Isolation and characterization of NgRLK1, a receptor-like kinase of Nicotiana glutinosa that interacts with the elicitin of Phytophthora capsici

Elicitins, extracellular proteins from Phytophthora fungi, elicit a hypersensitivity response (HR), including systemic acquired resistance, in some plants. The elicitin capsicein (~10 kDa) was purified by FPLC from culture filtrates of P. capsici. Purified native and recombinant capsicein induced a hypersensitive response in leaves of the non-host plants Nicotiana glutinosa and Brassica rapa subsp. pekinensis. To search for candidate capsicein-interacting proteins from N. glutinosa, a yeast two-hybrid assay was used. We identified a protein interactor that is homologous to a serine/threonine kinase of the plant receptor-like kinase (RLK) group and designated it NgRLK1. The ORF of NgRLK1 encodes a polypeptide of 832 amino acids (93,490 Da). A conserved domain analysis revealed that NgRLK1 has structural features typical of a plant RLK. NgRLK1 was autophosphorylated, with higher activity in the presence of Mn2+ than Mg2+

Effective mixing in a microfluidic chip using magnetic particles

We present a novel active mixing method in a microfluidic chip, where the controlled stirring of magnetic particles is used to achieve an effective mixing of fluids. To perform mixing, the ferromagnetic particles were embedded and manipulated under the influence of a rotating magnetic field. By aligning the magnetic beads along the magnetic field lines, rod-like structures are formed, functioning as small stir bars. Under higher flow conditions the particles did not form the typical rod structure but rather formed aggregates, which were even more beneficial for mixing. Our system reached a 96% mixing efficiency in a relatively short distance (800 mm) at a flow rate of 1.2-4.8 mm/s. These results demonstrate that our mixing method is useful for microfluidic devices with low aspect ratios and molecules with large molecular weights.This work was supported by a grant from the Innovative Research Institute for Cell Therapy (No. A06-2260-B81505- 06N1-15010A) and by the KOSEF through the Nano-Bioelectronics and Systems Research Center, Seoul National University. This work was also supported in part by MICE through the Molecular Evolutionary Computing (MEC) Project

Estimating the malaria transmission of Plasmodium vivax based on serodiagnosis

Background: Plasmodium vivax re-emerged in 1993 and has now become a major public health problem during the summer season in South Korea. The aim of this study was to interpret and understand the meaning of seroepidemiological studies for developing the best malaria control programme in South Korea. Methods: Blood samples were collected in Gimpo city, Paju city, Yeoncheon County, Cheorwon County and Goseong County of high risk area in South Korea. Microscopy was performed to identify patients infected with P. vivax. Antibody detection for P. vivax was performed using indirect fluorescent antibody test (IFAT). Results: A total of 1,574 blood samples was collected from participants in the study areas and evaluated against three parameters: IFAT positive rate, annual antibody positive index (AAPI), and annual parasite index (API). The IFAT positive rate was 7.24% (n = 114). Of the five study areas, Gimpo had the highest IFAT positive rate (13.68%) and AAPI (4.63). Yeongcheon had the highest API in 2005 (2.06) while Gimpo had the highest API in 2006 (5.00). No correlation was observed between any of the three parameters and study sites' distance from the demilitarized zone (DMZ). Conclusions: These results showed that P. vivax antibody levels could provide useful information about the prevalence of malaria in endemic areas. Furthermore, AAPI results for each year showed a closer relationship to API the following year than the API of the same year and thus could be helpful in predicting malaria transmission risks

Occurrence of microplastics in municipal sewage treatment plants: a review

Municipal sewage treatment plants (STPs) are thought to be important point sources of microplastics in freshwater systems and many peer-reviewed articles have been published on this issue since mid-2010s. In this review, we summarize existing literature on the occurrence of microplastics in STPs and experimental methods used for isolation and identification of microplastics. The number concentrations of microplastics in STP influents were 15.1-640 L-1, whereas those in the STP effluents were highly variable and ranged from not detectable to 65 L-1. For most of cases, conventional STPs are removing microplastics very effectively. Fragments and fibers are dominant shapes of microplastics. Thermoplastics (polyethylene and polypropylene) and polyester are the predominant materials recovered. Although further research is needed, size distribution of microplastics in STPs is likely to follow a power law, implying that different studies using different size cutoffs may be compared after establishing a power law relationship

Expression of GA733-Fc Fusion Protein as a Vaccine Candidate for Colorectal Cancer in Transgenic Plants

The tumor-associated antigen GA733 is a cell-surface glycoprotein highly expressed in colorectal carcinomas. In this study, 3 recombinant genes were constructed as follows: GA733 tagged to the ER retention sequence KDEL (GA733K), GA733 fused to the immunoglobulin Fc fragment (GA733-Fc), and GA733-Fc fused to the ER retention sequence (GA733-FcK). Agrobacterium-mediated transformation was used to generate transgenic plants expressing recombinant genes. The presence of transgenes was confirmed by genomic PCR. Western blot, confocal immunofluorescence, and sandwich ELISA showed the expression of recombinant proteins. The stability, flexibility, and bioactivity of recombinant proteins were analyzed and demonstrated through N-glycosylation analysis, animal trials, and sera ELISA. Our results suggest that the KDEL retained proteins in ER with oligomannose glycan structure and enhanced protein accumulation level. The sera of mice immunized with GA733-FcK purified from plants contained immunoglobulins which were at least as efficient as the mammalian-derived GA733-Fc at recognizing human colorectal cancer cell lines. Thus, a plant system can be used to express the KDEL fusion protein with oligomannose glycosylation, and this protein induces an immune response which is comparable to non-KDEL-tagged, mammalian-derived proteins

Rescue Endovascular Treatment to Prevent Neurological Deterioration in Acute Symptomatic Bilateral Vertebral Artery Occlusion

Bilateral vertebral artery occlusive disease has been considered as a favorable condition with good collaterals. However, the prognosis of acute ischemic stroke secondary to symptomatic bilateral vertebral artery occlusion (BVAO) and endovascular treatment (EVT) has rarely been reported. We retrospectively selected patients with acute ischemic stroke admitted for symptomatic BVAO between January 2020 and February 2023. All patients with ischemic stroke were evaluated for ischemic lesion and arterial status using brain imaging and angiography. The prognosis of acute stroke with symptomatic BVAO was compared between EVT and conventional treatment. Outcomes were evaluated using modified Rankin Scale (mRS) score at 3 months follow-up. Within the study period, 17 of 2,655 acute ischemic stroke patients were diagnosed with ischemic stroke with symptomatic BVAO. The median age of these patients was 70 (interquartile range 44–89) years, and 13 (76%) were male. Seven patients received emergent EVT with stenting and 10 patients received conventional medical treatment only. Nine of 10 patients with conventional treatment had in-hospital stroke progression and developed new ischemic lesions in the pons and midbrain. Five patients with fetal and hypoplastic posterior communicating artery presented bilateral cerebral peduncular lesions. At 3 months follow-up, 6 patients (35%) had favorable outcomes (mRS 0–2), of which 5 were treated with vertebral artery stenting and 1 received conventional treatment. Ischemic stroke in patients with acute symptomatic BVAO is uncommon. However, stroke progression is common, and the prognosis of most patients is poor. Rescue management such as EVT might be considered for symptomatic BVAO