Novel management indications for conservative treatment of chylous ascites after gastric cancer surgery

BACKGROUND

Chylous ascites (CA) presents a challenge as a relatively common postoperative complication in gastric cancer (GC). Primary conservative therapy involved total parenteral nutrition, continuous low-pressure drainage, somatostatin, and a low-fat diet. Drainage tube (DT) clamping has been presented as a potential alternative conservative treatment for GC patients with CA.

AIM

To propose novel conservative treatment strategies for CA following GC surgery.

METHODS

The data of patients with CA after GC surgery performed at the Fudan University Shanghai Cancer Center between 2006 and 2021 were evaluated retrospectively.

RESULTS

53 patients underwent surgery for GC and exhibited postoperative CA during the study period. Postoperative hospitalization and time of DT removal showed a significant positive association (R² = 0.979, P < 0.001). We further observed that delayed DT removal significantly extended the total and postoperative hospitalization, antibiotic usage duration, and hospitalization cost (postoperative hospitalization: 25.8 d vs 15.5 d, P < 0.001; total hospitalization: 33.2 d vs 24.7 d, P < 0.01; antibiotic usage duration: 10.8 d vs 6.2 d, P < 0.01; hospitalization cost: ¥9.2 × 10⁴vs ¥6.5 × 10⁴, P < 0.01). Multivariate analysis demonstrated that postoperative infection and antibiotic usage were independent factors for delayed DT removal. Furthermore, DT removal times were shorter in seven patients who underwent DT clamping (clamped DT vs normal group, 11.8 d vs 13.6 d, P = 0.047; clamped DT vs delayed group, 13.6 d vs 27.4 d, P < 0.001). In addition, our results indicated that removal of the DT may be possible after three consecutive days of drainage volumes less than 300 mL in GC patients with CA.

CONCLUSION

Infection and antibiotic usage were vital independent factors that influenced delayed DT removal in patients with CA. Appropriate standards for DT removal can significantly reduce the duration of hospitalization. Furthermore, DT clamping might be a recommended option for conservative treatment of postoperative CA.

The genomic architecture of EBV and infected gastric tissue from precursor lesions to carcinoma

BACKGROUND

Epstein-Barr virus (EBV)-associated gastric carcinomas (EBVaGCs) present unique molecular signatures, but the tumorigenesis of EBVaGCs and the role EBV plays during this process remain poorly understood.

METHODS

We applied whole-exome sequencing, EBV genome sequencing, and whole-genome bisulfite sequencing to multiple samples (n = 123) derived from the same patients (n = 25), which covered saliva samples and different histological stages from morphologically normal epithelial tissues to dysplasia and EBVaGCs. We compared the genomic landscape between EBVaGCs and their precursor lesions and traced the clonal evolution for each patient. We also analyzed genome sequences of EBV from samples of different histological types. Finally, the key molecular events promoting the tumor evolution were demonstrated by MTT, IC50, and colony formation assay in vitro experiments and in vivo xenograft experiments.

RESULTS

Our analysis revealed increasing mutational burden and EBV load from normal tissues and low-grade dysplasia (LD) to high-grade dysplasia (HD) and EBVaGCs, and oncogenic amplifications occurred late in EBVaGCs. Interestingly, within each patient, EBVaGCs and HDs were monoclonal and harbored single-strain-originated EBV, but saliva or normal tissues/LDs had different EBV strains from that in EBVaGCs. Compared with precursor lesions, tumor cells showed incremental methylation in promotor regions, whereas EBV presented consistent hypermethylation. Dominant alterations targeting the PI3K-Akt and Wnt pathways were found in EBV-infected cells. The combinational inhibition of these two pathways in EBV-positive tumor cells confirmed their synergistic function.

CONCLUSIONS

We portrayed the (epi) genomic evolution process of EBVaGCs, revealed the extensive genomic diversity of EBV between tumors and normal tissue sites, and demonstrated the synergistic activation of the PI3K and Wnt pathways in EBVaGCs, offering a new potential treatment strategy for this disease.

Abstract 361: Pleckstrin-2 as a prognostic factor and mediator of gastric cancer progression

Background: Pleckstrin-2 (PLEK2) is a crucial mediator of cytoskeletal reorganization. However, the potential roles and clinical significance of PLEK2 in gastric cancer are still unknown.

Methods: We aimed to illustrate the function of PLEK2 in gastric cancer. Pearson's correlation analysis was utilized to test the clinical impacts of the levels of PLEK2 in gastric cancer patients. Loss-of-function approaches were used to estimate the potential roles played by PLEK2 in modulating gastric cancer proliferation, self-renewal, and tumourigenicity. Immunoblotting and bioinformatics approaches were used to monitor the effect of PLEK2 on epithelial-mesenchymal transition (EMT) signalling pathways.

Results: In gastric cancer tissue samples examined by western blot and real-time PCR, there was an increased level of PLEK2 compared with that in matched non-tumour samples. Kaplan-Meier plotter analysis revealed that gastric cancer patients with higher PLEK2 levels had substantially poorer overall survival (p=0.0028) compared with gastric cancer patients with lower PLEK2 levels. The upregulation or downregulation of PLEK2 in gastric cancer cell lines effectively enhanced or inhibited cell proliferation and pro-invasive behaviour, respectively. Additionally, we also found that PLEK2 enhanced EMT concomitantly with a reduction in E-cadherin and an elevation in Vimentin.

Conclusions: Our findings demonstrated that PLEK2 plays a potential role in gastric cancer and may act as a prognostic factor for gastric cancer.

Citation Format: Bo Sun, Jian-Bin Xiang, Yi Xuan, Zong-You Chen, Xiao-Dong Gu, Da-Zhi Xu. Pleckstrin-2 as a prognostic factor and mediator of gastric cancer progression [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 361.

Pile-up effect in an infrared single-pixel compressive LiDAR system

Compressive sensing (CS) has been used in LiDAR systems utilizing one single-photon-counting avalanche diode. We demonstrate an unexpected grayscale inversed image of an object at an unchosen depth, which appears in the reconstruction of the infrared single-pixel LiDAR system due to the pile-up effect. A correction algorithm and the sparse measurement are proposed and experimentally verified to effectively reduce the photon pile-up influence, so that the negative images can be completely removed. The correction methods in this research can improve the accuracy and the flexibility of the single-pixel LiDAR systems employing detectors with a low maximum light count.

Comparison of efficacy in adjuvant chemotherapy regimens in patients with radically resected gastric cancer : a propensity-matched analysis

Background

We conducted the retrospective study to compare the efficacy of monotherapies versus two-drug regimens as postoperative chemotherapy for patients with radically resected gastric cancer.

Result

At a median follow-up of 5.3 years, no significant difference in terms of OS was observed between two groups, neither before nor after matching. After matching, median DFS was statistically significant between group A and B (median, 67.5 vs 101.0 months, respectively; hazard ratio [HR], 0.65; 95% CI, 0.45 to 0.95; P=0.027), which meant doublets prolonged DFS. In subgroup analysis, the patients of stage III receiving doublet achieved better OS than those receiving monotherapy. People who received doublet and were less than 65 years old, or male patients, or in T4 stage, or in N2 stage, or receiving subtotal gastrectomy had better DFS than those with monotherapy.

Method

A data set including 501 patients (monotherapy, n=107; doublet, n=394) was matched between the two groups (n=107 patients per group) using the propensity-matched study. The primary and secondary endpoint was overall survival(OS) and disease-free survival(DFS), respectively. Survival data was compared using the Kaplan-Meier method and Cox proportion hazards models for univariate and multivariate analyses.

Conclusion

The dual regimens seemed not to add overall survival benefits to patients receiving curative gastrectomy, compared with single-agent fluoropyrimidine as postoperative chemotherapy. However, dual regimens showed better disease-free survival.

Long non-coding RNA XIST regulates gastric cancer progression by acting as a molecular sponge of miR-101 to modulate EZH2 expression

BACKGROUND

Long non-coding RNAs (lncRNAs) have emerged as critical regulators of tumor progression. However, the role and molecular mechanism of lncRNA XIST in gastric cancer is still unknown.

METHODS

Real-time PCR analysis was performed to measure the expression levels of lncRNA XIST in gastric cancer tissues and cell lines, the correlation between lncRNA XIST expression and clinicopathological characteristics and prognosis was analyzed in gastric cancer patients. The biological function of lncRNA XIST on gastric cancer cells were determined both in vitro and in vivo. The regulating relationship between lncRNA XIST and miR-101 was investigated in gastric cancer cells.

RESULTS

lncRNA XIST was significantly up-regulated in gastric cancer tissues and cell lines. Overexpression of lncRNA XIST was markedly associated with larger tumor size, lymph node invasion, distant metastasis and TNM stage in gastric cancer patients. Functionally, knockdown of lncRNA XIST exerted tumor-suppressive effects by inhibiting cell proliferation, migration and invasion in vitro and tumor growth and metastasis in vivo. Furthermore, an inverse relationship between lncRNA XIST and miR-101 was found. Polycomb group protein enhancer of zeste homolog 2 (EZH2), a direct target of miR-101, could mediated the biological effects that lncRNA XIST exerted.

CONCLUSIONS

lncRNA XIST is up-regulated and is associated with aggressive tumor phenotypes and patient survival in gastric cancer, and the newly identified lncRNA XIST/miR-101/EZH2 axis could be a potential biomarkers or therapeutic targets for gastric cancer patients.

The regulation of Sema4D exodomain shedding by protein kinase A in platelets

We have previously shown that Sema4D expressed on the platelet plasma membrane can be cleaved by the metalloprotease ADAM17, producing a 120-kDa exodomain fragment that retains biological activity and remnant fragments of 24-28 kDa that remain associated with the platelet membrane. This process is modulated by calmodulin. Here we investigated the potential role of protein kinase A (PKA) in these events. Using a pharmacological approach, we now show that inhibition of PKA by H89 is sufficient to induce Sema4D exodomain shedding, while activation of PKA inhibits agonist-initiated shedding. Studies on the regulatory mechanism show that the shedding induced by PKA inhibition is mediated by ADAM17, but, unlike agonist-induced shedding, does not involve the dissociation of calmodulin from the Sema4D cytoplasmic domain. In attempt to identify the cleavage sites for shedding, we found that ADAM17 mediates variable cleavages in the juxtamembrane region. Therefore, our data reveal a potential regulatory mechanism for the shedding of Sema4D in platelets.

Noncanonical statistics of a finite quantum system with non-negligible system-bath coupling

The canonical statistics describes the statistical properties of an open system by assuming its coupling with the heat bath is infinitesimal in comparison with the total energy in thermodynamic limit. In this paper, we generally derive a noncanonical density matrix for the open system with a finite coupling to the heat bath, which deforms the energy shell to effectively modify the conventional canonical way. The obtained noncanonical distribution reflects the back action of system on the bath and thus depicts the statistical correlations between two subsystems by the mutual information as a result of energy conservation.

E3-ligase Skp2 regulates β-catenin expression and maintains hematopoietic stem cell homing

The homing ability of hematopoietic stem cells (HSCs) was a critical step for transplantation and subsequent hematopoiesis. Although the HSC transplantation was widely used for many diseases, the mechanism by which HSC homing was regulated remained poorly understood. F-box protein S-phase kinase associated protein2 (Skp2), a component of the Skp2-SCF E3 ligase complex, was regarded as a cell cycle regulator by controlling the level of p21 and p27 through ubiquitination. We recently reported an important role of Skp2 in maintaining HSC pool size, quiescent stage and self-renewal ability. In this current study, we showed that Skp2 was a novel and critical regulator for maintaining the homing of HSCs as well as their residence in the endosteal niche. Microarray analysis together with biochemical validations revealed that Skp2 deficiency profoundly reduced the expression of β-catenin and its target genes. Knockdown of β-catenin mimicked the decline of HSC homing upon Skp2 deficiency, suggesting that Skp2 may regulate β-catenin and its target gene expression to orchestrate HSC homing. Our study not only identified Skp2 as a new regulator for maintaining β-catenin expression and HSC homing, but also suggested that Skp2 may serve as a predictive marker for monitoring the transplantation efficiency.

Prognostic significance of overexpression of EZH2 and H3k27me3 proteins in gastric cancer

The enhancer of zeste homolog 2 (EZH2) methyl transferase and histone 3 lysine 27 (H3K27me3) protein can repress gene transcription, and their aberrant expression has been observed in various human cancers. This study determined their expression levels in gastric cancer tissues with reference to clinicopathological features and patient survival. We collected 117 gastric cancer and corresponding normal tissues for immunohistochemistry analysis. In gastric cancers, 82/117 (70.1%) were positive for EZH2 and 66/117 (56.4%) for H3K27me3 proteins in contrast to only 5.41% and 7.25% of normal gastric mucosa specimens, respectively. Kaplan-Meier survival data showed the average overall and disease-free survival of EZH2 high expression patients was 25.2 and 20.2 months, respectively, shorter than that with EZH2 low expression (40.5 and 35.9 months). The average overall survival and disease-free survival of high H3K27me3 expression patients was 23.4 and 17.4 months, shorter than without H3K27me3 expression (37.6 and 34.5 months). The average overall survival and disease-free survival of patients with both EZH2 and H3K27me3 expression was 18.8 and 12.9 months, respectively, shorter than that with either alone (34.7 and 31.2 months) or with low levels of both (43.9 and 39.9 months). Multivariate Cox regression analysis showed that H3K27me3 and EZH2 expression, tumor size differentiation and clinical stage were all independent prognostic factors for predicting patient survival. This study demonstrated that detection of both EZH2 and H3K27me3 proteins can predict poor survival of gastric cancer patients, superior to single protein detection. In addition, H3K27me3 and EZH2 protein expression could predict lymph node metastasis.

Time-varying pattern of recurrence risk for gastric cancer patients

This study analyzed the time-varying pattern of the recurrence risk for gastric cancer after surgery. A total of 1,222 gastric patients undergoing D2 resection surgery were studied retrospectively. The annual recurrence hazard curve for all of the populations showed one early peak and a late rise within 10 years after the surgery. The first major recurrence peak covers the first 3 years after the surgery, rising to a maximum at 1.5 years after surgery, followed by a decline until 7.5 years after the surgery, at which point the curve began to rise again. A subgroup analysis of this pattern also revealed that the curves of the patients with bigger tumors, poorly differentiated/undifferentiated adenocarcinomas, lymphatic/venous invasion, T3 and T4, node positive or with fewer lymph nodes retrieved were steeper. Chemotherapy can reduce the hazard rate for recurrence of gastric cancer. Our study confirms the time-varying pattern of the recurrence risk for gastric cancer, and it further supports the hypothesis of tumor dormancy after surgery. To effectively reduce the recurrence risk, new adjuvant therapies beyond chemotherapy may be needed.

Quantum Maxwell's demon in thermodynamic cycles

We study the physical mechanism of Maxwell's demon (MD), which helps do extra work in thermodynamic cycles with the heat engine. This is exemplified with one molecule confined in an infinitely deep square potential with a movable solid wall. The MD is modeled as a two-level system (TLS) for measuring and controlling the motion of the molecule. The processes in the cycle are described in a quantum fashion. It is discovered that a MD with quantum coherence or one at a temperature lower than the molecule's heat bath can enhance the ability of the whole working substance, formed by the heat engine plus the MD, to do work outside. This observation reveals that the essential role of the MD is to drive the whole working substance off equilibrium, or equivalently, to work between two heat baths with different effective temperatures. The elaborate studies with this model explicitly reveal the effect of finite size off the classical limit or thermodynamic limit, which contradicts common sense on a Szilard heat engine (SHE). The quantum SHE's efficiency is evaluated in detail to prove the validity of the second law of thermodynamics.

Relationship between H.Pylori infection and clinicopathological features and prognosis of gastric cancer

Background

Aimed to assess the relationship between H.Pylori and the clinicopathological features and prognosis of gastric cancer by quantitative detection of H.Pylori.

Methods

157 patients were enrolled, all patients had a record of clinicopathological parameters. Specimens including the tumor and non-neoplastic were detected for H.Pylori by Real-Time PCR and analyzed clinical data retrospectively. Variables independently affecting prognosis were investigated by means of multivariate analysis using the Cox proportional hazards model.

Results

H.Pylori infection was greater in non-neoplastic tissue than the tumor tissue (p < 0.05), H.Pylori infection and its copies were related to the tumor site and N staging (p < 0.05). Overall survival (OS) in all 157 patients has no correlation with the H.Pylori infection status (p = 0.715). As to the patients who underwent a curative surgery, relapse-free survival (RFS) has no correlation with the H.Pylori infection status (p = 0.639). Among the H.Pylori positive patients, OS and RFS of those with higher copies were longer than in patients with low copies, but there was no significant statistical difference.

Conclusions

H.Pylori infection status and its copies were related to N staging. The OS and RFS in patients with positive H.Pylori status has no significant difference from the patients with negative H.Pylori status.

[Relationship between the number of lymph node detection and prognosis in stage II gastric cancer after D(2) dissection]

OBJECTIVE

To explore the relationship between the lymph node count and prognosis in stage II gastric cancer.

METHODS

Retrospective analysis was performed for the 268 cases with gastric cancer who underwent parallel D(2) dissection between January 1990 and December 2006 in the Sun Yat-Sen Cancer Center. The Japanese Gastric Cancer Association(JGCA) 13th edition of pathological staging system was used to define stage II gastric cancer. Patients were followed up until December 2008. The Kaplan-Meier method and chi-square test were used for data analysis. All the data were analyzed using SPSS16.0 for Windows.

RESULTS

The average number of detected lymph nodes was 17.3+/-1.2. There were 109 patients with detected lymph node <15. The 1-, 3-, and 5-year survival rates were 92.7%, 67.8%, and 50.9%, respectively. The number of detected lymph node was > or =15 in 159 cases, and the 1-, 3-, and 5-year survival rates were 96.9 %, 81.0%, and 66.4%, respectively. The difference between two groups was statistically significant (P=0.003). Further analysis of the 199 cases with no lymph node metastasis (pN(0) group) showed that there were 95 cases with lymph nodes <15, and the 1-, 3-, and 5-year survival rates were 92.6%, 70.4%, and 55.9%, respectively. There were 104 patients with > or =15 lymph nodes, and the 1-, 3-, and 5-year survival rates were 97.1%, 84.4%, and 66.8%, respectively. The difference was also statistically significant (P=0.049). There were 69 cases with lymph node metastasis (PN(1) group), and the 1-, 3-, and 5-year survival rates of 14 patients with lymph nodes <15 were 92.9%,57.1%, and 34.3%, respectively. Comparing two groups, the survival rate was significantly different (P=0.034). There were 55 patients with > or =15 lymph nodes, and the 1-, 3-, and 5-year survival rates were 96.4%, 73.4%, and 63.8%. The difference was statistically significant (P=0.036).

CONCLUSION

In patients with stage II gastric cancer as defined by the JGCA 13th edition, the survival rate is better in patients with more than 15 detected lymph nodes as compared to those with less than 15.

Virological, serological and biochemical outcomes through 3 years of entecavir treatment in nucleoside-naive Chinese chronic hepatitis B patients

Hepatitis B virus (HBV) infection has a high prevalence in China. Entecavir has shown superior efficacy over lamivudine in Chinese nucleoside-naive chronic hepatitis B (CHB) patients over 48 weeks, with continued clinical benefit to 96 weeks. The present study evaluates the long-term efficacy of entecavir in Chinese CHB patients who continued entecavir treatment for 144 weeks. Patients receiving either entecavir 0.5 mg/day (n = 258) or lamivudine 100 mg/day (n = 261) entered the initial 96-week randomized, double-blind, controlled efficacy study. Patients who did not achieve a consolidated response [HBV DNA <0.7 MEq/mL; alanine aminotransferase (ALT) <1.25 x upper limit of normal; and if hepatitis B e antigen (HBeAg) positive at baseline, loss of HBeAg for ≥ 24 weeks] or who experienced viral breakthrough or relapse entered a 48-week entecavir rollover study. A total of 160 patients received continuous entecavir for 144 weeks; of these, 89% had undetectable serum HBV DNA, 86% showed ALT normalization, 20% reported HBeAg loss and 8% experienced HBeAg seroconversion. The cumulative rates of HBeAg loss and seroconversion were 36% and 27% at Week 144, respectively. The development of resistance was low, with three patients up to Week 96 and an additional two patients in Weeks 96-144 showing evidence of associated genotypic mutations. Entecavir was well tolerated. Adverse event rates were similar to those in lamivudine-treated patients, but patients receiving entecavir experienced fewer ALT flares. This study demonstrates that entecavir provides durable, long-term suppression of HBV DNA and ALT normalization in Chinese CHB patients, and is associated with low rates of emerging resistance. The results are consistent with the findings using entecavir globally and in Japan.

Higher percentage of CD133+ cells is associated with poor prognosis in colon carcinoma patients with stage IIIB

Background

Cancer stem cell model suggested that tumor progression is driven by the overpopulation of cancer stem cells and eradicating or inhibiting the symmetric division of cancer stem cells would become the most important therapeutic strategy. However, clinical evidence for this hypothesis is still scarce. To evaluate the overpopulation hypothesis of cancer stem cells the association of percentage of CD133⁺ tumor cells with clinicopathological parameters in colon cancer was investigated since CD133 is a putative cancer stem cell marker shared by multiple solid tumors.

Patients and methods

Tumor tissues matched with adjacent normal tissues were collected from 104 stage IIIB colon cancer patients who were subject to radical resection between January, 1999 to July, 2003 in this center. The CD133 expression was examined with immunohistochemical staining. The correlation of the percentage of CD133⁺ cell with clinicopathological parameters and patients' 5-year survival was analyzed.

Results

The CD133⁺ cells were infrequent and heterogeneous distribution in the cancer tissue. Staining of CD133 was localized not only on the glandular-luminal surface of cancer cells but also on the invasive budding and the poorly differentiated tumors with ductal structures. Both univariate and multivariate survival analysis revealed that the percentage of CD133⁺ cancer cells and the invasive depth of tumor were independently prognostic. The patients with a lower percentage of CD133⁺ cancer cells (less than 5%) were strongly associated with a higher 5-year survival rate than those with a higher percentage of CD133⁺ cancer cells (greater than or equal to 55%). Additionally, no correlation was obtained between the percentage of CD133⁺ cancer cells and the other clinicopathological parameters including gender, age, site of primary mass, pathologic types, grades, and invasive depth.

Conclusion

The fact that a higher percentage CD133⁺ cells were strongly associated with a poorer prognosis in patients with locally advanced colon cancer implicated that CD133⁺ cancer cells contribute to the tumor progression, and the overpopulation hypothesis of cancer stem cell seems reasonable.

Requirement of aurora-A kinase in astral microtubule polymerization and spindle microtubule flux

Mitotic Aurora-A kinase was found to be required for formation of bipolar spindle, ensuring accurate chromosome segregation in mitosis. Recently, Aurora-A was shown to promote Ran-GTP-induced spindle formation and astral microtubule development. Here, by selective immunodepletion, we showed that Aurora-A was required for centrosome- but not Ran-GTP-induced astral microtubule formation in Xenopus egg extracts. Aurora-A enhanced microtubule polymerization in both centrosome- and Ran-GTP-induced aster assemblies: shortening the timing of aster assembly and increasing the aster size. Indeed, adding of Aurora-A protein alone induced microtubule clustering, which was abrogated by Aurora kinase inhibitory small molecule ZM447439. In addition, we showed that Aurora-A was indispensable for Ran-GTP-induced bipolar spindle formation. Inhibition of Aurora-A activity by adding of kinase inactive dominant mutant led to spindle collapse and formation of monopolar spindle whereas minus-end motor protein dynein/dynactin inhibitor p50/dynamitin rescued the bipolar structure. Lastly, we revealed that Aurora-A was necessary for microtubule poleward flux and this requirement depended on kinase activity. Thus, we showed that Aurora-A promoted microtubule polymerization and maintained microtubule flux in ensuring proper bipolar spindle assembly.

[Influence of neoadjuvant chemotherapy on microsatellite instability in gastric carcinoma]

BACKGROUND & OBJECTIVE

Most results from clinical trials of neoadjuvant chemotherapy for gastric carcinoma are certain. Meanwhile, microsatellite instability (MSI) is thought to be a new mechanism of cell canceration. This study was to investigate the influence of neoadjuvant chemotherapy on MSI in gastric carcinoma.

METHODS

Two microsatellite loci D2S123 and D3S1298 in tumor samples from 48 patients with gastric carcinoma, received preoperative chemotherapy of 5-fluorouracil (5-FU) and leucovorin (CF), were analyzed by polymerase chain reaction (PCR), electrophoresis on 8% denatured polyacrylamide gel, and silver staining. The microsatellite statuses of preoperative and postoperative specimens were compared. Chi-square test was used to analyze the influence of neoadjuvant chemotherapy on MSI in gastric carcinoma.

RESULTS

The detection rate of MSI was significantly higher in preoperative samples than in postoperative samples (31.3% vs. 12.5%, P=0.026). After neoadjuvant chemotherapy, 9 cases changed from MSI-positive to MSI-negative, while no MSI-negative cases became MSI-positive.

CONCLUSION

The neoadjuvant chemotherapy regimen of 5-FU/CF can induce some MSI-positive gastric carcinoma change to MSI-negative, but has no effect on MSI-negative cases.

[Effects of antiviral effects of agents and prognosis of chronic hepatitis B.]

BACKGROUND

To analyze the effects of difference antiviral agents and the effects of the treatments on long-term prognosis.

METHODS

Retrospective research method was applied.

RESULTS

About 40% of the patients were treated with interferon or lamivudine. After the treatment, in lamivudine group, the negative rate of HBV DNA was the highest. In the interferon group, the sero conversion rates of HBeAg/HBeAb were 22.9%. In the antiviral treatment patients, the disease progression and the occurrence of cirrhosis and liver cancer were much lower than those of the control groups. The mortality of cirrhosis and liver cancer in the HBeAg/HBeAb sero converted group was much lower than that of the group without HBeAg/HBeAb sero conversion groups (P less than 0.05).

CONCLUSION

The antiviral effects of interferon and lamivudine were better than those of the other drug groups. The antiviral drugs could relieve the disease progression and reduce the mortality of cirrhosis and liver cancer.

[Infiltration length of gastric cancer on giant sections]

BACKGROUND & OBJECTIVE

The resection boundary for gastric cancer is controversial. The study was designed to investigate gastric wall infiltration length of gastric cancer.

METHODS

A total of 105 patients with gastric cancer who underwent gastrectomy at Cancer Center of Sun Yat-sen University from Apr. 2002 to Feb. 2004 were eligible. During gastrectomy, gastric wall lengths of 18 patients before traction (L1), after traction (L2), and after isolation (L3) were measured. Longitudinal specimen along the center of gastric cancer was fixed to measure the lengths of proximal and distal margins to the cancer. Giant section was observed under microscope to calculate the true infiltration length in proximal and distal margins according to the principle of the length changing uniformity.

RESULTS

In the 18 specimens, L2 was significantly longer than L1 and L3 (P < 0.05); no significant difference was showed between L1 and L3 (P > 0.05). The infiltration length of localized gastric cancer, including early stage cancer, Borrmann I type cancer, and Borrmann II type cancer, was less than 2 cmû that of invasive gastric cancer, including Borrmann III type cancer and Borrmann IV type cancer, was less than 5 cm.

CONCLUSION

The resection length for localized gastric cancer is at least 2 cm to tumor margin, and for invasive gastric cancer is at least 5 cm to tumor margin.

[Multivariate prognostic analysis in gastric carcinoma patients after radical operation]

BACKGROUND & OBJECTIVE

Whether received radical operation is an important prognostic factor of gastric carcinoma. But the long-term efficacies of radical operation on different patients are not the same. This study was to investigate prognostic factors of gastric carcinoma.

METHODS

Clinical data of 405 patients with gastric carcinoma, received radical operation from Jan. 1985 to Dec. 1995 in Cancer Center of Sun Yat-sen University, were analyzed retrospectively. Life table method was used to analyze survival rate, Wilcoxon test was used for statistical comparison, and Cox regression model was used for multivariate analysis.

RESULTS

The 5-year overall survival rate was 43.4%. The 5-year survival rates of patients in pathologic TNM (pTNM) stage I, II, III, and IV were 75.6%, 58.7%, 28.0%, and 18.4%, respectively (P < 0.01). The 5- year survival rates of patients with tumor sizes of less than 2.0 cm, 2.0-3.9 cm, 4.0-5.9 cm, 6.0-7.9 cm, and no less than 8.0 cm were 82.0%, 57.4%, 43.7%, 38.7%, and 26.9%, respectively (P < 0.05). In addition, the 5-year survival rate was higher in patients with perioperative chemotherapy than in patients without perioperative chemotherapy (47.2% vs. 37.8%, P < 0.05). Univariate analysis showed that perioperative chemotherapy, Borrmann type, tumor size, pathologic type, and pTNM stage were prognostic factors of gastric carcinoma. Multivariate analysis showed that pTNM stage, tumor size, and perioperative chemotherapy were independent prognostic factors of gastric carcinoma.

CONCLUSIONS

pTNM stage, tumor size, and perioperative chemotherapy are the most significant factors influencing prognosis of gastric carcinoma patients after radical operation. Perioperative chemotherapy contributes to enhance survival rate of gastric carcinoma patients.

Meta-analysis of intraperitoneal chemotherapy for gastric cancer

AIM

To assess the efficacy and safety of intraperitoneal chemotherapy in patients undergoing curative resection for gastric cancer through literature review.

METHODS

Medline (PubMed) (1980-2003/1), Embase (1980-2003/1), Cancerlit Database (1983-2003/1) and Chinese Biomedicine Database (1990-2003/1) were searched. Language was restricted to Chinese and English. The statistical analysis was performed by RevMan4.2 software provided by the Cochrane Collaboration. The results were expressed with odds ratio for the categorical variables.

RESULTS

Eleven trials involving 1 161 cases were included. The pooled odds ratio was 0.51, with a 95% confidence interval (0.40-0.65). Intraperitoneal chemotherapy may benefit the patients after curative resection for locally advanced gastric cancer, and the combination of intraperitoneal chemotherapy with hyperthermia or activated carbon particles may provide more benefits to patients due to the enhanced antitumor activity of drugs. Sensitivity analysis and fail-safe number suggested that the result was comparatively reliable. However, of 11 trials, only 3 studies were of high quality.

CONCLUSION

Intraperitoneal chemotherapy after curative resection for locally advanced gastric cancer may be beneficial to patients. Continuous multicenter, randomized, double blind, rigorously designed trials should be conducted to draw definitive conclusions.

[Palliative surgery combined with oxaliplatin-based chemotherapy in treatment of patients with advanced gastric cancer]

BACKGROUND & OBJECTIVE

Gastric cancer has the highest incidence rate and mortality rate among gastrointestinal malignancies. Twenty percent of the patients with dissectable gastric cancer cannot be cured simply by surgery due to local infiltration and distant metastasis. To evaluate the therapeutic effectiveness and safety of oxaliplatin combined with 5-fluorouracil and leucovorin on the patients with gastric carcinoma after palliative gastric resection, we analyzed all of the cases of gastric adenocarcinoma undergone palliative gastric resection in our Cancer Center in recent years.

METHODS

A total of 41 patients who underwent palliative gastric resection from Jan. 2000 to May 2004 in our Cancer Center were evaluated. Chemotherapy was given 8-18 days post-surgically with oxaliplatin (130 mg/m(2), intravenus infusion) on day 1, leukovorin (200 mg/m(2)) on day 1, 5-FU (500 mg/m(2), infusion) on day 1 followed by (5-FU 2600 mg/m(2), continuous infusion) for 48 h, the cycle was repeated every 4 weeks. Primary evaluation was performed after 3 cycles of chemotherapy. The chemotherapy was terminated in the patients without response to the treatment. In the patients with response to the treatment, the chemotherapy continued until 6-8 cycles for further analyses.

RESULTS

None of the patients died from surgery or chemotherapy. Complete response occurred in 2 cases, partial response occurred in 19 cases, stable disease in 8 cases, and progressive disease in 12 cases. The total response rate was 52.5%. The 1-year, 2-year, and 3-year survival rates were 71%, 43%, and 32%, respectively. The side effects included neuropathy, nausea, vomiting, and myelosuppression. No grade 3 or 4 myelosuppression was observed.

CONCLUSION

Palliative surgery in late stage gastric cancer followed by combination chemotherapy of oxaliplatin, 5-fluorouracil and leucovorin is a safe therapeutic modality with promising short-term effectiveness and mild side effects.

Meta-analysis of intraperitoneal chemotherapy for gastric cancer

AIM: To assess the efficacy and safety of intraperitoneal chemotherapy in patients undergoing curative resection for gastric cancer through literature review.

METHODS: Medline (PubMed) (1980-2003/1), Embase (1980-2003/1), Cancerlit Database (1983-2003/1) and Chinese Biomedicine Database (1990-2003/1) were searched. Language was restricted to Chinese and English. The statistical analysis was performed by RevMan4.2 software provided by the Cochrane Collaboration. The results were expressed with odds ratio for the categorical variables.

RESULTS: Eleven trials involving 1161 cases were included. The pooled odds ratio was 0.51, with a 95% confidence interval (0.40-0.65). Intraperitoneal chemotherapy may benefit the patients after curative resection for locally advanced gastric cancer, and the combination of intraperitoneal chemotherapy with hyperthermia or activated carbon particles may provide more benefits to patients due to the enhanced antitumor activity of drugs. Sensitivity analysis and fail-safe number suggested that the result was comparatively reliable. However, of 11 trials, only 3 studies were of high quality.

CONCLUSION: Intraperitoneal chemotherapy after curative resection for locally advanced gastric cancer may be beneficial to patients. Continuous multicenter, randomized, double blind, rigorously designed trials should be conducted to draw definitive conclusions.

[Efficiency of combined multiple organs resection in advanced gastric carcinoma]

BACKGROUND & OBJECTIVE

Presently, 26.05% of cases with gastric carcinoma hospitalized in Cancer Center of Sun Yat-sen University were revealed adjacent organs involvement in varying degrees in exploration. There have been many arguments about the issue of surgery therapy on these advanced gastric carcinomas for a long time. This study was designed to demonstrate the feasibility of combined multiple organs resection in such cases.

METHODS

Clinical data of 44 advanced gastric cancer patients received combined multiple organs resections from 1985 to 1995 in Cancer Center of Sun Yat-sen University were enrolled retrospectively. Among them, 34 cases received curative resection and 10 cases received palliative resection. The effects of two kinds of operations were analyzed.

RESULTS

Median survival time was 588 days (average is 1 676 days) in radical combined multiple organs resection group and 344 days (average is 1 045 days) in palliative resection group respectively (P >0.05). In addition, no serious complication occurred and no patients died of extended resection.

CONCLUSION

Combined multiple organs resection is practicable in curative therapy for gastric carcinoma; even palliative resection may have better treatment effect. So, if permission, radical combined multiple organs resection should be top-priority.

The female gender protects against pulmonary injury after trauma hemorrhagic shock

BACKGROUND

Previously, we have documented that lung injury after trauma-hemorrhagic shock (T/HS) is related to gut injury and that females are more resistant to T/HS-induced lung injury than males. However, it is not known if the estrus cycle stage at the time of injury influences the female rat's resistance to T/HS-induced lung injury. Therefore, the goal of this study was to determine if the protective effect of the female gender on lung injury after T/HS is estrus cycle stage-specific. To test this hypothesis, female rats were subjected to trauma (laparotomy) and hemorrhagic shock (T/HS) during different stages of the estrus cycle. Female animals subjected to trauma with sham hemorrhagic shock served as the control.

METHODS

Female Sprague-Dawley rats during the proestrus, estrus, metestrus, or diestrus stages of the menstrual cycle were subjected to a midline laparotomy (trauma) and either hemorrhagic shock (MAP = 30 mm Hg x 90 min) or sham shock. The total volume of blood necessary to induce and maintain the shock state was recorded. At the end of the shock period, the animals were resuscitated with their shed blood. At 6 h postresuscitation, the animals were sacrificed and lung permeability was measured using the Evans blue dye technique and by determining the bronchoalveolar (BALF) to plasma protein ratio. Additionally, pulmonary leukosequestration was quantitated by measuring pulmonary myeloperoxidase levels.

RESULTS

T/HS-induced lung injury and increased pulmonary leukosequestration were not observed in female rats in the proestrus or estrus stages of the menstrual cycle. In contrast, pulmonary permeability was increased significantly in the diestrus stage animals after T/HS. That is, the diestrus females subjected to T/HS had increased pulmonary permeability to Evans blue dye than sham or T/HS proestrus, estrus, and metestrus rats (6.49 +/- 1.33% versus 1.7 +/- 0.87%, 1.57 +/- 0.54%, 1.78 +/- 0.82%, 3.33 +/- 0.68%, p < 0.01, respectively). Similar results were obtained with the BALF protein/plasma protein ratio (0.15 +/- 0.017 versus 0.09 +/- 0.009, 0.09 +/- 0.03, 0.08 +/- 0.022, 0.11 +/- 0.029 p < 0.05, respectively). Although the T/HS metestrus rats had mildly increased lung permeability, this increase in T/HS-lung permeability did not reach statistical significance. Pulmonary myeloperoxidase levels after T/HS displayed a similar trend, with diestrus rats subjected to T/HS having the highest level of MPO (p < 0.05 versus sham or T/HS proestrus and estrus but not metestrus groups). Linear regression analysis of MPO versus Evans blue dye leak revealed a significant correlation between pulmonary neutrophil sequestration and lung leak (r = 0.9549; p < 0.0001).

CONCLUSION

Protection against T/HS-induced lung injury was greatest during the estrus and proestrus stages of the menstrual cycle and decreased with progression to diestrus. During the diestrus stage of the menstrual cycle when gonadal hormone levels are lowest, the rats are more sensitive to T/HS-induced lung injury, indicating that gonadal hormones modulate T/HS-induced lung injury.

Entry of gut lymph into the circulation primes rat neutrophil respiratory burst in hemorrhagic shock

OBJECTIVE

Endothelial cell injury by polymorphonuclear neutrophil (neutrophil [PMN]) respiratory burst after trauma and hemorrhagic shock (T/HS) predisposes subjects to acute respiratory distress syndrome and multiple organ failure. T/HS mesenteric lymph injures endothelial cell and lymph duct ligation (LDL) before T/HS prevents pulmonary injury. We investigated the role of mesenteric lymph in PMN priming by T/HS.

DESIGN

Prospective experiment in rats.

SETTING

University hospital laboratory.

SUBJECTS

Adult male rats.

INTERVENTIONS

Mesenteric lymph was obtained from rats undergoing T/HS (30 mm Hg, 90 mins) or sham shock (T/SS). Plasma was harvested from uninstrumented control (UC), T/HS, T/SS, and T/HS+LDL rats. PMNs were isolated from UC, T/HS, and T/HS+LDL rats.

MEASUREMENTS AND MAIN RESULTS

PMNs from UC rats were incubated in buffer, 1% T/HS lymph, and 1% T/SS lymph. PMNs from UC rats were incubated in UC, T/HS, T/SS, and T/HS+LDL plasma. PMN respiratory burst was initiated by using macrophage inflammatory protein (MIP)-2/platelet-aggregating factor (PAF) or phorbol myristate acetate. Cytosolic calcium ([Ca2+]i) responses to MIP-2/PAF were assayed in PMN from UC, T/HS, and T/HS+LDL rats. PMN preincubated in T/HS lymph showed significant elevations in MIP/PAF-elicited respiratory burst compared with T/HS lymph or buffer only (p <.05; analysis of variance/Tukey's test). T/HS lymph incubation also increased (p <.05) phorbol myristate acetate elicited respiratory burst compared with buffer or T/SS. Preincubation in T/HS plasma increased MIP-2/PAF-elicited respiratory burst (p <.05) compared with UC or T/SS plasma. LDL blocked T/HS priming of respiratory burst. Control PMN [Ca2+]i responses to MIP-2 and PAF were low. T/SS PMN were significantly more responsive, but the T/HS PMN showed still higher responses (p <.01). LDL reversed the priming of [Ca2+]i responses by T/HS (p <.01).

CONCLUSIONS

PMNs are primed by T/HS lymph but not T/SS lymph and by T/HS plasma but not T/SS plasma. LDL before shock prevents T/HS plasma from priming PMN. The magnitude of respiratory burst found here paralleled the [Ca2+]i responses seen to receptor dependent initiating agonists. Mesenteric lymph is both necessary and sufficient to prime PMN after T/HS in the rat, and it primes PMN in part by enhancing [Ca2+]i responses to G-protein coupled chemoattractants. Mesenteric lymph mediates postshock PMN dysfunction.

Hemorrhagic shock induced up-regulation of P-selectin expression is mediated by factors in mesenteric lymph and blunted by mesenteric lymph duct interruption

BACKGROUND

Previous studies have shown that mesenteric lymph duct interruption prevents lung injury and decreases lung neutrophil sequestration after hemorrhagic shock (HS). Since endothelial cells rapidly express P-selectin after ischemia/reperfusion injury and HS-induced lung injury appears to involve neutrophil-endothelial cell interactions, we tested the following two hypotheses. First, that HS increases endothelial cell P-selectin expression and that interruption of mesenteric lymph flow in vivo would diminish this expression. Second, that incubation of human umbilical vein endothelial cells with post-HS mesenteric lymph but not sham shock (SS) lymph or postshock portal vein plasma would up-regulate P-selectin expression.

METHODS

Pulmonary microvascular P-selectin expression was measured in male rats subjected to 90 minutes of HS (30 mm Hg), SS, or HS with lymphatic ligation, with a dual radiolabeled monoclonal antibody technique. The lungs from these animals were subsequently harvested and P-selectin expression was expressed as mean +/- SEM nanograms of monoclonal antibody per gram of tissue.

RESULTS

Pulmonary P-selectin expression was 2.0 +/- 0.4 after SS, 9.7 +/- 3.0 after HS, but decreased to 2.3 +/- 0.3 after HS with lymph interruption (p < 0.05 HS vs. SS or HS plus lymph ligation). Incubation of human umbilical vein endothelial cells with shock lymph collected 3 to 4 hours after shock resulted in a nearly fivefold increase in P-selectin expression (p < 0.001) as compared with SS lymph, lymph collected 6 hours after shock, or postshock portal vein plasma.

CONCLUSION

These results support the concept that gut-derived lymph promotes HS-induced lung injury through up-regulation of microvascular adhesion molecules and that intestinal lymph duct interruption may prevent distant organ injury by blunting the expression of these molecules.

Role of placental tissues in the intrauterine transmission of hepatitis B virus

OBJECTIVE

The purpose of this study was to determine the mechanism of intrauterine transmission of hepatitis B virus.

STUDY DESIGN

Placental tissues from 158 pregnant women who tested positive for hepatitis B surface antigen were examined for hepatitis B virus markers, Fc gamma receptors, and hepatitis B surface antigen-anti-hepatitis B surface antigen in different layers of cells.

RESULTS

It was shown that the hepatitis B virus infection rate among different layers of placental cells gradually decreased from the maternal side to the fetal side. Furthermore, the closer the infected cell layer was to the fetal side, the higher the risk of intrauterine hepatitis B virus infection. Fc gamma receptors were found on cells of both hepatitis B surface antigen positive and negative placentas; Fc gamma receptors III were found on trophoblastic cells and villous mesenchymal cells, and Fc gamma receptors II were found on only villous mesenchymal cells. Hepatitis B surface antigen-antibodies to hepatitis B surface antigen was detected in the cytoplasm and on the membrane of trophoblastic cells and villous mesenchymal cells in 2 hepatitis B surface antigen-positive placentas.

CONCLUSION

The results support the hypothesis that intrauterine hepatitis B virus transmission could be caused through "cellular transfer" in the placenta. One of the means of cellular transfer could be through Fc gamma receptor III-mediated entry of hepatitis B surface antigen-antibodies to hepatitis B surface antigen into cells.

Mesenteric lymph from rats subjected to trauma-hemorrhagic shock are injurious to rat pulmonary microvascular endothelial cells as well as human umbilical vein endothelial cells

Previously, we have documented that gut-derived lymph from rats subjected to trauma/hemorrhagic shock (T/HS) is injurious to human umbilical vein endothelial cells (HUVEC). To verify these findings in an all rat systems, the ability of T/HS lymph to increase rat pulmonary microvascular endothelial cell (RPMVEC) monolayer permeability and kill RPMVEC was compared with that observed with HUVECs. RPMVEcs isolated from male rats or HUVECs were grown in 24-well plates for the cytotoxicity assays or on permeable filters in a two-chamber system for permeability assays. Mesenteric lymph was collected from male rats subjected to trauma (laparotomy) plus hemorrhagic shock (T/HS group) or to a laparotomy plus sham-shock (T/SS group). The T/HS group had their mean arterial pressure decreased to 30 mmHg and kept there for 90 min. Lymph samples centrifuged to remove the cellular component were incubated with the RPMVECs or HUVECs at a 10% concentration. Neither T/SS lymph nor post-T/HS portal vein plasma was toxic to or increased the permeability of the RPMVECs or HUVECs. The pattern of cytotoxicity observed in the HUVECs incubated with T/HS mesenteric lymph was similar to that observed in the RPMVECs, as reflected by trypan blue dye exclusion, with more than 95% of the HUVECs and RPMVECs being killed after a 16-h incubation with T/HS mesenteric lymph. However, at earlier time points the amount of LDH released from the HUVEC cells incubated with T/HS lymph was greater than that observed with the PRMVEC, although trypan blue dye exclusion was similar. Similarly, incubation with 10% T/HS lymph increased the permeability of both HUVEC and RPMVEC monolayers more than 2-fold, even with an incubation period as short as 1 h. In conclusion, these results provide further evidence that T/HS lymph, but not T/SS lymph or post-T/HS portal vein plasma, is injurious to endothelial cells and that RPMVECs are as susceptible to injury as HUVECs. Additionally, these studies support the emerging concept that gut-induced distant organ injury is mediated by factors contained in mesenteric lymph.

Hypoxia combined with Escherichia coli produces irreversible gut mucosal injury characterized by increased intestinal cytokine production and DNA degradation

The objective of the present study was to determine whether hypoxia/reoxygenation in the absence or presence of intestinal bacteria would affect the integrity of the gut mucosal epithelium (as evidenced by histologic changes) and increase the local production of cytokines (interleukin 6 [IL-6] and tumor necrosis factor [TNF]). Rat ileal mucosal membranes were harvested and their electrophysiologic properties and barrier function were measured ex vivo in the Ussing chamber system. Membranes were exposed to normoxia, normoxia + Escherichia coli, hypoxia for 40 min followed by normoxia, or hypoxia for 40 min + E. coli followed by normoxia for 3 h. IL-6 and TNF levels were measured using cytokine-dependent cellular assays. Morphological changes and the degree of DNA fragmentation were used as quantitative markers of gut mucosal injury. Mucosal integrity was maintained in the normoxia group. The addition of bacteria increased the IL-6 response and reduced mucosal integrity. During the hypoxic period, a transient decline in resistance (R) occurred and cytokine production was reduced. In the hypoxic ileal membranes not exposed to E coli, reoxygenation reversed the change in R and increased IL-6 production. The combination of hypoxia/reoxygenation plus E. coli bacterial challenge resulted in the greatest extent of gut mucosal injury and increase in TNF production. The results of this study support the hypothesis that the combination of increased intestinal bacterial levels superimposed on an ischemia/reperfusion injury increases the magnitude of gut mucosal injury and the production and subsequent release of proinflammatory cytokines.

Hematopoietic failure after hemorrhagic shock is mediated partially through mesenteric lymph

OBJECTIVE

To determine whether hemorrhagic shock-induced bone marrow failure is mediated by the gut through the production of toxic mesenteric lymph and whether shock-induced bone marrow failure could be prevented by division of the mesenteric lymphatics.

DESIGN

Prospective, controlled study.

SETTING

University surgical research laboratory.

SUBJECTS

Male Sprague-Dawley rats.

INTERVENTIONS

Rats were divided into five groups: unmanipulated controls (n = 12), hemorrhagic shock with laparotomy (n = 8), hemorrhagic shock with mesenteric lymph duct ligation (n = 10), sham shock with laparotomy (n = 6), and sham shock with mesenteric lymph duct ligation (n = 7). At either 3 or 6 hrs after resuscitation, bone marrow was obtained for determination of early (cobblestone forming cells) and late (granulocyte-macrophage colony forming unit and erythroid burst forming unit) hematopoietic progenitor cell growth. Parallel cultures were plated with plasma (1% and 2% v/v) from all groups to determine the effect of lymphatic ligation on hematopoiesis.

MEASUREMENTS AND MAIN RESULTS

Bone marrow cellularity, cobblestone forming cells, granulocyte-macrophage colony forming unit, and erythroid burst forming unit growth in rats subjected to hemorrhagic with lymph duct ligation were similar to those observed in sham-treated animals and significantly greater than in rats subjected to shock and laparotomy without lymphatic duct ligation. Plasma from rats subjected to shock without lymph ligation was inhibitory to hematopoietic progenitor cell growth. In contrast, this shock-induced inhibition was not observed with plasma obtained from shocked rats that underwent mesenteric lymph ligation.

CONCLUSIONS

Hemorrhagic shock suppresses bone marrow hematopoiesis as measured by a decrease in early and late progenitor cell growth. This suppression appears mediated through mesenteric lymph as the effect is abrogated by mesenteric lymph duct ligation. These data clearly demonstrate a link between the gut and bone marrow failure after hemorrhagic shock

Identification of the epitopes on HCV core protein recognized by HLA-A2 restricted cytotoxic T lymphocytes

AIM: To identify hepatitis C virus (HCV) core protein epitopes recognized by HLA-A2 restricted cytotoxic T lymphocyte (CTL).

METHODS: Utilizing the method of computer prediction followed by a 4 h ⁵¹Cr release assay confirmation.

RESULTS: The results showed that peripheral blood mononuclear cells (PBMC) obtained from two HLA-A2 positive donors who were infected with HCV could lyse autologous target cells labeled with peptide “ALAHGVRAL (core 150-158)”. The rates of specific lysis of the cells from the two donors were 37.5% and 15.8%, respectively. Blocking of the CTL response with anti-CD4 mAb caused no significant decrease of the specific lysis. But blocking of CTL response with anti-CD8 mAb could abolish the lysis.

CONCLUSION: The peptide (core 150-158) is the candidate epitope recognized by HLA-A2 restricted CTL.

Injury-enhanced calcium mobilization in circulating rat neutrophils models human PMN responses

G-protein coupled (GPC) chemoattractants are important neutrophil (PMN) activators in human shock and sepsis, acting in part by increasing cytosolic calcium ([Ca2+]i). Rats are widely used as laboratory models of shock and sepsis, but reports of [Ca2+]i flux in circulating rat PMN are rare. Moreover, the [Ca2+]i values reported often differ markedly from human systems. We developed study methods where basal [Ca2+]i values in circulating rat PMN were comparable to human PMN, but rat PMN still mobilized calcium poorly after stimulation. Trauma (laparotomy) did not change rat PMN basal [Ca2+]i, but induced brisk [Ca2+]i responses to chemokine and lipid mediators that approximated human PMN responses. This was associated with marked loading of microsomal calcium stores. Formyl peptides still mobilized calcium less well in rat than human PMN. Normal rat PMN appear to circulate in a less mature or primed form than human PMN. A very limited injury rapidly converts rat PMN to a more activated phenotype. PMN thus activated act quite similar to human PMN in terms of GPC receptor-mediated calcium mobilization. Trauma enhances rat PMN responses to GPC agonists at least in part by loading cell calcium stores.

Factors larger than 100 kd in post-hemorrhagic shock mesenteric lymph are toxic for endothelial cells

BACKGROUND

Post-shock mesenteric lymph kills and injures endothelial cells (ECs), but neither the mechanism nor the mediators of lymph's toxic effect are known. Thus, in these studies we investigated and characterized potential factors that may be involved in lymph's toxic effect on ECs.

METHODS

Lymph was collected hourly from rats before shock, during the shock period, and for 6 hours post-shock and processed in several ways-including removal of cellular elements, freezing, heating, or separation by molecular weight-after which they were tested for toxicity (lactate dehydrogenase as a marker of cell injury and trypan blue as a marker of cell viability).

RESULTS

Controls consisting of medium, pre-shock lymph, and post-shock portal vein plasma had no EC toxicity. Lymph collected 1 to 3 hours post-shock resulted in the death of 90% to 95% of ECs and caused an 8- to 10-fold increase in lactate dehydrogenase release; however, this toxic effect waned by 4 hours post-shock. Endotoxin neutralization and immune cell removal did not decrease lymph cytotoxicity but complement inactivation did. By fractionating the toxic lymph samples by size, it appears that the putative EC cytotoxic mediator(s) is larger than 100,000 d.

CONCLUSIONS

Mesenteric lymph collected 1 to 3 hours after hemorrhagic shock is toxic to ECs, but this effect is lost by 4- to 5-hours post-shock and is not dependent on the presence of immune cells or endotoxin but does involve complement and other putative mediators of greater than 100,000 d.

A time course study of the protective effect of mesenteric lymph duct ligation on hemorrhagic shock-induced pulmonary injury and the toxic effects of lymph from shocked rats on endothelial cell monolayer permeability

BACKGROUND

We have previously documented that lymphatic duct division protects against shock-induced lung injury when tested 3 hours post-shock and that lymph collected at 3 hours post-shock increases endothelial cell monolayer permeability. However, whether lymph collected at other time points post-shock also increases endothelial cell permeability is not known. We tested the protective effects of lymphatic division on lung permeability at 6, 12, and 24 hours post-shock and the ability of lymph collected before, during, and hourly (up to 6 hours) after shock to increase endothelial cell monolayer permeability.

METHODS

At 3, 6, 12, or 24 hours after sham or actual shock (30 mm Hg for 90 min), lung permeability was measured by using Evans blue dye in rats subjected to sham or actual mesenteric duct ligation. In separate experiments, the ability of lymph collected from rats subjected to shock or sham shock to increase human umbilical vein endothelial cell (HUVEC) monolayer permeability to a 40 kd dextran rhodamine permeability probe. Lymph was tested at 10% and 1% concentrations.

RESULTS

Hemorrhagic shock induced a 3- to 4-fold increase in lung permeability compared with sham-shock rats when tested at 3, 6, 12, or 24 hours post-shock. Lymphatic division prevented this increase in lung permeability at each of these time points. Sham shock lymph did not increase HUVEC permeability, while lymph from the shocked rats did, whether tested at 1% or 10%. Lymph samples collected during the shock period and hourly for 6 hours post-shock all increased HUVEC permeability; however, the greatest relative increase in HUVEC permeability was observed in the 3- and 6- hour post-shock samples.

CONCLUSIONS

Lung injury after hemorrhagic shock appears to be caused by toxic factors carried in the mesenteric lymph, and factors capable of increasing HUVEC permeability initially appear in the lymph during the shock period and increase over time.

Chronic hepatitis B virus infection in Asian countries

Of the estimated 50 million new cases of hepatitis B virus (HBV) infection diagnosed annually, 5-10% of adults and up to 90% of infants will become chronically infected, 75% of these in Asia where hepatitis B is the leading cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma (HCC). In Indonesia, 4.6% of the population was positive for HBsAg in 1994 and of these, 21% were positive for HBeAg and 73% for anti-HBe; 44% and 45% of Indonesian patients with cirrhosis and HCC, respectively, were HBsAg positive. In the Philippines, there appear to be two types of age-specific HBsAg prevalence, suggesting different modes of transmission. In Thailand, 8-10% of males and 6-8% of females are HBsAg positive, with HBsAg also found in 30% of patients with cirrhosis and 50-75% of those with HCC. In Taiwan, 75-80% of patients with chronic liver disease are HBsAg positive, and HBsAg is found in 34% and 72% of patients with cirrhosis and HCC, respectively. In China, 73% of patients with chronic hepatitis and 78% and 71% of those with cirrhosis and HCC, respectively, are HBsAg positive. In Singapore, the prevalence of HBsAg has dropped since the introduction of HBV vaccination and the HBsAg seroprevalence of unvaccinated individuals over 5 years of age is 4.5%. In Malaysia, 5.24% of healthy volunteers, with a mean age of 34 years, were positive for HBsAg in 1997. In the highly endemic countries in Asia, the majority of infections are contracted postnatally or perinatally. Three phases of chronic HBV infection are recognized: phase 1 patients are HBeAg positive with high levels of virus in the serum and minimal hepatic inflammation; phase 2 patients have intermittent or continuous hepatitis of varying degrees of severity; phase 3 is the inactive phase during which viral concentrations are low and there is minimal inflammatory activity in the liver. In general, patients who clear HBeAg have a better prognosis than patients who remain HBeAg-positive for prolonged periods of time. The outcome after anti-HBe seroconversion depends on the degree of pre-existing liver damage and any subsequent HBV reactivation. Without pre-existing cirrhosis, there may be only slight fibrosis or mild chronic hepatitis, but with pre-existing cirrhosis, further complications may ensue. HBsAg-negative chronic hepatitis B is a phase of chronic HBV infection during which a mutation arises resulting in the inability of the virus to produce HBeAg. Such patients tend to have more severe liver disease and run a more rapidly progressive course. The annual probability of developing cirrhosis varies from 0.1 to 1.0% depending on the duration of HBV replication, the severity of disease and the presence of concomitant infections or drugs. The annual incidence of hepatic decompensation in HBV-related cirrhosis varies from 2 to 10% and in these patients the 5-year survival rate drops dramatically to 14-35%. The annual risk of developing HCC in patients with cirrhosis varies between 1 and 6%; the overall reported annual detection rate of HCC in surveillance studies, which included individuals with chronic hepatitis B and cirrhosis, is 0.8-4.1%. Chronic hepatitis B is not a static disease and the natural history of the disease is affected by both viral and host factors. The prognosis is poor with decompensated cirrhosis and effective treatment options are limited. Prevention of HBV infection thorough vaccination is still, therefore, the best strategy for decreasing the incidence of hepatitis B-associated cirrhosis and HCC.

A multicenter, randomized, controlled trial of interferon alfacon-1 compared with alpha-2a-interferon in Chinese patients with chronic hepatitis C virus infection

BACKGROUND

Alpha-interferons are the accepted therapy for patients infected with chronic hepatitis C virus (HCV) in China. However, consensus interferon (CIFN) for HCV treatment is effective in patients with chronic hepatitis C from Western countries.

METHODS

This randomized, controlled trial was conducted to determine the safety and efficacy of CIFN at two doses, and to compare it with alpha-2a-interferon (IFN-alpha-2a) in Chinese patients with chronic HCV. Interferon-naive patients with chronic HCV infection (n = 187) were randomly chosen to receive 15 microg CIFN or 9 microg or 3 MU IFN-alpha-2a subcutaneously, three times a week for 24 weeks, followed by a 24 week observation period. Efficacy was evaluated by the normalization of serum alanine aminotransferase (ALT) and the non-detectability disappearance of serum HCV-RNA by using reverse-transcription-polymerase chain reaction. The safety of CIFN was evaluated by recording the type and severity of adverse effects.

RESULTS

The combined ALT and HCV-RNA end-of-treatment and sustained responses were observed to be greater for treatment with 15 microg CIFN (59.0% and 55.7%, respectively) compared to IFN alpha-2a (36.1% and 39.3%, respectively; P = 0.01 for the end-of-treatment, P = 0.07 for the sustained response). The combined ALT and HCV-RNA end-of-treatment and sustained responses for treatment with 9 microg CIFN (both 49.2%) were higher than those for IFN-alpha-2a (not statistically significant). Data were analyzed by using a logistic-multiple-variate regression model, which indicated that the higher IFN dose (15 microg or 9 microg CIFN vs 3 MU IFN-alpha-2a; P < 0.01) appeared to be associated with a better sustained response. The type, frequency and severity of adverse effects were comparable across treatment groups.

CONCLUSIONS

Consensus interferon appears to be safe and effective at concentrations of 9 and 15 microg, but 15 microg CIFN may be more effective than 3 MU IFN-alpha-2a, without increased toxicity.

Acute lung injury after hemorrhagic shock is dependent on gut injury and sex

Recent studies have established gut-derived lymph rather than portal blood as the major source of toxic mediators after hemorrhagic shock that causes distant organ injury. Similarly, emerging data have identified sex as a major modifier of the response to injury and illness. Thus we tested the hypothesis that female rats would be more resistant to shock-induced lung injury than male rats because females are more resistant to shock-induced gut injury and produce mesenteric lymph that is less toxic to endothelial cells. Male and female rats were subjected to sham or hemorrhagic shock and lung permeability was quantitated by Evans blue dye and protein extravasation into the alveolar space. Next, mesenteric lymph collected from shocked and sham-shocked rats of both sexes was incubated with human umbilical vein endothelial cells (HUVECs) and assayed for toxicity. Trypan blue dye exclusion and the release of lactate dehydrogenase assessed HUVEC viability and injury respectively. Lastly, sections of the terminal ileum were histologically examined for evidence of shock-induced mucosal injury. Male rats but not female rats subjected to hemorrhagic shock had evidence of increased lung permeability and produced mesenteric lymph that was cytotoxic to HUVECs. Shock caused gut injury in the male rats whereas histological evidence of gut injury was not observed in the female rats. Hemorrhagic shock-induced lung injury depends on gut injury and mesenteric lymph appears to be the route by which gut-derived toxic factors exit the gut to cause lung injury. The resistance of female rats to shock-induced lung injury appears to be secondary to their resistance to shock-induced gut injury.

Mesenteric lymph duct ligation provides long term protection against hemorrhagic shock-induced lung injury

Recently we have shown that ligation of the main mesenteric lymph (MLN) duct prior to an episode of hemorrhagic shock (HS) prevents shock-induced lung injury. Yet, ligation or diversion of intestinal lymph immediately prior to injury is not clinically feasible. Diversion of intestinally derived lymph after injury to protect against secondary insults is possible, but it is not known how long the protective effects of lymph ligation would last. Thus, we tested whether ligation of the MLN duct seven days prior to HS would still be protective. Male Sprague-Dawley rats were subjected to laparotomy with or without MLN duct ligation. Seven days later, half of the sham and actual MLN duct ligated animals randomly were selected to undergo HS (30 mmHG for 90 min). The other half of the animals was subjected to sham shock. Lung permeability, pulmonary myeloperoxidase (MPO) activity, and bronchoalveolar fluid (BALF) protein content were used to determine lung injury. Lymphatic division 7 days prior to HS continued to prevent shock induced lung injury as assessed by a lower Evans Blue dye concentration, BALF protein and MPO activity. In addition, there was no evidence of Patent Blue dye in the previously ligated MLN duct. Since ligation of the main mesenteric lymphatic duct continues to protect against shock-induced lung injury 1 week after duct ligation, it is feasible that lymphatic ligation performed after an injury remains protective against certain secondary insults for at least 1 week.

Endotoxin-induced mesenteric microvascular changes involve iNOS-derived nitric oxide: results from a study using iNOS knock out mice

The administration of endotoxin alters intestinal blood flow, increases nitric oxide (NO) production, and induces gut barrier dysfunction. Thus, we investigated the hypothesis that microvascular reactivity and permeability of the mesenteric vascular bed are altered to a lesser degree in iNOS knock out (iNOS -/-) mice than their wild-type (iNOS +/+) litter mates after an endotoxin challenge. To test this hypothesis, we compared the microvascular response of iNOS knockout (iNOS -/-) mice after a topical or systemic endotoxin challenge against that of their wild-type litter mates (iNOS +/+). Intravital microscopy was used to measure arteriolar diameter and postcapillary venular permeability in the mouse ileum. Both parameters were determined by computer-assisted image analysis. Diameter was measured in A1, A2, and A3 arterioles (1, 2, 3 = rank of deployment). Changes in microvascular permeability were measured from changes in interstitial fluorescence caused by extravasation of fluorescein isothiocyanate (FITC)-dextran 150 (molecular weight = 150 kDa) and expressed as changes in integrated optical intensity (IOI). In the first series of experiments, endotoxin (100 microg/mL) was applied topically to the ileal segment. In the second series, endotoxin (10 mg/kg) was administered intraperitoneally (i.p.). Administration of topical or i.p.. endotoxin caused vasoconstriction and was associated with an early increase in permeability in both iNOS +/+ and -/- mice, although over time the responses of the iNOS -/- and iNOS +/+ mice diverged. Twenty minutes after topical endotoxin, the increase in permeability in iNOS -/- mice had reached a plateau whereas it continued to increase in the iNOS +/+ mice, such that at 80 min post-topical endotoxin, IOI was 27+/-7 in iNOS -/- vs. 39+/-5 in iNOS +/+ (P < 0.05). A similar permeability response was observed after i.p.. endotoxin, where the increase in post-capillary venular permeability was greater in the iNOS +/+ mice (P < 0.05). Both iNOS -/- and iNOS +/+ mice had a similar transient vasoconstrictive response after topical endotoxin challenge (reduction in A2 arteriolar diameters by -17+/-4% vs. -24+/-7%), with return to baseline values by 60-80 min post-endotoxin challenge. The iNOS +/+ but not the iNOS -/- mice manifested a secondary vasodilatory response that persisted throughout the experimental period. The arteriolar vasoreactive response of the iNOS -/- and iNOS +/+ mice to i.p.. endotoxin was similar to that of topical endotoxin, but of a lesser magnitude. In conclusion, the similarity in effects between topical and systemic endotoxin indicates that endotoxin causes microvascular dysfunction in the gut by directly on the microcirculation. In addition, our data suggest that NO production by iNOS is involved in the microvascular alterations associated with gut barrier dysfunction.

Gut-derived mesenteric lymph: a link between burn and lung injury

BACKGROUND

Previously, we showed that mesenteric lymph generated following hemorrhagic shock increases endothelial cell permeability and contributes to lung injury. It has also been shown that lymph produced at the site of burn injury plays a role in altering pulmonary vascular hemodynamics. In addition, previous experimental work has suggested that organs and tissues distant from the injury site may contribute to pulmonary dysfunction. One explanation would be that gut-derived inflammatory factors (in addition to those produced locally at the site of injury) are reaching the pulmonary circulation, where they exert their effects via the gut lymphatics.

HYPOTHESES

The 2 hypotheses herein were that (1) gut-derived factors carried in the mesenteric lymph of rats generated following thermal injury will contribute to lung injury and (2) intestinal bacterial overgrowth will potentiate the degree of burn-induced lung injury. These hypotheses were tested by examining the effect of mesenteric lymph flow interruption prior to thermal injury on burn-induced lung injury in rats with a normal intestinal bacterial flora and in rats with intestinal Escherichia coli overgrowth. These rats were termed E. coli-monoassociated rats.

METHODS

Normal intestinal bacterial flora and monoassociated male Sprague-Dawley rats were subjected to sham burn, 40% total body surface area burn, or lymphatic division plus burn. After 3 hours, 10 mg of Evans blue was injected to measure lung permeability. After the rats were killed, a bronchoalveolar lavage was performed and the fluid analyzed spectrophotometrically. Bronchoalveolar lavage fluid protein content, pulmonary myeloperoxidase activity, and alveolar apoptosis served to further quantitate lung injury.

RESULTS

Both normal intestinal bacterial flora and monoassociated-burned rats exhibited significant increases in lung permeability, bronchoalveolar lavage fluid protein content, myeloperoxidase activity, and alveolar apoptosis. The combination of monoassociation and thermal injury resulted in even further increases in lung injury over thermal injury alone. Lymphatic division prior to thermal injury ameliorated burn-induced increases in lung permeability, bronchoalveolar lavage fluid protein content, pulmonary myeloperoxidase accumulation, and alveolar apoptosis in both normal intestinal bacterial flora and monoassociated rats.

CONCLUSIONS

The results of this study support the hypothesis that gut-derived factors carried in the mesenteric lymph contribute to burn-induced lung injury and may therefore play a role in postburn respiratory failure and suggest that intestinal bacterial overgrowth primes the host such that when animals are exposed to a second stimulus (such as thermal injury) an exaggerated response occurs.

A miniaturized applanation tonometer

A miniaturized hand-held applanation tonometer is introduced, in which a special cone prism is employed to be an applanation probe to flatten the eye vertically. The self-weight of the probe is just the applanation force, and the applanation area of the ocular cornea is monitored by the optoelectronic signal. The preliminary test demonstrates its good clinical acceptance and its accuracy meeting clinical needs.

Long-term efficacy of recombinant interferon alpha 2a in the treatment of chronic hepatitis C: a randomized prospective study comparing two dose schedules in Chinese patients

BACKGROUND/AIMS

This study is the first randomized prospective clinical trial of interferon in hepatitis to be conducted according to the guidelines of Good Clinical Practice (GCP) in China. The object of this study is to compare the long-term efficacy of a dose of 3MU of recombinant IFN alpha 2a (rIFN-alpha 2a) three times a week (t.i.w.) for 6 months with a starting dose of 6MU for 3 months and subsequent reduction to 3 MU t.i.w for a further 3 months.

METHODOLOGY

Sixty-eight serological and histologically proven chronic hepatitis C patients with elevated serum ALT were randomized into two groups. A total of 63 patients were studied with full course of treatment. Five patients were withdrawn from the trial, 2 due to personal reasons and 3 due to adverse drug reactions during treatment. Thirty patients received 6MU IFN-alpha 2a t.i.w. for 3 months followed by 3MU t.i.w. for another 3 months (group A). Thirty-three patients received 3MU IFN-alpha 2a t.i.w. for 6 months (group B).

RESULTS

The sex, age, baseline serum bilirubin, ALT and AST levels were matched in both groups. At the end of 6 months the complete and partial response rates in group A were 60.0% and 16.7%, respectively, and the clearance of serum HCV-RNA was 53.3%. In group B, the complete and partial response rates were 72.7% and 3.0%, respectively, and the clearance of HCV-RNA was 61.3%. These patients were followed up for 6, 12, and 18 months after stopping treatment. In group A, the rates of complete normalization of ALT and clearance of serum HCV-RNA at 24 months were 50.0% and 60.0%, respectively. In group B, the rates of normalization of ALT and clearance of HCV-RNA at 24 months were 54.4% and 41.9%, respectively. The efficacy between the two groups showed no statistically significant difference; the response rates of treatment were similar to the patients with HCV genotype 1b and 2a. Six patients (10.8% of the study population) developed neutralization antibodies to IFN-alpha 2a during treatment, 4 of them responded to the treatment. Adverse drug reactions (ADR) were common, but most of them were tolerable and the incidence of ADR was similar in both groups.

CONCLUSIONS

IFN-alpha 2a is effective in the treatment of Chinese patients with chronic hepatitis C. The sustained response rates and ADR among two dose schedule groups are similar.