Gelatinous ascites: a cytohistologic study of pseudomyxoma peritonei in 67 patients

BACKGROUND

Pseudomyxoma peritonei (PMP) is a rare condition characterized by gelatinous ascites. Although the histologic attributes of PMP have been well studied, the cytologic features remain ill defined.

METHODS

We reviewed the peritoneal washings (PW) in 67 patients with PMP to identify cytomorphologic features useful in classifying cases as either disseminated peritoneal adenomucinosis (DPAM) or peritoneal mucinous carcinomatosis (PMCA). Histologic specimens were correlated with the cytologic diagnoses. Correlation between cytologic diagnosis and patient outcome was investigated.

RESULTS

Neoplastic epithelial cells were identified in 63 of 67 PW (94%). Concordance with the histologic diagnosis was obtained in 61 of 63 cases. Of these 36.5% were cytologically classified as DPAM with primary appendiceal neoplasms in 19 cases. Thirty-four of 63 cases (53.9%) were cytologically diagnosed as PMCA based on PW cytology. Most were of appendiceal or colonic origin. Four cases displayed cytologic features of both DPAM and PMCA. Two discordant cases each with a cytologic diagnosis of PMCA had an appendiceal adenoma. Acellular mucin alone was identified in the PW in four cases. Analysis of follow-up data revealed that cases diagnosed as DPAM had a better prognosis than those diagnosed as PMCA.

CONCLUSIONS

Cytomorphologic features of epithelial cells in PW material can accurately categorize cases of PMP as either DPAM or PMCA. Furthermore, this categorization appears to have important prognostic implications.

Prognostic value of hepatocyte proliferative activity after transjugular intrahepatic portosystemic shunt

OBJECTIVES

Previous data indicated that the proliferating cell nuclear antigen-labeling index (PCNA-LI) reflects the liver functional reserve in human liver cirrhosis. The aim of the study was to evaluate the hepatocyte proliferative activity as a marker for the outcome of patients after transjugular intrahepatic portosystemic shunt (TIPS).

METHODS

Twenty-eight consecutive patients were electively treated with TIPS for recurrent variceal bleeding (n = 14), refractory ascites (n = 12), or hydrothorax (n = 2). PCNA immunostaining was analyzed on methanol-fixed, paraffin-embedded liver biopsies.

RESULTS

After TIPS, six patients died within the first 3 months, eight other patients died later, two were transplanted, and 12 were alive at the time of analysis. Early death occurred in patients with refractory ascites (5/12) and/or in Child C patients (3/6). Among the evaluated variables, there was a statistical trend for the PCNA-LI to be lower in patients who died early after TIPS than in those having long term survival (1.55% vs 2.65%, p = 0.07). After TIPS insertion, the probability of remaining alive during the first 6 months of follow-up was significantly higher in patients with a preprocedural PCNA-LI > 2.9%.

CONCLUSIONS

The PCNA-LI measured on liver biopsy before the TIPS procedure might be a pre-TIPS marker to discriminate those patients for whom TIPS is likely to be beneficial.

Comparative immunochemical study of lectin-binding sites and cytoskeletal filaments in static and reactive mesothelium and adenocarcinoma

In cytological preparations, reactive mesothelial cells (RMC) in serous effusions are sometimes difficult to distinguish from adenocarcinoma cells (AC). RMC and AC can be distinguished by lectin-binding patterns, but the pattern of binding of lectins to normal mesothelium is not well defined. We investigated the expression of cytoskeletal filaments, cytokeratin (CK) and vimentin (VM), and the cell surface binding pattern of 10 lectins (HPA, SBA, ABA, DSA, PNA, RCA-I, UEA-I, LTA, WGA and ConA) in the serosa of 48 adenocarcinoma specimens. We also investigated the usefulness of six lectins (HPA, SBA, RCA-I, UEA-I, LTA and WGA) in identification of RMC and AC in 16 serous effusions. DSA reactivity was significantly higher (P < 0.05) in static mesothelial cells (SMC) than in RMC. Reactivity for LTA and ConA was significantly lower (P < 0.05) in SMC than in RMC. Anti-CK and anti-VM immunoreactivity was always positive in RMC and almost negative in SMC. In serous effusions, HPA, SBA and UEA-I binding was evident in 100, 88 and 81% of AC, respectively. Little to no binding of HPA, SBA or UEA-I was detected in RMC. Our results suggest that the morphological differences between SMC and RMC are likely to be due to differences in cytoskeletal composition, with accompanying changes in cell-surface lectin-binding patterns. HPA, SBA and UEA-I are likely to be useful markers for identification of RMC and AC in cytology.

Prognostic factors of patients with yolk sac tumors of the ovary

OBJECTIVE

Our purpose was to evaluate the prognostic factors in yolk sac tumors of the ovary.

STUDY DESIGN

We performed a retrospective review of 47 patients with yolk sac tumors of the ovary from 1979 to 1997.

RESULTS

Twenty-two patients had pure yolk sac tumors and 25 had germ cell tumors with yolk sac tissue as a component of the disease. The 5-year survival rate in stages I, II, III, and IV was 95%, 75%, 30%, and 25%, respectively. Patients with stage I disease had a more favorable prognosis than those with stage III and IV disease (P <.001). All patients who did not respond to chemotherapy died of this disease within 36 months of the first treatment. Chemotherapy regimens that included cisplatin gave better results than those without cisplatin (P <.05). The difference in prognosis was significant in cases in which the size of residual tumor was <2 cm in diameter (P <.01) and in cases in which ascites was either absent or <100 mL in volume (P <.05). Coexistence of other components of ovarian germ cell tumors in histologic specimens, preoperative serum alpha-fetoprotein level, fertility-sparing surgery, dissection of intrapelvic nodes, and p53 status had no significant correlation with the prognosis in this study.

CONCLUSIONS

Staging and tumor-reductive surgery strongly affected the prognosis of this disease. Tumor-reductive surgery is advisable when ascites is minimal. Cisplatin-based chemotherapy after surgery was superior to chemotherapy without cisplatin; however, p53 status seemed to have no impact on chemosensitivity in yolk sac tumors of the ovary.

The vascular endothelial growth factor receptor KDR/Flk-1 is a major regulator of malignant ascites formation in the mouse hepatocellular carcinoma model

The vascular endothelial growth factor-A (VEGF-A), also known as the vascular permeability factor (VPF), has been shown to play an important role in malignant ascites formation. The effects of VEGF-A are mediated through flt-1 and kinase insert domain-containing receptor/fetal liver kinase (KDR/Flk-1) receptors. It has been shown that KDR/Flk-1 is a predominant receptor in solid hepatocellular carcinoma (HCC) development, but the role of this receptor in hepatic ascites formation has not yet been elucidated. In this study, we examined the role of KDR/Flk-1 in the murine MH134 hepatic malignant ascites formation by means of VEGF-A- and KDR/Flk-1-specific neutralizing antibodies (VEGF-A nAb and KDR/Flk-1 nAb, respectively). The mean volume of ascites, number of tumor cells in ascites, and the peritoneal capillary permeability were significantly suppressed by VEGF-A nAb and KDR/Flk-1 nAb treatment. These inhibitory effects of KDR/Flk-1 nAb were more potent than those of VEGF-A nAb. The autophosphorylation of KDR/ Flk-1 in the peritoneal wall was almost completely abolished by KDR/ Flk-1 nAb, whereas a certain level of activation was still shown by VEGF-A nAb treatment. Another VEGF-family, VEGF-C, which also binds KDR/Flk-1, was detected in the ascites. Furthermore, in the therapeutic experiment, although both VEGF-A nAb and KDR/Flk-1 nAb prolonged the survival rate of ascites-bearing mice, the latter showed a more significant impact on the survival of animals. These results suggest that KDR/Flk-1 is a major regulator of malignant hepatic ascites formation, and that in addition to VEGF-A, VEGF-C may also be involved in the malignant ascites formation via KDR/ Flk-1 activation.

Lung mitochondrial dysfunction in pulmonary hypertension syndrome. I. Site-specific defects in the electron transport chain

The main objectives of this study were to determine a) site-specific defects in the electron transport chain of lung mitochondria of broilers with pulmonary hypertension syndrome (PHS), b) if these defects are attenuated by high dietary vitamin E, and c) if these defects have a genetic basis. In Experiment 1, lung mitochondria were isolated from broilers with and without PHS fed diets containing 15 IU and 100 IU dl-alpha-tocopherol acetate/kg (VE); the four treatments were control, VE, PHS, and VE-PHS, respectively. Hydrogen peroxide (H2O2) generation in isolated lung mitochondria was monitored by dichlorofluorosein (DCF) fluorescence in response to chemicals that inhibit electron flow at specific sites on the electron transport chain using a 96-well microplate with Cytoflour (excitation/emission 480/530 nm). Basal H2O2 production was higher in PHS than in control mitochondria. Differences in H2O2 production between control and PHS were magnified by inhibition of Complexes I and III (Coenzyme Q) of the respiratory chain in mitochondria. Functional defects in PHS mitochondria were attenuated by high dietary VE. In Experiment 2, basal H2O2 production and that following inhibition of Complexes I and III were lower in lung mitochondria isolated from broilers selected for genetic resistance to PHS than in nonselected birds in the base population. The results of this study indicate that site-specific defects in Complexes I and III may underlie lung mitochondrial dysfunction in broilers with PHS, that these defects are attenuated by high dietary vitamin E, and that these defects may be related to genetic predisposition to PHS.

Multisite control of the Crabtree effect in ascites hepatoma cells

AS-30D hepatoma cells, a highly oxidative and fast-growing tumor line, showed glucose-induced and fructose-induced inhibition of oxidative phosphorylation (the Crabtree effect) of 54% and 34%, respectively. To advance the understanding of the underlying mechanism of this process, the effect of 5 mM glucose or 10 mM fructose on the intracellular concentration of several metabolites was determined. The addition of glucose or fructose lowered intracellular Pi (40%), and ATP (53%) concentrations, and decreased cytosolic pH (from 7.2 to 6.8). Glucose and fructose increased the content of AMP (30%), glucose 6-phosphate, fructose 6-phosphate and fructose 1,6-bisphosphate (15, 13 and 50 times, respectively). The cytosolic concentrations of Ca2+ and Mg2+ were not modified. The addition of galactose or glycerol did not modify the concentrations of the metabolites. Mitochondria isolated from AS-30D cells, incubated in media with low Pi (0.6 mM) at pH 6.8, exhibited a 40% inhibition of oxidative phosphorylation. The data suggest that the Crabtree effect is the result of several small metabolic changes promoted by addition of exogenous glucose or fructose.

Serum and ascitic fluid nitrate levels in patients with cirrhosis

BACKGROUND

Increased nitric oxide level may play a critical role in the hemodynamic disturbances in patients with cirrhosis. There are few reports investigating the factors related to this increase and their results are controversial. The purpose of this study was to reveal the clinical importance of nitric oxide levels and the possible factors related to this increase in patients with cirrhosis.

METHODS

Serum and ascites nitrate levels were studied in 50 patients with cirrhosis and 10 control subjects.

RESULTS

All cirrhotic patients (groups 2, 3, 4, 5, 6) showed significant increase in serum nitrate levels in comparison with that in control subjects (group 1) (p<0.001). Serum nitrate levels were significantly higher (282.4+/-111.3 micromol/l; p<0.05) in patients with spontaneous bacterial peritonitis (group 2) when compared with those in cirrhotic patients without spontaneous bacterial peritonitis (group 3) (186.4+/-87.6 micromol/l). Ascitic fluid nitrate levels were significantly higher (302.4+/-66 micromol/l; p<0.001) in patients with spontaneous bacterial peritonitis (group 2) when compared with those in cirrhotic patients without spontaneous bacterial peritonitis (group 3) (135.4+/-65.8 micromol/l). Serum nitrate levels were significantly lower in cirrhotic patients without ascites (group 5) when compared with those in cirrhotic patients with ascites (group 3) (98.8+/-52.6 vs. 186.4+/-87.6 micromol/l; p<0.05). No significant differences were found among patients with severe anemia (groups 4, 6) and other cirrhotic patients (group 3) (174.5+/-54.5, 168.8+/-63.8 vs. 186.4+/-87.6 micromol/l; p>0.05). Cirrhotic patients with Child--Pugh B and C scores showed higher serum nitrate levels (179.4+/-81.1, 222.5+/-101.7 micromol/l; p<0.001) than did cirrhotic patients with Child--Pugh A score (85.8+/-59.7 micromol/l).

CONCLUSION

Our findings suggest that overproduction of nitric oxide in cirrhotic patients may be related to the severity of liver damage and spontaneous bacterial peritonitis but not related to their anemia.

Electron transport chain defect and inefficient respiration may underlie pulmonary hypertension syndrome (ascites)-associated mitochondrial dysfunction in broilers

By using a series of chemical inhibitors of mitochondrial respiration, a site-specific defect in the electron transport chain was identified in mitochondria obtained from broilers with pulmonary hypertension syndrome (PHS; ascites). Located at the succinate:ubiquinone oxido-reductase (Complex II:CoQ) interface, this defect would allow electrons to leak from the respiratory chain and consume oxygen by forming reactive oxygen species at a greater rate than in control mitochondria. Lower levels of the primary antioxidants, alpha- and beta-tocopherol, and glutathione (GSH) in PHS mitochondria confirmed the presence of oxidative stress. Respiration studies of PHS liver mitochondria also revealed disease-associated decreases in the respiratory control ratio (RCR, an index of electron transport chain coupling). Differences in the RCR as well as the adenosine diphosphate (ADP) to O ratio (an index of oxidative phosphorylation) between control and PHS mitochondria were accentuated by sequential additions of ADP to isolated mitochondria. In a second experiment, similar improvements in functional indices following sequential additions of ADP and responses to respiratory chain inhibitors were observed in liver mitochondria isolated from Single Comb White Leghorn (SCWL) males (resistant to PHS) similar to that observed in control broiler mitochondria in Experiment 1. The combined results indicate the presence of a site-specific defect at either Complex II, ubiquinone, or both in liver mitochondria obtained from broilers with PHS that may be responsible for the oxidative stress and mitochondrial dysfunction observed in this costly metabolic disease.

Biochemical characterization of the soluble form of tumor antigen MUC1 isolated from sera and ascites fluid of breast and pancreatic cancer patients

Transmembrane glycoprotein tumor antigen MUC1 that is overexpressed on pancreatic and breast tumor cells can be found in large amounts in soluble form in serum and ascites fluid. MUC1 has been identified as a target of human antitumor antibody and CTL responses that are generated in the absence of helper T cells. The soluble form of MUC1 should support generation of helper T cells, but we have found recently that this form, although effectively endocytosed by dendritic cells, remains trapped in early endosomes and is not trafficked to antigen-processing compartments. The exact biochemical structure of this form of MUC1 has not been elucidated to date, and it is thus not clear what structural characteristics may be responsible for its retention in early endosomes. We have purified soluble MUC1 from ascites fluid of breast/pancreatic cancer patients (ASC-MUC1) and quantitated O-linked carbohydrates. We have altered ASC-MUC1 by enzymatic treatment: trypsin or clostripain digestion, desialylation, and further in vitro glycosylation. We have found that desialylated ASC-MUC1 was further glycosylated by peptidyl N-acetylgalactosamine transferases and was not when sialic acid was present. These alterations created new forms of ASC-MUC1 that might be handled more efficiently by antigen-presenting cells to generate better tumor-specific immunity and used to identify structures that are directly involved in retention of this antigen in early endosomes.

Expression and mutation of p53 in tumor effusion cells of patients with ovarian carcinoma: response to cisplatin-based chemotherapy

p53 alterations are considered as one of the most important factors responsible for drug resistance in ovarian carcinomas, although the relationship between p53 gene status and response to cisplatin-based chemotherapy in ovarian cancer patients remains unclear. The aim of the study was to evaluate the relationship between p53 protein accumulation, p53 gene mutation and response to cisplatin-based chemotherapy in patients with ovarian carcinoma considering conventional clinicopathological parameters. Tissue sections and corresponding cyst and/or ascitic fluid cells from 79 patients with epithelial ovarian cancer were analyzed immunohistochemically for p53 expression. The PCR-SSCP analysis was performed in 25 cases and the results were compared with immunohistochemical data. It was demonstrated that p53 expression reaching approximately 50% of positive cells in immunostaining was usually associated with PCR-amplified exons showing abnormal migration and suspected for mutation. p53 gene changes were not correlated with histological structure, grade of differentiation or residual tumor after cytoreductive surgery, despite being detected more frequently in III/IV than in II FIGO stages and in patients with residual disease above 2 cm. A significant correlation between p53 accumulation and p53 gene alteration and poor response to cisplatin-based chemotherapy was shown. The overall survival time of patients decreased with an increase in p53 protein expression. A strong p53 expression especially accompanied by p53 changes detectable by PCR-SSCP analysis appears to be a good indicator of the resistance to cisplatin-based chemotherapy. The association between strong p53 overexpression and shorter overall survival time was also revealed.

Electrospray ionization mass spectrometry analysis of lysophospholipids in human ascitic fluids: comparison of the lysophospholipid contents in malignant vs nonmalignant ascitic fluids

Lysophospholipids (lyso-PLs), including various glycerol-based and sphingosine-based lysophospholipids, play important roles in many biochemical, physiological, and pathological processes. The classical methods to analyze these lipids involve gas chromatography and/or high-performance liquid chromatography, which are time-consuming, cumbersome, and sometimes inaccurate due to the incomplete separation of closely related lipid species. We now describe the quantitative analysis of lyso-PLs in ascites samples from patients with ovarian cancer using electrospray ionization spectrometry. Three new classes of lyso-PL molecules are detected: alkyl-LPA, alkenyl-LPA, and methylated lysophosphatidylethanolamine. Importantly, the following lysophospholipid species are significantly increased in ascites from patients with ovarian cancer, compared to patients with nonmalignant diseases (e.g., liver failure): LPA (including acyl-, alkyl-, and alkenyl-LPA species), lysophosphatidylinositol, and sphingosylphosphorylcholine. Lysophosphorylcholine contents are also significantly different among ascitic fluids from the two groups of patients. However, the total phosphate content in ascites samples from patients with ovarian cancer is not significantly different compared to that from patients with nonmalignant disease.

Expression of vascular endothelial growth factor by human renal cancer cells enhances angiogenesis of primary tumors and production of ascites but not metastasis to the lungs in nude mice

We determined the role that vascular endothelial growth factor (VEGF), also known as vascular permeability factor (VPF), plays in the progression of human renal cell cancer in nude mice. Low metastatic and low VEGF/VPF-expressing human renal cancer cells SN12C were transfected with the VEGF165 cDNA or plasmid alone as control. VEGF165-transfected SN12C cells produced large amounts of biologically active VEGF in culture that did not affect cell doubling time or confluence. Subsequent to implantation into the renal subcapsule of nude mice, the VEGF165-transfected SN12C cells produced fast-growing (PCNA labeling), large tumors that expressed high levels of VEGF/VPF and were well vascularized (CD3-positive vessels). The tumors produced hyperpermeability of peritoneal blood vessels (Evans blue dye-leak assay), bloody ascites, and short survival time. Parental or control transfected SN12C cells produced less vascularized, slower growing tumors with no ascites. Regardless of in vivo expression level of VEGF, the incidence of spontaneous lung metastasis was low, suggesting that in itself, the expression of VEGF/VPF by renal cancer cells is not sufficient to produce metastasis.

Markedly elevated levels of vascular endothelial growth factor, fibroblast growth factor, and interleukin 6 in Meigs syndrome

Analysis of serum and peritoneal and pleural fluid from a patient with Meigs' syndrome revealed high levels of vascular endothelial growth factor, fibroblast growth factor, and interleukin 6. Serum levels declined after removal of the ovarian tumor, along with resolution of ascites and hydrothorax. These findings suggest the involvement of these vasoactive factors in ascites and pleural fluid formation in Meigs' syndrome.

Pre-clinical study of the epinephrine-cisplatin association for the treatment of intraperitoneal carcinomatosis

We have previously shown that intraperitoneal (i.p.) epinephrine enhances tumour penetration and anti-cancer activity of i.p.-administered cisplatin in rats with peritoneal carcinomatosis. Here, we show a direct correlation between the i.p. epinephrine concentration and cisplatin accumulation in rat peritoneal tumour nodules up to a concentration of 5 mg/l. This concentration leads to a maximal 3.7-fold increase of tumour platinum content and a maximal vasoconstriction of the peritoneal and tumour superficial microcirculation when registered by a laser doppler probe. Further, epinephrine half-life was 20.8+/-3.6 min in the peritoneal cavity of two laparotomized pigs. In these animals, epinephrine plasma concentration, heart rate and systolic blood pressure were dependent on the intraperitoneal dose of epinephrine, and life-threatening signs were not observed in either animal. In conclusion, a 5 mg/l concentration of epinephrine could be safely maintained in peritoneal fluid by regular replacement. This concentration is sufficient to maintain a constant vasoconstriction of the peritoneal and tumoral microvascular bed, and enhance the slow diffusion of cisplatin into peritoneal tumour nodules in the course of per-operative intraperitoneal chemotherapy.

Use of a variety of biological parameters in distinguishing cirrhotic from malignant ascites

Twenty-two different protein measurements were taken in the serum and ascitic fluid of fifty consecutive patients in an attempt to investigate which tests are the most reliable for the differential diagnosis of ascites. Serum and ascitic fluid total proteins (TPR), albumin (ALB), lactate (LAC), ferritin (FER), C3 and C4 complement factors, C-reactive protein (CRP), ceruloplasmin (CER), alpha2-macroglobulin (alpha2MG), haptoglobin (HAP), alpha1-antitrypsin (alpha1AT), alpha1-acid glycoprotein (alpha1AG), transferrin (TRF), immunoglobulins IgG, IgA, IgM and cytokines such as interleukin-1alpha (IL-1alpha), interleukin-1beta (IL-1beta), interleukin-2 (IL-2), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) were measured to distinguish between malignant and cirrhotic ascites. Correlations and non-parametric Mann-Whitney tests were used for ascitic fluid:serum ratio comparisons between the two groups. Multivariate analyses were used to determine the most significant biochemical ratio predictors for the differential diagnosis and a recursive partitioning model was constructed. Highly positive correlations (r>0.50) were found between the ratios IgA, IgG, IgM, CER, alpha2 MG, HAP, alpha1AT, alpha1AG and TRF. There was evidence that TPR, ALB, LAC, FER, IgG, CER, alpha2MG, alpha1AT, alpha1AG, TRF and IL-8 ascitic fluid:serum ratios are significnatly higher in patients with malignant neoplasms than in cirrhotics. In the recursive partitioning model the most significant parameters were found to be the ratios of albumin and IL-1alpha. The model fitted allowed for 100% correct classification of ascites. In conclusion, we have shown that a simple and very accurate model based on two ascitic fluid: serum measurements is able to differentiate between malignant and non-malignant ascites.

Estimation of body water compartments in cirrhosis by multiple-frequency bioelectrical-impedance analysis

Estimation of total body water by measuring bioelectrical impedance at a fixed frequency of 50 kHz is useful in assessing body composition in healthy populations. However, in cirrhosis, the distribution of total body water between the extracellular and intracellular compartments is of greater clinical importance. We report an evaluation of a new multiple-frequency bioelectrical-impedance analysis technique (MFBIA) that may quantify the distribution of total body water in cirrhosis. In 21 cirrhotic patients and 21 healthy control subjects, impedance to the flow of current was measured at frequencies ranging from 4 to 1012 kHz. These measurements were used to estimate body water compartments and then compared with total body water and extracellular water determined by isotope methodology. In cirrhotic patients, extracellular water and total body water (as determined by isotope methods) were well predicted by MFBIA (r = 0.73 and 0.89, respectively). However, the 95% confidence intervals of the limits of agreement between MFBIA and the isotope methods were +/-14% and +/-9% for cirrhotics (extracellular water and total body water, respectively) and +/-9% and +/-9% for cirrhotics without ascites. The 95% confidence intervals estimated from the control group were +/-10% and +/-5% for extracellular water and total body water, respectively. Thus, despite strong correlations between MFBIA and isotope measurements, the relatively large limits of agreement with accepted techniques suggest that the MFBIA technique requires further refinement before it can be routinely used to determine the nutritional assessment of individual cirrhotic patients.

Fas receptor counterattack against tumor-infiltrating lymphocytes in vivo as a mechanism of immune escape in gastric carcinoma

We investigated the presence and functional status of surface expression of the Fas receptor (FasR) and its ligand (FasL) in tumor and tumor-infiltrating lymphocytes (TIL) in gastric carcinoma (n = 36) from the primary locus, metastatic gastric carcinoma (n = 30) from malignant ascites, and benign gastric mucosa (n = 30) for the control. The quantitative analysis was based on the percentage of positive cells by a flow cytometry. The results showed that the membrane-bound FasL molecule was constitutively expressed in primary and metastatic gastric carcinomas as well as normal gastric epithelium in nearly all the patients. In particular, metastatic carcinoma proved to aberrantly express the FasL molecule. On the other hand, FasR expression ranged from minimal or absent in primary and metastatic gastric carcinomas, suggesting that the carcinoma might be rendered less sensitive toward FasR-induced killing. Apoptotic tumor cells detected by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick and labeling (TUNEL) were barely identified in primary and metastatic carcinomas. In the analysis of TIL, the expression of FasR and FasL, and apoptotic TIL could not usually be observed in primary gastric carcinoma. In metastatic carcinoma, however, there was significant overexpression of FasR and FasL in immune TIL associated with a higher frequency of apoptotic cell death detected by TUNEL. The results suggest that metastatic carcinoma expressing FasL, but not FasL+ primary carcinoma, might evade the immune attack by apoptotic depletion of activated TIL through the FasR/FasL systems. These results provide the direct and quantitative evidence of FasR counterattacks and/or paracrine fratricides as a mechanism of tumor-immune escape in vivo in human cancer.

Neuronal nitric oxide synthase and systemic vasodilation in rats with cirrhosis

Cirrhosis is typically associated with a hyperdynamic circulation consisting of low blood pressure, low systemic vascular resistance (SVR), and high cardiac output. We have recently reported that nonspecific inhibition of nitric oxide synthase (NOS) with nitro-L-arginine methyl ester reverses the hyperdynamic circulation in rats with advanced liver cirrhosis induced by carbon tetrachloride (CCl(4)). Although an important role for endothelial NOS (eNOS) is documented in cirrhosis, the role of neuronal NOS (nNOS) has not been investigated. The present study was carried out to specifically investigate the role of nNOS during liver cirrhosis. Specifically, physiological, biochemical, and molecular approaches were employed to evaluate the contribution of nNOS to the cirrhosis-related hyperdynamic circulation in CCl(4)-induced cirrhotic rats with ascites. Cirrhotic animals had a significant increase in water and sodium retention. In the aorta from cirrhotic animals, both nNOS protein expression and cGMP concentration were significantly elevated compared with control. Treatment of cirrhotic rats for 7 days with the specific nNOS inhibitor 7-nitroindazole (7-NI) normalized the low SVR and mean arterial pressure, elevated cardiac index, and reversed the positive sodium balance. Increased plasma arginine vasopressin concentrations in the cirrhotic animals were also repressed with 7-NI in association with diminished water retention. The circulatory changes were associated with a reduction in aortic nNOS expression and cGMP. However, 7-NI treatment did not restore renal function in cirrhotic rats (creatinine clearance: 0.76 +/- 0.03 ml. min(-1). 100 g body wt(-1) in cirrhotic rats vs. 0.79 +/- 0.05 ml. min(-1). 100 g body wt(-1) in cirrhotic rats+7-NI; P NS. ). Taken together, these results indicate that nNOS-derived NO contributes to the development of the hyperdynamic circulation and fluid retention in cirrhosis.

Fasting exacerbates acute pancreatitis by occlusion of the common bile duct in rats

We examined the effects of fasting and non-fasting on gallstone-related acute pancreatitis by the occlusion of the common bile duct (OCD). We prepared a rat OCD-induced pancreatitis model under both fasting and non-fasting conditions, and we measured amylase activity in ascites as well as production of inflammatory cytokines and chemokines. We also examined the pathology of the pancreas, myeloperoxidase (MPO) activity in some tissues and mortality rates. In the fasted OCD group, ascites containing a large amount of amylase, interleukin 1beta (IL-1beta), interleukin 6 (IL-6), and cytokine-induced neutrophil chemoattractant-1 (CINC-1) as well as marked hemorrhage and necrosis of the pancreatic acinar cells were observed. Pulmonary MPO activity increased 3.4-fold compared to the control group. In the non-fasted OCD group, there was no development of ascites. Slight necrosis of acinar cells and slight increases in pulmonary MPO activity were observed. In addition, in the fasted OCD group, the cumulative mortality rate was 50% 6 days after ligation. However, in the non-fasted OCD group, none of the animals died. These results suggest that gallstone-related severe pancreatitis depends on fasting-related structural and/or functional changes in the pancreas. Moreover, increased production of inflammatory cytokines and chemokines in ascites under fasting condition may be involved in multiple organ failure resulting from severe acute pancreatitis.

Oxidative damage to mitochondria in normal and cancer tissues, and its modulation

Cellular damage induced by reactive oxygen species (ROS) in normal tissues has been implicated in the etiology of several human ailments. Among the subcellular organelles, damage to mitochondria is considered crucial and can lead to cytotoxicity and cell death. However, the same damage, if it is selectively induced in cancer tissues can lead to its cure. Hence analyzing the mechanisms of such damage and its modulation may result in better prevention or cure. Using mitochondria derived from rat brain/liver as well as sarcoma 180 ascites cells, we have examined the mechanisms of damage to lipid, as assessed by different products of lipid peroxidation and to proteins, as determined by loss of enzyme activity and protein oxidation. Mechanisms involved, in terms of scavenging of ROS have been determined using pulse radiolysis for hydroxyl radical and histidine destruction assay for singlet oxygen. Various ROS were generated using gamma-radiation, photosensitization etc. under different conditions. Some novel porphyrins, with potential uses in photodynamic therapy also were used as photosensitizers. Our study shows that ROS can induce significant oxidative damage in mitochondria from both normal and tumor tissues and this can be inhibited by natural antioxidants like tocotrienols, nicotinamide and caffeine. Damage, on the other hand, can be enhanced by deuteration of the buffer and oxygenation. Our results hence demonstrated that mitochondria were sensitive to damage by ROS and its modulation may have potential uses in prevention of the disease in normal tissues; if damage can be selectively induced in tumor, it can lead to its regression.

[Study on the regulatory effect of Chinese herbal medicine on peritoneal lymphatic stomata and in enhancing drainage of ascites in mice with liver fibrosis]

OBJECTIVE

To observe the regulatory effect of Chinese herbal medicine on peritoneal lymphatic stomata in carbon tetrachloride induced mouse model of liver fibrosis and its significance in treating ascites.

METHODS

(1) To form the mouse model of liver fibrosis by intragastric administration of carbon tetrachloride. (2) Two kinds of Chinese herbal compound prescriptions were given separately by gastrogavage to observe their effect on prevention and treatment of liver fibrosis. (3) Hematoxylin and eosin and van Gieson staining were used in the observation of pathology and histology. (4) Scanning electronmicroscope and computer image processing were used. (5) urinary volume and sodium ion concentration were measured.

RESULTS

The fibrotic change of the mouse models was alleviated with using both the prevention or treatment groups of the two compound prescriptions. The diameter of lymphatic stomata enlarged with increased number of opening and density of distribution. Urinary volume and sodium ion excretion increased after treatment. The effects displayed more significant in the group treated by compound prescription.

CONCLUSION

Both kinds of Chinese herbal compound prescriptions have marked effect in alleviating liver fibrosis, regulating peritoneal lymphatic stomata, improving the drainage from the peritoneal cavity, causing increase of urinary volume and sodium ion excretion to reduce the water and sodium retention, and thus have favorable therapeutic effect in treating ascites.

[Experimental study on CPT-11 intraperitoneal chemotherapy--metabolism of CPT-11 in malignant ascites]

The metabolism of CPT-11 in malignant ascites of gastric cancer patients with peritoneal seedings was studied in advance of the intraperitoneal chemotherapy of CPT-11 in humans. Malignant ascites and blood were drawn from gastric cancer patients. CPT-11 solution (20 mg/ml; 0.2 ml) was added into 3.8 ml ascites or plasma under 37 degrees C and CPT-11, SN-38 and SN-38GLU concentrations were measured with HPLC at times of 5, 30 and 60 minutes after addition of CPT-11. The change from CPT-11 to SN-38 was minimal not only in plasma, but also in malignant ascites. SN-38 GLU concentration was below the limit of measurement. This study showed that in malignant ascites, the enzymes such as carboxyesterase that convert CPT-11 to SN-38 were not present or minimal.