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Biomedical subjects

P Bonnin

Publications and source records attributed to P Bonnin.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

Simultaneous ultrasonic measurement of carotid blood flow and intracerebral haemodynamics in man.

Common carotid blood flow and middle cerebral artery velocities were determined simultaneously by using a range gated Doppler velocimeter and transcranial apparatus in ten subjects. Middle cerebral artery velocities were used as an index of cerebral resistance. Different gas mixture concentrations were breathed in order to change cerebral haemodynamic conditions. In each condition there was a simultaneous modification of blood gases and cervicocerebral haemodynamics in common carotid blood flow and cerebral vascular resistance index. Carotid blood flow and the resistance index in middle cerebral artery changed also on opposite side. Acute hypercapnia in normoxia increases common carotid blood flow by 33% and simultaneously decreases cerebral resistance index by 11%. Normocapnic hyperoxia was associated with a fall in common carotid blood flow by 13% and with an increase in cerebral resistance index by 7%. There was a inter-subject statistically significant relation between common carotid blood flow and index of cerebral resistances (0.78 < r < 0.98). However there was an individual reactivity with large scatter when data from different subjects were pooled. Nevertheless the results provide evidence that changes in middle cerebral artery resistance indices are reflected by common carotid blood flow modifications.

Adult↗
PubMedDate not supplied

[Our experience with clinical study of the eye in the near infrared region].

An instrumental setup has been developed in order to perform a quantitative clinical study of the reflectance of ocular tissues in several spectral ranges of the visible and the near infrared. The images recorded at different wavelengths are obtained nearly simultaneously from a CCD camera adapted to a retinal camera and connected to a microcomputer. The results of their analysis after processing are described. Each different type of lesion exhibits a typical spectral signature, demonstrating the value of this noninvasive extra ancillary test to help the differential diagnosis and the follow-up of choroidal tumors.

Eye Neoplasms↗
PubMedDate not supplied

[Osseous choristoma of the peripapillary choroid].

Two young women had an osseous choristoma of the juxtapapillary choroid. They were examined for a macular syndrome caused by a subretinal neovascular membrane with hemorrhage. The investigations led to the initial lesion: the osseous choristoma. Ophthalmoscopic findings, diagnosis and discussion are presented.

Adult↗