Murine graft-versus-host disease in an F1-hybrid model using IFN-gamma gene knockout donors

These experiments were performed to determine whether the absence of donor-derived IFN-gamma would influence the outcome of acute graft-vs-host disease (GVHD). Graft-vs-host reactions were induced in B6D2F1 hybrids using grafts from either IFN-gamma gene knockout (gko) or wild-type, C57BL/6J, parental strain donors. GVHD was equally lethal in both groups, but IFN-gamma gko graft recipients developed a more protracted form of the disease. These mice developed early wasting that persisted until death. IFN-gamma was present in spleen cell cultures from wild-type graft recipients, but was absent in cultures from IFN-gamma gko graft recipients. Both recipient groups showed macrophage priming for LPS-induced TNF-alpha release. Engraftment of donor-derived CD4+ and CD8+ cells was greater in IFN-gamma gko graft recipients. Pathologic changes in IFN-gamma gko graft recipients were different from those typically seen in acute GVHD. The syndrome developing in IFN-gamma gko recipients consisted of patchy alopecia, corneal dryness and clouding, and lymphocytic infiltration of the liver, pancreas, salivary gland, lung, and kidney. Lymphocytic infiltrates were also present in the epidermis and the epithelium of both bile and salivary gland ducts. Some of the lesions closely resembled those seen in the "sicca"/Sjogren's-like syndrome associated with chronic GVHD; however, there was no evidence of immune complex deposition in the kidney. These results indicate that GVHD in IFN-gamma gko graft recipients shares many features with acute GVHD, but both the duration of the disease and its pathologic manifestations are different. Our results suggest that IFN-gamma plays a significant role in the pathogenesis of acute GVHD by increasing the rate at which mortality develops.     

Effects of an explicit group contract on self-disclosure and group cohesiveness.

Assigned 96 male undergraduates to small groups based on their scores on a 40-item self-report survey derived from the Self-Disclosure Questionnaire. Half the groups received an explicit self-disclosure contract while the other half received no contract. Findings show that (a) the contract served to increase significantly both the frequency and depth of self-disclosure but did not affect the level of intimacy of topics discussed; and (b) the contract significantly enhanced the cohesiveness of the groups (i.e., attraction to the group) but had the opposite effect on members' mutual liking. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

以氧传感器为基的辅助电极型冶金传感器的研究进展

金属熔体的化学组成是金属冶炼过程的重要参数,固体电解质传感器可以提供金属冶炼过程中成分变化的实时信息;这些信息可以提高生产效率,提升产品质量.由于缺乏以待测元素为导电离子的固体电解质,除氧以外的一些元素的测量多通过在电解质的表面涂覆一层含待测元素和电解质中导电离子元素复合物的方法来实现.总结了氧传感器及其他元素成分传感器的研究进展,介绍了以氧传感器为基础的辅助电极型成分传感器,并对辅助电极型传感器的应用和发展进行了展望.     

Organic nitrates--new perspectives on an old drug group

A quarter of patients with erythropoietic protoporphyria develop mild to severe cholestatic liver disease. The determination of early indicators of hepatobiliary involvement are of pivotal importance to select patients for choleretic therapy. Porphyrin parameters were studied during ursodeoxycholic acid treatment in eight patients with protoporphyrin-associated liver disease and eight patients with liver failure before and after liver transplantation. The patients with intrahepatic cholestasis exhibited excessive protoporphyrinemia (27 mumol/l) compared with controls (normal < 0.64 mumol/l). Fecal protoporphyrin excretion decreased in patients with deterioration of liver function, whereas urinary coproporphyrin increased up to 2290 nmol/24 h (normal < 119 nmol/24 h). Coproporphyrin isomer I proportion increased to 71 +/- 10% (mean +/- SD, n = 8) in patients with terminal liver failure (normal < 31%). During therapy with ursodeoxycholic acid biochemical improvement occurred but without clinical remission in most cases. Eight patients underwent liver transplantation between 1987 and 1997. One patient died of liver failure. Two transplant recipients are in a good condition since 8 and 9 years, respectively. All explanted livers revealed micronodular cirrhosis and high protoporphyrin levels of about 25,000-fold (mean, n = 3). Immediately after liver transplantation protoporphyrin in erythrocytes decreased to 46-96% of pre-operative values. Coproporphyrin remained moderately elevated due to post-operative cholestasis. A post-operative rise in fecal protoporphyrin elimination reflected sufficient biliary clearence of protoporphyrin by the transplant. In conclusion, moderate coproporphyrinuria with isomer I is the earliest sign of liver complications in erythropoietic protoporphyria. Progression of protoporphyrin induced toxic liver injury is indicated by excessive protoporphyrinemia and coproporphyrinuria with an isomer I proportion > 71 +/- 10%, and reduction of fecal protoporphyrin excretion. Results suggest that therapy of intrahepatic cholestasis with ursodeoxycholic acid is only effective in the initial stages of liver disease in erythropoietic protoporphyria. In patients with severe cholestatic hepatic failure, liver transplantation is the treatment of choice.     

Identification of a major carbohydrate capping group of the L-selectin ligand on high endothelial venules in human lymph nodes as 6-sulfo sialyl Lewis X

We investigated the molecular species of sulfated sialyl Lewis X determinants, the putative L-selectin ligand, expressed on high endothelial venules (HEV) in human lymph nodes. Comparison of the reactivity pattern of HEV with the reactivity of the pure 6-sulfo, 6'-sulfo, or 6,6'-bissulfo sialyl Lewis X determinant with hitherto known anti-sialyl Lewis X antibodies strongly suggested 6-sulfo sialyl Lewis X to be the best candidate for the major sulfated sialyl Lewis X determinant on HEV, followed by 6,6'-bissulfo sialyl Lewis X, whereas 6'-sulfo sialyl Lewis X was unlikely. We newly generated monoclonal antibodies (mAbs) G152 and G72 directed against 6-sulfo sialyl Lewis X, which intensely labeled HEV in immunohistochemical examination and inhibited binding of recombinant L-selectin-IgG to HEV, suggesting that the determinant serves as a ligand for L-selectin. To test the concomitant expression of 6, 6'-bissulfo sialyl Lewis X, specific mAbs (G2706, G27011, G27037, and G27039) were generated, but all antibodies failed to react to HEV. Next, we established mAbs (AG97 and AG273) directed against 6-sulfo Lewis X, the asialo form of 6-sulfo sialyl Lewis X. The antibodies were not reactive to untreated HEV, but strongly reacted to sialidase-treated HEV. This indicated the predominance of the sialylated form of 6-sulfo sialyl Lewis X and minimal expression of its asialo form, corroborating that it was synthesized by fucosyltransferase VII, the isoenzyme that preferentially produces the sialylated form of the determinant.     

P204-H3cit-NdCl3体系负载有机反萃取的研究

非皂化P204-H3cit-NdCl3体系萃取分离稀土的方法有效地解决了传统萃取分离体系下,稀土工业生产存在皂化废水中氨氮含量高污染水资源等问题,但该体系反萃取的酸度过高而限制了该方法的进一步应用.通过单级和错流反萃取研究了反萃液酸度、反萃温度、反萃时间和反萃级数对反萃取率的影响,并以此为基础,进一步研究了0.6mol/L低酸度六级逆流反萃取.实验结果表明:与单级及错流反萃取相比,六级逆流反萃率可达到100%,酸利用率为50%左右,明显减少了酸耗,而且反萃余液酸度为0.3 mol/L左右,达到了现有稀土萃取分离的工业要求.该研究为非皂化P204-H3cit-NdCl3体系萃取稀土元素的应用提供了一定的依据.     

Studies with an intravas nylon device in rat

Contraceptive efficacy of an intravas device (IVD) was investigated in rat. The IVD used consisted of a nylon suture which did not occlude the lumen of the vas completely and permitted a free passage of spermatozoa. Its presence for periods ranging from 15 to 180 days did not produce any changes in the histology of the testis and epididymis; In the vas deferens the tall columnar ciliated epithelium was replaced by squamous epithelium. A spermatic granuloma developed on the vas at the entry of the IVD and its frequency of occurrence and size increased with the passage of time. The device caused an increase in the vasal protein, sialic acid and phospholipid content, and a decrease in the level of glycogen and alkaline phosphatase activity at 15 days. The level of portein, glycogen and alkaline phosphatase activity returned to normalcy at 90 days but the sialic acid and phospholipid content remained elevated. Notwithstanding these alterations the device failed to affect the spermatozoal number, morphology, motility and their fertilizing ability. The significance of these findings is discussed.     

Studies on the interaction of diflunisal ion with cyclodextrins using ion-selective electrode potentiometry

The interaction of diflunisal ion (DF) with beta-cyclodextrin (betaCD), gamma-cyclodextrin (gammaCD), and hydroxypropyl-beta-cyclodextrin (HPbetaCD) was studied in phosphate buffer, pH 7.4, at 5-37 degrees C and various CD concentrations using a home-made diflunisal ion-selective electrode. Typical direct binding plots and Scatchard plots were obtained with HPbetaCD. The Scatchard model for one class of binding sites was used for the estimation of binding parameters for the DF/HPbetaCD interaction. The estimates for n (number of binding sites per CD molecule) were in all cases very close to unity, indicating 1:1 complexation. The association constant (K) estimates decrease with increasing temperature. Sigmoidal direct binding plots and concave-downwards Scatchard plots were obtained with various betaCD or gammaCD concentrations. The Hill model was used for the estimation of the binding parameters for the DF/betaCD and DF/gammaCD interactions. Both the Hill coefficients and the binding constants were markedly dependent on the CD concentration. These findings indicate the cooperative character of DF/betaCD and DF/gammaCD interactions. The free energy change, DeltaG, and the thermodynamic parameters, DeltaH and DeltaS, were estimated for each of the interactions studied using the Van't Hoff equation.     

Dependence of developing group Ia afferents on neurotrophin-3

At birth, group Ia proprioceptive afferents and muscle spindles, whose formation is Ia afferent-dependent, are absent in mice carrying a deletion in the gene for neurotrophin-3 (NT-3-/-). Whether Ia afferents contact myotubes, resulting in the formation of spindles which subsequently degenerate, or whether Ia afferents and spindles never form was examined in NT-3-/- mice at embryonic days (E) 10.5-18.5 by light and electron microscopy. Three sets of data indicate that Ia neurons do not develop and spindles do not form in NT-3-deficient mice. First, peripheral projections of Ia afferents did not innervate hindlimbs of NT-3-/- mice, as reflected by a deficiency of nerve fibers in limb peripheral nerves and an absence of afferent nerve-muscle contacts and spindles in the soleus muscle at E13.5-E18.5. Second, central projections of Ia afferents did not innervate the spinal cord in the absence of NT-3, as shown by an atrophy of the dorsal spinal roots and absence of afferent projections from limb musculature to spinal motor neurons at E13.5 or E15.5. Lastly, the lumbar dorsal root ganglia (DRGs) at E10.5-E14.5, the stages of development that precede or coincide with the innervation of the spinal cord and hindlimbs by Ia afferents, were 20-64% smaller in mutant than in wild-type mice, presumably because the cell bodies of Ia neurons were absent in embryos lacking NT-3. The failure of Ia neurons to differentiate and/or survive and Ia afferent projections to form in early fetal mice lacking NT-3 suggests that NT-3 may regulate neuronal numbers by mechanisms operating prior to neurite outgrowth to target innervation fields. Thus, developing Ia neurons may be dependent on NT-3 intrinsic to the DRGs before they reach a stage of potential dependence on NT-3 retrogradely derived from skeletal muscles or spinal motor neurons.     

Studies on Processing of an Alnico Scrap

This paper presents the results of research and development work on processing of alnico scrap, a secondary resource of nickel and cobalt, generated during the manufacturing of alnico magnets. The scrap contains 8–10% nickel, 10–12% cobalt, 32–50% of iron, 8–10% aluminium, 2% copper and remaining silica. Various processes such as acid leaching, aqueous chlorine leaching, salt roasting and cupric chloride leaching were studied in detail. Of these cupric chloride leaching was found to be most effective with respect to recovery and purity. It has been possible to obtain pure nickel and cobalt salts by cupric chloride leaching of the scrap, solvent extraction and precipitation of the salts. The overall recovery by the above process was almost 99%.     

Studies on Processing of an Alnico Scrap

Abstract

This paper presents the results of research and development work on processing of alnico scrap, a secondary resource of nickel and cobalt, generated during the manufacturing of alnico magnets. The scrap contains 8-10% nickel, 10-12% cobalt, 32-50% of iron, 8-10% aluminium, 2% copper and remaining silica. Various processes such as acid leaching, aqueous chlorine leaching, salt roasting and cupric chloride leaching were studied in detail. Of these cupric chloride leaching was found to be most effective with respect to recovery and purity. It has been possible to obtain pure nickel and cobalt salts by cupric chloride leaching of the scrap, solvent extraction and precipitation of the salts. The overall recovery by the above process was almost 99%.     

Variant type of sialyl Lewis X antigen expressed on adult T cell leukemia cells is associated with skin involvement

Expression of a variant type of sialyl Le(x) antigen defined by 2F3 monoclonal antibody on leukemia cells was studied in 15 adult T cell leukemia (ATL) patients. The expression of 2F3-defined sialyl Le(x) antigen on CD4+CD45+ cells, which is an ATL cell-rich population, was higher in patients with skin involvement (50.1 +/- 23.1% were positive) than in patients without skin involvement (18.1 +/- 12.5%) (P < 0.01). The other surface markers including classical sialyl Le(x) antigen defined by SNH3 or FH6 and LFA-1, VLA-4, CD4, CD25, ICAM-1, Leu8, and HLA-DR did not show a significant difference regardless of skin involvement. In the skin lesion of four patients that we could examine, infiltrating leukemia cells strongly expressed 2F3-defined sialyl Le(x) antigen. In one patient, we could also examine the expression of classical sialyl Le(x) antigen defined by SNH-3 and CSLEX-1, but this was almost negligible. Both skin and lymph node biopsy specimens were examined in two patients. Leukemia cells in the skin strongly expressed 2F3-defined sialyl Le(x) antigen, while its expression was almost negligible on the leukemia cells in the lymph node. These findings suggest that the expression of 2F3-defined sialyl Le(x) antigen on ATL cells is associated with skin involvement of ATL.     

吹N2辅助扒除铁水脱硫渣工艺的水模型研究

采用铁水罐喷镁脱硫综合效果很好,但因喷吹后脱硫渣难以清理干净,进入转炉后,会导致回硫严重和给生产低硫钢带来困难.通过对铁水罐吹气除渣工艺进行水力学模型实验研究,确定了合理的铁水罐吹气除渣工艺参数,生产实践显示该工艺可获得良好的除渣效果.     

Studies on supratentorial subdural bleeding using a porcine model

A porcine model for an acute lethal arterial subdural bleeding in man is presented. Blood from the abdominal aorta was led via an electronic drop recorder into a collapsed intracranial subdural rubber balloon. Systemic arterial pressure (SAP), two intracranial pressures and 6 other vital parameters were monitored continuously in spontaneously breathing (n = 4) and mechanically ventilated (n = 4) pigs. In both animal groups bleeding caused an immediate rise in intracranial pressures (ICP) with transtentorial pressure gradients developing. As a result the cerebral perfusion pressures (CPP) decreased progressively, leading to an isoelectric EEG. In spontaneously breathing animals, the pressure changes resulted in apnoea within 2-4 minutes, irregularities in heart rhythm and in a marked rise in SAP (the Cushing reaction). A final collapse of all pressures occurred after 222 +/- 68 sec at a mean bleeding volume of 10.3 +/- 1.9 ml. In contrast, in mechanically ventilated animals, the course of bleeding was less dramatic. No change in cardiac rhythm or rise in SAP appeared despite a larger mean bleeding volume (12.0 +/- 1.6 ml). Instead, SAP slowly fell, reaching a level of approximately 40 mm Hg within 1 hour, while CPP concomitantly decreased from 120 mm Hg to 15 mm Hg. The findings in this and in a parallel study are explained in terms of the intracranial volume tolerance concept (Zwetnow et al. 1986). The beneficial effect of assisted ventilation on the course of subdural bleeding is multifactorial, involving both metabolic and mechanical mechanisms.