Potential application of antibody-mimicking peptides identified by phage display in immuno-magnetic separation of an antigen

Phage display was performed against human IgG (hIgG) through five rounds of 'biopanning'. Each round consisted of: (1) incubating a library of phage-displayed 12-mer peptides sequences on hIgG-coated magnetic beads, (2) washing the unbound phages, and (3) eluting the bound phages. The eluted phages were either amplified to enrich the pool of positive clones or subjected to the next round without amplification. Through ELISA, four clones (F9, D1, G5, and A10) showing specific binding affinity to hIgG were identified. Among these, F9 had the highest affinity (K(d)=6.2nM), only one order of magnitude lower than the native anti-hIgG antibody (0.66nM). Following the DNA sequences of the selected clones, four 12-mer peptides were chemically synthesized. Among them, D1 peptide showed the highest binding affinity to hIgG via SPR biosensor measurements. This peptide was conjugated to biofunctionalized magnetic beads, and its immuno-binding ability was compared with that of the native antibody immobilized to magnetic beads. The mol-to-mol binding efficacy of the peptide-coated magnetic beads was approximately 1000-fold lower than that of the antibody-coated magnetic beads. Our results suggest a feasibility of using antibody-mimicking peptides identified by phage display technique for immuno-magnetic separation of an antigen.     

Consequences of frugivore-mediated seed dispersal for the spatial and genetic structures of a neotropical palm

The idiosyncratic behaviours of seed dispersers are important contributors to plant spatial associations and genetic structures. In this study, we used a combination of field, molecular and spatial studies to examine the connections between seed dispersal and the spatial and genetic structures of a dominant neotropical palm Attalea phalerata. Field observation and genetic parentage analysis both indicated that the majority of A. phalerata seeds were dispersed locally over short distances (<30 m from the maternal tree). Spatial and genetic structures between adults and seedlings were consistent with localized and short-distance seed dispersal. Dispersal contributed to spatial associations among maternal sibling seedlings and strong spatial and genetic structures in both seedlings dispersed near (<10 m) and away (>10 m) from maternal palms. Seedlings were also spatially aggregated with juveniles. These patterns are probably associated with the dispersal of seeds by rodents and the survival of recruits at specific microsites or neighbourhoods over successive fruiting periods. Our cross-cohort analyses found palms in older cohorts and cohort pairs were associated with a lower proportion of offspring and sibling neighbours and exhibited weaker spatial and genetic structures. Such patterns are consistent with increased distance- and density-dependent mortality over time among palms dispersed near maternal palms or siblings. The integrative approaches used for this study allowed us to infer the importance of seed dispersal activities in maintaining the aggregated distribution and significant genetic structures among A. phalerata palms. We further conclude that distance- and density-dependent mortality is a key postdispersal process regulating this palm population.     

Adiponectin Profile in Asian Patients Undergoing Coronary Revascularization and Its Association With Plaque Vulnerability: IDEAS‐ADIPO Study

Despite potent insulin‐sensitizing, anti‐inflammatory, and antiatherogenic effects in animal studies, the relationship between serum adiponectin level and coronary artery disease in patients remains unclear. We determined the adiponectin profile in a cohort of multiethnic Asian patients with coronary artery disease, and the association between serum adiponectin level and culprit lesion necrotic core (NC) content. Ninety‐four Asian patients (BMI, 25.3 ± 3.7 kg/m²) undergoing percutaneous coronary intervention were recruited. The serum adiponectin level was measured (n = 94), and the baseline virtual histology intravascular ultrasound examination was analyzed (n = 88). The median level of adiponectin was 3.7 µg/ml (interquartile range, 2.8–4.5 µg/ml). The serum adiponectin level was below 10 µg/ml in 90 patients (95.7%) and below 6 µg/ml in 80 patients (85.1%). There was a significant association between ethnicity and serum adiponectin level (P = 0.048). The median adiponectin level was highest among the Chinese, followed by the Malay and the Indians. Serum adiponectin levels were positively associated with culprit lesion NC content. A 1‐µg/ml increase in log adiponectin was associated with a 3.04% (95% confidence interval: 0.33–5.44) increase in culprit lesion NC content. This association remains significant after adjusting for age, sex, ethnicity, low‐density lipoprotein cholesterol, high‐density lipoprotein cholesterol, and procedural indication. We found a low serum level of adiponectin in Asian patients and a significant ethnic effect on serum adiponectin level. Increased serum adiponectin levels were independently associated with increased culprit lesion NC burden, suggesting a role for adiponectin in modulating coronary plaque vulnerability.     

Fossil fishes from china provide first evidence of dermal pelvic girdles in osteichthyans

Background

The pectoral and pelvic girdles support paired fins and limbs, and have transformed significantly in the diversification of gnathostomes or jawed vertebrates (including osteichthyans, chondrichthyans, acanthodians and placoderms). For instance, changes in the pectoral and pelvic girdles accompanied the transition of fins to limbs as some osteichthyans (a clade that contains the vast majority of vertebrates – bony fishes and tetrapods) ventured from aquatic to terrestrial environments. The fossil record shows that the pectoral girdles of early osteichthyans (e.g., Lophosteus, Andreolepis, Psarolepis and Guiyu) retained part of the primitive gnathostome pectoral girdle condition with spines and/or other dermal components. However, very little is known about the condition of the pelvic girdle in the earliest osteichthyans. Living osteichthyans, like chondrichthyans (cartilaginous fishes), have exclusively endoskeletal pelvic girdles, while dermal pelvic girdle components (plates and/or spines) have so far been found only in some extinct placoderms and acanthodians. Consequently, whether the pectoral and pelvic girdles are primitively similar in osteichthyans cannot be adequately evaluated, and phylogeny-based inferences regarding the primitive pelvic girdle condition in osteichthyans cannot be tested against available fossil evidence.

Methodology/Principal Findings

Here we report the first discovery of spine-bearing dermal pelvic girdles in early osteichthyans, based on a new articulated specimen of Guiyu oneiros from the Late Ludlow (Silurian) Kuanti Formation, Yunnan, as well as a re-examination of the previously described holotype. We also describe disarticulated pelvic girdles of Psarolepis romeri from the Lochkovian (Early Devonian) Xitun Formation, Yunnan, which resemble the previously reported pectoral girdles in having integrated dermal and endoskeletal components with polybasal fin articulation.

Conclusions/Significance

The new findings reveal hitherto unknown similarity in pectoral and pelvic girdles among early osteichthyans, and provide critical information for studying the evolution of pelvic girdles in osteichthyans and other gnathostomes.     

Expression of recombinant anti‐colorectal cancer large single‐chain monoclonal antibody in insect cells

Colorectal cancer is the third most commonly diagnosed cancer in the world. Monoclonal antibody (mAb) CO17‐1A recognizes the tumor‐associated antigen GA733‐2, a cell surface glycoprotein highly expressed in colorectal carcinoma cells which is applicable for preventing and curing colorectal cancer. In this study, we tried to produce a new recombinant anti‐colorectal cancer large single chain (lsc) mAb based on mAb CO17‐1A in the baculovirus‐insect cell protein expression system. Two kinds of recombinant lsc mAbs were generated where variable light chain (VL) and heavy chain (HC) of mAb CO17‐1A were fused together by an interchain linker. The only difference between the two mAbs is based on fusion of an ER retention signal (KDEL) at its C‐terminus of HC. Polymerase chain reaction analysis verified the presence of both recombinant genes in the bacmid for generating viral expression vectors in insect cells. Western blot confirmed the expression of lsc mAbs in baculovirus‐infected insect cells. Cell enzyme linked immunosorbent assay (ELISA) showed that the mAbs from cell lysates bound to SW480 and SW620 human colorectal cancer cells. These results indicate that the baculovirus insect expression system can produce anti‐colorectal lsc mAb recognizing human colorectal cancer cells.     

Etoposide-resistant HT-29 human colon carcinoma cells during glucose deprivation are sensitive to piericidin A, a GRP78 down-regulator

Glucose deprivation, a pathophysiological cell condition, causes up-regulation of GRP78 and induction of etoposide resistance in human cancer cells. The induction of drug resistance can be partly explained by the fact that GRP78 can block activation of caspase-7 induced by treatment with etoposide. Therefore, downregulating GRP78 expression may be a novel strategy anticancer drug development. Based on that premise, we established a screening program for anticancer agents that exhibit preferential cytotoxic activity for etoposide-resistant cancer cells under glucose-deprived conditions. We recently isolated an active compound, AR-054, from the culture broth of Streptomyces sp., which prevents stress-induced etoposide resistance in vitro. AR-054 was identified as piericidin A, a prototypical compound, by ESI-MS analysis and various NMR spectroscopic methods. Here, we showed that piericidin A suppressed the accumulation of GRP78 protein and was also highly toxic to etoposide-resistant HT-29 cells, with IC50 values for colony formation of 6.4 and 7.7 nM under 2-deoxyglucose supplemented and glucose-deprived conditions, respectively. Interestingly, piericidin A had no effect under normal growth conditions. Therefore, we suggest that piericidin A prevents up-regulation of GRP78, and exhibits cytotoxicity in glucose-deprived HT-29 cells that are resistant to etoposide.     

Extracellular matrix proteins protect small cell lung cancer cells against apoptosis: a mechanism for small cell lung cancer growth and drug resistance in vivo.

Resistance to chemotherapy is a principal problem in the treatment of small cell lung cancer (SCLC). We show here that SCLC is surrounded by an extensive stroma of extracellular matrix (ECM) at both primary and metastatic sites. Adhesion of SCLC cells to ECM enhances tumorigenicity and confers resistance to chemotherapeutic agents as a result of beta1 integrin-stimulated tyrosine kinase activation suppressing chemotherapy-induced apoptosis. SCLC may create a specialized microenvironment, and the survival of cells bound to ECM could explain the partial responses and local recurrence of SCLC often seen clinically after chemotherapy. Strategies based on blocking beta1 integrin-mediated survival signals may represent a new therapeutic approach to improve the response to chemotherapy in SCLC.     

Termination of second trimester pregnancy with laminaria and intramuscular 16 phenoxy-ω-17,18,19,20 tetranor PGE2 methylsuldonylamide (sulprostone) — A randomised study

16 phenoxy-ω-17,18,19,20 tetranor PGE₂ methylsulfonylamide (Sulprostone) was used for termination of second trimester pregnancy in four groups of 30 patients. The drug was administered in intramuscular doses of either 0.5 mg four hourly or 1.0 mg 8 hourly. In two groups of 30 patients a medium size sterile laminaria was inserted into the cervical canal eight hours before the start of prostaglandin treatment. In the group treated with 1.0 mg sulprostone eight hourly, 96.7% of those with laminaria and 86.7% without laminaria aborted in respective mean times of 11.2 hrs and 17.5 hrs. All 30 patients (100%) in the laminaria group treated with 0.5 mg sulprostone four hourly aborted within 30 hours in a mean time of 10.4 hours compared with 26 patients (86.7%) in a mean time of 16.7 hours in the group without laminaria.One patient receiving 0.5 mg sulprostone four hourly (no laminaria) sustained a cervical tear requiring repair. The incidence of nausea, vomiting, diarrhoea, cold and shivering was low and similar in the four groups.