Pulmonary surfactant will secure free airflow through a narrow tube

Well functioning pulmonary surfactant is necessary to ensure alveolar stability. It is proposed that surfactant is also required to keep the finest cylindrical airways open, thereby securing an unrestricted flow of air to and from the alveoli. If the surfactant is inadequate in quality or quality there is a risk that liquid will accumulate in the most marrow section of the airway and form a blocking column. To study that possibility special glass capillaries were used. The glass capillaries were heated and extended to make a short section very narrow. In the lumen of that section a minute volume (1 microliter) of liquid was deposited, which formed a blocking column. When pressure was raised on one side of the column, it forced the liquid to move away from the narrow section. Pressure dropped to zero as air could pass, and if the liquid column consisted of calf lung surfactant extract (CLSE), pressure remained at zero because a new liquid column did not form. If, on the other hand, the liquid column consisted of saline solution it would repeatedly reform as soon as it had been pressed out of the capillary's narrow section. The same occurred if the CLSE suspension forming the liquid column was very dilute or contained inhibiting proteins. These observations did not require that the capillary consisted of the material glass; they were also noted when the narrow tube was outlined by epithelium.     

聚叶钗子股-中国兰科新记录种及形态特征增补(英文稿)

报道了产自滇东南的中国兰科植物一新记录种--聚叶钗子股（Luisia appressifolia Averyanov）。研究发现,已往文献报道该种时,对其花部特征（如花颜色、萼片及花瓣形状、大小等）的描述仅依据腊叶标本,因标本严重失水导致描述信息不准或缺失。本文根据新鲜植株和花部材料对该种相关形态特征给予了补充。     

Identification of blapsins A and B as potent small-molecule 14-3-3 inhibitors from the insect Blaps japanensis

In this study, we report three novel naturally occurring compounds, blapsins A (1) and B (2), and blapsamide (3) from the ethanol extract of the stink beetle, Blaps japanensis. The structures of these compounds were determined using spectroscopic methods. Compound 3 is a phenolic compound bearing a formamido group in the structure. Functional studies revealed that compounds 1 and 2 potently inhibited 14-3-3 protein-protein interactions (PPIs) with IC(50) values of 9.2 and 10.0 μM as determined by an ELISA assay, and 2.0 and 2.5 μM in an FP assay, respectively. These compounds represent the first example of natural small-molecule 14-3-3 inhibitors.     

Probe droplet arrays generated in the capillary for microarray analysis

Microarray technology is a useful tool for nucleic acid detection and has been widely used in biology and related research fields. However, the procedure is labor intensive and time consuming. Microfluidic chip-based microarrays save time with better performance, but the low spot density and probe number limit its applications. To develop high performance microarrays with high spot density within a microchannel, a method is reported here for preparing microarrays in a capillary by generating probe droplet arrays. The probes in droplets are immobilized onto the inner wall of the capillary to form a one-dimensional probe array, and then a sample solution is introduced to hybridize with the probe array. The effect of the capillary's inner diameter was evaluated to realize a high-density probe array. The processes of array generation and probe immobilization were studied to avoid possible cross contamination. The background from probe immobilization during the array generation and incubation was quantified to assure sensitivity. Multiple sample detection was also demonstrated within one capillary. The capillary based microarray assay had high spot density, easy fabrication, fast detection, high sensitivity and multiple sample capacity.     

Abundance, marker development and genetic mapping of microsatellites from unigenes in Brassica napus

Rapeseed (Brassica napus) is the second most important oil crop in the world after soybean. The repertoire of simple sequence repeat (SSR) markers for rapeseed is limited and warrants a search for a larger number of polymorphic SSRs for germplasm characterization and breeding applications. In this study, a total of 5,310 SSR-containing unigenes were identified from a set of 46,038 B. napus unigenes with an average density of one SSR every 5.75?kb. A set of 1,000 expressed sequence tag (EST)-SSR markers with repeat length ??18?bp were developed and tested for their ability to detect polymorphism among a panel of six rapeseed varieties. Of these SSR markers, 776 markers detected clear amplification products, and 511 displayed polymorphisms among the six varieties. Of these polymorphic markers, 195 EST-SSR markers, corresponding to 233 loci, were integrated into an existing B. napus linkage map. These EST-SSRs were randomly distributed on the 19 linkage groups of B. napus. Of the mapped loci, 166 showed significant homology to Arabidopsis genes. Based on the homology, 44 conserved syntenic blocks were identified between B. napus and Arabidopsis genomes. Most of the syntenic blocks were consistent with the duplication and rearrangement events identified previously. In addition, we also identified three previously unreported blocks in B. napus. A subset of 40 SSRs was used to assess genetic diversity in a collection of 192 rapeseed accessions. The polymorphism information content of these markers ranged from 0.0357 to 0.6753 with an average value of 0.3373. These results indicated that the EST-SSR markers developed in this study are useful for genetic mapping, molecular marker-assisted selection and comparative genomics.     

Antitumor activity of Pulsatilla chinensis (Bunge) Regel saponins in human liver tumor 7402 cells in vitro and in vivo

Pulsatilla chinensis (Bunge) Regel is a Chinese medicinal herb for "blood-cooling" and detoxification. Now it is used for the treatment of malignant tumor, but the antitumor mechanisms and toxic side effects of P. chinensis are unclear. The present study was undertaken to investigate if P. chinensis saponins (PRS) possesses anticancer effects and toxic side effects in human liver tumor 7402 cells in vitro and vivo. 7402 cells were treated with different concentrations of PRS for 24h. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell apoptosis was assessed by flow cytometry. The in vivo effect of PRS on 7402 tumor cells transplanted in athymic nude mice was investigated. 15 saponins were isolated and identified from PRS. PRS inhibited the proliferation of human liver tumor 7402 cells in vitro by apoptosis. 19 days after administration of PRS (100, 200mg/kg), the weight of tumor mass was markly decreased in nude mice. The anti-tumor effect of PRS in vivo was associated with a significant increase in the 7402 apoptosis rate. Although PRS inhibited the weight of mice, it showed almost no effect on leukocyte number, liver and spleen weight index. Light microscopic histopathological examination showed that PRS had no specific lesion in organ. These results suggested that P. chinensis saponins exert potential anticancer activity in treating tumors in nude mice and no toxic side effects.     

Electrical stimulation influences satellite cell proliferation and apoptosis in unloading-induced muscle atrophy in mice

Muscle atrophy caused by disuse is accompanied by adverse physiological and functional consequences. Satellite cells are the primary source of skeletal muscle regeneration. Satellite cell dysfunction, as a result of impaired proliferative potential and/or increased apoptosis, is thought to be one of the causes contributing to the decreased muscle regeneration capacity in atrophy. We have previously shown that electrical stimulation improved satellite cell dysfunction. Here we test whether electrical stimulation can also enhance satellite cell proliferative potential as well as suppress apoptotic cell death in disuse-induced muscle atrophy. Eight-week-old male BALB/c mice were subjected to a 14-day hindlimb unloading procedure. During that period, one limb (HU-ES) received electrical stimulation (frequency: 20 Hz; duration: 3 h, twice daily) while the contralateral limb served as control (HU). Immunohistochemistry and western blotting techniques were used to characterize specific proteins in cell proliferation and apoptosis. The HU-ES soleus muscles showed significant improvement in muscle mass, cross-sectional area, and peak tetanic force relative to the HU limb (p<0.05). The satellite cell proliferative activity as detected within the BrdU+/Pax7+ population was significantly higher (p<0.05). The apoptotic myonuclei (detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) and the apoptotic satellite cells (detected by cleaved Poly [ADP-ribose] polymerase co-labeled with Pax7) were reduced (p<0.05) in the HU-ES limb. Furthermore the apoptosis-inducing factor and cleaved caspase-3 were down-regulated while the anti-apoptotic Bcl-2 protein was up-regulated (p<0.05), in the HU-ES limb. These findings suggest that the electrical stimulation paradigm provides an effective stimulus to rescue the loss of myonuclei and satellite cells in disuse muscle atrophy, thus maintaining a viable satellite cell pool for subsequent muscle regeneration. Optimization of stimulation parameters may enhance the outcome of the intervention.