Forest characteristics and population structure of Glyptostrobus pensilis,a globally endangered relict species of southeastern China

The Chinese water pine Glyptostrobus pensilis is the sole surviving species of the genus Glyptostrobus. It is endemic to southern China, central Vietnam, and eastern Laos, and today it is nearly extinct in the wild. Forest community characteristics and population structure of G. pensilis in China have remained un-known up to now. We investigated six swamp forest stands and analyzed their forest community characteristics (i.e. vertical stratification, species composition, and diversity) and population structure, including the frequency distribution of DBH (diameter at breast height) and age-classes as found in Fujian Province, southeastern China. The vertical stratifications of all the forest stands were rather simple. The remaining wild specimens ranged from roughly 15 to some 357 years for an average of ca. 85 years, with only a few individuals less than 20 years old. Compared with the stands and populations of G. pensilis in Vietnam, the taxonomic compositions of the stands in the two regions were different, except for the dominant species-G. pensilis. The Shannon-Wiener index showed the overstory of each stand had much lower diversity (0.26 on average) in Fujian Province than that (1.97 on average) in Vietnam, whereas the diversity indices were about the same (around 2.41) for the understories in the two regions. Furthermore, we discovered 18 G. pensilis seedlings at the study sites in Fujian Province. This discovery demonstrates that G. pensilis regeneration is extremely poor and its populations are declining, although these populations are rela-tively healthier than those in Vietnam.     

Accumulation of sesquiterpenes and polysaccharides in cells of zedoary (Curcuma zedoaria Roscoe) cultured in a 10 L bioreactor

We developed a cell suspension culture system for zedoary (Curcuma zedoaria Roscoe), using 100 g fresh weight inoculum in a batch culture. The maximum cell biomass of 68.46 g/L fresh weight was obtained after 14 days of culture in a 10 L bioreactor with a pitch-blade impeller maintained at an agitation speed of 150 rpm and an aeration rate of 2.5 L/min. The accumulation of sesquiterpenes and polysaccharide in zedoary cells from 2 to 18 days was measured by HPLC and a phenol-sulfuric acid assay, respectively. The total polysaccharide concentration increased between 2 to 10 days of culture and reached a maximum value of 6.55%. HPLC revealed several eluted peaks of sesquiterpenes, which increased in amplitude from days 2 to 10. Furthermore, our results indicated that biotransformation occurred in the cell suspension, transforming certain sesquiterpenes into other types during culture.     

Counteraction of axonal growth inhibitory properties of Semaphorin 3A and myelin-associated proteins by a synthetic neurotrophic compound

One of the reasons for the lack of nerve regeneration in the CNS is the formation of a glial scar over-expressing multiple inhibitory factors including myelin-associated proteins and members of the Semaphorin family. Innovative therapeutic strategies must stimulate axon extension across the lesion site despite this inhibitory molecular barrier. We recently developed a synthetic neurotrophic compound combining an omega-alkanol with a retinol-like cycle (3-(15-hydroxy-pentadecyl)-2,4,4,-trimethyl-cyclohexen-2-one (tCFA15)). Here, we demonstrate that tCFA15 is able to promote cortical axon outgrowth in vitro even in the presence of the inhibitory Semaphorin 3A and myelin extracts. This growth-promoting effect is selectively observed in axons and requires multiple growth-associated intracellular pathways. Our results illustrate the potential use of synthetic neurotrophic compounds to promote nerve regeneration by counteracting the axonal growth inhibition triggered by glial scar-associated inhibitory factors.     

Expression Vectors for the Rapid Purification of Recombinant Proteins in <Emphasis Type="Italic">Bacillus subtilis</Emphasis>

We describe the construction of six novel plasmid-based IPTG-inducible expression vectors for Bacillus subtilis and related species. While one vector allows intracellular production of recombinant proteins, the second provides a strong secretion signal. The third vector allows addition of the c-Myc epitope tag, and the remaining three vectors provide the purification tags His and Strep. The versatility of all six vectors was demonstrated by the insertion of several reporter genes and by their regulated overexpression. Recombinant proteins with a His- or Strep-tag could be purified to near homogeneity in a single step.     

The Empirical Analysis of Cigarette Tax Avoidance and Illicit Trade in Vietnam, 1998-2010

Illicit trade carries the potential to magnify existing tobacco-related health care costs through increased availability of untaxed and inexpensive cigarettes. What is known with respect to the magnitude of illicit trade for Vietnam is produced primarily by the industry, and methodologies are typically opaque. Independent assessment of the illicit cigarette trade in Vietnam is vital to tobacco control policy. This paper measures the magnitude of illicit cigarette trade for Vietnam between 1998 and 2010 using two methods, discrepancies between legitimate domestic cigarette sales and domestic tobacco consumption estimated from surveys, and trade discrepancies as recorded by Vietnam and trade partners. The results indicate that Vietnam likely experienced net smuggling in during the period studied. With the inclusion of adjustments for survey respondent under-reporting, inward illicit trade likely occurred in three of the four years for which surveys were available. Discrepancies in trade records indicate that the value of smuggled cigarettes into Vietnam ranges from $100 million to $300 million between 2000 and 2010 and that these cigarettes primarily originate in Singapore, Hong Kong, Macao, Malaysia, and Australia. Notable differences in trends over time exist between the two methods, but by comparison, the industry estimates consistently place the magnitude of illicit trade at the upper bounds of what this study shows. The unavailability of annual, survey-based estimates of consumption may obscure the true, annual trend over time. Second, as surveys changed over time, estimates relying on them may be inconsistent with one another. Finally, these two methods measure different components of illicit trade, specifically consumption of illicit cigarettes regardless of origin and smuggling of cigarettes into a particular market. However, absent a gold standard, comparisons of different approaches to illicit trade measurement serve efforts to refine and improve measurement approaches and estimates.     

Loss of autophagy diminishes pancreatic beta cell mass and function with resultant hyperglycemia

Autophagy is a cellular degradation-recycling system for aggregated proteins and damaged organelles. Although dysregulated autophagy is implicated in various diseases including neurodegeneration, its role in pancreatic beta cells and glucose homeostasis has not been described. We produced mice with beta cell-specific deletion of Atg7 (autophagy-related 7). Atg7 mutant mice showed impaired glucose tolerance and decreased serum insulin level. beta cell mass and pancreatic insulin content were reduced because of increased apoptosis and decreased proliferation of beta cells. Physiological studies showed reduced basal and glucose-stimulated insulin secretion and impaired glucose-induced cytosolic Ca2+ transients in autophagy-deficient beta cells. Morphologic analysis revealed accumulation of ubiquitinated protein aggregates colocalized with p62, which was accompanied by mitochondrial swelling, endoplasmic reticulum distension, and vacuolar changes in beta cells. These results suggest that autophagy is necessary to maintain structure, mass and function of pancreatic beta cells, and its impairment causes insulin deficiency and hyperglycemia because of abnormal turnover and function of cellular organelles.     

A homologue of the breast cancer-associated gene BARD1 is involved in DNA repair in plants

hBRCA1 and hBARD1 are tumor suppressor proteins that are involved as heterodimer via ubiquitinylation in many cellular processes, such as DNA repair. Loss of BRCA1 or BARD1 results in early embryonic lethality and chromosomal instability. The Arabidopsis genome carries a BRCA1 homologue, and we were able to identify a BARD1 homologue. AtBRCA1 and the putative AtBARD1 protein are able to interact with each other as indicated by in vitro and in planta experiments. We have identified T-DNA insertion mutants for both genes, which show no visible phenotype under standard growth conditions and are fully fertile. Thus, in contrast to animals, both genes have no indispensable role during development and meiosis in plants. The two single as well as the double mutant are to a similar extent sensitive to mitomycin C, indicating an epistatic interaction in DNA crosslink repair. We could further demonstrate that in Arabidopsis BARD1 plays a prominent role in the regulation of homologous DNA repair in somatic cells.     

Novel quinoline derivatives as inhibitors of bacterial DNA gyrase and topoisomerase IV

A structurally novel set of inhibitors of bacterial type II topoisomerases with potent in vitro and in vivo antibacterial activity was developed. Dual-targeting ability, hERG inhibition, and pharmacokinetic properties were also assessed.     

Structure–activity relationship of human glutaminyl cyclase inhibitors having an N-(5-methyl-1H-imidazol-1-yl)propyl thiourea template

In an effort to design inhibitors of human glutaminyl cyclase (QC), we have synthesized a library of N-aryl N-(5-methyl-1H-imidazol-1-yl)propyl thioureas and investigated the contribution of the aryl region of these compounds to their structure–activity relationships as cyclase inhibitors. Our design was guided by the proposed binding mode of the preferred substrate for the cyclase. In this series, compound 52 was identified as the most potent QC inhibitor with an IC₅₀ value of 58 nM, which was two-fold more potent than the previously reported lead 2. Compound 52 is a most promising candidate for future evaluation to monitor its ability to reduce the formation of pGlu-Aβ and Aβ plaques in cells and transgenic animals.     

The Oncoprotein E2A-Pbx1a Collaborates with Hoxa9 To Acutely Transform Primary Bone Marrow Cells

A recurrent translocation between chromosome 1 (Pbx1) and 19 (E2A) leading to the expression of the E2A-Pbx1 fusion oncoprotein occurs in approximately 5 to 10% of acute leukemias in humans. It has been proposed that some of the oncogenic potential of E2A-Pbx1 could be mediated through heterocomplex formation with Hox proteins, which are also involved in human and mouse leukemias. To directly test this possibility, mouse bone marrow cells were engineered by retroviral gene transfer to overexpress E2A-Pbx1a together with Hoxa9. The results obtained demonstrated a strong synergistic interaction between E2A-Pbx1a and Hoxa9 in inducing growth factor-independent proliferation of transduced bone marrow cells in vitro and leukemic growth in vivo in only 39 +/- 2 days. The leukemic blasts which coexpress E2A-Pbx1a and Hoxa9 showed little differentiation and produced cytokines such as interleukin-3, granulocyte colony-stimulating factor, and Steel. Together, these studies demonstrate that the Hoxa9 and E2A-Pbx1a gene products collaborate to produce a highly aggressive acute leukemic disease.