Surgical outcomes of left hemicolon sparing resection versus extensive resection in treating synchronous colorectal cancer involving the right-sided colon and sigmoid colon or rectum.

BACKGROUND: There are different surgical strategies that can treat synchronous colorectal cancer (SCRC) involving separate segments, namely extensive resection (EXT) and left hemicolon-sparing resection (LHS). We aim to comparatively analyze short-term surgical results, bowel function, and long-term oncological outcomes between SCRC patients treated with the two different surgical strategies. METHODS: One hundred thirty-eight patients with SCRC lesions located in the right hemicolon and rectum or sigmoid colon were collected at the Cancer Hospital, Chinese Academy of Medical Sciences, and the Peking University First Hospital from January 2010 to August 2021 and divided into EXT group (n = 35) and LHS group (n = 103), depending on their surgical strategies. These two groups of patients were compared for postoperative complications, bowel function, the incidence of metachronous cancers, and prognosis. RESULTS: The operative time for the LHS group was markedly shorter compared with the EXT group (268.6 vs. 316.9 min, P = 0.015). The post-surgery incidences of total Clavien-Dindo grade ≥ II complications and anastomotic leakage (AL) were 8.7 vs. 11.4% (P = 0.892) and 4.9 vs. 5.7% (P = 1.000) for the LHS and EXT groups, respectively. The mean number of daily bowel movements was significantly lower for the LHS group than for the EXT group (1.3 vs. 3.8, P < 0.001). The proportions of no low anterior resection syndrome (LARS), minor LARS, and major LARS for the LHS and EXT groups were 86.5 vs. 80.0%, 9.6 vs. 0%, and 3.8 vs. 20.0%, respectively (P = 0.037). No metachronous cancer was found in the residual left colon during the 51-month (median duration) follow-up period. The overall and disease-free survival rates at 5 years were 78.8% and 77.5% for the LHS group and 81.7% and 78.6% for the EXT group (P = 0.565, P = 0.712), respectively. Multivariate analysis further confirmed N stage, but not surgical strategy, as the risk factor that independently affected the patients' survival. CONCLUSIONS: LHS appears to be a more appropriate surgical strategy for SCRC involving separate segments because it exhibited shorter operative time, no increase in the risk of AL and metachronous cancer, and no adverse long-term survival outcomes. More importantly, it could better retain bowel function and tended to reduce the severity of LARS and therefore improve the post-surgery life quality of SCRC patients.

Transanterior obturator nerve gateway: a novel approach to achieving intracorporeal distal rectal transection for ultralow rectal cancer.

BACKGROUND: Intracorporeal rectal transection at the anorectal junction for ultralow rectal cancer is technically difficult due to pelvic width and limited roticulation, which might require a transanal transection or an oblique transection with multiple firings. These procedures were reported to be associated with the increased risk of morbidity. To address these problems, we presented a novel technique Transanterior Obturator Nerve Gateway (TANG) to transect rectum for ultralow rectal cancer and evaluated its safety and feasibility in this study. METHODS: A total of 210 consecutive patients who underwent laparoscopic coloanal anastomosis with or without partial intersphincteric resection (CAA/pISR) for rectal cancers between January 2017 and January 2020 were included. Eighty of these patients were analyzed using propensity score matching (PSM). The perioperative characteristics, TANG-related variables, and genitourinary and anal function outcomes were analyzed. RESULTS: Among these enrolled patients, 170 patients underwent traditional transection, and 40 underwent TANG transection; the patients were matched to include 40 patients in each group by PSM. After PSM, there were no significant differences in the operating time (p = 0.351) or bleeding volume (p = 0.474) between the two groups. However, the TANG group had fewer cases of conversion to transanal transection (0 vs. 13, p < 0.001). Moreover, the patients in TANG group had a more desirable transection with longer distal resection margin (1.7 vs. 1.1 cm, p < 0.001), shorter stapling line (6.6 vs. 10.3 cm, p < 0.001) and fewer stapler firings (p < 0.001). The overall postoperative complication rates and genitourinary and anal function outcomes were not significantly different between the two groups. CONCLUSIONS: The TANG approach appears to be a safe, feasible and effective approach for intracorporeal ultralow rectal transection with more distal resection, more vertical transection and fewer stapler firings.

MicroRNA-19a targets tissue factor to inhibit colon cancer cells migration and invasion.

The over-expression of tissue factor (TF) and its roles in colon cancer progression have attracted much attention. However, the mechanisms regulating TF expression have not yet been shown in detail. In this study, we over-expressed miR-19a, miR20a and miR-106b in colon cancer cells, and evaluated their impact on TF expression and cellular function. We provide evidence demonstrating that miR-19a inhibited TF expression in vitro. Luciferase reporter assay confirmed that TF was a direct target of miR-19a because the miR-19a mediated repression of luciferase activity was abolished by mutation of the putative binding site. Moreover, miR-19a suppressed colon cancer cell migration and invasion. This effect was due to the indirect down-regulation of matrix metalloproteinase 9. Finally, we investigated the relevance of TF and miR-19a expression in a total of 48 paired colon cancer samples and revealed that miR-19a was inversely correlated with TF expression in stages I and II cases. Therefore, our results suggested that miR-19a was capable of suppressing TF expression in vitro and inhibiting cell migration and invasion. Although it was not the unique mechanism responsible for the expression of TF in vivo, miR-19a was inversely correlated with TF expression in early stage colon cancer patients.

[Experimental study of radiofrequency ablation of liver in swine].

OBJECTIVE: To explore the feasibility and efficacy of multiple-radiofrequency ablation (RFA) in swine liver. METHODS: One swine undergone percutaneous and intra-operative RFA for three times in succession (an interval of 5 days) guided by real-time ultrasound. Then 6 ablated lesions formed. The outcome of RFA and the change of tissues adjacent to ablated lesions (biliary, liver vascular and abdominal wall) were observed by trans-abdominal ultrasonography (US), contrast enhanced ultrasound (CEUS), intra-operative ultrasound (IOUS) and contrast enhanced computed tomography (CT). RESULTS: Bile duct dilatation was found beside primary porta hepatis on US, CT, IOUS after RFA. There was no thrombus in liver vein through the ablated lesion with electrodes parallel to primary porta hepatis. Two ablated lesions were incompletely fused together. Small thermal injury was observed on abdominal wall after an injection of saline into subcapsular gap. Subcapsular hepatic tissue around ablation lesion changed into coagulative necrosis from hyperemia with elapsing time. Carbonizing granule formed during RFA on the top of intro-operative radio-frequency electrode easily caused bleeding along the withdrawing passage. Gelfoam was helpful to stop bleeding during intro-operative RFA. Occluding blood flow into liver definitely enlarged ablated area with the same amount of RFA energy. CONCLUSION: Multiple-RFA is feasible and efficacious for patients with RFA indication. But the complications of RFA increase if the ablation areas are adjacent to such organs as bile duct, stomach, intestine and diaphragm, etc.

Prognostic values of the miR-17-92 cluster and its paralogs in colon cancer.

BACKGROUND: MicroRNAs have been shown to offer great potential in both the diagnosis and prognosis of cancer. Despite the well-established role of the miR-17-92 in cancer formation and progression, the contribution of each individual miRNA remains to be characterized. Thus, we investigated whether deregulation of the miR-17-92 associated with colon cancer prognosis. METHODS: Expression levels of the miR-17-92 cluster and its paralogs were determined in 48 colon tumor and 48 paired normal tissues by real-time qRT-PCR. Associations with miRNA expression, age, sex, TNM staging, and survival prognosis were evaluated. RESULTS: MiR-17-92 cluster and its paralogs were significantly overexpressed in colon tumor. No significant associations were found between the deregulation of certain miRNAs and the clinical and pathologic characteristics observed in patients. Kaplan-Meier curves demonstrated significantly reduced overall survival in patients expressing high levels of miR-17. In multivariate Cox models, miR-17 overexpression (HR 2.67; P = 0.007) and TNM staging (HR 8.87; P = 0.002) were significantly associated with a risk of death. CONCLUSIONS: The miR-17-92 cluster and its paralogs were significantly elevated in patients with colon cancer, and heightened expression of miR-17 was associated with poor survival. Moreover, miR-17 and TNM staging were both identified as significant, but independent, prognostic biomarkers in colon cancer.

Hyperthermia synergizes with tissue factor knockdown to suppress the growth and hepatic metastasis of colorectal cancer in orthotopic tumor model.

BACKGROUND: Tissue factor (TF) is a significant risk factor for tumor growth and hepatic metastasis in patients with colorectal cancer (CRC). This study aimed to investigate whether hyperthermia has synergistic anti-tumor effects with TF knockdown in suppressing CRC progression and metastasis in vitro and in vivo. METHODS: Human colorectal cancer LOVO cells were treated by hyperthermia at 44°C for 2 hr or/and TF siRNA. Then the cells were subjected to colony formation assay. Apoptosis was analyzed by flow cytometry, confocal microscopy, and transmission electron microscopy. The cell migration and invasion abilities were analyzed by wound healing and matrigel assay. In addition, orthotopic nude mice model of CRC was established. RESULTS: Hyperthermia synergized with TF knockdown to reduce colony formation ability, induce apoptosis, and suppress the migration and invasion of LOVO cells in vitro. Moreover, hyperthermia in combination with TF depletion inhibited the growth and hepatic metastasis of CRC in orthotopic nude mice model. Mechanistically, the synergistic effects were at least partly mediated by inducing JNK mediated apoptosis and suppressing matrix metalloproteinases (MMPs) mediated invasion. CONCLUSIONS: Hyperthermia in combination with TF-targeted therapy could be a potential approach for CRC treatment.

Tissue factor/activated factor VIIa induces matrix metalloproteinase-7 expression through activation of c-Fos via ERK1/2 and p38 MAPK signaling pathways in human colon cancer cell.

PURPOSE: Increased expression of tissue factor (TF) is associated with tumor invasion and metastasis in human colorectal cancer. We have previously observed that TF/FVIIa upregulates matrix metalloproteinase-7 (MMP-7) expression at the transcriptional level in colon cancer cells. MMP-7 overexpression is believed to play an important role in tumor invasion and metastasis. The aim of this study is to elucidate the molecular mechanisms by which TF/FVIIa induced MMP-7 expression and cell invasion in vitro. METHODS: Reverse transcription polymerase chain reaction, Western blot, luciferase assay, and chromatin immunoprecipitation (ChIP) were used to determine the potential mechanism and signaling pathways by which TF/FVIIa induced MMP-7 expression and cell invasion in LoVo cells. Small interfering RNA (siRNA) and cell invasion assay was used to examine whether blocking c-Fos expression could abolish FVIIa-mediated upregulation of MMP-7 and cell invasion in vitro. RESULTS: The results showed that FVIIa induced the upregulation of MMP-7 both at the mRNA and protein levels in a time- and dose-dependent manner and increased the invasive behavior of LoVo cells. FVIIa enhanced the promoter activity of MMP-7, and the activator protein-1 (AP-1) binding site was responsible for the activation. Site mutation of the AP-1 binding site in the promoter almost completely abolished FVIIa-mediated response. Furthermore, ChIP assay confirmed that FVIIa promoted the direct binding of c-Fos with the MMP-7 promoter in vivo. FVIIa also induced the expression and nuclear accumulation of the AP-1 subunit c-Fos. siRNA-mediated knockdown of c-Fos eliminated FVIIa-stimulated MMP-7 expression and cell migration in vitro. In addition, selective mitogen-activated protein kinase (MAPK) kinase (MEK1/2) inhibitor (PD98059) and p38 MAPK inhibitor SB203580 suppressed MMP-7 upregulation induced by FVIIa. CONCLUSIONS: Our data suggest that a novel TF/FVIIa/MAPK/c-Fos/MMP-7 axis plays an important role in modulating the invasion of colon cancer cells and blockage of this pathway holds promise to treat colon cancer metastasis.

Butyrate enhances intestinal epithelial barrier function via up-regulation of tight junction protein Claudin-1 transcription.

BACKGROUND: Barrier function is essential for the maintenance of normal intestinal function. Dysregulation of the intestinal barrier underlies a wide range of disorders. AIM: Previously, we found that sodium butyrate (NaB) decreased the molecular permeability of intestinal barrier in vivo model, but the mechanism by which NaB facilitated the tightness of tight junctions (TJs) in small intestinal epithelium needed further studies. METHODS: In vitro culture of the cdx2-IEC monolayer was used to mimic barrier function. The TJs were assessed by transepithelial electrical resistance (TEER) and paracellular flux of fluorescein isothiocyanate-conjugated dextran 40,000 (FD-40), Western blot, Q-RT-PCR, and immunofluorescence. Promoter and chromatin immunoprecipitation (ChIP) assays were also done to analyze the Claudin-1 gene. RESULTS: NaB decreased FD-40 flux, increased TEER and TJ protein Claudin-1 expression, induced ZO-1 and Occludin redistribution in cellular membrane, and reversed the damage effect after calcium (Ca(2+)) switch assay. Silencing Claudin-1 prevented protective function of NaB from enhancing intestinal barrier integrity. Further studies demonstrated that NaB increased Claudin-1 transcription by facilitating the interaction between transcription factor SP1 and a specific motif within the promoter region of Claudin-1. This SP1 binding motif was located upstream of the coding region (-138 to -76 bp) and indispensable for the transcription of Claudin-1 following NaB treatment. ChIP assay confirmed the association between SP1 and Claudin-1 promoter, and the elimination of the SP1 binding site by point mutation resulted in a significant loss of Claudin-1 transcription after NaB dealing. CONCLUSIONS: NaB enhanced intestinal barrier function through increasing Claudin-1 transcription via facilitating the association between SP1 and Claudin-1 promoter.

[Analysis of prognostic factors in patients with lymph node-negative rectal cancer].

OBJECTIVE: To investigate the risk factors for the prognosis in patients with node-negative rectal cancer. METHODS: Clinicopathological characteristics of 117 patients with lymph node-negative rectal carcinoma undergoing curative rectectomy from January 2005 to December 2008 were retrospectively analyzed. RESULTS: The overall 5-year survival rate was 91.5%. The univariate analysis revealed that tumor size(χ(2)=8.422,P=0.004), invasive depth(T staging, χ(2)=9.448,P=0.024), cell differentiation(χ(2)=26.571,P=0.000), pathologic type(χ(2)=4.712,P=0.030) and preoperative level of carcinoembryonic antigen(χ(2)=4.131,P=0.042) had significant effects on the survival. In multivariate analysis, the independent prognostic factors for these patients were tumor size (Wald=5.286,P=0.022), cell differentiation (Wald=7.172, P=0.007) and invasive depth (T staging, Wald=5.741, P=0.017). CONCLUSION: For node-negative rectal cancer patients, tumor size, poor differentiation and invasive depth are important markers to evaluate their prognosis.

[Logistic regression analysis of clinical and ultrasonic features of breast nodules].

OBJECTIVE: To create a breast nodule estimation model based on grayscale and color Doppler ultrasonography using Logistic regression that can screen out the specific features for distinguishing breast malignancy from benignancy. METHODS: From July, 2009 to May, 2010, 217 patients were enrolled in the study in peking university first hospital. Clinical data and ultrasonic features were evaluated in 219 breast nodules of 217 patients confirmed by surgical pathology. Logistic regression model was established to screen out significant ultrasonic indexes for differentiating breast malignancy from benignancy. A receiver operating characteristics curve was made to assess diagnostic value of the Logistic regression model. Correlation was analyzed between the Logistic regression model and surgical pathology. RESULTS: Logistic regression model: Logit(p) = -16.884 + 0.037 × age + 3.228 × longitudinal-transverse axis ratio + 1.412 × border + 2.663 × halo + 1.813 × microcalcium + 1.157 × resistance index + 2.204 × enlarged axillary lymph node (χ(2) = 167.107, P = 000). The areas of ROC curve for probability and identification of breast malignant and benign nodule were 0.948 and 0.882 respectively. Diagnostic sensitivity, specificity and accuracy were 91.6%, 84.9% and 88.9%. Logistic regression model positively correlated with surgical pathology (r = 0.768, P = 0.000). CONCLUSION: Our Logistic regression model can effectively differentiate malignant breast nodules from benign and can identify the ultrasonic features associated with breast cancer.

Nomogram for Predicting the Probability of Permanent Stoma after Laparoscopic Intersphincteric Resection.

PURPOSE: The purpose of this study was to determine the risk factors for the development of a permanent stoma in laparoscopic intersphincteric resection (LS-ISR) for ultralow rectal adenocarcinoma and to develop and validate a prediction model to predict the probability of permanent stoma after surgery. METHODS: A primary cohort consisting of 301 consecutive patients who underwent LS-ISR was enrolled in this study. Multivariable logistic regression analysis was used to identify risk factors and develop the nomogram. The performance of the nomogram was assessed with respect to its calibration, discrimination, and clinical usefulness. An independent validation cohort contained 91 consecutive patients from January 2012 to January 2019. RESULTS: The permanent stoma rate was 11.3% (34/301) in the primary cohort and 18.7% (17/91) in the validation cohort. Multivariable analysis revealed that nCRT (OR, 3.195; 95% CI, 1.169-8.733; P=0.024), ASA score of 3 (OR, 5.062; 95% CI, 1.877-13.646; P=0.001), distant metastasis (OR, 14.645; 95% CI, 3.186-67.315; P=0.001), and anastomotic leakage (OR, 11.308; 95% CI, 3.650-35.035; P<0.001) were independent risk factors for permanent stoma, and a nomogram was established. The AUCs of the nomogram were 0.842 and 0.858 in the primary and validation cohorts, respectively. The calibration curves showed good calibration in both cohorts. Decision curve analysis demonstrated that the nomogram was clinically useful. CONCLUSION: We developed and validated a nomogram for ultralow rectal adenocarcinoma patients who underwent LS-ISR, and the nomogram could help surgeons identify which patients are at a higher risk of a permanent stoma after surgery.

[Surgical complications after pancreatoduodenectomy: risk factors and treatments].

OBJECTIVE: To explore the impact factors and treatment of post pancreatoduodenectomy complications. METHODS: The clinical data of 412 cases between January 1995 and April 2010 underwent pancreatoduodenectomy were analyzed retrospectively. There were 232 male, 180 female. Univariate and multivariate logistic regression model were used to identify the risk factors related to occurrence of postoperative complications. RESULTS: The overall postoperative morbidity rate was 37.1% (153/412), and mortality rate was 4.6% (19/412). Total uncinate process resection, type of pancreatic-enteric anastomosis, duct diameter and pancreatic texture had effects on postoperative pancreatic fistula statistically. Total uncinate process resection, the amount of intra-operative blood loss ≥ 600 ml and pancreatic fistula were identified as significant risk factors for post pancreatoduodenectomy hemorrhage by means of univariate analysis. Delayed gastric empting occurrence in the patients with pylorus-preserving pancreaticoduodenectomy was higher than those with standard pancreaticoduodenectomy significantly. The multivariate Logistic regression analysis revealed that duct diameter and pancreatic texture were the independent risk factors of pancreatic fistula. Total uncinate process resection, the amount of intra-operative blood loss ≥ 600 ml and pancreatic fistula were independent risk factors of bleeding. There were no statistically significant differences between the radical group and the standard group when postoperative complication rates were analyzed (P < 0.05). CONCLUSIONS: Pancreaticojejunal anastomoses by means of duct-to-mucosa is fit for the patients with dilated pancreatic duct and end-to-end invaginated pancreaticojejunostomy is fit for the patients with undilated pancreatic duct. The prevention of postoperative bleeding depends on total uncinate process resection and meticulous hemostatic technique during operation. The pancreatic fistula is one of the most important factors which can result in postoperative bleeding. Pancreaticoduodenectomy combines with SMV/PV resection and extended lymphadenectomy do not significantly increase the morbidity rates.

[Surgical treatment and prognosis analysis of localized retroperitoneal Castleman disease: a study of 20 cases].

OBJECTIVE: To investigate the clinical characteristics, surgical treatment and prognosis analysis of localized retroperitoneal Castleman disease (CD), and to improve the level of diagnosis and treatment of retroperitoneal Castleman disease with paraneoplastic pemphigus (PNP). METHODS: The clinical data of retroperitoneal CD with PNP from January 1993 to May 2009 were compared with CD without PNP retrospectively, including clinical features, tumor site, lab examination, surgical treatment, pathologic subtype and results of surgery. RESULTS: (1) Retroperitoneal Castleman disease more likely originated in para-kidney and iliac fossa with middle age of 36 years old, especially in left retroperitoneum. Of the 20 cases, 18 tumors (90%) were hyaline vascular variants and 2 were mixed variants. There was no statistical difference in gender, age, tumor site and pathological subtype between two groups. (2) Retroperitoneal CD with PNP more likely complicated with bronchiolitis obliterans (BO) and high level of serum CEA/CA242. (3) Retroperitoneal Castleman tumors had clear margin, intact envelop and were easily resectable, however the biological behavior of CD with PNP might tend malignant changing, invade adjacent blood vessel or seed locally, and eventually relapse after operation. (4) The 5-year survival rate of retroperitoneal CD with PNP was 42.8%, significantly lower than those without PNP. The average survival time was 30 months. Bronchiolitis obliterans and radical resection were the key effect in prognosis of retroperitoneal CD. CONCLUSIONS: Retroperitoneal CD with PNP has distinctive clinical features. Early diagnosis, prompt removal of tumor and termination secretion of causative antibody are critical to the management of this disease.

[Lateral pelvic lymph node metastasis is an important prognostic factor for low rectal cancer].

OBJECTIVE: To evaluate the prognostic value of lateral pelvic lymph node metastasis on low rectal cancer. METHODS: One hundred and seventy-six patients with low rectal cancer who underwent radical resection combined with lateral pelvic lymph node dissection between 1994 and 2005 were reviewed. The data of the cases was investigated to define the prognostic value of lateral pelvic lymph node metastasis on the patients. RESULTS: Lateral node metastasis occurred in 33 patients (18.8%), and 51.5% of the metastasis occurred in internal iliac nodes or nodes at middle rectal roots and 39.4% in obturator nodes. Age < or =40 years, infiltrative cancer, T34 tumor, upward lymph node metastasis were risk factors for lateral node metastasis in low rectal cancer (P < 0.05). The overall 5-year survival rate was 64.1%, and it was 94.1%, 79.1%, 42.1% for patients with TNM stage I, II, III cancer, respectively. Tumor size, depth of infiltration, upward lymph node metastasis, lateral node metastasis was correlated significantly with prognosis (P < 0.05). The 5-year survival rate of the patients without lateral metastasis was 73.6%, which was significant higher than that of patients with lateral metastasis (21.4%, P < 0.05). CONCLUSION: Lateral pelvic lymph node metastasis is an important prognostic factor for low rectal cancer.

Crosstalk between TF/FVIIa and EGFR signaling in colorectal cancer cells.

TF/FVIIa (Tissue Factor/Active Coagulation factor VII) and EGFR (Epidermal Growth Factor Receptor) signaling both promote malignant progression of colorectal cancer. However, the crosstalk of these two signaling pathways in human colorectal cancer cells remains unclear. Here we detected the changes of mRNA profile in human colorectal cancer cell SW620 exposed to FVIIa. Microarray showed that mRNA levels of EGFR ligands were significantly upregulated. Western blot analysis confirmed the upregulation of EGFR ligands and the phosphorylation of EGFR at tyrosine-845 in colorectal cancer cells exposed to FVIIa. However, knockdown of TF by RNAi could block the upregulation of EGFR ligands induced by FVIIa stimulation. On the other hand, the expression of components of TF/FVIIa signaling was significantly upregulated in LoVo cells stimulated by EGF. However, the crosstalk between the two signaling pathways could not be detected in HT-29 colon cancer cells bearing wild-type KRAS. Taken together, our study suggest that the crosstalk between TF/FVIIa and EGFR signaling pathways in colon cancer cells depends on KRAS mutation.

[Efficacy analysis of neoadjuvant chemoradiotherapy combined with total pelvic exenteration in the treatment of primary T4b rectal cancer].

OBJECTIVE: To investigate the value of neoadjuvant chemoradiotherapy (nCRT) combined with total pelvic exenteration (TPE) in the treatment of primary T4b rectal cancer. METHODS: A retrospective cohort study was conducted to analyze the clinicopathological data of 31 patients with primary T4b rectal cancer who underwent TPE from January 2008 to December 2015 at Peking University First Hospital. INCLUSION CRITERIA: preoperative clinical stage (cTNM) was defined as cT4b primary rectal cancer with only front wall Invasion; the lower edge of tumor was within 10 cm from the anal margin; TPE was performed; R0 resection was confirmed by pathology. Patients with recurrent rectal cancer, distant metastasis, and undergoing TPE for non-rectal tumors were excluded. Patients were divided into nCRT group and non-nCRT group according to whether receiving nCRT before surgery. The nCRT group received long course radiotherapy (total dose 50 Gy in 25 daily fractions) with concomitant chemotherapy (Capecitabine), and the surgery was performed 6-8 weeks after the neoadjuvant chemoradiation, while the non-nCRT group received surgery directly. The intraoperative, postoperative and pathological conditions and local recurrence were compared between the two groups. The survival curves were drawn by Kaplan-Meier method and the survival of two groups were compared. RESULTS: A total of 31 patients were enrolled, including 13 patients in the nCRT group and 18 patients in the non-nCRT group. The baseline data, such as age, duration of disease, preoperative basic disease, body mass index, smoking rate, and tumor distance from the anal margin, were not significantly different between the two groups (all P>0.05). In the nCRT group and non-nCRT group respectively, the ratio of anal preservation was 30.8%(4/13) and 38.9%(7/18) (P=0.468), the median intraoperative blood loss was 1 000 ml and 800 ml (P=0.644), the operation time was (531.7±137.2) minutes and (498.0±90.1) minutes (P=0.703), the median hospital stay was 18 days and 14 days (P=0.400), the morbidity of complications within 30 days after surgery was 23.1%(3/13) and 38.9%(7/18)(P=0.452), the incidence of postoperative abdominal abscess was 15.4%(2/13) and 0 (P=0.168), the proportion of secondary surgery was 7.7%(1/13) and 11.1%(2/18)(P=1.000), whose differences were not significantly different. The proportion of postoperative pathological pT4b in whole group was 58.1%(18/31), including 53.8%(7/13) in nCRT group and 61.1%(11/18) in non-nCRT group, which was not significantly different between the two groups (P=0.691). The number of harvested lymph node in nCRT group was 13.5±5.9, which was significantly less than 23.0±11.8 in non-nCRT group (P=0.013). There was no pathological complete remission (ypCR) case in nCRT group, and among 13 patients, tumor regression grade (TRG) of 2, 3, 4, and 5 was in 1 case (7.7%), 6 cases (46.2%), 5 cases(38.5%), and 1 case (7.7%), respectively. The median follow-up time was 33 (2 to 115) months, and the follow-up rate was 93.5%(29/31). One case was lost in both the nCRT group and non-nCRT group. The 3-year disease-free survival rate was 43.5% in pooled data, and was 43.6% and 43.3% in nCRT group and non-CRT group respectively without significant difference (P=0.833). The 3-year overall survival rate was 51.1% in pooled data, and was 45.7% and 54.7% in nCRT group and non-nCRT group respectively without significant difference (P=0.653).The local recurrence rate of nCRT and non-nCRT groups was 8.3%(1/12) and 5.9%(1/17) respectively, and the distant metastasis rate was 50.0%(6/12) and 41.2%(7/17) respectively, whose differences were not statistically significant as well (P=1.000 and P=0.865, respectively). CONCLUSION: For primary T4b rectal cancer which can achieve R0 resection through total pelvic exenteration, neoadjuvant chemoradiotherapy has not been demonstrated any advantage in tumor regression, reducing local recurrence, or improving survival, and may increase postoperative complications.

[Genomic comparisons of multiresistant Pseudomonas aeruginosa isolates obtained from surgical intensive care unit].

OBJECTIVE: To investigate the genetic differences and their relativity with multi-drug resistance of Pseudomonas aeruginosa isolated. METHODS: Forty-nine Pseudomonas aeruginosa isolates were characterized by antimicrobial susceptibility and four-enzyme (I-CeuI, SpeI, SwaI, PacI) pulsed-field gel electrophoresis (PFGE). RESULTS: 85.7% of the P.aeruginosa isolates were MDR strains. Strains with PFGE pattern A were all susceptible to amikacin and cefepime, but were resistant to levofloxacin and meropenem. Strains with PFGE Patterns H and P had resistance to 6 - 8 different kinds of antibiotics. Strains with PFGE Patterns I and J were susceptible to all antibiotics tested in this study. Strains with other PFGE Patterns had intermediate resistance. PFGE pattern A was the dominant pattern, which accounted for 61.2% of all P.aeruginosa strains, 100% (2/2) in 2001, 65% (13/20) in 2002, 44.4% (8/18) in 2003 and 77.8% (7/9) in 2004. CONCLUSION: Four-enzyme combined PFGE analysis is highly discriminatory for the subtyping of MDR P.aeruginosa isolates.

[Hic-5/ARA55 inhibits the growth of Lovo cells by up-regulating the expression of P27].

OBJECTIVE: To investigate the effects of Hic-5/ARA55 on the growth of the human colorectal cancer cells (Lovo cells) and its mechanism. METHOD: Flow cytometry (FCM) was used to study the cell cycle of Lovo cells (Lovo group), Lovo cells stably transfected with empty vector (Lovo-Vector group) and the Lovo cells stably transfected with vector containing Hic-5/ARA55 (Lovo-Hic-5/ARA55 group). Western blot assay was used to detect the principal cyclins in the three groups, and Luciferase assay was used to study the mechanism between Hic-5/ARA55 and the only target cyclin. The cells from the three groups were inoculated subcutaneously into 7 nude mice (Balb/c nu/nu) respectively to observe the effects of Hic-5/ARA55 on the growth of the cells in vivo. Seven weeks later, the subcutaneous tumors were harvested and weighed. Then immunohistochemistry assay was used to detect Hic-5/ARA55 and the target cyclin in the tumors. RESULTS: The cell cycle was obviously delayed from G0/G1 to S stage in Lovo-Hic-5/ARA55 cells. A significantly higher expression of P27 was found in Lovo-Hic-5/ARA55 cells than in the other two groups. The weight of the subcutaneous tumors of Lovo-Hic-5/ARA55 cells, Lovo cells and Lovo-Vector cells were (0.33 +/- 0.23) g, (1.20 +/- 0.39) g and (1.30 +/- 0.49) g, respectively; the tumors of Lovo-Hic-5/ARA55 cells was significantly lighter than those of the other two groups (P<0.05). Hic-5/ARA55 and P27 were both over-expressed in implanted tumors of Lovo-Hic-5/ARA55 cells, while were both expressed lower or not expressed in the other two groups. And the expressions of Hic-5/ARA55 and P27 were highly positive correlated (r=0.816, P<0.05). CONCLUSION: Hic-5/ARA55 could inhibit the growth of Lovo cells both in vitro and in vivo by up-regulating the transcription of P27.

[The diagnosis and surgical management for patients with variants of hepatic arteries in the procedure of pancreaticoduodenectomy].

OBJECTIVE: To study the principle and surgical managements for the patients with anatomic variants of hepatic artery in the procedure of pancreaticoduodenectomy (PD). METHODS: One hundred and seventy-six patients who underwent PD between January 2000 and July 2007 were investigated retrospectively. Hepatic arterial variants were analyzed according to the intraoperative finding and CT imaging were reviewed postoperatively. RESULTS: Hepatic arterial variants were found intraoperatively in 20 cases of all 176 patients. Accessory right heptic artery, replaced right heptic artery and common heptic artery arising from the superior mesenteric artery (SMA) were present in 9 (5.1%), 5 (2.8%), 4 (2.3%) cases respectively,and replaced right heptic artery coming from the gastroduodenal artery was present in 2 cases (2.9%). All the variants of hepatic arteries arising from the superior mesenteric artery could be observed in spiral CT imaging. Most of the variant arteries were dissected intact intraoperatively except 2 cases with accessory right heptic artery arising from SMA. CONCLUSIONS: Performing CT scan preoperatively, especially CTA,is effective to diagnose these disorders. Skillful surgical techniques can manage the anatomic variants safely.

[Expression of proline-rich tyrosine kinase-2 in human primary colorectal carcinoma and its prognostic implication].

OBJECTIVE: To investigate the expression of proline-rich tyrosine kinase-2 (Pyk2) in human primary colorectal carcinoma (CRC) and it's prognostic significance. METHODS: The expression of Pyk2 was retrospectively examined with immunohistochemistry (IHC) in 108 tissues of primary CRC. The correlation of Pyk2 expression to prognosis and relevant clinical factors were analyzed. RESULTS: The rate of Pyk2 low-expression in CRC was 56.5% (61/108). The expression of Pyk2 correlated significantly to the histological grade (P < 0.05) and the TNM stage (P < 0.05), while no correlation between Pyk2 expression and age, tumor size (P > 0.05). Patients with Pyk2 over-expression had significantly higher 5-year survival rate (66.0%) than those with Pyk2 low-expression (31.4%). Pyk2 expression, together with carcinoma histologic grade and TNM stage were prognostic factors to CRC on the multivariate analysis. CONCLUSIONS: Pyk2 expression can be a prognostic factor to the CRC patients together with other predictors.