Changes in tau phosphorylation levels in the hippocampus and frontal cortex following chronic stress

Studies have indicated that early-life or early-onset depression is associated with a 2- to 4-fold increased risk of developing Alzheimer's disease (AD). In AD, aggregation of an abnormally phosphorylated form of the tau protein may be a key pathological event. Tau is known to play a major role in promoting microtubule assembly and stabilization, and in maintaining the normal morphology of neurons. Several studies have reported that stress may induce tau phosphorylation. The main aim of the present study was to investigate possible alterations in the tau protein in the hippocampus and frontal cortex of 32 male Sprague-Dawley rats exposed to chronic unpredictable mild stress (CUMS) and then re-exposed to CUMS to mimic depression and the recurrence of depression, respectively, in humans. We evaluated the effects of CUMS, fluoxetine, and CUMS re-exposure on tau and phospho-tau. Our results showed that a single exposure to CUMS caused a significant reduction in sucrose preference, indicating a state of anhedonia. The change in behavior was accompanied by specific alterations in phospho-tau protein levels, but fluoxetine treatment reversed the CUMS-induced impairments. Moreover, changes in sucrose preference and phospho-tau were more pronounced in rats re-exposed to CUMS than in those subjected to a single exposure. Our results suggest that changes in tau phosphorylation may contribute to the link between depression and AD.

Human endogenous retrovirus W family envelope gene activates the small conductance Ca2+-activated K+ channel in human neuroblastoma cells through CREB

Numerous studies have shown that human endogenous retrovirus W family (HERV-W) envelope gene (env) is related to various diseases but the underlying mechanism has remained poorly understood. Our previous study showed that there was abnormal expression of HERV-W env in sera of patients with schizophrenia. In this paper, we reported that overexpression of the HERV-W env elevated the levels of small conductance Ca(2+)-activated K(+) channel protein 3 (SK3) in human neuroblastoma cells. Using a luciferase reporter system and RNA interference method, we found that functional cAMP response element site was required for the expression of SK3 triggered by HERV-W env. In addition, it was also found that the SK3 channel was activated by HERV-W env. Further study indicated that cAMP response element-binding protein (CREB) was required for the activation of the SK3 channel. Thus, a novel signaling mechanism of how HERV-W env influences neuronal activity and contributes to mental illnesses such as schizophrenia was proposed.

Population pharmacokinetics of valnemulin in swine

This study was carried out in 121 pigs to develop a population pharmacokinetic (PPK) model by oral (p.o.) administration of valnemulin at a single dose of 10 mg/kg. Serum biochemistry parameters of each pig were determined prior to drug administration. Three to five blood samples were collected at random time points, but uniformly distributed in the absorption, distribution, and elimination phases of drug disposition. Plasma concentrations of valnemulin were determined by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The concentration-time data were fitted to PPK models using nonlinear mixed effect modeling (NONMEM) with G77 FORTRAN compiler. NONMEM runs were executed using Wings for NONMEM. Fixed effects of weight, age, sex as well as biochemistry parameters, which may influence the PK of valnemulin, were investigated. The drug concentration-time data were adequately described by a one-compartmental model with first-order absorption. A random effect model of valnemulin revealed a pattern of log-normal distribution, and it satisfactorily characterized the observed interindividual variability. The distribution of random residual errors, however, suggested an additive model for the initial phase (<12 h) followed by a combined model that consists of both proportional and additive features (≥ 12 h), so that the intra-individual variability could be sufficiently characterized. Covariate analysis indicated that body weight had a conspicuous effect on valnemulin clearance (CL/F). The featured population PK values of Ka , V/F and CL/F were 0.292/h, 63.0 L and 41.3 L/h, respectively.

Record performance of electrical injection sub-wavelength metallic-cavity semiconductor lasers at room temperature

We demonstrate a continuous wave (CW) sub-wavelength metallic-cavity semiconductor laser with electrical injection at room temperature (RT). Our metal-cavity laser with a cavity volume of 0.67λ3 (λ = 1591 nm) shows a linewidth of 0.5 nm at RT, which corresponds to a Q-value of 3182 compared to 235 of the cavity Q, the highest Q under lasing condition for RT CW operation of any sub-wavelength metallic-cavity laser. Such record performance provides convincing evidences of the feasibility of RT CW sub-wavelength metallic-cavity lasers, thus opening a wide range of practical possibilities of novel nanophotonic devices based on metal-semiconductor structures.

Population pharmacokinetics of cefquinome in pigs

This study was performed in 145 pigs to develop a population pharmacokinetics (PPK) model by i.m. administration of cefquinome (CEQ) at the dose of 2 mg/kg in the neck muscle. Serum physiological and biochemical parameters for each pig were determined before administration. After administration, 2-4 samples were collected at random, with the sampling point evenly distributed in the three periods (<1 h, 1-4 h and >4 h). The plasma concentration of CEQ was determined by high performance liquid chromatography with UV detector. The pharmacostatistical analyses of concentration-time data, weight, age, gender, serum physiological and biochemical parameters were performed with nonlinear mixed effect modeling (NONMEM). A one-compartmental model with first-order absorption and elimination adequately described the data from the study group. The optimal random effect model of pharmacokinetics parameters was of log-normal distribution and the residual errors assumed a mixed-type model (proportional and additive) to best explain intra-individual variability. Covariate analysis showed that body weight is positively correlated with apparent volume of distribution (V/F) and body clearance (CL/F). The typical PPK parameters of Ka , CL, and V were 0.564/h, 5.15 L/h, and 1.36 L, respectively.

Laboratory and field assessments of prey-mediated effects of transgenic Bt rice on Ummeliata insecticeps (Araneida: Linyphiidae)

One major concern regarding the release of Bt rice is its potential impact through tritrophic interactions on nontarget arthropods, especially natural enemies. We studied the effects of two Bt transgenic rice varieties, TT9- 3 and KMD1, expressing Cry1Ab/Cry1Ac and Cry1Ab, respectively, on a predatory ground spider [Ummeliata insecticeps (Bösenberg et Strand)] supplied with Bt rice-fed brown planthopper [Nilaparvata lugens (Stål)] nymphs. Although immunoassays confirmed that U. insecticeps ingested Bt insecticidal protein when supplied with Bt rice-fed N. lugens, no negative effects were found on its survival and development. Furthermore, the fecundity of U. insecticeps fed prey reared on Bt rice was not significantly different from that of those fed prey reared on non-Bt rice. A 3-yr field trial indicated that Bt rice did not significantly affect the population density of U. insecticeps in comparison with non-Bt rice. In conclusion, the Bt rice lines tested in this study had no adverse effects on the survival, developmental time, or fecundity of U. insecticeps in the laboratory or on population dynamics in the field.

Astrocytic activation in thoracic spinal cord contributes to persistent pain in rat model of chronic pancreatitis

One of the most important symptoms in chronic pancreatitis (CP) is constant and recurrent abdominal pain. However, there is still no ideal explanation and treatment on it. Previous studies indicated that pain in CP shared many characteristics of neuropathic pain. As an important mechanism underlying neuropathic pain, astrocytic activation is probably involved in pain of CP. Based on the trinitrobenzene sulfonic acid (TNBS)-induce rat CP model, we performed pancreatic histology to assess the severity of CP with semiquantitative scores and tested the nociceptive behaviors following induction of CP. Glial fibrillary acidic protein (GFAP) expressions in the thoracic spinal cord were observed by immunohistochemistry and real-time reverse transcription polymerase chain reaction (RT-PCR). Meanwhile, we injected intrathecally astrocytic specific inhibitor l-alpha-aminoadipate (LAA) and observed its effect on nociception induced by CP. Compared to the naive and sham group, TNBS produced long lasting pancreatitis, and persistent mechanical hypersensitivity in the abdomen that was evident 1 week after TNBS infusion and persisted up to 5 weeks. Compared with naive or sham operated rats, GFAP staining was significantly increased 5 weeks after CP induction. Real-time RT-PCR indicated that GFAP expression was significantly increased in TNBS treated rats compared to the sham group. TNBS-induced astrocytic activation was significantly attenuated by LAA, compared with the saline control. Treatment with LAA significantly, even though not completely, attenuated the allodynia. Our results provide for the first time that astrocytes may play a critical role in pain of CP. Some actions could be taken to prevent astrocytic activation to treat pain in CP patients.

Lead nephropathy: early leads from descriptive studies

Chronic lead exposure is recognized as a potential cause of hyperuricaemia, kidney damage and hypertension. The fascinating story of lead poisoning and nephrotoxicity illustrates the utility of descriptive studies in the early elucidation of a new disease entity. The pursuit towards understanding lead nephropathy is presented as a successful illustration of human occupational and public health.

[Stereotactic radiotherapy for multiple brain metastases]

BACKGROUND & OBJECTIVE

Stereotactic radiotherapy (SRT) has obvious advantages in treating intracranial tumors, but there are few reports about application of SRT to multiple intracranial tumors. This paper summarized the therapy outcome of patients with multiple brain metastases, and evaluated the efficacy and application of SRT.

METHODS

Clinical data of 136 patients with multiple brain metastases received radiotherapy from Jun. 1996 to Dec. 2002 were reviewed. Of the 136 patients, 52(38.2%) received conventional radiotherapy alone (CR group), 84(61.8%) received SRT or SRT plus whole brain radiotherapy (SRT group).

RESULTS

Clinical effective rate, and elimination rate of brain metastases (diameter of > 20 mm) were significantly higher in SRT group than in CR group (96.4% vs. 86.5%, P=0.02; 70.4% vs. 36.0%, P=0.007). Persistent brain edema rate was 8.3% in SRT group, and 9.6% in CR group (P=0.767). Intracranial tumor recurrence rate was 25.0% in SRT group, and 19.4% in CR group (P=0.653). Median survival time was significantly longer in SRT group than in CR group (10.5 months vs. 6.5 months, P=0.014); 1-year survival rate was significantly higher in SRT group than in CR group (40.5% vs. 21.2%, P=0.023).

CONCLUSION

Reasonable application of SRT could improve life quality and treatment outcome of patients with multiple brain metastases, reduce intracranial tumor recurrence and radiation damage, and prolong patients'survival time.

[Clinical observation of hypoxic radiotherapy for nasopharyngeal carcinoma]

BACKGROUND & OBJECTIVE

The clinical application of hypoxic radiotherapy (RT) was developed at a high speed in China in recent years. The protective effect of hypoxic RT on normal tissues has been proved. However, there was not an affirmative answer whether hypoxic RT had any protective effect on tumor. This study was designed to analyze this question by comparing clinical results of hypoxic RT with regular RT in nasopharyngeal carcinoma (NPC) patients.

METHODS

A series of 117 patients with NPC who underwent hypoxic RT or regular RT between March 1992 and June 2000 in PLA 309 Hospital was enrolled. The cancers were staged as I, II, III, and IV in 11, 30, 57, and 19 cases, respectively. Of these, 69 received hypoxic RT, and 48 received regular RT. There was no significant difference in age, sex, TNM staging, pathological type, adjuvant therapy between two groups (P>0.05). All patients underwent 6MV X-ray and 8-12 MeV electronic beam. The nasopharyngeal areas received dose of 72 Gy (range, 68 to 82 Gy), and neck positive lymph node regions received dose of 64 Gy (range, 60 to 70 Gy).

RESULTS

The incidence rates of 2-3 degree early irradiation toxicity of oropharynx mucous membrane, salivary gland, and II- III degree late dry mouth were 23.2%, 26.1%, 37.7% in hypoxic RT group and 77.1%, 62.5%, 91.7% in regular RT group, respectively(P<or=0.01). The incidence rates of local recurrence, neck recurrence and metastasis, distance metastasis were 14.5%, 23.2%, 21.7% in hypoxic RT group and 12.5%, 20.8%, 18.8% in regular RT group, respectively (P> 0.05). The 1-, 3-, 5-, 7-year survival rates were 97.1%, 83.7%, 74.4%, 54.5% in hypoxic RT group and 97.9%, 86.8%, 70.2%, 54.7% in regular RT group, respectively (P>0.05).

CONCLUSION

Hypoxia could alleviate irradiation toxicity and reduce complication rate of NPC patients. There is no significant difference between hypoxic RT and regular RT in tumor recurrence and metastasis and the survival rate of NPC. Further study is needed.

Coencapsulation of hepatocytes and bone marrow stem cells: in vitro conversion of ammonia and in vivo lowering of bilirubin in hyperbilirubemia Gunn rats

BACKGROUNDS/AIMS

This study investigates the ammonia removal capacity of coencapsulated hepatocytes and bone marrow stem cells in culture, and the treatment effect on hyperbilirubinemia Gunn rats when transplanted.

METHODS

The hepatocytes and bone marrow stem cells isolated from Wistar rats were encapsulated alone or coencapsulated. In vitro, the encapsulated cells were cultured in media supplemented with 2.4 mMol/L concentration of ammonium chloride and the ammonia removal and urea synthesis were evaluated. In vivo, the encapsulated cells were transplanted intraperitoneally into hyperbilirubinemia Gunn rats and plasma bilirubin levels were measured before and after transplantation at intervals of 85 days.

RESULTS

The ammonia removal capacity was maintained longer in the different ammonia concentration media in the coencapsulated hepatocytes and bone marrow cells culture. In the coencapsulation transplantation group, the plasma bilirubin levels were significantly lower than those in the group of hepatocytes encapsulation transplantation during the period of 3 to 10 weeks posttransplantion.

CONCLUSIONS

The coencapsulated heaptocytes and bone marrow cells when compared to encapsulated hepatocytes could improve the maintenance of hepatocyte function both in vitro of ammonia removal in culture, and in vivo of the lowering the Gunn rats blood total bilirubin when transplanted.

EGFR tyrosine kinase inhibitor AG1478 inhibits cell proliferation and arrests cell cycle in nasopharyngeal carcinoma cells

Nasopharyngeal carcinoma (NPC), which occurs with a high incidence in southern China and southeast Asia, is of epithelial origin with overexpression of EGF receptor. To study the effect of inhibition of EGFR signaling on nasopharyngeal carcinoma cell proliferation and cell cycle distribution, EGFR tyrosine kinase inhibitor AG1478 was employed to treat Nasopharyngeal Carcinoma CNE2 cells. The results showed that AG1478 inhibited proliferation of CNE2 cells. Immunoblot showed that AG1478 inhibited EGFR phosphorylation in CNE2 cells without reduced expression of EGFR protein. The activation of Akt and MAPK which are downstream molecules of EGFR signaling pathway, were also inhibited by AG1478. AG1478 induced cell cycle arrest in G1 phase, and the levels of protein p27 were significantly up-regulated. We concluded that inhibition of the EGFR signaling induced cell cycle arrest in G1 phase in CNE2 cells and p27 up-regulation was involved in this process. The EGFR kinase specific inhibitor is of potential to be developed into drugs for NPC treatment.

Multiple drug resistance phenotype of human endothelial cells induced by vascular endothelial growth factor 165

AIM

To investigate the effect of vascular endothelial growth factor 165 (VEGF165) on sensitivity of endothelial cells to anticancer drugs.

METHODS

Human dermal microvessel endothelial cells (HDMEC) were incubated with anticancer drugs in the presence of VEGF165. Survival of endothelial cells was assayed by MTT method. DNA fragments of apoptosis were detected by agarose electrophoresis. Potential mechanisms underlying the effect of VEGF165 on endothelial cells were investigated with RT-PCR and Western blot analysis.

RESULTS

VEGF165 induced the multidrug resistance phenotype of HDMEC to a wide variety of anticancer drugs such as epirubicin, cisplatin, etoposide, mytomycin C, vincristine, CPT-11, and taxol in vitro. This protective effect was partly due to the up-regulation of lung drug resistance protein (LRP) and multidrug resistance-associated protein (MRP), as well as the down-regulation of Bax protein induced by VEGF165.

CONCLUSION

VEGF165 induced multidrug resistance phenotype of endothelial cells, which implicated the anti-angiogenic effect of anticancer drugs might depend on microenvironment of tumors in vivo.

[Mechanism of apoptosis induced by squamocin in leukemia cells]

AIM

To investigate the mechanism of apoptosis of HL60 cells induced by the annonaceous acetogenin, squamocin.

METHODS

Induction of apoptosis was determined through Hoechst33258 dye staining and DNA agarose gel electrophoresis. Expression of the proteins was detected using Western blot analysis. Caspase-3 activity was detected using caspase-3 kit.

RESULTS

Treatment of HL-60 cells with squamocin resulted in extensive nuclear condensation, DNA fragmentation, cleavage of the death substrate poly(ADP-ribose) polymerase (PARP) and induction of caspase-3 activity. Pretreatment of HL-60 cells with caspase-3 specific inhibitor DEVD-CHO prevented squamocin-induced DNA fragmentation, PARP cleavage and cell death. Stress-activated protein kinase (SAPK/JNK) was activated after treatment with squamocin in HL-60 cells.

CONCLUSION

These results suggest that apoptosis of HL-60 cells induced by squamocin require caspase-3 activation, and could be related to SAPK activation.

Metabolism of ticlopidine by activated neutrophils: implications for ticlopidine-induced agranulocytosis

Ticlopidine is associated with a relatively high incidence of agranulocytosis and aplastic anemia. We have shown that other drugs associated with agranulocytosis are metabolized to reactive metabolites by activated human neutrophils or by HOCl, which is the major oxidant produced by activated neutrophils. We set out to test the hypothesis that ticlopidine also fits this pattern and is oxidized to a reactive intermediate by activated neutrophils and HOCl. As much as 8% ticlopidine was metabolized by activated human neutrophils to a dehydro-ticlopidine; however, this product did not account for all of the decrease in ticlopidine concentration. The oxidation products of ticlopidine by the combination of myeloperoxidase and hydrogen peroxide were the same as those by HOCl: dehydrogenated ticlopidine and 2-chloroticlopidine. A neutrophil-derived reactive metabolite of ticlopidine was trapped with GSH and the same ticlopidine-GSH conjugate was found in both the myeloperoxidase and HOCl systems. Evidence for the identity of the reactive metabolite was obtained by reaction of ticlopidine with HOCl in a flow reaction system coupled to a mass spectrometer. The mass spectra suggested that the reactive metabolite was a thiophene-S-chloride. We conclude that ticlopidine follows the same pattern of reactive metabolite formation by activated neutrophils as other drugs associated with a high incidence of agranulocytosis, and the putative thiophene-S-chloride formed by activated neutrophils may be responsible for ticlopidine-induced agranulocytosis.

[Effects of simulated weightlessness on carbohydrate intake and serum lipids]

OBJECTIVE

To observe the effects of simulated weightlessness on the nutritional state and contents of serum lipids in human.

METHOD

Eighteen healthy men were exposed to 21 d bed rest with -6 degrees head down tilt (HDT -6 degrees). Nutrients intake was calculated and the lipids levels were determined on the first, eleventh and twenty-first day.

RESULT

Intake of the three main nutrients, carbohydrates, protein and fat met the physiological requirement essentially, but carbohydrates intake was significantly reduced in the second week. There were no significant differences among the lipid levels during different periods.

CONCLUSION

Simulated weightlessness may exert a short-term and reversible influence on human nutritional intake except for lipids.

Apoptosis induced by ceramide in hepatocellular carcinoma Bel7402 cells

AIM

To study the biological function of ceramide signaling in Bel7402 cells.

METHODS

Inhibition of cell growth was assayed using MTT method. Morphologic assessment of apoptosis was performed with fluorescence microscope. DNA fragmentation was detected by electrophoresis and flow cytometry. The levels of protein p53, Bcl-2, and Bax were measured with Western blot.

RESULTS

Bel7402 cells treated with C2-ceramide underwent cell proliferation inhibition. IC50 value was 14.28 mumol.L-1. After treatment of Bel7402 with ceramide, the morphologic changes including reduction in volume, nuclear chromatin condensation, fluorescence strength were observed. SubG1 peaks were detected on flow cytometry (FCM). Agarose gel electrophoresis of DNA from cells treated with ceramide revealed "ladder" pattern. The Western blot assay from cell extracts showed that the levels of protein p53 were decreased after ceramide treatment. The levels of protein Bcl-2 were decreased also. But the levels of Bax protein showed no difference between untreated cells and treated cells.

CONCLUSION

Ceramide induces apoptosis in Bel7402 cells, related to Bcl-2 down-regulation.

[The equipment of using Azolla for O2-supplementation (correction of supplimentation) and its test]

The equipment of using Azolla for O2-supplementation and food-production in future space station was developed and tested. Dog was used as the O2-consuming animal. The design of this device considered both the requirement of Azolla growth, such as illumination, temperature, humidity, nutrition and biomass harvesting, and also the food supplement, excretion draining and temperature controlling for the dog under the condition of an airtight chamber for a relatively long duration. This device was preliminarily tested for O2-release by Azolla, and data about O2-supplement by Azolla were obtained.

Effect of mitoxantrone on DNA polymerase of Ehrlich ascites carcinoma cells

AIM

To study the effect of mitoxantrone (Mit) on DNA polymerases of tumor cells.

METHODS

DNA polymerases of Ehrlich ascites carcinoma cells were isolated by phosphocellulose column chromatography. The effects of Mit on DNA polymerase alpha, beta, and gamma were detected by method of K Ono.

RESULTS

Mit inhibited DNA polymerase alpha, beta, and gamma, IC50 values were 11.9, 6.5, and 11.9 mumol.L-1, and Ki 1.86, 2.22, and 2.05 mumol.L-1, respectively. The inhibitory mode of Mit on DNA polymerase alpha, beta, and gamma was competitive.

CONCLUSION

Mit is a strong inhibitor on DNA polymerase alpha, beta, and gamma. The inhibitory mode was competition with respect to template DNA.

Cytochrome P450 peroxidase/peroxygenase mediated xenobiotic metabolic activation and cytotoxicity in isolated hepatocytes

Cytochrome P450 (P450) can utilize organic hydroperoxides and peracids to support hydroxylation and dealkylation of various P450 substrates. However, the biological significance of this P450 peroxygenase/peroxidase activity in the bioactivation of xenobiotics in intact cells has not been demonstrated. We have shown that tert-butyl hydroperoxide (tBHP) markedly enhances 3-20-fold the cytotoxicity of various aromatic hydrocarbons and their phenolic metabolites. The tBHP-enhanced hepatocyte cytotoxicity of 4-nitroanisole (4-NA) and 4-hydroxyanisole (4-HA) was also accompanied by an increase in the hepatocyte O-demethylation of 4-NA and 4-HA up to 7.5- and 21-fold, respectively. Hepatocyte GSH conjugation by 4-HA was also markedly increased by tBHP. An LC/MS analysis of the GSH conjugates identified hydroquinone-GSH and 4-methoxy-catechol:GSH conjugates as the predominant adducts. Pretreatment of hepatocytes with P450 inhibitors, e.g., phenylimidazole, prevented tBHP-enhanced 4-HA metabolism, GSH depletion, and cytotoxicity. In conclusion, hydroperoxides can therefore be used by intact cells to support the bioactivation of xenobiotics through the P450 peroxidase/peroxygenase system.

Clozapine is oxidized by activated human neutrophils to a reactive nitrenium ion that irreversibly binds to the cells

Clozapine was oxidized to a reactive intermediate by HOCI, which is the major oxidant produced by activated neutrophils. A mass spectrum was obtained of this reactive intermediate by using a flow system in which the reactants were fed into a mixing chamber and the products flowed directly into a Sciex API III mass spectrometer. The intermediate was observed at m/z 325, which is 2 mass units less than the protonated molecular ion of the parent drug. This intermediate reacted with water to form several products with a m/z at 343. The same products were produced by the oxidation of clozapine by the combination of myeloperoxidase, hydrogen peroxide and chloride ion. The reactive intermediate was trapped by glutathione (GSH) and several conjugates were formed. Nuclear magnetic resonance spectra of the two major conjugates indicated GSH bound to the 6 and 9 positions of the aromatic ring. These data provide further evidence for the formation of a formal nitrenium ion in which the positive charge is highly delocalized. Clozapine was also oxidized by activated neutrophils, and in the presence of GSH, the same GSH conjugates were formed. When therapeutic concentrations of radiolabeled clozapine were used, up to 7% of the drug became irreversibly bound to the neutrophils. Covalent binding was inhibited by about 30% in the presence of 1 mM GSH but was almost abolished at 5 mM GSH. The putative nitrenium ion formed by activated leukocytes could be responsible for clozapine-induced agranulocytosis.

[Good regulation of acupuncture in simple obesity patients with stomach-intestine excessive heat type]

In order to investigate the regulatory effect of acupuncture on obesity patients with the Stomach-Intestine Excessive Heat Type, the pre-acupunctural and post-acupunctural obesity index and biochemical indices of 718 patients with simple obesity was observed. It was showed that the marked weight loss effects was achieved in the cases by acupuncture, while the biochemical indices improved. It suggests that acupuncture had a good regulatory effect on the function of nerve, endocrine, digestion and energy metabolism.

Oxidation of 5-aminosalicylic acid by hypochlorous acid to a reactive iminoquinone. Possible role in the treatment of inflammatory bowel diseases

5-Aminosalicylic acid (5-ASA) is an agent widely used in the treatment of inflammatory bowel disease. 5-ASA has been shown to be a potential scavenger of the oxidants, such as hypochlorous acid (HOCl), that are released by neutrophils present in inflammatory bowel disease. We studied the oxidation of 5-ASA by HOCl and characterized the reaction pathway involving reactive intermediates. The reactive intermediates in the reaction of 5-ASA with HOCl were identified by use of a flow system interfaced with a Sciex API III mass spectrometer. The mass spectral analysis revealed the formation of iminoquinone and quinone reactive intermediates. The major stable product formed was identified as gentisic acid. The iminoquinone and quinone intermediates were trapped by glutathione (GSH) and the products analyzed by LC/MS. The major conjugate was formed from the quinone with one dominant isomer. In contrast, three isomers of the iminoquinone-GSH conjugates were observed in almost equal proportion. Covalent binding of the reactive intermediates to the alpha-chain of human hemoglobin was also observed. We propose that the iminoquinone is the major intermediate formed in the scavenging of neutrophil-generated HOCl by 5-ASA. Although this reaction may inactivate HOCl and be responsible for the antiinflammatory effects of the drug, it also forms reactive intermediates that covalently bind to protein and may be responsible for adverse reactions that are associated with the use of the drug.

[Effects of wuzi yanzong pills on lipid in rats with alcohol-induced liver injury]

Experiments showed that in the rat model of alcohol-induced liver injury, a dosage of the pills (1-2g/kg, ig) could increase the cholesterol level, lower the triglyceride level, and improve the fatty degeneration and necrosis of liver (P < 0.05-0.01). The results suggest that the important mechanism of the pills in protecting and treating alcoholic fatty liver, lies in the regulation of metabolism of the lipid, especially of the triglyceride.