Inhibition of vessel allograft rejection by endothelial removal. Morphologic and ultrastructural changes.

The vascular endothelium plays an important and complex role in vascular allograft rejection. Antigens expressed by the endothelium can act to promote and be the target of rejection reactions, which often lead to thrombosis and ischemic necrosis of the allograft. In this study, segments of femoral artery and femoral vein with or without endothelium were grafted between allogenic or autologous control rats. Immunocompetent Lewis (RT1(1] recipient rats were randomly selected for groups (N = 14 for each) receiving the following: ACI- (RT1a) allografts with intact endothelium, allografts with endothelium removed before operation, autografts with endothelium, and autografts with endothelium removed. Rejection was assessed by graft patency as well as morphologic and ultrastructural changes. At 5 days, the allografts with intact endothelium were totally occluded, whereas allografts without endothelium remained patent, as did autologous control grafts with or without endothelium. Two additional groups (N = 14 each) receiving the de-endothelialized allografts or autografts were examined at 120 days after operation, revealing that grafts in both groups were still patent and had been re-endothelialized. These findings indicate that physical removal of vascular endothelium may depress vessel allograft rejection without immunosuppressive therapy.     

Body size, fatness, and leanness of Mexican American children in Brownsville, Texas: changes between 1972 and 1983.

Changes in the height, weight, body mass index, triceps skinfold, and arm and estimated midarm muscle circumferences in lower socioeconomic Mexican American children, 6 through 17 years of age, from Brownsville, Texas, were documented on the basis of surveys done in 1972 and 1983. With the exception of height in youths ages 14-17, all parameters show gains at most ages, and in particular an increase in fatness. Brownsville Mexican American youth are similar in height, weight, and the body mass index to Mexican American youth in other areas of Texas. These trends confirm the large proportion of relatively short but heavy children among Mexican Americans.     

Spermidine synthase of Escherichia coli: localization of the speE gene.

We have obtained Escherichia coli mutants lacking spermidine synthase (putrescine aminopropyltransferase) and have found that the mutated gene (speE) is located immediately upstream from the gene coding for S-adenosylmethionine decarboxylase (speD); these genes are located at 2.7 minutes on the E. coli chromosome. Both genes are present in a 1795-base-pair fragment of E. coli DNA that was cloned into pBR322. Deletion of 105 bases upstream of speE caused a coordinate loss of both activities, indicating that speE and speD constitute a single operon. speE and speD have also been cloned separately in a high-expression vector; strains carrying these plasmids overproduce the respective enzymes.     

中药延胡索的炮制研究

本文采用容量法及电位测定法分别测定了延胡索生品及醋炒、醋蒸、醋煮、酒炒和盐炒5种延胡索炮制品中的总生物碱含量,另采用薄层扫描法及紫外分光光度法测定上述6种样品中的延胡索乙素含量,并对各种样品进行了小白鼠止痛试验。实验结果表明,延胡索用醋炮制或用酒炮制均能提高其水煎液中总生物碱和延胡索乙素的煎出量,并能增强其止痛作用,其中醋制法较为显著。实验结果与临床上多用醋制延胡索入药的经验相符合。     

罂粟碱对大鼠单胺神经递质的影响

本文报道用高效液相色谱-电化学检测器方法,研究了罂粟碱对大鼠脑内及心脏单胺神经递质代谢的影响。结果表明:罂粟碱能显著增加大鼠纹状体及边缘区多巴胺代谢物二羟苯乙酸(DOPAC)和高香草酸(HVA),升高约50-70%。5-羟色胺代谢物5-羟吲哚醋酸(5HIAA)增加约30%,而对脑及心脏内的单胺递质本身含量未见有明显影响。     

Paracetamol absorption from a feeding jejunostomy.

Disposition of paracetamol oral elixir was determined in two male patients after administration via feeding jejunostomy and compared with four male controls who received the same dose by mouth. Area under the plasma concentration-time curve, elimination half-life, and time to maximum concentration were similar in both groups after 650 mg paracetamol elixir. The absolute amounts and ratio of paracetamol glucuronide to sulphate, the major urinary metabolites after therapeutic paracetamol doses, were similar after jejunal administration as compared to oral administration. Paracetamol is absorbed and biotransformed in a similar manner after either jejunal or oral administration. Therefore, it may be administered effectively via jejunostomy tube in patients who require this route of administration.     

Ultrastructural observations of organelle accumulation in the equine recurrent laryngeal nerve

Summary The left recurrent laryngeal nerves from five horses with sub-clinical neuropathy were examined by light and electron microscopy in a study designed to examine accumulation of axonal organelles at paranodal and internodal locations. Transverse sections of the nerve showed scattered fibres with split myelin sheaths and axonal accumulation of organelles. On longitudinal sections these collections were seen to result from an axonal outpouching in which dense lamellar bodies and mitochondria had accumulated. These paranodal collections, which could be found on both sides of the node, were often associated with infoldings of the terminal loops of myelin and with occasional paranodal demyelination. The fact that many of the organelles in the outpouches were lysosomal in nature was confirmed by their positive staining for cathepsin D activity. Longitudinal sections demonstrated a number of axons which were swollen over a long distance and which contained focal accumulations of similar organelles. In places, however, there was a clear separation between these organelles and the cytoskeletal proteins. In each case these swollen axons were surrounded by Schwann cell nuclei and their processes, forming well-ordered onion bulbs. The possibility that these two types of changes, i.e. the paranodal accumulations and the axonal swellings could result from a disturbance in axonal transport in this distal axonopathy is discussed.     

Effect of heat or chemical treatment on leptospiral antigens.

The use of bacterins is one of the primary methods in the control of leptospirosis in domestic animals, especially cattle, swine, and dogs. Bacterins have been made using chemically treated or heat-inactivated organisms. Many of the initial studies indicated that the bacterins gave complete protection, whereas later reports found that some inactivation methods resulted in bacterins that protect against death but not against kidney infection and renal shedding. This raised the possibility that some of the antigens had been altered. To investigate this possibility, we heat or chemically treated Leptospira interrogans serovar icterohaemorrhagiae CF-1, L. interrogans serovar canicola Moulton, L. interrogans serovar grippotyphosa SC4397, L. interrogans serovar hardjo Hardjoprajitno, and L. interrogans serovar pomona MLS. Temperatures used to determine alterations in antigens were 50, 56, 80, 100, and 121 degrees C. The chemicals used were formaldehyde, phenol, and thimerosal. Analysis was done using Laemmli gels and Western blots. We found that heating at 50 or 56 degrees C had the smallest effect on antigens, whereas heating at 80 or 100 degrees C caused the appearance of high-molecular-weight bands on Western blots. Heating at 121 degrees C caused almost all the bands to disappear, in both the stained gel and the Western blot. Both phenol and Formalin treatment altered proteins, whereas thimerosal treatment appeared to have little effect compared with heating at 50 degrees C.     

Elaboration by mammalian mesenchymal cells infected with Trypanosoma cruzi of a fibroblast-stimulating factor that may contribute to chagasic cardiomyopathy.

Myocardial fibrosis can occur as a complication of chronic infection of the heart with Trypanosoma cruzi (Chagas' disease) and can lead to serious disability. To assess whether there might be a direct relationship between intracellular parasitization and subsequent tissue fibrosis in this disease, we tested serum-free conditioned media from cultures of fibroblasts, vascular smooth-muscle cells, and myocardial cells for fibroblast-stimulating activity. Conditioned media from all infected cultures, but not from uninfected cultures, stimulated fibroblast [3H]thymidine incorporation, DNA and protein synthesis, and cell proliferation. Fibroblast-stimulating activity was also detected in extracts of amastigotes but not of trypomastigotes or epimastigotes. We conclude that parasitization of mesenchymal cells, including myocardial cells, results in elaboration of a fibroblast-stimulating factor(s), perhaps of parasite origin. We postulate that this factor may play a role in initiation of myocardial fibrosis in Chagas' disease.