Relationship between smoking and spontaneously healed pulmonary TB on chest radiography in a South Korean population.

SETTING: The Korea National Health and Nutrition Examination Survey is a national, population-based, cross-sectional surveillance programme.OBJECTIVE: 1) To investigate the prevalence of spontaneously healed pulmonary tuberculosis (SHPTB) on chest radiographs (CXRs) in South Korea, as well as its demographic and clinical associations, and 2) to determine the relationship between SHPTB and smoking.DESIGN: People with normal findings on CXRs (n = 24 190) and those with SHPTB (n = 1863) were compared in univariate, bivariate and multivariate analyses with respect to smoking and demographic and clinical factors.RESULTS: The prevalence of SHPTB was 7.2%. The proportion of patients with SHPTB tended to be higher in males, people of older age, ever smokers, as well as people with low body mass index and low education level. In bivariate analysis, after adjustments for age and sex, SHPTB was found more often among ex-smokers (P = 0.005) and current smokers (P = 0.024) than in non-smokers. Multivariate analyses revealed increased relative odds for SHPTB with increased age (P < 0.001), male sex (P < 0.001) and ex-smoker status (P = 0.016). Passive smoking was also significantly associated with SHPTB (P = 0.022).CONCLUSION: In addition to increasing the risk of active TB and negatively affecting the outcome of TB treatment, smoking is also associated with SHPTB, as detected on CXRs.

Relationship between airway obstruction and C-reactive protein levels in a community-based population of Korea.

OBJECTIVE: To examine the relationship between high-sensitivity C-reactive protein (hs-CRP) levels and lung function in a community-based cohort of South Korea.DESIGN: The Ansung-Ansan cohort database (an ongoing prospective study of a community-based population) was used in the analysis. We defined airway obstruction as the ratio between forced expiratory volume in 1 sec:forced vital capacity ratio (FEV1:FVC) of <95% of the predicted value for a healthy person. We also used the serum level of hs-CRP as a marker of inflammation. Multivariate analysis was performed with adjustment for the clinical characteristics of the participants.RESULTS: A total of 5528 individuals were eligible for the study. The average age was 55.1 years, and 47.8% were males. The prevalence of airway obstruction was 9.0%, and the mean hs-CRP level was 1.51 mg/dl. Serum hs-CRP levels increased with the severity of airway obstruction, and the latter worsened with an increase in the hs-CRP level. In multivariate analysis, as the hs-CRP level increased, FEV1 and FVC decreased. A higher FEV1:FVC ratio was associated with lower hs-CRP levels in males.CONCLUSION: Higher hs-CRP levels were associated with decreased FEV1 and FVC in a general population of Korea. The FEV1:FVC ratio decreased with an increase in the hs-CRP level in males.

Association between genetic variants in the IRGM gene and tuberculosis in a Korean population.

PURPOSE: To investigate immunity-related guanosine triphosphatase family M (IRGM) genetic variants associated with susceptibility to tuberculosis (TB) in a Korean population. METHODS: We conducted a prospective case-control study including 193 patients with active TB in Severance Hospital and 230 age- and sex-matched unrelated controls registered in Yonsei Cardiovascular Genome Center. Based on associations with other chronic inflammatory conditions, we analyzed the allele and genotype frequencies of rs72553867, rs10065172, and rs12654043 among patients with TB and healthy controls. RESULTS: The T allele of rs10065172 was significantly associated with protection against developing TB based on allele frequency [P = 0.042; odds ratio (OR) 0.75] and genotype distribution in the codominant model (P = 0.036; OR 0.73). CONCLUSIONS: This is the first study to identify a significant association between the IRGM single-nucleotide polymorphism (SNP) rs10065172 and susceptibility to active TB disease in an Asian population. The results suggest that IRGM genetic variants could be associated with susceptibility to active TB disease in the Korean population.

Association between vitamin D deficiency and tuberculosis in a Korean population.

BACKGROUND: Several in vitro studies have been conducted regarding the immunomodulatory and mycobactericidal roles of vitamin D in tuberculous infection. However, discrepancies exist among epidemiological studies. We compared vitamin D deficiency between patients with tuberculosis (TB) and healthy control subjects and identified risk factors for vitamin D deficiency. METHOD: This was an age- and sex-matched case-control analysis of 94 TB cohort and 282 Korean national survey participants. RESULTS: The median baseline 25-hydroxyvitamin D (25[OH]D) level in the TB group (9.86 ng/ml, IQR 7.19-14.15) was lower than in controls (16.03 ng/ml, IQR 12.38-20.30, P < 0.001). The prevalence of severe vitamin D deficiency was higher in patients with TB (51.1%) than in controls (8.2%, P = 0.001). The median 25(OH)D level increased from 11.40 ng/ml (IQR 7.85-15.73) to 13.18 ng/ml (IQR 10.60-19.71) after treatment completion (P = 0.037). On multivariate analysis, presence of TB and history of TB were independently associated with severe vitamin D deficiency. CONCLUSION: Patients with TB had a higher prevalence of vitamin D deficiency than control subjects in a Korean population. The median 25(OH)D level increased after TB treatment. Further studies are needed to establish a causal relationship.

Natural nanocontainer for the controlled delivery of glycerol as a moisturizing agent.

Natural halloysite nanotubes with a 15-nm internal lumen and a 50 nm outer diameter were investigated as a nanocontainer for the loading and extended release of glycerol for cosmetic applications. Cytotoxicity testing of the halloysite was conducted on 3T3 and MCF-7 cells, and the tubules showed no toxic effect on the cells for over 48 h. The capability of halloysite for loading glycerol was higher with the USA halloysite than with the New Zealand's, being approximately 20% and 2.3% by weight, respectively. The total elapsed time for releasing glycerol from the nanotubes exceeded 20 h. To further retard the glycerol release rate, the halloysite samples filled with glycerol were coated with several alternate layers of polyethyleneimine and polyacrylic acid. The release rate remained at the same level, however, probably due to the low molecular weight of the polyelectrolytes and the high solubility of glycerol in water.

Concurrent reactivation of latent EBV with hepatitis A can affect clinical feature of childhood hepatitis.

AIMS: Some children with acute hepatitis A virus (HAV) infection have concurrent Epstein-Barr virus (EBV) reactivation serologically. We studied the frequency of EBV reactivation during HAV infection and determined whether simultaneous occurrence of EBV reactivation and HAV infection affected the clinical features of HAV infection. METHODS: The medical records of patients under 19 years of age diagnosed with acute hepatitis A between January 1996 and June 2009 were reviewed. RESULTS: Among 72 patients with acute hepatitis A, 22 patients (30.6%) had EBV reactivation. A markedly prolonged duration of full recovery from hepatitis was observed in reactivated group. The peak levels of AST and ALT in reactivated group were higher than non-reactivated group (p = 0.012 and p < 0.001, respectively). Higher peak levels of AST and ALT in reactivated subgroups over 10 years old were observed compared to non-reactivated subgroup (p = 0.027 and p = 0.001, respectively). Duration of recovery showed significant differences between two subgroups. CONCLUSIONS: Concurrent reactivation of latent EBV and HAV infections is common. EBV reactivation with HAV infection adversely affects the clinical feature of hepatitis. Therefore, we should keep in mind that the concurrence especially in older children may cause worse injury to the liver.

Three point method to characterize low-pressure electronegative discharges using electrostatic probe.

Electrostatic probe measurements for low-pressure inductively coupled SF(6) plasmas are performed. From the current-voltage (I-V) curves of probe, the saturation currents of the positive ions and electrons and the electron temperature are measured. The electronegativity and the negative ion density are deduced by using the ratios of these parameters at three adjacent pressure points. The positive ion density is calculated by the orbital-motion-limited theory, and the electron temperatures are given either by the slope of the I-V curves or by the electron energy distribution function with the second derivative of I-V curves. The variations in the charged species density with pressure and power are investigated.

Deduction of edge electron density with multiply charged ions in ORNL volume-type electron cyclotron resonance ion source.

The electron densities in the argon plasmas of the ORNL 6 GHz electron cyclotron resonance (ECR) ion source with a flat central magnetic field have been deduced from the ion branches of the electric probe current-voltage curves measured in the edge region of the plasmas. To overcome the difficulties due to unknown velocities of multiply charged ions at the sheath edge, a modified generalized Bohm criterion for the ion sheath velocity is introduced and the mean velocity of all ionic charge states at the sheath edge is assumed to be equal to the sound velocity of the system of particles. The calculated electron densities and temperatures for different plasmas optimized for four charge state distributions are discussed.

Development of LiF:Mg,Cu,Si TL material (new KLT-300) with a low-residual signal and high-thermal stability.

LiF-based thermoluminescence (TL) materials have been widely used for radiation dosimetry due to their attractive features. LiF:Mg,Cu,P is one of the most sensitive tissue-equivalent TL materials, approximately 40 times more sensitive than LiF:Mg,Ti (TLD-100), but it has two main drawbacks: a thermal loss of the TL sensitivity when annealed at temperatures>240 degrees C, and a relatively high-residual signal. Recently, LiF:Mg,Cu,Na,Si TL material was developed to overcome these drawbacks at the Korea Atomic Energy Research Institute, but it provided only marginal improvements in reducing the residual signal. The newly developed LiF:Mg,Cu,Si TL material has a significantly lower residual signal and a better stability to thermal treatments. In this article, the preparation method and some dosimetric properties (sensitivity and residual signal) of the new LiF:Mg,Cu,Si TL material are presented. At the end of the preparation procedures, a dual-step annealing method is introduced and this has proved as a very efficient method to reduce the high-temperature peak and is the cause of residual signal. Therefore, the high-temperature peak in the glow curve was significantly reduced. The sensitivity is approximately 20 times higher than that of TLD-100 and the residual signal was estimated to be approximately 0.04%.

Immunopotentiating effect of a Fomitella fraxinea-derived lectin on chicken immunity and resistance to coccidiosis.

This study reports a novel immunopotentiating effect of a lectin (FFrL) extracted from the mushroom Fomitella fraxinea on poultry cell-mediated immunity and poultry coccidiosis. We describe the extraction of FFrL, its in vitro mitogenic activity and in vivo protection against an oral challenge infection with Eimeria acervulina. When tested on several cell types, crude FFrL agglutinated mouse erythrocytes and thymocytes and various other cells including murine and human cell lines. However, crude FFrL did not agglutinate human erythrocytes. Crude FFrL showed a potent mitogenic activity on chicken splenic lymphocytes, and at lower concentrations it exerted stronger mitogenic activity than Concanavalin A, a well-known potent mitogen for lymphocytes. Further, FFrL significantly induced (P < 0.05) nitric oxide secretion in HD11 cells and suppressed (P < 0.05) RP9 tumor cell growth in a dose-dependent fashion. When injected into 18-d-old chicken embryos followed by a posthatch oral E. acervulina challenge infection, FFrL treatment significantly protected chickens against weight loss associated with coccidiosis (P < 0.05). Injecting embryos with FFrL also resulted in significant reduction in oocyst shedding as compared with the control saline-injected birds (P < 0.05). The results of this study demonstrate that FFrL can be an effective growth promoting and immunostimulating agent in poultry during coccidiosis.

On the roles of the dopants in LiF: Mg,Cu,Na,Si thermoluminescent material.

In this paper, some results of the study on the roles of the dopants in the LiF:Mg,Cu,Na,Si thermoluminescent (TL) material that was developed at the Korea Atomic Energy Research Institute for radiation protection are presented. Although there have been many studies to investigate the roles of the dopants in LiF:Mg,Cu,P TL material in the TL process, there are some discrepancies in the understanding of the roles of Cu and P between various researchers. In case of LiF:Mg,Cu,Na,Si TL material, there are a few studies on the roles of the dopants. Three kinds of samples in each of which one dopant is excluded, and the optimised sample, were prepared for this study. The measurements and analysis of the three-dimensional TL spectra, based on the temperature, wavelength and intensity, and the glow curves for those samples are used in this study. The results show that Mg plays a role in the trapping of the charge carriers and Cu plays a role in the luminescence recombination process; however, the effect of Na and Si on the glow curve structure and the TL emission spectra is much less than that of Mg and Cu. It is considered that Na and Si each plays a role in the improvement of the luminescence efficiency.

A computer program for the deconvolution of thermoluminescence glow curves.

A quick and efficient computer program was developed in order to resolve the peaks from the thermoluminescence (TL) glow curve. The program was designed to be easily used on any MS Windows-based computer with a graphical user interface. In this program, a new method based on the general one-trap TL equation was adopted to analyse the TL glow curve with the traditional first-order, second-order and general-order kinetics model. The method described here, general approximation, generates TL glow peaks and interpolates the relevant TL parameters from the glow data. The program was tested with simulated and experimental TL glow data and the results were found to be adequate and reliable.

Developments in the synthesis of LiF:Mg,Cu,Na,Si TL material.

A procedure for synthesis of the highly sensitive pellet-type LiF:Mg,Cu,Na,Si thermoluminescent (TL) detector has been newly developed. It was found that the optimum concentrations of dopants for a pellet-type LiF:Mg,Cu,Na,Si TL detector were found to be Mg: 0.2 mol %, Cu: 0.05 mol %, Na: 0.9 mol%, and Si: 0.9 mol%. The TL sensitivity of this new detector was about 30 times higher than that of the TLD-100 by light integration measurements. Reusability study of the detector was carried out for 10 cycles. The results show that the coefficients of variation for each detector separately did not exceed 0.016, and that for all 10 detectors collectively was 0.0054.

Dosimetric properties of the newly developed KLT-300 (LiF:Mg,Cu,Na,Si) TL detector.

The dosimetric properties of the newly developed KLT-300 (KAERI LiF:Mg,Cu,Na,Si TL detector) in KAERI (Korea Atomic Energy Research Institute) were investigated. The sensitivity of the TL detector was about 30 times higher than that of the TLD-100 by light integration. In the study of the dose linearity of the detector, the dose response was very linear up to 10 Gy and a sublinear response was observed at higher doses. The energy response of the detector was studied for photon energies from 20 to 662 keV. The results show that a maximum response of 1.004 at 53 keV and a minimum response of 0.825 at 20 keV were observed. The reproducibility study for the TL detector was also carried out. The coefficients of variation for each detector separately did not exceed 0.016, and for all the 10 detectors collectively it was 0.0054. IEC Standard requires that the coefficient of variation shall not exceed 0.075. So, the reproducibility of this new TL detector sufficiently satisfied the IEC requirements. A detection threshold of the detector was investigated and found to be 70 nGy by Harshaw 4500 TLD Reader.

Differences in embryonic development in sensitive and resistant matings to pregnancy block stimuli in mice.

Pregnancy block from exposure to foreign male mouse pheromones is sensitive to both male and female mating strain, as well as the foreign male pheromone-producing strain. Incidence of pregnancy block by male pheromones in mice is different depending on the combination of females, stud males and stimulus males. BALB/cA females mated with BALB/cA males showed a 100% pregnancy block when exposed to males of the DDK strain (Chung et al., 1997). In contrast, BALB/cA females mated with males of dissimilar strain show high rates of pregnancy even if they are exposed to DDK males; this difference is thought to be due to the difference in viability of embryos (Chung et al., 1999). The present study investigated how development of BALB/cA and F1 embryos differ under the influence of pregnancy block stimuli. F1 embryos had significantly higher numbers of cells than did the BALB/cA embryos (P<0.05) at day 3 of pregnancy after exposure to DDK males or after bromocriptine (dopamine agonist, 4 mg kg(-1), i.p.) treatment. Histological observation after bromocriptine treatment revealed that: (i) on day 4 of pregnancy, BALB/cA embryos tended to form a large blastocoel, but showed abnormalities such as degeneration of primitive endoderm and depression of the outer trophoblast-distal endoderm layer at the periphery of the inner cell mass (ICM) or detachment of the ICM from the outer layer. In contrast, 60-70% of F1 embryos were normal late blastocysts and incipient egg cylinders, but 28-40% of early blastocysts were degenerating; and (ii) day 5 BALB/cA embryos were in the range from incipient egg cylinder with a large proamniotic cavity to ectoplacental cone only, but their proximal endoderm and trophoblast-distal endoderm layer were degenerating. In contrast, the F1 embryos were mostly at the egg cylinder stage and maintained normal structure except for occasional enlargement of the developing yolk sac cavity. These results indicate that the lining of the inner surface of trophoblast by distal endoderm layer may be more firmly established and that the inner environment for development of F1 embryos may be more effectively maintained, thereby making them more resistant to deleterious influences due to pregnancy block stimuli than are BALB/cA embryos.

Analysis of the glow curves obtained from LiF:Mg,Cu,Na,Si TL material using the general order kinetics model.

Three-dimensional thermoluminescence (TL) spectra based on temperature, wavelength and intensity for newly developed LiF:Mg,Cu,Na,Si TL material at the Korea Atomic Energy Research Institute (KAERI) were measured and analysed. The glow curves were obtained by integration of luminescence intensity over all wavelengths at each temperature, and various trapping parameters related to the traps were determined by analysing these curves. A computerised glow curve deconvolution (CGCD) method which was based on the general order kinetics (GOK) model was used for the glow curve analysis. The glow curves of LiF:Mg,Cu,Na,Si TL material were deconvoluted to six isolated glow curves which have peak temperatures at 333, 374, 426, 466, 483 and 516 K. The main glow peak of peak temperature at 466 K had activation energy of 2.06 eV and a kinetic order of 1.05. This TL material was also found to have three recombination centres, 1.80 eV, 2.88 eV and 3.27 eV by analysis of the TL spectra.

Pleckstrin homology domain interacts with Rkp1/Cpc2, a RACK1 homolog, to modulate Pck2-mediated signaling process in Schizosaccharomyces pombe.

Rkp1/Cpc2, a fission yeast RACK1 homolog, interacts with Pck2, a PKC homolog, and is involved in the regulation of pck2-mediated signaling process. The N-terminal region of split pleckstrin homology domain (nPH) in human PLC-gamma1 bound to Rkp1/Cpc2 concomitantly with Pck2. nPH inhibited kinase activity of GST-Pck2 purified from Schizosaccharomyces pombe in vitro. The lethality induced by pck2(+) overexpression was suppressed by coexpression of either rkp1(+) or nPH domain. This result suggests that Rkp1/Cpc2 interacts with PH domain-containing protein and regulates the Pck2-mediated signaling process in S. pombe.

In vitro development of reconstructed bovine embryos and fate of donor mitochondria following nuclear injection of cumulus cells.

In this study we examined the developmental potential of reconstructed embryos and the fate of donor mitochondria during preimplantation development after nuclear transfer in cattle. Isolated cumulus cells were used as donor cells in nuclear transfer. Cumulus cells labelled with MitoTracker Green FM fluorochrome were injected into enucleated bovine MII oocytes and cultured in vitro. MitoTracker labelling on donor cells did not have a detrimental effect on blastocyst formation following nuclear transfer. Cleavage rate was about 69% (56/81) and blastocyst formation rate was 6.2% (5/81) at 7 days after nuclear transfer. The labelled mitochondria dispersed to the cytoplasm and became distributed between blastomeres and could be identified up to the 8- to 15-cell stage. Small patches of mitochondria were detected in some 8- to 15-cell stage embryos (5/20). However, donor mitochondria were not detected in embryos at the 16-cell stage and subsequent developmental stages. In the control group, mitochondria could be identified in arrested 1-cell embryos up to 7 days after nuclear transfer. These results suggest that disappearance of the labelled donor mitochondria in nuclear transfer bovine embryos is not due to fading of the fluorochrome marker, but is rather an as yet undefined cytoplasmic event.

Helicobacter pylori infection in Korea.

Helicobacter pylori is a gram-negative bacterium that was first isolated in 1982. Since then, H. pylori infection in humans has been shown to be associated with gastritis, peptic ulcer disease, gastric carcinoma, and mucosa-associated lymphoid tissue (MALT) lymphoma as well. The epidemiology, transmission, and pathogenicity of H. pylori has been a subject of intensive study. Successful treatment improves the cure rate of peptic ulcerations and treatment with antimicrobials also decreases the recurrence rate of these diseases. Better regimens having less toxicity and a good eradication rate have also been developed. A better understanding of the pathophysiologic mechanisms relating to H. pylori induced mucosal damages would result in more options for the prevention of peptic ulcers and carcinogenesis. Korea has a relatively high incidence of H. pylori infection and gastric cancer. Growing interest has developed in view of its importance in being associated with various gastroduodenal diseases. Furthermore, along with a high incidence of H. pylori-related disease in Korea, because the interaction between H. pylori, host factors and environmental factors is important in disease pathogenesis, we need to have precise data on the characteristics of H. pylori-related diseases that occur in Korea. In the present report we review the epidemiology, transmission route, diagnosis, pathogenesis, treatment methods and relationship with gastroduodenal diseases with in special references to basic and clinical data that have been published.