Quantitative evaluation of glycan-binding specificity of recombinant concanavalin A produced in lettuce (Lactuca sativa).

Concanavalin A (ConA), a mannose (Man)-specific leguminous lectin isolated from the jack bean (Canavalia ensiformis) seed extracts, was discovered over a century ago. Although ConA has been extensively applied in various life science research, recombinant mature ConA expression has not been fully established. Here, we aimed to produce recombinant ConA (rConA) in lettuce (Lactuca sativa) using an Agrobacterium tumefaciens-mediated transient expression system. rConA could be produced as a fully active form from soluble fractions of lettuce leaves and purified by affinity chromatography. From 12 g wet weight of lettuce leaves, 0.9 mg rConA could be purified. The glycan-binding properties of rConA were then compared with that of the native ConA isolated from jack bean using glycoconjugate microarray and frontal affinity chromatography. rConA demonstrated a glycan-binding specificity similar to nConA. Both molecules bound to N-glycans containing a terminal Man residue. Consistent with previous reports, terminal Manα1-6Man was found to be an essential unit for the high-affinity binding of rConA and nConA, while bisecting GlcNAc diminished the binding of rConA and nConA to Manα1-6Man-terminated N-glycans. These results demonstrate that the fully active rConA could be produced using the A. tumefaciens-mediated transient expression system and used as a recombinant substitute for nConA.

Questionnaire-Based Survey on Diagnostic and Therapeutic Endoscopies and H. pylori Eradication for Elderly Patients in East Asian Countries.

BACKGROUND: Gastrointestinal endoscopy and Helicobacter pylori(H. pylori) eradication therapy are commonly performed even among the elderly population. The aim of this study was to understand the way endoscopists viewed the application of endoscopy and H. pylori eradication in the elderly of East Asian countries. METHODS: Self-administered questionnaires containing 13 questions on endoscopy and H. pylori eradication in the elderly were distributed to major institutions in Japan, South Korea, China, Indonesia, and the Philippines. RESULTS: Two hundred and fifteen endoscopists (111 in Japan, 39 in China, 24 in Korea, 21 in Indonesia, and 20 in the Philippines) participated in this study. In the institutions where these endoscopists were associated, around 50% of patients undergoing endoscopy were above the age of 60 years. The participating endoscopists indicated that the necessity of screening esophagogastroduodenoscopy and colonoscopy was lower in populations aged over 81 than the other age groups. They hesitated to perform therapeutic endoscopy, such as endoscopic submucosal dissection or endoscopic retrograde cholangiopancreatography, more often in patients over 85. They also hesitated to perform H. pylori eradication in patients aged over 81, especially in Japan. CONCLUSION: Endoscopists had significantly different attitudes regarding the indications for screening or therapeutic endoscopy and H. pylori eradication therapy in younger and elderly populations in East Asian countries.

Graft Failure after Uterus Transplantation in 16 Recipients: A Review.

Uterus transplantation (UTx) is now an alternative to surrogacy and adoption for women with uterine factor infertility to have children; however, there are still unresolved clinical and technical issues. One of these is that the graft failure rate after transplantation is somewhat higher than that of other life-saving organ transplants, which is a critical concern. Herein, we summarize the details of 16 graft failures after UTx with living or deceased donors using the published literature in order to learn from these negative outcomes. To date, the main causes of graft failure are vascular factors (arterial and/or venous thrombosis, atherosclerosis, and poor perfusion). Many recipients with thrombosis develop graft failure within one month of surgery. Therefore, it is necessary to devise a safe and stable surgical technique with higher success rates for further development in the UTx field.

The significance of pyrogenic polycyclic aromatic hydrocarbons in Borneo peat core for the reconstruction of fire history.

The reconstruction of fire history is essential to understand the palaeoclimate and human history. Polycyclic aromatic hydrocarbons (PAHs) have been extensively used as a fire marker. In this work, the distribution of PAHs in Borneo peat archives was investigated to understand how PAHs reflect the palaeo-fire activity. In total, 52 peat samples were analysed from a Borneo peat core for the PAH analysis. Pyrogenic PAHs consist of 2-7 aromatic rings, some of which have methyl and ethyl groups. The results reveal that the concentration of pyrogenic PAHs fluctuated with the core depth. Compared to low-molecular-weight (LMW) PAHs, the high-molecular-weight (HMW) PAHs had a more similar depth variation to the charcoal abundance. This finding also suggests that the HMW PAHs were mainly formed at a local fire near the study area, while the LMW PAHs could be transported from remote locations.