Clinicopathological and immunohistochemical study of 29 cases of solid-pseudopapillary neoplasms of the pancreas in patients under 20 years of age along with detailed review of literature

Background

Multiplex immunohistochemistry (mIHC) permits the labeling of six or more distinct cell types within a single histologic tissue section. The classification of each cell type requires detection of uniquely colored chromogens localized to cells expressing biomarkers of interest. The most comprehensive and reproducible method to evaluate such slides is to employ digital pathology and image analysis pipelines to whole-slide images (WSIs). Our suite of deep learning tools quantitatively evaluates the expression of six biomarkers in mIHC WSIs. These methods address the current lack of readily available methods to evaluate more than four biomarkers and circumvent the need for specialized instrumentation to spectrally separate different colors. The use case application for our methods is a study that investigates tumor immune interactions in pancreatic ductal adenocarcinoma (PDAC) with a customized mIHC panel.

Methods

Six different colored chromogens were utilized to label T-cells (CD3, CD4, CD8), B-cells (CD20), macrophages (CD16), and tumor cells (K17) in formalin-fixed paraffin-embedded (FFPE) PDAC tissue sections. We leveraged pathologist annotations to develop complementary deep learning-based methods: (1) ColorAE is a deep autoencoder which segments stained objects based on color; (2) U-Net is a convolutional neural network (CNN) trained to segment cells based on color, texture and shape; and (3) ensemble methods that employ both ColorAE and U-Net, collectively referred to as ColorAE:U-Net. We assessed the performance of our methods using: structural similarity and DICE score to evaluate segmentation results of ColorAE against traditional color deconvolution; F1 score, sensitivity, positive predictive value, and DICE score to evaluate the predictions from ColorAE, U-Net, and ColorAE:U-Net ensemble methods against pathologist-generated ground truth. We then used prediction results for spatial analysis (nearest neighbor).

Results

We observed that (1) the performance of ColorAE is comparable to traditional color deconvolution for single-stain IHC images (note: traditional color deconvolution cannot be used for mIHC); (2) ColorAE and U-Net are complementary methods that detect six different classes of cells with comparable performance; (3) combinations of ColorAE and U-Net in ensemble methods outperform ColorAE and U-Net alone; and (4) ColorAE:U-Net ensemble methods can be employed for detailed analysis of the tumor microenvironment (TME).

Summary

We developed a suite of scalable deep learning methods to analyze 6 distinctly labeled cell populations in mIHC WSIs. We evaluated our methods and found that they reliably detected and classified cells in the PDAC tumor microenvironment. We also utilized the ColorAE:U-Net ensemble method to analyze 3 mIHC WSIs with nearest neighbor spatial analysis. We demonstrate a proof of concept that these methods can be employed to quantitatively describe the spatial distribution of immune cells within the tumor microenvironment. These complementary deep learning methods are readily deployable for use in clinical research studies.

     

Effect of Nitric Oxide on Seed Germination and Seedling Development of Tomato Under Chromium Toxicity

Nitric oxide (NO), a signaling molecule with diverse physiological functions, improves immunity of the plant against different environmental stresses. Heavy metal stress-induced structural and functional damages in cells are common consequences. Seed germination and seedlings development are crucial phases in the life cycle of a plant. The present experiment was designed to investigate how NO suppresses hexavalent chromium Cr(VI)-provoked impairment in the key processes during seed germination and seedlings development of tomato. This study reports that Cr(VI) stress significantly impaired seed germination attributes and the activity of hydrolyzing enzymes, such as α-amylase (α-A) and protease (Pr). However, exogenous NO donor sodium nitroprusside substantially improved seed germination parameters and upregulation of α-A and Pr. Furthermore, NO improved the content of nitrogen (N), NO, and proline (Pro), and modulated the activity of enzymes involved in Pro and N-assimilation. Under Cr(VI) toxicity conditions, NO improved the content of metal ligation compounds (non-protein thiols and total thiols), ascorbate and glutathione (GSH), and maintained higher content of GSH in glutathione pool (GSH:GSSG) and suppressed the formation of 4-hydroxy-2-nonenal and protein carbonylation, and electrolyte leakage. It may be concluded that NO improved the activity of hydrolyzing and Pro and N-metabolism enzymes. Application of NO also enhanced non-enzymatic antioxidants, and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity under Cr(VI) toxicity conditions, thereby improved enhanced seed germination and seedlings vigor.

     

Analogues of 2′-hydroxychalcone with modified C4-substituents as the inhibitors against human acetylcholinesterase

A series of C4-substituted tertiary nitrogen-bearing 2′-hydroxychalcones were designed and synthesised based on a previous mixed type acetylcholinesterase inhibitor. Majority of the 2′-hydroxychalcone analogues displayed a better inhibition against acetylcholinesterase (AChE) than butyrylcholinesterase (BuChE). Among them, compound 4c was identified as the most potent AChE inhibitor (IC₅₀: 3.3 µM) and showed the highest selectivity for AChE over BuChE (ratio >30:1). Molecular docking studies suggested that compound 4c interacts with both the peripheral anionic site (PAS) and catalytic anionic site (CAS) regions of AChE. ADMET analysis confirmed the therapeutic potential of compound 4c based on its blood–brain barrier penetrating. Overall, the results suggest that this 2′-hydroxychalcone deserves further investigation into the therapeutic lead for Alzheimer’s disease (AD).     

Grafting experiments on the nature of the decline in N2 fixation during fruit development in soybean

A decline in nitrogen fixation at the time of pod-filling is persistently seen in soybeans. This phenomenon was studied by grafting experiments. Young scions with 3 nodes were grafted near the base of fruiting stocks which had passed their peak of nitrogen fixation. These grafts produced a second peak of nitrogen fixation on the same root system, indicating that the decline is reversible. If the scions were grafted near the apex of the fruiting stocks then the second peak of nitrogen fixation was very small. Thus, the translocation system could have an important role in regulating the decline in nitrogen fixation. Grafting of a second shoot of the same age as the rootstock, after the decline in nitrogen fixation, did not reduce the rate of decline even when the fruits from the scion were removed. It appears that physiological changes in different components of the shoot jointly regulate the decline in the rate of nitrogen fixation in soybeans.     

The effect of fruit development on the growth capacity of apical meristems

Summary The effect of fruit development prior to ripening on the growth of both axillary buds and grafted young buds was examined in pea (Pisum sativum L. var Alaska). While fruit development retards the growth of these apices it has no effect on their growth capacity or senescence as compared to deflowered plants.     

Senescence in Detached Oat Leaves I. Changes in Free Amino Acid Levels

Changes in the levels of free amino acids have been measuredduring light and dark senescence of oat leaf segments. Leaveswere aged either on water, 5 ppm kinetin or 30 ppm abscisicacid. The patterns with which levels of individual amino acidschange differ a great deal in leaves senescing either in darkor light, signifying that different mechanisms may regulateoat leaf senescence in light and dark. Levels of serine andmost of the other amino acids that increase substantially duringdark senescence of oat leaves change parallel to mitochondrialrespiration. Kinetin depresses the rise in amino acids justas it does with respiration in the dark. The synthesis of serineproteases does not seem to be limited by the availability ofendogenous serine. The levels of glutamine increase dramaticallyin leaves kept in light (ca. 2,200% of initial value within7 days) but only a little in the dark, which may reflect a possiblerole of photorespiration during the senescence of oat leavesin the light. Abscisic acid enhances the release of amino acidsmore strongly in the light than dark. The senescence promotingeffect of abscisic acid in the light seems to bring about changesin amino acid levels similar to those that appear in leavessenescing on water in the dark. ¹ Present address: C.F. Kettering Research Laboratory, 150 EastSouth College Street, Yellow Springs, Ohio 45387, U.S.A. (Received June 24, 1981; Accepted October 30, 1981)     

Leishmaniasis in the Middle East: Incidence and Epidemiology

Leishmaniasis is a major health problem worldwide, with several countries reporting cases of leishmaniasis resulting in loss of human life or a lifelong stigma because of bodily scars. The Middle East is endemic for cutaneous leishmaniasis, with countries like Syria reporting very high incidence of the disease. Despite several countries establishing national control programs for containing the sandfly vector and treatment of infection, the disease continues to spread. In addition to the endemicity of the region for leishmaniasis, the Middle East has seen a great deal of human migration either for earning of livelihood or due to political upheaval in the region. These factors contribute to the spread and proliferation of the causative species Leishmania and its sandfly host. This review discusses the current epidemiological scenario in Iraq, Syria, Saudi Arabia, and Jordan, emphasizing the number of cases reported, vector species, Leishmania species, and treatment available. The data is primarily from WHO reports for each country and current and old literature.     

Acceptance of trial of labor after cesarean (Tolac) among obstetricians in the Western Region of Saudi Arabia: A cross-sectional study

BackgroundBabies to women eligible for trial of labor after a cesarean (TOLAC) are sometimes delivered by cesarean section (CS). To obtain clinicians’ attitudes and beliefs about TOLAC, this study was designed to investigate the views of clinicians when advising TOLAC-eligible pregnant women about TOLAC, and to explore their reasons in favor of or against TOLAC.MethodsInterviews were carried out individually (face-to-face) with clinicians using a specially designed questionnaire to collect data from obstetricians in the Western Region of Saudi. Regression analysis was used as appropriate.ResultsAmong the 183 obstetricians included in the current study, approximately 79.2% were against offering TOLAC. However, most of the physicians (89.1%) were in favor of offering TOLAC to patients who had had a successful vaginal birth after CS. significant associations were found between physicians’ opposition to TOLAC and medical and most non-medical factors.ConclusionClinicians should recognize that the critical role they play in the delivery decision-making process and in boosting women’s confidence in TOLAC may be key to increasing the rate of TOLAC.