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Biomedical subjects

D A Auerbach

Publications and source records attributed to D A Auerbach.

5 recordsLinked to original sources
PubMed1983

Localized pulmonary interstitial emphysema: treatment by bronchial occlusion.

Selective bronchial occlusion for the treatment of localized cystic pulmonary interstitial emphysema (PIE) offers a means to facilitate weaning from ventilatory support and to preserve potentially functional lung parenchyma. We employed a commercially manufactured balloon catheter, placed under direct visualization to occlude a left mainstem bronchus in two cases of localized PIE. This is the safest method for selective bronchial occlusion so far reported. Therapeutic success was achieved with either continuous or intermittent bronchial occlusion. Evaluation of pulmonary function with nuclear scintigraphy aids in determining the most appropriate position for the occluding catheter and permits assessment of the resultant improvements in pulmonary function.

Bronchi↗
PubMed1981

Seesaw signal processing in pineal cells: homologous sensitization of adrenergic stimulation of cyclic GMP accompanies homologous desensitization of beta-adrenergic stimulation of cyclic AMP.

Studies of the adrenergic regulation of cyclic GMP in the pineal gland show that (-)-norepinephrine stimulates cyclic GMP primarily in pineal cells, rather than in nerve endings as previously thought. The response exhibits the interesting and unusual characteristic of homologous sensitization: It is maintained by neural stimulation and disappears gradually as a consequence of depressed neural stimulation, due to denervation or decentralization of the superior cervical ganglia or to constant light. The response is restored in intact animals that had been in a constant-light environment when they are returned to a normal light cycle and in ganglionectomized animals by norepinephrine treatment. These findings are especially interesting because the pineal adrenergic--cyclic AMP stimulus--response system exhibits homologous desensitization. The occurrence of homologous sensitization of a cyclic GMP response and desensitization of a cyclic AMP response, which we term seesaw signal processing, in the same tissue or cell has intriguing implications. It provides a mechanism through which the qualitative nature of a multicomponent response can be modified. Such a mechanism could play a role in signal processing by neural or neuroendocrine tissues that release two or more extracellular messages.

Animals↗
PubMed1981

Neonatal rat pinealocytes: typical and atypical characteristics of [125I]iodohydroxybenzylpindolol binding and adenosine 3',5'-monophosphate accumulation.

Techniques are described which make it possible to study beta-adrenergic receptors on intact neuroendocrine cells. Receptors were characterized on neonatal pinealocytes using the radioligand [125I]iodohydroxybenzylpindolol ([125I]IHYP). Specific binding of [125I]IHYP, which is 4-fold greater than nonspecific binding, is concentration and temperature dependent, reversible, and saturable. [125I]IHYP binds noncooperatively (Kd = 35 pM), and Scatchard analysis indicates that only a single class of receptor sites for [125I]IHYP is present. Under the conditions used, it appears that there are about 12,000 +/- 1,100 sites/cell. Inhibition of specific [125I]IHYP binding by beta-adrenergic agonists and antagonists is stereospecific, and the relative potency of agonists is characteristic of binding to beta-adrenergic receptors. Analysis of adrenergic stimulation of intracellular cAMP accumulation indicates that similar half-maximal concentrations of antagonists inhibit [125I]IHYP binding and adrenergically stimulated cAMP accumulation. In contrast, beta-adrenergic agonists are considerably more potent in stimulating cAMP than in inhibiting [125I]IHYP binding. Unexpected differences, not previously reportd, were found in the shapes of the cAMP accumulation dose-response curves of norepinephrine and isoproterenol. The relative potencies of these two agonists appear to be partially concentration dependent. This raises the possibility that there may be distinct differences in the intrinsic effects of these compounds on the regulation of intracellular cAMP accumulation in pinealocytes. (Endocrinology 108: 559, 1981)

Alprenolol↗