Inhibition of immune opsonin-independent phagocytosis by antibody to a pulmonary macrophage cell surface antigen

Unlike other hamster phagocytes, hamster pulmonary macrophages (PM) avidly ingest albumin-coated latex particles in the absence of serum. They also possess a highly specific cell surface antigen. To evaluate the relationship between these two characteristics, PM were incubated with mouse monoclonal antibody directed against the PM antigen. After unbound antibody was removed, the amount of bound antibody and the phagocytic capability of PM were measured by flow cytometry and fluorescence microscopy. Maximum antibody binding produced a 25% inhibition of ingestion. Particle attachment was not affected. This effect was antigen specific, since neither a nonspecific mouse myeloma protein of the same subclass nor a mouse antibody that bound to another hamster surface antigen had any effect on binding or ingestion. If antigen-specific F(ab')2 fragments were introduced both before and during the period of phagocytosis, the inhibition of particle ingestion approached 100%. Particle binding increased at low F(ab')2 concentrations but declined at higher concentrations. Because calcium may play a role in the ingestion process, the effect of antibody on 45Ca uptake was evaluated. It was observed that antigen-specific F(ab')2 fragments stimulated 45Ca uptake, whereas control antibodies did not. These results suggest that the antigen reacting with our anti-hamster PM monoclonal antibody is involved in immune opsonin-independent phagocytosis and that calcium participates in this phagocytic process.     

Comparative morphology of the foliage leaf epidermis, with emphasis on papillae characters, in key taxa of woody bamboos of the Asian tropics (Poaceae: Bambusoideae)

The foliage leaf epidermis of 35 species representing 12 key genera of woody bamboos of the Asian tropics was investigated using light and scanning electron microscopy. The results indicated that papillae forms and distributional patterns around the stomatal apparatus of the abaxial foliage leaf epidermis were usually constant and were of great taxonomic significance at the specific and generic levels. However, papillae characters were not suitable for dividing subtribes within woody bamboos of the Asian tropics. On the basis of papillae characters, Schizostachyum s.s. and Cephalostachyum were confirmed, but their delimitations should be modified. The transfer of Leptocanna chinensis and Schizostachyum sanguineum into Cephalostachyum was supported, and Cephalostachyum virgatum and C .  pergracile were confirmed to be members of Schizostachyum s.s. The subtribe Racemobambosinae did not obtain support and Racemobambos appeared to be better placed in subtribe Bambusinae. Neomicrocalamus was supported as a close relative and better treated as a synonym of Racemobambos . Gigantochloa was closely related to Dendrocalamus .  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 411–423.     

实夜蛾属二近缘种对寄主植物次生物质的反应:次生物质对幼虫生长和食物利用的影响

实夜蛾属(Heliothis)的棉铃虫(H. armigcra)和烟青虫(H. assulta)是近缘种,幼虫期取食多种相同的植物,其中含有不同的次生物质.本项工作是在人工饲料中分别加入0.5%的烟碱、番茄苷、棉子酚、丹宁酸等饲养早期六龄的幼虫,测定它们对生长和食物利用的影响.结果表明这些次生物质对两种幼虫有不同的作用:烟碱对棉铃虫没有明显影响,但对烟青虫的取食却有一定的刺激作用.丹宁酸、棉子酚、番茄苷可抑制两种幼虫的生长,而以番茄苷抑制烟青虫的生长最为显著.番茄苷主要通过抑制取食来影响幼虫的生长,而丹宁酸和棉子酚则具有降低消化率的作用.通过次生物质对这两种幼虫效应的比较可知,棉铃虫有较大的忍耐力.     

江苏泗洪下草湾中中新世脊椎动物群——6.鸟纲

本文记述了近年来在江苏泗洪下草湾组中补采到的6种鸟类,其中包括天岗琵鹭 Platalea tiangangensis sp. nov.和松林庄古石鸡 Palaeoalectoris songlinensis gen. et sp. nov.,前者系琵鹭属迄今最早的记录,后者为雉科鹑族目前已知最早的成员.     

锌和铜在生长抑素对链佐霉素引起的胰岛B细胞损伤的保护中的作用

我们以前的工作指出,生长抑素可以预防链佐霉素对大鼠胰岛B细胞的损伤。本工作测定给药前后大鼠血清和组织中Zn、Cu含量,以进一步观察链佐霉素破坏大鼠胰岛B细胞后生长抑素预防效应的可能机制。结果为:链佐霉素(STZ)(35mg/kg,ip)注射后24h的大鼠,血清Zn浓度下降,Cu浓度升高,Zn/Cu比值倒置;用生长抑素作预防性注射后,血清Zn浓度与正常对照水平相同,Cu浓度虽稍有升高,但Zn/Cu比值正常。保护组的血清Zn与损伤组比较,差异极为显著。两组的Zn/Cu比值同样也具有显著差异。在给药后72h,血清Zn/Cu比值在各组之间仍呈上述关系,但差异减小。在大鼠胰腺,注射链佐霉素后胰腺组织Zn浓度未见改变,但生长抑素作预防性注射可使组织锌含量增加。上述结果提示,在生长抑素对胰岛B细胞的保护机制中可能有Zn和Cu的参与。预防性注射生长抑素所引起的高Zn状态可能有利于机体细胞含Zn酶类的活性,增强已损伤细胞的修复。     

Stroke and coronary heart disease in mild hypertension: risk factors and the value of treatment

Further analyses of the Medical Research Council''s trial of drug treatment of mild hypertension were carried out to provide more detailed information on the benefits associated with treatment in various subgroups. The four main considerations in establishing a rational treatment policy were, firstly, the significant reduction in the stroke rate with active treatment; secondly, the absence of a significant overall treatment effect on myocardial infarction; thirdly, the knowledge that of 100 untreated men in the highest risk group (those aged 55-64 with high systolic pressure at entry who smoked), five would be expected to suffer a stroke and 10 a coronary event within five years; and, fourthly, the cost, in clinical and financial terms, of prolonged treatment. In the high risk group of 100 men treatment with bendrofluazide would result in the prevention of three or four of the five strokes but would have little effect on the expected numbers of myocardial infarctions. Treatment with propranolol in non-smoking men in the highest age and blood pressure categories would lead to a reduction in the number having strokes from three to one or two and might possibly reduce the number experiencing myocardial infarction from seven to four. Smokers treated with propranolol would not be expected to benefit. In women avoiding smoking was particularly important. The considerations for preventing stroke were similar to those in men, but no clear guideline was possible on the effect of lowering blood pressure for preventing myocardial infarction in women.Drug treatment reduces the attack rate of certain events in mild hypertension but should not be prescribed routinely for all patients with the disorder.     

山西忻州中新世鼠兔科化石

本文记述了山西忻州发现的跑兔属—新种.该种以个体较小, P~2 较简单,无前沟, M~2 后叶无后突, P_3 小,无前内沟与前外沟等特征与属型种 B. forsythmajori 相区别,命名为杨胡跑兔 B. yanghuensis sp. nov..新种在进化水平上较属型种稍原始,但两者显示出较近的系统关系.根据 B. yanghuensis sp. nov. 的进化水平,推断其地质时代可能为中中新世早期,约相当于欧洲 Orleanian 期.