The role of splenic macrophages in plasma tumor necrosis factor levels in endotoxemia

We investigated the function of splenic macrophages (M phi s) with respect to changes in plasma tumor necrosis factor (TNF) in lethally endotoxemic rats treated with gadolinium chloride (GdCl3), which blocks the phagocytosis of large liver M phi s. We also carried out an immunohistochemical study to investigate the change of populations of liver and splenic M phi s under the condition of dysfunction of liver M phi s with or without splenectomy. Twenty-four-hour survival rates were 100% in the GdCl3-treated group (n = 6) and 0% in the nontreated group (n = 6). These rates did not change with splenectomy. Immunohistochemical examination with the primary monoclonal antibodies ED1, ED2 and ED3 revealed that large liver M phi s were eliminated after GdCl3 injection, and that this was not related to splenectomy. The splenic M phi s were not affected by GdCl3 treatment. Plasma TNF levels did not differ between the GdCl3-treated and the nontreated groups, irrespective of whether splenectomy was performed. It was suggested that plasma TNF levels are not affected by the splenic M phi s and that they do not compensate for dysfunction of liver M phi s after GdCl3 treatment.     

Kupffer cell inactivation prevents lipopolysaccharide-induced structural changes in the rat liver sinusoid: an electron-microscopic study

Scanning and transmission electron-microscopic examination of the rat liver sinusoid was performed in this study after in vivo treatment of rats with gram-negative bacterial lipopolysaccharide (LPS, 1 mg/Kg(-1) body weight), with or without pretreatment with gadolinium chloride (GdCl3 10 mg(Kg(-1) body weight). Twenty-seven and 48 hours after GdCl3 administration, to inactivate/eliminate part of the Kupffer cell population, a decrease in the number of visualized Kupffer cells was observed, without evident effects on the sinusoidal endothelial cell or on the hepatocyte. Three and 24 hours after its administration, LPS produced ultrastructural changes in the sinusoid characterized by morphological evidence of Kupffer cell activation (i.e., swelling and expanded philopodia anchoring the Kupffer cell to the luminal surface of the sinusoidal wall), and a marked decrease in the population of endothelial cell fenestration. The reduction in the number of fenestrae was associated with a change in the diameter of fenestrae and can be interpreted as a component of the "capillarization" process of the hepatic sinusoid. Such ultrastructural changes were prevented by the administration of GdCl3 24 hours before LPS injection. Hence, these findings suggest that LPS-induced structural changes in the liver sinusoid are mediated by an LPS-induced Kupffer cell activation. Coupled with previous experimental data, showing similar effects of GdCl3 on one of the hepatic sinusoidal endothelial cell (SEC) functions, i.e., hyaluronan scavenging, the data presented in this study strongly support the view that Kupffer cells modulate both the hepatic SEC's functional as well as ultrastructural properties.     

Biochemical effects of gadolinium chloride in rats liver and kidney studied by ^1H NMR metabolomics

The biochemical effects of gadolinium chloride were studied using high-resolution IH nuclear magnetic resonance (NMR) spec-troscopy to investigate the biochemical composition of tissue (liver and kidney) aqueous extracts obtained from control and gadolinium chlo-ride (GdCl3) (10 and 50 mg/kg body weight, intraperitoneal injection, i.p.) treated rats. Tissue samples were collected at 48, 96 and 168 h p.d. after exposure to GdCl3, and extracted using methanol/chloroform solvent system. 1H NMR spectra of tissue extracts were analyzed by pat-tern recognition using principal components analysis. The liver damages caused by GdCl3 were characterized by increased succinate and de-creased glycogen level and elevated lactate, alanine and betaine concentration in liver. Furthermore, the increase of creatine and lactate, and decrease of glutamate, alanine, phosphocholine, glycophosphocholine (GPC), betaine, myo-inositoi and trimethylamine N-oxide (TMAO)levels in kidney illustrated kidney disturbance induced by GdCl3.     

GdCl_3·3H_2O-18C6-C_2H_5OH体系(25℃)的相化学及固态配合物的合成与表征

采用半微量相平衡方法研究了 Gd Cl3· 3H2 O - 18C6 - C2 H5 OH三元体系 (2 5℃ )的溶解度 ,测定了各饱和溶液的折光率 ,考察了相平衡过程中水的行为。绘制了体系的溶解度图与饱和溶液折光率曲线。发现了两种未见文献报道的配合物 :3Gd Cl3· 18C6· 9H2 O· C2 H5 OH与 Gd Cl3· 18C6· 3H2 O。前者为固液异成分溶解的配合物 ,后者为固液同成分溶解的配合物。制备了固态配合物 ,通过化学分析、IR、DTG、TG以及 DSC研究了配合物的组成与性质 ,由 DSC得到了配合物若干分解步骤的焓变。用热化学方法求得了固态配合物 Gd Cl3· 18C6· 3H2 O(s)的标准生成焓     

Time course study of the influence of acute iron overload on Kupffer cell functioning and hepatotoxicity assessed in the isolated perfused rat liver

This study tested the hypothesis that acute iron overload (500 mg/kg) alters Kupffer cell functioning by promoting free radical reactions associated with the respiratory burst of liver macrophages, assessed in the isolated perfused rat liver under conditions of Kupffer cell stimulation by carbon infusion and inactivation by gadolinium chloride pretreatment. Total serum and hepatic iron levels were markedly enhanced compared with control values 2 to 24 hours after iron treatment. Total liver O2 uptake progressively increased by iron overload reaching a maximum at 6 hours after treatment, an effect that was completely blocked by GdCl3. Concomitantly, carbon-induced GdCl3-sensitive liver O2 uptake was either enhanced by 119% at 2 hours after iron overload, diminished compared with control values at 4 hours, or abolished at 6 hours. Iron-overloaded rats showed a marked increase in liver sinusoidal lactate dehydrogenase efflux at 4 and 6 hours after treatment, an effect that is exacerbated by carbon infusion and reduced (69%-89%) by GdCl3 pretreatment. Both basal and carbon-induced lactate dehydrogenase effluxes returned to control values at 24 hours after iron overload concomitantly with depression of the basal O2 uptake, without development of iron-induced GdCl3-sensitive respiration or Kupffer cell activation by carbon infusion. It is concluded that iron overload induces a derangement in the Kupffer cell functional status represented by early increases in macrophage-dependent respiratory activity, which may contribute to the concomitant liver injury that developed and to the impairment of both hepatic respiration and the macrophage response to particle stimulation observed at later times after treatment.     

Inactivation of Kupffer cells prevents early alcohol-induced liver injury

It is well recognized that consumption of alcohol leads to liver disease in a dose-dependent manner; however, the exact mechanisms remain unclear. Hypoxia subsequent to a hypermetabolic state may be involved; therefore, when it was observed recently that inactivation of Kupffer cells prevented stimulation of hepatic oxygen uptake by alcohol, the idea that Kupffer cells participate in early events that ultimately lead to alcohol-induced liver disease became a real possibility. The purpose of this study was to test that hypothesis. Male Wistar rats were exposed to ethanol continuously by means of intragastric feeding for up to 4 weeks using the model developed by Tsukamoto and French. In this model, ethanol causes fatty liver, necrosis and inflammation--changes characteristic of alcohol-induced liver disease in human beings. Kupffer cells were inactivated by twice weekly treatment with gadolinium chloride (GdCl3), a selective Kupffer cell toxicant. AST levels were elevated to 192 +/- 13 and 244 +/- 56 IU/L in rats exposed to ethanol for 2 and 4 wk, respectively (control value, 88 +/- 7). This injury was prevented almost completely by GdCl3 treatment. Fatty changes, inflammation and necrosis were also all reduced dramatically by GdCl3 treatment. The average hepatic pathological score of rats treated with ethanol for 4 wk was 4.3 +/- 0.6, which was reduced significantly in ethanol- and GdCl3-treated rats to 1.8 +/- 0.5 (p < 0.05). Rates of ethanol elimination were elevated 2- to 3-fold in rats exposed to ethanol for 2 to 4 wk. This elevation was blocked by GdCl3 treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Daunomycin unfolds compactly packed DNA

Metabolic degradation of a soluble highly branched (-->3)-beta-D-glucan, SSG, was examined in mice using a macrophage blocker, gadolinium chloride (GdCl3). Intraperitoneally administered SSG distributed in the liver was slowly degraded, and after 5 weeks about 30% of the SSG became anionic. In addition, it is suggested that the metabolites would contain fewer branching points as assessed by the reactivity to limulus factor G. On the other hand, in the spleen, the molecular weight and the degree of branching of SSG were not changed for at least 5 weeks. Blockade of Kupffer cells by GdCl3 did not significantly change the distribution ratio of SSG in the liver. However, the treatment significantly delayed the degradation of SSG. These results suggested that Kupffer cells play important roles, not in the distribution, but in the oxidative degradation of SSG in the liver. In addition, splenic macrophages did not significantly contribute to the metabolic degradation of SSG.     

Operative strategy in patients with MRI-identified dual pathology and temporal lobe epilepsy

The liver is the most common site of hematogenous metastases from colorectal carcinoma. Kupffer cells (KC), which line the hepatic sinusoids, may form the first line of defense against circulating tumor cells. The purpose of this study was to determine the effect of hepatic metastases and intra-abdominal tumor growth on KC binding of human colorectal carcinoma (HCRC) cells. MIP-101, a poorly metastatic cell line, and CX-1, a highly metastatic cell line, were injected intrasplenically into nude mice and KC were isolated by collagenase perfusion at varying intervals after injection. Conditioned media were collected from MIP-101, CCL 188 and CX-1 to determine their in vitro effect on KC function. KC from MIP-101 injected mice (14% liver metastases, 100% splenic tumors) bound a significantly greater number of MIP-101 and clone A cells than CX-1 cells in vitro. KC isolated from mice 5 weeks after CX-1 injection (100% liver metastases) also showed increased binding of MIP-101 and clone A cells compared to CX-1 cells. Similar results were obtained when tumor cell binding to normal human liver KC was compared to binding to KC from human livers from patients with hepatic metastasis from colorectal cancer. In contrast KC obtained from mice 3 weeks after CX-1 injection (44% liver metastases) showed significantly decreased binding of MIP-101 and clone A cells. The conditioned medium from CX-1 cells significantly decreased the in vitro binding of both MIP-101 and CX-1 by KC. These results indicate that the ability of KC to bind HCRC cells (which precedes phagocytosis and tumor cell killing) is a dynamic function and affected by concomitant tumor growth. HCRC cells may alter KC function via the production of specific tumor-derived soluble factors. In order to devise new and more effective therapeutic options in the treatment of liver metastases the nature of this tumor cell-KC interaction must be better understood.     

Peroxisomes are involved in the swift increase in alcohol metabolism

The purpose of this study was to determine whether catalase-dependent alcohol metabolism is activated by alcohol (i.e., swift increase in alcohol metabolism). When ethanol or the selective substrate for catalase, methanol, was given (5.0 g/kg) in vivo 2 to 3 h before liver perfusion, methanol and oxygen metabolism were increased significantly. This increase was blocked when the specific Kupffer cell toxicant GdCl3 was administered 24 h before perfusion. These data support the hypothesis that catalase-dependent alcohol metabolism is activated by acute alcohol and that Kupffer cells are involved. Ethanol treatment in vivo increased ketogenesis from endogenous fatty acids nearly 3-fold and increased plasma triglycerides and hepatic acyl CoA synthetase activity; all increases were blocked by GdCl3. These findings support the hypothesis that ethanol increases H2O2 supply for catalase-dependent alcohol metabolism by increasing fatty acid supply. Infusion of oleate stimulated oxygen uptake 1.5-fold and methanol metabolism 4-fold, but these parameters were not altered by GdCl3. Moreover, the effects of ethanol treatment were blocked by the cyclooxygenase inhibitor indomethacin, and prostaglandin E2 (PGE2) was increased more than 200% in media from cultured Kupffer cells from rats treated with ethanol in vivo. Furthermore, lipoprotein lipase activity in retroperitoneal fat pads, which is known to be inhibited by PGE2, was reduced 70% by ethanol. These data are consistent with the hypothesis that Kupffer cells play a key role in activation of catalase-dependent alcohol metabolism, most likely by producing mediators (e.g., PGE2) that inhibit lipoprotein lipase, increase the supply of fatty acids to the liver, and increase generation of H2O2 via peroxisomal beta-oxidation.     

Primary immunodeficiency diseases at Red Cross War Memorial Children''s Hospital

BACKGROUND: Normally, a Buffalo (BUF) recipient (RT1b) rejects a heterotopically transplanted Lewis (LEW) heart (RT1l) drained into the portal vein (PV) within 14 days. However, the addition of PV administration of 25x10(6) ultraviolet B (UVB)-treated LEW spleen cells (SC) to BUF recipients 7 days before cardiac transplantation results in 70% long-term allograft survival. METHODS: In this study, we used gadolinium chloride (GdCl3) (7 mg/kg/day) to selectively block the phagocytosis of recipient hepatic Kupffer cells before PV injection of UVB-treated donor SC to examine the mechanism of tolerance induction, as measured by in vitro analysis of mixed lymphocyte culture (MLC), T cell cytotoxicity, T helper cell precursors (pTH), and cytotoxic T cell precursors (pCTL) by limiting dilution analysis. RESULTS: A BUF recipient that received untreated or gamma-irradiated LEW SC intraportally reacted to in vitro stimulation by LEW alloantigen with increased MLC proliferation, T cell cytotoxicity, pTH and pCTL frequencies, and interleukin-2 production. In contrast, SC from BUF that received UVB-treated LEW SC were hyporesponsive on MLC stimulation by donor LEW alloantigen and exhibited markedly reduced cytotoxicity, pTH and pCTL frequency, and interleukin-2 production. However, normal in vitro responsiveness resulted with stimulation by third-party Brown-Norway (RT1n) SC, thus indicating that the systemic hyporesponsiveness was specific for the UVB donor alloantigen given PV. On the other hand, GdCl3 given by intravenous injection daily for 3 days before PV alloantigen blocked the induction of in vitro hyporesponsiveness. CONCLUSION: Therefore, prevention of alloantigen sequestration by GdCl3 inhibition of hepatic Kupffer cell phagocytosis was pivotal in preventing the development of portal venous tolerance.     

Importance of diabetes mellitus and systemic hypertension rather than completeness of revascularization in determining long-term outcome after coronary balloon angioplasty (the LDCMC registry). Lady Davis Carmel Medical Center

To characterize KC 12291 (1-(5-phenyl-1,2, 4-thiadiazol-3-yl-oxypropyl)-3-[N-methyl-N-[2-(3,4-dimethoxy phenyl) ethyl] amino] propane hydrochloride), a newly synthezised inhibitor of voltage-gated Na+ channels, the effects of the agent on Na+ current and ischemia-induced Na+ overload were investigated in isolated cardiomyocytes, atria and saline-perfused hearts. As measured by the patch clamp technique, KC 12291 (1 microM) significantly reduced peak Na+ current after activation of voltage-gated Na+ channels in rat cardiomyocytes. Partial depolarization enhanced the inhibitory effects during steady state conditions of the channel. In isolated guinea pig atria, 1 microM KC 12291 had no effect on contractility under basal conditions but effectively delayed the onset and reduced the extent of anoxic contracture. The concentration-response curve was clearly shifted to the left when atria were partially depolarized by increased extracellular K+. As measured by 23Na NMR spectroscopy in isolated perfused guinea pig hearts, intracellular Na+ rose more than four-fold in a linear fashion during 60 min of low-flow ischemia. KC 12291 (1 microM) prevented Na+ overload within the initial 12 min of ischemia; thereafter the slope of Na+ accumulation was identical to controls. Electrical excitability of hearts, evaluated by intracardial ECG, completely ceased within 15 min after the onset of ischemia. KC 12291 (1 microM) accelerated this process by more than 6 min. The data provide first evidence that KC 12291 reduces Na+ influx through voltage-gated Na+ channels during ischemia and thus delays Na+ overload by enhancing the inexcitability of the heart.     

Expression of the neutrophil chemokine KC in the colon of mice with enterocolitis and by intestinal epithelial cell lines: effects of flora and proinflammatory cytokines

IL-10 plays an important role in preventing excessive inflammation to the normal flora in the intestinal lumen. The purpose of this study was to compare the effect of normal flora on inflammation in mice in which the IL-10 gene was disrupted. IL-10 knock-out mice housed in germfree conditions remained healthy while those housed in conventional conditions developed colitis after weaning, suggesting that IL-10 inhibits the adverse responses to luminal Ag. Crypt abscesses were present in virtually all of the diseased animals as evidenced by flattening of the epithelial cells and a large number of neutrophils in the lumen of the crypt. Since KC is a chemokine that is capable of recruiting neutrophils in mice, mRNA and protein for KC was measured. Increased levels of both KC mRNA and protein were detected in the colon of diseased mice. To determine whether the epithelial cells were capable of synthesizing KC and contributing to neutrophil accumulation in the crypts, a murine intestinal epithelial cell line (Mode-K) was shown to express mRNA and protein for KC. Two cytokines induced in association with colitis in these mice, TNF-alpha and IFN-gamma, increased the expression of KC mRNA and protein in murine epithelial cells. However, IL-10 was incapable of decreasing the induction of KC, even though the cells expressed the IL-10 receptor. These results suggest that the neutrophil chemokine KC is produced by gastrointestinal epithelial cells in response to inflammatory mediators that are expressed following exposure to normal flora in animals lacking IL-10.     

Activities of nucleoprotein particles derived from rat liver ribosome

80-S ribosomes and 60-S subunits from rat liver were treated at increasing KC1 concentrations giving protein-deficient ribosomal particles whose components were analyzed and their activity tested. Most of the activities assayed stand treatment up to KC1 concentrations of around 0.6 M; peptidyl transferase, measured by the fragment reaction, however was 50% inhibited by 0.5 M KC1 in 60-S subunits but not in 80-S ribosomes. Three proteins, L21, L26 and L31, might be implicated in this loss of activity. 60-S subunits forming part of the 80 S ribosome are more resistant to the salt treatment and the pattern of proteins released by the treatment differs from the one obtained from free 60-S subunits, implying perhaps a change of conformation of this subunit upon association to form 80-S couples. According to their resistance to release by KC1 the proteins of the large sub-unit can be divided into three groups: (1) easily removed, including proteins: L1, L11, L17 and L25 in 80-s subunits and in addition, L5, L8, L9, L13, L20, L22, L26, L29, L31 and L32/33 in 60-S subunits; (2) proteins resistant to release by high salt concentrations in 80-S ribosomes as well as in 60-S subunits, namely proteins L3, L14, L27, L36, L40, L41, X1 and X2; (3) the rest of the proteins which are released in a more or less continuous way throughout the treatment. 5 S RNA is not released by KC1 treatment at the concentrations used. The binding sites for the antibiotics trichodermin and anisomycin are affected in a different way by the salt treatment, indicating that they are structurally different.     

Role of free radicals in primary nonfunction of marginal fatty grafts from rats treated acutely with ethanol

Acute treatment with one large dose of ethanol, which mimics binge drinking, causes marginal fatty liver and decreases survival significantly after liver transplantation in rats, yet mechanisms remain unclear. Therefore, we evaluated the possible role of free radicals in primary nonfunction caused by acute ethanol. Female donor rats were administered ethanol (5 g/kg orally) 20 hr before explantation, and grafts were stored in UW cold storage solution for 24-42 hr before implantation. Free radicals were trapped with alpha-(4-pyridyl 1-oxide)-N-tert-butylnitrone after transplantation, and adducts were detected using electron spin resonance spectrometry. Ethanol increased a carbon-centered radical adduct in bile approximately 2-fold and elevated serum lipid hydroperoxides approximately 4-fold. Ethanol also increased transaminase release 3.7-fold and decreased bile production by 55%. Catechin, a free radical scavenger, minimized the increase in free radicals, blunted transaminase release, and elevated bile production significantly, indicating that free radical production plays an important role in ethanol-induced fatty graft injury. GdCl3 (20 mg/kg intravenously), a selective Kupffer cell toxicant, largely blocked the increases in free radical and lipid hydroperoxide production caused by ethanol. In addition, ethanol nearly doubled white blood cell adhesion after transplantation, leading to increased superoxide production in fatty grafts. GdCl3 largely blocked leukocyte adhesion as well as superoxide production. Allopurinol, an inhibitor of xanthine oxidase, also diminished free radical production, blunted transaminase release, and improved bile production in fatty grafts significantly. Taken together, we conclude that free radical formation increases in ethanol-induced fatty grafts due mainly to activation of Kupffer cells and increased adhesion of white blood cells. Antioxidants can effectively block free radical formation and minimize injury to marginal fatty grafts caused by binge drinking.     

Organisation and association of kappa-carrageenan helices under different salt conditions

Mixtures of the added salts NaI and CsI can be used to gradually 'tune' the propensity of kappa-carrageenan (KC) helices to aggregate in solution. We show that this method can be used to resolve the molecular events by which helix formation, under certain conditions, leads to gelation. We also present an overview of the various states of aggregation and organisation that appear for helical KC (non-degraded or ultrasonically degraded) when the NaI/CsI ratio and the concentration of KC are varied. A transition to rigid, superhelical rods is found above a well-defined fraction of cesium. This transition is reflected in a range of experimental measurements, such as cryo-transmission electron microscopy, optical rotation, viscometry and small deformation oscillatory measurements. The superhelical-rod state also seems essential for the association of KC with locust bean gum, and locust bean gum is found to stabilise this state. Novel states of KC alone have been found at cesium contents below the transition threshold. Non-degraded KC forms weak gels at sufficiently high concentrations (> ca. 1%). In contrast, ultrasonically degraded KC forms a chiral nematic liquid crystalline phase at sufficiently high concentrations (> ca. 5%) under these salt conditions.     

Time course of stomach mineralization, plasma, and urinary changes after a single intravenous administration of gadolinium(III) chloride in the male rat

In a previous experiment it was reported that the intravenous administration of gadolinium chloride (GdCl3) to rats results in a discrete band of interstitial mineralization in the fundic glandular mucosa of the stomach. To investigate the time course for the development of this lesion and its relationship to plasma calcium and phosphate concentrations, 2 experiments were carried out in male Sprague-Dawley rats given a single intravenous dose of 0.07 mmol/kg GdCl3. Plasma calcium and phosphate concentrations approximately doubled between 30 min and 12 hr postdose but had regressed back to near normal values by 24 hr. However, there were no observable clinical signs in treated animals. Histologically, there was progressive mineralization of the lamina propria of the neck region of the fundic glands from 6 hr postdose, forming a distinctive mineral band by 12 hr postdose. At 7 and 14 days postdose the mineral deposits were accompanied by mucous cell hyperplasia, interstitial fibrosis, and a very sparse infiltration of inflammatory cells. By 56 days postdose only occasional mineral deposits remained. Transmission electron microscopy showed mineral first nucleated on collagen in the interstitium, but there was no evidence of cell necrosis. X-ray microanalysis showed that the interstitial mineral was composed of calcium and phosphate in the form of hydroxyapatite; gadolinium (Gd) was only very rarely identified. These findings are consistent with metastatic mineralization. The source, cause, and the exact nature of the excess plasma calcium and phosphate are unknown, and the possible significance of this effect for clinical use of Gd-containing chelates in nuclear magnetic resonance imaging requires further investigation.     

均匀共沉淀法合成纳米Gd_2O_3:Eu粉体及其发光特性

以六次甲基网胺(hexamethylenetetramine,(CH2)6N4,HMT)为沉淀剂,在GdCl3和EuCl3混合溶液中,利用均匀共沉淀法制得了纳米颗粒.结果表明,获得的Gd2O3:Eu纳米颗粒近似为球形,尺寸均匀,平均粒径为100 nm,且每个球形颗粒由平均粒径为20 nm的微晶聚并而成.Gd2O3:Eu荧光粉在波长612 nm的红光发射来自Eu3+的5D0-7F2电偶极跃迁,发光强度随煅烧温度提高而增强,随Eu3+掺杂摩尔分数的提高而增强.Eu3+掺杂摩尔分数超过7%时,发生浓度淬灭,发光强度减弱.