Biomedical subjects

D G Gomez

Publications and source records attributed to D G Gomez.

22 records · Page 2Linked to original sources

PubMedDate not supplied

Diagnosis of cerebral ventriculomegaly in normal adult beagles using quantitative MRI.

The brain of 17 asymptomatic normal adult beagles was evaluated with magnetic resonance imaging. Lateral ventricular size was quantified using computer algorithms. In beagles with large ventricles, contrast medium was introduced into the cerebellomedullary cistern to determine whether obstructive hydrocephalus was present. Total lateral ventricular volume ranged from 77 mm3 to 11,726 mm3. Based on Gd-DTPA diffusion, the CSF flow pattern was considered normal and normal neural morphology was seen using electron microscopy. Results suggest a high incidence of clinically asymptomatic ventriculomegaly in normal adult beagles.

Animals↗

PubMedDate not supplied

Cerebrospinal fluid absorption in the rabbit: olfactory pathways.

Twenty rabbits were intrathecally perfused with horseradish peroxidase (HRP) without increasing the cerebrospinal fluid (CSF) pressure. Histologic and ultrastructural studies of the olfactory nerve and nasal mucosa showed HRP along the space between peri- and epineurium down to the smaller nerve branches in the mucosa. Within the mucosa, HRP leaked out from the epineurium and flowed into: (a) lymphatic vessels; (b) mucous glands and ducts; (c) intercellular spaces of the nasal pseudostratified nasal epithelium; and (d) venules. These findings could account for "bulk" flow CSF absorption into the lymphatic system, the nasal cavity, and to a lesser degree, the venous system; also explain CSF rhinorrhea in man and experimental animals; as well as lymphatic drainage of CSF into cervical lymph nodes.

Absorption↗

PubMedDate not supplied

Cerebrospinal fluid absorption in the rabbit. Inner ear pathways.

Fifteen adult rabbits were perfused intrathecally with horseradish peroxidase (HRP) for 20-30 min under conditions that prevented any increase in cerebrospinal fluid (CSF) pressure. Histologic and ultrastructural examination of the cochlea disclosed HRP deposits along the cochlear and vestibular branches of the auditory nerve and beyond their ganglia, in a) epineural and perineural spaces; b) intraneural spaces reaching the membrane of myelinated axons via nodes of Ranvier; and c) extending beyond the epineurium into area lymphatics. HRP was also found in the basilar membrane, along with deposits in the scalae tympani, vestibuli, media and the spiral ligament. The endolymph also received HRP which followed vestibular nerve fibers and penetrated between sustentacular and hair cells of the cristae ampullaris and both maculae. HRP permeated interendothelial spaces lining the modiolus to reach the scala vestibuli lymphatics close to all the above areas were also permeated by HRP, but the inner tunnel was devoid of the marker.

Absorption↗

PubMedDate not supplied

A canine model of acute hydrocephalus with MR correlation.

Within 3 hours of induction of acute hydrocephalus in a canine model, lateral ventricular CSF pressure increased from an initial average of 14.6 +/- 2.8 cm H2O to 40.2 +/- 5.7 cm H2O. Ventricular volumes, as measured from MR images, increased 1.45 +/- 0.94 cm3, 1.92 +/- 0.82 cm3, and 2.24 +/- 0.60 cm3 after 6, 24, and 48 hours, of hydrocephalus, respectively. This canine model was reliable and consistent with clinical conditions.

Acute Disease↗