Prolactin induces lipid synthesis of organ-cultured pigeon crops

The objective of this research was to examine the effects of prolactin (PRL) on the lipid synthesis of organ-cultured pigeon crops in vitro. In experiment 1, the histology, activities of enzymes, and expression of genes involved in metabolism and apoptosis of organ-cultured pigeon crops were analyzed over a 7-d culture period. The results showed that cultured crops maintained their structural integrity for up to 3 d in vitro. Beyond 3 d, caspase-3 activity and Bak1 gene expression increased with day of culture, whereas the activities of succinate dehydrogenase, Na+-K+-ATPase, Ca2+-Mg2+-ATPase, total ATPase, and gene expression of Bcl-2 and CK-19 diminished (P < 0.05). In experiment 2, the crops were cultured for 24, 36, and 48 h in medium containing 0, 25, or 50 ng/mL PRL, respectively, and the accumulation of lipid droplets, lipid content, and expression of fatty acid transportation- and lipogenesis-related genes were analyzed. The results showed that the crops with PRL supplements showed higher amounts of lipid droplets than those of the controls, and the droplets were mainly located in the basal nutritive layer in response to PRL. The efficacy of inducing lipid accumulation increased as the concentration of PRL increased. Crops with 50 ng/mL PRL incubated for 36 h displayed the maximal lipid content. Increasing the concentration of PRL from 0 to 50 ng/mL resulted in a dose-dependent increase in the expression of acetyl-CoA carboxylase, fatty acid synthase, fatty acid translocase, fatty acid binding protein 5, acyl-CoA binding protein, and peroxisome proliferator-activated receptor γ genes after incubation for 36 h (P < 0.05). Therefore, our results indicated that the organ-cultured pigeon crops maintained good viability for up to 3 d in vitro. Furthermore, PRL induced the lipid synthesis of organ-cultured pigeon crops in a dose- and time-dependent manner, which was related to the increased expression of genes involved in fatty acid transportation and lipogenesis.

Diagnostic value of negative enrichment and immune fluorescence in situ hybridization for intraperitoneal free cancer cells of gastric cancer

Objective

To explore the intraperitoneal free cancer cell (IFCC) detection value of negative enrichment and immune fluorescence in situ hybridization (NEimFISH) on chromosomes (CEN) 8/17.

Methods

To verify the reliability of NEimFISH, 29 gastric cancer tumors, their adjacent tissues and greater omental tissues were tested. Our study then included 105 gastric cancer patients for IFCC. We defined patients as IFCC-positive if a signal was detected, regardless of the detailed cancer cell numbers. A comparison of clinicopathological features was conducted among IFCC groups. We also compared the diagnosis value and peritoneal recurrence predictive value among different detection methods. The comparison of IFCC number was also conducted among different groups.

Results

A cutoff of 2.5 positive cells could distinguish all benign tissue samples and 97% of malignant tissue samples in our study. Compared to intestinal gastric cancer, patients with diffuse gastric cancer tended to have more IFCCs (6 vs. 4, P=0.002). The IFCC counts were often higher in the lymphovascular invasion positive group than negative group (3 vs. 1, P=0.022). All IFCC samples that were considered positive using conventional cytology were also found to be positive using NEimFISH. When compared to conventional cytology and paraffin pathology, NEimFISH had a higher IFCC positive rate (68.9%) and higher one-year peritoneal recurrence predictive value with area under the curve (AUC) of 0.922.

Conclusions

Gastric cancer could be effectively diagnosed by NEimFISH. The IFCC number found using NEimFISH on CEN8/17 is closely associated with Lauren type and vascular invasion of cancer. NEimFISH is a reliable detection modality with a higher positive detection rate, higher one-year peritoneal recurrence predictive value and quantitative features for IFCC of gastric cancer.

Changes in hormone profiles, growth factors, and mRNA expression of the related receptors in crop tissue, relative organ weight, and serum biochemical parameters in the domestic pigeon (Columba livia) during incubation and chick-rearing periods under artificial farming conditions

The present study was conducted to determine the changes in concentrations of hormones and growth factors and their related receptor gene expressions in crop tissue, relative organ weight, and serum biochemical parameters in male and female pigeons during incubation and chick-rearing periods under artificial farming conditions. Seventy-eight pairs of 60-week-old White King pigeons with 2 fertile eggs per pair were randomly divided into 13 groups by different breeding stages. Serum prolactin and insulin-like growth factor-1 (IGF-1) concentrations in crop tissue homogenates were the highest in both male and female pigeons at 1 d of chick-rearing (R1), while epidermal growth factor (EGF) in female pigeons peaked at d 17 of incubation (I17) (P < 0.05). mRNA expression of the prolactin and EGF receptors in the crop tissue increased at the end of incubation and the early chick-rearing stage in both sexes. However, estrogen, progesterone, and growth hormone receptor expression each decreased during the early chick-rearing stage (P < 0.05). In male pigeons, IGF-1 receptor gene expression reached its peak at R7, while in female pigeons, it increased at the end of incubation. The relative weight of breast and abdominal fat in both sexes and thighs in the males was lowest at R7, and then gradually increased to the incubation period level. Serum total protein, albumin, and globulin concentrations increased to the highest levels at I17 (P < 0.05). Total cholesterol, triglyceride, and low-density lipoprotein reached their highest values at I17 in male pigeons and R25 in female pigeons (P < 0.05). In conclusion, hormones, growth factors, and their receptors potentially underlie pigeon crop tissue development. Changes in organs and serum biochemical profiles suggested their different breeding-cycle patterns with sexual effects.

The effect of preoperative treatments on lymph node counts after total gastrectomy in esophagogastric adenocarcinoma

OBJECTIVES

This study aims to explore the effects of preoperative treatments on lymph nodes (LNs) counts after total gastrectomy with D2 lymphadenectomy in esophagogastric adenocarcinoma.

METHODS

A retrospective analysis was performed for 446 patients with locally advanced esophagogastric adenocarcinoma. The patients were divided into three groups: surgery first (SF), preoperative chemotherapy (PCT), and preoperative chemoradiotherapy (PCRT). Clinical-pathological data were analyzed.

RESULTS

The case number in SF, PCT, and PCRT groups was 281, 109, and 56, respectively, and the median total LNs count was 32.0 (10.0-102.0), 31.0 (12.0-62.0), and 25.5 (10.0-50.0), respectively, (P < 0.001). Univariate and multivariate analyses demonstrated the total LNs count was lower in PCRT than SF/PCT (P < 0.001), and had no correlation with tumor regression grades (TRGs). Subgroup comparison showed radiation target LNs count was lower in PCRT than SF/PCT (P < 0.001), and peritarget LNs count was lower in PCRT than SF (P = 0.002).

CONCLUSION

For esophagogastric adenocarcinoma, PCRT reduced total LNs count after total gastrectomy with D2 lymphadenectomy, whereas PCT did not. In the PCRT group, LNs count was lower in both radiation target and peritarget areas than in the SF group but only in radiation target area than in the PCT group. The correlation between TRGs and total LNs count remained unclear.

ABCC2-24C > T polymorphism is associated with the response to platinum/5-Fu-based neoadjuvant chemotherapy and better clinical outcomes in advanced gastric cancer patients

Several studies have evaluated the efficacy of neoadjuvant treatment using oxaliplatin and fluoropyrimidines in advanced gastric cancer (GC). However, preoperative biomarkers predictive of clinical outcome remain lacking. We examined polymorphisms in the MTHFR, DPYD, UMPS, ABCB1, ABCC2, GSTP1, ERCC1, and XRCC1 genes to evaluate their usefulness as pharmacogenetic markers in a cohort of 103 GC patients treated with preoperative chemotherapy. DNA was extracted from peripheral blood cells, and the genotypes were analyzed using a SNaPShot^TM assay, polymerase chain reaction amplification, and sequencing. The ABCC2-24C > T (rs717620) genotype was associated with pathologic response to neoadjuvant chemotherapy. Patients with the TT and TC genotypes responded to neoadjuvant chemotherapy 3.80 times more often than those with the CC genotype (95% CI: 1.27–11.32). Patients with the CC genotype also had poorer outcomes than those with other genotypes. Thus, ABCC2-24C > T polymorphism may help to predict the response to preoperative chemotherapy in GC patients.

Germline mutations in hereditary diffuse gastric cancer

Gastric cancer is one of the leading causes of cancer-related deaths worldwide. Among which, about 1%-3% of gastric cancer patients were characterized by inherited gastric cancer predisposition syndromes, knowing as hereditary diffuse gastric cancer (HDGC). Studies reported that CDH1 germline mutations are the main cause of HDGC. With the help of rapid development of genetic testing technologies and data analysis tools, more and more researchers focus on seeking candidate susceptibility genes for hereditary cancer syndromes. In addition, National Comprehensive Cancer Network (NCCN) guidelines recommend that the patients of HDGC carrying CDH1 mutations should undergo prophylactic gastrectomy or routine endoscopic surveillances. Therefore, genetic counseling plays a key role in helping individuals with pathogenic mutations make appropriate risk management plans. Moreover, experienced and professional genetic counselors as well as a systematic multidisciplinary team (MDT) are also required to facilitate the development of genetic counseling and benefit pathogenic mutation carriers who are in need of regular and standardized risk management solutions. In this review, we provided an overview about the germline mutations of several genes identified in HDGC, suggesting that these genes may potentially act as susceptibility genes for this malignant cancer syndrome. Furthermore, we introduced information for prevention, diagnosis and risk management of HDGC. Investigations on key factors that may have effect on risk management decision-making and genetic data collection of more cancer syndrome family pedigrees are required for the development of HDGC therapeutic strategies.

Anatomical variation of infra-pyloric artery origination: A prospective multicenter observational study (IPA-Origin)

Objective

Infra-pyloric artery (IPA) is an important anatomical landmark in treatment of gastric cancer and is the key vessel for pylorus-preserving gastrectomy and subgroup of infra-pyloric lymph nodes. However, its anatomical variation is not thoroughly understood. Our study aimed to clarify the origination of the IPA.

Methods

We did this prospective, multicenter, open-label, observational study at gastric surgery departments of 34 hospitals in China. Gastric cancer patients aged 18 years or older and scheduled to undergo elective total or distal gastrectomy were assigned. During the surgery, IPA dissecting and exposing the origination point with photographs or video clips were required. The primary outcome was the origination of the IPA. Analysis of variance, χ² tests and Fisher’s tests were used to analyze the differences between groups. The study is registered at Clinicaltrials.gov (No. NCT03071237).

Results

Between May 8 and July 31, 2017, 429 patients were assigned for the study, and 419 (97.7%) patients had the IPA dissected and recorded through photograph or video and were included in the primary outcome analysis. The median age was 62 years old, and 73.7% were male. Among the patients, 78.5% received laparoscopic surgery. Single IPA origination was identified in 398 (95.0%) patients, including gastroduodenal artery (GDA) in 154 (36.8%) patients, anterior superior pancreaticoduodenal artery (ASPDA) in 130 (31.0%) patients, and right gastroepiploic artery (RGEA) in 114 (27.2%) patients. Fifteen (3.6%) patients were identified with multiple IPA and 6 (1.4%) patients were identified as IPA absence. The differences in the distribution of surgical approach (P=0.003) and geographic area (P=0.030) were statistically significant. No difference was shown in sex, age, gastrectomy type, tumor location, and clinical T, N and M stage.

Conclusions

Our study found that the IPA originates from GDA, ASPDA and RGEA in similar proportions. Laparoscopic surgery may be more helpful in dissection of the IPA than open surgery.

Oxaliplatin plus S-1 or capecitabine as neoadjuvant or adjuvant chemotherapy for locally advanced gastric cancer with D2 lymphadenectomy: 5-year follow-up results of a phase IIIII randomized trial

Objective

To compare the effect of neoadjuvant chemotherapy (NACT) with adjuvant chemotherapy (ACT) using oxaliplatin plus S-1 (SOX) or capecitabine (CapeOX) on gastric cancer patients with D2 lymphadenectomy.

Methods

This was a two-by-two factorial randomized phase II−III trial, and registered on ISRCTN registry (No. ISRCTN12206108). Locally advanced gastric cancer patients were randomized to neoadjuvant SOX, neoadjuvant CapeOX, adjuvant SOX, or adjuvant CapeOX arms. Primary analysis was performed on an intention-to-treat (ITT) basis using overall survival (OS) as primary endpoint.

Results

This trial started in September 2011 and closed in December 2012 with 100 patients enrolled. Treatment completion rate was 56%, 52%, 38% and 30% in the four arms, respectively. NACT group had fewer dropouts due to unacceptable toxicity (P=0.042). Surgical complication rate did not differ by the four groups (P=0.986). No survival significant difference was found comparing NACT with ACT (P=0.664; 5-year-OS: 70% vs. 74% respectively), nor between the SOX and CapeOX groups (P=0.252; 5-year-OS: 78% vs. 66% respectively). Subgroup analysis showed SOX significantly improved survival in patients with diffuse type (P=0.048).

Conclusions

No significant survival difference was found between NACT and ACT. SOX and CapeOX had good safety and efficacy as neoadjuvant regimens. Diffuse type patients may survive longer due to SOX.

Construction and external validation of a nomogram that predicts lymph node metastasis in early gastric cancer patients using preoperative parameters

Objective

To create a nomogram to predict the incidence of lymph node metastasis (LNM) in early gastric cancer (EGC) patients and to externally validate the nomogram.

Methods

To construct the nomogram, we retrospectively analyzed a primary cohort of 272 EGC patients. Univariate analysis and a binary logistic regression were performed. A nomogram predicting the incidence of LNM in EGC patients was created. The discrimination ability of the nomogram was measured using the concordance index (c-index), and the nomogram was also calibrated. Then, another prospective cohort of 81 patients was analyzed to validate the nomogram.

Results

In the primary cohort, LNM was pathologically confirmed in 37 (13.6%) patients. In multivariate analysis, the presence of an ulcer, the maximum lesion diameter observed via gastroscopy, the thickness of the lesion observed via endoscopic ultrasonography, and the presence of enlarged lymph nodes on computed tomography (CT) were independent risk factors for LNM. A nomogram was then created based on the regression model with the c-index of 0.905, and the calibration curve of the nomogram fell approximately on the ideal 45-degree line. The cut-off score of the nomogram was 110, and the sensitivity, specificity, positive predictive and negative predictive values of the nomogram in the primary cohort were 81.1%, 86.0%, 47.6% and 96.7%, respectively, and in the prospective validation cohort were 75.0%, 91.0%, 60.0% and 95.5%, respectively. The calibration curve of the external validation cohort was almost on the 45-degree line.

Conclusions

We developed an effective nomogram predicting the incidence of LNM for EGC patients.

[Analysis of risk factors on pulmonary infection after D2 lymphadenectomy gastrectomy for gastric cancer]

OBJECTIVE

To explore the risk factors of pulmonary infection after D2 radical gastrectomy of gastric cancer in order to guide clinical measures to reduce the incidence of pulmonary infection.

METHODS

Clinical data of 371 patients undergoing D2 radical gastrectomy at Division 2 of Gastrointestinal Cancer Center from October 2014 to October 2016 were collected for retrospective cohort study. Associated risk factors of pulmonary infection after D2 radical gastrectomy of gastric cancer were analyzed. Diagnosis criteria of pulmonary infection: occurrence of new pulmonary rales; new infiltrative change or consolidation in chest by imaging examination; with at least one of the following: temperature ≥38.5centi-degree, emergence of new purulent sputum or sputum character change, isolated pathogens from bronchial brush biopsy or tracheal secretion culture.

RESULTS

Of 371 patients, 265 were males and 106 were females. The average age was 59.1(22-80) years old. There were 38(10.2%) cases of pulmonary infection after radical resection of gastric cancer. Univariate analysis showed that smoking history, intra-operative blood loss ≥200 ml, total gastrectomy, and gastric intubation ≥6 d were associated with pulmonary infection after D2 radical gastrectomy (all P<0.05). Six cases quitted smoking 2 weeks before operation with pulmonary infection incidence of 8.1%(6/74), and 16 patients did not quit smoking 2 weeks before operation with pulmonary infection incidence of 21.1%(16/76), and the difference was statistically significant (χ²=4.0387, P=0.0445). Multivariate Logistic regression analysis showed that postoperative gastric intubation ≥6 d (OR=4.335, 95%CI: 1.088 to 4.586, P=0.05), smoking history (OR=3.469, 95%CI: 1.056 to 5.252, P=0.043) and intra-operative blood loss ≥200 ml (OR=3.931, 95%CI: 1.350 to 10.574, P=0.013) were independent risk factors of pulmonary infection after D2 radical gastrectomy of gastric cancer.

CONCLUSION

For gastric cancer patients undergoing D2 radical gastrtectomy with smoking history, greater blood loss during operation and postoperative gastric intubation ≥6 d, surgeons must pay attention to the prevention of postoperative pulmonary infection.

Changes in hepatic glucose and lipid metabolism-related parameters in domestic pigeon (Columba livia) during incubation and chick rearing

This study aimed to evaluate the hepatic glucose and lipid metabolism-related parameters of adult male and female White King pigeons (Columba livia) during incubation and chick rearing. At day 4 (I4), 10 (I10) and 17 (I17) of incubation and day 1 (R1), 7 (R7), 15 (R15) and 25 (R25) of chick rearing, livers were sampled from six pigeons for each sex. Glycogen and fat contents, activities of glycolytic enzymes (hexokinase, HK; 6-phosphofructokinase, 6-PFK), and genes expressions of key enzymes involved in glycolysis (pyruvate kinase, PK; glucokinase, GK), gluconeogenesis (phosphoenolpyruvate carboxykinase cytosolic, PCK1; fructose-1,6-bisphosphatase, FBP1; glucose-6-phosphatase, G6Pase), fatty acid synthesis (fatty acid synthase, FAS; acetyl-CoA carboxylase, ACC) and fatty acid β-oxidation (carnitine palmitoyltransferase 1, CPT1; acyl-CoA 1, ACO) were measured. In male and female pigeon livers, glycogen content and HK activity dramatically increased after I17 and after R1, respectively; expressions of FBP1 and G6Pase genes were maximized at R15; activity of 6-PFK and expressions of PK and CPT1 genes were highest at R7; fat content and expressions of FAS and ACC genes steeply increased from I10 to R1. In females, hepatic expressions of GK and PCK1 genes were greatest at R7 and I17, respectively; however, in males, both of them were maximized at R15. Hepatic expression of ACO gene was significantly enhanced at R1 compared to I17 and R7 in males, whereas it was notably up-regulated at I17 and R7 in females. Furthermore, expressions of PCK1, GK, FAS and ACC genes were in significant relation to fat content in the livers of female pigeons, while fat content in male pigeons was highly correlated with expression of PCK1, ACC, CPT1 and ACO genes. In conclusion, regulations of glucose and lipid metabolic processes were enhanced in parent pigeon livers from terminal phases of incubation to mid phase of chick rearing with sexual effects.

Clonality analysis of synchronous gastro-oesophageal junction carcinoma and distal gastric cancer by whole-exome sequencing

Gastro-oesophageal junction (GEJ) carcinoma and distal gastric cancer (GC) have distinct epidemiology and clinical features and their relationship is uncertain. Synchronous multiple gastric cancers located mostly at proximal and distal sites provide rare specimens for investigating the comprehensive genomic relationships among these cancers in the context of identical genetic circumstances. Formalin-fixed, paraffin-embedded (FFPE) samples from 12 patients with synchronous GEJ carcinoma and distal GC were collected in this study. Whole-exome sequencing (WES) was performed using normal tissues as a control. Mutational profiling, clonality analysis, a detailed clinico-pathological review, determination of MSI status, EBER in situ hybridization (ISH), and programmed cell death 1 (PD-1)/programmed death-ligand 1 (PD-L1) immunohistochemical staining were performed. Twenty-three of the 24 samples were microsatellite-stable (MSS). Subclonal analysis revealed that nine pairs of GEJ and distal GC tumours in neoadjuvant chemotherapy naïve patients developed independently from different origins. Two patients who received neoadjuvant chemotherapy shared clonal origins with highly similar somatic alterations. The remaining one patient who shared a rare mutation died within 6.2 months at the N3 stage. However, the enriched pathway identified from the overall mutation spectra in distal GC and GEJ carcinoma showed the close relationship of these cancers. Thus, although these cancers may have similar characteristics, histopathological and genetic profiling from single tumour specimens may still underestimate the mutational burden and somatic heterogeneity of multiple GCs. In addition, this series of cases also showed a PD-L1 expression rate of 58.3% and 66.7% in distal GC and GEJ carcinoma, respectively, with all the cases expressing PD-1. This result suggests the potential benefit of immunotherapeutic treatments. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Depth of tumor invasion and tumor-occupied portions of stomach are predictive factors of intra-abdominal metastasis

Objective

Diagnostic laparoscopy is recommended for the pretherapeutic staging of gastric cancer to detect any unexpected or unconfirmed intra-abdominal metastasis. The aim of this study was to evaluate the role and indications of diagnostic laparoscopy in the detection of intra-abdominal metastasis.

Methods

Standard diagnostic laparoscopy with peritoneal cytology examination was performed prospectively on patients who were clinically diagnosed with primary local advanced gastric cancer (cT≥2M0). We calculated the rate of intra-abdominal metastases identified by diagnostic laparoscopy, and examined the relationship between peritoneal dissemination (P) and cytology results (CY). Split-sample method was applied to find clinical risk factors for intra-abdominal metastasis. Multivariate logistic regression analysis and receiver-operator characteristic (ROC) analysis were performed in training set to find out risk factors of intra-abdominal metastasis, and then validate it in testing set.

Results

Out of 249 cM0 patients, 51 (20.5%) patients with intra-abdominal metastasis were identified by diagnostic laparoscopy, including 20 (8.0%) P1CY1, 17 (6.8%) P0CY1 and 14 (5.6%) P1CY0 patients. In the training set, multivariate logistic regression analysis and ROC analysis showed that the depth of tumor invasion on computer tomography (CT) scan ≥21 mm and tumor-occupied ≥2 portions of stomach are predictive factors of metastasis. In the testing set, when diagnostic laparoscopy was performed on patients who had one or two of these risk factors, the sensitivity and positive predictive value for detecting intra-abdominal metastasis were 90.0% and 32.1%, respectively.

Conclusions

According to our results, depth of tumor invasion and tumor-occupied portions of stomach are predictive factors of intra-abdominal metastasis.

Postoperative chemotherapy with S-1 plus oxaliplatin versus S-1 alone in locally advanced gastric cancer (RESCUE-GC study): a protocol for a phase III randomized controlled trial

BACKGROUND

The ACTS-GC study had shown postoperative adjuvant therapy with S-1 improved survival of patients with locally advanced gastric cancer. Addition of oxaliplatin to S-1 is considered to be acceptable as one of the treatment options for gastric cancer patients after radical gastrectomy with D2 lymph node excision.

METHODS

We have commenced a randomized phase III trial in December 2016 to evaluate S-1 plus oxaliplatin compared with S-1 alone in the adjuvant setting for locally advanced gastric cancer. A total of 564 patients will be accrued from 13 Chinese institutions in two years. The primary endpoint is 3-year relapse-free survival. The secondary endpoints are 5-year overall survival, proportion of patients who complete the postoperative chemotherapy and incidence of adverse events.

ETHIC AND DISSEMINATION

The trial has been approved by the institutional review board of each participating institution and it was activated on December, 2016. The enrollment will be finished in December, 2018. Patient's follow-up will be ended until December, 2023.

TRIAL REGISTRATION

ClinicalTrials.gov, identifier: NCT02867839. Registered on August 4, 2016.

Molecular cloning, characterization, and expression analysis of ghrelin and cholecystokinin in the pigeon (Columba livia)

Ghrelin and cholecystokinin (CCK) are multifunctional peptides. In the current study, complete sequences of ghrelin (800 bp) and CCK (739 bp) were firstly cloned in Columba livia by using rapid amplification of cDNA ends (RACE) method. The open reading frames of ghrelin (351bp) and CCK (393bp) encoded 116 amino acids and 130 amino acids, respectively. Sequence comparison indicated that pigeon ghrelin and CCK shared high identity with those reported in other avian species. Quantitative real-time PCR analysis found that ghrelin and CCK mRNAs expressed in three intestinal segments of pigeon during development. Both ghrelin and CCK showed generally higher expressions at days posthatch than embryonic periods regardless of intestinal segments. In duodenum and ileum, the expressions of ghrelin and CCK mRNA reached the peak values at 8 d posthatch. Jejunum CCK mRNA level increased linearly after hatching, and reached the highest point at posthatch 28 d. Based on documented effects of long chain fatty acids (LCFAs) on pigeon ghrelin and CCK expression were also investigated in vitro. Higher concentrations (50 μM or 250 μM) of linoleic acid, α-linolenic acid or arachidonic acid can significantly increase ghrelin mRNA level in pigeon jejunum. However, for oleic acid, the induction of ghrelin gene expressions needed a lower concentration (5 μM). 5 μM of linoleic acid, α-linolenic acid or arachidonic acid and 250 μM palmitic acid repressed CCK expression significantly. A higher concentration (250 μM) of oleic acid or α-linolenic acid can up-regulate CCK mRNA level significantly. Our results indicated that ghrelin and CCK may act key functions in pigeon intestine development and their expressions could be regulated by LCFAs.

Free choice feeding of whole grains in meat-type pigeons: 1. effect on performance, carcass traits and organ development

The effects of 5 different feeding systems on the performance, carcass traits and organ development were studied in pigeon squabs. The 5 treatments were (1) whole grains of maize, pea and wheat plus concentrate feed; (2)whole grains of maize and wheat plus concentrate feed (CWC); (3) whole grains of maize and pea plus concentrate feed; (4)whole grain of maize plus concentrate feed (CC); and (5) compound feed (CF). Feed intake of parent pigeons increased significantly from 0 to 21 d and it was higher in the CF treatment. Body weight of squabs in the CWC treatment was the highest among the 5 treatments in 4 weeks. Body weight losses of parental pigeons during the rearing period were not significantly different among the 5 treatments. Protein intake in CC and CWC treatments was lower than that of the other three treatments. The CWC treatment had the highest daily weight gain and the lowest feed conversion ratio. Treatments were statistically similar in the relative weight of carcass, breast and thigh. CF had the lower relative weight of abdominal fat. Relative weight of gizzard in the CF treatment was significantly lower than that of CWC. It was concluded that the application of free choice feeding of whole grains of maize and wheat plus concentrate feed increased the body weight of 28-d-old pigeon squabs and decreased the feed conversion rate of parent pigeons. This feeding strategy could be commercially interesting in meat-type pigeon production.

Clinical study of harvesting lymph nodes with carbon nanoparticles in advanced gastric cancer: a prospective randomized trial

Background

The objective of this study is to evaluate the efficiency and safety of carbon nanoparticles (CNPs) for harvesting lymph nodes (LNs) in cases of advanced gastric cancer (AGC).

Methods

Patients with previously untreated resectable AGC were eligible for inclusion in this study. All patients were randomly allocated to two subgroups. In the experimental group, 1.0 mL of CNP was injected into the subserosa of the stomach around the tumor before gastrectomy with D2 dissection. The same procedure was performed directly without any coloring material in the control arm. Following surgery, LNs were harvested, colored LNs were counted, and the diameters were measured by the investigator and pathologist.

Results

Thirty patients were enrolled in the study. We observed no serious adverse effects related to CNP injection. The rate of stained LNs was 46.6 %. The mean number of harvested LNs was larger in the experimental than in the control group (38.33 vs 28.27, p = 0.041). A smaller diameter of LNs was recorded in the experimental arm (3.32 vs 4.30 mm, p = 0.023). In addition, we developed a model for predicting the total number of LNs based on the data from CNP-stained LNs and metastatic LNs (MLNs).

Conclusions

CNP is a safe material. Surgeons could harvest more LNs in patients with AGC. The harvest of an increased number of smaller diameters of LNs may be beneficial. Further study is warranted to demonstrate the model’s practicality.

A nomogram for predicting the likelihood of lymph node metastasis in early gastric patients

Background

Early gastric cancer is defined as a lesion confined to the mucosa or submucosa, regardless of the size or lymph node metastasis. Treatment methods include endoscopic mucosal resection or endoscopic submucosal dissection, wedge resection, laparoscopically assisted gastrectomy and open gastrectomy. Lymph node metastasis is strong related with survival and recurrence. Therefore, the likelihood of lymph node metastasis is one of the most important factors when determining the most appropriate treatment.

Methods

We retrospectively analyzed 597 patients who underwent D2 gastrectomy for early gastric cancer. The relationship between lymph node metastasis and clinicopathological features was analyzed. Using multivariate logistic regression analyses, we created a nomogram to predict the lymph node metastasis probability for early gastric cancer. Receiver operating characteristic analyses was performed to assess the predictive value of the model.

Results

In the present study, 58 (9.7 %) early gastric cancer patients were histologically shown to have lymph node metastasis. The multivariate logistic regression analysis demonstrated that the age at diagnosis, differentiation status, the presence of ulcers, lymphovascular invasion and depth of invasion were independent risk factors for lymph node metastasis in early gastric cancer. Additionally, the tumor macroscopic type, size and histology type significantly correlated with these important independent factors. We constructed a predictive nomogram with these factors for lymph node metastasis in early gastric cancer patients, and the discrimination was good with the AUC of 0.860 (95 % CI: 0.809–0.912).

Conclusions

We developed an effective nomogram to predict the incidence of lymph node metastasis for early gastric cancer patients.

Nomogram for predicting lymph node metastasis rate of submucosal gastric cancer by analyzing clinicopathological characteristics associated with lymph node metastasis

BACKGROUND

To combine clinicopathological characteristics associated with lymph node metastasis for submucosal gastric cancer into a nomogram.

METHODS

We retrospectively analyzed 262 patients with submucosal gastric cancer who underwent D2 gastrectomy between 1996 and 2012. The relationship between lymph node metastasis and clinicopathological features was statistically analyzed. With multivariate logistic regression analysis, we made a nomogram to predict the possibility of lymph node metastasis. Receiver operating characteristic (ROC) analysis was also performed to assess the predictive value of the model. Discrimination and calibration were performed using internal validation.

RESULTS

A total number of 48 (18.3%) patients with submucosal gastric cancer have pathologically lymph node metastasis. For submucosal gastric carcinoma, lymph node metastasis was associated with age, tumor location, macroscopic type, size, differentiation, histology, the existence of ulcer and lymphovascular invasion in univariate analysis (all P<0.05). The multivariate logistic regression analysis identified that age ≤50 years old, macroscopic type III or mixed, undifferentiated type, and presence of lymphovascular invasion were independent risk factors of lymph node metastasis in submucosal gastric cancer (all P<0.05). We constructed a predicting nomogram with all these factors for lymph node metastasis in submucosal gastric cancer with good discrimination [area under the curve (AUC) =0.844]. Internal validation demonstrated a good discrimination power that the actual probability corresponds closely with the predicted probability.

CONCLUSIONS

We developed a nomogram to predict the rate of lymph node metastasis for submucosal gastric cancer. With good discrimination and internal validation, the nomogram improved individualized predictions for assisting clinicians to make appropriated treatment decision for submucosal gastric cancer patients.

Controlling angiogenesis in gastric cancer: A systematic review of anti-angiogenic trials

PURPOSE

Angiogenesis is a promising therapeutic target to inhibit tumor growth. This review summarizes data from clinical trials of anti-angiogenic agents in gastric cancer.

DESIGN

A systematic search of PubMed, Embase and conference databases is performed to identify clinical trials with specific anti-angiogenic agents in gastric cancer treatment

RESULTS

The risk of disease progression (37-52%) and death (19-22%) with ramucirumab as second-line treatment decreases in phase III trials in advanced gastric cancer. No significant improvement in overall survival (OS) with the addition of bevacizumab to chemotherapy is shown. Bevacizumab or ramucirumab combined with traditional chemotherapy is associated with higher adverse event rate compared to chemotherapy alone. Except for apatinib, phase II trials of other tyrosine kinase inhibitors (TKIs) may improve overall response rate, but there are no significant improvements in OS and progression-free survival (PFS) when combined with chemotherapy.

CONCLUSION

Phase III trials in advanced gastric cancer have demonstrated improved outcome with ramucirumab as second-line treatment. Most of the other studies on anti-angiogenic agents in gastric cancer have reported improvement in response rate but not in OS compared to chemotherapy alone. Future research is expected in optimizing the anti-angiogenic therapy combined with traditional treatment.

Incidence and risk of peripheral neuropathy with nab-paclitaxel in patients with cancer: a meta-analysis

Nab-paclitaxel, a Cremophor EL-free formulation of paclitaxel, is used to treat various malignancies. Peripheral neuropathy is one of its major toxicities, although the overall incidence remains unclear. We performed a meta-analysis to calculate the incidence of peripheral neuropathy in cancer patients treated with nab-paclitaxel and to compare the relative risk (RR) with conventional taxanes. The electronic databases were searched for relevant clinical trials. Eligible studies included phase II and III prospective clinical trials of cancer patients treated with nab-paclitaxel with toxicity profile on peripheral neuropathy. Statistical analyses were done to calculate summary incidences, RRs and 95% confidence intervals (CI), using fixed-effects or random-effects models based on the heterogeneity of the included studies. Nineteen trials were selected for the meta-analysis, yielding a total of 2878 cancer patients. The overall incidences of peripheral neuropathy (all-grade) was 51.0% (95% CI: 45.1-57.6%), and that of high-grade peripheral neuropathy was 12.4% (9.8-15.7%). The RRs of peripheral neuropathy of nab-paclitaxel compared to taxanes were not increased for all-grade and high-grade peripheral neuropathy. Nab-paclitaxel is associated with an increased risk of developing peripheral neuropathy. Future clinical studies are still needed to investigate the risk reduction and possible use of nab-paclitaxel.

Gastrectomy in comprehensive treatment of advanced gastric cancer with synchronous liver metastasis: a prospectively comparative study

Background

Systemic chemotherapy is the key treatment for advanced gastric cancer. The benefit of adjuvant surgery following preoperative chemotherapy in gastric cancer with liver metastasis has not been well established.

Methods

Forty-nine gastric cancer patients diagnosed with synchronous liver metastasis initially treated with chemotherapy were categorized into the following two groups: surgery group: 25 patients who underwent gastrectomy and subsequently received postoperative chemotherapy and control group: 24 patients who received chemotherapy alone.

Results

The median overall survival of patients in the surgery group and control group was 20.5 and 9.1 months, respectively, (P = 0.006). The median progression-free survival in the surgery group was 10.9 months, with statistical significance when compared with 5.0 months in the control group (P = 0.001). Multivariate analysis demonstrated that response to chemotherapy was the only independent factor in predicting prognosis. The survival of patients who achieved partial response (PR) was prolonged if they received adjuvant surgery (P = 0.024). No significant difference in the survival of patients underwent combined hepatic resection when compared with patients performed gastrectomy only.

Conclusions

For gastric cancer with synchronous liver metastasis, adjuvant gastrectomy followed by chemotherapy might be beneficial for survival comparing with chemotherapy alone, especially in patients response to initial preoperative chemotherapy.

Electronic supplementary material

The online version of this article (doi:10.1186/s12957-015-0627-1) contains supplementary material, which is available to authorized users.

Validation of the Memorial Sloan-Kettering Cancer Center Nomogram to Predict Overall Survival After Curative Colectomy in a Chinese Colon Cancer Population

BACKGROUND

Colon cancer nomogram designed by Memorial Sloan-Kettering Cancer Center (MSKCC) is an online prediction tool to predict overall survival for individual patient after curative resection. However, this model was never externally validated. We evaluated the accuracy of this nomogram in an independent external Chinese cohort.

METHODS

Clinical data from 1005 patients who underwent primary curative-intent surgery at Peking University Cancer Hospital & Institute between 1996 and 2008 were used for external validation. Clinicopathologic characteristics and the performance of the MSKCC nomogram for prediction of overall survival were evaluated for 985 patients with complete data by using concordance index (C-index) and calibration plot.

RESULTS

The C-index for the MSKCC nomogram was 0.71 in the Chinese cohort, compared with 0.67 for American Joint Committee on Cancer (AJCC) stage (P < .0001). This suggests that the nomogram discriminates overall survival better than AJCC staging system. Calibration plot showed a good calibration of the nomogram in the validation cohort. Furthermore, the MSKCC nomogram prediction illustrated the heterogeneity for survival of Chinese patients within each AJCC stage.

CONCLUSIONS

The MSKCC nomogram for colon cancer provides more accurate survival predictions than the AJCC staging system when applied to an external Chinese cohort. The MSKCC nomogram improved individualized prediction of survival and may aid in more accurate patient counseling, selection of various treatment options, and follow-up scheduling.

Hyperthermic intraperitoneal chemotherapy plus simultaneous versus staged cytoreductive surgery for gastric cancer with occult peritoneal metastasis

BACKGROUND

Our aim is to evaluate the safety and efficacy of two treatment strategies, hyperthermic intraperitoneal chemotherapy (HIPEC) plus simultaneous versus staged cytoreductive surgery (CRS) in patients with occult peritoneal metastasis of gastric cancer (GC).

METHODS

We retrospectively reviewed 26 GC patients who were potential curatively resectable by pre-operative evaluation and found occult peritoneal metastasis by diagnostic laparoscopy. Patients were treated by HIPEC plus either simultaneous CRS (CRS+HIPEC group, n = 11) or staged CRS after systematic chemotherapy (HIPEC+Chemo+CRS group, n = 15).

RESULTS

There is no mortality observed in both groups. The treatment complications in two group is comparable (P = 0.683), with 26.7% (4/15) in HIPEC+Chemo+CRS group, and 36.4% (4/11) in CRS+HIPEC group, respectively. The compliance of patients undergoing subsequent chemotherapy is higher in HIPEC+Chemo+CRS group (93.3%, 14/15) than that of CRS+HIPEC group (45.5%, 5/11) (P = 0.021). The mean interval time between CRS and first post-CRS systematic chemotherapy were 42.0 ± 12.0 days in HIPEC+Chemo+CRS group versus 69.8 ± 36.3 in CRS+HIPEC group (P = 0.163), respectively. The median OS in the HIPEC+Chemo+CRS group was 25.0 months, while 28.2 months in the CRS+HIPEC group (P = 0.738).

CONCLUSION

For resectable GC patients with laparoscopic findings of occult peritoneal metastasis, HIPEC plus staged CRS is with better tolerance and compliance than simultaneous CRS.

LAPTM4B-35, a cancer-related gene, is associated with poor prognosis in TNM stages I-III gastric cancer patients

Background

Lysosome-associated transmembrane protein 4β-35 (LAPTM4B-35), a member of the mammalian 4-tetratransmembrane spanning protein superfamily, has been reported to be overexpressed in several cancers. However the expression of LAPTM4B-35 and its role in the progression of gastric cancer (GC) remains unknown. The aim of this study was to investigate LAPTM4B-35 expression in GC, its potential relevance to clinicopathologic parameters and role of LAPTM4B-35 during gastric carcinogenesis.

Methods

In the present study, paraffin-embedded specimens with GC (n = 240, including 180 paired specimens) and 24 paired fresh frozen tissues were analyzed. qRT-PCR and immunohistochemistry (IHC) were used to analyze the expression of LAPTM4B-35 in GC. The effects of LAPTM4B-35 on GC cell proliferation, migration and invasion were determined by overexpression and knockdown assays.

Results

IHC showed that LAPTM4B-35 was expressed in 68.3% (123/180) of GC tissues, while in 16.1% (29/180) of their paired adjacent noncancerous gastric tissues (P = 0.000). LAPTM4B-35 mRNA levels in GC tissues were also significantly elevated when compared with their paired adjacent noncancerous tissues (P = 0.017). Overexpression of LAPTM4B-35 was significantly associated with degree of differentiation, depth of invasion, lymphovascular invasion and lymph node metastasis (P<0.05). Kaplan-Meier survival curves revealed that patients with LAPTM4B-35 expression had a significant decrease in overall survival (OS) in stages I-III GC patients (P = 0.006). Multivariate analysis showed high expression of LAPTM4B-35 was an independent prognostic factor for OS in stage I-III GC patients (P = 0.025).

Conclusion

These findings indicate that LAPTM4B-35 overexpression may be related to GC progression and poor prognosis, and thus may serve as a new prediction marker of prognosis in GC patients.

The extent of inflammatory infiltration in primary cancer tissues is associated with lymphomagenesis in immunodeficient mice

Xenotransplantation of human cancers into immunodeficient mice is a very useful approach for studying human tumor biology. However, the occasional occurrence of lymphomagenesis in some mice can spoil the model and must be investigated in detail. We found that a high percentage (32.5%, 26/80) of cancer patient-derived xenografts (PDXs) resembled lymphoma in NOD/SCID mice. Of the 26 xenografts, 23 were human-derived expressing human CD45 (hCD45+) and proved to be of the B-cell subtype (CD3-/CD20+), and they were all positive for Epstein - Barr virus (EBV). The remaining 3 xenografts proved to be mouse-derived for both hCD45- and negative amplification of a human gene. The most interesting finding is that gastric cancer had much higher rates (24/126, 19.0%) of lymphoma formation in the PDX model than did colorectal cancer (1/43, 2.3%). Statistical analysis revealed that cancer type and inflammation in the parent tumor are significantly associated with lymphomagenesis. Further validation discovered lymphomagenesis by inoculating only gastritis mucosa. Therefore, our findings suggest that it is necessary to take precautions when directly xenografting cancer tissues with remarkable baseline inflammation, such as gastric cancer into immunodeficient NOD/SCID strains. Further, the established xenograft models should be validated by both leukocyte markers and human gene signatures.

Prognostic role of lymph node metastasis in early gastric cancer

OBJECTIVE

To clarify the relationship between clinicopathological features and lymph node metastasis and to propose the potential indications of lymph node metastasis for prognosis in early gastric cancer (EGC) patients.

METHODS

We retrospectively observed 226 EGC patients with lymph node resection, and analyzed the associations between lymph node metastasis and clinicopathological parameters using the chi-square test in univariate analysis and logistic regression analysis in multivariate analysis. Overall survival analysis was determined using the Kaplan-Meier and log-rank test. We conducted multivariate prognosis analysis using the Cox proportional hazards model.

RESULTS

Of all the EGC patients, 7.5% (17/226) were histologically shown to have lymph node metastasis. The differentiation, lymphovascular invasion and depth of invasion were independent risk factors for lymph node metastasis in EGC. The 5- and 10-year survival rates were significantly lower in patients with lymph node metastasis than in those without and the patients also had shorter progress-free survival time. Lymph node metastasis and tumor size were independent prognostic factors for EGC. The status of the lymph nodes was a significant factor in predicting recurrence or metastasis after surgery.

CONCLUSIONS

The undifferentiated carcinoma and lymphovascular and/or submucosal invasion were associated with a higher incidence of lymph node metastasis in EGC patients, whom need to perform subsequent D2 lymphadenectomy or laparoscopic lymph node dissection and more rigorous follow-up or additional chemotherapy/radiation after D2 gastrectomy for poor prognosis and high recurrence/metastasis rate.

Publishing in open access era: focus on respiratory journals

We have entered an open access publishing era. The impact and significance of open access is still under debate after two decades of evolution. Open access journals benefit researchers and the general public by promoting visibility, sharing and communicating. Non-mainstream journals should turn the challenge of open access into opportunity of presenting best research articles to the global readership. Open access journals need to optimize their business models to promote the healthy and continuous development.

Build infrastructure in publishing scientific journals to benefit medical scientists

There is urgent need for medical journals to optimize their publishing processes and strategies to satisfy the huge need for medical scientists to publish their articles, and then obtain better prestige and impact in scientific and research community. These strategies include optimizing the process of peer-review, utilizing open-access publishing models actively, finding ways of saving costs and getting revenue, smartly dealing with research fraud or misconduct, maintaining sound relationship with pharmaceutical companies, and managing to provide relevant and useful information for clinical practitioners and researchers. Scientists, publishers, societies and organizations need to work together to publish internationally renowned medical journals.

Level of circulating PD-L1 expression in patients with advanced gastric cancer and its clinical implications

OBJECTIVE

The programmed cell death-1 receptor/programmed cell death-1 ligand (PD-1/PD-L1) pathway plays a crucial role in tumor evasion from host immunity. This study was designed to evaluate the association between circulating PD-L1 expression and prognosis in patients with advanced gastric cancer.

METHODS

Totally 80 advanced gastric cancer patients and 40 health controls from Beijing Cancer Hospital were enrolled in the present study. Circulating PD-L1 expression was tested by enzyme-linked immunosorbent assay (ELISA). The associations between the expression level of PD-L1 and clinicopathological features and prognosis were analyzed statistically.

RESULTS

Expression of PD-L1 in advanced gastric cancer patients was significantly up-regulated compared with health people (P=0.006). The expression of PD-L1 was significantly correlated with differentiation and lymph node metastasis (P=0.026 and P=0.041, respectively). Although we didn't find significant difference in all advanced gastric cancer patients with different PD-L1 expression, the adenocarcinoma patients with higher up-regulated PD-L1 expression had much better prognosis than low expression patients (65.6% vs. 44.7%, P=0.028).

CONCLUSIONS

PD-L1 was elevated in advance gastric cancer patients and may play an important role in tumor immune evasion and patients prognosis.

Therapeutic implications of mTOR inhibitors in the treatment of gastric cancer

Gastric cancer remains one of the most common types of cancer worldwide, and most patients present withadvanced disease. Sixty percent of these patients eventually relapse after curative surgical resection, and combinationchemotherapy regimens only provide limited survival benefits. Mammalian target of rapamycin (mTOR) is a new targetof cancer therapies. Preclinical data suggest that the suppression of the mTOR pathway inhibits the progression of gastriccancer in vitro and in animal models. In clinical trials, the mTOR inhibitor, everolimus, was well tolerated in phase I/IIstudies on patients with metastatic gastric cancer. The efficacy of everolimus was promising in a phase II clinical trial, butin a recently published phase III clinical trial everolimus monotherapy do not significantly improve the overall survival ofpatients with advanced gastric cancer who had been previously treated with one or two lines of systemic chemotherapy.Phosphoinositide 3-kinase/mTOR dual inhibitors have not yet entered early-stage clinical trials in patients with advanced gastric cancer. Further studies are needed to establish the role of mTOR inhibitors for the treatment of gastric cancer.

Clinicopathological and prognostic differences between mucinous gastric carcinoma and signet-ring cell carcinoma

OBJECTIVE

To analyze the differences in clinicopathologic characteristics and prognosis between mucinous gastric carcinoma (MGC) and signet-ring cell carcinoma (SRCC).

METHODS

Clinicopathologic and prognostic data of 1,637 patients with histologically confirmed MGC or SRCC who received surgical operations in the Department of Gastroenterological Surgery, Beijing Cancer Hospital between December 2004 and December 2009 were retrospectively collected and analyzed. The clinicopathological features were analyzed statistically using χ(2) test. Survival was analyzed using the Kaplan-Meier method and multivariate analysis of Cox proportional hazards regression model (backward, stepwise).

RESULTS

A total of 181 patients with gastric cancer (74 MGC, 107 SRCC) were included. MGC, when compared with SRCC, was featured by senile patients, stage III and IV, upper third stomach, large tumor size, positive lymph node metastasis, and positive lymphatic vascular invasion (P<0.05). The overall 5-year survival rate showed no difference between the two groups (48.8% vs. 44.8%, P>0.05). However, the survival rate for MGC patients was significant lower than that for SRCC patients when compared among the age <60 years, negative distant metastasis, and tumor localized at upper third stomach (P<0.05). Multivariate Cox proportional hazards models revealed that distant metastasis was a significant independent prognostic indicator in MGC group, and lymph node metastasis and distant metastasis was significant independent prognostic indicators in SRCC group.

CONCLUSIONS

While compared with SRCC, MGC is associated with a more aggressive tumor biologic behavior. There is no statistically significant difference in distant metastasis, an independent prognostic indicator for both MGC and SRCC, which might be the reason for no significant difference of the overall survival rate between the patients with MGC and SRCC.

LGR5 is a promising biomarker for patients with stage I and II gastric cancer

OBJECTIVE

To investigate Leucine-rich repeat-containing G protein-coupled receptor 5 (LGR5) expressions in gastric cancer and to evaluate its clinical significance.

METHODS

LGR5 expression was assessed by immunohistochemistry in 257 gastric cancer patients after surgery. The relationships between LGR5 expression and clinicopathological features and patients prognosis were statistically analyzed.

RESULTS

The expression of LGR5 was significantly higher in gastric cancers as a cancer stem cell marker than in adjacent normal tissues (P<0.001), and more frequently in patients with intestinal type, well-moderate differentiation and stage I and II (P<0.05). Although we found gastric cancer patients with LGR5 positive expression had a poorer prognosis, it didn't meet statistical significance (P>0.05). LGR5 negative expression was significantly related to the favorable overall survival in stage I and II gastric cancer patients (P<0.05). Furthermore, patients with high LGR5 expression tended to be more likely to get progression and have poorer progress-free survival (P<0.05). Multivariate Cox regression analysis revealed that LGR5 expression was an independent factor of overall survival for the patients with stage I and II gastric cancer (P<0.05).

CONCLUSIONS

Our results show that LGR5 may play an important role in tumorigenesis and progression and would be a powerful marker to predict the prognosis of patients with stage I and II gastric cancer.

Multi-subunit assembly of the Pyrococcus furiosus small heat shock protein is essential for cellular protection at high temperature

The hyperthermophilic archaeon, Pyrococcus furiosus, expresses a small, alpha-crystallin-like protein in response to exposure to extreme temperatures, above 103 degrees C. The P. furiosus small heat shock protein (Pfu-sHSP) forms large oligomeric complexes. Based on the available crystal structures of the Methanocaldococcus jannaschii and wheat sHSPs, the protruding carboxy terminal domain is probably involved in subunit interactions. We constructed Pfu-sHSP mutants to analyze chaperone function and to study multi-subunit assembly. The results confirmed that the carboxy terminus of Pfu-sHSP is involved in inter-dimer interactions, whereas the amino terminal deletion mutant still exhibited the wild-type assembly characteristics. The ability to form oligomeric complexes via the carboxy terminal domain was shown to be necessary for thermotolerance of Escherichia coli overexpressing Pfu-sHSP. The amino terminal domain was not required for inter-species thermotolerance.

Dynamic regimes and correlated structural dynamics in native and denatured alpha-lactalbumin

Understanding the mechanisms of protein folding requires knowledge of both the energy landscape and the structural dynamics of a protein. We report a neutron-scattering study of the nanosecond and picosecond dynamics of native and the denatured alpha-lactalbumin. The quasielastic scattering intensity shows that there are alpha-helical structure and tertiary-like side-chain interactions fluctuating on sub-nanosecond time-scales under extremely denaturing conditions and even in the absence of disulfide bonds. Based on the length-scale dependence of the decay rate of the measured correlation functions, the nanosecond dynamics of the native and the variously denatured proteins have three dynamic regimes. When 0.05<Q<0.5 A(-1) (where the scattering vector, Q, is inversely proportional to the length-scale), the decay rate, Gamma, shows a power law relationship, Gamma proportional to Q(2.42+/-0.08), that is analogous to the dynamic behavior of a random coil. However, when 0.5<Q<1.0 A(-1), the decay rate exhibits a Gamma proportional to Q(1.0+/-0.2) relationship. The effective diffusion constant of the protein decreases with increasing Q, a striking dynamic behavior that is not found in any chain-like macromolecule. We suggest that this unusual dynamics is due to the presence of a strongly attractive force and collective conformational fluctuations in both the native and the denatured states of the protein. Above Q>1.0 A(-1) is a regime that displays the local dynamic behavior of individual residues, Gamma proportional to Q(1.8+/-0.3). The picosecond time-scale dynamics shows that the potential barrier to side-chain proton jump motion is reduced in the molten globule and in the denatured proteins when compared to that of the native protein. Our results provide a dynamic view of the native-like topology established in the early stages of protein folding.

[Observation on sex-linkage inheritance of skin color in some local breeds of chicken]

The sex-linkage inheritance of skin color was observed in some local breeds of chicken. The results showed that there was a pair of melanin genes PP in autosomes in Taihe Silky Fowl, an Id gene in sex chromosome in Xianju Fowl, Xiaoshan Fowl and Beijing You Fowl, and an id gene in sex chromosome in Langshan Fowl, Gushi Fowl and Taihe Silky Fowl, respectively. The offspring produced by crossing of Taihe Silky Fowl(Male) with the fowl(Female) carrying Id gene (such as Xianju Fowl, Xiaoshan Fowl and Beijing You Fowl) can autosexingly determinate by skin color, male chicken has yellow skin, female chicken has black skin.

The C-terminal domain of nucleolin accelerates nucleic acid annealing

We report that the abundant nucleolar protein nucleolin accelerates nucleic acid annealing. Nucleolin accelerates annealing of complementary oligonucleotides and of oligonucleotides that contain a limited number of mismatches. The annealing activity of nucleolin can be localized to a C-terminal region consisting of two RNA binding domains (RBD3 and RBD4) and the RGG(9) domain (RBD3-RBD4-RGG(9)). This same region mediates self-association of nucleolin. The RGG(9) domain of nucleolin, believed to mediate interactions between nucleolin and several ribosomal proteins, is neither sufficient for self-association, as determined by small-angle X-ray scattering, nor can it independently accelerate annealing. Acceleration of nucleic acid annealing by nucleolin is likely to depend on self-association of nucleolin molecules bound to nucleic acid.

A view of dynamics changes in the molten globule-native folding step by quasielastic neutron scattering

In order to understand the changes in protein dynamics that occur in the final stages of protein folding, we have used neutron scattering to probe the differences between a protein in its folded state and the molten globule states. The internal dynamics of bovine alpha-lactalbumin (BLA) and its molten globules (MBLA) have been examined using incoherent, quasielastic neutron scattering (IQNS). The IQNS results show length scale dependent, pico-second dynamics changes on length scales from 3.3 to 60 A studied. On shorter-length scales, the non-exchangeable protons undergo jump motions over potential barriers, as those involved in side-chain rotamer changes. The mean potential barrier to local jump motions is higher in BLA than in MBLA, as might be expected. On longer length scales, the protons undergo spatially restricted diffusive motions with the diffusive motions being more restricted in BLA than in MBLA. Both BLA and MBLA have similar mean square amplitudes of high frequency motions comparable to the chemical bond vibrational motions. Bond vibrational motions thus do not change significantly upon folding. Interestingly, the quasielastic scattering intensities show pronounced maxima for both BLA and MBLA, suggesting that "clusters" of atoms are moving collectively within the proteins on picosecond time scales. The correlation length, or "the cluster size", of such atom clusters moving collectively is dramatically reduced in the molten globules with the correlation length being 6.9 A in MBLA shorter than that of 18 A in BLA. Such collective motions may be important for the stability of the folded state, and may influence the protein folding pathways from the molten globules.

Design of single-layer beta-sheets without a hydrophobic core

The hydrophobic effect is the main thermodynamic driving force in the folding of water-soluble proteins. Exclusion of nonpolar moieties from aqueous solvent results in the formation of a hydrophobic core in a protein, which has been generally considered essential for specifying and stabilizing the folded structures of proteins. Outer surface protein A (OspA) from Borrelia burgdorferi contains a three-stranded beta-sheet segment which connects two globular domains. Although this single-layer beta-sheet segment is exposed to solvent on both faces and thus does not contain a hydrophobic core, the segment has a high conformational stability. Here we report the engineering of OspA variants that contain larger single-layer beta-sheets (comprising five and seven beta-strands) by duplicating a beta-hairpin unit within the beta-sheet. Nuclear magnetic resonance and small-angle X-ray scattering analyses reveal that these extended single-layer beta-sheets are formed as designed, and amide hydrogen-deuterium exchange and chemical denaturation show that they are stable. Thus, interactions within the beta-hairpin unit and those between adjacent units, which do not involve the formation of a hydrophobic core, are sufficient to specify and stabilize the single-layer beta-sheet structure. Our results provide an expanded view of protein folding, misfolding and design.

A method for determining transmembrane helix association and orientation in detergent micelles using small angle x-ray scattering

Solution small angle x-ray scattering can be used to study the association of transmembrane proteins solubilized in detergent micelles. We have used the alpha-helical transmembrane domain of the human erythrocyte glycophorin A (GpA) fused to the carboxyl terminus of monomeric staphylococcal nuclease (SN/GpA) as a model system for study. By matching the average electron density of the detergent micelles to that of the buffer solution, the micelle contribution to the small angle scattering vanishes, and the molecular weight and the radius of gyration of the proteins can be determined. SN/GpA has been found to dimerize in a zwitterionic detergent micelle, N-dodecyl-N,N-(dimethylammonio)butyrate (DDMAB), whose average electron density naturally matches the electron density of an aqueous buffer. The dimerization occurs through the transmembrane domains of GpA. With the aid of the nuclease domain scattering, the orientation of the helices within a dimer can be determined to be parallel by radius of gyration analysis. The association constant of a mutant (G83I) that weakens the GpA dimerization has been determined to be 24 microM in the DDMAB environment. The experimental methods established here could be used to apply solution small angle x-ray scattering to studying the association and interactions of other membrane proteins.

Multistep denaturation of Borrelia burgdorferi OspA, a protein containing a single-layer beta-sheet

Outer surface protein A (OspA) from the Lyme disease spirochete, Borrelia burgdorferi, is a dumbbell-shaped protein in which two globular domains are connected by a three-stranded beta-sheet segment that is solvent-exposed on both faces. Previous studies showed that the whole protein, including the single-layer beta-sheet, is highly rigid. To elucidate the folding mechanism and the role of the central beta-sheet in the formation of the rigid molecule, we investigated the equilibrium thermal denaturation reaction of OspA. We applied differential scanning calorimetry, heteronuclear NMR spectroscopy, and solution small-angle X-ray scattering (SAXS) to characterize the reaction in detail. All three techniques revealed that OspA denatures in two separable cooperative transitions. NMR measurements on OspA specifically 15N-labeled at Lys residues identified the locations of the two folding units and revealed that the C-terminal segment is less stable than the remaining N-terminal segment. The boundary between the two folding units is located within the central beta-sheet. The interconversion among the three folding states (fully folded, C-terminus unfolded, and fully denatured) is slow relative to chemical shift differences (<24 Hz), indicating that there are significant kinetic barriers in the denaturation reactions. SAXS measurements determined the radius of gyration of the native protein to be 25.0 +/- 0.3 A, which increases to 34.4 +/- 1.0 A in the first transition, and then to 56.1 +/- 1.6 A in the second transition. Thus, the intermediate state, in which the C-terminal folding unit is already denatured, is still compact. These results provide a basis for elucidating the folding mechanism of OspA.