Biomedical subjects

Atsushi Sawamura

Publications and source records attributed to Atsushi Sawamura.

4 recordsLinked to original sources

PubMed2006

An alternative pathway for fibrinolysis is activated in patients who have undergone cardiopulmonary bypass surgery and major abdominal surgery.

INTRODUCTION: We conducted this prospective study in order to investigate the hypotheses that an alternative pathway for fibrinolysis is activated in patients who have undergone cardiopulmonary bypass (CPB) surgery and major abdominal surgery and that the levels of fibrin degradation products digested by polymorphonuclear neutrophil elastase (elastase-XDP) and the D-dimer increase in the patients' plasma. MATERIALS AND METHODS: We studied a total of 77 patients who were scheduled to undergo either CPB surgery (36 patients) or major abdominal surgery (41 patients) and then measured the elastase-XDP and D-dimer levels at several time points both during and after the surgeries. The CPB surgery was divided into surgery for aortic dissection (AD) and cardiac surgery. The major abdominal surgery consists of hepatic resection and esophagectomy. RESULTS: The elastase-XDP and D-dimer levels significantly increased in the patients who underwent both CPB surgery and major abdominal surgery. The elastase-XDP levels in AD surgery showed highest values at the end of the CPB, while the levels in the other surgeries reached their peak on the day after the surgery. Statistical difference was seen in the levels of elastase-XDP among the three subgroups undergoing a hepatic resection. While we found significant correlations between the levels of elastase-XDP and D-dimer in patients undergoing CPB surgery and a subsegmentectomy of a cirrhotic liver, the correlation coefficients were markedly low in comparison to those of the other surgeries. CONCLUSIONS: Our findings demonstrated that the elastase-mediated pathway of fibrinolysis is activated to varying degrees depending on the surgery performed. Variations in the correlation coefficients between the levels of elastase-XDP and D-dimer may suggest that elastase-mediated fibrinolysis play a different role from the physiological fibrinolysis mediated by plasmin.

Cardiopulmonary Bypass↗

PubMed2006

First day dynamic changes in antithrombin III activity after supplementation have a predictive value in critically ill patients.

To evaluate the changes in the antithrombin III (antithrombin) values after initial supplementation to predict outcome in critically ill patients, we conducted a retrospective study. All consecutive patients admitted to the intensive care unit (ICU) and treated with antithrombin were enrolled in the study. Initial doses of 1,500 IU or 30 IU/kg antithrombin concentrates were administered over an hour. The clinical backgrounds of the patients were collected from computer-based records. Serial data of antithrombin were collected from the first day of administration (Day 0) to days 1-4. The patients were subdivided into two groups based on whether they demonstrated an increased antithrombin activity of more than 60% on the first day after the initial supplementation (responders) or not (nonresponders). Four hundred thirty-five patients were enrolled in the present study. Two hundred eighty-eight patients could achieve an antithrombin activity of more than 60%. The outcome was significantly different between the two groups. A logistic regression analysis revealed the day 1 antithrombin level and an initial increase of less than 60% after supplementation to be independently associated with ICU mortality. We also found a significant increase in the platelet counts and fibrinogen levels, and a decrease in the disseminated intravascular coagulation (DIC) scores for the responders. In conclusion, our findings demonstrated the first-day dynamic change in antithrombin activity, and not the basal level, to be able to predict critically ill patient death. This dynamic change was associated with an improvement in the platelet counts, fibrinogen levels, and the DIC score.

Adult↗

PubMed2004

Systemic inflammation and disseminated intravascular coagulation in early stage of ALI and ARDS: role of neutrophil and endothelial activation.

To determine the existence of a close link between inflammation and coagulation in patients with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) and to examine their prognostic value in the development of ARDS and clinical outcome, we made a prospective cohort study. The study subjects consisted of 57 patients: 19 patients with ARDS and 38 patients with ALI as defined by a Lung Injury Score of > or =2.5 and 1.0 to less than 2.5, respectively. According to the outcome, the patients were subdivided into the survivors and the nonsurvivors. Ten normal healthy volunteers served as control subjects. Plasma levels of soluble L-, P-, and E-selectins, intercellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), thrombomodulin (sTM), and neutrophil elastase were measured within 24 h after the diagnosis of ALI or ARDS. The number of systemic inflammatory response syndrome (SIRS) criteria being met by the patients and the disseminated intravascular coagulation (DIC) scores were determined simultaneously. The number of SIRS criteria and the DIC scores of the patients with ALI or ARDS showed high values, and more than half of the patients were complicated by DIC. The levels of sL-selectin in both groups of the patients were significantly lower than those of the control subjects. All other soluble adhesion molecules, neutrophil elastase, and sTM in the patients with ALI and ARDS were markedly elevated than those in the control subjects. The levels sICAM-1, sVCAM-1, and sTM in the ARDS patients significantly increased compared with the ALI patients. The number of SIRS criteria and the DIC scores in the nonsurvivors showed higher values than those in the survivors. In addition, we found significant differences in the levels of soluble adhesion molecules, neutrophil elastase, and sTM between the survivors and the nonsurvivors. In conclusion, we found a concurrent activation of both inflammation and coagulation in the patients with ALI or ARDS. The results also suggest that systemic activation of inflammation and coagulation associated with endothelial injury has prognostic value for the development of ARDS and poor outcome.

Disseminated Intravascular Coagulation↗

PubMed2002

Electrophysiological, behavioral and metabolical features of globus pallidus seizures induced by a microinjection of kainic acid in rats.

There has been few studies of the globus pallidus in relation to epilepsy. In this study, kainic acid (KA)-induced globus pallidus seizure was electrophysiologically, electroencephalographically, histopathologically and metabolically investigated in rats. Sixteen Wistar rats weighing 250-350 g were used. Under intraperitoneal pentobarbital anesthesia, a stainless-steel cannula was inserted stereotaxically into the left globus pallidus pars externa (GPe) for KA injection. For recording EEG, a depth electrode was inserted into the left GPe, just posterior to the tip of the injection guide cannula. Electrodes were also inserted into the right globus pallidus and bilateral sensorimotor cortex (SMC). EEG changes after KA injection were classified as follows: Continuous low-voltage spikes were observed in the left GPe on EEG at stage 1. Intermittent multiple spikes and wave complexes began to propagate to the left SMC at stage 2. Continuous spikes and wave complexes began to propagate to the bilateral SMC at stage 3. Secondary generalized seizures were observed at stage 4. Globus pallidus seizures recurred every 7-9 min and lasted for 4-6 h. However, the seizures gradually subsided and became normal within 18 h. No spontaneous seizure was detected for the next 30 days. Histopathological study revealed a small gliotic lesion with neuronal cell loss around the cannula tip. Neither degeneration nor neuronal cell loss in the ipsilateral hippocampus were observed. The autoradiogram using [14C]2-deoxyglucose during seizure status demonstrated a remarkable increase of local cerebral glucose utilization not only in the GPe but also in the GPi. An increase glucose metabolism was also found in the follows: the medial and lateral septal nucleus, substantia nigra, hippocampus, frontal cortex, parietal cortex, piriform cortex, entorhinal cortex, accumbens nucleus, ventral and lateral nucleus of the thalamus, amygdala, and ventral nucleus of hypothalamus. KA injection into the unilateral GPe evoked not only epileptic excitation of the cortex but also transient enhancement of the globus pallidus-substantia nigra circuit.

Action Potentials↗