Technical Evaluation of a Naso-Ruminal Instrument for Collection of Ruminal Samples in Non-Fistulated Cows

The sampling method used is of great importance for the estimation of the microbial activity and biochemical status in ruminal fluid (Stöber & Tiefenbach 1958, Keindorf 1974, Behravesh 1984). Several methods have been used for sampling of ruminal fluid in non-fistulated animals (Sørensen & Schambye 1955, Perk 1958, Schultz & Hiepe 1958, Keindorf & Link 1971). However, the conventional methods of collecting ruminal fluid either by stomach tube (Thygesen probe with a filter ad modum Sørensen & Schambye (1955)), or through a puncture low in the left flank, do not produce representative samples comparable in quality or quantity to samples collected directly through a rumen fistula. The puncture methods usually produce a very small volume of material, and they often leave the cow with an inflammatory reaction in the flank. Many research workers have demonstrated contamination with saliva in samples drawn through a peroral stomach tube, resulting inter alia in a higher pH value than in samples collected through fistula (Dirksen 1970, Behravesh 1984). Since changes in the fermentative reactions of high-yielding cows are receiving much research emphasis today, it has been our aim to construct an instrument suitable for collecting single or continuous samples for diagnostic as well as research purposes, which are comparable in quality and quantity to samples obtained through a rumen fistula. The idea of making the naso-ruminal sampler was inspired by the construction of the COMET Naso-Reticular Instrument (Hekmati et al. 1985).     

Bacterial Community Profiling of Milk Samples as a Means to Understand Culture-Negative Bovine Clinical Mastitis

Inflammation and infection of bovine mammary glands, commonly known as mastitis, imposes significant losses each year in the dairy industry worldwide. While several different bacterial species have been identified as causative agents of mastitis, many clinical mastitis cases remain culture negative, even after enrichment for bacterial growth. To understand the basis for this increasingly common phenomenon, the composition of bacterial communities from milk samples was analyzed using culture independent pyrosequencing of amplicons of 16S ribosomal RNA genes (16S rDNA). Comparisons were made of the microbial community composition of culture negative milk samples from mastitic quarters with that of non-mastitic quarters from the same animals. Genomic DNA from culture-negative clinical and healthy quarter sample pairs was isolated, and amplicon libraries were prepared using indexed primers specific to the V1–V2 region of bacterial 16S rRNA genes and sequenced using the Roche 454 GS FLX with titanium chemistry. Evaluation of the taxonomic composition of these samples revealed significant differences in the microbiota in milk from mastitic and healthy quarters. Statistical analysis identified seven bacterial genera that may be mainly responsible for the observed microbial community differences between mastitic and healthy quarters. Collectively, these results provide evidence that cases of culture negative mastitis can be associated with bacterial species that may be present below culture detection thresholds used here. The application of culture-independent bacterial community profiling represents a powerful approach to understand long-standing questions in animal health and disease.     

非洲隔囊蚁巢伞的化学成分研究(英文)

从肯尼亚安波塞利产的隔囊蚁巢伞(Termitomyces schimperi)子实体中分离得到8个已知化合物,通过波谱方法鉴定它们的结构为(22E,24R)-麦角甾-5,7,22-三烯-3β-醇(1),(3β,5α,9α-三羟基麦角甾-7,22-二烯-6-酮(2),5α,8α-过氧-(22E,24R)-麦角甾-6,22-二烯-3β-醇(3),麦角甾-4,6,8(14),22-四烯-3-酮(4),D-阿拉伯糖醇(5),D-半乳糖醇(6),脑苷脂B(7)和脑苷脂D(8)。所有化合物均首次从该真菌中分离得到。     

Cellobiose Transport by Mixed Ruminal Bacteria from a Cow

The transport of cellobiose in mixed ruminal bacteria harvested from a holstein cow fed an Italian ryegrass hay was determined in the presence of nojirimycin-1-sulfate, which almost inhibited cellobiase activity. The kinetic parameters of cellobiose uptake were 14 μM for the K_m and 10 nmol/min/mg of protein for the V_max. Extracellular and cell-associated cellobiases were detected in the rumen, with both showing higher V_max values and lower affinities than those determined for cellobiose transport. The proportion of cellobiose that was directly transported before it was extracellularly degraded into glucose increased as the cellobiose concentration decreased, reaching more than 20% at the actually observed levels of cellobiose in the rumen, which were less than 0.02 mM. The inhibitor experiment showed that cellobiose was incorporated into the cells mainly by the phosphoenolpyruvate phosphotransferase system and partially by an ATP-dependent and proton-motive-force-independent active transport system. This finding was also supported by determinations of phosphoenolpyruvate phosphotransferase-dependent NADH oxidation with cellobiose and the effects of artificial potentials on cellobiose transport. Cellobiose uptake was sensitive to a decrease in pH (especially below 6.0), and it was weakly but significantly inhibited in the presence of glucose.     

A Procedure for Clustering Means of Unequal-Sized Samples in ANOVA

The proposed procedure “SECOLICO” is based on the sequential construction of linear contrasts. After an analysis of variance the procedure is able to classify the treatments represented by mean values of unequal-sized samples made at random into distinguishable groups. For the purpose of illustrating the procedure “SECOLICO” a simplified example is given.     

Comparative Grouping of Mastitis Streptococci by Means of Co-Agglutination and Precipitation

Two hundred bovine mastitis streptococcal strains belonging to groups B, C, E, G and L were tested comparatively by means of the co-agglutination and precipitation technique. Identical results were obtained with the two tests in 191, or 95.5 %, of the strains. Six strains, which could not be grouped by co-agglutination, proved to belong to group B when grouped by precipitation. On the other hand, one strain which proved to belong to group G and two strains to group L when grouped by co-agglutination, could not be grouped by precipitation. Some cross-reactivity was observed between groups A and C, B and G, B and L. Only a few L strains showed marked cross-reactivity which was not easily distinguished from specific reactions. However, the cross-reactivity ought to be eliminated by dilution or adsorption. Using the precipitation test as a supplementary method, the easy and rapid co-agglutination test was found to be a suitable procedure for routine grouping of mastitis streptococci.     

A Comparative Study of Bivalves Which Bore Mainly by Mechanical Means

This account of the boring mechanisms of those bivalve groupswhich bore mainly by mechanical means attempts to show partlyby reference to published accounts of boring and partly fromour own recent observations of certain characteristics of theboring process in the Pholadidae and Petricolidae, that in contrastto the movements of burrowing forms from which originally allthe boring movements derive, the process of boring makes fewdemands on the hydrodynamic system of the bivalve. The characteristicsof the boring process are closely related to the movements inmodern forms having epifaunal or infaunal habits, supportingthe suggestions of Yonge (1963) concerning the origin of thishabit in the Bivalvia. In all groups in which boringis mechanical,the shell forms the boring tool. However, in those groups inwhich boring has its origin in the epifaunal habit, the majorforce applied to the shell in abrading the burrow isprovidedby contractions of the pedal or byssal retractor muscles. Inthe Adesmacea alone, where boring has been derived from a deepburrowing habit, the adductor muscles provide the major forcein abrasion, and the basic digging cycle has become specializedby the addition of the rocking action of the valves which succeedsretraction. In the former group the ligament is retained andprovides the strong outward force with which the shell is heldagainst the wall of the burrow. In the latter group, the ligamentis reduced, allowing the valves to rock, but here the reciprocalaction of the adductors allows the valves to diverge anteriorlyas the large posterior retractor muscle contracts. In the morespecialized species, water pressure plays a minor role, themaximum pressures recorded being associated with actions subordinateto those involved primarily in abrasion, such as rotation inthe burrow or expulsion of debris from the burrow aspseudofeces.The least specialized borers, such as Petricola, resemble burrowingforms in the importance of the hydrodynamic role of the bodyfluids. In all groups there is a tendency for hypertrophy totake place in the muscles which produce the main boring effect,and for their action to be applied with maximum mechanical advantageagainst a fulcrum provided in most cases by the foot.     

Toxicological Aspect of Some Selected Medicinal Plant Samples Collected from Djelfa,Algeria Region

Biological Trace Element Research - Instrumental neutron activation analysis (INAA) has been used to determine the concentration of some toxic chemical elements in a variety of aromatic plants...     

Chemical Offense by Means of Toxicysts in the Freshwater Ciliate,Coleps hirtus

Coleps hirtus is a small common freshwater ciliate belonging to the protostomatid group, its body covered by calcified plates assembled to form an armor. Coleps feeds on bacteria, algae, flagellates, living and dead ciliates, animal and plant tissues. To assist its carnivorous feeding the ciliate is equipped with offensive extrusomes (toxicysts), clustering mainly in and around its oral aperture. In this study, we isolated the discharge of the toxicysts from living cells, evaluating its cytotoxic effects against various ciliate species, and demonstrating that it is essential for the effectiveness of Coleps’ predatory behavior. The analysis of the toxicyst discharge performed by liquid chromatography‐electrospray‐mass spectrometry and gas chromatography‐mass spectrometry, revealed the presence of a mixture of 19 saturated, monounsaturated and polyunsaturated free fatty acids with the addition of a minor amount of a diterpenoid (phytanic acid).     

Characterization of Esterases Produced by a Ruminal Bacterium Identified as Butyrivibrio fibrisolvens

A method of obtaining clones of Tetrahymena pyriformis on solid medium has been developed. The medium consists of a basal layer of 1.5% agar topped with 2 ml of 0.3% agar in sterile, plastic petri plates (100 by 15 mm). Both agar layers contain either 2% proteose peptone and 0.1% liver extract (complex medium) or defined medium supplemented with proteose peptone. After drying, 0.5 ml of liquid culture is spread evenly over the top agar, and the plates are then sprinkled lightly and evenly with autoclaved dry Sephadex G-25 (fine). Cell colonies can be observed after 5 days of incubation either by viewing with a microscope or without the aid of a microscope after staining. Plating efficiency is high on either complex or defined medium with a number of strains of Tetrahymena, both micronucleate and amicronucleate. Colonies can be picked and transferred to liquid culture for further growth. The existence of clones was demonstrated by plating a mixture of two different drug-resistant mutants. The method should prove useful in selective procedures for the isolation of mutants and for determining survival after treatments such as ultraviolet irradiation.     

开展院前检查合理缩短术前平均住院日的做法

通过成立院前准备中心,应用院前检查入院模式,优化院前入院流程,帮助缩短术前平均住院日和提高科室床位周转率,提升入院服务患者体验和满意度,推进医院质量内涵建设,实现提质增效。

     

The Heavy Metal Content of Wild Edible Mushroom Samples Collected in Canakkale Province,Turkey

In this study, concentrations of heavy metals (Cd, Cr, Cu, Pb, and Zn) were determined in three edible mushroom species (Lactarius deliciosus, Russula delica, and Rhizopogon roseolus) collected in five sampling sites in Canakkale province, Turkey. Mean values of Cd, Cr, Cu, Pb, and Zn were 0.72, 0.26, 28.34, 1.53, and 64.62 mg/kg, respectively. The highest concentrations of Cd, Cu, Pb, and Zn were determined in species R. delica, while Cr was observed in L. deliciosus. In terms of the nutritional aspect, taking into account the concentration of Provisional Tolerable Weekly Intake recommended by FAO/WHO, the maximum concentration of Cd is a restrictive factor for consumption of the collected mushroom species. The concentrations of the other elements have no health risks when consumed at optimal levels.