The advent of the global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) necessitates a thorough study of the stability and transmissibility in the environment. We characterized the stability of SARS-CoV-2 in three water matrices: fresh, tap, and seawater. The minimum infective dose of SARS-CoV-2 in Vero cells was confirmed to be 10 3 PFU/mL. The stability of SARS-CoV-2 varied according to the water matrix: infective SARSCoV-2 was undetectable after treatment with fresh water and seawater, but remained detectable for 2 days in tap water, when starting with an initial concentration of 10 4 PFU/mL. When the starting concentration was increased to 10 5 PFU/mL, a similar trend was observed. In addition, viral RNA persisted longer than infectious virus in all water matrices. This study was conducted in stagnant water containing a significantly high titer of virus, thus, human-to-human transmission of SARS-CoV-2 through the actual aquatic environment is expected to be rare.

No abstract available.
Humans ; Infant, Newborn*

The CD8(+)CD28(+) T cells have known to mediate major histocompatibility complex class I-restricted cytolysis and to secret an HIV-1 inhibitory factor. As HIV infection lead to dramatic changes within the cellular immune system, the cellular cytotoxicities decrease in the duration of the HIV infection. To determine the importance of the cellular cytotoxicities in long-term nonprogression, we tried to compare CD28 expression on total T, CD4(+) T, and CD8(+) T cells as one of methods for cellular cytotoxicity measurements between long-term nonprogressor and normal person or between long-term nonprogressor and rapid progressor. The median percentages and counts of CD4(+) T cells of the norrnal, the long-term nonprogressor, and the rapid progressor groups were 39.9 and 0.96 * 10(9) cells/L, 24.6 and 0.58 * 10(9) cells/L, 9.9 and 0.15 * 10 cells/L, respectively. As a result of comparison of the cells having CD28 surface molecules on CD8(+) T cells in the long-term nonprogressor and the rapid progressor group, they showed over 5 times lower than that in the normal group. Especially, the long-term nonprogressor regarded to the healthy HIV-infected patient showed much lower CD28 expression on total T, CD4(+) T, and CD8(+) T cells than those of the normal person. The proportions of CD4'CD28 T and CD3CD28 T cell subsets showed the significant difference between the LTNP and the RP group. In conclusion, although HIV-infected patients were LTNPs having the steady CD4(+) T cell counts and no clinical symptoms, we suggested that HIV led to abnormality within the lymphocyte subsets such as the altered expression of CD28 molecules on various T cell subsets and this result would cause deficiency of host immune function and failure of control of HIV replication by anergy in T cell subsets.
Cell Count ; HIV ; HIV Infections ; HIV-1 ; Humans ; Immune System ; Lymphocyte Subsets ; Major Histocompatibility Complex ; T-Lymphocyte Subsets* ; T-Lymphocytes

Acute thyroid abscess is an uneommon type of neck infection. We experieneed a case of staphylococcal thyroid abscess in 29 year old man, diagnosed by needle aspira~tion and culture of the aspirate. The patient had complained fever and slowly growing anterior neck swelling. Needle aspiration of the cold nodule prior to broad spectrum antibiotics was performed. After Surgical excision combined with antibiotics, he was discharged with elinical improvement. The laboratory diagnosis and clinical course was summarized and is reported with relevent references.
Abscess ; Anti-Bacterial Agents ; Clinical Laboratory Techniques ; Fever ; Humans ; Neck ; Needles ; Staphylococcus aureus ; Staphylococcus ; Thyroid Gland

For 16 years after the finding of HIV as an agent of AIDS in 1981, HIV therapeutic drugs of reverse transcriptase inhibitors (AZT, ddI, ddC, d4T) and protease inhibitors have been developed. Recent studies also were focused on a combination therapy by using HIV therapeutic drugs or natural compounds. Korean red ginseng (KRG) of natural compounds has been well known as a good reinforcement agent in Asia. The percentage of CD3+CD4+ T cell in nine HIV-infected patients without KRG treatment averaged 17.8% on baseline and decreased 15.8% after 6 months, whereas the percentage of the cell in fifteen HIV-infected patients with KRG treatment averaged 15.3% on baseline and increased up to 18.9% after the same period. The average percentage of CD3+CD8+ T cell of KRG-nontreated and KRG-treated HIV patients increased after 6 months 47.8% to 50.7% and 44.7% to 51.4%, respectively; and the average percentage of B and NK cell in the KRG-nontreated and KRG-treated HIV patients decreased 9.4% to 7.9% and 13.0% to 9.7%, 8.9% to 8.5% and 16.2% to 11.6%, respectively, KRG, therefore, didn't have any effects on the CD3+CD8+ T cell, B cell, and NK cell. However, it seems that KRG has a potential activity for stimulating the
Asia ; HIV ; Humans ; Killer Cells, Natural ; Lymphocyte Subsets* ; Lymphocytes* ; Panax* ; Protease Inhibitors ; Reverse Transcriptase Inhibitors

OBJECTIVE: The purpose of this study was to determine differential findings between Type I degenerative endplate changes and diskitis on MR images. MATERIALS AND METHODS: MR images(T1, T2 weighted or Gradient echo) of L-spine in twelve patients with a Type I degenerative endplate change and nine patients with diskitis were reviewed for the morphologic and signal intensity changes of intervertebral disc, vertebral endplate and vertebral body. RESULTS: involvement of the marrow of one side of intervertebral disk was noted in 33%(4/12) of Type I endplate changes, and 11%(1/9) of diskitis. Decreased signal intensity of intervertebral disc was seen in 92% (11/12) of Type I endplate changes, and 11%(1/9) of diskitis on T2 weighted or Gradient echo image. Loss of intranuclear cleft signal was noted in 17%(2/12) of Type I endplate changes, and 78%(7/9) of diskitis. Even disc space narrowing was seen in all cases of Type I endplate changes, but uneven narrowing was seen in 44%(4/9) of diskitis. Only partial cortical disruption was noted in 42%(5/12) of Type I endplate changes, while partial or total cortical disruption was noted in 89%(8/9) of diskitis. The extent of marrow involvement more than 2/3 was noted in 8%(1/12) of Type I endplate changes, but 56%(5/9) of diskitis. The margin of signal intensity change was well defined in 33%(4/12) of Type I endplate changes, but that of diskitis was ill defined in all cases(9/9). Gadolinium enhancement was homogeneous in all cases(5/5) of Type I endplate changes, and 63%(5/8) of diskiris. CONCLUSION: We conclude that involvement of one side of endplate, decreased signal intensity of intervertebral disc on T2 weighted or gradient echo image, even narrowing of disc space, lesser extent of marrow involvement, well defined margin and homogeneous enhancement pattern are the findings of Type I degenerative endplate changes on MR images.
Bone Marrow ; Diagnosis, Differential* ; Discitis* ; Gadolinium ; Humans ; Intervertebral Disc ; Magnetic Resonance Imaging*

BACKGROUND: Quality control is important for accurate diagnosis of human immunodeficiency virus (HIV) infection, and proficiency testing with external quality controls is an important part of quality control. This study intended to develop and supply customized external quality controls for HIV antigen/antibody testing fitted with currently used reagents for standardization of HIV infection diagnosis and evaluation of HIV testing competency of laboratories in Korea. METHODS: Serological tests and inactivation were performed on the obtained HIV antibody positive plasma. To manufacture quality controls having the required antibody titers, dilution ratio was searched using VIDAS (bioMérieux, France), Architect (Abbott Laboratories, USA), and Cobas 8000 (Roche Diagnostics, Germany) analyzers. Diluted source plasma was divided into aliquots after filtering. Homogeneity and stability of the produced external quality controls were evaluated. RESULTS: The collected HIV antibody positive plasma was confirmed by Western blot. Dilution ratios for source plasma were produced for each analyzer showing signal-to-cut-off 2–3, 5–7, and 15–16 reactivity. Diluted plasma was made to 1 mL aliquots and total set of 1,500 external quality controls for HIV antigen/antibody were manufactured. Produced controls satisfied the required criteria of homogeneity and showed less than 10% coefficient of variation for stability except negative controls. CONCLUSIONS: Customized external quality controls were developed and qualified for HIV testing reagents used in Korea. Continuous external quality control assessment for HIV tests with controls would be required.
Blotting, Western ; Diagnosis ; HIV Infections ; HIV* ; Humans* ; Indicators and Reagents ; Korea* ; Plasma ; Quality Control* ; Serologic Tests

To evaluate MR findings of soft tissue masses in extremities and to find the helpful findings of distinguish benignity from malignancy, 28 soft tissue masses (22 benign and 6 malignant) in extremities were reviewed. T1-weighted, proton density, T2-weighted and Gd-DTPA enhanced images were obtained. MR images allowed a specific diagnosis in a large number of benign masses, such as hemangioma(8/9), lipoma(2/2), angiolipoma(1/1), epidermoid cyst(2/2), myositis ossificans(1/1), synovial chondromatosis(1/1) and pigmented villonodular synovitis (1/2). Specific diagnosis was difficult in the rest of the masses including malignancy. However, inhomogenous signal intensities with necrosis and inhomogenous enhancement may suggest malignant masses.
Diagnosis ; Extremities ; Gadolinium DTPA ; Myositis ; Necrosis ; Protons ; Synovitis, Pigmented Villonodular

For the adequate intraarticular exposure in medial talar dome lesions, medial malleolar osteotomy is necessary in some cases. Many operative techniques including transverse, oblique, inverted V-shape, crescentic and step-cut osteotomies of the medial malleolus have been described previously. But their techniques have several problems such as nonunion, rotation and limited access to lesions. So we introduce the new reverse chevron medial malleolar osteotomy which provides excellent access to lesions, good stability and a broad cancellous surface for rapid healing.
Osteotomy* ; Talus

PURPOSE: The aneurysmal aortitides could be classified into 4 categories by clinical features, and each category has a different principle of treatment and prognosis. The purposes of this study were 1) to classify the CT findings of the aneurysmal aortitides by the 4 categories-aortic aneurysm, aortic dissection, penetrating atheromatous aortic ulcer, and annuloaortic ectasis, and 2) to evaluate the complications of each category. MATERIALS AND METHODS: We reviewed the CT findings of 33 cases of aneurysmal aortitides, and classified them into the above-mentioned 4 categories. Thirty-two patients were examined with CT with or without ultrasound, angiography, echocardiography, or MRI. Among them, 15 cases were confirmed with operation and the rest were diagnosed with radiologic and clinical findings. RESULTS: There were 17 aortic aneurysms, 9 aortic dissections, 4 penetrating atheromatous aortic ulcers, and 3 annuloaortic ectases. Aortic rupture, the most serious complication of aortitides, occurred in 9 cases. The causes of the rupture were aortic dissection, aneurysm, and penetrating aortic ulcer in descending order of frequency. The most frequent site of rupture was retroperitoneum. CONCLUSION: Using CT with or without other diagnostic tools, we could classify the aneurysmal aotitides into 4 categories and evaluate the complications.
Aneurysm* ; Angiography ; Aortic Aneurysm ; Aortic Rupture ; Aortitis* ; Classification* ; Echocardiography ; Humans ; Magnetic Resonance Imaging ; Prognosis ; Rupture ; Ulcer ; Ultrasonography