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Objectives This study evaluated the response in Daegu, Korea to the first wave of the coronavirus disease 2019 (COVID-19) pandemic according to a public health emergency response model. Methods After an examination of the official data reported by the city of Daegu and the Korea Centers for Disease Control and Prevention, as well as a literature review and advisory meetings, we chose a response model. Daegu’s responses were organized into 4 phases and evaluated by applying the response model. Results In phase 1, efforts were made to block further transmission of the virus through preemptive testing of a religious group. In phase 2, efforts were concentrated on responding to mass infections in high-risk facilities. Phase 3 involved a transition from a high-intensity social distancing campaign to a citizen participation–based quarantine system. The evaluation using the response model revealed insufficient systematic preparation for a medical surge. In addition, an incorporated health-related management system and protection measures for responders were absent. Nevertheless, the city encouraged the participation of private hospitals and developed a severity classification system. Citizens also played active roles in the pandemic response by practicing social distancing. Conclusions This study employed the response model to evaluate the early response in Daegu to the COVID-19 pandemic and revealed areas in need of improvement or maintenance. Based on the study results, creation of a systematic model is necessary to prepare for and respond to future public health emergencies like the COVID-19 pandemic.

ObjectiveTo explore the incidence, characteristics, complications and socioeconomic impacts associated with falls in community-dwelling elderly.MethodsFrom September 1, 2015 to October 12, 2015, a questionnaire-based survey was conducted involving a total of 2,012 elderly who lived in Guro-gu (Seoul), Yeongdeungpo-gu (Seoul), Yangpyeong-gu (Gyeonggi-do), Dalseong-gu (Daegu), and Jung-gu (Daegu). The subjects were interviewed using a structured questionnaire to obtain demographic characteristics and comprehensive falling histories. The socioeconomic cost related to falls was estimated using the statistical data provided by the Health Insurance Review and Assessment Service.ResultsFalls were recorded in 666 out of the 2,012 subjects (33.1%) during the past year. Frequent falls occurred during December, in the afternoons, when the floor was slippery. The most common injuries included the low back and the most common injury type was sprain. The total direct costs related to falls involving the 2,012 subjects were 303,061,019 KRW (Korean won). The average medical cost related to falls in the 2,012 subjects was 150,627 KRW and the average medical cost of 666 subjects who experienced falls was 455,047 KRW. Estimates of the total population over the age of 60 years showed that the annual direct costs associated with falls in Korea over the age of 60 years were about 1.378 trillion KRW.ConclusionThis study was conducted to explore the incidence, characteristics, complications, and socioeconomic impacts of falls in community-dwelling elderly. This study is expected to be used as a source of basic data for the establishment of medical policy for the elderly and the development of a fall prevention program for the elderly in Korea.

Summary: Purpose: This study aimed to examine levels of stress and professionalism of nurses who provided nursing care during the 2015 Middle East respiratory syndrome outbreak based on their experience, to investigate the nurses' intention to respond to possible future outbreaks in relation to their experience during the outbreak, and to determine the relationship between the outbreak experience and nursing intention considering stress and professionalism. Methods: A self-administered questionnaire was designed based on modifications of related questionnaires, and used to assess levels of stress, professionalism, and nursing intention according to participants' experiences during the outbreak. Multiple regression analysis was used to examine the relationship between the outbreak nursing experience and nursing intention considering stress and nursing professionalism. Results: The overall stress, professionalism, and nursing intention scores for the firsthand experience group were 33.72, 103.00, and 16.92, respectively, whereas those of the secondhand experience group were 32.25, 98.99, and 15.60, respectively. There were significant differences in professionalism and nursing intention scores between the groups (p = .001 and p

Objectives The objective of the present study was to compare prognosis of patients with gastric or colorectal cancer according to places where they received surgeries. Methods The cancer patients underwent surgeries in sampled hospitals located in Daegu were matched 1:1 to the patients who visited sampled hospitals in Seoul using propensity score method. After the occurrences of death were examined, Kaplan-Meier method was used for survival analysis and the log-rank test was performed to compare the survival curves. Results A total of six out of 291 gastric cancer patients who had surgeries in Daegu died (2.1%) and ten deaths (3.4%) occurred from patients went Seoul hospitals. Out of 84 gastric cancer patients who had chemotherapy after surgeries in Daegu, 13 (15.5%) patients died while 18 (21.4%) deaths occurred among patients underwent surgeries in Seoul. Six deaths (6.9%) out of 87 colorectal cancer patients who had surgeries in Daegu were reported. Five patients (5.7%) died among the patients underwent surgeries in Seoul. Among the colorectal cancer patients with chemotherapy after surgeries, 13 patients (12.4%) who visited hospitals in Daegu and 14 (13.3%) patients who used medical centers in Seoul died. There were no significant differences according to places where patients used medical services. Conclusions The result of this study is expected to be used as basic data for policy making to resolve centralization problem of cancer patients and to help patients to make rational choices in selection of medical centers.

Objectives: The purposes of this study were to examine the status of children and adolescents with regard to enrollment in private medical insurance (PMI) and to investigate its influence on their utilization of medical services. Methods: The present study assessed 2973 subjects younger than 19 years of age who participated in five consecutive Korea Health Panel surveys from 2009 to 2012. Results: At the initial assessment, less than 20% of the study population had not enrolled in any PMI program, but this proportion decreased over time. Additionally, the number of subjects with more than two policies increased, the proportions of holders of indemnity-type only (‘I’-only) and of fixed amount+indemnity-type (‘F+I’) increased, whereas the proportion of holders with fixed amount-type only (‘F’-only) decreased. Compared with subjects without private insurance, PMI policyholders were more likely to use outpatient and emergency services, and the number of policies was proportionately related to inpatient service utilization. Regarding out-patient care, subjects with ‘F’-only PMI used these services more often than did uninsured subjects (odds ratio [OR], 1.69), whereas subjects with ‘I’-only PMI or ‘F+I’ PMI utilized a broad range of inpatient, outpatient, and emergency services relative to uninsured subjects (ORs for ‘I’-only: 1.39, 1.63, and 1.38, respectively; ORs for ‘F+I’: 1.67, 2.09, and 1.37, respectively). Conclusions: The findings suggest public policy approaches to standardizing PMI contracts, reform in calculation of premiums in PMI, re-examination regarding indemnity insurance products, and mutual control mechanisms to mediate between national health insurance services and private insurers are required.

Objectives: This community-based cohort study was performed to investigate the incidence of and factors related to self-reported fragility fractures among middle-aged and elderly women living in rural Korea. Methods: The osteoporosis cohort recruited 430 women 40 to 69 years old in 1999, and 396 of these women were followed over 11 years. In 1999, questionnaires from all participants assessed general characteristics, medical history, lifestyle, menstrual and reproductive characteristics, and bone mineral density. In 2010, self-reported fractures and the date, site, and cause of these fractures were recorded. Cox proportional hazards models were used to calculate hazard ratios (HRs). Results: Seventy-six participants among 3949.7 person-years experienced fragility fractures during the 11-year follow-up. The incidence of fragility fractures was 1924.2 per 100 000 person-years (95% confidence interval [CI], 1491.6 to 2356.8). In the multivariate model, low body mass index (HR, 2.66; 95% CI, 1.13 to 6.24), a parental history of osteoporosis (HR, 2.03; 95% CI, 1.18 to 3.49), and postmenopausal status (HR, 3.50; 95% CI, 1.05 to 11.67) were significantly related to fragility fracture. Conclusions: Fracture prevention programs are needed among postmenopausal, rural, Korean women with a low body mass index and parental history of osteoporosis Korea.

Purpose Recently, reports in the mass media have implicated that bicycle riding increases the risk of erectile dysfunction and prostatic diseases. So, we evaluate the impact of bicycle riding on erectile function and lower urinary tract symptoms (LUTS) in healthy general men. Methods From 26 June 2010 to 20 July 2010, we investigate degree of LUTS (voiding and storage symptoms), using International Continence Society-male Questionnaire (ICS-mQ) and erectile function using International Index of Erectile Function-5 Questionnaire (IIEF-5) in 5 work places (personnel of public office, hospital, university, etc.) of which bicycle riding club members were doing active club activities. Respondents, who participated in club activities for 6 months and longer, were classified as the bicycle club (142 men; age, 44.02±8.56). Ones who do not ride bicycles were classified as the control group (83 men; age, 42.13±7.85). People who were having the history of urological and other chronic diseases (diabetes, vascular disease, heart disease, etc) were excluded from both groups. Results Bicycle club is not significantly associated with increased prevalence of LUTS (bicycle club, 2.1 to 57.7% control, 4.8 to 73.5%) and erectile dysfunction (bicycle club, 46.1% control, 55.4%). The total mean score (storage/voiding/erectile function) of bicycle club (13.93±1.95/11.14±3.49/20.46±5.30) were not significantly different from control (14.35±2.49/11.52±3.38/20.40±4.07) (P=0.190 to 0.968). Conclusions These results suggested that bicycle riding as exercise or hobby has no negative effect on LUTS and erectile function in healthy general men, although this research data were limited to the questionnaire analysis.

BackgroundThe aim of the present study was to determine the population-based prevalence of diabetes mellitus (DM) and prediabetes in a rural district of Daegu City, Korea.MethodsBetween August and November 2003, a community-based health survey of adults aged 20 years and older was performed in the rural district of Dalseong-gun in Daegu City. A total of 1,806 of all eligible individuals agreed to participate. Fasting plasma glucose was measured in all participants. Two hour oral glucose tolerance was measured in the 1,773 participants for whom there was neither an established diagnosis of DM nor evidence of DM according to fasting glucose levels. The prevalence of DM and prediabetes was determined according to the 2003 criteria of the American Diabetes Association. Subjects with prediabetes were classified into one of three categories of glucose intolerance: isolated impaired fasting glucose (IFG); isolated impaired glucose tolerance (IGT); or combined IFG and IGT.ResultsThe prevalence of DM was 12.2%. The highest prevalence rates were observed in subjects in their seventies. A total of 34.7% of all subjects who were assigned a diagnosis of DM in the present study had not been diagnosed previously. The prevalence of prediabetes was 22.7%. The highest prevalence rates were observed in subjects in their fifties.ConclusionThe present study identified prevalence rates of 12.2% for DM (age-standardized prevalence rate [ASR], 6.8%), and 22.7% for prediabetes (ASR 18.5%). These results emphasize the need for community health promotion strategies to prevent or delay the onset of DM in individuals with prediabetes.

Acinetobacter baumannii, a strictly aerobic, non-fermentative, Gram-negative coccobacillary rod-shaped bacterium, is an opportunistic pathogen in humans. We recently isolated a multidrug-resistant A. baumannii strain KBN10P02143 from the pus sample drawn from a surgical patient in South Korea. We report the complete genome of this strain, which consists of 4,139,396 bp (G + C content, 39.08%) with 3,868 protein-coding genes, 73 tRNAs and six rRNA operons. Identification of the genes related to multidrug resistance from this genome and the discovery of a novel conjugative plasmid will increase our understanding of the pathogenicity associated with this species.

BackgroundInhibitor of apoptosis proteins (IAPs) belong to a pivotal antiapoptotic protein family that plays a crucial role in tumorigenesis, cancer progression, chemoresistance and poor patient-survival. X-linked inhibitor of apoptosis protein (XIAP) is a prominent member of IAPs attracting intense research because it has been demonstrated to be a physiological inhibitor of caspases and apoptosis. Recently, an evolutionarily conserved ubiquitin-associated (UBA) domain was identified in XIAP and a number of RING domain-bearing IAPs. This has placed the IAPs in the group of ubiquitin binding proteins. Here, we explore the three-dimensional structure of the XIAP UBA domain (XIAP-UBA) and how it interacts with mono-ubiquitin and diubiquitin conjugates.Principal findingsThe solution structure of the XIAP-UBA domain was determined by NMR spectroscopy. XIAP-UBA adopts a typical UBA domain fold of three tightly packed α-helices but with an additional N-terminal 3(10) helix. The XIAP-UBA binds mono-ubiquitin as well as Lys48-linked and linear-linked diubiquitins at low-micromolar affinities. NMR analysis of the XIAP-UBA-ubiquitin interaction reveals that it involves the classical hydrophobic patches surrounding Ile44 of ubiquitin and the conserved MGF/LV motif surfaces on XIAP-UBA. Furthermore, dimerization of XIAP-UBA was observed. Mapping of the self-association surface of XIAP-UBA reveals that the dimerization interface is formed by residues in the N-terminal 3(10) helix, helix α1 and helix α2, separate from the ubiquitin-binding surface.ConclusionOur results provide the first structural information of XIAP-UBA and map its interaction with mono-ubiquitin, Lys48-linked and linear-linked diubiquitins. The notion that XIAP-UBA uses different surfaces for ubiquitin-binding and self-association provides a plausible model to explain the reported selectivity of XIAP in binding polyubiquitin chains with different linkages.

Purpose: We assessed medication nonadherence, categorized as intentional or unintentional, and related factors in elderly patients with hypertension, correlating the data with measurement of blood pressure as the final target of medication adherence and other possible influencing factors, such as lifestyle. Patients and methods: Subjects were aged ≥65 years, resided in a rural area, and were taking antihypertensive drugs. The survey was conducted in July 2014. Participants were divided into the following three groups: "Adherence", "Unintentional nonadherence", and "Intentional nonadherence". Individual cognitive components, such as necessity and concern as well as self-efficacy and other related factors, were compared according to adherence groups. The interrelationships between those factors and nonadherence were tested using structural equation modeling analysis. Results: Of the 401 subjects, 182 (45.6%) were in the adherence group, 107 (26.7%) in the unintentional nonadherence group, and 112 (27.9%) in the intentional nonadherence group. Necessity and self-efficacy were found to have a significant direct influence on unintentional nonadherence behaviors (necessity β=-0.171, P=0.019; self-efficacy β=-0.433, P,0.001); concern was not statistically significant (β=-0.009, P=0.909). Necessity was found to have significant direct and indirect impact on intentional nonadherence (direct β=-0.275, P=0.002; indirect β=-0.113, P=0.036). Self-efficacy had no significant direct effect on intentional nonadherence though it had the only significant indirect effect on intentional nonadherence (direct β=-0.055, P=0.515; indirect β=-0.286, P,0.001). Concern had no significant influence on intentional or on unintentional nonadherence (direct β=0.132 0.132, P=0.151; indirect β=-0.006, P=0.909). Conclusion: Unintentional nonadherence should be regularly monitored and managed because of its potential prognostic significance. Interventions addressing cognitive factors, such as beliefs about medicine or self-efficacy, are relatively difficult to implement, but are essential to improve medication adherence. [ABSTRACT FROM AUTHOR]

Vitamin D plays an important role in skeletal health throughout life. Some studies have hypothesised that vitamin D may reduce the risk of other diseases. Our study aimed to estimate age-specific and sex-specific serum 25-hydroxyvitamin D (25(OH)D) status and to identify the determinants of serum 25(OH)D status in Hong Kong, a subtropical city in southern China. In 2009-2010, households in Hong Kong were followed up to identify acute respiratory illnesses, and sera from 2694 subjects were collected in three to four different study phases to permit measurement of 25(OH)D levels at different times of the year. A questionnaire survey on diet and lifestyle was conducted among children, with simultaneous serum collection in April and May 2010. The mean of serum 25(OH)D levels in age groups ranged from 39 to 63 nmol/l throughout the year with the mean values in all age groups in spring below 50 nmol/l. Children aged 6-17 years, and girls and women had significantly lower serum 25(OH)D levels than adults, and boys and men, respectively (all P<0·001). We estimated that serum 25(OH)D levels in Hong Kong followed a lagged pattern relative to climatic season by 5 weeks with lowest observed levels in early spring (March). For children aged 6-17 years, reporting a suntan, having at least 1 servings of fish/week and having at least 1 serving of eggs/week were independently associated with higher serum 25(OH)D levels. Adequate sunlight exposure and increased intake of dietary vitamin D could improve vitamin D status, especially for children and females in the winter and spring. [ABSTRACT FROM AUTHOR]

X-linked inhibitor of apoptosis protein (XIAP)-associated factor 1 (XAF1) has been implicated as a novel tumor suppressor, which was proposed to exert pro-apoptotic effect by antagonizing the anticaspase activity of XIAP. Here, we delineated the domain architecture of XAF1 by applying limited proteolysis and peptide mass fingerprinting analysis. Our results indicated that XAF1 has a distinct domain organization, with a highly compact N-terminal domain (XAF1NTD) followed by a middle domain (XAF1MD), a 42-residue unstructured linker and a C-terminal domain (XAF1CTD). The search of XIAP binding region within XAF1 revealed that a modest affinity XIAPRING binding site (dissociation constant, Kd, ∼18 μ M) is located at the C-terminal portion of XAF1. This C-terminal region, embracing XAF1CTD and a flexible tail at C-terminus (residue Thr251-Ser301), is functionally identified as XIAPRING-binding domain of XAF1 (XAF1RBD) in the present study. We have also mapped the interaction sites for XAF1RBD on XIAPRING by using NMR spectroscopy. By applying in vitro ubiquitination assay, we observed that XAF1RBD/XIAP interaction is essential for the ubiquitination of GST-XAF1RBD fusion protein. In addition, the C-terminal XAF1 fragment harboring XAF1RBD was found to be substantially ubiquitinated by XIAPRING. Base on these observations, we speculate a possible role of XAF1RBD in targeting XAF1 for XIAP-mediated ubiquitination. [ABSTRACT FROM AUTHOR]

Background: Inhibitor of apoptosis proteins (IAPs) belong to a pivotal antiapoptotic protein family that plays a crucial role in tumorigenesis, cancer progression, chemoresistance and poor patient-survival. X-linked inhibitor of apoptosis protein (XIAP) is a prominent member of IAPs attracting intense research because it has been demonstrated to be a physiological inhibitor of caspases and apoptosis. Recently, an evolutionarily conserved ubiquitin-associated (UBA) domain was identified in XIAP and a number of RING domain-bearing IAPs. This has placed the IAPs in the group of ubiquitin binding proteins. Here, we explore the three-dimensional structure of the XIAP UBA domain (XIAP-UBA) and how it interacts with monoubiquitin and diubiquitin conjugates. Principal Findings: The solution structure of the XIAP-UBA domain was determined by NMR spectroscopy. XIAP-UBA adopts a typical UBA domain fold of three tightly packed α-helices but with an additional N-terminal 310 helix. The XIAP-UBA binds mono-ubiquitin as well as Lys48-linked and linear-linked diubiquitins at low-micromolar affinities. NMR analysis of the XIAP-UBA-ubiquitin interaction reveals that it involves the classical hydrophobic patches surrounding Ile44 of ubiquitin and the conserved MGF/LV motif surfaces on XIAP-UBA. Furthermore, dimerization of XIAP-UBA was observed. Mapping of the self-association surface of XIAP-UBA reveals that the dimerization interface is formed by residues in the N-terminal 310 helix, helix α1 and helix α2, separate from the ubiquitin-binding surface. Conclusion: Our results provide the first structural information of XIAP-UBA and map its interaction with mono-ubiquitin, Lys48-linked and linear-linked diubiquitins. The notion that XIAP-UBA uses different surfaces for ubiquitin-binding and self-association provides a plausible model to explain the reported selectivity of XIAP in binding polyubiquitin chains with different linkages. [ABSTRACT FROM AUTHOR]

The purpose of this study is to comprehensively evaluate potential functional polymorphisms in the P21 gene in relation to the risk of lung cancer. We first determined the frequencies of P21 polymorphisms in 27 healthy Koreans, and then examined three polymorphisms (−2266G > A, S31R, and IVS2 + 16G > C), based on their frequencies and haplotype-tagging status, in a case–control study. Individuals with at least one −2266A allele were at a significantly decreased risk of lung cancer compared with those harboring the −2266 GG genotype [adjusted odds ratio (OR) = 0.71, 95% confidence interval (CI) = 0.53–0.95, P = 0.02). The haplotypes (ht2–4) carrying 31R or IVS2 + 16C alleles were associated with a significantly decreased risk of lung cancer compared with the haplotype 31S/IVS2 + 16G, which carried wild-type alleles at both loci (adjusted OR = 0.65, 95% CI = 0.50–0.83, P = 0.007)]. When the −2266A allele and ht2–4 were considered to be protective alleles, the risk of lung cancer decreased in a dose-dependent manner as the number of protective alleles increased ( P = 0.0002). These results suggest that a combined analysis of these three P21 polymorphisms might better predict the risk of lung cancer than the analysis of a single polymorphism. [ABSTRACT FROM AUTHOR]

Background and objectives: Epidermal growth factor (EGF) plays an important role in tumourigenesis by binding with its receptor, EGFR. Variations in the DNA sequence in the EGF gene can lead to an alteration in EGF production and/or activity, which can affect an individual's susceptibility to lung cancer. To test this hypothesis, this study examined the association between the +61 A>G polymorphism in the 5′-untranslated region of the EGF gene and the risk of lung cancer in a Korean population. Methods: The EGF+61 A>G genotype was determined in 432 lung cancer patients and 432 healthy age- and gender-matched control subjects. Results: The +61 AA and +61 AG genotypes were not significantly associated with the risk of lung cancer compared with the +61 GG genotype (adjusted OR = 1.02, 95% CI: 0.77–1.37; and adjusted OR = 0.81, 95% CI: 0.51–1.29, respectively). In addition to the reference model, the EGF+61 A>G polymorphism had no significant association with the risk of lung cancer under both dominant and recessive models for the +61A allele (adjusted OR = 0.98, 95% CI: 0.74–1.29; and adjusted OR = 0.80, 95% CI: 0.51–1.24, respectively). Conclusion: These results suggest that the EGF+61 A>G polymorphism may not significantly affect the susceptibility to lung cancer in the Korean population. [ABSTRACT FROM AUTHOR]

Background: Cyclooxygenase-2 (COX-2) plays an important role in the development of lung cancer. DNA sequence variations in the COX-2 gene may lead to altered COX-2 production and/or activity, and so they cause inter-individual differences in the susceptibility to lung cancer. To test this hypothesis, we investigated the association between the 8473T>C polymorphism in the 3'-untranslated region of the COX-2 gene and the risk of lung cancer in a Korean population. Methods: The COX-2 genotypes were determined using PCR-based primer-introduced restriction analysis in 582 lung cancer patients and in 582 healthy controls that were frequency-matched for age and gender. Results: The distribution of the COX-2 8473T>C genotypes was not significantly different between the overall lung cancer cases and the controls. However, when the cases were categorized by the tumor histology, the combined 8473 TC + CC genotype was associated with a significantly decreased risk of adenocarcinoma as compared with the 8473 TT genotype (adjusted OR = 0.64; 95% CI = 0.46-0.90, P = 0.01). On the stratification analysis, the protective effect of the combined 8473 TC + CC genotype against adenocarcinoma was statistically significant in the males, older individuals and ever-smokers (adjusted OR = 0.59; 95% CI = 0.39-0.91, P = 0.02; adjusted OR = 0.55; 95% CI = 0.33-0.93, P = 0.03; and adjusted OR = 0.57; 95% CI = 0.37-0.87, P = 0.01, respectively). Conclusion: These findings suggest that the COX-2 8473T>C polymorphism could be used as a marker for the genetic susceptibility to adenocarcinoma of the lung. [ABSTRACT FROM AUTHOR]

Serum gamma-glutamyltransferase (GGT) concentration, within its normal range, has recently been proposed as a reliable marker of oxidative stress. Oxidative stress plays a central pathogenic role in many metabolic and/or cardiovascular diseases, incidences of which have recently increased in South Korea. Since serum GGT has strong associations with these diseases and their risk factors, the authors hypothesized a corresponding secular trend of increasing serum GGT levels in South Korea. Study subjects were 8,072 male workers at a large steel company who were aged 2444 years at baseline and had received annual physical examinations from 1996 to 2003. The secular trend was a 0.1066-units/liter increase in ln(GGT) level per calendar year (a 180% increase during the 7-year follow-up period) (p < 0.01). Adjustment for body mass index, alcohol consumption, smoking, exercise, and cholesterol level as time-dependent covariates did not change the results. Although cholesterol is commonly used as a marker of epidemiologic transition, there was a less dramatic secular trend in ln(serum cholesterol) level, and it disappeared after adjustment for the secular trend in serum GGT. These findings suggest that serum GGT concentration can be used as a sensitive marker of epidemiologic transition, and they portend a continuing rise in incidences of metabolic and/or cardiovascular diseases in this population in the coming years. [ABSTRACT FROM AUTHOR]

X-linked inhibitor of apoptosis protein (XIAP), a leading member of the family of inhibitor of apoptosis (IAP) proteins, is considered as the most potent and versatile inhibitor of caspases and apoptosis. It has been reported that XIAP is frequently overexpressed in cancer and its expression level is implicated in contributing to tumorigenesis, disease progression, chemoresistance and poor patient-survival. Therefore, XIAP is one of the leading targets in drug development for cancer therapy. Recently, based on bioinformatics study, a previously unrecognized but evolutionarily conserved ubiquitin-associated (UBA) domain in IAPs was identified. The UBA domain is found to be essential for the oncogenic potential of IAP, to maintain endothelial cell survival and to protect cells from TNF-α-induced apoptosis. Moreover, the UBA domain is required for XIAP to activate NF-κB. In the present study, we report the near complete resonance assignments of the UBA domain-containing region of human XIAP protein. Secondary structure prediction based on chemical shift index (CSI) analysis reveals that the protein is predominately α-helical, which is consistent with the structures of known UBA proteins. [ABSTRACT FROM AUTHOR]

Two series of aliphatic hydrocarbon-based G1-G3 dendritic 2-ureido-4-pyrimidinones (UPy) (S-Gn)₂ and (L-Gn)₂, differing from one another by the distance between the branching juncture to the urea end, were prepared and characterized. These hydrocarbon dendrons were also appended to a p-aminonitrobenzene solvatochromic chromophore in order to probe their microenvironment polarity. While positive solvatochromism was observed which indicated the chromophore was solvent accessible, there was no significant difference between the microenvironment polarities on going from the G1 to the G3 dendrons. The self-assembling behavior and tautomeric preference of the dendritic UPy derivatives were examined by ¹H NMR spectroscopy. The dimerization constants (K(dim*)) of the DDAA tautomers were unchanged at 10⁷ M⁻¹ in CDCl₃ at both 25 and 50°C, which were comparable to those of UPy compounds bearing other nonpolar substituents. Furthermore, the lower limits on the K'(dim*) of the DADA tautomeric forms of the (S-Gn)₂ and (L-Gn)₂ series were determined to be 10⁶ and 10⁵ M⁻¹ in CDCl₃, respectively. It was found that a closer proximity of the dendron branching juncture to the UPy unit could lead to a destabilization effect on the dimeric states. Hence, the (L-Gn)₂ dimers are more stable than those of (S-Gn)₂ in the DDAA form, but the latter are more stable than the former in the tautomeric DADA state. This study showed that both the highly nonpolar microenvironment and the proximity of the dendritic branching juncture to the UPy motif could alter the strength and profile of the hydrogen bond-mediated self-assembling process.

[reaction: see text] A new series of self-assembling G1-G3 dendronized dimers bearing oligoether dendrons and a dimeric 2-ureido-4-pyrimidinone (UPy) quadruple hydrogen-bonding core were prepared and characterized. It was found that the nonpolar microenvironment created by the dendrons preserved the UPy unit in its DDAA tautomeric form. As a result, the stabilities of the dimers were exceptionally strong for all three generations (K(dim) > 2 x 10(7) M(-)(1) in CDCl(3) at 25 degrees C). Furthermore, the steric size of the dendrons did not exhibit a significant effect on their dimerization behavior.