Diagnostic performance and image quality of an image-based denoising algorithm applied to radiation dose-reduced CT in diagnosing acute appendicitis.

PURPOSE: To evaluate diagnostic performance and image quality of ultralow-dose CT (ULDCT) in diagnosing acute appendicitis with an image-based deep-learning denoising algorithm (IDLDA). METHODS: This retrospective multicenter study included 180 patients (mean ± standard deviation, 29 ± 9 years; 91 female) who underwent contrast-enhanced 2-mSv CT for suspected appendicitis from February 2014 to August 2016. We simulated ULDCT from 2-mSv CT, reducing the dose by at least 50%. Then we applied an IDLDA on ULDCT to produce denoised ULDCT (D-ULDCT). Six radiologists with different experience levels (three board-certified radiologists and three residents) independently reviewed the ULDCT and D-ULDCT. They rated the likelihood of appendicitis and subjective image qualities (subjective image noise, diagnostic acceptability, and artificial sensation). One radiologist measured image noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). We used the receiver operating characteristic (ROC) analyses, Wilcoxon's signed-rank tests, and paired t-tests. RESULTS: The area under the ROC curves (AUC) for diagnosing appendicitis ranged 0.90-0.97 for ULDCT and 0.94-0.97 for D-ULDCT. The AUCs of two residents were significantly higher on D-ULDCT (AUC difference = 0.06 [95% confidence interval, 0.01-0.11; p = .022] and 0.05 [0.00-0.10; p = .046], respectively). D-ULDCT provided better subjective image noise and diagnostic acceptability to all six readers. However, the response of board-certified radiologists and residents differed in artificial sensation (all p ≤ .003). D-ULDCT showed significantly lower image noise, higher SNR, and higher CNR (all p < .001). CONCLUSION: An IDLDA can provide better ULDCT image quality and enhance diagnostic performance for less-experienced radiologists.

Risk of hematologic malignant neoplasms from head CT radiation in children and adolescents presenting with minor head trauma: a nationwide population-based cohort study.

OBJECTIVES: The carcinogenic risks of CT radiation in children and adolescents remain debated. We aimed to assess the carcinogenic risk of CTs performed in children and adolescents with minor head trauma. METHODS: In this nationwide population-based cohort study, we included 2,411,715 patients of age 0-19 with minor head trauma from 2009 to 2017. We excluded patients with elevated cancer risks or substantial past medical radiation exposure. Patients were categorized into CT-exposed or CT-unexposed group according to claim codes for head CT. The primary outcome was development of hematologic malignant neoplasms. Secondary outcomes included development of malignant solid neoplasms and benign neoplasms in the brain. We measured the incidence rate ratio (IRR) and incidence rate difference (IRD) using G-computation with Poisson regression adjusting for age, sex, hospital setting, and the type of head trauma. RESULTS: Hematologic malignant neoplasms developed in 100 of 216,826 patients during 1,303,680 person-years in the CT-exposed group and in 808 of 2,194,889 patients during 13,501,227 person-years in the CT-unexposed group. For hematologic malignant neoplasms, the IRR was 1.29 (95% CI, 1.03-1.60) and the IRD was 1.71 (95% CI, 0.04-3.37) per 100,000 person-years at risk. The majority of excess hematologic malignant neoplasms were leukemia (IRR, 1.40 [98.3% CI, 1.05-1.87]; IRD, 1.59 [98.3% CI, 0.02-3.16] per 100,000 person-years at risk). There were no between-group differences for secondary outcomes. CONCLUSIONS: Radiation exposure from head CTs in children and adolescents with minor head trauma was associated with an increased incidence of hematologic malignant neoplasms. CLINICAL RELEVANCE STATEMENT: Our study provides a quantitative grasp of the risk conferred by CT examinations in children and adolescents, thereby providing the basis for cost-benefit analyses and evidence-driven guidelines for patient triaging in head trauma. KEY POINTS: • This nationwide population-based cohort study showed that radiation exposure from head CTs in children and adolescents was associated with a higher incidence of hematologic malignant neoplasms. • The incidence rate of hematologic malignant neoplasms in the CT-exposed group was 29% higher than that in the CT-unexposed group (IRR, 1.29 [95% CI, 1.03-1.60]), and there were approximately 1.7 excess neoplasms per 100,000 person-years at risk in the CT-exposed group (IRD, 1.71 [0.04-3.37]). • Our study provides a quantified grasp of the risk conferred by CT examinations in children and adolescents, while controlling for biases observed in previous studies via specifying CT indication and excluding patients with predisposing conditions for cancer development.

Enrichment of the exocytosis protein STX4 in skeletal muscle remediates peripheral insulin resistance and alters mitochondrial dynamics via Drp1.

Mitochondrial dysfunction is implicated in skeletal muscle insulin resistance. Syntaxin 4 (STX4) levels are reduced in human diabetic skeletal muscle, and global transgenic enrichment of STX4 expression improves insulin sensitivity in mice. Here, we show that transgenic skeletal muscle-specific STX4 enrichment (skmSTX4tg) in mice reverses established insulin resistance and improves mitochondrial function in the context of diabetogenic stress. Specifically, skmSTX4tg reversed insulin resistance caused by high-fat diet (HFD) without altering body weight or food consumption. Electron microscopy of wild-type mouse muscle revealed STX4 localisation at or proximal to the mitochondrial membrane. STX4 enrichment prevented HFD-induced mitochondrial fragmentation and dysfunction through a mechanism involving STX4-Drp1 interaction and elevated AMPK-mediated phosphorylation at Drp1 S637, which favors fusion. Our findings challenge the dogma that STX4 acts solely at the plasma membrane, revealing that STX4 localises at/proximal to and regulates the function of mitochondria in muscle. These results establish skeletal muscle STX4 enrichment as a candidate therapeutic strategy to reverse peripheral insulin resistance.

Effects of dietary trans-9 octadecenoic acid, trans-11 vaccenic acid and cis-9, trans-11 conjugated linoleic acid in mice.

The aim of the present study was to investigate the effects of dietary trans fatty acids in mice. Following the administration of a 0.5/100 g diet of trans-9 octadecenoic acid (EA), trans-11 vaccenic acid (TVA) or cis-9, trans-11 conjugated linoleic acid (CLA) for 4 weeks, the body weights and the weights of the liver, testis and mediastinal adipose tissue (MAT) of the animals gradually decreased (P<0.05). The EA group exhibited the lowest levels of magnesium and triglycerides (P<0.05). CLA increased villus length (P<0.05), while EA and TVA decreased villus length (P<0.05). The TVA group exhibited the lowest levels of low-density lipoprotein and tumor necrosis factor-α (P<0.05). Taken together, EA, TVA and CLA affected the physiological conditions of mice differently. The potential effects of three well-known fatty acids, including trans-9 octadecenoic acid (EA), trans-11 vaccenic acid (TVA) and cis-9, trans-11 conjugated linoleic acid (CLA), in animals or humans remain to be elucidated. Therefore, in the present study, 32 animals were randomly divided into four groups and administered a 0.5/100 g diet of EA, TVA or CLA for 4 weeks. The results demonstrated that the body weights and the weights of the liver, testis and mediastinal adipose tissue (MAT) of the animals gradually decreased (P<0.05). Blood was collected individually via the external jugular veins and the EA group exhibited the lowest levels of magnesium and triglycerides (P<0.05). CLA increased villus length (P<0.05), while EA and TVA decreased villus length (P<0.05). The TVA group exhibited the lowest levels of low-density lipoprotein and tumor necrosis factor-α (P<0.05). Taken together, EA, TVA and CLA affected the physiological conditions of mice differently and these may further our understanding of the various effects of these fatty acids on animals and humans.

Association of protein expression in isolated milk epithelial cells and cis-9, trans-11 conjugated linoleic acid proportions in milk from dairy cows.

BACKGROUND: The effects of the individual variation among dairy cows on the synthesis of cis-9, trans-11 conjugated linoleic acid (CLA) are still not well characterised. Therefore, the protein expression profiles of isolated milk epithelial cells (MECs) were detected by two-dimensional electrophoresis and their correlation with the various proportion of cis-9, trans-11 CLA were evaluated. RESULTS: Although animals were offered the same diet, the proportion of cis-9, trans-11 CLA in group High (1.02 ± 0.10%) was twice as high as that in group Low (0.59 ± 0.14%) (P < 0.05). MECs with the characteristics of native epithelial cells were successfully isolated from the milk and these cells had no obvious RNA degradation or were hardly contaminated with leucocytes or blood red cells. Moreover, the protein expression pattern of cathelicidin 5 in isolated MECs was positive, whereas annexin I (confirmed by real-time polymerase chain reaction), ZW10 interactor and κ-casein were negatively related to the proportion of cis-9, trans-11 CLA in the milk fat. CONCLUSION: The varied individual content of cis-9, trans-11 CLA in cows may be associated with annexin I. These findings may provide some theoretical basis for studies concerning the effects of the individual variation among dairy cows of the synthesis of cis-9, trans-11 CLA. © 2013 Society of Chemical Industry.

Vitamin D binding protein plays an important role in the progression of endometriosis.

Endometriosis, characterized by the growth of the endometrial gland and stroma outside the uterine cavity, is a gynecological disorder affecting 6­10% of women of reproductive age. However, the pathogenesis of endometriosis and the molecular mechanisms involved in the progression of this disease remain to be clarified. Therefore, in this study two-dimensional gel electrophoresis (2­DE) combined with mass spectrometry (MS) were applied to explore endometrial proteins with a role in the progression of endometriosis. Expression of global proteins in ectopic endometrial tissue (n=13; endometriosis group) was compared with that of the normal endometrial tissue (n=6; control group). Sixteen differently expressed proteins, including Vitamin D binding protein (DBP), with various functions were primarily identified in the ectopic endometrial tissue. DBP was confirmed to be significantly increased in the ectopic endometrial tissue compared with that in the normal endometrial tissue (P<0.05). Results of the present study therefore showed that DBP may play an important role in the progression of endometriosis.

Identification of biomarkers for endometriosis in eutopic endometrial cells from patients with endometriosis using a proteomics approach.

Endometriosis is a gynecological disease defined as the presence of endometrial tissue outside the uterine cavity, which is caused by various factors. Proteomic analysis of two sets of eutopic endometrial cells collected from the menstrual blood of females with (n=6; n=3) or without (n=6; n=3) endometriosis was performed to identify novel potential biomarkers for endometriosis. The data revealed that samples from endometriosis patients had stem cell characteristics, as they had higher mRNA expression levels of octamer-binding transcription factor 4 (Oct-4), C-X-C chemokine receptor type 4 (CXCR4), SRY-box containing gene 2 (SOX2) and mesenchymal-epithelial transition factor (MET) compared with that of the normal controls. Three proteins, collapsin response mediator protein 2 (CRMP2), ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCH-L1) and myosin regulatory light polypeptide 9 (MYL9), were simultaneously identified from the two sets of samples from females with or without endometriosis by two-dimensional electrophoresis (2-DE). A difference in CRMP2 expression was confirmed with western blotting. Taken together, the results suggest that CRMP2 plays a role in the pathogenesis of endometriosis.

Identification and characterization of a serine protease inhibitor of Paragonimus westermani.

Paragonimus westermani is a trematode parasite that causes pulmonary and/or extrapulmonary granulomatous disease in humans. In this study, we identified a full-length gene encoding a novel serine protease inhibitor of P. westermani (PwSERPIN) and characterized the biochemical properties of the recombinant protein. PwSERPIN had an open reading frame of 1,164 bp, which encoded 387 amino acid residues. Sequence analysis of the primary structure of PwSERPIN revealed that it had the essential structural motifs which were well conserved among the serine protease inhibitor (serpin) superfamily and had shown 16.5-29.6% sequence identities with previously reported serpins from other helminthic parasites. No signal peptide or N-glycosylation site was found in the sequence. Genomic DNA structure analysis showed that PwSERPIN comprised six exons separated by five introns. The bacterially expressed recombinant PwSERPIN effectively inhibited the activities of trypsin, thrombin, and chymotrypsin in a dose-dependent manner, but showed lower inhibitory capacity on cathepsin G and elastases. Expression of PwSERPIN was detected throughout various developmental stages of the parasite, from metacercariae to adult worms, and the transcription level gradually increased with the maturation of the parasite. PwSERPIN was identified in the soluble extract of the parasite, but not in the excretory and secretory products (ESP) and in the insoluble extract of the parasite. These results collectively suggest that the PwSERPIN is an intracellular serpin of P. westermani and that might play primary roles in regulating the activities of intracellular serine proteases of the parasite.

Interferon gamma has dual potential in inhibiting or promoting survival and growth of hematopoietic progenitors: interactions with stromal cell-derived factor 1.

We explored the possibility that interferon gamma (IFN-gamma) has bidirectional functions in the survival and growth of hematopoietic progenitors, especially with regard to interactions with stromal cell-derived factor 1 (SDF-1). IFN-gamma partially rescued normal bone marrow CD34+ cells and colony-forming cells from apoptosis induced by serum and hematopoietic growth factor (HGF) deprivation, and SDF-1 further enhanced cell survival. Short-term IFN-gamma treatment of CD34+ cells in the absence of serum and HGFs enhanced the clonal growth of the cells in synergy with SDF-1. In contrast, IFN-gamma inhibited the clonal growth of hematopoietic progenitor cells in a standard methylcellulose clonogenic assay and inhibited the HGF-mediated survival of normal CD34+ cells. The addition of SDF-1 did not alter these outcomes. IFN-gamma did not enhance SDF-1-induced activation of PI3K/Akt or up-regulate the expression of CXCR4 or its function in bone marrow CD34+ cells. IFN-gamma up-regulated Socs1 messenger RNA expression in normal CD34+ cells, which was further enhanced with the addition of HGFs. These results indicate that IFN-gamma, partly in concert with SDF-1, exerts dual effects on the survival and growth of hematopoietic progenitor cells; the effects of IFN-gamma on hematopoietic progenitor cells can differ, depending on the particular in vitro experimental conditions, especially the presence of HGFs.

Overexpression of stromal cell-derived factor-1 enhances endothelium-supported transmigration, maintenance, and proliferation of hematopoietic progenitor cells.

To clarify the direct effects of aberrant overexpression of stromal cell-derived factor-1 (SDF-1) by the human endothelium on circulating progenitor cells, we overexpressed the SDF-1 gene in human umbilical vein endothelial cells using an adenoviral vector (HUVEC/AdeSDF-1) and examined the endothelium-supported trafficking and growth of hematopoietic progenitor cells (HPCs) in mobilized peripheral blood (mPB). In culture, the HUVEC/AdeSDF-1 monolayers induced the migration of mPB CD34(+) cells underneath the endothelium within a few hours, whereas HUVEC monolayers that expressed the LacZ gene (HUVEC/AdeLacZ) did not have this effect. In the Transwell system, the HUVEC/AdeSDF-1 cells supported a higher level of spontaneous transmigration of mPB CD34(+) cells than did the HUVEC/AdeLacZ cells. The co-culturing of mPB CD34(+) cells with HUVEC/ AdeSDF-1 cells led to a greater expansion of CD45(+) cells and colony-forming cells and reduced cellular apoptosis. Furthermore, the co-culturing of mPB CD34(+) cells with HUVEC/AdeSDF-1 cells led to the formation of numerous cobblestone-like areas, whereas co-cultures of mPB CD34(+) cells and HUVEC/AdeLacZ supported only a few cobblestone-like areas. These results indicate that SDF- 1 produced by endothelial cells plays an important role not only in the transmigration but also in the growth of HPCs that are in contact with endothelial cells. Our findings suggest that the enhanced expression and production of SDF-1 in the endothelium are essential steps for stem cell or progenitor cell recruitment to specific tissues and for the maintenance of these cells in situ.

Direct and indirect effects of androgens on survival of hematopoietic progenitor cells in vitro.

Androgens remain a common treatment for certain type of anemia, based upon its myelostimulating effects; however, it has not been established whether androgens affect apoptosis of hematopoietic progenitor cells (HPCs). We investigated the effects of the androgens, such as testosterone, 5beta-dihydrotestosterone (5-DHT), and oxymetholone, on apoptosis of normal hematopoietic progenitor cells in vitro. Androgens did not rescue normal bone marrow (BM) CD34+ cells and colony-forming cells (CFCs), other than mature erythroid CFCs, from apoptosis induced by serum- and growth factor deprivation. Oxymetholone did not affect growth factor-mediated survival of normal CD34+ cells or its inhibition by interferon-gamma (IFN-gamma). In a standard methylcellulose clonogenic assay, low concentrations of oxymetholone and 5-DHT stimulated the clonal growth of colony-forming unit (CFU)-erythroid, but did not affect growth of CFU-granulocyte/macrophage or burst-forming unit-erythroid. Oxymetholone and 5-DHT stimulated the production of stem cell factor in normal bone marrow stromal cells (BMSCs) via transcriptional regulation. In agreement with this, oxymetholone-treated BMSCs better supported the survival of HPCs. These data indicate that survival-enhancing or growth-stimulatory effects of androgens on hematopoietic progenitor cells are minimal and mostly restricted to mature erythroid progenitors, and its myelostimulating effects could be attributed, at least in part, to the stimulation of production of hematopoietic growth factors in BMSCs.

Human bone marrow endothelial cells elaborate non-stromal-cell-derived factor-1 (SDF-1)-dependent chemoattraction and SDF-1-dependent transmigration of haematopoietic progenitors.

This study investigated human bone marrow endothelial cells (BMEC) chemoattractive activity in relation to haematopoietic cell trafficking. BMEC-conditioned medium induced chemoattraction of haematopoietic progenitor cells. Migration was not inhibited by pretreating the cells with pertussis toxin (PTX) or 12G5, indicating that the chemoattractive activity was not dependent on stromal-cell-derived factor-1 (SDF-1). Spontaneous migration, but not SDF-1-mediated chemotaxis of haematopoietic progenitors, was better supported by BMEC as compared with umbilical vein endothelial cells. The superior migration was abolished by pretreating the cells with PTX, indicating that BMEC-derived SDF-1 favours bone marrow endothelium, with better transmigration of haematopoietic progenitors.