Genetic characterization of avian polyomaviruses identified from psittacine birds in South Korea.

Budgerigar fledgling disease (BFD) is a contagious disease caused by avian polyomavirus (APV) in psittacine birds and causes high mortality rates. Here, eight APV-positive cases were confirmed from dead parrots or parrot tissue samples by polymerase chain reaction (PCR). Full-length genome sequencing showed high nucleotide identity (98.84-100%) between the APV strains. Phylogenetic analysis revealed that two genogroups were cocirculating in South Korea. The nucleotide sequences of five strains, collected from different parrot species, were identical; however, pathological lesions were observed in only two parrots, both aged 2 months. Pathology included necrotic spots in the liver, subcutaneous haemorrhage, hepatomegaly, ascites, intranuclear inclusion bodies, hepatocyte karyomegaly, hepatic necrosis, and bile duct proliferation. This suggests that the pathogenicity of APV might be host age-dependent regardless of the host species. This study improves our understanding of APV pathogenicity and provides a more detailed genetic characterization of APV strains.RESEARCH HIGHLIGHTS Eight APV strains were identified in South Korea from 2019 to 2021.By phylogenetic analysis, South Korean APV strains were classified into two clades.

Application of metagenomics for diagnosis of broilers displaying neurological symptoms.

BACKGROUND: Thirty-two-day-old broiler chickens at a farm located in northwestern South Korea displayed adverse neurological symptoms including limping, lying down, and head shaking. Approximately 2.1% of chickens died or were culled due to severe symptoms. Five carcasses were submitted to the Avian Disease Division of the Animal and Plant Quarantine Agency (APQA) for disease diagnosis. RESULTS: Broilers displayed severe pericarditis and perihepatitis associated with gross lesions. Broilers also displayed microscopic lesions in the cerebrum and in the granular layer of the cerebellum, which were associated with multifocal perivascular cuffing and purulent necrosis in the cerebrum, and severe meningitis with heterophil and lymphocyte infiltration. Staphylococcus spp. were identified in the liver and heart using bacteriological culture. PCR/RT-PCR assays revealed that broilers were negative for avian Clostridium botulinum, Newcastle disease virus, and avian encephalomyelitis virus. Bacterial and viral metagenomic analysis of brain sample further revealed the presence of Pseudomonas spp. and Marek's disease virus, which are known etiological agents of chicken meningoencephalitis. CONCLUSIONS: This study reports a diagnostic analysis of gross and histopathological lesions from 32-day-old broilers displaying unique neurological symptoms that revealed the presence of the several neurological diseases including meningoencephalitis. The causative agents associated with meningoencephalitis of broilers that had not been identified by routine diagnostic methods could be diagnosed by metagenomics, which proves the usefulness of metagenomics as a diagnostic tool for unknown neurological diseases in broilers.

The Development of Novel Reverse Transcription Loop-Mediated Isothermal Amplification Assays for the Detection and Differentiation of Virulent Newcastle Disease Virus.

Newcastle disease (ND) is a highly pathogenic viral infection of poultry with significant economic impacts worldwide. Despite the widespread use of vaccines, ND outbreaks continue to occur even within vaccinated poultry farms. Furthermore, novel Newcastle disease virus (NDV) genotypes are emerging in poultry, increasing the need for the development of rapid, accurate, and simple diagnostic methods. We therefore developed two novel sets of visual reverse transcription loop-mediated isothermal amplification (RT-LAMP) assays based on highly conserved regions of the HN and F genes. The limits of detection of the NDV-Common-LAMP assay, for all the NDV strains, were 103.0 EID50/0.1 mL for Kr005 and 102.0 EID50/0.1 mL for Lasota within 35 min. The sensitivity of the NDV-Patho-LAMP assay, used for the strain differentiation of virulent NDV, was 102.0 EID50/0.1 mL for Kr005. No amplification was detected for the non-NDV templates. Next, we probed 95 clinical strains and 7 reference strains with the RT-LAMP assays to assess the feasibility of their use in diagnostics. We observed no cross-reactivity across the 102 strains. Furthermore, there was 100% congruence between the RT-LAMP assays and full-length sequencing of the target genes, indicating the potential for visual RT-LAMP in the identification and differentiation of NDV. These novel RT-LAMP assays are ideally suited for the field or resource-limited environments to facilitate the faster detection and differentiation of NDV, which can reduce or avoid further spread.

Nursing experience during COVID-19 pandemic in Korea: a qualitative analysis based on critical components of the professional practice models.

BACKGROUND: Nurses have an essential role and responsibility to work at the forefront of patient care during the COVID-19 pandemic. Although the press and public have praised the dedication of nurses in the COVID-19 pandemic, there are several points to consider for nursing professional development. The purpose of this study is to collect the experiences of the nursing profession in the COVID-19 pandemic through interviews, seek improvements for the development of the nursing profession, and suggest directions for the future. METHOD: This qualitative study adopts semi-structured interviews analyzing the nursing experience of the COVID-19 pandemic based on the professional practice models (PPMs). Ten nurses with at least two years of working experience and thorough work changes in the COVID-19 pandemic from various settings have participated in the study. RESULTS: We identified thirty-nine problematic codes and nineteen improvement codes which mapped to 12 key concepts and corresponded to 6 constructs of the PPM model. CONCLUSION: Nurses had to take on tasks beyond their duties in urgent situations, which restrained nurses from concentrating on their work. Clarifying working boundaries is fundamental for collaborative care and independent nursing practice. Collaboration and communication among healthcare workers based on mutual understanding can create a respectful working environment. Although there were many difficulties due to the uncertain situation, we can find that the nursing profession can make achievements through systematic and organizational support for sticking to the basics of nursing, securing technical expertise, cultivating critical thinking, and developing various professional attributes. In this way, the establishment of roles based on professional values and duties and the ascertainment of clear boundaries for nursing will ultimately help to improve the quality of patient care.

Identification of Campylobacter jejuni and Chlamydia psittaci from cockatiel (Nymphicus hollandicus) using metagenomics.

BACKGROUND: In July 2015, the carcasses of 11 cockatiels were submitted for disease diagnosis to the Avian Disease Division of the Animal and Plant Quarantine Agency of Korea. The cockatiels, which appeared dehydrated and underweight, had exhibited severe diarrhea and 22 % mortality over 2 weeks. Traditional diagnosis did not reveal the causes of these symptoms. METHODS: We conducted metagenomics analysis on intestines and livers from the dead cockatiels using Illumina high-throughput sequencing. To obtain more accurate and longer contigs, which are required for further genetic characterization, we compared the results of three de novo assembly tools (metaSPAdes, MEGAHIT, and IDBA-UD). RESULTS: Sequence reads of Campylobacter jejuni (C. jejuni) and Chlamydia psittaci (C. psittaci) were present in most of the cockatiel samples. Either of these bacteria could cause the reported symptoms in psittaciformes. metaSPAdes (ver.3.14.1) identified the 1152 bp flaA gene of C. jejuni and the 1096 bp ompA gene of C. psittaci. Genetic analysis revealed that flaA of C. jejuni was recombinant between C. jejuni and Campylobacter coli, and that ompA of C. psittaci isolated from cockatiel was closely related to strains isolated from humans. CONCLUSIONS: C. jejuni and C. psittaci were detected in cockatiels in the Republic of Korea using metagenomic analysis. This approach is useful for understanding pathogens of pet birds. Three de novo assemblers were compared to obtain accurate contigs from large quantities of reads, and sequences of C. jejuni and C. psittaci generated by metaSPAdes were analyzed.

Characterization of antigenic variant infectious bursal disease virus strains identified in South Korea.

Infectious bursal disease (IBD) is one of the most important immunosuppressive diseases of young chickens, causing considerable economic losses to the poultry industry. More than 30 years ago, an antigenic variant (av) pathotype of the IBD virus (IBDV) was reported to originate in, and subsequently spread among, poultry farms in the USA. Recently, a novel avIBDV lineage was identified in China and was shown to exhibit clear differences in its pathogenicity as well as molecular characteristics compared with the previously isolated variant strains. In this study, we conducted a passive surveillance of chicken carcasses submitted to our research division from June-December 2019, and detected the IBDV strains by reverse transcription PCR. Five avIBDV strains were isolated, and their pathogenicity was determined by necropsy and molecular analysis. Additionally, a coinfection field case involving an avIBDV strain and a very virulent IBDV (vvIBDV) strain was identified. Multiple sequence alignment and phylogenetic analysis of partial viral protein 1 (VP1) and hypervariable region (hv) VP2 genes revealed that those strains originated from two different avIBDV lineages. The co-occurrence of two sub-groups of avIBDVs in South Korea confirms for the first time the evolution of antigenic variant IBDV strains, and highlights the urgency for the development of new strategies for IBDV intervention in South Korea.RESEARCH HIGHLIGHTS Five avIBDV strains were identified in South Korea by passive surveillance test in 2019.A coinfection between two IBDV strains from different genogroups was reported in a field case.By phylogenetic analysis, Korean avIBDVs belonged to two distinct lineages of antigenic variant genogroup.

Viral metagenomic analysis of chickens with runting-stunting syndrome in the Republic of Korea.

BACKGROUND AND AIMS: Runting-stunting syndrome (RSS) in chickens, also known as malabsorption syndrome, which is characterized by mild to severe enteritis and diagnosed through typical histopathologic examination as well as clinical signs, results in considerable economic losses. Despite the many studies carried out over decades to determine the etiologic agents of RSS involved in the disease, several outbreaks remained without the elucidation of, potentially multiple, etiologies involved. METHODS: We performed comparative analysis of viral metagenomes from four chicken flocks affected with RSS using next-generation sequencing. Primers for the detection of chicken enteric viruses were designed from the sequencing data obtained with metagenomics. Multiplex reverse transcription-polymerase chain reaction (PCR) and PCR were performed to detect a variety of etiological agents previously described in natural cases of RSS. RESULTS: The most abundant viral families identified in this study were Astroviridae, Picornaviridae, Parvoviridae, Caliciviridae, Reoviridae and Picobirnaviridae. Chicken astrovirus sequences were present in all four samples, suggesting an association between chicken astrovirus and RSS and chicken astrovirus as a candidate pathogen responsible for RSS. Picobirnavirus and the newly identified chapparvovirus were found in chickens in the Republic of Korea for the first time, and the genetic diversity of enteric viruses and viral communities was showed. CONCLUSIONS: Chicken astrovirus was consistently detected in broilers affected with RSS and the result of this study may contribute to knowledge of enteric diseases and viruses in chickens.

Prevalence of Campylobacter species in wild birds of South Korea.

Campylobacter species cause human gastrointestinal infections worldwide. They commonly inhabit intestines of avian species including wild birds. They might play a role in the spread of infections to humans and other bird species. The prevalence of Campylobacter species in 2164 faecal samples of wild birds (representing 71 species and 28 families) captured across the Korean peninsula was evaluated in this study. The overall prevalence was 15.3% (332/2164). Bird species belonging to the family Charadriidae had the highest isolation rate (30.0%), followed by those belonging to the families Ardeidae (26.4%), Turdidae (21.9%), and Anatidae (15.3%). The prevalence of Campylobacter spp. differed significantly according to migratory habit. Stopover birds were the most commonly infected (19.0%), followed by winter migratory (16.7%) and summer migratory birds (12.3%). However, indigenous birds showed very low prevalence (2.7%). Antimicrobial susceptibility tests were performed for 213 isolates. Results showed that Campylobacter jejuni isolates (n = 169) exhibited resistance to nalidixic acid (5.3%), ciprofloxacin (3.0%), and tetracycline (1.8%), while Campylobacter lari (n = 1) displayed resistance to nalidixic acid and ciprofloxacin. However, all Campylobacter coli isolates (n = 20) were susceptible to all antimicrobials tested. This is the first report on the prevalence of Campylobacter species in wild birds that seasonally or indigenously inhabit the Korean peninsula. Our results indicate that the overall prevalence of Campylobacter in wild birds is moderate. Therefore, birds might serve as significant reservoirs for Campylobacter pathogens.

Autonomy-supportive, Web-based lifestyle modification for cardiometabolic risk in postmenopausal women: Randomized trial.

The management of cardiometabolic risk factors, such as abdominal obesity, dyslipidemia, hypertension, and hyperglycemia, is essential for the health of postmenopausal women. In this study, we identified the effects of autonomy-supportive, Web-based lifestyle modification for the management cardiometabolic risk of postmenopausal women, and assessed the mediation effect of intrinsic motivation. This study was a randomized trial involving 71 postmenopausal Korean women. For the intervention group, we provided the Web-based autonomy supports for 12 weeks; however, for the control group, individual consultations on healthy lifestyle was conducted at the first meeting. In the intervention group, cardiometabolic risks ameliorated as follows: waist circumference and waist-to-height ratio decreased by 3.9 cm and 0.03 cm, respectively; triglycerides decreased by 8.5 mg/dl; triglycerides-to-high-density-lipoprotein cholesterol ratio decreased by 0.21; systolic blood pressure decreased by 3.3 mmHg, and the visceral adiposity index decreased. Among the subdomain of intrinsic motivation, perceived competence, effort/importance, and perceived choice showed an association with waist circumference changes. Web-based autonomy supports can be effective in implementation and maintenance, and the amelioration of cardiometabolic risk in postmenopausal women.

Pathologic Changes in Wild Birds Infected with Highly Pathogenic Avian Influenza A(H5N8) Viruses, South Korea, 2014.

In January 2014, an outbreak of infection with highly pathogenic avian influenza (HPAI) A(H5N8) virus began on a duck farm in South Korea and spread to other poultry farms nearby. During this outbreak, many sick or dead wild birds were found around habitats frequented by migratory birds. To determine the causes of death, we examined 771 wild bird carcasses and identified HPAI A(H5N8) virus in 167. Gross and histologic lesions were observed in pancreas, lung, brain, and kidney of Baikal teals, bean geese, and whooper swans but not mallard ducks. Such lesions are consistent with lethal HPAI A(H5N8) virus infection. However, some HPAI-positive birds had died of gunshot wounds, peritonitis, or agrochemical poisoning rather than virus infection. These findings suggest that susceptibility to HPAI A(H5N8) virus varies among species of migratory birds and that asymptomatic migratory birds could be carriers of this virus.

Identification of a picornavirus from chickens with transmissible viral proventriculitis using metagenomic analysis.

Transmissible viral proventriculitis (TVP), an infectious disease in chickens, is responsible for economic losses in the commercial poultry industry. The major etiologic agent, however, is unknown. Using metagenomics, we compared the diversity of viruses present in proventriculus samples from flocks diagnosed with TVP to those of healthy flocks in South Korea between 2003 and 2012. Each sample had a mean of 21,538,726 sequence reads generated by high-throughput sequencing, with a mean length of 160 nt. Enrichment in viral sequences suggested that at least three viruses were present in each TVP sample. Although we could not determine a pathogen of TVP that matched the known morphology, picornavirus sequences were present in all five disease samples, suggesting an association with TVP. The five samples yielded 1,045-1,720 bp contigs with 81-84 % nt sequence identity to turkey hepatitis virus (accession number: HM751199). Whole-genome analysis indicated that the QIA01 strain of the novel picornavirus was similar to turkey hepatitis virus in the P2 and P3 regions (82.7 % nt and 95.5 % aa sequence identity), but different in the structural region and partial 2A peptides (56.2 % nt and 23.9 % aa sequence identity). In addition, the QIA01 virus was similar (87.0 % nt and 95.6 % aa sequence identity) to chicken megrivirus, recently detected in chickens with malabsorption syndrome in Hungary. Our results are useful for understanding the genetic diversity of avian picornaviruses and for classifying chicken megrivirus as a pathogen affecting the digestive tract of chickens.

Analysis of signs and pathology of H5N1-infected ducks from the 2010-2011 Korean highly pathogenic avian influenza outbreak suggests the influence of age and management practices on severity of disease.

We compared the clinical signs, histopathological lesions and distribution of viral antigens among infected young (meat-type) and older (breeder) ducks that were naturally infected with the highly pathogenic avian influenza (HPAI) virus during the 2010-2011 Korean outbreak. The meat-type ducks had a high mortality rate (30%) and showed severe neurological signs such as head tremors and paresis. In contrast, HPAI-infected breeder ducks had minimal clinical signs but a decreased egg production rate. The histopathological characteristics of infected meat-type ducks included necrotic lesions of heart and brain, which may have primarily contributed to the high mortality rate. In contrast, the breeder ducks only presented necrotic splenitis, and viral antigens were only detected in the trachea, lungs and spleen. Younger ducks had a high viral titre in the organs, high levels of viral shedding and a high mortality rate after experimental HPAI virus infection. Compared to the breeder ducks, the meat-type ducks were raised in smaller farms that had poor quarantine and breeding facilities. It is therefore possible that better biosecurity in the breeder farms could have reduced the infection dose and subsequently the severity of the disease. Thus, age and management may be the influencing factors for HPAI susceptibility in ducks.

Single-tube nested PCR assay for the detection of avian botulism in cecal contents of chickens.

This paper describes a novel diagnostic method for the detection of avian botulism caused by Clostridium botulinum type C and C/D, using single-tube nested PCR assay. This assay was developed to overcome the disadvantages of bioassays used in experiments with mice. Three primer pairs including an antisense primer were designed to target the N-terminal of the toxin gene from C. botulinum types C and C/D. The specificity of the PCR assay was confirmed by using 33 bacterial strains and chicken cecal contents from farms that experienced botulism outbreaks. The detection limit for purified DNA was 1.1 fg/µl, and for bacterial spores was 4.3 spores/200 mg of cecal contents. While checking for specificity of the PCR assay, the reactions with the templates form C. botulinum type C and C/D which were tested became positive, but the rest of the reactions turned negative. However, the results for all clinical samples (n = 8) were positive. The PCR assay results for cecal samples obtained from 300 healthy chickens (150 Korean native chickens and 150 broilers) were all negative. This assay is rapid and straightforward and evades ethical issues associated with mouse bioassay. Moreover, it is more economical than real-time PCR.

Characterization of Clostridium perfringens isolates obtained from 2010 to 2012 from chickens with necrotic enteritis in Korea.

Clostridium perfringens produces diverse virulent toxins that cause necrotic enteritis in poultry, resulting in a great negative impact on the poultry industry. To study the characteristics of C. perfringens in chickens, we isolated 88 strains from chickens (1 strain per flock) with necrotic enteritis. The isolated bacterial strains were screened for toxin type and antimicrobial susceptibility. Necropsy of 17 chickens that died from necrotic enteritis revealed that their intestines were dilated with inflammatory exudates and characterized by mucosal necrosis. All the isolated strains were identified as toxin type A using multiplex PCR for toxin typing. We found that the rate of netB-positive strains isolated from dead chickens was significantly higher (8 of 17) than the rate among healthy chickens (2 of 50). We performed antimicrobial susceptibility test with 20 selected antimicrobial agents using the disk diffusion test and found that 30 tested strains were completely resistant to 5 antibiotics and partially resistant to 6 antibiotics whereas all the strains were susceptible to 9 antimicrobial agents. Using pulsed-field gel electrophoresis analysis, the 17 strains were divided into 13 genetic clusters showing high genetic diversity. In conclusion, C. perfringens strains isolated from Korean poultry showed a high resistance to antimicrobial drugs and high genetic diversity, suggesting that continuous monitoring is essential to prevent outbreaks of necrotic enteritis in chickens.

Genetic and pathogenic characteristics of H1 avian and swine influenza A viruses.

This study examined the potential for cross-species transmission of influenza viruses by comparing the genetic and pathogenic characteristics of H1 avian influenza viruses (AIVs) with different host origins in Korea. Antigenic and phylogenetic analyses of H1 AIVs circulating in Korea provided evidence of genetic similarity between viruses that infect domestic ducks and those that infect wild birds, although there was no relationship between avian and swine viruses. However, there were some relationships between swine and human viral genes. The replication and pathogenicity of the H1 viruses was assessed in chickens, domestic ducks and mice. Viral shedding in chickens was relatively high. Virus was recovered from both oropharyngeal and cloacal swabs up to 5-10 days post-inoculation. The titres of domestic duck viruses in chickens were much higher than those of wild-bird viruses. Both domestic duck and wild-bird viruses replicated poorly in domestic ducks. None of the swine viruses replicated in chickens or domestic ducks; however, six viruses showed relatively high titres in mice, regardless of host origin, and induced clinical signs such as ruffled fur, squatting and weight loss. Thus, although the phylogenetic and antigenic analyses showed no evidence of interspecies transmission between birds and swine, the results suggest that Korean H1 viruses have the potential to cause disease in mammals. Therefore, we should intensify continuous monitoring of avian H1 viruses in mammals and seek to prevent interspecies transmission.

Occurrence of avian botulism in Korea during the period from June to September 2012.

Botulism is a paralytic disease caused by the botulinum neurotoxin produced by Clostridium botulinum. In the summer season in Korea, intensive outbreaks of avian botulism were reported in both poultry and wild birds, including five Korean native chicken farms (HanHyup NO.3), one pheasant (Phasianus colchicus karpowi) farm, and one community of spot-billed ducks (Anas poecilorhyncha). The affected domestic birds showed 24.5% to 58.3% mortality, with specific clinical signs including ataxia, limber neck, and diarrhea. To confirm the botulinum toxin, neutralization tests were performed on sera (four Korean native chicken farms and one pheasant farm) or culture supernatant (spot-billed ducks). Additionally, the contents of the cecum and liver from poultry presenting signs suggestive of botulism were inoculated to isolate the pathogen. The toxin genes were then detected by polymerase chain reaction (PCR). Through the neutralization tests, it was possible to diagnose the botulism and, except in the case of one Korean native chicken farm, to identify the type of pathogen. Using detection by PCR, except in two cases of the Korean native chicken farms, the botulinum toxin gene was found. Additionally, in four cases, it was possible to identify the C/D mosaic type using PCR. This paper reports the first occurrence of avian botulism in domestic birds and the first detection of botulism caused by this mosaic type in Korea.

Upconverting-photon quenching-mediated perforation influx as an intracellular delivery method using posAuNP@UCNPs nanocomposites for osteoarthritis treatment.

Photoporation techniques based on plasmonic nanoparticles such as gold nanoparticles have been extensively studied for the intracellular delivery of substances via cell membrane disruption. However, the clinical application of AuNP is challenging due to its absorption in the 500 nm region of the light spectrum. To overcome this challenge, upconversion nanoparticles were employed to stimulate AuNP at NIR wavelengths. posAuNP@UCNPs nanocomposites were produced by coating 30 nm UCNPs on 80 nm AuNPs using DOPA-PEI, which were then irradiated with 980 nm NIR light to facilitate their intracellular delivery. TEM and DLS confirmed that posAuNP and UCNP combine to form nanocomposites. Additionally, multiphysics simulation was used to analyze the distribution of the posAuNP electric field based on morphological differences that change as the UCNP ratio increases. Next, effective LED irradiation conditions were established by applying upconverting-photon quenching-mediated perforation influx to C28/I2 cells as suspensions or spheroids. posAuNP@UCNP nanocomposites were confirmed to be effective for the delivery of baricitinib as a treatment for osteoarthritis in a three-dimensional osteoarthritis model. Finally, chondrocyte differentiation was induced through intracellular delivery of baricitinib using posAuNP@UCNPs. The findings suggest that posAuNP@UCNPs have great potential as a tool for non-invasive drug delivery via UCPPin.

An Amplicon-Based Application for the Whole-Genome Sequencing of GI-19 Lineage Infectious Bronchitis Virus Directly from Clinical Samples.

Infectious bronchitis virus (IBV) causes a highly contagious respiratory disease in chickens, leading to significant economic losses in the poultry industry worldwide. IBV exhibits a high mutation rate, resulting in the continuous emergence of new variants and strains. A complete genome analysis of IBV is crucial for understanding its characteristics. However, it is challenging to obtain whole-genome sequences from IBV-infected clinical samples due to the low abundance of IBV relative to the host genome. Here, we present a novel approach employing next-generation sequencing (NGS) to directly sequence the complete genome of IBV. Through in silico analysis, six primer pairs were designed to match various genotypes, including the GI-19 lineage of IBV. The primer sets successfully amplified six overlapping fragments by long-range PCR and the size of the amplicons ranged from 3.7 to 6.4 kb, resulting in full coverage of the IBV genome. Furthermore, utilizing Illumina sequencing, we obtained the complete genome sequences of two strains belonging to the GI-19 lineage (QX genotype) from clinical samples, with 100% coverage rates, over 1000 × mean depth coverage, and a high percentage of mapped reads to the reference genomes (96.63% and 97.66%). The reported method significantly improves the whole-genome sequencing of IBVs from clinical samples; thus, it can improve understanding of the epidemiology and evolution of IBVs.

Light emitting diode (LED) irradiation of liposomes enhances drug encapsulation and delivery for improved cancer eradication.

Liposomes are widely used as drug delivery nanoplatforms because of their versatility and biocompatibility; however, their ability to load certain drugs may be suboptimal. In this study, we generated liposomes using a combination of DSPE and DSPE-PEG-2 k lipids and loaded them with doxorubicin (DOX) and paclitaxel (PTX), to investigate the effects of light emitting diode (LED) irradiation on liposome structure and drug loading efficiency. Scanning and transmission electron microscopy revealed that the surface of liposomes irradiated with blue or near-infrared LEDs (LsLipo) was rougher and more irregular than that of non-LED-irradiated liposomes (NsLipo). Nuclear magnetic resonance analysis showed that the hydrogen peak originating from the lipid head groups was lower in LsLipo than in NsLipo preparations, indicating that LED irradiation changed the chemical and physical properties of the liposome. Structural changes, such as reduced rigidity, induced by LED irradiation, increased the loading efficiency of DOX and PTX. In vitro and in vivo experiments showed that LsLipo were more effective at inhibiting the growth of cancer cells than NsLipo. Our findings suggest that LED irradiation enhances the drug delivery efficacy of liposomes and offer new possibilities for improving drug delivery systems.

Application of real-time reverse transcription polymerase chain reaction to the detection the matrix, H5 and H7 genes of avian influenza viruses in field samples from South Korea.

BACKGROUND: The rapid and accurate identification of the H5 and H7 subtypes of avian influenza (AI) virus is an important step for the control and eradication of highly pathogenic AI outbreaks and for the surveillance of AI viruses that have the potential to undergo changes in pathogenicity in poultry and wild birds. Currently, real-time reverse transcription polymerase chain reaction (RRT-PCR) is routinely used for the rapid detection of the H5 and H7 genes, but misidentification is frequent for emergent isolates and viruses isolated from diverse regions due to the high sequence variation among AI viruses. FINDINGS: In this study, an RRT-PCR method was tested for the detection of matrix, H5 and H7 genes from diverse subtypes of AI viruses and from field samples obtained through AI surveillance in South Korea over the last four years. Both RRT-PCR and conventional experiment (virus isolation using egg inoculation followed by reverse transcription polymerase chain reaction) agreed on the virus-positive samples. And the comparison of the results with 174 clinical samples showed a high level of agreement without decreasing the specificity and sensitivity. CONCLUSIONS: This assay could be useful tool for the rapid detection of AI using the field samples from domestic poultry and wild birds in South Korea, and continuous regional updates is needed to validate primer sets as the AI virus evolves.