贵州沿河土地坳下奥陶统牙形石

本文报道了采自贵州沿河土地坳下奥陶统的牙形石,计有２５属３９种,根据牙形石组合特片分析,认为其与黔北其它地区下奥陶统牙形石组合面貌基本一致,属北大西洋牙形石动物地理区。     

鱼腥藻HB1017株化能异养生长的研究

以葡萄糖和蔗糖为碳源,检测了六株（种）鱼腥藻的化能异养生产能力。其中鱼腥藻ＨＢ１０１７株化能异养生长较快,鱼腥藻ＨＢ０株化能异养生长缓慢,其余四种鱼腥藻不能进行化能异养生长。鱼腥藻ＨＢ１０１７株能利用果糖、葡萄糖、蔗糖为底物进行化能异养生长,但生长速率依次递减,差别显著。８磅湿热灭菌的果糖和蔗糖,与过滤灭菌的相比,只能维持低得多的化能异养生长速率。然而,８磅湿热灭菌的葡萄糖能维持比过滤法灭菌的高得     

生态环境对白芷产量质量的影响

生态环境对白芷产量质量的影响陈兴福,丁德蓉,刘岁荣,卢进,黄文秀（四川省中医药研究院药物种植研究所,南川６４８４０８）ＥｆｆｅｃｔｏｆＥｃｏ－ＥｎｖｉｒｏｎｍｅｎｔｏｎＤａｈｕｒｉａｎＡｎｇｅｌｉｃａＹｉｅｌｄａｎｄＩｔｓＱｕａｌｉｔｙ￥ＣｈｅｎＸｉ...     

Glycerol kinase as a substitute for dihydroxyacetone kinase in a mutant of Klebsiella pneumoniae.

With dihydroxyacetone as the sole source of carbon and energy, constitutively synthesized glycerol kinase of the glp system supported aerobic growth of Klebsiella pneumoniae mutants lacking the inducible dihydroxyacetone kinase of the dha system. Glycerol kinase had an apparent Km of 0.01 mM for its physiological substrate and 1 mM for its surrogate substrate. However, the growth rate on dihydroxyacetone of cells relying on glycerol kinase increased with the concentration of the carbon and energy source up to 50 mM, suggesting that permeation is rate limiting.     

Suppression of the immune response to immunotoxins with anti-CD4 monoclonal antibodies.

Treatment of normal mice with a mAb to CD4 (GK1.5) was explored as a means of inhibiting the antibody response to an immunotoxin. Three days of pretreatment with 200 micrograms of GK1.5 completely abrogated the primary antibody response to a 3-micrograms dose of a mutant diphtheria toxin conjugated to an anti-transferrin receptor antibody. The same dose and schedule of anti-CD4 antibody significantly reduced and delayed, but did not prevent, the anamnestic antitoxin response in animals that had been previously primed to the immunotoxin. Three daily injections of anti-CD4 antibodies followed by weekly doses of immunotoxin resulted in a 3-wk delay in the development of antitoxin antibodies, and the kinetics of the antitoxin response correlated with the kinetics of recovery of CD4+ T cells in the spleen and lymph nodes. The antitoxin response to repeated doses of immunotoxin was completely abrogated when anti-CD4 antibodies were given every 2 wk throughout the course of immunotoxin treatment. Thus, transient depletion of Th cells during treatment can block the immune response to an immunotoxin. There was no evidence of tolerance induction with this regimen.     

转移及非转移肿瘤移植后615小鼠血液流变学变化的研究

血道高转移瘤株FC、淋巴合并血道高转移瘤株U14、淋巴道高转移瘤株H22、非转移瘤株P615分别接种于336只纯系近交615小鼠.不同时间取血并处死动物,进行组织学及血液流变学检查.将转移瘤发展过程分为潜伏期、侵袭期、转移早、中、晚期,非转移瘤发展过程分为潜优期、增殖期、囊腔形成期及中心坏死期.本实验结果显示,不同转移能力及途径肿瘤发展的不同时期血液流变学变化规律不同,因而表明肿瘤侵袭、转移与血液流变学变化之间存在互为因果的紧密关系.其临床诊断及治疗意义被讨论.     

Incomplete fatty acid oxidation. The production and epimerization of 3-hydroxy fatty acids.

3-Hydroxydicarboxylic acids are major urinary metabolites derived from fatty acid metabolism. These compounds are produced from the omega-oxidation of 3-hydroxy fatty acids. The production of the precursor 3-hydroxy fatty acids from incomplete beta-oxidation of fatty acids in rat liver mitochondria was investigated. Independent of the chain length or the concentration of fatty acid substrates, the accumulation of 3-hydroxyacyl intermediates was relatively constant at the concentration of 3-5 nmol/mg of mitochondrial protein. The extent of the incomplete oxidation was the same in Percoll gradient-purified mitochondria. Rotenone treatment increased the production of 3-hydroxy fatty acids. 3-Hydroxy fatty acids did not exist as pure L-enantiomer as expected from beta-oxidation. Instead, these metabolites were epimerized to a near racemic mixture of D- and L-isomers with a slightly dominant D-isomer (58 +/- 3%). By using deuterium-isotope labeling, the mechanism of epimerizartion was shown to be a rapid dehydration-rehydration through trans-2-enoyl-CoA. In addition, cis-3 and trans-3 fatty acids were produced; these metabolites were derived from the isomerization of trans-2-enoyl-CoA. Epimerase and isomerase were thought to be enzymes involved in the oxidation of unsaturated fatty acids. Current data have shown that the metabolism of these acids is actually through NADPH-dependent reduction pathways. The activities of epimerase and isomerase detected in rat liver mitochondria possibly function mainly in the metabolism of saturated fatty acids in a reverse role to the conventional concept.     

Leukemia inhibitory factor/differentiation-stimulating factor (LIF/D-factor): regulation of its production and possible roles in bone metabolism.

Leukemia inhibitory factor/differentiation-stimulating factor (LIF/D-factor), expression of its mRNA, and possible roles in bone metabolism were studied in murine primary and clonal osteoblast-like cells. Local bone-resorbing factors such as IL-1, TNF alpha, and LPS strongly induced expression of LIF/D-factor mRNA in both clonal MC3T3-E1 cells and primary osteoblast-like cells. Neither parathyroid hormone nor 1 alpha,25-dihydroxyvitamin D3 stimulated expression of LIF/D-factor mRNA. LIF/D-factor per se did not stimulate expression of its own mRNA. Appreciable amounts of LIF/D-factor were detected in synovial fluids from rheumatoid arthritis (RA) patients but not in those with osteoarthritis (OA). Simultaneous treatment with LIF/D-factor, IL-1, and IL-6 at the concentrations found in synovial fluids from RA patients greatly enhanced bone resorption, though these cytokines did not stimulate bone resorption when separately applied. This suggests that LIF/D-factor produced by osteoblasts is in concert with other bone-resorbing cytokines such as IL-1 and IL-6 involved in the bone resorption seen in the joints of RA patients. LIF/D-factor specifically bound to MC3T3-E1 cells with an apparent dissociation constant of 161 pM and 1,100 binding sites/cell. LIF/D-factor dose-dependently suppressed incorporation of [3H]thymidine into MC3T3-E1 cells. In addition, it potentiated the alkaline phosphatase activity induced by retinoic acid, though LIF/D-factor alone had no effect on enzyme activity. These results suggest that LIF/D-factor is involved in not only osteoclastic bone resorption but also osteoblast differentiation in conjugation with other osteotropic factors.