[Analysis of the clinical characteristics of acute myeloid leukemia related to the treatment of hematological and solid tumors]

Objective: To compare and analyze the clinical characteristics of acute myeloid leukemia (AML) related to the treatment of hematological tumors and solid tumors. Methods: The laboratory and clinical data of 41 patients with treatment-related AML (t-AML) in the Department of Hematology, Henan Cancer Hospital from January 2014 to December 2021 were retrospectively analyzed, and they were divided into hematological tumor group and solid tumor group. Survival analysis was performed using the Kaplan-Meier method and Log rank test. Results: The median interval from the first tumor diagnosis to t-AML in 41 patients was 21.0 (16.5-46.0) months; 24 (58.5%) had abnormal expression of lymphoid antigen, 28 (68.3%) had abnormal karyotype, 18 cases (43.9%) were positive for fusion gene, and 28 cases (68.3%) were positive for gene mutation; the median recurrence-free survival (RFS) was 11.0 months, and the median overall survival (OS) was 11.5 months. The proportion of acute promyelocytic leukemia ([APL], 0.0, 0/13), complete response ([CR],18.2%, 2/11), median OS (4.5 months) and median RFS (2.5 months) of t-AML patients in the hematological tumor group were significantly lower than those in the solid tumor group (35.7%, 10/28; 68.0%, 17/25; not reach; not reach), but the proportion of M4 /M5 (93.2%,12/13) was significantly higher than that in the solid tumor group (53.6%,15/18; all P values<0.05). Through subgroup analysis, the proportion of patients with positive PML-RARa and good prognosis karyotypes in the solid tumor group (35.7%, 10/28; 46.4%, 13/28) was significantly higher than that in the hematological tumor group (0.0, 0/13; 0.0, 0/13; P<0.05), while the proportion of patients with intermediate karyotypes (42.9%, 12/28) was significantly lower than that in the hematological tumor group (84.6%, 11/13; P<0.05), the difference was statistically significant. The CR rate (90.0%, 9/10), median OS (not reach) and median RFS (not reach) in the t-APL group were higher than those in the t-AML (without t-APL) group (38.5%, 10/26; 6 months; 8 months; P<0.05). After excluding the effect of t-APL patients, there was no significant difference in the CR rate, median OS and median RFS between the solid tumor group (8; 9 months; not reach) and the hematological tumor group (2; 4 months; 2 months; P>0.05). Univariate analysis showed that the primary tumor belongs to hematological tumor was a common risk factor for OS and RFS in t-AML patients (P<0.10). Conclusions: Compared with patients with t-AML secondary to solid tumors, patients with t-AML secondary to hematological tumors have poorer treatment effects and poorer prognosis. After excluding the effect of t-APL patients, there are no significant differences in the treatment efficacy and prognosis between the two types of t-AML patients.

[Efficacy and safety of pulsed radiofrequency combined with gabapentin in the treatment of acute herpetic neuralgia]

Objective: To explore the clinical efficacy and safety of pulsed radiofrequency (PRF) combined with gabapentin in the treatment of acute herpetic neuralgia (AHN). Methods: A total of 123 AHN patients were retrospectively selected in Henan Provincial People's Hospital from November 2019 to July 2022, who were divided into two groups based on treatment methods: control group (treated with gabapentin, n=61) and study group (treated with gabapentin and PRF, n=62). The visual analog scale (VAS) was utilized for pain severity assessment and the self-rating scale for sleep (SRSS) was utilized for sleep quality evaluation. The differences in serum levels of interleukin (IL)-10, chemokine ligand 10 (CXCL-10), prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2), IL-2 and IL-6 before and after treatment were compared between the two groups. The overall treatment effectiveness and the occurrence rates of postherpetic neuralgia and adverse reactions were evaluated in both groups. Results: Among the study group patients, 28 were male and 34 were female, and the age was (62.8±8.5) years. Among the control group patients, 35 were male and 26 were female, and the age was (64.0±7.8) years. The VAS scores of the study group before and after treatment were 7.96±1.33 and 1.52±0.60, respectively, while the control group were 7.68±1.52 and 2.70±0.64. The SRSS scores before and after treatment in the study group were 31.74±5.90 and 12.06±2.81, respectively, while those in the control group were 33.10±5.54 and 14.14±2.96, respectively. Before treatment, there were no statistically differences of the VAS scores and SRSS scores in both groups (all P>0.05). After treatment, the VAS scores and SRSS scores in both groups decreased compared with before treatment (all P<0.05), the study group's VAS scores and SRSS scores were lower than those in the control group (all P<0.05). Before treatment, there were no statistically differences of the serum levels of IL-10, CXCL-10, PGE2, COX-2, IL-2 and IL-6 in both groups (all P>0.05). After treatment, the serum levels of IL-10, CXCL-10, PGE2, COX-2 and IL-6 in both groups decreased compared with before treatment, while the IL-2 level increased. Additionally, the study group had lower serum levels of IL-10, PGE2, COX-2 and IL-6 compared with the control group (all P<0.05). After treatment, the study group had 35 cases of cure, 26 cases of effectiveness, and 1 case of ineffectiveness, while the control group had 22 cases of cure, 31 cases of effectiveness, and 8 cases of ineffectiveness. The overall treatment efficacy of the study group was better than that of the control group (P=0.012). The incidence of postherpetic neuralgia in the study group after treatment was 16.1% (10/62), which was lower than that in the control group, which was 37.7% (23/61) (P<0.05). There were no statistically differences of the occurrence rates of adverse reactions in both groups (all P>0.05). Conclusion: Combining PRF with gabapentin for the treatment of AHN demonstrates better overall efficacy and safety, which can more effectively alleviate pain, improve sleep, and reduce inflammatory cytokine levels.

[Efficacy and safety of high-voltage pulsed radiofrequency combined with pregabalin on severe thoracic postherpetic neuralgia]

Objective: To investigate the efficacy and safety of high-voltage pulse radiofrequency combined with pregabalin on severe thoracic postherpetic neuralgia (PHN). Methods: A total of 103 patients with PHN who were admitted to the Department of Pain Medicine of Henan Provincial People's Hospital from May 2020 to May 2022 were retrospectively selected, including 50 males and 53 females, and aged 40 to 79 (65.4±9.2) years. The patients were divided into two groups according to the treatment methods they received: the control group (n=51) and the study group (n=52). The patients in the control group were treated with oral pregabalin, and the patients in the study group received pregabalin plus high-voltage pulse radiofrequency therapy. The pain intensity and efficacy of the two groups were evaluated before treatment and 4 weeks after treatment. The pain intensity, the sleep quality and the efficacy of treatment was evaluated by visual analogue scale (VAS) score, Pittsburgh Sleep Quality Index (PSQI) score and nimodipine method, respectively. The levels of pain mediators including serum neuropeptide Y (NPY), prostaglandin E2 (PGE2), substance P (SP) and β-endorphin were measured. The differences of the above indicators and the incidence of adverse reactions were compared between the two groups. Results: The VAS scores of the study group and the control group before treatment were 7.94±0.76 and 8.20±0.81, and PSQI scores were 16.84±3.90 and 16.29±3.84, respectively, with no statistically significant differences (both P>0.05). After 4 weeks of treatment, the VAS scores of the two groups were 2.84±0.80 and 3.35±0.87, and PSQI scores were 6.78±1.90 and 7.98±2.40, respectively, and the VAS score and PSQI score in the study group were lower than those in the control group (both P<0.05). There were no significant differences of the serum levels of NPY, PGE2, SP and β-endorphin before treatment in the study group and control group (all P>0.05). After 4 weeks of treatment, the levels of NPY, PGE2, SP and β-Endorphin in the study group were (240.7±26.8) ng/L, (74.4±8.6) μg/L, (108.9±15.7) ng/L and (4.4±0.9) ng/L, which were lower than those in the control group [(268.1±29.4) ng/L, (79.7±8.3) μg/L, (115.2±16.2) ng/L, (5.2±1.3) ng/L, respectively], with statistically significant differences (all P<0.05). After treatment, 29 cases were cured, 16 cases were markedly effective and 6 cases were effective in the study group, while 16 cases, 24 cases and 8 cases were cured, markedly effective and effective in the control group, respectively. The overall efficacy of patients in the study group was better than that in the control group (Z=-2.32, P=0.018). The incidence of adverse reactions in the study group and control group was 11.5% (6/52) and 7.8% (4/51), respectively, with no statistically significant difference (χ2=0.40, P=0.527). Conclusion: High-voltage pulse radiofrequency combined with pregabalin can significantly improve the pain intensity and sleep quality of patients with severe thoracic PHN and reduce the levels of pain mediators, with a high safety profile.

[Chest hemorrhage after left total pulmonary resection for secondary rifampin-resistant tuberculosis:a case report]

The patient had received five courses of anti-tuberculosis treatment for recurrent tuberculosis. The drug sensitivity test results of the first three courses showed drug-sensitive pulmonary tuberculosis, and the fourth diagnosis was rifampin-resistant tuberculosis (RR-TB), complicated by chronic obstructive pulmonary disease, type Ⅱ respiratory failure, pulmonary heart disease, and heart failure (grade Ⅲ). The patient stopped taking the anti-tuberculosis drugs on his own in the eighth month of receiving the resistant treatment. After admission, the symptoms improved temporarily after receiving oxygen therapy, anti-infection, and anti-tuberculosis treatment. Because of hemoptysis, the patient underwent arterial embolization by catheterization, but a large amount of hemoptysis occurred shortly thereafter. Emergency left total lung resection and gauze packing for hemostasis were performed. After surgery, the patient's vital signs were maintained with mechanical ventilation and vasopressors. Forty-eight hours after surgery, the gauze was removed, and the patient underwent tracheotomy, enteral nutrition, and anti-tuberculosis treatment. After discharge, the patient underwent rehabilitative exercise and anti-resistant tuberculosis therapy. The patient's condition remained stable for more than six months of follow-up.

[Efficacy and safety of high-voltage pulsed radiofrequency combined with pregabalin on severe thoracic postherpetic neuralgia]

Objective: To investigate the efficacy and safety of high-voltage pulse radiofrequency combined with pregabalin on severe thoracic postherpetic neuralgia (PHN). Methods: A total of 103 patients with PHN who were admitted to the Department of Pain Medicine of Henan Provincial People's Hospital from May 2020 to May 2022 were retrospectively selected, including 50 males and 53 females, and aged 40 to 79 (65.4±9.2) years. The patients were divided into two groups according to the treatment methods they received: the control group (n=51) and the study group (n=52). The patients in the control group were treated with oral pregabalin, and the patients in the study group received pregabalin plus high-voltage pulse radiofrequency therapy. The pain intensity and efficacy of the two groups were evaluated before treatment and 4 weeks after treatment. The pain intensity, the sleep quality and the efficacy of treatment was evaluated by visual analogue scale (VAS) score, Pittsburgh Sleep Quality Index (PSQI) score and nimodipine method, respectively. The levels of pain factors including serum neuropeptide Y (NPY), prostaglandin E2 (PGE2), substance P (SP) and β-Endorphin were measured. The differences of the above indicators and the incidence of adverse reactions were compared between the two groups. Results: The VAS scores and PSQI scores of the study group and the control group before treatment were (7.94±0.76), (8.20±0.81), (16.84±3.90) and (16.29±3.84), respectively, with no statistically significant difference (both P>0.05). After 4 weeks of treatment, the VAS scores and PSQI scores of the two groups were (2.84±0.80), (3.35±0.87), (6.78±1.90) and (7.98±2.40), respectively, and the VAS score and PSQI score in the study group were lower than those in the control group (both P<0.05). Serum levels of NPY, PGE2, SP and β-Endorphin were (298.5±31.0) ng/L, (92.3±11.0) μg/L, (156.8±21.4) ng/L, and (8.6±1.6) ng/L in the study group and (304.2±28.6) ng/L, (94.4±12.9) μg/L, (152.7±23.8) ng/L and (8.2±1.8) ng/L in the control group, with no significant differences (all P>0.05). After 4 weeks of treatment, levels of NPY, PGE2, SP and β-Endorphin were (240.7±26.8) ng/L, (74.4±8.6) μg/L, (108.9±15.7) ng/L and (4.4±0.9) ng/L, which were lower than those in the control group [(268.1±29.4) ng/L, (79.7±8.3) μg/L, (115.2±16.2) ng/L, (5.2±1.3) ng/L, respectively], with statistically significant differences (all P<0.05). After treatment, 29 cases were cured, 16 cases were markedly effective and 6 cases were effective in the study group, while 16 cases, 24 cases and 8 cases were cured, markedly effective and effective in the control group. The overall efficacy of patients in the study group was better than that in the control group (Z=-2.32, P=0.018). The incidence of adverse reactions in the study group and control group was 11.5% (6/52) and 7.8% (4/51), respectively, with no statistically significant difference (χ²=0.40, P=0.527). Conclusion: High-voltage pulse radiofrequency combined with pregabalin can significantly improve the pain and sleep quality of patients with severe thoracic PHN and reduce the level of pain factors, with a high safety profile.

[Evaluation of uniportal video-assisted thoracoscopic decortication in treatment of drug-resistant tuberculous empyema]

Objective: To examine the safety and efficacy of the uniportal video-assisted thoracoscopic decortication in treatment of drug-resistant tuberculosis empyema. Methods: From January 2018 to December 2020, 122 cases of tuberculous empyema treated by decortication in Department of Surgery, Wuhan Pulmonary Hospital were retrospectively analyzed, including 100 males and 22 females, aged(M(IQR)) 29.5(28.0) years (range: 13 to 70 years). According to the surgical approach and drug resistance, patients with drug-resistant tuberculosis who underwent uniportal video-assisted thoracoscopic decortication were included in group A (n=22), and those who underwent thoracotomy decortication were included in group B (n=28). Drug-sensitive patients who underwent uniportal video-assisted thoracoscopic decortication were included in group C (n=72). There was no statistical difference in the baseline data of the three groups (P>0.05). The operation, early postoperative recovery, and prognosis-related indicators were compared among three groups by Kruskal-Wallis test and χ² test by Mann-Whitney U test and Bonferroni method between groups A and B, groups A and C. Results: The intraoperative blood loss of group A, group B, and group C was 200(475) ml, 300(200) ml, and 225(300) ml, respectively. There was no significant difference in intraoperative hemorrhage (H=2.74, P=0.254) and treatment outcome (χ²=4.76, P=0.575) among the three groups. Compared with group B, the operation time of group A (302.5(187.5) minutes vs. 200.0(60.0) minutes, U=171.0, P=0.007) and postoperative pulmonary reexpansion duration (4.5(3.0) months vs. 3.0 (2.2) months, U=146.5, P=0.032) were longer, and the postoperative drainage duration (9.5(7.8) days vs. 13.0(10.0) days, U=410.0, P=0.044), and the postoperative hospitalization time (12.0(7.8) days vs. 14.5(4.8) days, U=462.2, P=0.020) were shorter. There was no significant difference in complications between group A and group B (63.6%(14/22) vs. 71.4%(20/28), χ²=0.34, P=0.558). Compared with group C, the postoperative drainage duration of group A (9.5(7.8) days vs. 7.0(4.0) days, U=543.5, P=0.031), the postoperative hospitalization time (12.0(7.8) days vs. 9.0(4.0) days, U=533.0, P=0.031) and postoperative pulmonary reexpansion duration (4.5(3.0) months vs. 3.0(2.0) months, U=961.5, P=0.001) were longer. The operation time (302.5(187.5) minutes vs. 242.5(188.8) minutes, U=670.5, P=0.278), and complications (63.6%(14/22) vs. 40.3%(29/72), χ²=3.70, P=0.054) were not different between group A and group C. Conclusions: For drug-resistant tuberculous empyema, the uniportal video-assisted thoracoscopic decortication can achieve the same good therapeutic effect as drug-sensitive tuberculous empyema, and it is as safe as thoracotomy. At the same time, it has the advantage of minimally invasive and can accelerate the early postoperative recovery of patients.

ac4C acetylation of RUNX2 catalyzed by NAT10 spurs osteogenesis of BMSCs and prevents ovariectomy-induced bone loss

N-acetyltransferase 10 (NAT10) is the key enzyme for N4-acetylcytidine (ac4C) modification of mRNA, which participates in various cellular processes and is related to many diseases. Here, we explore the relationships among osteoblast differentiation, NAT10, and ac4C, and we found that NAT0 expression and the ac4C level of total RNA were decreased in the bone tissues of bilateral ovariectomized (OVX) mice and osteoporosis patients. Adenoviruses overexpressing NAT10 reversed bone loss, and Remodelin, an NAT10 inhibitor, enhanced the loss of bone mass in OVX mice. Moreover, bone marrow-derived mesenchymal stem cells (BMSCs) with low-level ac4C modification formed fewer calcium nodules in vitro with NAT10 silencing, whereas BMSCs with high-level ac4C modification formed more calcium nodules with NAT10 overexpression. Moreover, we demonstrated that the ac4C level of runt-related transcription factor 2 (RUNX2) mRNA was increased after BMSCs were cultured in osteogenic medium (OM) and decreased after NAT10 silencing. The RUNX2 mRNA half-life and protein expression decreased after silencing NAT10 in BMSCs. Therefore, NAT10-based ac4C modification promotes the osteogenic differentiation of BMSCs by regulating the RUNX2 ac4C level. Because abnormal levels of NAT10 are probably one of the mechanisms responsible for osteoporosis, NAT10 is a new potential therapeutic target for this disease.

[Electrophysiological characteristics and therapeutic efficacy of radiofrequency ablation of focal atrial tachycardia originating from the right atrial appendage during pregnancy]

Objective: To analyze the electrophysiological characteristics and the therapeutic efficacy of irrigated-tip catheter radiofrequency ablation(RFA) without radiation for pregnant women with focal atrial tachycardia(AT) originating from the right atrial appendage (RAA). Methods: Data from 55 women with focal AT, who underwent radiofrequency ablation (RFA) in the First Affiliated Hospital of Zhengzhou University from October 2016 to March 2019, were screened. 2 non-pregnant women with right atrial appendage tachycardia (RAAT) and 4 pregnant women with non-RAAT were excluded. The remaining 49 cases were divided into RAAT during pregnancy group (n=6, including 4 cases of tachycardia-induced cardiomyopathy) and non-pregnant and non-RAAT group (control, n=43). Under the guidance of three-dimensional mapping system, the earliest activation site was identified, RFA with the irrigated catheter without x-ray fluoroscopy was performed in RAAT patients during pregnancy, all patients in control group underwent non-zero-ray ablation. Patients were followed up at 3, 6, 12 months post procedure, and yearly follow up thereafter in outpatient clinic. Electrocardiogram or Holter monitoring was performed during follow up. AT recurrence and surgical complications were recorded during follow up. At 6 months after RFA, echocardiography examination and laboratory examination including N-terminal B-type brain natriuretic peptide measurement were performed in the pregnant patients, delivery results were also recorded in the pregnant patients. The electrophysiological characteristics of RAAT during pregnancy were analyzed, the therapeutic efficacy of RFA was compared between the two groups. Results: This study is a retrospective study. Age ((30.7±6.2)years vs. (57.2±11.7)years), left ventricular ejection fraction ((46.0±12.8)% vs. (60.1±5.9)%), proportions of organic heart disease (0% vs. 58%) were significantly lower in the RAAT patients during pregnancy group than in control group (P<0.05), while proportions of patients with persistent tachycardia (100% vs. 7%), symptoms of chest distress and palpitation (6/6 vs. 49%) and left ventricular ejection farction≤50% (4/6 vs. 9%) were significantly higher in RAAT group than in control group (P<0.05), heart rate was similar between the two groups ((163.7±11.1)beats/minutes vs. (153.7±15.2)beats/minutes, P>0.05). The characteristic P-wave morphology was observed in RAAT patients during pregnancy, i.e, P wave was mostly upright (5/6) in inferior-leads (Ⅱ, Ⅲ, aVF) and in lead I and aVL, deep and wide negative P wave was found in V₁ lead (5/6), and gradually became positive from V₂-V₆. The mean tachycardia cycle length was (361.7±38.5) ms. Three-dimensional mapping showed that the origin points of the 6 RAAT pregnant patients were all scattered in the local region, the local region was ablated accordingly, 2 patients (2/6) received extensive ablation of local areas. Immediate successful rate was similar between the two groups (6/6 vs. 93%). During follow up ((15.3±4.0) months), no complications were observed after RFA, postoperative recurrence rate was similar (1/6 vs. 12%). Uncomplicated delivery was reported in all 6 pregnant RAAT post ablation. Normal cardiac structure and function was observed in the 4 pregnant patients with tachycardia-induced cardiomyopathy post ablation. Compared to pre-ablation phase, reduced left atrial dimension ((30.3±1.3) mm vs. (36.8±6.7) mm, P>0.05), increased left ventricular ejection fraction ((64.0±2.9)% vs. (39.8±10.7)%), reduced left ventricular end-diastolic dimension ((44.8±4.0) mm vs. (60.0±2.9) mm) and reduced N-terminal B-type natriuretic peptide value ((136.2±47.5) ng/L vs. (3 408.4±901.3) ng/L) were observed at 6 months post ablation (P<0.05). Conclusion: The electrophysiological characteristics are suggestive for focal AT originating from RAA during pregnancy. Under the guidance of 3-dimension activation mapping, no fluoroscopic RFA with irrigated-tip catheter is a safe and effective strategy for the treatment of focal RAAT during pregnancy.

Experimental evidence for terahertz emission of continuum electrons in the dual-color laser field

Terahertz (THz) wave generation (TWG) in a dual-color laser is investigated with joint measurements between THz and third-harmonic generation, where the relative phase delay of dual-color fields is determined in situ in sub-wavelength accuracy, allowing for the clarification of the TWG mechanism in a direct comparison with various theoretical predictions. The delay- and polarization-dependent experiment validates that the continuum-continuum transition within the escaped electron wavepacket in the single atom gives birth to THz emission, while the bound energetic level does not contribute to TWG. TWG from atoms and molecules would provide an all-optical, vacuum-free, and ultrafast tool to record the spatiotemporal evolution of tunneling electron wavepackets.

Primary Tumor Sidedness Predicts Bevacizumab Benefit in Metastatic Colorectal Cancer Patients

The emerging debate between primary tumor location and clinical outcome of bevacizumab treated metastatic colorectal cancer (mCRC) continues. The aim of the present study is to investigate the association between the primary tumor location and clinical outcome of 115 mCRC patients receiving bevacizumab based treatment. A meta-analysis including 21 studies was carried out to confirm the conclusion. In our prospective study, we found that right-sided mCRC commonly occurred in older cases (p = 0.03) with multiple-site metastasis (p = 0.03). Progression-free survival (PFS) of the left-sided patients undergoing bevacizumab plus a FOLFIRI regimen was superior to the right-sided cases (p = 0.03, crude HR = 0.31, 95%CI = 0.11-0.87; adjusted HR = 0.21, 95%CI = 0.06-0.66). The meta-analysis confirmed that efficacy of bevacizumab-based treatment in left-sided mCRC patients was better than the right-sided cases in the overall population (P h = 0.24, combined OR = 1.36, 95%CI = 1.07-1.72), RAS/BRAF wild-type (P h = 0.19, combined OR = 1.66, 95%CI = 1.17-2.34), clinical trial (P h = 0.23, combined OR = 1.42, 95%CI = 1.07-1.88), Caucasian population (P h = 0.18, combined OR = 1.37, 95%CI = 1.02-1.85) and first-line (P h = 0.19, combined OR = 1.48, 95%CI = 1.13-1.96) subgroups. Improved survival of bevacizumab plus chemotherapy treated left-sided mCRC patients was observed in the overall population [P h < 0.01, combined MSR = 1.09, 95%CI = 1.00-1.18 for PFS; P h < 0.01, combined MSR = 1.24, 95%CI = 1.13-1.36 for overall survival (OS)], especially in the RAS/BRAF wild-type (P h = 0.09, combined MSR = 1.10, 95%CI = 1.03-1.19 for PFS; P h = 0.02, combined MSR = 1.34, 95%CI = 1.21-1.49 for OS). These findings indicate that primary tumor sidedness can predict clinical outcome of bevacizumab-treated RAS/BRAF wild-type mCRC patients and the left-sided patients may benefit more from bevacizumab plus FOLFIRI.

[Risk-factor analysis of poor graft function after allogeneic hematopoietic stem cell transplantation for severe aplastic anemia]

目的

探讨重型再生障碍性贫血（SAA）患者行异基因造血干细胞移植（allo-HSCT）后发生植入功能不良（PGF）的危险因素。

方法

回顾性分析111例行allo-HSCT的SAA患者临床资料及移植情况，采用Cox比例风险模型对可能影响PGF的因素进行单因素及多因素分析。

结果

在111例行allo-HSCT的SAA患者中，共有16例发生了PGF（14.4%）。多因素分析结果显示，非血缘供者（HR＝2.656，95%CI 1.204～5.858，P＝0.016）及移植前血清铁蛋白浓度（SF）>1 000 µg/L（HR＝3.170，95%CI 1.400～7.180，P＝0.006）是发生PGF的独立危险因素。

结论

非血缘供者及移植前SF>1 000 µg/L的患者移植后容易发生PGF。

Ultrafast Mapping of Coherent Dynamics and Density Matrix Reconstruction in a Terahertz-Assisted Laser Field

A time-resolved spectroscopic protocol exploiting terahertz-assisted photoionization is proposed to reconstruct transient density matrix. Population and coherence elements are effectively mapped onto spectrally separated peaks in photoionization spectra. The beatings of coherence dynamics can be temporally resolved beyond the pulse duration, and the relative phase between involved states is directly readable from the oscillatory spectral distribution. As demonstrated by a photoexcited multilevel open quantum system, the method shows potential applications for subfemtosecond time-resolved measurements of coherent dynamics with free electron lasers and tabletop laser fields.

Laser frequency stabilization using a commercial wavelength meter

We present the characterization of a laser frequency stabilization scheme using a state-of-the-art wavelength meter based on solid Fizeau interferometers. For a frequency-doubled Ti-sapphire laser operated at 461 nm, an absolute Allan deviation below 10^-9 with a standard deviation of 1 MHz over 10 h is achieved. Using this laser for cooling and trapping of strontium atoms, the wavemeter scheme provides excellent stability in single-channel operation. Multi-channel operation with a multimode fiber switch results in fluctuations of the atomic fluorescence correlated to residual frequency excursions of the laser. The wavemeter-based frequency stabilization scheme can be applied to a wide range of atoms and molecules for laser spectroscopy, cooling, and trapping.

[The relationship between the radioresistance of pancreatic cancer cell SW1990 and the induction of the Epithelial-Mesenchymal Transition: an in vitro study]

Objective: To investigate the relationship between the radioresistance of pancreatic cancer cell SW1990 and the induction of the Epithelial-Mesenchymal Transition (EMT). Methods: The radio-resistant pancreatic cancer cell SW1990-R were established by using the method of radiating pancreatic cancer cell SW1990 step by step and repeatedly. Then the changes of the morphology of the cell was observed by inverted phase contrast microscope, the radioresistance of SW1990-R was detected by colony-forming assay, and the apoptosis rate of the two cell lines after radiation were measured by flow cytometry. Then invasiveness and EMT-related genes was measured by trans-well test and qRT-PCR. Finally, the model of transplanted tumor on nude mouse was used to confirm the relationship between the radioresistance of pancreatic cancer cell SW1990 and the induction of EMT. Results: Compared with SW1990, SW1990-R had a lower radiosensitivity (survival fraction in 2 Gy, SF₂: 0.326 3±0.007 3 vs 0.840 8±0.001 9, P<0.05) and lower apoptosis rate[(6.12±1.27) % vs (16.87±1.73)%, P<0.05]. Meanwhile, the invasive ability of SW1990-R were significant higher than that of SW1990 cell. According to the result of both in vivo and in vitro experiment, SW1990-R had a higher expression level of Vimentin and Snail, and lower expression level of E-cadherin when compared with SW1990. Conclusion: Compared with SW1990, the radio-resistant pancreatic cancer cell SW1990-R can induce the Epithelial-mesenchymal transition.

Post-processing phase-correction algorithm in two-dimensional electronic spectroscopy

In a typical two-dimensional electronic spectroscopy (2DES) experiment, the timing errors of the coherence and emission time when determining the absolute time zeros usually introduce extraneous spectral phase slopes and distort the 2D spectrum. In this work, a phase-correction method that merely relies on the data post-processing algorithm is proposed. The method allows reconstructing the spectrum by simply subtracting the artificial linear spectral-phase slopes from the phase component of the 2D spectrum along both coherence and emission frequency axes. The new method has the advantages of ease of implementation and no need for the supplementary experiments and iterative fitting algorithm as commonly-used phasing methods, which may improve the phasing issue in 2DES and serve as a cross-check of now available phasing methods.

Precise phase determination with the built-in spectral interferometry in two-dimensional electronic spectroscopy

A new method determining the precise phase of pulse sequences in two-dimensional electronic spectroscopy (2DES) is proposed merely using the already built-in spectral interferometry. The approach is easily implemented without the supplementary instrumental construction, only at the expense of a few additional scanning and data-fitting processes. This method is executed with the sample in place, effectively avoiding the phase ambiguities of the beam propagation in samples, thus calibrating the absolute phase at the exact interaction region. The new proposed method is expected to improve the phasing procedure in 2DES in a more convenient way.

Variations of rhizosphere bacterial communities in tea (Camellia sinensis L.) continuous cropping soil by high-throughput pyrosequencing approach

AIMS

The goal was to investigate the dynamics of soil bacterial community in the chronosequence tea orchards.

METHOD AND RESULTS

In this study, soils from tea orchards with continuously cropping histories for 1, 10 and 20 years were collected for investigating rhizosphere bacterial communities using 454 pyrosequencing. The results indicated that Gammaproteobacteria, Alphaproteobacteria, Acidobacteria and Actinobacteria were the main phyla in the tea orchard soils and accounted for more than 60% of the bacterial sequences. At the genus level, the relative abundance of beneficial bacteria, such as Pseudomonas, Rhodanobacter, Bradyrhizobium, Mycobacterium and Sphingomonas, significantly decreased in the 20-year tea orchard soils. Similar patterns of bacterial community structure were observed between 1-year and 10-year tea orchards, which significantly differed from those of 20-year tea orchards. Redundancy analysis indicated that soil organic carbon and pH showed high correlations (positive or negative) with the majority of the taxa.

CONCLUSION

Long-term tea cultivation altered the composition and structure of soil bacterial community, which led to the reduction in the beneficial bacteria.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results can provide clues on how to regulate the soil microbial community and maintain the health of soils in tea orchard systems.

Prechemotherapy neutrophil : lymphocyte ratio is superior to the platelet : lymphocyte ratio as a prognostic indicator for locally advanced esophageal squamous cell cancer treated with neoadjuvant chemotherapy

The study aimed to evaluate the prognostic significance of prechemotherapy neutrophil to lymphocyte ratio and platelet to lymphocyte ratio, and preoperative neutrophil to lymphocyte ratio and platelet to lymphocyte ratio in locally advanced esophageal squamous cell cancer. We analyzed retrospectively locally advanced esophageal squamous cell cancer patients who had received neoadjuvant chemotherapy before undergoing a radical esophagectomy between 2009 and 2012. Neutrophil to lymphocyte ratio and platelet to lymphocyte ratio before chemotherapy and before the surgery were calculated. Univariate analyses showed that prechemotherapy neutrophil to lymphocyte ratio >5 (P = 0.048, hazard ratio = 2.86; 95% confidence interval: 1.01-8.12) and prechemotherapy platelet to lymphocyte ratio >130 (P = 0.025, hazard ratio = 5.50; 95% confidence interval: 1.23-24.55) were associated significantly with overall survival (OS), and prechemotherapy platelet to lymphocyte ratio >130 (P = 0.026, hazard ratio = 3.18; 95% confidence interval: 1.15-8.85) was associated significantly with progression-free survival. However, only prechemotherapy neutrophil to lymphocyte ratio >5 (P = 0.024, hazard ratio = 3.50; 95% confidence interval: 1.18-10.40) remained significantly associated with OS in multivariate analyses. Neither preoperative neutrophil to lymphocyte ratio nor platelet to lymphocyte ratio was associated with OS or progression-free survival. The prechemotherapy neutrophil to lymphocyte ratio >5 to preoperative neutrophil to lymphocyte ratio ≤5 group showed significantly worse OS than the prechemotherapy neutrophil to lymphocyte ratio ≤5 to preoperative neutrophil to lymphocyte ratio ≤5 group (P = 0.050). The prechemotherapy platelet to lymphocyte ratio >130 to preoperative platelet to lymphocyte ratio ≤130 group (P = 0.016) and platelet to lymphocyte ratio >130 to preoperative platelet to lymphocyte ratio >130 group (P = 0.042) showed significantly worse OS than the prechemotherapy platelet to lymphocyte ratio ≤30 to preoperative platelet to lymphocyte ratio ≤130 group. In conclusions, prechemotherapy neutrophil to lymphocyte ratio is an independent prognostic factor for OS in patients with advanced esophageal squamous cell cancer treated with neoadjuvant chemotherapy, and, as an adverse prognostic predictor, increased prechemotherapy neutrophil to lymphocyte ratio is superior to platelet to lymphocyte ratio. Maintaining a low neutrophil to lymphocyte ratio and platelet to lymphocyte ratio throughout treatment is a predictor of better OS.

Practical considerations in the clinical application of whole-exome sequencing

Despite the exciting advent of whole-exome sequencing (WES) in medical genetics practices, the optimal interpretation of results requires further actions such as reconsidering clinical information and obtaining further laboratory testing. There are no published data to guide clinicians in this process. In a retrospective study on 93 patients who underwent clinical WES, we set out to assess and resolve these practical challenges. With the laboratories reporting a molecular diagnostic rate of 25.8%, the medical geneticists and the laboratories were 90% concordant in their interpretation of the WES results. Divergence occurred when the medical geneticist reconsidered clinical information and/or additional information regarding pathogenicity of a variant. Variants of uncertain significance were reported in 86% of patients, with 53.7% needing follow-up, such as additional laboratory tests and genotyping of family members. By layering clinical data (e.g. mode of inheritance and phenotypic fit) on to the laboratory results, we developed clinical categories for the WES results. These categories of definite diagnosis (14/93), likely diagnosis (8/93), possible diagnosis (13/93) and no diagnosis (58/93) could be used to convey results to patients uniformly. Our framework for a clinically informed interpretation of the results enhances the utility of WES within medical genetics practices.

Multiple ionization and fragmentation dynamics of molecular iodine studied in IR-XUV pump-probe experiments

The ionization and fragmentation dynamics of iodine molecules (I(2)) are traced using very intense (∼10(14) W cm(-2)) ultra-short (∼60 fs) light pulses with 87 eV photons of the Free-electron LASer at Hamburg (FLASH) in combination with a synchronized femtosecond optical laser. Within a pump-probe scheme the IR pulse initiates a molecular fragmentation and then, after an adjustable time delay, the system is exposed to an intense FEL pulse. This way we follow the creation of highly-charged molecular fragments as a function of time, and probe the dynamics of multi-photon absorption during the transition from a molecule to individual atoms.

Propagation characteristics of a focused laser beam in a strontium barium niobate photorefractive crystal under reverse external electric field

The propagation characteristics of a focused laser beam in a SBN:75 photorefractive crystal strongly depend on the signal-to-background intensity ratio (R=I_s/I_b) under reverse external electric field. In the range 20>R>0.05, the laser beam shows enhanced self-defocusing behavior with increasing external electric field, while it shows self-focusing in the range 0.03>R>0.01. Spatial solitons are observed under a suitable reverse external electric field for R=0.025. A theoretical model is proposed to explain the experimental observations, which suggest a new type of soliton formation due to "enhancement" not "screening" of the external electrical field.

Electron rearrangement dynamics in dissociating I(2)^(n+) molecules accessed by extreme ultraviolet pump-probe experiments

The charge rearrangement in dissociating I_{2}^{n+} molecules is measured as a function of the internuclear distance R using extreme ultraviolet pulses delivered by the free-electron laser in Hamburg. Within an extreme ultraviolet pump-probe scheme, the first pulse initiates dissociation by multiply ionizing I_{2}, and the delayed probe pulse further ionizes one of the two fragments at a given time, thus triggering charge rearrangement at a well-defined R. The electron transfer between the fragments is monitored by analyzing the delay-dependent ion kinetic energies and charge states. The experimental results are in very good agreement with predictions of the classical over-the-barrier model demonstrating its validity in a thus far unexplored quasimolecular regime relevant for free-electron laser, plasma, and chemistry applications.

Time-resolved measurement of interatomic coulombic decay in Ne2

The lifetime of interatomic Coulombic decay (ICD) [L. S. Cederbaum et al., Phys. Rev. Lett. 79, 4778 (1997)] in Ne2 is determined via an extreme ultraviolet pump-probe experiment at the Free-Electron Laser in Hamburg. The pump pulse creates a 2s inner-shell vacancy in one of the two Ne atoms, whereupon the ionized dimer undergoes ICD resulting in a repulsive Ne+(2p(-1))-Ne+(2p(-1)) state, which is probed with a second pulse, removing a further electron. The yield of coincident Ne+-Ne2+ pairs is recorded as a function of the pump-probe delay, allowing us to deduce the ICD lifetime of the Ne2(+)(2s(-1)) state to be (150±50)  fs, in agreement with quantum calculations.

Accuracy of CT-guided biopsies in 158 patients with thoracic spinal lesions

BACKGROUND

Inconsistent accuracies of CT-guided thoracic spinal biopsies have been reported in previous studies.

PURPOSE

To determine the accuracy of CT-guided thoracic spinal biopsy, to compare the results with those previously reported, and to determine if there are any factors that influence the accuracy of CT-guided thoracic spinal biopsy.

MATERIAL AND METHODS

In total, 158 consecutive CT-guided percutaneous thoracic spine procedures (performed at the Department of Spinal Surgery, Xi'an Red Cross Hospital between April 2000 and July 2010) were reviewed. The 158 lesions were categorized by location and radiographic features. Pathological and clinical follow-up were used to determine accuracy.

RESULTS

The diagnostic accuracy of CT-guided thoracic spinal biopsy was 90.5% overall. Biopsy of metastatic bone disease (98.2%) was significantly more accurate than biopsies of primary tumors (80.9%) and of hematological malignancies (47.0%) (P < 0.05 and P < 0.005, respectively). The diagnostic accuracy of CT-guided thoracic spinal biopsy was significantly higher for the lower thoracic spine (97.6%) than for the middle (90.0%) or upper thoracic spine (80.4%) (P < 0.05 and P < 0.025, respectively). The diagnostic accuracy was significantly higher for lytic lesions (96.4%) than for sclerotic lesions (81.3%) (P < 0.010). The accuracy of biopsies performed using the transpedicular approach (91.0%) was not significantly different from that of biopsies performed using posterolateral approaches (91.5%) (0.25 < P < 0.5).

CONCLUSION

Percutaneous CT-guided thoracic spinal biopsy is a viable alternative to open surgical biopsy. The diagnostic accuracy was not affected by any of the variables except for lesion level, histology, and radiographic features.

Second-order autocorrelation of XUV FEL pulses via time resolved two-photon single ionization of He

Second-order autocorrelation spectra of XUV free-electron laser pulses from the Spring-8 Compact SASE Source (SCSS) have been recorded by time and momentum resolved detection of two-photon single ionization of He at 20.45 eV using a split-mirror delay-stage in combination with high-resolution recoil-ion momentum spectroscopy (COLTRIMS). From the autocorrelation trace we extract a coherence time of 8 ± 2 fs and a mean pulse duration of 28 ± 5 fs, much shorter than estimations based on electron bunch-length measurements. Simulations within the partial coherence model [Opt. Lett. 35, 3441 (2010)] are in agreement with experiment if a pulse-front tilt across the FEL beam diameter is taken into account that leads to a temporal shift of about 6 fs between both pulse replicas.

The role of serum basic fibroblast growth factor, estradiol and urine basic fibroblast growth factor in differentiating infantile haemangiomas from vascular malformations

OBJECTIVE

To investigate the role of serum basic fibroblast growth factor (bFGF), estradiol (E2) and urine bFGF in differentiating infantile haemangiomas from vascular malformations.

METHOD

Between October 2007 and January 2009, 97 patients with haemangiomas and 25 patients with vascular malformations who had not been treated previously were included in this prospective study. Forty-eight patients with cleft lip and/or palate were selected as controls. The age of all subjects ranged from 1 to 30 months. The serum and urine levels of bFGF were determined by enzyme-linked immunosorbent assay (ELISA). The serum levels of E2 were examined via radioimmunoassay. All data were analysed with SPSS 11.5 software package.

RESULTS

The concentration of serum and urine bFGF was significantly different among the three groups (haemangiomas, vascular malformations and controls) (P = 0.027, P = 0.001). Significantly different urine bFGF levels were found in patients with proliferating and involuting haemangiomas (P = 0.04). The serum E2 levels were significantly higher in patients with haemangiomas than vascular malformations (P = 0.001) and controls (P = 0.001).

CONCLUSION

Serum bFGF and E2 as well as urine bFGF can be used to supplement the clinical diagnosis of congenital vascular anomalies. Urine bFGF combined with serum E2 may be the most potential markers for diagnosing haemangiomas and determining the proliferating stage of haemangiomas.

Ultrafast extreme ultraviolet induced isomerization of acetylene cations

Ultrafast isomerization of acetylene cations ([HC=CH](+)) in the low-lying excited A(2)Σ(g)(+) state, populated by the absorption of extreme ultraviolet (XUV) photons (38 eV), has been observed at the Free Electron Laser in Hamburg, (FLASH). Recording coincident fragments C(+) + CH2(+) as a function of time between XUV-pump and -probe pulses, generated by a split-mirror device, we find an isomerization time of 52±15 fs in a kinetic energy release (KER) window of 5.8<KER<8 eV, providing clear evidence for the existence of a fast, nonradiative decay channel.

Few-photon multiple ionization of N2 by extreme ultraviolet free-electron laser radiation

Few-photon multiple ionization of N2 was studied differentially in a reaction microscope using 44 eV, approximately 25 fs, intense ( approximately 10(13) W/cm(2)) photon pulses from FLASH. Sequential ionization is observed to dominate. For various intermediate charge states N(2)(n+0 we find a considerable excess of photons absorbed compared to the minimum number that would energetically be required. Photoionization of aligned N(2)(n+) ions, produced by photon absorption in sequential steps, is explored and few-photon absorption pathways are traced by inspecting kinetic energy releases and fragment-ion angular distributions.

An inexact multi-objective dynamic model and its application in China for the management of municipal solid waste

With the development of science and technology, solid waste management has become a serious environmental problem for most communities all over the world. This paper presents a multi-objective optimization model for the management of municipal solid waste (MSW) via an uncertainty approach. In this model, the system cost of solid waste management and the environmental impact are considered as the main objectives, and some necessary constraints based on the characteristics of China are included; additionally, Pollution loss theory is applied to evaluate the environmental impact. This model is applied to the City of Fo Shan, China. Compared with the primary project of Fo Shan, which is provided by the government, the results of the optimization procedure show that the overall system cost could be reduced by $1-2.4/ton, i.e., $3.7 million/yr. The model presented in this paper was proven to be an effective response to the multi-objective solid waste management problem, and provides a new technique to optimize MSW management and operation. Why is the optimization result better? By analyzing the modelling with respect to function, constraints, and results, we conclude that the profit would be augmented due to the amount of the waste that would be treated by recycling technology, which would increase rapidly during the planning time; thus, the total system cost could be reduced accordingly.

Recoil-ion momentum distributions for two-photon double ionization of He and Ne by 44 eV free-electron laser radiation

Recoil-ion momentum distributions for two-photon double ionization of He and Ne (variant Planck's over omega=44 eV) have been recorded with a reaction microscope at FLASH (the free-electron laser at Hamburg) at an intensity of approximately 1 x 10(14) W/cm2 exploring the dynamics of the two fundamental two-photon-two-electron reaction pathways, namely, sequential and direct (or nonsequential) absorption of the photons. We find strong differences in the recoil-ion momentum patterns for the two mechanisms pointing to the significantly different two-electron emission dynamics and thus provide serious constraints for theoretical models.

Characterizing effects of uncertainties in MSW composting process through a coupled fuzzy vertex and factorial-analysis approach

A coupled fuzzy vertex and factorial-analysis approach was developed in this study for systematically characterizing effects of uncertainties in a municipal solid waste composting process. A comprehensive composting process model was also embedded into the system framework and used to address substrate decomposition and biomass growth, as well as the interactions between moisture contents, temperatures, and oxygen concentrations. The applicability of the proposed method was verified through a custom-made pilot-scale composting system. Results from fuzzy simulation indicated that the fuzzy vertex method could effectively communicate implicit knowledge into dynamic simulations and thus provide valuable information for enhancing composting process control under uncertainty. The factorial analysis was effective in quantifying the proportion to which the uncertainty of each single or interactive effect of model parameters contributes to the overall uncertainty of the system outcomes. Thus, sensitive parameters that may lead to errors or unreasonable predictions can be determined. The proposed study system could not only be used in characterizing combined effects of uncertainties for composting processes, but was also applicable to many other environmental modelling systems.

Few-photon multiple ionization of ne and ar by strong free-electron-laser pulses

Few-photon multiple ionization of Ne and Ar atoms by strong vacuum ultraviolet laser pulses from the free-electron laser at Hamburg was investigated differentially with the Heidelberg reaction microscope. The light-intensity dependence of Ne2+ production reveals the dominance of nonsequential two-photon double ionization at intensities of I<6x10(12) W/cm2 and significant contributions of three-photon ionization as I increases. Ne2+ recoil-ion-momentum distributions suggest that two electrons absorbing "instantaneously" two photons are ejected most likely into opposite hemispheres with similar energies.

Autism as a disorder of neural information processing: directions for research and targets for therapy

The broad variation in phenotypes and severities within autism spectrum disorders suggests the involvement of multiple predisposing factors, interacting in complex ways with normal developmental courses and gradients. Identification of these factors, and the common developmental path into which they feed, is hampered by the large degrees of convergence from causal factors to altered brain development, and divergence from abnormal brain development into altered cognition and behaviour. Genetic, neurochemical, neuroimaging, and behavioural findings on autism, as well as studies of normal development and of genetic syndromes that share symptoms with autism, offer hypotheses as to the nature of causal factors and their possible effects on the structure and dynamics of neural systems. Such alterations in neural properties may in turn perturb activity-dependent development, giving rise to a complex behavioural syndrome many steps removed from the root causes. Animal models based on genetic, neurochemical, neurophysiological, and behavioural manipulations offer the possibility of exploring these developmental processes in detail, as do human studies addressing endophenotypes beyond the diagnosis itself.

Numerical simulation of Ca2+ "sparks" in skeletal muscle

A three dimensional (3D) model of Ca(2+) diffusion and binding within a sarcomere of a myofibril, including Ca(2+) binding sites troponin, parvalbumin, sarcoplasmic reticulum Ca(2+) pump, and fluorescent Ca(2+)-indicator dye (fluo-3), was developed to numerically simulate laser scanning confocal microscope images of Ca(2+) "sparks" in skeletal muscle. Diffusion of free dye (D), calcium dye (CaD), and Ca(2+) were included in the model. The Ca(2+) release current was assumed to last 8 ms, to arise within 4 x 10(-5) microm(3) at the triad and to be constant during release. Line scan confocal fluorescence images of Ca(2+) sparks were simulated by 3D convolution of the calculated distribution of CaD with a Gaussian kernel approximating the point spread function of the microscope. Our results indicate that the amplitude of the simulated spark is proportional to the Ca(2+) release current if all other model parameters are constant. For a given release current, the kinetic properties and concentrations of the binding sites and the diffusion parameters of D, CaD, and Ca(2+) all have significant effects on the simulated Ca(2+) sparks. The simulated sparks exhibited similar amplitudes and temporal properties, but less spatial spread than experimentally observed sparks.

Endomorphin-1 mediates 2 Hz but not 100 Hz electroacupuncture analgesia in the rat

This work was designed to elucidate the possible involvement of endogenous endomorphin-I (EM1) in analgesia induced by electroacupuncture of low or high frequencies. Taking radiant heat tail flick latency (TFL) as an indication of nociception, rats were subjected to intrathecal (i.t.) injection of 10 microl antiserum against EM1 (EM1-AS) or normal rabbit serum (NRS, as control) and then followed by 2 or 100 Hz electroacupuncture stimulation for 30 min. The analgesia induced by 2 Hz electroacupuncture was attenuated by i.t. injection of EM1-AS at 1:10 and 1:100 but not at 1:1000 dilution. No such suppressive effect was observed for 100 Hz EA analgesia when EM1-AS was injected i.t. at any dilutions. These results indicate that EM1 is involved in 2 Hz but not 100 Hz electroacupuncture analgesia at spinal level.

Paternal deletion from Snrpn to Ube3a in the mouse causes hypotonia, growth retardation and partial lethality and provides evidence for a gene contributing to Prader-Willi syndrome

Prader-Willi syndrome (PWS) is caused by paternal deficiency of human chromosome 15q11-q13. There is conflicting evidence from human translocations regarding the direct involvement of SNRPN in the pathogenesis of PWS and it is not known if the phenotypic features result from the loss of expression of a single imprinted gene or multiple genes. In an attempt to dissect genotype/phenotype correlations for the homologous region of mouse chromosome 7C, we prepared three mutant genotypes: (i) mice with a deletion of Snrpn exon 2, which removes a portion of a small, upstream open reading frame (ORF); (ii) mice with double targeting for Snrpn exon 2 and Ube3a; (iii) mice deleted from Snrpn to Ube3a, removing coding exons for both loci and intervening genes. Mice deleted for Snrpn exon 2 have no obvious phenotypic abnormalities and switching of the genomic imprint for the region is conserved. Mice carrying the Snrpn - Ube3a deletion on the paternal chromosome showed severe growth retardation, hypotonia and approximately 80% lethality before weaning. The surviving mice were fertile and were not obese up to 14 months of age. The deletion was transmitted for multiple generations and continued to cause partial lethality when inherited paternally, but not when inherited maternally. The normal imprinted expression and methylation patterns of necdin, a gene outside the deletion region, indicate that the deletion is not an imprinting mutation. The data suggest the presence of a paternally expressed structural gene between Snrpn and Ipw whose deficiency causes lethality, although other possibilities exist, including position effects on expression of imprinted genes or that simultaneous deficiency of both ORFs of Snrpn causes lethality.

Carcinogen and dietary lipid regulate ras expression and localization in rat colon without affecting farnesylation kinetics

Epidemiological and experimental data suggest that dietary fiber and fat are major determinants of colorectal cancer. However, the mechanisms by which these dietary constituents alter the incidence of colon cancer have not been elucidated. Evidence indicates that dominant gain-of-function mutations short-circuit protooncogenes and contribute to the pathogenesis of cancer. Therefore, we began to dissect the mechanisms whereby dietary fat and fiber, fed during the initiation, promotion and progression stages of colon tumorigenesis, regulate ras p21 localization, expression and mutation frequency. Male Sprague-Dawley rats (140) were provided with corn oil or fish oil and pectin or cellulose plus or minus the carcinogen azoxymethane (AOM) in a 2 x 2 x 2 factorial design and killed after 34 weeks. We have previously shown adenocarcinoma incidence in these animals to be 70.3% (52/74) for corn oil + AOM and 56.1% (37/66) for fish oil + AOM (P < 0.05). Total ras expression as well as ras membrane:cytosol ratio was 4- to 6-fold higher in colon tumors than in mucosa from AOM- or saline-injected rats. Expression of ras in the mucosal membrane fraction was 13% higher for animals fed corn oil compared with fish oil feeding (P < 0.05), which is noteworthy since ras must be localized at the plasma membrane to function. The elevated ras membrane:cytosol ratio in tumors was not due to increased farnesyl protein transferase activity or prenylation state, as nearly all detectable ras was in the prenylated form. Phosphorylated p42 and p44 mitogen activated protein kinase (ERK) expression was two-fold higher in tumor extracts compared with uninvolved mucosa from AOM- and saline-injected rats (P < 0.05). The frequency of K-ras mutations was not significantly different between the various groups, but there was a trend toward a greater incidence of mutations in tumors from corn oil fed rats (85%) compared with fish oil fed rats (58%). Our results indicate that the carcinogen-induced changes in ras expression and membrane localization are associated with the in vivo activation of the ERK pathway. In addition, suppression of tumor development by dietary n-3 polyunsaturated fatty acids may be partly due to a combined effect on colonic ras expression, membrane localization, and mutation frequency.

Mutation of the Angelman ubiquitin ligase in mice causes increased cytoplasmic p53 and deficits of contextual learning and long-term potentiation

The E6-AP ubiquitin ligase (human/mouse gene UBE3A/Ube3a) promotes the degradation of p53 in association with papilloma E6 protein, and maternal deficiency causes human Angelman syndrome (AS). Ube3a is imprinted with silencing of the paternal allele in hippocampus and cerebellum in mice. We found that the phenotype of mice with maternal deficiency (m-/p+) for Ube3a resembles human AS with motor dysfunction, inducible seizures, and a context-dependent learning deficit. Long-term potentiation (LTP) was severely impaired in m-/p+ mice despite normal baseline synaptic transmission and neuroanatomy, indicating that ubiquitination may play a role in mammalian LTP and that LTP may be abnormal in AS. The cytoplasmic abundance of p53 was increased in postmitotic neurons in m-/p+ mice and in AS, providing a potential biochemical basis for the phenotype through failure to ubiquitinate and degrade various effectors.

Non-invasive detection of fecal protein kinase C betaII and zeta messenger RNA: putative biomarkers for colon cancer

We have developed a non-invasive method utilizing feces, containing sloughed colonocytes, as a sensitive technique for detecting diagnostic colonic biomarkers. In this study, we used the rat colon carcinogenesis model to determine if changes in fecal protein kinase C (PKC) expression have predictive value in monitoring the neoplastic process. Weanling rats were injected with saline or azoxymethane (AOM) and 36 weeks later fecal samples and mucosa were collected, poly A+ RNA isolated, and quantitative RT-PCR performed using primers to PKC betaII and zeta. Fecal PKC betaII and zeta mRNA levels were altered by the presence of a tumor, with tumor-bearing animals having a 3-fold higher (P < 0.05) PKC betaII expression as compared with animals without tumors. In addition, AOM-injection increased mucosal PKC betaII mRNA expression compared with saline controls. No effect of tumor incidence on mucosal PKC betaII expression was observed. In contrast, fecal PKC zeta expression was 2.5-fold lower (P < 0.05) in animals injected with azoxymethane versus saline. Since tumor incidence exerts a reciprocal effect on fecal PKC betaII and zeta mRNA expression, data were also expressed as the ratio between PKC betaII and zeta. The isozyme ratio was strongly related to tumor incidence, i.e. ratio for animals with tumors was 2.18 +/- 1.25, animals without tumors was 0.50 +/- 0.16, P = 0.025. We demonstrate that the expression of fecal PKC betaII and zeta may serve as a noninvasive marker for development of colon tumors. A sensitive technique for the detection of colon cancer is of importance since early diagnosis can substantially reduce mortality.

Modulation of intracellular second messengers by dietary fat during colonic tumor development

In conclusion, dietary n-3 polyunsaturated fatty acids found in fish oil are capable of suppressing carcinogen-induced ras activation in the colon prior to overt neoplasia. This in turn blocks the oncogene driven increase in colonic diacylglycerol mass, preventing the persistent activation and chronic down-regulation of PKC isozymes, thereby maintaining tissue PKC levels. Since the maintenance of crypt PKC levels may sustain the homeostatic balance between cell proliferation, differentiation and apoptosis, the ability of dietary n-3 polyunsaturated fatty acids to block the carcinogen-induced decrease in steady-state levels of colonic mucosal PKC may in part explain why these fatty acids protect against colon tumorigenesis. Additional studies are required in order to elucidate the mechanisms by which select dietary lipids reduce colonic tumor incidence. This research focus is absolutely essential, because if we do not know why a dietary component is protective or promotive of cancer, then we have no right to attempt to modify eating behaviors.

Dietary fat and fiber modulate the effect of carcinogen on colonic protein kinase C lambda expression in rats

To elucidate the mechanisms by which dietary factors influence the risk of colon cancer, we investigated the effect of select dietary fats and fibers on atypical protein kinase C (PKC) lambda expression. Azoxymethane- and saline (control)-injected rats were fed diets containing either corn oil or fish oil (15 g/100 g) and either cellulose or pectin (6 g/100 g) and killed at two time points (15 and 37 wk) in a 2 x 2 x 2 x 2 factorial design. Colonic PKC lambda protein and mRNA levels were determined using immunoblotting and relative competitive polymerase chain reaction, respectively. Azoxymethane suppressed cytosolic PKC lambda protein levels compared with the saline controls at both time points, and this suppression was partially blocked by fish oil feeding at 15 wk and pectin at 37 wk. Also, at 15 wk, azoxymethane-injected rats fed corn oil had higher levels of membrane PKC lambda relative to the other treatment groups. Overall, expression of PKC lambda mRNA was not correlated with differences in the respective isozyme protein levels. Therefore, the chemopreventive effects of dietary fish oil and pectin are associated with the blockage of azoxymethane-induced alterations in colonic PKC lambda protein expression.

The E6-Ap ubiquitin-protein ligase (UBE3A) gene is localized within a narrowed Angelman syndrome critical region

Angelman syndrome (AS) and Prader-Willi syndrome (PWS) are distinct clinical phenotypes resulting from maternal and paternal deficiencies, respectively, in human chromosome 15qll-q13. Although several imprinted, paternally expressed transcripts have been identified within the PWS candidate region, no maternally expressed gene has yet been identified within the AS candidate region. We have developed an integrated physical map spanning the PWS and AS candidate regions and localized two breakpoints, including a cryptic t(14;15) translocation associated with AS and a non-AS 15q deletion, which substantially narrow the AS candidate region to approximately 250 kb. Mapping data indicate that the entire transcriptional unit of the E6-AP ubiquitin-protein ligase (UBE3A) gene lies within the AS region. The UBE3A locus expresses a transcript of approximately 5 kb at low to moderate levels in all tissues tested. The mouse homolog of UBE3A was cloned and sequenced revealing a high degree of conservation at nucleotide and protein levels. Northern and RT-PCR analysis of Ube3a expression in mouse tissues from animals with segmental, paternal uniparental disomy failed to detect substantially reduced or absent expression compared to control animals, failing to provide any evidence for maternal-specific expression from this locus. Recent identification of de novo truncating mutations in UBE3A taken with these observations indicates that mutations in UBE3A can lead to AS and suggests that this locus may encode both imprinted and biallelically expressed products.

Dietary fish oil blocks carcinogen-induced down-regulation of colonic protein kinase C isozymes

In order to elucidate the influence of dietary constituents on colonic intracellular signal transduction, the effect of different fats on rat colonic epithelial protein kinase C (PKC) alpha (classical), delta (novel) and lambda-zeta (atypical) expression was determined in carcinogen-treated animals. Sprague-Dawley rats were provided with one of two fats (corn oil and fish oil); plus or minus the carcinogen azoxymethane (AOM) and killed at two time points (15 and 37 weeks) in a 2x2x2 factorial design. At 5 and 6 weeks of age, animals were injected s.c. with either AOM at a dose of 15 mg/kg body weight or saline once a week for 2 weeks and continued on the same diet until termination of the study. At 15 and 37 weeks after the second injection, 10 rats from each treatment group were killed. Colonic PKC alpha, delta and lambda-zeta steady-state protein and mRNA levels were determined using immunoblotting and relative quantitative polymerase chain reaction, respectively. Colonic mucosa from rats injected with AOM had significantly suppressed membrane and cytosolic PKC alpha and cytosolic lambda-zeta protein levels (P < 0.05) as compared to saline-injected control animals at both time points. In contrast, rats fed fish oil diets had significantly higher (P < 0.05) cytosolic PKC delta and lambda-zeta protein levels relative to animals fed corn oil diets. However, the effect of diet and AOM on the steady-state expression of PKC alpha, delta and zeta mRNA was not consistent with changes in the respective isozyme protein levels, suggesting regulation at the post-transcriptional level. These data demonstrate that dietary fish oil blocks the carcinogen-induced decrease in the steady-state levels of colonic mucosal PKC delta and lambda-zeta, which may in part explain why this fat source protects against colon cancer development.

Butyrate alters activity of specific cAMP-receptor proteins in a transgenic mouse colonic cell line

There is great interest in utilizing butyrate as a chemotherapeutic agent. To elucidate its mechanism of action, the effect of butyrate on cAMP receptor protein kinase (PKA) activity in young adult mouse colon (YAMC) cells isolated from transgenic mice bearing a temperature sensitive mutation of the SV40 large T antigen gene was investigated. Conditionally immortalized cultures were plated at the permissive temperature (33 degrees C) or growth arrested by incubation at the nonpermissive temperature (39 degrees C). In addition, cells were incubated at 33 degrees C with or without 1 mmol/L butyrate for 24 h. Butyrate treatment reduced cell proliferation by 28% and enhanced apoptosis by 350% compared with cultures not exposed to butyrate. The PKA type I/II isozyme activity ratio was lower (P < 0.05) in cells incubated with butyrate. The relative level of PKA I isozyme was higher in proliferating cells at 33 degrees C (63% of total PKA), while the relative level of PKA II was higher in nonproliferating cells undergoing apoptosis at 39 degrees C (59% of total PKA). Neither incubation conditions (33 vs. 39 degrees C) nor butyrate treatment altered total PKA activity. When YAMC cells were incubated with 8-CI-cAMP, an activator of PKA II, growth was markedly inhibited in cells at both temperatures. Consistent with in vitro data, increased PKA I isozyme levels were associated with dysregulated growth in vivo. Specifically, the relative level of PKA I isozyme was three- to fivefold higher in rat colonic tumors compared with normal nontransformed colonic mucosa. These data indicate that the biological effects of butyrate on colonocyte proliferation and apoptosis are associated with changes in PKA isozyme-dependent signal transduction, and the YAMC cell line is a relevant model to examine the molecular mechanisms by which dietary-derived factors affect relative cancer risk.

De novo truncating mutations in E6-AP ubiquitin-protein ligase gene (UBE3A) in Angelman syndrome

Angelman syndrome (AS) is associated with maternal deletions of human chromosome 15q11-q13 and with paternal uniparental disomy for this region indicating that deficiency of an imprinted, maternally expressed gene within the critical interval is the likely cause of the syndrome. Although the gene for E6-AP ubiquitin-protein ligase (UBE3A) was mapped to the critical region for AS, evidence of expression from both parental alleles initially suggested that it was an unlikely candidate gene for this disorder. Because attempts to identify any novel maternally expressed transcripts were unsuccessful and because the UBE3A gene remained within a narrowed AS critical region, we searched for mutations in UBE3A in 11 AS patients without known molecular defects (large deletion, uniparental disomy, or imprinting mutation). This analysis tested the possibility that deficiency of an undefined, maternally expressed transcript or isoform of the UBE3A gene could cause AS. Four mutations were identified including a de novo frameshift mutation and a de novo nonsense mutation in exon 3 and two missense mutations of less certain significance. The de novo truncating mutations indicate that UBE3A is the AS gene and suggest the possibility of a maternally expressed gene product in addition to the biallelically expressed transcript. Intragenic mutation of UBE3A in AS is the first example of a genetic disorder of the ubiquitin-dependent proteolytic pathway in mammals. It may represent an example of a human genetic disorder associated with a locus producing functionally distinct imprinted and biallelically expressed gene products.

Dietary (n-3) polyunsaturated fatty acids suppress murine lymphoproliferation, interleukin-2 secretion, and the formation of diacylglycerol and ceramide

Elucidation of the mechanism(s) by which dietary fish oil, enriched in eicosapentaenoic acid (EPA, 20:5(n-3)] and docosahexaenoic acid [DHA, 22:6(n-3)], suppresses the inflammatory process is essential in maximizing this potentially therapeutic effect. Murine T-lymphocyte function and signal transduction were examined in response to a low fat, short term diet enriched in highly purified EPA or DHA ethyl esters. For 10 d, mice were fed comparable diets containing either 3% safflower oil ethyl esters (SAF), 2% SAF + 1% arachidonic acid triglyceride (AA), 2% SAF + 1% EPA, or 2% SAF + 1% DHA. Concanavalin A-induced T-lymphocyte proliferation in splenocyte cultures was significantly suppressed by dietary EPA and DHA while AA had no effect relative to the SAF control. The suppressed proliferative response in EPA- and DHA-fed mice was preceded temporally by a significant reduction in IL-2 secretion. Kinetics of mitogen-induced diacyl-sn-glycerol (DAG) and ceramide production did not differ significantly between SAF and AA diet groups. In contrast, DAG production was significantly suppressed in EP- and DHA-fed mice relative to the SAF and AA groups. The reduced DAG mass was paralleled by reduced ceramide mass following EPA and DHA feeding compared to the SAF and AA groups. Thus, low dose, short term dietary exposure to highly purified EPA or DHA appears to suppress mitogen-induced T-lymphocyte proliferation by inhibiting IL-2 secretion, and these events are accompanied by reductions in the production of essential lipid second messengers, DAG and ceramide.

Dietary fat and fiber differentially alter intracellular second messengers during tumor development in rat colon

The effect of fat, fiber and carcinogen on colonic epithelial intracellular second messengers 1,2-diacyl-sn-glycerol (DAG), ceramide, and the steady-state level of phospholipase C (PLC-gamma1) was determined in 160 male Sprague-Dawley rats (10 rats per group). The study was a 2 x 2 x 2 x 2 factorial design with two types of fat (corn oil or fish oil), two types of fiber (cellulose or pectin), two injected subgroups (with or without azoxymethane (AOM), and two time points (15 and 37 weeks). At the final time point (37 weeks) there were an additional 20 rats per diet in each of the carcinogen-treated groups for tumor analyses only (n = 80), for a total of 240 animals in the entire study. At each time point (15 and 37 weeks), 80 rats were killed and colonic mucosa obtained for DAG, ceramide and PLC-gamma1 assays. At the first time point (15 weeks), there was no microscopic evidence of tumors. At the final time point (37 weeks), fish oil resulted in a lower proportion of animals with adenocarcinomas relative to corn oil feeding (56.1 % versus 69.6 %, P < 0.05). There was no significant main effect of fiber on the percentage of animals with tumors. At 15 weeks post-injection, AOM injected animals fed corn oil-containing diets had a significantly (P < 0.001) higher DAG mass and steady-state levels of PLC-gamma1 compared with AOM-injected animals fed fish oil and saline injected rats on all diets. Animals fed corn oil diets also had a significantly (P < 0.01) elevated mucosal ceramide mass compared with fish oil fed animals. Moreover, rats injected with AOM had a significantly (P < 0.02) elevated colonic mucosal DAG/ceramide ratio versus saline injected animals. In contrast, dietary fiber had no effect on any of the parameters measured at 15 weeks. However, at 37 weeks post-injection, dietary fiber significantly altered DAG (P < 0.02), and PLC-gamma1 expression (P < 0.05) in the absence of an effect on tumor incidence. These data demonstrate that the ability of dietary fish oil to reduce experimental colon carcinogenesis may be mediated by changes in colonic intracellular mediators during the initial stages of tumorigenesis.