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Biomedical subjects

M Globus

Publications and source records attributed to M Globus.

60 records · Page 4Linked to original sources

Differentiation in vitro of innervated tail regenerates in larval Ambystoma.

Larval Ambystoma tail regenerates, innervated by the intact spinal cord, were cultured with their epidermal covering in modified Parker's medium (CMRL-1415) and the morphological integrity of the explanted regenerates was maintained with consistent success. The results show that the larval urodele tail blastema is capable of undergoing growth and differentiation when isolated in vitro and regeneration follows the normal in vivo pattern. A diffuse aggregate of blastema cells, which extended caudally from the cut end of the notochord at the time of explantation, underwent differentiation in vitro in the presence of the regenerating spinal cord. The importance of the nerve in regeneration is discussed in relation to the in vitro system.

Ambystoma↗

In vitro studies of limb regeneration in adult Diemictylus viridescens: neural dependence of blastema cells for growth and differentiation.

Explants of 99 adult newt forelimb blastemata (21- to 24-day regenerates) were cultured, with and without implanted dorsal root ganglia, in modified Parker's medium (CMRL-1415) for periods of 72-144 h. Growth and differentiation of the cultured blastemata were compared with ganglionated and non-ganglionated controls fixed at the start of the culture period. The results of these experiments establish that implanted spinal ganglia are able to sustain growth and differentiation of forelimb blastemata in vitro: active proliferation amongst the blastema cells was found to be correlated with the presence of an implanted ganglion. In addition, the blastema cells exhibited a differential growth response which was most pronounced when the ganglion was eccentrically implanted 2-3 days before explantation of the limb regenerate. These results suggest that a causal relationship exists between the position of the implanted ganglion and the localization of growth within the blastema. The nerve influence, believed to be mediated by a chemical factor(s), was localized in the region of the implanted neurons, indicating that a close association between the nerves and the responding blastema cells is essential for normal growth. The importance of the physical presence of nerves for the cultivation of blastemata in vitro is emphasized.

Animals↗

The effect of chronic propranolol therapy on regional cerebral blood flow in hypertensive patients.

In 31 hypertensive patients the effect of chronic oral administration of the beta blocking agent propranolol on regional cerebral blood flow (rCBF) was studied, using the non-invasive 133Xenon inhalation technique. The results of the measurements were compared to the rCBF obtained in an age-matched normal control group. Our study shows that during long-term therapy with low doses of propranolol (less than 120 mg/daily) the rCBF is unaffected, but it is increased significantly if higher doses (greater than 120 mg/daily) are used. In all six patients who served as their own control, as they had basic rCBF measurements before or during low-dose propranolol, the rCBF on high-dose propranolol became significantly increased. The possible mechanisms which may cause the increased rCBF on high-dose propranolol are discussed.

Administration, Oral↗