• Title/Summary/Keyword: cell infection

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Pathophysiology, classification, and complications of common asymptomatic thrombocytosis in newborn infants

  • Jeon, Ga Won
    • Clinical and Experimental Pediatrics
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    • v.65 no.4
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    • pp.182-187
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    • 2022
  • We frequently encounter newborn infants with thrombocytosis in the neonatal intensive care unit. However, neonatal thrombocytosis is not yet fully understood. Thrombocytosis is more frequently identified in newborns and young infants, notably more often in those younger than 2 years than in older children or adults. The production of megakaryocytes (megakaryopoiesis) and platelets (thrombopoiesis) is mainly regulated by thrombopoietin (TPO). Increased TPO levels during infection or inflammation can stimulate megakaryopoiesis, resulting in thrombopoiesis. TPO concentrations are higher in newborn infants than in adults. Levels increase after birth, peak on the second day after birth, and start decreasing at 1 month of age. Initial platelet counts at birth increase with gestational age. Thus, preterm infants have lower initial platelet counts at birth than late-preterm or term infants. Postnatal thrombocytosis is more frequently observed in preterm infants than in term infants. A high TPO concentration and low TPO receptor expression on platelets leading to elevated plasma-free TPO, increased sensitivity of megakaryocyte precursor cells to TPO, a decreased red blood cell count, and immaturity of platelet regulation are speculated to induce thrombocytosis in preterm infants. Thrombocytosis in newborn infants is considered a reactive process (secondary thrombocytosis) following infection, acute/chronic inflammation, or anemia. Thrombocytosis in newborn infants is benign, resolves spontaneously, and, unlike in adults, is rarely associated with hemorrhagic and thromboembolic complications.

Management and rehabilitation of moderate-to-severe diabetic foot infection: a narrative review

  • Chi Young An;Seung Lim Baek;Dong-Il Chun
    • Journal of Yeungnam Medical Science
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    • v.40 no.4
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    • pp.343-351
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    • 2023
  • Diabetic foot is one of the most devastating consequences of diabetes, resulting in amputation and possibly death. Therefore, early detection and vigorous treatment of infections in patients with diabetic foot are critical. This review seeks to provide guidelines for the therapy and rehabilitation of patients with moderate-to-severe diabetic foot. If a diabetic foot infection is suspected, bacterial cultures should be initially obtained. Numerous imaging studies can be used to identify diabetic foot, and recent research has shown that white blood cell single-photon emission computed tomography/computed tomography has comparable diagnostic specificity and sensitivity to magnetic resonance imaging. Surgery is performed when a diabetic foot ulcer is deep and is accompanied by bone and soft tissue infections. Patients should be taught preoperative rehabilitation before undergoing stressful surgery. During surgical procedures, it is critical to remove all necrotic tissue and drain the inflammatory area. It is critical to treat wounds with suitable dressings after surgery. Wet dressings promote the formation of granulation tissues and new blood vessels. Walking should begin as soon as the patient's general condition allows it, regardless of the wound status or prior walking capacity. Adequate treatment of comorbidities, including hypertension and dyslipidemia, and smoking cessation are necessary. Additionally, broad-spectrum antibiotics are required to treat diabetic foot infections.

SARS-CoV-2 Infection of Airway Epithelial Cells

  • Gwanghui Ryu;Hyun-Woo Shin
    • IMMUNE NETWORK
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    • v.21 no.1
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    • pp.3.1-3.16
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    • 2021
  • Coronavirus disease 2019 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading worldwide since its outbreak in December 2019, and World Health Organization declared it as a pandemic on March 11, 2020. SARS-CoV-2 is highly contagious and is transmitted through airway epithelial cells as the first gateway. SARS-CoV-2 is detected by nasopharyngeal or oropharyngeal swab samples, and the viral load is significantly high in the upper respiratory tract. The host cellular receptors in airway epithelial cells, including angiotensin-converting enzyme 2 and transmembrane serine protease 2, have been identified by single-cell RNA sequencing or immunostaining. The expression levels of these molecules vary by type, function, and location of airway epithelial cells, such as ciliated cells, secretory cells, olfactory epithelial cells, and alveolar epithelial cells, as well as differ from host to host depending on age, sex, or comorbid diseases. Infected airway epithelial cells by SARS-CoV-2 in ex vivo experiments produce chemokines and cytokines to recruit inflammatory cells to target organs. Same as other viral infections, IFN signaling is a critical pathway for host defense. Various studies are underway to confirm the pathophysiological mechanisms of SARS-CoV-2 infection. Herein, we review cellular entry, host-viral interactions, immune responses to SARS-CoV-2 in airway epithelial cells. We also discuss therapeutic options related to epithelial immune reactions to SARS-CoV-2.

In Vitro and in Vivo Effects of Nitrofurantoin on Experimental Toxoplasmosis

  • Yeo, Seon-Ju;Jin, ChunMei;Kim, SungYeon;Park, Hyun
    • Parasites, Hosts and Diseases
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    • v.54 no.2
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    • pp.155-161
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    • 2016
  • Toxoplasma gondii is an important opportunistic pathogen that causes toxoplasmosis, which has very few therapeutic treatment options. The most effective therapy is a combination of pyrimethamine and sulfadiazine; however, their utility is limited because of drug toxicity and serious side effects. For these reasons, new drugs with lower toxicity are urgently needed. In this study, the compound, (Z)-1-[(5-nitrofuran-2-yl)methyleneamino]-imidazolidine-2,4-dione (nitrofurantoin), showed anti-T. gondii effects in vitro and in vivo. In HeLa cells, the selectivity of nitrofurantoin was 2.3, which was greater than that of pyrimethamine (0.9). In T. gondii-infected female ICR mice, the inhibition rate of T. gondii growth in the peritoneal cavity was 44.7% compared to the negative control group after 4-day treatment with 100 mg/kg of nitrofurantoin. In addition, hematology indicators showed that T. gondii infection-induced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, biochemical parameters involved in liver injury, were reduced by nitrofurantoin significantly. Moreover, nitrofurantoin exerted significant effects on the index of antioxidant status, i.e., malondialdehyde (MDA) and glutathione (GSH). The nitrofurantoin-treated group inhibited the T. gondii-induced MDA levels while alleviating the decrease in GSH levels. Thus, nitrofurantoin is a potential anti-T. gondii candidate for clinical application.

Isotyping of Immunoglobulin G Responses of Ruminants and Mice to Live and Inactivated Antigens of Cowdria ruminantium the Causative Agent of Cowdriosis in Ruminants

  • Kibor, A.C.;Sumption, K.J.;Paxton, E.A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.16 no.4
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    • pp.541-548
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    • 2003
  • The Immunoglobulin $IgG_1$ and $IgG_2$ isotype immune responses of domestic ruminants and mice to Cowdria. ruminantium live infection or by immunization with inactivated organisms were determined by the enzyme linked immunosorbent assay and Western blotting. Immunization of goats with inactivated elementary bodies (IEBs) led to a predominant $IgG_1$ isotype response. This indicated that a Th2 response was induced. After challenge, the IgG isotype responses were mixed whereby both $IgG_1$ and $IgG_2$ antibodies were detected. Two goats that survived virulent challenge had a predominant $IgG_2$ isotype response. In cattle live infection by natur l challenge or experiment led to a predominant $IgG_1$ isotype response. Immunization of cattle with IEBs however led to mixed IgG responses characterized by similar $IgG_1$ and $IgG_2$ ratios. In the mouse live infection led to a predominant $IgG_2$ isotype response. This indicated the mouse developed a true Th1 type cell mediated immune response when inoculated with live organisms. Immunization with inactivated organisms on the other hand led to a dominant $IgG_1$ response. It is evident from this work that the immune responses of ruminants and mice to C. ruminantium are different and that using mice as the experimental model for immune responses to Cowdria ruminantium. is not the appropriate.

Phloretin Protects Macrophages from E. coli-Induced Inflammation through the TLR4 Signaling Pathway

  • Chauhan, Anil Kumar;Jang, Mihee;Kim, Yangmee
    • Journal of Microbiology and Biotechnology
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    • v.30 no.3
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    • pp.333-340
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    • 2020
  • Macrophages are the cells of the first-line defense system, which protect the body from foreign invaders such as bacteria. However, Gram-negative bacteria have always been the major challenge for macrophages due to the presence of lipopolysaccharides on their outer cell membrane. In the present study, we evaluated the effect of phloretin, a flavonoid commonly found in apple, on the protection of macrophages from Escherichia coli infection. RAW 264.7 cells infected with standard E. coli, or virulent E. coli K1 strain were treated with phloretin in a dose-dependent manner to examine its efficacy in protection of macrophages. Our results revealed that phloretin treatment reduced the production of nitric oxide (NO) and generation of reactive oxygen species along with reducing the secretion of proinflammatory cytokines induced by the E. coli and E. coli K1 strains in a concentration-dependent manner. Additionally, treatment of phloretin downregulated the expression of E. coli-induced major inflammatory markers i.e. cyclooxygenase-2 (COX-2) and hemeoxygenase-1 (HO-1), in a concentration dependent manner. Moreover, the TLR4-mediated NF-κB pathway was activated in E. coli-infected macrophages but was potentially downregulated by phloretin at the transcriptional and translational levels. Collectively, our data suggest that phloretin treatment protects macrophages from infection of virulent E. coli K1 strain by downregulating the TLR4-mediated signaling pathway and inhibiting NO and cytokine production, eventually protecting macrophages from E. coli-induced inflammation.

Construction and Characterization of Transformed Insect Cells Expressing Baculovirus Very Late Factor in an Infection-Independent Manner

  • Park, Hye-Jin;Lee, Kwang-Sik;Cho, Eun-Sook;Yun, Eun-Young;Kang, Seok-Woo;Kim, Keun-Young;Sohn, Hung-Dae;Jin, Byung-Rae
    • International Journal of Industrial Entomology and Biomaterials
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    • v.2 no.1
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    • pp.19-26
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    • 2001
  • Transformed Spodoptera frugiperda (Sf9) cells expressing baculovirus very late factor (VLF-1) were constructed by using Autograha nuclear polyhedrosis virus (AcNPV) immediate earthy gene (ie1). Neomycin-resistance gene as a selectable marker was introduced under the control of AcNPV ie1 promoter, and Bombyx mori nuclear polyhedrosis (BmNPV-K1) vlf-1 gene was introduced under the control of the Drosophila heat shock protein gene (hspr70) promoter to yield dual expression plasmid with two independent transcription units. It was transfected into Sf9 cells and cell clones expressing vlf-1 were selected by G4l8 treatment. Genomic DNA from transformed cells was isolated and integration of AcNPV iel harboring vlf-1 was confirmed by PCR using AcNPV iel-specific primers and Southern blot analysis. The transformed cells expressing VLF-1 in an infection-independent manner expressed foreign gene product of recombinant baculovirus in the earlier stage of infection compared with control Sf9 cells. These results suggest the possible to develop highly efficient transformed insect cells for baculovirus expression vector system.

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Therapeutic efficacy of the liposome incorporated buparvaquone on experimental Theileria sergenti infection in calves (리포좀 피포성 buparvaquone의 Theileria sergenti 인공감염 송아지에 대한 치료효과)

  • Kim, Doo
    • Korean Journal of Veterinary Research
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    • v.33 no.1
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    • pp.137-143
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    • 1993
  • This study was carried out to completelycure the experimental bovine theileriasis with small unilamella vesicle liposome incorporated buparvaquone which was effective both to schizonts in lymphocyte of lymph nodes and piroplasmic stage in erythrocytes. Small unilamella vesicle liposome incorporated buparvaquone was prepared by French pressure cell method using egg phosphatidylcholine. The diameter of the vesicles was ranged from 5 to 220 nm, but the most vesicles were ranged from 10 to 50 nm in diameter. The incorporation rate for buparvaquone was 100%. Parasitaemia of the 10 calves inoculated with $5{\times}10^8$ erythrocytes infected with Theileria sergenti were first detected from on day 16 to day 23 after inoculation. In calves treated with a dose rate 2.5 mg/kg BW of free buparvaquone, a gradual decrease in piroplasmic parasitaemia was observed following treatment to day 5. However parasitaemia levels returned to near pretreatment values after approximately 60 days. In calves treated with a dose rate 5.0mg/kg BW of free buparvaquone, parasitaemia were disappeared on day 3 after treatment, but there was a mild recrudescence of infection on day 28 after treatment. In calves treated intraavenously with a dose rate 2.5 mg/kg BW of buparvaquone incorporated in liposome, the calves were all cured on day 2 or day 3 after treatment. In calves treated subcutaneously and intraperiotoneally with a dose rate 2.5 mg/kg BW of buparvaquone incorporated in liposome, parasitaemia were disappeared on day 3 or day 4 after treatment, but there was a mild recrudescence of infection on day 40 or day 45 after treatment.

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Analysis of Transcriptional Profiles to Discover Biomarker Candidates in Mycobacterium avium subsp. paratuberculosis-Infected Macrophages, RAW 264.7

  • Cha, Seung Bin;Yoo, Anna;Park, Hong Tae;Sung, Kyoung Yong;Shin, Min Kyoung;Yoo, Han Sang
    • Journal of Microbiology and Biotechnology
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    • v.23 no.8
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    • pp.1167-1175
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    • 2013
  • Paratuberculosis (PTB) or Johne's disease is one of the most serious chronic debilitating diseases of ruminants worldwide that is caused by Mycobacterium avium subsp. paratuberculosis (MAP). MAP is a slow-growing bacterium that has very long latent periods, resulting in difficulties in diagnosing and controlling the disease, especially regarding the diagnosis of fecal shedders of MAP without any clinical signs. Based on this situation, attempts were made to identify biomarkers that show early responses to MAP infection in a macrophage cell line, RAW 264.7. In response to the infection with the bacterium, a lot of genes were turned on and/or off in the cells. Of the altered genes, three different categories were identified based on the time-dependent gene expression patterns. Those genes were considered as possible candidates for biomarkers of MAP infection after confirmation by quantitative RT-PCR analysis. To the best of our knowledge, this is the first attempt at discovering the host transcriptomic biomarkers of PTB, although further investigation will be required to determine whether these biomarker candidates are associated within the natural host.

A TREMATODE GENUS BACCIGER PARASITIC IN BIVALVES (조개류에 기생하는 Bacciger속 흡충류에 관한 연구)

  • CHUN Seh-Kyu;KIM Young-Gill
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.13 no.4
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    • pp.173-178
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    • 1980
  • Cercaria larvae of Bacciger harengulae which is parasitic to Meretrix lusoria, rapes japonica and Solen strictus were studied in terms of their morphology and incidence of infection rate. The host bivalves were collected from Naechodo, Okgu-gun during the Period from January to November in 1980. The tail of the cercaria bears 27 pairs of tufts of setae, the tufts being composed of 6 fine rays. Oral sucker, intestine, ventral sucker and a pair of testes are distinctive. The excretory duct bears numerous granules of various size, and the flame-cell arrangement is represented by a formula 2[(3+3)+(3+3)]=24. The cercaria is somewhat similar to the previously known Cercaria pectinata . It is however conformed that present cercaria belongs to Bacciger harengulae. Infection rate showed seasonal variation and host selectivity. Higher infections were observed in Solen strictus, and lower in Meretrix lusoria. Generally, the larger bivalves over 2-3 years old showed the higher infection rate.

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