Erythropoiesis in steel mutant mice: effects of erythropoietin in vitro

Adult SI/SI-d mutant mice have severe macrocytic, normochromic anemia. Moreover these animals are unresponsive to the stimulation of erythropoietin in vivo. By means of a bone marrow cell suspension culture system, the present investigation shows that in adult SI/SI-d marrow, there are cells capable of responding in vitro to erythropoietin in a normal fashion. Moreover, the erythropoietin present in SI/SI-d serum is biologically active in vitro without any prior biochemical modification. These observations support the suggestion that there is a defect in differentiation in the erythroid cell lines of SI/SI-d mice in vivo due to an abnormal hemopoietic microenvironment.     

苦参碱对脂多糖／痤疮丙酸杆菌诱导的小鼠肝炎及产生肿瘤坏死因子的影响

用小鼠致死性肝炎模型和ＴＮＦ体外诱生的方法，研究苦参碱（Ｍａｔ）对脂多糖（ｌｉｐｏｐｏｌｙｓａｃｃｈａｒｉｄｅｓ，ＬＰＳ）诱导的经痤疮丙酸杆菌（ｐｒｏｐｉｏｎｉｂａｃｔｅｒｉｔｔｍａｃｎｅｓ，ＰＡ）预刺激的小鼠产生肿瘤坏死因子（ＴＮＦ）以及致死性肝炎的影响。结果表明：Ｍａｔ（１０，５０ｍｇ·ｋｇ￣（－１），ｉｐ，ｂｉｄ×３ｄ）可降低血清ＴＮＦ和ＡＬＴ水平及小鼠对ＬＰＳ致死毒性的敏感性，并可在体外抑制ＬＰＳ诱导的经ＰＡ预刺激的小鼠腹腔巨噬细胞释放ＴＮＦ。提示Ｍａｔ的保肝作用与其抑制ＴＮＦ释放有关。     

Evidence for biological activity of two N-terminal fragments of neurotensin, neurotensin1–8 and neurotensin1–10

Intracisternal (i.c.) administration of the endogenous tridecapeptide neurotensin (NT) has been previously shown to significantly reduce the incidence of cold-restraint stress (CRS)-induced gastric ulcers in rats. In this study we confirm the cytoprotective activity of central NT, and document structure-activity relationships for this effect of NT. When tested in a dose equimolar to 17.9 nmol of NT the NT analogs [Gln4]NT, D-Trp11-NT, and D-Arg8-NT were cytoprotective, whereas D-Arg9-NT was not. Gonadotropin-releasing hormone (Gn-RH) and melanocyte-stimulating hormone-release inhibiting factor (MIF-1), two oligopeptides structurally unrelated to NT exhibited no cytoprotective efficacy in this paradigm. The C-terminal fragments of NT, xenopsin and NT8-13, and the N-terminal fragment NT1-6 were completely ineffective. Finally, NT1-8 and NT1-10, two N-terminal fragments of NT produced significant cytoprotective activity at this dose level. The cytoprotection afforded by NT1-8 and NT1-10, like that of NT, was dose-dependent with ED50's similar to that of NT (NT = 16.2 nmol, NT1-8 = 17.8 nmol and NT1-10 = 19.9 nmol). In conclusion, we demonstrate that smaller molecular weight forms of NT thought to be degradation products of NT can effectively exert biological effects.     

Ileal meconium plugs

Eleven cases of neonatal intestinal obstruction associated with a white ileal meconium plug are described; 6 of these presented with complications--such as, giant meconium pseudocyst, perforation, volvulus, or atresia. Most of these complications are presumed to have arisen during the intrauterine period. Only one patient could be relieved of the ileal meconium plug by enemas. The condition of ileal meconium plug is not as benign as a meconium plug in the rectum or distal colon. A plea is made to restrict the name meconium plug syndrome to cases in which the meconium plug is white and chalky and the consequent intestinal obstruction can be relieved by enemas, without evidence of intestinal dysfunction in later life.     

Metabolic competence and susceptibility of intestinal epithelium to genotoxic injury during regeneration

The carcinogenic potency of many mutagens is increased in conditions of tissue regeneration. This involves fundamental changes of cellular division and differentiation, in intestinal epithelium. However, effects on epithelial capacity for carcinogen metabolism and susceptibility to genotoxic injury are unknown. Using a novel rat model, this study assessed expression of cytochrome P450 mono- oxygenases (Cyps), glutathione S-transferases (GSTs) and uridine diphosphoglucuronosyl transferase (UGT) in intestinal epithelium during sequential stages of regeneration. Enzyme induction and DNA adduct formation were also assessed after benzo[a]pyrene (BaP) exposure. Control assays were carried out in normal intestinal epithelium. Fewer phase I and II xenobiotic metabolizing enzymes were expressed in regenerating intestinal epithelium than in normal control intestinal epithelium (GSTA3, UGT in regeneration vs Cyp2B, GSTA1/2, GSTA4, GSTP1, UGT in control). Benzo[a]pyrene induced GSTA3 and UGT in regeneration vs Cyp1A, Cyp2B, GSTA1/2, GSTA3, GSTA4, GSTP1 and UGT in control normal intestinal epithelium. Benzo[a]pyrene induced low levels of GSTA3 in early regenerating intestinal epithelium but induction increased by >2- fold at late stage regeneration. Higher levels of benzo[a]pyrene 7,8- diol-9,10-epoxide (BPDE) DNA adducts were formed at early stages of regeneration, than at later stages. Intestinal epithelium displayed reduced metabolic competence and differential susceptibility to genotoxic injury from BaP, during regeneration.      

Focal nodular hyperplasia and hepatic adenoma: comparison of angiography, CT, US, and scintigraphy

The authors reviewed 23 cases of focal nodular hyperplasia and 13 cases of hepatic adenoma, all of which were confirmed pathologically. All solitary masses that exhibited normal or increased uptake of technetium 99m-sulfur colloid were shown to be hyperplasia; while previous criteria such as a central blood supply on angiograms or a central scar on computed tomography (CT) or ultrasound (US) scans were helpful, they were relatively infrequent. A mass that was slightly hypodense and homogeneous on a CT or US scan and highly vascular with an intense capillary stain on an angiogram was almost always hyperplasia. Acute hemorrhage within a focal hepatic tumor was common in adenoma but did not occur in hyperplasia.     

A clinical and immunologic study of blood transfusion and postoperative bacterial infection in spinal surgery

Allogeneic blood transfusion has been implicated as an independent risk factor for postoperative bacterial infection in clinical and animal studies. The association among transfusion, quantitative immunologic factors, and infection was examined in 102 patients undergoing 109 spinal fusion procedures. In 60 procedures, patients received autologous blood only; in 24 procedures, they received at least 1 unit of allogeneic blood, and in 25 procedures, they received no transfusions. Twenty-two patients developed bacterial infections, in 8 cases while in hospital and in 14 cases after discharge. Univariate analysis revealed that patients who received any allogeneic blood and those who received no allogeneic blood differed significantly in the rate of hospital-acquired infection (20.8 vs. 3.5%), length of stay (12.3 vs. 9.7 days), days of fever greater than or equal to 38 degrees C (4.0 vs. 2.9), days on antibiotics (3.9 vs. 2.5), duration of surgery (309 vs. 231 min), blood loss (1343 vs. 887 mL), surgeon, and postoperative drop in natural killer (NK) cells (-174 vs. -42/microL). Multivariate logistic and linear regressions revealed that the number of allogeneic units transfused was the only significant predictor of in-hospital infection (p = 0.016) or days on antibiotics and length of stay. None of the clinical, surgical, or transfusion variables was significantly associated with posthospital infection, although a significantly greater drop in NK cells had occurred in patients who developed infection (p = 0.0035). These data strongly implicate allogeneic transfusion as a risk factor for in-hospital postoperative bacterial infection.(ABSTRACT TRUNCATED AT 250 WORDS)