Circulating antibodies to p16 protein-derived peptides in breast cancer

Overexpression of the p16 protein has been reported in breast cancer and may trigger the secretion of antibodies against itself. Circulating anti-p16 antibodies that were detected with a recombinant protein have been reported in breast cancer. The present study was designed to determine whether the levels of circulating IgG antibody to p16 protein-derived linear antigens are altered in breast cancer. An enzyme-linked immunosorbent assay (ELISA) was developed in-house to determine circulating IgG against peptide antigens derived from the p16 protein in 152 female breast cancer patients and 160 healthy female subjects. The Student's T-test revealed that breast cancer patients exhibited significantly higher levels of anti-p16 IgG antibody compared to control subjects (T=2.02, P=0.045). In addition, ductal cancer appeared to be the main type contributing to the increased levels of circulating anti-p16 antibodies (T=2.08, P=0.038). Of all four stages of breast cancer, stage I was associated with the highest levels of IgG antibody (T=2.02, P=0.045) and receiver operating characteristic (ROC) analysis demonstrated that the area under the ROC curve was 0.74 (95% confidence interval: 0.65-083) and that the sensitivity against a specificity of 90% was 30.3%. Therefore, the levels of circulating IgG antibody to the p16 protein may be a potential biomarker for early diagnosis of breast cancer.

Experimental research on the management of combined radiation-burn injury in China

Combined radiation-burn injury can occur in people exposed to nuclear explosions, nuclear accidents or radiological terrorist attacks. Using different combined radiation-burn injury animal models, the pathological mechanisms underlying combined radiation-burn injury and effective medical countermeasures have been explored for several years in China, mainly at our institute. Targeting key features of combined radiation-burn injury, several countermeasures have been developed. Fluid transfusion and the calcium antagonist verapamil can prevent early shock and improve myocardial function after combined radiation-burn injury. Recombinant human interleukin 4 (rhIL-4) is able to effectively reduce bacterial infection and increase intestinal immunological ability. Chitosan-wrapped human defensin 5 (HD5) and glucagon-like peptide 2 (GLP-2) nanoparticles can increase the average survival time of animals with severe combined radiation-burn injury. After treatment by cervical sympathetic ganglia block (SB), hematopoietic function is promoted and the release of inflammatory cytokines is suppressed. The optimal time for escharectomy and allo-skin grafting is 24 h after injury. Transfusion of irradiated (20 Gy) or stored (4°C, 7 days) blood improves the survival of allo-skin grafting and allo-bone marrow cells. In conclusion, as our understanding of the mechanisms of combined radiation-burn injury has progressed, new countermeasures have been developed for its treatment. Because of the complexity of its pathology and the difficulty in clinical management, further efforts are needed to improve the treatment of this kind of injury.

Protective effect of atorvastatin on radiation-induced vascular endothelial cell injury in vitro

Vascular endothelial cells are very sensitive to ionizing radiation, and it is important to develop effective prevent agents and measures in radiation exposure protection. In the present study, the protective effects of atorvastatin on irradiated human umbilical vein endothelial cells (HUVEC) and the possible mechanisms were explored. Cultured HUVEC were treated by atorvastatin at a final concentration of 10 µ mol/ml for 10 minutes, and then irradiated at a dose of 2 Gy or 25 Gy. Twenty-four hours after irradiation, apoptosis of HUVEC was monitored by flow cytometry, and the expression of thrombomodulin (TM) and protein C activation in HUVEC was respectively assessed by flow cytometry and spectrophotometry. After treatment with atorvastatin for 24 h, the rate of cell apoptosis decreased by 6% and 16% in cells irradiated with 2 Gy and 25 Gy, respectively. TM expression increased by 77%, 59%, and 61% in untreated cells, 2 Gy irradiation-treated cells, and 25 Gy irradiation-treated cells, respectively. The protein C levels in 2 Gy and 25 Gy irradiation-treated cells were reduced by 23% and 34% when compared with untreated cells, but up-regulated by 79% and 76% when compared with cells which were irradiated and treated with atorvastatin. In conclusion, these data indicate that atorvastatin exerts protective effects on irradiated HUVEC by reducing apoptosis by up-regulating TM expression and enhancing protein C activation in irradiated HUVEC.

Effects of serum from rats with combined radiation-burn injury on the growth of hematopoietic progenitor cells

BACKGROUND

This study aims to observe the effects of blood serum from rats with radiation injury, burn injury, and combined radiation-burn injury on the growth of hematopoietic progenitor cells and to explore the possible mechanisms.

METHODS

Serum from rats with radiation injury, burn injury, and combined radiation-burn injury were collected at 3 hours, 12 hours, 24 hours, 48 hours, 72 hours, and 96 hours after injury and then was added to the culture medium to see its effect on the growth of hematopoietic progenitor cells (HPCs) at a final protein concentration of 10 microg/mL. Radioimmunoassay and enzyme-linked immunosorbent assay were employed to measure the level of tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 in each group, and the effect of TNF-alpha and IL-6 on the growth of HPC was also observed.

RESULTS

The number of HPCs colonies formed after addition of the serum from rats with burn or combined radiation-burn injuries was significantly higher than that from normal rats at 3 hours, 12 hours, 24 hours, 48 hours, 72 hours, and 96 hours after injury and reached its peak value at 24 hours after injury. However, fewer HPCs colonies were found after the addition of the serum from irradiated rats. At the same time, the levels of TNF-alpha and IL-6 in the serum of burn group and combined radiation-burn injury group were significantly higher than that of normal group, and much higher than that of the irradiation injury group (p < 0.01). Also, TNF-alpha and IL-6 demonstrated promoting effect on the growth of HPC.

CONCLUSION

Serum from rats with burn injury and combined radiation-burn injury stimulates the growth of HPCs, while serum from irradiated rats shows inhibitory effects on the growth of HPCs. These effects may lie in the different level of TNF-alpha and IL-6 in the serum of each group.

[Effects of blood serum from rats with combined radiation-thermal injury on the bone marrow hematopoietic progenitor cells growth]

To observe the effects of blood serum from rats with radiation injury, thermal injury and combined radiation-thermal lesions on growth of hematopoietic progenitor cells and the change of their serum cytokine levels, total body irradiation of rats was performed with 12 Gy gamma ray from a (60)Co source, and 30% total body surface area III degree thermal lesion on the back was inflicted with a 5 kW bromotungsten lamp. The blood serum from these animals was collected at 3, 12, 24, 48, 72 and 96 hours after injury. Then the blood serum was added to the culture medium of erythrocyte progenitor cells (CFU-E, BFU-E) or granulocyte-macrophage progenitor cells (CFU-GM) at final concentration of 10 microg/ml. The results showed that the colony number of CFU-E, BFU-E and CFU-GM formed after addition of the blood serum from rats with thermal or combined radiation-thermal injury was significantly higher than that from normal rats at 3, 12, 24, 48, 72 and 96 hours after injury and reached its peak value at 24 hours after injury (342.8, 261.6 and 228.4% respectively from burned rats, 252.4, 205.1 and 174.2% respectively from rats with combined radiation-thermal injury as compared with that of normal rats). However, a few CFU-E, BFU-E or CFU-GM formation was found after addition of the blood serum from irradiated rats. At the same time, the level of TNF alpha and IL-6 in serum of burn group and combined radiation-thermal injury group was markedly higher than that of normal group, even more higher than that of irradiation injury group (P < 0.01). It is concluded that the blood serum from rats with thermal lesion or combined radiation-thermal injury improves the growth of erythrocyte and granulocyte progenitor cells. On the contrary, the blood serum from the irradiated rats shows the inhibiting effects, definitely related to their serum cytokines changes.

[Pathological changes in allogenic skin in combined radiation-burn injury in rats]

Skin allografts were transplanted to rats inflicted with third degree burns of 15% of BSA alone or combined with 5 Gy gamma ray radiation. Histopathological, histochemical and ultrastructural changes of the allografts were examined at different postoperative periods. In burned rats, allografts began to be rejected on the 8th postoperative day, showing degeneration and necrosis of its epithelial cells. Only in one rat it survived on the 14th day (10%), and all allografts were rejected before the 19th day. In contrast to this, most allografts (60-80%) on the rats with combined injury survived well for a period of 29 days. Epithelial cells and collagen fibers of the allografts degenerated in 1 to 4 days postoperation, and recovered to near normal during 9 to 14 days. During 24 to 29 days postoperation, the epithelial cells and appendices appeared almost normal in texture except an infiltration of a few lymphocytes and monocytes. The restoration of degenerated collagen, however, was slower than that of degenerated epithelium. The result shows that the survival time of skin allografts in severe combined radiation burn injury is prolonged than that in burns.

Ultrastructural changes of bone marrow megakaryocytes in several types of injury

Seventy-one dogs were used in this study. Bone marrow tissues were examined by LM and EM and the peripheral blood platelets were counted. On the basis of previous research, megakaryocytophagia in bone marrow was confirmed. It was also proved that neutrophilic granulocytes participate in the autophagocytosis reaction in the body. Megakaryocytophagia plays a major role in the elimination of degenerate megakaryocytes in the marrow. The pathological change in megakaryocytes is considered to be one of the important causes of decrease in number and impairment of function of the platelets in burn, blast injury and burn-blast combined injury.