Mechanism of histone deacetylase inhibitor Trichostatin A induced apoptosis in human osteosarcoma cells

Although histone deacetylase (HDAC) inhibitors are emerging as a promising new treatment strategy in malignancy, how they exert their effect on osteosarcoama cells is as yet unclear. This study was undertaken to investigate the underlying mechanism of a HDAC inhibitor Trichostatin A (TSA)-induced apoptosis in a osteosarcoma cell line HOS. We observed that TSA treatment decreased the viability of the cells and prominently increased acetylation of histone H3. Evidence was obtained indicating that TSA induced apoptosis of HOS cells as follows: (1) Generation of DNA fragmentation; (2) activation of procaspase-3; (3) cleavage of PARP; and (4) increase of DNA hypoploidy. The reduction of MMP and the release of cytochrome c to cytosol were also shown, indicating that TSA induces apoptosis in HOS cells in a histone acetylation- and mitochondria-dependent fashions. We also examined whether TSA can sensitize HOS cells to the action of an antitumor agent genistein. The combination therapy of TSA and genistein showed synergistic anticancer effect indicating that TSA can be considered as a novel therapeutic strategy for osteosarcoma not only from its direct apoptosis-inducing activity but also from the possibility of sensitization to other antitumor agents.

Proteomic Characterization of Rat Liver Exposed to 2,3,7,8-Tetrachlorobenzo-p-dioxin

Dioxins are a class of polyhalogenated aromatic hydrocarbons that induce a wide spectrum of toxic responses in experimental animals. In this study, 2,3,7,8-tetrachlorobenzo-p-dioxin (TCDD) was exposed to two SD rat groups; one group for short-term exposure at a single dose of 1, 10, 20 and 50 mug/kg body weight (group 1) and the other for long-term exposure at daily and-low dose of 0.01, 0.1, 1 and 2.5 microg/kg body weight (group 2) for a month. Two-dimensional electrophoresis (2-DE) was utilized to resolve the protein profile of rat liver exposed to TCDD at different doses. In the analysis of 2-DE of the group 1, two new-expressed spots and seven volume-increased spots were detected and identified by ESI-Q-TOF MS/MS; especially, proteasome subunit beta type 3 was increased in all doses. In addition, in the group 2, six volume-increased spots were screened; particularly, histidine triad nucleotide binding protein was increased in both 0.1 microg/kg dose and 1 microg/kg dose. The identified proteins were confirmed using Western blot. Among the identified proteins, apolipoprotein A-IV may protect lipid peroxidation and atherosclerosis induced by TCDD exposure and the expression level of phosphoglycerate mutase increases due to hyperthyroidism induced by TCDD exposure.

An efficient proteomics based strategy for the functional characterization of a novel halophilic enzyme fromHalobacterium salinarum

The extremely halophilic archaeon, Halobacterium salinarum grows in environments containing over 25% NaCl. The enzymes of this organism have thus been adapted to be active and stable in hypersaline conditions, which makes them strong candidates as robust industrial enzymes. In this study, the proteomics approach was applied to screen novel halophilic enzymes. We focused initially on proteins that are differentially expressed under different salt concentrations in culture media. After two-dimensional gel electrophoresis over a pH 3.5-4.5 range, 29 differentially expressed protein spots were identified by tandem mass spectrometry and six of these had no similarity to preexisting genes of known function. To predict the function of them, we used various bioinformatic methods. Among other proteins, we selected Vng0487h, which showed a high similarity to acetyltransferases. As a step toward assaying the enzymatic activity of this protein, we cloned the Vng0487h gene of H. salinarum and expressed and purified the recombinant protein with a glutathione-S-transferase (GST) tag in Escherichia coli. Using a GST-pulldown assay, a protein fragment derived from E. coli could interact with recombinant Vng0487h, and was identified to be the ribosomal protein L3. This protein showed high sequence homology with ribosomal protein L7/12 from E. coli and ribosomal protein L13p from H. salinarum. This suggests that Vng0487h acetylates a subunit of ribosomal protein, possibly L13p, in H. salinarum. During the present study, an efficient procedure was established to screen novel halophilic enzymes, and to predict and assess their functions.

Spectrum of lymph node pathology in adult onset Still's disease; analysis of 12 patients with one follow up biopsy

BACKGROUND

Adult onset Still's disease (AOSD) is a rare systemic inflammatory disorder of unknown aetiology, frequently accompanying multiple lymphadenopathy. It often mimics malignant lymphoma, and immunohistochemical and molecular studies are needed for definite diagnosis.

AIMS

To aid in diagnosis and understand the pathogenesis of the disease by clarifying lymph node (LN) pathology in AOSD.

METHODS

Thirteen biopsies (one follow up biopsy) and medical records of 12 patients were reviewed. Immunohistochemistry, polymerase chain reaction for T cell receptor gamma chain (TCRgamma) and immunoglobulin heavy chain gene rearrangement, and Epstein-Barr virus in situ hybridisation were performed.

RESULTS

Histologically, LN lesions were classified into four patterns. The most common (six biopsies) showed paracortical hyperplasia, with prominent vascular proliferation, scattered large B/T immunoblasts, and infiltration by reactive lymphocytes and inflammatory cells. In the second pattern (two biopsies), paracortical hyperplasia was accompanied by massive sinus histiocytosis and S-100 positive histiocyte aggregates. The third pattern (three patients) showed an exuberant immunoblastic reaction, in the form of patchy/diffuse infiltration of large T immunoblasts with high mitotic activity, although clonal rearrangement of the TCRgamma gene was not detected. The fourth pattern showed distinct follicular hyperplasia (two cases). One patient with a follow up biopsy showed a pattern change from pronounced follicular hyperplasia to atypical paracortical hyperplasia.

CONCLUSIONS

AOSD LN lesions show a dynamic histological spectrum, including atypical paracortical hyperplasia, burnt out histiocytic reaction, exuberant immunoblastic reaction, and follicular hyperplasia. During the course of disease, LN reactivity changes and mixed B and T cells are involved in the pathogenesis.

Identification and characterization of inosine monophosphate dehydrogenase fromHalobacterium salinarum

Extremely halophilic Archaea, Halobacterium salinarum live in hypersaline habitats and maintain an osmotic balance of their cytoplasm by accumulating high concentrations of salt (mainly KCl). Therefore, their enzymes adapted to high NaCl concentrations offer a multitude of acutal or potential applications such as biocatalysts in the presence of high salt concentrations. In this study, the protein expression profile of H. salinarum cultured under different NaCl concentrations (3.5 M, 4.3 M, and 6.0 M) was investigated using two-dimensional gel electrophoresis (2-DE). As a result of 2-DE, the protein spots concentrated in acidic range at pH 3-10 were separated effectively using pH 3.5-4.5 ultrazoom IPG DryStrips. The proteins which proved to be upregulated or downregulated in 2-DE gel were digested with trypsin and identified with matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) and electrospray ionization quadrupole (ESI-Q) TOF-mass spectrometry. Most proteins were identified as known annotated proteins based on sequence homology and few as unknown hypothetical proteins. Among proteins identified, an enzyme named inosine monophosphate dehydrogenase (IMPDH) was selected based on the possibility of its industrial application. IMPDH gene (1.6 kb fragment) expected to exist in H. salinarum was amplified by polymerase chain reaction (PCR) and expressed in Escherichia coli strain, BL21 (DE3) using a pGEX-KG vector. Recombinant IMPDH purified from H. salinarum has a higher activity in the presence of salt than in the absence of salt.

Differential expression of proteins in rat plasma exposed to benzene

Benzene, a ubiquitous environmental contaminant, is an important solvent in the chemical industry and is also known as a constituent of petroleum. It has been reported that benzene is associated with hematotoxicity including leukemia in humans and cancer in laboratory animals. To study protein expression alterations in rat plasma exposed to benzene, rats were exposed to levels of 1, 10, 100 ppm benzine for 6 h/day and 5 d/week for 2 or 6 weeks. Two-dimensional gel electrophoresis of rat plasma was carried out, and approximately 1000 protein spots were detected on the gels. The 11 spots which showed significantly different expression were selected and identified with matrix-assisted laser desorption/ionization-time of flight-mass spectrometry. Analyzing the targeted 11 spots, there was no correlation between the 2 and 6 weeks benzene-inhaled groups on up-regulated proteins (zinc finger protein, and tristetraprolin) and on down-regulated proteins (cAMP-regulated guanine nucleotide exchange factor II, protein kinase and unknown protein). The overexpressed proteins (inhibitor of kappaB-like protein, GTP-binding protein rab14, T-cell receptor alpha chain, and somatostatin transactivating factor-1) were detected only in groups inhaling benzene for 6 weeks. Among them the expression level of T-cell receptor alpha chain was confirmed by Western blot.

Monitoring protein expression by proteomics: human plasma exposed to benzene

Low levels and long term exposure to benzene is associated with hematotoxicity including aplastic anemia, acute myelogenous leukemia, and lymphoma. Current biomonitoring methods such as urinary phenol, S-phenylmercapturic acid, and trans-trans muconic acid were found to be unreliable as analytical methods to detect benzene exposure. Therefore, to search for a specific protein for biomonitoring benzene exposure, we investigated plasma proteins from workers (n = 50) at a printing company who were exposed to benzene, by two-dimensional gel electrophoresis. The protein profiles are significantly different (p < 0.05) between benzene exposed and unexposed groups, as identified by matrix-assisted laser desorption ionization/time of flight mass spectrometry and confirmed by Western blot analyses. T cell receptor beta chain (TCR beta), FK506-binding protein, and matrix metalloproteinase-13 were expressed only in benzene exposed workers. In addition, interleukin-4 receptor alpha chain and T cell surface glycoprotein CD1b precursor were found to be up-regulated in the plasma of benzene exposed workers. When we treated Jurkat cells with benzene (10 microM-10 mM), TCR beta expression was increased in the membrane more than 6-9-fold compared to untreated cells. In addition, the amount of TCR beta released into the culture media, at benzene concentrations greater than 50 microM, increased up to 10 mM. Therefore, TCR beta levels in plasma could be used as a biomarker and a possible therapeutic target for benzene exposure.

Human β-defensin 2 is induced by interleukin-1b in the corneal epithelial cells

Mammalian epithelia produce the various antimicrobial peptides against the bacterial or viral infection, thereby acting as the active immune modulators in the innate immunity. In this study, we examined the effects of the various proinflammatory cytokines or LPS on cell viability and antimicrobial beta-defensin gene expressions in human corneal epithelial cells. Results showed that the cytokines or LPS did not exert severe cytotoxic effects on the cells, and that beta-defensin 1 was constitutively expressed, while beta-defensin 2 was specifically induced by IL-1beta, supporting the idea that these cytokines or LPS involve the defense mechanism in the cornea. Furthermore, the reporter and gel shift assay to define the induction mechanism of beta-defensin 2 by IL-1beta demonstrated that the most proximal NF-kappaB site on the promoter region of beta-defensin 2 was not critical for the process. Data obtained from the normal or patients with the varying ocular diseases showed that our in vitro results were relevant in the clinical settings. Our results clearly demonstrated that beta-defensin 1 and 2 are important antimicrobial peptides in the corneal tissues, and that the mechanistic induction process of beta-defensin 2 by IL-1beta is not solely dependent on proximal NF-kappaB site activation, thus suggesting that the long distal portion of the promoter is needed for the full responsiveness toward IL-1beta.

Insulin microcrystal suspension as a long-acting formulation for pulmonary delivery

Pulmonary delivery provides the most promising non-parenteral route of insulin administration. Insulin was used as a model protein to demonstrate the feasibility of using protein crystals for the pulmonary delivery of a sustained-release protein drug formulation. Insulin microcrystals with a mean diameter of 3 microm were prepared using a seed zone method. The yield of crystallization was very high (95.8 +/- 0.97%), and the microcrystals were recovered with high efficiency (>98%) by centrifugation. Morphological examination using scanning electron microphotography showed the microcrystals to be of a homogeneous rhombohedral shape, with some rhombus forms, without aggregates. After the administration of 32 U/kg of the microcrystal suspension to STZ-induced diabetic SD rats by intratracheal instillation, the blood glucose levels were reduced and hypoglycemia was prolonged over 13 h, as compared to the insulin solution. The percent minimum reductions of the blood glucose concentration (% MRBG) produced by the microcrystal suspension and insulin solution reached 36.5 and 37.2%, respectively, of the initial level, and the percent total reductions in blood glucose (% TRBG(13 h)) were 34.4 and 25.0%, respectively. In the case of inhalation using a sieve-type ultrasonic nebulizer, the % MRBG produced by the microcrystal suspension and insulin solution were 21.7 and 26.3%, respectively, of the initial level, and the % TRBG(13 h) were 66.7 and 58.4%, respectively. However, the hypoglycemic effects of the microcrystal suspension were prolonged over 7 h, which compares favorably with the insulin solution (P<0.5 by unpaired t-test). These results could be attributed to the sustained-release of insulin from the microcrystals, which were deposited widely throughout the entire lung.

Neuropeptide Y promotes beta-cell replication via extracellular signal-regulated kinase activation

AIMS/HYPOTHESIS

Previous studies have shown that neuropeptide Y (NPY) gene expression and release are increased in hyperphagic ob/ob mice and diabetic rats. Therefore, we hypothesized that orexigenic agent, NPY, has the effect on the obesity and diabetes. To elucidate the relationship, we have studied the regulatory role of NPY on islet cells.

METHODS

Isolated islets were incubated with NPY or NPY Y1 receptor specific antagonist, BIBP3226. Proliferation, apoptosis, and Y1 receptor expression were identified by immunohistochemistry. We studied that ERK1/2 mediates the NPY pathway with PD98059 (MAP kinase inhibitor), wortmannin (phosphatidylinositol 3-kinase inhibitor), and BIM-1 (protein kinase C inhibitor). After NPY-treated islets were exposed to high glucose, insulin levels were detected.

RESULTS

beta-Cell replication was enhanced in a dose-dependent manner, but without any changes on the other cells in islet. NPY Y1 receptors were expressed on islet and NPY induced phosphorylation of ERK1/2 rapidly and transiently. PD98059 (MAPK kinase inhibitor) and BIM-1 (protein kinase C inhibitor) inhibited activation of ERK1/2 by NPY, but wortmannin (phosphatidylinositol 3-kinase inhibitor) did not. Exposure of NPY-treated islets to high glucose showed the decreasing trend of insulin secretion.

CONCLUSION/INTERPRETATION

Our data suggest that NPY promotes beta-cell replication via extracellular signal-regulated kinase activation and inhibits glucose-stimulated insulin secretion.

Proteomic analysis of plasma proteins of workers exposed to benzene

In this study, we analyzed the proteins in plasma of workers exposed to benzene by two-dimensional gel electrophoresis, in the hope of finding a specific protein suitable for the biomonitoring of benzene exposure. Comet assays were also carried out to evaluate lymphocytes DNA damage. Fifty workers from a printing company and 38 matched unexposed healthy subjects were enrolled in the study. DNA damage was found to be significantly higher in the exposed workers than in the controls. The tail moments of the two groups were 2.07 +/- 0.35 and 1.48 +/- 0.41, respectively (P < 0.0001). The mean values of trans, trans-muconic acid (t,t-MA) in workers exposed to benzene and in unexposed subjects were 1.011 +/- 0.249 and 0.026 +/- 0.028 mg/g creatinine, respectively. Protein profiles were significantly different (P < 0.05) in the two groups, as identified by matrix-assisted laser desorption ionization/time of flight (MALDI-TOF) mass spectrometry and confirmed by Western blot. T cell receptor beta chain (TCR beta), FK506-binding protein (FKBP51) and matrix metalloproteinase-13 (MMP13) were found to be up-regulated in the benzene-exposed workers. In addition, the correlation between TCR beta and the tail moments of lymphocytes was statistically significant (r-value, 0.428). We conclude that TCR beta in plasma could be used for the early detection of exposure to benzene.

Isolation of ethanol-induced genes in pancreatic β-cells by representational difference analysis (RDA)

Recent epidemiological studies suggest that alcohol consumption is one of the risk factors leading to type 2 diabetes, but the direct effect of ethanol on beta-cell gene expression is not known. Here, using cDNA RDA method, we isolated 43 ethanol-induced genes in pancreatic beta-cells, and confirmed their differential expression by Northern blot or semi-quantitative RT-PCR. These genes were further categorized by the functional criteria based on the published data; Translation, Transcription, Metabolism, Signal transduction, Transport, Structure, Cytoskeleton, Regulation, or Putative/Unknown genes. The effects of each gene on beta-cell function need to be further investigated, however, the present data strongly suggest that these genes might be related to the metabolic alterations caused by ethanol as indicated in earlier study. In particular, RPS3 gene expression was increased by ethanol, glucosamine, and cytokines, implying that ethanol might decrease the metabolic activity by oxidative stress in beta-cells. Therefore, cloning of these genes in full-length and the detailed studies of each gene on beta-cell functions might provide clues on the pathophysiology of type 2 diabetes caused by alcohol.

Treatment of strong nitrogen swine wastewater in a full-scale sequencing batch reactor

Treatment of swine wastewater containing strong nitrogen was attempted in a full-scale SBR. The strongest swine wastewater was discharged from a slurry-type barn and called swine-slurry wastewater (SSW). Slightly weaker wastewater was produced from a scraper-type barn and called swine-urine wastewater (SUW). TCOD, NH4+-N and TSS in raw SSW were 23,000-72,000 mg/L, 3,500-6,000 mg/L and 17,000-50,000 mg/L, respectively. A whole cycle of SBR consists of 4 sub-cycles with anoxic period of 1 hr and aerobic period of 3 hr. The maximum loading rates of both digested-SSW and SUW were similar to 0.22 kg NH4+-N/m3/day whereas the maximum loading rates of raw SSW was up to 0.35 TN/m3/day on keeping the effluent quality of 60 TN mg/l. The VFAs portion of SCOD in raw SSW was about more than 60%. The VFAs in SUW and digested-SSW were about 22% and 15%, respectively. NH4+-N and PO4(3-)-P in SSW were removed efficiently compared to those in digested-SSW and DUW because SSW had high a C/N ratio and readily biodegradable organic. High concentration of organic was useful to enhance denitrification and P uptake. Also the amount of external carbon for denitrification was reduced to 5% and 10% of those for digested-SSW and SUW.

External carbon feeding strategy for enhancing nitrogen removal in SBR

Effective method for feeding an external carbon source (ECS) in SBR was investigated to enhance denitrification based on modifying the anoxic/aerobic sub-cycle for swine wastewater treatment. The wastewater discharged from the scraper-type barns contains relatively low readily biodegradable organic. Therefore NOx-N was accumulated during repeating sub-cycle in SBR operation. When acetic acid was fed as ECS during the final sub-cycle, the maximum nitrogen removal rate was 0.22 kg N/m3/d. This was due to both less denitrification rate during the sub-cycle period and inhibition of denitrification by pH drop during the final cycle. The pH drop was caused by a large amount of ECS feeding to remove high concentration of NOx-N in the final period. To overcome these limitations and achieve higher nitrogen removal rate, the intermittent ECS feeding method with raw wastewater at every anoxic period was developed. Using the modifying ECS feeding method, the removal rate was increased to 0.45 kg N/m3/d without NOx-N accumulation.

Improvement of the two-dimensional gel electrophoresis analysis for the proteome study ofHalobacterium salinarum

Inherent problems exist in the use of two-dimensional gel electrophoresis (2-DE) for sample preparation and separation of proteins from Halobacterium salinarum. In particular, proteins from cells grown in 25% NaCl are difficult to resolve by 2-DE due to the abundance of salt. To remove salts, a 3 kDa molecular weight cut-off column was used. When soluble proteins were separated by 2-DE, most of the proteins were concentrated in the acidic range. For separation of proteins in the pH 3-6 range, ultrazoom immobilized pH gradient strips were used. In addition, sample separation using a IPGphor/Multiphor combined system was a more effective method for the proteome analysis of acidic proteins than using IPGphor for the isoelectric focusing step.

Analysis of proteins expressed in rat plasma exposed to dioxin using 2-dimensional gel electrophoresis

Dioxins are a class of polyhalogenated aromatic hydrocarbons that induces a wide spectrum of toxic responses in animals. In this study, two groups of Sprague-Dawley rats were exposed to 2,3,7,8-tetrachlorobenzo-p-dioxin (TCDD); one group received short-term exposure at a single dose of 1, 10, 20 or 50 microg/kg body weight and the other received long-term exposure to a daily low dose of 0.01, 0.1, 1 or 2.5 microg/kg body weight for one month. Two-dimensional electrophoresis was utilized to resolve the protein profile of rat plasma exposed to TCDD at different doses. One novel and three volume-increased spots were identified and characterized by matrix-assisted laser desorption/ionization-time of flight mass spectrometry and electrospray-ionization on quadropole-TOF2 mass spectrometry. The novel protein was identified as plasma glutathione peroxidase precursor and the volume-increased proteins were cytokeratin 8 polypeptide, Ig lambda-1 chain C region and Ig lambda-2 chain C region. These proteins may be used as biomarkers to diagnose dioxin exposure and may help in understanding the toxic effects of dioxins.

Enhancement of mouse pancreatic regeneration and HIT-T15 cell proliferation with rat pancreatic extract

In this study, the effects of rat pancreatic extract (RPE) on regeneration of impaired mouse pancreas and proliferation of beta-cell line (HIT-T15) were investigated. RPE from the regenerating pancreas (2 days after 60% pancreatectomy) was treated to cure streptozotocin (STZ) induced diabetes in BALB/c mice. RPE-treated BALB/c mice for 21 consecutive days became euglycemic by day 30 and remained normoglycemic during a 150 day follow-up. Saline treated mice remained hyperglycemic sustained uncontrolled hyperglycemia. Islet neogenesis was observed in RPE-treated mice and confirmed by use of immunocytochemistry. Morphometric analysis of pancreas in reverted RPE-treated mice showed a new population of small islets compared with saline controls and an increased islet number. When HIT-T15 cells were treated with RPE, HIT-T15 cell proliferation and insulin secretion increased with increases in the RPE concentration. These results imply that RPE have the regeneration factors and help in the cure of diabetes.

Microcrystallization of indomethacin using a pH-shift method

This study developed a microcrystallization process for indomethacin, a nonsteroidal anti-inflammatory drug (NSAID), using a pH-shift method in aqueous solution. The physicochemical properties of the microcrystals produced were similar to those of the standard crystalline powder in X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FT-IR) analyses, except for a lower XRD peak height and a slightly lower melting temperature (Tm) (1.5 degrees C). Phase contrast microscopy and scanning electron microscopy (SEM) showed that the indomethacin microcrystals were plate-like with a uniform size distribution (mean diameter =10.4+/-0.4 microm). In the initial phase, the dissolution rate of the indomethacin microcrystals was about 2.2 times higher than that of the standard crystalline powder. The biological activity of the indomethacin microcrystals was about 20% higher than that of the standard crystalline powder in their ability to inhibit the proliferation of colon cancer cells (HT-29).

DNA damage in T- and B-lymphocytes and granulocytes in emission inspection and incineration workers exposed to polycyclic aromatic hydrocarbons

In this study, we investigated by using comet assay the effects of polycyclic aromatic hydrocarbon (PAH) as a major factor on DNA damage of workers exposed to exhaust fumes. Twenty-four workers from three automobile emission inspection companies, 28 workers from a waste incinerating company, and 43 matched, unexposed healthy subjects were enrolled in the study. The mean values of 1-hydroxypyrene (1-OHP) in automobile emission inspection and waste incineration workers were 0.27+/-0.19 and 0.57+/-0.46 micromol/mol creatinine, respectively, and the mean values of 2-naphthol in automobile emission inspectors and waste incineration workers were 4.80+/-4.01 and 8.30+/-4.79 mol/mol creatinine, respectively. Significant difference in urinary metabolites, 1-hydroxypyrene and 2-naphthol was found between smokers and non-smokers in exposed groups and it may be due to the amounts of smoking cigarettes. In T-lymphocytes, DNA damage in control subjects, emission inspection workers and incineration workers were 1.42+/-0.22, 1.41+/-0.22 and 1.76+/-0.27, respectively. DNA damage of B-lymphocytes in the three groups showed the most significant differences of three cell types. The tail moments of the B-lymphocytes of control subjects, emission inspection and incineration workers were 1.40+/-0.27, 2.44+/-0.32 and 2.36+/-0.37, respectively. In granulocytes, DNA damage was also different, the tail moments being 2.72+/-0.59, 3.32+/-0.38 and 2.85+/-0.49, respectively. Although 1-OHP and 2-naphthol levels were statistically increased in smokers in workers exposed to PAHs, exposed smoking and non-smoking workers did not show any significantly difference in terms of Olive tail moments. Our results suggest that PAH causes single strand DNA breakage in human T- and B-lymphocytes, and granulocytes. A comparison of DNA damage in three groups showed that B-lymphocytes are useful target in the biomonitoring of human exposure.

Development of an effective sample preparation method for the proteome analysis of body fluids using 2-D gel electrophoresis

A sample preparation is still the most critical step in two-dimensional electrophoresis (2-DE) and should be optimized for each type of sample. In this study, a protein extraction method from body fluids was developed using a combined centrifugal filter device and a sample treating buffer. When plasma, amniotic fluid, urine, and tear were tested with this method, the recovery of protein reached almost 90% and high-quality separation of 2-DE gel was obtained.

Microbial retention characteristics of sterilizing-grade membrane filters with alginate substituted for oil-based products

For oil-based products, FDA recommends substitution of the oil with a compound which has similar viscosity and physical characteristics. In this study, a substitute for oil-based products was screened by measuring the viscosity and filterability, and examined for the presence of cell clumps in the various test fluids using an optical microscopy. The viscosity of the test fluids measured in the range of about 60-75 cP. Brevundimonas diminuta (formerly Pseudomonas diminuta), a standard challenge test organism for validation of 0.2 micron rated membrane filters, formed clumps in oils (corn, olive, sesame, and soybean) and polyethylene glycol (PEG, Molecular Weight (MW) = 400 and 1,000). During the viability test, cells suspended in 80% glycerol showed a ten-fold mortality rate after an exposure for 6 hours, but there was no significant change in viability in alginate (low, medium, and high viscosity) for 24 hours. These results suggested that alginate is better suited as a substitute for oil-based products than 80% glycerol. Since high viscosity fluids take longer to filter, the glycerol mortality rate would influence the challenge test negatively. A scaled-down filtration system has been developed for the described trials, and the bacterial challenge and bubble point tests have been performed in 1.6% alginate (66.7 cP), which was the choice of carrier fluid.

Tumor removal enhances immunity induced by B7.1

Costimulation of tumor T cells by B7.1 has been shown to be important for eliciting cell-mediated anti-tumor immunity. We constructed a stable B7.1 gene transfectant of a poorly immunogenic murine sarcoma, Moloney murine sarcoma virus-induced tumor cell line (MMSV). This transfectant, MMSV-B7.1, failed to produce any tumor development in syngeneic mouse models. When MMSV-B7.1 was simultaneously injected with wild-type MMSV, about half of the coinjected mice remained tumor free and displayed an increase in T cell population, upregulation of the mRNA level of various cytokines such as IL-4, IL-5, IL-10, IL-13, IL-15 and IFN-gamma, and complete rejection of reinjected MMSV. To investigate whether MMSV-B7.1 demonstrates any vaccinal effect, the transfectant was injected following the surgical removal of the primary tumor mass. Following a re-challenge with wild-type MMSV, all vaccinated mice maintained their tumor free status and displayed a rapid recovery of down-regulated cytokine levels. The results suggest that B7.1 vaccination after tumor removal might be useful for the prevention of tumor recurrence.

Der p 2 isoallergens have different allergenicity, and quantification with 2-site ELISA using monoclonal antibodies is influenced by the isoallergens

BACKGROUND

Der p 2 isoallergens have been reported and the possibility of different allergenicity has also been suggested. In addition, the quantification with 2-site ELISA may be affected by the isoallergens.

OBJECTIVES

Two different recombinant Der p 2 (rDer p 2) isoallergens were compared in terms of human IgE responses and the reliability of quantification of them with two-site ELISA kits which use monoclonal antibodies (mAbs) as capture and detection of Der p 2.

METHODS

Seven different Der p 2 cDNA from the cultured Dermatophagoides pteronyssinus (DP) were cloned and polymorphism in nine amino acid residues was found. Two different recombinant isoallergens (rDer p 2A and rDer p 2B) were expressed and compared to their human IgE immune responses by ELISA and the ELISA inhibition test with 23 sera of DP-allergic patients. The reliability of quantification of two different available 2-site ELISA kits, which used mAbs for capture and detection of Der p 2, was evaluated.

RESULTS

The ELISA optical density of rDer p 2B-specific IgE (sIgE) was higher than that of rDer p 2A (P < 0.001). The ELISA inhibition curve of rDer p 2B sIgE in pool I sera (n = 5; high sIgE both to rDer p 2A and rDer p 2B) did not show any differences in the 50% inhibition concentration and maximum inhibitory percentage of rDer p 2A and rDer p 2B sIgE. However, with pool II sera (n = 5; markedly higher sIgE to rDer p 2B than rDer p 2A), the 50% inhibitory concentrations (10 microg/mL vs. 40 ng/mL) and maximum inhibitory percentage (61% vs. 99%) of rDer p 2B sIgE with the two recombinant isoallergens were quite different. rDer p 2B could be quantified with two different 2-site ELISA kits, but rDer p 2A was detected by only one kit.

CONCLUSION

We conclude that isoallergens of Der p 2 may have different IgE immune responses. Quantification of Der p 2 with 2-site ELISA kits that adopted mAbs, might be affected by the prevalent form of the isoallergens in reservoir dust.

Ethanol decreases basal insulin secretion from HIT-T15 cells

Various epidemiological studies suggest that alcohol intake is one of the risk factors leading to type II or non-insulin-dependent diabetes mellitus (NIDDM), but the effect of alcohol on beta-cell function remains unexplored. To study the mechanism of the diabetogenic action of ethanol, we investigated the effect of ethanol on beta-cell functions using a single clonal beta-cell line, HIT-T15 cells. When HIT cells were treated with ethanol, the metabolic activity judged by MTT assay was inhibited in dose- and time dependent manners, but cytotoxicity was not observed. Ethanol also inhibited basal insulin secretion by 30% compared to the untreated control. However, glucose-stimulated insulin secretion was not impaired by ethanol although the basal insulin secretion was inhibited. These results imply that ethanol exert beta-cells to overwork in order to compensate inhibition of the basal secretion. This finding may at least in part explain the diabetogenic action of ethanol.

Color characteristics of low-chroma and high-translucence dental resin composites by different measuring modes

The objective of the described research was the evaluation of the effects of the differences in the color-measuring geometry (SCE, SCI) and the standard illuminant on the color and color change after polymerization and thermocycling of resin composites. White, translucent, and conventional shades of two brands of resin composites were measured before and after polymerization and after thermocycling according to the CIE L*a*b* color scale on a reflection spectrophotometer with SCE and SCI geometry under the standard illuminants A, D65, and C. Under both SCE and SCI modes, the color differences (DeltaE*) of specimens between the values measured under illuminants A and D65 or A and C were larger than those between D65 and C in unpolymerized, polymerized, and thermocycled conditions. With SCE geometry, DeltaE* after polymerization of the white shade group was 8.7-9.8 under D65, and was higher than the conventional shade group (p < 0.05) in both materials. With SCE geometry, DeltaE* between polymerized and thermocycled white, translucent shade was 4.4-7.1 under D65. With SCI geometry, the results were in general agreement with those of SCE mode. After polymerization, DeltaE* measured under illuminant A was generally higher than that under D65 or C (p < 0.01). After thermocycling, the color change was different depending on the color-measuring geometry and standard illuminant.

Changes in the cell size of Brevundimonas diminuta using different growth agitation rates

Brevundimonas diminuta (ATCC 19146) is a standard organism for validation of sterilizing-grade membrane filters. Cell size is critical for the determination of retention characteristics of 0.2 micron rated membrane filters. In this study, cell size changes of B. diminuta cultured under different physiologic states and variable agitations at 50, 100 and 200 rpm were measured by a particle size analyzer and scanning electron microscope (SEM). The smallest cells were obtained at initial stationary phase in saline lactose broth (SLB) as a shaking culture at 50 rpm. Cells grown under agitation at 50, 100 and 200 rpm showed an increase of specific growth rate (mu), about 2.9, 3.6 and 3.6 fold, respectively, compared to the non-agitated cells in SLB media. These results suggested that the cell size decreased proportionally with increase of the specific growth rate (mu) in SLB. These size changes were associated with penetration through a 0.2 micron rated cellulose acetate filter. A scale-down filtration system was developed and performed bacterial challenge test and bubble point test with cells cultured in SLB. Cells grown under agitation conditions in SLB were not retained by 0.2 micron rated membrane filter.

Analysis of alkali-soluble glucan produced by Saccharomyces cerevisiae wild-type and mutants

The alkali-soluble glucan of the yeast cell wall contains beta-(1,3)- and (1,6)-D-linkages and systemically enhances the immune system. To isolate Saccharomyces cerevisiae mutants producing glucan with a high degree of beta-(1,6)-D-glycosidic bonds, a wild-type strain was mutagenized with ultraviolet light. The mutants were then selected by treatment with 1.0 mg laminarinase, endo-beta-(1,3)-D-glucanase/ml. The alkali-soluble glucan was extracted by modified alkalysis followed by the Cetavlon method and concanavalin-A chromatography. The prepared alkali-soluble glucans from the wild-type and the mutants were compared with respect to yield and polymer structure using gas chromatography, 13C-NMR spectrometry, high performance liquid, and multi-angle laser light scattering and refractive index detectors. The results indicated that the S. cerevisiae mutants had ten-fold more alkali-soluble glucan than the wild-type. Structural analysis revealed that the alkali-soluble glucan from the mutants also had a higher degree of beta-(1,6)-D-linkage than that from the wild-type.

High-level TNF-alpha secretion and macrophage activity with soluble beta-glucans from Saccharomyces cerevisiae

We have previously reported that water-soluble beta-glucan completely devoid of mannoprotein and purified from the yeast cell wall effectively stimulated the macrophage function (Biosci. Biotechnol., Biochem., 65, 4, 837-841 (2001)). In this present study, to increase the yield of water-soluble beta-glucan, the wild type of Sacharomyces cerevisiae, JH, was treated with a combination of UV irradiation and laminarinase (endo-beta-(1,3)-glucanase) to yield the laminarinase-resistant mutants, JUL1 and JUL3. Water-soluble beta-glucans that were free of mannoprotein from JH, JUL1 and JUL3 were purified and their effects on TNF-alpha secretion and phagocytosis by macrophages were evaluated. Crude beta-glucan was first solubilized from the yeast cell wall by alkaline extraction and then subjected to an acid treatment. The residual mannoprotein was completely removed by DEAE and ConA chromatography. The yield of water-soluble beta-glucan in both mutants (JUL1, 5.11%; JUL3, 5.76%) was about 5-fold higher than that of the wild type (1.16%). The water-soluble beta-glucan from JH induced TNF-alpha secretion slightly more than that from JUL1 or JUL3: TNF-alpha secretion by JH at 50, 200, 500 microg/ml of beta-glucan was 11-17% more than that by JUL1 or JUL3 for the same treatment. Beta-glucan from the wild type stimulated phagocytosis slightly more than that from the mutants. These mutants could therefore effectively produce purified water-soluble beta-glucan with immune activity.

Clinicopathologic characteristics of Epstein-Barr virus-incorporated gastric cancers in Korea

We evaluated the rate of Epstein-Barr virus (EBV) infection in gastric carcinomas of Korean patients and investigated the associations between EBV infection and clinicopathological characteristics, the survival rates of patients, and p53 overexpression. EBV-encoded small RNA (EBER)-in situ hybridization and immunohistochemistry for p53 protein were done in 306 consecutive gastric carcinoma cases, of which 17 (5.6%) showed EBV infection. Of these 17 EBV-positive cases, one case strongly expressed p53 protein, while 98 (34%) of 285 EBV-negative cases overexpressed p53 (p < 0.05). The EBV-positive gastric carcinomas tended to have lymphoid stroma. They were mostly of the poorly differentiated type, negative for p53 immunoexpression, more prevalent in male patients, and diffuse according to Lauren's classification (p < 0.05). There was no significant difference in the survival rate for the EBV status. In conclusion, the EBV infection rate among gastric carcinomas in Korea is similar to that ascertained in other countries. An inverse correlation between EBV and p53 overexpression was disclosed. Further study is needed to find out whether or not two genetic changes could be functionally overlapping during gastric carcinogenesis.

Malignant triton tumor of the nasal cavity

BACKGROUND

Malignant triton tumor is usually an aggressive sarcoma consisting of a malignant schwannoma with rhabdomyoblastic differentiation. However, malignant triton tumor of the nasal cavity is very rare.

METHODS

A case report of a 38-year-old woman with polypoid mass, which bled easily in the right nasal cavity, and nasal obstruction is presented with a review of the literature pertaining to this unusual case.

RESULTS

The malignant triton tumor was treated with wide surgical excision followed by radiation therapy. Histopathological diagnosis of the malignant triton tumor was made on the surgical specimen. The patient's postoperative course was unremarkable, and follow-up at 5 years reveals no evidence of disease.

CONCLUSIONS

A malignant triton tumor in the nasal cavity is a rare disease. Head and neck surgeons should recognize the possibility of malignant triton tumor occurring in the nasal cavity.

Gastric mucosa-associated lymphoid tissue lymphoma: spectrum of findings at double-contrast gastrointestinal examination with pathologic correlation

Mucosa-associated lymphoid tissue (MALT) is found in the surface epithelium of the stomach. MALT lymphoma is extranodal lymphoma originating from MALT. In the stomach, a strong association with Helicobacter pylori infection has been demonstrated. Low-grade gastric MALT lymphoma has been reported to have variable features at upper gastrointestinal (UGI) examination. Twenty-two patients with low-grade MALT lymphoma had ulcers (n = 11), fold thickening (n = 7), mucosal nodularity (n = 7), masses (n = 6), or prominent areae gastricae (n = 4) at UGI examination. Six patients with high-grade MALT lymphoma had masses (n = 4), fold thickening (n = 3), ulcers (n = 1), or mucosal nodularity (n = 1) at UGI examination. These findings were similar to those in gastric carcinoma or gastritis. Differentiation of low-grade MALT lymphoma from gastritis or gastric carcinoma was more difficult than differentiation of high-grade MALT lymphoma. Lesions of MALT lymphoma associated with H pylori gastritis were diffuse or multiple in 65% of cases; however, lesions of MALT lymphoma without proved H pylori gastritis were focal or solitary in 80% of cases. Therefore, multiplicity of lesions in MALT lymphoma was closely associated with H pylori infection.

Heterogeneity of IgE epitopes of vinyl sulphone reactive dye: human serum albumin that react with IgE

BACKGROUND

Vinyl sulphone reactive dye (vRD), which consists of vinyl sulphone reactive groups and a chromogen, can elicit IgE-mediated occupational asthma (OA) by haptenation. Human serum albumin (HSA) is known as the most reliable carrier protein for the vRD, the IgE epitopes of vRD-HSA are not well characterized. In this study we evaluated the epitope of vRD-HAS-specific IgE.

METHODS

Two vRD (Remazole Black-GR and Remazole Orange-3R), Procion Red-MX-5B, which has a dichlorotriazine reactive group, and vinyl sulphone (VS), were haptenated to HSA, respectively. vRD-HSA was denatured by heat or mercaptoethanol treatment and the allergenicities of denatured and non-denatured vRD-HSA were compared by ELISA and IgE immunoblotting using the sera of six vRD-OA patients. vRD-HSA-specific, Procion Red-MX-5B (pRD)-HSA-specific and VS-HAS-specific IgE were also measured with ELISA and the cross-reactivity between them was evaluated with ELISA inhibition.

RESULTS

Denaturation of vRD-HSA by heat affected its allergenicity markedly in five of six sera of RD-OA. When vRD was conjugated to the pre-heated HSA, its allergenicity also disappeared or was markedly attenuated compared with the vRD-HSA in five of six sera. Mercaptoethanol treatment markedly affected the allergenicity of the RD-HSA in all six RD-OA sera. Immunoblotting from non-denatured PAGE showed strong IgE affinity to vRD-HSA but immunoblotting from denatured SDS PAGE did not show IgE affinity. Among six RD-OA patients, five and four patients had pRD-HSA-specific and VS-HSA-specific IgE, respectively. However, the vRD-HSA-specific IgE was neither inhibited by pRD-HSA nor VS-HSA CONCLUSION: We considered that the conformational structure of HSA would be critical for the IgE epitopes during the haptenation process and both of the chromogen and reactive groups of the vRD would contribute to the formation of IgE epitope. Our results also confirmed the heterogeneity of IgE epitopes in the RD-HSA complex.

Imaging of occupational lung disease

Occupational lung disease comprises a wide variety of disorders caused by the inhalation or ingestion of dust particles or noxious chemicals. These disorders include pneumoconiosis, asbestos-related pleural and parenchymal disease, chemical pneumonitis, occupational infection, hypersensitivity pneumonitis, and organic dust toxic syndrome. Most of these disorders produce diffuse lung disease. Although many of the disorders can be detected at chest radiography, high-resolution computed tomography (CT) has been shown to be superior to chest radiography in depicting parenchymal, airway, and pleural abnormalities. Some occupational lung diseases have characteristic radiologic features suggesting the correct diagnosis, whereas in others, a combination of clinical features, related occupational history, radiologic findings, and literature supporting an association between the exposure and the disease process is required for diagnosis. With advances in chest radiology, including high-resolution CT, radiologists play a key role in the clinical evaluation of occupational lung diseases and should continue their involvement in the diagnosis and treatment of these diseases.

Use of vascularized fibular grafts as a salvage procedure for previously failed spinal arthrodesis

STUDY DESIGN

A case series of spinal arthrodesis performed with vascularized fibular grafts is presented.

OBJECTIVES

The use of vascularized fibular grafts to obtain anterior spinal fusion in patients with complex spinal disorders and poor fusion environments is described.

SUMMARY OF BACKGROUND DATA

The fusion success of spinal arthrodesis is dependent on numerous factors, such as the substrate used for arthrodesis (i.e., graft), the biology of the fusion bed, and local host factors. Vascularized grafts have higher success rates for union and can better overcome a poor fusion bed than nonvascular grafts. However, they are associated with higher donor site morbidity and greater technical difficulty.

METHODS

Three patients with complex medical histories portending a difficult spinal fusion were treated with anterior arthrodesis using vascularized fibular autografts. Vascular patency was confirmed by bone scintigraphy, and osseous union by radiography and computed tomography.

RESULTS

All patients had successful osseous fusion in 3 to 6 months. Deformity was improved. Patients reported decreased pain and resumption to previous activities at 24 months follow-up. There were no complications.

CONCLUSIONS

A vascularized fibular graft is a useful alternative to standard grafts for spinal arthrodesis. Vascularized fibular grafts provide high fusion rates, rapid incorporation, and increased mechanical strength, and thus heal better in a suboptimal graft bed. The procedure is technically demanding, often requiring the expertise of a microvascular surgeon for obtaining the graft and achieving anastomosis. It is best suited in cases where significant difficulty in obtaining a spinal fusion is anticipated.

Comparison of color of resin composites of white and translucent shades with two shade guides

PURPOSE

The purpose of this study was to compare the color of resin composites of white, translucent, and conventional shades with shade guides, based on the analysis of the color distribution of shade guides. The influence of color measuring mode, specular component included (SCI) or excluded (SCE), was also determined.

MATERIALS AND METHODS

The labial portions of shade guide tabs (Vita and Chromascop) were polished flat with up to 2400-grit SiC paper. Color coordinates were measured according to CIE L*a*b* color scale on a reflection spectrophotometer with both the SCE and SCI modes. The color coordinates of white, translucent, and conventional shades of two brands of resin composites were measured and compared with those of the shade guides.

RESULTS

There was no logical order in the color distribution of the two shade guides. The color of white and translucent shades of resin composites was located on the low CIE a* and CIE b* value area. The CIE L*, a*, b* values of resin composite with the same color designations were different, depending on the brand of material. The color difference (deltaE*) of shade guides by the measuring mode (SCE vs. SCI) was between 3.2 and 6.5.

Coexpression of Bcl-6 and CD10 in diffuse large B-cell lymphomas: significance of Bcl-6 expression patterns in identifying germinal center B-cell lymphoma

Most follicular lymphomas (FLs) transform to diffuse lymphoma eventually, comprising a significant proportion of diffuse large B-cell lymphoma (DLBCL). Judging by bcl-2 rearrangement (bcl-2R), one third of DLBCLs are believed to be of FL derivation in the Western population. However, bcl-2R is not specific and is not detectable in every case of FL. In East Asia, FL is uncommon but DLBCL is not. The proportion of tumors of FL origin in DLBCL is not known in this region. The coexpression of Bcl-6 and CD10 proteins, a reliable marker to identify germinal center (GC) B-cell lymphoma including FL, was analyzed in primary nodal DLBCLs (n = 104) diagnosed at major hospitals in Seoul during a recent 2-year period, along with well-defined cases (n = 17) of nodal FL as controls. Bcl-2 protein expression (n = 77) was also studied along with bcl-2R (n = 64), by polymerase chain reaction. Formalin-fixed archival specimens were used in all these assays. The Bcl-6/CD10 coexpression was observed in 35 DLBCLs (34%) and 14 FLs (82%), and most of them showed a pattern of Bcl-6 expression similar to that of the GC. Bcl-2 expression or bcl-2R did not correlate with Bcl-6/CD10 coexpression. Histologically, compartmentalizing sclerosis was associated with a high rate of the coexpression (8 of 10). In conclusion, to detect GC B-cell lymphoma in routine biopsy specimens, a pattern of Bcl-6 staining similar to the GC must be identified. Bcl-6+/CD10+ GC B-cell lymphomas thus defined comprised one third of primary nodal DLBCLs in Korea. The incidence rate is similar to that in the West. The reasons for the discrepancy between the incidence of GC B-cell lymphoma and the paucity of the follicular pattern in East Asian subjects warrant further studies.

Color stability of glass-ionomers and polyacid-modified resin-based composites in various environmental solutions

PURPOSE

To evaluate the degree of color stability of glass-ionomers (GIs) and polyacid modified resin-based composites (PMRBCs) in various environmental solutions.

MATERIALS AND METHODS

Seven polyacid-based esthetic restorative materials were used: three chemical-cured GIs, one resin-modified GI and three polyacid-modified RBCs. A light-cured resin-based composite (RBC) (Z 100) was used as a control. Disk type specimens were prepared and were aged in four different solutions (deionized water, 0.1 mole acetic acid solution, 75% ethanol, and 10% hydrogen peroxide solution) for 1, 7, 14, 21, 28, and 56 days. The specimens were kept at 37 degrees C throughout the study. Color coefficients (CIE L*a*b*) were measured by a reflection spectrophotometer with SCE mode, and the surface of specimens was examined by a stereo zoom microscope.

RESULTS

In deionized water, all specimens showed an acceptable color stability. All of the GIs and PMRBCs showed significant color change in 0.1 mole acetic acid solution. The light-cured resin-modified GI showed a significant color change in 75% ethanol solutions. 10% hydrogen peroxide solution resulted in degradation and a high degree of color change for chemical-cured GIs. The light-cured resin-modified GI and PMRBCs showed high color change in 10% hydrogen peroxide solution. The light-cured RBC (Control), showed excellent color stability in all experimental solutions.

Occupational asthma due to formaldehyde

Formaldehyde is a low molecular weight chemical and can elicit acute and chronic health related problems. Most of the inhaled formaldehyde is retained in the upper respiratory tract due to its extraordinary solubility. Therefore, cases of formaldehyde-induced occupational asthma are sporadic despite its widespread use in industrial processes. We herein report upon a case of occupational asthma due to formaldehyde, which was confirmed by workplace challenge including working environmental assessments, and by formaldehyde inhalation challenge using a specially designed closed-circuit apparatus. To investigate the possible involvement of an IgE-mediated mechanism, both in vitro and in vivo tests were done. IgE antibody specific for formaldehyde-human serum albumin conjugate (F-HSA) was not detected by ELISA, and no specific cutaneous reactivity to F-HSA was noted by either skin prick or intradermal test. The patient was diagnosed with formaldehyde-induced occupational asthma not associated with an IgE mediated mechanism.

Simultaneous organic and nitrogen removal from municipal landfill leachate using an anaerobic-aerobic system

An anaerobic-aerobic system including simultaneous methanogenesis and denitrification was introduced to treat organic and nitrogen compounds in immature leachate from a landfill site. Denitrification and methanogenesis were successfully carried out in the anaerobic reactor while the organic removal and nitrification of NH4+,-N were carried out in the aerobic reactor when rich organic substrate was supplied with appropriate hydraulic retention time. The maximum organic removal rate was 15.2 kg COD/m3 d in the anaerobic reactor while the maximum NH4+-N removal rate and maximum nitrification rate were 0.84kg NH4+-N/m3/d and 0.50kg NO3--N/m3/d, respectively, in the aerobic reactor. The pH range for proper nitrification was 6-8.8 in the aerobic reactor. The organic compounds inhibited nitrification so that the organic removal in the anaerobic reactor could enhance the nitrification rate in the following aerobic reactor. The gas production rate was 0.33 m3/kg COD and the biogas compositions of CH4, CO2, and N2 were kept relatively constant, 66-75, 22-32, and 2-3%, respectively.

2-(Allylthio)pyrazine, a cancer chemopreventive agent, inhibits liver fibrosis induced by dimethylnitrosamine in rats: role of inhibition of transforming growth factor-beta1 expression

Exposure to nitrosamines may be the occupational risk factor for liver cirrhosis. 2-(Allylthio)pyrazine, a chemopreventive agent, inhibits CYP2E1 and induces phase II enzymes. We examined the effects of 2-(allylthio)pyrazine on hepatic fibrosis, a prepathologic state of cirrhosis, and on the expression of transforming growth factor-beta1 induced by dimethylnitrosamine. Treatment of rats with dimethylnitrosamine for 4 weeks increased plasma alanine/aspartate amino-transferase and y-glutamyl transpeptidase activities, and bilirubin content, whereas the total plasma protein and albumin levels were decreased. 2-(Allylthio)pyrazine inhibited dimethylnitrosamine-induced increases in the enzyme activities and bilirubin, and restored the plasma protein and albumin contents. Masson's trichrome staining showed that dimethylnitrosamine induced liver fibrosis, the extent of which was reduced by 2-(allylthio)pyrazine treatments. Reverse transcription-polymerase chain reaction analysis revealed that 2-(allylthio)pyrazine inhibited production of transforming growth factor-beta1 mRNA by dimethylnitrosamine. These results demonstrated that 2-(allylthio)pyrazine might inhibit dimethylnitrosamine-induced liver fibrosis due to suppression of CYP2E1 expression and transforming growth factor-beta1 production.

In vitro model using mouse hepatocytes for study of alcohol stress

In this study, the effects of ethanol and allyl alcohol on primary mouse hepatocytes were investigated. No cytotoxicity was observed by ethanol treatments, but more toxicity to cells was found in the response to allyl alcohol treatment. The expression of cytochrome P450 2E1 (CYP2E1), phase I enzyme was examined in response to ethanol and allyl alcohol. Both xenobiotics induced CYP2E1 up to 1.5 to approximately 5 fold at the protein level. The effects of insulin on CYP2E1 expression were also measured. Insulin, which has been regarded as an essential hormone for primary hepatocytes, was shown to decrease the level of CYP2E1 protein, and did not affect cell viability. These results on CYP2E1 induction demonstrate that primary mouse hepatocytes, when using ethanol and allyl alcohol as substrates and in insulin-free medium, provide a suitable system for the studies of the role of CYP2E1 in xenobiotic metabolism and toxicity.

Role of skin prick test and serological measurement of specific IgE in the diagnosis of occupational asthma resulting from exposure to vinyl sulphone reactive dyes

OBJECTIVES

Some patients with occupational asthma resulting from exposure to reactive dyes have skin reactivity to the causative dyes and specific IgE to reactive dyes have been found in these patients. However, the usefulness of skin prick tests (SPTs) and serological measurement of specific IgE in screening, diagnosis, and monitoring the occupational asthma resulting from exposure to reactive dyes have not yet been assessed. In this study, the clinical validation of SPTs and measurement of specific IgE to vinyl sulphone reactive dyes by enzyme linked immunosorbent assay (ELISA) was evaluated.

METHODS

42 Patients with occupational asthma from reactive dyes (true positive group) were enrolled. In these the causative reactive dye was confirmed by bronchial challenge test. 93 Asymptomatic factory workers with negative challenge to the reactive dye (true negative group) and 16 unexposed controls with negative challenge to the reactive dye were also enrolled. Skin prick tests were done with 10 mg/ml reactive dye in 0.4% phenol/0.9% saline. IgE specific to reactive dye conjugated to human serum albumin (HSA) was measured with enzyme linked immunosorbent assays (ELISAs).

RESULTS

None of the unexposed controls had a positive response to SPTs. The sensitivity (76.2% v 53.7%), specificity (91.4% v 86.0%), positive predictive value (80.0% v 62.9%), and negative predictive value (89.5% v 80.8%) of SPTs were higher than those of ELISAs. The mean weal size of reaction to reactive dye was weakly correlated with the ELISA optical density of IgE to reactive dye conjugate in patients with occupational asthma from reactive dyes (n=41, r=0.337, p<0.05). In four patients with occupational asthma from reactive dyes and eight control subjects exposed to reactive dye, IgE specific to reactive dye conjugated to HSA was detected with ELISA even though they showed negative skin reactivity. Six patients completely avoided the reactive dye for a mean (SD) 27.8 (10.3) months, IgE specific to reactive dyes decreased in all six patients (p<0.05) during this time.

CONCLUSIONS

Both SPTs and detection of IgE specific to reactive dye in serum samples could be valuable for screening, diagnosis, and monitoring occupational asthma resulting from exposure to reactive dyes. These two tests would complement each other.

Clinical applications of forced oscillation techniques (FOT) in patients with bronchial asthma

BACKGROUND

Forced oscillation technique (FOT) is a method to characterize the mechanical properties of the respiratory system over a wide range of frequencies. Its most important advantage is to require minimal cooperation from the subject. This study was performed to evaluate the usefulness of the FOT applications in patients with bronchial asthma by estimating the associations between asthma severity and FOT parameters, and the relationships between FOT and spirometry parameters.

METHODS

216 patients with asthma were enrolled in this study. Patients were classified into 3 different groups according to their symptoms and pulmonary functions. Respiratory impedance, resistance (at 5 Hz, 20 Hz, 35 Hz) and resonant frequency were measured by FOT. FEV1, FVC and MMEF were measured with conventional spirometry.

RESULTS

There were significant differences of resonant frequency, resistance at 5 Hz and 20 Hz, resistance difference at 5 Hz and 20 Hz according to asthma severity (p < 0.05, respectively). Resonant frequency, resistance at 5 Hz, and impedance were significantly correlated with FEV1 (r = -0.55, -0.48, -0.49, p < 0.05, respectively), and with MMEF in patients with normal pulmonary function (r = -0.37, -0.35, -0.34, p < 0.05, respectively). Resistance at 5 Hz had similar reproducibility compared to FEV1 (resistance at 5 Hz, r = 0.78 vs FEV1, r = 0.79).

CONCLUSION

FOT is a useful and alternative method to evaluate the clinical status of bronchial asthma. Further studies will be needed to clarify its value for a wide range of clinical applications.

Congenital monoblastic leukemia with 9;11 translocation in monozygotic twins : a case report

We report an autopsy case of congenital monoblastic leukemia that developed in monozygotic twins. The twin presented with progressive hepatosplenomegaly at 4 weeks after birth. One twin died of massive bleeding and hypovolemic shock before the treatment started. At autopsy, the liver was diffusely enlarged and showed a diffuse whitish discoloration except for the subcapsular and perivenular areas. Microscopic examination disclosed infiltration of histiocyte-like atypical cells along the sinusoids and portal areas of the liver. Spleen, lymph nodes and choroid plexus were also infiltrated by the tumor cells. However, bone marrow involvement of the tumor was minimal although multifocal. On immunohistochemical staining, these atypical cells were reactive for CD68 (PGM-1) and lysozyme, suggesting that the tumor cells might have been derived from mono- histiocyte. Cytogenetic study revealed 9;11 translocation, which is frequently associated with acute monoblastic leukemia. To the best of our knowledge, this is the first report of congenital monoblastic leukemia of monozygotic twins in Korea.

Short-term phytohaemagglutinin-activated mononuclear cells induce endothelial progenitor cells from cord blood CD34+ cells

Endothelial progenitor cells (EPCs) were recently demonstrated to exist in human cord blood. Phytohaemagglutinin (PHA), a potent mitogen for mononuclear cells was used to induce EPCs from unsorted cord blood mononuclear cells (CBMCs). Adherent cells in clusters appeared approximately 24 h after CBMCs were cultured in plain Roswell Park Memorial Institute media containing 10% fetal bovine serum (culture media) and PHA. Adherent cells were further propagated for 1 week in plain culture media. Flow cytometry and Di-I staining analyses showed that CD45-, CD34+, Flk-1+, CD31+ or VE-cadherin+ EPCs were induced and that they were mainly from the CD34+ cell compartment. When enriched CD34+ cells alone were stimulated with culture supernatant of the PHA-activated CBMCs, they neither proliferated readily nor induced EPCs. Because EPCs first appeared within the clustering cells that expressed high levels of fibronectin and vascular endothelial growth factor (VEGF), our data suggest that both cell-cell/cell-matrix interaction and the local VEGF action are important in the induction of EPCs. Thus, we demonstrate for the first time that EPCs are induced from human cord blood stem cell populations that interact with neighbouring PHA-activated CBMCs. This finding may have a significant implication in inflammatory cell-mediated vasculogenesis and angiogenesis in vivo.