LC-MS-Based Direct Quantification of MicroRNAs in Rat Blood

MicroRNA (miRNA) has recently garnered significant research attention, owing to its potential as a diagnostic biomarker and therapeutic target. Liquid chromatography-mass spectrometry (LC-MS) offers accurate quantification, multiplexing capacity, and high compatibility with various matrices. These advantages establish it as a preferred technique for detecting miRNA in biological samples. In this study, we presented an LC-MS method for directly quantifying seven miRNAs (rno-miR-150, 146a, 21, 155, 223, 181a, and 125a) associated with immune and inflammatory responses in rat whole blood. To ensure miRNA stability in the samples and efficiently purify target analytes, we compared Trizol- and proteinase K-based extraction methods, and the Trizol extraction proved to be superior in terms of analytical sensitivity and convenience. Chromatographic separation was carried out using an oligonucleotide C18 column with a mobile phase composed of N-butyldimethylamine, 1,1,1,3,3,3-hexafluoro-2-propanol, and methanol. For MS detection, we performed high-resolution full scan analysis using an orbitrap mass analyzer with negative electrospray ionization. The established method was validated by assessing its selectivity, linearity, limit of quantification, accuracy, precision, recovery, matrix effect, carry-over, and stability. The proposed assay was then applied to simultaneously monitor target miRNAs in lipopolysaccharide-treated rats. Although potentially less sensitive than conventional methods, such as qPCR and microarray, this direct-detection-based LC-MS method can accurately and precisely quantify miRNA. Given these promising results, this method could be effectively deployed in various miRNA-related applications.

Elevating the charge separation of MgFe2O4 nanostructures by Zn ions for enhanced photocatalytic and photoelectrochemical water splitting

Magnesium ferrites (MgFe₂O₄) are important class of ferrites that have been receiving greater attention as promising excellent photocatalyst due to its low cost, wide light spectrum response and environment-friendly nature. However, its poor electronic conductivity and fast charge carrier recombination hinders its electrocatalytical applications. Hence, accelerating charge carriers separation efficiency is important to modify the photoelectrochemical performance of MgFe₂O₄. Herein, novel Zn ions doped MgFe₂O₄ nanospheres are fabricated for the first time. Zn ions are doped into MgFe₂O₄ nanostructures from surface to enhance their charge separation efficiency. The doped MgFe₂O₄ nanostructures show significant photocatalytic activity and enhanced photocurrent density than that of pristine MgFe₂O₄.The improved photoelectrocatalytic performance is attributed to doping effect, were Zn ions actually enhance the conductivity. Zn ions enhance the activity of MgFe₂O₄ and accelerate the charge transfer properties in MgFe₂O₄. The results highlight that Zn doped MgFe₂O₄ nanospheres could be a potential candidate for photocatalytic and photoelectrochemical applications.

Neodymium (Nd) based oxide perovskite nanostructures for photocatalytic and photoelectrochemical water splitting functions

Neodymium (Nd) based perovskite (Nd_1-xCo_xFeO₃) nanostructures were processed to address the rising energy and environment crisis through offering solutions by photocatalytic and photoelectrochemical (PEC) water splitting reactions. The impact of cobalt (Co) ions on the physicochemical properties of Nd-perovskites were studied using X-ray diffraction (XRD), Raman and electron microscopic instruments. The interaction of metal ions was studied in depth via X-ray photoelectron spectroscopy (XPS). Absorption and photoluminescence signals inferred the optical band gap to be lowered and defect states to increase upon Co substitution. Improved photocatalytic efficacy in Nd_1-xCo_xFeO₃ was evaluated by comparative studies using NdFeO₃. Secondly, the enhanced conductivities in Nd_1-xCo_xFeO₃ studied via Nyquist plot was found to be advantageous in photoelectrode fabrication for PEC functions. Time-dependent photocurrent density results affirmed the stability in processed devices. Co ions were also inferred to boost the separation of charge carriers effectively. The improved performance in Nd_1-xCo_xFeO₃ nanostructures were well justified to the successful incorporation of Co ions that sway the Nd-O, Co-O and Co-Fe-O bondings and boost the photon absorption and electronic conductivity to facilitate the observed performance.

Screening of Phosphodiesterase-5 Inhibitors and Their Analogs in Dietary Supplements by Liquid Chromatography-Hybrid Ion Trap-Time of Flight Mass Spectrometry

An accurate and reliable method based on ion trap–time of flight mass spectrometry (IT–TOF MS) was developed for screening phosphodiesterase-5 inhibitors, including sildenafil, vardenafil, and tadalafil, and their analogs in dietary supplements. Various parameters affecting liquid chromatographic separation and IT–TOF detection were investigated, and the optimal conditions were determined. The separation was achieved on a reversed-phase column under gradient elution using acetonitrile and water containing 0.2% acetic acid at a flow rate of 0.2 mL/min. The chromatographic eluents were directly ionized in the IT–TOF system equipped with an electrospray ion source operating in the positive ion mode. The proposed screening method was validated by assessing its linearity, precision, and accuracy. Sequential tandem MS was conducted to obtain structural information of the references, and the fragmentation mechanism of each reference was proposed for providing spectral insight for newly synthesized analogs. Structural information, including accurate masses of both parent and fragment ions, was incorporated into the MSⁿ spectral library. The developed method was successfully applied for screening adulterated dietary supplement samples.

Analysis of Nicotine Metabolites in Hair and Nails Using QuEChERS Method Followed by Liquid Chromatography-Tandem Mass Spectrometry

Many studies have analyzed nicotine metabolites in blood and urine to determine the toxicity caused by smoking, and assess exposure to cigarettes. Recently, hair and nails have been used as alternative samples for the evaluation of smoking, as not only do they reflect long-term exposure but they are also stable and easy to collect. Liquid-liquid or solid-phase extraction has mainly been used to detect nicotine metabolites in biological samples; however, these have disadvantages, such as the use of toxic organic solvents and complex pretreatments. In this study, a modified QuEChERS method was proposed for the first time to prepare samples for the detection of nicotine metabolite cotinine (COT) and trans-3′-hydroxycotinine (3-HCOT) in hair and nails. High-performance liquid chromatography–tandem mass spectrometry (LC–MS/MS) was used to analyze traces of nicotine metabolites. The established method was validated for selectivity, linearity, lower limit of quantitation, accuracy, precision and recovery. In comparison with conventional liquid-liquid extraction (LLE), the proposed method was more robust, and resulted in higher recoveries with favorable analytical sensitivity. Using this method, clinical samples from 26 Korean infants were successfully analyzed. This method is expected to be applicable in the routine analysis of nicotine metabolites for environmental and biological exposure monitoring.

Dual-graft adult living donor liver transplantation with ABO-incompatible graft: short-term and long-term outcomes

ABO-incompatible (ABOi) dual-graft (DG) adult living donor liver transplantation (ALDLT) is not commonly performed due to its inherently intricate surgical technique and immunological complexity. Therefore, data are lacking on the short- and long-term clinical outcomes of ABOi DG ALDLT. We performed a retrospective study by reviewing the medical records of patients who underwent ABOi DG ALDLT between 2008 and 2014. Additionally, computed tomography volumetric analysis was conducted to assess the graft regeneration rate. The mean age of a total of 28 recipients was 50.2 ± 8.5 years, and the mean model for end-stage liver disease score was 12.2 ± 4.6. The 1-, 3-, and 5-year patient survival rate was 96.4% during the mean follow-up period of 57.0 ± 22.4 months. The 1-, 3-, and 5-year graft survival rate was 96.4%, 94.2%, and 92.0%, respectively, and no significant differences were observed between ABO-compatible (ABOc) and ABOi grafts (P = .145). The biliary complication rate showed no significant difference (P = .195) between ABOc and ABOi grafts. Regeneration rates of ABOi grafts were not significantly different from those of ABOc grafts. DG ALDLT with ABOi and ABOc graft combination seems to be a feasible option for expanding the donor pool without additional donor risks.

Classification of the medicinal plants of the genus Atractylodes using high-performance liquid chromatography with diode array and tandem mass spectrometry detection combined with multivariate statistical analysis

Analytical methods using high-performance liquid chromatography with diode array and tandem mass spectrometry detection were developed for the discrimination of the rhizomes of four Atractylodes medicinal plants: A. japonica, A. macrocephala, A. chinensis, and A. lancea. A quantitative study was performed, selecting five bioactive components, including atractylenolide I, II, III, eudesma-4(14),7(11)-dien-8-one and atractylodin, on twenty-six Atractylodes samples of various origins. Sample extraction was optimized to sonication with 80% methanol for 40 min at room temperature. High-performance liquid chromatography with diode array detection was established using a C18 column with a water/acetonitrile gradient system at a flow rate of 1.0 mL/min, and the detection wavelength was set at 236 nm. Liquid chromatography with tandem mass spectrometry was applied to certify the reliability of the quantitative results. The developed methods were validated by ensuring specificity, linearity, limit of quantification, accuracy, precision, recovery, robustness, and stability. Results showed that cangzhu contained higher amounts of atractylenolide I and atractylodin than baizhu, and especially atractylodin contents showed the greatest variation between baizhu and cangzhu. Multivariate statistical analysis, such as principal component analysis and hierarchical cluster analysis, were also employed for further classification of the Atractylodes plants. The established method was suitable for quality control of the Atractylodes plants.

Abstract P5-04-20: TLE1 protein expression in HER2-positive and triple-negative breast cancer

Purpose

Transducin-like enhancer protein 1 (TLE1) is a member of the Groucho (Gro)/TLE family of transcriptional co-repressors that regulate the transcriptional activity of a wide range of genes. TLE1 has been shown to be a specific and diagnostically useful immunohistochemical marker for synovial sarcoma. However, there have been few reports of the status of TLE1 in breast cancers. The purpose of this study was to clarify the nuclear expression of TLE1 in 511 Korean breast cancers by immunohistochemistry (IHC) and to correlate the findings to clinicopathologic variables including prognostic significance.

Methods

IHC was performed on tissue microarrays (TMAs) in 511 cases of breast cancer. Associations between the TLE1 expression and the clinicopathologic characteristics were retrospectively analyzed. Progression-free survival and disease-specific survival was assessed by the Kaplan–Meier method and Cox regression model.

Results

Of 511 cases of breast cancer, high expression of the TLE1 was detected in 63 (12.3%) cases. TLE1-high expression was strongly associated with HER2-positive breast cancer phenotype (p < 0.001) and triple-negative breast cancer phenotype (p < 0.001). Furthermore, high TLE1was significantly associated with high histologic grade (p < 0.001), node-negative (p =0.011), estrogen receptor negativity (p < 0.001), progesterone receptor negativity (p < 0.001), CK5/6 positivity (p < 0.001), epidermal growth factor receptor positivity (p < 0.001), high ki-67 proliferative index (p < 0.001) and high p53 expression (p < 0.001). Survival analysis demonstrated no significant association between TLE1 expression and disease progression and cancer-related death (p =0.112 and p =0.068, respectively).

Conclusion

Our results show that high TLE1expression is significantly associated with HER2-positive and triple-negative breast cancer. TLE1 may represent a potential therapeutic target for this aggressive disease, which warrants further investigation.

Citation Format: Lee HJ, Oh M-H, Lee J-H, Cho HD, Jang S-H, Jung HY, Kim K-J. TLE1 protein expression in HER2-positive and triple-negative breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-04-20.

Thermal Conductivity of ZnO Single Nanowire

The thermal conductivity of a single ZnO nanowire with diameter of ~150 nm was measured using a four-point-probe 3omega method over a temperature range of 140-300 K. The measured ther- mal conductivity of ZnO nanowire is strongly reduced compared to bulk ZnO crystal due to the enhanced phonon-boundary and impurity (isotope) scattering. The maximum of the thermal conductivity is shifted to a higher temperature than that of bulk counterpart. Temperature dependent measurements show that beyond the low-temperature maximum, the thermal conductivity decreases with temperature as T(-1.5) indicating strong impurity (isotope) scattering at intermediate and high temperatures.

Fine needle aspiration cytology of primary pulmonary paraganglioma. A case report

BACKGROUND

Primary pulmonary paragangliomas are rare tumors. To our knowledge, there is no prior report on fine needle aspiration cytology (FNAC) in pulmonary paraganglioma.

CASE

A 34-year-old man presented with an incidentally found solitary pulmonary mass. FNAC showed papillarylike clusters of epithelioid cells with round to oval nuclei, evenly dispersed chromatin, micronucleoli and occasional anisonucleosis. These cytologic features were suggestive of a sclerosing hemangioma or bronchioloalveolar carcinoma. A right lower lobectomy revealed a primary pulmonary paraganglioma.

CONCLUSION

The possibility of pulmonary paraganglioma should be considered in the differential diagnosis of FNAC showing pseudopapillary clusters of epithelioid cells.

A case of retroperitoneal lipoleiomyoma

We report a case of lipoleiomyoma which arose in retroperitoneum and presented with progressively distended abdomen in a 56-yr-old woman. The tumor was well encapsulated and consisted of two components, benign smooth muscle cells and mature adipose tissue without any atypia. It is likely to be mistaken as extrarenal angiomyolipoma, well-differentiated liposarcoma and leiomyoma with fatty change. We review the histologic characteristics of previously reported myolipoma and describe essential points of differential diagnosis.

Dermatomyositis without elevation of creatine kinase presented as bronchiolitis obliterans organizing pneumonia

A case of dermatomyositis presented as bronchiolitis obliterans organizing pneumonia has been rarely reported. We describe a 46-year-old female patient with dermatomyositis without elevation of creatine kinase presented as bronchiolitis obliterans organizing pneumonia. She was treated with prednisolone and azathioprine. Over a 2-year follow-up she has had no elevation of creatine kinase. The patient remains asymptomatic and has no medication for dermatomyositis and bronchiolitis obliterans organizing pneumonia two years after initial treatment. It has been suggested that the prognosis of dermatomyositis without creatine kinase elevation may be poor. Because the prognosis of bronchiolitis obliterans organizing pneumonia is generally believed to be good, we tentatively suggest that the normal value of creatine kinase in dermatomyositis does not always seem to herald a poor prognosis, an associated malignancy or severe interstitial lung disease.

Interslice coding for medical three-dimensional images using an adaptive mode selection technique in wavelet transform domain

In this article the authors propose a novel interslice coding algorithm especially appropriate for medical 3-dimensional (3D) images. The proposed algorithm is based on a video coding algorithm using motion estimation/compensation and transform coding. In the algorithm, warping is adopted for motion compensation. Then, by using adaptive mode selection, an MC residual image and original image are mixed up in the wavelet transform domain for improvement in coding performance. The mixed image is then compressed by the zerotree coding method. It is proven that the adaptive mode selection technique in the wavelet transform domain is very useful for medical 3D image coding. Simulation results show that the proposed scheme provides good performance, regardless of interslice distance, and is prospective for medical 3D image compression.

Infection with Helicobacter pylori expressing the cagA gene is not associated with an increased risk of developing peptic ulcer diseases in Korean patients

BACKGROUND

Helicobacter pylori strains possessing the cagA gene have been postulated to have a disease-specific relationship to peptic ulcer. The purpose of this study was to investigate the relationship between the infection with Helicobacter pylori expressing the cagA gene and the development of peptic ulcer diseases in Korean patients.

METHODS

Genomic DNA and bacterial mRNA in the gastric mucosa were amplified by polymerase chain reaction (PCR) and reverse transcription PCR, using synthetic oligonucleotide primers to cagA genes to compare the prevalence of cagA genes in 35 patients with non-ulcer gastritis and 99 patients with gastric or duodenal ulcer disease (53 and 46, respectively). Two different primer sets for the cagA gene were used. The first primer set amplified a 298-bp region (nucleotides 1751-2048), and the second set amplified a 349-bp region (nucleotides 1228-1249).

RESULTS

The expected 298 and 349-bp PCR amplicons were identified as follows: 1) 32 (91.4%) and 30 (85.7%) of 35 non-ulcer gastritis patients; 2) 5 1 (96.2%) and 50 (94.3%) of 53 benign gastric ulcer patients; and 3) 46 (100.0%) and 40 (87.0%) of 46 duodenal ulcer patients, respectively.

CONCLUSION

These results strongly suggest that the cagA gene will not prove to be a useful marker to distinguish disease-specific H. pylori strains in the development of peptic ulcer diseases in Korean patients.