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Biomedical subjects

R Motoki

Publications and source records attributed to R Motoki.

At least 19 recordsLinked to original sources
PubMed1995

Pharmacological approaches to reduce perioperative transfusion requirements in the aged.

Although iron deficiency is undoubtedly the commonest cause of anaemia even in elderly people, the aetiology is not always clear owing to various underlying diseases. Correction of anaemia is sometimes needed before surgery. The use of drugs that may influence blood coagulation, such as aspirin (acetylsalicylic acid), should be checked. Perioperative allogenic blood transfusion can often be avoided by the use of autologous blood and improved surgical techniques. Autologous blood donations are preferable in cases of planned surgery. Epoetin (recombinant human erythropoietin) in combination with iron supplementation facilitates the donation of autologous blood, even in elderly patients. Another method of avoiding allogenic blood transfusion is the collection and reuse of the blood a patient sheds in operations. During and/or after surgery, many haemostatic agents are available. Moreover, recent developments in gene engineering have enabled the utilisation of recombinant cytokines and coagulation factors. Further work remains to be done to define the proper use of these agents.

Aged↗
PubMed1995

Effect and safety of liposome-encapsulated hemoglobin neo red cells (NRCs) as a perfusate for total cardiopulmonary bypass.

We developed a liposome encapsulated hemoglobin named Neo Red Cells (NRC), NRC (1) readily circulates, (2) shows a high oxygen transport efficiency, and (3) has a strong capsule membrane. In this study, we evaluated the effect of NRC as a priming solution for total cardiopulmonary bypass (TCPB) using a dog. The TCPB was started after removal of 57.1-73.3% of autologous blood and continued for 7 hours. During TCPB using NRC, the vascular resistance (VR) decreased to 1/4 of VR when red blood cells (RBC) were used. This change suggests that NRC, the viscosity of which is lower than that of RBC, reduced the load on the circulation system. The oxygen volume delivered by NRC was higher than that delivered by RBC, resulting in a greater oxygen consumption with NRC. During TCPB using NRC, the serum LDH level was lower than that using RBC. So we concluded that NRC compensated for the reduction in the oxygen transport ability, which is a disadvantage of dilution TCPB, and further increased the circulation improving effect and anti-hemolytic effect, which are advantages of the procedure. It, thus, enhanced both the safety and effectiveness of dilution TCPB.

Animals↗
PubMed1995

[Experimental studies on the influence of duodenal contents on the mucosa of gastric remnant].

Using the PCNA staining method, we examined the histopathological changes and cytokinetics on the gastric mucosa of the gastric remnant at the anastomosis 10, 20 and 50 weeks after gastrectomy. We conducted the distal gastrectomy in rats and divided them into three groups: Group 1, in which "a sham" operation was performed; Group 2, in which reflux of duodenum fluids was prevented by Roux-en Y anastomosis; and Group 3, in which reflux of duodenum fluids was allowed by gastro-jejunal anastomosis. Adenocarcinoma developed only at the anastomosis of the afferent loops in animals of Group 3 directly exposed to duodenum fluid. The PCNA labeling index at the anastomosis of the afferent loop was high from the early stages. In addition, labeling index tended to increase gradually, and PCNA positive cells were diffusely scattered, which indicated acceleration of cytosis. From these results, we concluded that the reflux of duodenum fluid was essential for the development of cancer in the remnant stomach. Moreover, cytosis was closely related to the development of epithelial cancer of the gastric mucosa at the anastomosis of the remnant stomach.

Adenocarcinoma↗
PubMed1995

[Respiratory failure after surgery for esophageal cancer and hypercoagulability].

Operation of esophageal cancer accompanies a big surgical stress and postoperative pulmonary complications such as respiratory failure are observed at high frequencies. On the other hand, when a big stress is added to a body, a state of hypercoagulation in which blood coagulation mechanism is abnormally enhanced appears and this state is closely related to organ failures but has many unknown points. So, we examined 39 patients given excision of esophageal cancer with respect to occurrence of postoperative respiratory failures, participation of coagulopathy in aggravation and their degrees before and after the operation to find out the relationship between postoperative respiratory failure and the state of hypercoagulation. We gave a diagnosis of respiratory failure to the patients whose respiratory index exceeded 1.5 on the day after operation but did not show atelectasis or hydrothorax. As a result, respiratory failures were observed in 7 out of 39 cases (17.9%). When a risk score (RS) of postoperative respiratory failure was determined using multivalent analysis (quantification type II) with preoperative factors such as age and function of heart, lung, liver, and kidney as well as preoperative blood coagulation factors, RS = 2.87 (antithrombin-III (AT-III) less than 75%) +1.89 (age over 70 years) +1.78 (respiratory index over 0.15) +1.44 (serum albumin less than 3.0 mg/dl) +1.28 (cardiac index less than 3.0 l/min/m2) was obtained and a drop in preoperative AT-III was considered a risk for occurrence of post operative respiratory failure. In contrast, referring changes in postoperative value of blood coagulation factors, a distinct rise in fibrinogen (FBG) appeared in early stage after operation in the respiratory failure group compared to the control group (p < 0.01). Moreover, recovery in AT-III of blood coagulation factors and in plasminogen and antiplasmin of fibrinolytic factors was delayed (p < 0.05) indicating promotion of postoperative hypercoagulation state and delay in recovery of coagulation-fibrinolysis factors. However, participation of platelet factors was absent.

Age Factors↗
PubMed1994

Iron and erythropoietin measurement in autologous blood donors with anemia: implications for management.

BACKGROUND: The importance of autologous blood donation for elective surgery is recognized, and the method is being used at many hospitals. Not all patients are able to deposit a sufficient amount of blood before surgery because they cannot recover rapidly enough from phlebotomy-induced anemia. The ability to donate sufficient blood for autologous use was studied in patients who are particularly susceptible to phlebotomy-induced anemia. STUDY DESIGN AND METHODS: Of 840 patients who donated blood for autologous use in elective surgery from November 1987 through May 1993, 20 with rheumatoid arthritis, 24 with iron deficiency anemia, and 37 aged 65 years and above with normocytic anemia were compared with 24 nonanemic elderly patients who donated a total of 1000 mL of blood for autologous use. Patients received iron sulfate orally and donated blood once a week until operation. RESULTS: The amount of blood collected before surgery per control patient was more than that in others. Consequently, there was a tendency to allogeneic blood transfusion in patients with rheumatoid arthritis or elderly patients. The ferritin levels in controls and in patients with iron deficiency anemia during the donation period were almost within the normal range in spite of iron supplementation, which implied a good utilization of iron sulfate for erythropoiesis. On the other hand, the rise in ferritin levels in the elderly and in patients with rheumatoid arthritis suggested inappropriate iron availability for erythropoiesis and resulted in an increase in iron storage. Since an adequate endogenous erythropoietin response to phlebotomy-induced anemia was not observed in these patients, impaired erythropoietin production was considered one of the reasons for anemia. CONCLUSION: Patients with iron deficiency anemia are able to continue donating blood for autologous use so long as they have sufficient iron supplementation. However, the elderly or those with rheumatoid arthritis occasionally fail to donate a sufficient volume of blood before surgery as a result of phlebotomy-induced anemia, which is caused in turn by impaired erythropoietin production.

Adult↗
PubMed1994

Effect of neo red cells on hemodynamics and blood gas transport in canine hemorrhagic shock and its safety for vital organs.

The purpose of this study was to evaluate the effects of liposome encapsulated hemoglobin named "Neo Red Cells (NRC)" on canine hemorrhagic shock model and its safety for the vital organs in a whole blood exchange model. HEMORRHAGIC SHOCK: Nine adult mongrel dogs were used. Under mechanical ventilation inhaling room air, blood was withdrawn via an artery at a rate of 40 ml/min in order to induce hemorrhagic shock (systolic pressure below 60 mm Hg) and then NRC was transfused. For each animal, three to five cycles of bloodletting and NRC transfusion were performed. After blood exchange, total peripheral resistance index (TPRI) decreased and cardiac index (CI) increased. These changes were more marked in the high exchange group (exchange rate over 88%; five animals) than in the low exchange group (less than 88%; four animals), indicating that the low viscosity NRC reduced the load on the circulatory system. The A-V difference in oxygen content per lg hemoglobin was greater after blood exchange, indicating that oxygen binding capacity of NRC is higher than that of red blood cells. WHOLE BLOOD EXCHANGE: Five beagles were used for the blood exchange. The blood was withdrawn from an artery at a rate of 15 ml/min and NRC was infused at the same time. A dog whose blood was exchanged with hydroxyethylstarch instead of NRC died within 15 hours after blood exchange. Three dogs whose blood was exchanged with NRC (exchange rate was from 82 to 90%) have been living over a year without any side effects. A dog sacrificed on the 15th postoperative day for autopsy, microscopically showed no side effects in vital organs. We conclude that NRC is more suitable than natural blood for treatment of hemorrhagic shock and safe for vital organs.

Animals↗
PubMed1994

[Malrotation].

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Female↗
PubMed1994

[A ornithine decarboxylase activity and proliferating cell nuclear antigen in gastric cancer].

To investigate ornithine decarboxylase (ODC) activity and proliferating cell nuclear antigen (PCNA) in gastric cancer, ODC activity and PCNA were measured in 50 resected samples. The relationship between both and clinicopathologic factors was examined. ODC activity was 473.3 +/- 54.7 pmol CO2/60 min/mg protein in tumors, and 273.5 +/- 38.3 pmol CO2/60 min/mg protein in normal mucosa. ODC activity in tumors was significantly higher than that of normal mucosa. ODC activity in tumors was significantly high in gross type 4, maximum diameter more than 10 cm, depth se, infiltrative growth (INF) gamma, positive lymph vessel invasion and positive lymph node metastasis. PCNA-LI was 24.7 +/- 1.5% in tumors, and 13.9 +/- 1.1% in normal mucosa. PCNA-LI of tumors was significantly higher than that of normal mucosa. PCNA-LI of tumors was significantly high in gross type 2, histological type tub 2 and por, depth ss beta and se, IFN beta, positive lymph vessel invasion, positive venous invasion, and positive lymph node metastasis. ODC activity and PCNA-LI were closely related in normal mucosa, showing a correlation coefficient of 0.730. On the other hand, their relationship was weak in tumors, showing a correlation coefficient of 0.417. These results suggest the differentiation of value between ODC activity and PCNA-LI in gastric cancer. In gastric cancer, ODC activity and PCNA-LI in tumors may be good markers of lymph node metastasis. Furthermore, PCNA-LI may be a good marker of hematogenous metastasis.

Adult↗
PubMed1994

[Malrotation].

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Female↗
PubMed1993

Oxygen transport capacity and hemodynamic effect of newly developed artificial blood "Neo Red Cells (NRC)".

The purpose of this study was to evaluate liposome-encapsulated hemoglobin, named Neo Red Cells (NRC), on hemodynamics and oxygen-transport capacity in a blood exchange experiment. The experiment was carried out in nine mongrel dogs. Depending on the percentage of blood exchange with NRC, the animals were divided into two groups; Group I (4 animals with an exchange rate less than 88%), and Group II (5 animals with an exchange rate over 88%). After blood exchange, total peripheral vascular resistance index (TPRI) decreased and cardiac index (CI) increased. These changes were more marked in Group II than in Group I, thus showing that NRC relieved the burden on the heart, probably due to the fact that the viscosity of NRC is 2 cp which is less than 1/3 that of whole blood. The oxygen binding capacity per 1g hemoglobin in NRC was 2-4 times as much as red blood cells. Thus, NRC was superior to natural red blood cells in terms of oxygen transport capacity and its effects on the circulatory system.

Animals↗
PubMed1993

[Evaluation of factors aggravating and delaying recovery from postoperative hypercoagulable state in patients operated on for esophageal cancer].

When a living body is invaded to a high degree, a hypercoagulable state develops. The radical operation for esophageal cancer is known as a very high risk operation. The purpose of this study is to evaluate in detail the postoperative changes in platelet, coagulation and fibrinolytic systems, in 34 patients operated on for esophageal cancer, and to clarify the factors contributing to both the aggravation and delay of recovery from the postoperative hypercoagulable state. Operating time and blood loss during surgery were factors aggravating the postoperative hypercoagulable state. The mechanism of coagulation progressed significantly in those patients requiring 500 minutes or more operating time and having a blood loss of 600 ml or more during surgery. Age was seen as an important factor delaying recovery, as the recovery of the coagulative parameters was delayed significantly in patients aged 70 or above. Hepatic function was the most important of post operative organ functions. Renal, cardiac and respiratory functions were unrelated to the postoperative hypercoagulable state.

Blood Coagulation↗
PubMed1993

[Postoperative arrhythmia after operation of esophageal cancer].

The postoperative arrhythmias (exclusive of sinus tachycardia) was reviewed in 77 patients (male: 69, female: 8, mean age: 63.9 years) who underwent esophagectomy for esophageal carcinoma. The results were as follows: 1. The incidence of postoperative arrhythmias in all patients but seven who had preoperative chronic atrial fibrillation (af) or pacemaker rhythm was 47.1%, and af was observed most frequently (45.5%). Postoperative arrhythmias occurred in patients with abnormal preoperative electrocardiographic findings more often than in those with normal preoperative electrocardiographic findings (53% vs 41%). The incidence of postoperative arrhythmias in aged patients (> or = 66 years old) was significantly higher than that in younger patients (< or = 65 years old) (64% vs 35%, p < 0.05). Other risk factors for postoperative arrhythmias were sex and history of hypertension. 2. Postoperative arrhythmias occurred more often in patients who underwent blunt dissection of the thoracic esophagus and reconstruction using the whole stomach via the posterior mediastinal route than in those who underwent esophagectomy with right thoracotomy and reconstruction using the gastric tube via the poststernal route (60.0% vs 45.0%). 3. Most supraventricular premature contractions and ventricular premature contractions occurred immediately after surgery or on the first postoperative day, and af often occurred during the first postoperative night or the second postoperative day. 4. For treatment, various antiarrhythmic agents were administered according to the patient's condition. Glucose-insulin-kalium therapy was especially effective (63%). None of the arrhythmias was fatal.

Aged↗
PubMed1992

Study of effect of the newly developed artificial blood "Neo Red Cells (NRC)" on hemodynamics and blood gas transport in canine hemorrhagic shock.

The purpose of this study is to evaluate the newly developed liposome-encapsulated hemoglobin, named Neo Red Cells (NRC), in the treatment of hemorrhagic shock. The particle size of NRC is 180 +/- 88 nm, the hemoglobin concentration is 5.6 g/dl, the viscosity is 2 cp and P50 is 49.5 mmHg. The experiment was carried out on six mongrel dogs suffering hemorrhagic shock. Blood was extracted from the femoral artery and blood pressure became lower than 60 mmHg. NRC in amount equal to the amount of blood extracted was transfused immediately. Inhalating normal room air, the above manipulation was repeated 3-5 times. After 59% to 88% blood exchange using NRC, the total peripheral vascular resistance index (TPRI) was reduced and the cardiac index (CI) was increased, thereby alleviating the burden on the heart. The reduction of TPRI in the presence of hemorrhagic shock is presumed to be due to the small size of the NRC granules and their low viscosity. As the exchange rate increased, the oxygen consumption (VO2) increased remarkably, presumably due to the increase of CI and A-V difference of oxygen content. The conclusion of the study is that NRC is more suitable than natural blood for the treatment of hemorrhagic shock.

Animals↗
PubMed1992

[Study of surgical treatment and nonsurgical treatment as palliation for unresectable esophageal cancer].

A retrospective study was carried out to evaluate treatment in 24 patients with unresectable esophageal cancer who underwent bypass operation (group A; n = 11) or esophageal prosthesis intubation (group B; n = 13), regarding food intake, quality of life and survival. The results were as follows: 1) According to the preoperative or intraoperative findings, all the patients, except one case is group A, were diagnosed as A3 (2 case in group B had a esophago-bronchial fistula). 2) After surgery, oral food intake was possible in only 2 patients in group A, and intake of a regular diet was possible in all patients in group B, after intubation. 3) In group A, none of the patients except 1, could be discharged because of postoperative complication, and they died in the hospital. The mean postoperative survival period was 63 +/- 74 days. On the other hand, fatal complications were not observed in group B, and 8 patients were discharged from the hospital (2 of them could resume work). The mean survival period, including 1 survivor, was 136 +/- 101 days, that is significantly longer than that in group A (p < 0.05). From these results, we concluded that esophageal intubation is useful for cases of unresectable esophageal cancer.

Aged↗