Case Report Unclassified mixed germ cell-sex cord-stromal tumor with multiple malignant cellular elements in a young woman: a case report and review of the literature

Abstract: Unclassified mixed germ cell-sex cord-stromal tumor composed of germ cells and sex cord derivatives is a rare neoplasm. Approximately 10% of such tumors have malignant germ cell components. We report the case of a 28 year-old female with a right adnexal mass measuring 8 cm in greatest dimension, containing areas with both germ cell and sex cord components. The germ cell portion contained multiple growth patterns with a malignant appearance, while the sex cord element consisted mainly of annular tubules. Within the malignant germ cell elements was a dysgerminoma that accounted for approximately 75% of the tumor volume. Other malignant germ cell elements included yolk sac tumor, embryonal carcinoma, and choriocarcinoma, which comprised about 15% of the tumor volume. The annular tubule structures comprised about 10% of the total tumor volume. To our knowledge, this is the first case reported in the literature of an unclassified mixed germ cell-sex cord-stromal tumor associated with embryonal carcinoma components. The patient had a 46XX karyotype, regular menstrual periods, and no evidence of gross abnormalities in the contralateral ovary. The patient remained clinically well and disease-free 2 years after surgery. In addition to a thorough case description, the literature concerning this entity is reviewed and discussed

Case Report Low-grade endometrioid carcinoma of the ovary associated with undifferentiated carcinoma: case report and review of the literature

Abstract: The association of low-grade endometrioid carcinoma with undifferentiated carcinoma (UC) was first reported in endometrium carcinoma, termed with dedifferentiated carcinoma (DC). However, the coexistence of lowgrade endometrioid carcinoma (LGEC) or serous carcinoma (LGSC) with UC has received minimal attention in ovary, and the behavior of this kind of neoplasm remains at further discussion. In this study, we reported a case of lowgrade ovarian endometrioid carcinoma associated with UC and reviewed another four cases previously reported. We found a histological continuity between the LGEC and UC components in H&E section, which suggested a dedifferentiation from LGEC to UC components. In summary, this kind of pathological type has aggressive behavior and these patients have very poor prognosis regardless of the amount of undifferentiated carcinoma

Expression of Hemolysin Is Regulated Under the Collective Actions of HapR, Fur, and HlyU in Vibrio cholerae El Tor Serogroup O1

The biotype El Tor of serogroup O1 and most of the non-O1/non-O139 strains of Vibrio cholerae can produce an extracellular pore-forming toxin known as cholera hemolysin (HlyA). Expression of HlyA has been previously reported to be regulated by the quorum sensing (QS) and the regulatory proteins HlyU and Fur, but lacks the direct evidence for their binding to the promoter of hlyA. In the present work, we showed that the QS regulator HapR, along with Fur and HlyU, regulates the transcription of hlyA in V. cholerae El Tor biotype. At the late mid-logarithmic growth phase, HapR binds to the three promoters of fur, hlyU, and hlyA to repress their transcription. At the early mid-logarithmic growth phase, Fur binds to the promoters of hlyU and hlyA to repress their transcription; meanwhile, HlyU binds to the promoter of hlyA to activate its transcription, but it manifests direct inhibition of its own gene. The highest transcriptional level of hlyA occurs at an OD600 value of around 0.6–0.7, which may be due to the subtle regulation of HapR, Fur, and HlyU. The complex regulation of HapR, Fur, and HlyU on hlyA would be beneficial to the invasion and pathogenesis of V. cholerae during the different infection stages

Investigating the neural mechanisms of transcranial direct current stimulation effects on human cognition: current issues and potential solutions

Transcranial direct current stimulation (tDCS) has been studied extensively for its potential to enhance human cognitive functions in healthy individuals and to treat cognitive impairment in various clinical populations. However, little is known about how tDCS modulates the neural networks supporting cognition and the complex interplay with mediating factors that may explain the frequently observed variability of stimulation effects within and between studies. Moreover, research in this field has been characterized by substantial methodological variability, frequent lack of rigorous experimental control and small sample sizes, thereby limiting the generalizability of findings and translational potential of tDCS. The present manuscript aims to delineate how these important issues can be addressed within a neuroimaging context, to reveal the neural underpinnings, predictors and mediators of tDCS-induced behavioral modulation. We will focus on functional magnetic resonance imaging (fMRI), because it allows the investigation of tDCS effects with excellent spatial precision and sufficient temporal resolution across the entire brain. Moreover, high resolution structural imaging data can be acquired for precise localization of stimulation effects, verification of electrode positions on the scalp and realistic current modeling based on individual head and brain anatomy. However, the general principles outlined in this review will also be applicable to other imaging modalities. Following an introduction to the overall state-of-the-art in this field, we will discuss in more detail the underlying causes of variability in previous tDCS studies. Moreover, we will elaborate on design considerations for tDCS-fMRI studies, optimization of tDCS and imaging protocols and how to assure high-level experimental control. Two additional sections address the pressing need for more systematic investigation of tDCS effects across the healthy human lifespan and implications for tDCS studies in age-associated disease, and potential benefits of establishing large-scale, multidisciplinary consortia for more coordinated tDCS research in the future. We hope that this review will contribute to more coordinated, methodologically sound, transparent and reproducible research in this field. Ultimately, our aim is to facilitate a better understanding of the underlying mechanisms by which tDCS modulates human cognitive functions and more effective and individually tailored translational and clinical applications of this technique in the future

Molecular Characterization of Transcriptional Regulation of rovA by PhoP and RovA in Yersinia pestis

BACKGROUND: Yersinia pestis is the causative agent of plague. The two transcriptional regulators, PhoP and RovA, are required for the virulence of Y. pestis through the regulation of various virulence-associated loci. They are the global regulators controlling two distinct large complexes of cellular pathways. METHODOLOGY/PRINCIPAL FINDINGS: Based on the LacZ fusion, primer extension, gel mobility shift, and DNase I footprinting assays, RovA is shown to recognize both of the two promoters of its gene in Y. pestis. The autoregulation of RovA appears to be a conserved mechanism shared by Y. pestis and its closely related progenitor, Y. pseudotuberculosis. In Y. pestis, the PhoP regulator responds to low magnesium signals and then negatively controls only one of the two promoters of rovA through PhoP-promoter DNA association. CONCLUSIONS/SIGNIFICANCE: RovA is a direct transcriptional activator for its own gene in Y. pestis, while PhoP recognizes the promoter region of rovA to repress its transcription. The direct regulatory association between PhoP and RovA bridges the PhoP and RovA regulons in Y. pestis

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Yiquan Shi's Quick Files

The Quick Files feature was discontinued and it’s files were migrated into this Project on March 11, 2022. The file URL’s will still resolve properly, and the Quick Files logs are available in the Project’s Recent Activity

South China Sea Wind-Wave Characteristics. Part I: Validation of Wavewatch-III Using TOPEX/Poseidon Data

A full-spectral third-generation ocean wind-wave model, Wavewatch-III, has been implemented in the South China Sea (SCS) for investigating wind-wave characteristics. This model was developed at the Ocean Modeling Branch of the National Centers for Environmental Prediction (NCEP). The NASA QuickSCAT data (0.258 resolution) 2 times daily were used to simulate the wind waves for the entire year of 2000. The significant wave heights from Wavewatch-III are compared to the TOPEX/Poseidon (T/P) significant wave height data over the satellite crossover points in SCS. The model errors of significant wave height have Gaussian-type distribution with a small mean value of 0.02 m (almost no bias). The model errors are comparable to the T/P altimeter accuracy (0.5 m) in the central SCS and are smaller than the T/P altimeter accuracy in the northern and southern SCS, which indicates the capability of Wavewatch-III for SCS wave simulation

Validation of Wavewatch-III Using TOPEX/POSEIDON Data

Proceedings of SPIE Conference on Remote Sensing of the Ocean and Sea Ice, 98-107A full-spectral thrid-generation ocean wind-wave model, Wavewatch-III, has been implemented in the South China Sea (SCS) for investigating the wind wave characteristics. This model was developed at the Ocean Modeling Branch of the National Centers for Environmental Prediction (NCEP). The NASA QuickScat data (0.25 degrees resolution) two times daily were used to simulate the wind waves for the whole year in 2000. The significant wave heights from Wavewatch-III are compared to the TOPEX/POSEIDON (T/P) significant wave height data over the satellite crossover points in SCS. The model errors of significant wave height have Gaussian-type distribution with small mean value of 0.02 m (almost no bias). The model errors are comparable to the T/P altimeter accuracy (0.5 m) in the central SCS and smaller than the T/P altimeter accuracy in the northern and southern SCS, which indicates the capacity of Wavewatch-III for SCS wave simulation