The 2023 extreme coastal El Niño: Atmospheric and air-sea coupling mechanisms.

In the boreal spring of 2023, an extreme coastal El Niño struck the coastal regions of Peru and Ecuador, causing devastating rainfalls, flooding, and record dengue outbreaks. Observations and ocean model experiments reveal that northerly alongshore winds and westerly wind anomalies in the eastern equatorial Pacific, initially associated with a record-strong Madden-Julian Oscillation and cyclonic disturbance off Peru in March, drove the coastal warming through suppressed coastal upwelling and downwelling Kelvin waves. Atmospheric model simulations indicate that the coastal warming in turn favors the observed wind anomalies over the far eastern tropical Pacific by triggering atmospheric deep convection. This implies a positive feedback between the coastal warming and the winds, which further amplifies the coastal warming. In May, the seasonal background cooling precludes deep convection and the coastal Bjerknes feedback, leading to the weakening of the coastal El Niño. This coastal El Niño is rare but predictable at 1 month lead, which is useful to protect lives and properties.

Obesity-induced oxidative stress and mitochondrial dysfunction negatively affect sperm quality.

Obesity is a systemic metabolic disease that can induce male infertility or subfertility through oxidative stress. The aim of this study was to determine how obesity impairs sperm mitochondrial structural integrity and function, and reduces sperm quality in both overweight/obese men and mice on a high-fat diet (HFD). Mice fed the HFD demonstrated higher body weight and increased abdominal fat content than those fed the control diet. Such effects accompanied the decline in antioxidant enzymes, such as glutathione peroxidase (GPX) and catalase and superoxide dismutase (SOD) in testicular and epidydimal tissues. Moreover, malondialdehyde (MDA) content significantly increased in sera. Mature sperm in HFD mice demonstrated higher oxidative stress, including increased mitochondrial reactive oxygen species (ROS) levels and decreased protein expression of GPX1, which may impair mitochondrial structural integrity and reduce mitochondrial membrane potential (MMP) and ATP production. Moreover, cyclic AMPK phosphorylation status increased, whereas sperm motility declined in the HFD mice. Clinical studies demonstrated that being overweight/obese reduced SOD enzyme activity in the seminal plasma and increased ROS in sperm, accompanied by lower MMP and low-quality sperm. Furthermore, ATP content in the sperm was negatively correlated with increases in the BMI of all clinical subjects. In conclusion, our results suggest that excessive fat intake had similar disruptive effects on sperm mitochondrial structure and function, as well as oxidative stress levels in humans and mice, which in turn induced lower sperm motility. This agreement strengthens the notion that fat-induced increases in ROS and impaired mitochondrial function contribute to male subfertility.

Southern hemisphere eastern boundary upwelling systems emerging as future marine heatwave hotspots under greenhouse warming.

Marine heatwaves (MHWs) exert devastating impacts on ecosystems and have been revealed to increase in their incidence, duration, and intensity in response to greenhouse warming. The biologically productive eastern boundary upwelling systems (EBUSs) are generally regarded as thermal refugia for marine species due to buffering effects of upwelling on ocean warming. However, using an ensemble of state-of-the-art high-resolution global climate simulations under a high carbon emission scenario, here we show that the MHW stress, measured as the annual cumulative intensity of MHWs, is projected to increase faster in the Southern Hemisphere EBUSs (Humboldt and Benguela current systems) than in their adjacent oceans. This is mainly because the additional warming caused by the weakened eastern boundary currents overwhelms the buffering effect of upwelling. Our findings suggest that the Southern Hemisphere EBUSs will emerge as local hotspots of MHWs in the future, potentially causing severe threats to the ecosystems.

Surface warming-induced global acceleration of upper ocean currents.

How the ocean circulation changes in a warming climate is an important but poorly understood problem. Using a global ocean model, we decompose the problem into distinct responses to changes in sea surface temperature, salinity, and wind. Our results show that the surface warming effect, a robust feature of anthropogenic climate change, dominates and accelerates the upper ocean currents in 77% of the global ocean. Specifically, the increased vertical stratification intensifies the upper subtropical gyres and equatorial currents by shoaling these systems, while the differential warming between the Southern Ocean upwelling zone and the region to the north accelerates surface zonal currents in the Southern Ocean. In comparison, the wind stress and surface salinity changes affect regional current systems. Our study points a way forward for investigating ocean circulation change and evaluating the uncertainty.

Experience of repair ventricular septal defect with left superior vena cava through right axillary thoracotomy.

OBJECTIVE: To summarize the experience in the treatment of repair ventricular septal defect with left superior vena cava (LSVC) through right axillary thoracotomy. To explore the surgical strategy of treating VSD with LSVC through right axillary thoracotomy. METHODS: right axillary thoracotomy and median sternotomy were performed in 73 cases of ventricular septal defect with LSVC in our center from 2018 to 2019. Perioperative data and surgical information were analyzed retrospectively. RESULTS: There were 54 cases of R-group and 19 cases of S-group with median age of 0.8 years (0.5-1.6years). In the 73 patients, 21(38.9%) were men and 52 (61.1%) women. The operation time of R-group was shorter than S-group, p<0.05. The postoperative drainage in R-group was less than S-group, p<0.05. The mechanical ventilation time was longer in the S-group than in the R-group, p<0.05. There were no deaths, serious complications and readmission in the follow-up 6 months(3-10months). CONCLUSION: Right axillary thoracotomy is a safe procedure with excellent cosmetic and clinical results for ventricular septal defect with left superior vena cava. It has the advantages of short operation time, less bleeding and short postoperative time.

Application of propofol combined with sevoflurane anesthesia in staged hepatectomy liver detachment and portal vein ligation.

The aim of the present study was to investigate the application of propofol combined with sevoflurane anesthesia in associating liver partition and portal vein ligation for staged hepatectomy (ALPPS). A retrospective analysis of 40 patients with liver cancer who underwent ALPPS was performed. The study included 21 (control group) and 19 (observation group) patients who were administered propofol anesthesia and propofol in combination with sevoflurane anesthesia, respectively. Changes in liver function indicators, routine blood parameters and blood coagulation function, as well as cognitive function (mini-mental state examination) were recorded. The total bilirubin and direct bilirubin levels and the alanine aminotransferase (ALT) level after the first- and second-stage operation in the two groups was also higher than that prior to the first-stage operation (P<0.05), and the ALT level was significantly lower in the two groups after the second-stage operation compared with that prior to the second-stage operation (P<0.05). The AST level after the first- and second-stage operation was lower than that prior to the first- and second-stage operation, respectively (P<0.05). The white blood cell count after the second-stage operation was significantly lower compared with that prior to the second-stage operation (P<0.05). The plasma fibrinogen (FIB) level was higher after the first-stage operation compared with that prior to the first-stage operation (P<0.05). The prothrombin time in the two groups of patients was higher after the second-stage operation compared with that prior to the second-stage operation (P<0.05), whereas the FIB level was lower (P<0.05) and the international normalized ratio was not significantly different (P>0.05). The degree of cognitive decline prior to the first/second-stage operation, according to mini-mental state examination scores, was different from that after the first/second-stage operation (P<0.05). In conclusion, propofol combined with sevoflurane has a good application value in ALPPS.

CMTM6 and PD-L1 coexpression is associated with an active immune microenvironment and a favorable prognosis in colorectal cancer.

BACKGROUND: CKLF-like MARVEL transmembrane domain-containing 6 (CMTM6), a programmed death-ligand 1 (PD-L1) regulator, is widely expressed in various tumors and regulates the immune microenvironment. However, its prognostic value remains controversial, and the roles of CMTM6 in colorectal cancer (CRC) are still unknown. In this study, we aimed to elaborate the expression patterns of CMTM6 and PD-L1 in CRC and investigate their relationship with the infiltration of T cells and the prognosis of patients with CRC. METHODS: Analysis of CMTM6 mRNA levels, gene ontology enrichment analysis and single-sample gene set enrichment analysis were performed in a The Cancer Genome Atlas colon cancer cohort. The expression of CMTM6 and PD-L1 and the infiltration of T cells in tumor tissues from our cohort containing 156 patients with CRC receiving adjuvant chemotherapy and 77 patients with CRC without chemotherapy were examined by immunohistochemistry assay. RESULTS: CMTM6 expression was upregulated in CRC compared with normal colon tissues, and CMTM6 levels were lower in advanced tumors than in early-stage tumors. High expression of CMTM6 correlated with lower pT stage and more CD4+/CD8+ tumor-infiltrating lymphocytes (TILs) and predicted a favorable prognosis in CRC. PD-L1 was expressed in CRC tissues at a low level, and PD-L1 positivity in tumor stroma (PD-L1(TS)), but not PD-L1 positivity in cancer cells (PD-L1(CC)), was associated with an increased density of CD4+ TILs and a favorable prognosis. The coexpression status of CMTM6 and PD-L1(TS) divided patients with CRC into three groups with low, moderate and high risks of progression and death, and patients with CMTM6High/PD-L1(TS)+ status had the longest survival. Moreover, the prognostic value of CMTM6/PD-L1 expression was more significant in patients with CRC treated with adjuvant chemotherapy than in those not treated with chemotherapy. CONCLUSION: CMTM6 has a critical impact on the immune microenvironment and can be used as an independent prognostic factor for CRC. The coexpression status of CMTM6 and PD-L1 can be used as a new classification to stratify the risk of progression and death for patients with CRC, especially for patients receiving adjuvant chemotherapy. These findings may provide insights into improving responses to immunotherapy-included comprehensive treatment for CRC in the future.

Genome-wide RNAi Screening Identifies RFC4 as a Factor That Mediates Radioresistance in Colorectal Cancer by Facilitating Nonhomologous End Joining Repair.

PURPOSE: Neoadjuvant chemoradiotherapy (neoCRT) is a standard treatment for locally advanced rectal cancer (LARC); however, resistance to chemoradiotherapy is one of the main obstacles to improving treatment outcomes. The goal of this study was to identify factors involved in the radioresistance of colorectal cancer and to clarify the underlying mechanisms. EXPERIMENTAL DESIGN: A genome-wide RNAi screen was used to search for candidate radioresistance genes. After RFC4 knockdown or overexpression, colorectal cancer cells exposed to X-rays both in vitro and in a mouse model were assayed for DNA damage, cytotoxicity, and apoptosis. Moreover, the regulatory effects and mechanisms of RFC4 in DNA repair were investigated in vitro. Finally, the relationships between RFC4 expression and clinical parameters and outcomes were investigated in 145 patients with LARC receiving neoCRT. RESULTS: RFC4, NCAPH, SYNE3, LDLRAD2, NHP2, and FICD were identified as potential candidate radioresistance genes. RFC4 protected colorectal cancer cells from X-ray-induced DNA damage and apoptosis in vitro and in vivo. Mechanistically, RFC4 promoted nonhomologous end joining (NHEJ)-mediated DNA repair by interacting with Ku70/Ku80 but did not affect homologous recombination-mediated repair. Higher RFC4 expression in cancer tissue was associated with weaker tumor regression and poorer prognosis in patients with LARC treated with neoCRT, which likely resulted from the effect of RFC4 on radioresistance, not chemoresistance. CONCLUSIONS: RFC4 was identified as a radioresistance factor that promotes NHEJ-mediated DNA repair in colorectal cancer cells. In addition, the expression level of RFC4 predicted radiotherapy responsiveness and the outcome of neoadjuvant radiotherapy in patients with LARC.

Coupled ocean-atmosphere dynamics of the 2017 extreme coastal El Niño.

In March 2017, sea surface temperatures off Peru rose above 28 °C, causing torrential rains that affected the lives of millions of people. This coastal warming is highly unusual in that it took place with a weak La Niña state. Observations and ocean model experiments show that the downwelling Kelvin waves caused by strong westerly wind events over the equatorial Pacific, together with anomalous northerly coastal winds, are important. Atmospheric model experiments further show the anomalous coastal winds are forced by the coastal warming. Taken together, these results indicate a positive feedback off Peru between the coastal warming, atmospheric deep convection, and the coastal winds. These coupled processes provide predictability. Indeed, initialized on as early as 1 February 2017, seasonal prediction models captured the extreme rainfall event. Climate model projections indicate that the frequency of extreme coastal El Niño will increase under global warming.

EGFR mono-antibody salvage therapy for locally advanced and distant metastatic penile cancer: Clinical outcomes and genetic analysis.

PURPOSE: There are limited therapeutic options for patients with advanced penile squamous cell carcinoma (PSCC) after chemotherapy failure. Thus, we evaluated the feasibility of salvage treatment using the epidermal growth factor receptor (EGFR) mono-antibody nimotuzumab in chemotherapy-failed PSCC patients and explored potential response or resistance biomarkers. MATERIALS AND METHODS: Six chemotherapy-failed PSCC patients with locally advanced disease or distant metastasis were enrolled consecutively to nimotuzumab treatment. Clinical responses and side effects were evaluated, and genetic characteristics of cancer specimens were analyzed through the next-generation sequencing of hotspot regions in cancer-related genes. RESULTS: Two of 6 patients showed partial responses, one was identified as having stable disease, while the other 3 had disease progression after nimotuzumab therapy. Side effects were all welltolerated. Genetic analysis revealed that TP53, CDKN2A, RB1, SMAD4, FLT3, and PIK3CA were the most frequently mutated genes in PSCC specimens, while altered KRAS, HRAS, EGFR, ERBB2, and FLT3 may be correlated with nimotuzumab resistance. Furthermore, 3 patients that were human papillomavirus-positive each showed clinical response or stable disease. CONCLUSIONS: EGFR mono-antibody may be a potential modality for locally advanced PSCC patients after chemotherapy failure. Further large-scale clinical studies are needed to elucidate the role of human papillomavirus status and critical gene mutations in the clinical response to EGFR-targeted therapy.

SUV39H2 promotes colorectal cancer proliferation and metastasis via tri-methylation of the SLIT1 promoter.

Suppressor of variegation 3-9 homolog 2 (SUV39H2) is a member of the SUV39H subfamily of lysine methyltransferases. Its role in colorectal cancer (CRC) proliferation and metastasis has remained unexplored. Here, we determined that SUV39H2 was upregulated in CRC tissues compared with that in adjacent non-neoplastic tissues. Further statistical analysis revealed that high SUV39H2 expression was strongly associated with distant metastasis (P = 0.016) and TNM stage (P = 0.038) and predicted a shorter overall survival (OS; P = 0.018) and progression-free survival (PFS; P = 0.018) time for CRC patients. Both in vitro and in vivo assays demonstrated that ectopically expressed SUV39H2 enhanced CRC proliferation and metastasis, while SUV39H2 knockdown inhibited CRC proliferation and metastasis. A molecular screen of SUV39H2 targets found that SUV39H2 negatively regulated the expression of SLIT guidance ligand 1 (SLIT1). Moreover, rescue assays suggested that SLIT1 could antagonize the function of SUV39H2 in CRC. Mechanistic studies indicated that SUV39H2 can directly bind to the SLIT1 promoter, suppressing SLIT1 transcription by catalyzing histone H3 lysine 9 (H3K9) tri-methylation. In summary, we propose that SUV39H2 can predict CRC patient prognosis and stimulate CRC malignant phenotypes via SLIT1 promoter tri-methylation.

ARHGEF19 interacts with BRAF to activate MAPK signaling during the tumorigenesis of non-small cell lung cancer.

Rho guanine nucleotide exchange factors (RhoGEFs) are proteins that activate Rho GTPases in response to extracellular stimuli and regulate various biologic processes. ARHGEF19, one of RhoGEFs, was reported to activate RhoA in the Wnt-PCP pathway controlling convergent extension in Xenopus gastrulation. The goal of our study was to identify the role and molecular mechanisms of ARHGEF19 in the tumorigenesis of non-small cell lung cancer (NSCLC). ARHGEF19 expression was significantly elevated in NSCLC tissues, and ARHGEF19 levels were significantly associated with lymph node status, distant metastasis and TNM stage; Patients with high ARHGEF19 levels had poor overall survival (OS) and progression-free survival (PFS). Our investigations revealed that ARHGEF19 overexpression promoted the cell proliferation, invasion and metastasis of lung cancer cells, whereas knockdown of this gene inhibited these processes. Mechanistically, ARHGEF19 activated the mitogen-activated protein kinase (MAPK) pathway in a RhoA-independent manner: ARHGEF19 interacted with BRAF and facilitated the phosphorylation of its downstream kinase MEK1/2; both the Dbl homology (DH) and Pleckstrin homology (PH) domains of ARHGEF19 were indispensable for the phosphorylation of MEK1/2. Furthermore, downregulation of miR-29b was likely responsible for the increased expression of ARHGEF19 in lung cancer tissues and, consequently, the abnormal activation of MAPK signaling. These findings suggest that ARHGEF19 upregulation, due to the low expression of miR-29 in NSCLC tissues, may play a crucial role in NSCLC tumorigenesis by activating MAPK signaling. ARHGEF19 could serve as a negative prognostic marker as well as a therapeutic target for NSCLC patients.

BST2 confers cisplatin resistance via NF-κB signaling in nasopharyngeal cancer.

Concurrent/adjuvant cisplatin-based chemoradiotherapy is regarded as the standard of treatment for locoregionally advanced nasopharyngeal carcinoma (NPC). However, patients who do not respond to cisplatin suffer, rather than benefit, from chemotherapy treatment. The goal of this study was to identify molecules involved in cisplatin resistance and to clarify their molecular mechanisms, which would help in the discovery of potential therapeutic targets and in developing a personalized and precise treatment approach for NPC patients. We previously generated a cisplatin-sensitive NPC cell line, S16, from CNE2 cells and found that eIF3a, ASNS and MMP19 are upregulated in S16 cells, which contributes to their cisplatin sensitivity. In this study, we found that BST2 is downregulated in cisplatin-sensitive S16 cells compared with CNE2 cells. Knockdown of BST2 in NPC cells sensitized their response to cisplatin and promoted cisplatin-induced apoptosis, whereas exogenous overexpression of BST2 increased their cisplatin resistance and inhibited cisplatin-induced apoptosis. Further investigation demonstrated that BST2-mediated cisplatin resistance depended on the activation of the NF-κB signaling pathway and consequent upregulation of anti-apoptotic genes, such as Bcl-XL and livin. Moreover, an analysis of clinical data revealed that a high BST2 level might serve as an independent indicator of poor prognosis in patients with locally advanced NPC treated with platinum-based chemoradiotherapy. These findings suggest that BST2 likely mediates platinum resistance in NPC, offering guidance for personalized and precise treatment strategies for patients with NPC.