Yoshio Izumi

Safety and efficacy of hemoglobin-vesicles and albumin-hemes

Summary Keio University and Waseda University have worked together on artificial O2 carrier research for 20 years in close cooperation. Two candidate materials have been selected from the viewpoints of safety, efficacy, and cost performance. One is Hemoglobin-vesicles (HbV) and the other is albumin-heme (rHSA-heme). This chapter summarizes our video presentation that introduced the recent results of our research into HbV and rHSA-heme.

Prediction of anti-tumour effect of thermochemotherapy with in vitro thermochemosensitivity testing for non-small cell lung cancer

Purpose: We investigated whether it is possible to predict the antitumour effects of thermochemotherapy from the results of anticancer agent sensitivity testing. Materials and Methods: We produced a nude mouse cancer model using 4 lung cancer cell lines. Animals were divided into 4 groups: Thermotherapy (HT group), chemotherapy (CT group), thermochemotherapy (HT+CT group), and no therapy (NT group). Comparison of in vivo and in vitro effects were performed using cisplatin (CDDP), doxorubicin (ADR) and vinorelbine (NVB). In vivo thermotherapy was performed using the Thermotron RF IV, and radiofrequency (RF) capacitative hyperthermia device that induces a localised temperature of 42.0°C for 45 min. The collagen gel embedded culture drug sensitivity test (CD-DST) was used for in vitro chemosensitivity analysis of the anticancer agents. In vitro thermochemotherapy was performed using a modified CD-DST method, with the incubator set at 42.0° for the first hour of the 24 hours drug exposure period. Results: A good correlation was seen between in vivo and in vitro treated/control ratios (T/C%) in the HT group (R = 0.91, p = 0.09). Good correlations were also seen between in vivo and in vitro T/C in all cell lines in the CT group (R = 0.759, p = 0.09) and the HT+CT group (R = 0.65, p = 0.02). True positive rate was 87.5% (7/8), and true negative rate was 100% (4/4). Sensitivity, specificity and accuracy were 100% (7/7), 80% (4/5), and 91.7% (11/12) respectively. Conclusion: A modified CD-DST using an exposure temperature of 42°C can be used to predict the antitumour effect of thermochemotherapy.

Moderate hypoglycemia induces ultrastructural changes in perivascular nerve terminals of cat cerebral arteries

A quantitative morphological analysis of the perivascular nerve terminals of cerebral arteries during moderate hypoglycemia was performed. 5-Hydroxydopamine (5-OHDA) was applied to discriminate dense-cored vesicles, related to noradrenaline, and clear vesicles, related to acetylcholine, under the electron microscope. Five hypoglycemic and 5 normoglycemic cats, all receiving 5-OHDA, were compared. In both the middle cerebral artery and vertebral artery, the dense-cored vesicles were significantly smaller and clear vesicles were significantly larger in hypoglycemia than in normoglycemia. These morphological changes in the vesicles may indicate hyperactivity of the sympathetic system and hypoactivity of the parasympathetic system of the cerebral vessels during hypoglycemia.

Research and development of Haemoglobin vesicle, a cellular type artificial oxygen carrier

Transfusion is an indispensable therapeutic modality in the scenes of every medical field such as emergency medicine, surgery, obstetrics and haematology. To secure safe and reliable transfusion system, we have to pay great attention to the collection, examination, transportation, storage, transfusion of donated blood, and posttransfusion follow up. Since collected donated blood keep its effect within 3 weeks (in Japan), we have to accept the disposition of expired blood. In Japan, due to the declining birthrate and growing population of elderly people, it is suspected that supply and demand of donated blood will show shortage in the near future. To solve these problems, research and development of artificial oxygen carrier has been continued. Artificial oxygen carrier has several advantages compared with the donated blood such as long shelf life, no blood typing, basically no possibility of infectious diseases. Using these characteristics, artificial oxygen carrier can compensate the weak point of transfusion medicine. HbV is one of the cellular type Hb-based oxygen carriers. As chemically modified Hb based oxygen carrier has shown several side-effects (oesophageal dysfunction, vasoconstriction, toxicity of cardiomyocyte), cellular structure is thought ideal to avoid these side-effects. The size of liposome, composition of membrane, way to modify membrane to avoid cellular interaction, Hb concentration, stability in storage, metabolism, was first to be solved. Waseda-Keio group has worked out to solve these problems step by step. Physicochemical characteristics are shown in Table 1. In regards to the development of HbV, many studies have been conducted. • Physico-chemical characteristics of HbV [1,2,3,4] (1) Stable homogeneous thin phospholipid membrane. Assembly of HbV was empowered by molecular association technology. (2) Highly concentrated purified haemoglobin solution was encapsulated in the liposome. (3) Modification of membrane prevent self aggregation as well as less interaction with cellular component in the blood such as leucocyte, platelet. (4) p50 is adjustable when proper allosteric effecter is contained inside the liposome. We have conducted several preclinical studies using small and medium sized animal [5, 6, 7]. • Safety and effectiveness of HbV (1) Forty per cent and 50% haemorrhagic shock followed by resuscitation in rat and Beagle with HbV solution showed satisfactory safety profile as well as effectiveness. (2) Exchange transfusion with HbV solution using rat showed that stable maintenance of circulation was possible up to 90% exchange. (3) Influence to coagulation system was analyzed and the results showed little alteration in coagulation system when 40% of blood was exchanged. (4) Long-term observation to clarify chronic influence on organ function in 40% haemorrhagic shock resuscitation model in rat and Beagle has done and organ function and haematological data was within normal range during 1-year study period. (5) Half life of HbV in rat was measured using isotopic labelled HbV and the study revealed that in rat, half life of HbV was 24 h. In human, half life in blood stream was estimated 3 days. (6) Metabolism of HbV was studied in rat. HbV was phagocytosed by resident macrophage in spleen and liver and was metabolized within 3 weeks. Mouse Correspondence: H. Horinouchi, Department of Surgery, Keio University, School of Medicine, Shinonomachi 35 Shinjuku, Tokyo 160-8582, Japan E-mail: horinouc@a8.keio.jp Table 1 Physicochemical characteristics of HbV