AIM: To study the mechanism of the inhibitory effect of human polymorphonuclear leukocytes (PMN) on the production of tumor necrosis factor-? (TNF-?) in U937 cells. METHODS: PMA differentiated U937 cells were cocultured with PMN in the presence of lipopolysaccharide. Sodium azide was added in the culture. The supernatants of cell culture were collected and TNF-? was assayed with ELISA. RESULTS:The inhibitory effect of PMN on the production of TNF-? in U937 cells was observed. Sodium azide restored the TNF-? production in U937 cells/PMN coculture to the extent of 45% in concentration of about 10～15 ?mol/L. These concentrations of sodium azide did not affect TNF-? production by U937 cells. The restoration effect of sodium azide on PMN inhibition was not related to blocking of myeloperoxidase (MPO) activity. The MPO inhibitors 3-amino-1,2,4,-triazole and 4-aminobenzoyl hydrazide had few effect on PMN inhibition. CONCLUSION: These results indicated that PMN inhibition depended on the cell-cell interactions. Sodium azide may be a useful reagent for further studying this mechanism.

Since the endotoxic fever is mediated essentially by endogenous pyrogen (EP), we have examined the possibility that the central cAMP is involved in the mechanism of biphasic fever induced by endotoxin, as in the case of biphasic fever induced by EP. The results showed that administration of endotoxin in rabbits elicited typical biphasic fever. The fluctuation of concentration of cAMP in cerebrospinal fluid (CSF) paralleled with the change of the rectal temperature, similar to that of the bipbasic fever caused by EP. Raised level of cAMP in plasma was observed only in the first phase. The cAMP concentration in CSF correlated positively with the febrile response. The correlation of cAMP levels in CSF and plasma was observed only in the first phase but not in all the febrilic periods. These findings indicated that the mechanism of endotoxic biphasic fever is associated with the Change of central cAMP. Content. The raised level of cAMP in CSF during fever is likely to represent the biosynthsis in brain regions. However, the possibility that the raised cAMP in plasma enters CSF in the first phase is not excluded.

The signals of body temperature from 4 different febrile patterns were sampled for power spectral analysis. The results showed that the spectrums had no difference between their distribution in frequency domain, only a low frequency peak has been seen. The values of the power spectrum varied directly to the intensity of the febrile responses. A high degree of relationship was found between the power spectral density and thermal response index (TRI).

Objective To summarize the damaging effect of infectious burden on cognition and the potential mechanisms, and reveal a newly insight into the prevention and treatment of cognitive impairment.Methods Based on the PUBMED, CBM and CNKI database, the articles involving the definition of infectious burden and the relationship between infectious burden and cognition were searched with the main key words infectious burden , cognition and inflammation.Results This study finally included 42 articles from the primarily retrieved 342 articles.Overall, the definition of infectious burden remains controversial.Infectious burden was related to cognitive impairment whereas the potential mechanisms had not been fully elucidated.Conclusion Infectious burden is the risk factor of cognitive impairment via the possible mechanisms of inflammation,vascular lesion and neuronal toxicity.

The bystander effect(BE) plays an important role in the gene therapy of cancer by the herpes thymidine kinase/ganciclovir(HSV-TK/GCV) system.It enhances the therapeutic efficacy of this system.Up to now,the exact underlying mechanism of the bystander effect remains unclear.A large body of evidence has indicated a close correlation of the connexin expression and gap junction in the targeted cells to the bystander effect.Here the publications concerning the relationship of gap junction with the bystander effect in the HSV-TK/GCV treatment have been reviewed.The possible cell death signals that can be transferred through gap junction to induce the bystander effect are also discussed.

Objective To discuss the feasibility and safety of early enteral nutrition (EN) on treatment of severe acute pancreatitis (SAP) and its influence. Methods The advancement about application of early EN on treatment of SAP in recent years were reviewed. Results In patients with SAP, early EN via catheter placed in the jejunum could protect the integrity of intestinal barrier and reduce infectious complications. But no consensus had been reached about the starting time, ingredient and infusion mode yet. Conclusion Early EN may have positive effects on treatment of SAP, but further researches are still needed.

Periodontal ligament stem cells(PDLSCs) are not only the crucial type of cells in maintaining dynamic homeostasis and wound repair of periodontal tissues but also the basis for novel therapeutic strategy for periodontal regeneration.Although possessing the excellent proliferation and differentiation ability,PDLSCs behave differently under various conditions representative of several influential factors.Understanding of these influential factors will help us to exploit more about PDLSCs,and more importantly,lead a new modality in treating periodontal diseases based on stem cells.Here we review multiple important factors affecting function of PDLSCs and propose its use in future regenerative therapy of periodontal defects.

Objective To investigate the early neurotoxicity of rotenone on dopaminergic neurons and explore an ideal tissue model. Methods A long-term midbrain slice culture system of SD pup was established according to the interface tissue culture method.After rotenone was added for some time,its toxic effects on the whole slices and the dopaminergic neurons were identified through the measurements of lactate dehydrogenase(LDH) released into the medium from the slices and dopamine(DA) content from the cultured tissue,as well as the observations of immunohistochemistry for tyrosine hydroxylase(TH). Results In those cultures exposed to rotenone for 24 h,the level of DA in tissue dramatically decreased with the concentrations rising.The processes of TH-positive neurons in slices demonstrated some morphological changes,such as appearance of string of beads,reduce of numbers and even disappearance.The content of dopamine in tissue was dominantly decreased with 5 nmol/L rotenone for 14 days,although its cellular morphology was not seen to change.Conclusion Long-time stable midbrain slice culture system has been set up successfully.The neurotoxicity of rotenone on the whole slices and dopaminergic neurons shows a dose-dependent manner.The functional damages on the neurons may be earlier than their morphological changes,of which the injury in the processes of neurons seems to be an early characteristic.

Stathmin is a novel member of microtubule-destabilizing proteins that play a critical role in the regulation of the dynamic equilibrium of microtubules during different phases of the cell cycle.The overexpression of stathmin was found in different type of cancer.Inhibition of stathmin expression in malignant cells may interfere with their orderly progression through the cell cycle.Overexpression of stathmin can affect the action of antimicrotuble drugs by markedly decreasing binding of paclitaxel,and increasing binding of Vinca alkaloids.In addition,stathmin provides an attractive molecular target for cancer therapy.It may be possible to combine adenovirus-mediated anti-stathmin ribozyme therapy with a chemotherapeutic agent such as taxol to obtain a more potent antiproliferative and antitumor effect.

Objective To explore the clinical features,diagnosis and treatment of solid-pseudopapillary tumor(SPT)of pancreas.Methods The clinical data of 19 patients with SPT treated in 8 years were studied retrospectively,included 3 males and 16 females.Results The type of operation was decided by the size and location of tumor.Pancreatic leakage was a familiar complication,there were 9 cases.Patients were followed up from 3 to 70 months,and no recurrence or metastsis was found.Conclusion Pancreas SPT is a rare type neoplasm of pancreas.Pancreas SPT is affecting primarily young women,complete resection results in excellent prognosis.