Bowel migration in the normal fetus: US detection

Ten fetuses underwent ultrasound scanning at 7-10 weeks gestational (postmenstrual) age. In all cases, an echogenic mass measuring 0.5-1.0 cm was demonstrated within the base of the umbilical cord at its insertion into the fetal abdomen. No area with echogenicity characteristic of the small bowel was identified within the lower part of the fetal abdomen. All fetuses were reexamined 4-12 weeks later, at which time the mass in the umbilical cord was no longer seen, and normal fetal bowel was visualized in the lower abdominal cavity of the fetus. This sequence of findings appears to represent the sonographic demonstration of normal fetal bowel migration early in gestation and should not be confused with defects of the abdominal wall such as omphalocele or gastroschisis.     

Fibronectin in artery subendothelium is important for platelet adhesion

The role of subendothelial fibronectin in platelet interaction with subendothelium was studied. Human umbilical artery subendothelium was exposed to flowing blood containing 111In-labeled platelets in an annular perfusion chamber. Platelet adhesion was determined from the 111In radioactivity on the vessel wall. When perfusions were performed for five minutes at a wall shear rate of 1,800 s-1, platelet adhesion was the same whether normal plasma or fibronectin-free plasma was used. Preincubation of subendothelium with rabbit anti-human fibronectin serum, however, resulted in a marked inhibition of platelet adhesion. Preincubation with normal rabbit serum had no effect. Platelet adhesion was also diminished when the vessel wall was preincubated with anti- fibronectin IgG fraction or F(ab')2 fragment. After the latter preincubations, frozen sections of 4 micron were incubated with fluorescein isothiocyanate-conjugated goat anti-rabbit IgG, F(ab')2 fragment specific. Fluorescence was seen throughout the subendothelium both before and after perfusion. No fluorescence was seen when subendothelium was preincubated with normal rabbit IgG or F(ab')2 or with anti-fibronectin IgG that had been absorbed with purified fibronectin. After absorption of anti-fibronectin IgG with purified fibronectin, the inhibiting effect on platelet adhesion was also no longer present. Preincubation of the vessel wall with anti-fibronectin IgG reduced platelet adhesion significantly at a wall shear rate of 800 s-1. This effect was even greater at 1,800 s-1. At low shear rate (400 s-1), there was no inhibition.     

芳基卤的Suzuki交叉偶联反应

空间位阻、对空气稳定的单氧氯化膦与Pd2（dba）3反应原位形成复合物,可促进芳基硼酸与芳基卤的Suzuki交叉偶联反应。芳基卤上有吸电子基时反应性更高,羰基及氰基无需保护。13例收率66％～93％。     

Expression of adhesion molecules on CD34+ cells: CD34+ L-selectin+ cells predict a rapid platelet recovery after peripheral blood stem cell transplantation

Adhesion molecules play a role in the migration of hematopoietic progenitor cells and regulation of hematopoiesis. To study whether the mobilization process is associated with changes in expression of adhesion molecules, the expression of CD31, CD44, L-selectin, sialyl Lewisx, beta 1 integrins very late antigen 4 (VLA-4) and VLA-5, and beta 2 integrins lymphocyte function-associated 1 and Mac-1 was measured on either bone marrow (BM) CD34+ cells or on peripheral blood CD34+ cells mobilized with a combination of granulocyte colony- stimulating factor (G-CSF) and chemotherapy. beta 1 integrin VLA-4 was expressed at a significantly lower concentration on peripheral blood progenitor cells than on BM CD34+ cells, procured either during steady- state hematopoiesis or at the time of leukocytapheresis. No differences in the level of expression were found for the other adhesion molecules. To obtain insight in which adhesion molecules may participate in the homing of peripheral blood stem cells (PBSCs), the number of CD34+ cells expressing these adhesion molecules present in leukocytapheresis material was quantified and correlated with hematopoietic recovery after intensive chemotherapy in 27 patients. The number of CD34+ cells in the subset defined by L-selectin expression correlated significantly better with time to platelet recovery after PBSC transplantation (r = - .86) than did the total number of CD34+ cells (r = -.55). Statistical analysis of the relationship between the number of CD34+L-selectin+ cells and platelet recovery resulted in a threshold value for rapid platelet recovery of 2.1 x 10(6) CD34+ L-selectin+ cells/kg. A rapid platelet recovery (< or = 14 days) was observed in 13 of 15 patients who received > or = 2.1 x 10(6) CD34+ L-selectin+ cells/kg (median, 11 days; range, 7 to 16 days), whereas 10 of 12 patients who received less double positive cells had a relative slow platelet recovery (median, 20 days; range, 13 to 37 days). The L-selectin+ subpopulation of CD34+ cells also correlated better with time to neutrophil recovery (r = - .70) than did the total number of reinfused CD34+ cells (r = -.51). However, this latter difference failed to reach statistical significance. This study suggests that L-selectin is involved in the homing of CD34+ cells after PBSC transplantation.     

Percutaneous transluminal renal angioplasty: initial and long-term results

Renal artery stenosis in 201 patients with hypertension was treated with percutaneous transluminal renal angioplasty (PTRA). A total of 213 procedures were performed as treatment of 262 separate stenosis. The stenosis was caused by atherosclerosis in 134 cases and by fibromuscular dysplasia (FMD) in 52 cases; the cause was indeterminate in 27 cases. Of the 213 procedures, 172 were successful or resulted in improvement, for a technical success rate of 80.8%. The initial clinical results could be evaluated in 210 cases; cure or improvement was achieved in 80%. There were 23 cases in which neither technical nor clinical success was achieved. Data on the remaining 187 cases were the basis of this long-term follow-up study. The cumulative patency rate at 5 years was 80% in the atherosclerosis group, 89% in the FMD group, and 74% in the indeterminate group. The mortality was less than 1%. Because spasm occurred in 33 cases, causing an infarction in ten instances, antispasmodic medication seems warranted. These long-term results indicate that PTRA is the treatment of choice in patients with renovascular hypertension.