THE ROLE OF STRESS HORMONES IN THE CONTROL OF GRANULOCYTE PRODUCTION

It has previously been indicated that the inhibitory power of the granulocytic chalone is not influenced by adrenalin. It is now shown that this is true both in absence and in presence of exogenous hydrocortisone. It is also shown that hydrocortisone itself does not cause significant inhibition of DNA synthesis in rat bone marrow cells in vitro, but that it does act to augment the inhibitory effect which the granulocytic chalone induces. It is suggested that the primary action of hydrocortisone may be on the cell membrane which changes the cell wall permeability to chalone, perhaps by reducing its rate of loss from the cells.     

THE INTRACELLULAR DISTRIBUTION OF SOME METALLIC ELEMENTS IN LEAVES

Stocking , C. Ralph , and Alpaslan Ongun . (U. California, Davis.) The intracellular distribution of some metallic elements in leaves. Amer. Jour. Bot. 49(3): 284–289. Illus. 1962.—A comparison of the potassium, sodium, calcium, magnesium, and nitrogen levels of chloroplasts isolated in an aqueous sucrose medium and by the nonaqueous method reveals that large amounts of these elements are lost from the plastids during their isolation in sucrose solution. Nonaqueously isolated chloroplasts of bean and tobacco leaves contained over 40% of the total leaf potassium, magnesium, and calcium. High levels of nitrogen up to 70% of the total leaf nitrogen were found associated with nonaqueously isolated chloroplasts. As much as 40–50% of this nitrogen is lost when chloroplasts are isolated in a sucrose solution. Electron photomicrographs of nonaqueously isolated chloroplasts reveal only a partial disruption of the internal structure and a loss of the plastid membrane during isolation.     

REGULATION OF BONE MARROW CELL GROWTH IN DIFFUSION CHAMBERS: THE EFFECT OF GRANULOCYTE EXTRACTS

Hypotonic lysis of mature human blood granulocytes yielded an extract which reduced granulopoiesis and enhanced macrophage formation of mouse bone marrow cells cultured for 7 days in diffusion chambers (DC). The low molecular weight fraction (MW < 15,000–25,000 Daltons) obtained by Amicon filtration of the extract, reduced granulopoiesis without affecting macrophage formation. The high molecular weight fraction (MW > 15,000–25,000 Daltons) reduced the number of granulocytes and increased the number macrophages. Erythrocyte extract increased the macrophage formation in DC but did not alter the number of granulocytes. The spleen colony assay showed that the granulocyte extract increased the number of CFU-S in DC. It is suggested that the granulocyte extract contain an inhibitor of stem cell differentiation to myeloid cells thereby reducing the number of proliferative granulocytes in DC 7 days later. The inhibitor of differentiation may lead to an increased self renewal of the stem cell in the DC system.     

GRANULOCYTE DYNAMICS AND THE QUESTION OF INEFFECTIVE GRANULOPOIESIS

A simple analysis was developed to compare granulocyte production in marrow with granulocyte turnover in peripheral blood of the dog. the analysis is anchored to the relative number of granulopoietic and erythropoietic cells that are flashlabeled with tritiated thymidine. This provides a convenient measure of relative production rates, since there is little, if any, difference in the duration of the respective DNA synthesis periods. the latter was confirmed in the present work by comparison of myeloid and erythroid cells in respect to (1) labeled mitosis curves and (2) changes in labeling intensity with constant infusion of tritiated thymidine. the ratio of flash-labeled granulocyte to erythrocyte progenitors was unity (1.02 ± 0.05) in the eight dogs studied, which means that gross production rates were essentially the same. Since net production as revealed by peripheral blood turnover is greater for erythrocytes than for granulocytes, it follows that there must be some ineffective granulopoiesis. This may correspond to over half of the total production. It is suggested that this phenomenon, which apparently occurs in man as well as in dog, could represent an important feature of granulocyte regulation.     

PROLIFERATION OF ERYTHROID AND GRANULOCYTE PROGENITORS IN THE SPLEEN AS A FUNCTION OF STEM CELL DOSE

A study of the kinetics of cellular proliferation, in the morphologically unrecognizable haemopoietic progenitor cell compartment, as a function of injected CFU-S dose has been carried out in the spleens of lethally X-irradiated mice using ³H-TdR labelling. Amplification in this proliferating cell compartment was observed to decline as CFU-S dose increased. The number of divisions in the differentiated line arising from CFU-S up to the first appearance of recognizable erythroid precursors were calculated to be 9.2, 12.5, 15 and 17 for the 2, 0.35, 0.05 and 0.007 femur equivalent doses respectively. The growth of cell populations arising from CFU-S was biphasic, with a rapid initial phase having a doubling time of about 6.3 hr, and a slow phase of doubling time around 1 day. Analysis of the rapid phase by the FLM method gave a cycle time of 5.6 hr. Recognizable labelled erythroid precursors were detected at the same time as, or just after, the change in slope of the growth curve. Significant numbers of proliferating (labelled) granulocytes only appeared in the spleens of animals receiving the higher marrow doses (2 and 0.35 femur). The erythroid to granulocyte ratio was also a decreasing function of marrow dose.     

放射性肺损伤细胞渗出及SP-A表达的实验研究

目的探讨急性放射性肺损伤不同时间点病理和肺泡灌洗液与肺泡表面活性蛋白A(SP-A)表达的变化。方法健康雄性Wistar大鼠40只随机分为对照组(C组)和照射组(R组)。行6MV-X线全胸野照射,剂量率2Gy/min,单次剂量15Gy,源皮距1m,照射面积4.5cm×4.5cm。于照射后第1,2,4,8周取肺组织作HE、Masson染色,肺泡灌洗液进行细胞计数,蛋白免疫印迹(Westernblot)检测肺组织中SP-A蛋白表达。结果HE和Masson染色提示照射后的第1周始肺泡腔有炎性细胞渗出,继之间质水肿,第4及8周出现肺泡腔变小甚至结构破坏,局部实变,肺间质出现胶原纤维;肺泡灌洗液的细胞总数照射组与对照组相比各时间段都明显增高(P<0.01);照射组各时间点SP-A蛋白表达均明显下降(P<0.001),以第1、8周下降最为明显,第2、4周出现回升。结论SP-A蛋白参与放射性肺损伤的发生、发展过程,为进一步探讨放射性肺损伤的发病机制提供了实验依据。     

有关节肢动物系统发育若干问题的研究进展

近年来对节肢动物系统发育问题的认识有了相当大的变化,尤其是支序分析研究方法的使用,以及来自分子系统学和分子发育生物学的证据,成为继比较形态学之后有力的研究手段,近年来的研究显示线虫,缓步类和有爪类是节肢动物的近缘类群,而非以前绝大多数学者所认为的软体动物的环节动物,对于节肢动物门的单系性及其内部类群间关系的问题,目前倾向于认为（1）节肢动物为单系群;（2）由甲壳类,六足类和多足类联合形成单系群－具颚类;（3）与六足类分子系统学两方面研究的支持;对第3点的争议虽较大,但就论据而言确为优势观点。     

ADVENTURES IN THE STUDY OF BREATHING

Perfect coordination is required between the amount of air breathed to ventilate the air cells of the lungs and the amount of blood pumped through them by the heart.Over-ventilation often accompanies severe emotional disturbances with far-reaching effects on the functions of the brain and other organs. Of particular interest are the effects of altering breathing upon angina pectoris.In conditions with under-ventilation the effects are serious because the carbon dioxide which accumulates acts as a narcotic on the nerve centers which control breathing. If oxygen is given to such patients they may be made much worse and become unconscious. Morphine and other narcotics also make matters worse.Under-ventilation in patients with over-distention of the air cells of the lungs results in a chronic form of carbon dioxide poisoning, so that the lungs may fail in ventilatory function. Recent work by Whittenberger has shown how to combat this situation by mechanical over-ventilation. As the excess of carbonic acid is removed the narcotic effect of the gas is lessened and the nerve center governing breathing resumes more normal operation under which the effect of oxygen is no longer deleterious.     

紫杉类化合物研究进展

自本世纪70年代从欧洲红豆杉树皮中提取分离得到具有抗癌活性的天然产物紫杉醇以来,关于红豆杉属植物的研究已取得了许多进展。本文就1990年以后发表的有关文献。对该属植物的化学成分研究、合成方法、细胞培养技术及构效关系研究进行综述。     

INFLUENCE OF AGE AND ANTIGENIC STIMULATION ON GRANULOCYTE AND MACROPHAGE PROGENITOR CELLS IN THE MOUSE SPLEEN

The frequency and proliferative activity of granulocytic and macrophage progenitor cells were determined in the spleens of C₅₇BL, BALD/c, NZB and CBA mice. These cells were detected by their capacity to form granulocytic and/or macrophage colonies ( in vitro colony-forming cells, CFC) in agar culture. In vitro CFCs were low in frequency in the adult spleen (4–28/10⁵ cells) compared with the bone marrow (180–280/10⁵ cells). However, the neonatal spleen, both in germfree and conventional mice, contained high levels of in vitro CFCs. From the low suiciding index with tritiated thymidine and the small numbers of cluster-forming cells in relation to colony numbers, many in vitro CFCs in the adult C₅₇BL spleen appear to be in a non-cycling state. The level and activity of in vitro CFCs were extremely low in the spleen of adult germfree CBA mice but were greatly increased in conventional mice following the injection of a bacterial antigen.     

CONTROL OF GRANULOCYTE PRODUCTION

In normal conditions the granulocytic cell population is prevented from excessive cell proliferation by a humoral mechanism based on a specific feedback inhibitor, granulocytic chalone. In conditions of acute functional demand a tissue-specific stimulator, granulocytic antichalone, replaces chalone in rat serum. Mature granulocytes contain, and presumably produce, the chalone which is also present in fresh normal serum. Thus, the inhibitor is both humoral and present within the same cell system on which it acts: the action of this chalone is target tissue specific as it only inhibits granulocytic precursor cells in normal rat bone marrow in vitro. Granulocytic chalone and antichalone were partly purified by gel filtration on Sephadex; the elution parameters suggested molecular weights of 4000 and 30,000–35,000, respectively. Granulocytic chalone was not separated from the erythrocytic chalone (present in fresh normal serum and in blood erythrocytes) on Sephadex; however, separation at the cellular level was easily achieved.