Predictive factors of bacteremia in patients with febrile urinary tract infection: an experience at a tertiary care center

PURPOSE

To investigate the clinical features in adult patients with febrile urinary tract infection (UTI) who visited the emergency department (ED) and to determine the predictive factors of bacteremia among the initial presenting clinical features.

METHODS

This retrospective cohort study was conducted at the ED of a tertiary hospital in Korea from 1 January 2012 to 31 December 2012. All adult patients who were diagnosed with febrile UTI and for whom data on blood and urine cultures were available were included in the study. Clinical examinations and laboratory tests were performed at the initial presentation.

RESULTS

A total of the 325 patients with febrile UTI (median age: 60 years) were included for analysis, of whom 82 % were female. Bacteremia was detected in 106 of the 325 patients (32.6 %), with Escherichia coli the most frequent pathogen detected (59.7 % of cases). Between the bacteremic and non-bacteremic groups, there was significant difference in age (67 vs. 57 years, respectively), flank pain (16 vs. 7.8 %), suprapubic discomfort (0 vs. 4.6 %), body temperature (38.8 vs. 38.3 °C), respiratory rate (21 vs. 20/min), platelet count (170 vs. 186 × 10(3)/μL), C-reactive protein (10.2 vs. 8.3 mg/dL), and procalcitonin (1.5 vs. 0.3 ng/mL) (P < 0.05 for all). In the multivariate logistic regression analysis, age [odds ratio (OR) 1.03; 95 % confidence interval (CI) 1.01-1.05], systolic blood pressure of <90 mmHg (OR 3.27; 95 % CI 1.13-9.45), body temperature of >39 °C (OR 4.26; 95 % CI 2.28-7.96), and procalcitonin level of >0.5 ng/dL (OR 2.03; 95 % CI 1.07-3.86) were significantly associated with bacteremia.

CONCLUSION

Among our adult patients with febrile UTI, age, systolic blood pressure, body temperature, and procalcitonin were significantly associated with bacteremia. We therefore suggest that these factors should be considered when deciding upon treatment options for febrile UTI patients at the ED.

Gamma band activity associated with BCI performance: simultaneous MEG/EEG study

While brain computer interface (BCI) can be employed with patients and healthy subjects, there are problems that must be resolved before BCI can be useful to the public. In the most popular motor imagery (MI) BCI system, a significant number of target users (called “BCI-Illiterates”) cannot modulate their neuronal signals sufficiently to use the BCI system. This causes performance variability among subjects and even among sessions within a subject. The mechanism of such BCI-Illiteracy and possible solutions still remain to be determined. Gamma oscillation is known to be involved in various fundamental brain functions, and may play a role in MI. In this study, we investigated the association of gamma activity with MI performance among subjects. Ten simultaneous MEG/EEG experiments were conducted; MI performance for each was estimated by EEG data, and the gamma activity associated with BCI performance was investigated with MEG data. Our results showed that gamma activity had a high positive correlation with MI performance in the prefrontal area. This trend was also found across sessions within one subject. In conclusion, gamma rhythms generated in the prefrontal area appear to play a critical role in BCI performance.

The impact of saddle embolism on the major adverse event rate of patients with non-high-risk pulmonary embolism

OBJECTIVE

Wider application of CT angiography (CTA) improves the diagnosis of acute pulmonary embolism (PE). It also permits the visualisation of saddle embolism (SE), namely thrombi, which are located at the bifurcation of the main pulmonary artery. The aim of this study was to assess the prevalence of SE and whether SE predicts a complicated clinical course in patients with non-high-risk PE.

METHODS

In total, 297 consecutive patients with non-high-risk PE confirmed using CTA in the emergency department were studied. The presence of SE and its ability to predict the occurrence of major adverse events (MAEs) within 1 month were determined.

RESULTS

Of the 297 patients, 27 (9.1%) had an SE. The overall mortality at 1 month was 12.5%; no significant difference was observed between the SE and non-SE groups (18.5% vs 11.9%, p=0.32). However, patients with SE were more likely to receive thrombolytic therapy (29.6% vs 8.1%, p<0.01) and had significantly more MAEs (59.3% vs 25.6%, p<0.01).

CONCLUSION

At the time of diagnosis, SE, as determined using CTA, is associated with the development of MAE within 1 month. It may be a simple method for risk stratification of patients with non-high-risk PE.

ADVANCES IN KNOWLEDGE

The prognosis of patients with SE, especially those who are haemodynamically stable, is unclear. This study shows that patients with SE, determined with CTA, is associated with the development of MAE.

High theta and low alpha powers may be indicative of BCI-illiteracy in motor imagery

In most brain computer interface (BCI) systems, some target users have significant difficulty in using BCI systems. Such target users are called ‘BCI-illiterate’. This phenomenon has been poorly investigated, and a clear understanding of the BCI-illiteracy mechanism or a solution to this problem has not been reported to date. In this study, we sought to demonstrate the neurophysiological differences between two groups (literate, illiterate) with a total of 52 subjects. We investigated recordings under non-task related state (NTS) which is collected during subject is relaxed with eyes open. We found that high theta and low alpha waves were noticeable in the BCI-illiterate relative to the BCI-literate people. Furthermore, these high theta and low alpha wave patterns were preserved across different mental states, such as NTS, resting before motor imagery (MI), and MI states, even though the spatial distribution of both BCI-illiterate and BCI-literate groups did not differ. From these findings, an effective strategy for pre-screening subjects for BCI illiteracy has been determined, and a performance factor that reflects potential user performance has been proposed using a simple combination of band powers. Our proposed performance factor gave an r = 0.59 (r² = 0.34) in a correlation analysis with BCI performance and yielded as much as r = 0.70 (r² = 0.50) when seven outliers were rejected during the evaluation of whole data (N = 61), including BCI competition datasets (N = 9). These findings may be directly applicable to online BCI systems.

Quantitative statistical methods for image quality assessment

Quantitative measures of image quality and reliability are critical for both qualitative interpretation and quantitative analysis of medical images. While, in theory, it is possible to analyze reconstructed images by means of Monte Carlo simulations using a large number of noise realizations, the associated computational burden makes this approach impractical. Additionally, this approach is less meaningful in clinical scenarios, where multiple noise realizations are generally unavailable. The practical alternative is to compute closed-form analytical expressions for image quality measures. The objective of this paper is to review statistical analysis techniques that enable us to compute two key metrics: resolution (determined from the local impulse response) and covariance. The underlying methods include fixed-point approaches, which compute these metrics at a fixed point (the unique and stable solution) independent of the iterative algorithm employed, and iteration-based approaches, which yield results that are dependent on the algorithm, initialization, and number of iterations. We also explore extensions of some of these methods to a range of special contexts, including dynamic and motion-compensated image reconstruction. While most of the discussed techniques were developed for emission tomography, the general methods are extensible to other imaging modalities as well. In addition to enabling image characterization, these analysis techniques allow us to control and enhance imaging system performance. We review practical applications where performance improvement is achieved by applying these ideas to the contexts of both hardware (optimizing scanner design) and image reconstruction (designing regularization functions that produce uniform resolution or maximize task-specific figures of merit).

Conversion of twice-daily tacrolimus to once-daily tacrolimus formulation in stable pediatric kidney transplant recipients: pharmacokinetics and efficacy

The pharmacokinetics, efficacy and safety of once-daily tacrolimus formulation (Tac-OD) were assessed in 34 stable pediatric kidney transplant recipients. Enrolled patients received their dose of twice-daily tacrolimus formulation (Tac-BID) on study Days 0 through 7. On the morning of study Day 8, the total daily doses for patients were converted to Tac-OD on a 1:1 basis and maintained on a once-daily morning dosing regimen. Tacrolimus pharmacokinetic profiles were obtained on study Days 7, 14 and 28 (after dose adjustment). Although the mean C0 concentrations (4.10 ± 1.16-3.53 ± 1.10 ng/mL, p = 0.004), and AUC0-24 (151.8 ± 41.6-129.8 ± 39.3 ng h/mL, p < 0.001) were decreased significantly after a 1:1 based conversion, there was high interindividual variability. The dose of Tac-OD was decreased in 26.5% and increased in 44.1% of patients. The resultant tacrolimus dose and pharmacokinetic profiles on study Day 28 were comparable to those on Day 7. There were no serious adverse events. In conclusion, Tac-BID can be safely converted to Tac-OD in stable pediatric kidney transplant patients with the heightened therapeutic drug monitoring. Effects of drug conversion on the cardiovascular risk factors, neurological side effects and adherence should be further evaluated.

Influence of Low Molecular Weight Additives on Die Extrusion Rheometer Flow of Thermoplastic Melts

An experimental study of slippage induced in various thermoplastics in rheometers by the presence of small amount of low molecular weight additives is described. Capillary and cone-plate experiments are reported. A series of polymers of varying polarity including polyethylene, polypropylene, polystyrene, poly (methyl methacrylate) and polyamide 12 are compared. Five eighteen-carbon amphiphilic ω-compounds are used as additives including octadecanoic acid, octadecanamide, octadecanol, calcium stearate and zinc stearate. The greatest effects were found in polyethylene and polypropylene. Little or no effects are found with the other polymers. The most effective additives were octadecanoic acid and zinc stearate. Octadecanamide and octadecanol had some effectiveness. Mechanisms for this behavior are described.

Die Wall Effects, Contact Angles and Slippage in the Flow of Polymer Melts and Polymer-Particulate Compounds with Carboxylic Acids in a Slit Die

An experimental study of the influence of carboxylic acid additive in polyethylene/filler and polystyrene/filler compounds in slit die is described. Slit die extrusion experiments and contact angle measurements are reported. A series of fillers of varying particle size including carbon black, calcium carbonate, zinc oxide, and talc are compared. Aliphatic fatty acids, especially octadecanoic acid were used as additives. The greatest viscosity reduction was found in polyethylene/(carbon black) and polystyrene/(calcium carbonate) compounds. Smaller effects are found with the other polyethylene/filler compounds and none in polystyrene/filler compounds. Contact angle experiments indicated carboxylic acid layers on the die surfaces for the polyethylene and not the polystyrene compounds. Mechanisms for this behavior are discussed.

"Trophoblast islands of the chorionic connective tissue" (TICCT): a novel placental histologic feature

INTRODUCTION

We found isolated or clustered trophoblasts in the chorionic connective tissue of the extraplacental membranes, and defined this novel histologic feature as the "trophoblast islands of the chorionic connective tissue" (TICCT). This study was conducted to determine the clinical significance of TICCT.

METHODS

Immunohistochemistry for cytokeratin-7 was performed on the chorioamniotic membranes (N = 2155) obtained from singleton pregnancies of 1199 uncomplicated term and 956 preterm deliveries. The study groups comprised 1236 African-American and 919 Hispanic women. Gestational age ranged from 24(+0) weeks to 41(+6) weeks. Multiple logistic regression analysis was performed to investigate the magnitude of association between patient characteristics and the presence of TICCT.

RESULTS

The likelihood of TICCT was significantly associated with advancing gestational age both in term (OR: 1.29, 95% CI: 1.16-1.45, p < 0.001) and preterm deliveries (OR: 1.19, 95% CI: 1.07-1.32, p = 0.001) . Hispanic women were less likely than African-American women to have TICCT across gestation in term (OR: 0.23, 95% CI: 0.18-0.31, p < 0.001) and preterm pregnancies (OR: 0.41, 95% CI: 0.29-0.58, p < 0.001). Women with a female fetus were significantly more likely to have TICCT than women with a male fetus, in both term (OR: 1.64, 95% CI: 1.28-2.11, p < 0.001) and preterm gestations (OR: 2.04, 95% CI: 1.46-2.85, p < 0.001). TICCT was 40% less frequent in the presence of chronic placental inflammation [term (OR: 0.60, 95% CI: 0.45-0.81, p = 0.001) and preterm gestations (OR: 0.58, 95% CI: 0.40-0.84, p = 0.003)] and in parous women at term (OR: 0.60, 95% CI: 0.44-0.81, p = 0.001).

CONCLUSIONS

Our findings suggest that the duration of pregnancy, fetal sex, and parity may influence the behavior of extravillous trophoblast and placental mesenchymal cells.

Comparison of frequency difference reconstruction algorithms for the detection of acute stroke using EIT in a realistic head-shaped tank

Imaging of acute stroke might be possible using multi-frequency electrical impedance tomography (MFEIT) but requires absolute or frequency difference imaging. Simple linear frequency difference reconstruction has been shown to be ineffective in imaging with a frequency-dependant background conductivity; this has been overcome with a weighted frequency difference approach with correction for the background but this has only been validated for a cylindrical and hemispherical tank. The feasibility of MFEIT for imaging of acute stroke in a realistic head geometry was examined by imaging a potato perturbation against a saline background and a carrot-saline frequency-dependant background conductivity, in a head-shaped tank with the UCLH Mk2.5 MFEIT system. Reconstruction was performed with time difference (TD), frequency difference (FD), FD adjacent (FDA), weighted FD (WFD) and weighted FDA (WFDA) linear algorithms. The perturbation in reconstructed images corresponded to the true position to <9.5% of image diameter with an image SNR of >5.4 for all algorithms in saline but only for TD, WFDA and WFD in the carrot-saline background. No reliable imaging was possible with FD and FDA. This indicates that the WFD approach is also effective for a realistic head geometry and supports its use for human imaging in the future.

Joint L1 and total variation regularization for fluorescence molecular tomography

Fluorescence molecular tomography (FMT) is an imaging modality that exploits the specificity of fluorescent biomarkers to enable 3D visualization of molecular targets and pathways in vivo in small animals. Owing to the high degree of absorption and scattering of light through tissue, the FMT inverse problem is inherently ill-conditioned making image reconstruction highly susceptible to the effects of noise and numerical errors. Appropriate priors or penalties are needed to facilitate reconstruction and to restrict the search space to a specific solution set. Typically, fluorescent probes are locally concentrated within specific areas of interest (e.g., inside tumors). The commonly used L(2) norm penalty generates the minimum energy solution, which tends to be spread out in space. Instead, we present here an approach involving a combination of the L(1) and total variation norm penalties, the former to suppress spurious background signals and enforce sparsity and the latter to preserve local smoothness and piecewise constancy in the reconstructed images. We have developed a surrogate-based optimization method for minimizing the joint penalties. The method was validated using both simulated and experimental data obtained from a mouse-shaped phantom mimicking tissue optical properties and containing two embedded fluorescent sources. Fluorescence data were collected using a 3D FMT setup that uses an EMCCD camera for image acquisition and a conical mirror for full-surface viewing. A range of performance metrics was utilized to evaluate our simulation results and to compare our method with the L(1), L(2) and total variation norm penalty-based approaches. The experimental results were assessed using the Dice similarity coefficients computed after co-registration with a CT image of the phantom.

P3-14-16: Molecular Phenotype and the Use of HER-2 Targeted Agents Influence the Accuracy of Breast MRI after Neoadjuvant Chemotherapy

Background: Improved understanding of factors affecting the accuracy of breast magnetic resonance imaging (MRI) after neoadjuvant systemic therapy (NST) can lead to more tailored use of MRI in deciding surgical extent after NST.

Materials and Methods: We analyzed the imaging and clinicopathologic data of 463 patients who underwent NST. We aimed to investigate whether the molecular subtypes, as well as the use of targeted therapies, were associated with changes in the accuracy of MRI predicting residual tumor extent.

Results: The accuracy of MRI predicting the residual tumor extent was most accurate in triple negative breast cancer and was least accurate in Luminal A subtype (Pearson's correlation coefficient of 0.754 and 0.531, respectively). Multivariate analysis suggested estrogen receptor status as an independent factor influencing the MRI accuracy. In HER2−amplified tumors, the use of HER2−targeted agents was associated with less accurate MRI prediction. Dual HER2−blockade by using trastuzumab and pertuzumab resulted in lowest MRI accuracy among the patients treated with HER2−targeted agents.

Conclusion: The accuracy of MRI in predicting residual tumor extent was lowest in ER positive tumors treated with NST. In HER2 positive tumors, the use of HER2−targeted agents resulted in less accurate MRI after NST.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-14-16.

P2-08-12: Additional Lesion Found in Preoperative Breast MRI; Is Routine Use Justified?

Preoperative breast MRI has been increasingly performed in patients with newly diagnosed breast cancer due to its high sensitivity in assessing the extent and additional malignant foci. But due to it's low specificity, role of routine preoperative breast MRI has become an issue. In this study we aught to analyze the characteristics of the additional lesion found in preoperative breast MRI and to evaluate the clinicopathological factors in association with likelihood of having additional malignancy.

We retrospectively reviewed 2491 patients who undergone surgery due to breast cancer in Seoul National University Hospital(SNUH) between Jan 2006 and Dec 2010. Neoadjuvant chemotherapy cases, patients undergone initial sonography in other center or ones with prior excision were excluded and total 1068 patients were analyzed. The additional lesion was defined as the lesion not found in initial sonography and detected in preoperative breast MRI. The pathology of the additional lesion was reviewed and the association between the clinicopathologic factors and additional malignancy were evaluated. Accuracy of breast MRI was estimated regarding cancer yield, positive predictive value(PPV).

Mean age at diagnosis was 50.9 years (21 to 85 years). Overall detection rate of additional lesion was 26.2%(280 out of 1068). Mean size of the additional lesion was 9.8mm(3-51). Additional lesions consist of 99(35.4% of 280) C4 or higher, 174(62.1% of 280) below C4, 7(2.5% of 280) C0 lesions. Among them 100 patients undergone onstage surgery. 5(55% of 100) lesions were in ipsilateral breast and 45(45% of 100) in contralateral breast. Breast conserving surgery and mastectomy rate of the 100 onstage-operation group was 36% versus 64% and 64.6% versus 35.4% in total 1068 patients, showing no significant change of operation method of the primary cancer owing to additional lesion.

Among the 100 patients, 54(19.3% of 280) were benign, 3(1.1% of 280) were atypical ductal hyperplasia, 13(4.6% of 280) were in situ carcinoma, 19(6.8% of 280) were invasive carcinoma and 11(3.9% of 280) were unknown. Cancer yield was 2.99%(32 out of 1068) and PPV of preoperative breast MRI was 39.0%(31 out of 82).

In univariate analysis, young age and premenopausal patients showed to have higher rate of additional cancer found in MRI(p=0.022, p=0.036). Breast density, size and LN status of the primary cancer didn't show significancy and neither the hormone receptor status with each p value 0.705, 0.381, 0.973, 0.375 respectively. Lobular carcinoma(ILC or mixed IDC with ILC) and low grade carcinoma showed significancy of having additional malignancy (p=0.019, 0.022). In multivariate analysis age, low grade carcinoma and lobular carcinoma showed independent association with p value 0.014, 0.039, 0.035 respectively(HR 0.95, 95%CI:0.94 o 0.99),(HR 0.39, 95%CI:0.16 to 0.96),(HR 5.66, 95%CI:1.13 to 28.39).

Routine preoperative breast MRI use can result in overtreatment also with delay in surgical management. In our data, younger age, low grade carcinoma, lobular carcinoma showed independent association having additional malignant foci in breast MRI. With the basis of mammography and sonography, preoperative breast MRI should only be done when additional gain is considered to overcome the flaws.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-08-12.

Effects of genome-wide copy number variation on expression in mammalian cells

Background

There is only a limited understanding of the relation between copy number and expression for mammalian genes. We fine mapped cis and trans regulatory loci due to copy number change for essentially all genes using a human-hamster radiation hybrid (RH) panel. These loci are called copy number expression quantitative trait loci (ceQTLs).

Results

Unexpected findings from a previous study of a mouse-hamster RH panel were replicated. These findings included decreased expression as a result of increased copy number for 30% of genes and an attenuated relationship between expression and copy number on the X chromosome suggesting an Xist independent form of dosage compensation. In a separate glioblastoma dataset, we found conservation of genes in which dosage was negatively correlated with gene expression. These genes were enriched in signaling and receptor activities. The observation of attenuated X-linked gene expression in response to increased gene number was also replicated in the glioblastoma dataset. Of 523 gene deserts of size > 600 kb in the human RH panel, 325 contained trans ceQTLs with -log₁₀ P > 4.1. Recently discovered genes, ultra conserved regions, noncoding RNAs and microRNAs explained only a small fraction of the results, suggesting a substantial portion of gene deserts harbor as yet unidentified functional elements.

Conclusion

Radiation hybrids are a useful tool for high resolution mapping of cis and trans loci capable of affecting gene expression due to copy number change. Analysis of two independent radiation hybrid panels show agreement in their findings and may serve as a discovery source for novel regulatory loci in noncoding regions of the genome.

Optimal rebinning of time-of-flight PET data

Time-of-flight (TOF) positron emission tomography (PET) scanners offer the potential for significantly improved signal-to-noise ratio (SNR) and lesion detectability in clinical PET. However, fully 3D TOF PET image reconstruction is a challenging task due to the huge data size. One solution to this problem is to rebin TOF data into a lower dimensional format. We have recently developed Fourier rebinning methods for mapping TOF data into non-TOF formats that retain substantial SNR advantages relative to sinograms acquired without TOF information. However, mappings for rebinning into non-TOF formats are not unique and optimization of rebinning methods has not been widely investigated. In this paper we address the question of optimal rebinning in order to make full use of TOF information. We focus on FORET-3D, which approximately rebins 3D TOF data into 3D non-TOF sinogram formats without requiring a Fourier transform in the axial direction. We optimize the weighting for FORET-3D to minimize the variance, resulting in H(2)-weighted FORET-3D, which turns out to be the best linear unbiased estimator (BLUE) under reasonable approximations and furthermore the uniformly minimum variance unbiased (UMVU) estimator under Gaussian noise assumptions. This implies that any information loss due to optimal rebinning is as a result only of the approximations used in deriving the rebinning equation and developing the optimal weighting. We demonstrate using simulated and real phantom TOF data that the optimal rebinning method achieves variance reduction and contrast recovery improvement compared to nonoptimized rebinning weightings. In our preliminary study using a simplified simulation setup, the performance of the optimal rebinning method was comparable to that of fully 3D TOF MAP.

CYP2D6 and ESR genotypes in adjuvant tamoxifen treatment for early breast cancer

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Background: The pharmacokinetics and pharmacodynamics of tamoxifen may influence the clinical outcome and tolerability of adjuvant treatment with tamoxifen in breast cancer. We investigated the effects of polymorphisms of CYP2D6, ESR1, and ESR2 for tamoxifen therapy in early stage breast cancer patients.

Methods: Tissue DNA from 187 patients who received tamoxifen only as an adjuvant systemic therapy between 1997 and 2002 were extracted and genotyped for polymorphisms of CYP2D6 (*2A, *10, *14, *41) and estrogen receptor (ESR1, ESR2). While CYP2D6*10, *14 and *41 have been reported to be associated with decreased activation of tamoxifen, CYP2D6*2A, ESR1 PvuII CC and ESR2-02 GG have been associated with enhanced activity of tamoxifen. Statistical analyses include Fisher exact test, Chi-square and Kaplan-Meier analyses.

Results: Median age was 43 years (range 25-49). Most of the patients (170/187) were stage I, while other patients were stage 0 (1/187) and stage II (17/187). None of the patients had nodal metastasis. Median follow-up was 100 months (7-166). Allele frequencies were as follows: CYP2D6*10, 0.69; *14, 0.02; *41, 0.01; *2A, 0.64; ESR1 PvuII C allele, 0.25; ESR2-02 G allele, 0.98. Each genotype group did not show significant differences in age, stage, pT, tumor size and follow up period. Twelve percent (24/187) had received tamoxifen therapy for less than 24 months. Of the 24 patients, 67% (16) discontinued tamoxifen therapy related to tolerability issues. Recurrence occurred in 12 patients (6.4%). There was no association between genotypes with either recurrence or tamoxifen duration < 2 years. Although statistically nonsignificant, patients with either CYP2D6*2A homozygote, ESR1 PvuII CC genotype, ESR2-02 GG genotype tended to have a longer DFS when compared concomitantly to wild-type (p=0.445).

Conclusions: Polymorphsims for CYP2D6*2A,*10, *14, *41, ESR1 PvuII, ESR2-02 did not show significant associations with either recurrence or tamoxifen duration > 2 years. However, grouped analysis for CYP2D6*2A, ESR1 PvuII, ESR2-0210 genotypes need further evaluation regarding with tamoxifen outcome.