Antirheumatic drug effects on neutrophil response to chemotactic factors: a comparison of analytical techniques

A recently reported technique employing the leukotactic index which represents all migrating cells in vitro neutrophil chemotaxis systems, was compared to the leading front technique for assaying antirheumatic drug effects on this important neutrophil function. Normal human neutrophils were treated with therapeutic concentrations of aspirin, gold sodium thiomalate, D-penicillamine, and azathioprine. The responses of these cells and of control cells to neutrophil-immune complex-serum-derived chemotactic factors were assayed in Boyden chambers. Significant (P less than 0.05) inhibition was observed by the leading front technique only for D-penicillamine at high concentrations. Significant (P less than 0.01) inhibition was seen with D-penicillamine at therapeutic plasma levels with the leukotactic index technique. Gold sodium thiomalate and aspirin at high concentrations also produced significant (P less than 0.01 and P less than 0.05) inhibition of chemotaxis as assayed by the leukotactic index procedure. Azathioprine had no significant effects when studied with either technique. These results indicate that the leukotactic index may be a more sensitive technique for quantitating neutrophil migration in response to chemotactic factors and may therefore provide useful additional information for determining the effects of antirheumatic drugs on this important neutrophil function.     

红树林湿地恢复技术的研究进展

本文从红树林育苗造林技术、次生林改造技术和红树植物引种试种与种源选择的研究等方面试述红树林湿地恢复技术的研究进展,并针对我国的目前现状,提出今后亟待加强研究的如下几个方面:加强红树植物引种扩种,恢复植被,提高红树林生态工程质量的原理研究;监测外来引进种对我国红树林湿地的生态影响;研究半红树植物在沿海防护林体系工程建设中的作用;加强红树植物对潮汐水位适应能力的研究;开展红树人工林生态恢复过程中的综合定位观测等。     

Comparison of two histological techniques for age determination in small cetaceans

Age estimation in odontocetes is based on counts of growth layer groups (GLGs) deposited in recording structures such as teeth. Generally, tooth sections are obtained using a cryostat microtome. However, some researchers prefer obtaining thin sections using a traditional paraffin microtome. Little information is available on the application of this technique to dolphin teeth. Our main aim was to investigate if the paraffin technique can be a viable alternative. We considered whether estimated age would be affected by preparation technique, staining method, and section thickness, while controlling for effects of species, body length, and sex. We also analyzed whether the staining method would affect readability of GLGs and age reading variability. Teeth from 86 individuals (representing seven species) were used, but not all were prepared using both techniques because sufficient teeth were not available in all cases. Although the staining method had significant effects on the estimated age using both techniques, the variability of GLG counts was small and appeared to be similar for both techniques. Using Mayer's hematoxylin stained sections of 8 μm thickness, good agreement of ages was obtained from both techniques, with more preparations classified as "good quality" for the paraffin technique. Mayer's hematoxylin provided the best contrast of the GLGs when using the paraffin technique. We conclude that the paraffin technique is viable and represents a cost-effective alternative to a cryostat microtome when preparing cetacean teeth for age determination.     

基于大叶藻成苗率的新型海草播种技术评价

蛤蜊播种技术是一种新型海草播种技术,该技术中,种子通过糯米糊粘在蛤蜊贝壳上,随蛤蜊穴居被埋入底质。为评价蛤蜊和糯米糊对种子成苗率的影响,以菲律宾蛤仔(Ruditapes philippinarum)和大叶藻(Zostera marina)种子为试验对象,设置了直接播撒种子(A1组)、直接埋种(A2组)、包埋糯米后播撒(B1组)、包埋糯米后埋入底质(B2组)、蛤蜊播种(C)5种处理,每种处理设置3个重复,在实验室的水槽中对其进行试验。结果表明:糯米糊对种子萌发有负面影响,但由于蛤蜊的行为使底质具有透气性,减轻了糯米糊对种子萌发的影响,种子成苗率可达到23.2%;海区试验中利用蛤蜊播种的两个样方中的成苗率分别为19.1%和9.9%。试验表明,蛤蜊播种技术适合作为一种经济、有效的播种技术用于海区海草床的建立和修复。     

One step forward: contrasting the effects of Toe clipping and PIT tagging on frog survival and recapture probability

Amphibians have been declining worldwide and the comprehension of the threats that they face could be improved by using mark–recapture models to estimate vital rates of natural populations. Recently, the consequences of marking amphibians have been under discussion and the effects of toe clipping on survival are debatable, although it is still the most common technique for individually identifying amphibians. The passive integrated transponder (PIT tag) is an alternative technique, but comparisons among marking techniques in free‐ranging populations are still lacking. We compared these two marking techniques using mark–recapture models to estimate apparent survival and recapture probability of a neotropical population of the blacksmith tree frog, Hypsiboas faber. We tested the effects of marking technique and number of toe pads removed while controlling for sex. Survival was similar among groups, although slightly decreased from individuals with one toe pad removed, to individuals with two and three toe pads removed, and finally to PIT‐tagged individuals. No sex differences were detected. Recapture probability slightly increased with the number of toe pads removed and was the lowest for PIT‐tagged individuals. Sex was an important predictor for recapture probability, with males being nearly five times more likely to be recaptured. Potential negative effects of both techniques may include reduced locomotion and high stress levels. We recommend the use of covariates in models to better understand the effects of marking techniques on frogs. Accounting for the effect of the technique on the results should be considered, because most techniques may reduce survival. Based on our results, but also on logistical and cost issues associated with PIT tagging, we suggest the use of toe clipping with anurans like the blacksmith tree frog.     

Picrosirius red staining of cardiac muscle following phosphomolybdic acid treatment

When the picrosirius red technique was applied to cardiac muscle sections, intense yellow myocyte staining sometimes obscured thin collagenous septa. The picrosirius red technique was modified to include treatment of the sections in 0.2% (w/v) aqueous phosphomolybdic acid prior to staining. With 1-5 min treatment, cytoplasmic staining was eradicated; diminution of collagen staining occurred only with long treatments at much higher concentrations of phosphomolybdic acid. Using this phosphomolybdic acid-picrosirius red technique, collagenous septa as thin as 0.2-0.5 micron and fine collagen fibers making up the septa were clearly discernible. The technique also worked well on sections stained by other techniques and then destained. The phosphomolybdic acid-picrosirius red technique should be useful in experiments designed to investigate the effects of collagen distribution on the electrical and mechanical behavior of cardiac muscle.     

Picrosirius Red Staining of Cardiac Muscle Following Phosphomolybdic Acid Treatment

When the picrosirius red technique was applied to cardiac muscle sections, intense yellow myocyte staining sometimes obscured thin collagenous septa. The picrosirius red technique was modified to include treatment of the sections in 0.2% (w/v) aqueous phosphomolybdic acid prior to staining. With 1-5 min treatment, cytoplasmic staining was eradicated; diminution of collagen staining occurred only with long treatments at much higher concentrations of phosphomolybdic acid. Using this phosphomolybdic acid-picrosirius red technique, collagenous septa as thin as 0.2-0.5 /im and fine collagen fibers making up the septa were clearly discernible. The technique also worked well on sections stained by other techniques and then destained. The phosphomolybdic acid-picrosirius red technique should be useful in experiments designed to investigate the effects of collagen distribution on the electrical and mechanical behavior of cardiac muscle.     

The cytochemical localization of succinic dehydrogenase in the sperm mitochondria of the gastropod Biomphalaria glabrata. A comparison of two methods.

The mitochondrial derivative of the sperm of the gastropod pulmonate Biomphalaria glabrata was studies to ascertain succinic dehydrogenase localization cytochemically. Two techniques were compared. One technique depends on a tetrazolium salt that yields an osmiophilic formazan upon reduction. The other technique is dependent on the reduction of copper ferricyanide. The effects of several electron transport inhibitors were studied. The reaction product observed in the matrix of the mitochondrial derivative using the former technique is sensitive to rotenone and is believed to be nicotinamide adenine dinucleotide-dependent. The reaction product observed in the intracristal spaces using the copper ferricyanide method is insensitive to rotenone and is believed to cytochemically demonstrate succinic dehydrogenase in this material.     

乳化溶剂挥发法制备纳米粒

目的：建立乳化溶剂挥发法制备纳米粒的方法。方法：采用单因素法和正交设计法考察不同影响因素对乳化溶剂挥发法所制得的纳米粒粒径、包封率和载药量的影响。结果：采用乳化溶剂挥发法,通过改变处方和工艺因素所制得的纳米粒,外观圆整,大小均匀,粒径可控,包封率多数可达50%以上。结论：优化确立了乳化溶剂挥发法制备纳米粒的处方和工艺,可以制备满足不同要求的纳米粒。     

No evidence for observer effects on Lark Sparrow nest survival

ABSTRACT Methods for monitoring bird nests might influence rates of nest predation, but the effects of various methods (e.g., visual markers and observer visitation rates) are often separately investigated among disparate avian taxa and geographic regions. Few investigators have explored the potential effects observers might have on nest success of grassland birds, despite concerns regarding population declines of these species in North America. We examined the possible effects of three monitoring techniques on daily nest survival of Lark Sparrows (Chondestes grammacus): (1) presence or absence of visible markers near nests, (2) observer visitation frequency, and (3) presence or absence of data loggers in nests. We monitored 113 Lark Sparrow nests during the 2009 breeding season. Of these nests, 88.5% failed due to predation, abandonment, weather, or unknown causes, yielding an overall nest success estimate of 9.8% based on daily survival estimation. Main effects of each monitoring technique appeared in top (ΔAICc <2) logistic exposure models. However, 95% confidence intervals around parameter estimates for each technique included zero, indicating no significant effects on daily nest survival. Our results suggest that the nest‐monitoring techniques we used had no effect on Lark Sparrow nest success and, if true, nest survival of other songbirds in arid grasslands of the Great Plains may also be unaffected by cautious nest monitoring. However, we cannot rule out the possibility that any effects of the various techniques in our study were masked by locally intense nest predation. Therefore, additional study is needed to determine if there may be observable variation in nest survival among various nest‐monitoring treatments in other areas of the southern Great Plains where nest predation is less frequent.     

A blood sampling technique for prehatched chicks

ABSTRACT Collecting blood from neonatal or prehatched chicks is sometimes necessary, requiring specialized blood collection techniques and skills. However, such sampling can be difficult and could potentially have adverse effects. I developed a method for collecting blood from chicks still in an egg. The technique involves enlarging the pipping hole, removing the chick's head to take blood from a jugular vein, and returning the chick into its original position in the egg to complete hatching back in the nest. I used this technique on Crested Tern (Thalasseus bergii) chicks (N= 13), with no apparent adverse effects to growth or short‐term survival. The amount of blood extracted (0.1–0.15 ml) was sufficient for a blood smear, hematocrit, and total white blood cell count. This method should be useful for eggs as small as 40 mm in length; eggs smaller than this would likely not be good candidates for this technique because eggshells may be too thin to safely handle. This technique may be useful for investigators studying the immunological and endocrinological transition between embryos and hatchlings.     

A technique for quantifying the amount of macromolecule injected into cells of the early mouse embryo

A simple technique for the quantification of the volume injected into an individual mouse egg or blastomere is described. The method does not seem to have deleterious effects on development, allows the progeny of the injected cell to be identified and permits the measurement of the injected volume to be made up to 48 h after the time of injection.     

Study of aluminum toxicity by means of vital staining profiles in four cultivars of Phaseolus vulgaris L

Aluminum toxicity is a very important factor limiting crop productivity on acid soils. Early effects of aluminum toxicity comprise inhibition of cell division and effects on root elongation. The plasma membrane can be the primary target of aluminum toxicity and thus, vital staining techniques could be a powerful tool in determining effects of metal stress on the plasma membrane.

In this paper, we discuss the effects of Al on growth and membrane integrity by staining root tips with a mixture of fluorescein diacetate and propidium iodide.

The results show a good correlation between results from growth measurement and the vital staining. From the comparison of the luminosity patterns generated by vital staining it is easy to determine Al-resistant varieties, revealing this technique as a powerful and fast method for determining tolerance to Al in different varieties.     

Non-invasive in situ simultaneous measurement of multi-parameter mechanical properties of red blood cell membrane

The purpose of this study was to develop a new dynamic image analyzing technique that will give us the ability to measure the viscoelastic parameters of individual living red blood cells non-invasively, in situ and in real time. With this technique, the bending modulus Kc, the shear elasticity μ and their ratio ε were measured under different temperatures, oxygen partial pressures and osmotic pressures. The results not only show the effects of external conditions on mechanical properties of cell membranes including deformability,flexibility, adhesive ability and plasticity, but also demonstrate that the technique can be used to measure cell membrane parameters continuously under several physiological and pathological conditions.     

Comparison of checkerboard and time-kill methods for the analysis of two antibiotics combined

Activity interaction analysis of two antibiotics by two methods: checkerboard and "time-kill" was compared during this study. Combinations of procaine penicillin, polymyxin B and bacitracin with neomycin and procaine penicillin with dihydrostreptomycin were examined. Checkerboard method is the most widely used technique for antimicrobials interactions analyses. The "time-kill" method, performed by the broth macrodilution technique, provides a dynamic picture of antimicrobial action and interaction over time (based on serial colony counts). Differences of "time-kill" method and the checkerboard technique, allow single visual examination (after 16 to 24 hours of incubation). Additive and inhibition effects were observed in combinations of neomycin with beta-lactam antibiotic (procaine penicillin) and peptide antibiotics (bacitracin and polymyxin B) on clinical strain S. Enteritidis IL 35 "Time-kill" method also confirmed observations mentioned above. In combinations of procaine penicillin with dihydrostreptomycin on strains E. coli IL 531 and E. coli IL 256 synergy effects on checkerboard technique were noticed. Such observation was not confirmed by the "time-kill" method. The methodologies and definitions of synergism are variable and not standardized. This situation should be improved, because comparison of the results obtained by different methods becomes a very difficult task.     

Reconstruction of NOESY maps. A requirement for a reliable conformational analysis of biomolecules using 2D NMR

The modelling of the conformation of a biomolecule in solution is based mainly on the internuclear distances deduced from measurements of nuclear Overhauser effects (nOe) in NOESY correlation maps. The distances are then used as restraints in the energy minimization procedure, which leads to one or several optimized conformations. A general and safe technique for validating these structures with respect to the experimental data is here proposed: from the internuclear distances, the relaxation matrix can be computed under the assumption of a unique rotational correlation time. By stepwise integration of these relaxation equations, the NOESY maps can be accurately reconstructed for any mixing time. Because multi-spin effects are correctly taken into account, any difference between the experimental and theoretical maps can be easily interpreted in terms of conformation, and possible inconsistencies due to conformational averaging can be pointed out. The technique is illustrated for a bacterial lipopeptide, mycosubtilin, the spectrum of which is completely assigned.     

Comparison of the capabilities of accelerated solvent extraction and sonication as extraction techniques for the quantification of kavalactones in Piper methysticum (Kava) roots by high performance liquid chromatography with ultra violet detection

A conventional extraction technique of sonication has been compared, in terms of extraction efficiency, extraction time and amount of solvent, with the more novel technique of accelerated solvent extraction for the extraction of kavain from the powdered roots of Piper methysticum (Kava) with acetone. The extracts were analysed using high-performance liquid chromatography with ultra violet detection. The effects of varying solvent volume and extraction time upon the quantity of kavain extracted with sonication, and the effects of varying temperature upon the kavain extraction efficiency by ASE, were investigated. ASE was found to be more efficient with respect to time and solvent volume required; however, a good agreement was found between the kavain concentration obtained using both extraction techniques.     

Determination of inhibitory effects in fermentation processes by microcalorimetric techniques

A microcalorimetric kinetic method for determining the inhibition effects in fermentation is described. In order to determine the possibilities of this methodology, the inhibitory effect of ethanol on the microaerobic fermentation of xylose by Pichia stipitis is studied. Results are compared with those ones obtained by using the classic kinetic method. Microcalorimetry appears to be an interesting technique for accurately determining inhibitory effects, specially in very slow processes.     

毛细管电泳在细菌分离分析中的应用

介绍了近年来毛细管电泳技术在细菌分离分析方面的研究进展。毛细管电泳以细菌表面的特征信息为分离的基础,可以快速鉴定相应的菌株,可以对微生物进行快速定量,可以反映细菌特殊时期的生理特征,也可以研究微生物与分子之间的相互作用。同时应用该技术可分离分析自然界不能纯培养的微生物。因而毛细管电泳分离与检测细菌方法的建立及其应用在分离科学和微生物学方面都有很大的实际意义。     

The use of solid-state NMR and X-ray crystallography as complementary tools for studying molecular recognition

Solid-state NMR is rapidly becoming available as a routine technique for studying the structure of crystalline or noncrystalline solids. This technique has an advantage over crystallography in that single crystals are not necessary, but it has the disadvantage that the information obtained does not produce a direct picture of the molecule and its environment. On the other hand, solid-state NMR can be done on mixtures, and it gives information about phase distribution in a manner similar to that of X-ray powder pattern analysis.Crystallographic effects such as polymorphism, multiple molecules per asymmetric unit, disorder and salvation can frequently be detected using NMR. Sometimes molecular point group symmetry can also be deduced based on the number of independent nuclei that are detected. The NMR method is sensitive to changes in the electronic structure of a molecule as sensed by the nuclei, and the effects are measured as changes in the isotropic chemical shift of individual nuclei.In this paper, we will give examples of the combined use of X-ray crystallography and ¹³CP/MAS (cross polarization/magic angle spinning) NMR for studying hostguest materials and cocrystals. We have learned how to use NMR to tell us about keto/enol composition in the solid state, to detect the presence of trapped solvent molecules, to detect hydrogen-bond formation and to evaluate molecular conformation and unusual packing pattern effects. We will also present a brief background of the ¹³CP/MAS NMR technique and three case studies in which solid-state NMR and X-ray crystallography are used together to understand materials' structures and properties