RESPIRATORY MECHANICS AND NEURAL RESPIRATORY DRIVE OF UNTREATED GASPING DURING CARDIAC ARREST IN A PORCINE MODEL.

ABSTRACT: Introduction: Although the effects on hemodynamics of gasping during cardiac arrest (CA) have received a lot of attention, less is known about the respiratory mechanics and physiology of respiration in gasping. This study aimed to investigate the respiratory mechanics and neural respiratory drive of gasping during CA in a porcine model. Method: Pigs weighing 34.9 ± 5.7 kg were anesthetized intravenously. Ventricular fibrillation (VF) was electrically induced and untreated for 10 min. Mechanical ventilation (MV) was ceased immediately after the onset of VF. Hemodynamic and respiratory parameters, pressure signals, diaphragmatic electromyogram data, and blood gas analysis data were recorded. Results: Gasping was observed in all the animals at a significantly lower rate (2-5 gaps/min), with higher tidal volume ( VT ; 0.62 ± 0.19 L, P < 0.01), and with lower expired minute volume (2.51 ± 1.49 L/min, P < 0.001) in comparison with the baseline. The total respiratory cycle time and the expiratory time tended to be lengthened. Statistically significant elevations in transdiaphragmatic pressure, the pressure-time product of diaphragmatic pressure, and the mean of root mean square diaphragmatic electromyogram values (RMSmean) were observed ( P < 0.05, P < 0.05, and P < 0.001, respectively); however, VT /RMSmean and transdiaphragmatic pressure/RMSmean were reduced at all time points. The partial pressure of oxygen showed a continuous decline after VF to reach statistical significance in the 10th minute (9.46 ± 0.96 kPa, P < 0.001), whereas the partial pressure of carbon dioxide tended to first rise and then fall. Conclusions: Gasping during CA was characterized by high VT , extremely low frequency, and prolonged expiratory time, which may improve hypercapnia. During gasping, increased work of breathing and insufficient neuromechanical efficacy of neural respiratory drive suggested the necessity of MV and appropriate management strategies for MV during resuscitation after CA.

Clinical characteristics of Hepatoid adenocarcinoma of the lung: Four case reports and literature review.

PURPOSE: Hepatoid adenocarcinoma of the lung (HAL) is a rare form of lung cancer, which is characterized by its morphologic hepatoid features. The clinical characteristics and prognosis of this rare form of lung cancer remain obscure. METHODS: The clinical courses of four cases of HAL were reported. A literature search was performed up to December 31, 2020, using the electronic databases PubMed and Web of Science. RESULTS: Including the present 4 cases, a total of 42 cases of HAL have been reported in the literature. The median age was 58.5 years old (range, 36-73 years). 36 (85.7%) patients were male. 26 (61.9%) patients had a history of smoking, the median amount of smoking was 40 pack years (range, 8-180). The most common site of the primary tumor was the right upper lobe (22 cases, 52.3%) and the left upper lobe (10 cases, 23.8%). 21 patients (50%) had pretreatment serum AFP levels higher than the upper limit, and 4 patients (9.5%) had normal pretreatment serum AFP levels. Treatment of HAL included surgery, chemotherapy, radiotherapy, tyrosine kinase inhibitors (TKIs), anti-angiogenesis therapy, and anti-PD-1/PD-L1 monoclonal antibody. Overall, the prognosis of HAL was poor, with median overall survival (OS) of 14 months. CONCLUSIONS: HAL is an aggressive tumor, with a poor prognosis and male predominance, which tends to occur in heavy smokers and affects the right upper lobe of the lung.

Chemical multi-fingerprinting of exogenous ultrafine particles in human serum and pleural effusion.

Ambient particulate matter pollution is one of the leading causes of global disease burden. Epidemiological studies have revealed the connections between particulate exposure and cardiovascular and respiratory diseases. However, until now, the real species of ambient ultrafine particles (UFPs) in humans are still scarcely known. Here we report the discovery and characterization of exogenous nanoparticles (NPs) in human serum and pleural effusion (PE) samples collected from non-occupational subjects in a typical polluted region. We show the wide presence of NPs in human serum and PE samples with extreme diversity in chemical species, concentration, and morphology. Through chemical multi-fingerprinting (including elemental fingerprints, high-resolution structural fingerprints, and stable iron isotopic fingerprints) of NPs, we identify the sources of the NPs to be abiogenic, particularly, combustion-derived particulate emission. Our results provide evidence for the translocation of ambient UFPs into the human circulatory system, and also provide information for understanding their systemic health effects.

MSCs exosomal miR-1470 promotes the differentiation of CD4+CD25+FOXP3+ Tregs in asthmatic patients by inducing the expression of P27KIP1.

Exosomes derived from Mesenchymal Stem Cells (MSCs) possesses similar immunomodulatory effect as MSCs. It had been suggested that MSCs exosomes contain higher level of miR-1470 compared to exosomes derived from fibroblast. Here, we show that MSCs exosomal miR-1470 can elevate the proportion of CD4+CD25+FOXP3+ regulatory T cells (Tregs) in asthmatic patients. Moreover, mechanistic studies revealed that miR-1470 can promote the upregulation of P27KIP1 by directly targeting the 3' region of c-Jun mRNA. Furthermore, miR-1470 mimic transfection could significantly upregulate the proportion of CD4+CD25+FOXP3+ Tregs in CD4+ T cells. P27KIP1 knockdown via siRNA silencing significantly inhibited the proportion of CD4+CD25+FOXP3+ Tregs with over-expression of miR-1470, which indicates that miR-1470 induces the differentiation of CD4+CD25+FOXP3+ Tregs through P27KIP1.

Analyses of changes in myocardial long non-coding RNA and mRNA profiles after severe hemorrhagic shock and resuscitation via RNA sequencing in a rat model.

BACKGROUND: Ischemia-reperfusion injury has been proven to induce organ dysfunction and death, although the mechanism is not fully understood. Long non-coding RNAs (lncRNAs) have drawn wide attention with their important roles in the gene expression of some biological processes and diseases, including myocardial ischemia-reperfusion (I/R) injury. In this paper, a total of 26 Sprague-Dawley (SD) rats were randomized into two groups: sham and ischemia-reperfusion (I/R) injury. Hemorrhagic shock was induced by removing 45% of the estimated total blood volume followed by reinfusion of shed blood. High-throughput RNA sequencing was used to analyze differentially expressed (DE) lncRNAs and messenger RNAs (mRNAs) in the heart tissue 4 h after reperfusion. Myocardial function was also evaluated. RESULTS: After resuscitation, the decline of myocardial function of shocked animals, expressed by cardiac output, ejection fraction, and myocardial performance index (MPI), was significant (p < 0.05). DE lncRNAs and mRNAs were identified by absolute value of fold change ≥ 2 and the false discovery rate ≤ 0.001. In rats from the I/R injury group, 851 lncRNAs and 1015 mRNAs were significantly up-regulated while 1533 lncRNAs and 1702 m RNAs were significantly down-regulated when compared to the sham group. Among the DE lncRNAs, we found 12 location-associated with some known apoptosis-related protein-coding genes which were up-regulated or down-regulated accordingly, including STAT3 and Il1r1. Real time PCR assays confirmed that the expression levels of five location-associated lncRNAs (NONRATT006032.2, NONRATT006033.2, NONRATT006034.2, NONRATT006035.2 and NONRATT029969.2) and their location-associated mRNAs (STAT3 and Il1r1) in the rats from the I/R injury group were all significantly up-regulated versus the sham group. CONCLUSIONS: The DE lncRNAs (NONRATT006032.2, NONRATT006033.2, NONRATT006034.2 and NONRATT006035.2) could be compatible with their role in myocardial protection by stimulating their co-located gene (STAT3) after hemorrhagic shock and resuscitation. The final prognosis of I/R injury might be regulated by different genes, which is regarded as a complex network.

A novel long noncoding RNA OECC promotes colorectal cancer development and is negatively regulated by miR-143-3p.

Emerging evidence indicates that aberrant long non-coding RNA (lncRNA) expression contributes to CRC pathogenesis. To explore the biological functions of lncRNAs in CRC and to identify the underlying mechanisms, we first conducted a lncRNA microarray assay to investigate lncRNA expression patterns in CRC. We identified a novel lncRNA OECC, originating from chromosome 8q24 that is highly expressed in CRC tissues and cell lines and has a positive correlation with liver metastasis. Attenuation of lncRNA OECC expression prohibited CRC cell proliferation, induced apoptosis, and inhibited migration. Furthermore, an inverse correlation between lncRNA OECC and miR-143-3p was observed. Bioinformatic analyses predicted, and a luciferase reporter assay demonstrated, that lncRNA OECC is a direct target of miR-143-3p, leading to down-regulation in the expression of its target genes, the NF-κB and p38 MAPK pathways. Taken together, our results suggest that lncRNA OECC is overexpressed in CRC and may play an oncogenic role through NF-κB and p38 MAPK pathway activation via miR-143-3p.

Mesenchymal stem cell exosomes promote immunosuppression of regulatory T cells in asthma.

Mesenchymal stem cells (MSCs) and regulatory T cells (Tregs) are both potent immune-modulators. The aberrant proliferation and function of Tregs plays an important role in the development of asthma. Our previous studies have demonstrated the role of MSCs in promoting proliferation and immune-modulating of Tregs, as well as alleviating airway inflammation of asthmatic mice. In the present study, we isolated exosomes secreted by MSCs and investigated their immunomodulation effect on peripheral blood mononuclear cells (PBMCs) of asthmatic patient. We found that MSC exosomes upregulated IL-10 and TGF-ß1 from PBMCs, thus promoting proliferation and immune-suppression capacity of Tregs. Furthermore, antigen presenting cells (APCs) but not CD4+ T cells-dependent pathway was shown to be possible mechanism involved in MSC exosome-mediated regulation. Our data elucidated the key role of exosomes in immune-modulation of MSCs, and suggested the therapeutic potential of MSC exosomes for asthma.

Anti-PD-1/PD-L1 antibody versus conventional chemotherapy for previously-treated, advanced non-small-cell lung cancer: a meta-analysis of randomized controlled trials.

BACKGROUND: The anti-PD-1/PD-L1 monoclonal antibody has showed promising results in various cancers via enhancing T cell functions. However, many questions remain in the role and safety in previously-treated, advanced non-small-cell lung cancer (NSCLC). Thus, we conducted a meta-analysis incorporating all available evidences to evaluate the efficacy and safety of anti-PD-1/PD-L1 antibody compared with chemotherapy. METHODS: PubMed, Web of Science and the Cochrane Library database were searched for the studies about the efficacy and safety of anti-PD-1/PD-L1 antibody in previously-treated, progressive NSCLC patients. Only randomized controlled trials (RCTs) comparing anti-PD-1/PD-L1 antibody with conventional chemotherapy in NSCLC were included. Overall survival (OS) in the intention-to-treat population was the primary outcome. The secondary outcomes were: progression-free survival (PFS) in the intention-to-treat population, objective response rate (ORR), the incidence of adverse events, OS and PFS in different PD-L1 expression subgroups. RESULTS: Four trials with a total of 2,174 patients were included. Anti-PD-1/PD-L1 antibody showed a significant benefit to OS in the intention-to-treat population [combined hazard ratio (HR) 0.67; 95% CI: 0.61-0.75, P<0.00001], a 33% reduction in the relative risk of death. PFS also favored anti-PD-1/PD-L1 antibody (HR 0.81, 95% CI: 0.70-0.95, P=0.009). The ORR was significantly higher with anti-PD-1/PD-L1 antibody than those with chemotherapy (RR of nonresponse, 0.92; 95% CI: 0.89-0.95, P<0.00001). Anti-PD-1/PD-L1 antibody was associated with greater efficacy than chemotherapy across the end points of OS and PFS when tumor PD-L1 expression scored ≥1%, ≥5%, and ≥50%, except for tumor PD-L1 expression scored <1%. The group receiving anti-PD-1/PD-L1 antibody had lower rates of treatment-related adverse events of any grade (RR 0.77; 95% CI: 0.73-0.81, P<0.00001) and treatment-related adverse events of grade 3-5 (RR 0.24; 95% CI: 0.14-0.41, P<0.00001). CONCLUSIONS: Anti-PD-1/PD-L1 antibody significantly improved survival compared with chemotherapy in previously-treated, progressive NSCLC patients. Besides, it also had a better safety profile.

CD80 and CD86 knockdown in dendritic cells regulates Th1/Th2 cytokine production in asthmatic mice.

Dendritic cells (DCs) are associated with the activation and differentiation of T helper (Th) cells. Cluster of differentiation (CD)80 and CD86, the co-stimulatory molecules highly expressed in DCs, have are prominent in promoting the differentiation of Th cells toward Th2 cells. However, little is known about the effect of CD80 and CD86 knockdown on Th1/Th2 cytokine production in mature DCs (mDCs). The aim of the present study was to investigate whether small-interfering RNA (siRNA) could suppress the surface expression of CD80 and CD86 in mDCs. The effects of CD80 and CD86 knockdown in mDCs on Th1/Th2 cytokine expression were examined using an asthmatic murine model. DCs were isolated, separated and cultured in vitro. Flow cytometry was used to examine the expression of CD11c, CD80 and CD86 on the DCs. The DCs were transfected with CD80- and CD86-specific siRNA, while non-siRNA and negative siRNA controls were also designed. Then, the mRNA and protein expression levels of CD80 and CD86 were determined by reverse transcription-quantitative polymerase chain reaction and flow cytometry, respectively. The levels of interferon (IFN)-γ and interleukin (IL)-4 produced by T cells co-cultured with mDCs were measured by enzyme-linked immunosorbent assay. Substantial downregulation of CD80 and CD86 mRNA and protein levels were observed in the mDCs following transfection with siRNA. The level of IFN-γ produced by T cells co-cultured with mDCs was significantly increased in the siRNA group, while IL-4 production was significantly decreased. These results show that specific targeting of CD80 and CD86 with siRNA is able to suppress CD80/CD86 expression and consequently regulate Th1/Th2 cytokine levels by increasing IFN-γ production and decreasing IL-4 levels in an asthmatic murine model.

Mesenchymal stem cells suppress T cells by inducing apoptosis and through PD-1/B7-H1 interactions.

Mesenchymal stem cells (MSCs) exert a suppressive role toward T cells which has been widely studied in recent decades. However, the underlying mechanisms utilized by MSCs are still not fully elucidated. Herein, we performed traditional suppressive assays using co-cultured MSCs and conventional CD4(+)CD25(-) T cells (Tconv) with and without transwell systems. We showed that the expression of programmed cell death-1 receptor (PD-1) on activated Tconv was significantly elevated after they were exposed to MSCs. And we demonstrated that PD-1/B7-H1 pathway was involved in the suppression of MSCs on activated Tconv. Further analysis revealed that the up-regulation of PD-1 was related to an increasing apoptosis of activated Tconv. Finally, we demonstrated that the PD-1/B7-H1 pathway was not related to the elevated immunosuppressive cytokines including IL-10 and TGF-ß1 which in turn played dispensable roles in the up-regulation of PD-1 on activated Tconv in MSC-Tconv co-culture systems.

Immunomodulation of mesenchymal stromal cells on regulatory T cells and its possible mechanism.

Mesenchymal stromal cells (MSCs) and regulatory T cells (Tregs) have both garnered abundant interests from immunologists worldwide, as both MSCs and Tregs can be considered immunosuppressive in their own right. But a little attention has been paid to the impacts of MSCs on Tregs. To clarify the effects of MSCs on Tregs, we performed the coculture systems within MSCs and Tregs. We confirmed that MSC-exposed Tregs are capable of more immunosuppressive than Tregs without coculturing with MSCs. And this augmenting suppressive capacity was accompanied with an upregulation of programmed cell death 1 receptor (PD-1) on Tregs. Importantly, we found that cell viability of Tregs was excluded from the influences of MSCs. Finally, we showed that PD-1/B7-H1 interactions and IL-10 might be responsible for the enhanced suppressive capability of MSC-exposed Tregs. Further analysis revealed that PD-1/B7-H1 interactions were not responsible for the productions of IL-10 and TGF-ß1 in the MSC-Treg coculture systems; in contrast, IL-10 rather than TGF-ß1 played a role in the upregualtion of PD-1. Furthermore, this is the first explorative study to evaluate the immunomodulation of MSCs on the suppressive capacity of Tregs in MSC-Treg in vitro coculture setting.