Detection and typing of vancomycin-resistance genes of enterococci from clinical and nosocomial surveillance specimens by multiplex PCR

Ninety-three clinical isolates of vancomycin-resistant enterococci (VRE) collected from nine hospitals in Taiwan were examined for the presence of vanA, vanB, vanC1, or vanC2/vanC3 genes by a multiplex PCR. Forty-seven of these VRE isolates were vanA positive, 1 contained both vanC1 and vanA, 40 harboured vanB, 2 were vanC1, and 3 were identified to be vanC2/vanC3. Twenty-four vanA isolates were sensitive to teicoplanin and thus did not have a typical VanA phenotype. Five isolates with the VanC phenotype harboured vanB. None of the 40 clinically isolated vancomycin-susceptible E. faecium or E. faecalis and the vancomycin-resistant Leuconostoc and Pediococcus isolates were positive for any of the van genes. While performing nosocomial surveillance, VRE were isolated from 47 of 467 rectal swabs by culture. Compared with the conventional culture method, the sensitivity and specificity of the multiplex PCR for detecting and identifying vancomycin-resistance genes in enterococci directly from culture-positive broth were 97.9% and 100%, respectively. The results suggest that genotypic characterization of vancomycin-resistance is necessary for all clinical VRE isolates and that the multiplex PCR assay can be an alternative method for this purpose.

Reperfusion pulmonary edema after pulmonary endarterectomy

Pulmonary artery thromboendarterectomy is a potentially curative procedure in chronic, major vessel thromboembolic pulmonary hypertension. However, persistent pulmonary hypertension and unrelenting reperfusion edema have serious complications, often requiring prolonged mechanical ventilation. A 50-year-old man who was diagnosed with a thromboembolism in both pulmonary arteries underwent a bilateral pulmonary endarterectomy. He received O2-isoflurane-fentanyl anesthesia. When the lungs were reperfused with CPB weaning, massive hemorrhage occurred in the left lung. After the operation, the patient was taken to the intensive care unit. Mechanical ventilation was performed immediately and then both inhaled NO and i.v. furosemide therapies were administered. The patient was discharged from ICU 15 days postoperation.

Distribution and cytokine production of CD4 and CD8 T-lymphocyte subsets in patients with acute asthma attacks

BACKGROUND

The activation of T cells and the elevation of Th2-type cytokines have been observed in asthmatic patients, but the relative role of CD4 and CD8 T cell is still unclear.

OBJECTIVE

To investigate the role of T cell subset in patients with acute asthma attacks, we analyzed the distribution, activation status, and cytokine production of CD4 and CD8 cells.

METHODS

The percentages of the CD4 and CD8 cell in peripheral blood (PB) and bronchoalveolar lavage (BAL) fluid were analyzed by flow cytometry. The cytokines (IL-4, IL-5, and IFN-gamma) and soluble IL-2 receptor (sIL-2R) were measured by ELISA in culture supernatants of CD4 and CD8 cells purified from PB.

RESULTS

The CD4/CD8 ratio in PB of asthmatic patients was significantly higher than that of controls, which was significantly reduced after treatment. In contrast, there was a tendency to high percentage of CD8 cells in asthmatic patients as compared with controls in BAL, which resulted in a decreased CD4/CD8 ratio. Comparing the T cell subsets in BAL with paired PB in asthma, the CD4 cells were higher in PB, but CD8 cells were higher in BAL. The IL-4, IL-5, and sIL-2R produced by CD4 cells were significantly higher than those produced by CD8 cells in asthmatic patients.

CONCLUSIONS

Our results provide evidence that activated CD4 T cells increase and produce type 2 cytokines in PB, but CD8 T cell are more sequestrated than CD4 T cells in the airway during an acute asthma attack.

An application of artificial neural intelligence for personal dose assessment using a multi-area OSL dosimetry system

Significant advances have been made in recent years to improve measurement technology and performance of phosphor materials in the fields of optically stimulated luminescence (OSL) dosimetry. Pulsed and continuous wave OSL studies recently carried out on alpha-Al2O3:C have shown that the material seems to be the most promising for routine application of OSL for dosimetric purposes. The main objective of the study is to propose a new personal dosimetry system using alpha-Al2O3:C by taking advantage of its optical properties and energy dependencies. In the process of the study, a new dose assessment algorithm was developed using artificial neural networks in hopes of achieving a higher degree of accuracy and precision in personal OSL dosimetry system. The original hypothesis of this work is that the spectral information of X- and gamma-ray fields may be obtained by the analysis of the response of a multi-element system. In this study, a feedforward neural network using the error back-propagation method with Bayesian optimization was applied for the response unfolding procedure. The validation of the proposed algorithm was investigated by unfolding the 10 measured responses of alpha-Al2O3:C for arbitrarily mixed photon fields which range from 20 to 662 keV.

Melittin exerts multiple effects on the release of free fatty acids from L1210 cells: lack of selective activation of phospholipase A2 by melittin

Melittin is known as a phospholipase A2 (PLA2) activator, but the selectivity of its effect on PLA2 is uncertain. We examined the selectivity of melittin effect on the release of free fatty acids (FFAs) from L1210 cells using various inhibitors. A systemic lipid analysis by HPLC and GLC revealed that melittin induced release of various FFAs including saturated, monounsaturated, and polyunsaturated FFAs. Various PLA2 inhibitors examined exerted only minimal effects on the melittin-induced arachidonic acid (AA) and palmitic acid (PAL) releases. Specific inhibitors of phosphatidylinositol-phospholipase C (U73122) and diacylglycerol lipase (RHC80267) exerted significant inhibitory effects on both AA and PAL releases. These results suggest that melittin-induced FFA release is most likely due to multiple participations of various types of lipases. Since BAPTA/AM, an intracellular Ca2+ chelator, did not influence the FFA release, the Ca2+ influxed by melittin appeared not to be a key factor for the FFA release. The mimicking of the melittin-induced FFA release by digitonin, a membrane-permeabilizing agent, implies that the membrane-perturbing action of melittin is likely the cause of the FFA release. Melittin also induced release of multiple FFAs from other cell lines including P388D1 and HL60. The rapid melittin-stimulated phospholipase D (PLD) observed in L1210 cells appeared not directly related to the steady release of FFA, as indicated by the fact that the PLD was not blocked by RHC80267. In view of melittin's multiple effects on the composition of cellular lipids, we conclude that melittin does neither exclusively release any single FFA nor selectively activate PLA2 in L1210 cells. The problem of using melittin as a PLA2 activator is discussed.

Primary endobronchial leiomyosarcoma. Diagnosis following expectoration of tumor fragment

A case is presented with spontaneous expectoration of a small piece of solid tissue. Pathologic examination of the expectorated tissue was found to be consistent with leiomyosarcoma. After further work-up, there was no evidence of another primary site of leiomyosarcoma except for the right lower lobe. Right lower lobectomy was performed. The surgical specimen showed a tumor that was histologically identical to the patient's previous expectorated tissue. To the authors' knowledge, this is the first report of partial expectoration of a primary endobronchial leiomyosarcoma.

Crystal structure of activated CheY. Comparison with other activated receiver domains

The crystal structure of BeF(3)(-)-activated CheY, with manganese in the magnesium binding site, was determined at 2.4-A resolution. BeF(3)(-) bonds to Asp(57), the normal site of phosphorylation, forming a hydrogen bond and salt bridge with Thr(87) and Lys(109), respectively. The six coordination sites for manganese are satisfied by a fluorine of BeF(3)(-), the side chain oxygens of Asp(13) and Asp(57), the carbonyl oxygen of Asn(59), and two water molecules. All of the active site interactions seen for BeF(3)(-)-CheY are also observed in P-Spo0A(r). Thus, BeF(3)(-) activates CheY as well as other receiver domains by mimicking both the tetrahedral geometry and electrostatic potential of a phosphoryl group. The aromatic ring of Tyr(106) is found buried within a hydrophobic pocket formed by beta-strand beta4 and helix H4. The tyrosine side chain is stabilized in this conformation by a hydrogen bond between the hydroxyl group and the backbone carbonyl oxygen of Glu(89). This hydrogen bond appears to stabilize the active conformation of the beta4/H4 loop. Comparison of the backbone coordinates for the active and inactive states of CheY reveals that only modest changes occur upon activation, except in the loops, with the largest changes occurring in the beta4/H4 loop. This region is known to be conformationally flexible in inactive CheY and is part of the surface used by activated CheY for binding its target, FliM. The pattern of activation-induced backbone coordinate changes is similar to that seen in FixJ(r). A common feature in the active sites of BeF(3)(-)-CheY, P-Spo0A(r), P-FixJ(r), and phosphono-CheY is a salt bridge between Lys(109) Nzeta and the phosphate or its equivalent, beryllofluoride. This suggests that, in addition to the concerted movements of Thr(87) and Tyr(106) (Thr-Tyr coupling), formation of the Lys(109)-PO(3)(-) salt bridge is directly involved in the activation of receiver domains generally.

[Removal of the 3'- and 5'-untranslated region amplifies expression of the erythropoietin gene in mammalian cells]

The effect of the 5T- and 3T-untranslated regions (UTR) of human erythropoietin gene (gEpo) on its expression in mammalian cells was investigated. 5T-UTR-deleted, 3T-UTR-deleted, and 5T,3T-UTR-deleted gEpos were transfected into COS-7 cells, and the amount of transiently expressed Epo was measured. Cells transfected with the 5T,3T-UTR-deleted gEpo showed the highest expression, 2.6 times that with wild-type gEpo. Northern blot analysis indicated that the enhanced expression of 5T,3T-UTR-deleted gEpo might be related with the transcription efficiency.

Colour stability of a new light-cured ceramic stain system subjected to glazing temperature

A light-cured ceramic stain system (Orbit LC) offers promise as an effective method for surface characterization of ceramic restorations. This study evaluated colour change after glazing procedures for six commonly used stains from this novel system. One hundred and five ceramic specimens were made of the same enamel porcelain powder and standardized in size. The stains were applied on ceramic blocks and light-cured according to the manufacturer's recommendations. Porcelain colour was then measured with a calibrated colorimeter before and after each glazing procedure. The CIEL*a*b* colour co-ordinates were obtained as a measure of the direction and magnitude of colour change. Colour changes were noted for all six stains when subjected to the first glazing procedure (DeltaE* = 1.25-4.73). Brown, orange and green stains showed the greatest colour shifts (DeltaE* > 3.3), which might be considered clinically significant. However, the colour change is not of the same pattern in the colour space. Compared with the first glazing procedure, the second and third glazing procedures demonstrated less effect on the colour stability of the stains (DeltaE* = 0.36-1.12). The results provide important information about colour shifts in the system, which require overcorrection during stain application.

Fine needle aspiration cytology of late-stage callus in stress fracture. A case report

BACKGROUND

Fine needle aspiration cytology (FNAC) is effective in the diagnosis of bone lesions when combined with careful radiologic and clinical evaluation. The cytologic features of callus have not been described before in the English-language literature.

CASE

An 18-year-old female presented with a pain in the right lower leg that had been present for two months. Clinical and radiologic findings suggested either stress fracture or periosteal osteosarcoma. The aspiration specimen showed individually scattered, oval cells with moderate amounts of pale pink cytoplasm. The cells contained a single eccentrically located nucleus with evenly distributed, fine chromatin. Osteoclastic giant cells were scattered in the smears. A cytologic diagnosis of benign bone-forming lesion, compatible with callus in fracture, was made. The diagnosis of late-stage callus was confirmed by subsequent histologic examination.

CONCLUSION

Typical cases of stress fracture do not need histologic examination, but some cases may be confused with benign and malignant bone tumors. The typical and unique cytologic features of late-stage callus combined with clinical and radiologic findings may prevent the use of more invasive diagnostic procedures and can be a choice for management.

Levels of PCDDs and PCDFs in two kinds of fast foods in Korea

We initiated an attempt to gather preliminary Korean fast food data on the concentrations, whole weight and international toxic equivalent (TEQ), in two kinds of fast foods, hamburger and fried chicken. The levels of polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs) in hamburgers are detected to be lower than in fried chickens. Total TEQ level of PCDDs in fried chicken is 47.45 times higher than in hamburger. In case of PCDFs, it is 48.61 times. Even though these are compared to the only one brand and three samples each, we think that these high levels of PCDDs/PCDFs in fried chicken are very important data because of the potentially increasing daily intake. If we continue to survey for PCDDs/PCDFs in fast foods more even, especially fried chicken, these data will be useful to calculate the estimated daily intake of TEQ levels of PCDDs/PCDFs in Korea.

A simple and efficient in vitro method for metabolism studies of radiotracers

In vitro metabolism of acetylcholinesterase inhibitors containing 3-[(18)F]fluoromethylbenzyl- ([(18)F]1) and 4-[(18)F]fluorobenzyl-piperidine moieties ([(18)F]2) was studied and compared with the in vivo metabolism. Defluorination of the [(18)F]1 mainly occurred to generate [(18)F]fluoride ion both in vitro and in vivo. In contrast, the [(18)F]2 was converted into an unknown polar metabolite in both metabolism methods and another metabolite, 4-[(18)F]fluorobenzoic acid in vitro. These results demonstrated that the in vitro method can be used to predict the in vivo metabolism of both radiotracers.

The survey of PCDDs and PCDFs in the ambient air of the urban and industrial sites in Korea, 1998-99

A comprehensive quality survey for PCDDs/PCDFs in ambient air has been studied in Korea for two years. Monitoring was undertaken at two locations throughout Seoul (urban site) and Incheon (industrial site) in winter and spring. The periods are during 16 to 17 March 1998, 21 to 22 January 1999 and 28 to 29 April 1999 (Seoul) and 25 to 26 March 1998, 18 to 19 January 1999 and 26 to 27 April 1999 (Incheon). The values of PCDDs/PCDFs in ambient air were expressed as concentrations and international TEF values. The contents of PCDDs/PCDFs in urban site (Seoul) were lower than in industrial site (Incheon). The measurements in wintertime were higher than in springtime. The contents of 2,3,4,7,8-PeCDF with half toxicity of 2,3,7,8-TCDD were high. Thus we assumed to have an interest to the contents of 2,3,4,7,8-PeCDF. In this study, sample size was small (sample number was only 18) and sampling period was limited by 24 h. Therefore, we need more widespread and long-term surveys in order to estimate the human exposure by inhalation.

Helium in one-dimensional nanopores: free dispersion, localization, and commensurate/incommensurate transitions with nonrigid orbitals

The single-particle states of helium within a bundle of carbon nanotubes can range from nearly free-particle dispersion to localization, even within a single bundle. At intermediate effective masses, the corrugation in the external potential can be comparable to the intrasite He-He hard-core interaction. This results in a commensurate/incommensurate transition, where the mobility of the doubly occupied domain-wall solitons at high density greatly exceeds the corresponding hole mobility below the transition.

Production of microbial polyester by fermentation of recombinant microorganisms

Polyhydroxyalkanoates (PHAs) can be produced from renewable sources and are biodegradable with similar material properties and processibility to conventional plastic materials. With recent advances in our understanding of the biochemistry and genetics of PHA biosynthesis and cloning of the PHA biosynthesis genes from a number of different bacteria, many different recombinant bacteria have been developed to improve PHA production for commercial applications. For enhancing PHA synthetic capacity, homologous or heterologous expression of the PHA biosynthetic enzymes has been attempted. Several genes that allow utilization of various substrates were transformed into PHA producers, or non-PHA producers utilizing inexpensive carbon substrate were transformed with the PHA biosynthesis genes. Novel PHAs have been synthesized by introducing a new PHA biosynthesis pathway or a new PHA synthase gene. In this article, recent advances in the production of PHA by recombinant bacteria are described.

Gastric lymphangioma

Gastric lymphangioma is a rare benign gastric tumor composed of unilocular or multilocular lymphatic spaces. On gastrofiberscopy a submucosal tumor covered with smooth transparent normal mucosa is revealed in the stomach with or without a stalk. Endoscopic ultrasonography has become an indispensable tool for differentiating these gastric tumors. Treatment of lymphangioma depends on its size, location, and presence of complications. Endoscopic resection is safe and easy and plays an important role in confirming the diagnosis and treatment of the tumors especially of small-sized ones. We report a case of gastric lymphangioma in a 68-yr-old woman who presented with nausea and vague epigastric discomfort for two months. She was diagnosed by gastrofiberscopy with endoscopic ultrasonography and treated successfully with endoscopic resection by strip biopsy method.

Effects of gentamicin and pH on [Ca2+]i in apical and basal outer hair cells from guinea pigs

Aminoglycosides are widely used antibiotics and frequently produce acute ototoxicity. In this study we attempted to comparatively investigate the effects of gentamicin on Ca2+ influx of apical and basal outer hair cells (OHCs) isolated from guinea-pig cochlea. Since the solution of gentamicin sulfate salt is acidic (pH 3.1-3.3), we also explored the effect of external acidification on Ca2+ influx. By means of fura-2 microspectrofluorimetry, we measured the intracellular calcium concentration ([Ca2+]i) of OHCs bathed in Hanks' balanced salt solution (pH 7.40) during either a resting state or high K+-induced depolarization. Our results show that at the resting state, the baseline [Ca2+]i in apical OHCs (94+/-2.0 nM) was slightly lower than that in basal OHCs (101.1+/-2.4 nM). By contrast, the increase in [Ca2+]i evoked by high K+ depolarization in apical OHCs was about two-fold greater than that in basal OHCs. Nifedipine (30 microM) abolished the increased [Ca2+]i in both types of OHCs, suggesting that Ca2+ influx was mainly through L-type Ca2+ channels of OHCs. While gentamicin and extracellular acidification (pH 7.14) can separately attenuate this increase in [Ca2+]i in both types of OHCs, their suppressive effects are additive in basal OHCs, but not in apical OHCs. The implications of these findings are that: (1) apical and basal OHCs behave differently in response to depolarization-increased [Ca2+]i, and (2) basal OHCs are more vulnerable to the impairment of Ca2+ entry during depolarization by a combination of gentamicin and extracellular acidification, which is correlated with the clinical observation that ototoxicity of aminoglycosides at the basal coil of OHCs is more severe than that at the apical coils. Moreover, the possibility that extracellular acidification may enhance the acute ototoxic effects of aminoglycosides should be considered especially in topical applications.

Suppression by a sesquiterpene lactone from Carpesium divaricatum of inducible nitric oxide synthase by inhibiting nuclear factor-kappaB activation

Excessive nitric oxide (NO) produced by inducible NO synthase (iNOS) acts as a causative regulator in various inflammatory disease states. Carpesium divaricatum has been used in Korean traditional herbal medicine for its antipyretic, analgesic, vermifugic, and anti-inflammatory properties. We investigated the molecular mechanism for the suppression of lipopolysaccharide/interferon-gamma (LPS/IFN-gamma)-induced NO production in RAW 264.7 macrophages by the sesquiterpene lactone 2beta,5-epoxy-5,10-dihydroxy-6alpha-angeloyloxy-9beta-isobutyloxy-germacran-8alpha,12-olide (C-1), which has been identified recently as a new compound from C. divaricatum. C-1 decreased NO production in LPS/IFN-gamma-stimulated RAW 264.7 cells in a concentration-dependent manner, with an IC50 of approximately 2.16 microM; however, it had no direct effect on the iNOS activity of fully LPS/IFN-gamma-stimulated RAW 264.7 cells. Furthermore, treatment with C-1 led to a decrease in iNOS protein and mRNA. These effects appear to be due to inhibition of nuclear factor-kappaB (NF-kappaB) activation through a mechanism involving stabilization of the NF-kappaB/inhibitor of the kappaB (I-kappaB) complex, since inhibition of NF-kappaB DNA binding activity by C-1 was accompanied by a parallel reduction of nuclear translocation of subunit p65 of NF-kappaB and I-kappaBalpha degradation. Taken together, the results suggest that the ability of C-1 to inhibit iNOS gene expression may be responsible, in part, for its anti-inflammatory effects.

Murine model of atopic dermatitis associated with food hypersensitivity

BACKGROUND

Atopic dermatitis (AD) is an eczematous skin eruption that generally begins in early infancy and affects up to 12% of the population. The cause of this disorder is not fully understood, although it is frequently the first sign of atopic disease and is characterized by an elevated serum IgE level, eosinophilia, and histologic tissue changes characterized early by spongiosis and a CD4(+) T(H)2 cellular infiltrate. Hypersensitivity to foods has been implicated as one causative factor in up to 40% of children with moderate-to-severe AD.

OBJECTIVE

The purpose of this study was to establish a murine model of food-induced AD.

METHODS

Female C3H/HeJ mice were sensitized orally to cow's milk or peanut with a cholera toxin adjuvant and then subjected to low-grade allergen exposure. Histologic examination of skin lesions, allergen-specific serum Ig levels, and allergen-induced T-cell proliferation and cytokine production were examined.

RESULTS

An eczematous eruption developed in approximately one third of mice after low-grade exposure to milk or peanut proteins. Peripheral blood eosinophilia and elevated serum IgE levels were noted. Histologic examination of the lesional skin revealed spongiosis and a cellular infiltrate consisting of CD4(+) lymphocytes, eosinophils, and mast cells. IL-5 and IL-13 mRNA expression was elevated only in the skin of mice with the eczematous eruption. Treatment of the eruption with topical corticosteroids led to decreased pruritus and resolution of the cutaneous eruption.

CONCLUSION

This eczematous eruption resembles AD in human subjects and should provide a useful model for studying immunopathogenic mechanisms of food hypersensitivity in AD.

Development of a personal dosimetry system based on optically stimulated luminescence of alpha-Al2O3:C for mixed radiation fields

To develop a personal optically stimulated luminescence (OSL) dosimetry system for mixed radiation fields using alpha-Al2O3:C, a discriminating badge filter system was designed by taking advantage of its optically stimulable properties and energy dependencies. This was done by designing a multi-element badge system for powder layered alpha-Al2O3:C material and an optical reader system based on high-intensity blue light-emitting diode (LED). The design of the multielement OSL dosimeter badge system developed allows the measurement of a personal dose equivalent value Hp(d) in mixed radiation fields of beta and gamma. Dosimetric properties of the personal OSL dosimeter badge system investigated here were the dose response, energy response and multi-readability. Based on the computational simulations and experiments of the proposed dosimeter design, it was demonstrated that a multi-element dosimeter system with an OSL technology based on alpha-Al2O3:C is suitable to obtain personal dose equivalent information in mixed radiation fields.

Binding of oral streptococci to human fibrinogen

The interaction of oral streptococci with human fibrinogen was investigated. Streptococcus gordonii was chosen as a representative species to study the binding to fibrinogen. S. gordonii DL1 adhered to immobilized fibrinogen and bovine serum albumin. Binding to immobilized fibrinogen was saturable, concentration and temperature dependent. The binding of S. gordonii DL1 to fibrinogen was inhibited by anti-fibrinogen antibody. Heating of the bacteria for 1 h at 95 degrees C resulted in 90% inhibition of the binding. Trypsin treatment of the bacteria resulted in decreased binding. Neither lipoteichoic acid nor culturing of the bacteria in a sucrose-supplemented medium had any effect on the binding. S. gordonii, Streptococcus sanguinis, Streptococcus mitis, and Streptococcus oralis bound to the immobilized fibrinogen, but mutans streptococci did not. None of the oral streptococci tested bound to the fibrinogen in fluid phase. These results suggest that the binding of S. gordonii DL1 to immobilized fibrinogen is mediated through a specific protein adhesin-receptor interaction, and fibrinogen acts as a cryptitope.

Hepatitis C virus core protein potentiates c-Jun N-terminal kinase activation through a signaling complex involving TRADD and TRAF2

The hepatitis C virus (HCV) core protein is a multifunctional viral nucleocapsid protein. Previously, it has been demonstrated that the HCV core protein interacts with the cytoplasmic domain of tumor necrosis factor receptor 1 (TNFR1). Since the TNFR1 is engaged in stimulation of transcriptional factor NF-kappaB and AP-1 through activation of IkappaB kinase and c-Jun N-terminal kinase (JNK, or stress-activated protein kinase), respectively, we have examined whether the interaction between core protein and TNFR1 can modulate JNK. In this study, we demonstrate that the HCV core protein synergistically activates TNFalpha-induced JNK at a core concentration dependent manner in human embryonic kidney (HEK) 293 cells. HCV core-mediated synergism of JNK activation was also detected in stable cells expressing HCV core protein. Furthermore, we demonstrate that HCV core protein does not compete with TNF receptor-associated death domain (TRADD) for its interaction with the death domain of TNFR1. Our in vivo data show that HCV core and TRADD form a ternary complex with TNFR1. These findings suggest that the HCV core protein modulates TNFR1 signaling and may, thus, play a role in chronic infection of HCV patients.