临床输液监控系统的设计

本文针对临床输液过程中出现的漏、停、输液速度改变等各种问题，讨论了一由单台微机和多个单片机通讯实现的多床输液自动监控、自动反应、自动报答系统的可行性，并给出了主要部分的硬件、软件设计方法。     

血清α-L-岩藻糖苷酶对原发性肝癌的诊断价值

用分光比色法测定血清α-L-岩藻糖苷酶(AFU),研究其对36例原发性肝癌(PHC)、30例肝硬化(LC)、16例转移性肝癌(MC)、11例良性肝脏占位性病变(BSOL)、22例慢性肝炎(CH)和20例胃肠道恶性肿瘤(EMT)患者的临床应用价值。在肝脏占位性病变组中对AFU,AFP和α_1AT进行比较研究。结果表明:PHC组血清AFU活力显著高于其余各组,AFU,AFP和α_1AT对PHC诊断敏感性分别为75％,61.1％和66.7％,可靠性分别为81.7％,83.9％和65.6％,三项指标联测则PHC诊断阳性率可提高到91.7％。AFU活力与PHC肿瘤大小、AFP含量无相关,与α_1AT呈正相关。本文资料表明:AFU可作为PHC血清标志物,对AFP阴性病例尤有价值。     

Cyclosporine overcomes cold preservation/reperfusion injury of liver graft: Chemokine release and liver ultrastructure

There is a growing body of evidence that the cytokine, tumor necrosis factor-α (TNF-ga), plays an important role in the development of hepatic ischemia/reperfusion injury. We found that the immunosuppressants, cyclosporine-A (CsA), azathioprine, and FK506, have protective effects on such injury. The purpose of the present study was to elucidate mechanisms involved in these beneficial effects of the immunosuppressant, CsA, on liver injury following cold preservation and transplantation, with special reference to the suppression of TNF-α release. Rat livers were stored in Euro-Collins solution (EC) at 4°C for 6h and orthotopically transplanted. The animals allotted to two groups: group A (untreated controls) and group B (CsA pretreatment of recipients). CsA (10 mg/kg, p.o.) was given for 3 consecutive days preoperatively. CsA pretreatment of the recipients significantly improved the 2-week survival rate (0/6 for group A, 3/6 for group B;P<0.05) and this was associated with a significant decrease in serum TNF-α levels 2h posttransplantation (group A, 69.8±15.7 pg/ml; group B, 22.8±6.8; mean±SEM;n=12 each;P<0.05) and amelioration of sinusoidal endothelial injury, assessed by electron microscopy. Plasma endotoxin levels following reperfusion of the grafts were not altered by the CsA therapy. Morphologically, CsA pretreatment of the recipients did not alter activation of Kupffer cells. CsA pretreatment of the recipient aids in preventing cold preservation/reperfusion injury of the liver graft, possibly by modulating effects of TNF-α.     

Immunology

A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in immunology.     

应用吻合器行中、下段直肠癌切除术后吻合口漏──附10例报告

我科自１９８１年３月至１９９１年１２月应用吻合器行中、下段直肠癌切除术６７例，同期发生吻合口漏１０例（１４９％）。本文分析了吻合口漏发生的因素。病变部位、病灶范围、术中操作技术、术前肠道灌洗以及术后骶前引流是影响吻合口漏的重要因素。本文总结了吻合口漏的治疗方法，提倡保守治疗，或加作暂时性横结肠造口术。     

Depletion of O6-alkylguanine-DNA alkyltransferase by O6-benzylguanine in three-dimensional collagen cultures of normal human breast epithelial cells.

O6-Alkylguanine--DNA alkyltransferase (AGT) is a protein which removes the promutagenic O6-alkylguanine lesion induced in DNA by alkylating agents. Our results demonstrate that freshly isolated organoids from reduction mammoplasty specimens contain significant levels of AGT activity. AGT activity in breast epithelial cells shows interindividual variation. Constitutive levels of AGT activity remain unchanged during short-term serum-free culture of breast epithelial cells inside three-dimensional rat-tail collagen gel matrix. In the present study, we optimized conditions for depleting AGT activity in human breast epithelial cells cultured in three-dimensional collagen gel matrix using O6-methylguanine and O6-benzylguanine which are substrates for AGT. AGT activity was efficiently inactivated by exposure of cells to O6-methylguanine or O6-benzylguanine. Inactivation with O6-benzylguanine was more rapid, of greater magnitude and consistency and occurred at lower concentrations than with O6-methylguanine. Near-complete inactivation (> 99.5%) of AGT activity was reproducibly achieved with 50 microM O6-benzylguanine. In contrast, 500 microM O6-methylguanine was needed to obtain a maximal effect and this reduced AGT activity by only 53-93% of control. Within 30 min of adding the free base, 50 microM O6-benzylguanine depleted 95% of the levels of AGT compared to 30% inhibition with 500 microM O6-methylguanine. The profile for restoration of AGT activity was different following a 24 h incubation and subsequent removal of each of the guanine derivatives. AGT activity levels remained undetectable for at least 2 days after removal of 50 microM O6-benzylguanine from the medium and recovered to only 53% of control values after an additional 3 days. AGT activity levels remained undetectable for at least 2 days after removal of 50 microM O6-benzylguanine from the medium and recovered to only 53% of control values after an additional 3 days. In contrast, following removal of 500 microM O6-methylguanine, the activity was restored from its nadir of 16% of control values reaching pretreatment levels after 5 days. These results suggest that treatment with O6-benzylguanine may be used to modulate the incidence of transforming mutations in cultured human breast epithelial cells treated with chemical carcinogens which give rise to O6-alkylguanine adducts.     

Clinical analysis of congenital bile duct dilatation: Experience with 160 patients over a 7-year period

From July 1989, to June 1996, 160 patients with congenital bile duct dilatation (CBD) were treated at our institution. The incidence of CBD at our institution has increased annually. In approximately 90% of patients with CBD there was associated anomalous arrangement of the pancreaticobiliary ductal system, and we concluded that this was one of the main causes of CBD. Pediatric endoscopic retrograde cholangiopancreatography was first introduced to China in 1989, and has been successfully performed in 90.2% of 92 patients at our institution. We found that age at diagnosis was closely related to the subtype, complications, and mortality of CBD. The subtype also correlated with the presenting symptoms. One hundred and forty-seven of the 160 patients underwent surgery. Of these 147 patients, 136 (92.5%) were cured with normal liver function and 9 (6.1%) improved with liver impairment. Two patients died, one of postoperative pneumonia and one of liver failure. We conclude that early radical surgery and careful postoperative follow-up are essential in the prevention of CBD complications such as cholangitis, pancreatitis, biliary stones, and development of carcinoma. This article is based on a special lecture delivered before the 19th meeting of the Japanese Society of Pancreatico-biliary Maljunction, on September 14, 1996, in Tokyo     

Effects of hyperthermia on natural killer cells: inhibition of lytic function and microtubule organization.

Cells with natural killer activity (NK) may play an important role in host defence against tumour cells. The lytic function of NK cells is very sensitive to hyperthermic inactivation. However, cells with NK activity isolated from rat spleen and exposed to 41-42.5 degrees C for 30 min could partially recover their cytotoxic activity after incubation at 37 degrees C. The recovered cytotoxicity was still NK-specific, as it only resulted in the lysis of YAC-1 sensitive targets, and could not lyse NK-resistant P815 mastocytoma cells. Conjugate formation assay using NK cells labelled with specific monoclonal antibody (mAb) 3.2.3 indicated that the binding of NK cells to targets was not significantly affected by heat treatment. Compared to controls, however, microtubule organizing centre (MTOC) reorientation towards the region of intercellular contact was reduced by 40% in heated effector cells. This was accompanied by a greater inhibition (62-77%) of NK lytic activity. Kinetic analysis indicated that MTOC reorientation capacity recovered following incubation at 37 degrees C. MTOC recovery was maximal 4 h after treatment whereas that of lytic activity peaked at 6 h. These data indicate that NK cells recover NK-specific lytic activity after heat inactivation. Moreover, our study demonstrates that hyperthermia interferes with post-binding MTOC reorientation, and further supports a role for microtubule in secretory processes involved in NK-mediated cytolysis.     

Enhancement of fibronectin synthesis and fibrillogenesis by BMP-4 in cultured rat osteoblast.

The skeletal extracellular matrix produced by osteoblasts contains the glycoprotein fibronectin (Fn), which regulates the adhesion, differentiation, and function of osteoblasts. Fn fibrillogenesis is involved in the process of bone mineralization. Bone morphogenetic proteins (BMPs) can be isolated from organic bone matrix and are able to initiate de novo cartilage and bone formation. In this study, the effect of BMP-4 on Fn fibrillogenesis in cultured rat osteoblasts was examined. BMP-4 enhanced Fn synthesis and extracellular Fn assembly in primary cultured osteoblasts. In addition, the extracellular assembly of Fn from exogenously applied soluble human Fn was also increased by BMP-4. It has been reported that alpha5beta1 integrin is related to Fn fibrillogenesis. The synthesis of both alpha5 and beta1 integrins was upregulated by BMP-4. Immunocytochemistry showed that the clustering of alpha5 and beta1 integrins was also increased by BMP-4. BMP-4 increased fibril formation of Fn and the adhesion of osteoblasts onto Fn matrix, which was inhibited by disintegrin triflavin and Gly-Arg-Gly-Asp-Ser (GRGDS) peptide. Phosphorylation of extracellular signal-regulated kinase (ERK) and focal adhesion kinase (FAK) was increased by BMP-4. Enhancement of extracellular Fn fibrillogenesis and the mRNA expression of beta1 integrin by BMP-4 were inhibited by ERK kinase (MEK) inhibitor PD98059. These results suggest that the enhancement of extracellular Fn fibrillogenesis by BMP-4 in cultured osteoblasts is related to the increase of the synthesis of Fn and clustering of alpha5 and beta1 integrins. ERK is involved in the signaling pathway of BMP-4 in regulating Fn fibrillogenesis in osteoblasts.