CD11b+Gr-1low cells that accumulate in M.leprae-induced granulomas of the footpad skin of nude mice have the characteristics of monocytic-myeloid-derived suppressor cells / 나학회지

CD11b+Gr-1low cells that are increased in the lungs of a Mycobacterium (M) tuberculosisinfection mouse model have the characteristics of monocytic (M) - myeloid - derived suppressor cells (MDSCs) and harbor M.tuberculosis. Interestingly, a high number of M-MDSCs have also been observed in skin lesions of patients with lepromatous leprosy.We hypothesized that CD11b+Gr-1low cells might be involved in the pathogenesis of leprosy, as they are in tuberculosis. In the current study, we investigated the issue of whether CD11b+Gr-1low cells accumulate in Mycobacterium (M) leprae-induced granulomas of the footpad skin of nude mice. Our results show that CD11b+Gr-1low cells began to accumulate in the 7-month-old M.leprae-induced granulomas and were replaced by other leukocytes, including CD11b + Gr-1 high over time during M.leprae infections. CD11b+Gr-1low cells expressed the surface markers of M-MDSC, Ly6C high and Ly6G low . In addition, CD11b+Gr-1low cells have the nuclei of a mononuclear cell type and expressed higher levels of arginase 1 (Arg1) and inducible NO synthetase (iNOS).Furthermore, they showed a higher infection rate by M.leprae. Taken together, our results indicate that the inoculation with M.leprae induced an accumulation of CD11b+Gr-1low at a relatively early stage, 7-month-old M.leprae-induced granulomas, and that CD11b+Gr-1low have the characteristics of M-MDSC and may act as a reservoir for M.leprae.

Vitamin D Receptor Gene TaqI, BsmI and FokI Polymorphisms in Korean Patients with Tuberculosis

BACKGROUND: The active metabolite (1, 25-dihydroxycholecalciferol) of vitamin D (25-hydroxycholecalciferol) leads to activation of macrophages and deficiency of vitamin D seems to be involved in the risk of tuberculosis. The effects of vitamin D are exerted by interaction with the vitamin D receptor (VDR) and may be influenced by polymorphism in the VDR gene. In this study, variation in the VDR gene was investigated in Korean population with tuberculosis. METHODS: We typed three VDR polymorphisms of restriction endonuclease sites for TaqI, BsmI and FokI in 155 patients with tuberculosis and 105 healthy volunteers. RESULTS: The frequencies of FokI genotypes determined from TB patients were 29.13% for FF, 56.31% for Ff, and 14.56% for ff. We observed 1.4-fold increased prevalence of the Ff genotype in TB patients compared with normal healthy groups (p=0.0857). However, there was no significant association between the genotype groups, TB patient and normal control, for FokI polymorphism. There was also no significant association between VDR gene and tuberculosis in another polymorphism (BsmI and TaqI). CONCLUSION: Three polymorphisms (TaqI, BsmI and FokI) in the VDR gene do not appear to be responsible for host susceptibility to human tuberculosis in Korean population.

Vitamin D Receptor Gene TaqI, BsmI and FokI Polymorphisms in Korean Patients with Tuberculosis

BACKGROUND: The active metabolite (1, 25-dihydroxycholecalciferol) of vitamin D (25-hydroxycholecalciferol) leads to activation of macrophages and deficiency of vitamin D seems to be involved in the risk of tuberculosis. The effects of vitamin D are exerted by interaction with the vitamin D receptor (VDR) and may be influenced by polymorphism in the VDR gene. In this study, variation in the VDR gene was investigated in Korean population with tuberculosis. METHODS: We typed three VDR polymorphisms of restriction endonuclease sites for TaqI, BsmI and FokI in 155 patients with tuberculosis and 105 healthy volunteers. RESULTS: The frequencies of FokI genotypes determined from TB patients were 29.13% for FF, 56.31% for Ff, and 14.56% for ff. We observed 1.4-fold increased prevalence of the Ff genotype in TB patients compared with normal healthy groups (p=0.0857). However, there was no significant association between the genotype groups, TB patient and normal control, for FokI polymorphism. There was also no significant association between VDR gene and tuberculosis in another polymorphism (BsmI and TaqI). CONCLUSION: Three polymorphisms (TaqI, BsmI and FokI) in the VDR gene do not appear to be responsible for host susceptibility to human tuberculosis in Korean population.

GS28 Protects Neuronal Cell Death Induced by Hydrogen Peroxide under Glutathione-Depleted Condition

Golgi SNAP receptor complex 1 (GS28) has been implicated in vesicular transport between intra-Golgi networks and between endoplasmic reticulum (ER) and Golgi. Additional role(s) of GS28 within cells have not been well characterized. We observed decreased expression of GS28 in rat ischemic hippocampus. In this study, we examined the role of GS28 and its molecular mechanisms in neuronal (SK-N-SH) cell death induced by hydrogen peroxide (H2O2). GS28 siRNA-transfected cells treated with H2O2 showed a significant increase in cytotoxicity under glutathione (GSH)-depleted conditions after pretreatment with buthionine sulfoximine, which corresponded to an increase of intracellular reactive oxygen species (ROS) in the cells. Pretreatment of GS28 siRNA-transfected cells with p38 chemical inhibitor significantly inhibited cytotoxicity; we also observed that p38 was activated in the cells by immunoblot analysis. We confirmed the role of p38 MAPK in cotransfected cells with GS28 siRNA and p38 siRNA in the cell viability assay, flow cytometry, and immunoblot. Involvement of apoptotic or autophagic processes in the cells was not shown in the cell viability, flow cytometry, and immunoblot analyses. However, pretreatment of the cells with necrostatin-1 completely inhibited H2O2-induced cytotoxicity, ROS generation, and p38 activation, indicating that the cell death is necroptotic. Collectively these data imply that H2O2 induces necroptotic cell death in the GS28 siRNA-transfected cells and that the necroptotic signals are mediated by sequential activations in RIP1/p38/ROS. Taken together, these results indicate that GS28 has a protective role in H2O2-induced necroptosis via inhibition of p38 MAPK in GSH-depleted neuronal cells.

A Case Study on Engineering Failure Analysis of Link Chain

OBJECTIVES: The objective of this study was to investigate the effect of chain installation condition on stress distribution that could eventually cause disastrous failure from sudden deformation and geometric rupture. METHODS: Fractographic method used for the failed chain indicates that over-stress was considered as the root cause of failure. 3D modeling and finite element analysis for the chain, used in a crane hook, were performed with a three-dimensional interactive application program, CATIA, commercial finite element analysis and computational fluid dynamic software, ANSYS. RESULTS: The results showed that the state of stress was changed depending on the initial position of the chain that was installed in the hook. Especially, the magnitude of the stress was strongly affected by the bending forces, which are 2.5 times greater (under the simulation condition currently investigated) than that from the plain tensile load. Also, it was noted that the change of load state is strongly related to the failure of parts. The chain can hold an ultimate load of about 8 tons with only the tensile load acting on it. CONCLUSION: The conclusions of this research clearly showed that a reduction of the loss from similar incidents can be achieved when an operator properly handles the installation of the chain.

A Case Study on Engineering Failure Analysis of Link Chain

OBJECTIVES: The objective of this study was to investigate the effect of chain installation condition on stress distribution that could eventually cause disastrous failure from sudden deformation and geometric rupture. METHODS: Fractographic method used for the failed chain indicates that over-stress was considered as the root cause of failure. 3D modeling and finite element analysis for the chain, used in a crane hook, were performed with a three-dimensional interactive application program, CATIA, commercial finite element analysis and computational fluid dynamic software, ANSYS. RESULTS: The results showed that the state of stress was changed depending on the initial position of the chain that was installed in the hook. Especially, the magnitude of the stress was strongly affected by the bending forces, which are 2.5 times greater (under the simulation condition currently investigated) than that from the plain tensile load. Also, it was noted that the change of load state is strongly related to the failure of parts. The chain can hold an ultimate load of about 8 tons with only the tensile load acting on it. CONCLUSION: The conclusions of this research clearly showed that a reduction of the loss from similar incidents can be achieved when an operator properly handles the installation of the chain.

Rifampicin Inhibits the LPS-induced Expression of Toll-like Receptor 2 via the Suppression of NF-kappaB DNA-binding Activity in RAW 264.7 Cells

Rifampicin is a macrocyclic antibiotic which is used extensively for treatment against Mycobacterium tuberculosis and other mycobacterial infections. Recently, a number of studies have focused on the immune-regulatory effects of rifampicin. Therefore, we hypothesized that rifampicin may influence the TLR2 expression in LPS-activated RAW 264.7 cells. In this study, we determined that rifampicin suppresses LPS-induced TLR2 mRNA expression. The down-regulation of TLR2 expression coincided with decreased production of TNF-alpha. Since NF-kappaB is a major transcription factor that regulates genes for TLR2 and TNF-alpha, we examined the effect of rifampicin on the LPS-induced NF-kappaB activation. Rifampicin inhibited NF-kappaB DNA-binding activity in LPS-activated RAW 264.7 cells, while it did not affect IKKalpha/beta activity. However, rifampicin slightly inhibited the nuclear translocation of NF-kappaB p65. In addition, rifampicin increased physical interaction between pregnane X receptor, a receptor for rifampicin, and NF-kappaB p65, suggesting pregnane X receptor interferes with NF-kappaB binding to DNA. Taken together, our results demonstrate that rifampicin inhibits LPS-induced TLR2 expression, at least in part, via the suppression of NF-kappaB DNA-binding activity in RAW 264.7 cells. Thus, the present results suggest that the rifampicin-mediated inhibition of TLR2 via the suppression of NF-kappaB DNA-binding activity may be a novel mechanism of the immune-suppressive effects of rifampicin.

Mutations in folP1, rpoB, and gyrB associated with multiple drug resistance in Mycobacterium leprae isolates from South Korea / 나학회지

The emergence of multiple drug resistant Mycobacterium leprae has emphasized the need for early decision of effective antileprosy drug in the treatment for leprosy patients. Mutations in the genes associated with multiple drug resistance in Mycobacterium leprae isolates from 17 South Korean patients, who were already confirmed to have mutations in folP1 gene, were investigated using a PCR - single strand conformation polymorphism (SSCP) - DNA sequencing assay. Two strains, which has double mutations, were found in the two unrelated patients : one missense mutation in folP1 (Arg 55 for Pro) and in rpoB (Gly 522 for Ser), and in folP1 (Ala 53 for Thr) and in gyrB (Asn 426 for Asp), respectively. The patients were treated with the long monotheraphy of dapsone or with the inappropriate regimen of antileprosy drugs. These results emphasize the importance of multi-drug theraphy in order to prevent mult-idrug resistance and assist in the choice of the appropriate regimens for treating leprosy.

Effects of Dexamethasone on expressions of IFN-gamma and IL-4 by PBMCs in response to IL-12 / 나학회지

Dexamethasone is a widely used anti-inflammatory agent for a broad spectrum of diseases. The effectiveness of this agent is thought to be due to the capacity to modulate cytokine production in inflammatory cells. We examined the effects of dexamethasone on expressions of interferon gamma (IFN-gamma) and interleukin 4 (IL-4) by human peripheral blood mononuclear cells (PBMCs) in response to interleukin 12 (IL-12). Dexamethasone (10-5 M) inhibited IFN-gamma secretion, through direct suppression of IFN-gamma, IL-12 receptor (IL-12R) -beta1, and -beta2 expressions. Conversely dexamethasone increased IL-4 secretion as well as IL-4 expressions by PBMCs in response to IL-12. In addition, dexamethasone increased expression of suppressor of cytokine signalling (SOCS)-1, which inhibits JAK-STAT pathway of IL-12R signalling. The result of our study suggested that dexamethasone directly inhibited IFN-gamma expression, through suppression of IL-12 signalling and indirectly increases IL-4 expression, through suppression of IFN-gamma expression.

The application of TD (Touch-Down) PCR in Diagnosis of leprosy and Detection of MDT-resistant M. leprae / 나학회지

There are several methods for diagnosis of leprosy, including AFB stain, the measurement of PGL-1 (phenolic glycolipid - 1) antigen titer, and DNA-PCR. In this study, we have used the DNA-PCR amplifying the RLEP repetitive sequence. Our result showed that the RLEP primer offered the more sensitive detection and identification of M. leprae DNA in clinical specimens, compared with the other primer, for example, 18-kDa antigen gene. To screen the resistant M. leprae strain of MDT (Multi-Drug Therapy), we have used the TD (Touch-Down) PCR. We arranged and amplified sequences of the genes, folP, rpoB, gyr, 23S rRNA, in M. leprae involved in MDT-resistance, and could obtain the PCR product each gene, simultaneously. This method, based on annealing temperature, was useful to the detection for diagnosis and the screen of MDT-resistant strain of M. leprae, rapidly. Thus, we suggest that the RLEP primer and TD-PCR method are effective in assessing the diagnosis of leprosy and the identification of drug-resistant M. leprae.

The effect of TLR2 mutation in IL-12 production according to type of leprosy / 나학회지

Recently, many reports suggest that the activation of Toll-like receptor 2 (TLR2) by microbial lipoproteins may initiate innate defense mechanism against infectious pathogens. Especially, TLR2 is critical in the immune response to mycobacterial infections and the mutations in the TLR2 have been shown to confer the susceptibility to severe infection with mycobacteria. A previous study reported that there is a mutation of TLR2 (TLR2-R677W) in lepromatous leprosy. In this study, thus, we performed the functional study on TLR2 by measurement of IL-12 production in serum and monocytes from leprosy patients with TLR2 mutation (R677W) to verify the relation between TLR2 and the susceptibility to leprosy. Tuberculoid leprosy patients showed higher serum levels of IL-12p70 compared with those of lepromatous leprosy. In contrast with the lepromatous leprosy patient with TLR2 mutation, especially, the group with wild-type TLR2 showed 2-fold increase levels of IL-12p70. Functional studies demonstrated that monocytes from patient with the TLR2 mutation, in comparison to the wild-type TLR2, is significantly less responsive to Mycobacterium leprae lysate. Our results reveal that TLR2 has a important role in the IL-12 production from monocytes and the susceptibility of lepromatous leprosy.

Optimization for cell lysate preparation of M. leprae from infected nude mouse / 나학회지

The method of cell lysate preparation of M. leprae is an important technique in the study of leprosy. This report describes the optimization of method for cell lysate preparation of M. leprae obtained from infected nude mouse. After M. leprae isolated from nude mouse foot-pad was disrupted by sonication, it was centrifuged and then whole lysate was prepared. With this method it was possible to isolate 0.3 mg whole cell lysate using 20 mg of M. leprae. By SDS-PAGE and Coomassie blue staining, the number of protein in M. leprae is less than that of other bacteria, for example, E. coli and M. smegmatis. It is likely that this is due to the small genome size. This work will contribute to the analysis of new protein antigen of M. leprae and the basic study for the development of vaccine in leprosy.

HLA-A, B and DRB1 Genes Related with Susceptibility and Type of Hansen's Disease / 나학회지

To find out whether the susceptibility to Hansen's disease are associated with HLA genes, serological and nucleotide typing of HLA-A, B, and DRB1 alleles have been conducted in 301 Hansen's disease patients[190 Multibacillary cases(MB, LL/BL), 111 Paucibacillary cases(PB, TT/BT) confirmed at the time of diagnosis, almost of them were treated with Multidrug therapy] and 928 healthy controls from a population in Seoul and Northern area of Han River in Kyunggi Province, Korea. HLA-A30[relative risk(RR) 1.58, chi-square=4.89, P=0.04] was significantly associated with Hansen's disease. In contrast to HLA-B27(RR 0.20, chi-square=11.34, P=0.0002), which was negatively associated with Hansen's disease as a whole, in MB and PB separately, HLA-B52(RR 1.97, chi-square=6.89, P=0.002) and B46(RR 1.63, chi-square=4.84, P=0.04) were significantly increased in Hansen's disease. DRB1*02 was associated with MB(LL/BL)[RR 1.96, chi-square=13.47, P=0.0004] but not with PB(TT/BT). Further works about oligonuceotide typing of DQA,B, and DPB1 are ongoing. High resolution study to define DRB1*02 alleles will be performed.

Interferon-gamma (IFN-gamma) increases CD1 expression through inhibition of IL-10 secretion from M.leprae-infected macrophages of lepromatous leprosy / 나학회지

The CD1 system is a novel antigen-presenting system for T cell recognition of lipid and glycolipids in antimicrobial immunity. Lepromatous leprosy is characterized by lack of cell-mediated immunity against M.leprae. The lack of cell-mediated immunity in lepromatous leprosy has been suggested to be correlated with weak CD1 expression on antigen presenting cells. In order to define how CD1 is down-regulated on M. leprae-infected antigen-presenting cells, we examined effects of interferon-gamma(IFN-gamma) on interleukin-10 (IL-10) secretion and CD1 expression of M.leprae-infected macrophages from granuloma of lepromatous leprosy. Our results showed that a significant trend of increased CD1 expression in response to decresed IL-10 secretion from M.leprae-infected macrophages by IFN-gamma. These results suggest that the local cytokine milieu, especially the balance between IFN-gamma and IL-10, is an important determinant in the regulation of CD1 in lepromatous lesions.

Primary Ovarian Leiomyosarcoma: A case report

Primary leiomyosarcoma is a rare tumor of the ovary. We experienced a case of primary ovarian leiomyosarcoma in a 68 year old woman. Microscopically, the tumor was characterized by interlacing bundles of plump spindle cells that showed immunoreactivity for alpha-smooth muscle actin, pleomorphic multinucleated giant cells and an increased mitotic rate. Ultrastructural features included abundant smooth muscle type filaments and irregular bodies. Consequently, this case has led us to propose ultrastructural and immunohistochemical criteria for primary ovarian leiomyosarcoma.

Tubular Apocrine Adenoma: A case report

Tubular apocrine adenoma is a rare benign tumor occuring most often on the scalp. We examined a case of a 69-year-old female who had a well demarcated solid nodule on the scalp. Pathol Microscopically, the tumor was composed of lobules of tubular structures. The tumor lobules were surrounded by a stroma of dense fibrous connective tissue. The tubular structures were usually formed of two rows of epithelial cells. In some areas, the widely dilated tubular structures showed papillary projections into the cavities. Some epithelial cells showed liculoma on decapitation secretion into the cystic structure. Problems of differential diagnosis with other adnexal tumors are briefly discussed.

Sebaceous Trichofolliculoma: A case report

Sebaceous trichofolliculoma is a variant of trichofolliculoma which occurs in the sebaceous areas rich in follicles and is a relatively rare skin tumor. This tumor is a clinically and histologically easy tumor to recognize that is well differentiated. We examined a case of a consists of a 21-year-old female who had a pedunculated nodule on her scalp. Microscopically, the tumor was large, had a centrally located cavity lined by squamous epithelium and radially arranged sebaceous follicles connected to the cavity. No cytological atypia or recurrence after excision was found.

HgCl2 Toxicity on Cultured Renal Tubular Cells of Rabbit

To understand the mechanism of cell injury when exposed to HgCl2, monitoring of cytosolic ionized free Ca2+([Ca2+]i), viability test, measurement of the amount of ATP, and Ca-ATPase activity were evaluated in cultured rabbit renal tubular cells(RTC) exposed to HgCl2. The results were as follows: 1) HgCl2 was cytotoxic to rabbit RTC at all doses except 10 uM and the rate of killing displayed a dose- and time-dependent relationship. 2) The absence of extracellular Ca provided partial protection from irreversible injury induced by HgCl2. 3) The increasing pattem of [Ca2+]i varied according to the concentrations of HgCl2. At the low concentrations of HgCl2 (2.5-10 microM), the level of [Ca2+]i increased slowly over the flat 2-3 min and then achieved plateau-state. In contrast, at the high concentrations of HgCl2 (25-100 microM) the level of [Ca2+]i achieved peak within 1 min and then decreased to a plateau state under normal concentrations. 4) The level of ATP was decreased to 27.5% of that of normal control cells within 3 min by using a treatment of 100 microM HgCl2. 5) HgCl2 did not affect the Ca2+ ATPase activity by enzyme histochemical observation. These findings suggest that the elevation of [Ca2+]i in response to the HgCl2-induced injury is an important event in accelerating injury that ultimately leads to cell death. But other possibilities such as HgCl2 might have direct deleterious effects on the also should be considered.

Production of PGE2 and H2O2 from Alveolar Macrophage Stimulated by Silica / 결핵

BACKGROUND: The pathogenesis of silicosis has been focused on the interaction between alveolar macrophages and silica particle. Although fibrosis in silicosis has been studied extensively, the mechanism is still not fully understood. There is increasing evidence that monokines and arachidonic acid metabolites produced by macrophage are involved in pathogenesis of silicosis. Recently, it was reported that prostaglandin E2 produced from macrophage counteracts the stimulatory effects of other monokines on fibroblast proliferation or collagen production. Until now, it was remained uncertain by which mechanism silica particle may activate alveolar macrophage to an enhanced release of prostaglandin E2. METHODS: In order to investigate the relationship between the activity of alveolar macrophage and the production of PGE2 from activated alveolar macrophage, the authors measured hydrogen peroxide and PGE2 from alveolar macrophages activated by silica in vitro and from alveolar macrophages in the silicotic nodules from rat. Experimental silicosis was induced by intratracheal infusion of silica(SiO2) suspended in saline (50 mg/ml) in Sprague-Dawley rats. RESULTS: 1) The silicotic nodules with fibrosis were seen from the sections of rat lung at 60 days after intratracheal injection with 50 mg aqueous suspension of silica. 2) In vitro, silica caused the dose dependent increase of hydrogen peroxide(p0.05) release from alveolar macrophages. Alveolar macrophages from rats with silicotic nodules released more hydrogen peroxide and PGE2 than those of control group(p<0.05). CONCLUSION: These results suggest that silica particle could activate macrophage directly and enhanced the release of PGE2 and hydrogen peroxide from the alveolar macrophage.

Acardiac Fetus with Encephalocele: A case report

The acardiac fetus is a rare type of fetal monster in which, as the name implies, the heart is completely absent. Acardius occurs only in a pair monozygotic twin, and shows various other defects in addition to the absence of the heart. Our autopsy case is acardiac anceps. He weighed 1,980 gm and the height was 33 cm. The brain is poorly developed, 60 gm in weight and similar to reversed snowman (3.5x2.8x2.8, 1.5x1.5x1.3 cm). Encephalocele, 6 cm in diameter, was communicated with the brain by a tract which contains nervous tissue and primitive choroid plexus. The upper extremities were absent, while the vertebrae and lower extremities were relatively well developed. The heart, lungs, stomach, liver, and spleen were absent, but the kidney, genital organs and urinary bladder were present. The intestine was seperated into two segments which were blindly ended, 32 cm and 15 cm in length, respectively.