Spatio-temporal distribution and characteristics of PAHs in sediments from Masan Bay, Korea

The distribution of polycyclic aromatic hydrocarbons (PAHs) has been investigated in the surface and core sediments from Masan Bay, Korea. Total PAHs in the surface sediments ranged from 207 to 2670 ng/g dry weight with a mean value of 680 ng/g. Qualitative similarity and quantitative difference between inner and outer bay indicate that the main sources of PAHs are located in the inner bay and outer bay is also affected by the same sources. Vertical distribution of PAHs revealed that three distinctive stages could be differentiated with the help of PCA analysis. The highest concentration (industrialization stage) appeared between late 1950s and 1980, which was 10 years later than other developed countries. A strong pyrolytic source fingerprint has been detected with slight influence of petrogenic sources, and diagenetic PAH, perylene also contributed. Total organic carbon normalized PAHs (sum of 13 PAHs, 8.85-88.0 microg/g OC) were under the threshold effects concentration (TEC, 290 microg/g OC).

Accumulation of butyl- and phenyltin compounds in starfish and bivalves from the coastal environment of Korea

Triphenyltin (TPT) and tributyltin (TBT) concentrations were determined in two starfish species (Asteria pectinifera and Asterias amurensis), bivalves (Crassostrea gigas or Mytilus edulis), and seawater samples from sites around the coasts of Korea. Both TPT and TBT concentrations in starfish ranged from 8 to 1560 ng/g and from <2 to 797 ng/g as Sn on a dry weight basis, respectively. TPT concentration accounted for 75.4% and 86.4% of total phenyltin concentration in A. pectinifera and A. amurensis, respectively, while monobutyltin, a degradation product of TBT, accounted for 86.3% and 57.2% of total butyltin, respectively. Triphenyltin concentrations in A. pectinifera were significantly correlated to water and bivalve TPT concentrations, which implies that dietary uptake of TPT from contaminated prey as well as direct uptake from surrounding water contribute to TPT body residues in the starfish. Starfish could be target organisms for monitoring TPT compound in the marine environment, due to their high accumulation and low degradation capacity towards TPT.

Seasonal and spatial distribution of nonylphenol and IBP in Saemangeum Bay, Korea

In order to investigate spatial and temporal distribution of organic pollutants in the Saemangeum Bay, organophosphorus pesticides (10), alkylphenols (8), chlorophenols (2), bisphenol A were analyzed from the surface seawater taken in 2002-2003. Most of the analytes were not detected in all stations except nonylphenol and S-benzyl-O,O-di-isopropyl phosphorothioate (IBP). Concentrations of nonylphenol and IBP ranged from ND to 298 ng/l and from ND to 1840 ng/l, respectively. The high levels of nonylphenol and IBP were found in the estuary areas of Mangyeong and Dongjin River. The levels of nonylphenol and IBP in surface seawater varied through seasons and the high levels of nonylphenol and IBP were in summer season (August). Based on real time monitoring of IBP and on correlation between concentrations of target compounds and contents of salinity in seawater, physical mixing and diffusion of seawater were found to be the major factors that affect the spatial distribution of IBP and nonylphenol in the Saemangeum Bay environment.

Assessment of butyl- and phenyltin pollution in the coastal environment of Korea using mussels and oysters

Butyl- and phenyltin residues in bivalves were quantified around the coast of Korean peninsula in 1995-1998 and 2001. Butyltin compounds were detected at all the sites surveyed, whereas phenyltins were detected at 41 out of 67 sites in 1995-1998. Tributyltin (TBT) concentrations in bivalves ranged 48-2800 ng Sn/g on dry weight basis. Triphenyltin (TPT) concentrations ranged <3-1820. The mean TPT concentration was 3.5 times less than that of TBT. Spatial distribution of TBT was closely related to boating and dry-docking activities. TPT concentration in bivalves showed significant correlation with TBT. Concentrations of TBT in bivalves, 2001 are not significantly changed compared to those in 1995-1998. However, TPT concentrations in bivalves steeply decreased in 2001. High concentration of TBT and lesser extent TPT and their nation-wide distribution indicate that organotins are one of major organic pollutants in the marine environment of Korea.

Phylogenetic analysis based on genome-scale metabolic pathway reaction content

Phylogenetic classifications based on single genes such as rRNA genes do not provide a complete and accurate picture of evolution because they do not account for evolutionary leaps caused by gene transfer, duplication, deletion and functional replacement. Here, we present a whole-genome-scale phylogeny based on metabolic pathway reaction content. From the genome sequences of 42 microorganisms, we deduced the metabolic pathway reactions and used the relatedness of these contents to construct a phylogenetic tree that represents the similarity of metabolic profiles (relatedness) as well as the extent of metabolic pathway similarity (evolutionary distance). This method accounts for horizontal gene transfer and specific gene loss by comparison of whole metabolic subpathways, and allows evaluation of evolutionary relatedness and changes in metabolic pathways. Thus, a tree based on metabolic pathway content represents both the evolutionary time scale (changes in genetic content) and the evolutionary process (changes in metabolism).

Liposome-complexed adenoviral gene transfer in cancer cells expressing various levels of coxsackievirus and adenovirus receptor

PURPOSE

Loss of coxsackievirus and adenovirus receptor (CAR) is frequently observed in malignant cancer, hampering adenoviral gene therapy approaches. Complexing adenovirus with cationic liposomes can increase adenoviral transgene expression, particularly in cells with CAR-deficiency. We investigated whether other factors such as lipid composition might be involved in determining the efficiency of liposome-complexed adenoviral gene transfer in cancer cells.

MATERIAL AND METHODS

Human cancer cell lines with different expression levels of CAR were infected with a GFP transgene. The efficiency of transgene expression was assessed by determining GFP expression using FACS analysis.

RESULTS

The efficiency of liposome-complexed adenoviral gene transfer was dependent on the lipid composition constituting liposomes. Polyethylene glycol (PEG)-containing liposomes were most effective in increasing liposome-complexed adenoviral gene transfer. In CAR-deficient cells, use of PEG-containing liposomes enhanced adenoviral gene transfer, whereas in CAR-expressing cells enhancement varied depending on cell type. In some CAR-expressing cells, the effect of liposome complexing was even comparable to that in CAR-deficient cells. Increased adenoviral transgene expression following complexing with PEG-containing liposomes correlated with liposome uptake in cancer cells.

CONCLUSIONS

Liposome-complexed adenoviral gene transfer appears to depend on lipid composition and the level of liposome uptake by cancer cells, in addition to CAR levels. Our study suggest that these multiple factors should be considered in designing liposome-complexed adenoviral vectors to improve outcomes of current adenoviral cancer gene therapies.

Batch and continuous cultures of Mannheimia succiniciproducens MBEL55E for the production of succinic acid from whey and corn steep liquor

Mannheimia succiniciproducens MBEL55E isolated from bovine rumen is able to produce a large amount of succinic acid in a medium containing glucose, peptone, and yeast extract. In order to reduce the cost of the medium, whey and corn steep liquor (CSL) were used as substrates for the production of succinic acid by M. succiniciproducens MBEL55E. Anaerobic batch cultures of M. succiniciproducens MBEL55E in a whey-based medium containing CSL resulted in the production of succinic acid with a yield of 71% and productivity of 1.18 g/l/h, which are similar to those obtained in a whey-based medium containing yeast extract (72% and 1.21 g/l/h). Anaerobic continuous culture of M. succiniciproducens MBEL55E in a whey-based medium containing CSL resulted in a succinic acid yield of 69% and a succinic acid productivity as high as 3.90 g/l/h. These results show that succinic acid can be produced efficiently and economically by M. succiniciproducens MBEL55E from whey and CSL.

Accumulation of tributyltin in olive flounder, Paralichthys olivaceus: its effect on hepatic cytochrome P450

Accumulation of tributyltin (TBT) was determined in liver of olive flounder exposed to TBT (3.65, 36.5, 365, 3,650, and 7,300 ng Sn/L) for 10 or 30 days, followed by 60 days depuration. Effect of TBT on hepatic cytochrome P450 content was also measured in liver of olive flounder. TBT was highly accumulated in liver of fish during the 10- to 30-day exposures, and hepatic cytochrome P450 content decreased with increasing TBT concentration. Hepatic cytochrome P450 contents were affected in olive flounder exposed to even environmentally relevant TBT concentrations, such as 3.65 ng Sn/L. In addition, the liver TBT levels demonstrated strong negative correlation to the hepatic cytochrome P450 content. The effects started to appear from 20 ng Sn/g dry weight of TBT in liver. Tributyltin concentrations and hepatic cytochrome P450 were also determined in feral fine-spotted flounder. The relationship between other organic pollutants known as cytochrome P450 inducers (e.g., polychlorinated biphenyls) as well as TBT and hepatic cytochrome P450 in the feral fish implied that TBT even at ppt level could impose antagonistic effects on hepatic cytochrome P450 induction.

Daeganghwal-tang inhibits the stem cell factor-induced migration and inflammatory cytokines secretion in mast cells

Traditional Oriental medicinal prescription, Daeganghwal-tang (DGHT) has been used for the treatment of rheumatoid arthritis (RA) in Korea. However, its effect in experimental models remains unknown. Recent reports suggest that in patients with RA, synovial mast cells increase in number and show signs of activation and inflammatory cytokines secretion. Our results show that stem cell factor (SCF) is a potent chemotactic factor for the mast cells in vitro. The chemotactic response to SCF was blocked by DGHT. When DGHT (1mg/ml) was added, the secretion of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta and IL-6 was inhibited by 60.1, 81.8, 72.5%, respectively in phorbol 12-myristate 13-acetate (PMA) plus calcium ionophore A23187-stimulated HMC-1 cells. In addition, the expression of TNF-alpha mRNA in HMC-1 cells was inhibited by DGHT (1mg/ml). These findings indicate that DGHT inhibits SCF-induced migration and PMA plus calcium ionophore-stimulated inflammatory cytokines secretion in mast cells.

Horizontal and vertical distribution of PCBs and chlorinated pesticides in sediments from Masan Bay, Korea

Horizontal and vertical distributions of organochlorine compounds (OCs) were determined in sediments from Masan Bay. The concentrations of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs), HCB, hexachlorocyclohexanes (HCHs) and chlordane related compounds (CHLs) in sediments were in the range of 1.24-41.4, 0.28-89.2, 0.02-0.59, nd-1.03, and nd-2.56 ng/g, respectively. The spatial distribution of OCs showed a negative gradient from the inner of the bay to outer part of the bay, indicating that the source of OCs was probably located inside the bay. Compositional pattern of PCB congeners showed a relatively high concentration of high-chlorinated congeners in the inner part of the bay and a relatively low concentration of low-chlorinated congeners in the outer part. In sediment core from Masan Bay maximum concentrations of PCBs and DDTs are observed in the subsurface samples and correspond to an age of early 1980s and late 1960s. The concentration profiles of PCBs and DDTs in sediments of Masan Bay appear to correspond to use of PCBs and DDTs in Korea.

Biological conversion of wood hydrolysate to succinic acid by Anaerobiospirillum succiniciproducens

Anaerobiospirillum succiniciproducens grew on a minimal salts medium containing wood hydrolysate (equivalent to 27 g glucose l(-1)) and, when supplemented with 10 g corn steep liquor l(-1) as a complex nitrogen source, succinic acid at 24 g l(-1) was obtained (yield = 88% w/w glucose). This may therefore be an economical method to produce succinic acid.

Degradation of IkappaBalpha in activated RAW264.7 cells is blocked by the phosphatidylinositol 3-kinase inhibitor LY294002

The mechanism by which lipopolysaccharide (LPS) or phorbol 12-myristate 13-acetate (PMA) induces production of proinflammatory cytokines in murine macrophages, and the role of phosphatidylinositol 3-kinase (PI3-kinase) have not been well investigated. Activation of nuclear factor kappaB (NF-kappaB) is initiated by the phosphorylation of the inhibitory subunit, IkappaB, which targets IkappaB for degradation and leads to the release of active NF-kappaB. In this study we demonstrate that 2-(4-morpholinyl)-8-phenylchromone (LY294002), which inhibits PI3-kinase, specifically inhibited degradation of IkappaBalpha in RAW264.7 cells stimulated with interferon-gamma (IFN-gamma) plus LPS or IFN-gamma plus PMA. To elucidate the importance of this activity in RAW264.7 cells, we examined tumor necrosis factor-alpha (TNF-alpha) and interleukin (IL)-6 production in the activated cells. Pretreatment of the cells with LY294002 resulted in the inhibition of TNF-alpha and IL-6 production in RAW264.7 cells stimulated with IFN-gamma plus LPS or IFN-gamma plus PMA. Furthermore, LY294002 inhibited the production of nitric oxide (NO) in RAW264.7 cells stimulated with IFN-gamma plus LPS or IFN-gamma plus PMA. LY294002 also inhibited inducible NO synthase (iNOS) mRNA expression in the activated RAW264.7 cells. In conclusion, the present results suggest that PI3-kinase is involved in the signal transduction pathway responsible for LPS- or PMA-mediated TNF-alpha and IL-6 production, and that LY294002 inhibits NO generation through blocking the degradation of IkappaBalpha in activated RAW264.7 cells.

Horizontal and vertical distribution of butyltin compounds in sediments from shipyards in Korea

Butyltin compounds were quantitatively determined in surface sediment and sediment core samples near shipyards in the south coast of Korea, which is one of the major ship building industries in the world. Tributyltin (TBT) concentrations reached up to 46100 ng Sn/g on a dry-weight basis at the front of the shipyard. Horizontal distribution of butyltin compounds was closely related to dry-docking activities. Butyltin concentrations were relatively low where remote from the sources. The vertical distribution of TBT in sediment cores showed active use of TBT in Korean peninsula for the past decades. The increase of TBT concentrations in sediment core according to estimated sediment age demonstrated a positive correlation with the increase of gross tonnage of ships built in the shipyard for 20 years. High TBT residue levels in sediment core samples raise concerns over persistence of the compound in the marine environment.

Fenofibrate lowers abdominal and skeletal adiposity and improves insulin sensitivity in OLETF rats

The effect of peroxisome proliferator-activated receptor (PPAR)-alpha activators on the liver is well established, but the other effects on muscle and adipose tissue about lipid metabolism and insulin sensitivity are not clear. We investigated whether PPAR-alpha activation affects adiposity of skeletal muscle as well as adipose tissue and improves insulin sensitivity in spontaneous type 2 diabetes model, Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Thirty-three weeks of aged, 20 male OLETF rats were divided into two groups. Control group (n=10) was fed with chow and treatment group (n=10) with chow contained fenofibrate for 7 weeks. At the age of 40 weeks, all rats were examined with MRI, intravenous glucose tolerance test, and then sacrificed for measurement of fat mass and RNA analyses. The total fat (the sum of subcutaneous, mesenteric, epididymal, and retroperitoneal fat pads) measured by dissection was significantly reduced in treatment group. The signal intensity of muscular adiposity was significantly decreased in treatment group. The mRNA levels of FAT/CD36 and mitochondrial carnitine palmitoyltransferase I (M-CPT I) in liver were remarkably increased. Fasting plasma insulin and leptin levels, insulin response after intravenous glucose loading and homeostasis model assessment insulin resistance (HOMA(IR)) index were lowered in treatment group. Fenofibrate increase mitochondrial fatty acid beta-oxidation in liver but not in skeletal muscle and lower the plasma levels of triglyceride and free fatty acid. It might result in reduction of adiposity of truncal adipose tissue and skeletal muscle. We suggest that reduction of adiposity in trunk and skeletal muscle might improve insulin sensitivity.

Isolation and characterization of a new succinic acid-producing bacterium, Mannheimia succiniciproducensMBEL55E, from bovine rumen

A novel succinic acid-producing bacterium was isolated from bovine rumen. The bacterium is a non-motile, non-spore-forming, mesophilic and capnophilic gram-negative rod or coccobacillus. Phylogenetic analysis based on the 16S rRNA sequence and physiological analysis indicated that the strain belongs to the recently reclassified genus Mannheimia as a novel species, and has been named Mannheimia succiniciproducens MBEL55E. Under 100% CO(2) conditions, it grows well in the pH range of 6.0-7.5 and produces succinic acid, acetic acid and formic acid at a constant ratio of 2:1:1. When M. succiniciproducensMBEL55E was cultured anaerobically in medium containing 20 g l(-1) glucose as carbon source, 13.5 g l(-1) of succinic acid was produced.

Importance of redox balance on the production of succinic acid by metabolically engineered Escherichia coli

We had previously shown that succinic acid production in a pfl ldhA double mutant strain of Escherichia coli could be enhanced by amplifying the malic enzyme activity. However, recombinant E. coli NZN111 (F- Apfl::Cam ldhA::Kan) harboring pTrcML, a plasmid containing the E. coli malic enzyme gene, produced a considerable amount of malic acid along with the desired product, succinic acid. To have an insight into the intracellular metabolism, metabolic control analysis was carried out. From the results of a simulation, it was predicted that supplying additional reducing power could enhance succinic acid production. More reduced carbon substrate sorbitol was thus examined for the possibility of matching the potential during succinic acid production. When NZN111 (pTrcML) was cultured in LB medium containing 20 g sorbitol/l under a CO2 atmosphere, 10 g succinic acid/l was produced. The apparent yield of succinic acid was 1.1 g succinic acid/g sorbitol, which is 85% of the maximum theoretical yield. Therefore, it was found that redox balancing was important for the enhanced production of succinic acid in metabolically engineered E. coli.

Experimental and theoretical analysis of wavelet-based denoising filter for echocardiographic images

One of the most significant features of diagnostic echocardiographic images is to reduce speckle noise and make better image quality. In this paper we proposed a simple and effective filter design for image denoising and contrast enhancement based on multiscale wavelet denoising method. Wavelet threshold algorithms replace wavelet coefficients with small magnitude by zero and keep or shrink the other coefficients. This is basically a local procedure, since wavelet coefficients characterize the local regularity of a function. After we estimate distribution of noise within echocardiographic image, then apply to fitness Wavelet threshold algorithm. A common way of the estimating the speckle noise level in coherent imaging is to calculate the mean-to-standard-deviation ratio of the pixel intensity, often termed the Equivalent Number of Looks(ENL), over a uniform image area. Unfortunately, we found this measure not very robust mainly because of the difficulty to identify a uniform area in a real image. For this reason, we will only use here the S/MSE ratio and which corresponds to the standard SNR in case of additivie noise. We have simulated some echocardiographic images by specialized hardware for real-time application;processing of a 512*512 images takes about 1 min. Our experiments show that the optimal threshold level depends on the spectral content of the image. High spectral content tends to over-estimate the noise standard deviation estimation performed at the finest level of the DWT. As a result, a lower threshold parameter is required to get the optimal S/MSE. The standard WCS theory predicts a threshold that depends on the number of signal samples only.

Geographical distribution and accumulation features of organochlorine residues in bivalves from coastal areas of South Korea

As a part of Mussel Watch Program in Korea, the contamination levels and accumulation features of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were assessed for 82 bivalve samples collected from 66 sites along the entire coast of Korea. The dry weight based sigmaPCBs and sigmaOCPs ranged from 4.4 ng g(-1) to 422.0 ng g(-1) (geometric mean = 36.9 ng g(-1)) and from 9.95 ng g(-1) to 131.37 (34.88) ng g(-1), respectively. PCB was predominant in Korean coast, followed by DDTs, HCHs, and Chlordanes. From the observed log normal distribution of PCB and each OCP, low- and high-levels were defined as geometric mean +/- 1 S.D., respectively. The levels at the sites near urban and/or industrial areas often exceeded the high-levels and the spatial distributions of sigmaDDTs and sigmaCHLs were correlated with that of sigmaPCBs, indicating terrestrial input pathways. Even distribution of sigmaHCHs suggested a possibility of atmospheric input pathway of HCHs. The observed isomer ratios of DDTs, HCHs, and CHLs indicated that aging has occurred.

Alternative transcriptional initiation and splicing of mouse Lamc2 message

To investigate the mechanism of two forms of messages (5.1 and 2.4 kb) in mouse Lamc2, a gene encoding for the gamma2 chain of epithelial cell-specific laminin 5, we analyzed approximately 40 kb of genomic DNA containing the sequences from the first intron to the 23rd exon to the 3' untranscribed region. With the 5' rapid amplification of cDNA end (RACE) and primer extension technique using RNA from mouse kidney and thymic epithelial cells, we found that the smaller message starts at the 2895th base of the cDNA within the 19th exon. Upstream sequences of this alternative start site showed the promoter activity in the reporter assay with the secreted form of alkaline phosphatase (SEAP). We also identified a novel alternatively spliced exon (exon 19B) that includes two stop codons. These results revealed two possible additional open reading frame that are different from the previously described alternative human gamma2 peptide. Therefore, the mechanism for generating smaller message and the event of alternative splicing are quite distinct between mouse and human Lamc2, although genomic organization is highly conserved. The significance of the presence of alternative message is discussed.

Effect of hypothermia on bilirubin-induced alterations in brain cell membrane function and energy metabolism in newborn piglets

The aim of this study was to evaluate the effects of hypothermia on bilirubin-induced alterations in brain cell membrane function and energy metabolism in the developing brain. Thirty-seven newborn piglets were divided randomly into four groups: normothermic control (NC, n=9); hypothermic control (HC, n=7); normothermic bilirubin infusion (NB, n=11); and hypothermic bilirubin infusion (HB, n=10) groups. In bilirubin infusion groups (NB and HB), a loading dose of bilirubin (35 mg/kg) was given over 5 min, followed by a continuous infusion (25 mg/kg/h) for 4 h. The control groups (NC, HC) received a bilirubin-free buffer solution. Sulfadimethoxine was administered to animals in all experimental groups. Rectal temperature was maintained between 38.0 and 39.0 degrees C in normothermic groups, and between 34.0 and 35.0 degrees C in hypothermic groups for 4 h after the start of bilirubin infusion. The final blood and brain bilirubin concentrations in the bilirubin infusion groups (NB and HB) were not significantly different. Decreased cerebral cortical cell membrane Na(+),K(+)-ATPase activity and increased lipid peroxidation products observed in the NB group, indicative of bilirubin-induced brain damage, were significantly attenuated in the HB group. Hypothermia also significantly improved the bilirubin-induced reduction in brain ATP and phosphocreatine levels and increase in blood and brain lactate levels. In summary, hypothermia significantly attenuated the bilirubin-induced alterations in brain cell membrane function and energy metabolism in the newborn piglet. These findings suggest the possibility that hypothermia could be a good neuroprotective therapeutic modality in neonatal bilirubin encephalopathy.

Genetic variations of cholesterol ester transfer protein gene in Koreans

An absence of cholesterol ester transfer protein (CETP, protein; CETP, gene) results in an increase of the apolipoprotein AI levels and a decrease in the low density lipoprotein (LDL) levels. Thus, the CETP polymorphism is important in the assessment of risk of atherosclerosis. This study was conducted to elucidate the genotype distributions of the CETP polymorphism and association with plasma lipid levels in Koreans. The genotypes of the TaqI A and B polymorphic loci were associated with plasma triglyceride levels in the control and coronary artery disease (CAD) groups. There was linkage disequilibrium between TaqI A and B loci in the control group (chi2 = 5.58, p < 0.05). Association studies of the CETP polymorphism have been carried out mainly with Caucasian populations; however, the results have not been consistent among different populations. A possible explanation for this diversity among populations may be differences in genetic backgrounds, which may be more important than environmental factors. We discuss the reasons for the incompatibility of the CETP polymorphism among populations.

Epithelioid angiosarcoma of the pleura: a case report

Angiosarcomas of the pleura are very rare tumors and it is difficult to differentiate them from other common pleural tumors such as mesothelioma and metastasic carcinoma clinically and pathologically. We report a case of a young Korean woman with angiosarcoma arising in the pleura. A 34-yr-old woman presented with dyspnea and chest tightness and pain for several months. A computed tomographic scan of the chest showed diffuse thickening of the left pleura and effusion with passive atelectasis. At thoracotomy the left pleura was thick and indurated. Histologically, the decorticated pleura revealed infiltration of sheets or cords of polygonal and epithelioid tumor cells showing rudimentary vascular differentiation. Immunohistochemically, the tumor cells were strongly positive for CD31, CD34, and vimentin, whereas weakly positive for factor VIII, and negative for cytokeratin, which are characteristic and specific findings of angiosarcoma.

The haplotype analyses using multiple markers of the apolipoprotein B gene in patients with coronary artery disease

The high level of low density lipoprotein (LDL) is a risk factor for cardiovascular disease. Apolipoprotein (apo) B is a major protein component of LDL and plays an important role in the maintenance of cholesterol homeostasis. In this study, six polymorphic sites of the apoB gene were anlaysed in 235 patients with coronary artery disease (CAD) and 216 normal control subjects. There were no significant differences in the allele frequencies of apoB polymorphisms between the control and patient groups. However, haplotype frequencies were significantly different between the CAD patients and control (p<0.05). In addition, the allelic distributions of both EcoRI and MspI polymorphisms in Koreans were similar to those in Chinese but significantly different from those in Caucasians. ApoB polymorphisms showed no association with plasma lipid levels. In conclusion, haplotype analysis of the apoB gene using multiple diallelic markers might be a useful marker for Korean CAD patients.

Circling mouse: possible animal model for deafness

Mutant mice with abnormalities are potentially useful as models for studying human defects. Here we report a group of mice with abnormal behavioral patterns. A new spontaneous mutant mouse exhibited hyperactive behavior at about seven days of age, followed by tight circling behavior. Breeding studies suggest that this mutation is caused by a single gene defect inherited in an autosomal recessive manner. Consequently, this mutation is referred to as a circling (cir) mouse mutation with the gene symbol cir. Auditory test results identified clearly the hearing loss of the cir, compared with wild-type mice. Pathologic studies confirmed developmental defects in cochlea and spiral ganglions that were correlated to the abnormal behavior observed in the cir mice. Thus, cir mice may be useful as a model for studying inner ear abnormalities and deafness in humans.

Hypermethylation of tumor-related genes in genitourinary cancer cell lines

Hypermethylation of CpG island is a common mechanism for the inactivation of tumor-related genes. In the present study, we analyzed 13 genitourinary cancer cell lines for aberrant DNA methylation of 5 tumor-related genes using methylation- specific polymerase chain reaction (MSP). GSTP1 was methylated in 5 (38.5%), E-cadherin in 1 (8%), VHL in 1 (8%), and MGMT and hMLH1 in none (0%). Six out of thirteen genitourinary cancer cell lines had methylation of at least one of five genes; 5 had one gene methylated, and, 1 had two genes methylated. Methylation of these 5 genes was not detected in any of the bladder cancer cell lines. GSTP1 was methylated in all of the 3 prostate cancer cell lines. We conclude that aberrant hypermethylation may be an important mechanism for the inactivation of cancer-related genes in kidney and prostate cancer cell lines.

Arsenic trioxide is a potent inhibitor of the interaction of SMRT corepressor with Its transcription factor partners, including the PML-retinoic acid receptor alpha oncoprotein found in human acute promyelocytic leukemia

The SMRT corepressor complex participates in transcriptional repression by a diverse array of vertebrate transcription factors. The ability to recruit SMRT appears to play a crucial role in leukemogenesis by the PML-retinoic acid receptor alpha (RARalpha) oncoprotein, an aberrant nuclear hormone receptor implicated in human acute promyelocytic leukemia (APL). Arsenite induces clinical remission of APL through a incompletely understood mechanism. We report here that arsenite is a potent inhibitor of the interaction of SMRT with its transcription factor partners, including PML-RARalpha. Arsenite operates, in part, through a mitogen-activated protein (MAP) kinase cascade culminating in phosphorylation of the SMRT protein, dissociation of SMRT from its nuclear receptor partners, and a relocalization of SMRT out of the nucleus into the cytoplasm of the cell. Conversely, inhibition of this MAP kinase cascade attenuates the effects of arsenite on APL cells. Our results implicate SMRT as an important biological target for the actions of arsenite in both normal and neoplastic cells.

Metabolic flux analysis for succinic acid production by recombinant Escherichia coli with amplified malic enzyme activity

A pfl ldhA double mutant Escherichia coli strain NZN111 was used to produce succinic acid by overexpressing the E. coli malic enzyme. Escherichia coli strain NZN111 harboring pTrcML produced 6 and 8 g/L of succinic acid from 20 g/L of glucose in flask culture at 37 degrees C and 30 degrees C, respectively. When NZN111(pTrcML) was cultured at 30 degrees C with intermittent glucose feeding the final succinic acid concentration obtained was 9.5 g/L and the ratio of succinic acid to acetic acid was 13:1. This system could not be analyzed by conventional metabolic flux analysis techniques, since some pyruvate and succinic acid were accumulated intracellularly. Therefore, a new flux analysis method was proposed by introducing intracellular pyruvate and succinic acid pools. By this new method the concentrations of intracellular metabolites were successfully predicted and the differences between the measured and calculated reaction rates could be considerably reduced.

Changes in external ear resonance after 3 types of surgery in the patients with chronic otitis media

OBJECTIVE

This study was designed to identify the external ear resonance characteristics of patients with tympanic membrane perforation and to investigate subsequent changes in external ear resonance, depending on the length of the postoperative period and which of 3 different types of operation was performed: tympanoplasty with canal wall-up mastoidectomy, epitympanoplasty, and canal wall-down mastoidectomy.

STUDY DESIGN AND SETTING

A total of 227 ears of 188 patients and 96 control ears comprised the study. We measured the gain and frequency of the first peak of external ear resonance with a real ear analyzer.

RESULTS

Gain and frequency of the first peak recorded in the preoperative group did not differ from those of the control group. However, negative peaks appeared around 1 to 1.5 kHz in half of these ears. The gain increased markedly in all 3 postoperative groups. The canal wall-down mastoidectomy and epitympanoplasty groups showed significantly lower frequencies compared with the tympanoplasty with canal wall-up mastoidectomy and control groups, but there was no difference between them. The increased gain diminished over time, but the peak gain did not equalize with that of the controls, even after 15 months.

CONCLUSIONS

Additional gain should be considered of around 1 to 1.5 kHz for hearing aid users with tympanic membrane perforation. Postoperative changes in external ear resonance should be expected in patients with chronic otitis media, suggesting that fine readjustments of the hearing aid may be necessary.

Genetic variations of the paraoxonase gene in patients with coronary artery disease

OBJECTIVES

Paraoxonase (PON) plays an important role in preventing low density lipoprotein (LDL) oxidation and thus may be involved in protection against atherosclerosis. Several studies have suggested that genetic variations of the PON gene are associated with plasma HDL levels and coronary artery disease (CAD). This study was conducted to elucidate the association between three polymorphisms of the PON1 and PON2 genes and Korean patients with CAD.

DESIGN AND METHODS

One hundred ninety-one patients with CAD and 113 age-matched normal controls were examined by polymerase chain reaction (PCR). The PCR products were analyzed for PON polymorphisms by restriction enzyme digestion.

RESULTS

There was linkage disequilibria between each polymorphism pair in the CAD and control groups. The Hsp92II polymorphism at codon 54 of the PON1 gene was positively associated with HDL-cholesterol levels in the control group (p = 0.02). An association between the AlwI polymorphism and HDL-cholesterol level appeared statistically significant in women of the normal group (p = 0.04). In addition, the DdeI and AlwI polymorphisms were positively associated with HDL (p = 0.02) and LDL (p = 0.03) levels in men of the CAD group, respectively.

CONCLUSIONS

Our study suggested a gene-gene interaction between the PON1 and PON2 polymorphisms for CAD risk. However, we could not exclude the possibility that these polymorphisms may have linkage disequilibrium with a tightly linked PON3 locus or significant atherosclerotic alleles of nearby genes. Family studies may, therefore, help to confirm the role of the PON polymorphism for CAD risk.

Five-lipoxygenase inhibitors can mediate apoptosis in human breast cancer cell lines through complex eicosanoid interactions

Many arachidonic acid metabolites function in growth signaling for epithelial cells, and we previously reported the expression of the major arachidonic acid enzymes in human breast cancer cell lines. To evaluate the role of the 5-lipoxygenase (5-LO) pathway on breast cancer growth regulation, we exposed cells to insulinlike growth factor-1 or transferrin, which increased the levels of the 5-LO metabolite, 5(S)-hydrooxyeicosa-6E,8C,11Z,14Z-tetraenoic acid (5-HETE), by radioimmunoassay and high-performance liquid chromatography. Addition of 5-HETE to breast cancer cells resulted in growth stimulation, whereas selective biochemical inhibitors of 5-LO reduced the levels of 5-HETE and related metabolites. Application of 5-LO or 5-LO activating protein-directed inhibitors, but not a cyclooxygenase inhibitor, reduced growth, increased apoptosis, down-regulated bcl-2, up-regulated bax, and increased G1 arrest. Exposure of breast cancer cells to a 5-LO inhibitor up-regulated peroxisome proliferator-activated receptor (PPAR)a and PPARg expression, and these same cells were growth inhibited when exposed to relevant PPAR agonists. These results suggest that disruption of the 5-LO signaling pathway mediates growth arrest and apoptosis in breast cancer cells. Additional experiments suggest that this involves the interplay of several factors, including the loss of growth stimulation by 5-LO products, the induction of PPARg, and the potential activation of PPARg by interactions with shunted endoperoxides.

Expression of the c-erb-B2 and p53 protein in gallbladder carcinomas

Gallbladder carcinoma is the most common malignancy of the biliary tract in Korea and known to be more common in East Asia and Latin America than in Europe and North America. However, their exact histopathological characteristics and carcinogenesis are not well-elucidated. A total of 71 cases of gallbladder carcinomas, two cases of gallbladder dysplasia and 20 cases of gallbladder adenoma were immunohistochemically studied to evaluate the expression of c-erb-B2 and p53 proteins in the light of their relationship with various prognostic factors. Thirty-three gallbladder carcinomas (46.5%) showed positive staining for c-erb-B2, but none of the dysplasia and adenoma were positive (p<0.05). c-erb-B2 was stained in the cell membrane of the cancer cells. Adjacent normal mucosa was negative for c-erb-B2 staining. Forty-eight gallbladder carcinomas (67.6%) showed positive staining in the nucleus for p53 protein. None of the cases with dysplasia, adenoma, and normal mucosa stained positive for p53 protein. There was no significant correlation between c-erb-B2 and p53 expression and age, gender, histological tumor grade, and tumor stage. In the multivariate analysis, tumor stage approached statistical significance (p=0.05), but c-erb-B2 and p53 expression was not significant (p=0.14 and p=0.29, respectively). The mean survival periods of the c-erb-B2 positive and negative groups were 26 months and 52 months, respectively (p=0.02). However, the mean survival periods of the p53 protein positive and negative patients were 34 months and 35 months, respectively (p=0.45). In conclusion, our results suggest that c-erb-B2 and p53 protein expression is strongly associated with neoplastic progression in gallbladder carcinomas, and that c-erb-B2 expression identifies patients with a worse prognosis.

MR findings of tuberculous dactylitis: case report

A case of tuberculous dactylitis in an immunocompetent patient is presented and the radiographic findings and differential diagnosis discussed. MR image, although nonspecific, was helpful for differential diagnosis and evaluating the extent of the lesion. Although this is a rare condition, the diagnosis should be considered when dealing with an unusual destructive bony lesion.

ORE9, an F-box protein that regulates leaf senescence in Arabidopsis

Senescence is a sequence of biochemical and physiological events that constitute the final stage of development. The identification of genes that alter senescence has practical value and is helpful in revealing pathways that influence senescence. However, the genetic mechanisms of senescence are largely unknown. The leaf of the oresara9 (ore9) mutant of Arabidopsis exhibits increased longevity during age-dependent natural senescence by delaying the onset of various senescence symptoms. It also displays delayed senescence symptoms during hormone-modulated senescence. Map-based cloning of ORE9 identified a 693-amino acid polypeptide containing an F-box motif and 18 leucine-rich repeats. The F-box motif of ORE9 interacts with ASK1 (Arabidopsis Skp1-like 1), a component of the plant SCF complex. These results suggest that ORE9 functions to limit leaf longevity by removing, through ubiquitin-dependent proteolysis, target proteins that are required to delay the leaf senescence program in Arabidopsis.

Novel findings in inhibition of mast cell-dependent immediate-type cutaneous reactions by Gahmi-Shini-San

This report describes an inhibitory effect of Gahmi-Shini-San (GSS) on mast cell-mediated immediate-type allergic reactions. GSS is an Oriental herbal medication, which has been successfully used in Korea for the treatment of allergic disorders, mainly skin anaphylactic diseases. GSS inhibited the ear swelling response induced by intradermal injection of compound 48/80 in a mouse model on a concentration-dependent basis. The mast cells in mouse ear tissue were stained by alcian blue/nuclear fast red. GSS significantly inhibited the compound 48/80-induced degranulation from mast cells in ear tissue. GSS dose-dependently inhibited the histamine release from the rat peritoneal mast cells by compound 48/80. We also studied the effect of GSS on mast cell-dependent passive cutaneous anaphylaxis activated by dinitrophenyl IgE antibody. GSS showed inhibition of passive cutaneous anaphylaxis following oral administration. These results indicated that GSS has inhibitory effect on mast cell-dependent immediate type cutaneous reactions.

Results of hyperamplification of centrosomes in naturally developing tumors of dogs

OBJECTIVE

To evaluate results of centrosome hyperamplification in naturally developing tumors of dogs.

SAMPLE POPULATION

Tumor specimens from 9 dogs with tumors (rhabdomyosarcoma, osteosarcoma, chondrosarcoma, myxosarcoma, and mammary gland tumor) and 2 canine osteosarcoma cell lines.

PROCEDURE

3 antibodies for centrosome proteins (ie, anti-gamma-tubulin, anti-BRCA1, and anti-pericentrin) were used for immunohistochemical analysis. Double immunostaining for centrosomes was used to confirm the specificity of these antibodies for centrosomes. Mutational analysis of the canine p53 gene was carried out by polymerase chain reaction-single-strand conformation polymorphism analysis, and expression of canine MDM2 protein was evaluated by use of immunohistochemical analysis, using anti-MDM2 antibody.

RESULTS

Immunohistochemical analysis of dog osteosarcoma cell lines with apparent aneuploidy revealed frequent hyperamplification of centrosomes in the osteosarcoma cell lines. Similar hyperamplified centrosomes were detected in the tumor tissues from all of the 9 tumors. The frequency of cells with hyperamplified centrosomes (3 to 20/cell) in each tumor tissue ranged from 9.50 to 48.1%, whereas centrosome hyperamplification was not observed in normal lymph nodes from these dogs. In 8 of the 9 tumors, mutation of p53 gene or overexpression of MDM2, or both, was detected.

CONCLUSIONS AND CLINICAL RELEVANCE

Various types of naturally developing tumors in dogs often have hyperamplification of centrosomes associated with chromosome instability. Hyperamplification of centrosomes is a novel tumor marker for use in cytologic and histologic examinations of clinical specimens obtained from dogs.

Inflammatory pseudotumour involving the skull base and cervical spine

Inflammatory pseudotumour (IPT) is an idiopathic condition characterized by sclerosing inflammation, which mimics a neoplastic process. IPT involving the skull base and cervical spine is distinctly rare and usually indistinguishable from aggressive neoplasms or infection. We report a case of IPT involving the skull base and cervical spine. Initially the patient complained of headache and hearing loss without other neurological dysfunction. Two cycles of oral systemic steroid therapy resulted in only partial responses. Low dose radiotherapy was followed by quadriparesis as the lesion infiltrated into the cervical vertebral bodies. Subsequently a second course of radiation was administered to the whole cervical spine. Marked improvement was observed clinically and radiologically; however, the patient gradually deteriorated and died of sepsis. Given the aggressive nature of disease and the complications related to the long-term treatment, we suggest that a more aggressive therapeutic approach is suitable in extensive IPT of the skull base.

8-Cl-cAMP induces cell cycle-specific apoptosis in human cancer cells

8-Cl-cyclic adenosine monophosphate (8-Cl-cAMP) has been known to induce growth inhibition and differentiation in a variety of cancer cells by differential modulation of protein kinase A isozymes. To understand the anticancer activity of 8-Cl-cAMP further, we investigated the effect of 8-Cl-cAMP on apoptosis in human cancer cells. Most of the tested human cancer cells exhibited apoptosis upon treatment with 8-Cl-cAMP, albeit with different sensitivity. Among them, SH-SY5Y neuroblastoma cells and HL60 leukemic cells showed the most extensive apoptosis. The effect of 8-Cl-cAMP was not reproduced by other cAMP analogues or cAMP-elevating agents, showing that the effect of 8-Cl-cAMP was not caused by simple activation of protein kinase A (PKA). However, competition experiments showed that the binding of 8-Cl-cAMP to the cAMP receptor was essential for the induction of apoptosis. After the treatment of 8-Cl-cAMP, cells initially accumulated at the S and G2/M phases of the cell cycle and then apoptosis began to occur among the population of cells at the S/G2/M cell cycle phases, indicating that the 8-Cl-cAMP-induced apoptosis is closely related to cell cycle control. In support of this assumption, 8-Cl-cAMP-induced apoptosis was blocked by concomitant treatment with mimosine, which blocks the cell cycle at early S phase. Interestingly, 8-Cl-cAMP did not induce apoptosis in primary cultured normal cells and non-transformed cell lines, showing that 8-Cl-cAMP-induced apoptosis is specific to transformed cells. Taken together, our results show that the induction of apoptosis is one of the mechanisms through which 8-Cl-cAMP exerts anticancer activity.

Low tibial osteotomy for moderate ankle arthritis

Low tibial osteotomy is one of the significant advances of ankle reconstruction techniques that has been made recently in an effort to halt arthritis in its early stages and leave fusion as the last, not the only, alternative treatment of ankle arthritis. From 1989 to 1995, we performed 18 low tibial osteotomies which included 6 cases of post-traumatic arthritis and 12 cases of degenerative arthritis. The ages of the 7 male and 11 female patients ranged from 18 to 78 years with an average of 41.9 years. The follow-up period lasted a mean of 47.7 months, ranging from 25 to 82 months. The average functional score changed from 49.6 pre-operatively to 88.5 at the last follow up, and showed yearly improvement. Complications included one case of late infection and two cases of implant failure, none of which led to nonunion. The indication for low tibial osteotomy is the intermediate stage of moderate ankle arthritis with a medial joint lesion and intact lateral facet. Using pressure redistribution on the joint surface, this procedure is an alternative treatment for ankle arthritis which may save an arthritic ankle from the fate of fusion or at least postpone fusion surgery.

Natural exopolysaccharides enhance survival of lactic acid bacteria in frozen dairy desserts

Viable lactic acid-producing bacteria in frozen dairy desserts can be a source of beta-galactosidase for persons who absorb lactose insufficiently. However, freezing kills many of the cells, causing loss of enzymatic activity. Cultures selected for high beta-galactosidase activities and high survival rates in the presence of bile were examined for survivability during freezing in reduced-fat ice cream. Encapsulated S. thermophilus strains survived better than their nonencapsulated mutants in reduced-fat ice cream after freezing and frozen storage at -29 degrees C for 16 d (28 vs. 19%). However, a small nonencapsulated strain of Lactobacillus delbrueckii sp. bulgaricus survived better than the large encapsulated strain in reduced-fat ice cream. Factors that improved survival of encapsulated S. thermophilus 1068 in ice cream were 1) harvest of cells in the late-log phase of growth at 37 degrees C rather than at 40, 42.5, or 45 degrees C; 2) overrun at 50% rather than 100%; and 3) storage at -17 degrees C rather than -23 or -29 degrees C. Survival of strain ST1068 was unaffected by 1) neutralization of acid during growth or 2) substitution of nitrogen for air in building overrun.

Changes in external ear resonance after ventilation tube (Grommet) insertion in children with otitis media with effusion

As otitis media with effusion is common in children, the effects of a ventilation tube should be taken into account in the prescription of hearing aids for children. In ears with a ventilation tube, the external auditory canal communicates directly with the middle ear space, and so the impedance of the middle ear may change. Consequently, this will affect external-ear resonance. The aim of this study is to observe the effects of the tympanic membrane perforations caused by the ventilation tube on external-ear resonance. We selected 30 ears with otitis media with effusion to measure external-ear resonance before and after ventilation tube insertion. We compared the external-ear resonance of a control group with that of the otitis media with the effusion group and two types of ventilation-tube groups, respectively. In the subjects who have otitis media with effusion, the average gain of the peak resonance was larger than that in the control group. After ventilation-tube insertion, the amplitude of the gain decreased to the same level as the control group, but a characteristic negative gain appeared around 1000 Hz in about half of all cases. This negative gain was observed more frequently in the ventilation tube with a larger diameter. The raised peak resonance gain in the otitis media with effusion group decreased to a level roughly the same as that of the control group after ventilation-tube insertion. Provision of an additional gain in the low frequencies around 1000 Hz should be considered for patients with a ventilation tube when prescribing hearing aids.

The SMRT corepressor is a target of phosphorylation by protein kinase CK2 (casein kinase II)

The Silencing-Mediator for Retinoid/Thyroid hormone receptors (SMRT) interacts with, and mediates transcriptional repression by, a variety of eukaryotic transcription factors, including the nuclear hormone receptors. The ability of SMRT to function as a transcriptional 'corepressor' is regulated by a variety of signal transduction pathways. We report here that SMRT is a phosphoprotein in vivo, and is also phosphorylated in vitro by unfractionated cell extracts. A major site of phosphorylation of SMRT is a protein kinase CK2 motif centered on serine 1492, and located within a C-terminal SMRT domain that mediates interaction of the corepressor with the nuclear hormone receptors. Phosphorylation of SMRT by CK2 stabilizes the ability of the SMRT protein to interact with nuclear hormone receptors. Our results indicate that SMRT is a member of an expanding family of transcriptional regulators that are modified, and potentially regulated, in response to protein kinase CK2.

Genetic variation of the methylenetetrahydrofolate reductase and cystathionine beta-synthase genes in Korean patients with coronary artery disease and a new polymorphism in intron 7

We investigated polymorphisms of methylenetetrahydrofolate reductase (MTHFR) and cystathionine beta-synthase (CBS) genes in Korean patients with coronary artery disease (CAD) and identified a new polymorphism (c-->t) in intron 7 of the CBS gene using the single-strand conformation polymorphism method. No significant differences were found in allele frequencies for either gene between the CAD and normal groups although the frequency of the so-called thermolabile MTHFR polymorphism, a proposed risk factor for CAD, was higher in Koreans than in other populations studied. The relatively low incidence of CAD in Korea suggests that this MTHFR polymorphism is not causative in this population.

Caspase-mediated Cdk2 activation is a critical step to execute transforming growth factor-beta1-induced apoptosis in human gastric cancer cells

Although TGF-beta1, a growth inhibitor, is known to also induce apoptosis, the molecular mechanism of this apoptosis is largely undefined. Here, we identify the mechanism of TGF-beta1-induced apoptosis in SNU-16 human gastric cancer cells. Cell cycle and TUNEL analysis showed that, upon TGF-beta1 treatment, cells were initially arrested at the G1 phase and then driven into apoptosis. Of note, caspase-3 was activated in accordance with TGF-beta1-induced G1 arrest. Activated caspase-3 is targeted to cleave p21(cip1), p27(kip1), and Rb, which play important roles in TGF-beta-induced G1 arrest, into inactive fragments. Subsequently, Cdk2 was aberrantly activated due to the cleavage of p21 and p27. We found that the inhibition of Cdk2 activity efficiently blocks TGF-beta1-induced apoptosis, whereas it did not prevent caspase-3 activation or the subsequent cleavage of target proteins. In contrast, the suppression of caspase-3 activity inhibited the cleavage of target proteins, the activation of Cdk2, and the induction of apoptosis. Taken together, our results suggest that activation of caspase-3 by TGF-beta1 may initiate the conversion from G1 cell cycle arrest to apoptosis via the cleavage of p21, p27 and Rb, which in turn causes Cdk2 activation and, most significantly, Cdk2 activation as a downstream effector of caspase is a critical step for the execution of TGF-beta1-induced apoptosis.

Tuberculous versus pyogenic arthritis: MR imaging evaluation

PURPOSE

To assess magnetic resonance (MR) imaging features in differentiating tuberculous arthritis from pyogenic arthritis.

MATERIALS AND METHODS

Findings in 29 patients with tuberculous arthritis were compared with those of 13 patients with pyogenic arthritis. Bone erosion, marrow signal intensity, synovial lesion signal intensity, boundaries (smooth or irregular) for extraarticular extension of infection, and abscess rim enhancement (thin and smooth or thick and irregular) were analyzed.

RESULTS

Bone erosion was more common in patients with tuberculous arthritis (24 [83%] of 29) than in those with pyogenic arthritis (six [46%] of 13) (P =.026), while subchondral marrow signal intensity abnormality was seen more frequently in patients with pyogenic arthritis (12 [92%] of 13) than in those with tuberculous arthritis (17 [59%] of 29) (P =.036). On T2-weighted images, there was no significant difference between the synovial lesion signal intensities of tuberculous arthritis and pyogenic arthritis. Lesions in 16 (70%) of 23 patients with tuberculous arthritis and two (17%) of 12 patients with pyogenic arthritis had smooth extraarticular boundaries, while those in seven (30%) of 23 patients with tuberculous arthritis and 10 (83%) of 12 patients with pyogenic arthritis had irregular boundaries (P =.005). Tuberculous abscesses (16 [100%] of 16) had thin and smooth rim enhancement, while most pyogenic abscesses (five [71%] of seven) had thick and irregular rims (P =.001).

CONCLUSION

MR imaging of bone abnormalities, extraarticular lesions, and associated abscesses provides useful information in the differentiation of tuberculous arthritis and pyogenic arthritis.

Sonography of acute osteomyelitis in rabbits with pathologic correlation

RATIONALE AND OBJECTIVES

Ultrasonography (US) has a potential role in the diagnosis of osteomyelitis. The purpose of this study was to determine the characteristic sonographic features of acute osteomyelitis and correlate them with pathologic findings.

MATERIALS AND METHODS

An experimental model of acute osteomyelitis was produced in the tibiae of 20 rabbits. Daily US and plain radiography were performed for 2 weeks. The authors evaluated periosteal reaction, subperiosteal fluid collection, and soft-tissue changes seen with US. A hypoechoic band and a hyperechoic line lying along the cortex were considered positive signs of subperiosteal fluid collection and periosteal reaction, respectively. The findings of periosteal reaction were compared for US and radiography, and pathologic findings were also correlated.

RESULTS

The most common sonographic finding was a hypoechoic band along the cortex (21 [75%] of 28 tibiae), usually associated with a linear periosteal reaction (20 [71%] of 28). This juxtacortical abnormal echogenicity corresponded to periosteal elevation with loose fibrovascular connective tissue and granulation, associated with subperiosteal abscess formation. The periosteal reactions were detected with US before they were seen on radiographs. The periosteum showed gradual thickening during the disease process. In 50% of infected tibiae, inflammation or abscess formation was observed in the surrounding soft tissue.

CONCLUSION

US readily demonstrates juxtacortical abnormal echogenicity and soft-tissue infection related to acute osteomyelitis. The abnormal echogenicity correlated well with the pathologic findings of periosteal reaction and subperiosteal abscess.

Left atrial myxosarcoma with systemic metastasis: a case report

The term myxosarcoma is currently not used in standard classification for soft tissue tumors, but restricted to cardiac tumors. Primary cardiac myxosarcoma is a very rare disease and is difficult to differentiate from myxoma clinically and pathologically. We report a case of left atrial myxosarcoma with widespread systemic metastasis in a 21-yr-old male. The patient presented with sudden onset of intermittent dyspnea and orthopnea. Echocardiography showed a mobile, pedunculated tumor, 7.5x5x2 cm in size, at left atrium. Histologically, the excised tumor showed an amorphous finely fibrillar and mucinous stroma, in which irregular cords and clusters of lepidic cells and large stellate cells with plump vesicular nuclei resembled the usual type of cardiac myxoma were noted. And it showed focally cellular area with great nuclear pleomorphism and frequent mitoses. The patient received combination chemotherapy, peripheral blood stem cell collection transplantation and operations for systemic metastases in the brain, skeletal muscle and lung. He is alive at present 37 months after initial diagnosis and has no more new metastatic lesion.

Are there any links between Hop Japanese pollen and other weed pollens or food allergens on skin prick tests?

Recent investigations suggest that the importance of Hop Japanese pollen, which has been known as one of the major causative weed pollens, is increasing in this country. There have been few data dealing with the allergenic relationship between Hop J pollen and other food or inhalant allergens. Among 2909 patients who visited the Allergy Clinic of Ajou University Hospital, Suwon, Korea, 471 patients sensitized to Hop J, mugwort, or ragweed pollens on skin-prick test were enrolled. Positive rates to common inhalant or food allergens and their allergenic relationships with other pollens or food allergens were analyzed based upon skin-prick test results. The positive rates to sunflower, fat hen, nettle, grass (Bermuda, Orchard) and tree (alder, birch, and poplar) pollen were significantly higher in those sensitized to Hop J pollen than in those of negative responders (p < 0.05, respectively). No significant associations were noted with ragweed or mugwort pollen (p > 0.05, respectively). In regard to food-related allergens, an association was noted between Hop (Humulus lupulus) or celery allergens in those sensitized to Hop J pollen (p < 0.05, respectively). Hop J pollen may have possible links with celery, Hop, and sunflower pollens on skin-prick test. Further in vitro investigations will be needed to evaluate the possibility of cross-reacting components between them.

Effect of retinoids on growth inhibition of two canine melanoma cell lines

Two new canine melanoma cell lines (CMM1 and CMM2) were established from the patients with oral malignant melanomas. Histopathological type of both CMM1 and CMM2 was a mixed cell type consisted of spindle-shaped cells, polygonal cells, and oval cells. Doubling time of CMMI and CMM2 were 18.4 +/- 1.96 hr and 21.0 +/- 0.73 hr, respectively. The effect of two kinds of retinoids (all-trans retinoic acid and 9-cis retinoic acid) on the proliferation of these cells were examined by morphological changes, proliferation assay and apoptosis assay. However, the retinoids did not suppress growth rate of these cells. This result suggests that retinoids used in this study did not induce differentiation, apoptosis, and growth inhibition of the canine melanoma cell lines.