Development and Validation of a Prediction Model of the Risk of Pneumonia in Patients with SARS-CoV-2 Infection.

Objective: To establish a prediction model of pneumonia risk in SARS-CoV-2-infected patients to reduce unnecessary chest CT scans. Materials and Methods: The model was constructed based on a retrospective cohort study. We selected SARS-CoV-2 test-positive patients and collected their clinical data and chest CT images from the outpatient and emergency departments of Hunan Provincial People's Hospital, China. Univariate and multivariate logistic regression and least absolute shrinkage and selection operator (LASSO) regression were utilized to identify predictors of pneumonia risk for patients infected with SARS-CoV-2. These predictors were then incorporated into a nomogram to establish the model. To ensure its performance, the model was evaluated from the aspects of discrimination, calibration, and clinical validity. In addition, a smoothed curve was fitted using a generalized additive model (GAM) to explore the association between the pneumonia grade and the model's predicted probability of pneumonia. Results: We selected 299 SARS-CoV-2 test-positive patients, of whom 205 cases were in the training cohort and 94 cases were in the validation cohort. Age, CRP natural log-transformed value (InCRP), and monocyte percentage (%Mon) were found to be valid predictors of pneumonia risk. This predictive model achieved good discrimination of AUC in the training and validation cohorts which was 0.7820 (95% CI: 0.7254-0.8439) and 0.8432 (95% CI: 0.7588-0.9151), respectively. At the cut-off value of 0.5, it had a sensitivity and specificity of 70.75% and 66.33% in the training cohort and 76.09% and 73.91% in the validation cohort, respectively. With suitable calibration accuracy shown in calibration curves, decision curve analysis indicated high clinical value in predicting pneumonia probability in SARS-CoV-2-infected patients. The probability of pneumonia predicted by the model was positively correlated with the actual pneumonia classification. Conclusion: This study has developed a pneumonia risk prediction model that can be utilized for diagnostic purposes in predicting the probability of pneumonia in patients infected with SARS-CoV-2.

Endoplasmic Reticulum Stress Induces HRD1 to Protect Alveolar Type II Epithelial Cells from Apoptosis Induced by Cigarette Smoke Extract.

BACKGROUND/AIMS: Cigarette smoking is a major risk factor of chronic obstructive pulmonary disease. This study aimed to examine the effects of cigarette smoke extract (CSE) on alveolar type II epithelial cells (AECII) and investigate the underlying mechanism. METHODS: Primary AECII were isolated from rat lung tissues and exposed to CSE. Apoptosis was detected by flow cytometry. Protein expression was detected by Western blot analysis. RESULTS: Primary rat AECII maintained morphological and physiological characteristic after 3 passages. CSE increased the expression of ER specific pro-apoptosis factors CHOP and caspase 12, and the phosphorylation of JNK in AECII. CSE activated ER stress signaling and increased the phosphorylation of PERK, eIF2α and IRE1. Furthermore, CSE induced the expression of Hrd1, a key factor of ER-associated degradation, in AECII. Knockdown of Hrd1 led to more than 2 fold increase of apoptosis, while overexpression of Hrd1 attenuated CSE induced apoptosis of AECII. CONCLUSIONS: Our results suggest that ER stress induces HRD1 to protect alveolar type II epithelial cells from apoptosis induced by CSE.

[Regulatory mechanism of Siah1 in the pathogenesis of rat hypoxic pulmonary hypertension].

OBJECTIVE: To explore the regulatory mechanism of Siahl in the pathogenesis of hypoxic pulmonary hypertension (HPH) in rats. METHODS: According to the random number table, 40 adult male Wistar rats were randomly divided into 5 groups (n = 8 each). And the animals were exposed to normoxia or hypoxia for 3, 7, 14 or 21 days respectively. The HPH model was established by normobaric intermittent hypoxia. Mean pulmonary arterial pressure (mPAP), ratio of vascular wall area to total vascular area (WA%), ratio of vascular lumen area to total vascular area (LA%) and right ventricle hypertrophy index (RVHI) were measured. The mRNA and protein relative levels of hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) were detected by in situ hybridization and immunohistochemistry respectively. Reverse transcriptase-polymerase chain reaction ( RT-PCR) and in situ hybridization were used to determine the relative expressions of mRNA of hypoxia-inducible factor-1 (FIH) and Siahl. Immunohistochemistry and Western blot were employed to determine the relative expressions of proteins of FIH and Siahl. RESULTS: The levels of mPAP, WA% and LA% were significantly higher after 7-day hypoxia than those in normoxic control (21. 3 1. 6) vs (15. 9 ± 1. 3) mmHg (1 mmHg = 0. 133 kPa), (41.4 ± 2.8)% vs (35.0 ± 2.2)%, (58.6 ± 2.8)% vs (65.0 ± 2.2)%, all P <0.05). The level of RVHI was significantly higher after 14-day hypoxia than that in normoxic control ((27. 0 ± 1. 8) % vs (3. 2 ± 2. 1) %, P <0. 05). The relative expression of HIF-1α mRNA was significantly higher after 14-day hypoxia than that in normoxic control (0. 188 ± 0. 014 vs 0. 150 ± 0. 014, P < 0. 05). The relative expression of HIF-1α protein was significantly higher after 3-day hypoxia than that in normoxic control (0. 186 ± 0.014 vs 0. 067 ± 0.008, P <0.05). The relative levels of VEGF mRNA and protein were significantly higher after 7-day hypoxia than those in normoxic control (0. 152 ± 0. 019 vs 0. 057 ± 0. 007, 0. 176 ± 0. 017 vs 0. 083 ± 0. 010, both P <0. 05). The relative expression of FIH mRNA had little changes after exposure to hypoxia compared with normoxia. However the related expression of FIH protein was markedly lower after 7-day hypoxia than that in normoxic control (0. 166 ± 0. 015 vs 0. 200 ± 0. 017, P < 0. 05). The relative levels of Siahl mRNA and protein were markedly higher after 7-day hypoxia than those in normoxic control (0. 144 ± 0. 014 vs 0. 067 ± 0. 010, 0. 136 ± 0. 017 vs 0. 084 ± 0. 019, both P <0. 05). Linear correlation analysis showed that HIF-1α protein was positively correlated with the relative levels of VEGF mRNA and VEGF protein (r = 0. 545, 0. 523, both P <0. 01) while FIH protein was negatively correlated with the relative levels of VEGF mRNA and VEGF protein (r = -0. 785, -0. 788, both P < 0. 01). There was a positive correlation between the relative levels of Siahi mRNA and Siahl protein (r = 0. 823, P <0. 01) while a negative correlation existed between the relative levels of Siahl protein and FIH protein (r = -0. 671, P <0. 01). CONCLUSIONS: Under chronic hypoxia, Siahl is transcriptionally induced in pulmonary arterioles and it facilitates the degradation and decline of FIR in rats. And deceased FIH protein in pulmonary arterioles under hypoxia may attenuate its inhibitory effect on the transactivational activity of HIF-l a and promote the transactivation of such HIF-1α target gene as VEGF. Thus it is probably implicated in the pathogenesis of HPH.

Subarachnoid hemorrhage with Takotsubo syndrome as the prominent manifestation: A case and literature review.

Background: Takotsubo syndrome, which is often induced by physical or psychological stress, is typically a cardiac syndrome with transient left ventricular dysfunction in the absence of obstructive coronary artery disease. Subarachnoid hemorrhage with typical symptoms and signs is frequently reported, whereas the incidence of subarachnoid hemorrhage with Takotsubo syndrome as the prominent manifestation without a typical headache is rarely reported. Case description: We present a rare case of a 63-year-old male patient with cough and fever as the first manifestations, accompanied by mild dizziness, headache, and mental discomfort; however, the patient was eventually diagnosed with atypical subarachnoid hemorrhage with Takotsubo syndrome. The patient underwent general anesthesia downwards stent-assisted spring coil embolization and was discharged from the hospital after postoperative treatment consisting of anti-cerebrovascular spasm, anti-platelet aggregation, and cerebrospinal fluid replacement. Conclusion: This case demonstrates the association between Takotsubo syndrome and subarachnoid hemorrhage. When patients present with unexplained pulmonary edema with mild neurologic symptoms, clinicians should be alerted to subarachnoid hemorrhage and Takotsubo syndrome.

The role of endoplasmic reticulum stress in emphysema results from cigarette smoke exposure.

Apoptosis is of considerable importance in the pathogenesis of emphysema, and recent studies show that endoplasmic reticulum (ER) stress is involved in emphysema. In our research, we investigated the role of protein kinase RNA (PKR)-like ER kinase (PERK)/ eukaryotic initiation factor 2 alpha (eIF2α) pathway, the CCAAT enhancer-binding protein-homologous protein (CHOP) expression, caspase-12 activation and apoptosis in emphysema results from cigarette smoke (CS) exposure. Expression of phosphorylated-PERK (p-PERK), phospholated-eIF2α (p-eIF2α),CHOP and caspase-12 as well as the apoptosis rate are remarkably increased in rats after exposure to 2 months CS compared with control rats, significantly elevated in rats exposed to 4 months CS over rats exposed only to 2 months CS, and slightly decreased in ex-smoking rats in contrast to rats exposed to 4 months CS. Taken together, our results show that CS induces ER stress in lung epithelial cells, which may subsequently lead to lung injury in rats, and this might be a novel target for protection of pulmonary epithelial cells from ER stress injury in emphysema.

The mechanism of ions in pulmonary hypertension.

Pulmonary hypertension（PH）is a kind of hemodynamic and pathophysiological state, in which the pulmonary artery pressure (PAP) rises above a certain threshold. The main pathological manifestation is pulmonary vasoconstriction and remodelling progressively. More and more studies have found that ions play a major role in the pathogenesis of PH. Many vasoactive substances, inflammatory mediators, transcription-inducing factors, apoptosis mediators, redox substances and translation modifiers can control the concentration of ions inside and outside the cell by regulating the activity of ion channels, which can regulate vascular contraction, cell proliferation, migration, apoptosis, inflammation and other functions. We all know that there are no effective drugs to treat PH. Ions are involved in the occurrence and development of PH, so it is necessary to clarify the mechanism of ions in PH as a therapeutic target for PH. The main ions involved in PH are calcium ion (Ca2+), potassium ion (K+), sodium ion (Na+) and chloride ion (Cl-). Here, we mainly discuss the distribution of these ions and their channels in pulmonary arteries and their role in the pathogenesis of PH.

Good's syndrome with diffuse panbronchiolitis as the prominent manifestation: A case and literature review.

Good's syndrome (GS) is characterized by thymoma combined with adult-onset immunodeficiency. Diffuse panbronchiolitis (DPB) is a chronic inflammatory airway disease, which predominantly affects East Asians. Japanese scholars have reported extensively about GS combined with DPB or DPB-like pulmonary manifestation. However, such reports are rare in China. We report here a case of GS in China with DPB as the prominent manifestation and carry out a literature review accordingly. Our review indicates that in adults with DPB-like clinical manifestations, thymic lesions should be excluded and related immune function tests should be performed to exclude GS to avoid missed diagnosis and misdiagnosis.

CHOP overexpression sensitizes human non-small cell lung cancer cells to cisplatin treatment by Bcl-2/JNK pathway.

C/EBP homologous protein (CHOP), a 29 kDa cellular protein, plays a role in regulating tumor proliferation, differentiation, metabolism, cell death, and in tumor resistance to chemotherapy. Non-small cell lung cancer (NSCLC) is a tumor of the respiratory system and drug resistance is prevalent among NSCLC clinical cell cultures. Herein, our study elucidated the effect of CHOP on NSCLC cells with cisplatin resistance and its mechanism. In a NSCLC cell line with cisplatin-resistance, CHOP expression was decreased, compared with A549 cells. Overexpression of CHOP decreased the cell viability and enhanced cell apoptosis in the cells treated with cisplatin. Expression of CHOP also inhibited the cell proliferation and metastasis. CHOP increased the therapeutic effect of cisplatin on NSCLC cells through the Bcl-2/JNK pathway. In summary, CHOP regulated cisplatin resistance in cells of NSCLC by promoting the expression of apoptotic proteins and inhibiting the Bcl-2/JNK signaling pathway, indicating the antitumor effects of CHOP.

Expression and role of factor inhibiting hypoxia-inducible factor-1 in pulmonary arteries of rat with hypoxia-induced hypertension.

Hypoxia-inducible factor-1alpha subunit (HIF-1alpha) plays a pivotal role during the development of hypoxia-induced pulmonary hypertension (HPH) by transactivating it' target genes. As an oxygen-sensitive attenuator, factor inhibiting HIF-1 (FIH) hydroxylates a conserved asparagine residue within the C-terminal transactivation domain of HIF-1alpha under normoxia and moderate hypoxia. FIH protein is downregulated in response to hypoxia, but its dynamic expression and role during the development of HPH remains unclear. In this study, an HPH rat model was established. The mean pulmonary arterial pressure increased significantly after 7 d of hypoxia. The pulmonary artery remodeling index became evident after 7 d of hypoxia, while the right ventricular hypertrophy index became significant after 14 d of hypoxia. The messenger RNA (mRNA) and protein expression of HIF-1alpha and vascular endothelial growth factor (VEGF), a well-characterized target gene of HIF-1alpha, were markedly upregulated after exposure to hypoxia in pulmonary arteries. FIH protein in lung tissues declined after 7 d of hypoxia and continued to decline through the duration of hypoxia. FIH mRNA had few changes after exposure to hypoxia compared with after exposure to normoxia. In hypoxic rats, FIH protein showed significant negative correlation with VEGF mRNA and VEGF protein. FIH protein was negatively correlated with mean pulmonary arterial pressure, pulmonary artery remodeling index and right ventricular hypertrophy index. Taken together, our results suggest that, in the pulmonary arteries of rat exposed to moderate hypoxia, a time-dependent decrease in FIH protein may contribute to the development of rat HPH by enhancing the transactivation of HIF-1alpha target genes such as VEGF.

[The expression and possible role of SENP1 in the pulmonary vascular wall of rat during the development of hypoxic pulmonary hypertension].

OBJECTIVE: To investigate the dynamic expression and role of SENP1 (SUMO-specific proteases-1) in the pulmonary vascular wall of rat during the development of hypoxic pulmonary hypertension (HPH). METHODS: Forty adult male Wistar rats were randomly divided into 5 groups (n = 8), and exposed to normoxia (Control group) or exposed to hypoxia for 3, 7, 14 or 21 d, respectively. The HPH models were established by normobaric intermittent hypoxia. Mean pulmonary arterial pressure (mPAP), right ventricle hypertrophy index (RVHI), and vessel morphometry were measured. Reverse transcriptase-polymerase chain reaction(RT-PCR) and in situ hybridization were used to determine the mRNA expression of SENP1. Immunohistochemistry and Western blot were used to determine the protein expression of SENP1. RESULTS: The hypoxic rats developed pulmonary vascular remodeling in pulmonary arterioles after 7 d of hypoxia exposure. Pulmonary vascular remodeling in pulmonary arterioles significantly increased after 14 d of hypoxia. The level of mPAP in hypoxic rats increased significantly after 7 d of hypoxia, reached its peak after 14 d of hypoxic exposure. RVHI was markedly increased after 14 d of hypoxia. In situ hybridization and immunohistochemical analysis showed that SENP1 mRNA and protein were positively stained in control. SENP1 mRNA expression had little changes after exposure to hypoxia compared with the control, however, SENP1 protein expression was declined gradually after 7 d of hypoxia. The results of RT-PCR and Western blot showed that the same dynamic expression of SENP1 mRNA and protein in lung tissues of rats. Linear correlation analysis showed that SENP1 protein were negatively correlated with mPAP, pulmonary vascular remodeling index and RVHI. CONCLUSION: Under chronic hypoxia, SENP1 protein can be degradated. The dynamic expression of SENP1 protein may play a role in implicating in the development of HPH.