Biomedical subjects

C Oresajo

Publications and source records attributed to C Oresajo.

6 recordsLinked to original sources

PubMed1997

Alpha hydroxyacids modulate stratum corneum barrier function.

Alpha hydroxyacids (AHAs) are used to enhance stratum corneum desquamation and improve skin appearance. The purpose of this study was to evaluate whether some AHAs improve skin barrier function and prevent skin irritation. Eleven healthy subjects (aged 28 +/- 6 years, mean +/- SD) entered the study. Six test sites of 8 x 5 cm (four different AHAs, vehicle only (VE) and untreated control (UNT) were selected and randomly rotated on the volar arm and forearm. The four different AHAs at 8% concentration in base cream were glycolic acid (GA), lactic acid, tartaric acid (TA) and gluconolactone (GLU). The products were applied twice a day for 4 weeks (2 mg/cm2). At week 4, a 5% sodium lauryl sulphate (SLS) challenge patch test was performed under occlusion for 6 h (HillTop chamber, 18 mm wide) on each site. Barrier function and skin irritation were evaluated by means of evaporimetry (Servomed EP-1) and chromametry (a* value, Minolta CR200) weekly, and at 0, 24 and 48 h after SLS patch removal. No significant differences in transepidermal water loss (TEWL) and erythema were observed between the four AHAs at week 4. After SLS challenge, GLU- and TA-treated sites resulted in significantly lower TEWL compared with VE, UNT (P < 0.01) and GA (P < 0.05) both at 24 and 48 h. Similarly, a* values were significantly reduced after irritation in GLU- and TA-treated sites. This study shows that AHAs can modulate stratum corneum barrier function and prevent skin irritation; the effect is not equal for all AHAs, being more marked for the molecules characterized by antioxidant properties.

Adult↗

PubMed1992

Photoprotective effects of sunscreens in cosmetics on sunburn and Langerhans cell photodamage.

It has become common practice to add sunscreening agents of variable potency to cosmetics to protect against the adverse effects of ultraviolet (UV) radiation exposure. The purpose of this study was to determine whether cosmetic preparations containing sunscreening agents protected against the adverse effects of acute UV radiation exposure and, if so, to identify the components responsible for the photoprotective effects. Pretreatment of skin with one such cosmetic product provided complete protection against UV-induced erythema, sunburn cell formation and Langerhans cell damage in volunteers, skin types II and III, whose skin was exposed to a 1.5 minimal erythema dose daily for 4 consecutive days. When individual components of the cosmetic preparation were analyzed for their photoprotective activities, it was found that both the cinnamate and benzophenone sunscreen combination and an extract of baker's yeast present in the preparation had photoprotective properties. These studies indicate that incorporation of photoprotective agents into cosmetic preparations provides a beneficial function and should therefore be encouraged.

Adolescent↗

PubMed1986

Enrichment of dystrophy-associated antigen from erythrocyte membranes of mice with muscular dystrophy.

In a previous report, it was shown that erythrocyte membranes from mice with muscular dystrophy of strain 129/ReJ-dy manifest a unique antigen. In the current study, this antigen was enriched from solubilized membranes by a two-step solid phase immunoadsorbent. The enriched fraction retained antigenicity as well as a reduced set of electrophoretic forms of protein over that seen in solubilized membranes. The enriched fraction contained no novel molecular weight species but several were noticeably enriched, particularly at 54,000 daltons.

Animals↗

PubMed1985

Effect of adroxazine, a heterocyclic compound of the adrenals, on the rate of replication of lymphoblastoid cells.

It has been found that the addition of 10(-2)-10(-8) microL/mL of adroxazine, heterocyclic compound of the adrenals, to the tissue culture medium increases the rate at which three strains of lymphoblastoid cells replicate. For example, the addition of 10(-5) micrograms/mL of adroxazine to cultured L5178Y cells decreases their doubling time from approximately 11 to 8 h and addition of 10(-3) micrograms/mL of adroxazine to the tissue culture medium of Huly-16 or Huly-29 cells decreases their doubling time from approximately 43 to 34 and 36 h, respectively. Other concentrations of adroxazine, from 10(-2) to 10(-8) micrograms/mL, cause a less but measurable decrease in doubling time. The effect of adroxazine on the rate of incorporation of [3H]thymidine into acid-precipitable material by lymphoblastoid cells was found to parallel the effect of adroxazine on doubling time. The effect of adroxazine on the length of DNA synthesis and mitosis was calculated from the percent of cells that are labeled with [3H]thymidine during a 20-min interval and the percent of cells in mitosis, respectively. Results showed that adroxazine does not decrease the length of DNA synthesis or mitosis, but markedly decreases the sum of pre- and post-mitotic resting times (TG2 + TG1). Addition of 10(-3) micrograms/mL of adroxazine to the medium decreases the resting times of Huly-16 cells from approximately 20 to 10 h and Huly-29 cells from approximately 12 to 5 h. Addition of 10(-5) micrograms/mL of adroxazine to the medium decreases the resting time of L5178Y cells from 3.3 to 0.1 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗

PubMed1981

Effect of tumors on the concentration of leucogenenol in the serum of mice.

It was found that inoculation of several strains of mice with several types of tumor cells resulted, within 24 hr, in a significant decrease in the serum leucogenenol levels of the mice. Serum leucogenenol levels of the mice inoculated with tumors that are rejected become normal or temporarily above normal at approximately the time the tumor is observed to be rejected. Contrariwise, serum leucogenenol levels of mice inoculated with tumors that are not rejected remain at significantly lower than normal levels during the life of the mice. Unlike tumors, skin allografts increase serum leucogenenol levels. When tumors are rejected because of the previous immunization of the mice, serum leucogenenol levels become normal at approximately the time the tumor is observed to be rejected. Excision of the tumor after 1 week of growth, with the consequent recovery of the mice, is accompanied by a recovery of normal serum leucogenenol levels. Also, it was found that injection of mice with a cell-free 0.9% NaCl solution extract of a tumor results in a temporary decrease in serum leucogenenol levels comparable to that observed with the inoculation of a viable tumor which lasts from 24 to 96 hr. It is suggested that the suppression of serum leucogenenol levels is one of the factors responsible for the immunosuppression associated with a growing tumor.

Animals↗

PubMed1980

Leucogenenol a thymothyroid hormone.

Thymectomy and, to a lesser extent, thyroidectomy cause a significant decrease in the serum leucogenenol levels of rats. Daily injections of neonatally thymectomized mice with leucogenenol causes the mice to maintain a normal level of neutrophils and lymphocytes in their circulation. The thymus and thyroid are the only tissues in rats and mice that afford radioactive leucogenenol when incubated in a medium containing radioactive D-glucose. It is concluded that the thymus and possibly the thyroid are responsible for the normal biosynthesis of leucogenenol in animals.

Adrenal Glands↗