Vitamin A Acid Research Articles

Efficacy comparison of clobetasol propionate ointment and vitamin A acid cream in the treatment of skin papule type amyloidosis

Objective To compare clinical efficacy of clobetasol propionate ointment and vitamin A acid cream in the treatment of skin papule type amyloidosis.Methods 100 cases of skin papule type amyloidosis were randomly divided into the observation group and control group,each had 50 patients.The control group was treated with Vitamin A acid cream while the observation group used clobetasol propionate ointment for treatment.Skin lesion area,infiltration,skin color,skin itching score as well as the cure rate and efficiency were compared after 4 weeks of treatment.Results The two groups' symptoms was improved,symptom scores was decreased gradually after treatment than before,the observation group's symptom scores at 1,2,3,4 weeks were (9.35 ± 1.88),(6.54 ±2.16),(4.08 ±1.32),(2.04 ± 0.95) points which was significant better than (10.86 ± 2.08),(7.98 ± 2.57),(6.25 ± 1.44),(4.56 ± 1.18) points of the control group,the difference of two groups was statistically significant (t =6.22,6.71,7.30,7.41,all P ＜ 0.05) ;4 weeks after treatment,the observation group's efficience and cure rates were 94％ and 34％,significantly higher than 70％ and 22％ of the control group,the difference was statistically significant (x2 =9.040,8.391,all P ＜ 0.05).Conclusion Clobetasol propionate ointment has a exact effect in treatment of skinpapule type amyloidosis than vitamin A acid cream,which is worthy of clinical application. Key words: clobetasol propionate ointment; Vitamin A acid cream; skin papule type amyloidosis; symptom

Context is key in the gut

The vitamin-A metabolite retinoic acid normally favours immune tolerance in the gut. But in coeliac disease — an intestinal inflammatory disorder due to adverse reactivity to a dietary protein — it may do just the opposite. See Letter p.220 The vitamin A metabolite retinoic acid is shown to act synergistically with the cytokine interleukin-15 (IL-15) to induce IL-12p70 production by intestinal dendritic cells, thereby promoting an inflammatory T-cell response to dietary antigens. IL-15 is upregulated in the guts of patients with coeliac disease, and this new work points to a previously unknown involvement of IL-15 and retinoic acid in promoting an inflammatory immune response to gluten.

Topical retinoic acid treatment of photoaged skin: its effects on hyaluronan distribution in epidermis and on hyaluronan and retinoic acid in suction blister fluid.

Topical treatment with retinoic acid (tretinoin, vitamin A acid) has been reported to partly reverse signs of photodamage. To determine whether the histochemical distribution of hyaluronan (hyaluronic acid, HYA) in the epidermis and dermis and the amounts of HYA and retinoic acid in suction blister fluid were influenced by such topical treatment, 14 subjects healthy apart from moderate photodamage were instructed to treat the lateral forearm with 0.01-0.05% retinoic acid cream for 6 months. In a study of the short-term effects, another six subjects applied 0.05% retinoic acid cream for 2 weeks. After 6 months the thickness of the vital epidermis had increased by 23%. The HYA staining was based on a specific immunohistochemical method in which hyaluronan-binding protein is used. Before treatment HYA was seen as a meshwork around the cells in the upper half of the stratum spinosum. After 6 months of treatment this meshwork had increased in thickness by 31% compared with pretreatment specimens. The HYA staining was already intense in the papillary dermis before treatment and no difference was observed after 6 months' treatment. The mean concentration of HYA in blister fluid had increased significantly (43%) after 2 weeks of treatment whereas after 6 months there was no significant difference in this respect between the treated and untreated arm. The increase in the thickness of the epidermal HYA meshwork after 6 months and the blister fluid HYA after 2 weeks may indicate that HYA is involved in the epidermal change induced by topical retinoic acid therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of vitamin A acid (tretinoin) after epidermal application in the rat

Effect of vitamin A acid (tretinoin) after epidermal application in the rat

An Electron Microscopic Study of Experimentally‐induced Comedo and Effects of Vitamin A Acid on Comedo Formation

The mechanisms of comedogenesis and comedolysis were investigated at the ultrastructural level after applying oleic acid (OA) only, or oleic acid together with vitamin A acid (VAA), to rabbit ears daily for two weeks. 1) In the follicular epithelium of the experimentally-induced comedo (EIC) by OA, several ultrastructural changes similar to those in human comedo were observed. EIC in rabbit ears appeared to be induced both by the hyperkeratinization of the follicular epithelium and by the delayed desquamation of horny cells due to the persistence of intercellular binding apparatus. 2) VAA strongly inhibited the formation of EIC. In the follicular epithelium, two different types of changes, non-cohesive hyperkeratinization and inhibition of keratinization, were observed. These represent the cell injury and recovery stages, respectively. VAA induced the disturbance of follicular epithelial keratinization and reduction of intercellular bindings between horny cells. These effects might prevent the cohesion and accumulation of horny cells and inhibit EIC formation. 3) The number of Odland bodies (Ods) showed an inverse correlation with the cohesion of horny layer. These findings support the theory that Ods have a desquamating function as extracellular lysosomes. The change in Ods would also contribute to both EIC formation by OA and the inhibition by VAA. In addition, VAA caused a characteristic increase in Ods with lamellar structures. It is suggested that Ods with lamellar structures have a desquamating function.

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Slice tissues of rat lung were preincubated with vitamin A (VA) or vitamin A acid (VAA) and then incubated with endotoxin. After the reaction, the amount of LTC4, LTB4 and 6-KPGF1α in the reactive solution were analysed quantitatively by RIA following the method of Salali or Powell et al. TLC4 was significantly suppressed by 10-6M VA. And 10-8M VA still showed this suppression. The induction of LTB4 was also suppressed significantly by 10-7M VA. VAA suppressed the induction of LTC4 significantly at the concentration from 10-7M to 10-9M. And 10-8M VAA showed the most significant suppression. The induction of LTB4 was also suppressed significantly by 10-9M VAA but was accelated by 10-7M. However VAA did not interfere the synthesis of 6-KPGF1α. The values of LTB4 and LTC4 determined by RIA were confirmed by the combined method of HPLC and RIA. These suggest that VA and VAA will suppress the synthesis of lipoxygenase products specifically in vitro experiment as well as in vivo experiment already shown in the former report.

Evidence of a role for retinoic acid (vitamin A-acid) in the maintenance of testosterone production in male rats.

Animals maintained on retinol (vitamin A-alcohol)-deficient diets exhibit testicular atrophy and loss of the germinal epithelium. Retinoic acid (vitamin A-acid), when fed to retinol-deficient animals, does not prevent these lesions and had thus been thought not to play a role in the tests. Serum testosterone (T) levels, determined by RIA, in retinol-deficient rats were determined to be significantly lower than in control rats. In contrast, retinoic acid-fed, retinol-deficient rats exhibited serum T concentrations similar to those of control rats. No difference in immunoreactive serum LH levels was observed in the three groups. The response of serum T to ip administration of LH in retinol-deficient animals relative to basal levels was similar to that observed in control as well as retinoic acid-fed, retinol-deficient rats. These results show that while basal T production in retinol-depleted rats is decreased, LH-stimulated T synthesis is unaffected. Furthermore, retinoic acid, in the absence of retinol, can support T production, suggesting that contrary to present dogma, retinoic acid plays a role in testis.

The therapeutic uses of topical vitamin A acid.

Topical vitamin A acid (VAA) has various mechanisms of action which may be responsible for its therapeutic success in many different disorders. Although the absorption, metabolism, and excretion of VAA are not completely understood, VAA appears to remain mainly on the skin surface. The question of carcinogenicity is unresolved, and more research is needed to clarify this problem. This article reviews the literature regarding the therapeutic uses of VAA and summarizes various investigators' experiences with VAA.

Experimental investigations on the influence upon the chemical carcinogenesis. IInd communication: studies with 3,4-benzopyrene.

After subcutaneous application of 0.5 mg 3,4-benzopyrene (BP) to Sprague-Dawley-rats on the 2nd day of life, 50% of the animals developed local fibrosarcomas after 250 +/- 70 days. Additional treatment with immunostimulating (BCG, albumin, vitamin A-acid) or immunodepressive agents (hydrocortisone, cyclophosphamide, methotrexat) which was started 6 days after birth and maintained throughout life, did not influence carcinogenesis with respect to tumor incidences and induction periods of tumors.

Experimental investigations on the influence upon the chemical carcinogenesis. IIIrd communication: studies with 1,2-dimethylhydrazine.

After ten times monthly, subcutaneous, injections of 30 mg/kg 1,2-dimethylhydrazine (DMH) to Sprague-Dawley-rats, malignant tumors were found in approximately 90% of the animals after a mean induction period of approximately 330 days. Injections were started on the 2nd day of life and maintained during 10 months. 72% of the tumors induced were formed in the colon, 17% were squamous cell carcinomas of the ear duct, adenosarcomas of the kidney and hepatocellular carcinomas were found in 13 and 11% of the animals, respectively. Additional treatment with immunodepressive (cyclophosphamide, methotrexat, hydrocortisone) and immunostimulating substances (BCG, albumin, vitamin A-acid) as well as an enzyme-stimulating agent (Luminal) did not alter incidences and induction periods of tumors. After application of a vegetarian diet, the rate of liver and kidney tumors was diminished significantly and induction periods of intestinal and ear duct tumors increased.

Kinetics of cell proliferation in normal epidermis before and after application of 1 per cent vitamin A-acid solution (author's transl)

A 1 per cent Vitamin A-acid solution was applied externally for 2 weeks on normal epidermis. The result was an acute dermatitis, characterized by hyperproliferation and shortened phases of cell cycle. There was no increase in the proliferative activity of lymphoid cells in the moderate dermal infiltrate.

Growth Stimulation of Cultured Postembryonic Epidermal Cells by Vitamin a Acid

Guinea-pig epidermal cells were grown in vitro after release by gentle trypsin treatment. The cells formed clusters from which DNA-synthesizing cells grew to form confluent cell sheets. Treatment of the cultures with vitamin A acid (VAA) significantly increased cellular attachment in the first hours after seeding. This was followed by a steep rise in DNA synthesis as revealed by autoradiography and liquid scintillation counting. The increase was approximately 6-fold compared to the controls. Cellular out growth was considerably accelerated as shown by cell density counts. The results show that in vitro VAA exhibits potent mitogenic activity. Culturing of postembryonic epidermal cells seems to be greatly facilitated by the use of this compound.

The action of topical vitamin A acid on normal epidermis and non-involved epidermis of psoriatics. A morphological and enzymatic study.

ABSTRACTTopical application under occlusion of 0.1% Vitamin A Acid (VAA) in polyethylene glycol to the non‐involved skin of psoriatics and to the skin of normal controls resulted in keratolysis, acanthosis, glycogen accumulation, and increased enzyme activity, though the changes are more marked in the former. Those changes occurred during the first week of application and did not progress further, in fact continued application resulted in a biochemical return toward normal.A Koebner phenomenon was not seen and the test is therefore not useful in bringing out latent psoriasis.

In Vitro-effects of vitamin A acid

The in vitro-effect of vitamin A acid (VAA) upon DNA synthesis was studied in three different cell types: lymphocytes, epidermal cells grown as primary cultures and subcultured fibroblasts. The incorporation of3H-TdR after exposure of the culture to various concentrations of VAA was determined by liquid scintillation counting.

Prophylaxis of chemically induced papillomas and carcinomas of mouse skin by vitamin A-acid.

Oral verabreichte Vitamin-A-Saure besitzt bei Mausen eine prophylaktische Wirkung auf die Entstehung von hauptpapillomen und Hautkarzinomen. die mittels lokaler Applikation von Dimethylbenzanthracen und Krotonol erzeugt wurden. Vitamin-A-Saure verzogert das Auftreten, verlangsamt das Wachstum und fuhrt zur Ruckbildung von Papillomen. Ferner wird die Induktion von Karzinomen gehemmt. Diese treten bei prophylaktischer Verabreichung von Vitamin-A-Saure verzogert und in deutlich verringerter Anzahl auf. Der Wirkungsmechanismus wird diskutiert.

The crystal and molecular structure of the five-membered-ring analogue of vitamin-A acid

The crystal and molecular structure of the five-membered-ring analogue of vitamin-A acid

MECHANISMS OF PARAKERATOSIS

SUMMARY. The removal of the horny layer of the guinea-pig ear by tape stripping causes rapid development of a parakeratotic scale during the first 12 hr. Some epidermal cells, which were labelled with 3H-Thymidine when stripping was performed, could be detected autoradiographically in the parakeratotic stratum corneum a few hours later. Since the proliferative response of the epidermis is retarded after vigorous stripping, these cells have become parakeratotic due to exposure and subsequent cell death. Topical application of Vitamin A-acid produces morphological alterations of the keratogenous zone together with increased DNA-synthesis in the lower portion of the epidermis, leading to the persistence of nuclei in the stratum corneum. Prolonged treatment with Vitamin A-acid and Hexadecane increases the epidermal thickness to values such as are found in psoriasis. The turnover time of this hyperplastic epidermis is reduced to about 3 days, yet no parakeratosis can be found. These observations lead to the conclusion that maximally stimulated epidermopoiesis does not result in parakeratosis unless there is a defect in cell differentiation.

Reaction products of vitamin A acid with antimony trichloride.

Reaction products of vitamin A acid with antimony trichloride.

Vitamin A acid from retinene.

Vitamin A acid from retinene.

Studies on the function of vitamin A in mucopolysaccharide biosynthesis

An in vitro system of rat colon segments and of rat colon homogenates was elaborated, which incorporated [ 35S]sulfate and [ 14C]glucose into mucopolysaccharide. Mucopolysaccharide was identified by paper chromatography and paper electrophoresis along with chondroitin sulfate carrier; by co-precipitation and dialysis with chondroitin sulfate; by hydrolysis and identification of labeled sulfate or labeled glucosamine. The homogenate system required adenosine triphosphate, diphosphopyridine nucleotide, glucose and glutamine. The level of incorporation was lowered to about one-half in colon segments and homogenates from vitamin A-deficient rats. Vitamin A, vitamin A-aldehyde and vitamin A-acid (but no other fat-soluble vitamin tested) restored incorporation to normal. With graded levels of vitamin A added, a maximum of incorporation was reached to 10 μg/6 mg of protein in the homogenates. Using glucosamine or galactosamine instead of glucose and glutamine, or uridine diphosphate acetylglucosamine, uridine diphosphate glucuronic acid, uridine diphosphate glucose and acetylglucosamine, incorporation of labeled sulfate was still dependent on vitamin A. This fact shows that the vitamin may be required either in the polymerisation reaction of the uridine derivatives, or the activation or transfer of sulfate. It was shown that the vitamin A-destroying enzyme lipoxidase can lower or abolish incorporation into mucopolysaccharide.