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Biomedical subjects

R E Farber

Publications and source records attributed to R E Farber.

At least 19 recordsLinked to original sources
PubMed1996

Relationship of 133Xe cerebral blood flow to middle cerebral arterial flow velocity in men at rest.

Cerebral blood flow (CBF) was measured by 133Xe clearance simultaneously with the velocity of blood flow through the left middle cerebral artery (MCA) over a wide range of arterial PCO2 in eight normal men. Average arterial PCO2, which was varied by giving 4% and 6% CO2 in O2 and by controlled hyperventilation on O2, ranged from 25.3 to 49.9 mm Hg. Corresponding average values of global CBF15 were 27.2 and 65.0 ml 100 g min-1, respectively, whereas MCA blood-flow velocity ranged from 42.8 to 94.2 cm/s. The relationship of CBF to MCA blood-flow velocity over the imposed range of arterial PCO2 was described analytically by a parabola with the equation: CBF = 22.8 - 0.17 x velocity + 0.006 x velocity2 The observed data indicate that MCA blood-flow velocity is a useful index of CBF response to change in arterial PCO2 during O2 breathing at rest. With respect to baseline values measured while breathing 100% O2 spontaneously, percent changes in velocity were significantly smaller than corresponding percent changes in CBF at increased levels of arterial PCO2 and larger than CBF changes at the lower arterial PCO2. These observed relative changes are consistent with MCA vasodilation at the site of measurement during exposure to progressive hypercapnia and also during extreme hyperventilation hypocapnia.

Adult↗
PubMed1995

A longitudinal study of the T cell activation marker CD26 in chronic progressive multiple sclerosis.

Activated T cells are implicated in the pathogenesis of multiple sclerosis (MS), an autoimmune demyelinating disease of the central nervous system. Serial measurements of T cell activation molecules and T cell subpopulations were performed over 12 months in patients with chronic progressive multiple sclerosis and healthy controls, and correlated with clinical indices of disease progression measured by standardized disability scores. Of the markers studied, the activation molecule CD26 appeared to exhibit a more consistent pattern and to be elevated in MS patients; therefore we concentrated our attention on this marker, especially in view of recent evidence of its role in T cell activation. In this small patient group, the elevation of CD26 in the MS patients did not reach statistical significance, when compared to the level in the controls. Interestingly, the percentage of CD26 but not CD25 or HLA-DR correlated with the MS patients' disability scores. However, the clinical significance of this observation as an indication of disease activity in chronic progressive MS remains to be demonstrated in studies of larger patient populations.

Adult↗
PubMed1995

Spontaneous intracranial hypotension: headache with a reversible Arnold-Chiari malformation.

Spontaneous intracranial hypotension is characterized by severe postural headache in the setting of low CSF pressure, usually attributed to a cryptic CSF leak. We report a patient whose prolonged refractory headache was characterized by the clinical symptoms of occipital neuralgia, but was also associated with the radiographic appearance of an Arnold-Chiari malformation, type I and low CSF pressure. After extensive diagnostic evaluation, CT cisternomyelography ultimately demonstrated a CSF leak at the C2 vertebral level. Symptomatic relief was sustained only with long-term theophylline administration. The apparent Arnold-Chiari malformation resolved with treatment of the low CSF pressure.

Adult↗