantennaryN-acetyllactosamine type. Taking into account the molecular mass, the carbohydrate content and structure it may be concluded that each of the constituent glycoproteins contain fiveN-glycosidically linked glycans.Abbreviations HpxB1 hemopexin phenotype B1 - Man mannose - Gal galactose - GlcNAc N-acetylglucosamine - NeuAc N-acetylneuraminic acid - GlcNAc-ol N-acetylglucosaminitol     

Population suppression for control of the blowfly Lucilia sericata and sheep blowfly strike

Abstract.

• 1 The control of ovine myiasis by suppression of populations of the blowfly Lucifia sericata was investigated experimentally on three farms in the south-west of England in 1992 and 1993.
• 2 In blind trials, sheep on one farm (control) were given two doses of placebo, on a second two doses of the larvicide cyromazine (Vetrazin®, CibaGeigy), and on a third cyromazine and a subsequent dose of placebo.
• 3 The first treatment was given shortly before the predicted spring emergence of L.sericata and the second shortly before the predicted emergence of the second generation. Previous simulation analysis had identified strategic early-season treatment as the optimum for blowfly population suppression.
• 4 On both treatment farms significantly smaller L.sericata populations were recorded throughout 1992 and the incidence of strike was significantly lower than on the control farm. The results show that appropriate early-season timing of sheep treatment can suppress populations of L.sericata and could be used by farmers to reduce the incidence of blowfly strike.
• 5 The results suggest, however, that the effectiveness of population suppression and strike incidence may have been influenced by immigration into the control areas and by adverse weather, the latter changing the susceptibility of sheep to strike and resulting in rising strike incidence even when L.sericata population densities were low. In practice, therefore, blowfly population suppression should be employed as a component of an integrated strike management programme.