Multiplex TaqMan qPCR Assay for Detection, Identification, and Quantification of Three Sclerotinia Species

White mold (orSclerotinia stem rot), caused bySclerotinia species, is a major air, soil, or seed-transmitted disease affecting numerous crops and wild plants. Microscopic or culturebased methods currently available for their detection and identification are time-consuming, laborious, and often erroneous. Therefore, we developed a multiplex quantitative PCR (qPCR) assay for the discrimination, detection, and quantification of DNA collected from each of the three economically relevant Sclerotinia species, namely, S. sclerotiorum, S. minor, and S. nivalis. TaqMan primer/probe combinations specific for each Sclerotiniaspecies were designed based on the gene sequences encoding aspartyl protease. High specificity and sensitivity of each probe were confirmed for sclerotium and soil samples, as well as pure cultures, using simplex and multiplex qPCRs. This multiplex assay could be helpful in detecting and quantifying specific species of Sclerotinia, and therefore, may be valuable for disease diagnosis, forecasting, and management.

Uncharted Diversity and Ecology of Saprolegniaceae (Oomycota) in Freshwater Environments

The fungal-like family Saprolegniaceae (Oomycota), also called “water mold,” includes mostly aquatic saprophytes as well as notorious aquatic animal pathogens. Most studies on Saprolegniaceae have been biased toward pathogenic species that are important to aquaculture rather than saprotrophic species, despite the latter’s crucial roles in carbon cycling of freshwater ecosystems. Few attempts have been made to study the diversity and ecology of Saprolegniaceae; thus, their ecological role is not well-known. During a survey of oomycetes between 2016 and 2021, we investigated the diversity and distribution of culturable Saprolegniaceae species in freshwater ecosystems of Korea. In the present study, members of Saprolegniaceae were isolated and identified at species level based on their cultural, morphological, and molecular phylogenetic analyses. Furthermore, substrate preference and seasonal dynamics for each were examined. Most of the species were previously reported as animal pathogens; however, in the present study, they were often isolated from other freshwater substrates, such as plant debris, algae, water, and soil sediment. The relative abundance of Saprolegniaceae was higher in the cold to cool season than that in the warm to hot season of Korea. This study enhances our understanding of the diversity and ecological attributes of Saprolegniaceae in freshwater ecosystems.

Emergence of a New Rust Disease of Virginia Creeper (Parthenocissus quinquefolia) through a Host Range Expansion of Neophysopella vitis

Virginia creeper (or five-leaved ivy; Parthenocissus quinquefolia) is one of the most popular and widely grown climbers worldwide. In September 2021, Virginia creeper leaves with typical rust symptom were found in an arboretum in Korea, with severe damage. Globally, there is no record of a rust disease on Virginia creeper. Using morphological investigation and molecular phylogenetic inferences, the rust agent was identified as Neophysopella vitis, which is a rust pathogen of other Parthenocissus spp. including Boston ivy (P. tricuspidata). Given that the two ivy plants, Virginia creeper and Boston ivy, have common habitats, especially on buildings and walls, throughout Korea, and that N. vitis is a ubiquitous rust species affecting Boston ivy in Korea, it is speculated that the host range of N. vitis may recently have expanded from Boston ivy to Virginia creeper. The present study reports a globally new rust disease on Virginia creeper, which could be a major threat to the ornamental creeper.

Chemokine Receptor Profiles of T Cells in Patients with Age-Related Macular Degeneration

Purpose@#To evaluate the expression of multiple chemokine receptors in peripheral blood T cells from patients with age-related macular degeneration (AMD). @*Materials and Methods@#Peripheral blood mononuclear cells and/or aqueous humor were obtained from 24 AMD patients and 24 age- and sex-matched healthy controls. Chemokine receptor expression on T cells from peripheral blood was determined by multicolor flow cytometry. The levels of chemokines and cytokines in the aqueous humor from 12 AMD patients and six healthy controls were assessed. @*Results@#AMD patients had increased expressions of CCR4 in CD4 + T cells (p=0.007) and CRTh2 in CD8 + T cells (p=0.002), and decreased expressions of CXCR3 in CD4+T cells (p=0.029) and CXCR3, CCR5, and CX 3CR1 in CD8+T cells (p=0.005, 0.019, and 0.007, respectively). Monocyte chemoattractant protein-1 levels were increased in the aqueous humor from AMD patients (p=0.018), while the levels of interleukin (IL)-4 and IL-22 were significantly decreased compared to controls (p=0.018 and 0.041, respectively). @*Conclusion@#The chemokine receptor profiles of T cells are altered in AMD patients compared to healthy controls without noticeable associations with chemokine levels in the aqueous humor. Further evaluation is needed to clarify the role of these alterations in AMD pathogenesis.

Co-Occurrence of Two Phylogenetic Clades of Pseudoperonospora cubensis, the Causal Agent of Downy Mildew Disease, on Oriental Pickling Melon

The genus Pseudoperonospora, an obligate biotrophic group of Oomycota, causes the most destructive foliar downy mildew disease on many economically important crops and wild plants. A previously unreported disease by Pseudoperonospora was found on oriental pickling melon (Cucumis melo var. conomon) in Korea, which is a minor crop cultivated in the temperate climate zone of East Asia, including China, Korea, and Japan. Based on molecular phylogenetic and morphological analyses, the causal agent was identified as Pseudoperonospora cubensis, and its pathogenicity has been proven. Importantly, two phylogenetic clades of P. cubensis, harboring probably two distinct species, were detected within the same plots, suggesting simultaneous coexistence of the two clades. This is the first report of P. cubensis causing downy mildew on oriental pickling melon in Korea, and the confirmation of presence of two phylogenetic clades of this pathogen in Korea. Given the high incidence of P. cubensis and high susceptibility of oriental pickling melon to this disease, phytosanitary measures, including rapid diagnosis and effective control management, are urgently required.

Co-Occurrence of Two Phylogenetic Clades of Pseudoperonospora cubensis, the Causal Agent of Downy Mildew Disease, on Oriental Pickling Melon

The genus Pseudoperonospora, an obligate biotrophic group of Oomycota, causes the most destructive foliar downy mildew disease on many economically important crops and wild plants. A previously unreported disease by Pseudoperonospora was found on oriental pickling melon (Cucumis melo var. conomon) in Korea, which is a minor crop cultivated in the temperate climate zone of East Asia, including China, Korea, and Japan. Based on molecular phylogenetic and morphological analyses, the causal agent was identified as Pseudoperonospora cubensis, and its pathogenicity has been proven. Importantly, two phylogenetic clades of P. cubensis, harboring probably two distinct species, were detected within the same plots, suggesting simultaneous coexistence of the two clades. This is the first report of P. cubensis causing downy mildew on oriental pickling melon in Korea, and the confirmation of presence of two phylogenetic clades of this pathogen in Korea. Given the high incidence of P. cubensis and high susceptibility of oriental pickling melon to this disease, phytosanitary measures, including rapid diagnosis and effective control management, are urgently required.

High-Temperature-Tolerant Fungus and Oomycetes in Korea, Including Saksenaea longicolla sp. nov

Global temperatures are steadily increasing, leading to significant changes in microbial diversity and ecology. In the present study, we isolated high-temperature-growing fungi and fungi-like group (Oomycota) strains from freshwater environments of Korea and identified them based on cultural, morphological, and multilocus phylogenetic analyses. As a result, we introduce Saksenaea (Fungi) isolates as a new species, Saksenaea longicolla sp. nov. and record Phytophthora chlamydospora and P. lagoariana (Oomycota) new to Korea. In the growth experiments, they exhibited high-temperature tolerance, which can grow at 35–40°C but become inactive at 4 °C and below. This study confirms the presence of high-temperature-tolerant fungi and oomycetes in Korea and suggests that the Korean climate conditions are changing in favor of these species. This indicates that climate warming is altering microbial distributions in freshwater environments.

Rediscovery of Seven Long-Forgotten Species of Peronospora and Plasmopara (Oomycota)

The family Peronosporaceae, an obligate biotrophic group of Oomycota, causes downy mildew disease on many cultivated and ornamental plants such as beet, cucumber, grape, onion, rose, spinach, and sunflower. To investigate the diversity of Peronosporaceae species in Korea, we performed morphological analysis for dried plant herbariums with downy mildew infections by two largest genera, Peronospora and Plasmopara. As a result, it was confirmed that there are five species of Peronospora and two species of Plasmopara, which have been so far unrecorded in Korea, as well as rarely known in the world; Pl. angustiterminalis (ex Xanthium strumarium), Pl. siegesbeckiae (ex Siegesbeckia glabrescens), P. chenopodii-ambrosioidis (ex Chenopodium ambrosioides), P. chenopodii-ficifolii (ex Chenopodium ficifolium), P. clinopodii (ex Clinopodium cf. vulgare), P. elsholtziae (ex Elsholtzia ciliata), and P. lathyrina (ex Lathyrus japonicus). In addition, their phylogenetic relationship was inferred by molecular sequence analysis of ITS, LSU rDNA, and cox2 mtDNA. By rediscovering the seven missing species and barcoding their DNA sequences, this study provides valuable insights into the diversity and evolutionary studies of downy mildew pathogens.

Plasmopara elegantissima sp. nov. (Oomycota, Peronosporales), a Downy Mildew Species Specialized to Impatiens textori (Balsaminaceae)

Over the past 15 years, downy mildew became the most destructive foliar disease in cultivated Impatiens species (Balsaminaceae) worldwide. A previous study had revealed that the causal agent was not Plasmopara obducens (Oomycota, Peronosporales) but Plasmopara destructor on Impatiens walleriana, and Plasmopara velutina on Impatiens balsamina. This hints to a relatively high degree of specialization of Plasmopara on Balsaminaceae.Therefore, it was the aim of the present study to perform multigene phylogenetic analysis and detailed morphological investigation for several Korean downy mildew samples parasitic to cultivated I. walleriana, and I. balsamina, but also to a northeast Asian wild plant, Impatiens textori. It was revealed that I. textori harbors a new species, which is introduced and described here as Plasmopara elegantissima.

Macruropyxis fraxini on Fraxinus rhynchophylla: Confirmation in the Korean Peninsula after 82 Years and the First Record in South Korea

Macruropyxis fraxini has been recorded on several species of Fraxinus in China, Japan, Russia (Far East), and North Korea since its first recorded observation as a rust fungus on F. rhynchophylla in Jilin, China, in 1899. In the Korean Peninsula, the rust fungus was first recorded on F. rhynchophylla in 1935, based on four specimens collected at Mt. Kumgangsan, Gangwondo Province, in the North Korean territory. We confirmed this rust in the Korean Peninsula after 82 years. The rust fungus was identified based on morphological characteristics and a molecular phylogenetic analysis. This is the first record of M. fraxini in South Korea.

Results of total knee arthroplasty for painless, stiff knees

Background@#Stiff knees, like completely ankylosed or arthrodesed knees, can be painless. Total knee arthroplasty (TKA) for these painless, stiff knees is technically demanding. However, it can correct the alignment and advance the range of motion to improve quality of life. So, we reviewed the preoperative and postoperative results of functional and pain scores, range of motion (ROM) and complications in painless, stiff knees treated by TKA. @*Methods@#Fifteen painless, stiff knees underwent TKA from January 1998 to January 2017. The mean follow-up period was 15.4 (2.4–22.2) years. All the knees were completely ankylosed or arthrodesed. Clinical outcome and complications were evaluated using medical record review, serial plan radiography, ROM assessment, Knee Society score (KSS), Knee Society function score (FS), and a visual analog scale for pain (VAS). @*Results@#All patients were satisfied with their operated knees. Mean KSS and FS scores were improved from 36 and 50.9 to 76.9 and 67.2, respectively (P < 0.001 and P = 0.01). The mean ROM increased from 0º preoperatively to 77.6º (15–130) at the final follow-up (P < 0.001). The mean VAS had worsened from 0 preoperatively to 0.2 postoperatively, however it was not significant (P = 0.1). Major postoperative complications were reported in five of the knees (33.3%). @*Conclusions@#The results of TKA for painless, stiff knees were satisfactory with improved ROM and quality of life. Although some patients had mild pain and complications postoperatively, they were satisfied with the result. However, our study recommends that surgeons should consider the high rate of complications in the completely ankylosed or arthrodesed knees.

Macruropyxis fraxini on Fraxinus rhynchophylla: Confirmation in the Korean Peninsula after 82 Years and the First Record in South Korea

Macruropyxis fraxini has been recorded on several species of Fraxinus in China, Japan, Russia (Far East), and North Korea since its first recorded observation as a rust fungus on F. rhynchophylla in Jilin, China, in 1899. In the Korean Peninsula, the rust fungus was first recorded on F. rhynchophylla in 1935, based on four specimens collected at Mt. Kumgangsan, Gangwondo Province, in the North Korean territory. We confirmed this rust in the Korean Peninsula after 82 years. The rust fungus was identified based on morphological characteristics and a molecular phylogenetic analysis. This is the first record of M. fraxini in South Korea.

Results of total knee arthroplasty for painless, stiff knees

Background@#Stiff knees, like completely ankylosed or arthrodesed knees, can be painless. Total knee arthroplasty (TKA) for these painless, stiff knees is technically demanding. However, it can correct the alignment and advance the range of motion to improve quality of life. So, we reviewed the preoperative and postoperative results of functional and pain scores, range of motion (ROM) and complications in painless, stiff knees treated by TKA. @*Methods@#Fifteen painless, stiff knees underwent TKA from January 1998 to January 2017. The mean follow-up period was 15.4 (2.4–22.2) years. All the knees were completely ankylosed or arthrodesed. Clinical outcome and complications were evaluated using medical record review, serial plan radiography, ROM assessment, Knee Society score (KSS), Knee Society function score (FS), and a visual analog scale for pain (VAS). @*Results@#All patients were satisfied with their operated knees. Mean KSS and FS scores were improved from 36 and 50.9 to 76.9 and 67.2, respectively (P < 0.001 and P = 0.01). The mean ROM increased from 0º preoperatively to 77.6º (15–130) at the final follow-up (P < 0.001). The mean VAS had worsened from 0 preoperatively to 0.2 postoperatively, however it was not significant (P = 0.1). Major postoperative complications were reported in five of the knees (33.3%). @*Conclusions@#The results of TKA for painless, stiff knees were satisfactory with improved ROM and quality of life. Although some patients had mild pain and complications postoperatively, they were satisfied with the result. However, our study recommends that surgeons should consider the high rate of complications in the completely ankylosed or arthrodesed knees.

Characterization of Achlya americana and A. bisexualis (Saprolegniales, Oomycota) Isolated from Freshwater Environments in Korea

Many members of the Saprolegniales (Oomycete) cause mycoses and disorders of fishes, of which Achlya and Saprolegnia are most ubiquitous genera worldwide. During a survey of the diversity of freshwater oomycetes in Korea, we collected seven isolates of Achlya, for which morphological and molecular phylogenetic analyses enabled them to identify as Achlya americana and Achlya bisexualis. In Korea, only a species of Achlya, A. prolifera, has been previously found to cause seedling rot on rice (Oryza sativa), but none of the two species have been reported yet. Importantly, A. bisexualis was isolated from a live fish, namely rice fish (Oryzias sinensis), as well as freshwater, and this is the first report of Achlya-causing mycoses on freshwater fishes in Korea. The presence of A. americana and A. bisexualis on live fish in Korea should be closely monitored, as considering the well-known broad infectivity of these species it has the potential to cause an important emerging disease on aquaculture industry.

Diversity of Aspergillus, Penicillium, and Talaromyces Species Isolated from Freshwater Environments in Korea

In order to elucidate the fungal diversity and community structure in freshwater environments, numerous fungal strains were isolated from freshwater, submerged soils, twigs, dead insects, etc. Among them, the present study has focused specifically on Aspergillus, Penicillium, and Talaromyces species, which produce diverse useful metabolites in general. Twelve strains of Aspergillus isolated were identified as A. japonicus (n = 5), A. tubingensis (3), A. niger (2), and A. flavus (2), 10 strains of which belong to Aspergillus section Nigri, named black Aspergillus. Eight strains of Penicillium were identified as P. brasilianim (n = 3), P. oxalicum (2), P. crustosum (1), P. expansum (1), and P. piscarium (1). Two different strains of Talaromyces were identified as T. pinophilus and T. versatilis. Thus far, Penicillium piscarium and Talaromyces versatilis have been unrecorded in Korea, for which we provide detailed morphological and molecular characteristics.

Phytopythium and Pythium Species (Oomycota) Isolated from Freshwater Environments of Korea

Oomycetes are widely distributed in various environments, including desert and polar regions. Depending upon different habits and hosts, they have evolved with both saprophytic and pathogenic nutritional modes. Freshwater ecosystem is one of the most important habitats for members of oomycetes. Most studies on oomycete diversity, however, have been biased mostly towards terrestrial phytopathogenic species, rather than aquatic species, although their roles as saprophytes and parasites are essential for freshwater ecosystems. In this study, we isolated oomycete strains from soil sediment, algae, and decaying plant debris in freshwater streams of Korea. The strains were identified based on cultural and morphological characteristics, as well as molecular phylogenetic analyses of ITS rDNA, cox1, and cox2 mtDNA sequences. As a result, we discovered eight oomycete species previously unknown in Korea, namely Phytopythium chamaehyphon, Phytopythium litorale, Phytopythium vexans, Pythium diclinum, Pythium heterothallicum, Pythium inflatum, Pythium intermedium, and Pythium oopapillum. Diversity and ecology of freshwater oomycetes in Korea are poorly understood. This study could contribute to understand their distribution and ecological function in freshwater ecosystem.

Two-Round Mixed Lymphocyte Reaction for Evaluation of the Functional Activities of Anti-PD-1 and Immunomodulators

Immune checkpoint inhibitors (ICIs), such as anti-PD-1 and anti-PD-L1 Abs, have shown efficacy for the treatment of various cancers. Although research has actively sought to develop new ICIs and immunomodulators, no efficient in vitro assay system is available to evaluate their functional activities. In the present study, we established a two-round MLR with human PBMCs for evaluation of the T cell-activating capacity of anti-PD-1 and other immunomodulators. We initially performed conventional MLR for this purpose. However, anti-PD-1 blocking Abs could not increase the proliferation of allo-reactive T cells in conventional MLR because PD-L1+ and PD-L2+ cells disappeared gradually during MLR. Therefore, we re-applied the same stimulator PBMCs to the allo-stimulated responder cells as a second-round MLR on day 6 when anti-PD-1 or immunomodulators were also added. In this two-round MLR, the proliferation of allo-reactive T cells was enhanced by anti-PD-1 in a dose-dependent manner or by immunomodulators, such as lenalidomide and galunisertib, a TGF-β receptor-1 inhibitor. Proliferation was further increased by the combination of immunomodulators with anti-PD-1. Here, we established a modified two-round MLR method with human PBMCs for evaluation of the functional activities of anti-PD-1 and immunomodulators.

Bremia itoana (Oomycota, Peronosporales), a Specialized Downy Mildew Pathogen on an East Asian Plant, Crepidiastrum sonchifolium (Asteraceae)

Crepidiastrum sonchifolium, a flowering plant in the daisy family (Asteraceae), is native to East Asia. In Korea, this plant is a locally cultivated vegetable, and its market size is gradually growing. Since the plants with downy mildew infection were initially found at a private farm of Chuncheon city, the occurrences have continued in commercial farms of other regions, highlighting that this disease is spreading throughout Korea. The pathogen was attributed to a member of the genus Bremia that contains many specialized species, each of which displays a narrow host spectrum on Asteraceae. Based on morphological and molecular phylogenetic analyses, along with the high host specificity recently proven for Bremia species, the identity of the causal agent was confirmed as a so far undescribed species of Bremia. Here, we introduce Bremia itoana sp. nov., specific to C. sonchifolium.

Common Peroneal Nerve Palsy Associated with Multiple Knee Ligament Injury / 대한스포츠의학회지

Common peroneal nerve (CPN) injury associated with multiple-ligament knee injury is relatively rare. A 38-year-old male presented with left knee pain occurred during ssireum (Korean wrestling). The patient exhibited positive Lachman, grade 3 varus stress, and also positive dial testing at 30°. Sensory loss of some area of left foot and foot drop were observed. Magnetic resonance imaging showed complete anterior cruciate ligament (ACL) rupture and posterolateral corner (PLC) injury. Motor nerve conduction velocity indicated left CPN palsy. ACL and PLC reconstructions were performed 10 days after injury and nerve exploration was done simultaneously. Neurolysis and primary repair were also performed. At 26 months after injury, muscle power of the tibialis anterior and extensor hallucis longus improved to grade 3, and sensation in CPN area recovered to about 60%. There was good stability in injured knee. To the best of our knowledge, this is the first case report describing CPN palsy with multiple-ligament knee injury during ssireum.

Comparison of Revision Rates Due to Aseptic Loosening between High-Flex and Conventional Knee Prostheses

PURPOSE: The purpose was to evaluate and compare the revision rate due to aseptic loosening between a high-flex prosthesis and a conventional prosthesis. MATERIALS AND METHODS: Two thousand seventy-eight knees (1,377 patients) with at least 2 years of follow-up after total knee arthroplasty were reviewed. Two types of implants were selected (LPS-Flex and LPS, Zimmer) to compare revision and survival rates and sites of loosened prosthesis component. RESULTS: The revision rate of the LPS-Flex (4.9%) was significantly higher than that of the conventional prosthesis (0.6%) (p<0.001). The 5-, 10-, and 15-year survival rates were 98.9%, 96.2% and 92.0%, respectively, for the LPS-Flex and 99.8%, 98.5% and 93.5%, respectively, for the LPS. The survival rate of the high-flex prosthesis was significantly lower than that of the conventional prosthesis, especially in the mid-term period (range, 5 to 10 years; p=0.002). The loosening rate of the femoral component was significantly higher in the LPS-Flex prosthesis (p=0.001). CONCLUSIONS: The LPS-Flex had a higher revision rate due to aseptic loosening than the LPS prosthesis in the large population series with a long follow-up. The LPS-Flex should be used carefully considering the risk of femoral component aseptic loosening in the mid-term (range, 5 to 10 years) follow-up period after initial operation.