CT radiomics facilitates more accurate diagnosis of COVID-19 pneumonia: compared with CO-RADS.

BACKGROUND: Limited data was available for rapid and accurate detection of COVID-19 using CT-based machine learning model. This study aimed to investigate the value of chest CT radiomics for diagnosing COVID-19 pneumonia compared with clinical model and COVID-19 reporting and data system (CO-RADS), and develop an open-source diagnostic tool with the constructed radiomics model. METHODS: This study enrolled 115 laboratory-confirmed COVID-19 and 435 non-COVID-19 pneumonia patients (training dataset, n = 379; validation dataset, n = 131; testing dataset, n = 40). Key radiomics features extracted from chest CT images were selected to build a radiomics signature using least absolute shrinkage and selection operator (LASSO) regression. Clinical and clinico-radiomics combined models were constructed. The combined model was further validated in the viral pneumonia cohort, and compared with performance of two radiologists using CO-RADS. The diagnostic performance was assessed by receiver operating characteristics curve (ROC) analysis, calibration curve, and decision curve analysis (DCA). RESULTS: Eight radiomics features and 5 clinical variables were selected to construct the combined radiomics model, which outperformed the clinical model in diagnosing COVID-19 pneumonia with an area under the ROC (AUC) of 0.98 and good calibration in the validation cohort. The combined model also performed better in distinguishing COVID-19 from other viral pneumonia with an AUC of 0.93 compared with 0.75 (P = 0.03) for clinical model, and 0.69 (P = 0.008) or 0.82 (P = 0.15) for two trained radiologists using CO-RADS. The sensitivity and specificity of the combined model can be achieved to 0.85 and 0.90. The DCA confirmed the clinical utility of the combined model. An easy-to-use open-source diagnostic tool was developed using the combined model. CONCLUSIONS: The combined radiomics model outperformed clinical model and CO-RADS for diagnosing COVID-19 pneumonia, which can facilitate more rapid and accurate detection.

Hydrogen sulfide treatment alleviated ventilator-induced lung injury through regulation of autophagy and endoplasmic reticulum stress.

Mechanical ventilation has significant therapeutic benefits, but it may cause or aggravate lung injury, which is called ventilator-induced lung injury (VILI). Endogenous hydrogen sulfide (H2S) has roles including regulating inflammation, and promoting vasodilatation; it also exhibits anti-oxidative stress and anti-fibrosis effects. H2S has been reported to alleviate lung injury, but the effects and mechanism of H2S on VILI remain unclear. The present study established a rat model of VILI and treated them with H2S, then measured the changes in respiratory function indicators, lung tissue histopathology, and oxidative, inflammatory, and apoptotic indicators. The effect of H2S on autophagy in the VILI model and the involvement of endoplasmic reticulum (ER) stress were also investigated. To further explore the mechanism, L2 alveolar epithelial cells were treated with cyclic strain to mimic mechanical strain along with the H2S donor NaHS, and the involvement of the NF-κB/MAPK signaling pathway was examined. The results showed that H2S significantly alleviated VILI and inhibited the inflammation and oxidative stress induced by VILI. H2S also significantly reduced autophagy and ER stress in rats. The phosphorylation of IRE1α, PERK and eIF2α and the expression of nuclear ATF4, and GADD34 in L2 cells were all significantly reduced with NaHS. Nuclear NF-κB p65, MAPK p38, JNK, and ERK were all activated by cyclic strain, but inhibited by the ER stress inhibitor 4-PBA or NaHS. Our findings revealed that H2S treatment alleviated VILI by regulating autophagy and ER stress, and the PERK/eIF2α/ATF4/GADD34 and NF-κB/MAPK pathways were involved in the underlying mechanism.

STYK1 promotes cancer cell proliferation and malignant transformation by activating PI3K-AKT pathway in gallbladder carcinoma.

Gallbladder carcinoma (GBC) is the most common malignancy of the biliary tract with extremely poor prognosis. The malignant transformation of GBC is associated with cell proliferation, invasion, and epithelial-mesenchymal transition (EMT). However, the molecular mechanisms underlying GBC progression are poorly understood. We found that serine threonine tyrosine kinase 1 (STYK1) was elevated in GBC and was negatively correlated with clinical outcomes and prognosis. Overexpression of STYK1 in GBC cell lines gave rise to increased cell proliferation, colony formation, migration and invasion, thus committing cells to undergoing EMT. In contrast, silence of STYK1 led to opposite effects on cell transformation. Consistent with STYK1 gene knockdown, AKT specific inhibitor MK2206 abrogated tumor promoting action induced by STYK1, suggesting that PI3K/AKT pathway is essential for the oncogenic role of STYK1 in GBC. STYK1 shRNA in GBC cells inhibited development of xenografted tumors compared with control cells. Collectively, our findings suggest that STYK1 is a critical regulator of tumor growth and metastasis, and may serve as a potential target for GBC therapy.

Intravenous polymyxins: Revival with puzzle.

With the increasing incidence of multi-drug resistant strains, especially carbapenem resistant strains, polymyxsins (mainly colistin and polymyxin B) based regimens seem to be a revival as an effective treatment of last resort in these infections. Evidence from 47 clinical trials or case series we reviewed showed that polymyxins based regimens are effective and have less toxicity compared with previous trials. When used alone, the mortality of intravenous polymyxsins ranged from 0% to 74.3%, clinical response (cure and improvement) rate was 7-82.1%, and microbiological eradication was 27.3-73.9%. The main reasons for the combination therapy are to get potential synergistic effects and to prevent the selection of heteroresistant strains. Several studies showed combination therapy seemed to be more effective than monotherapy, though a few doubts remain. Clinically, polymyxsins can be used in combination with several antibiotics, such as carberpenem, sulbactam, tigecycline, fosfomycin, glycopeptide, rifampicin and so on, but the optimal combination regimen is yet to be confirmed. The optimal dose of polymyxins is also controversial. With the limited clinical evidence, it's suggested loading dose regimens may be more effective, but more attention should be paid to adverse effects. Although recommended in some studies, high dose polymxins regimens with inconsistent clinical evidence need more trials to confirm. It is important to note that concerning dosing regimens, colistin and polymyxin B are not quite the same. In renal impaired patients polymyxin B should be prescribed without dosing adjustment. Risk of renal failure may increase in the following situations, such as the combination of intravenous colistin plus intravenous vancomycin, higher doses-colistin, and intravenous colistin combined with inhalational colistin. In conclusion, there're still controversies in combination regimens, dosing strategies and so on. Prospective trials of lager sample size are needed.

Aortic intramural hemorrhage: A distinct disease entity with mystery.

Aortic intramural hemorrhage (IMH) is one of the disease processes that comprise the spectrum of acute aortic syndrome (AAS) with clinical manifestations and a mortality rate similar to those of classic aortic dissection (AD). However, IMH should be considered as a distinct disease entity rather than a precursor to classic dissection because of differences in their pathology, etiology, natural history, and imaging findings. Multidetector computed tomography (CT) is recommended as the first-line diagnostic imaging modality for IMH, but transesophageal echocardiography (TEE) and magnetic resonance imaging (MRI) are also helpful. There is still debate over the appropriate treatment of IMH. Medical treatment of type B IMH appears effective and safe, while surgical treatment is recommended for type A IMH. Thoracic endovascular aortic repair (TEVAR) is a promising treatment for selected patients, and more clinical evidence needs to be assembled.

Conditional Tissue-Specific Foxa2 Ablation in Mouse Pancreas Causes Hyperinsulinemic Hypoglycemia: RETRACTED.

The forkhead/winged helix transcription factor Foxa2 is a major upstream regulator of Pdx1, a transcription factor necessary for pancreatic development. In the present study, we conditionally knocked out Foxa2 in Pdx1-expressing domain and further analyzed the contribution of Foxa2 to α- and ß-cell development and the effect of Foxa2 deletion on plasma insulin, glucagon, and glucose levels. Homozygous pdx1 Foxa2 mice and heterozygous pdx1 Foxa2 mice were generated by homologous recombination using a Foxa2 gene-targeting vector. α- and ß-cell mass was examined by immunofluorescence microscopy. Plasma glucose, insulin, and plasma were measured at postnatal day 10. For pdx1 lineage tracing studies, heterozygous pdx1 Foxa2 EYFP and homozygous pdx1 Foxa2 EYFP mice were used. Our immunofluorescence analysis revealed that in the pancreas sections of the homozygous mutant mice, Foxa2 was virtually absent from non-ß cells and its expression almost exclusively coincided with remnant ß cells. The density of both α and ß cells apparently decreased in the pancreas of the heterozygous mutant mice and in the pancreas of the homozygous mutant mice, α cells lost its predominance and ß cells increased proportionally. Direct Pdx1 cell lineage tracing revealed that, on embryonic day 18.5, in the homozygous mutant mice, Pdx1 expression coincided almost exclusively with that of insulin-secreting ß cells. Chemiluminescence assays revealed that heterozygous pdx1 Foxa2 mice had significantly lower insulin levels than control mice (P < 0.01). However, no apparent difference was observed between homozygous pdx1 Foxa2 mice and control mice (P > 0.05). Chemiluminescence assays also showed that Foxa2 deletion significantly depressed plasma glucagon levels in both homozygous pdx1 Foxa2 mice and heterozygous pdx1 Foxa2 mice (P < 0.01 vs. controls). Plasma glucose on postnatal day 10 was significantly lower in homozygous pdx1 Foxa2 mice compared with control mice (P < 0.01). Our study demonstrates that homozygous Foxa2 ablation leads to an imbalance in ß/α ratio, profound hypoglucagonemia, inappropriate hyperinsulinemia, and hypoglycemia in mice. Our conditional tissue-specific Foxa2 ablation mouse model will be useful in elucidating regulation of normal and abnormal α- and ß-cell differentiation and pinpointing novel targets for diabetes control.

Simvastatin Ameliorates PAK4 Inhibitor-Induced Gut and Lung Injury.

P21 activated kinase 4 (PAK4), a key regulator of cytoskeletal rearrangement and endothelial microparticles (EMPs), is released after lipopolysaccharide (LPS) stimulation. In addition, it participates in LPS-induced lung injury. In this study, forty-eight Sprague Dawley (SD) rats were divided into two groups, including PAK4 inhibitor (P) and PAK4 inhibitor + simvastatin (P + S) treatment groups. All rats were given PAK4 inhibitor (15 mg/kg/d) orally. Immediately after PAK4 inhibitor administration, simvastatin was injected intraperitoneally to P + S group animals at 20 mg/kg/day. Then, treatment effects on the intestinal mucosal barrier and lung injury caused by PAK4 inhibitor and simvastatin were assessed. The results showed that gut Zonula Occludens- (ZO-) 1, PAK4, mitogen-activated protein kinase 4 (MPAK4), and CD11c protein levels were reduced, while plasma endotoxin levels were increased after administration of PAK4 inhibitor. Furthermore, compared with normal rats, wet-to-dry (W/D) values of lung tissues and circulating EMP levels were increased in the treatment group, while PAK4 and CD11c protein amounts were reduced. Therefore, in this lung injury process induced by PAK4 inhibitor, the protective effects of simvastatin were reflected by intestinal mucosal barrier protection, inflammatory response regulation via CD11c+ cells, and cytoskeleton stabilization. In summary, PAK4 is a key regulator in the pathophysiological process of acute lung injury (ALI) and can be a useful target for ALI treatment.

IGF-1 protects tubular epithelial cells during injury via activation of ERK/MAPK signaling pathway.

Injury of renal tubular epithelial cells can induce acute renal failure and obstructive nephropathy. Previous studies have shown that administration of insulin-like growth factor-1 (IGF-1) ameliorates the renal injury in a mouse unilateral ureteral obstruction (UUO) model, whereas the underlying mechanisms are not completely understood. Here, we addressed this question. We found that the administration of IGF-1 significantly reduced the severity of the renal fibrosis in UUO. By analyzing purified renal epithelial cells, we found that IGF-1 significantly reduced the apoptotic cell death of renal epithelial cells, seemingly through upregulation of anti-apoptotic protein Bcl-2, at protein but not mRNA level. Bioinformatics analyses and luciferase-reporter assay showed that miR-429 targeted the 3'-UTR of Bcl-2 mRNA to inhibit its protein translation in renal epithelial cells. Moreover, IGF-1 suppressed miR-429 to increase Bcl-2 in renal epithelial cells to improve survival after UUO. Furthermore, inhibition of ERK/MAPK signaling pathway in renal epithelial cells abolished the suppressive effects of IGF-1 on miR-429 activation, and then the enhanced effects on Bcl-2 in UUO. Thus, our data suggest that IGF-1 may protect renal tubular epithelial cells via activation of ERK/MAPK signaling pathway during renal injury.

Conditional Tissue-Specific Foxa2 Ablation in Mouse Pancreas Causes Hyperinsulinemic Hypoglycemia.

The forkhead/winged helix transcription factor Foxa2 is a major upstream regulator of Pdx1, a transcription factor necessary for pancreatic development. In the present study, we conditionally knocked out Foxa2 in Pdx1-expressing domain and further analyzed the contribution of Foxa2 to α- and ß-cell development and the effect of Foxa2 deletion on plasma insulin, glucagon, and glucose levels. Homozygous pdx1 Foxa2 mice and heterozygous pdx1 Foxa2 mice were generated by homologous recombination using a Foxa2 gene-targeting vector. α- and ß-cell mass was examined by immunofluorescence microscopy. Plasma glucose, insulin, and plasma were measured at postnatal day 10. For pdx1 lineage tracing studies, heterozygous pdx1 Foxa2 EYFP and homozygous pdx1 Foxa2 EYFP mice were used. Our immunofluorescence analysis revealed that in the pancreas sections of the homozygous mutant mice, Foxa2 was virtually absent from non-ß cells and its expression almost exclusively coincided with remnant ß cells. The density of both α and ß cells apparently decreased in the pancreas of the heterozygous mutant mice and in the pancreas of the homozygous mutant mice, α cells lost its predominance and ß cells increased proportionally. Direct Pdx1 cell lineage tracing revealed that, on embryonic day 18.5, in the homozygous mutant mice, Pdx1 expression coincided almost exclusively with that of insulin-secreting ß cells. Chemiluminescence assays revealed that heterozygous pdx1 Foxa2 mice had significantly lower insulin levels than control mice (P < 0.01). However, no apparent difference was observed between homozygous pdx1 Foxa2 mice and control mice (P > 0.05). Chemiluminescence assays also showed that Foxa2 deletion significantly depressed plasma glucagon levels in both homozygous pdx1 Foxa2 mice and heterozygous pdx1 Foxa2 mice (P < 0.01 vs. controls). Plasma glucose on postnatal day 10 was significantly lower in homozygous pdx1 Foxa2 mice compared with control mice (P < 0.01). Our study demonstrates that homozygous Foxa2 ablation leads to an imbalance in ß/α ratio, profound hypoglucagonemia, inappropriate hyperinsulinemia, and hypoglycemia in mice. Our conditional tissue-specific Foxa2 ablation mouse model will be useful in elucidating regulation of normal and abnormal α- and ß-cell differentiation and pinpointing novel targets for diabetes control.

Candidemia: incidence rates, type of species, and risk factors at a tertiary care academic hospital in China.

OBJECTIVES: To investigate the incidence rates of candidemia in hospitalized patients and to identify differences in risk factors of patients with Candida albicans and non-C. albicans and with Candida guilliermondii and non-C. guilliermondii candidemia. METHODS: Non-immunosuppressed, non-neutropenic inpatients with candidemia diagnosed after admission were included in this retrospective observational study at a tertiary academic hospital in China. RESULTS: During the study period (January 2009 to December 2011), 238 eligible patients had candidemia episodes with an incidence rate 5.4%. Of these patients, 29.8% had candidemia due to C. albicans, 27.7% due to C. parapsilosis, and 16.4% due to C. guilliermondii. Diabetes was a significant risk factor for patients with candidemia due to C. albicans (35.2%, 25/71) compared to candidemia due to non-C. albicans spp (13.2%, 22/167) (odds ratio (OR) 0.2792, 95% confidence interval (CI) 0.144-0.5412; p < 0.001). Compared to patients with candidemia due to non-C. guilliermondii spp, preterm birth with low birth weight (OR 0.0887, 95% CI 0.0398-0.1977; p < 0.001), intravenous nutrition (OR 0.0662, 95% CI 0.0226-0.1938), and surgery (OR 0.0662, 95% CI 0.0226-0.1938; p < 0.001) were significant risk factors for candidemia due to C. guilliermondii. Furthermore, compared to patients with candidemia due to C. albicans, patients with candidemia due to C. guilliermondii had markedly higher rates of central venous catheterization (85.9%, 61/71 vs. C. guilliermondii: 100%, 39/39; p = 0.013) and intravenous nutrition (89.7%, 35/39 vs. C. albicans: 42.2%, 30/71; p < 0.001). CONCLUSIONS: Candidemia due to C. albicans ranks first in incidence, and candidemia due to C. guilliermondii occurs in a significant proportion of our hospitalized patients.

Identification and differentiation of Candida parapsilosis complex species by use of exon-primed intron-crossing PCR.

The Candida parapsilosis complex is composed of Candida parapsilosis sensu stricto, Candida orthopsilosis, Candida metapsilosis, and the closely related species Lodderomyces elongisporus. An exon-primed intron-crossing PCR assay was developed here to distinguish the members of the species complex on the basis of the distinct sizes of amplicons, and Candida orthopsilosis and Candida metapsilosis were further discriminated by restriction enzyme analysis.