Experimental intrahepatic portacaval anastomosis: use of expandable Gianturco stents

Original Gianturco expandable stents and their modifications were used to create an experimental intrahepatic portacaval anastomosis (EIPCA) in 30 young domestic swine without portal hypertension. The study focused on the design of a suitable stent, the technique of its application, and the evaluation of short-term patency of the EIPCA. A stent with a 2.5-cm-long body and wire skirts on both ends was most suitable for EIPCA creation. Well-positioned stents shunted most of the portal blood in the inferior vena cava circulation and remained patent for 4-6 weeks. Ingrowth of liver parenchyma and abundant proliferation of the intima and connective tissue inside the stent lumen in these rapidly growing animals gradually decreased EIPCA patency, and thrombus formation with diminished blood flow closed them completely.     

A new model to study acute and chronic renal failure

Many models have been developed to study renal function following injury. Two types of studies have evolved: acute--to define the acute renal injury and chronic--to determine the pattern of recovery. Current models allow either study alone to be performed, but they lack the flexibility to combine the studies. In this study of renal ischemia, a model was designed which solved this problem. The authors constructed a model for performing a unilateral nephrectomy and episiotomy on female dogs. Catheters were placed in the renal vein, vena cava, and aorta, and a renal artery flow cuff was applied. The catheters and wires were buried in a subcutaneous pocket and were exteriorized after a recovery of several weeks. The episiotomy allowed easy intermittent Foley catheterization. With the animals awake and in a harness, parameters of renal function were measured: renal extraction, filtration fraction, fractional excretion, osmolar clearance, and free water clearance. Glomerular filtration rate and renal plasma flow were calculated by inulin and paramino hippurate clearances. The animals were studied in diuretic and antidiuretic states. In addition, renal artery flow was determined by the Doppler flow cuff. All parameters were determined every half hour in the acute setting, then every day in the chronic setting. The model was easily reproducible and functioned well in the authors' renal ischemia studies. Initial experiments with 1 hour of warm ischemia produced a greater than 50 per cent reduction in GFR acutely. Chronic studies showed a GFR with a return toward normal. All model construction purposes and plans were met.(ABSTRACT TRUNCATED AT 250 WORDS)     

Infection of human monocytes with HIV-1Ba-L. Effect on accessory cell function for T-cell proliferation in vitro

Major laboratory manifestations of human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS) include altered levels of circulating CD4+ lymphocytes and decreased in vitro T-cell mitogenic responses. Since T-cell proliferation is regulated by monocytes (M phi), studies were undertaken to determine whether defective M phi function contributes to these poor mitogenic responses. M phi were isolated from peripheral blood mononuclear cells (PBMC) of normal donors by adherence to plastic. After 5 days in culture, the adherent cells were inoculated with the HIV-1 M phi-tropic strain, Ba-L. Under these conditions HIV infection in M phi can be detected 5-7 days after inoculation. Ten to fourteen days postinoculation, the adherent cells were harvested with lidocaine and cocultured with fresh autologous T cells and T-cell mitogens in a 3-day assay. We found decreased proliferative anti-CD3 responses to Leu4 and OKT3 and variable responses to concanavalin A (Con A) by T cells cultured with HIV-infected monocytes compared with T cells cultured with uninfected M phi. Supernatants from HIV-infected M phi cultures decreased proliferative responses of normal PBMC to anti-CD3 monoclonal antibodies. Heat-activated supernatants had the same effect. Inhibitors of HIV binding did not restore proliferative responses of HIV-infected cultures to normal levels. These results indicate that HIV infection of M phi causes the release of soluble factor(s) that suppress anti-CD3-induced T-cell proliferative responses.     

国产沉香化学成分的研究——Ⅲ.异白木香醇的结构测定和低沸点成分的分离与鉴定

自国产沉香(Aquilaria sinensis)[瑞香科(Thymeleaceae)植物]的挥发油中,经硅胶柱层析和离心薄层层析分离得到一新的倍半萜,命名为异白木香醇(isobaimuxinol),根据光谱(IR,¹HNMR,¹³CNMR,2 D-NMR和MS)分析确定其结构式为(Ⅰ)所示,并用X-光衍射晶体解析进一步确定了其立体化学。同时,也从该植物挥发油的低沸点部分分离得到四个已知化合物:苄基丙酮,对甲氧基苄基丙酮,茴香酸和β-沉香呋喃。这些化合物均为首次从该植物中得到。     

Ioversol for intravenous urography: A comparison study

A new nonionic, low-osmolar iodinated contrast media, ioversol, was compared with another low-osmolar, nonionic contrast media, iohexol, in 80 patients undergoing intravenous urography. There were 40 patients in each contrast group. Patients were assessed for changes in vital signs, patient tolerance (heat and pain), and other adverse effects. Double-blind evaluation was also performed for comparison of the urogram image quality. There were no severe, life-threatening reactions for either contrast group. Ten patients (25%) receiving ioversol and seven (17.5%) receiving iohexol perceived body heat related to the injection of contrast material. Two patients (5%) in each group experienced mild nausea. Two patients (5%) of each group experienced noted unpleasant taste, and two patients (5%) of the iohexol group complained of headache. Vital signs remained stable without significant change in both groups, and image quality was considered equivalent. The results indicate that the two contrast agents are equivalent in image quality, safety, and incidence of adverse effects.     

Mood and spatial memory: emotion and right hemisphere contribution to spatial cognition.

Depressed persons show an impairment of spatial cognition that may reflect the influence of affective arousal on right hemisphere cognition. We examined normal university students to determine whether individual differences in mood and arousal levels would be related to performance on a spatial memory task. Right-hemisphere specialization for this spatial memory task was confirmed by a left field advantage for the targets and this field asymmetry was enhanced as task difficulty was increased. Event-related brain potentials (ERPs), assessed with a 64-channel sensor array, showed a processing negativity contralateral to the target in the P300 interval (300-500 ms after the target appeared). This effect increased as task difficulty was increased. A stronger posterior negativity for good (rather than bad) targets may suggest that attention was allocated toward the good locations. A suggestion of right hemisphere sensitivity to mood in this normal sample was a tendency for the subjects high in Negative Arousal not to show the normal right hemisphere (left field) superiority for the spatial memory task. Interestingly, a medial frontal lobe negativity was elicited in the ERPs by the bad targets, perhaps paralleling the error-related negativity observed in other paradigms. This medial frontal negativity was also seen in response to the feedback stimulus for the bad targets. Motivation may be important to this frontal effect: It was enhanced for subjects describing themselves as high in either positive or negative affective arousal during the task.