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Biomedical subjects

E Tsuchida

Publications and source records attributed to E Tsuchida.

At least 73 records · Page 4Linked to original sources
PubMed1993

Balloon occlusion of a spontaneous carotid-cavernous fistula in Ehlers-Danlos syndrome type IV.

A case of spontaneous carotid-cavernous fistula associated with Ehlers-Danlos syndrome Type IV was treated successfully by transarterial balloon embolization. To minimize the stress to the arterial wall, we detached three silastic balloons with low-attachment force in the cavernous sinus with the aid of a proximal balloon to control the high flow of the fistula. To achieve complete obliteration, we had to inflate the third balloon to dimensions that occluded the cavernous portion of the internal carotid artery. Patients with Ehlers-Danlos syndrome Type IV carry a high risk when undergoing any diagnostic or therapeutic endovascular procedure due to the fragility of their blood vessels. Recognition of this entity is important and special attention should be paid to its pathophysiology for a successful treatment.

Adult↗
PubMed1993

Synthesis of porphinatoirons having an alkyl amphiphilic chain and their O2 binding properties in lipid bilayers.

Synthesis and characterization of two amphiphilic tetraphenylporphinatoiron complexes having a glycerophosphocholine or an alkyl phosphoserine group are described. These porphinatoiron(II) complexes with 1-dodecyl-2-methyl-imidazole (L2MIm) were efficiently embedded in the bilayer of a phospholipid vesicle due to their high compatibility with lipids, similar to the heme substituted with four alkyl amphiphilic chains (lipid-heme). Oxygen transporting ability of the phospholipid vesicles embedded with hemes were similar to that of hemoglobin (Hb) in red blood cells.

Carbon Monoxide↗
PubMed1992

Lipid microsphere containing lipophilic heme: preparation and oxygen transportation under physiological conditions.

Lipophilic heme (1-laurylimidazole-ligated 5,10,15,20-tetrakis(alpha, alpha, alpha, alpha-o- pivalamidophenyl)porphinatoiron(II) complex) is solubilized in lipid (triglyceride) at high concentrations and emulsified with a phospholipid in physiological salt solution, giving a deeply red-colored suspension of lipid microspheres (approx. 250 nm in diameter). The heme forms an oxygen adduct in a similar manner as oxyhemoglobin and the lipid microspheres take up and release oxygen reversibly at 37 degrees C in the aqueous medium. The oxygen-transporting ability is comparable with that of the red blood cell. Intravenous injection of the heme/lipid microsphere solution to rabbits demonstrates that it transports oxygen even in vivo and that it is cleared from the blood stream with a half-life time of approx. 1 h.

Animals↗
PubMed1992

Paraplegia due to a ruptured aneurysm of the distal posterior inferior cerebellar artery.

A case of paraplegia was due to a ruptured aneurysm of the distal posterior inferior cerebellar artery. The paraplegia was caused by a unilateral lesion located between the cervicomedullary junction and the C2 level, where it involved both crossed and uncrossed pyramidal fibres projecting to the lower extremities. Since a vascular lesion near the cervicomedullary junction is likely to be missed, special attention should be paid to this region when investigating subarachnoid haemorrhage with paraplegia.

Arteries↗
PubMed1992

Synthesis and characterization of artificial red cell (ARC).

An unsaturated lipid made from 2,4-octadecadienoic acid was used as a component of phospholipid vesicles. The vesicles (0.2 micron phi) was prepared by an extrusion method, and the unsaturated lipid was polymerized with gamma-ray. Vesicles constructed from the polylipid show enormous stability during long term storage in frozen state and can be handled easily. Negative effect could not be confirmed in vitro tests. This system satisfies all the physiological conditions, such as oxygen transport ability and solution properties as a blood substitute.

Animals↗
PubMed1992

Oxygen-transport and solution properties of polylipid/Hb vesicles (ARC).

Polymerized phospholipid vesicle encapsulating Hb (polylipid/Hb vesicle) was prepared from a mixture of unsaturated phospholipid, cholesterol and unsaturated fatty acid and polymerization by gamma-ray irradiation. The average radius of resulting vesicles was 203 +/- 39 nm and concentrated Hb (30 wt%) was efficiently encapsulated. gamma-Ray polymerization proceeds theoretically at low temperature (4 degrees C). P50 and oxygen transporting efficiency were adjusted to 40 mmHg and 40%, respectively. Oncotic pressure and solution viscosity can be controlled to the same values as blood.

Blood Substitutes↗
PubMed1992

Development of analytical methods to evaluate SFH.

For the determination of stroma content in SFH, two analytical methods were developed, the HPLC-UV for phospholipids and the enzyme immunoassay for blood group antigen. These analytical methods were applied to evaluate three representative SFH preparations. The 36,000 x g centrifugation method was shown to contain higher amount of stroma components. On the other hand, the BMM-40 nm and the ultrafiltration method with a 100 kd membrane was shown to remove more than 99.7% of phospholipids and almost all of blood group antigen from hemoglobin solutions. These results demonstrated that these analytical methods were very useful in evaluating any highly purified hemoglobin solutions.

ABO Blood-Group System↗
PubMed1992

Characteristics of polylipid/Hb vesicles (ARC) (in vitro and in vivo test).

Polylipid/Hb vesicle, which is polymerized phospholipid vesicles (200 nm) encapsulating concentrated Hb solution, has been established by us as an artificial red cell (ARC). ARC can be easily adjusted to physiological conditions (viscosity, density and oncotic pressure etc) as the same of human blood. Our ARC has excellent blood compatibility (no effect on coagulation, no hemolysis and no red cell aggregation). Neither acute toxicity nor damage of internal organs was confirmed. Oxygen transporting capacity was almost the same as human blood, and the half life in blood stream was ca. 13 hrs.

Animals↗
PubMed1992

Stability and blood compatibility of polylipid/Hb.

The Polylipid/Hb vesicle is a new artificial red cell (ARC) based on liposome-encapsulated Hb. Advantages are derived from the stabilized liposomal bilayer membranes, obtained by polymerization of 1,2-bis(2,4-octadecadienoyl)-sn-glycero-3-phospho choline (DODPC). Furthermore, blood compatibility in vitro are good.

Blood Coagulation↗
PubMed1988

Liposome/heme as a totally synthetic oxygen carrier.

We synthetically derived protoheme (oxygen-binding site of hemoglobin) to an amphiphilic heme compound and embedded it in the phospholipid bilayer of liposomes, not in an aqueous inside region of liposomes. This liposome/heme transports oxygen efficiently under physiological conditions. Characteristics of our totally synthetic liposome/heme as an artificial oxygen carrier, are summarized as follows. (i) Oxygen-binding is reversible and very rapid. (ii) The oxygen volume dissolved in the fluid is similar or superior to that of blood. (iii) The oxygen-binding affinity is close to that of blood. (iv) The particle size is smaller than 0.1 micron. (v) It is physically and mechanically stable under shear stress and storage. (vi) The components are synthetic derivatives of protoheme and phospholipid originated in nature. The advantages (i)-(iii) and brilliant red color of the solution are derived from the fact that our totally synthetic liposome/heme, transports oxygen in the same principle of red blood cells. When the liposome/heme solution was mixed with human blood, the liposome/heme delivered oxygen to blood in the mixture system. The oxygen-exchanging of the liposome/heme with blood was also tested ex-vivo using an artificial lung apparatus. The oxy liposome/heme was circulated through A-V of a dog leg, and the oxygen concentration was kept at a high level. This demonstrates the fact that the synthetic liposome/heme transports and delivers oxygen to the muscle tissue. Application to extracorporeal circulation and transfusion test will also be reported.

Animals↗
PubMed1987

Clearance and tissue distribution of functionalized polymeric liposomes from the blood stream of rats.

Polymeric liposomes containing a synthetic porphinato-iron-imidazole complex (hemoglobin or red blood cell model) were labeled by introducing 1,2-di[1-14C]palmitoyl-sn-glycero-3-phosphocholine into their polymerized bilayers. After intravenous injection into rats, their clearance from a blood stream was measured. The apparent half-life time (50% disappearance time) was about 14 +/- 2 h. Their tissue distribution was determined with time by whole autoradiographic measurement.

Animals↗
PubMed1986

Interactions of functionalized polymeric liposomes having a porphinato-iron complex with some biological cells and components in vitro.

The hemocompatibility of functionalized polymeric liposome particles (diameter: 20-32 nm), which have a synthetic porphinato-iron complex in their polymerized bilayers and can carry oxygen, was studied in vitro. The ultramicroparticles did not induce hemolysis, platelet aggregation and plasma coagulation directly and were stable against hydrolysis by phospholipases A2 and D.

Animals↗
PubMed1984

Enzymatic reduction of synthetic polymer-bound hemin derivatives: efficient method to prepare a heme-oxygen adduct in cooled aqueous medium.

Synthetic polymer-bound hemin (iron(III) protoporphyrin IX) derivatives were effectively reduced by ferredoxin and ferredoxin-NADP reductase system. The resultant polymer-bound heme (iron(II) protoporphyrin IX) derivatives formed oxygen adducts with a lifetime of ca. 1 hr in aqueous solution at -30 degrees C. The reduction rate is discussed in terms of the structure of the hemin derivatives.

Animals↗
PubMed1983

Liposomal heme as oxygen carrier under semi-physiological conditions. Orientation study of heme embedded in a phospholipid bilayer by an electrooptical method.

The meso-tetra(alpha,alpha,alpha,alpha(o-pivalamidophenyl]porphinato iron-mono(1-lauryl-2-methylimidazole) complex embedded in the bilayer of dimyristoylphosphatidylcholine (liposomal heme) binds molecular oxygen reversibly at pH 7 and 37 degrees C. Orientation of the iron porphyrin complex in the phospholipid bilayer was studied by electric birefringence and dichroism. It was observed that both the phospholipid bibilayer of liposome and the porphyrin plane are oriented nearly in parallel to the electric field. Therefore the angle between the porphyrin plane and the bilayer is considered to be practically small.

Circular Dichroism↗