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The effects of sewage irrigation on the seedling growth of wheat and its activate oxygen metabolism were studied by water cultivation experiments. The results showed that compared with control, the wheat under sewage irrigation was short and small, and its roots number, fresh/dry weight of stem or root, and content of soluble protein decreased drastically. The content of chlorophyll decreased, while the Cyta/Cytb and membrane lipid peroxidation were increased. The sensitivity of pigment content of wheat leaf undr sewage irrigation was in order of Chlorophyll b > Chlorophyll a > Carotenoid. Furthermore, the POD, SOD and CAT activities of the wheat went down in varying degrees, and the SOD was the most susceptible enzyme to waste water stress. In this paper, the activities of POD, SOD and CAT decreased in 19.1%-33.1%, 37.8%-47.8% and 30.2%-35.9%, respectively.

Microglia are endogenous brain macrophages that show distinct phenotypes such as expression of myeloid antigens, ramified morphology, and presence within the neural parenchyma. They play significant roles in a number of human CNS diseases including AIDS dementia. Together with monocyte-derived (perivascular) macrophages, microglia represent a major target of HIV-1 infection. However, a recent report challenged this notion based on findings in SIV encephalitis. This study concluded that perivascular macrophages can be distinguished from parenchymal microglial cells by their expression of CD14 and CD45, and that macrophages, but not microglia, are productively infected in SIV and HIV encephalitis. To address whether parenchymal microglia are productively infected in HIV encephalitis, we analyzed expression of CD14, CD45 and HIV-1 p24 in human brain. Microglia were identified based on their characteristic ramified morphology and location in the neural parenchyma. We found that parenchymal microglia are CD14+ (activated), CD45+ (resting and activated), and constitute approximately two thirds of the p24+ cells in HIV encephalitis cases. These results demonstrate that microglia are major targets of infection by HIV-1, and delineate possible differences between HIVE and SIVE. Because productively infected tissue macrophages serve as the major viral reservoir, these findings have important implications for AIDS.

Microglia are pivotal in the pathogenesis of AIDS dementia, as they serve as the major target of HIV infection in the CNS. In addition, activation of microglia correlates best with clinical dementia. Although the beta-chemokine RANTES/CCL5 is important in modulating HIV infection as well as cellular activation, no information is available regarding how its expression is regulated in microglia by HIV-1. Here we report that RANTES/CCL5 expression is induced in microglia by HIV-1, but that this requires infection by HIV-1. This conclusion was supported by (1) the delayed kinetics coinciding with viral replication; (2) the lack of effect of X4 viruses; (3) inhibition by the reverse transcriptase inhibitor AZT, and (4) the lack of effect of cytokine antagonists or antibodies. Interestingly, RANTES/CCL5 production was dependent on the viral accessory protein Vpr, in addition to Nef, demonstrating a novel role for Vpr in chemokine induction in primary macrophage-type cells. Furthermore, the specific p38 MAP kinase inhibitor SB203580 augmented chemokine expression in microglia, indicating a negative role played by p38. These data suggest unique features of RANTES/CCL5 regulation by HIV-1 in human microglial cells.

Experiments in heavy-fermion metals and related theoretical work suggest that critical local-moment fluctuations can play an important role near a zero-temperature phase transition. We study such fluctuations at the quantum critical point of a Kondo impurity model in which the density of band states vanishes as /epsilon/(r) at the Fermi energy (epsilon=0). The local spin response is described by a set of critical exponents that vary continuously with r. For 0

Significant numbers of patients with acquired immunodeficiency syndrome (AIDS) develop CNS infection primarily in macrophages and microglial cells. Therefore, the regulation of human immunodeficiency virus type 1 (HIV-1) infection and activation of the brain mononuclear phagocytes subsequent to infection are important areas of investigation. In the current report, we studied the role of granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage-CSF (M-CSF) in the expression of antiviral beta-chemokines and HIV-1 p24 in cultures of primary human fetal microglia. We found that stimulation with GM-CSF or M-CSF induced macrophage inflammatory proteins (MIP-1alpha and MIP-1beta) and augmented RANTES expression, after HIV-1 infection of microglia. This was not due to the effect of GM-CSF on viral expression because GM-CSF was neither necessary nor stimulatory for viral infection, nor did GM-CSF enhance the expression of env-pseudotyped reporter viruses. Blocking GM-CSF-induced microglial proliferation by nocodazole had no effect on beta-chemokine or p24 expression. The functional significance of the GM-CSF-induced beta-chemokines was suggested by the finding that, in the presence of GM-CSF, exogenous beta-chemokines lost their anti-HIV-1 effects. We further show that although HIV-1-infected microglia produced M-CSF, they failed to produce GM-CSF. In vivo, GM-CSF expression was localized to activated astrocytes and some inflammatory cells in HIV-1 encephalitis, suggesting paracrine activation of microglia through GM-CSF. Our results demonstrate a complex interplay between CSFs, chemokines, and virus in microglial cells and may have bearing on the interpretation of data derived in vivo and in vitro., (Copyright 2002 Wiley-Liss, Inc.)

Integrins alpha9beta1 and alpha4beta1 form a distinct structural class, but while alpha4beta1 has been subjected to extensive study, alpha9beta1 remains poorly characterized. We have used the small molecule N-(benzenesulfonyl)-(L)-prolyl-(L)-O-(1-pyrrolidinylcarbonyl)tyrosine (3) to investigate the biochemical properties of alpha9beta1 and directly compare these properties with those of alpha4beta1. Compound 3 has a high affinity for both integrins with K(D) values of < or =3 and 180 pM for alpha9beta1 in 1 mM Mn2+ (activating) and 1 mM Ca2+ and 1 mM Mg2+ (nonactivating) conditions and < or =5 and 730 pM for alpha4beta1 under the corresponding conditions. Ca2+ treatment promoted the binding of 3 to both integrins (EC50 = 30 microM Ca2+ in both cases). Compound 3 binding to both integrins was also stimulated by the addition of the activating monoclonal antibody TS2/16. These findings indicate that the mechanisms by which metal ions and TS2/16 regulate ligand binding to alpha9beta1 and alpha4beta1 are similar. The binding of 3 to both integrins induced the mAb 9EG7 LIBS epitope, a property consistent with occupancy of the receptor's ligand binding site by 3. But whereas EGTA treatment inhibited the binding of 9EG7 to alpha4beta1, it stimulated the binding of 9EG7 to alpha9beta1. The 9EG7 and TS2/16 effects point to contributions of the beta1-chains on binding. Cross-linking data revealed that the integrin alpha-chains are also involved in binding the small molecule, as stable linkages were observed on both the alpha9 chain of alpha9beta1 and the alpha4 chain of alpha4beta1. Extensive structure-activity analyses with natural and synthetic ligands indicate distinct features of the ligand binding pockets. Most notable was the estimated >1000-fold difference in the affinity of the integrins for VCAM-1, which binds alpha4beta1with an apparent K(D) of 10 nM and alpha9beta1 with an apparent K(D) of >10 microM. Differences were also seen in the binding of alpha9beta1 and alpha4beta1 to osteopontin. Compound 3 competed effectively for the binding of VCAM-1 and osteopontin to both integrins. While these studies show many similarities in the biochemical properties of alpha9beta1 and alpha4beta1, they identify important differences in their structure and function that can be exploited in the design of selective alpha9beta1 and alpha4beta1 inhibitors.

Objective: To investigate the effect of Ginkgo biloba extract (GBE) on acute lung injury(ALI) induced by lipopolysaccharide (LPS) in aging rats., Methods: The rats were randomly divided into two parts: six rats served as normal controls; 18 rats were used for producing the aging animal model ( D-gal 50 mg/kg body weight was injected intraperitoneally, once a day for 6 weeks). The aging rats were then randomly divided into 3 groups: 6 rats as the aging control group; another 6 as the LPS treated aging group (LPS,5 mg/kg body weight intravenous injection); and the third as the GBE+LPS group (6 rats, GBE was started 7 days before the experiment,given once a day via the esophagus, the amount of flavone glycosides administered being 8 mg/kg body weight, and on the day of experiment, one dose of GBE was given 2 hours before LPS administration ). The samples were collected 2 hours after LPS or saline administration., Results: Compared with normal controls, the SOD activity in red cells and the Na(+) -K(+) -ATPase activity in the lung tissue decreased markedly (all P < 0.05), but the LDH activity increased (P < 0.05) in the aging rats. ALI was observed in the aging rats 2 hours after LPS administration. Compared with the aging control, in the LPS treated rats, there were more inflammatory cells in the lung tissue; protein content in bronchial alveolar lavage fluid (BALF) and the pulmonary permeability index (PPI) increased significantly (all P < 0.001); LD, MDA, NO(2) (-)/NO(3)(-), ET-1 and TNF-alpha content and LDH activity in blood, and MPO activity in lung tissue all increased significantly. On the contrary, SOD activity in red cells and Na(+) -K(+) -ATPase activity in lung tissue decreased markedly (P < 0.05, P < 0.01). These changes, except SOD, were markedly attenuated in the GBE+LPS rats., Conclusions: The anti-oxidant activity was decreased in D-gal-induced aging rats. Intravenous administration of LPS caused acute lung injury in aging rats. GBE had protective effect on ALI induced by LPS.

When a metal undergoes a continuous quantum phase transition, non-Fermi-liquid behaviour arises near the critical point. All the low-energy degrees of freedom induced by quantum criticality are usually assumed to be spatially extended, corresponding to long-wavelength fluctuations of the order parameter. But this picture has been contradicted by the results of recent experiments on a prototype system: heavy fermion metals at a zero-temperature magnetic transition. In particular, neutron scattering from CeCu6-x Aux has revealed anomalous dynamics at atomic length scales, leading to much debate as to the fate of the local moments in the quantum-critical regime. Here we report our theoretical finding of a locally critical quantum phase transition in a model of heavy fermions. The dynamics at the critical point are in agreement with experiment. We propose local criticality to be a phenomenon of general relevance to strongly correlated metals.

Nitric oxide (NO) produced by microglia has been implicated in the pathogenesis of various central nervous system diseases; however, the intracellular signal pathways for the production of NO are not well known. Protein kinase C (PKC) plays a key role in a variety of signal transduction processes. To elucidate how PKC regulates microglial NO production, we examined the effects of PKC inhibitors on lipopolysaccharide (LPS)-stimulated NO production by primary cultured rat microglia. Staurosporine, a non-selective PKC inhibitor, increased LPS-induced production of NO at 0.1-10 nM range of concentration. Protein kinase A (PKA) inhibitor, H89, did not affect LPS-induced NO production, suggesting that staurosporine effect is not mediated by inhibition of PKA. However, other two PKC inhibitors, whose specificities for PKC isoforms were different, Gö6976 and Ro-32-0432, exhibited different effects on NO production from staurosporine; the former inhibited and the latter showed no effect. Interestingly, an activator of PKC, phorbol 12-myristate 13-acetate (PMA) also increased LPS-induced production of NO at 1-10 nM range of concentration, suggesting that prolonged incubation with PMA caused down-regulation of PKC. These results indicate that the inhibition or down-regulation of some PKC isoforms causes the enhancement of NO production. The different effects of PKC inhibitors on the NO production suggest that the different PKC isoforms play different roles in regulation of NO production in microglia.

Microglial activation has recently been recognized as a cause of damage in various neurodegenerative diseases. A possible mechanism underlying this damage is the activation of microglia by serum factors leaked through a disruption of the blood-brain barrier, which in turn trigger microglial cell proliferation and the release of various substances toxic to neurons, such as superoxide (O(2)(-)). We recently reported that serum albumin enhanced O(2)(-) production in cultured rat microglia stimulated by phorbol ester. In the present report, we identify the active site of this enhancement within the albumin molecule. We purified an active subfragment from trypsin-treated bovine serum albumin that was composed of 12-mer and 33-mer peptides connected by a disulfide bond. The chemically synthesized 12-mer peptide showed activity within a concentration range ( approximately 10(-7) M:) equivalent to that of albumin. The activities of a series of synthesized peptides conclusively indicated that the minimum active sequence was Leu-His-Thr-Leu. The present study may shed light on the mechanism of neuronal cell damage in various neurodegenerative diseases.

The pathological activation of microglia has been implicated in ischemic neuronal damage and some neurodegenerative diseases; however, the mechanism of microglial activation is not well understood. Previously, we showed that a serum factor, albumin, increased O(2)(-) production by cultured microglia (Si et al., 1997, Glia 21: 413-418). In the present study, we found that serum also enhanced lipopolysaccharide (LPS)-induced production of nitric oxide and tumor necrosis factor-alpha, which are other important neurotoxins released by activated microglia. In the presence of 0.1% normal rat serum, the half-effective concentration for LPS decreased from 300 to 1 ng/ml. The factor seemed to be a relatively high-molecular-weight protein because the factor was retained after a molecular sieve (50 kDa) membrane separation. The factor was labile to trypsinization and heat treatment at 72 degrees C for 5 min but was stable at 56 degrees C for 60 min. Several purified serum proteins including albumin could not mimic the enhancing effect of serum. Acute-phase serum showed a potent enhancing effect at a 10 times lower concentration than the normal serum. By gel filtration chromatography, the enhancing effect observed was a single peak at about 60 kDa. These results suggest that some serum protein infiltrates into brain parenchyma after blood-brain barrier disruption and such protein may result in neuronal damage by activating microglia to release neurotoxins in some central nervous system diseases., (Copyright 2000 Academic Press.)

Microglial activation has been considered as a result of neuronal damage, however, recently it becomes to recognize as a possible cause of the damage in various neurodegenerative diseases. To elucidate the mechanism of the microglial activation, we examined the time course of lipopolysaccharide (LPS)-induced change in morphology and the release of cytokines and nitric oxide (NO) in cultured microglia from neonatal rat brains. With addition of 1 microg/ml LPS, the cell morphology was drastically changed within 3 h from amoeboid shape to bipolar rod shape. The peak time of such morphological change was at 6 h and then returned to small round shape gradually. This transient change in morphology was completely inhibited by 0.1 mM dibutyryl-cAMP. On the other hand, the release of cytokines and NO showed different time courses after stimulation by LPS; at first tumor necrosis factor (TNF)-alpha was released within 1 h lag time, secondly interleukin (IL)-1beta within 3 h, thirdly IL-6, and at last NO was released with about 6 h lag time. The addition of dibutyryl cAMP markedly inhibited the release of TNF-alpha and IL-1beta, but not IL-6 and NO at all. These results suggest that there are at least two different intracellular signaling pathways of LPS-induced microglial activation; one for early release of TNF-alpha and IL-1beta sensitive to dibutyryl-cAMP and the other for late release of IL-6 and NO insensitive to dibutyryl-cAMP. The transient morphological change seems to be associated with the early release based on the sensitivity to dibutyryl-cAMP.

The present paper is to study the effects of electroacupuncture (EA) on acute ischemic stroke patient and acute cerebral ischemic rat. In clinic, 42 acute ischemic stroke patients were randomly divided into 2 therapeutic groups: drug group and EA+ drug group. Neurological deficits of patients were evaluated before and after the treatment by Chinese Stroke Scale. The results showed that the acute ischemic stroke patients treated by drug or EA+ drug were all partially recovered, but the clinical functional recovery in EA+ drug group was significantly better than in the drug group (P < 0.01). In laboratory, the model of reversible middle cerebral artery occlusion (MCAO) was used in rats. The somatosensory evoked potential (SEP) was recorded before and after MCAO. EA was applied one hour after cerebral ischemia and once a day after reperfusion for 7 days in EA+ MCAO group. It was shown that the amplitude of P1-N1 wave of SEP before MCAO was 100%. After MCAO 30 min the P1-N1 wave of SEP on the ipsilateral side of MCAO was decreased to 2.2 +/- 3% (MCAO group), 1.9 +/- 2% (MCAO+ EA group); and then recovered to 25.5 +/- 14.1% (MCAO group), 58.6 +/- 27.2% (MCAO+ EA group) after 7 days of reperfusion following MCAO 2 hours. The above results indicated that EA could promote the recovery of neurological function in acute ischemic stroke patients and SEP on MCAO rats.

Microglial activation and disruption of blood-brain barrier (BBB) are known to occur and contribute to neuronal damages in cerebral ischemic conditions and in some neurodegenerative diseases. To investigate whether a serum factor leaked out from circulation enhances microglial activation, we examined the effect of normal rat serum on superoxide (O2-) production by cultured microglia. Microglia cultured from neonatal rat brains were studied on their O2- production induced by the addition of phorbol myristate acetate by a method of acetyl-cytochrome c reduction. The O2- production was significantly increased by the addition of 0.01% rat serum, and the maximal enhancement was observed at about 0.1% rat serum. After the serum was fractionated using a molecular sieve membrane, we observed the enhancing effect only in a greater molecular weight fraction (>50 kDa). Furthermore, three kinds of bovine serum albumin (BSA) with different purity, and human serum and plasma albumins, also enhanced O2- production to a similar extent to that by rat serum. However, other proteins tested showed no significant effect. The enhancement of O2- production by BSA was observed dose-dependently, and the effect of 50 microg/ml of purified BSA was equivalent to that of 0.1% rat serum, suggesting that albumin itself enhances O2- production by microglia. These results imply that albumin leaked out through impaired BBB may activate microglia and that the potentiation of O2- production by albumin results in the pathogenesis of neuronal damage in cerebral ischemia and some neurodegenerative diseases.

As a part of host-defense immune system, macrophages can response to a variety of stimulants and produce superoxide. We examined the effect of adenosine as a modulator on superoxide production induced by phorbol ester in rat peritoneal macrophages, using an acetyl-cytochrome c reduction method for its detection. 2-Cl-adenosine, a least metabolizable analog of adenosine, inhibited the superoxide production in a dose-dependent manner, and also showed the increasing effect on intracellular cAMP level. Superoxide production was also inhibited by the several reagents which increased intracellular cAMP level, including dibutyryl-cAMP. 8-bromo-cAMP (cell permeable cAMP analogs), forskolin (an adenyl-cyclase activator). Ro 20-1724 (an phosphodiesterase inhibitor), and propentofylline (a xanthine derivative), but not 8-bromo-cGMP (cell permeable cGMP analog). These results suggest that a high level of extracellular adenosine may attenuate immunity through regulating macrophage functions. On the other hand, the tissue damage which is resulted from an over-production of superoxide can be protected by adenosine and its related drugs via an elevation of intracellular cAMP level.

Propentofylline is a xanthine derivative that has been known to protec t neurons against ischemia-induced damage. To assess its neuroprotective mechanisms, we examined the effect of propentofylline on microglial proliferation that is thought to play an important role in neuronal damage. We determined the proliferation of microglia cultured from neonatal rat brains by measuring [3H]thymidine update. Propentofylline inhibited microglial proliferation in a dose dependent manner; EC50 was about 3 mu M. Similar results were observed with 2-chloroadenosine (agonist for A1 and A2 adenosine receptors) and 2-chloro-N6-cyclopentyladenosine (A1 receptor agonist) but not with 2-p-(2-carboxyethyl)phenethylamino-5'-N-ethyl-carboxamidoadenosine hydrochloride (A2 receptor agonist). However, 8-cyclopentyl-1,3-dipropylxathine (A1 receptor antagonist) could not reverse the inhibitory effect of propentofylline. Our results suggest that the neuroprotection by propentofylline is, as least in part, due to the direct effect of the drug on microglia and that the drug inhibits the proliferation via a certain mechanism not directly mediated by adenosine receptors.

Aim: To study the effect of colchicine on hepatic glycosaminoglycan (GAG) metabolism in mice infected with Schistosoma japonicum., Methods: The amount of GAG was measured in the liver of mice infected with Schistosoma japonicum for 6-16 wk and treated with colchicine., Results: Six weeks after infection, the GAG content of infected mice's livers and uninfected control was 14 +/- 2 micrograms/g liver and 4 +/- 1 microgram/g liver, respectively. The GAG content reached a peak about 6 times of the normal level in the 10th wk after infection, being 56 +/- 9 micrograms/g and 10 +/- 1 microgram/g for infected and uninfected mice respectively, and then declined. Treatment of infected mice with colchicine reduced the total GAG content to 22 +/- 3 micrograms/g liver, but not suppress the GAG content below the normal level in the 10th wk. Microscopic hepatic egg granuloma., Conclusion: Colchicine may exerts its GAG reduction effect through the suppression of granuloma formation.

Pulmonary arterial pressure (PAP) was increased obviously in rats after 3 days of normobaric hypoxic exposure and reached a maximum at 14 days of hypoxia. It remained at the same level during prolonged hypoxic exposure of up to 21 days. Right ventricular weight (RV/LV+S) and hydroxyproline (HP) content in the pulmonary artery began to increase at day 7. HP content had increased much faster than the relative rate of increase of PAP after 14 days, but HP content in the thoracic aorta showed no change. The relative proportion of type I to III collagen increased significantly, and compliance of the pulmonary vessels obviously decreased. All parameters returned to the normal range within 14 days after recovery from hypoxia, except for HP content as expressed per vessel. 764-3 treatment obviously attenuated most of the changes caused by hypoxia, though it had no effect on compliance of the pulmonary vessels. It is suggested that collagen, especially type I collagen, accumulation may play an important role in maintaining pulmonary hypertension. 764-3 has certain protective effects and may be useful in the treatment of early chronic obstructive pulmonary disease.

The pulmonary edema (PE) induced by adrenaline (AD) administration is similar to neurogenic PE. Anisodamine (ADM, 654-2, 30 mg/kg) and tetramethylpyrazine (TMP, 120 mg/kg) have shown significant preventive effects. Electron microscopic observation was carried out to study the changes of microvascular permeability, and the dynamic change of mean pulmonary arterial pressure (PAP, 40 rats), mean pulmonary arterial wedge pressure (PAWP, 20 rats) and mean carotid arterial pressure (CAP) were also measured. The results suggested that both ADM and TMP have significant inhibitory effects on PAWP and CAP increase, as well as on the damage responsible for the increase of microvascular and alveolar permeability.

Pulmonary edema (PE) which is similar to the neurogenic type was induced by adrenaline (AD) administration (0.1 mg/kg) in rats. Acute progressive respiratory distress, cyanosis and dyspnea occurred. All the experimental animals in the PE group died within 20 min after AD injection, with a pulmonary index (PI) of 1.70 +/- 0.47 (mean +/- S) which was much higher than that in the normal group. The mortality rate was 100%. It was found that in rats with PE, a protein-rich fluid filled the alveolar and interstitial spaces, and ecchymosis occurred. The capillary permeability as estimated by Evans blue injection showed that Evans blue from extraction fluid and bronchoalveolar lavage (BAL) in the PE rats was at a much higher level than that in the normal control (NC) rats. In anisodamine (ADM, 654-2) and tetramethylpyrazine (TMP) treated rats, almost all the damage was diminished or absent, and the mortality rates were decreased from 100% to 4.4% and 20%, respectively. 654-2 and TMP could significantly inhibit the increase of pulmonary permeability.

Two new human recombinant interleukin-2 (rIL-2), 125-Ser-rIL-2, and 125-Ala-rIL-2, were generated by protein engineering technique. Both of them maintained the proliferation of natural killer (NK) cells, CTLL-2 cells and their long-term propagations. The mutated new rIL-2 also enhanced the bioactivity of NK cells and the cytotoxicity of tumor-infiltrating lymphocytes (TIL) against the target tumor cells. The above results were all compared with that of the native rIL-2 and a similarity between them was found, which indicates that new type rIL-2 could be used for adoptive immunotherapy of malignant diseases.