Resting macrophages produce distinct metabolites from exogenous arachidonic acid

Resident mouse peritoneal macrophages rapidly metabolize free arachidonic acid (20:4) in the absence of a discernible trigger. After a 20-min incubation in serumless medium, one-third of the fatty acid was found esterified in cell phospholipid and two-thirds was metabolized to oxygenated products which were recovered in the culture medium. The 20:4 oxygenated metabolites were identified by reverse-phase high performance liquid chromatography as hydroxyeicosatetraenoic acids (HETEs) and 6-keto prostaglandin F(1a) (6-ketoPGF(1a)), the stable form of prostacyclin, together with prostaglandin E(2) (PGE(2)) in proportions of 67:24:9. Inhibitor studies using indomethacin, nordihydroguaiaretic acid, and 5,8,11,14-eicosatetraenoic acid confirmed these metabolites to be lipoxygenase and cyclo-oxygenase products. The proportion of products differs considerably from those generated from phospholipid 20:4 in response to a phagocytic stimulus (HETEs:6-ketoPGF(1a):PGE(2):leukotriene C, 15:25:40: 15-20). Cornyebacterium parvum-elicited macrophages incorporated a higher percentage (70 percent) of exogenously supplied 20:4 and converted less than 20 percent of the fatty acid to oxygenated metabolites. Cyclo-oxygenase products (PGE(2), PGF(2a), TXB(2), and 6-ketoPGF(1a)) represented the major 20:4 metabolites (74 percent) synthesized by these activated macrophages. Esterification of 20:4 into cell phospholipids appeared not to be an initial obligatory step for synthesis of 20:4 oxygenated products by this route. To the contrary, incorporation of 20:4 into cell lipids and metabolism via the cyclo-oxygenase and lipoxygenase pathways represent distinct metabolic fates of exogenously supplied 20:4. These observations establish that resting macrophages contain high levels of cyclo-oxygenase and lipoxygenase activity and suggest macrophages can synthesize lipid mediators of inflammation in the absence of an inflammatory stimulus.     

肝癌介入治疗后并发急性上消化道大出血12例

[目的]探讨肝癌介入治疗后并发急性上消化道大出血的原因及防治措施。[方法]2512例肝癌患者采用Seldinger技术经股动脉穿刺，将导管插至肝固有动脉以远．一次性注入化疗药物及碘油混悬剂。[结果]12例于介入治疗后12h内出现上消化道大出血．经降门静脉压及止血等治疗后，10例出血停止，2例死亡。[结论]碘油逆流入门静脉引起门脉高压和（或）加重原有门静脉高压．导致食管下段胃底静脉破裂是出血的主要原因，降门静脉压是治疗的有效方法．     

Effect of food on the absorption of frusemide and bumetanide in man

1 The influence of food on the absorption of frusemide and bumetanide was compared in two separate randomized crossover studies. 2 On three separate occasions frusemide 40  mg was administered to eight healthy male volunteers intravenously, orally in the fasting state and orally after a standard breakfast. Blood and urine were collected at intervals over 8  h and urine alone for a further 16  h. The study was then repeated in nine healthy volunteers using intravenous and oral bumetanide 2  mg. 3 Breakfast significantly reduced the peak plasma concentration of frusemide from 2.35±0.49 to 0.51±0.19  mg l⁻¹ (95% confidence intervals (95% CI)=1.39 to 2.28  mg l⁻¹) and delayed the time to peak concentration from 0.69±0.21 to 1.91±0.93  h (95% CI=0.41 to 2.03  h). The oral bioavailability of frusemide was significantly reduced by approximately 30% (75.6±10.6 to 43.2±16.8%; 95% CI=13.5 to 51.4%). 4 With bumetanide, the meal also significantly reduced the peak concentration from 0.097±0.015 to 0.036±0.012  mg l⁻¹ (95% CI=0.048 to 0.073  mg l⁻¹) and delayed the time to peak from 0.53±0.08 to 1.36±0.72  h (95% CI=0.23 to 1.44  h). However, food had no statistically significant effect on the bioavailability and urinary recovery of bumetanide. 5 In this study, the absorption of bumetanide was affected less than frusemide by food.     

Multispectral analysis of MR images of the breast

Preliminary investigations were conducted into the potential of magnetic resonance (MR) images for tissue classification of the breast on the basis of relative signal intensity. Multispectral techniques originally developed by the National Aeronautics and Space Administration for satellite image analysis were used in sequence selection, image data correction, image standardization, and image interpretation. Numerous sequence combinations with varying repetition times (TR) and echo times (TE) were considered, and a triplet was selected consisting of long TR/long TE, short TR/short TE, and an opposed phase sequence with intermediate TR and TE. Correction to remove system-imposed intensity inhomogeneities was required for all images. Image standardization based on fat and pectoral muscle signals was necessary for intercase comparisons. Multispectral images obtained based on this analysis suggest the feasibility of intensity-based image classification.     

Human immunodeficiency virus-type 1 replication can be increased in peripheral blood of seropositive patients after influenza vaccination

Despite considerable evidence that cell activation enhances human immunodeficiency virus-type 1 (HIV-1) replication in vitro, there is very little data on the role of immune activation on in vivo HIV-1 replication. In this study, we examined the effect of influenza vaccination on HIV-1 replication in the peripheral blood of 20 study subjects, and in 14 control subjects who did not receive influenza vaccination. Blood was obtained from each subject on three occasions during the month before vaccination and again on three occasions during the following month. Over the study period, there was little change in levels of proviral DNA in peripheral blood mononuclear cells (PBMCs). However, peak PBMC viral RNA levels after influenza vaccination were significantly increased over the mean of prevaccination values. This change was not observed to the same extent in unvaccinated controls. Therefore, this is the first report showing that HIV-1 replication can increase in temporal association with influenza vaccination. Our results suggest that continued immunologic (antigenic) stimulation may result in increased virus load in vivo. To address the appropriateness of influenza vaccination in HIV-infected patients, expanded studies will be required to examine specific and generalized immune responses to vaccination, and differences in patient response based on disease stage.     

Transhepatic balloon dilation of the distal common bile duct and ampulla of Vater for removal of calculi

In 17 patients with common bile duct calculi, percutaneous transhepatic balloon dilation of the distal common bile duct and the ampulla of Vater (hepaticopancreatic ampulla) was performed. The calculi were pushed into the duodenum with the catheter, and all were removed without significant complications. This method of calculus removal is an effective alternative to surgery or endoscopic sphincterotomy.