Caught Right on the Spot: Isolation and Characterization of Clade 2.3.4.4b H5N8 High Pathogenicity Avian Influenza Virus from a Common Pochard (Aythya ferina) Being Attacked by a Peregrine Falcon (Falco peregrinus).

We isolated a high pathogenicity avian influenza (HPAI) virus from a common pochard (Aythya ferina) that was being attacked by a bird of prey in South Korea in December 2020. Genetic analyses indicated that the isolate was closely related to the clade 2.3.4.4b H5N8 HPAI viruses found in South Korea and Japan during the winter season of 2020-2021. The histopathological examination revealed multifocal necrotizing inflammation in the liver, kidney, and spleen. Viral antigens were detected in the liver, kidney, spleen, trachea, intestine, and pancreas, indicating the HPAI virus caused a systemic infection. The presence of immunoreactivity for the viral antigen was observed in the cells involved in multifocal necrotic inflammation. Notably, epitheliotropic-positive patterns were identified in the epithelial cells of the trachea, mucosal epithelium of the intestine, and ductular epithelium of the pancreas. These findings provide direct evidence supporting the possibility of HPAI transmission from infected waterfowl to predators.

Detectado en el acto: Aislamiento y caracterización de un virus de la influenza aviar de alta patogenicidad del clado 2.3.4.4b H5N8 de un porrón común (Aythya ferina) atacado por un halcón peregrino (Falco peregrinus). Se aisló un virus de la influenza aviar (HPAI) de alta patogenicidad de un porrón común (Aythya ferina) que estaba siendo atacado por un ave rapaz en Corea del Sur en diciembre de 2020. Los análisis genéticos indicaron que el aislado estaba estrechamente relacionado con virus de influenza aviar de alta patogenicidad H5N8, clado 2.3.4.4 b encontrados en Corea del Sur y Japón durante la temporada de invierno de 2020­2021. El examen histopatológico reveló inflamación necrotizante multifocal en hígado, riñón y bazo. Se detectaron antígenos virales en el hígado, el riñón, el bazo, la tráquea, el intestino y el páncreas, lo que indica que este virus de alta patogenicidad causó una infección sistémica. Se observó la presencia de inmunorreactividad para el antígeno viral en las células involucradas en la inflamación necrótica multifocal. En particular, se identificaron patrones epiteliotrópicos positivos en las células epiteliales de la tráquea, el epitelio mucoso del intestino y el epitelio ductular del páncreas. Estos hallazgos proporcionan evidencia directa que respalda la posibilidad de transmisión de HPAI de aves acuáticas infectadas a especies depredadoras.

Establishing veterinary graduation competencies and its impact on veterinary medical education in Korea.

Competencies are defined as an observable and assessable set of knowledge, skills, and attitudes. Graduation competencies, which are more comprehensive, refer to the required abilities of students to perform on-site work immediately after graduation. As graduation competencies set the goal of education, various countries and institutions have introduced them for new veterinary graduates. The Korean Association of Veterinary Medical Colleges has recently established such competencies to standardize veterinary education and enhance quality levels thereof. The purpose of this study is to describe the process of establishing graduation competencies as well as their implication for veterinary education in Korea. Graduation competencies for veterinary education in Korea comprise 5 domains (animal health care and disease management, one health expertise, communication and collaboration, research and learning, and veterinary professionalism). These are further divided into 11 core competencies, and 33 achievement standards, which were carefully chosen from previous case analyses and nation-wide surveys. Currently, graduation competencies are used as a standard for setting clear educational purposes for both instructors and students. Establishing these competencies further initiated the development of detailed learning outcomes, and of a list of basic veterinary clinical performances and skills, which is useful for assessing knowledge and skills. The establishment of graduation competencies is expected to contribute to the continuous development of Korean veterinary education in many ways. These include curriculum standardization and licensing examination reform, which will eventually improve the competencies of new veterinary graduates.

Whole genome sequencing and phylogenetic analysis of African swine fever virus detected in a backyard pig in Mongolia, 2019.

African swine fever (ASF) is a highly contagious and fatal disease affecting domestic and wild pigs caused by the African swine fever virus (ASFV). Since the first outbreak in China in August 2018, ASF has spread rapidly in Asia. and the first case in Mongolia was confirmed in January 2019. In this study, we report the first whole genome sequence of an ASFV (ASFV SS-3/Mongolia/2019) detected from a backyard pig in Mongolia in February 2019 using whole genome sequencing. We analyzed their phylogenetic relationship with other genotype II ASFVs from Eurasia. The ASFV SS-3/Mongolia/2019 belonged to genotype II (p72 and p54), serogroup 8 (CD2v), Tet-10a variant (pB602L), and IGRIII variant (intergenic region between the I73R/I329L genes). A total of five amino acid substitutions were observed in MGF 360-10L, MGF 505-4R, MGF 505-9R, NP419L, and I267L genes compared to the ASFV Georgia 2007/1 virus. ML phylogenetic analysis of the whole genome sequence showed that the virus shares a high nucleotide sequence identity with ASFVs recently identified in Eastern Europe and Asia and clustered with the ASFV/Zabaykali/WB5314/2020|Russia|2020 virus which was identified at the border between the Russian Federation and Mongolia in 2020. Our results suggest that trans boundary spread of ASF occurred through close geographic proximity.

Clinical evaluation of toll-like receptor-5 agonist for radiation-induced oral mucositis in beagle dogs.

This study aimed to evaluate the clinical safety and validate the radiomitigative effect of KMRC011, against radiation-induced oral mucositis in beagle dogs. Clinical safety was evaluated by assessing tolerability, complete blood tests, and plasma biochemistry after drug administration. The radiomitigative effect of KMRC011 was evaluated macropathologically and histopathologically after inducing oral mucositis iatrogenically using 20 Gy irradiation. The plasma concentration of interleukin-6 was measured via enzyme-linked immunosorbent assay, as a biomarker of KMRC011 bioreactivity. Decreased tolerability, increased neutrophil count, hepatic enzyme concentration, C-reactive protein concentration, and interleukin-6 concentration after the administration was observed and ceased within 24 h without additional treatment. Although all animals included in the present study developed severe mucositis in the late course of the study, animals administered KMRC011 showed less erythema, ulcer, inflammatory infiltration. These results suggest that KMRC011 may be used as an adjuvant for radiotherapy without severe adverse effects, especially during short-term radiotherapy, such as hypofractionated radiotherapy or stereotactic radiotherapy.

Disinfection of various materials with 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride in hatchery facilities.

OBJECTIVE: Surface disinfection is important in the proper running of livestock farms. However, disinfection of farm equipment and facilities is difficult because they are made of different materials, besides having large surface areas and complex structures. 3-(trimethoxysilyl)-propyldimethyloctadecyl ammonium chloride (Si-QAC) is a quaternary ammonium salt-based disinfectant that attaches to various surfaces by forming covalent bonds and maintains its disinfecting capacity for a considerable time. Our aim was to evaluate the potential use of Si-QAC for disinfection of farm equipment and facilities. METHODS: The short- and long-term antimicrobial and antiviral effects of Si-QAC were evaluated in both laboratory and farm settings using modified quantitative assessment method based on the standard operating procedures of the United States Environmental Protection Agency. RESULTS: Si-QAC was highly effective in controlling the growth of the Newcastle disease virus and avian pathogenic Escherichia coli. Electron microscopy revealed that the mechanism underlying the disinfection activity of Si-QAC was associated with its ability to damage the outer membrane of the pathogen cells. In the field test, Si-QAC effectively reduced viral contamination of surfaces of equipment and space. CONCLUSION: Our results suggest that Si-QAC has great potential as an effective chemical for disinfecting farm equipment and facilities. This disinfectant could retain its disinfection ability longer than other commercial disinfectants and contribute to better farm biosecurity.

The Microvillar and Solitary Chemosensory Cells as the Novel Targets of Infection of SARS-CoV-2 in Syrian Golden Hamsters.

Patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019, suffer from respiratory and non-respiratory symptoms. Among these symptoms, the loss of smell has attracted considerable attention. The objectives of this study were to determine which cells are infected, what happens in the olfactory system after viral infection, and how these pathologic changes contribute to olfactory loss. For this purpose, Syrian golden hamsters were used. First, we verified the olfactory structures in the nasal cavity of Syrian golden hamsters, namely the main olfactory epithelium, the vomeronasal organ, and their cellular components. Second, we found angiotensin-converting enzyme 2 expression, a receptor protein of SARS-CoV-2, in both structures and infections of supporting, microvillar, and solitary chemosensory cells. Third, we observed pathological changes in the infected epithelium, including reduced thickness of the mucus layer, detached epithelia, indistinct layers of epithelia, infiltration of inflammatory cells, and apoptotic cells in the overall layers. We concluded that a structurally and functionally altered microenvironment influences olfactory function. We observed the regeneration of the damaged epithelium, and found multilayers of basal cells, indicating that they were activated and proliferating to reconstitute the injured epithelium.

Thermal Image Scanning for the Early Detection of Fever Induced by Highly Pathogenic Avian Influenza Virus Infection in Chickens and Ducks and Its Application in Farms.

Highly pathogenic avian influenza (HPAI) is considered as one of the most devastating poultry diseases. It is imperative to immediately report any known outbreaks to the World Organization for Animal Health. Early detection of infected birds is of paramount importance to control virus spread, thus minimizing the associated economic loss. In this study, thermal imaging camera devices were used to detect change in the maximum surface temperature (MST) of chickens (n = 5) and ducks (n = 2) as an early indicator of experimental HPAI infection. The MST of both chickens and ducks increased at least 24 h before the manifestation of clinical signs of HPAI infection, depending on the severity of the infection. The basal MST was recorded for broiler chickens housed under small pen and normal farm conditions without intentional infection. A threshold cutoff of MST was established based on the circadian rhythm of normal MST. This study suggests that thermal imaging of chickens and ducks is a promising tool to screen any potential HPAI-infected flock in order to expedite HPAI diagnosis.

Stressors Predicting Depression, Anxiety, and Stress in Korean Veterinary Students.

Psychological distress has a negative impact on professional development in health care professions. In this article, we measured the prevalence of students' depression, anxiety, and stress using the DASS-21 questionnaire in 10 veterinary colleges in Korea to investigate the stressors that contribute to these forms of psychological distress. The prevalence of academic and relationship types of stressors were higher than others. The proportion of students above a severe level of depression, anxiety, and stress on the DASS-21 scales was 30.9, 35.8, and 43.2%, respectively. The DASS-21 scores mediated the relationship between the perceived frequency of stressors and the respondents' satisfaction with their education and career. Statistical analysis revealed that female and pre-clinical students are more vulnerable to depression, anxiety, and stress. The findings of the article indicate the gravity of Korean veterinary students' mental and psychological state, emphasizing the importance of comprehensive management of students' mental health.

Potential use of 3-(trimethoxysilyl)propyldimethyl octadecyl ammonium chloride as an antimicrobial and antiviral agent for the disinfection of personal protective equipment.

Currently, no vaccine or established therapeutic agents are available for coronavirus disease 2019. The sharp increase in demand for personal protective equipment (PPE) necessitates an improvement in the protective efficacy of PPE. We evaluated the potential antimicrobial and antiviral effects of a surface-coating disinfectant (3-(trimethoxysilyl)propyldimethyl octadecyl ammonium chloride, Si-QAC) when applied onto PPE. Si-QAC-pre-coated PPE was artificially contaminated with either influenza virus or Salmonella. The results showed significantly reduced influenza and Salmonella titers in Si-QAC-coated PPE; these antimicrobial effects lasted 7 days. This suggests that this surface-coating disinfectant effectively reduces pathogen contamination of PPE, enabling their safe and long-term use.

Comparative evaluation of canine cadaver embalming methods for veterinary anatomy education.

Formalin-embalmed cadavers have been extensively used to teach anatomy. Although they ensure the preservation of anatomical structures without microbial contamination, they are considerably rigid and cannot be used to study the joint and muscle movements. Moreover, formalin irritates the eyes and airways and is carcinogenic on chronic exposure. To overcome the disadvantages of formalin-fixed cadavers, we investigated the usefulness of alternative embalming methods using saturated salt solution (SS) and Thiel's solution (TS). We compared the three solutions based on the following parameters: cost of the embalming solution; preservation of anatomical structure, color, flexibility, and texture; and microbial contamination. Convenience of anatomical structure identification and preferences in anatomical laboratory practice were evaluated using questionnaires answered by veterinary undergraduate students. Cost of the embalming solution was the lowest for formalin solution (FS) and most expensive for TS. All cadavers were successfully preserved without significant putrefaction and were useful for teaching veterinary anatomy. Cadavers embalmed with SS or TS were superior in facilitating joint and muscle movement. Compared to FS, the color and texture of muscles and internal organs were similar to those of living animals and there was no irritating and offensive smell in SS and TS cadavers. Students preferred the SS and TS cadavers for their usefulness in identification of anatomical structures, highlighting their usefulness in veterinary anatomy education.

Increased calcium-mediated cerebral processes after peripheral injury: possible role of the brain in complex regional pain syndrome.

BACKGROUND: Among various diseases that accompany pain, complex regional pain syndrome (CRPS) is one of the most frustrating for patients and physicians. Recently, many studies have shown functional and anatomical abnormalities in the brains of patients with CRPS. The calcium-related signaling pathway is important in various physiologic processes via calmodulin (CaM) and calcium-calmodulin kinase 2 (CaMK2). To investigate the cerebral mechanism of CRPS, we measured changes in CaM and CaMK2 expression in the cerebrum in CRPS animal models. METHODS: The chronic post-ischemia pain model was employed for CRPS model generation. After generation of the animal models, the animals were categorized into three groups based on changes in the withdrawal threshold for the affected limb: CRPS-positive (P), CRPS-negative (N), and control (C) groups. Western blot analysis was performed to measure CaM and CaMK2 expression in the rat cerebrum. RESULTS: Animals with a decreased withdrawal threshold (group P) showed a significant increment in cerebral CaM and CaMK2 expression (P = 0.013 and P = 0.021, respectively). However, groups N and C showed no difference in CaM and CaMK2 expression. CONCLUSIONS: The calcium-mediated cerebral process occurs after peripheral injury in CRPS, and there can be a relationship between the cerebrum and the pathogenesis of CRPS.

Ginseng Gintonin Attenuates Lead-Induced Rat Cerebellar Impairments during Gestation and Lactation.

Gintonin, a novel ginseng-derived lysophosphatidic acid receptor ligand, improves brain functions and protects neurons from oxidative stress. However, little is known about the effects of gintonin against Pb-induced brain maldevelopment. We investigated the protective effects of gintonin on the developing cerebellum after prenatal and postnatal Pb exposure. Pregnant female rats were randomly divided into three groups: control, Pb (0.3% Pb acetate in drinking water), and Pb plus gintonin (100 mg/kg, p.o.). Blood Pb was increased in dams and pups; gintonin treatment significantly decreased blood Pb. On postnatal day 21, the number of degenerating Purkinje cells was remarkably increased while the number of calbindin-, GAD67-, NMDAR1-, LPAR1-immunoreactive intact Purkinje cells, and GABA transporter 1-immunoreactive pinceau structures were significantly reduced in Pb-exposed offspring. Following Pb exposure, gintonin ameliorated cerebellar degenerative effects, restored increased pro-apoptotic Bax, and decreased anti-apoptotic Bcl2. Gintonin treatment attenuated Pb-induced accumulation of oxidative stress (Nrf2 and Mn-SOD) and inflammation (IL-1ß and TNFα,), restoring the decreased cerebellar BDNF and Sirt1. Gintonin ameliorated Pb-induced impairment of myelin basic protein-immunoreactive myelinated fibers of Purkinje cells. Gintonin attenuated Pb-induced locomotor dysfunctions. The present study revealed the ameliorating effects of gintonin against Pb, suggesting the potential use of gintonin as a preventive agent in Pb poisoning during pregnancy and lactation.

Effects of ascorbic acid treatment on developmental alterations in calcium-binding proteins and gamma-aminobutyric acid transporter 1 in the cerebellum of lead-exposed rats during pregnancy and lactation.

In the present study, we investigated the effects of lead (Pb) and ascorbic acid co-administration on rat cerebellar development. Female rats were randomly divided into the following groups: control, Pb, and Pb plus ascorbic acid (PA) groups. From one week prior to mating, female rats were administered Pb (0.3% Pb acetate in drinking water) and ascorbic acid (100 mg/kg, oral intubation). The chemical administration was stopped on postnatal day 21 when the morphology of the offspring's cerebellum is similar to that of the adult brain. The blood Pb level was significantly increased following long-term Pb exposure. Ascorbic acid reduced Pb levels in the dams and offspring. Nissl staining demonstrated that the number of Purkinje cells was significantly reduced following Pb exposure, while ascorbic acid ameliorated this effect in the cerebellum of the offspring. Calcium-binding proteins, such as calbindin, calretinin, and parvalbumin were commonly expressed in Purkinje cells, and Pb exposure and ascorbic acid treatment resulted in similar patterns of change, namely Pb-induced impairment and ascorbic acid-mediated amelioration. The gamma-aminobutyric acid transporter 1 (GABAT1) is expressed in the pinceau structure where the somata of Purkinje cells are entwined in inhibitory synapses. The number of GABAT1-immunoreactive synapses was reduced following Pb exposure, and ascorbic acid co-treatment prevented this effect in the cerebellar cortex. Therefore, it can be concluded that ascorbic acid supplementation to mothers during gestation and lactation may have potential preventive effects against Pb-induced impairments in the developing cerebellum via protection of inhibitory neurons and synapses.

Effects of Ascorbic Acid on Osteopontin Expression and Axonal Myelination in the Developing Cerebellum of Lead-Exposed Rat Pups.

Osteopontin (OPN) is a multi-functional protein that binds to integrin and calcium-binding phosphoprotein. OPN is required for normal neuronal development and its axonal myelination. We studied the combined effect of lead (Pb) and ascorbic acid treatment on OPN expression in the developing cerebellum. We randomly divided pregnant female rats into three groups: control, Pb (lead acetate, 0.3%, drinking water), and Pb plus ascorbic acid (PA; ascorbic acid, 100 mg/kg, oral intubation) groups. The blood level of Pb was significantly increased, while ascorbic acid reduced Pb levels in the dams and pups. At postnatal day (PND) 21, results from Nissl staining and OPN immunohistochemistry demonstrated that OPN was detected in the Purkinje cell layer in the cerebellum. Ascorbic acid treatment mitigated Pb exposure-induced reduction in the number of intact Purkinje cells and OPN immunoreactive Purkinje cells in the cerebellum of pups. In addition, Pb-induced reduction in the number of oligodendrocytes and myelin-associated glycoprotein is associated with the malformation of the myelin sheath. Ascorbic acid provided protection from Pb-induced impairments. Pb-induced structural deficits in the cerebellum resulted in functional deterioration observed during locomotive tests (bar holding test and wire mesh ascending test), while ascorbic acid ameliorated these harmful effects. Present results suggest that the change of OPN is associated with myelination in the developing cerebellum. The results also demonstrated that exposure to Pb is harmful, while ascorbic acid treatment is beneficial.

Increased cerebral nuclear factor kappa B in a complex regional pain syndrome rat model: possible relationship between peripheral injury and the brain.

PURPOSE: Complex regional pain syndrome (CRPS) is a rare but refractory pain disorder. Recent advanced information retrieval studies using text-mining and network analysis have suggested nuclear factor kappa B (NFκB) as a possible central mediator of CRPS. The brain is also known to play important roles in CRPS. The aim of this study was to evaluate changes in cerebral NFκB in rats with CRPS. MATERIALS AND METHODS: The chronic post-ischemia perfusion (CPIP) model was used as the CRPS animal model. O-rings were applied to the left hind paws of the rats. The rats were categorized into three groups according to the results of behavioral tests: the CPIP-positive (A) group, the CPIP-negative (B) group, and the control (C) group. Three weeks after the CPIP procedure, the right cerebrums of the animals were harvested to measure NFκB levels using an ELISA. RESULTS: Animals in group A had significantly decreased mechanical pain thresholds (P<0.01) and significantly increased cerebral NFκB when compared to those in groups B and C (P=0.024). CONCLUSION: This finding indicates that peripheral injury increases cerebral NFκB levels and implies that minor peripheral injury can lead to the activation of pain-related cerebral processes in CRPS.

Ascorbic Acid Mitigates D-galactose-Induced Brain Aging by Increasing Hippocampal Neurogenesis and Improving Memory Function.

Ascorbic acid is essential for normal brain development and homeostasis. However, the effect of ascorbic acid on adult brain aging has not been determined. Long-term treatment with high levels of D-galactose (D-gal) induces brain aging by accumulated oxidative stress. In the present study, mice were subcutaneously administered with D-gal (150 mg/kg/day) for 10 weeks; from the seventh week, ascorbic acid (150 mg/kg/day) was orally co-administered for four weeks. Although D-gal administration alone reduced hippocampal neurogenesis and cognitive functions, co-treatment of ascorbic acid with D-gal effectively prevented D-gal-induced reduced hippocampal neurogenesis through improved cellular proliferation, neuronal differentiation, and neuronal maturation. Long-term D-gal treatment also reduced expression levels of synaptic plasticity-related markers, i.e., synaptophysin and phosphorylated Ca2+/calmodulin-dependent protein kinase II, while ascorbic acid prevented the reduction in the hippocampus. Furthermore, ascorbic acid ameliorated D-gal-induced downregulation of superoxide dismutase 1 and 2, sirtuin1, caveolin-1, and brain-derived neurotrophic factor and upregulation of interleukin 1 beta and tumor necrosis factor alpha in the hippocampus. Ascorbic acid-mediated hippocampal restoration from D-gal-induced impairment was associated with an enhanced hippocampus-dependent memory function. Therefore, ascorbic acid ameliorates D-gal-induced impairments through anti-oxidative and anti-inflammatory effects, and it could be an effective dietary supplement against adult brain aging.

Ascorbic Acid Attenuates Lead-Induced Alterations in the Synapses in the Developing Rat Cerebellum.

We evaluated the effect of lead (Pb) and ascorbic acid treatment of pregnant female rats on cerebellar development in pups. Pb was administered in drinking water (0.2% Pb acetate), and ascorbic acid (100 mg/kg) was administered through oral intubation. Fifteen female rats were randomly classified into control, Pb, and Pb plus ascorbic acid (PA) groups. The treatment of Pb and ascorbic acid treatments were terminated after birth to evaluate the effects on the gestational development of the cerebellum. At postnatal day 21 (PND21), pups were sacrificed, and blood Pb level was analyzed. Blood Pb levels of pups and dams were highest in the Pb group and reduced in the PA group. Immunohistochemistry and immunoblot assays were conducted to study the cerebellar expression levels of synaptic proteins. Along with a significant reduction in Purkinje cells, the reduction in presynaptic (synaptophysin) and postsynaptic (postsynaptic density protein 95, N-methyl-D-aspartate receptor subtype 1) marker proteins was observed in Pb-exposed pups. Ascorbic acid treatment significantly prevented Pb-induced impairment in the cerebellar synaptic proteins. Hypothesizing that brain-derived neurotrophic factor (BDNF) might be affected by Pb exposure given its importance in the regulation of synaptogenesis, we observed a Pb-induced decrease and ascorbic acid-mediated increase of BDNF in the cerebellum. Luxol fast blue staining and myelin basic protein analysis suggest that ascorbic acid treatment ameliorated the Pb exposure-induced reduction in the axonal fibers in the developing cerebellum. Overall, we conclude that ascorbic acid treatment during pregnancy can prevent Pb-induced impairments in the cerebellar development in rats.

Ascorbic Acid Supplementation Prevents the Detrimental Effects of Prenatal and Postnatal Lead Exposure on the Purkinje Cell and Related Proteins in the Cerebellum of Developing Rats.

We investigated the effects of lead (Pb) and ascorbic acid co-administration on rat cerebellar development. Prior to mating, rats were randomly divided into control, Pb, and Pb plus ascorbic acid (PA) groups. Pregnant rats were administered Pb in drinking water (0.3% Pb acetate), and ascorbic acid (100 mg/kg) via oral intubation until the end of the experiment. Offspring were sacrificed at postnatal day 21, the age at which the morphology of the cerebellar cortex in developing pups is similar to that of the adult brain. In the cerebellum, Pb exposure significantly reduced Purkinje cells and ascorbic acid prevented their reduction. Along with the change of the Purkinje cells, long-term Pb exposure significantly reduced the expression of the synaptic marker (synaptophysin), γ-aminobutyric acid (GABA)-synthesizing enzyme (glutamic acid decarboxylase 67), and axonal myelin basic protein while ascorbic acid co-treatment attenuated Pb-mediated reduction of these proteins in the cerebellum of pups. However, glutamatergic N-methyl-D-aspartate receptor subtype 1 (NMDAR1), anchoring postsynaptic density protein 95 (PSD95), and antioxidant superoxide dismutases (SODs) were adversely changed; Pb exposure increased the expression of NMDAR1, PSD95, and SODs while ascorbic acid co-administration attenuated Pb-mediated induction. Although further studies are required about the neurotoxicity of the Pb exposure, the results presented here suggest that developmental Pb exposure disrupted normal development of Purkinje cells by increasing glutamatergic and oxidative stress in the cerebellum. Additionally, ascorbic acid co-treatment is beneficial in attenuating prenatal and postnatal Pb exposure-induced maldevelopment of Purkinje cells in the developing cerebellum.

Neonatal influenza virus infection affects myelination in influenza-recovered mouse brain.

Influenza virus infection is a zoonosis that has great socioeconomic effects worldwide. Influenza infection induces respiratory symptoms, while the influenza virus can infect brain and leave central nervous system sequelae. As children are more vulnerable to infection, they are at risk of long-term neurological effects once their brains are infected. We previously demonstrated that functional changes in hippocampal neurons were observed in mice recovered from neonatal influenza infection. In this study, we investigated changes in myelination properties that could affect neural dysfunction. Mice were infected with the influenza virus on postnatal day 5. Tissues were harvested from recovered mice 21-days post-infection. The expression levels for myelin basic protein (MBP) were determined, and immunohistochemical staining and transmission electron microscopy were performed. Real-time polymerase chain reaction and Western blot analyses showed that mRNA and protein expressions increased in the hippocampus and cerebellum of recovered mice. Increased MBP-staining signal was observed in the recovered mouse brain. By calculating the relative thickness of myelin sheath in relation to nerve fiber diameter (G-ratio) from electron photomicrographs, an increased G-ratio was observed in both the hippocampus and cerebellum of recovered mice. Influenza infection in oligodendrocyte-enriched primary brain cell cultures showed that proinflammatory cytokines may induce MBP upregulation. These results suggested that increased MBP expression could be a compensatory change related to hypomyelination, which may underlie neural dysfunction in recovered mice. In summary, the present results demonstrate that influenza infection during the neonatal period affects myelination and further induces functional changes in influenza-recovered mouse brain.

Ultrastructural Changes and Expression of PCNA and RPE65 in Sodium Iodate-Induced Acute Retinal Pigment Epithelium Degeneration Model.

Alteration in retinal pigment epithelium (RPE) results in the visual dysfunction and blindness of retinal degenerative diseases. Injection of sodium iodate (NaIO3) generates degeneration of RPE. We analyzed the sequential ultrastructure and expression of proliferating cell nuclear antigen (PCNA) and retina-specific RPE65 in NaIO3-induced retinal degeneration model. Adult male rats were injected 1% NaIO3 (50 mg/kg) and eyes were enucleated at 1, 3, 5, 7 and 14 days post-injection (DPI), fixed, and processed for histological analysis. NaIO3-induced retinal degeneration was successfully established. At 1 DPI, most RPE cells were degenerated and replaced by a few proliferating RPE cells in the peripheral area. At 3 DPI, the RPE and photoreceptor out segments (POS) underwent a marked morphological change, including POS disruption, accumulation of residual bodies in RPE and POS, and hyperplasia of the RPE cell. At 5 DPI, POS showed a maximum increase in the outer segment debris and the retina showed partial detachment. These abnormal morphological changes gradually decreased by day 7. At 14 DPI, the damaged RPE and POS were partially regenerated from the peripheral to the central region. Expression of PCNA and RPE65 increased from day 3 onward. The damaged RPE showed earlier expression of PCNA and RPE65 than POS. The RPE damaged by NaIO3 rapidly proliferated to put down roots on Bruch's membrane from the peripheral retina and proliferation and hyperplasia of the RPE had a regular direction of progress. Therefore, NaIO3-induced acute changes in retina mimic the patho-morphologic features of RPE-related diseases.