Newly Developed Sex-Specific Z Score Model for Coronary Artery Diameter in a Pediatric Population

BACKGROUND

This study aimed to generate a Z score calculation model for coronary artery diameter of normal children and adolescents to be adopted as the standard calculation method with consensus in clinical practice.

METHODS

This study was a retrospective, multicenter study that collected data from multiple institutions across South Korea. Data were analyzed to determine the model that best fit the relationship between the diameter of coronary arteries and independent demographic parameters. Linear, power, logarithmic, exponential, and square root polynomial models were tested for best fit.

RESULTS

Data of 2,030 subjects were collected from 16 institutions. Separate calculation models for each sex were developed because the impact of demographic variables on the diameter of coronary arteries differs according to sex. The final model was the polynomial formula with an exponential relationship between the diameter of coronary arteries and body surface area using the DuBois formula.

CONCLUSION

A new coronary artery diameter Z score model was developed and is anticipated to be applicable in clinical practice. The new model will help establish a consensus-based Z score model.

Study on transient photocurrent induced by energy level defect of schottky diode irradiated by high power pulsed laser

The transient photocurrent is one of the key parameters of the spatial radiation effect of photoelectric devices, and the energy level defect affects the transient photocurrent. In this paper, by studying the deep level transient spectrum of a self-designed Schottky diode, the defect properties of the interface region of the anode metal AlCu and Si caused by high-temperature annealing at 150 ℃, 200 ℃ and 300 ℃ for 1200 h have been quantitatively analyzed. The study shows that the defect is located at the position of + 0.41 eV on the valence band, the concentration is 2.8 [Formula: see text] 1013/cm2, and the capture cross section is [Formula: see text] = 8.5 [Formula: see text] 1017. The impurity energy level mainly comes from the diffusion of Al atom in anode metal. We found that the defect did not cause the electrical performance degradation and obvious morphology change of the device, but the transient photocurrent increased significantly. The reason is that the high temperature treatment results in a growth in the density of states at the interface between AlCu-Si. The more mismatched dislocations and recombination center increased the reverse current of the heterojunction. The above view is proved by the TCAD simulation test.

[Cystic echinococcosis of the waist and hip: a case report]

A patient with cystic echinococcosis was presented with primary lesions in the waist and hip. The case was misdiagnosed as subcutaneous abscess at initial diagnosis, and then definitively diagnosed as echinococcosis by means of imaging examinations and anti-Echinococcus antibody test. This case was reported with aims to improve the awareness of cystic echinococcosis among clinical physicians to avoid and reduce the misdiagnosis and missing diagnosis.

Correction: The Rho/ROCK pathway for lysophosphatidic acid-induced proteolytic enzyme expression and ovarian cancer cell invasion

The original version of this article contained an error in the published figures Fig 2 and Fig 3f, where the information was inadvertently duplicated. This error does not alter the conclusions of the paper. The corrected figures are published in this correction notice. The authors sincerely apologize for this error.

[Transmission cluster and network of HIV-1 CRF01_AE strain in China, 1996-2014]

Objective: To understand the transmission patterns and risk factors of HIV-1 strain CRF01_AE subtypes in China, and to provide guidance for the implementation of precise intervention. Methods: A total of 2 094 CRF01_AE pol sequences were collected in 19 provinces in China between 1996 and 2014. Phylogenetic tree was constructed by PhyML 3.0 software to select the transmission clusters. Transmission network was constructed by Cytoscape 3.6.0, which was further used for exploring of the major risk factors. Results: Of the 2 094 sequences, 12.18% (255/2 094) were in clusters. A total of 82 transmission clusters were identified. The numbers of clusters and contained sequences in intra-provincial transmission (61, 173) were significantly more than those in inter-provincial transmission (21, 82). The ratio of transmission clustering in MSM increased over time from 2.41% (2/83) during 1996-2008 to 23.61% (72/305) during 2013-2014, showing a significant upward trend (χ(2)=27.800, df=1, P=0.000). The proportion of MSM with inter-provincial transmission clusters were higher than those with intra-provincial transmission clusters, which increased from 0.67% (2/297) during 1996-2008 to 6.36%(30/472) during 2013-2014, showing a significant upward trend (χ(2)=20.276, df=1, P=0.000). The transmission rate in homosexuals of the inter-transmission clusters (86.59%, 71/82) was higher than that of intra-provincial transmission clusters (56.65%, 98/173), and the difference was statistically significant (χ(2)=22.792, P=0.000). The proportion of inter-provincial transmission clusters with more than 2 transmission routes (33.33%, 7/21) was higher than that of intra-provincial clusters (13.11%, 8/61), and the difference was statistically significant (χ(2)=4.273, P=0.039). Results from the transmission network analysis indicated that the proportion of high risk population (degree≥4) with inter-provincial transmission clusters (51.22%, 42/82) was significantly higher than that with intra-provincial transmission clusters (26.59%, 46/173), and the difference was statistically significant (χ(2)=14.932, P=0.000). Inter-provincial clusters were mainly detected in and and MSM. Conclusions: Complex transmission networks were found for HIV-1 CRF01_AE strains in the mainland of China. Inter-provincial transmission clusters increased rapidly, MSM played an important role in the wide spread of the strain. More researches in transmission networks are needed to guide the precision intervention.

Abstract P5-07-10: The prognostic significance of estrogen formation as a consequence of aromatase expression in tumor microenvironment

Estrogen synthesis via aromatase in adipose tissue has an important role in progression of postmenopausal breast cancer. The increased local concentrations of estrogen in breast cancer via aromatase overexpression within the tumor tissue have been demonstrated by some investigators. Although aromatase inhibitor is the standard endocrine therapy for postmenopausal breast cancer patients, it is not uncommon for patients to have poor compliance to the drugs due to their side effects. This research is based on the hypothesis that if aromatase expression is related to prognosis and if therapeutic effect varies depending on the degree of aromatase expression, then this study may be able to suggest a new guideline in terms of choosing between aromatase inhibitors and tamoxifen.

Methods: 154 postmenopausal breast cancer patients who underwent surgery and aromatase inhibitor therapy in Busan Paik Hospital, Inje University from January 2005 to December 2010 were enrolled. Patients with DCIS or stage IV breast cancer were excluded. Patients' clinicopathological data were collected and TMA blocks were created for immunohistochemistry studies to examine aromatase expression.

Results: The recurrence has occured in 7 patients (6.9%). Stage, tumor size and number of lymph node metastasis were related to increased risk of recurrence (p=0.051, 0.043, 0.001). The aromatase expression in cancer cells had significant correlation with clinical stage (p=0.041). There was also a positive correlation between Ki67 and aromatase expression in cancer tissue (p=0.006). However, aromatase expression in cancer, stromal, and adipose tissue had no relationship with recurrence (p=0.410, 0.627, 0.552).

Correlation between clinicopathologic factors and aromatase expression (Linear by linear association and Spearman's correlation coefficient test)Site of aromatase expressionERPRKi67P53BMIStageIn Cancer0.6060.5920.0060.4510.9560.041In Stroma0.2200.4710.5840.3290.3670.229In Adipose0.9880.2650.1590.1170.7701.000

Conclusions: Aromatase expression in cancer cells was correlated with clinical stage. This implies that aromatase expression might have a role of prognostic marker in addition to role of treatment indicator. There was no direct correlation between aromatase expression and recurrence.

Citation Format: Kim TH, Lee A, Han JW, Jung SJ, Byun K-D. The prognostic significance of estrogen formation as a consequence of aromatase expression in tumor microenvironment [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-07-10.

[The timing of renal replacement therapy on mortality in patients with acute renal injury: a reanalysis of two recently published randomized control trials]

To investigate the sources of inconsistent findings between two randomized control trials["initiation strategies for renal-replacement therapy in the intensive care unit"(AKIKI trial) vs"effect of early vs delayed initiation of renal replacement therapy on mortality in critically ill patients with acute kidney injury"(ELAIN trial) ], regarding"timing of renal replacement therapy (RRT) on mortality in patients with acute kidney injury (AKI). By reanalysis of the published data, it was found that demographics, severity of primary disease and stage of AKI before initiation of RRT were quite different between AKIKI and ELAIN trials. Interestingly, similar mortalities were demonstrated in late group of ELAIN trial, both of early and late groups of AKIKI trial [all patients were classified at Kidney Disease: Improving Global Outcomes (KDIGO) classification stage 3 of AKI, P>0.05] although a significant reduction of mortality was determined in early group of ELAIN trial (KDIGO stage 2 of AKI).Therefore, it was concluded that inconsistent results were largely attributable to the heterogeneity of enrolled patients between ELAIN vs AKIKI trials, including demographics and severity of AKI(AKI stage) before initiation of RRT.

Specific PCR detection of Fusarium oxysporum f. sp. raphani: a causal agent of Fusarium wilt on radish plants

Fusarium oxysporum, a causal agent of Fusarium wilt, is one of the most important fungal pathogens worldwide, and detection of F. oxysporum DNA at the forma specialis level is crucial for disease diagnosis and control. In this study, two novel F. oxysporum f. sp. raphani (For)-specific primer sets were designed, FOR1-F/FOR1-R and FOR2-F/FOR2-R, to target FOQG_17868 and FOQG_17869 ORFs, respectively, which were selected based on the genome comparison of other formae speciales of F. oxysporum including conglutinans, cubense, lycopersici, melonis, and pisi. The primer sets FOR1-F/FOR1-R and FOR2-F/FOR2-R that amplified a 610- and 425-bp DNA fragment, respectively, were specific to For isolates which was confirmed using a total of 40 F. oxysporum isolates. From infected plants, the FOR2-F/FOR2-R primer set directly detected the DNA fragment of For isolates even when the radish plants were collected in their early stage of disease development. Although the loci targeted by the For-specific primer sets were not likely involved in the pathogenesis, the primer set FOR2-F/FOR2-R is available for the determination of pathogenicity of radish-infecting F. oxysporum isolates. This study is the first report providing novel primer sets to detect F. oxysporum f. sp. raphani.

SIGNIFICANCE AND IMPACT OF THE STUDY

Because plant pathogenic Fusarium oxysporum has been classified into special forms based on its host specificity, identification of F. oxysporum usually requires a pathogenicity assay as well as knowledge of the morphological characteristics. For rapid and reliable diagnosis, this study provides PCR primer sets that specifically detect Fusarium oxysporum f. sp. raphani (For) which is a devastating pathogen of radish plants. Because one of the primer sets directly detected the DNA fragment of For isolates from infected plants, the specific PCR method demonstrated in this study will provide a foundation for integrated disease management practices in commodity crops.

Medium- or Higher-Dose Acetylsalicylic Acid for Acute Kawasaki Disease and Patient Outcomes

OBJECTIVE

To investigate the effect of medium- or higher-dose acetylsalicylic acid (ASA) for treating acute-phase Kawasaki disease to prevent coronary artery aneurysm (CAA).

STUDY DESIGN

Among the children with acute Kawasaki disease investigated in the eighth nationwide survey in the Republic of Korea, 8456 children with adequate data were included in this study. The subjects were divided into 2 groups according to the use of medium- or higher-dose ASA (≥30 mg/kg/day), or-low dose ASA (3-5 mg/kg/day) during the acute febrile phase. Both z- score-based criteria and Japanese criteria for CAA were used.

RESULTS

The prevalence of CAA based on z-score (24.8% vs 18.3%; P = .001) and on the Japanese criteria (19.0% vs 10.4%; P < .001) was higher in the 7947 patients who received medium- or higher-dose ASA compared with the 509 patients who received low-dose ASA. The use of medium- or higher-dose ASA was a significant predictor of CAA based on both sets of criteria by univariate analysis (based on z-score: OR, 1.472, 95% CI, 1.169-1.854, P = .001; based on Japanese criteria: OR, 2.013, 95% CI, 1.507-2.690, P < .001) and multivariate logistic regression analysis (OR, 1.527, 95% CI, 1.166-2.0, P = .003 and OR, 2.198, 95% CI, 1.563-3.092, P < .001, respectively).

CONCLUSIONS

The use of medium- or higher-dose ASA in acute Kawasaki disease did not prevent CAA. A future randomized controlled trial is needed to determine the optimum dose of ASA.

Application of emitter-sample hybrid terahertz time-domain spectroscopy to investigate temperature-dependent optical constants of doped InAs

We investigate temperature-dependent carrier dynamics of InAs crystal by using reflection-type terahertz time-domain spectroscopy, particularly with a recently developed emitter-sample hybrid structure. We successfully obtain the optical conductivity in a terahertz frequency of bulk InAs whose dc conductivity is in the range of 100-150  Ω^-1 cm^-1. We find that both real and imaginary parts of the optical conductivity can be fit well with the simple Drude model, and the free-carrier density and the scattering rate obtained from the fit are in good agreement with corresponding values obtained by using other techniques, such as the Hall measurement and the dc-resistivity measurement. These results clearly demonstrate that the proposed technique of adopting the emitter-sample hybrid structure can be exploited to determine temperature-dependent optical constants in a reflection geometry and hence to investigate electrodynamics of bulk metallic systems.

Prediction of nonresponsiveness to medium-dose intravenous immunoglobulin (1 g/kg) treatment: an effective and safe schedule of acute treatment for Kawasaki disease

Purpose

Medium-dose (1 g/kg) intravenous immunoglobulin (IVIG) is effective in the majority of patients with Kawasaki disease (KD) but some patients who do not respond to medium-dose IVIG are at high risk for the development of coronary artery lesions (CALs). The purpose of this study was to identify the clinical predictors associated with unresponsiveness to medium-dose IVIG and the development of CALs.

Methods

A retrospective study was performed in 91 children with KD who were treated with medium-dose IVIG at our institution from January 2004 to December 2013. We classified the patients into responders (group 1; n=68) and nonresponders (group 2; n=23). We compared demographic, laboratory, and echocardiographic data between the 2 groups.

Results

Multivariate logistic regression analysis identified 6 variables as predictors for resistance to medium-dose IVIG. We generated a predictive scoring system assigning 1 point each for percentage of neutrophils ≥65%, C-reactive protein≥100 mg/L, aspartate aminotransferase≥100 IU/L, and alanine aminotransferase≥100 IU/L, as well as 2 points for less than 5 days of illness, and serum sodium level≤136 mmol/L. Using a cutoff point of ≥4 with this scoring system, we could predict nonresponsiveness to medium-dose IVIG with 74% sensitivity and 71% specificity.

Conclusion

If a patient has a low-risk score in this system, medium-dose IVIG can be recommended as the initial treatment. Through this process, we can minimize the adverse effects of high-dose IVIG and incidence of CALs.

Usefulness of anterior uveitis as an additional tool for diagnosing incomplete Kawasaki disease

PURPOSE

There are no specific tests for diagnosing Kawasaki disease (KD). Additional diagnostic criteria are needed to prevent the delayed diagnosis of incomplete Kawasaki disease (IKD). This study compared the frequency of coronary artery lesions (CALs) in IKD patients with and without anterior uveitis (AU) and elucidated whether the finding of AU supported the diagnosis of IKD.

METHODS

This study enrolled patients diagnosed with IKD at The Catholic University of Korea, Uijeongbu St. Mary's Hospital from January 2010 to December 2014. The patients were divided into 2 groups: group 1 included patients with IKD having AU; and group 2 included patients with IKD without AU. We analyzed the demographic and clinical data (age, gender, duration of fever, and the number of diagnostic criteria), laboratory results, and echocardiographic findings.

RESULTS

Of 111 patients with IKD, 41 had uveitis (36.98%, group 1) and 70 did not (63.02%, group 2). Patients in group 1 had received a diagnosis and treatment earlier, and had fewer CALs (3 of 41, 1.7%) than those in group 2 (20 of 70, 28.5%) (P=0.008). All 3 patients with CALs in group 1 had coronary dilatation, while patients with CALs in group 2 had CALs ranging from coronary dilatation to giant aneurysm.

CONCLUSION

The diagnosis of IKD is challenging but can be supported by the presence of features such as AU. Group 1 had a lower risk of coronary artery disease than group 2. Therefore, the presence of AU is helpful in the early diagnosis and treatment of IKD and can be used as an additional diagnostic tool.

Self-expandable metal stents for malignant esophageal obstruction: a comparative study between extrinsic and intrinsic compression

Self-expandable metal stents (SEMSs) are effective for malignant esophageal obstruction, but usefulness of SEMSs in extrinsic lesions is yet to be elucidated. This study is aimed at evaluating the clinical usefulness of SEMSs in the extrinsic compression compared with intrinsic. A retrospective review was conducted for 105 patients (intrinsic, 85; extrinsic, 20) with malignant esophageal obstruction who underwent endoscopic SEMSs placement. Technical and clinical success rates were evaluated and clinical outcomes were compared between extrinsic and intrinsic group. Extrinsic group was mostly pulmonary origin. Overall technical and clinical success rate was 100% and 91%, respectively, without immediate complications. Extrinsic and intrinsic group did not differ significantly in clinical success rate. The median stent patency time was 131.3 ± 85.8 days in intrinsic group while that of extrinsic was 54.6 ± 45.1 due to shorter survival after stent insertion. The 4-, 8-, and 12-week patency rates were 90.5%, 78.8%, and 64.9% respectively in intrinsic group, while stents of extrinsic group remained patent until death. Uncovered, fully covered, and double-layered stent were used evenly and the types did not influence patency in both groups. In conclusion, esophageal SEMSs can safely and effectively be used for malignant extrinsic compression as well as intrinsic.

Antifungal activity of rimocidin and a new rimocidin derivative BU16 produced by Streptomyces mauvecolor BU16 and their effects on pepper anthracnose

AIMS

The objective of this study was to explore antifungal metabolites targeting fungal cell envelope and to evaluate the control efficacy against anthracnose development in pepper plants.

METHODS AND RESULTS

A natural product library comprising 3000 microbial culture extracts was screened via an adenylate kinase (AK)-based cell lysis assay to detect antifungal metabolites targeting the cell envelope of plant-pathogenic fungi. The culture extract of Streptomyces mauvecolor strain BU16 displayed potent AK-releasing activity. Rimocidin and a new rimocidin derivative, BU16, were identified from the extract as active constituents. BU16 is a tetraene macrolide containing a six-membered hemiketal ring with an ethyl group side chain instead of the propyl group in rimocidin. Rimocidin and BU16 showed broad-spectrum antifungal activity against various plant-pathogenic fungi and demonstrated potent control efficacy against anthracnose development in pepper plants.

CONCLUSIONS

Antifungal metabolites produced by S. mauvecolor strain BU16 were identified to be rimocidin and BU16. The compounds displayed potent control efficacy against pepper anthracnose.

SIGNIFICANCE AND IMPACT OF THE STUDY

Rimocidin and BU16 would be active ingredients of disease control agents disrupting cell envelope of plant-pathogenic fungi. The structure and antifungal activity of rimocidin derivative BU16 is first described in this study.

Serum 25-hydroxyvitamin D level and the risk of mild cognitive impairment and dementia: the Korean Longitudinal Study on Health and Aging (KLoSHA)

OBJECTIVE

The association of low vitamin D status with mild cognitive impairment (MCI), a preclinical condition that can lead to dementia, has not yet been fully explored. Our aim was to investigate the association between vitamin D status and the future risk of MCI and dementia in older adults.

DESIGN, SETTING AND PARTICIPANTS

We conducted a population-based prospective study as a part of the Korean Longitudinal Study on Health and Aging. Four hundred and twelve elderly participants who completed evaluations of cognitive function and metabolic parameters in 2005-2006 and 2010-2011 were analysed.

MAJOR OUTCOME MEASURE

The rate of development of MCI or dementia during the study period was compared according to baseline vitamin D status. Binary logistic regression analysis was performed to investigate any independent association between vitamin D status and the risks of MCI or dementia.

RESULTS

Among 405 subjects that remained after excluding seven demented subjects at baseline, 338 subjects remained unchanged or improved in their diagnosis for cognitive function during the study period, whereas 67 subjects showed progression to MCI or dementia. When analyzing 236 subjects whose baseline mini-mental state examination (MMSE) scores were <27, severe vitamin D deficiency at baseline, defined as <25 nmol/l, was independently associated with the progression of cognitive impairment. Among 297 subjects who were normal at baseline, 50 acquired MCI and 247 remained normal. Severe vitamin D deficiency was also independently associated with the development of MCI when analyzing 145 subjects whose baseline MMSE scores were <27.

CONCLUSION

Severe vitamin D deficiency was independently associated with the future risk of MCI as well as dementia, especially in older adults whose baseline MMSE scores had decreased only modestly.

Normal left ventricular torsion mechanics in healthy children: age related changes of torsion parameters are closely related to changes in heart rate

Background and Objectives

This study was aimed at assessing left ventricular torsion (LVtor) mechanics using speckle tracking echocardiography (STE), establishing normal reference values of principal LVtor parameters, and analyzing the age-related changes in normal children.

Subjects and Methods

Eighty children (aged 3 months to 15 years) with normal cardiac function and rhythm were recruited. LVtor parameters including rotations, twist and untwist, torsion, and their rate indices were measured using STE. Age and heart rate related changes of the parameters were analyzed.

Results

Speckle tracking echocardiography analyses for LVtor parameters had excellent reliability in 64 of 80 subjects (80%) (intraclass correlation coefficients; 0.93-0.97). Early systolic twist (EST) motions (-8.4--0.1°) were observed in all subjects during an early 20±7% of systolic time intervals. The peak systolic twist and torsion were 17.0±6.5° and 2.9±1.3°/cm, respectively. The peak twist velocity was recorded at 51±13% of systolic time and the peak untwist velocity at 13.8±11.5% of diastolic time intervals. Multivariate analysis showed that heart rate change was an independent predictor of changes in torsion parameters; significantly decreasing LV length-normalized apical and basal rotation, torsion, and twist and untwist rate with increasing age. Isovolumetric recoil rate was independent of change in age and heart rate.

Conclusion

Left ventricle showed unique torsion mechanics in children with EST, torsion, and untwists. Heart rate was an independent predictor of the change in torsion parameters with aging.

Extraction of optical constants using multiple reflections in the terahertz emitter-sample hybrid structure

To extract optical constants of nontransmitted samples in the terahertz (THz) spectral region, we employ a THz emitter-sample hybrid structure where THz pulses are generated at the emitter surface and multiply reflected at the interface between the THz emitter and the sample. Since each THz electric field profile appears well separated in a time domain, we could obtain the amplitude and phase spectra for each pulse from the Fourier transform, and determine the optical constants of the sample numerically based on the Fresnel equations. We applied this technique for doped semiconductors, and found that obtained optical constants are in good agreement with the values determined by using other conventional THz techniques.

Short-term effects of topical cyclosporine A 0.05% (Restasis) in long-standing prosthetic eye wearers: a pilot study

PURPOSE

Long-standing prosthetic eye wearing induces ocular surface inflammation. We investigated the short-term effects of topical cyclosporine A 0.05% (Restasis) in patients with ocular discomfort resulting from long-standing prosthetic eye wearing.

METHODS

This was a prospective, interventional case series. Patients who were unilateral prosthetic eye wearers over a period of 5 years were enrolled at a single institution from March to July 2013. The subjects were instructed to instill topical cyclosporine A 0.05% twice per day. Measurements were made pre-treatment and after 1 and 3 months of treatment. Outcome measures were the ocular symptom score, the lid margin abnormality score, the Schirmer test, and the tear meniscus amount, using Fourier-domain optical coherence tomography.

RESULTS

In total, 20 consecutive patients (mean age: 60.1 years, 8 males, 12 females) were included. Ocular symptoms were improved after treatment for 1 month in all patients (ocular symptom score pre-treatment 76.83 vs 46.75 after treatment; P<0.001). There was no statistically significant difference in lid margin abnormality score or tear meniscus amount. The Schirmer test results were improved after treatment for 3 months (pre- and after treatment, 6.70 vs 11.40; P<0.001).

CONCLUSIONS

Topical cyclosporine A 0.05% showed a satisfactory effect in long-standing prosthetic eye wearers. Ocular symptoms were markedly relieved in all subjects after treatment for 1 month.

Evaluation of the Temporal Association between Kawasaki Disease and Viral Infections in South Korea

Background and Objectives

This study is aimed at elucidating potential temporal associations between the occurrence of Kawasaki disease (KD) and various viral infections.

Subjects and Methods

We obtained monthly patterns of KD from the seventh nationwide survey and viral detection data from the Korea Centers for Disease Control and Prevention from 2009 to 2011 and evaluated temporal correlations between them for each month. The respiratory viruses detected using a multiplex real-time-polymerase chain reaction kit were influenza virus (A/H1N1, A/H3N2, A/H5N1, and B), adenovirus, parainfluenza virus (type 1, 2, 3), respiratory syncytial virus (type A, B), human rhinovirus, human coronavirus (OC43/229E, NL63), human bocavirus, and enterovirus.

Results

We obtained data from a total of 13031 patients who were treated for acute KD from 87 hospitals with pediatric residence programs. During this survey, KD showed highest overall incidence in summer and winter seasons and lowest incidence in February and October. We received viral detection data for a total of 14267 patients. Viral detection was highest during winter and spring seasons. The most commonly detected virus was human rhinovirus (32.6%), followed by influenza virus (26.8%). The monthly incidence of KD showed significant correlation with the monthly overall viral detection (p=0.022, r=0.382). In particular, human bocavirus and enterovirus have significant correlations with monthly patterns of KD occurrence (p=0.032 and p=0.007, respectively) and influenza virus correlated with KD occurrence with borderline significance (p=0.063).

Conclusion

The temporal association between monthly occurrence of KD and viral detection suggests the etiologic importance of precedent infection in the development of KD.

Baseline heart rate variability in children and adolescents with vasovagal syncope

Purpose

This study aimed to evaluate the autonomic imbalance in syncope by comparing the baseline heart rate variability (HRV) between healthy children and those with vasovagal syncope.

Methods

To characterize the autonomic profile in children experiencing vasovagal syncope, we evaluated the HRV of 23 patients aged 7-18 years and 20 healthy children. These children were divided into preadolescent (<12 years) and adolescent groups. The following time-domain indices were calculated: root mean square of the successive differences (RMSSD); standard deviation of all average R-R intervals (SDNN); and frequency domain indices including high frequency (HF), low frequency (LF), normalized high frequency, normalized low frequency, and low frequency to high frequency ratio (LF/HF).

Results

HRV values were significantly different between healthy children and those with syncope. Student t test indicated significantly higher SNDD values (60.46 ms vs. 37.42 ms, P=0.003) and RMSSD (57.90 ms vs. 26.92 ms, P=0.000) in the patient group than in the control group. In the patient group, RMSSD (80.41 ms vs. 45.89 ms, P=0.015) and normalized HF (61.18 ms vs. 43.19 ms, P=0.022) were significantly higher in adolescents, whereas normalized LF (38.81 ms vs. 56.76 ms, P=0.022) and LF/HF ratio (0.76 vs. 1.89, P=0.041) were significantly lower in adolescents. In contrast, the control group did not have significant differences in HRV values between adolescents and preadolescents.

Conclusion

The results of this study indicated that children with syncope had a decreased sympathetic tone and increased vagal tone compared to healthy children. Additionally, more severe autonomic imbalances possibly occur in adolescents than in preadolescents.

Development and characterization of new microsatellites for walnut (Juglans regia)

The expressed sequence tag (EST) database represents a potentially valuable resource for the development of simple sequence repeat (SSR) markers for use in evolutionary studies. EST-SSRs reveal polymorphisms not only within the source taxon, but in related taxa as well. In this paper, we describe a case study in which the publicly available walnut (Juglans regia) EST database was used to develop SSR markers for use in the genetic analysis of the widespread Juglans nigra and Carya cathayensis and an endangered species Annamocarya sinensis. A total of 7262 unigenes, including 1911 contigs and 5351 singletons, were obtained from 13,559 ESTs retrieved from the NCBI database. The 7262 unigenes were further reduced to 706 EST-SSR sequences containing 805 SSR loci. Then, 309 EST-SSR primers were randomly designed, and 77 were identified with five high across-species transferability cross-species: namely, J. regia, J. nigra, C. cathayensis, Carya dabieshanensis, and A. sinensis. Thirteen highly polymorphic EST-SSRs were further used for genetic analyses in these above five species.

Conservation genetics of Annamocarya sinensis (Dode) Leroy, an endangered endemic species

The endangered perennial plant Annamocarya sinensis (Dode) Leroy is a tertiary relict tree restricted to southeastern China and northern Vietnam. To explore endangerment mechanisms, develop protection strategies, and guide reintroduction efforts for this species, we investigated genetic diversity and population structure by surveying 70 individuals from three distinct populations using 12 polymorphic microsatellite markers. We found high genetic diversity for A. sinensis as indicated by high allelic diversity (allelic number = 4.667 ± 0.436, effective number of alleles = 2.913 ± 0.249), excess heterozygosity (observed heterozygosity = 0.586 ± 0.039, expected heterozygosity = 0.582 ± 0.029), and low fixation index (-0.028 ± 0.057). Our research revealed low genetic differentiation (FST = 0.066 ± 0.011) and no correlation between genetic distance and geographic distance. Analysis of molecular variance attributed 87% of the variance to differences within the population, whereas 13% was distributed among populations. The protection strategy should aim to protect as many populations as possible. Promoting sexual reproduction among various genotypes and establishing an outcrossing program are advisable for A. sinensis.

Recent incidence of congenital heart disease in neonatal care unit of secondary medical center: a single center study

Purpose

With feasibility in the diagnoses of congenital heart disease (CHD) in the antenatal period, we suspect changes have occurred in its incidence. No data have been reported about the current incidence of simple forms of CHD in Korea. We have attempted to assess the recent incidence and characteristics of CHD in the neonatal care unit of a secondary referral medical center.

Methods

Medical records of 497 neonatal care unit patients who underwent echocardiography in the past 5 years were reviewed. Pre-term infants with patent ductus arteriosus and other transient, minimal lesions were excluded from this study.

Results

Although the number of inpatients remained stable, the incidence of simple forms of CHD showed a gradual decrease over the 5-year study period; a markedly low incidence of complex forms was seen as well. CHD was observed in 3.7% full-term and 6.8% pre-term infants. CHD was observed in 152 infants weighing >2,500 g (3.5% of corresponding birth weight infants); 65 weighing 1,000 to 2,500 g (9.3%); and 6 weighing <1,000 g (8.0%). The incidence of CHD was higher in the pre-term group and the low birth weight group than in each corresponding subgroup (P<0.001); however, the incidence of complex CHD in full-term neonates was high. The number of patients with extracardiac structural anomalies has also shown a gradual decrease every year for the past 5 years.

Conclusion

Findings from our study suggest that the recent incidence and disease pattern of CHD might have changed for both complex and simple forms of CHD in Korea.

Epidemiology of Kawasaki disease in infants 3 months of age and younger

Purpose

This study investigated the epidemiology of Kawasaki disease (KD) in infants ≤3-month-old.

Methods

To study the epidemiology of KD in Korea, data for 27,851 KD patients were collected on a 3-year basis between 2000 and 2008 in a retrospective survey. From this, data for 609 KD patients ≤3-month-old were analyzed and compared with the data for KD patients >3-month-old.

Results

The 609 KD patients ≤3-month-old (385 males and 224 females) constituted 2.2% of the KD patients. They included 25 infants <1-month-old, 198 infants ≤1- to 2-month-old, and 386 infants >2- and 3-months-old. The ratio of males to females was 1.72:1. The incidence of coronary artery (CA) dilatation (19.9% vs. 18.7%) and CA aneurysms (3.4% vs. 2.6%) detected by echocardiography did not differ significantly between patients with KD younger and older than 3-month-old.

Conclusion

Compared with the data for the KD patients >3-month-old, the data for the 609 patients ≤3-month-old did not show a significantly higher incidence of CA dilatation or CA aneurysms.

Establishment of secondary iron overloaded mouse model: evaluation of cardiac function and analysis according to iron concentration

Periodic blood transfusion can lead to secondary iron overload in patients with hematologic and oncologic diseases. Iron overload can result in iron deposition in heart tissue, which decreases cardiac function and can ultimately lead to death due to dilated cardiomyopathy and cardiac failure. In this study, we established murine model of secondary iron overload, studied the changes in cardiac function with echocardiography, and examined the histopathologic changes. Three experimental groups of the six week-old C57/BL mice (H-2(b)) were injected intraperitoneally with 10 mg of iron dextran daily 5 days a week for 2, 4, and 6 weeks. Cumulative doses of iron for the three experimental groups were 100, 200, and 300 mg, while the control groups were injected with the same amounts of phosphate-buffered saline. We studied the cardiac function under anesthesia with echocardiography using a GE Vivid7 Dimension system. Plasma iron levels and liver iron contents were measured. The hearts and livers were harvested and stained with H&E and Perls Prussian blue for iron, and the levels of iron deposit were examined. We assessed the cardiac measurements after adjustment for weight. On echocardiography, thicknesses of the interventricular septum and posterior ventricular wall (PS) during diastole showed correlation with the amount of iron deposit (P < 0.01). End-diastolic volume showed dilatation of the left ventricle in the 300 mg group (P < 0.01). Changes in the fractional shortening were not statistically significant (P = 0.07). Plasma iron levels and liver iron contents were increased proportionally according to the amount of iron loaded. The histopathologic findings of PS and liver showed higher grade of iron deposit proportional to the cumulated iron dose. In this study, we present an animal model which helps understand the cardiac function changes in patients with secondary iron overload due to repeated blood transfusions. Our results may help characterize the pathophysiologic features of cardiomyopathy in patients with secondary iron overload, and our model may be applied to in vivo iron-chelating therapy studies.

A case of hemolytic uremic syndrome preceded by intussusception

Hemolytic-uremic syndrome (HUS) is the most common cause of acute renal failure in young children. It is classically characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and uremia. Further, not only is intussusception one of the differential diagnoses of HUS but it may also become a complication during disease progression. We report a case of HUS preceded by intussusception in a previously healthy 17-month-old boy. The patient presented at the emergency department with bloody stools that developed the day after reduction of intussusception. HUS was diagnosed 4 days after the reduction of intussusception. The patient was provided only supportive care and his laboratory test findings were normal at discharge.

Epidemiological features of Kawasaki disease in Korea, 2006-2008

BACKGROUND

The aim of this study was to estimate the incidence and describe the epidemiological characteristics of Kawasaki disease among children in Korea.

METHODS

Questionnaires for surveying the epidemiology of Kawasaki disease were distributed to a total of 101 hospitals that conduct pediatric residency programs. Then, we retrospectively obtained the data, which covered a three-year period (2006-2008) and analyzed them.

RESULTS

During the three-year study period, a total of 9039 cases of Kawasaki disease were reported from 84 hospitals (response rate, 83.2%), comprising 5375 boys and 3664 girls (male:female ratio, 1.47:1). The outbreak rate per 100,000 children <5 years old was 108.7 in 2006, 118.3 in 2007 and 112.5 in 2008 (average rate, 113.1). The seasonal distribution showed a slightly higher incidence rate in winter and summer. The patients' mean age of onset was 32.6 months, while the proportions of sibling cases and recurrent cases were 0.17% and 2.2%, respectively. Coronary arterial abnormalities were detected during follow up by echocardiogram in 17.5% of all cases including dilatations (16.4%) and aneurysms (2.1%).

CONCLUSIONS

The average annual incidence rate of Kawasaki disease in Korea has been continuously increasing, and reached 113.1/100,000 children <5 years old, which is the second highest rate in the world.

Clinical manifestations of CNS infections caused by enterovirus type 71

PURPOSE

Enterovirus 71, one of the enteroviruses that are responsible for both hand-foot-and-mouth disease and herpangina, can cause neural injury. During periods of endemic spread of hand-foot-andmouth disease caused by enterovirus 71, CNS infections are also frequently diagnosed and may lead to increased complications from neural injury, as well as death. We present the results of our epidemiologic research on the clinical manifestations of children with CNS infections caused by enterovirus 71.

METHODS

The study group consisted of 42 patients admitted for CNS infection by enterovirus 71 between April 2009 and October 2009 at the Department of Pediatrics of 5 major hospitals affiliated with the Catholic University of Korea. We retrospectively reviewed initial symptoms and laboratory findings on admission, the specimen from which enterovirus 71 was isolated, fever duration, admission period, treatment and progress, and complications. We compared aseptic meningitis patients with encephalitis patients.

RESULTS

Of the 42 patients (23 men, 19 women), hand-foot-and-mouth disease was most prevalent (n=39), followed by herpangina (n=3), upon initial clinical diagnosis. Among the 42 patients, 15 (35.7%) were classified as severe, while 27 (64.3%) were classified as mild. Factors such as age, fever duration, presence of seizure, and use of intravenous immunoglobulin (IVIG) were statistically different between the 2 groups.

CONCLUSION

Our results indicate that patients with severe infection caused by enterovirus 71 tended to be less than 3 years old, presented with at least 3 days of fever as well as seizure activity, and received IVIG treatment.

Lysophosphatidic acid augments human hepatocellular carcinoma cell invasion through LPA1 receptor and MMP-9 expression

Lysophosphatidic acid (LPA), produced extracellularly by autotaxin (ATX), has diverse biological activities implicated in tumor initiation and progression, including increasing cell survival, angiogenesis, invasion and metastasis. ATX, LPA and the matrix metalloproteinase (MMP)-9 have all been implicated in hepatocellular carcinoma (HCC) invasion and metastasis. We, thus sought to determine whether ATX with subsequent LPA production and action, including induction of MMP-9 could provide a unifying mechanism. ATX transcripts and LPA receptor type 1 (LPA1) protein are elevated in HCC compared with normal tissues. Silencing or pharmacological inhibition of LPA1 significantly attenuated LPA-induced MMP-9 expression and HCC cell invasion. Further, reducing MMP-9 activity or expression significantly inhibits LPA-induced HCC cell invasion, demonstrating that MMP-9 is downstream of LPA1. Inhibition of phosphoinositide-3 kinase (PI3K) signaling or dominant-negative mutants of protein kinase Cδ and p38 mitogen-activated protein kinase (MAPK) abrogated LPA-induced MMP-9 expression and subsequent invasion. We thus demonstrate a mechanistic cascade of ATX-producing LPA with LPA activating LPA1 and inducing MMP-9 through coordinate activation of the PI3K and the p38 MPAK signaling cascades, providing novel biomarkers and potential therapeutic targets for HCC.

Infliximab treatment for refractory kawasaki disease in korean children

Background and Objectives

This was a multicenter study to evaluate the usefulness of the tumor necrosis factor-alpha (TNF-α) blocker infliximab for treatment of Korean pediatric patients with refractory Kawasaki disease (KD).

Subjects and Methods

Data from 16 patients throughout Korea who were diagnosed with refractory KD and received infliximab were collected retrospectively.

Results

Complete response to therapy with cessation of fever occurred in 13 of 16 patients. C-reactive protein (CRP) concentrations decreased following infliximab infusion in all 14 patients in whom it was measured before and after treatment. There were no infusion reactions or complications associated with infliximab except in 1 case with acute hepatitis occurring during treatment followed by calculous cholecystitis 4 months later. Fifteen patients had coronary artery (CA) abnormalities before infliximab therapy. Three had transient mild dilatation and 9 had CA aneurysms, with subsequent normalization in 4 patients, persistent mild dilatation in 3, persistent aneurysm in 2, and there were 3 cases (2 with CA aneurysm, 1 with mild CA dilatation) without follow-up echocardiography.

Conclusion

The results of this study suggest that infliximab may be useful in the treatment of refractory KD, and it appears that there is no significant further progression of CA lesions developing after infliximab treatment. Multicenter trials with larger numbers of patients and long-term follow-up are necessary to assess the clinical efficacy and safety of infliximab in refractory KD.

Regulation of the formation and trafficking of vesicles from Golgi by PCH family proteins during chemotaxis

Previous study demonstrated that WASP localizes on vesicles during Dictyostelium chemotaxis and these vesicles appear to be preferentially distributed at the leading and trailing edge of migrating cells. In this study, we have examined the role of PCH family proteins, Nwk/Bzz1p-like protein (NLP) and Syndapin-like protein (SLP), in the regulation of the formation and trafficking of WASP-vesicles during chemotaxis. NLP and SLP appear to be functionally redundant and deletion of both nlp and slp genes causes the loss of polarized F-actin organization and significant defects in chemotaxis. WASP and NLP are colocalized on vesicles and interactions between two molecules via the SH3 domain of NLP/SLP and the proline-rich repeats of WASP are required for vesicle formation from Golgi. Microtubules are required for polarized trafficking of these vesicles as vesicles showing high directed mobility are absent in cells treated with nocodazole. Our results suggest that interaction of WASP with NLP/SLP is required for the formation and trafficking of vesicles from Golgi to the membrane, which might play a central role in the establishment of cell polarity during chemotaxis.

Comprehensive clinical follow-up of late effects in childhood cancer survivors shows the need for early and well-timed intervention

BACKGROUND

Due to recent advances in treatment, nearly 80% of childhood cancer patients become long-term survivors. Studies on the late effects of survivors are under way worldwide. However, data on Asian survivors remain limited.

METHODS

Data on 241 survivors at the Long-term Follow-up Clinic in Severance Hospital, South Korea, were collected and late effects were confirmed by oncologists.

RESULTS

The median follow-up from diagnosis was 7.8 years. Late effects were identified in 59.8% of survivors and 23.2% had two or more late effects. Grade 3 or higher late effects were present in 10.8%. The most common late effects involved endocrine system (29.0%). Late effects were present in 95.7% of brain tumor survivors and 36.0% of Wilms' tumor survivors. Chemotherapy, hematopoietic stem-cell transplantation and radiotherapy were significant factors associated with the number and severity of late effects (P < 0.05). Brain tumor survivors had more severe late effects (P < 0.001), whereas Wilms' tumor survivors had fewer and milder late effects (P < 0.05).

CONCLUSION

The observation that over 50% of cancer survivors suffered from late effects during the short follow-up period and that a high frequency of endocrine late effects was present indicates the need for early and well-timed intervention of the survivors.

Polymorphisms of human leukocyte antigen genes in korean children with Kawasaki disease

BACKGROUND

Kawasaki disease is a leading cause of acquired heart disease in children. The prevalence rate varies in different ethnic groups. Recently, with the clinical application of molecular genetic technology, human leukocyte antigen (HLA) polymorphisms associated with several diseases have been identified by DNA analysis. This study aimed to assess the association of HLA alleles with susceptibility and complications of Kawasaki disease in Korean children.

METHODS

In this study, DNA was extracted from 74 children with a diagnosis of Kawasaki disease. The polymorphisms of the HLA-A, -B, -C, and -DRB1 alleles of patients with Kawasaki disease were determined by polymerase chain reaction (PCR)-amplification refractory mutation system (ARMS) and PCR-sequence-specific primer (SSP) analysis. The polymorphisms identified were compared with those of 159 normal healthy control subjects.

RESULTS

There was a significant increase in the frequencies of the HLA-B35, -B75, and -Cw09 alleles in patients with Kawasaki disease compared with the healthy control group. There was no increase in the frequency of HLA-DRB1 alleles among the Kawasaki disease patients compared with a healthy control group. When the patients with Kawasaki disease were divided into two subgroups, with or without coronary complications, the Kawasaki disease patients with coronary complications showed a significantly increased frequency of the HLA-DRB1*11 allele compared with the healthy control group and increased frequency of HLA-DRB1*09 in a comparison of the subgroups.

CONCLUSIONS

This study suggests that polymorphisms in some alleles of B and C in HLA class I genes are associated with Kawasaki disease in Korean children.

Safety and immunogenicity of a vaccine targeting human papillomavirus types 6, 11, 16 and 18: a randomized, placebo-controlled trial in 176 Korean subjects

Human papillomavirus (HPV) is a major causative agent of anogenital warts and a necessary cause of cervical cancer. This report will serve to assess the safety and immunogenicity of quadrivalent (types 6, 11, 16, and 18) HPV L1 virus-like particle (VLP) vaccine in the Korean population. We performed a randomized, double-blind, placebo-controlled study in 176 volunteers aged 9-23 years. Using a 2:1 ratio for randomization, 117 women were assigned to quadrivalent HPV (20 mug type 6, 40 mug type 11, 40 mug type 16, and 20 mug type 18) vaccine and 59 women to placebo. Individuals received vaccine at day 1, month 2, and month 6 and provided blood samples for analysis at enrollment at month 7. Analyses were done as specified in the study protocol. Quadrivalent HPV vaccine was generally well tolerated, with no vaccine-related serious adverse experiences. Quadrivalent HPV vaccine induced seroconversion for each vaccine-related HPV type. At month 7, vaccine-induced type-specific antibody titer was high. In conclusion, administration of quadrivalent HPV VLP vaccine to Korean women aged 9-23 years was generally well tolerated and highly immunogenic.

Epidemiologic picture of Kawasaki disease in Korea, 2000-2002

BACKGROUND

The aim of this study was to investigate the incidence rate and epidemiologic patterns of Kawasaki disease in Korea for a 3 year period during 2000 to 2002.

METHODS

An epidemiologic survey on Kawasaki disease was retrospectively performed. The questionnaire was sent to all 112 hospitals having pediatric residency programs, and obtained data were analyzed.

RESULTS

The 9150 cases of Kawasaki disease from 92 hospitals which responded (response rate, 82.1%) included 5515 males and 3635 females (male : female ratio, 1.52:1). The incidence rate per 100,000 children <5 years old was 73.7 in 2000, and increased to 90.8 in 2001, and 95.5 in 2002 (average rate, 86.4). The monthly number of patients was slightly higher in May, June and July. Their mean age of onset, the proportion of sibling cases, and a rate of recurrent cases were 30.5 months, 0.17%, and 2.9%, respectively. Coronary arterial abnormalities occurred in 18.6% of cases including dilatations of 17.3% and aneurysms of 3.1%.

CONCLUSION

The average annual incidence, 86.4/100 000 in children <5 years old is the second highest rate in the world.

Alteration of biochemical profiles after high-dose intravenous immunoglobulin administration in Kawasaki disease

Intravenous immunoglobulin (IVIG) has been used as an immunomodulatory treatment for several immune-mediated diseases. Early effects of high-dose IVIG treatment on biochemical profiles including lipids and proteins were evaluated in patients with Kawasaki disease (KD). Twelve children with KD (9 boys) were treated with IVIG at 2 g/kg over a period of 12 h. Serial sera samples were collected from the patients four times: before IVIG treatment and 2 h, 24 h and 7 d after IVIG treatment. The samples were frozen at -20 degrees C before biochemical analysis. A significant decrease in albumin concentration was found 2 h and 24 h after IVIG treatment, but this recovered to the pretreatment level after 7 d. Total cholesterol and triglyceride increased slightly after 7 d. A significant decrease in HDL-cholesterol and C-reactive protein was seen 2 h and 24 h after IVIG treatment.

CONCLUSION

High-dose IVIG affects immediate changes in protein profiles and HDL-cholesterol in KD. Changes in HDL-cholesterol induced by IVIG may be the result of changes in systemic protein metabolism.

Activation of p21(WAF1/Cip1) transcription through Sp1 sites by histone deacetylase inhibitor apicidin: involvement of protein kinase C

We previously reported that apicidin, a novel histone deacetylase inhibitor, inhibited the proliferation of tumor cells via induction of p21(WAF1/Cip1). In this study, we determined the molecular mechanisms by which apicidin induced the p21(WAF1/Cip1) gene expression in HeLa cells. Apicidin induced p21(WAF1/Cip1) mRNA independent of the de novo protein synthesis and activated the p21(WAF1/Cip1) promoter through Sp1-3 site located at -82 and -77 relative to the transcription start site. This transcriptional activation appears to be mediated by protein kinase C (PKC), because calphostin C, a PKC inhibitor, significantly attenuated the activation of p21(WAF1/Cip1) promoter via Sp1 sites, which was accompanied by a marked suppression of p21(WAF1/Cip1) mRNA and protein expression induced by apicidin. Consistent with the transcriptional activation of p21(WAF1/Cip1) promoter by apicidin, apicidin treatment led to the translocation of PKCepsilon from cytosolic to particulate fraction, which was reversed by pretreatment with calphostin C, indicating the involvement of PKC in the transcriptional activation of p21(WAF1/Cip1) via Sp1 sites by apicidin. However, the PKC-mediated transcriptional activation of p21(WAF1/Cip1) by apicidin appears to be independent of the histone hyperacetylation, because apicidin-induced histone hyperacetylation was not affected by calphostin C. Furthermore, a PKC activator, phorbol 12,13-dibutyrate, alone induced the transcriptional activation of p21(WAF1/Cip1) promoter, p21(WAF1/Cip1) mRNA, and protein expression without induction of the histone hyperacetylation, suggesting that the transcriptional activation of p21(WAF1/Cip1) by apicidin might have been mediated by a mechanism other than chromatin remodeling through the histone hyperacetylation. Taken together, these results suggest that the PKC signaling pathway plays a pivotal role in the transcriptional activation of the p21(WAF1/Cip1) gene by apicidin.

Enzymatic activation of autotaxin by divalent cations without EF-hand loop region involvement

Autotaxin (ATX) is a recently described member of the nucleotide pyrophosphatase/phosphodiesterase (NPP) family of proteins with potent tumor cell motility-stimulating activity. Like other NPPs, ATX is a glycoprotein with peptide sequences homologous to the catalytic site of bovine intestinal alkaline phosphodiesterase (PDE) and the loop region of an EF-hand motif. The PDE active site of ATX has been associated with the motility-stimulating activity of ATX. In this study, we examined the roles of the EF-hand loop region and of divalent cations on the enzymatic activities of ATX. Ca(2+) or Mg(2+) was each demonstrated to increase the PDE activity of ATX in a concentration-dependent manner, whereas incubation of ATX with chelating agents abolished this activity, indicating a requirement for divalent cations. Non-linear regression analysis of enzyme kinetic data indicated that addition of these divalent cations increases reaction velocity predominantly through an effect on V(max.) Three mutant proteins, Ala(740)-, Ala(742)-, and Ala(751)-ATX, in the EF-hand loop region of ATX had enzymatic activity comparable to that of the wild-type protein. A deletion mutation of the entire loop region resulted in slightly reduced PDE activity but normal motility-stimulating activity. However, the PDE activity of this same deletion mutant remained sensitive to augmentation by cations, strongly implying that cations exert their effect by interactions outside of the EF-hand loop region.

Monitoring of deep brain temperature in infants using multi-frequency microwave radiometry and thermal modelling

In this study we present a design for a multi-frequency microwave radiometer aimed at prolonged monitoring of deep brain temperature in newborn infants and suitable for use during hypothermic neural rescue therapy. We identify appropriate hardware to measure brightness temperature and evaluate the accuracy of the measurements. We describe a method to estimate the tissue temperature distribution from measured brightness temperatures which uses the results of numerical simulations of the tissue temperature as well as the propagation of the microwaves in a realistic detailed three-dimensional infant head model. The temperature retrieval method is then used to evaluate how the statistical fluctuations in the measured brightness temperatures limit the confidence interval for the estimated temperature: for an 18 degrees C temperature differential between cooled surface and deep brain we found a standard error in the estimated central brain temperature of 0.75 degrees C. Evaluation of the systematic errors arising from inaccuracies in model parameters showed that realistic deviations in tissue parameters have little impact compared to uncertainty in the thickness of the bolus between the receiving antenna and the infant's head or in the skull thickness. This highlights the need to pay particular attention to these latter parameters in future practical implementation of the technique.