Nomogram Based on Clinical Characteristics to Predict 28-Day Mortality Among Patients with CRAB-BSI.

BACKGROUND: The drug resistance of carbapenem-resistant Acinetobacter baumannii bloodstream infections (CRAB-BSI), especially hospital-acquired infections, has promoted their rapid and vast spread. It is necessary to use reliable methods to establish better prediction models. According to Cox proportional hazards regression, a nomogram was established. METHODS: A retrospective cohort study among patients who were diagnosed with CRAB-BSI was performed from January 2020 to December 2022. Univariate and multivariate Cox proportional hazards regression analyses were used to determine independent prognostic factors regarding CRAB-BSI. Then, nomograms were used to calculate the area under the curve (AUC), C-index, and calibration curve to determine the predictive accuracy and dis-criminability. Decision curve analysis (DCA) was employed to further confirm the clinical effectiveness of the nomogram. RESULTS: A total of 98 cases were included in the comparison between the 28-day mortality group consisting of 32 patients and the 28-day survival group with 66 patients. The use of cefoperazone-sulbactam was significantly higher among patients who survived than among those who died. Univariable analysis revealed that factors such as primary diagnosis, time to inadequate antimicrobial therapy, and high serum creatinine and procalcitonin (PCT) levels were more prevalent in the mortality group. However, only primary diagnosis, time to inadequate antimicrobial therapy, and high PCT levels emerged as statistically significant risk factors for death in multivariate analysis and were used to construct the nomogram. The nomogram validation exhibited excellent performance. CONCLUSIONS: The nomogram was sufficiently accurate to predict the risk and prognostic factors of CRAB-BSI, allowing for individualized clinical decisions for future clinical work. The cefoperazone-sulbactam did have an effect, but more studies are needed to interpret it.

[Time-related association between fluid balance and prognosis in sepsis patients: a cohort study based on MIMIC-IV database].

OBJECTIVE: To investigate time-related association between fluid balance and prognosis in sepsis patients. METHODS: A retrospective cohort study was conducted based on the data of sepsis patients in the Medical Information Database for Intensive Care-IV 2.0 (MIMIC-IV 2.0) from 2008 to 2019. Sepsis patients aged ≥ 18 years who were admitted to intensive care unit (ICU) for at least 2 days were included. The daily fluid balance and cumulative fluid balance (CFB) were calculated from days 1 to 7 after ICU admission. According to CFB,the patients were divided into negative fluid balance group (CFB% < 0%), fluid balance group (0% ≤ CFB% ≤ 10%), and fluid overload group (CFB% > 10%). In-hospital mortality was the primary outcome. Multifactorial Logistic regression was used to analyze time-related association between different CFB and the risk of in-hospital mortality in patients with sepsis during 7 days after ICU admission. In addition, subgroup analysis was performed on patients with septic shock and patients with sepsis who stayed in the ICU for 7 days or longer. RESULTS: A total of 11 437 patients with sepsis were included, of which 6 595 were male and 4 842 were female. The mean age was (64.4±16.4) years. A total of 10 253 patients (89.6%) survived and 1 184 patients (10.4%) died during hospitalization. Compared with the survival group, patients in the death group were older, lighter, had higher sequential organ failure assessment (SOFA), simplified acute physiology score II (SAPS II), longer ICU stay, higher incidence of septic shock, and higher proportion of invasive mechanical ventilation, renal replacement therapy (RRT) and vasoactive drugs. In terms of comorbidities, congestive heart failure, renal disease, liver disease, and malignancy were more common in the death group. The death group had a higher daily fluid balance than the survival group during 7 days after ICU admission, the CFB in the two groups gradually increased with length of ICU stay. After adjusting variables such as age, gender, race, SOFA score, SAPS II score, comorbidities, and the use of invasive mechanical ventilation, RRT and vasoactive drugs, multivariate Logistic regression analysis showed that fluid overload on day 1 after ICU admission was a protective factor for the reduced risk of in-hospital mortality in sepsis patients [odds ratio (OR) = 0.74, 95% confidence interval (95%CI) was 0.64-0.86, P = 0.001]. However, fluid overload on day 3 was a risk factor for in-hospital mortality in sepsis patients (OR = 1.70, 95%CI was 1.47-1.97, P < 0.001) and the risk of in-hospital mortality was significantly increased from day 4 to day 7. Furthermore, the same results were obtained in patients with septic shock and sepsis patients who stayed in the ICU for 7 days or longer. CONCLUSIONS: Fluid overload on day 1 was associated with reduced in-hospital mortality. However, from the third day, fluid overload increases the risk of in-hospital mortality. Thus, managing fluid balance at different times may improve prognosis.

Intensivists' cognizance of nutrition management and its determinants in ICUs in Guizhou province, China.

BACKGROUND AND OBJECTIVES: To investigate the Intensivists' cognizance of nutritional management and its determinants, and to provide evidence for standardizing nutritional therapy with protocols. METHODS AND STUDY DESIGN: From April to July 2021, a multi-stage sampling method was used to investigate the nutritional cognizance of critical care physicians in secondary and tertiary hospitals in Guizhou Province, China; Questionnaires and scales were used as survey tools. The questionnaires sought general information about the respondents and documented their nutrition cognizance and practice. Five scalar dimensions explored nutritional management, with answers scored for 1-5 points, 3 points being the pass score. RESULTS: 322 respondents from 147 hospitals were surveyed. The average score was passable, but not good at 3.37±0.71 (p<0.01 with 3.0 as reference). Among the five dimensions, evaluation and monitoring of nutritional status had the highest score (3.79±0.67, p<0.01), the understanding of nutritional preparations had the lowest (3.09±0.86, p>0.05), and the scores of other dimensions ranged from 3.21 to 3.49. Almost 70% of intensivists said that they would give priority to other than nutritional therapeutic measures in actual clinical practice. But 96% thought it necessary to strengthen and emphasise nutritional management. CONCLUSIONS: Critical care physicians' knowledge and understanding of nutritional therapy are limited, especially in the use of supportive preparations; Recourse to protocols and standardized nutritional management of assistance may depend on training, assigned role, peer expectations and health system policy, each of which has the potential for advancement in the interest of better nutritional care in provincial Guizhou.

Risk Factors and Management of Postoperative Pancreatic Fistula Following Pancreaticoduodenectomy: Single-center Experience.

Pancreatic fistula (PF) remains the most frequent complication after pancreaticoduodenectomy (PD). This study was undertaken to explore the risk factors of postoperative PF following PD and discuss the management of PF in our center. A single-center respective study, involving 241 patients who underwent PD between September 2015 and June 2018, was conducted. Differences in the demographic data, preoperative, intraoperative and postoperative variables between the group with PF [International Study Group on Pancreatic Surgery (ISGPS) grade B/C] and the group without PF (no PF and ISGPS grade BL) were evaluated. The diagnosis and grading of PF were in strict accordance with ISGPS. Risk factors were analyzed by univariate analysis and multivariate logistic regression analysis. The results showed that postoperative PF occurred in 50 (20.7%) of the patients; 25 (10.4%) patients had a PF type BL, 46 (19.1%) patients developed a PF type B and 4 (1.6%) had a PF type C. Univariate analysis showed that fasting blood glucose (P=0.02), pancreatic texture (P< 0.001) and pancreatic duct diameter (P=0.01) were correlated with PF. Multivariate logistic regression analysis identified one independent risk factor for postoperative PF: soft pancreatic texture (OR=3.251, P=0.002). Among the cases, there were three postoperative deaths, giving a 60-day hospital mortality rate of 1.2% (3/241), and the mortality related to PF was 4.0% (2/50). One of the patients died from multiple organ failure caused by postoperative abdominal hemorrhage. In conclusion, soft pancreatic texture is an independent risk factor for PF. Surgeons should be well aware of this risk factor when performing a PD.

High risk factors of pancreatic carcinoma.

Over the past decades, cancer has become one of the toughest challenges for health professionals. The epidemiologists are increasingly directing their research efforts on various malignant tumor worldwide. Of note, incidence of cancers is on the rise more quickly in developed countries. Indeed, great endeavors have to be made in the control of the life-threatening disease. As we know it, pancreatic cancer (PC) is a malignant disease with the worst prognosis. While little is known about the etiology of the PC and measures to prevent the condition, so far, a number of risk factors have been identified. Genetic factors, pre-malignant lesions, predisposing diseases and exogenous factors have been found to be linked to PC. Genetic susceptibility was observed in 10% of PC cases, including inherited PC syndromes and familial PC. However, in the remaining 90%, their PC might be caused by genetic factors in combination with environmental factors. Nonetheless, the exact mechanism of the two kinds of factors, endogenous and exogenous, working together to cause PC remains poorly understood. The fact that most pancreatic neoplasms are diagnosed at an incurable stage of the disease highlights the need to identify risk factors and to understand their contribution to carcinogenesis. This article reviews the high risk factors contributing to the development of PC, to provide information for clinicians and epidemiologists.

Minimally invasive percutaneous catheter drainage versus open laparotomy with temporary closure for treatment of abdominal compartment syndrome in patients with early-stage severe acute pancreatitis.

This study aimed to examine the clinical efficacy of minimally invasive percutaneous catheter drainage (PCD) versus open laparotomy with temporary closure in the treatment of abdominal compartment syndrome (ACS) in patients with early-stage severe acute pancreatitis (SAP). Clinical data of 212 patients who underwent PCD and 61 patients who were given open laparotomy with temporary closure in our hospital over the last 10-year period were retrospectively analyzed, and outcomes were compared, including total and post-decompression intensive care unit (ICU) and hospital stays, physiological data, organ dysfunction, complications, and mortality. The results showed that the organ dysfunction scores were similar between the PCD and open laparotomy groups 72 h after decompression. In the PCD group, 134 of 212 (63.2%) patients required postoperative ICU support versus 60 of 61 (98.4%) in the open laparotomy group (P<0.001). Additionally, 87 (41.0%) PCD patients experienced complications as compared to 49 of 61 (80.3%) in the open laparotomy group (P<0.001). There were 40 (18.9%) and 32 (52.5%) deaths, respectively, in the PCD and open laparotomy groups (P<0.001). In conclusion, minimally invasive PCD is superior to open laparotomy with temporary closure, with fewer complications and deaths occurring in PCD group.

Etiology, pathology, management and prognosis of chronic pancreatitis in Chinese population: A retrospective study.

The purpose of this study was to investigate the etiology, pathological characteristics, management and prognosis of chronic pancreatitis in the Chinese population. The clinical data of 142 patients with chronic pancreatitis were retrospectively studied. All patients were of Chinese nationality and hospitalized from January 2008 to December 2011. Their ages ranged from 14 to 76 years, with a mean of 43 years. Of 142 patients, there were 72 cases of obstructive chronic pancreatitis (50.70%), 19 cases of alcoholic chronic pancreatitis (13.38%), 14 cases of autoimmune pancreatitis (9.86%) and 37 cases of undetermined etiology (26.06%). Pathologically, the average inflammatory mass diameter was 3.8 ± 3.3 cm, biliary obstruction occurred in 36 cases, gall stones in 70 cases, calcification in 88 cases, ductal dilatation in 61 cases, side branch dilatation in 32 cases, ductal irregularity in 10 cases, lymphocytic inflammation in 23 cases, obliterative phlebitis in 14 cases, extra pancreatic lesion in 19 cases and fibrosis in 142 cases. Location of pancreatic lesion in the region of head (n=97), neck (n=16), body (n=12), tail (n=15) and whole pancreas (n=2) influenced the choice of surgical procedures. Ninety-four patients (66.20%) received surgical treatment and 33.80% received other treatments. After operation, 80.85% of 94 patients experienced decreased pain, and 8.51% of 94 showed recovery of endocrine function but with a complication rate of 12.77%. All the operations were performed successfully. According to the pain scale of European Organization for Research and Treatment of Cancer (QLQ-C30) a decrease from 76 ± 22 to 14 ± 18 was observed. Etiology, pathological characteristics, management and prognosis of chronic pancreatitis in the Chinese population vary from others.

Heparin inhibits the inflammatory response induced by LPS and HMGB1 by blocking the binding of HMGB1 to the surface of macrophages.

High mobility group box 1 protein (HMGB1), a nuclear non-histone DNA-binding protein, is secreted extracellularly during inflammation and is a late mediator of inflammatory responses. The pro-inflammatory activity of recombinant HMGB1 proteins is dependent upon the formation of complexes with other mediators, such as lipopolysaccharide (LPS). This study investigated the influence of heparin on LPS+HMGB1-mediated inflammatory responses in cultured macrophages and a murine sepsis model. HMGB1 promoted the phosphorylation of p38 and ERK1/2. HMGB1 enhanced the induction of the pro-inflammatory cytokine, TNF-α, by LPS in macrophages. Heparin blocked the binding of HMGB1 to the surface of macrophages, and suppressed the phosphorylation of p38 and ERK1/2, but not JNK; TNF-α secretion was also decreased. However, heparin alone did not affect LPS-induced production of TNF-α. Heparin reduced lethality in mice exposed to LPS+HMGB1. To conclude, heparin inhibited LPS-induced HMGB1-amplified inflammatory responses by blocking HMGB1 binding to macrophage surfaces. Heparin could be used therapeutically as an effective inhibitor of HMGB1-associated inflammation.

Surgical treatment of chronic pancreatitis in young patients.

The main treatment strategies for chronic pancreatitis in young patients include therapeutic endoscopic retrograde cholangio-pancreatography (ERCP) intervention and surgical intervention. Therapeutic ERCP intervention is performed much more extensively for its minimally invasive nature, but a part of patients are referred to surgery at last. Historical and follow-up data of 21 young patients with chronic pancreatitis undergoing duodenum-preserving total pancreatic head resection were analyzed to evaluate the outcomes of therapeutic ERCP intervention and surgical intervention in this study. The surgical complications of repeated therapeutic ERCP intervention and surgical intervention were 38% and 19% respectively. During the first therapeutic ERCP intervention to surgical intervention, 2 patients developed diabetes, 5 patients developed steatorrhea, and 5 patients developed pancreatic type B pain. During the follow-up of surgical intervention, 1 new case of diabetes occurred, 1 case of steatorrhea recovered, and 4 cases of pancreatic type B pain were completely relieved. In a part of young patients with chronic pancreatitis, surgical intervention was more effective than therapeutic ERCP intervention on delaying the progression of the disease and relieving the symptoms.

Overexpression of membrane-type 2 matrix metalloproteinase induced by hypoxia-inducible factor-1α in pancreatic cancer: Implications for tumor progression and prognosis.

Membrane-type 2 matrix metalloproteinase (MT2-MMP) has been identified as a powerful modulator of the pericellular environment that promotes tumor invasion and metastasis. In this study, we investigated the association of MT2-MMP and hypoxia-inducible factor-1α (HIF-1α) expression in pancreatic cancer with regard to their clinical prognostic significance. Of the tissue specimens obtained from the 78 patients included in this study, 46 (59%) were found to be positive for MT2-MMP immunostaining and MT2-MMP expression was colocalized with HIF-1α in pancreatic cancer. Using the Spearman's rank analysis, the protein and mRNA expression level of MT2-MMP was found to be significantly correlated with HIF-1α and CD34-microvascular density in pancreatic cancer. Furthermore, the expression of MT2-MMP in response to hypoxia was increased in a time-dependent manner and the promoter luciferase reporter revealed upregulation of MT2-MMP expression induced by HIF-1α in pancreatic cancer cells. Moreover, the Cox regression model indicated that MT2-MMP was an independent prognostic factor in patients with pancreatic cancer. Our results demonstrated that the overexpression of MT2-MMP was induced by HIF-1α in response to hypoxia and was an independent prognostic factor for pancreatic cancer progression.

[Phosphatidylinositol 3-kinase/mammalian target of rapamycin pathway is critical for survival and proliferation of pancreatic cancer stem-like side population cells].

OBJECTIVE: To isolate and identify the side population (SP) cells in pancreatic cancer and investigate the role of phosphatidylinositol 3-kinase/mammalian target of rapamycin (PI3K/mTOR) pathway in the survival and proliferation of them. METHODS: Pancreatic cancer cell of the lines PANC-1, BXPC-3, ASPC-1, PC-3, and SW-1990 were cultured. Hoechst 33432 staining and fluorescence-activated cell sorter (FACS) were used to sort the SP cells. Verapamil, inhibitor of ATP binding cassette (ABC) transporter, was added before the Hoechst 33342 inoculation to observe its influence on the SP proportion. Media with LY294002, specific inhibitor of P13K, or rapamycin, specific inhibitor of mammalian target of rapamycin (mTOR), were used to culture PANC-1 cells to observe the survival of cells. Twenty-one NOD-SCID mice were randomly divided into 7 equal groups. Four groups were inoculated subcutaneously with SP cells of the concentrations of 5x10(5), 5x10(4), 5x10(3), or 1x10(3) at the right axillary fossa and with non-SP cells at the left then Hoechst 33342 staining, flow cytometric sorting were used to detect the content of SP cells at the left axillary fossa. The other 3 groups were injected subcutaneously with non-Hoechst 33342 treated cells of the concentrations of 5x10(5), 5x10(4), 5x10(3), or 1x10(3) at the right axillary fossa and PBS at the left axillary fossa. Ten weeks later the mice were killed to undergo pathological examination. RESULTS: All cell lines were found to exhibit verapamil-sensitive SP cells except BXPC-3 cells. The SP cell proportion of the PANC-1 cells was 7.84%. No SP cell was found in the cells treated with verapamil. The colony-formation ability of the SP cells was (43.7+/-3.1)%, significantly higher than those of the non-SP cells and cells without Hoechst 33342 cells [(8.3+/-1.6)% and (10.2+/-1.9)% respectively, both P=0.000]. The tumorigenic ability of the SP cells was 100 times as those of the non-SP cells and Hoechst 33342 un-treated cells. After addition of LY294002 and rapamycin the fractions of the SP cells in the in PANC-1 cells decreased from (7.60+/-0.27)% to (1.90+/-0.22)% and (1.14+/-0.20)% respectively, both P=0.000, and they preferentially inhibited the SP cells rather than non-SP cells. CONCLUSION: SP cells are enriched in pancreatic cancer stem-like cells. PI3K/mTOR pathway is critical for pancreatic SP cells maintenance that can be selected as a new target for inhibiting cancer stem-like cells.

Delayed ethyl pyruvate therapy attenuates experimental severe acute pancreatitis via reduced serum high mobility group box 1 levels in rats.

AIM: To investigate the effect of delayed ethyl pyruvate (EP) delivery on distant organ injury, survival time and serum high mobility group box 1 (HMGB1) levels in rats with experimental severe acute pancreatitis (SAP). METHODS: A SAP model was induced by retrograde injection of artificial bile into the pancreatic ducts of rats. Animals were divided randomly into three groups (n = 32 in each group): sham group, SAP group and delayed EP treatment group. The rats in the delayed EP treatment group received EP (30 mg/kg) at 12 h, 18 h and 30 h after induction of SAP. Animals were sacrificed, and samples were obtained at 24 h and 48 h after induction of SAP. Serum HMGB1, aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN), and creatinine (Cr) levels were measured. Lung wet-to-dry-weight (W/D) ratios and histological scores were calculated to evaluate lung injury. Additional experiments were performed between SAP and delayed EP treatment groups to study the influence of EP on survival times of SAP rats. RESULTS: Delayed EP treatment significantly reduced serum HMGB1 levels, and protected against liver, renal and lung injury with reduced lung W/D ratios (8.22 +/- 0.42 vs 9.76 +/- 0.45, P < 0.01), pulmonary histological scores (7.1 +/- 0.7 vs 8.4 +/- 1.1, P < 0.01), serum AST (667 +/- 103 vs 1 368 +/- 271, P < 0.01), ALT (446 +/- 91 vs 653 +/- 98, P < 0.01) and Cr (1.2 +/- 0.3 vs 1.8 +/- 0.3, P < 0.01) levels. SAP rats had a median survival time of 44 h. Delayed EP treatment significantly prolonged median survival time to 72 h (P < 0.01). CONCLUSION: Delayed EP therapy protects against distant organ injury and prolongs survival time via reduced serum HMGB1levels in rats with experimental SAP. EP may potentially serve as an effective new therapeutic option against the inflammatory response and multiple organ dysfunction syndrome (MODS) in SAP patients.

Differentiation of CD24- pancreatic ductal cell-derived cells into insulin-secreting cells.

Pancreatic progenitor cells represent both a potential source of transplantable islets for the treatment of diabetes and a valuable instrument for the investigation of the tumorigenesis of pancreatic carcinoma. It has been reported that pancreatic ductal cells of adults have the characteristics of pancreatic progenitors, but whether these cells can generate endocrine cells requires verification. Here, the differentiation of daughter cells of CD24(-) pancreatic ductal cells into insulin-secreting cells in vitro is reported. Crude pancreatic ductal cells were first obtained from adult mice by gradient centrifugation, and then the CD24(-) cells were isolated with a fluorescence-activated cell sorter. The isolated cells were cultured in serum-containing medium at clonal density to form epithelial colonies (ECs). The ECs were then stimulated with basic fibroblast growth factor (bFGF). After 72 h, insulin-secreting cells were observed in the ECs. These results indicate that the daughter cells of CD24(-) pancreatic ductal cells can differentiate into insulin-secreting cells in vitro when stimulated with exogenous bFGF. Therefore, CD24(-) pancreatic ductal cells have the potential to be pancreatic progenitor cells.

Persistence of side population cells with high drug efflux capacity in pancreatic cancer.

AIM: To investigate the persistence of side population (SP) cells in pancreatic cancer and their role and mechanism in the drug resistance. METHODS: The presentation of side population cells in pancreatic cancer cell line PANC-1 and its proportion change when cultured with Gemcitabine, was detected by Hoechst 33342 staining and FACS analysis. The expression of ABCB1 and ABCG2 was detected by real-time PCR in either SP cells or non-SP cells. RESULTS: SP cells do exist in PANC-1, with a median of 3.3% and a range of 2.1-8.7%. After cultured with Gemcitabine for 3 d, the proportion of SP cells increased significantly (3.8% +/- 1.9%, 10.7% +/- 3.7%, t = 4.616, P = 0.001 < 0.05). ABCB1 and ABCG2 expressed at higher concentrations in SP as compared with non-SP cells (ABCB1: 1.15 +/- 0.72, 5.82 +/- 1.16, t = 10.839, P = 0.000 < 0.05; ABCG2: 1.16 +/- 0.75, 5.48 +/- 0.94, t = 11.305, P = 0.000 < 0.05), which may contribute to the efflux of fluorescent staining and drug resistance. CONCLUSION: SP cells with inherently high resistance to chemotherapeutic agents do exist in pancreatic cancers, which may be candidate cancer stem cells contributing to the relapse of the tumor.

[Expression of sonic hedgehog, EGFR and PCNA proteins in pancreatic cancer and their correlations to cell proliferation].

BACKGROUND & OBJECTIVE: Sonic hedgehog (SHH) signaling pathway is important for modulating cellular interaction in the development of mammalian embryo. Epidermal growth factor receptor (EGFR) has been involved in the regulation of cell proliferation and differentiation. Proliferating cell nuclear antigen (PCNA) is an indicator of cell proliferation. This study was to investigate the expression of SHH, EGFR and PCNA in pancreatic cancer, and explore their correlations to cell proliferation. METHODS: The expression of SHH, EGFR, and PCNA in 49 specimens of pancreatic cancer and 49 specimens of normal pancreatic tissues adjacent to cancer was detected by immunohistochemistry. Their interrelations were analyzed. RESULTS: The positive rates of SHH and EGFR were significantly higher in pancreatic cancer than in normal tissue adjacent to cancer (79.6% vs.14.3%, 73.5% vs.16.3%, P<0.05). The expression of SHH and EGFR in pancreatic cancer had no correlation to patientsoage, tumor size, pathologic type, and tumor site (P>0.05), but were correlated to lymph node metastasis and TNM stage (P<0.05). The strong positive rate of PCNA was significantly higher in pancreatic cancer than in normal tissues (83.7% vs. 20.4%, P<0.05). SHH expression was positively correlated to EGFR expression (r1=0.232, P<0.05). SHH and EGFR expression were positively correlated to PCNA expression(r2=0.412, P<0.05û r3=0.186, P<0.05). CONCLUSION: SHH and EGFR signal pathways are active in pancreatic carcinoma, and are closely correlated to cancer cell proliferation.

In vitro pancreas duodenal homeobox-1 enhances the differentiation of pancreatic ductal epithelial cells into insulin-producing cells.

AIM: To observe whether pancreatic and duodenal homeobox factor-1 enhances the differentiation of pancreatic ductal epithelial cells into insulin-producing cells in vitro. METHODS: Rat pancreatic tissue was submitted to digestion by collegenase, ductal epithelial cells were separated by density gradient centrifugation and then cultured in RPMI1640 medium with 10% fetal bovine serum. After 3-5 passages, the cells were incubated in a six-well plate for 24 h before transfection of recombination plasmid XlHbox8VP16. Lightcycler quantitative real-time RT-PCR was used to detect the expression of PDX-1 and insulin mRNA in pancreatic epithelial cells. The expression of PDX-1 and insulin protein was analyzed by Western blotting. Insulin secretion was detected by radioimmunoassay. Insulin-producing cells were detected by dithizone-staining. RESULTS: XlHbox8 mRNA was expressed in pancreatic ductal epithelial cells. PDX-1 and insulin mRNA as well as PDX-1 and insulin protein were significantly increased in the transfected group. The production and insulin secretion of insulin-producing cells differentiated from pancreatic ductal epithelial cells were higher than those of the untransfected cells in vitro with a significant difference (1.32 +/- 0.43 vs 3.48 +/- 0.81, P < 0.01 at 5.6 mmol/L; 4.86 +/- 1.15 vs 10.25 +/- 1.32, P < 0.01 at 16.7 mmol/L). CONCLUSION: PDX-1 can differentiate rat pancreatic ductal epithelial cells into insulin-producing cells in vitro. In vitro PDX-1 transfection is a valuable strategy for increasing the source of insulin-producing cells.

PDX-1 expression and proliferation of duct epithelial cells after partial pancreatectomy in rats.

BACKGROUND: The pancreas has a strong regeneration potential in mammals. Previous studies suggested that pancreas regeneration is correlated with proliferation and differentiation of pancreatic stem cells, but the field of pancreatic stem cells is still in its infancy. This study was undertaken to detect the expression of pancreas/duodenal homeobox-1 (PDX-1) and proliferation of pancreatic duct epithelial cells in remnant pancreas during regeneration after partial pancreatectomy in rats, and characterize the source of pancreatic stem cells. METHODS: Partial pancreatectomy (90%) was performed on four- to five-week-old Sprague-Dawley rats, and duct epithelial cells and acinar cells were detected by immunohistochemical staining and scored using the 5-bromo-2-deoxyuridine (BrdU) labelling index at various time points. Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR) were used to assess the expression of PDX-1 protein and mRNA, respectively. RESULTS: At 24 hours after partial pancreatectomy, proliferation started in the main, large and small duct cells, and persisted in small duct cells to day 5. The experimental and control groups were significantly different (P<0.001). BrdU-positive acinar cells were greatly increased and reached a peak on day 5. PDX-1 protein was only faintly detectable in pancreatic ductal cells on day 1 after partial pancreatectomy. On days 2 and 3, a 2-3 fold increase in PDX-1 protein was observed, corresponding to the characteristic 42 kD protein in Western blotting. The operated and sham-operated groups also differed significantly (P<0.05). PDX-1 protein expression on days 5 and 7 after operation did not differ from that of the control group. RT-PCR revealed that PDX-1 mRNA expression did not significantly differ between the operated group and the sham-operated group at various time points. CONCLUSIONS: Pancreatic stem cells in pancreatic ductal epithelial cells are involved in the regeneration of remnant pancreas and the expression of PDX-1 in ductal cells is due to posttranscriptional regulation.

Blockade of sonic hedgehog signal pathway enhances antiproliferative effect of EGFR inhibitor in pancreatic cancer cells.

AIM: To investigate the expression of sonic hedgehog (SHH) and epidermal growth factor receptor (EGFR) signal molecules in pancreatic cancer cells, and to assess the inhibitory effects through the blockade of the SHH and EGFR signaling pathways by cyclopamine and Iressa, respectively. METHODS: The expression of SHH and EGFR in pancreatic cancer cell lines (PANC-1, SUIT-2, and ASPC-1) was detected by RT-PCR and Western blot analysis. After treatment with different concentrations of cyclopamine, alone or in combination with Iressa, the antiproliferative effect on pancreatic cancer cells was analyzed by methyl thiazolyl tetrazolium assays. A flow cytometry analysis was used to detect the cellular cycle distribution and apoptosis of pancreatic cancer cells. RESULTS: All of the 3 pancreatic cancer cell lines expressed SHH, Smoothened (SMO), and EGFR. Cyclopamine could downregulate the expression of EGFR in all cell lines. Cyclopamine or Iressa could induce a growth inhibitory effect in a dose-dependent manner. Moreover, the combined use of 2.5 micromol/L cyclopamine and 1 micromol/L Iressa induced an enhanced inhibitory effect and a greater apoptosis rate than any agent alone. The percentage of the cell population of the G0/G1 and sub-G1 phases was significantly increased along with the increasing dose of cyclopamine and/or Iressa. CONCLUSION: The blockade of the sonic hedgehog signal pathway enhances the antiproliferative effect of the EGFR inhibitor through the downregulation of its expression in pancreatic cancer cells. The simultaneous blockade of SHH and EGFR signaling represents possible targets of new treatment strategies for pancreatic carcinoma.

Pancreas duodenal homeobox-1 expression and significance in pancreatic cancer.

AIM: To study the correlations of Pancreas duodenal homeobox-1 with pancreatic cancer characteristics, including pathological grading, TNM grading, tumor metastasis and tumor cell proliferation. METHODS: Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect PDX-1 mRNA expression in pancreatic cancer tissue and normal pancreatic tissue. The expression of PDX-1 protein was measured by Western blot and immunohistochemistry. Immunohistochemistry was also used to detect proliferative cell nuclear antigen (PCNA). Correlations of PDX-1 with pancreatic cancer characteristics, including pathological grading, TNM grading, tumor metastasis and tumor cell proliferation, were analyzed by using c2 test. RESULTS: Immunohistochemistry showed that 41.1% of pancreatic cancers were positive for PDX-1 expression, but normal pancreatic tissue except islets showed no staining for PDX-1. In consistent with the result of imunohistochemistry, Western blot showed that 37.5% of pancreatic cancers were positive for PDX-1. RT-PCR showed that PDX-1 expression was significantly higher in pancreatic cancer tissues than normal pancreatic tissues (2(-3.56 +/- 0.35) vs 2(-8.76 +/- 0.14), P < 0.01). Lymph node metastasis (P < 0.01), TNM grading (P < 0.05), pathological grading (P < 0.05) and tumor cell proliferation (P < 0.01) were significantly correlated with PDX-1 expression levels. CONCLUSION: PDX-1 is re-expressed in pancreatic cancer, and PDX-1-positive pancreatic cancer cells show more malignant potential compared to PDX-1-negative cells. Therefore, PDX-1-positive cells may be tumor stem cells and PDX-1 may act as alternate surface marker of pancreatic cancer stem cells.

[Indication and choice of operation technique for duodenum-preserving resection of pancreatic head: 22 cases reports].

OBJECTIVE: To analyze the indication and choice of operation technique for duodenum-preserving resection of pancreatic head. METHODS: The Clinical material of the 22 patients who received duodenum-preserving resection of pancreatic head (DPPHR) from January 2001 to January 2006 was analyzed. Of the 22 cases, 8 cases presented with mucinous cystadenoma, 2 cases with mucinous cystadenocarcinoma, 4 cases with solid-pseudopapillary tumors, 2 cases with pancreatic endocrine tumors, 4 cases with chronic pancreatitis, 1 case with lymph epidermis cyst, 1 case with serous cystadenoma. The indication, choice of operation technique of DPPHR and the prevention and management of the post-operative complications were investigated. RESULTS: No patient died of the operation. Three cases (13.6%) developed pancreatic fistula after the operation, 1 case (4.5%) developed biliary fistula, 1 case (4.5%) developed abdominal infection and 2 cases of duodenal fistula occurred (9.1%). CONCLUSIONS: DPPHR retains the continuity of stomach, duodenum and biliary ducts. The operation is safe and it reduces wounds and excision scope. This procedure can be used in benign and low malignant lesions in the head and neck of the pancreas.