Effects of quorum quenching on temporal succession of activated sludge microbial community in a membrane bioreactor.

AIMS: Quorum quenching (QQ) is an attractive strategy for mitigating biofouling in membrane bioreactors (MBRs). However, the effects of QQ on the activated sludge (AS) process have not been adequately evaluated. This study investigated the long-term effects of QQ on a laboratory-scale anoxic-oxic MBR, focusing on AS performance and microbial community. METHODS AND RESULTS: Anoxic-oxic MBRs with and without QQ were operated for 91 days. QQ did not affect COD and TN removal efficiencies over the experimental period, during which its activity remained >90%. QQ reduced floc size by approximately 8% but had no effect on biomass concentration. AS microbial communities were regularly analysed using massively parallel sequencing. AS bacterial communities were temporally dynamic irrespective of QQ presence, for example, a temporal increase in bacterial diversity and a temporal decay of community similarity. QQ counteracted the temporal change in diversity and the temporal distance-community decay. Community comparison revealed that QQ changed the successional trajectory of the AS community at a late period, because it decelerated temporal changes of specific members, such as Thiothrix and Sphingomonadaceae*. Correlation networks revealed that QQ increased network clustering, complexity and density. The combined results suggest that the tighter microbial association by QQ increased the community resistance. CONCLUSIONS: QQ can enhance the diversity and stability of the AS community in MBR by counteracting the innate temporal change in community structure. SIGNIFICANCE AND IMPACT OF THE STUDY: Our findings are useful for the further advancement of QQ-based strategies in engineered microbial environments.

Mesoscopic Energy Minimization Drives Pseudomonas aeruginosa Biofilm Morphologies and Consequent Stratification of Antibiotic Activity Based on Cell Metabolism.

Segregation of bacteria based on their metabolic activities in biofilms plays an important role in the development of antibiotic resistance. Mushroom-shaped biofilm structures, which are reported for many bacteria, exhibit topographically varying levels of multiple drug resistance from the cap of the mushroom to its stalk. Understanding the dynamics behind the formation of such structures can aid in design of drug delivery systems, antibiotics, or physical systems for removal of biofilms. We explored the development of metabolically heterogeneous Pseudomonas aeruginosa biofilms using numerical models and laboratory knockout experiments on wild-type and chemotaxis-deficient mutants. We show that chemotactic processes dominate the transformation of slender and hemispherical structures into mushroom structures with a signature cap. Cellular Potts model simulation and experimental data provide evidence that accelerated movement of bacteria along the periphery of the biofilm, due to nutrient cues, results in the formation of mushroom structures and bacterial segregation. Multidrug resistance of bacteria is one of the most threatening dangers to public health. Understanding the mechanisms of the development of mushroom-shaped biofilms helps to identify the multidrug-resistant regions. We decoded the dynamics of the structural evolution of bacterial biofilms and the physics behind the formation of biofilm structures as well as the biological triggers that produce them. Combining in vitro gene knockout experiments with in silico models showed that chemotactic motility is one of the main driving forces for the formation of stalks and caps. Our results provide physicists and biologists with a new perspective on biofilm removal and eradication strategies.

Comparison of clinical outcomes of patients with serial negative surveillance cultures according to a subsequent polymerase chain reaction test for carbapenemase-producing Enterobacterales.

BACKGROUND: Carbapenemase-producing Enterobacterales (CPE) are of serious concern worldwide due to high morbidity and mortality. AIM: To evaluate the impact of the result of a subsequent polymerase chain reaction (PCR) test for carbapenemase after serial negative surveillance cultures on positive culture conversion in patients with three consecutive negative surveillance cultures for CPE, and to identify risk factors for conversion. METHODS: A retrospective study of patients with positive CPE cultures on CHROMagar KPC medium was performed in a Korean tertiary hospital from October 2018 to December 2022. PCR for blaKPC, blaNDM, blaIMP, blaVIM, blaGES, and blaOXA-48 was performed after three consecutive negative rectal swab cultures. Clinical characteristics and outcomes of patients were compared according to whether follow-up PCR was positive (CNPP) or negative (CNPN). FINDINGS: Of 1075 patients with positive CPE cultures, 150 (14.0%) yielded three consecutive negative rectal swab cultures. Of these, 50 (33.3%) were CNPP, and 100 (66.7%) were CNPN. Risk factors associated with a positive PCR result on multivariate analysis were: age, central venous catheter, and Escherichia coli infection. CNPP patients were more likely to have positive culture conversion for CPE than CNPN patients (39/44 (88.6%) vs 21/50 (42.0%), P<0.001). In multivariate analysis, independent risk factors for culture conversion were: a positive PCR result after surveillance cultures, diabetes mellitus, central venous catheter, and Klebsiella pneumoniae. CONCLUSION: CNPP patients have higher rates of culture conversion than CNPN patients, and a follow-up PCR test after serial negative surveillance cultures is useful in deciding whether or not to discontinue contact precautions.

Evaluation of hepatic injury in acute carbon monoxide-poisoned patients in emergency department.

INTRODUCTION: The affinity of hemoglobin for carbon monoxide (CO) is 250 times higher than that for oxygen. Therefore, exposure to CO leads to a reduction in oxygen delivery to tissues, resulting in cellular hypoxia and affects whole body. Hepatic dysfunction in critically ill patients is related to poor outcome, but few studies have been conducted on this subject that occurs after CO poisoning. This study aims to conduct a study of hepatic injury in CO-poisoned patients in emergency department (ED). METHODS: This retrospective observational study collected data from patients who were diagnosed with acute CO poisoning at the ED between June 2011 and May 2018 in local tertiary-care hospital (Wonju, Republic of Korea). The primary end point of this study was to describe the prevalence of hepatic injury in acute CO-poisoned patients. The secondary goals were to investigate the recovery trends of hepatic injury caused by acute CO poisoning and the relation to neurologic outcome and mortality. RESULTS: Eight hundred ninety-four patients were enrolled in the final analysis, 128 cases (14.3%) had subclinical hepatic injury and 15 (1.6%) cases had hepatic injury. The relationship with mortality was not statistically significant. However, the hepatic injury group was higher incidence of intensive care unit admission and other complications. Patients in the hepatic injury group recovered through conservative management within 1 week of being admitted to the ED. CONCLUSIONS: While CO-induced hepatic injury is relatively uncommon, it can be associated with complications and poor neurologic outcome. However, CO-induced hepatic injury was not found to have a statistically significant effect on mortality rate.

Early cidofovir administration might be associated with a lower probability of respiratory failure in treating human adenovirus pneumonia: a retrospective cohort study.

OBJECTIVE: To compare outcomes of early and delayed treatment with cidofovir for human adenovirus (HAdV) pneumonia. METHODS: A retrospective cohort study in Korean military hospitals was conducted between January 2012 and December 2018. Patients with potentially severe HAdV pneumonia with risk factors for respiratory failure were included and divided into early (within 7 days from symptom onset) and delayed (after 7 days from symptom onset) treatment groups. The primary outcome was respiratory failure development within 21 days after symptom onset. RESULTS: A total of 89 patients with potentially severe HAdV pneumonia were enrolled in the cohort; they included 62 early and 27 delayed treatment patients. All patients were males in their early 20s. Significantly fewer patients in the early treatment group progressed to respiratory failure (8/62, 12.9%), compared to the delayed group (18/27, 66.7%, p < 0.001). Early treatment was associated with a lower 21-day probability of respiratory failure by the Kaplan-Meier method (p < 0.001). On multivariate analysis, monocyte count, hypoxaemia, confusion, whole lung involvement, and early cidofovir treatment within 7 days from symptom onset were included, and monocyte count (HR 0.995, 95%CI 0.991-1.000, p 0.042), confusion (HR 4.964, 95%CI 1.189-20.721, p = 0.028), and early cidofovir treatment (HR 0.319, 95%CI 0.115-0.883, p = 0.028) were significantly associated with respiratory failure. CONCLUSIONS: Early administration of cidofovir was associated with a lower hazard for respiratory failure development. It is suggested that cidofovir be administered within 7 days from symptom onset to prevent respiratory failure in patients with potentially severe HAdV pneumonia.

C/EBPbeta modulates the early events of keratinocyte differentiation involving growth arrest and keratin 1 and keratin 10 expression.

The epidermis is a stratified squamous epithelium composed primarily of keratinocytes that become postmitotic and undergo sequential changes in gene expression during terminal differentiation. The expression of the transcription factor CCAAT/enhancer binding protein beta (C/EBPbeta) within mouse epidermis and primary keratinocytes has recently been described; however, the function of C/EBPbeta within the epidermal keratinocyte is unknown. We report here that transient transfection of mouse primary keratinocytes with a C/EBP-responsive promoter-reporter construct resulted in a sevenfold increase in luciferase activity when keratinocytes were switched to culture conditions that induce growth arrest and differentiation. Forced expression of C/EBPbeta in BALB/MK2 keratinocytes inhibited growth, induced morphological changes consistent with a more differentiated phenotype, and upregulated two early markers of differentiation, keratin 1 (K1) and keratin 10 (K10) but had a minimal effect on the expression of late-stage markers, loricrin and involucrin. Analysis of the epidermis of C/EBPbeta-deficient mice revealed a mild epidermal hyperplasia and decreased expression of K1 and K10 but not of involucrin and loricrin. C/EBPbeta-deficient primary keratinocytes were partially resistant to calcium-induced growth arrest. Analysis of terminally differentiated spontaneously detached keratinocytes or those induced to differentiate by suspension culture revealed that C/EBPbeta-deficient keratinocytes displayed striking decreases in K1 and K10, while expression of later-stage markers was only minimally altered. Our results demonstrate that C/EBPbeta plays an important role in the early events of stratified squamous differentiation in keratinocytes involving growth arrest and K1 and K10 expression.

Risk factors for suboptimal drug concentration of posaconazole oral suspension in patients with hematologic malignancy.

Absorption of posaconazole oral suspension is influenced by several factors including diet, medications, and mucosal integrity. However, there are few prospective data about which is the most important modifiable factor in routine clinical practice. We prospectively analyzed clinical risk factors associated with low posaconazole trough concentrations in 114 patients receiving anticancer chemotherapy due to acute myeloid leukemia or myelodysplastic syndrome who received posaconazole oral suspension. In multivariate analyses, risk factors for drug level<500ng/mL included low calorie intake, mucositis≥grade 2, H2 blocker famotidine and proton-pump inhibitor. The only significant risk factor for drug level<700ng/mL was famotidine use (adjusted relative risk, 3.18; 95% confidence interval, 1.07-9.11; P=0.038). In conclusion, medication of H2 blocker famotidine should be cautious in patients with hematologic malignancy receiving posaconazole suspension.

Epidemiological characteristics of occupational blood exposures of healthcare workers in a university hospital in South Korea for 10 years.

This study investigated the epidemiological characteristics of occupational blood exposures (OBEs) of healthcare workers (HCWs) in South Korea, and examined trends of OBEs after implementing blood exposure prevention (BEP) programmes. The study was conducted between 1 January 1992 and 31 December 2001 at a university-affiliated acute care hospital in Seoul. The BEP programmes comprised in-service education, hepatitis B virus (HBV) vaccination, and postexposure evaluation and prophylaxis. From 959 reported cases of OBEs, the crude incidence density (ID) was 2.62 cases per 100 person-years. The major risk groups for OBEs were physicians (ID 4.34) and new employees. The major type of OBE was from sharps injuries, including needlesticks (94.0%). OBE cases occurred more frequently during the spring (36.4%). The frequency of the serological tests of anti-hepatitis B surface antigen of HCWs changed significantly each year (P<0.05). The major serological risk for source patients was HBV (52.1%), but the risks for hepatitis C virus (HCV) and human immunodeficiency virus (HIV) increased significantly each year (P<0.05). There were no seroconversion cases following OBEs among the tested HCWs. In summary, we established the epidemiological characteristics of OBEs in a South Korean university hospital, and reduced the risk of OBEs of major risk groups by BEP programmes. We also found an increase in the risk of HCV and HIV during the study period, suggesting that OBEs could be a serious threat to HCWs.

Mammary pseudoangiomatous stromal hyperplasia presenting as an axillary mass.

Pseudoangiomatous stromal hyperplasia (PASH) of the breast is characterized by interanastomosing slit-like spaces lined with spindle-shaped cells in an abundant fibrous stroma. PASH is a relatively common incidental finding in the breast tissue removed for other reasons and rarely presents as a localized mass. The etiology of PASH is unknown, but hormonal factors are thought to be involved. Accessory breast tissue is subject to all pathologic changes found in the normal breast. We report a case of PASH that presented as a palpable axillary mass in a 43-year-old woman. To our knowledge, PASH has not previously been reported in the axillary accessory breast tissue. The spindle stromal cells in our patient showed immunophenotypic characteristics of myofibroblastic differentiation. Immunoreactivity for progesterone receptor was noted in the spindle cells. These findings support the hypothesis that endogenous hormones are involved in the development of PASH.

The Bradyrhizobium japonicum hsfA gene exhibits a unique developmental expression pattern in cowpea nodules.

The Bradyrhizobium japonicum host-specific fixation gene hsfA was identified as essential for nitrogen fixation on cowpea, but not required for nitrogen fixation on soybean or siratro. The DNA sequence of the hsfA promoter contains a consensus RpoN, -24/-12 binding site, suggesting the involvement of a regulatory protein that binds to an upstream activating sequence (UAS). To further explore the regulation of this interesting gene, serial deletions of the hsfA promoter were made and fused with the beta-glucuronidase (GUS) gene. The HsfA3 deletion, containing 60 bp 5' of the -24/-12 sequence, showed a similar level of GUS expression to that shown by the longest fusion construct (HsfA1), containing 464 bp of upstream sequence. In contrast, the HsfA4-GUS fusion, containing only 20 bp 5' of the -24/-12 region, showed no GUS activity, delimiting the location of a putative UAS to a 40-bp region. During nodule development, GUS expression first appeared in nodules 12 days postinoculation (dpi) and reached a maximum level of expression in approximately 17-day-old nodules. By 28 dpi, HsfA-GUS expression had returned to a low, basal level. These data were consistent with the detection of hsfA mRNA by in situ hybridization in 17-day-old nodules, but not in 28-day-old nodules. In contrast to the stage-specific expression in cowpea, HsfA-GUS expression increased with nodule development in HsfA3-inoculated soybean. These data indicate that HsfA expression is regulated in cowpea in a unique developmental manner and that the DNA regulatory regions that control this expression are confined to a short, promoter-proximal region.

Expression of CCAAT/enhancer binding proteins (C/EBP) is associated with squamous differentiation in epidermis and isolated primary keratinocytes and is altered in skin neoplasms.

The epidermis is a stratified squamous epithelium composed primarily of keratinocytes that undergo sequential changes in gene expression during differentiation. CCAAT/enhancer binding proteins (C/EBP) are members of the bZIP family of DNA binding proteins/transcription factors. Northern analysis demonstrated that C/EBPalpha, C/EBPbeta, and C/EBPdelta mRNA are expressed in mouse epidermis and their mRNA levels were generally greater than those observed in other tissues known to express high levels of C/EBP. Western analysis of isolated epidermal cell nuclei demonstrated the presence of a 42 and 30 kDa C/EBPalpha protein and 35 kDa C/EBPbeta protein. Immunohistochemical localization of C/EBPalpha and C/EBPbeta in intact interfollicular epidermis revealed that C/EBPbeta expression is exclusive to the nuclei of a three-cell cluster of suprabasal keratinocytes that is morphologically consistent with the central column of the epidermal proliferative unit, and that C/EBPalpha is expressed in the nuclei and cytoplasm of suprabasal keratinocytes and weakly expressed in a perinuclear manner in some basal keratinocytes. In squamous cell carcinomas the expression of C/EBPalpha and C/EBPbeta was greatly diminished as both the intensity of nuclear staining and the number of cells expressing C/EBPalpha and C/EBPbeta were reduced. In isolated primary mouse keratinocytes, calcium-induced differentiation was accompanied by specific temporal changes in the expression of C/EBPalpha, C/EBPbeta, and C/EBPdelta mRNA and C/EBPalpha and C/EBPbeta protein. These results implicate a role for the C/EBP family in the regulation of genes involved in or specifically expressed during the process of squamous differentiation in epidermis.

Epidermal protein kinase C-beta 2 is highly sensitive to downregulation and is exclusively expressed in Langerhans cells: downregulation is associated with attenuated contact hypersensitivity.

Treatment of mice with multiple topical applications of 12-O-tetradecanoylphorbol-13-acetate (TPA) or diacylglycerol resulted in a preferential decrease in epidermal protein kinase C-beta 2 (PKC-beta 2) compared with PKC-alpha as determined by western analysis. When PKC-alpha was decreased by 40%, PKC-beta 2 could no longer be detected, suggesting that PKC-beta 2 is more sensitive to downregulation, and/or specific epidermal cell types that contain PKC-beta 2 are more sensitive to TPA/diacylglycerol. To address this issue, we isolated Langerhans cells (LCs) from epidermal cell suspensions with immunomagnetic beads and an antibody to the class II major histocompatibility complex. Northern blot analysis revealed a PKC-beta 2 signal in isolated LCs that was 40-fold greater than that observed in unfractionated epidermal cells, and no PKC-beta 2 signal was detected in epidermal cells depleted of LCs, indicating that PKC-beta 2 is expressed exclusively in LCs within the epidermis. Western blot analysis confirmed the presence of PKC-beta 2 in LCs. PKC-beta 2 was highly sensitive to downregulation, because a single application of TPA resulted in a 90% loss of PKC-beta 2 within 6 h without a decrease in the number of LCs. To determine whether the decreased level of PKC-beta 2 within LCs was associated with an alteration in contact hypersensitivity, we treated mice with only a single application of TPA, and 6 hours later mice were sensitized with 2,4-dinitrofluorobenzene on the same dorsal area. Subsequent challenge revealed a 60% decrease in contact hypersensitivity in TPA-treated mice. These data indicate that (i) within the epidermis, PKC-beta 2 is highly sensitive to downregulation and is exclusively expressed in LCs, and (ii) the downregulation of PKC-beta 2 is associated with impaired LC function with respect to contact hypersensitivity.

Multicenter surveillance study for nosocomial infections in major hospitals in Korea. Nosocomial Infection Surveillance Committee of the Korean Society for Nosocomial Infection Control.

BACKGROUND: The goals of a surveillance for nosocomial infections (NIs) are to observe the magnitude and characteristics of NIs and to plan and evaluate policies and guidelines of infection control. This study was designed to determine the rate and distribution of NIs and their causative pathogens in Korean hospitals. METHODS: Prospective surveillance was performed at 15 acute care hospitals with more than 500 beds during a 3-month period from June to August 1996. The case-finding methods were laboratory-based surveillance for patients in the general wards and a direct review of medical charts done regularly for all the patients in the intensive care units. RESULTS: A total of 3162 NIs were found among 85,547 discharged patients, with an overall nosocomial infection rate of 3.70 per 100 patients discharged. Urinary tract infections constituted 30.3% of all NIs. Other infections were pneumonias, 17.2%, surgical site infections, 15.5%, and primary bloodstream infections, 14.5%. The infection rate was the highest in neurosurgery (14.21), followed by neurology (8. 62) and ontology services (6.70). The infection rate in intensive care units was higher than it was in the general wards (10.74 vs 2. 57, P =.001). The commonly isolated organisms were Staphylococcus aureus (17.2%), Pseudomonas aeruginosa (13.8%), and Escherichia coli (12.3%). CONCLUSIONS: This first multicenter surveillance study provided extensive information on the current status and trends of NIs in major hospitals in Korea. The results may contribute to the evaluation of infection control programs and the development of effective strategies in these hospitals.

In vivo evaluation of polymeric micellar paclitaxel formulation: toxicity and efficacy.

Although the current clinical formulation of paclitaxel (Taxol) has a promising clinical activity against a wide variety of tumors, it has significant toxic side effects, some of which are associated with its formulation in a 1:1 (v/v) mixture of Cremophor EL and dehydrated alcohol. One of the problems associated with the intravenous administration of paclitaxel is its low solubility in water. Our study was designed to evaluate the pharmacokinetics, tissue distribution, toxicity and efficacy of a paclitaxel (Genexol)-containing biodegradable polymeric micellar system (Genexol-PM) in comparison to Taxol. Genexol-PM was newly developed by using a low molecular weight, nontoxic and biodegradable amphiphilic diblock copolymer, monomethoxy poly(ethylene glycol)-block-poly(D,L-lactide) (mPEG-PDLLA) and paclitaxel (Genexol, Samyang Genex Co., Seoul, Korea). In a human cancer cell line model, Genexol-PM and Taxol showed comparable in vitro cytotoxicity against human ovarian cancer cell line OVCAR-3 and human breast cancer cell line MCF7. The maximum tolerated dose (MTD) of Genexol-PM and Taxol in nude mice was determined to be 60 and 20 mg/kg, respectively. The median lethal dose (LD(50)) in Sprague--Dawley rats was 205.4 mg/kg (male) and 221.6 mg/kg (female) for Genexol-PM, while 8.3 mg/kg (male) and 8.8 mg/kg (female) for Taxol. After intravenous administration of Genexol-PM in murine B16 melanoma-induced female SPF C57BL/6 mice at a dose of 50 mg/kg, the area under the plasma concentration-time curve (AUC) was similar to Taxol((R)) at a dose of 20 mg/kg, but biodistribution of paclitaxel after administration of Genexol-PM showed 2 to 3-fold higher levels in tissues including liver, spleen, kidneys, lungs, heart and tumor as compared to Taxol. The in vivo antitumor efficacy of Genexol-PM as measured by reduction in tumor volume of SKOV-3 human ovarian cancer implanted in nude (nu/nu) athymic mice and MX-1 human breast cancer implanted in Tac:Cr:(NCr)-nu athymic mice was significantly greater than that of Taxol. The results of cytotoxicity, MTD, LD(50) and antitumor efficacy suggest that Genexol-PM may have a great advantage over present-day chemotherapy with Taxol.

A Target-Site-Specific Screening System for Antifungal Compounds on Appressorium Formation in Magnaporthe grisea.

ABSTRACT Chemical fungicides are a major method of control for plant diseases in spite of potential negative effects on the environment and the appearance of resistant strains. Development of new chemical fungicides has been largely dependent upon in vivo efficacy tests in the greenhouse or in fields, which is in contrast to target-oriented in vitro screening systems widely used in the pharmaceutical field. To establish a target-site-specific screening system for antifungal compounds, specific inhibition on appressorium formation of the rice blast fungus Magnaporthe grisea was employed. For many plant-pathogenic fungi, including M. grisea, appressorium formation is an essential step to infect host plants. Among 1,000 culture filtrates of members of the class Actinomycetes and fungi, five (A5005, A5008, A5314, A5387, and A5397) from the class Actinomycetes showed differential inhibitory effects on appressorium formation of M. grisea in a dosage-dependent manner. Three (A5005, A5314, and A5387) of these were further fractionated into ethyl acetate and water fractions. The ethyl acetate fraction of A5005 and both the ethyl acetate and water fractions from A5314 and A5387 inhibited appressorium formation, while conidial germination remained little affected. Inhibition of appressorium formation by the ethyl acetate or water fraction was reversed by the exogenous addition of cyclic AMP. Significantly reduced numbers of conidia with appressoria were observed on rice leaves in the presence of culture filtrates. Furthermore, these culture filtrates also exhibited significant disease control of rice blast in the greenhouse. This rapid and target-oriented screening system could be adopted to screen candidate compounds for rice blast control and could be applicable for other appressorium-forming, plant-pathogenic fungi.

A Gene-for-Gene Relationship Underlying the Species-Specific Parasitism of Avena/Triticum Isolates of Magnaporthe grisea on Wheat Cultivars.

ABSTRACT To elucidate genetic mechanisms of the species-specific parasitism of Magnaporthe grisea, a Triticum isolate (pathogenic on wheat) was crossed with an Avena isolate (pathogenic on oat), and resulting F(1) progeny were subjected to segregation analyses on wheat cvs. Norin 4 and Chinese Spring. We found two fungal loci, Pwt3 and Pwt4, which are involved in the specific parasitism on wheat. Pwt3 operated on both cultivars while Pwt4 operated only on 'Norin 4'. Using the cultivar specificity of Pwt4, its corresponding resistance gene was successfully identified in 'Norin 4' and designated as Rmg1 (Rwt4). The presence of the corresponding resistance gene indicated that Pwt4 is an avirulence locus. Pwt3 was assumed to be an avirulence locus because of its temperature sensitivity. We suggest that gene-for-gene interactions underlie the species-specific parasitism of M. grisea.

Inter-relationships between arteriosclerotic risk factors: a meta-analysis.

This study was performed to clarify the overall inter-relationships between the arteriosclerotic risk factors, including smoking, alcoholic consumption, obesity, serum cholesterol and triglyceride levels, high density lipoprotein, and systolic and diastolic blood pressure using a meta analysis method. The subjects of this study were included in 24 primary studies reported in Korea since 1980, which concerned arteriosclerotic risk factors. The results show that smoking is significantly associated with total cholesterol (R = .04), triglyceride (R = .10) and HDL-cholesterol (R = -.06). Alcohol consumption is also significantly and positively associated with all three serum lipid parameters: cholesterol (R = .04), triglyceride (R = .08) and HDL-cholesterol (R = .10). The effect of smoking and alcohol consumption on cholesterol levels were found to be almost equal. However, smoking has a predominant effect on triglyceride, whereas, alcohol consumption exerts an influence primarily on the HDL-cholesterol level. Obesity was positively correlated with cholesterol (R = .25) and triglyceride (R = .21), however, it was negatively correlated with HDL-cholesterol (R = -.14). It appears that the serum lipid parameter, which shows strongest correlation with obesity, is the total cholesterol level. Obesity also showed a significant correlation with systolic (R = .19) and diastolic blood pressure (R = .13). Blood pressure was also positively correlated with cholesterol (R = .18) and triglyceride (R = .26), however, it correlated negatively with HDL-cholesterol (R = -.23). In conclusion, the overall inter-relationships between the arteriosclerotic risk factors; smoking, alcohol consumption, obesity, serum lipid level and blood pressure were all found to be significant.

The compound relationship of smoking and alcohol consumption with obesity.

The purpose of this study was to examine 1) whether the relationship between smoking and obesity was linear or non-linear (specifically U-shaped), and 2) if this relationship was proved to U-shaped, whether it was due to the interaction of the effects of smoking and alcohol consumption on obesity. The present study was performed using cross sectional data taken from the medical records of 400 male patients. Data was analyzed using linear and curvilinear estimation, Fisher's exact test, and two-way ANCOVA. The relationship between smoking intensity and BMI was able to be explained significantly by a quadratic model, rather than by linear model. As has been shown in other studies, this relationship was parabolic (or U-shaped), though it was not particularly remarkable. This U-shaped relationship appeared to be due to the interaction of the effects of smoking intensity and alcohol consumption on BMI. On the other hand, the relationship between smoking intensity and the percentage of body fat was able to be explained significantly by a linear as well as a quadratic model. Additionally, the interaction effect between smoking intensity and alcohol consumption did not influence the percentage of body fat significantly. In conclusion, there is no doubt that smoking and obesity are both serious health hazards. Based on the results of this and other studies, it can be confirmed that heavy smoking has a positive relationship with obesity. Therefore, the health benefits of smoking cessation, as well as the correction of unhealthy habits such as alcohol consumption should be clearly emphasized.

Epidemiological typing of methicillin-resistant Staphylococcus aureus outbreak isolates by pulsed-field gel electrophoresis and antibiogram.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common nosocomial pathogens. In April 1997, there were five MRSA-infected patients among 16 patients in the Neonatal Intensive Care Unit (NICU), Seoul National University Hospital, which is a tertiary-care hospital with 1,500 beds. The infections had spread from twin patients with MRSA who had transferred from Hospital C. MRSA was isolated from the axilla of 15 (94%) of the 16 patients, including the two patients with obvious infections. Three (19%) of 16 doctors and nine (30%) of 30 nurses had MRSA colonization of the anterior nares. Six different PFGE patterns (A through F) were identified in the 53 isolates of MRSA tested. Twelve of 13 isolates from infected sites of five patients showed pattern F. Three MRSA strains obtained from hospital C showed closely or possibly related pattern F. MRSA of type F was isolated from three of 16 patients' axilla, and one of 3 doctors' and three of 30 nurses' nasal swabs. The antibiogram code for 12 of 13 MRSA isolates from five infected patients was 66,754. PFGE patterns of these isolates were either F, F1, F2 or Fa. Only one of three strains isolated from clinical specimens of patients in Hospital C showed the antibiogram code 66754, although they were all PFGE types F1 and Fa. In conclusion, the presumptive sources of the outbreak of MRSA infection in NICU were the twin patients transferred from hospital C. Antibiogram correlated reasonably well to the PFGE type. An effective notification system is needed when a MRSA-infected patient is transferred to another hospital to control the spread of the infection.

Meteorological effects on the evolution of high ozone episodes in the greater Seoul area.

Three high O3 episodes--7 days in 1992 (July 3-July 9), 9 days in 1994 (July 21-July 29), and another 3 days in 1994 (August 22-August 24)--were selected on the basis of morning (7:00 a.m.-10:00 a.m.) average wind direction and speed and daily maximum O3 concentrations in the greater Seoul, Korea, of 1990-1997. To better understand their characteristics and life cycles, surface data from the Seoul Weather Station (SWS) and surface and 850-hPa wind field data covering northeast Asia around the Korean Peninsula were used for the analysis. In the July 1992 episode, westerly winds were most frequent as a result of the influence of a high-pressure system west of the Korean Peninsula behind a trough. In contrast, in the July 1994 episode, easterly winds were most frequent as a result of the effect of a typhoon moving north from the south of Japan. Despite different prevailing wind directions, the peak O3 concentrations for each episode occurred when a sea/land breeze developed in association with weak synoptic forcing. The August 1994 episode, which was selected as being representative of calm conditions, was another typical example in which a well-developed