Differential Expression, Shedding, Cytokine Regulation and Function of TNFR1 and TNFR2 in Human Fetal Astrocytes

Tumor necrosis factor (TNF) -alpha induces pleiotropic cellular effects through a 55kDa, type 1 receptor (TNFR1) and a 75kDa type 2 receptor (TNFR2). Moreover, it participates in the pathogenesis of several CNS diseases, including demyelinating diseases. TNF- receptors are differentially expressed and are regulated in many cell types. However, data regarding the TNF-alpha receptor expression and regulation in human astrocytes is limited to date. We investigated TNF-alpha receptor expression, its regulation by cytokines, and its functional role in primary cultured human fetal astrocytes, which are the most abundant cellular population in the central nervous system and are known to be immunologically active. In this study, astrocytes were found to constitutively and predominantly transcribe, translate and shed TNFR1 rather than TNFR2, but TNFR2 expression was increased by adding TNF-alpha, IL-1, and IFN-gamma, but not by adding LPS. To determine the functional roles of TNFR1 and TNFR2 on TNF induction, we investigated NF-kappaB activation and TNF-alpha induction after neutralizing TNFR1 and TNFR2 by an antibody treatment. We found that NF-kappaB activation and TNF-alpha induction are blocked by TNFR1 neutralizing antibody treatments.

Studies on the Population of Toxigenic Fungi in Foodstuffs

These studies were carried out to detect the presence of mycotoxin producing fungi in various foodstuffs in Korea. The experiments were divided into three parts: bacteriologic, toxicologic and electron microscopic studies. From the 133 various samples, 425 colonies of fungi were isolated. In 405 of the 426 colonies it was possible to identify 17genera. Among the identified strains the predominant genera were Penicillum, Aspergillus and Alternaria. In the cytotoxicity test, 18 strains showed imld to severe toxic effects in mice, 19 strains showed toxic effects on HeLa cells. In electron microscopic studies of liver cells from aninals which had been treated with toxin-like substances, the liver cells showed the cytoplasmic changes dilatation of endoplasmic reticulum, swelling of mitochondria and increased number of lipid and glycogen particles. Alterations of nuclear envelape were also noted.

In vitro antibacterial activity of WCM 302, a substance obtained from culture filtrate of streptomyces sp. 302, against staphylococcus aureus

No abstract available.

Effects of Culture Condition on Secretion of Phospholipase from Candida albicans / 대한의진균학회지

BACKGROUND: The dimorphic yeast, Candida albicans, is considered as a dangerous opportunistic pathogen in immunocompromised hosts. Several phospholipases of C. albicans are known to be secreted into the culture medium. Phospholipases have been proposed as a virulence factor in the pathogenesis of Candida infections. OBJECTIVE: In order to investigate enzyme production, we examined culture condition of secreted phospholipase production from C. albicans. METHODS: C. albicans ATCC 10231 was cultivated in various media at 37 degrees C for 3 days. Phospholipase activity was measured by fatty acid soap precipitation in plate containing 0.04% lecithin, 0.1 M citrate buffer, pH 4.2 and 1.5% noble agar. RESULTS: Phospholipase was highly induced when C. albicans was cultivated in broth medium (containing glucose 2%, albumin 0.2% and Fe++ ion 0.01%) and Saboulaud's dextrose agar supplemented with 0.01% sodium deoxycholate. CONCLUSION: Highly induction of secreted phospholipase by albumin from C albicans may be play an important role in tissue invasion in the pathogenesis of C. albicans.

Serum Indeces Protein Fibrils Expression in Candida albicans

The fibrillar coat of Candida albicans is of interest as its significance in antigenicity, antiphagocytosis, and adherence to host tissues. The partial biochemical properties and ultrastructure of fibrillar coat induced by rabbit sera were examined. The induced fibrillar layer was destroyed by treatments of lyticase, proteinase K and dithiothreitol. The total protein concentration of fibrillar cell wall lysate was higher than that of non-fibrillar cell wall lysate, but the total sugar concentration was similar. On SDS-PAGE analysis, the protein profiles between in fibrillar cells and in non-fibrillar cells were shown to be different. In fibrillar cells, the major bands of cell wall lysate were 83, 66, 54, 47, 33, and 26 kDa in dithiothreitol-treated lysate. The proteins of 26 and 19 kDa were predominant in lyticase-treated lysate. Although the fibrillar thickness and protein amount of cell wall lysate were increased in according to the incubation time, the protein profiles did not changed. These results suggest that the proteins of 83, 66, 54, 47, 33, 26, and 19 kDa may be major constituents of fibrillar coat in C. albicans.

Tumor cell growth inhibitory factor in the culture filtrate of the streptomyces 1. in vitro cytotoxicity of tumor cell growth inhibitory factor

No abstract available.

The presumptive identification of Candida albicans with germ tube induced by high temperature

For direct identification of Candida albicans from other Candida species, the chlamydospore formation and the mycelial transition induced by high temperature and by sera were examined in 198 Candida isolates. The germ tubes of C. albicans developed early at 30 min in high temperature-induction, but at 60 min in serum-induction. C. albicans generated germ tubes well at concentrations lower than 2 x 10(7) cells/ml, but the germ tube formation was markedly restrained at concentrations higher than 4 x 10(7) cells/ml. In a serum-free, yeast extract-peptone-dextrose (YEPD) medium, C. albicans grew as a yeast form at 30 degrees C and as a mycelial form at 35-42 degrees C. Mycelial development was maximal at 37 degrees C in serum and at 39 degrees C in YEPD. Germ tubes were formed within 30 min in YEPD at 39 degrees C, but after 60 min in serum at 37 degrees C. Our examination showed that the 39 degrees C-induced germ tube formation tests were very reliable (sensitivity 100%, specificity 100%) at discerning C. albicans from other Candida species. These results suggest that the high temperature-induced germ tube formation testing could be a useful identification method of C. albicans in clinical laboratories.

Antibacterial Activity of an Antibiotic (K-681) from Streptomyces sp. 681 against Staphylococcus aureus

The antimicrobial agents reduced infectious diseases significantly. However, antibiotic resistance has followed for almost every antimicrobial agent. Especially, Staphylococcus aureus was one of the most notorious for the multidrug resistance. Streptomyces sp. 681 has been selected for antibiotic-producing strain against methicillin-resistant Staphylococcus aureus (MRSA) from 1,000 strains of Actinomycetales which had been isolated from soil. In antimicrobial susceptibility test, all of the test strains were susceptible to vancomycin. However, most strains of Staphylococcus aureus were found to be resistant to methicillin. Ninety eight (75%) strains out of 129 strains showed multiple resistance pattern to more than 5 antimicrobial agents. The MIC values of the purified antibiotic (K-681) were 1-32 ug/ml against Gram-positive bacteria compared to >128 ug/ml against Grarn-negative bacteria or fungi. The MIC was 8 ug/ml for 90% of the 129 clinical isolates of S. aureus. The antibiotic showed no cytotoxicity against P 388, HeLa, and S180 at the concentration of 500 ug/ml.

Detection of the anti-neural antibodies in the sera of leprosy patients

No abstract available.

Studies of the AntimicrobiaI Activities of Active Alkaline-Glutaraldehyde in Vitro Tests / 대한마취과학회지

The discovery of an ideal technique for sterilising contaminated respirators and other anesthesia equipment remains a major problems, The antimicrobial activities of a recently discovered disinfectant alktaline-glutaraldehyde(Cidex), studied in vitro against various species of bacteria and fungi. The antimicrobial activity tests were performed according to the modified Kolmer method. The testing organisms were cultured in broth media at 37 degrees C and 25 degrees C for 18 hours to 14 days, and the disinfectant was diluted with sterile distilled;water to 0.4% and 2.0%. One milliliter of cultured broth was transferred into disinfectant-containing media and after 1, 2, 5, 10, 20, 30 and 60 minutes, one loopful of the mateials was removed from the media and inoculated into the broth media. All of the subcultures were incubated at 37 degrees C for 24 hours and fungal subcultures were incubated at 25 degrees C for 14 days. Results were obtained as follows: 1) Most of the bacteria were completely growth-inhibited by treatment with 0.4% active alkaline-glutaraldehyde solution for 2 minutes except a few strains such as St. aureus, B. subtilis and M. tuberculosis, which required from 16 to 20 min. 2) Mycobacterium tuberculosis was relatively resistant but it could be growth-inhibited by treatment with 2.0% solution for 2 minutes. 3) Growth inhibiting of fungi could be obtained by treatment with 2.0% solution for 5 to 10 minutes.

Vascular Endothelial Growth Factor Expression in Human Trohoblast Cell Line

No Abstract Available.

Vascular Endothelial Growth Factor Expression in Human Trohoblast Cell Line

No Abstract Available.

Regulation of TNF - alpha Gene Expression in Human Fetal Astrocytes

Tumor necrosis factor-n (TNF - alpha) involved in the pathogenesis of multiple sclerosis and contribute to the degeneration of oligodendrocytes as well as neurons. TNF - alpha is produced by miocroglia and astrocytes, which also produce hormones and cytokines that influence its biological activity. Astrocytes, the major glial cells in the CNS, are capable of producing TNF - alpha at both the mRNA and protein levels in response to interleukine-1 (IL-1) or TNF - alpha. Two immunosuppressive cytokines, transforming growth factor - beta (TGF - beta) and IL-10, have been shown to influence glial cell function. TGF - beta can modulate the activity of glial cells by inhibiting interferon-gamma (IFN - gamma) induced expression of class II major histocompatibility complex (MHC) molecules on astrocytes and microglia. To explore the role of astrocytes in the production of TNF - alpha, astrocytes were pretreated with IL-10 or TGF - beta and then stimulated with IL-1p to determine their effects on TNF - alpha production. The secretion of TNF - alpha by human fetal astrocytes was markedly inhibited by TGF - beta at a low concentration. In contrast IL-10 had no effect on TNF - alpha mRNA level. These results show that TGF - beta may regulate the expression of TNF - alpha in activated human fetal astrocytes.

Identification of Differentially Expressed Genes in Human Fetal Astrocytes

No Abstract Available.

Optimum Culture Conditions for Production of Proteinases secreted by Candida albicans , C. tropicalis , and C. parapsilosis

In the present study, culture conditions to secrete proteinases from C. albicans, C. tropicalis and C. parapsilosis were examined. All three Candida species were found to secrete proteinases from acceleration phase to stationary phase, although the proteinase activities in culture filtrate were maximal during late exponential or early stationary phase. The proteinase activity in the culture filtrate of C. albicans cells grown at 30'C, was much higher than those grown at either 20 or 37'C. In culture of C. tropicalis and C. parapsilosis, the highest activity was found in culture filtrate grown at 37C. C. albicans secreted proteinases well in medium at initial pH 4.0-7.0. The optimal initial pH of medium for proteinase secretion was 7.0 for C. tropicalis and 5.0-6.0 for C. parapsilosis. All three Candida species secreted proteinases to greater amount in aerobic state. The most effective carbon source for proteinase secretion was xylose, glucose, maltose and sucrose for C. albicans, xylose for C. tropicalis and trehalose for C. parapsilosis. The effects of proteins, hydrolyzed proteins, ammonium sulfate as a sole nitrogen source on proteinase secretion were examined. Bovine serum albumin was the most effective nitrogen source of those tested and a little proteinase activity was detected in the culture filtrates when yeast cells were incubated in the medium containing ammonium sulfate. C. parapsilosis secreted proteinases to greater amount than the other Candida species in all nitrogen sources under study, indicating that C. parapsilosis proteinase would not be a inducible but a constitutive enzyme.

Comparison of Virulence Factor Expression between Blood Isolates of Candida albicans and Commensal Strain Isolated from Healthy Volunteers

In the present study, we investigated the differences in the levels of expression of virulence factors between blood isolates of Candida albicans and commensal strain isolated from the oral cavities of health volunteers, and correlations between virulence factors. Blood isolates of 33 and commenal isolates of 71 were characterized by putative virulence factors such as proteinase production (PROT), an ability to adhere to epithelial cells (ADH), cell surface hydrophobicity (CSH), phospholipase production (PLASE), and hyphal transition (GERM). In PROT, ADH, CSH, and PLASE, the means of expression of blood isolates were higher compared with those of commensal isolates, however statistical significance was only shown in CSH (p=0.036). On the contrary, mean expression of GERM of blood isolates was lower than that of commensal isolates. Of relationships between virulence factors, although a negative correlation of PROT with CSH was obtained, the correlation was relatively low (r=-0.316, p=0.001). These results suggest that higher expression of CSH is a more distinguishing character in virulent blood isolates of C. albicans and that the expression of virulence factors are independent.

The p16INK4A Expression in Stomach Cancer , Colon Cancer and Hepatoma Cell Lines / 대한암학회지

PURPOSE: The p16(INK4A) gene encodes a specific inhibitor of cell cycle progression. In recent years, genetic deletion and altered expression of p16(INK4A) gene were frequently showed in many human cancers. So, the p16(INK4A) gene is considered as tumor suppressor gene. However, there has been a few data for the p16(INK4A) in gastric cancer, colon cancer, and hepatoma.So.we investigated the genetic deldtion and altered expression of p16(INK4A) in gastric cancer, colon cancer and hepatoma cell lines. MATERIALS AND METHODS: The homozygous deletion of p16(INK4A) was examined by using PCR and the protein expression of p16(INK4A) by using Western blotting in cancer cell lines established from Korean patients: stomach cancer, colon cancer and hepatoma cell lines. RESULTS: Homozygous deletion of p16(INK4A) was detected only 1 stomach cancer cell line out of 13 cell lines examined. The p16(INK4A) was detected in 3 of 13 cancer cell line. These results showed the low frequency of p16(INK4A) homozygous deletion and high frequency of p16(INK4A) expression alteration in stomach cancer, colon cancer and hepatoma cell lines. CONCLUSION: In this study, it may be suggested that the altered pl6(INK4A) expression as well as p16(INK4A) gene deletion play important role in oncogenesis. Further studies to determine the mechanism of p16(INK4A) gene inactivation are expected.

Seroreactivities of proteinases of Candida albicans, C. tropicalis, and C. parapsilosis in sera from various Candida species-infected mice

From the culture filtrates of C. albicans, C. tropicalis and C. parapsilosis, proteinases were purified using a series of chromatographic steps consisting of DEAE-Sepharose, Sephacryl S-200 and size-exclusion HPLC which removed contaminating mannoproteins and extraneous proteins. Anti-Candida proteinase antibodies in sera from mice infected with various Candida species were detected using ELISA for serodiagnosis of candidiasis. Three proteinases were blotted by homologous and heterologous anti-proteinase antisera on Western blot analysis. All sera from six Candida species-infected mice were reactive with proteinases of C. albicans, C. tropicalis, and C. parapsilosis, although C. glabrata, C. guilliermondii, and C. krusei did not secrete proteinase. The seroreactivities of proteinase with sera from mice infected with homologous C. albicans and C. tropicalis were higher than those with sera from heterologous Candida species-infected mice. These results suggest that three proteinases have at least one common epitope, but its application for diagnosis of candidiasis should be considered with limits of specificity.

The Effect of Rabbit Serum on the Expression of Cell Surface Hydrophobicity in Candida albicans / 대한의진균학회지

No abstract available.

Search for Genes Potentially Related to Germ Tube Formation in Candida albicans by Differential-Display Reverse Transcription Polymerase Chain Reaction

Candida albicans exhibits the ability to grow in either a yeast or a mycelia form in response to different environmental factors. The mycelia form, found in infected tissues, is important as a virulence factor in the adherence of the organism to the host epithelium. In vitro, the morphological transition can be induced by environmental shifts in the growing conditions, or by a variety of exogenous factors, including ambient pH, nutritional status and temperature. The differential-display reverse transcription polymerase chain reaction (DDRT-PCR) is a powerful technique for comparing gene expression between cell types, stages of development or differentiation. Hyphae related genes were identified and characterized using a PCR-based differential display. Candida albicans formed a germ tube when cultured in rabbit serum, RPMI 1640 medium or 39degrees C-YPD medium. We gained 21 cDNA bands showing a different expression pattern from that of the uninduced culture. DNA was extracted from the same location of the isolated bands, and PCR was performed under the same conditions, which reamplified the PCR product, showing the specific expression patterns according to the culture conditions. We cloned 18 germ tube-related cDNA clones (inserts average size is 80 - 700 bp) and sequenced them. The nucleotide sequences of the 18 clones were identified through in the present study from GenBank, and were found to have the accession number (AF405213-AF405230). We could not find any nucleotide sequence having a high homology with these clones. This study could form a part of the projects in the search for genes related to the germ tube formation of C. albicans.