The blood coagulation system of 66 consecutive patients undergoing consecutive liver transplantations was monitored by thrombelastograph and analytic coagulation profile. A poor preoperative coagulation state, decrease in levels of coagulation factors, progressive fibrinolysis, and whole blood clot lysis were observed during the preanhepatic and anhepatic stages of surgery. A further general decrease in coagulation factors and platelets, activation of fibrinolysis, and abrupt decrease in levels of factors V and VIII occurred before and with reperfusion of the homograft. Recovery of blood coagulability began 30-60 min after reperfusion of the graft liver, and coagulability had returned toward baseline values 2 hr after reperfusion. A positive correlation was shown between the variables of thrombelastography and those of the coagulation profile. Thrombelastography was shown to be a reliable and rapid monitoring system. Its use was associated with a 33% reduction of blood and fluid infusion volume, whereas blood coagulability was maintained without an increase in the number of blood product donors. Keywords BLOOD-coagulation; LIVER-transplantationLiver transplantation, which began as highly experimental surgery 20 yr ago, is now recognized as a major means of therapy for patients with end-stage liver disease (1). However, massive blood loss during liver transplantation is still a major concern. The liver produces most of the blood coagulation factors, so it is not surprising that we see very low levels of these factors and prolonged prothrombin time (PT) and activated partial thromboplastin time (aPTT) in many patients receiving liver transplants (2). Frequently we have seen thrombocytopenia, which may result from gastrointestinal bleeding, splenomegaly, or malnutrition (3). At the same time, numerous collateral channels and portal hypertension, together with increased capillary fragility, make maintenance of surgical hemostasis very difficult.Previous studies on the blood coagulation system in humans and in animals undergoing liver transplantation have demonstrated dilutional coagulopathy associated with massive blood transfusion, decreased fibrinogen levels, and thrombocytopenia (4,5). Fibrinolysis, beginning during the anhepatic stage of surgery and becoming "explosive" on reperfusion of the homograft, has been reported (6). A consumption coagulopathy accompanied by an increased level of fibrin degradation products appeared to play a major role (7). However, these observations were limited to a few patients in the early era of liver transplantation, and comprehensive information is still lacking.Another difficulty in the intraoperative management of liver transplantation has been actively monitoring the coagulation system and determining the appropriate treatment during dynamic blood volume changes. The use of the thrombelastograph (TEG) was suggested by von Kaulla et al. (4) and Howland et al. (8). However, the efficacy of thrombelastographic monitoring of blood coagulation during liver transplantatio...

Orthotopic liver transplantation is frequently associated with hyperfibrinolysis. the origin and clinical relevance of which is largely unknown. In 20 orthotopic liver transplantations, we studied the occurrence and systemic effects of hyperfibrinolysis. Severe fibrinolysis was defined to be present when the euglobulin-clot lysis time and the whole-blood-clot lysis time, as measured by thrombelastography, were shorter than 60 and 90 min, respectively, at some time during the operation.

Cerebral arterial bifurcations in rats were treated to induce cerebral aneurysms experimentally, and flow patterns of latex particles introduced under a constant flow rate were analyzed with a 16-mm cine-camera and videocassette recorder. Cerebral aneurysms were produced by ligating one common carotid artery, inducing experimental hypertension, and feeding the animals beta-aminopropionitrile. After perfusion and fixation, samples of cerebral arterial bifurcations with shallow invaginations and with small aneurysms were obtained and used for analysis. Bifurcations in rats without experimental treatment were used as control specimens. Flow studies in the control bifurcations showed that the apical intimal pad, not the apex itself, acted as the flow divider. Small particles tended to accumulate at the region just distal to the apical intimal pad, where the initial aneurysmal changes are known to occur. This indicates stagnation of flow at that site. In the bifurcations with shallow invaginations and small aneurysms, a marked pressure gradient was present at the proximal end of the aneurysm orifice. A tendency for stagnation of small particles near the aneurysm wall was also observed. The wall shear stress was highest at the distal end of the aneurysmal orifice, which may be responsible for the development of these lesions.

Saccular cerebral aneurysms were successfully induced in two monkeys treated with ligation of the common carotid artery, experimental hypertension, and beta-aminopropionitrile feeding. The cerebral aneurysms developed on the large arteries at the base of the brain, such as the anterior communicating artery and the internal carotid artery at the origin of the posterior communicating artery. Because of the similarity of the monkey to man as a species, the present results strongly suggest the significance of postnatal aggravating factors in the development of cerebral aneurysms in man.

Six intraoperative blood samples were obtained at intervals from each of 100 individuals undergoing their first liver transplants. The patients fell into the following diagnostic categories: postnecrotic cirrhosis 28, primary biliary cirrhosis 20, sclerosing cholangitis 19, miscellaneous diseases 14, carcinoma/neoplasia 12 and fulminant hepatitis 7. Coagulation factor values in the initial (baseline) blood samples varied by patient diagnosis. In general, all factor levels were reduced except factor VIII:C, which was increased to almost twice normal. The slight intraoperative changes in factors II, VII, IX, X, XI and XII suggested that a steady-state relationship existed between depletion (consumption/bleeding) and repletion (transfusion, transit from extra-to intravascular space), even in the anhepatic state. In contrast, there were rapid and very significant falls in factor VIII and fibrinogen and a less pronounced decrease in factor V, all reaching their nadirs in early to mid-Stage III. The cause of these coagulation changes appears to be activation of the fibrinolytic system. Liver transplantation has been used to treat end-stage liver disease caused by a wide variety of congenital or acquired disorders. Improved methods for procurement and preservation of the donor livers, innovative surgical techniques and improved immunosuppressive agents have made liver transplantation feasible for many patients with severely damaged liver parenchyma, vasculature or bile ducts. However, one of the major difficulties has been the need for multiple blood transfusions, which reflects the large loss of blood during the operation. This study deals with intraoperative changes in coagulation parameters and the quantities of red blood cells (RBC) transfused. MATERIALS AND METHODS PatientsDuring an approximate 2-year period, intraoperative coagulation studies were carried out on 100 adult individuals undergoing their first liver transplants. All of these transplants were done with an axillofemoral venous bypass using tubing with a heparinized surface (ARGYLE ® tubing) which shunted the major blood flow away from the operative area. No patient received systemic heparin. All patients were transfused with a premixed "cocktail" of equal volumes (250 ml) of RBC, fresh-frozen plasma and Plasmalyte A ® , which contained 526 mg per 100 ml sodium chloride, 502 mg per 100 ml sodium gluconate, 368 mg per 100 ml sodium acetate trihydrate, 37 mg per 100 ml potassium chloride, 30 mg per 100 ml Copyright © 1989 The patients were categorized by pathological diagnosis as previously described (2). An additional diagnostic group, fulminant hepatitis, was included. The 100 patients fell into the six diagnostic groups shown in Table 1. The largest group comprised 28 patients with postnecrotic cirrhosis (PNC) and included patients with chronic active hepatitis, lupoid hepatitis or cryptogenic cirrhosis. The second largest group contained 20 female patients with primary biliary cirrhosis (PBC). An additional 19 patients had primary sclerosing...

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Attention Restoration Theory argues that natural objects such as trees and flowers have psychological restoration effects. However, relevant studies have been mostly based on survey methods, and few of them suggest guidelines for restoration environments. This study, therefore, aims to verify the restorative effect of natural objects using eye-tracking methods and a survey regarding visual aesthetics, complexity, and the Perceived Restorativeness Scale, as well 25 various images divided into 4 types: natural scene and close view, natural scene and distant view, built scene and close view, and built scene and distant view. The analysis showed that natural scenes had a stronger positive restorative effect compared to built scenes regardless of differences in the distance. In terms of the overall landscape composition, visual characteristics such as visual aesthetics and complexity had a statistically significant relationship with restorative effect. Additionally, an eye-tracking method was found to be a valid and useful tool for studying the restorative environments by significant differences in the scan path length depending on the four types of landscape images. This study ultimately provides an overview regarding restorative design guidelines not only by using natural elements but also by considering landscape composition in terms of complexity, openness, and so on.

Excitatory postsynaptic currents (EPSCs) were induced in layer II-V pyramidal cells in the frontal cortex of the young rat (postnatal day 14-21) by stimulation of layers II/III in the presence of bicuculline using the whole-cell patch-clamp technique. EPSCs usually consisted of fast and slow components that were sensitive to CNQX and APV, respectively. In response to paired stimuli of identical strength, paired pulse depression (PPD) was seen for these EPSCs. The PPD of fast EPSCs was most pronounced at an interstimulus interval (ISI) of 200-300 msec and ceased to occur at ISIs greater than 3-5 sec, while the PPD of slow EPSCs became most pronounced at an ISI of 500-1000 msec and ceased to occur at ISIs greater than 10 sec. The PPD of fast EPSCs was attenuated by (-)-baclofen (1-5 microM) and removed by 2-hydroxy-saclofen (0.2-0.4 mM). By contrast, the PPD of slow EPSCs consisted of early and late components that were attenuated by (-)-baclofen and muscarine (1-5 microM), respectively. The late PPD of slow EPSCs induced in the presence of baclofen was removed by pirenzepine (1-3 microM). Thus, fast and slow components of glutamatergic EPSCs displayed two distinct PPDs. These results suggest that a part of the glutamatergic afferents likely arising from layer II/III pyramidal cells may terminate predominantly on NMDA receptors in pyramidal cells of the frontal cortex and receive distinct presynaptic inhibition through at least the muscarinic receptors.