Sclerotomal origin of smooth muscle cells in the wall of the avian dorsal aorta.

The dorsal aorta is the earliest formed intraembryonic blood vessel. It is composed of an inner lining consisting of endothelial cells and an outer wall consisting of smooth muscle cells (SMCs) and fibrocytes. Aortic SMCs have been suggested to arise from several developmental lineages. Cephalic neural crest provides SMCs of the proximal part of the aorta, and SMCs of the distal part are derived from the paraxial mesoderm. Here, we show by using quail-chick chimerization that in the avian embryo, SMCs in the wall of the dorsal aorta at trunk level arise from the sclerotome. Our findings indicate a two-step process of aortic wall formation. First, non-paraxial mesoderm-derived mural cells accumulate at the floor of the aorta. We refer to these cells as primary SMCs. Second, SMCs from the sclerotome are recruited to the roof and sides of the aorta, eventually replacing the primary SMCs in the aortic floor.     

Gamma/delta T cells and the diagnosis of coeliac disease.

Gamma/delta T cells are increased in the gut epithelium of patients with coeliac disease compared with normal controls. The aim of this study was to determine whether the increase in gamma delta intraepithelial lymphocytes (IEL) is specific for coeliac disease, in which case it could be of diagnostic importance. Biopsies were obtained from children with no intestinal disease, coeliac disease, cow-milk-sensitive enteropathy/post-enteritis syndrome (CMSE PES) and miscellaneous other enteropathies (n = 67). Intraepithelial CD3+ and gamma delta T cells were identified in frozen sections using peroxidase immunohistochemistry. In normal biopsies there were 0-7 gamma delta IEL/100 cells in the epithelium. In untreated coeliac patients this increased to 9-22 gamma delta IEL/100 cells in the epithelium (P = 0.000004). Of 27 patients with morphologic intestinal damage which was not due to coeliac disease, four with CMSE/PES had gamma delta IEL/100 cells in the epithelium in the same range as the patients with coeliac disease. Of these, two had high densities of CD3+ IEL in the epithelium and were indistinguishable from patients with untreated coeliac disease. The other two could be excluded as possible coeliacs because their CD3+ IEL/100 epithelial cells were in the normal range. Thus an increase in gamma delta IEL is not specific for coeliac disease. However, enumeration of both of gamma delta IEL and CD3+ IEL densities will be useful in the exclusion of coeliac disease as a diagnosis in some children.     

Monocytes secrete factors regulating glycosaminoglycan synthesis in mesangial cells in vitro.

The present study was conducted to determine the manner in which monocytes increase mesangial matrices, particularly glycosaminoglycans (GAGs) which interact with various other matrix components such as collagens, laminin, fibronectin and lipoproteins. A supernatant of human peripheral blood monocyte cultures activated by lipopolysaccharide (LPS) contains stimulating factors for glycosaminoglycan synthesis in rat mesangial cells (MCs). The culture supernatant in this study was concentrated and fractionated by gel chromatography and the GAG-stimulatory factor was found to have a molecular weight of 10-17 kD. This factor was shown to be present in fractions different from that of IL-1. Gel and ion-exchange chromatography studies of GAGs synthesized by MCs indicated the elution patterns of GAGs in the presence and absence of the monocyte culture supernatant to be essentially the same. Local infiltration of monocytes into the glomerulus, often seen in various types of glomerular injury, may be an important factor in the accumulation of the mesangial matrix.     

Cytotoxic effects of ingested Staphylococcus aureus on bovine endothelial cells: Role of S. aureus α-hemolysin

Previously we observed that Staphylococcus aureus phagocytized by cultured bovine endothelial cells do not proliferate intracellularly, but are cytotoxic to bovine endothelial cells. To investigate S. aureus virulence factors which may be produced intracellularly and cause lysis of endothelial cells, we tested S. aureus mutants defective in production of one or more potential virulence factors and corresponding parent strains for cytotoxicity to endothelial cell monolayers subsequent to being ingested. Following incubation of endothelial cell monolayers with S. aureus for 3.5 h, cultures were supplemented with lysostaphin to destroy extracellular but not intracellular S. aureus. At subsequent times, viability of endothelial cells was assayed by retention of ³H-adenine and the number of intracellular S. aureus was measured. The cytotoxic activity of S. aureus culture supernatants was also characterized. The results indicate that S. aureus α-hemolysin is cytotoxic to bovine endothelial cells and plays an important role in the damage suffered by bovine endothelial cell monolayers following ingestion of S. aureus. Ingestion of α-hemolysin-producing S. aureus by endothelial cells in vivo might be expected to result in destruction of endothelium followed by development of platelet-fibrin vegetations. This possible sequence of events is compatible with the frequently fulminant course of S. aureus endocarditis.     

Microcarrier cell culture: Vero cells on cytodex® 1

Summary All the necessary steps required for the cultivation of Vero cells on microcarriers are described. These procedures are used routinely in our laboratories for the growth of Vero cells on Cytodex 1. Consistent, high density, final yields of more than 10⁶ cells/ml of culture medium are obtained. The protocols described here can be modified for the growth of a variety of anchorage-dependent cell types. Culture parameters important for the successful exploitation of microcarrier cell culture technology are discussed.     

Social isolation stress augments angiogenesis induced by colon 26-L5 carcinoma cells in mice

We have previously shown that tumor necrosis factor-α (TNF-α), which is an important angiogenesis-related factor, was over-secreted in male BALB/c mice under social isolation stress as compared with the control, and closely associated with a remarkable elevation of tumor invasion and metastasis of colon 26-L5 carcinoma cells. In the present study, we explored the effect of isolation stress on the angiogenesis caused by colon 26-L5 carcinoma cells in vivo and in vitro. Social isolation lead to the enhancement of tumor growth after intrahepatic implantation with a fragment of colon 26-L5 tumor. Angiogenic response (number of vessels oriented towards tumor mass) and tumor growth (size) were significantly increased in the socially isolated mouse relative to that in the group-housed mice. Furthermore, higher protein level of hepatic TNF-α was found in the stressed mice than that in the control. Expression of mRNA for vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) were also elevated in the tumor regions and liver tissues of the stressed mice in comparison with that in group-housed mice. On the other hand, hepatic sinusoidal endothelial (HSE) cells treated with TNF-α exhibited a marked promotion of the migration, invasion, expression of mRNA for matrix metalloproteinase (MMP)-9, and tube-like formation, but no cytotoxicity against the cells in vitro. The above data suggest that the social isolation stress augmented the tumor-induced angiogenesis probably by up-regulating the angiogenesis-related factors, including TNF-α, VEGF and HGF, and consequently mediating the functions of endothelial cells such as migration, invasion, and tube-like formation.     

Mutations in activation-induced cytidine deaminase in patients with hyper IgM syndrome

Recent studies have shown that mutations in a newly described RNA editing enzyme, activation-induced cytidine deaminase (AID), can cause an autosomal recessive form of hyper IgM syndrome. To determine the relative frequency of mutations in AID, we evaluated a group of 27 patients with hyper IgM syndrome who did not have defects in CD40 ligand and 23 patients with common variable immunodeficiency. Three different mutations in AID were identified in 18 patients with hyper IgM syndrome, including 14 French Canadians, 2 Lumbee Indians, and a brother and sister from Okinawa. No mutations were found in the remaining 32 patients. In the group of patients with hyper IgM syndrome, the patients with mutations in AID were older at the age of diagnosis, were more likely to have positive isohemagglutinins, and were less likely to have anemia, neutropenia, or thrombocytopenia. Lymphoid hyperplasia was seen in patients with hyper IgM syndrome and normal AID as well as the patients with hyper IgM syndrome and defects in AID.     

Effects of two antiandrogen treatments on hirsutism and insulin sensitivity in women with polycystic ovary syndrome

Thirty-two women with polycystic ovary syndrome (PCOS) wereallocated to two antiandrogen treatment regimens; 28 women completedthe trial. Twenty women were treated with ethinyloestradioland cyproterone acetate (EO-CA) cyclically for 6 months andeight women were treated with the gonadotrophin releasing hormone(GnRH) analogue, goserelin for 6 months. Effects on hirsutism,insulin sensitivity (estimated by glucose clamp technique),blood lipids and hormones were measured. Women treated withEO-CA showed a reduction in hirsutism (P <0.05), and decreasedserum androgen concentrations (P <0.001) as well as reducedinsulin sensitivity (P <0.05). In women treated with goserelin,serum androgen concentrations also decreased (P <0.001),but there was no significant reduction of hirsutism. This group,however, showed an improved insulin sensitivity (P <0.05)despite an unchanged body mass index. Bone mineral density wasunaltered in both treatment groups. The reduction in androgenconcentrations caused by EO-CA was not paralleled by increasedinsulin sensitivity, most probably due to the effect of ethinyloestradiolper se. In contrast, the reduction in androgen concentrationsby goserelin was accompanied by an improved insulin sensitivity.     

Interferon-alpha and dexamethasone inhibit adhesion of T cells to endothelial cells and synovial cells

We investigated whether interferon-gamma (IFN-gamma), interferon-alpha (IFN-alpha) and glucocorticoids affected the adhesion of T cells to human umbilical endothelial cells or human synovial cells. About 30% of peripheral blood T cells could bind to unstimulated endothelial cells, but only a few T cells could bind to unstimulated synovial cells. When both endothelial cells and synovial cells were cultured with recombinant IFN-gamma (rIFN-gamma), the percentage of T cell binding to both types of cells increased in a dose-dependent manner. rIFN-alpha and dexamethasone blocked the T cell binding to unstimulated endothelial cells. Furthermore, rIFN-alpha and dexamethasone suppressed T cell binding to both endothelial cells and synovial cells stimulated by IFN-gamma, and also inhibited intercellular adhesion molecule-1 (ICAM-1) expression on both endothelial cells and synovial cells stimulated by IFN-gamma. These results suggest that IFN-alpha and glucocorticoids may inhibit T cell binding to endothelial cells or synovial cells by modulating adhesion molecule expression on these cells.     

颈椎间管壁骨质增生的观察及其意义

在甘肃地区出土的成人颈椎骨骼标本390套(2730块)上,观测了钩椎关节、椎间关节、横突孔和椎体后缘的骨质增生,出现率高达22.5%。增生骨唇占据椎间管、横突孔和椎管的情况分轻、中、重三度.