[Correlation between pelvic relapses of rectal cancer after radical and R0 resection: A regression model-based analysis]

Objective: To propose a new staging system for presacral recurrence of rectal cancer and explore the factors influencing radical resection of such recurrences based on this staging system. Methods: In this retrospective observational study, clinical data of 51 patients with presacral recurrence of rectal cancer who had undergone surgical treatment in the Department of Gastrointestinal Surgery, Peking University People's Hospital between January 2008 and September 2022 were collected. Inclusion criteria were as follows: (1) primary rectal cancer without distant metastasis that had been radically resected; (2) pre-sacral recurrence of rectal cancer confirmed by multi-disciplinary team assessment based on CT, MRI, positron emission tomography, physical examination, surgical exploration, and pathological examination of biopsy tissue in some cases; and (3) complete inpatient, outpatient and follow-up data. The patients were allocated to radical resection and non-radical resection groups according to postoperative pathological findings. The study included: (1) classification of pre-sacral recurrence of rectal cancer according to its anatomical characteristics as follows: Type I: no involvement of the sacrum; Type II: involvement of the low sacrum, but no other sites; Type III: involvement of the high sacrum, but no other sites; and Type IV: involvement of the sacrum and other sites. (2) Assessment of postoperative presacral recurrence, overall survival from surgery to recurrence, and duration of disease-free survival. (3) Analysis of factors affecting radical resection of pre-sacral recurrence of rectal cancer. Non-normally distributed measures are expressed as median (range). The Mann-Whitney U test was used for comparison between groups. Results: The median follow-up was 25 (2-96) months with a 100% follow-up rate. The rate of metachronic distant metastasis was significantly lower in the radical resection than in the non-radical resection group (24.1% [7/29] vs. 54.5% [12/22], χ²=8.333, P=0.026). Postoperative disease-free survival was longer in the radical resection group (32.7 months [3.0-63.0] vs. 16.1 [1.0-41.0], Z=8.907, P=0.005). Overall survival was longer in the radical resection group (39.2 [3.0-66.0] months vs. 28.1 [1.0-52.0] months, Z=1.042, P=0.354). According to univariate analysis, age, sex, distance between the tumor and anal verge, primary tumor pT stage, and primary tumor grading were not associated with achieving R0 resection of presacral recurrences of rectal cancer (all P>0.05), whereas primary tumor pN stage, anatomic staging of presacral recurrence, and procedure for managing presacral recurrence were associated with rate of R0 resection (all P<0.05). According to multifactorial analysis, the pathological stage of the primary tumor pN1-2 (OR=3.506, 95% CI: 1.089-11.291, P=0.035), type of procedure (transabdominal resection: OR=29.250, 95% CI: 2.789 - 306.811, P=0.005; combined abdominal perineal resection: OR=26.000, 95% CI: 2.219-304.702, P=0.009), and anatomical stage of presacral recurrence (Type III: OR=16.000, 95% CI: 1.542 - 166.305, P = 0.020; type IV: OR= 36.667, 95% CI: 3.261 - 412.258, P = 0.004) were all independent risk factors for achieving radical resection of anterior sacral recurrence after rectal cancer surgery. Conclusion: Stage of presacral recurrences of rectal cancer is an independent predictor of achieving R0 resection. It is possible to predict whether radical resection can be achieved on the basis of the patient's medical history.

[Cross-sectional study of low anterior resection syndrome in patients who have survived more than 5 years after sphincter-preserving surgery for rectal cancer]

Objective: In this study, we aimed to investigate the prevalence of low anterior resection syndrome (LARS) in patients who had survived for more than 5 years after sphincter-preserving surgery for rectal cancer and to analyze its relationship with postoperative time. Methods: This was a single-center, retrospective, cross-sectional study. The study cohort comprised patients who had survived for at least 5 years (60 months) after undergoing sphincter- preserving radical resection of pathologically diagnosed rectal adenocarcinoma within 15 cm of the anal verge in the Department of Gastrointestinal Surgery, Peking University People's Hospital from January 2005 to May 2016. Patients who had undergone local resection, had permanent stomas, recurrent intestinal infection, local recurrence, history of previous anorectal surgery, or long- term preoperative defecation disorders were excluded. A LARS questionnaire was administered by telephone interview, points being allocated for incontinence for flatus (0-7 points), incontinence for liquid stools (0-3 points), frequency of bowel movements (0-5 points), clustering of stools (0-11 points), and urgency (0-16 points). The patients were allocated to three groups based on these scores: no LARS (0-20 points), minor LARS (21-29 points), and major LARS (30-42 points). The prevalence of LARS and major LARS in patients who had survived more than 5 years after surgery, correlation between postoperative time and LARS score, and whether postoperative time was a risk factor for major LARS and LARS symptoms were analyzed. Results: The median follow-up time of the 160 patients who completed the telephone interview was 97 (60-193) months; 81 (50.6%) of them had LARS, comprising 34 (21.3%) with minor LARS and 47 (29.4%) with major LARS. Spearman correlation analysis showed no significant correlation between LARS score and postoperative time (correlation coefficient α=-0.016, P=0.832). Multivariate analysis identified anastomotic height (RR=0.850, P=0.022) and radiotherapy (RR=5.760, P<0.001) as independent risk factors for major LARS; whereas the postoperative time was not a significant risk factor (RR=1.003, P=0.598). The postoperative time was also not associated with LARS score rank and frequency of bowel movements, clustering, or urgency (P>0.05). However, the rates of incontinence for flatus (3/31, P=0.003) and incontinence for liquid stools (8/31, P=0.005) were lower in patients who had survived more than 10 years after surgery. Conclusions: Patients with rectal cancer who have survived more than 5 years after sphincter-preserving surgery still have a high prevalence of LARS. We found no evidence of major LARS symptoms resolving over time.

[Anastomotic vessels between superior mesenteric artery and inferior mesenteric artery: controversies and advances]

The anastomotic vessels between the superior mesenteric artery and the inferior mesenteric artery are vital to maintain the blood supply of the anastomosis and residual colon after colectomy. However, current studies of anastomotic vessels are facing four major obstacles: confusing nomenclature, large variability in data, diversification of research methods and incomplete information records. The existence of marginal artery has been widely proved, and its significance for blood supply is well recognized by relevant studies. In contrast, the Riolan's arch, whose connotations constantly changed over history, can not refer to a specific structure accurately. Researchers should abolish the controversial names such as Riolan's arch, select appropriate research methods and record the anastomotic vessels in detail, so as to improve the comparability between different results. The study of anastomotic vessels can help us to identify potential vascular disease, select the appropriate surgical approach, and provide appropriate treatment of the vessels in the operating area, so as to provide a theoretical foundation and practical basis for fine surgical maneuvers.

[Influence of different sphincter-preserving surgeries on postoperative defecation function]

Advances in surgical techniques and treatment concept have allowed more patients with low rectal cancer to preserve sphincter without sacrificing survival benefit. However, postoperative dysfunctions such as fecal incontinence, frequency, urgency, and clustering often occur in patients with low rectal cancer. The main surgical procedures for low rectal cancer include low anterior rectum resection (LAR), intersphincteric resection (ISR), coloanal anastomosis (Parks) and so on. The incidence of major LARS after LAR is up to 84.6%. The postoperative function of ISR is even worse than LAR. Moreover, the greater the extent of resection ISR surgery, the worse the postoperative function. There are few studies on the function of Parks procedure. Current evidence suggests that the short-term function of Parks procedure is inferior to LAR, but function can gradually recovered over time. Colorectal surgeons have attempted to improve postoperative defecation by modifying bowel reconstructions. Current evidence suggests that J pouch or end-to-side anastomosis during LAR does not reduce the incidence of defecation disorders. Pouch reconstruction during ISR cannot reduce the incidence of severe LARS either. In general, the protection of postoperative defecation function in patients with low rectal cancer still has a long way to go.

[Research progress of colorectal surgery in 2021 and future prospects]

In recent years, with the wide application of immune score and liquid biopsy to guide the accurate diagnosis and precise treatment of colorectal cancer, colorectal surgery develops more rationally and scientifically. The strategy of organ function protection in colorectal surgery gradually attracts more and more attention. The continuous development of comprehensive treatments, such as targeted therapy and immunotherapy, provides more choices for colorectal cancer patients. Several significant progress in surgical strategies for benign colorectal diseases challenges the traditional concepts as well. The advances in medical science and the innovation of concepts and ideas set high new standards for the development of colorectal surgery in China. Efforts are required to improve the standardization of diagnosis and treatment of colorectal disease. There is still a long way to go to explore patient-centered new technologies, new concepts and new fields of accurate diagnosis and precise treatment in colorectal surgery.

[Research progress of sexual dysfunction following rectal cancer surgery]

Sexual dysfunction with the incidence of 5%-90% is a common postoperative complication of rectal cancer and the ratio of men and women is similar. Sexual function is innervated by the abdominal-pelvic autonomic nerve. Different sexual dysfunctions can be caused by different parts and degrees of injury in autonomic nerve during operations of rectal cancer. With the development of pelvic autonomic nerves preservation in rectal cancer radical resection, postoperative sexual function can be protected. There may be many factors increasing the incidence of postoperative sexual dysfunction in rectal cancer, such as postoperative psychological factors, stoma, abdominal-perineal resection and radiotherapy. The effects of laparoscopic surgery, robotic surgery, transanal total mesorectal excision and lateral lymph node dissection on postoperative sexual function remain controversial. Based on the multidisciplinary cooperation model, attention should be paid to psychological intervention of patients and their partners. In clinical practice, for male using phosphodiesterase-5 inhibitors, vacuum erectile devices, injection of vasodilators through the penis or urethra, and for female local application of estrogen and lubricants in the vagina are effective treatment for postoperative sexual dysfunction of rectal cancer. In addition, stem cell therapy has a promising prospect for sexual dysfunction.

[Research progress of single-incision laparoscopic radical gastrectomy]

Gastric cancer is one of the most common malignant diseases in the world, which has a high incidence in our country and threatens people's health seriously. Laparoscopic radical gastrectomy is one of the main methods of surgical treatment for gastric cancer, whose clinical application has a history of near 30 years. With the in-depth understanding of minimally invasive surgery and the improvement of patients' cosmetic demand, single-incision laparoscopic surgery has emerged. Since the first report of single-incision laparoscopic radical gastrectomy in 2010, its safety has been preliminarily confirmed. While this result still needs to be further verified by more prospective randomized controlled studies. Compared with traditional laparoscopic radical gastrectomy, single-incision laparoscopic radical gastrectomy has the advantages of less trauma, less postoperative pain and faster postoperative recovery. So it has been favored by surgeons. However, the steeper learning curve and difficult operation of single-incision laparoscopic radical gastrectomy limit its promotion in clinical applications. At present, there are still controversies and confusions in the single-incision laparoscopic radical gastrectomy. This article elucidates the advances and existing problems of single-incision laparoscopic radical gastrectomy.

[Fat1 inhibits cell proliferation via ERK signaling pathway in esophageal squamous cell carcinoma]

Objective: To clarify the mechanism of Fat1 on the proliferation of esophageal squamous cell carcinoma (ESCC). Methods: KYSE450 cells were transfected with Plko.1-puro-GFP-shRNA-Fat1 plasmid and real time polymerase chain reaction (PCR) was used to verify the efficiency of Fat1 knockdown. The effects of Fat1 and extracellular regulated protein kinase (ERK) pathway inhibitor U0126 on the proliferation of ESCC cells were detected by methyl thiazolyl tetrazolium (MTT). Colony formation assay was used to detect the colony formation ability. Cell cycle was detected by live cell imaging. Western blot was used to observe the level of target protein. Mouse xenograft assay was applied to detect the effect of Fat1 knockdown on KYSE450 cell tumor growth. Immunohistochemistry was used to detect the expressions of related proteins in tumor sections. Results: The efficiency of Fat1 knockdown was (77.1±6.9)% in Fat1 sh1 group and (77.7±7.1)% in Fat1sh2 group. Compared with the control group, the cell proliferation and the expression of p-ERK1/2 were significantly increased in Fat1 sh1 and Fat1sh2 group (P<0.05). After U0126 treatment, the effect of Fat1 knockdown on the proliferation of KYSE450 cells disappeared, and the expression of p-ERK1/2 in KYSE450 cells decreased to a level similar to that in the control group. The number of cell clones in the control group was (72±8), lower than (155±28) and (193±9) in the Fat1sh1 and Fat1sh2 groups, respectively (P<0.05). In KYSE450 cell, division time was shortened from 1 622±32 min in control group to 1 408±29 min in Fat1 sh1 group, the difference was statistically significant (P<0.05). Compared with the control group, the tumor volume of Fat1 knockdown group increased significantly. The tumor weight of control group and Fat1 knockdown group were (0.224±0.028) g and (1.532±0.196) g, respectively, at 4 weeks after inoculation, and the difference was statistically significant (P<0.05). Conclusion: Fat1 inhibits cell proliferation via ERK signaling in ESCC.

[Research progress of different bowel reconstructions for postoperative functional protection during low anterior resections of rectal cancer]

Straight coloanal anastomosis (SCA), colonic J-pouch anastomosis (CJP), transverse coloplasty pouch anastomosis (TCP), and side-to-end anastomosis (SEA) are the most commonly used procedures of bowel reconstructions in the low anterior resections (LAR) of rectal cancer. Different bowel reconstruction procedures greatly affect postoperative bowel function, urinary function and sexual function. SCA is the most traditional procedure. CJP has been studied extensively and well-developed reconstruction method; however, recent studies have shown that CJP has the highest morbidity of complications, so the clinical application of CJP is limited. SEA is not inferior to CJP and SCA in the short-term and long-term defecation function, urination function, and sexual function, with reliable operational safety, so it is expected to become an alternative to SCA and CJP. The research on TCP is lacking, but there are some related clinical trials currently underway, and the results are worth expecting. The improvement and innovation of bowel reconstructions provide a bright prospect for better functional prognosis in patients with rectal cancer.

[Pros and cons of perioperative therapy in the protection of organ function in rectal cancer]

The goal of rectal cancer treatment should be to better protect organ function and improve patients' quality of life on the basis of ensuring radical resection. The current evidence has proved the superiority of perioperative chemoradiotherapy in reducing local recurrence and improving long-term survival. From the perspective of organ function protection, however, perioperative chemoradiotherapy has both disadvantages and advantages. Despite the great help in improving long-term outcomes, adverse reactions of chemoradiotherapy can aggravate defecation, urination and sexual dysfunction. Also, for patients with significant or complete remission, if the treatment strategy of local resection or close follow-up is selected, organ function can be preserved to the greatest extent. The key to the choice of treatment is to evaluate preoperatively whether pathological complete response is achieved. It should be kept in mind that preserving organ itself is not the same as protecting organ function. For patients who need perioperative chemoradiation, the optimal treatment methods should be chosen based on the patient's condition. Surgeons should fully evaluate organ function before operation, select the appropriate treatment strategy, pay special attention to the protection of important organs and nerves during surgeries, and carry out close postoperative follow-up and organ function rehabilitation as soon as possible, so as to reduce the incidence of dysfunction and the impact on the quality of life.

[Guidance of magnetic resonance imaging for target area delineation of postoperative presacral recurrence of rectal cancer]

Objective: Presacral recurrence of rectal cancer have altered the adjacent structures of original pelvic organs due to the previous radical surgery of rectal cancer, and the boundary between recurrent tumor tissues and pelvic internal structures is not clear. Conventional CT examination has poor soft tissue resolution, which makes it difficult to accurately delineate the target area of radiotherapy. This study aimed to explore the guiding role of magnetic resonance imaging (MRI) in delineating the target area of presacral recurrence after radical resection of rectal cancer. Methods: A descriptive case series research method was adopted. From May 2014 to May 2019, the clinical data of 30 patients with presacral recurrence after radical resection of rectal cancer were collected, who were admitted to Peking University People's Hospital, confirmed by pathology or discussed by multidisciplinary team (MDT), with complete MRI, CT and case information. According to the gross tumor volume (GTV) with presacral recurrence outlined in CT and MRI images, including presacral recurrent lesions (GTVT) and metastatic lymph nodes (GTVN), the GTV volume was calculated, and the tumor boundary and diameter were measured. The differences between MRI and CT were compared. Results: The volume of GTVT-CT was larger than that of GTVT-MR in all the 30 patients. The median volume of GTVT-CT was 67.86 (range 5.12-234.10) cm(3), which was significantly larger than 43.02 (range 3.42-142.50) cm(3) of GTVT-MR with statistically significant difference (Z=-4.288, P<0.001). The mean volume of GTVN outlined by CT and MRI was (0.43±0.11) cm(3) and (0.40±0.10) cm(3) respectively without statistically significant difference (t=1.550, P=0.132). The mean values of boundary and radial line of the presacral lesions on CT images were all longer than those on MRI images. The vertical diameter of GTVT on CT and MRI images was (6.66±2.92) cm and (5.17±2.40) cm (t=5.466, P<0.001); the anterior boundary was (3.24±2.51) cm and (2.69±2.48) cm (t=4.685, P<0.001); the anteroposterior diameter was (4.92±2.02) cm and (4.04±1.57) cm (t=6.210, P<0.001); the left boundary was (3.05±1.00) cm and (2.64±0.78) cm (t=2.561, P=0.016); the right boundary was 2.66 (0.00-4.23) cm and 1.82 (-1.10-3.59) cm (Z=-3.950, P<0.001); the transverse diameter was (5.01±1.78) cm and (3.82±1.29) cm (t=4.648, P<0.001), respectively, whose differences were all statistically significant. MRI was superior to CT in judging the involvement of anterior organs, such as intestine, prostate, bladder and the posterior sacrum. Fifteen patients received radiotherapy according to the target area guided by MRI and 10 patients obtained clinical symptom relief. Conclusion: Compared with CT, the GTV of postoperative presacral recurrence of rectal cancer outlined in MRI images is smaller, and MRI can determine the boundary between tumor and surrounding normal tissues more precisely, so it can show the invasion range of tumor more accurately and guide the accurate implementation of radiotherapy.

[Diagnosis and treatment of pneumatosis cystoides intestinalis]

Pneumatosis cystoides intestinalis (PCI) is a rare disease, which is characterized by the accumulation of gas cysts located in the submucosa or subserosa of the gastrointestinal tract. It can occur in the whole or part of the gastrointestinal tract from the esophagus to the rectum, but clinically the main involved sites are the colon and small intestine. PCI can also appear in other sites such as mesentery, the greater omentum and the hepatogastric ligament. In recent years, with the renewal of imaging method, the detection rate of PCI has been on the rise. Most patients with PCI have no obvious symptoms or only non-specific symptoms of the digestive tract like abdominal distension, abdominal pain, diarrhea, hematochezia, etc. The atypical clinical symptoms of PCI can easily lead to missed diagnosis or misdiagnosis. A small amount of patients would have complications like peritonitis and even perforation of the digestive tract. The therapeutic principle for these patients is different from that for patients with acute abdomen. The prognosis of PCI depends on its severity and comorbidities. In this article, a literature review would be conducted on the epidemiological characteristics, etiology and pathogenesis, clinical manifestations, diagnosis and treatment of PCI, which might help clinical doctors with diagnosis and treatment of the disease.

[Evidence-based standardized diagnosis and treatment of small gastrointestinal stromal tumors]

The actual incidence of small gastrointestinal stromal tumors (GIST) increases gradually. Although the biological behavior of most of small GIST is benign or indolent, a few small GIST can develope to recurrence and metastasis with biological invasive behavior. Identification of biological behavior and malignant potential is the cornerstone of treatment. For non-gastric small GIST, surgery is always the treatment of choice. Regarding gastric small GIST, close follow-up is acceptable for patients without risk factors detected by endoscopic ultrasonography. Surgery should be suggested for those with high risks, or significant growth of tumor during follow-up. Complete resection with function preservation is the principle of surgery. Besides, individualized treatment should also be taken into consideration.

[Clinicopathological features and prognosis in patients with presacral recurrent rectal cancer]

Objective: To investigate the clinicopathological features and prognostic factors in patients with presacral recurrent rectal cancer (PRRC). Methods: PRRC was defined as recurrence of rectal cancer after radical surgery involving posteriorly the presacral soft tissue, the sacrum/coccyx, and/or sacral nerve root. The diagnosis is confirmed with clinical symptoms (pain of pelvis/back/lower limb, bloody stools, increased frequency of defecation, and abnormal secretions), physical examination of perineal or pelvic masses, radiological findings, colonoscopy with histopathological biopsy, and the evaluation by multi-disciplinary team (MDT). Inclusion criteria: (1) primary rectal cancer undergoing radical surgery without distant metastasis; (2) PRRC was diagnosed; (3) complete inpatient, outpatient and follow-up data. According to the above criteria, clinical data of 72 patients with PRRC in Peking University People's Hospital from January 2008 to December 2017 were retrospectively analyzed. The clinicopathological features and follow-up data were summarized. Cox proportional hazard models was used to analyze the prognostic factors of PRRC. Results: Among 72 patients, 45 were male and 27 were female with a male-to-female ratio of 1.7:1.0. The median age at recurrence was 58 (34 to 83) years and the median interval from surgery to recurrence was 2.0 (0.2 to 17.0) years. The main symptom was pain in 48.6% (35/72) of patients. In addition, gastrointestinal symptoms were found in 25.0% (18/72) of patients. The presacral recurrent sites were presacral fascia in 36 (50.0%) patients, lower sacrum (S3~S5 or coccyx) in 25 (34.7%) patients, and higher sacrum (S1~S2) in 11 (15.3%) patients. Forty-seven (65.3%) patients underwent radical surgery (abdominal resection, abdominoperineal resection, sacrectomy, abdominosacral resection), 12 (16.7%) underwent non-radical surgery (colostomy, cytoreductive surgery), and 13 (18.1%) did not undergo any surgery but only receive palliative chemoradiotherapy and nutritional support treatment. Thirty-three (45.8%) patients received radiotherapy and/or chemotherapy (oxaliplatin, 5-fluorouracil, capecitabine, irinotecan, etc.). All the patients received follow-up, and the median follow-up time was 19 (2 to 72) months. The median overall survival time was 14 (1 to 65) months. The 1- and 3-year overall survival rates were 67.1% and 32.0%, respectively. Univariate analysis showed that age at recurrence (P=0.031) and radical resection (P<0.001) were associated with prognosis. Multivariate analysis demonstrated that radical resection was independent factor of good prognosis (RR=0.140, 95%CI: 0.061-0.322, P<0.001). Conclusions: Patients tend to develop presacral recurrent rectal cancer within 2 years after primary surgery. The main symptom is pain. Patients undergoing radical resection have a relatively good prognosis.

[Comparison of clinical efficacy among different surgical methods for presacral recurrent rectal cancer]

Objective: To investigate the efficacy and prognosis of three surgical methods for presacral recurrent rectal cancer (PRRC). Methods: A retrospective cohort study was carried out. Case inclusion criteria: (1) primary rectal cancer without distant metastasis and undergoing radical surgery; (2) patients undergoing radical surgery after the diagnosis of PRRC; (3) complete inpatient, outpatient and follow-up data. Clinical data of 47 patients meeting the above criteria who underwent operation at the Department of Gastrointestinal Surgery, The Peking University People's Hospital from January 2008 to December 2017 were reviewed and analyzed retrospectively. Of the 47 patients, 31 were male and 16 were female; the mean age was 57 years old; 9 (19.1%) were low differentiation or signet ring cell carcinoma, 38 (80.9%) were medium differentiation; 19 (40.4%) received neoadjuvant therapy. According to operative procedure, 22 patients were in the abdominal/abdominoperineal resection group, 15 in the sacrectomy group and 10 in the abdominosacral resection group. The operative data, postoperative data and prognosis were compared among the three groups. Survival curve was conducted using the Kaplan-Meier method, and log-rank test was used to compare survival difference among three groups. Results: There were no significant differences in baseline data among three groups (all P>0.05). All the 47 patients completed the radical resection successfully. The mean operation time was (4.7±2.1) hours, the median intraoperative blood loss was 600 ml, and the median postoperative hospitalization time was 17 days. Fifteen cases (31.9%) had perioperative complications, of which 3 cases were grade III-IV. There was no perioperative death. The mean operative time was (7.4±1.6) hours in the abdominosacral resection group, (4.9±1.6) hours in the abdominal/abdominoperineal resection group, and (3.0±1.1) hours in the sacroectomy group, with a significant difference (F=25.071, P<0.001). There were no significant differences in intraoperative blood loss, postoperative hospitalization days and perioperative complications among the three groups (all P>0.05). The median follow-up period of all the patients was 24 months, 12 cases (25.5%) developed postoperative dysfunction. The incidence of postoperative dysfunction in the abdominosacral resection group was 5/10, which was higher than 4/15 in the sacrectomy group and 3/22 (13.6%) in the abdominoperineal resection group with statistically significant difference (χ(2)=9.307, P=0.010). The 1-year and 3-year overall survival rates were 86.1% and 40.2% respectively. The 1-year overall survival rates were 86.0%, 86.7% and 83.3%, and the 3-year overall survival rates were 33.2%, 40.0% and 62.5% in the abdominal/abdominoperineal resection group, sacrectomy group and abdominosacral resection group, respectively, whose difference was not statistically significant (χ(2)=0.222, P=0.895). Conclusions: Abdominal/abdominoperineal resection, sacrectomy and abdominosacral resection are all effective for PRRC. Intraoperative function protection should be concerned for patients undergoing abdominosacral resection.

[Controversy and consideration of high and low ligation of inferior mesenteric artery in radical resection of rectal cancer]

Radical resection is one of the most important treatment for rectal cancer, which requires not only removal of adequate bowel and mesorectum around the tumor, but also thorough lymphadenectomy. Besides, postoperative complications are surgeons' concerns as well. According to different ways to manage inferior mesenteric artery, procedures could be divided into two groups: inferior mesenteric artery (IMA) high ligation and low ligation, which lead to various outcomes of the extent of lymph nodes dissection, survival, preservation of intestinal blood supply, incidence of anastomotic leakage, and postoperative functions including defecation function, urinary function and sexual function. Author believes that for those patients with clinical stage T1, low ligation and D2 lymph nodes dissection could be considered. However, for patients with locally advanced carcinomas (clinical stage T2+or N+), especially suspicious metastasis of lymph nodes around IMA root, high ligation and D3 lymph node dissection is suggested to ensure en bloc resection. As for those patients with high risks for compromised intestinal blood supply, preservation of left colic artery plus D3 lymph nodes dissection might be a feasible way. Intraoperative indocyanine green fluorescent imaging might play a role in quality control of lymphadenectomy.

[Comparative study of functional prognosis of transanal total mesorectal excision and conventional total mesorectal excision based on propensity score matching]

Objective: To compare the postoperative functional prognosis of transanal mesorectal excision (taTME) and conventional total mesorectal excision (TME) in rectal cancer. Methods: Totally 49 patients underwent taTME and 478 patients underwent conventional TME at Department of Gastroenterological Surgery, Peking University People's Hospital from January 2015 to December 2019 were retrospectively collected. Propensity score matching method was used to perform 1 versus 1 matching between the taTME and conventional TME groups, and 36 pairs of patients were successfully matched. After matching, the median age of patients in taTME group and conventional TME group was 60.5 (16.0) years and 60.5 (13.0) years (M(Q(R))), respectively, and the proportion of male patients was 66.7% (24/36) and 55.6% (20/36) , respectively. EORTC QLQ-C30 scale was used to assess quality of life, low anterior resection syndrome (LARS) scale and Wexner constipation score were used to evaluate anal function, international prostate symptom score (IPSS) was used to evaluate urinary function,international index of erectile function (IIEF) -5 and female sexual function index (FSFI) score were used to evaluate male and female sexual function, respectively, and generalized anxiety disorder (GAD-7) and patient health questionnaire (PHQ-9) scale were used to evaluate psych function. The t test, Mann-Whitney U test, χ(2) test, and Fisher exact test were used for comparison between groups, and Wilcoxon rank sum test or McNemar test was used for comparison between paired data. Results: There were no significant differences in surgery time, postoperative hospital stays, conversion rate, morbidity rate, surgery cost, and numbers of lymph node yield between the two groups (all P>0.05). Compared with the conventional TME group, the intraoperative blood loss in the taTME group was significantly higher (100 (100) ml vs. 80 (50) ml, U=424.5, P=0.010), the prophylactic stoma rate was significantly higher (96.9%(31/36) vs. 63.6%(21/36), χ(2)=11.218, P<0.01), the total hospitalization cost was significantly lower (74 297.7 (16 746.4) CNY vs. 91 781.3 (26 228.4) CNY, U=413.0, P=0.008). There were no significant differences in anal and urinary function between the two groups (LARS scalescore: Z=-0.513, P=0.608, Wexner constipation score: Z=-0.992, P=0.321, IPSS: Z=-1.807, P=0.071). In terms of psych function, significant difference in GAD-7 scale was seen between the two groups (Z=-2.311, P=0.021), patients with generalized anxiety disorder accounting for 26.7% (8/30) and 46.9% (15/32), respectively. Conclusions: Compared with conventional TME surgery, taTME has a significantly increased blood loss and prophylactic stoma rate. There are no significant difference in the incidence of postoperative anal, urinary, and sexual dysfunction between taTME and conventinal TME. taTME can alleviate the financial burden and general anxiety disorder to a certain extent.

[Surgical treatment of presacral recurrent rectal cancer]

Presacral recurrent rectal cancer (PRRC) which involves the presacral fascia or/and sacral bone is one of the classification of locally recurrent rectal cancer. Presacral fascia or/and sacral bone involvement and posterior fixation make treatment difficult. In recent years, there are many researches on the diagnosis, surgical treatment and surgical methods of PRRC. The major therapeutic principle of PRRC is to perform radical resection with combined therapy under the evaluation of the multidisciplinary team (MDT). Among the surgical methods, abdominal resection or abdominoperineal resection, sacrectomy and abdominosacral resection are the common surgical methods for the treatment of PRRC. Recent articles revealed that limited sacrectomy could also result in good efficacy, provided strict indications for this procedure. With the development of minimally invasive technology, the application of laparoscopic technology in PRRC has been increasingly emphasized. In summary, the surgical principle of PRRC has shifted from solely pursuring radical resection to obtaining good efficacy as well as reduced morbidity with individualized management. In this article, the research progress of surgical methods of presacral recurrent rectal cancer in recent years are reviewed in order to provide reference to clinical diagnosis and treatment.

[Procedure for prolapse and hemorrhoids versus stapled transanal rectal resection in the treatment of grade IV hemorrhoids]

Objective: To compare the efficacy and safety of two procedures in the treatment of hemorrhoid: the procedure for prolapse and hemorrhoids (PPH) and stapled transanal rectal resection (STARR). Methods: A retrospective cohort research was conducted. Clinical data of 263 patients undergoing the first elective surgery for grade IV hemorrhoids by the same team of surgeons at our department from January 2015 to December 2016 were analyzed retrospectively, while those had other anorectal diseases, emergency surgery, inflammatory bowel disease, tumor and incomplete clinical data were excluded. PPH was performed in 129 patients and STARR was performed in 134 patients. PPH procedure: a circular purse 2-0 string suture was made at 4 cm above the dentate line; in accordance with the standard protocol, the PPH circular stapling devicewas introduced; the suture was closed, and a pull-through followed; the traction was continued; the stapler was fired; the prolapsed mucosa and submucosa were removed. STARR procedure: 3-5 needles were sutured in the anterior rectal mucosa, protecting the posterior wall mucosa; with the help of a finger the PPH stapler was inserted into the vaginal lumen; the sutures were hooked from both sides of the stapler to maintain traction; according to the disease condition, the suturewas tightened appropriately; stapler was screwed and activated; the anterior wall mucosa was removed; the joint of the both ends of anastomosis was cut; the posterior wall mucosa was removed as well. The short-term efficacy, surgical safety and prognosis of the two groups were compared. Results: There were 67 males (51.9%) in the PPH group and 57 (42.5%) males in the STARR group. The median age of the two groups was 51.0 (22.0, 80.0) years and 49.0 (24.0, 74.0) years, respectively. There were no significant differences in the baseline data between the two groups (all P>0.05). No significant differences in the intraoperative bleeding, length of hospital stay, postoperative analgesic drug use, postoperative bleeding, postoperative infection, etc. were found between two groups (all P>0.05). As compared to PPH group, STAAR group had longer operation time and higher hospitalization cost with significant differences [(44.0±19.3) minutes vs. (26.3±8.5) minutes, t=9.701, P=0.001; (11 047±473) yuan vs. (7674±309) yuan, t=32.826, P=0.001]. One case in STAAR group developed rectovaginal fistula. The median follow-up period of the whole group was 40 (33, 52) months. A total of 108 cases in STARR group and 114 cases in PPH group completed the follow-up. The 3-year disease-relapse rate was 0 in STARR group and 4.2% in PPH group (P=0.042). Conclusion: STARR procedure can improve the prognosis in the treatment of grade IV hemorrhoid, but attention should be paid to the development of complications.

[Application of indocyanine green fluorescence imaging in colorectal cancer surgery]

Indocyanine green (ICG) fluorescence imaging has been widely used in surgery. In colorectal surgery specifically, more and more studies have shown that intraoperative fluorescence imaging is a safe and feasible method to assess anastomotic perfusion, and its use may decrease the incidence of anastomotic leakage. Meanwhile, indocyanine green can also be used to mark the location of lesion, identify sentinel lymph nodes, protect the ureter, and so on. It can also provide detection and guidance in the operation of peritoneal metastasis and liver metastasis of colorectal cancer. The application of indocyanine green fluorescence imaging can offer great value for surgery through improving the accuracy and outcomes of oncological resections. According to existing studies, we are still at an early application stage of indocyanine green fluorescence imaging technology in colorectal surgery. Lacking prospective randomized controlled studies, neither standards nor guidelines for injection dosage, site and observation period are satisfactory. Therefore, deep researches and establishment of standardized operational procedure are required to enhance the safety and accuracy of tumor resection and improve outcomes.

[The significance of lymph node yield in rectal cancer after neoadjuvant chemotherapy]

Neoadjuvant therapy has become an indispensable part of the treatment in locally advanced mild-low rectal cancer. Neoadjuvant therapy can cause the regression of the tumor body as well as drainage lymph nodes, which may influence the size, number, and metastatic status of the lymph nodes. In clinical practice, the total number of lymph nodes detected in rectal cancer treated with neoadjuvant therapy were significantly decreased, making it difficult to meet the standard of the NCCN guideline that at least 12 regional lymph nodes should be harvested. The optimal detection of yielded lymph nodes in rectal cancer is essential for accurate staging, response assessment, and adjuvant treatment decision. The lymph node diameter is significantly reduced after neoadjuvant therapy in locally advanced rectal cancer. In general, the number of detected lymph nodes is significantly reduced without additional pathological examination. The detected lymph nodes would increase by deliberate pathological examination, improvement of the detection method, or using a lymph node tracer. However, whether the number of detected lymph nodes is still needed to meet the requirements of the NCCN guideline, and the relationship between the number of detected lymph nodes and the prognosis are still controversial. At present, the number of negative lymph nodes, LNR, LODDS, etc. can be also used to predict prognosis in addition to ypN staging. For patients with ypN0 and ypN+ stage, different evaluation methods can be selected. For patients with ypN0, the number of detected lymph nodes still has important clinical significance for the prognosis and treatment decision. This article will introduce the related issues, and provide more evidence-based diagnosis and treatment practice.

[Detection of preoperative chemoradiotherapy sensitivity molecular characteristics of rectal cancer by transcriptome second generation sequencing]

OBJECTIVE

To detect the preoperative chemoradiotherapy sensitivity molecular characteristics of rectal cancer by transcriptome second generation sequencing.

METHODS

The clinicopathological data of 30 patients with locally advanced rectal cancer were collected prospectively, including 9 indicators (general conditions, imaging data before radiotherapy and chemotherapy, pathological data of biopsy before radiotherapy and chemotherapy, and tumor differentiation degree, etc.), in order to analyze the correlation between them and tumor regression grading (TRG) after radiotherapy and chemotherapy for rectal cancer. At the same time, frozen specimens of colonoscopy biopsy before neoadjuvant therapy were collected from these 30 patients, and transcriptome second-generation sequencing was performed for bioinformatics analysis to screen out the genes that might drive the radio chemotherapy sensitivity of rectal cancer.

RESULTS

Among the 30 patients with rectal cancer, 9 had complete pathological remission, 12 had partial remission, and 9 had poor remission. The degree of pathological TRG remission after radiotherapy and chemotherapy for rectal cancer was negatively correlated with the preoperative MRI T stage (P=0.046), and positively correlated with preoperative MRI rectal cancer extravascular invasion (EMVI) (P=0.003). Transcriptome second-generation sequencing of the obtained 217 transcripts (P<0.05) for signal pathway enrichment analysis, and multiple cell signal transduction pathways related to antigen presentation could be found. The high expression of HSPA1A, HSPA1B and EXOSC2 was positively correlated with postoperative pathological remission (P<0.05). The high expression of DNMBP, WASH8P, FAM57A, and SGSM2 was positively correlated with postoperative pathological remission (P<0.05).

CONCLUSION

Preoperative NMR detection of extra-tumoral vascular invasion (EMVI-positive) in patients with rectal cancer was significantly better than that of EMVI-negative patients after chemoradiotherapy. Patients with high expressions of HSPA1A, HSPA1B and EXOSC2 had poor postoperative pathological remission, while patients with high expressions of genes, such as DMNMB, WASH8P, FAM57A, and SGSM2 had good postoperative pathological remission. Based on the molecular characteristics of rectal cancer radiotherapy and chemotherapy, attempts to block or enhance the molecular pathways associated with chemosensitivity of rectal cancer, are to be made to further explore new candidate therapeutic targets that can increase the sensitivity of radiotherapy and chemotherapy for rectal cancer.

[Efficacy of Weitan Waifu patch on the postsurgical gastroparesis syndrome of gastrointestinal cancer: a multi-center trial]

Objective: To investigate the safety and efficacy of the Weitan Waifu patch on the postsurgical gastroparesis syndrome (PGS) of gastrointestinal cancer. Methods: The multi-center, double-blind, randomized controlled trial was conducted with superiority design. Patients with PGS of gastrointestinal cancer diagnosed in 4 AAA hospitals and the abdominal symptom manifested as cold syndrome by Chinese local syndrome differentiation were recruited. These patients were randomly divided into two groups according to 1∶1 proportion. Placebo or Weitan Waifu patch was applied in control group or intervention group, respectively, based on the basic treatments, including nutrition support, gastrointestinal decompression, promoting gastric dynamics medicine.Two acupuncture points (Zhongwan and Shenque) were stuck with placebo in control group or patch in treatment group. The intervention course was 14 days or reached the effective standard. Results: From July 15, 2013 to Jun 3, 2015, 128 participants were recruited and 120 eligible cases were included in the full analysis set (FAS), and 60 cases in each group. 88 cases were included in the per-protocol set (PPS), including 45 cases in the treatment group and 43 cases in the control group. In the FAS, the clinical effective rate in the treatment group was 68.3%, significantly superior than 41.7% of the control group (P=0.003). The medium time of effective therapy in the treatment group was 8 days, significantly shorter than 10 days in the control group (P=0.017). In the FAS, 3 adverse events occurred in the treatment group, including mild to moderate decrustation, pruritus and nausea. The incidence rate of adverse events was 5.0% (3/60) and these symptoms were spontaneously remitted after drug withdrawal. No severe adverse events were observed in the control group. There was no significant difference between these two groups (P=0.244). Conclusion: Weitan Waifu patch is a safely and effectively therapeutic method for patients with PGS (cold syndrome) of gastroenterological cancer. Trial registration: International Standard Randomized Controlled Trial Number Register, ISRCTN18291857.

[Adenocarcinoma in a Meckel's diverticulum with multiple liver metastases and gastrointestinal hemorrhage: a case report]

Meckel's diverticulum is the most common congenital anomaly of the gastrointestinal tract, affecting approximately 2% of the population. It is a true diverticulum occurring on the anti-mesenteric border of the distalileum, typically within 100 cm of the ileo-caecal valve. Neoplasms arising in Meckel's diverticula are uncommon, and those reported in the literature are mainly carcinoid tumors, followed by gastrointestinal stromal tumors (GIST) and benign leiomyomas. Adenocarcinomas are extremely rare. Tumors in Meckel's present non-specifically with gastrointestinal complaints, such as bleeding, obstruction, inflammation or perforation. The suspicion of a Meckel's tumor is often not thought of at the initial. In this article we describe a 57-year-old woman who presented with massive rectal bleeding and severe anemia, later found to be caused by a adenocarcinoma arising from Meckel's diverticulum. The tumor was unfortunately highly aggressive. Multiple liver metastases had already existed when we discovered the primary mass. Later we performed a partial resection of the ileumto cease the bleeding. Meckel's diverticulum and the tumor were resected simultaneously. The pathological diagnosis confirmed adenocarcinoma arising from the Meckel's diverticulum. The final stage was pT4NxM1, stage IV according to the Union for International Cancer Control (UICC) classification. After operation we gave the patient first-line, mFOLFOX6 chemotherapy, but it turned out to be not effective. Rapid progress of the liver metastases and suspicion of multiple lung metastasis in short time after therapy indicated a bad outcome. We believe this is the first case of adenocarcinoma in a Meckel's diverticulum to be reported in domestic literature. The diagnosis of Meckel's tumor should be considered as inpatients'acute gastrointestinal complaints; when found incidentally at laparotomy, it should be carefully examined for any gross abnormality and resection should be considered.

Clinical analysis of patients of cirrhosis complicated with adrenal insufficiency

OBJECTIVE

To evaluate the level of cortisol and adrenocorticotrophic hormone (ACTH) in patients with cirrhosis and to investigate the clinical significance and characteristics of cirrhosis with adrenal insufficiency (AI).

PATIENTS AND METHODS

A total of 118 patients that were hospitalized in the Department of Gastroenterology of Xiangyang Hospital affiliated to Hubei University due to cirrhosis were selected and chemiluminescence assay was used to measure the basal level of cortisol and ACTH in their blood. All the 118 patients with cirrhosis were divided into two groups, cirrhosis with AI group and cirrhosis without AI group and comparison and analysis of the clinical characteristics and prognosis of the two groups were undertaken. About 39 patients with gastrointestinal polyps were used as control group.

RESULTS

The basal level of cortisol of the patient group 329.67±136.1 nmol/l was significantly lower than that of the normal control 460.7±165.48 nmol/l (p<0.05). Of the 118 patients with cirrhosis, 32 patients had AI (32/118). Compared with the cirrhosis without AI group, cirrhosis with AI group had significantly increased spontaneous bacterial peritonitis (SBP), Child classes, Child scores, MELD scores and case fatality and the difference was statistically significant (p<0.05). The level of albumin and high-density lipoprotein-cholesterol (HDL-C) in 32 patients with cirrhosis and AI was significantly reduced and the prevalence rate of facial pigmentation and ascites were significantly higher (p<0.05). But, there was no statistically significant difference between cirrhosis with AI and cirrhosis without AI (p>0.05) in other clinical characteristics and laboratory parameters studied.

CONCLUSIONS

The basal level of cortisol in patients with cirrhosis was significantly reduced and about 27% of cirrhosis patients had AI. Patients of the later kind had a higher prevalence rate of SBP, worse hepatic impairment and higher mortality, thus resulting in poor prognosis.

The Cardioprotective Effects of Late-Phase Remote Preconditioning of Trauma Depends on Neurogenic Pathways and the Activation of PKC and NF-κB (But Not iNOS) in Mice

BACKGROUND

A superficial abdominal surgical incision elicits cardioprotection against cardiac ischemia-reperfusion (I/R) injury in mice. This process, called remote preconditioning of trauma (RPCT), has both an early and a late phase. Previous investigations have demonstrated that early RPCT reduces cardiac infarct size by 80% to 85%. We evaluated the cardioprotective and molecular mechanisms of late-phase RPCT in a murine I/R injury model.

METHODS

Wild-type mice, bradykinin (BK) 2 receptor knockout mice, 3M transgenic mice (nuclear factor κB [NF-κb] repressor inhibitor of nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor alpha [IκBα((S32A, S36A, Y42F))]), and inducible nitric oxide synthase (iNOS) knockout mice were analyzed using a previously established I/R injury model. A noninvasive abdominal surgical incision was made 24 hours prior to I/R injury and the infarct size was determined at 24 hours post-I/R injury.

RESULTS

The results indicated that a strong cardioprotective effect occurred during late-phase RPCT (58.42% ± 1.89% sham vs 29.41% ± 4.00% late RPCT, mean area of the infarct divided by the mean area of the risk region; P ≤ .05; n = 10). Furthermore, pharmacological intervention revealed the involvement of neurogenic signaling in the beneficial effects of late RPCT via sensory and sympathetic thoracic nerves. Pharmacological experiments in transgenic mice-implicated BK receptors, β-adrenergic receptors, protein kinase C, and NF-κB but not iNOS signaling in the cardioprotective effects of late RPCT.

CONCLUSION

Late RPCT significantly decreased myocardial infarct size via neurogenic transmission and various other signaling pathways. This protective mechanism differentiates late and early RPCT. This study describes a new cardiac I/R injury prevention method and refines the concept of RPCT.

Screening of molecular markers linked to dwarf trait in crape myrtle by bulked segregant analysis

Plant height is one of the most important traits of plant architecture as it modulates both economic and ornamental values. Crape myrtle (Lagerstroemia indica L.) is a popular ornamental woody plant because of its long-lasting mid-summer bloom, rich colors, and diversified plant architecture. These traits also make it an ideal model of woody species for genetic analysis of many ornamental traits. To understand the inheritance of plant height and screen for genes modulating plant height in Lagerstroemia, segregation of the plant height trait was analyzed using the F1 population of L. fauriei (standard) x L. indica 'Pocomoke' (dwarf) with 96 seedlings, while dwarf genes were screened using the bulked segregant analysis method, combined with 28 amplified fragment length polymorphism primers and 41 simple sequence repeat primers. The results showed that the dwarf trait of crape myrtle was controlled by a major gene and modified by minor genes. An amplified fragment length polymorphism marker, M53E39-92, which was 23.33 cM from the loci controlling the dwarf trait, was screened. These results provide basic information for marker-assisted selection in Lagerstromia and cloning of dwarf genes in future studies.

Ent-16β,17-dihydroxy-kauran-19-oic acid, a kaurane diterpene acid from Siegesbeckia pubescens, presents antiplatelet and antithrombotic effects in rats

The antiplatelet and antithrombotic effects of ent-16β,17-dihydroxy-kauran-19-oic acid (DDKA) isolated from Siegesbeckia pubescens were investigated with different methods both in vitro and in vivo. We tested the antithrombotic activity of DDKA in arterio-venous shunt model. The effects of DDKA on adenosine diphosphate (ADP)-, Thrombin-, Arachidonic acid-induced rat platelets aggregation were tested in vitro. We also assessed its bleeding side effect by measuring coagulation parameters after intravenous administration for 5 days and investigated the potential mechanisms underlying such activities. In vivo, DDKA significantly reduced thrombus weight in the model of arterio-venous shunt. Meanwhile, DDKA increased plasma cAMP level determined by radioimmunoassay in the same model. Notably, DDKA prolonged PT and APTT in rats after intravenous administration DDKA for successive 5 days. In vitro, pretreatment with DDKA on washed rat platelets significantly inhibited various agonists stimulated platelet aggregation and caused an increase in cAMP level in platelets activated by ADP. These findings support our hypothesis that DDKA possesses antiplatelet and antithrombotic activities. The mechanisms underlying such activities may involve the anticoagulatory effect and cAMP induction.

Carcinosarcoma of pancreas with liver metastasis combined with gastrointestinal stromal tumour of the stomach: is there a good prognosis with the complete resection?

We report a carcinosarcoma of the pancreas with liver metastasis combined with gastrointestinal stromal tumour (GIST) of the stomach in a 72-year-old woman who presented with right upper quadrant pain, nausea and vomiting. A radical resection including pancreaticoduodenectomy, left hepatic lobe resection and local resection of the gastric mass was performed. The tumour in the head of pancreas was found to be grossly yellow-white, and it infiltrated the common bile duct and duodenum; the mass of the liver metastasis is solitary. Pathologic examination showed two components separated from each other: one component was a conventional infiltrating pancreatic ductal adenocarcinoma, and the other component showed sarcomatous growth pattern composed of pleomorphic spindle cells. The neoplasm of the stomach was confirmed a low malignant potential GIST by histology and immunohistochemistry. The patient was obliged to be in hospital because of abnormal bowel function; moreover, surveillance CT scans performed at 1.5 months post-operatively showed multiple liver metastasis and recurrence in the tail of pancreas. Unfortunately, the patient died of multiple organ failure at 2 months post-operatively. To our knowledge, this is the first experience report about surgical treatment of carcinosarcoma of pancreas with liver metastasis combined with GIST of the stomach. The patient performed a radical surgery for the metastatic carcinosarcoma even if that could be resected completely did not have a good consequence.

Allogeneic Dendritomas Induce Anti-tumour Immunity Against Metastatic Colon Cancer

Colon cancer (CC) is one of the most common malignancies in the Western world. Although surgical resection is the first choice worldwide, at this point an effective approach for the treatment of patients with metastasis and cancer recurrence post-operation has not yet been found. The aim of this study was to investigate the role of the allogeneic dendritomas from fusion of dendritic cells (DC) and metastatic CC cells in the activation of anti-tumour immunity against metastatic CC. Dendritomas were generated by fused allogeneic human peripheral blood DC with metastatic CC cells using 50% polyethylene glycol. The proliferation of the T cells and the toxicity of the cytotoxic T lymphocytes were observed after T cell pulsed with allogeneic dendritomas. The activated ratios of CD4+T helper 1 and CD8+Tc1 cells were about 51.55 and 65.60% after T cells were mixed with fusions for 24 h, which higher than those of controls. The proliferation of T cells were significantly higher than those of control after T cell pulsed with dendritomas (P < 0.01). Significantly, the activated CD8+ T lymphocytes effectively lysed the CC cells. These results demonstrate that allogeneic dendritomas activate T-cell responses against metastatic CC cells.

Recent improvements in prediction of protein structure by global optimization of a potential energy function

Recent improvements of a hierarchical ab initio or de novo approach for predicting both alpha and beta structures of proteins are described. The united-residue energy function used in this procedure includes multibody interactions from a cumulant expansion of the free energy of polypeptide chains, with their relative weights determined by Z-score optimization. The critical initial stage of the hierarchical procedure involves a search of conformational space by the conformational space annealing (CSA) method, followed by optimization of an all-atom model. The procedure was assessed in a recent blind test of protein structure prediction (CASP4). The resulting lowest-energy structures of the target proteins (ranging in size from 70 to 244 residues) agreed with the experimental structures in many respects. The entire experimental structure of a cyclic alpha-helical protein of 70 residues was predicted to within 4.3 A alpha-carbon (C(alpha)) rms deviation (rmsd) whereas, for other alpha-helical proteins, fragments of roughly 60 residues were predicted to within 6.0 A C(alpha) rmsd. Whereas beta structures can now be predicted with the new procedure, the success rate for alpha/beta- and beta-proteins is lower than that for alpha-proteins at present. For the beta portions of alpha/beta structures, the C(alpha) rmsd's are less than 6.0 A for contiguous fragments of 30-40 residues; for one target, three fragments (of length 10, 23, and 28 residues, respectively) formed a compact part of the tertiary structure with a C(alpha) rmsd less than 6.0 A. Overall, these results constitute an important step toward the ab initio prediction of protein structure solely from the amino acid sequence.

The relationship between biological activity and the electronic structure and transfer of the whole acidic PLA2 molecule in ab initio level

The electronic structure of the whole molecule of acidic phospholipase A2 (PLA2) from the venom of Agkistrodon halys pallas (A. halys pallas) has been calculated using the extended negative factor counting (ENFC) method in which dimers were calculated at the ab initio level using a minimal basis set, with simulation of the aqueous environment. Hopping conductivities were determined by the use of random walk theory. The results show that the frontier orbitals are mainly localized to residues which are involved in the biological activity of acidic PLA2. The C-terminal region might play some important role in biological activity because of its active electrons. The aromatic patch on the surface of the enzyme, together with two neighbouring acidic residues, has very active electrons that may be responsible for the inhibition of platelet aggregation. Trp30, which is involved in the interfacial recognition region, may transfer its electrons to the aggregated substrate. It is also concluded that the conductivity of the protein is caused mainly by holes transported through the valence band rather than electrons transferred in the conductive band. The a.c. conductivity of acidic PLA2 confirms that proteins, if doped, are amorphous conductors. Moreover, the a.c. conductivities of acidic PLA2 are approximately one order of magnitude higher than those of some other proteins. This suggests that the toxicity of acidic PLA2 may be related to its high a.c. conductivity.

Electronic energy levels and hopping conductivity of an entire molecule of hagfish insulin

The quantum-chemical calculation of an entire molecule of hagfish insulin was done by the ENFC method in which the matrix elements were calculated at the ab initio level using a minimal basis set with simulation of the aqueous solution environment. The ac conductivity for hagfish insulin was also calculated at the ab initio level by random walk theory. All the results were compared with those of pig insulin. It is shown that the reduction of HOMOs and LUMOs localized on the active sites of hagfish insulin agrees with the decrease in the biological reactivity of the insulin. The analysis of primary hopping events showed that a different sequence could influence the biological activity of insulin through the distribution of the hopping centers and the quantities of the hopping frequencies. The curve of the frequency versus ac conductivity of hagfish insulin shows that the different amino acid sequences of proteins influence the hopping conductivity. However, the electronic properties of native proteins are dominated by the three-dimensional conformations. Finally, the electronic mechanism of trans-membrane signal transforms by insulin and its receptor, which had been proposed by Ye and Ladik, was clearly described.