BackgroundThe Fas receptor/ligand system including soluble forms is the most important apoptotic initiator in the liver. Dysregulation of this pathway may contribute to abnormal cell proliferation and cell death and is regarded as one of the mechanisms preventing the immune system from rejecting the tumor cells.ObjectivesTo analyze the role of Fas system Fas/ Fas ligand (Fas/ FasL) in the multi-step process of hepatic fibrosis/carcinogenesis, and to use of the serum markers as possible candidate biomarkers for early detection of hepatocellular carcinoma (HCC).Patients and MethodsNinety patients were enrolled: 30 cases of chronic hepatitis C (CHC) without cirrhosis, 30 cases of CHC with liver cirrhosis, and 30 cases of HCC and hepatitis V virus (HCV) infection. Ten wedge liver biopsies, taken during laparoscopic cholecystectomy, were served as normal controls. Serum soluble Fas (sFas) levels were measured using ELISA technique; Fas and FasL proteins were detected in hepatic tissue by indirect Immuno-histochemical technique (IHC); electron microscopic (EM) and immune electron microscopic examinations were performed for detection of Fas expression on lymphocytes.ResultsHepatic expression of both Fas and FasL as well as expression of Fas on separated lymphocytes were significantly increased in the diseased groups (P < 0. 01) compared to the control specimens. The highest expression was noticed in CHC specimens, particularly with the necro-inflammatory activity and advancement of the fibrosis. The sFas in cirrhotic patients and HCC were significantly higher than that in normal controls and CHC without cirrhosis group (P < 0.01).ConclusionsApoptosis and the Fas system were significantly involved in the process of converting liver cirrhosis into hepatocellular carcinoma. Down-regulation of Fas expression, up regulation of FasL expression in hepatocytes, and elevation of serum sFas levels were important in tumor evasion from immune surveillance, and in hepatic carcinogenesis.

The present work was designed to evaluate the functional and ultrastructural changes in platelets during and after major liver resection in healthy pigs as a trial to predict changes occurring in healthy liver donors. Measures to ensure the safety of the donor hepatectomy remain the main concern. Fifteen healthy pigs were prepared for liver resection by right trisegmentectomy. Blood samples were collected as such: one before the operation, two during the operation (one after the mobilization and other after the resection of the liver) and two after the operation (day 7 and day 14). Platelet count and markers of platelet activation, platelet factor 4 and beta-thromboglobulin, were measured. Separated platelets from peripheral blood and the resected liver were examined by electron microscopy. Platelet count was significantly dropped after hepatic mobilization and resection [(P < 0.05) and (P < 0.01), respectively] in comparison to normal level. On day 7, it increased significantly (P < 0.05). On day 14, it increased to become nonsignificantly different from preoperative count. beta-Thromboglobulin and platelet factor 4 were significantly increased after hepatic mobilization and resection [(P < 0.05) and (P < 0.01), respectively]. On day 7, they decreased to become nonsignificantly different from normal level. On day 14, they significantly reincreased (P < 0.01). Electron microscopic examination of platelets revealed all signs of activation after hepatic mobilization and resection. These changes disappeared on day 7 and reobserved on day 14. Liver surgery causes an acute and profound drop in platelet count and an increase in platelet activation. It is necessary to give proper systemic coagulant therapy in addition to platelet transfusion at the end of surgery for 1 week in case of hepatic resection.

The present research evaluated the intradialytic and postdialytic changes in platelet factor-4 and beta-thromboglobulin plasma levels by enzyme-linked immunoadsorbent assay method and platelet aggregation by ADP as well as flow cytometric percentage of annexin-V-positive platelets as a measure of phosphatidylserine externalization and ultrastructural examination of platelets in 37 uremic patients on regular hemodialysis and 25 age-matched and sex-matched controls. Platelet factor-4 plasma levels increased, remain consistently high during hemodialysis session (20.24 +/- 3.05 IU/ml after 30 min, P < 0.001 and 23.67 +/- 3.68 IU/ml after 240 min, P < 0.001) and returned to control values (6.10 +/- 1.54 IU/ml) only after 24 h following the end of the session. beta-Thromboglobulin showed a trend similar to that of platelet factor-4. Platelet aggregation by ADP showed reduced function in comparison with controls (69.32 +/- 12.37 versus 91.95 +/- 1.59%, P < 0.001). Flow cytometric percentage of annexin-V-positive platelet was significantly elevated (P < 0.001) in uremic patients when compared with normal controls. Ultrastructural studies of platelets 30 min after starting of dialysis showed degranulation of its granules and at 240 min showed complete degranulation, whereas in the postdialytic phase (12 h after the end of dialysis) refilled alpha-granules started to appear. Positive correlations were found between platelet concentration and platelet factor-4 and beta-thromboglobulin plasma levels during and after dialysis (P < 0.001) and with annexin-V-positive platelets percentage (P < 0.001). In conclusion, activated platelets were found in chronic hemodialysis patients, a finding that may explain why uremic patients often suffer from thrombotic accidents. The platelet activation is associated with exposure of phosphatidylserine on the platelet exterior. Platelet factor-4 and beta-thromboglobulin are released from platelets as a result of a defect in their granules membrane as shown by the electron microscopy, mainly as a consequence of the blood-membrane contact during dialysis, and they return only slowly to control values.

This work assess serum levels of soluble Fas form (sFas) in patients with different stages of laryngeal squamous cell carcinoma(LSCC) to investigate its prognostic significance. We correlate its levels with the morphological changes of peripheral blood cells via buffy coat examinatin. The study population included 70 patients clinically diagnosed and pathohistologically confirmed LSCC in addition to 20 healthy controls. According to TNM classification 33(47.1%) patients were in stage I (group I) and 24(34.3%) in stage II (group II) , 13(18.5%) in stage III (group III). The results revealed that the mean serum level of sFas (pg/ml) in the control group was 51.2, in group I was 66.33, in group II was 81.33 and in group III was 112.45. Statistical analysis of the mean of sFas by ELISA test in the patients' groups in comparison to the control revealed a significant increase of both group II and III in comparison to the control group (P  0.01) but there was no significant difference (P  0.05) between group I in comparison to either the control or group II. There was a significant difference (P  0.05) between group I in comparison to group III. LM examination revealed massive extent of the apoptotic cells in group III when compared to both group I and group II. EM examination of the buffy coat revealed apoptotic changes, mainly in the peripheral blood mononuclear cells (PBMNCs), represented by surface membrane ruffles and blebs with clumped nuclear chromatin and vacuolated cytoplasm. In conclusion, this study may help us to better understand one of the escape mechanisms in cancer larynx. This mechanism is represented by the significant increase in both the serum level of sFas and the morphological apoptotic changes that detected in PBMNCs. Soluble Fas may contribute to the progression of laryngeal cancer. It can be used as an attractive target for anticancer therapy and may be considered as a marker of disease progression and poor prognosis in laryngeal cancer.

No abstract