Changes in autophagy proteins in a rat model of controlled cortical impact induced brain injury

Autophagy has been implicated in several neurodegenerative diseases and recently its role in acute brain injury has received increased interest. In our study, we investigated the profiles of autophagy-linked proteins (MAP-LC3 (Atg8), beclin-1 (Atg6) and the beclin-1-binding protein, bcl-2, following controlled cortical impact injury in rats—a model for moderate-to-severe traumatic brain injury. We observed significant increases in the levels of the processed form of LC3 (LC3-II) in the ipsilateral cortex 2 h to 2 days after injury when compared to sham. Furthermore, the beclin-1/bcl-2 ratio in the ipsilateral cortex was found to have increased from 1 and 2 days after injury. Since both of these changes are established autophagy-enabling events, and, based on these data, we propose that autophagy, plays a role in the manifestation of cell injury following brain trauma.     

Differential ConA-enriched urinary proteome in rat experimental glomerular diseases

Glomerular diseases are leading causes of end-stage renal diseases worldwide. They are considered to be consequences of injury primarily to the three types of glomerular cells. Differential diagnosis typically relies on invasive biopsy findings. We expected that injuries of different glomerular cells would cause different changes in urinary proteome. The goal of this study was to identify differential urinary proteins distinguishing between injuries of different glomerular cells before significant histopathologic changes. Adriamycin nephropathy and Thy1.1 glomerulonephritis were employed as models with different primary impaired cells. ConA-enriched urinary glycoproteome on day3 were profiled by gel-free shotgun tandem mass spectrometry, and compared with self-healthy controls to identify differential urinary proteins for each model. By comparing the changes of the differential proteins between these two models, we identified 39 proteins with different directions of changes, which may potentially be useful in differentiation; and 7 proteins with the same direction of changes, which may be potential indicators of early renal damage. These differential proteins were of several origins: plasma proteins, proteins with urine or kidney specificity, proteins without tissue-specificity (mainly inflammatory mediators) etc. Our results may help better understand the effects of injuries of different glomerular cells at the initial stage, and lead to the discovery of novel early diagnostic markers for human focal segmental glomerulosclerosis (FSGS) and mesangioproliferative glomerulonephritis (MsPGN) which have the same primary impaired cells with adriamycin nephropathy and Thy1.1 glomerulonephritis, respectively.     

Interspecific Variation in RGR and the Underlying Traits among 24 Grass Species Grown in Full Daylight

Abstract: A growth analysis was conducted with 24 central European grass species in full daylight to test whether traits underlying interspecific variation in relative growth rate (RGR) are the same in full daylight as they are at lower light, and whether this depends on the ecological characteristics of the studied species, i.e., their requirements with respect to nutrient and light availability.
In contrast to studies with herbaceous species at lower light, net assimilation rate (NAR) contributed more than leaf area ratio (LAR) or specific leaf area (SLA) to interspecific variation in RGR. This was associated with a larger interspecific variation in NAR than found in experiments with lower light. Without the two most shade-tolerant species, however, the contribution of LAR and its components to interspecific variation in RGR was similar or even higher than that of NAR.
Leaf dry matter content correlated negatively with RGR and was the only component of LAR contributing in a similar manner to variation in LAR and RGR. There was a positive correlation between NAR and biomass allocation to roots, which may be a result of nutrient-limited growth. RGR correlated negatively with biomass allocation to leaves. Leaf thickness did not correlate with RGR, as the positive effect of thin leaves was counterbalanced by their lower NAR.
Low inherent RGR was associated with species from nutrient-poor or shady habitats. Different components constrained growth for these two groups of species, those from nutrient-poor habitats having high leaf dry matter content, while those from shady habitats had thin leaves with low NAR.     

Preliminary analysis of mitochondrial DNA variation in a southern feeding group of eastern North Pacific gray whales

Although the majority of eastern North Pacific(ENP) gray whales migrate to feeding grounds inthe Bering and Chukchi Seas, some terminate themigration in more southerly areas such asBritish Columbia (BC). Long-term sightingstudies in Clayoquot Sound (CS), BC, indicatethat approximately 35–50 individuals exhibitlong-term fidelity to this site. To determinethe sex composition (based on genetic sexing)of CS gray whales and to assess whethermatrilineal site-fidelity occurs in CS, wecollected skin biopsy samples from 16 CSindividuals (`residents') and 41 samples fromother areas (representative of the overallpopulation in the ENP: `non-residents'). Atotal of 27 polymorphic sites defined 24haploytpes among the 57 samples sequenced forHV1 of the mtDNA control region. Thenucleotide and haplotype diversities of thesesamples were 0.017 (SE = 0.0012) and 0.94(SE = 0.0019), respectively. Neighbor-joininganalysis revealed five lineages each of whichcontained haplotypes that were observed in bothresidents and non-residents. Residents did notdiffer significantly from non-residents, and nosignificant sex-ratio bias was found. Thesedata suggest a level of diversity that isinconsistent with a severe historicalbottleneck, and given the available samplesize, do not indicate matrilineally directedfidelity to Clayoquot Sound.     

长脐红豆幼苗生长对不同土壤氮磷添加的响应及其对土壤养分的反馈

以热带豆科树种长脐红豆(Ormosia balansae Drake)幼苗为研究对象, 开展苗期控制试验, 共设置了5个添加氮(N, N1—N5)和2个添加磷(P, LP—HP)梯度, 观察长脐红豆在不同土壤N、P添加条件下的生长表现及对土壤养分的反馈。测定的植物和土壤响应指标包括: 植株地上和地下生长量、叶面积、叶和根的N、P含量、根际和非根际土壤N、P含量等。结果表明: (1)从苗高、总叶面积、地上生物量、地下生物量、总根长和根表面积这6个指标总体来看, 在低磷(LP)条件下, 中、高浓度的N添加(N4、N5)对长脐红豆生长有抑制作用; 高磷(HP)条件下, 高浓度的N添加(仅有N5)对长脐红豆生长有抑制作用; 表明长脐红豆的最适生长N浓度会随P添加浓度增加而升高; (2)随着N添加浓度的增加, 根和叶的全N含量呈先增加后减小的趋势, N4处理条件下达到最大; 根和叶的全P含量却呈现相反趋势, 符合元素稀释效应。叶的N:P>16, 且P浓度<1.0 mg•g-1, 表明长脐红豆生长受P限制; (3)基于氨态氮、硝态氮和有效P这3个肥力指标, 长脐红豆苗期非根际土壤肥力>根际土壤肥力, 表明豆科树种长脐红豆在其幼苗期共生根瘤尚未明显形成时期, 需补充适量N、P养分供给。     

胰酶对皮肤角质细胞分离和传代的影响

考察不同的胰酶浓度及其作用时间对角质细胞分离和传代的影响。实验发现在胰酶浓度 0.25%时作用5min可获得的总活细胞量和有克隆形成能力的细胞量均优于其它培养条件 ;而在胰酶浓度0.05%时作用 5min可获得最大的原代角质细胞贴壁率。随着胰酶浓度的提高 ,传代角质细胞的贴壁率和贴壁速率常数以及克隆形成率均随之增加 ,因此在传代培养时使用 0.25%胰酶浓度进行消化较为适宜.     

安徽两种蜜蜂种群的春季繁殖及数量动态特征

1997～ 1999年在皖中和皖西、皖南山区对意大利蜜蜂 (ApismelliferaLigusticaSpi.)和中华蜜蜂(ApisceranaceranaFeb .)种群数量动态进行系统观察研究 .结果表明 ,蜜蜂种群数量明显受气候和蜜粉源植物的影响 ,周年呈现“两高”(春、秋 )和两低 (夏、冬 )的变化模式曲线 ;意大利蜜蜂春繁及秋季更新速度明显快于中华蜜蜂 ,但越夏效果不及中华蜜蜂 .意大利蜜蜂的性比值为 (314.4± 2 89.9)∶1～ (32 9.4± 30 5 .8)∶1,中华蜜蜂为 (334.2± 2 35 .5 )∶1～ (413 .1± 377.2 )∶1,雄蜂呈季节性出现 .蜜蜂种群内年龄组配在不断变化 .     

Static and dynamic light scattering approach to the hydration of hemoglobin and its supertetramers in the presence of osmolites.

We used static and dynamic light scattering for comparing the mass (MW) and hydrodynamic radius (R(h)) of several hemoglobin systems, namely human hemoglobin, bovine hemoglobin, human hemoglobin cross-linked with a sebacyl residue, and bovine hemoglobin cross-linked with an adipoyl residue. We measured the MW and R(h) of these systems in 0.1M phosphate buffer at pH 7.0 in the absence and in the presence of either betaine or glycerol up to 1.7 molal concentrations. The 90 degrees scattering was measured with a photon counting machine equipped with a diode laser at 783 nm. The Rayleigh ratio [R(theta)] of the instrument was estimated using R(theta) = 7.19E-6 cm(-1) for toluene at 783 nm. The refractive index increment of hemoglobin solutions was measured using a laser beam at 750 nm. We estimated a value dn/dc = 0.210 cm3/g in the absence and dn/dc = 0.170 in the presence of 1.7 molal osmolites. For all systems both in liganded and unliganded form, the static light scattering data showed a 16% mass increase with increasing concentration of osmolites. The hydrodynamic radii of all investigated systems in the presence and absence of osmolites were close to 3.17 nm. Assuming a partial specific volume nu = 0.739 for hemoglobin, and using spherical geometry, the estimated average hydration volume of hemoglobin was 32.6 L/mole in the absence of osmolites. It decreased to 23.5 L/mole in the presence of 1.7 molal osmolites. Assuming that the density of water in the hydration volume is D = 1.0 g/cm3, the hydration of Hb was 0.51 gH2O/gHb, with a surface density of 0.20 molH2O/A2. The hydration decreased to 0.33 gH2O/gHb and 0.14 molH2O/A2 in the presence of 1.7 molal osmolites. The decreased hydration was compensated by the increased mass (i.e., decreased surface area per unit volume) so that the thickness of the water shell around these proteins remained close to a single layer of water molecules. These findings indicate that the combination of static and dynamic light scattering offer unique means for investigating the relevance of water activity on the structure and function of biological macromolecules. In the case of hemoglobin, the data suggest that the decreased oxygen affinity in the presence of osmolites reported by Colombo et al. (M. F. Colombo, D. C. Rau, and V. A. Parsegian Science, 1992, Vol. 256, pp. 655-659), as due to ligand linked water binding on hemoglobin surface, is part of a complex phenomenon involving the hydration shell of hemoglobin and the formation of low affinity supertetrameric molecules.     

Rainfall, phycocyanin, and N:P ratios related to cyanobacterial blooms in a Korean large reservoir

Nutrient concentrations and other environmental factors were measured in the Daechung Reservoir for 25 weeks from spring until autumn in 1999. The high irradiance after heavy rainfall provided optimal meteorological conditions for bloom formation during summer, therefore, rain would also appear to forecast imminent bloom. The bloom formation was largely governed by cyanobacteria, in particular, Microcystis spp. and Anabaenaspp. Phycocyanin showed higher correlation with cyanobacteria (r = 0.744, P < 0.001) compared to chlorophyll-a(r = 0.599, P < 0.01). Therefore, phycocyanin was more accurate and useful than chlorophyll-a in quantitatively measuring cyanobacterial blooms. The atomic N:P ratio of the particulate form also showed a high correlation with cyanobacteria (r = 0.541, P < 0.01), increasing from 4.3 to 14.6 during bloom formation, while that of the dissolved form decreased from 25.5 to 8.7. These results indicated that the algae assimilated N significantly without comparable P uptake during the blooming season, which was in sharp contrast to the excessive storage of P during the spring.     

Horizontal variation of biomass and C:N:P ratios of benthic algae in lakes

The horizontal variation of chlorophyll a (chl a) and C:N:P (carbon:nitrogen:phosphorus) ratio was estimated for benthic algal communities attached to living substrates (mussels and macrophytes) and to rocks and stones in three lakes of different trophy. Samples were taken in a nested hierarchical design with replicates separated by several cm, dm, 10 m, and km. The observed horizontal variation of chl a, C:N, and C:P ratios did not differ for horizontal scales, substrates, or lakes. Although the investigated lakes were quite unlike regarding nutrient status, light regime, or morphology, the patchiness was similar in all lakes. Moreover, patchiness was also similar on stones, macrophytes and mussels, although those substrates differed in longevity and surface structure. Similar patchiness regardless of scale, substrate, or sampled lake, implies the possibility of using an optimal sampling design calculated for one lake and substrate also in other lakes and on other substrates.