PubMed Health⌕ Search

Biomedical subjects

D Weingarten

Publications and source records attributed to D Weingarten.

8 recordsLinked to original sources
PubMed1987

Indoor and outdoor efficacy testing of a broad-spectrum sunscreen against ultraviolet A radiation in psoralen-sensitized subjects.

The efficacy of a sunscreen containing an investigational drug, butyl methoxydibenzoylmethane in combination with padimate O against the erythemogenic effect of ultraviolet A (UVA) radiation was evaluated in two double-blind studies involving subjects sensitized with topical 8-methoxypsoralen. UVA radiation was supplied from either a filtered solar simulator (indoors) or filtered sunlight (outdoors). Five formulations were tested: 3% butyl methoxydibenzoylmethane and 7% padimate O, 7% padimate O, 5% octyl salicylate, and 3% oxybenzone, 3% butyl methoxydibenzoylmethane alone, 7% padimate O alone, and vehicle. Sunscreen protection against the erythemogenic effect of UVA radiation was expressed as phototoxic protection factors. The phototoxic protection factor for each sunscreen was derived from a ratio of the minimal phototoxic dose of UVA radiation that produced delayed erythema on sunscreen-protected and unprotected skin. The combination of 3% butyl methoxydibenzoylmethane and 7% padimate O provided significantly greater protection than the other sunscreen formulations, and for each sunscreen the phototoxic protection factors determined indoors and outdoors were comparable.

4-Aminobenzoic Acid↗
PubMed1986

PUVA therapy for psoriasis: comparison of oral and bath-water delivery of 8-methoxypsoralen.

A direct clinical comparison has been made of the efficacy of oral 8-methoxypsoralen with bath-water delivery of 8-methoxypsoralen during psoralen ultraviolet A (PUVA) phototherapy for a group of forty patients with stable plaque-type psoriasis vulgaris. The 8-methoxypsoralen concentration was 3.7 mg/liter in the bath water. The efficacy of these treatments was assessed by their ability to improve or clear the psoriasis. The skin of eight of the twenty patients with oral psoralen cleared, and another eight showed good improvement. Of the twenty patients who received 8-methoxypsoralen in bath water, eight patients had clearing of the skin, whereas nine patients had good improvement during the initial 8-week treatment period. Administration of 8-methoxypsoralen in bath water required much lower ultraviolet A irradiance to achieve maximum improvement. There were no systemic side effects in the patients treated by bath-water delivery; however, some patients did develop phototoxic erythema. Minimal phototoxic doses were also studied in patients and in volunteers using both routes of psoralen delivery. The minimal phototoxic dose threshold after psoralen bath delivery gradually declined over five treatments from 5.3 +/- 0.6 joules/cm2 to 2.8 +/- 0.3 joules/cm2, suggesting an accumulation of psoralen in the skin with this method of drug delivery. Bath-water delivery of 8-methoxypsoralen was therefore found to be as effective as oral administration of 8-methoxypsoralen and yet required smaller amounts of ultraviolet A radiation and yielded fewer side effects. It would thus seem to be confirmed as a useful alternative means of 8-methoxypsoralen administration in PUVA therapy.

Administration, Oral↗
PubMed1985

Glucocorticoid-mediated increases in glycerol phosphate dehydrogenase activity is inhibited by the phorbol ester tumor promoters.

An oligodendroglial specific property, glucocorticoid regulation of glycerol-3-phosphate dehydrogenase (GPDH) levels, was inhibited in C6 rat glioma cells when 4 beta-phorbol 12-myristate 13-acetate (PMA) was added to the cultures. PMA inhibited GPDH induction in both logarithmic- and stationary-phase cells. These events are most likely mediated through the phorbol ester receptor since the ability of various phorbol ester analogs to compete with the ligand [3H]4 beta-phorbol 12,13-dibutyrate for binding to the receptor correlates with the ability the particular analog has to inhibit GPDH induction. Additionally, like tumor promotion in vivo, the inhibition of GPDH induction is reversible. The PMA effect is not restricted to the C6 cell line since PMA also inhibits GPDH inducibility in another rat glioma cell line. This PMA-mediated event has been partially characterized. PMA did not affect the overall rate of protein or RNA synthesis. It was ineffective in altering both glucocorticoid accumulation to the nucleus and the rate of GPDH degradation. It appears likely that PMA's inhibitory action occurs at the transcriptional or translational level.

Animals↗
PubMed1978

In vitro nuclear 3H-hydrocortisone binding in the hypothalamus of the pig.

Hypothalamic cell nuclear uptake and binding of 3H-hydrocortisone (3H-HC)-receptor complexes were studied in a cell-free system. Greater net concentrations of radioactivity were found in the 0.4 M KCl non-extractable fraction (sediment) in the first 20 min of incubation and in the 0.4 M KCl extractable fraction (supernatant) from 30 to 60 min. Incubation in low ionic strength medium favored localization of radioactivity in the supernatant, whereas high ionic strength promoted greated localization in the sediment. Specific binding in the supernatant was non-saturable, but reached a plateau in the sediment at about 5 X 10(-8)M 3H-HC. The observed value of Kd for binding in the nuclear sediment was 4.88 X 10(9)M-1 and the maximum number of binding sites was 8.8 femtomoles/mg DNA. RNA polymerase activity increased by 59% in the presence of hormone-receptors over that in the presence of free hormone in buffer.

Animals↗