Both Plasmodium spp. and Toxoplasma gondii are important apicomplexan parasites, which infect humans worldwide. Genetic analyses have revealed that 33% of amino acid sequences of inner membrane complex from the malaria parasite Plasmodium berghei is similar to that of Toxoplasma gondii. Inner membrane complex is known to be involved in cell invasion and replication. In this study, we investigated the resistance against T. gondii (ME49) infection induced by previously infected P. berghei (ANKA) in mice. Levels of T. gondii-specific IgG, IgG1, IgG2a, and IgG2b antibody responses, CD4+ and CD8+ T cell populations were found higher in the mice infected with P. berghei (ANKA) and challenged with T. gondii (ME49) compared to that in control mice infected with T. gondii alone (ME49). P. berghei (ANKA) + T. gondii (ME49) group showed significantly reduced the number and size of T. gondii (ME49) cysts in the brains of mice, resulting in lower body weight loss compared to ME49 control group. These results indicate that previous exposure to P. berghei (ANKA) induce resistance to subsequent T. gondii (ME49) infection.
Amino Acid Sequence ; Animals ; Antibody Formation ; Body Weight ; Brain ; Humans ; Immunoglobulin G ; Malaria ; Membranes ; Mice ; Parasites ; Plasmodium berghei ; Plasmodium ; Toxoplasma ; Toxoplasmosis

Toxoplasma gondii is a ubiquitous protozoan parasite responsible for causing toxoplasmosis. Preventive measures for toxoplasmosis are currently lacking and as such, development of novel vaccines are of urgent need. In this study, we generated 2 virus-like particles (VLPs) vaccines expressing T. gondii rhoptry protein 4 (ROP4) or rhoptry protein 18 (ROP18) using influenza matrix protein (M1) as a core protein. Mice were intranasally immunized with VLPs vaccines and after the last immunization, mice were challenged with ME49 cysts. Protective efficacy was assessed and compared by determining serum antibody responses, body weight changes and the reduction of cyst counts in the brain. ROP18 VLPs-immunized mice induced greater levels of IgG and IgA antibody responses than those immunized with ROP4 VLPs. ROP18 VLPs immunization significantly reduced body weight loss and the number of brain cysts in mice compared to ROP4 VLPs post-challenge. These results indicate that T. gondii ROP18 VLPs elicited better protective efficacy than ROP4 VLPs, providing important insight into vaccine design strategy.
Animals ; Antibody Formation ; Body Weight ; Body Weight Changes ; Brain ; Immunization ; Immunoglobulin A ; Immunoglobulin G ; Influenza, Human ; Mice ; Parasites ; Toxoplasma ; Toxoplasmosis ; Vaccines

Toxoplasma gondii ME49 infections are typically diagnosed by serological tests. However, serological diagnosis of RH strain-induced toxoplasmosis remains unknown. In order to develop seradiagnosis of above 2 kinds of infections, we generated recombinant virus-like particles (VLPs) displaying the T. gondii rhoptry protein 4 (ROP4) and evaluated their potential in T. gondii ME49 or RH strain infection diagnostics. Mice were orally infected with either the tachyzoites of T. gondii (RH) or cysts of T. gondii (ME49) at various dosages, and sera were collected at regular intervals. ELISA-based serological tests were performed to assess IgG, IgM, and IgA antibody responses against ROP4 VLP antigen and tissue lysate antigen (TLA). Compared to TLA, IgG, IgM, and IgA levels to ROP4 VLP antigen were significantly higher in the sera of T. gondii RH-infected mice 1 and 2 week post-infection (PI). T. gondii-specific IgG antibody was detected at 1, 2, 4, and 8 week PI in the T. gondii ME49-infected mice with infection dose-dependent manner. These results indicated that the ROP4 VLP antigen was highly sensitive antigens detecting T. gondii RH and ME49 antibodies at an early stage.

Purpose: The purpose of this study was to describe changes in positive psychological capital, organizational commitment and burnout according to work periods for new nurses. Methods: A longitudinal study was done using surveys of 91 nurses from a tertiary hospital located in Seoul, South Korea. Data were collected from these newly graduated nurses during the period from July 2018 to September 2019, three times (2 months, 4 months and 6 months after starting to work). Results: Hope of positive psychological capital decreased after 6 months of work (F=7.11, p=.001) and organizational commitment decreased after 4 months of work (F=15.30, p<.001). Factors influencing participants' burnout included the optimism of positive psychological capital and continuance of organizational commitment. These factors explained 51.3% of the variance in burnout (F=48.47, p<.001). Conclusion Organizational support for new nurses is urgently needed. It is necessary to develop programs to strengthen the positive psychological capital of newly graduated nurses to reduce their burnout and to help their job adaptation.

PURPOSE: Islet cell transplantation, as an alternative approach to endocrine cell replacement to treat the diabetes mellitus, has received significant attention because it holds several advantages over whole gland transplantation. However cell damage from islet isolation and immunologic rejection after transplantation prevent from successful clinical application for diabetic patients. Culture of cells at low temperature has known to stabilize the cell viability, and to decrease the immunologic antigenicity. Aim of this study is to investigate the effect of culture at 24oC on cell viability, cellular function, immunogenicity and cytokine profiles in rat pancreas islet. METHODS: Pancreas islets were isolated from Lewis rat and cultured at 24oC or 37oC during 14 days. Islet recovery after culture period was counted as islet equivalent number, and islet viability was examined with fluorescent vital staining (FDA/PI). Islet function was measured with glucose stimulation test. Annexin V expression and MHC class I and II expression were measured with flow cytometric assay for apoptosis and immunogenicity respectively. Lymphocyte cell proliferation through mixed lymphocyte islet culture was examined with WST-1 proliferation assay. Cytokine profiles were analyzed with quantitative real time RT-PCR. All these parameters were measured on 1, 3, 5, 7, 14 culture days after islet isolation. RESULTS: Islet recovery was higher in islet cultured at 24oC than in islet cultured at 37oC without change of viability. Insulin secretion after glucose stimulation was more effective in 24oC culture condition. Decrease of apoptotic cell death was demonstrated in 24oC cultured islet. MHC class I and II expression on islets and lymphocyte proliferation when cocultured with islets were less prominent in 24oC cultured islet. TNF-alpha and IL-4 cytokine expression was higher in islet cultured at 24oC than in islet cultured at 37oC. IL-1beta and IL-10 cytokine expression were similar in both culture condition. CONCLUSION: This study demonstrated that cell recovery and function are increased in islet cultured at 24oC than in islet cultured at 37oC while antigenicity and proinflammatory cytokine expression are decreased. Low temperature culture can be a good approach to prevent the loss of islet mass, and to reduce the immunologic rejection of transplanted islet for successful clinical islet transplantation.
Animals ; Annexin A5 ; Apoptosis ; Cell Death ; Cell Proliferation ; Cell Survival ; Diabetes Mellitus ; Endocrine Cells ; Glucose ; Humans ; Insulin ; Interleukin-10 ; Interleukin-4 ; Islets of Langerhans Transplantation ; Islets of Langerhans* ; Lymphocytes ; Pancreas* ; Rats* ; Tumor Necrosis Factor-alpha

Toxoplasma gondii can infect humans worldwide, causing serious diseases in pregnant women and immunocompromised individuals. T. gondii rhoptry protein 13 (ROP13) is known as one of the key proteins involved in host cell invasion. In this study, we generated virus-like particles (VLPs) vaccine expressing T. gondii rhoptry ROP13 and investigated VLPs vaccine efficacy in mice. Mice immunized with ROP13 VLPs vaccine elicited significantly higher levels of T. gondii-specific IgG, IgG1, IgG2a, and IgA antibody responses following boost immunization and challenge infection, whereas antibody inductions were insignificant upon prime immunization. Differing immunization routes resulted in differing antibody induction, as intranasal immunization (IN) induced greater antibody responses than intramuscular immunization (IM) after boost and challenge infection. IN immunization induced significantly higher levels of IgG and IgA antibody responses from feces, antibody-secreting cells (ASCs), CD4⁺ T, CD8⁺ T cells and germinal center B cell responses in the spleen compared to IM immunization. Compared to IM immunization, IN immunization resulted in significantly reduced cyst counts in the brain as well as lesser body weight loss, which contributed to better protection. All of the mice immunized through either route survived, whereas all naïve control mice perished. These results indicate that the ROP13 VLPs vaccine could be a potential vaccine candidate against T. gondii infection.
Animals ; Antibody Formation ; Antibody-Producing Cells ; Body Weight ; Brain ; Feces ; Female ; Germinal Center ; Humans ; Immunization ; Immunoglobulin A ; Immunoglobulin G ; Mice ; Pregnant Women ; Spleen ; T-Lymphocytes ; Toxoplasma

Afferent loop syndrome (ALS) is a rare cause of recurrent pancreatitis. Recurrent pancreatitis in association with ALS can develop due to impaired outflow of pancreatic juice or reflux of enteric secretions caused by increased intraluminal duodenal pressure. Here, we report a case of ALS presenting as recurrent acute pancreatitis due to chronic intermittent partial obstruction of the third portion of the duodenum caused by postoperative adhesion. Interestingly, pancreatic histology showed a granulocytic epithelial lesion, which is a diagnostic feature of type 2 autoimmune pancreatitis (AIP, idiopathic duct centric chronic pancreatitis [IDCP]). From this case we learned that the diagnosis of type 2 AIP should be made in the appropriate clinical setting.
Afferent Loop Syndrome ; Diagnosis ; Duodenal Obstruction ; Duodenum ; Pancreatic Juice ; Pancreatitis ; Pancreatitis, Chronic

Afferent loop syndrome (ALS) is a rare cause of recurrent pancreatitis. Recurrent pancreatitis in association with ALS can develop due to impaired outflow of pancreatic juice or reflux of enteric secretions caused by increased intraluminal duodenal pressure. Here, we report a case of ALS presenting as recurrent acute pancreatitis due to chronic intermittent partial obstruction of the third portion of the duodenum caused by postoperative adhesion. Interestingly, pancreatic histology showed a granulocytic epithelial lesion, which is a diagnostic feature of type 2 autoimmune pancreatitis (AIP, idiopathic duct centric chronic pancreatitis [IDCP]). From this case we learned that the diagnosis of type 2 AIP should be made in the appropriate clinical setting.

Hair loss is a common condition that can have a negative impact on an individual’s quality of life. The severe side effects and the low efficacy of current hair loss medications create unmet needs in the field of hair loss treatment. Hyaluronan and Proteoglycan Link Protein 1 (HAPLN1), one of the components of the extracellular matrix, has been shown to play a role in maintaining its integrity. HAPLN1 was examined for its ability to impact hair growth with less side effects than existing hair loss treatments. HAPLN1 was predominantly expressed in the anagen phase in three stages of the hair growth cycle in mice and promotes the proliferation of human hair matrix cells. Also, recombinant human HAPLN1 (rhHAPLN1) was shown to selectively increase the levels of transforming growth factor-β receptor II in human hair matrix cells. Furthermore, we observed concomitant activation of the ERK1/2 signaling pathway following treatment with rhHAPLN1. Our results indicate that rhHAPLN1 elicits its cell proliferation effect via the TGF-β2-induced ERK1/2 pathway. The prompt entering of the hair follicles into the anagen phase was observed in the rhHAPLN1-treated group, compared to the vehicle-treated group. Insights into the mechanism underlying such hair growth effects of HAPLN1 will provide a novel potential strategy for treating hair loss with much lower side effects than the current treatments.

Malaria is a global disease affecting a large portion of the world’s population. Although vaccines have recently become available, their efficacies are suboptimal. We generated virus-like particles (VLPs) that expressed either apical membrane antigen 1 (AMA1) or microneme-associated antigen (MIC) of Plasmodium berghei and compared their efficacy in BALB/c mice. We found that immune sera acquired from AMA1 VLP- or MIC VLP-immunized mice specifically interacted with the antigen of choice and the whole P. berghei lysate antigen, indicating that the antibodies were highly parasite-specific. Both VLP vaccines significantly enhanced germinal center B cell frequencies in the inguinal lymph nodes of mice compared with the control, but only the mice that received MIC VLPs showed significantly enhanced CD4+ T cell responses in the blood following P. berghei challenge infection. AMA1 and MIC VLPs significantly suppressed TNF-α and interleukin-10 production but had a negligible effect on interferon-γ. Both VLPs prevented excessive parasitemia buildup in immunized mice, although parasite burden reduction induced by MIC VLPs was slightly more effective than that induced by AMA1. Both VLPs were equally effective at preventing body weight loss. Our findings demonstrated that the MIC VLP was an effective inducer of protection against murine experimental malaria and should be the focus of further development.