Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019.In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virusinfected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

Background: As the number of large-scale studies involving multiple organizations producing data has steadily increased, an integrated system for a common interoperable format is needed. In response to the coronavirus disease 2019 (COVID-19) pandemic, a number of global efforts are underway to develop vaccines and therapeutics. We are therefore observing an explosion in the proliferation of COVID-19 data, and interoperability is highly requested in multiple institutions participating simultaneously in COVID-19 pandemic research. Results: In this study, a laboratory information management system (LIMS) approach has been adopted to systemically manage various COVID-19 non-clinical trial data, including mortality, clinical signs, body weight, body temperature, organ weights, viral titer (viral replication and viral RNA), and multiorgan histopathology, from multiple institutions based on a web interface. The main aim of the implemented system is to integrate, standardize, and organize data collected from laboratories in multiple institutes for COVID-19 non-clinical efficacy testings. Six animal biosafety level 3 institutions proved the feasibility of our system. Substantial benefits were shown by maximizing collaborative high-quality non-clinical research. Conclusions This LIMS platform can be used for future outbreaks, leading to accelerated medical product development through the systematic management of extensive data from non-clinical animal studies.

OBJECTIVE: To evaluate the bioactivity, and the biomechanical and bone-regenerative properties of Ti6Al4V miniscrews subjected to anodization, cyclic precalcification, and heat treatment (APH treatment) and their potential clinical use. METHODS: The surfaces of Ti6Al4V alloys were modified by APH treatment. Bioactivity was assessed after immersion in simulated body fluid for 3 days. The hydrophilicity and the roughness of APH-treated surfaces were compared with those of untreated (UT) and anodized and heat-treated (AH) samples. For in vivo tests, 32 miniscrews (16 UT and 16 APH) were inserted into 16 Wistar rats, one UT and one APH-treated miniscrew in either tibia. The miniscrews were extracted after 3 and 6 weeks and their osseointegration (n = 8 for each time point and group) was investigated by surface and histological analyses and removal torque measurements. RESULTS: APH treatment formed a dense surface array of nanotubular TiO2 layer covered with a compact apatite-like film. APH-treated samples showed better bioactivity and biocompatibility compared with UT and AH samples. In vivo, APH-treated miniscrews showed higher removal torque and bone-to-implant contact than did UT miniscrews, after both 3 and 6 weeks (p < 0.05). Also, early deposition of densely mineralized bone around APH-treated miniscrews was observed, implying good bonding to the treated surface. CONCLUSIONS: APH treatment enhanced the bioactivity, and the biomechanical and bone regenerative properties of the Ti6Al4V alloy miniscrews. The enhanced initial stability afforded should be valuable in orthodontic applications.
Alloys* ; Body Fluids ; Hot Temperature* ; Hydrophobic and Hydrophilic Interactions ; Immersion ; Osseointegration ; Rats, Wistar ; Tibia ; Torque

Tetanus is a neurologic disorder caused by a tetanospasmin released from Clostridium tetani and usually occurs following a stab wound or dirty abrasion. Tetanus is uncommon in Korea due to the introduction of vaccination programs. Furthermore, tetanus associated with a gangrenous perforation of the small bowel is extremely rare. We report a case of tetanus developed in a patient who was diagnosed with a gangrenous perforation of the small bowel. This is the first reported case in Korea.
Clostridium tetani ; Digestive System Surgical Procedures ; Humans ; Intestinal Perforation ; Korea ; Metalloendopeptidases ; Nervous System Diseases ; Tetanus ; Tetanus Toxin ; Vaccination ; Wounds, Stab

Capillary hemangioma of the trachea is an extremely rare benign tumor in adults. We present the case of a 28-year-old woman with hemoptysis owing to a tumor of the proximal trachea. The tumor was removed by rigid bronchoscopy. The resulting specimens showed capillary hemangioma without any signs of malignant transformation. This presentation is the first case in Korea. Although tracheal capillary hemangioma is a rare disease, we should consider it as a possible cause of hemoptysis in the young adult.
Adult ; Bronchoscopy ; Capillaries ; Female ; Hemangioma, Capillary ; Hemoptysis ; Humans ; Korea ; Rare Diseases ; Trachea ; Young Adult

BACKGROUND: Skin cancer is one of the most preventable cancers by sun-protection and sunscreen is the most commonly used method of sun protection. OBJECTIVES: The aim of this study is to evaluate the awareness of harmful effects of sun exposure and behavior of sunscreen use in Korean. METHODS: One thousand, two hundred and seventy-four subjects who visited Dermatology Department at Asan Medical Center between April and July 2000 were interviewed. The questionnaire provided information about demographic characteristics, daily sun-exposure time, and sunburn history in the year before. It also included the questions about the causes of wrinkle, sunspot, chloasma, and skin cancer, as the awareness of the harmful effects of sun exposure. The use of sunscreen or other sun-protective methods, and the knowledge about sun protection factor (SPF) were also reported. RESULTS: The harmful effects of the sun in causing wrinkle, sunspot, chloasma, and skin cancer were conceived by 11.1%, 24.4%, 41.4%, and 44.3% of the respondents respectively. Thirty nine percent of the respondents used sunscreens, and the other 61% hardly knew necessity of sunscreens. Those who understood the meaning of sun protection factor(SPF) were 23.7%. Sun-protective methods except using sunscreens were use of a hat or a cap(53.2%), long-sleeved clothing(27.2%), a parasol(27.0%), heavy make-up(11.2%), and a towel(3.8%). Male respondents, people who were younger than 20 or older than 70, and those who had not sunburned the year before were less likely to use sunscreens. CONCLUSION: The results indicate an urgent need for education about the harmfulness of sun exposure as well as benefits of sunscreens.
Chungcheongnam-do ; Surveys and Questionnaires ; Dermatology ; Education ; Humans ; Male ; Melanosis ; Skin Neoplasms ; Solar Activity ; Solar System* ; Sun Protection Factor ; Sunburn ; Sunscreening Agents

We report the case of a 48-year-old man presenting with a pubic nodule and multiple ulcers on penis and scrotum. He had a kidney transplantation two months ago and has been taking cyclosporine, prednisolone, and mycophenolate mofetil. The biopsy specimen from the nodule showed vasculitis and multiple cytomegalic cells in dermis. The biopsy specimen from the scrotal ulcer showed a cluster of multinucleated giant cells and acantholysis in epidermis and cytomegalic cells and vasculitis in dermis, suggestive of HSV infection in epidermis and CMV infection in dermis. Specific immunoperoxidase for CMV antigens positively stained cytomegalic endothelial cells and fibroblasts in both specimens. Evidence of CMV viremia as pp65 was detected in circulating polymorphonuclear leukocytes by immunocytochemical tests although there was no evidence of other organ involvement. Immediately, he was placed on intravenous ganciclovir therapy for 3 weeks. The lesions cleared leaving scars and he was discharged in good general condition.
Acantholysis ; Biopsy ; Cicatrix ; Cyclosporine ; Cytomegalovirus ; Dermis ; Endothelial Cells ; Epidermis ; Fibroblasts ; Ganciclovir ; Giant Cells ; Humans ; Immunocompromised Host* ; Kidney Transplantation ; Male ; Middle Aged ; Neutrophils ; Penis ; Prednisolone ; Scrotum ; Ulcer* ; Vasculitis ; Viremia

We report a case of ruptured mycotic aneurysm involving innominate artery requiring an urgent surgical treatment. A 62-yr-old woman presented with fever and dyspnea. Previously, she was diagnosed with colon cancer and received right hemicolectomy and one cycle of adjuvant chemotherapy. On echocardiogram, pericardial effusion was noted and emergency pericardiocentesis was performed. CT scan revealed aortic aneurysm involving ascending aorta and innominate artery, and thrombi surrounding those structures. Patch repair of the defect in the ascending aorta and ringed Goretex graft to bypass the innominate and ascending aorta were performed. We believe that this is the first case of ruptured mycotic aneurysm involving innominate artery.
Aneurysm, Infected/*surgery ; Aorta/pathology ; Aortic Aneurysm/surgery ; Brachiocephalic Trunk/pathology ; Colonic Neoplasms/drug therapy/surgery ; Female ; Human ; Middle Aged ; Tomography, X-Ray Computed ; Transplants

Local cutaneous reactions have been reported at injection sites of interferon therapy, but these are usually erythema or rarely induration. Skin necrosis at the injection site is rare. We describe here a patient with multiple sclerosis who presented with cutaneous necrosis at the injection sites of interferon-β. Biopsy of the necrotic lesion showed dermal vessel thrombosis and complete ischemic coagulative necrosis of epidermis and dermis.
Biopsy ; Dermis ; Epidermis ; Erythema ; Humans ; Interferon-beta* ; Interferons ; Multiple Sclerosis ; Necrosis* ; Skin* ; Thrombosis

A 28-year-old woman presented with multiple whiplash-like eruptions of 4-days' duration around both ankles, feet, knees, and hands after contact with a jellyfish. Histological examination showed epidermal necrosis with intraepidermal vesicles containing neutrophils and red blood cells, dermal necrotic vasculitis, diffuse dermal infiltration of neutrophils, lymphocytes, and beanbag cells, and degeneration of collagen fibers.
Adult ; Ankle ; Collagen ; Dermatitis* ; Erythrocytes ; Female ; Foot ; Hand ; Humans ; Knee ; Lymphocytes ; Necrosis ; Neutrophils ; Vasculitis