CSNK2A1 confers gemcitabine resistance to pancreatic ductal adenocarcinoma via inducing autophagy

Gemcitabine, a pivotal chemotherapeutic agent for pancreatic ductal adenocarcinoma (PDAC), frequently encounters drug resistance, posing a significant clinical challenge with implications for PDAC patient prognosis. In this study, employing an integrated approach involving bioinformatic analyses from multiple databases, we unveil CSNK2A1 as a key regulatory factor. The patient-derived xenograft (PDX) model further substantiates the critical role of CSNK2A1 in gemcitabine resistance within the context of PDAC. Additionally, targeted silencing of CSNK2A1 expression significantly enhances sensitivity of PDAC cells to gemcitabine treatment. Mechanistically, CSNK2A1's transcriptional regulation is mediated by H3K27 acetylation in PDAC. Moreover, we identify CSNK2A1 as a pivotal activator of autophagy, and enhanced autophagy drives gemcitabine resistance. Silmitasertib, an established CSNK2A1 inhibitor, can effectively inhibit autophagy. Notably, the combinatorial treatment of Silmitasertib with gemcitabine demonstrates remarkable efficacy in treating PDAC. In summary, our study reveals CSNK2A1 as a potent predictive factor for gemcitabine resistance in PDAC. Moreover, targeted CSNK2A1 inhibition by Silmitasertib represents a promising therapeutic strategy to restore gemcitabine sensitivity in PDAC, offering hope for improved clinical outcomes.

A radiomics-based interpretable model to predict the pathological grade of pancreatic neuroendocrine tumors

OBJECTIVES

To develop a computed tomography (CT) radiomics-based interpretable machine learning (ML) model to predict the pathological grade of pancreatic neuroendocrine tumors (pNETs) in a non-invasive manner.

METHODS

Patients with pNETs who underwent contrast-enhanced abdominal CT between 2010 and 2022 were included in this retrospective study. Radiomics features were extracted, and five radiomics-based ML models, namely logistic regression (LR), random forest (RF), support vector machine (SVM), XGBoost, and GaussianNB, were developed. The performance of these models was evaluated using a time-independent testing set, and metrics such as sensitivity, specificity, accuracy, and the area under the receiver operating characteristic curve (AUC) were calculated. The accuracy of the radiomics model was compared to that of needle biopsy. The Shapley Additive Explanation (SHAP) tool and the correlation between radiomics and biological features were employed to explore the interpretability of the model.

RESULTS

A total of 122 patients (mean age: 50 ± 14 years; 53 male) were included in the training set, whereas 100 patients (mean age: 48 ± 13 years; 50 male) were included in the testing set. The AUCs for LR, SVM, RF, XGBoost, and GaussianNB were 0.758, 0.742, 0.779, 0.744, and 0.745, respectively, with corresponding accuracies of 73.0%, 70.0%, 77.0%, 71.9%, and 72.9%. The SHAP tool identified two features of the venous phase as the most significant, which showed significant differences among the Ki-67 index or mitotic count subgroups (p < 0.001).

CONCLUSIONS

An interpretable radiomics-based RF model can effectively differentiate between G1 and G2/3 of pNETs, demonstrating favorable interpretability.

CLINICAL RELEVANCE STATEMENT

The radiomics-based interpretable model developed in this study has significant clinical relevance as it offers a non-invasive method for assessing the pathological grade of pancreatic neuroendocrine tumors and holds promise as an important complementary tool to traditional tissue biopsy.

KEY POINTS

• A radiomics-based interpretable model was developed to predict the pathological grade of pNETs and compared with preoperative needle biopsy in terms of accuracy. • The model, based on CT radiomics, demonstrated favorable interpretability. • The radiomics model holds potential as a valuable complementary technique to preoperative needle biopsy; however, it should not be considered a replacement for biopsy.

[Characteristics of genioglossus neuromuscular activity in patients with obstructive sleep apnea during drug-induced sleep]

Objective: To analyze genioglossus (GG) activation responses to the negative pressure of upper airway cavity during awake and different sleep stages in patients with different obstructive sleep apnea (OSA) graduation. Methods: This prospective cohort study started from August 2019 to January 2021, recruited 42 male OSA patients aged from 21 to 59 (38.77±8.42) years. After completing whole night polysomnography (PSG) and upper airway CT, each subject underwent drug-induced sleep with simultaneous monitoring of genioglossal electromyography (GGEMG) and pressure of epiglottis (Pepi). Subjects were divided into three groups of mild OSA(7 males), moderate OSA(12 males), and severe OSA(23 males). The differences in upper airway CT measurements, parameters of GGEMG and Pepi during awake and induced sleep were compared. Statistical analysis was conducted by SPSS 21.0. Results: There was no significant difference in the GGEMG parameters between the mild and moderate groups. In wakefulness, the peak phasic GGEMG of the severe group was higher than the mild group (t=1.249, P=0.025), with no statistically difference in the corresponding Pepi. In the sleep onset, the GGEMG parameters and Pepi in severe group were higher than the other two groups. Linear regression analysis of the maximum GGEMG and maximum Pepi at the end of obstructive apnea (OA) in all moderate plus severe patients (n=35) was shown nonlinear correlation (r=0.28, P=0.694). The airway length of the glossopharyngeal cavity was linearly correlated with the maximum Pepi of OA (r=0.468, R2=0.219, P=0.005). Conclusions: The individual difference of GG activation in OSA patients is related to the severity of the disease (frequency of respiratory events) and negative pressure stimulation. In moderate and severe OSA patients, GG activity is not in harmony with the corresponding negative pressure stimulation, which may be one of the mechanisms leading to the aggravation of OSA.

[A single-center study on the distribution and antibiotic resistance of pathogens causing bloodstream infection in patients with hematological malignancies]

Objective: To study the incidence of bloodstream infections, pathogen distribution, and antibiotic resistance profile in patients with hematological malignancies. Methods: From January 2018 to December 2021, we retrospectively analyzed the clinical characteristics, pathogen distribution, and antibiotic resistance profiles of patients with malignant hematological diseases and bloodstream infections in the Department of Hematology, Nanfang Hospital, Southern Medical University. Results: A total of 582 incidences of bloodstream infections occurred in 22,717 inpatients. From 2018 to 2021, the incidence rates of bloodstream infections were 2.79%, 2.99%, 2.79%, and 2.02%, respectively. Five hundred ninety-nine types of bacteria were recovered from blood cultures, with 487 (81.3%) gram-negative bacteria, such as Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa. Eighty-one (13.5%) were gram-positive bacteria, primarily Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecium, whereas the remaining 31 (5.2%) were fungi. Enterobacteriaceae resistance to carbapenems, piperacillin/tazobactam, cefoperazone sodium/sulbactam, and tigecycline were 11.0%, 15.3%, 15.4%, and 3.3%, with a descending trend year on year. Non-fermenters tolerated piperacillin/tazobactam, cefoperazone sodium/sulbactam, and quinolones at 29.6%, 13.3%, and 21.7%, respectively. However, only two gram-positive bacteria isolates were shown to be resistant to glycopeptide antibiotics. Conclusions: Bloodstream pathogens in hematological malignancies were broadly dispersed, most of which were gram-negative bacteria. Antibiotic resistance rates vary greatly between species. Our research serves as a valuable resource for the selection of empirical antibiotics.

Comprehensive multimodal management of borderline resectable pancreatic cancer: Current status and progress

Borderline resectable pancreatic cancer (BRPC) is a complex clinical entity with specific biological features. Criteria for resectability need to be assessed in combination with tumor anatomy and oncology. Neoadjuvant therapy (NAT) for BRPC patients is associated with additional survival benefits. Research is currently focused on exploring the optimal NAT regimen and more reliable ways of assessing response to NAT. More attention to management standards during NAT, including biliary drainage and nutritional support, is needed. Surgery remains the cornerstone of BRPC treatment and multidisciplinary teams can help to evaluate whether patients are suitable for surgery and provide individualized management during the perioperative period, including NAT responsiveness and the selection of surgical timing.

Unique genetic profiles from cerebrospinal fluid cell-free DNA in leptomeningeal metastases of EGFR-mutant non-small-cell lung cancer: a new medium of liquid biopsy

Background

Leptomeningeal metastases (LM) are more frequent in non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations. Due to limited access to leptomeningeal lesions, the purpose of this study was to explore the potential role of cerebrospinal fluid (CSF) as a source of liquid biopsy in patients with LM.

Patients and methods

Primary tumor, CSF, and plasma in NSCLC with LM were tested by next-generation sequencing. In total, 45 patients with suspected LM underwent lumbar puncture, and those with EGFR mutations diagnosed with LM were enrolled.

Results

A total of 28 patients were enrolled in this cohort; CSF and plasma were available in 26 patients, respectively. Driver genes were detected in 100% (26/26), 84.6% (22/26), and 73.1% (19/26) of samples comprising CSF cell-free DNA (cfDNA), CSF precipitates, and plasma, respectively; 92.3% (24/26) of patients had much higher allele fractions in CSF cfDNA than the other two media. Unique genetic profiles were captured in CSF cfDNA compared with those in plasma and primary tissue. Multiple copy number variations (CNVs) were mainly identified in CSF cfDNA, and MET copy number gain identified in 47.8% (11/23) of patients was the most frequent one, while other CNVs included ERBB2, KRAS, ALK, and MYC. Moreover, loss of heterozygosity (LOH) of TP53 was identified in 73.1% (19/26) CSF cfDNA, which was much higher than that in plasma (2/26, 7.7%; P < 0.001). There was a trend towards a higher frequency of concomitant resistance mutations in patients with TP53 LOH than those without (70.6% versus 33.3%; P = 0.162). EGFR T790M was identified in CSF cfDNA of 30.4% (7/23) of patients who experienced TKI progression.

Conclusion

CSF cfDNA could reveal the unique genetic profiles of LM and should be considered as the most representative liquid biopsy medium for LM in EGFR-mutant NSCLC.

[Effectiveness of continuous positive airway pressure ventilation in improving genioglossus electromyography in patients with moderate to severe obstructive sleep apnea]

Objective: To compare the changes of genioglossus electromyography (GGEMG) with and without continuous positive airway pressure (CPAP) ventilation in moderate to severe obstructive sleep apnea (OSA) patients. Methods: Each of subjects, including male snorers and non-snorers, underwent polysomnography (PSG) with synchronous GGEMG recording with intra-oral bipolar silver ball electrodes at the Sleep Center of Beijing Tsinghua Changgung Hospital from August 2016 to Sepember 2017. Manual CPAP pressure titration and with GGEMG were performed in patients diagnosed moderate to severe OSA. T-test was used to compare the changes of GGEMG in OSA group (n=12, AHI (65.90+23.67) events/h) and control group (n=6, AHI(2.30+1.93) events/h) before and after CPAP treatment. Results: Variables of GGEMG (including tonic, peak and phasic GGEMG) were higher in OSA group than in control group during both wakefulness and non rapid eye movement(NREM) sleep. However, with CPAP treatment, the GGEMG variables were significantly decreased in OSA group during NREM sleep(tonic GGEMG: 1.23%±0.73% vs. 2.54%±1.12%, t=4.024, P=0.002; peak GGEMG: 12.37%±13.19% vs. 26.98%±15.52%, t=2.795, P=0.017; phasic GGEMG: 3.81%±2.47% vs. 8.82%±3.84%, t=5.113, P<0.001). Conclusions: CPAP treatment can eliminate respiratory events and maintain airway patency. It is helpful to normalize the excessive GGEMG response in OSA patients during sleep, which has therapeutic significance to alleviate and prevent genioglossal neuromuscular lesions.

[Polysomnographic comparation between dexmedetomidine-induced sleep and natural sleep]

Objective: To compare the parameters of polysomnography (PSG) in sleep structure and respiratory events between dexmedetomidine-induced sleep and natural sleep. Methods: From April 2016 to September 2018, a total of 44 patients with obstructive sleep apnea (OSA) and 3 patients with simple snoring completed PSG monitor both in natural sleep and dexmedetomidine-induced sleep in Department of Otorhinolaryngology Head and Neck Surgery, Beijing Tsinghua Changgung Hospital. The PSG parameters were statistically analysed with SPSS 22.0 software. Results: The average dose of dexmedetomidine was (104.60±27.93) μg, and there was no significant difference between the induced-sleep efficiency and the natural sleep efficiency (82.14%±16.66% vs. 86.50%±9.18%, t=-1.559, P>0.05). There was no rapid eye movement(REM) stages in all 47 subjects and only 1 case of them had non-rapid eye movement(NREM) stage 3 in induced sleep. The percentage of NREM1 in total sleep time was statistically different between the two groups (42.10%±26.71% vs. 17.47%±11.68%, t=5.997, P<0.001),but there was no significant difference in the percentage of NREM2 in total sleep time between the two groups (56.96%±26.0% vs. 62.95%±9.03%, t=-1.521, P=0.135). About respiratory events, there were significant differences in apnea hypopnea index ((46.29±20.23)/h vs. (39.67±25.41)/h), obstructive apnea index (25.20[10.50,45.40]/h vs. 16.20[3.30,35.20]/h) between induced-sleep and natural sleep (t=2.297, Z=-3.008, all P<0.05), these difference were more significant in mild-to-moderate OSA. There were no statistically significant differences in central apnea index (0.00[0.00,2.80]/h vs. 0.40[0.10,1.20]/h), mixed apnea index (0.00[0.00,6.20]/h vs. 0.00[0.00,3.40]/h, hypopnea index (4.20[0.00,3.30]/h vs. 12.00[5.20,17.40]/h), Z=-0.110,-0.508,-1.544, all P>0.05). There were statistical differences in the lowest oxygen saturation (84.77%±7. 59% vs. 80.21%±11.62%, t=2.558, P=0.014). Conclusions: There is no significant difference in sleep efficiency and NREM2 between dexmedetomidine induced sleep and natural sleep.NREM3 sleep is rare induced, but REM sleep is none of all. And dexmedetomidine induced sleep may aggravate obstructive sleep apnea, but not central apnea.

[The effect of genioglossus activity to velopharyngeal surgery in patient with obstructive sleep apnea hypopnea syndrome]

Objective: To investigate the effect of genioglossus (GG) activation at sleep onset on the outcome of velopharyngeal surgery in obstructive sleep apnea hypopnea syndrome (OSAHS) patients. Methods: Thirty-five patients between April 2014 and February 2015 in Beijing Tongren Hospital with OSAHS underwent overnight polysomnography with synchronous genioglossus electromyography (GGEMG) using intraoral electrodes. The upper airway (UA) anatomy was evaluated by three-dimensional computer tomography (3D-CT) in OSAHS patients. Then, all of the patients received velopharyngeal surgery, including revised uvulopalatopharyngoplasty (UPPP) with uvula preservation or UPPP combined transpalatal advancement pharyngoplasty. All patients were followed-up using polysomnography 3-6 months after surgery. T-test or Wilcoxon test were used to compare the variables between groups, and Spearman correlation analysis was used to test the correlation between parameters. Results: Thirty-five patients received velopharyngeal surgery. Twenty-two patients (62.86%) were responders, and 13 patients (37.14%) were non-responders. Responders had a higher mean GGEMG during sleep onset (15.31±3.74 vs. 9.92±2.93, t=4.504, P=0.001). The decreased AHI was significantly positively related to the sleep onset mean GGEMG (r=0.541, P=0.004) and the change in GGEMG (r=0.422, P=0.028). The decreased AHI was significantly negatively related to the minimal cross sectional airway area (mCSA,ρ=0.629,P=0.000) and the minimal lateral airway dimension (mLAT, ρ=0.484, P=0.009) at velopharynx. Conclusions: The outcome of velopharyngeal surgery was affected by the mean GGEMG during sleep onset. We speculated that the patient with higher GGEMG at sleep onset and narrower velopharynx were more suitable candidates for velopharyngeal surgery.

[Analysis of polysomnography results between pre- and post-operation in pediatric obstructive sleep apnea hypopnea syndrome patients]

Objective: To determine the objective effects of adenotonsillectomy on pediatric obstructive sleep apnea hypopnea syndrome (OSAHS) through analyzing the polysomnography (PSG) results between pre and post-operation. Methods: A total of 56 pediatric OSAHS patients were included who underwent adenoidectomy or/and tonsillectomy and completed PSG follow-up from January 1, 2017 to March 31, 2018. All the pediatric patients who underwent adenoidectomy or/and tonsillectomy during the research period were arranged to take a preoperative PSG study. Patients who were diagnosed OSAHS would be encouraged to complete a follow-up PSG study ranged from1 to 3 months after surgery. The parameters of respiration and sleep architecture of PSG were compared and analyzed. The paired student t test was used to compare preoperative and postoperative mean values. The unpaired student t test was used to compare quantitative variables among different groups. The rank sum test was used if the data were abnormal distribution. Results: Totally 238 patients completed preoperative PSG study, 62 patients were diagnosed as pediatric OSAHS, 56 eligible patients finished post-operative PSG. Hypopnea was the majority in all type of respiratory events in 56.45% (35/62) subjects, while central apnea as the majority in 29.03% (18/62) subjects who can also get significant CAI decrease after surgery. However, obstructive apnea as the majority only exist in 14.52% (9/62) subjects. The short-term cure rate of pediatric OSAHS was 85.71% (48/56). The postoperative AHI, MAI, CAI, HI, ODI, LoSpO(2), percentage of stage I sleep and arousal index were significantly decreased, however, the OAI was no statistical decrease. The percentage of stage Ⅱ and rapid eye movement (REM) sleep were significantly increased, while no significant change in percentage of slow wave sleep and sleep efficiency(t=2.32, P=0.017). Conclusions: Pediatric OSAHS manifest different characteristics of respiratory events from that of adults. Adenotonsillectomy can significant decrease respiratory events and improve sleep architecture, however, there are still some patients who can't be completely relieved with adenotonsillectomy.

[In vitro study of the effect of human antigen R on lysosomal acidification during autophagy in mouse cardiomyocytes]

Objective: To investigate the effect of human antigen R on lysosomal acidification during autophagy in mouse cardiomyocytes cultured in vitro. Methods: The hearts of 20 C57BL/6 mice aged 1-2 days no matter male or female were isolated to culture primary cardiomyocytes which were used in the following experiments. (1) The cells were divided into 5 groups according to the random number table (the same grouping method below), i. e., normal control group and sugar-free serum-free 0.5, 1.0, 3.0, and 6.0 h groups. The cells in normal control group were routinely cultured for 54.0 h with Dulbecco's modified Eagle medium/nutrient mixture F12 (DMEM/F12) medium (the same regular culture condition below), and the cells in sugar-free serum-free 0.5, 1.0, 3.0, and 6.0 h groups were firstly regularly cultured for 53.5, 53.0, 51.0, 48.0 h and then cultured with replaced sugar-free serum-free medium for 0.5, 1.0, 3.0, and 6.0 h, respectively. The protein expressions of microtubule-associated protein 1 light chain 3 Ⅱ (LC3Ⅱ), autophagy-related protein 5, and adenosine triphosphatase V1 region E1 subunit (ATP6V1E1) were detected by Western blotting. (2) The cells were divided into normal control group and sugar-free serum-free 3.0 h group. The cells in corresponding groups were treated the same as those in experiment (1), and the cell lysosomal acidification level was observed and detected under a laser scanning confocal microscope. (3) Two batches of cells were grouped and treated the same as those in experiment (1). The protein expression of human antigen R in the whole protein of cells of one batch and its protein expression in the cytoplasm and nucleus protein of cells of the other batch were detected by Western blotting. (4) The cells were divided into normal control group, simple control small interfering RNA (siRNA) group, simple human antigen R-siRNA1 (HuR-siRNA1) group, simple HuR-siRNA2 group, sugar-free serum-free 3.0 h group, sugar-free serum-free+ control siRNA group, sugar-free serum-free+ HuR-siRNA1 group, and sugar-free serum-free+ HuR-siRNA2 group. After 48 hours of regular culture, the cells in simple control siRNA group and sugar-free serum-free+ control siRNA group were transfected with negative control siRNA for 6 h, the cells in simple HuR-siRNA1 group and sugar-free serum-free+ HuR-siRNA1 group were transfected with HuR-siRNA1 for 6 h, and the cells in simple HuR-siRNA2 group and sugar-free serum-free+ HuR-siRNA2 group were transfected with HuR-siRNA2 for 6 h. Hereafter, the cells in these 8 groups were continuously cultured for 48 h with regular conditon, and then the cells in normal control group and each simple siRNA-treated group were replaced with DMEM/F12 medium, the cells in the other groups were replaced with sugar-free serum-free medium, and they were cultured for 3 h. The protein expression of human antigen R in the whole protein of cells was detected by Western blotting. (5) Two batches of cells were divided into sugar-free serum-free+ control siRNA group and sugar-free serum-free+ HuR-siRNA1 group, and the cells in corresponding groups were treated the same as those in experiment (4). The distribution and expression of human antigen R in the cells of one batch were observed and detected by immunofluorescence method, and the lysosomal acidification level in the cells of the other batch was observed and detected under a laser scanning confocal microscope. (6) Three batches of cells were divided into sugar-free serum-free 3.0 h group, sugar-free serum-free+ control siRNA group, sugar-free serum-free+ HuR-siRNA1 group, and sugar-free serum-free+ HuR-siRNA2 group, and the cells in corresponding groups were treated the same as those in experiment (4). The protein expressions of cathepsin D in the whole protein of cells of one batch, human antigen R in the cytoplasm protein of cells of one batch, and ATP6V1E1 in the whole protein of cells of the other batch were detected by Western blotting. (7) The cells were divided into normal control group, sugar-free serum-free 3.0 h group, sugar-free serum-free+ control siRNA group, and sugar-free serum-free+ HuR-siRNA1 group, and the cells in corresponding groups were treated the same as those in experiment (4). The mRNA expression of ATP6V1E1 in cells was detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. The sample number of each experiment was 3. Data were processed with independent data t test, one-way analysis of variance, least significant difference t test, and Bonferroni correction. Results: (1) Compared with those of normal control group, the protein expressions of LC3Ⅱ and ATP6V1E1 in the whole protein of cells of sugar-free serum-free 1.0, 3.0, and 6.0 h groups were significantly increased (t=12.16, 4.05, 4.82, 11.64, 3.29, 8.37, P<0.05 or P<0.01). Compared with that of normal control group, the protein expression of autophagy-related protein 5 in the whole protein of cells of sugar-free serum-free 0.5, 1.0, 3.0, and 6.0 h groups was significantly increased (t=6.88, 10.56, 5.76, 9.91, P<0.05 or P<0.01). (2) Compared with 1.03±0.08 of normal control group, the lysosomal acidification level in the cells of sugar-free serum-free 3.0 group (2.92±0.30) was significantly increased (t=6.01, P<0.01). (3) There was no statistically significant difference in the overall comparison of protein expression of human antigen R in the whole protein of cells among the 5 groups (F=1.09, P>0.05). Compared with that of normal control group, the protein expression of human antigen R in the cytoplasm protein of cells was significantly increased in sugar-free serum-free 1.0, 3.0, and 6.0 h groups (t=43.05, 11.07, 5.39, P<0.05 or P<0.01), while the protein expression of human antigen R in the nucleus protein of cells was significantly decreased in sugar-free serum-free 3.0 and 6.0 h groups (t=11.18, 12.71, P<0.01). (4) Compared with that of simple control siRNA group, the protein expression of human antigen R in the whole protein of cells of simple HuR-siRNA1 group and simple HuR-siRNA2 group was significantly decreased (t=4.82, 4.44, P<0.05). Compared with that of sugar-free serum-free+ control siRNA group, the protein expression of human antigen R in the whole protein of cells of sugar-free serum-free+ HuR-siRNA1 group and sugar-free serum-free+ HuR-siRNA2 group was significantly decreased (t=4.39, 6.27, P<0.05). (5) Compared with those of sugar-free serum-free+ control siRNA group, the distribution of human antigen R in the cytoplasm of cells and its expression level were significantly decreased in sugar-free serum-free+ HuR-siRNA1 group (t=10.13, P<0.01). Compared with 1.00±0.06 of sugar-free serum-free+ control siRNA group, the lysosomal acidification level (0.73±0.06) in the cells of sugar-free serum-free+ HuR-siRNA1 group was significantly decreased (t=3.28, P<0.01). (6) Compared with those of sugar-free serum-free+ control siRNA group, the protein expressions of cathepsin D in the whole protein of cells, human antigen R in the cytoplasm protein of cells, and ATP6V1E1 in the whole protein of cells were significantly decreased in sugar-free serum-free+ HuR-siRNA1 group and sugar-free serum-free+ HuR-siRNA2 group (t=4.16, 3.99, 4.81, 5.07, 11.68, 12.97, P<0.05 or P<0.01). (7) Compared with that of normal control group, the mRNA expression of ATP6V1E1 in the cells of sugar-free serum-free 3.0 h group was significantly increased (t=5.51, P<0.05). Compared with that of sugar-free serum-free+ control siRNA group, the mRNA expression of ATP6V1E1 in the cells of sugar-free serum-free+ HuR-siRNA1 group was significantly decreased (t=5.97, P<0.05). Conclusions: After sugar-free serum-free treatment in vitro, the autophagy in mouse primary cardiomyocytes is activated, the lysosomal acidification is enhanced, and the expression of human antigen R in cytoplasm is increased. Human antigen R function is activated and involved in maintaining lysosomal acidification during autophagy in mouse cardiomyocytes.

[Influence of nicotinic acid adenine dinucleotide phosphate on autophagy in hypoxic cardiomyocytes of rats and its mechanism]

Objective: To investigate influence of nicotinic acid adenine dinucleotide phosphate (NAADP) on autophagy in hypoxic cardiomyocytes of rats and its mechanism. Methods: Five neonatal Sprague-Dawley rats were collected and sacrificed to harvest the hearts, and primary cardiomyocytes were separated for the following experiments. (1) Primary cardiomyocytes were collected and divided into normoxia group, hypoxia 9 h group, and hypoxia 9 h+ NAADP group according to random number table, with 5 wells in each group. Cells in normoxia group were cultured routinely in the constant temperature incubator at 37 ℃ for 9 hours. Cells in hypoxia 9 h group and hypoxia 9 h+ NAADP group were cultured in hypoxic incubator with volume fraction 94% nitrogen, 5% carbon dioxide, and 1% oxygen for 9 hours. Before hypoxia, cells in hypoxia 9 h+ NAADP group were dealt with final amount-of-substance concentration 10 μmol/L NAADP. Cell counting kit 8 was used to measure cell viability. (2) Primary cardiomyocytes were collected and divided into normoxia group, hypoxia 9 h group, hypoxia 9 h+ NAADP group, hypoxia 9 h+ tran-Ned-19 group, and hypoxia 9 h+ trans-Ned-19+ NAADP group according to the random number table, with 2 wells in each group. Cells in normoxia group were cultured routinely in the constant temperature incubator at 37 ℃ for 9 hours. And cells in the other 4 groups were cultured in hypoxic incubator as that in experiment (1) Before hypoxia, cells in hypoxia 9 h+ NAADP group were dealt with amount-of-substance concentration 10 μmol/L NAADP, cells in hypoxia 9 h+ tran-Ned-19 group were dealt with amount-of-substance concentration 1 μmol/L trans-Ned-19, and cells in hypoxia 9 h+ trans-Ned-19 + NAADP group were dealt with amount-of-substance concentration 10 μmol/L NAADP and 1 μmol/L trans-Ned-19. Protein expressions of microtubule associated protein 1 light chain 3-Ⅱ and P62 were detected by Western blotting. (3) Primary cardiomyocytes were collected and grouped as those in experiment (1). The lysosomal acidity was determined by immunofluorescence method. Data were processed with one-way analysis of variance and least-significant difference test. Results: (1) The cell viability in normoxia group was 1.114±0.024, which was significantly higher than 0.685±0.079 of cells in hypoxia 9 h group (P<0.01). The cell viability of hypoxia 9 h+ NAADP group was 0.886±0.061, which was obviously higher than that of cells in hypoxia 9 h group (P<0.05). (2) Expressions of microtubule-associated protein 1 light chain 3-Ⅱ and P62 of cells in hypoxia 9 h group were significantly higher than those of cells in normoxia group (P<0.01). Compared with those in hypoxia 9 h group, expression of P62 in hypoxia 9 h+ NAADP group was significantly decreased (P<0.01), while expression of microtubule-associated protein 1 light chain 3-Ⅱ did not change significantly (P>0.05). There were no significantly statistical difference in expressions of microtubule-associated protein 1 light chain 3-Ⅱ and P62 between hypoxia 9 h group and hypoxia 9 h+ trans-Ned-19 group (P>0.05). Compared with those of cells in hypoxia 9 h+ NAADP group, expression of P62 of cells in hypoxia 9 h+ trans-Ned-19+ NAADP group was obviously increased (P<0.01), while expression of microtubule-associated protein 1 light chain 3-Ⅱ did not change significantly (P>0.05). (3) The intensity of green fluorescence of cells in normoxia group was strong and co-localized well with red fluorescence, and internal environment of lysosome was with stronger acidity. The intensity of green fluorescence in cells of hypoxia 9 h group was significantly lower than that of cells in normoxia group, and acidity of internal environment of lysosome was weakened. The intensity of green fluorescence and acidity of internal environment of lysosome in hypoxia 9 h+ NAADP were significantly stronger than those of cells in hypoxia 9 h group, but significantly lower than those of cells in normoxia group. Conclusions: NAADP can improve myocardial cell viability through acidifying internal environment of lysosome of cardiomyocyte after hypoxia, promoting degradation of autophagosomes, reducing autophagic lysosomal accumulation, and repairing damaged autophagic flow.

[Effects of decline of pH value on cardiomyocyte viability of rats and the mechanism]

Objective: To explore the effects of decline of pH value on cardiomyocyte viability of rats, and to analyze the possible mechanism. Methods: Hearts of five newborn Sprague-Dawley rats were isolated, and then primary cardiomyocytes were cultured and used in the following experiments. (1) The primary cardiomyocytes were divided into pH 7.4+ 6 h, pH 7.0+ 6 h, pH 6.5+ 6 h, pH 6.0+ 6 h, pH 6.5+ 1 h, and pH 6.5+ 3 h groups according to the random number table, with 4 wells in each group. After being routinely cultured for 48 h (similarly hereinafter), cells in pH 7.4+ 6 h, pH 7.0+ 6 h, pH 6.5+ 6 h, and pH 6.0+ 6 h groups were cultured with pH 7.4, pH 7.0, pH 6.5, and pH 6.0 DMEM-F12 medium (similarly hereinafter), respectively, and then they were cultured for 6 h. Cells in pH 6.5+ 1 h and pH 6.5+ 3 h groups were cultured with pH 6.5 medium, and then they were cultured for 1 h and 3 h, respectively. Viability of cells was detected by methyl-thiazolyl-tetrazolium (MTT) method. (2) The primary cardiomyocytes were divided into pH 7.4, pH 6.5, and pH 6.5+ taxol groups according to the random number table, with 2 wells in each group. Cells in pH 7.4 group were cultured with pH 7.4 medium, while cells in pH 6.5 and pH 6.5+ taxol groups were cultured with pH 6.5 medium. Cells in pH 6.5+ taxol group were added with taxol of a final molarity of 0.2 μmol/L in addition, and then they were cultured for 6 h. Morphology and density of microtubule of cells was detected by immunofluorescence assay. (3) The primary cardiomyocytes were grouped and treated as in experiment (2), with 2 wells in each group. The expressions of polymerized microtubulin and free microtubulin were determined with Western blotting. (4) The primary cardiomyocytes were grouped and treated as in experiment (2), with 4 wells in each group. Viability of cells after treated with taxol was detected by MTT method. Data were processed with one-way analysis of variance and LSD-t test. Results: (1) The viability of cells in pH 7.4+ 6 h, pH 7.0+ 6 h, pH 6.5+ 6 h, pH 6.0+ 6 h, pH 6.5+ 1 h, and pH 6.5+ 3 h groups were 1.00±0.08, 0.90±0.08, 0.85±0.06, 0.83±0.04, 0.91±0.10, and 0.89±0.10, respectively. Compared with that in pH 7.4+ 6 h group, viability of cells in pH 7.0+ 6 h, pH 6.5+ 6 h, pH 6.0+ 6 h, pH 6.5+ 1 h, and pH 6.5+ 3 h groups were all decreased in different degrees (t=2.476, 4.002, 4.996, 2.168, 2.400, P<0.05). (2) Microtubules of cells in pH 7.4 group were radially distributed around the nucleus with clear tubular structure. Compared with that in pH 7.4 group, the skeleton of microtubules of cells in pH 6.5 group was obviously damaged, with broken structure of microtubule and reduced density. Compared with that in pH 6.5 group, the damage degree of microtubules of cells in pH 6.5+ taxol group was obviously alleviated, and the structure of microtubules basically returned to normal. (3) Compared with that in pH 7.4 group, the expression of free microtubulin of cells in pH 6.5 group was significantly increased (t=3.030, P<0.05), while the expression of polymerized microtubulin of cells was significantly decreased (t=8.604, P<0.05). Compared with that in pH 6.5 group, the expression of free microtubulin of cells in pH 6.5+ taxol group was significantly decreased (t=4.559, P<0.05), while the expression of polymerized microtubulin of cells was significantly increased (t=5.472, P<0.05). (4) Viability of cells in pH 7.4, pH 6.5, and pH 6.5+ taxol groups were 1.00±0.10, 0.83±0.04, and 0.93±0.10, respectively. Compared with that in pH 7.4 group, the viability of cells in pH 6.5 group was obviously declined (t=4.412, P<0.05). Compared with that in pH 6.5 group, the viability of cells in pH 6.5+ taxol group was obviously increased (t=2.461, P<0.05). Conclusions: The decline of pH value reduces the viability of cardiomyocytes of rats through destroying the skeleton of microtubule. Stabilizing microtubule skeleton can significantly reduce acidic treatment-induced damage and ameliorate cardiomyocyte viability.

[Sorafenib combined with chemotherapy and donor lymphocyte infusion as salvage therapy in patients with FLT3-positive acute myeloid leukemia relapse after allogeneic hematopoietic stem cell transplantation]

To explore the efficacy of sorafenib combined with chemotherapy and donor lymphocyte infusion (DLI) in patients with FLT3-positive acute myeloid leukemia (AML) relapsed after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Of the 14 patients relapsed after allo-HSCT, 9 achieved complete remission after salvage therapy of sorafenib combined with chemotherapy and DLI, 6 with complete molecular remission, 2 with partial remission, and 3 with no response. With a median follow up of 220 (range, 30-1 782) days after post-transplantation relapse, 7 patients were still alive and 7 died. Salvage therapy of sorafenib combined with chemotherapy and DLI shows a decent therapeutic effect for FLT3-positive AML relapsed after allo-HSCT.

[Otolaryngologist's perspective in childhood adenotonsillar hypertrophy]

The hypertrophy of adenoid and tonsillar is the most common cause of obstructive sleep apnea hypopnea syndrome(OSAHS) in children, which require early diagnosis and standardized treatment to improve behavior, attention and cognitive abilities. Adenotonsillectomy is the primary treatment for pediatric OSAHS with adenotonsillar hypertrophy. Meanwhile, the interest in antiinflammatory agents, such as intranasal corticosteroids and leukotriene antagonists, for childhood OSAHS has also increased.

Spectral and spatial resolving of photoelectric property of femtosecond laser drilled holes of GaSb(1-x)Bi(x)

Femtosecond laser drilled holes of GaSbBi were characterized by the joint measurements of photoconductivity (PC) spectroscopy and laser-beam-induced current (LBIC) mapping. The excitation light in PC was focused down to 60 μm presenting the spectral information of local electronic property of individual holes. A redshift of energy band edge of about 6-8 meV was observed by the PC measurement when the excitation light irradiated on the laser drilled holes. The spatial resolving of photoelectric property was achieved by the LBIC mapping which shows "pseudo-holes" with much larger dimensions than the geometric sizes of the holes. The reduced LBIC current with the pseudo-holes is associated with the redshift effect indicating that the electronic property of the rim areas of the holes is modified by the femtosecond laser drilling.

Freshwater toxic cyanobacteria induced DNA damage in apple (Malus pumila), rape (Brassica napus) and rice (Oryza sativa)

Cyanobacteria in freshwater ecosystems can present a harmful effect on growth and development of plants through irrigation with contaminated water. In this study, the effects of microcystins (MCs)-containing cyanobacteria extract (CE) on DNA damage of apple, rape and rice were investigated to explore the phytotoxic mechanism of MCs through DNA fragmentation and RAPD analysis. Determination of DNA fragmentation by fluorescent dye DAPI showed that significant DNA damage was observed in rice seedlings after exposure to CE while DNA fragmentation in rape seedlings and apple cultures did not differ significantly between treatment and control groups. Qualitative characterization of genomic DNA fragmentation by agarose gel electrophoresis supported the quantitative determination using DAPI. The main changes in RAPD profiles of rape seedlings following exposure of lower doses of CE were variation in band intensity for the primers F03 and S01, while higher doses of CE caused loss of normal bands and appearance of new bands except band intensity changes. The data presented here demonstrate that DNA damage in plants occurs following exposure of microcystins, and the polymorphic RAPDs may be used as an investigation tool for environmental toxicology and as a useful biomarker for the detection of genotoxic effects of microcystins on plants.

Enhanced two-photon biosensing with double-clad photonic crystal fibers

A double-clad photonic crystal fiber was used to improve detection efficiency over a standard single-mode fiber in a two-photon fluorescence detection scheme in which the dye was excited and the fluorescence was detected back through the same fiber.

Adaptive correction of depth-induced aberrations in multiphoton scanning microscopy using a deformable mirror

We demonstrate adaptive aberration correction for depth-induced spherical aberration in a multiphoton scanning microscope with a micromachined deformable mirror. Correction was made using a genetic learning algorithm with two-photon fluorescence intensity feedback to determine the desired shape for an adaptive mirror. For a 40x/0.6 NA long working distance objective, the axial scanning range was increased from 150 mm to 600 mm.

On-demand droplet spotter for preparing pico- to femtoliter droplets on surfaces

A droplet spotter for on-demand generation of pico- to femtoliter droplets was developed to meet the requirement for high-density spotting of chemicals on a surface. Our droplet spotter involves applying a approximately 1000-V and approximately 10-ms pulse voltage to the tip of a capillary tube (o.d. approximately 18 microns; i.d. approximately 11 microns) supplied with water or a dye solution. The capability of the spotter was demonstrated by preparing a microarray of dye molecules. The microarray was prepared by spotting approximately 30-fL droplets of a dye solution on a surface at the density of one spot per 20 x 20 micron 2.

Real three-dimensional microstructures fabricated by photopolymerization of resins through two-photon absorption

Effective energy windows for two-photon absorption (TPA) photopolymerization of resins were investigated and, with a properly selected laser pulse energy, exquisite three-dimensional (3D) microstructures with submicrometer spatial resolution were achieved. The results show the inherent utility of TPA in the fabrication of real 3D patterns. In particular, we propose and utilize a resin pre-exposure technique by which freely movable components affixed to an axle are built, demonstrating a new application of TPA in laser microfabrication.

Atomic force microscopy of DNA molecules stretched by spin-coating technique

We have developed an effective approach to stretching DNA molecules with the flow of fluid generated by spin coating. Well-stretched A DNA molecules were observed using atomic force microscopy. Substrate properties sensitively affected the stretching behavior of DNA. Our experimental findings revealed that a mica surface treated with crystal violet, a cationic dye molecule, is suitable to the spin-coating procedure for stretching DNA. Moreover, compared with relaxed DNA, we observed reduced height of the stretched DNA, which was attributed mainly to elongation force applied to the DNA molecules from the fluid flow and strong adhesion force between DNA and the substrate. This simple and effective method for preparing stretched DNA could be useful in physically mapping genomic DNA in a high throughput.

Changes in cardiovascular activity during an increase in biliary tract pressure in rabbits

In order to study the mechanism of decreased blood pressure caused by an acute increase in biliary tract pressure, we observed house rabbit model of self-made caecus for changes in cardiovascular function when biliary tract pressure was increased. It was found that both the blood pressure and cardiac output evidently decreased (P < 0.05) parallelly, and the systolic pressure decreased more markedly than diastolic pressure. At the same time there was fluctuation in heart rate and in central venous pressure; but there was no significant difference between them (P > 0.05), suggesting that in the absence of infective agents, the increased biliary tract pressure can bring about a decrease in cardiac output, which is an important factor contributing to an early blood pressure decrease in acute cholangitis of severe type (ACST).

[Outcome of pregnancy complicated by hepatitis A in the urban districts of Shanghai]

In 1988, during an epidemic 431 cases of hepatitis A among a group 7,476 pregnant women were in the 12 Women Health Units at urban area of Shanghai, accounting for a morbidity rate of 5,765.1/100,000 pregnant women. The ratio of spontaneous abortion, induced abortion and term delivery were 18:15:67. There were 16 perinatal deaths in the 288 delivered cases. The perinatal mortality rate was 55.6/1,000 and its relative risk, as compared with that of the whole Shanghai Urban Districts was 4.1, at the same time, 83 cases of pregnancies associated with Hepatitis A (all confirmed by anti-hepatitis A Virus IgM assay) were studied in detail in the Shanghai Municipal Women Health Institute. The average birth weight of the new born was slightly lower and the mortality rate was significantly higher than those in a control group of 168 cases, there was no fetal infection as evidenced by fetal blood anti HAV IgM.