Animal models for the risk assessment of viral pandemic potential / 한국실험동물학회지

Pandemics affect human lives severely and globally. Experience predicts that there will be a pandemic for sure although the time is unknown. When a viral epidemic breaks out, assessing its pandemic risk is an important part of the process that characterizes genomic property, viral pathogenicity, transmission in animal model, and so forth. In this review, we intend to figure out how a pandemic may occur by looking into the past influenza pandemic events. We discuss interpretations of the experimental evidences resulted from animal model studies and extend implications of viral pandemic potentials and ingredients to emerging viral epidemics. Focusing on the pandemic potential of viral infectious diseases, we suggest what should be assessed to prevent global catastrophes from influenza virus, Middle East respiratory syndrome coronavirus, dengue and Zika viruses.

Towards the Application of Human Defensins as Antivirals

Defensins are antimicrobial peptides that participate in the innate immunity of hosts. Humans constitutively and/or inducibly express α- and β-defensins, which are known for their antiviral and antibacterial activities. This review describes the application of human defensins. We discuss the extant experimental results, limited though they are, to consider the potential applicability of human defensins as antiviral agents. Given their antiviral effects, we propose that basic research be conducted on human defensins that focuses on RNA viruses, such as human immunodeficiency virus (HIV), influenza A virus (IAV), respiratory syncytial virus (RSV), and dengue virus (DENV), which are considered serious human pathogens but have posed huge challenges for vaccine development for different reasons. Concerning the prophylactic and therapeutic applications of defensins, we then discuss the applicability of human defensins as antivirals that has been demonstrated in reports using animal models. Finally, we discuss the potential adjuvant-like activity of human defensins and propose an exploration of the ‘defensin vaccine’ concept to prime the body with a controlled supply of human defensins. In sum, we suggest a conceptual framework to achieve the practical application of human defensins to combat viral infections.

Original Antigenic Sin Response to RNA Viruses and Antiviral Immunity

The human immune system has evolved to fight against foreign pathogens. It plays a central role in the body's defense mechanism. However, the immune memory geared to fight off a previously recognized pathogen, tends to remember an original form of the pathogen when a variant form subsequently invades. This has been termed 'original antigenic sin'. This adverse immunological effect can alter vaccine effectiveness and sometimes cause enhanced pathogenicity or additional inflammatory responses, according to the type of pathogen and the circumstances of infection. Here we aim to give a simplified conceptual understanding of virus infection and original antigenic sin by comparing and contrasting the two examples of recurring infections such as influenza and dengue viruses in humans.

Original Antigenic Sin Response to RNA Viruses and Antiviral Immunity

The human immune system has evolved to fight against foreign pathogens. It plays a central role in the body's defense mechanism. However, the immune memory geared to fight off a previously recognized pathogen, tends to remember an original form of the pathogen when a variant form subsequently invades. This has been termed 'original antigenic sin'. This adverse immunological effect can alter vaccine effectiveness and sometimes cause enhanced pathogenicity or additional inflammatory responses, according to the type of pathogen and the circumstances of infection. Here we aim to give a simplified conceptual understanding of virus infection and original antigenic sin by comparing and contrasting the two examples of recurring infections such as influenza and dengue viruses in humans.

CT Findings of Normal Pancreatic Tail: Variety of Morphology and Location

PURPOSE: To determine the morphology and location of normal pancreatic tail, as seen on abdominal CT. MATERIALS AND METHODS: A hundred and one patients without pancreatic disease underwent CT scanning. We thendetermined how to relate the location of the pancreatic tail with the splenic hilum, left kidney, and pancreaticbody. We compared the thickness of the tail with that of the body and analysed of the morphology of the tail. RESULTS: Seventy-seven percent of all pancreatic tails were located below the splenic hilum, with 59% of thisproportion located located 1 to 2 cm below. Fifty percent of tails were located at the level of the uppermostquarter of the left kidney, and a further 27% at the level of the second quarter ; 75% were located in theventrolateral portion of this kidney and 23% in the ventral portion. In 48% of patients, the pancreatic tail andbody were the same thickness, and in a further 48%, the tail was thicker than the body. In 34% of patients, thetail showed focal bulging, and in another 32%, it tapered smoothly. Forty seven percent of tails were locatedbelow the pancreatic body and a further 37% were found at the same level as the body. CONCLUSION: Abdominal CTscans showed differing morphology and location of the pancreatic tail. The recognition of these variations willdiminish speculation as to their true nature.