Systematic assessment of South Korea’s capabilities to control COVID-19

South Korea’s COVID-19 control strategy has been widely emulated. Korea’s ability to rapidly achieve disease control in early 2020 without a “Great Lockdown” despite its proximity to China and high population density make its achievement particularly intriguing. This paper helps explain Korea’s pre-existing capabilities which enabled the rapid and effective implementation of its COVID-19 control strategies. A systematic assessment across multiple domains demonstrates that South Korea’s advantages in controlling its epidemic are owed tremendously to legal and organizational reforms enacted after the MERS outbreak in 2015. Successful implementation of the Korean strategy required more than just a set of actions, measures and policies. It relied on a pre-existing legal framework, financing arrangements, governance and a workforce experienced in outbreak management.     

In vitro cellular immune responses to recombinant antigens of Mycobacterium avium subsp. paratuberculosis

Five recombinant antigens (Ags; 85A, 85B, 85C, superoxide dismutase [SOD], and 35-kDa protein) were purified from Mycobacterium avium subsp. paratuberculosis and evaluated for their ability to stimulate peripheral blood mononuclear cells (PMBCs) from fecal-culture-positive cows (low and medium shedders) and culture-negative healthy cows. Recombinant Ags 85A, 85B, and 85C induced significant lymphocyte proliferation as well as the production of gamma interferon (IFN-gamma), interleukin-2 (IL-2), IL-12, and tumor necrosis factor alpha (TNF-alpha), but not IL-4, from low and medium shedders. The 85 antigen complex did not stimulate PMBC proliferation from culture-negative healthy cows. The 35-kDa protein also induced significant lymphocyte proliferation as well as the production of IFN-gamma and IL-4 from low and medium shedders. CD4(+) T cells and CD25(+) (IL-2R) T cells were stimulated the most by 85A and 85B, while the 35-kDa protein primarily stimulated CD21(+) B cells involved in humoral immune responses. Interestingly, SOD was less immunostimulatory than other antigens but strongly induced gammadelta(+) T cells, which are thought to be important in the early stages of infection, such as pathogen entry. These data provide important insight into how improved vaccines against mycobacterial infections might be constructed.     

Osteosarcomatosis

A review of the 690 cases of osteosarcoma in the radiographic file of the Armed Forces Institute of Pathology revealed 29 cases of "osteosarcomatosis" (multiple skeletal sites of osteosarcoma). Fifteen of these patients were 18 years old and under and manifested rapidly appearing, usually symmetric, sclerotic metaphyseal lesions. The remaining 14 patients were more than 18 years old and had fewer, asymmetric sclerotic lesions. In most patients (28 of 29), a radiographically dominant skeletal tumor was seen. Pulmonary metastases occurred in the majority of patients and were detected at the same time as the bone lesions. These 29 patients were studied with regard to demographic data and skeletal distribution and radiographic appearance of their lesions. As a result of the findings, a metastatic origin from a primary dominant osteosarcoma is favored over a multifocal origin as the basis for osteosarcomatosis. Osteosarcomatosis is more commonly encountered in the mature skeleton than has been previously recognized.     

Pretreatment of low dose radiation reduces radiation-induced apoptosis in mouse lymphoma (EL4) cells

Induction of an adaptive response to ionizing radiation in mouse lymphoma (EL4) cells was studied by using cell survival fraction and apoptotic nucleosomal DNA fragmentation as biological end points. Cells in early log phase were pre-exposed to low dose of γ-rays (0.01 Gy) 4 or 20 hrs prior to high dose γ-ray (4, 8 and 12 Gy for cell survival fraction analysis; 8 Gy for DNA fragmentation analysis) irradiation. Then cell survival fractions and the extent of DNA fragmentation were measured. Significant adaptive response, increase in cell survival fraction and decrease in the extent of DNA fragmentation were induced when low and high dose γ-ray irradiation time interval was 4 hr. Addition of protein or RNA synthesis inhibitor, cycloheximide or 5,6-dichloro-1-β-d-ribofuranosylbenzimidazole (DRFB), respectively during adaptation period, the period from low dose γ-ray irradiation to high dose γ-ray irradiation, was able to inhibit the induction of adaptive response, which is the reduction of the extent DNA fragmentation in irradiated EL4 cells. These data suggest that the induction of adaptive response to ionizing radiation in EL4 cells required both protein and RNA synthesis.     

Flavonoids fromCirsium rhinoceros

Six flavonoids were isolated from the aerial parts ofCirsium rhinoceros. The flavonoids were identified as apigenin, luteolin, pectolinarigenin-7-O-β-D-glucopyranoside, linarin, pectolinarin and hispidulin-7-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside on the basis of chemical and spectral evidence.     

Limitations in the use of tubulin polymerization assays as a screen for the identification of new antimitotic agents: The potent marine natural product curacin A as an example

Curacin A is a newly isolated lipid natural product that binds in the colchicine site of tubulin and inhibits mitosis. We have examined its effects on tubulin polymerization, studied by turbidimetry, under three reaction conditions. In 1.0 M glutamate + 1.0 mM MgCl₂, with a 37°C reaction temperature, we could find no concentration of curacin A that completely inhibited polymerization. A maximal inhibitory effect on turbidity development (about 50%) was observed with 5 m?M drug. Higher drug concentrations induced an abnormal polymerization reaction, which at 40 m?M differed little from the control reaction except for slightly delayed depolymerization in response to reducing the temperature to 0°C. In 0.8 M glutamate (no MgCl₂), with a 30°C reaction temperature, complete inhibition did occur at 3–5 m?M drug, but higher drug concentrations again induced an abnormal polymerization reaction. With 40 m?M curacin A this reaction was also similar to the control reaction, except that cold-induced depolymerization was slightly enhanced relative to the control. When polymerization was induced by microtubule-associated proteins, maximal inhibition of turbidity development (about 70%) occurred with 2 m?M drug, with higher curacin A concentrations inducing abnormal polymerization reactions that reached about 60% of the control turbidity readings. Under all three reaction conditions the polymer induced by high concentrations of curacin A consisted of large aggregates of tightly coiled spiral fibers that had a 2–3 filament substructure. The implications of these findings with curacin A are discussed in terms of the use of tubulin polymerization assays as a screen for identifying new antimitotic drugs. © 1995 Wiley-Liss, Inc.

1 This article is a US Government work and, as such, is in the public domain in the United States of America.

     

Immunohistochemical analysis of Fas ligand expression in normal human tissues

Cross-linking of Fas and Fas ligand (FasL) induces apoptosis in Fas-bearing cells and regulates apoptosis. Fas is widely expressed in normal human tissues, but FasL expression has been considered to be restricted to lymphoid tissues. Recent studies have demonstrated that FasL is also expressed in some nonlymphoid tissues. To screen the in situ expression of FasL in normal human tissues, immunohistochemistry was performed using paraffin-embedded human tissues. FasL immunostaining was easily detected in testis, neurons, trophoblasts, tonsil, lymph node, Paneth cells, hepatocytes, renal tubular epithelium and bronchial epithelium, consistent with previous reports. Surprisingly, FasL was also expressed in many other cell types, including thymic medulla, skeletal muscle, cardiac muscle, pituitary gland, parathyroid gland, prostate glands, oocytes, epithelium of fallopian tube, endometrial glands, and gastric parietal cells. These findings demonstrate that FasL is widely expressed in human tissues and suggest that wide but cell-type specific expression of FasL may not only be implicated in the regulation of immune homeostasis but also in the regulation of cell death and life in many cell types in vivo.     

Colorectal mucinous carcinoma: findings on MRI

PURPOSE: The purpose of this work was to define the characteristic MR features of colorectal mucinous carcinomas and to correlate the mucin pool with the signal intensity of this tumor. METHOD: MRI of 12 cases of pathologically proven colorectal carcinoma containing mucin was evaluated. We analyzed the signal intensity of tumor on T1- and T2-weighted MR images and correlated the area of intratumoral high signal intensity on T2-weighted images with the mucinous pool on the pathologic specimens. Two radiologists independently estimated the area of high signal intensity in the tumor on T2-weighted images and one pathologist estimated the amount of mucinous pool in the pathologic specimen. RESULTS: In 9 (75%) of 12 cases, focal or diffuse high signal intensity areas were detected on T2-weighted fast spin echo images. In seven cases in which mucin pools were seen macroscopically, partial (n = 3) or diffuse high signal intensity areas were noted on the T2-weighted images. Among the five cases in which microscopic mucinous pools were detected on the pathologic slides, three cases showed no high signal foci on MR images, and in the remaining two cases, high signal intensity areas were noted as small foci. CONCLUSION: Intratumoral high signal intensity on T2-weighted fast spin echo MR images occurs in mucinous carcinomas and correlates with the mucin pools on pathologic specimens.     

Transfer of extensor carpi radialis longus or brevis for opponensplasty

For the restoration of thumb opposition many types of tendon transfer techniques have been described. The flexor digitorum superficialis (FDS) of the ring finger is commonly selected as a motor. On occasion, however, the quality of the flexor muscles of the fingers or wrist is not good enough for tendon transfer and another available muscle must be selected. In this situation, we have preferred to use an extensor carpi radialis longus (ECRL) or brevis (ECRB) transfer to restore opposition of the thumb. Follow-up examination, at an average 5 years and 10 months after operation, showed that the results of ten of 11 transfers were excellent and the other was good.     

The publication rates of presentations at major Spine Specialty Society meetings (NASS, SRS, ISSLS)

STUDY DESIGN: A review of all the presentations at three major spine specialty meetings held over a 3-year period. OBJECTIVES: To determine the rate of publication in peer-reviewed journals after presentations at major spine meetings conducted annually by the following three organizations: North American Spine Society (NASS), Scoliosis Research Society (SRS), and International Society for the Study of the Lumbar Spine (ISSLS). SUMMARY OF BACKGROUND DATA: The rate of publication for presentations at national and international meetings has been determined for medical and surgical subspecialties. This rate has been used to judge the quality of the content of the meetings and to determine the validity of the research presentations. METHODS: All presentations either in poster or oral presentation form were entered into a database covering a 3-year period for spine specialty meetings conducted annually by the following three organizations: NASS 1990 to 1992, SRS 1991 to 1993, and ISSLS 1991 to 1993. A computer search for each abstract was performed with the Melvyl Medline Plus database to determine if the abstract had been published in a peer-reviewed journal from 1990 to the end of 1997. Publication rates for presentations at these three meetings were determined over a 3-year period. RESULTS: A total of 1186 abstracts were listed over a 3-year period in the final programs of these three meetings for the years 1991 to 1993 (SRS, ISSLS) and 1990 to 1992 (NASS). Of these 1186 abstracts, 516 were published in peer-reviewed journals, giving an overall publication rate of 43.5%. The publication rates for the three different meetings (NASS, SRS, ISSLS) were similar, with values of 40%, 47%, and 45% respectively. More than 90% of the publications resulting from these meetings were published within a period of 4 years from the data of the meeting. CONCLUSIONS: The publication rates of presentations at three major spine specialty meetings are high and quite comparable with the publication rates of meetings in other medical subspecialties. This reflects the high quality of the meeting programs and validates their selection process.