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Biomedical subjects

S A Baranowitz

Publications and source records attributed to S A Baranowitz.

6 recordsLinked to original sources
PubMed1995

Acetaminophen toxicity is substantially reduced by beta-carotene in mice.

Acetaminophen is toxic in overdose and even at routine therapeutic doses in glutathione-deficient populations such as alcoholics and AIDS patients. We were intrigued by the fact that beta-carotene is stored in the liver, the major organ of detoxification, and we speculated that dietary supplementation of beta-carotene would enhance the liver's ability to withstand toxic challenge from acetaminophen. We present a series of experiments which demonstrate that beta-carotene can prevent death or ameliorate toxicity from acetaminophen in mice.

Acetaminophen↗
PubMed1989

Regeneration, neural crest derivatives and retinoids: a new synthesis.

Consideration of recent data from diverse fields of biology permits the presentation of a general theory to explain the underlying mechanism and phylogenetic distribution of vertebrate regenerative capacity. It is suggested that dermal xanthophores, which are neural crest derivatives that contain carotenoid pigments, serve as storage reservoirs for proretinoids. At trauma, carotenoids are released and are converted to retinoids. The spatial distribution of xanthophores at the amputation site determines the amount of carotenoids released, which in turn determines the number of cells which will participate in regeneration and their degree of dedifferentiation. It also influences the proliferative and morphogenetic potential of the blastema. The theory is based on several factors. (1) The pluripotency of neural crest derivatives in general and that of chromatophores in particular; (2) The storage metabolism of carotenoids, especially their convertability to retinoids; (3) The known roles of retinoids in regeneration; (4) Evidence suggesting a relationship between carotenoids and regeneration in invertebrates; and (5) Dynamic characteristics of regenerating systems. The theory is experimentally testable with currently available technology. Specific review of data concerning urodele lens regeneration illustrates the theory. Evidence from amphibian limb regeneration is also presented. Methods of evaluation of other regeneration systems are outlined.

Amphibians↗
PubMed1979

Lizard and newt tail regeneration: a quantitative study.

Almost perfect fits of the Gompertz equation to the growth in length of tail regenerates in the lizard, Lacerta lepida, and the newt, Notophthalmus viridescens, were obtained. Comparison of certain parameters of the equation with published mitotic index data suggests that the Gompertz equation characterizes each system at least from the time that significant mitotic activity is first observed histologically. An objective method for comparing the regeneration periods of the two species is described and applied. A unified hypothesis derived from consideration of properties of the Gompertz equation successfully accounts for the following phenomena reported, but previously unexplained, in the literature: (1) proximal amputations result in longer regenerates than do distal amputations; (2) proximal amputations elicit greater absolute rates of elongation (in mm/day) than do distal amputations; (3) the percent replaced of the length removed is rather constant, regardless of the absolute length regenerated; and (4) one of the parameters of the Gompertz equation appears to be lognormally distributed in a regenerating population. (See text for references.) A computerized interactive graphical system for normalizing growth equations of individual regenerates and integrating the mathematical model with potential candidates for biological control factors is briefly described.

Animals↗