No abstract available.
Staphylococcus aureus* ; Staphylococcus* ; Streptomyces*

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.
Astrocytes* ; Cytokines ; Gene Expression* ; Humans* ; Interferon-gamma ; Interleukin-10 ; Major Histocompatibility Complex ; Microglia ; Multiple Sclerosis ; Necrosis ; Neuroglia ; Neurons ; Oligodendroglia ; RNA, Messenger ; Transforming Growth Factors

No Abstract Available.
Astrocytes* ; Humans*

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.
Actinomycetales ; Anti-Infective Agents ; Bacteria ; Communicable Diseases ; Drug Resistance, Microbial ; Drug Resistance, Multiple ; Fungi ; Gram-Positive Bacteria ; Methicillin ; Methicillin-Resistant Staphylococcus aureus ; Soil ; Staphylococcus aureus* ; Staphylococcus* ; Streptomyces* ; Vancomycin

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.
Candida albicans* ; Candida* ; Epithelial Cells ; Healthy Volunteers* ; Hydrophobic and Hydrophilic Interactions ; Phospholipases ; Virulence Factors ; Virulence* ; Volunteers

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.
Acceleration ; Ammonium Sulfate ; Candida albicans* ; Candida* ; Carbon ; Glucose ; Hydrogen-Ion Concentration ; Maltose ; Nitrogen ; Peptide Hydrolases* ; Serum Albumin, Bovine ; Sucrose ; Trehalose ; Xylose ; Yeasts

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.
Animal ; Aspergillus/isolation & purification ; Cereals* ; Food Microbiology* ; Fungi* ; Hela Cells ; Human ; Liver/ultrastructure ; Mice ; Mice, Inbred ICR ; Mycotoxins/isolation & purification* ; Penicillium/isolation & purification

No abstract available.
Streptomyces*

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.
Candida albicans* ; Candida* ; Cell Wall ; Dithiothreitol ; Electrophoresis, Polyacrylamide Gel ; Endopeptidase K

No Abstract Available.
Cell Line* ; Humans* ; Vascular Endothelial Growth Factor A*