[The evaluation of isoflurane's effect on the cochlear blood flow by laser doppler flowmetry]. / Valutazione mediante flussimetria laser Doppler degli effetti dell'isoflurano sul flusso ematico cocleare.

Laser-Doppler flowetry is actually the method of choice in cochlear blood flow measurement. The Authors analyze, by means of laser doppler flowmetry, the effect of isoflurane, an anesthetic drug with an hypotensive effect, on cochlear blood flow on 10 patients submitted to miringoplasty. A slight increase of cochlear blood flow was recorded in each subject nevertheless a significative reduction of systemic pressure. Since normally hypotension determines a reduction of cochlear blood flow, the Authors state that isoflurane has a protective effect on this microcircular district.

[Study of cutaneous microcirculation using the laser-Doppler method in syndrome X]. / Lo studio del microcircolo cutaneo con metodica laser Doppler nella sindrome X.

Aim of the study was to verify the relationship between syndrome X and generalized microangiopathy. Three groups of patients were selected: Group A, 11 patients with typical syndrome X; Group B, 8 patients with atypical chest pain; Group C, 12 control normal subjects. Microvascular circulation was investigated with a laser Doppler Periflux PF3 at rest (15 min); during ischemia (3 min); during post-ischemic hyperemia on the plantar side of the big toe (where arterovenous anastomoses are particularly abundant) and on the dorsum of the foot (where these anastomoses are very scanty). During each recording we calculated: the mean flux value (FV); the mean concentration of moving blood cells (CMBC); the FV/CMBC ratio (which is related to the flow velocity); the mean percent increase of the three parameters during hyperemia. Patients with syndrome X as compared to the other subjects showed: 1) a significantly higher FV/CMBC ratio at rest and during hyperemia both on the plantar side of the big toe (respectively p = 0.01 and 0.015) and on the dorsum of the foot (respectively p = 0.011 and 0.006). These findings suggest a higher flow velocity in microvascular circulation; significantly lower percent increase of FV and CMBC during hyperemia in the plantar side of the big toe (respectively p = 0.04 and 0.014) but not on the dorsum. The increase of flow velocity at rest and low vasodilatatory reserve after ischemia in an area which is rich of arterovenous anastomoses in patients with syndrome X might be explained by the presence of a basal arterovenous hyperstomia.

[The measurement of cochlear flow by laser Doppler in man: the preliminary results]. / Misurazione del flusso cocleare mediante laser Doppler nell'uomo: risultati preliminari.

Laser-Doppler flowmetry is presently one of the methods of choice in measuring cochlear blood flow. The techniques is non-invasive and is based on the frequency shift of the laser beam induced by the red blood cell movement. Previous studies of cochlear blood flow carried out on animals and humans demonstrated the reliability of laser-Doppler flowmetry and its usefulness in understanding inner ear microcirculation physiology. In this paper we present preliminary data obtained from three patients examined under general anesthesia while undergoing tympanoplasty. Results showed that tracings, whose baseline is proportional with the blood flow, are characterized by waves correlated to pulse beat and automatic ventilation. Moreover, intrinsic contractions of inner ear vessels (waves of vasomotion) as exist in cerebral microcirculation, were observed. Pharmacological hypotension hypocapnia and the application of epinephryne determine a significant reduction of cochlear blood flow. These results suggest that while cochlear blood flow is related to systemic pressure, it has an intrinsic control system. As well since we did not obtain any modification in bone conduction threshold after surgery, we conclude that laser-Doppler flowmetry is a safe technique.

Distribution and development of substance P immunoreactive axons in the chick cornea and uvea.

A study was made of the distribution of Substance P-immunoreactive fibers in chick cornea and uvea in whole mount preparation, using the indirect immunofluorescence technique. The development of these fibers during embryogenesis was also investigated. SP-fibers were present in all chick eye structures, in the various prenatal and postnatal stages examined. Their distribution was comparable with that observed by other workers in mammals. Transformation of the iris musculature from smooth to striated, during development, is not accompanied by significant changes in SP-ergic innervation.

[Morphological relations of sarcolemma, cytoplasmic organelles, and nuclei of the junctional and extrajunctional zones]. / Relazioni morfologiche tra il sarcolemma, gli organelli citoplasmatici e il nucleo della zona giunzionale e della zona extragiunzionale.

In intercostal rat muscles an ultrastructural comparison has been made of the relationships existing in the myofibre between sarcolemma, cytoplasmic organules and nuclei in the end-plate sole and extrajunctional areas. Remarkable differences are described. Particularly, in the end-plate sole area relationships between the perinuclear membrane and the floor of the infoldings are very tight. In the extrajunctional areas, close relationships between the portion of perinuclear membrane that is turned towards the interior of the myofibre and the membranous structures of the triad are frequent.

The two prolongations of spinal ganglia neuroblasts: an ultrastructural study during chick embryo development.

Peripheral and central prolongations of chick embryo spinal ganglia neuroblasts were studied and compared at an ultrastructural level during development. Important differences in the terminal tracts of the prolongations and their endings were demonstrated. The possibility of environmental influences being responsible for structural differences in the two prolongations is suggested. It was not possible, at any stage of development, to demonstrate significant polarization of any cytoplasmatic structure in the emerging cones.