IN-VITRO GALLSTONE LITHOTRIPSY WITH A TUNABLE-DYE LASER AND AN ULTRASONIC CAVITATION WIRE

SummaryPlatelets were found to aggregate spontaneously when exposed to ultrasound generated by a commercial therapeutic device. At a given frequency, aggregation was found to be a dose-related phenomenon, increasing intensities of ultrasound inducing more extensive and more rapid aggregation. At any single intensity, the extent aggregation was increased as the frequency of the applied ultrasound was decreased (from 3.0 to 0.75 MHz).Ultrasound-induced platelet aggregation was found to be related to overall platelet sensitivity to adenosine diphosphate. More sensitive platelets were found to aggregate spontaneously at lower intensities of sound, and also the maximum extent of aggregation was found to be greater. Examination of ultrasound-induced platelet aggregates by electron microscopy demonstrated that the platelets had undergone the release reaction.The observation that haemoglobin was released from erythrocytes in whole blood irradiated under identical physical conditions suggests that the platelets are being distrupted by ultrasonic cavitation (violent gas/bubble oscillation).It is postulated that overall platelet aggregation is the result of two distinct effects. Firstly, the direct action of ultrasonic cavitation disrupts a small proportion of the platelet population, resulting in the liberation of active substances. These substances produce aggregation, both directly and indirectly by inducing the physiological release reaction in adjacent undamaged platelets.

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Action spectra determined with tunable dye laser light for light-induced proton efflux and uptake in membrane vesicles of Halobacterium halobium.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(19)85686-7 ◽

1980 ◽

Vol 255 (8) ◽

pp. 3245-3247

Author(s):

R.V. Greene ◽

R.E. MacDonald ◽

G.J. Perrault

Keyword(s):

Laser Light ◽

Membrane Vesicles ◽

Dye Laser ◽

Halobacterium Halobium ◽

Proton Efflux ◽

Action Spectra ◽

Tunable Dye Laser

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Tunable dye laser with an acoustooptic CaMoO4filter

Soviet Journal of Quantum Electronics ◽

10.1070/qe1988v018n04abeh011551 ◽

1988 ◽

Vol 18 (4) ◽

pp. 453-455 ◽

Cited By ~ 5

Author(s):

M M Mazur ◽

Kh M Makhmudov ◽

V I Pustovoĭt

Keyword(s):

Dye Laser ◽

Tunable Dye Laser

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Application of the 1-µsec pulsed-dye laser to the treatment of experimental cerebral vasospasm

Journal of Neurosurgery ◽

10.3171/jns.1991.75.2.0271 ◽

1991 ◽

Vol 75 (2) ◽

pp. 271-276 ◽

Cited By ~ 12

Author(s):

Atsushi Teramura ◽

Robert Macfarlane ◽

Christopher J. Owen ◽

Ralph de la Torre ◽

Kenton W. Gregory ◽

...

Keyword(s):

Cerebral Vasospasm ◽

Basilar Artery ◽

Laser Energy ◽

Autologous Blood ◽

Preliminary Investigation ◽

Dye Laser ◽

Pulsed Dye Laser ◽

Content Type

✓ Laser energy of 480 nm was applied in 1-µsec pulses varying between 2.2 and 10 mJ to in vitro and in vivo models of cerebral vasospasm. First, the pulsed-dye laser was applied intravascularly via a 320-µm fiber to basilar artery segments from six dogs. The segments were mounted in a vessel-perfusion apparatus and constricted to, on average, 70% of resting diameter by superfusion with dog hemolysate. Immediate increase in basilar artery diameter occurred to a mean of 83% of control. In a second model, the basilar artery was exposed transclivally in the rabbit. In three normal animals, superfusion of the artery with rabbit hemolysate resulted in a reduction of mean vessel diameter to 81% of control. Following extravascular application of the laser, vessels returned to an average of 106% of the resting state. In six rabbits, the basilar artery was constricted by two intracisternal injections of autologous blood, 3 days apart. Two to 4 days after the second injection, the basilar artery was exposed. Extravascular laser treatment from a quartz fiber placed perpendicular to the vessel adventitia resulted in an immediate 53% average increase in caliber to an estimated 107% of control. No reconstriction was observed over a period of up to 5 hours. Morphologically, damage to the arterial wall was slight. This preliminary investigation suggests that the 1-µsec pulsed-dye laser may be of benefit in the treatment of cerebral vasospasm.

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