Spin independence of the strongly enhanced effective mass in ultra-clean SiGe/Si/SiGe two-dimensional electron system

The effective mass at the Fermi level is measured in the strongly interacting two-dimensional (2D) electron system in ultra-clean SiGe/Si/SiGe quantum wells in the low-temperature limit in tilted magnetic fields. At low electron densities, the effective mass is found to be strongly enhanced and independent of the degree of spin polarization, which indicates that the mass enhancement is not related to the electrons' spins. The observed effect turns out to be universal for silicon-based 2D electron systems, regardless of random potential, and cannot be explained by existing theories.

Plasma EBV DNA in Nasopharyngeal Cancer (NPC) Treated with Definitive Radiotherapy (RT)

PURPOSE/OBJECTIVE(S)

EBV DNA has well-studied roles in NPC including early detection and surveillance. There are limited North American data on EBV DNA testing. Our center has used EBV DNA testing since 2010. We hypothesized: (1) higher first post-RT EBV DNA level is associated with worse prognosis, and (2) surveillance EBV DNA is specific for recurrence at a low detection threshold.

MATERIALS/METHODS

We retrospectively reviewed all patients with non-metastatic (TNM-7 stage I-IVB) NPC treated with definitive RT/chemoRT (CRT) ± adjuvant chemotherapy (AC) between 2010-2017. EBV DNA was assayed by quantitative PCR in a CAP/CLIA-certified laboratory and reported in copies/mL of plasma. Pre-RT is defined as 0-90 days before the first RT fraction and post-RT within one year after RT. We report log odds ratios (LOR) from a linear model of T- and N-category with log-adjusted EBV DNA as the response variable. Survival outcomes were analyzed with log-rank tests and Cox multivariate analyses (MVA) adjusted for age, stage, and treatment, reporting hazard ratios (HR). A total of 95% confidence intervals of LOR and HR are reported. The detection threshold that maximized the F1 accuracy score was considered optimal.

RESULTS

Of 271 patients in the study window, 179 had pre-RT +/- post-RT EBV DNA testing. Six received RT, 43 CRT, and 130 CRT+AC. With 7-yr median follow-up, 37 recurred and 37 died. Detectable pre-RT EBV DNA was found in 154 (86%) with a median of 928 copies/mL (range: 1-239214). EBV DNA level correlated with higher N category (LOR: 0.28, 0.15-0.42, p<0.001), but not T category (0.04, -0.06-0.13, p = 0.5). Above-median pre-RT EBV DNA was associated with worse recurrence-free survival (RFS) by log-rank test (p = 0.016) and Cox MVA (HR: 2.2, 1.1-4.8, p = 0.03) along with N category, age, and no AC. Post-RT EBV DNA was available in 99 patients at a median of 54 days. RFS, progression-free survival (PFS), and overall survival (OS) were worse in patients with detectable post-RT EBV DNA (Table). RFS and PFS drop further to 20% if EBV DNA was detectable after the full treatment (RT±AC, n = 71). In Cox MVA, post-RT EBV DNA remained independently prognostic (Table). EBV DNA was performed within 30 days of recurrence in 30 patients, and 24 were detectable (80% sensitivity). Conversely, of 152 patients without recurrence and at least 3-yr follow-up, 95 had post-RT EBV DNA testing and 84 were undetectable (88% specificity). An EBV DNA threshold of 31 copies maximized F1 accuracy metric, yielding 74% sensitivity and 97% specificity.

CONCLUSION

Pre-RT EBV DNA is prognostic and associated with higher N-category. Post-RT EBV DNA is a strong, independent predictor of RFS, PFS, and OS; 31 copies/mL may be a useful threshold to detect recurrence.

Dawn of Staging for Head and Neck Soft Tissue Sarcoma: Validation of the Novel 8th Edition AJCC T Classification and Proposed Stage Groupings

PURPOSE/OBJECTIVE(S)

After decades of stagnation, the 8th edition TNM (TNM8) introduced a new T classification for head and neck (HN) soft tissue sarcomas (STS). New size cutoffs of 2 and 4 cm define T1-3, and a novel T4 category is defined by local invasion of adjoining structures. These size cutoffs had been chosen arbitrarily to advance data collection in this unique disease site since literature showed approximately 70% of HN STS did not reach the previous size threshold (5 cm) for the existing T1 category. The definition of the TNM8 T categories also align with mucosal HN cancers. No stage grouping for HN STS was defined since this new classification required more data collection to derive stage groups. This study aims to validate the TNM8 T classification and to propose stage groupings.

MATERIALS/METHODS

Clinical data of all adult (>16 years) HN STS patients treated from 1988 - 2019 with curative intent in our tertiary cancer center were retrieved from a prospective database, and supplemented with chart review. As per TNM8, cutaneous angiosarcoma, embryonal and alveolar rhabdomyosarcoma, Kaposi sarcoma, and dermatofibrosarcoma protuberans were excluded due to their different behavior. Multivariate analysis (MVA) identified prognostic factors for overall survival (OS). Adjusted hazard ratios (AHR) and recursive partitioning analysis (RPA) were used to derive stage groupings. Stage grouping performance for OS was assessed and also compared against the existing TNM8 groups for non-HN STS.

RESULTS

A total of 221 patients (N1: 2; M1: 2) were included. Of the 219 M0 patients, 63% were males; median tumor size was 3.0 cm (range: 0.3-14.0); the proportion of TNM8 T1-T4 were 35%, 34%, 26%, and 5%, respectively. Median follow up was 5.9 years. Five-year OS was 79%. MVA confirmed the prognostic value of T category (T4 HR 7.73, 95% CI 3.62-16.5) and grade (G2/3 vs G1 HR 3.7, 95% CI 1.82-7.53), in addition to age (HR 1.03, 95% CI 1.01-1.04) (all p<0.001) for OS. AHR model derived T1-3_Grade 1 as stage 1; T1-3_Grade 2/3 as stage II; and T4_any Grade or any T_N1 as stage III (Table 1); the corresponding 5-year OS was 93%, 73%, and 38%, respectively. Both patients with M1 died within 1.5 years after diagnosis and M1 disease was designated stage IV. The AHR-grouping outperformed the RPA and non-HN TNM8 stage grouping for hazard consistency, hazard discrimination, percent variance explained, hazard difference, and sample size balance.

CONCLUSION

The novel T4 category introduced in TNM8 is associated with a >7 fold increased risk of death. Grade continues to be a critical prognostic factor in HN STS. The TNM8 HN STS T classifications have been validated, and the proposed new stage groupings with TNM8 incorporating grade have excellent performance for OS.

Outcomes after Contemporary Definitive Radiotherapy Alone in Patients with TNM-7 Stage III/IV Head and Neck Squamous Cell Carcinoma

PURPOSE/OBJECTIVE(S)

This study was undertaken to determine outcomes and prognostic factors of definitive intensity-modulated radiotherapy (IMRT) alone for patients with TNM-7 stage III/IV HNSCC who did not receive concurrent chemotherapy.

MATERIALS/METHODS

We evaluated TNM-7 stage III/IV HNSCC patients treated with definitive IMRT alone in our institution from 2004-2019. Patients were reclassified according to TNM-8 staging. Stage II HPV+ oropharyngeal cancers (OPC) were subdivided into T1-2N2 and T3N0-2 for analysis. The rationale for chemotherapy omission was obtained retrospectively from clinical documentation. Recurrence-free survival (RFS) and overall survival (OS) were estimated stratified by HPV status (determined by p16 staining, sometimes supplemented by HPV DNA testing). Multivariable analysis (MVA) identified prognostic factors for RFS and OS, taking into account stage and IMRT regimen. Age, performance status, and smoking were also examined for OS.

RESULTS

A total of 1083 patients were included (460 HPV+ and 623 HPV-). Reasons for omission of chemotherapy were: age >70 years or frailty (n = 551, 51%), cisplatin contraindication (n = 241, 22%), patient refusal (n = 106, 10%), and clinician's decision (n = 185, 17%). Median age was 67 years for HPV+ and 70 years for HPV- cohorts. IMRT mostly utilized altered fractionation regimens (n = 1016, 94%): moderately accelerated (Acc) (70 Gy/35 fractions [f]/6 weeks [w], 55%), hypofractionated (Hypo) (60 Gy/25f/5w, 14%), and hyperfractionated-accelerated (Hyper) (64 Gy/40f/4w, 25%). Median follow-up was 5 years. Five-year RFS and OS for HPV+ TNM-8 stage I/T1-2N2/T3N0-N2/III were 89%/86%/76%/52% and 83%/80%/64%/33% respectively (p<0.01). The same outcomes for HPV- TNM-8 stage III/IVA/IVB were 58%/52%/39% and 47%/27%/13%, respectively (p<0.01). MVA confirmed that HPV+ T3N0-2 subset within stage II and stage III (vs stage I) had lower RFS, and HPV- stage IVA and IVB (vs stage III) carried worse RFS and OS (Table).

CONCLUSION

Despite the retrospective nature and inherent selection bias, this large single institutional study shows that altered fractionated IMRT alone is an acceptable alternative for elderly, frail or cisplatin ineligible patients with HPV+ stage I/IIA (T1-2N2) OPC. Patients with HPV+ T3N0-2/stage III OPC and HPV- stage III/IV HNSCC have poor outcomes with IMRT alone and may benefit from alternative strategies.

The Prognostic and Predictive Value of Pre-Treatment Total Lymphocyte Count in HPV+ Oropharyngeal Carcinoma Receiving Definitive (Chemo-) Radiation

PURPOSE/OBJECTIVE(S)

Evidence of prognostic importance of pre-radiotherapy (RT) total lymphocyte counts (TLC) and interaction with addition of cisplatin (CRT) in HPV-positive oropharyngeal carcinoma (HPV+OPC) is conflicting. Recent data suggest patients with high TLC may not benefit from the addition of chemotherapy (Price et al, JCO 2022). We assess the prognostic and predictive value of TLC in a large single center HPV+OCP cohort.

MATERIALS/METHODS

All HPV+OPC patients treated at a single academic center with definitive RT/CRT between 2005-2018 were included. Pre-treatment TLC up to 6 weeks prior to RT start were considered. Multivariable analysis (MVA) was applied to assess the prognostic importance of TLC (continuous variable), adjusted for age, gender, performance status, TNM-8 stage, and smoking status in the CRT and RT subgroups. The actuarial rates of locoregional control (LRC), distant control (DC), and overall survival (OS) were calculated using Kaplan-Meier and competing risk methods, stratified by low vs high TLC (determined using Contal and O'Quigley method for optimal cutoff).

RESULTS

Among 1153 eligible patients, 707 (61%) were treated with CRT. Median age was 59.7 (range 22.7-92.2) years. 526 patients were (46%) TNM-8 stage I, 366 (32%) stage II and 261 (23%) stage III. Median TLC was 1.6 x 109/L (range 0.1-8.5). Median follow-up was 5.5 years. On MVA, TLC was prognostic for patients receiving CRT (OS [adjusted hazard ration (aHR) 0.55 (0.38-0.79), p = 0.002], DC [aHR 0.57 (0.37-0.88), p = 0.011], LRC [aHR 0.57 (0.36-0.89), p = 0.014]) but not RT (OS [aHR 1.04 (0.82-1.31), p = 0.74], LRC [aHR 1.26 (0.86-1.85), p = 0.23], DC [aHR 0.87 (0.64-1.19), p = 0.4)]. The optimal TLC cut-off for OS with CRT was 1.9 x 109/L. Low vs high TLC patients receiving CRT had significantly inferior 5-year DC (87% vs 93%, p = 0.017) and OS (84% vs 90%, p = 0.026). The benefit of higher TLC was most evident in stage II disease (table 1). CRT vs RT improved OS for stage II/III disease at high and low TLC.

CONCLUSION

Pre-treatment TLC is prognostic in a large cohort of HPV+OPC patients receiving CRT but not RT alone. Further investigation of the interaction of cisplatin and immune response during RT is warranted. The omission of chemotherapy based on TLC is not supported.

Outcomes of Head and Neck Cutaneous Angiosarcoma Treated in the IMRT Era

PURPOSE/OBJECTIVE(S)

Clinical behavior, natural history, and varied presentations of cutaneous angiosarcomas of the head and neck region (HN), in conjunction with its rarity, have rendered standardization of treatment elusive. We aimed to assess outcomes and patterns of failure for patients treated with surgery and radiation (Sx+RT), and radiation alone (RT).

MATERIALS/METHODS

A retrospective review of all HN angiosarcoma patients amenable for upfront Sx or RT in our institution between 2004-2018 was completed. Generally, treatment included Sx when feasible, and RT for large or extensive/ill-defined tumors. Demographic, tumor characteristics, local (LC), regional (RC), distant control (DC), and overall survival (OS), as well as patterns (in-field, marginal, out-of-field) of local failure at 5-year were estimated. Univariate analysis (UVA) was conducted to assess association with outcomes.

RESULTS

A total of 33 patients were eligible (14 Sx+RT and 19 RT). Tumor locations were: scalp (16, 48%). face (n = 12, 36%), and overlapping (5, 15%). Lesion types were: nodular (n = 23, 70%), flat (n = 4, 12%) and mixed (n = 6, 18%). Tumor size was larger in the RT group (median: 10.00 vs 2.85 cm, p<0.01). RT and Sx+RT patients had otherwise similar baseline characteristics: median age 74.3; male 70%; and ECOG performance status ≤1 85%. RT dose fractionations ranged from 50-70 Gy in 25-35 fractions in the RT group and 50-66 Gy in 25-33 fractions in the Sx+RT group. Four (12%) patients received neoadjuvant chemotherapy. Median follow up was 5.5 years. Five-year LC, RC, DC, and OS for RT vs Sx+RT groups were 68% vs 85% (p = 0.28); 95% vs 86% (p = 0.89); 79% vs 86% (p = 0.39); and 45% vs 55% (p = 0.71), respectively. The in-field/marginal/out-of-field local failure rate at 5 years were 16% vs 7% (p = 0.46), 26% vs 15% (p = 0.41), and 13% vs 0% (p = 0.24) for the RT vs Sx+RT groups, respectively. UVA showed that scalp location and ulceration/bleeding were strong adverse features for OS. Bone invasion was significantly associated with lower DC (Table). Lesion type (nodular/flat/mixed), tumor size, and treatment type (Sx+RT vs RT), were not significantly associated with LC or pattern of local failure.

CONCLUSION

Scalp tumors, as compared to face, portended poorer prognosis, and ulceration/bleeding and bone invasion were associated with increased distant metastases. Sx+RT was the preferred treatment modality when possible and typically used for smaller and better defined tumors. RT was reserved for larger and extensive/ill-defined disease; despite this, in the IMRT era, RT achieves reasonable rates of control, markedly superior to historical series.

[Anatomical classification of and laparoscopic surgery for left-sided colorectal cancer with persistent descending mesocolon]

Objective: To investigate anatomical morphology and classification of persistent descending mesocolon (PDM) in patients with left-sided colorectal cancer, as well as the safety of laparoscopic radical surgery for these patients. Methods: This is a descriptive study of case series. Relevant clinical data of 995 patients with left colon and rectal cancer who had undergone radical surgery in Fujian Medical University Union Hospital from July 2021 to September 2022 were extracted from the colorectal surgery database of our institution and retrospectively analyzed. Twenty-four (2.4%) were identified as PDM and their imaging data and intra-operative videos were reviewed. We determined the distribution and morphology of the descending colon and mesocolon, and evaluated the feasibility and complications of laparoscopic surgery. We classified PDM according to its anatomical characteristics as follows: Type 0: PDM combined with malrotation of the midgut or persistent ascending mesocolon; Type 1: unfixed mesocolon at the junction between transverse and descending colon; Type 2: PDM with descending colon shifted medially (Type 2A) or to the right side (Type 2B) of the abdominal aorta at the level of the origin of the inferior mesentery artery (IMA); and Type 3: the mesocolon of the descending-sigmoid junction unfixed and the descending colon shifted medially and caudally to the origin of IMA. Results: The diagnosis of PDM was determined based on preoperative imaging findings in 9 of the 24 patients (37.5%) with left-sided colorectal cancer, while the remaining diagnoses were made during intraoperative assessment. Among 24 patients, 22 were male and 2 were female. The mean age was (63±9) years. We classified PDM as follows: Type 0 accounted for 4.2% (1/24); Type 1 for 8.3% (2/24); Types 2A and 2B for 37.5% (9/24) and 25.0% (6/24), respectively; and Type 3 accounted for 25.0% (6/24). All patients with PDM had adhesions of the mesocolon that required adhesiolysis. Additionally, 20 (83.3%) of them had adhesions between the mesentery of the ileum and colon. Twelve patients (50.0%) required mobilization of the splenic flexure. The inferior mesenteric artery branches had a common trunk in 14 patients (58.3%). Twenty-four patients underwent D3 surgery without conversion to laparotomy; the origin of the IMA being preserved in 22 (91.7%) of them. Proximal colon ischemia occurred intraoperatively in two patients (8.3%) who had undergone high ligation at the origin of the IMA. One of these patients had a juxta-anal low rectal cancer and underwent intersphincteric abdominoperineal resection because of poor preoperative anal function. Laparoscopic subtotal colectomy was considered necessary for the other patient. The duration of surgery was (260±100) minutes and the median estimated blood loss was 50 (20-200) mL. The median number of No. 253 lymph nodes harvested was 3 (0-20), and one patient (4.2%) had No.253 nodal metastases. The median postoperative hospital stay was 8 (4-23) days, and the incidence of complications 16.7% (4/24). There were no instances of postoperative colon ischemia or necrosis observed. One patient (4.2%) with stage IIA rectal cancer developed Grade B (Clavien-Dindo III) anastomotic leak and underwent elective ileostomy. The other complications were Grade I-II. Conclusions: PDM is frequently associated with mesenteric adhesions. Our proposed classification can assist surgeons in identifying the descending colon and mesocolon during adhesion lysis in laparoscopic surgery. It is crucial to protect the colorectal blood supply at the resection margin to minimize the need for unplanned extended colectomy, the Hartmann procedure, or permanent stomas.

[Anatomical and histological investigation of the area anterior to the anorectum passing through the levator hiatus]

Objective: To document the anatomical structure of the area anterior to the anorectum passing through the levator hiatus between the levator ani slings bilaterally. Methods: Three male hemipelvises were examined at the Laboratory of Clinical Applied Anatomy, Fujian Medical University. (1) The anatomical assessment was performed in three ways; namely, by abdominal followed by perineal dissection, by examining serial cross-sections, and by examining median sagittal sections. (2) The series was stained with hematoxylin and eosin to enable identification of nerves, vessels, and smooth and striated muscles. Results: (1) It was found that the rectourethralis muscle is closest to the deep transverse perineal muscle where the longitudinal muscle of the rectum extends into the posteroinferior area of the membranous urethra. The communicating branches of the neurovascular bundle (NVB) were identified at the posterior edge of the rectourethralis muscle on both sides. The rectum was found to be fixed to the membranous urethra through the rectourethral muscle, contributing to the anorectal angle of the anterior rectal wall. (2) Serial cross-sections from the anal to the oral side were examined. At the level of the external anal sphincter, the longitudinal muscle of the rectum was found to extend caudally and divide into two muscle bundles on the oral side of the external anal sphincter. One of these muscle bundles angled dorsally and caudally, forming the conjoined longitudinal muscle, which was found to insert into the intersphincteric space (between the internal and external anal sphincters). The other muscle bundle angled ventrally and caudally, filling the gap between the external anal sphincter and the bulbocavernosus muscle, forming the perineal body. At the level of the superficial transverse perineal muscle, this small muscle bundle headed laterally and intertwined with the longitudinal muscle in the region of the perineal body. At the level of the rectourethralis and deep transverse perineal muscle, the external urethral sphincter was found to occupy an almost completely circular space along the membranous part of the urethra. The dorsal part of the external urethral sphincter was found to be thin at the point of attachment of the rectourethralis muscle, the ventral part of the longitudinal muscle of the rectum. We identified a venous plexus from the NVB located close to the oral and ventral side of the deep transverse perineal muscle. Many vascular branches from the NVB were found to be penetrating the longitudinal muscle and the ventral part of rectourethralis muscle at the level of the apex of the prostate. The rectourethral muscle was wrapped ventrally around the membranous urethra and apex of the prostate. The boundary between the longitudinal muscle and prostate gradually became more distinct, being located at the anterior end of the transabdominal dissection plane. (3) Histological examination showed that the dorsal part of the external urethral sphincter (striated muscle) is thin adjacent to the striated muscle fibers from the deep transverse perineal muscle and the NVB dorsally and close by. The rectourethral muscle was found to fill the space created by the internal anal sphincter, deep transverse perineal muscle, and both levator ani muscles. Many tortuous vessels and tiny nerve fibers from the NVB were identified penetrating the muscle fibers of the deep transverse perineal and rectourethral muscles. The structure of the superficial transverse perineal muscle was typical of striated muscle. These findings were reconstructed three-dimensionally. Conclusions: In intersphincteric resection or abdominoperineal resection for very low rectal cancer, the anterior dissection plane behind Denonvilliers' fascia disappears at the level of the apex of the prostate. The prostate and both NVBs should be used as landmarks during transanal dissection of the non-surgical plane. The rectourethralis muscle should be divided near the rectum side unless tumor involvement is suspected. The superficial and deep transverse perineal muscles, as well as their supplied vessels and nerve fibers from the NVB. In addition, the cutting direction should be adjusted according to the anorectal angle to minimize urethral injury.

[The value of MR diffusion tensor imaging in assessing white matter changes in short-term methamphetamine withdrawal]

Objective: To explore the value of MRI diffusion tensor imaging (DTI) in the white matter changes of short-term methamphetamine (MA) abstinence. Methods: The data of DTI, demographics features, general information of addiction and impulsivity scale eleven (BIS-11) of 55 short-term MA addicts who were from Changsha, Zhuzhou and Yueyang compulsory detoxification centers in Hunan province, including 40 males and 15 females, aged 14-45 (37.24±7.31) years old, and 52 healthy controls, including 40 males and 12 females aged 18-59 (40.3±9.1) years were collected prospectively from August 2017 to December 2018. The differences of DTI indicators between the two groups were compared by tract-based spatial statistics (TBSS), and then the correlation between the different indicators and the age of first MA use, time of MA use, daily dose used, BIS-11 score were performed. Results: There were significant differences in BIS total score(P<0.001), BIS motivational impulsivity(P<0.001) and BIS attentional impulsivity(P=0.003) between MA group and healthy control group in short-term withdrawal. And compared with the healthy control group, the fractional anisotropy (FA) (0.58±0.02 vs 0.56±0.02,0.77±0.02 vs 0.75±0.04,0.79±0.04 vs 0.76±0.06; all P<0.05), axial diffusivity (AD) (0.57±0.01 vs 0.56±0.02,P=0.001) and mean diffusivity (MD) (0.66±0.02 vs 0.65±0.02,0.52±0.07 vs 0.51±0.06; both P<0.05)values in the MA group were all increased (P<0.05), but there was no significant difference in the radial diffusivity (RD) value (P>0.05). The white matter areas with increased FA value were located in the knee and body of corpus callosum, bilateral anterior corona radiata and left superior corona radiata; the areas with increased AD value were located in the knee, body and pressure of corpus callosum, bilateral anterior limb of internal capsule, posterior limb of internal capsule, anterior, superior and posterior corona radiata, external capsule and superior longitudinal fasciculus; and the areas with increased MD value were mainly located in the right superior longitudinal fasciculus, anterior and posterior limb of internal capsule. The corpus callosum, where there was a difference in FA between the two groups, was positively correlated with the daily dose of MA (r=0.301, P=0.026). Conclusion: MA addicted individuals with short-term withdrawal have white matter edema and damage, and the degree of corpus callosum damage is positively correlated with the daily dose of MA,which is helpful to understand the pathophysiological process of white matter damage in the nervous system and the potential mechanism of neuropsychiatric symptoms in short-term withdrawal MA addicted individuals.

[Delayed gastric emptying after surgery for transverse colon cancer: diagnosis, management and prevention]

Delayed gastric emptying is a syndrome of gastric motility disorder with slow gastric emptying as the main sign, provided that mechanical factors such as intestinal obstruction and anastomotic stricture are excluded. The incidence of delayed gastric emptying after colon cancer surgery is 1.4%, mainly after transverse colon cancer surgery. Most of the studies on delayed gastric emptying are case reports, lacking systematic studies. The diagnoses and treatments can be draw on the experience of delayed gastric emptying after pancreatic surgery. Our retrospective study indicated that the incidence of delayed gastric emptying after surgery for transverse colon cancer was 4.0%, higher than that for other colon cancer. Patients who underwent gastrocolic ligament lymph node dissection were at higher risk than those who did not (3.6% vs. 0.8%). Gastrocolic ligament lymph node dissection and stress are causative factors for delayed gastric emptying after surgery for transverse colon cancer. We add the gastrografin test upon the diagnostic criteria of the International Study Group for Pancreatic Surgery, which is simple and practical. Nasogastric tube decompression, enteral nutrition combined with parenteral nutrition, glucocorticoids, and prokinetic agents can cure most patients with postoperative delayed gastric emptying. All the patients with postoperative delayed gastric emptying were cured in our studies. Strict indications for gastrocolic ligament lymph node dissection (patients with cT3-4 and cN+) may decrease the occurrence of delayed gastric emptying after surgery for transverse colon cancer.

Vacuum-Assisted Interfacial Polymerization Technique for Enhanced Pervaporation Separation Performance of Thin-Film Composite Membranes

In this work, thin-film composite polyamide membranes were fabricated using triethylenetetramine (TETA) and trimesoyl chloride (TMC) following the vacuum-assisted interfacial polymerization (VAIP) method for the pervaporation (PV) dehydration of aqueous isopropanol (IPA) solution. The physical and chemical properties as well as separation performance of the TFCVAIP membranes were compared with the membrane prepared using the traditional interfacial polymerization (TIP) technique (TFCTIP). Characterization results showed that the TFCVAIP membrane had a higher crosslinking degree, higher surface roughness, and denser structure than the TFCTIP membrane. As a result, the TFCVAIP membrane exhibited a higher separation performance in 70 wt.% aqueous IPA solution at 25 °C with permeation flux of 1504 ± 169 g∙m-2∙h-1, water concentration in permeate of 99.26 ± 0.53 wt%, and separation factor of 314 (five times higher than TFCTIP). Moreover, the optimization of IP parameters, such as variation of TETA and TMC concentrations as well as polymerization time for the TFCVAIP membrane, was carried out. The optimum condition in fabricating the TFCVAIP membrane was 0.05 wt.% TETA, 0.1 wt% TMC, and 60 s polymerization time.

[Prevalence and influencing factors of Enterobius vermicularis infections among children in Fanxian County of Henan Province in 2019]

OBJECTIVE

To investigate the prevalence and influencing factors of Enterobius vermicularis infections among children in Fanxian County, Henan Province in 2019, so as to provide insights into the management of enterobiasis.

METHODS

Five kindergartens were selected in urban and rural areas of Fanxian County, Henan Province using the stratified sampling method in 2019, and a census of E. vermicularis infections was performed among all children in the kindergartens. E. vermicularis eggs were detected using adhesive and scotch cellophane-tape anal swab methods, and the basic characteristics of children and their families, health habits and the kindergartens' information were investigated with questionnaires. Logistic regression analysis was used to investigate the risk factors and protective factors of pinworm infection in children.

RESULTS

A total of 671 children were tested, and the mean prevalence of E. vermicularis infections was 15.50% (104/671). The prevalence of E. vermicularis infections was higher among children in rural kindergartens (28.13%, 72/256) than in urban kindergartens (7.71%, 32/415) (χ² = 50.380, P < 0.01), and greater in private kindergartens (32.26%, 60/186) than in public kindergartens (9.07%, 44/485) (χ² = 55.183, P < 0.01). There was no gender-specific prevalence of E. vermicularis infections among children (χ² = 1.442, P > 0.05), and the prevalence of E. vermicularis infections presented a tendency towards a rise with age (χ²_trend = 8.373, P < 0.05) and school grade (χ²_trend = 30.274, P < 0.05). Logistic regression analysis identified rural kindergartens and high grades as risk factors, and separate washing of children's and adults' cloths, frequent bathing and frequent dinnerware disinfection in kindergartens as protective factors for E. vermicularis infections among children. In addition, there was no significant difference in the detection of E. vermicularis infections among children by using adhesive (73.08%, 76/104) and scotch cellophane-tape anal swab methods (56.73%, 59/104) (χ² = 3.959, P > 0.05).

CONCLUSIONS

The prevalence of E. vermicularis infection is high among children in Fanxian Country, Henan Province. Health education and surveillance of enterobiasis are required to be intensified among children in rural kindergartens and senior grades and their parents and teachers.

The Potential Impact and Usability of the Eighth Edition TNM Staging Classification in Oral Cavity Cancer

AIMS

In the current eighth edition head and neck TNM staging, extranodal extension (ENE) is an adverse feature in oral cavity squamous cell cancer (OSCC). The previous seventh edition N1 with ENE is now staged as N2a. Seventh edition N2+ with ENE is staged as N3b in the eighth edition. We evaluated its potential impact on patients treated with surgery and postoperative intensity-modulated radiotherapy (IMRT).

MATERIALS AND METHODS

OSCC patients treated with primary surgery and adjuvant (chemo)radiotherapy between January 2005 and December 2014 were reviewed. Cohorts with pathological node-negative (pN-), pathological node-positive without ENE (pN+_pENE-) and pathological node-positive with ENE (pN+_pENE+) diseases were compared for local control, regional control, distant control and overall survival. The pN+ cohorts were further stratified into seventh edition N-staging subgroups for outcomes comparison.

RESULTS

In total, 478 patients were evaluated: 173 pN-; 159 pN+_pENE-; 146 pN+_pENE+. Outcomes at 5 years were: local control was identical (78%) in all cohorts (P = 0.892), whereas regional control was 91%, 80% and 68%, respectively (P < 0.001). Distant control was 97%, 87%, 68% (P < 0.001) and overall survival was 75%, 53% and 39% (P < 0.001), respectively. Overall survival for N1 and N2a subgroups was not significantly different. In the seventh edition N2b subgroup of pENE- (n = 79) and pENE+ (n = 79) cohorts, overall survival was 67% and 37%, respectively. In the seventh edition N2c subgroups, overall survival for pENE- (n = 17) and pENE+ (n = 38) cohorts was 65% and 35% (P = 0.08), respectively. Overall, an additional 128 patients (42% pN+) were upstaged as N3b.

CONCLUSIONS

When eighth edition staging was applied, stage migration across the N2-3 categories resulted in expected larger separations of overall survival by stage. Patients treated with primary radiation without surgical staging should have outcomes carefully monitored. Strategies to predict ENE preoperatively and trials to improve the outcomes of pENE+ patients should be explored.

Ergosta-7,9(11),22-trien-3β-ol Alleviates Intracerebral Hemorrhage-Induced Brain Injury and BV-2 Microglial Activation

Intracerebral hemorrhage (ICH) is a devastating neurological disorder characterized by an exacerbation of neuroinflammation and neuronal injury, for which few effective therapies are available at present. Inhibition of excessive neuroglial activation has been reported to alleviate ICH-related brain injuries. In the present study, the anti-ICH activity and microglial mechanism of ergosta-7,9(11),22-trien-3β-ol (EK100), a bioactive ingredient from Asian medicinal herb Antrodia camphorate, were evaluated. Post-treatment of EK100 significantly attenuated neurobehavioral deficit and MRI-related brain lesion in the mice model of collagenase-induced ICH. Additionally, EK100 alleviated the inducible expression of cyclooxygenase (COX)-2 and the activity of matrix metalloproteinase (MMP)-9 in the ipsilateral brain regions. Consistently, it was shown that EK100 concentration-dependently inhibited the expression of COX-2 protein in Toll-like receptor (TLR)-4 activator lipopolysaccharide (LPS)-activated microglial BV-2 and primary microglial cells. Furthermore, the production of microglial prostaglandin E₂ and reactive oxygen species were attenuated by EK100. EK100 also attenuated the induction of astrocytic MMP-9 activation. Among several signaling pathways, EK100 significantly and concentration-dependently inhibited activation of c-Jun N-terminal kinase (JNK) MAPK in LPS-activated microglial BV-2 cells. Consistently, ipsilateral JNK activation was markedly inhibited by post-ICH-treated EK100 in vivo. In conclusion, EK100 exerted the inhibitory actions on microglial JNK activation, and attenuated brain COX-2 expression, MMP-9 activation, and brain injuries in the mice ICH model. Thus, EK100 may be proposed and employed as a potential therapeutic agent for ICH.

[Construction of artificial neural network model for predicting the efficacy of first-line FOLFOX chemotherapy for metastatic colorectal cancer]

Objective: To explore and establish an artificial neural network (ANN) model for predicting the efficacy of first-line FOLFOX chemotherapy for metastatic colorectal cancer. Methods: A set of FOLFOX chemotherapy data from a group of patients with metastatic colorectal cancer (mCRC) (GSE104645) was downloaded from the GEO database as a training set. According to the FOLFOX protocol, the efficacy was divided into two groups: the chemo-sensitive group (including complete response and partial response) and the chemo-resistant group (including stable disease and progressive disease), including 31 cases in the sensitive group and 23 in the resistant group. Then, chip data (accessible number: GSE69657) from Fujian Medical University Union Hospital were chosen as a test set. A total of 30 patients were enrolled in the study, including 13 in the sensitive group and 17 in the resistant group. The batch effect correction was performed on the expression values of the two sets of matrices using the R 3.5.1 software Combat package. The gene expression difference of sensitive and resistant group in GSE104645 was analyzed by the GEO2R platform. P<0.05 and the absolute value of log(2)FC>0.33 (FC abbreviation of fold change) were used as the threshold value to screen the drug resistance and sensitive genes of the FOLFOX regimen. An ANN was constructed using the multi-layer perceptron (MLP) to perform the FOLFOX regimen on the GSE104645 dataset. The GSE69657 expression matrix and clinical efficacy parameters were then used for retrospective verification. Receiver operating characteristic(ROC) curves were used to evaluate the test results and predictive power. Results: A total of 2, 076 differentially expressed genes in GSE104645 were selected, of which 822 genes were up-regulated and 1, 254 genes were down-regulated in the chemo-resistance group. The down-regulated genes were sensitive genes. GO analysis of the biological processes in which the differentially expressed genes were involved, revealed that they were mainly involved in the regulation of substance metabolism. A total of 39 genes were included in the final model construction. This was a neural network model with two hidden layers. The accuracy of predicting training samples and test samples was 75.7% and 76.5%, respectively, and the area under the ROC curve was 0.875. The chip data set of our department (GSE69657) was set as the test set, and the area under the ROC curve was 0.778. Conclusions: In this study, an artificial neural network model is successfully constructed to predict the efficacy of first-line FOLFOX regimen for metastatic colorectal cancer based on the microarray, and an independent external verification is also conducted. The model has good stability and well prediction efficiency. Besides, the results of this study suggest that the gene functions related to oxaliplatin resistance are mainly enriched in the regulation process of substance metabolism.

Optimal Performance of Thin-Film Composite Nanofiltration-Like Forward Osmosis Membranes Set Off by Changing the Chemical Structure of Diamine Reacted with Trimesoyl Chloride through Interfacial Polymerization

Thin-film composite (TFC) polyamide membranes formed through interfacial polymerization can function more efficiently by tuning the chemical structure of participating monomers. Accordingly, three kinds of diamine monomers were considered to take part in interfacial polymerization. Each diamine was reacted with trimesoyl chloride (TMC) to manufacture TFC polyamide nanofiltration (NF)-like forward osmosis (FO) membranes. The diamines differed in chemical structure; the functional group present between the terminal amines was classified as follows: aliphatic group of 1,3-diaminopropane (DAPE); cyclohexane in 1,3-cyclohexanediamine (CHDA); and aromatic or benzene ring in m-phenylenediamine (MPD). For FO tests, deionized water and 1 M aqueous sodium sulfate solution were used as feed and draw solution, respectively. Interfacial polymerization conditions were also varied: concentrations of water and oil phases, time of contact between the water-phase solution and the membrane substrate, and polymerization reaction time. The resultant membranes were characterized using attenuated total reflectance-Fourier transform infrared spectroscopy, field emission scanning electron microscopy, atomic force microscopy, and surface contact angle measurement to identify the chemical structure, morphology, roughness, and hydrophilicity of the polyamide layer, respectively. The results of FO experiments revealed that among the three diamine monomers, CHDA turned out to be the most effective, as it led to the production of TFC NF-like FO membrane with optimal performance. Then, the following optimum conditions were established for the CHDA-based membrane: contact between 2.5 wt.% aqueous CHDA solution and polysulfone (PSf) substrate for 2 min, and polymerization reaction between 1 wt.% TMC solution and 2.5 wt.% CHDA solution for 30 s. The composite CHDA-TMC/PSf membrane delivered a water flux (Jw) of 18.24 ± 1.33 LMH and a reverse salt flux (Js) of 5.75 ± 1.12 gMH; therefore, Js/Jw was evaluated to be 0.32 ± 0.07 (g/L).

Modifying Cellulose Acetate Mixed-Matrix Membranes for Improved Oil-Water Separation: Comparison between Sodium and Organo-Montmorillonite as Particle Additives

In this study, cellulose acetate (CA) mixed-matrix membranes were fabricated through the wet-phase inversion method. Two types of montmorillonite (MMT) nanoclay were embedded separately: sodium montmorillonite (Na-MMT) and organo-montmorillonite (O-MMT). Na-MMT was converted to O-MMT through ion exchange reaction using cationic surfactant (dialkyldimethyl ammonium chloride, DDAC). Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS) compared the chemical structure and composition of the membranes. Embedding either Na-MMT and O-MMT did not change the crystallinity of the CA membrane, indicating that the nanoclays were dispersed in the CA matrix. Furthermore, nanoclays improved the membrane hydrophilicity. Compared with CA_Na-MMT membrane, CA_O-MMT membrane had a higher separation efficiency and antifouling property. At the optimum concentration of O-MMT in the CA matrix, the pure water flux reaches up to 524.63 ± 48.96 L∙m^-2∙h^-1∙bar^-1 with over 95% rejection for different oil-in-water emulsion (diesel, hexane, dodecane, and food-oil). Furthermore, the modified membrane delivered an excellent antifouling property.

Surface Properties, Free Volume, and Performance for Thin-Film Composite Pervaporation Membranes Fabricated through Interfacial Polymerization Involving Different Organic Solvents

The type of organic solvents used in interfacial polymerization affects the surface property, free volume, and separation performance of the thin-film composite (TFC) polyamide membrane. In this study, TFC polyamide membrane was fabricated through interfacial polymerization between diethylenetriamine (DETA) and trimesoyl chloride (TMC). Four types of organic solvent were explored in the preparation of pervaporation membrane. These are tetralin, toluene, hexane, and isopentane. The solubility parameter distance between organic solvents and DETA follows in increasing order: tetralin (17.07 MPa1/2) < toluene (17.31 MPa1/2) < hexane (19.86 MPa1/2) < isopentane (20.43 MPa1/2). Same trend was also observed between the organic solvents and DETA. The larger the solubility parameter distance, the denser and thicker the polyamide. Consequently, field emission scanning electron microscope (FESEM) and positron annihilation spectroscopy (PAS) analysis revealed that TFCisopentane had the thickest polyamide layer. It also delivered the highest pervaporation efficiency (permeation flux = 860 ± 71 g m-2 h-1; water concentration in permeate = 99.2 ± 0.8 wt%; pervaporation separation index = 959,760) at dehydration of 90 wt% aqueous ethanol solution. Furthermore, TFCisopentane also exhibited a high separation efficiency in isopropanol and tert-butanol. Therefore, a suitable organic solvent in preparation of TFC membrane through interfacial polymerization enables high pervaporation efficiency.

Assessing the Performance of Thin-Film Nanofiltration Membranes with Embedded Montmorillonites

In this study, the basal spacing of montmorillonite (MMT) was modified through ion exchange. Two kinds of MMT were used: sodium-modified MMT (Na-MMT) and organo-modified MMT (O-MMT). These two particles were incorporated separately into the thin-film nanocomposite polyamide membrane through the interfacial polymerization of piperazine and trimesoyl chloride in n-hexane. The membrane with O-MMT (TFNO-MMT) has a more hydrophilic surface compared to that of membrane with Na-MMT (TFNNa-MMT). When various types of MMT were dispersed in the n-hexane solution with trimesoyl chloride (TMC), O-MMT was well-dispersed than Na-MMT. The poor dispersion of Na-MMT in n-hexane led to the aggregation of Na-MMT on the surface of TFNNa-MMT. TFNO-MMT displayed a uniform distribution of O-MMT on the surface, because O-MMT was well-dispersed in n-hexane. In comparison with the pristine and TFNNa-MMT membranes, TFNO-MMT delivered the highest pure water flux of 53.15 ± 3.30 L∙m-2∙h-1 at 6 bar, while its salt rejection for divalent ions remained at 95%-99%. Furthermore, it had stable performance in wide operating condition, and it exhibited a magnificent antifouling property. Therefore, a suitable type of MMT could lead to high separation efficiency.

[Rectum-preserving surgery after consolidation neoadjuvant therapy or totally neoadjuvant therapy for low rectal cancer: a preliminary report]

Objective: To investigate the feasibility and safety of sphincter-preserving surgery after neoadjuvant chemoradiotherapy (nCRT) with consolidation chemotherapy in the interval period or total neoadjuvant therapy (TNT) for low rectal cancer. Methods: A descriptive case series study was carried out. Clinical data of patients with locally advanced low rectal cancer (LALRC) who achieved complete clinical response (cCR) or nearly cCR (near-cCR) after nCRT at the Department of Colorectal Surgery of Fujian Medical University Union Hospital from May 2015 to February 2019 were retrospectively analyzed. Case inclusion criteria: (1) Low rectal adenocarcinoma within 6 cm from the anal verge. (2) After nCRT, tumor presented markedly regression as mucosal nodule or abnormalities, superficial ulcer, scar or a mucosal erythema (< 2 cm); no regional lymph node metastasis or distant metastasis was found in rectal ultrasonography, pelvic MRI and PET-CT; MRI showed obvious fibrosis in the original tumor site; and post-treatment CEA was normal. (3) The patient and the family members adhered to receive the transanal full-thickness local excision with informed consent. (4) When the residual lesions were difficult to detect after nCRT, patients received the watch and wait (W&W) strategy. Exclusion criteria: (1) Before nCRT, pathological results showed poorly differentiated or signet-ring cell carcinoma; lateral lymph node metastasis was suspected. (2) When the residual lesion size was more than 3 cm after nCRT, it was difficult to perform local excision. The consolidation nCRT group received 3-4 cycles of CAPOX regimen (oxaliplatin and capecitabine) or six cycles of mFOLFOX6 (oxaliplatin, leucovorin, and 5-fluorouracil) combined with the long-course radiotherapy (intensity-modulated radiation therapy with a total dose of 50.4Gy). Patients with concurrent chemotherapy more than or equal to five cycles of CAPOX or eight cycles of mFOLFOX6 were defined as total neoadjuvant therapy (TNT) group. Local resection was recommended for patients who were near-cCR according to modified MSKCC criteria 8-33 weeks after the end of radiotherapy. Patients with a near-cCR, who were judged as ycN0 according to PET-CT and MRI and were ypT0 after local excision, could enter the W&W strategy. Patients with pathologic stage more advanced than ypT1, and those with positive resection margin, or lymphovascular invasion were recommended for salvage radical surgery after local excision. The ypT1 patients with a negative resection margin and without lymphovascular invasion might receive the W&W management carefully if they refused radicalsurgery to sacrifice the sphincter for low rectal cancer. Results: Of 32 patients, 14 were males and 18 were females with the average age of 59 years old. Twenty-three patients underwent consolidation nCRT, and 9 received TNT. The first evaluation after treatments showed 19 cases with cCR and 13 with near-cCR. Twenty-nine patients received local excision while 3 patients with undetectable lesions received W&W policy. Four cases (12.5%) underwent salvage radical surgery with abdominoperineal resection. After local excision, 3 cases underwent salvage radical surgery immediately, and the final pathologic result was ypT3N0, ypT2N0, and ypT2N0 respectively, of whom 2 cases were in the group of consolidation CRT and 1 was in the TNT group. Of these 3 cases, 1 case with an initial cT3 stage showed a pathologic stage of ypT1 and a negative circumferential resection margin after consolidation nCRT and local excision, however, the final pathologic stage was ypT3 with fragmented tumor deposits in the mesorectum after the salvage radical surgery. Meanwhile 1 patient in the TNT group receiving W&W suffered from intraluminal regrowth after 7.4 months follow-up and underwent salvage abdominoperineal resection. One patient in the consolidation nCRT group died of stroke 42.5 months after local resection. Another patient in the TNT group had cerebral metastasis 10 months after the W&W policy, but no local recurrence was found in the pelvic cavity, then received resection of the metastatic tumors. The average follow-up for all the patients was 23 (5-51) months. The cumulative local regrowth rate was 5.0%. The overall survival rate was 85.7%, and the sphincter-preservation rate was increased from 25.0% (28/32) in the original plan to 87.5% (28/32) actually. The 3-year disease-free survival rate was 89.7%. The 3-year organ-preserving survival rate was 85.7%, and the 3-year stoma-free survival rate was 82.5%. At present, 31 patients still survived. Conclusions: After nCRT with consolidation chemotherapy or TNT for low rectal cancer, patients with cCR, ycN0 according to PET-CT and MRI, and ypT0 after local excision, can consider the W&W strategy. Strict patient selection with a near-cCR for local resection and sphincter-preserving strategy can reduce the local regrowth of cancer, and the short-term outcomes are satisfactory.

Zwitterion Co-Polymer PEI-SBMA Nanofiltration Membrane Modified by Fast Second Interfacial Polymerization

Nanofiltration membranes have evolved as a promising solution to tackle the clean water scarcity and wastewater treatment processes with their low energy requirement and environment friendly operating conditions. Thin film composite nanofiltration membranes with high permeability, and excellent antifouling and antibacterial properties are important component for wastewater treatment and clean drinking water production units. In the scope of this study, thin film composite nanofiltration membranes were fabricated using polyacrylonitrile (PAN) support and fast second interfacial polymerization modification methods by grafting polyethylene amine and zwitterionic sulfobutane methacrylate moieties. Chemical and physical alteration in structure of the membranes were characterized using methods like ATR-FTIR spectroscopy, XPS analysis, FESEM and AFM imaging. The effects of second interfacial polymerization to incorporate polyamide layer and ‘ion pair’ characteristics, in terms of water contact angle and surface charge analysis was investigated in correlation with nanofiltration performance. Furthermore, the membrane characteristics in terms of antifouling properties were evaluated using model protein foulants like bovine serum albumin and lysozyme. Antibacterial properties of the modified membranes were investigated using E. coli as model biofoulant. Overall, the effect of second interfacial polymerization without affecting the selectivity layer of nanofiltration membrane for their potential large-scale application was investigated in detail.

Development and validation of a clinical prediction-score model for distant metastases in major salivary gland carcinoma

BACKGROUND

The most common pattern of failure in major salivary gland carcinoma (SGC) is development of distant metastases (DMs). The objective of this study was to develop and validate a prediction score for DM in SGC.

PATIENTS AND METHODS

Patients with SGC treated curatively at four tertiary cancer centers were divided into discovery (n = 619) and validation cohorts (n = 416). Multivariable analysis using competing risk regression was used to identify predictors of DM in the discovery cohort and create a prediction score of DM; the optimal score cut-off was determined using a minimal P value approach. The prediction score was subsequently evaluated in the validation cohort. The cumulative incidence and Kaplan-Meier methods were used to analyze DM and overall survival (OS), respectively.

RESULTS

In the discovery cohort, DM predictors (risk coefficient) were: positive margin (0.6), pT3-4 (0.7), pN+ (0.7), lymphovascular invasion (0.8), and high-risk histology (1.2). High DM-risk SGC was defined by sum of coefficients greater than two. In the discovery cohort, the 5-year incidence of DM for high- versus low-risk SGC was 50% versus 8% (P < 0.01); this was similar in the validation cohort (44% versus 4%; P < 0.01). In the pooled cohorts, this model performed similarly in predicting distant-only failure (40% versus 6%, P < 0.01) and late (>2 years post surgery) DM (22% versus 4%; P < 0.01). Patients with high-risk SGC had an increased incidence of DM in the subgroup receiving postoperative radiation therapy (46% versus 8%; P < 0.01). The 5-year OS for high- versus low-risk SGC was 48% versus 92% (P < 0.01).

CONCLUSION

This validated prediction-score model may be used to identify SGC patients at increased risk for DM and select those who may benefit from prospective evaluation of treatment intensification and/or surveillance strategies.

[Identification of gene biomarkers to predict responses to neoadjuvant chemoradiotherapy in patients with rectal cancer and pathways enrichment analysis]

Objective: To screen out the potential gene biomarkers to predict responses to neoadjuvant chemoradiotherapy (CRT) in patients with rectal cancer and to explore the main downstream pathways of resistance. Methods: The gene expression profiles (GSE35452) of locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy from 46 specimens (24 responders, TRG 0/1, and 22 non-responders, TRG 2/3) were downloaded from the GEO database. The differentially expressed genes were identified to screen out the potential biomarkers by use of the GCBI platform. GO and KEGG pathways enrichment analysis were performed to integrate enrichment results of differentially expressed genes. Signal-signal interaction network was constructed and analyzed to screen out potential main downstream pathways. Results: A total of 1079 differentially expressed genes were screened, including 657 up-regulated and 422 down-regulated ones. Among these genes, REG4 had the maximum fold change value of -6.029 491. In GO term, these differentially expressed genes were mainly enriched in molecule metabolic process, cell cycle, DNA-dependent transcription, signal transduction and apoptotic process. The KEGG pathways enrichment analysis showed that the differentially expressed genes were enriched in 65 KEGG pathways, including metabolic pathways, cell cycle and metabolism pathways. Signal-signal interaction network analysis showed that MAPK signaling pathway and cell cycle pathway might play a determinant role in the development of neoadjuvant chemoradiotherapy resistance. Further analysis showed that CDKN1B, CDKN2A, RBL1, TFDP1, CCND2, CCNE2, CDC6 and CDK6 in cell cycle might induce chemoradiotherapy resistance by blocking G1/S phase cell cycle arrest, decreasing the apoptosis of tumor cells and increasing S phase ratio of chemoradiotherapy resistance. Conclusion: G1/S phase cell cycle arrest blocking plays an important role in the development of chemoradiotherapy resistance in patients with rectal cancer. Moreover, the key genes, such as REG4, may be useful in predicting responses to neoadjuvant chemoradiotherapy.

[Effects of artesunate combined with bortezomib on apoptosis and autophagy of acute myeloid leukemia cells in vitro and its mechanism]

Objective: To investigate the effects of artesunate combined with bortezomib on the proliferation, apoptosis and autophagy of human acute myeloid leukemia cell lines MV4-11, and its mechanisms. Methods: MTT method was used to determine the anti-proliferation effect of different concentrations of artesunate, bortezomib and their combination on MV4-11 cells. The cell apoptosis were analyzed by flow cytometry. The expression of cleaved-Caspase-3, Bcl-2 family protein (Bcl-2, Mcl-1, Bim, Bax) and autophagy-related protein LC3B were assayed by Western blot. Results: Artesunate displayed a proliferation inhibition effect on MV4-11 with dose- and time-dependent manner, the IC(50) of artesunate on MV4-11 after 48 hours was 1.44 μg/ml. Bortezomib displayed a proliferation inhibition effect on MV4-11 with dose-dependent manner, the IC(50) of bortezomib on MV4-11 after 48 hours was 8.97 nmol/L. The combination of artesunate (0.75, 1.0 μg/ml) and Bortezomib (6, 8 nmol/L) showed higher inhibition on MV4-11 than artesunate or bortezomib alone in the same concentration gradient after 48 hours (P<0.05) . The cooperation index of the two drugs were all less than 1. The 48 h apoptotic rate of artesunate (1.5 μg/ml) on MV4-11 was (15.27±2.18) %, (19.85±3.23) % of bortezomib (8 nmol/L) , (81.67±5.96) % of combination of the two drugs, significantly higher than the single group (P<0.05) . When combination of the two drugs on MV4-11 after 24 hours, the levels of pro-apoptotic protein Bim and the cleaved activation of Caspase-3 and autophagy-related protein LC3B were up-regulated and the anti-apoptotic protein Bcl-2 expressions was down-regulated. Conclusion: Combination of artesunate with bortezomib shows a significant synergistic effects on proliferation, apoptosis and autophagy of MV4-11 cell lines, which may be associated with Bcl-2 family proteins expression.