The effects of prostaglandin E1 on the pepsin activities in gastric mucosa and juice.

Prostaglandin E1 elevated pepsin activity in gastric mucosa but lowered pepsin activity in the gastric juice of rats treated by pylorus ligation and intragastric administration of hydrochloric acid. In these animals zymogen granules with low electron density were numerous in the gastric chief cells following prostaglandin E1 treatment. The prostaglandin E1-induced increase in mucosal pepsin activity was slightly inhibited by actinomycin D and there was no apparent increase in 3H-thymidine incorporation into gastric mucosa following treatment with prostaglandin E1. It is suggested that prostaglandin E1 causes an elevation of pepsin activity in the gastric mucosa by stimulating pepsin synthesis and perhaps also by facilitating pepsin release from zymogen granules. However, it also appears to inhibit pepsin release from the mucosa into the gastric cavity judging by the decrease of pepsin activity in gastric juice. The reduced pepsin activity in gastric juice may account, in part, for the reported anti-ulcerative action of prostaglandin.     

An N-linked high-mannose type oligosaccharide, expressed at the major outer membrane protein of Chlamydia trachomatis, mediates attachment and infectivity of the microorganism to HeLa cells.

The structure of the carbohydrate of the 40-kD major outer membrane component of Chlamydia trachomatis and its role in defining infectivity of the organism were investigated. The oligosaccharides were released from the glycoprotein by N-glycanase digestion, coupled to a 2-aminopyridyl residue, and subjected to two-dimensional sugar mapping technique. The major fractions consisted of "high-mannose type" oligosaccharides containing 8-9 mannose residues. Bi- and tri-antennary "complex type" oligosaccharides having terminal galactose were detected as minor components. These oligosaccharides were N-linked and contained no sialic acid. This structural profile is consistent with our previous characterization based on lectin-binding and glycosidase digestion. Functional specificity of identified chlamydial oligosaccharides was analyzed using glycopeptides fractionated from ovalbumin and structurally defined oligosaccharides from other sources. The glycopeptide fraction having high-mannose type oligosaccharide, as compared to those having complex or hybrid-type, showed a stronger inhibitory effect on attachment and infectivity of chlamydial organisms to HeLa cells. Among high-mannose type oligosaccharides, the strongest inhibition was observed with mannose 8 as compared with mannose 6, 7, or 9. These results indicate that a specific high-mannose type oligosaccharide linked to the major outer membrane protein of C. trachomatis mediates attachment and infectivity of the organism to HeLa cells.     

西洛他唑对磷脂多糖诱导的粘附及粘附分子释放的影响

目的　研究磷酸二酯酶 3型抑制剂西洛他唑对磷脂多糖 (LPS)诱导的粘附及血管内皮细胞 (ECs)释放可溶性细胞粘附分子 (sCAMs)的影响。方法　体外培养第 4～ 6代人脐静脉血管内皮细胞 (HUVECs) ,以LPS(5mg·L- 1)刺激 ,并与西洛他唑 (1～ 10 μmol·L- 1)共培养 2 4h ,观察西洛他唑对由LPS诱导的HUVECs与中性粒细胞之间的粘附的影响 ;另取培养上清 ,以ELISA法测定HUVECs释放可溶性血管细胞粘附分子 1(sVCAM 1)、细胞间粘附分子 1(sICAM 1)以及E 选择素 (sE selectin ,sELAM 1)。结果　西洛他唑抑制由LPS诱导的HUVECs与中性粒细胞之间的粘附以及HUVECs释放sVCAM 1,而对sICAM 1和sE 选择素无影响。并且 ,该药对于sVCAM 1的抑制作用被蛋白激酶A(PKA)抑制剂H 89所阻断。结论　西洛他唑对由细胞因子LPS诱导的粘附反应以及ECs释放sVCAM 1有抑制作用 ,后者可能与PKA依赖性通路相关     

Levels of Rheumatoid Factor Isotypes, Metalloproteinase-3 and Tissue Inhibitor of Metalloproteinase-1 in Synovial Fluid from Various Arthritides

When synovial effusion is the only symptom, it is often difficult to make an exact diagnosis of the arthritic disease. To distinguish various types of arthritis with synovial effusion, we measured the levels of matrix metalloproteinase-3 (MMP-3, Stromelysin), tissue inhibitor of metalloproteinase-1 (TIMP-1) and rheumatoid factor (RF) isotypes in synovial fluid (SF) from patients with rheumatoid arthritis (RA), osteoarthritis (OA), pyogenic arthritis (PA), pseudogouty arthritis (PG), gouty arthritis (GA) and traumatic arthritis (TA). SF was aspirated from the knee joint or the ankle joint. Levels of IgG-, IgM- and IgA-RF isotypes were measured by ELISA. Levels of MMP-3 and TIMP-1 in SF were simultaneously determined by a one-step EIA system. Levels of IgG-RF, IgM-RF and MMP-3 in SF from RA patients were significantly higher than those in OA, PA, PG, GA and TA. However, IgA-RF in SF from RA patients, when compared with PA and GA, did not show a significantly increased level. In addition, TIMP-1 in SF from RA, when compared with PA and TA, also has not shown a significantly increased level. Therefore, in addition to analysing clinical data, measurements of IgG-RF, IgM-RF and MMP-3 in SF may contribute in distinguishing RA from other arthritic diseases. Received: 18 January 1999 / Accepted: 15 June 1999