Orientation of glutaraldehyde-fixed erythrocytes in strong static magnetic fields

Higashi, Taneaki; Sagawa, Shiro; Ashida, Noboru; Takeuchi, Tetsuya

doi:10.1002/(sici)1521-186x(1996)17:4<335::aid-bem10>3.0.co;2-n

Cited by 49 publications

(48 citation statements)

References 11 publications

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“…The magnetic orientation of biological cells and molecules in static magnetic ®elds has been reported for purple membranes from halophiles (Halobacterium alobium) [Neugebauer et al, 1977], erythrocytes [Murayama M, 1965;Higashi et al, 1993aHigashi et al, , 1995Suda et al, 1994], platelets [Yamagishi et al, 1992;Higashi et al, 1993b], and ®brin ®bers [Yamagishi et al, 1990;Iwasaka et al, 1994]. Purple membranes of halophiles are oriented perpendicular to the magnetic ®eld [Neugebauer et al, 1977].…”

Section: Introductionmentioning

confidence: 99%

“…Purple membranes of halophiles are oriented perpendicular to the magnetic ®eld [Neugebauer et al, 1977]. In contrast, intact erythrocytes are oriented with their disk plane parallel to it [Higashi et al, 1993a]. These orientations can be explained mainly by the diamagnetic anisotropy of two cell membrane components, the lipid bilayer and the transmembrane proteins.…”

Section: Introductionmentioning

confidence: 99%

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Orientation of bull sperms in static magnetic fields

Emura

Ashida

Higashi

et al. 2000

Bioelectromagnetics

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The orientation of bull sperm cells in static magnetic fields was investigated by microscopic observation. The bull sperm, which has a very flat head, was fixed and its motion was stopped by glutaraldehyde. It was oriented with the whole body and the flat head perpendicular to the direction of the magnetic field. The diamagnetic cell components, such as the cell membrane, the DNA in the head, and the microtubule in the tail, were thought to contribute to this orientation, because bull sperm does not have paramagnetic components. For quantitative measurement of the orientation, the intensity of transmitted light through glutaraldehyde-fixed bull sperm suspension in a photometric cell was determined. The intensity changed slightly in proportion to the mean degree of orientation of the sperms. It increased sigmoidally depending on the intensity of the magnetic field and reached 100% at just below 1 T. The magnetic orientation is very strong in comparison to that of erythrocytes or platelets. By studying the response of the bull sperm to the magnetic field, it will be possible to understand its microstructure in more detail.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Orientation of bull sperms in static magnetic fields

Emura

Ashida

Higashi

et al. 2000

Bioelectromagnetics

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“…The hematocrit value of erythrocyte suspensions with several osmolalities was adjusted to the same value. The samples were equilibrated in air for at least 1 h before ESR measurement to obtain diamagnetic oxyhemoglobin [Higashi et al, 1993]. The cells were used within 6 h after collection of blood.…”

Section: Methodsmentioning

confidence: 99%

“…The remaining determinant which cannot cause the magnetic enhancement for isotropic spheres, is a magnetic ®eld±induced increase in an intracellular adhesive membrane area due to the magnetic orientation of an anisotropic erythrocyte [Suda and Ueno, 1994;Higashi et al, 1995Higashi et al, , 1996Suda and Ueno, 1996]. It is noted that the possibility of the existence of the above-mentioned determinants is not completely eliminated.…”

Section: Mass Conservation Of Intracellular Hemoglobin the Equation mentioning

confidence: 99%

“…However, the cause of the phenomenon has not yet been identi®ed. Possible physical mechanisms underlying the magnetic enhancement of aggregation are, for example, a) a magnetic ®eld induced increase in an intercellular adhesive force per unit membrane area, b) an increase in the adhesive area due to magnetic orientation of the erythrocyte [Suda and Ueno, 1994;Higashi et al, 1995;Higashi et al, 1996;Suda and Ueno, 1996], or c) an increase adhesive area due to greater membrane deformability, and so on. The purpose of this study is to determine the origin of this phenomenon.…”

Section: Introductionmentioning

confidence: 99%

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Osmolality dependence of erythrocyte sedimentation and aggregation in a strong magnetic field

Iino

Okuda

2000

Bioelectromagnetics

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In order to specify the major determinant of the magnetic enhancement of erythrocyte sedimentation observed previously, the dependence of erythrocyte sedimentation rate (ESR) on osmolality was measured under a strong magnetic field. Even at hypotonic osmolality, an increase in ESR due to aggregation was observed in plasma solution as compared with that without aggregation in saline solution. However, the magnetic field did not enhance ESR at hypotonic osmolality, when the cell shape was an isotropic sphere (spherocyte). Thus, we narrowed our search to a mechanism that would explain the enhanced ESR found specifically in anisotropic erythrocytes. It was concluded that the major determinant can only work for anisotropic erythrocytes and is a magnetic field-induced increase in an intermembrane adhesive area due to magnetic orientation of anisotropic erythrocytes.

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Biological effects and health implications in magnetic resonance imaging

Kangarlu

Robitaille

2000

Concepts Magn. Reson.

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Orientation of glutaraldehyde-fixed erythrocytes in strong static magnetic fields

Cited by 49 publications

References 11 publications

Orientation of bull sperms in static magnetic fields

Orientation of bull sperms in static magnetic fields

Osmolality dependence of erythrocyte sedimentation and aggregation in a strong magnetic field

Biological effects and health implications in magnetic resonance imaging

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