Hydrolytic enzymes in the sebaceous glands of the domestic cat

The distribution and activities of some hydrolytic enzymes in various portions of the sebaceous glands of the domestic cat have been studeid. The results point to the outstanding importance of none-specific esterases and lipases for sebum production, which generally appears to be abundant in thickly-haired mammals. The activities of the lysosomal enzymes demonstrated were connected with autolytic processes during sebaceous gland cell differentiation. There was a strong aryl-sulphatase reaction in the sebum of the sebaceous gland excretory ducts.     

Advances and perspectives in acne therapy

Acne is one of the most common diseases in dermatology. It is of considerable esthetic significance, which explains the mental stress in affected patients. Although acne almost always heals spontaneously in early adulthood, treatment measures can shorten the course, reduce the severity of the disease, and avoid complications such as scarring. Treatment has changed substantially in recent years. In accordance with pathogenic principles, effective treatment is possible. In most patients, a combination of drugs aimed at correcting abnormal keratinization and reducing the proliferation of Propionibacterium acnes is sufficient to control the disease. For more severely affected patients with no response to this approach, therapy to suppress sebum production is indicated. Of all therapeutic modalities available, only oral isotretinoin alters the natural course of the disease. In acne inversa, surgical management should be undertaken as early as possible.     

Acne: physiopathology and clinical aspects

Acne is easy to diagnose, but its physiopathology is complex and not yet fully elucidated. However, the three factors that are necessary to the genesis of acne are well defined, being seborrhoea, obstruction of the hair follicle and the sebaceous gland, and inflammation of the follicle. To this must be added a genetic predisposition. While the skin lesions leave little doubt about the diagnosis, a thorough examination is needed to evaluate the part due to sebum retention (comedos, microcysts) and that due to inflammatory elements (papules, pustules, nodules), for the lesions are so polymorphous that it would be better to speak of acnes rather than acne. A good knowledge of clinical and physiopathological data leads to the appropriate treatment, since almost all therapeutic failures result from a misappreciation of acne.     

Caffeine deprivation affects vigilance performance and mood

Cytochromes P-450 are a supergene family of enzymes involved in the metabolism of a wide range of endogenous and foreign compounds. The existing genetic variations of the distinct isozymes lead to interindividually different metabolic capacity. Since vitamin A, endogenous retinoids and their natural metabolites are morphogenic for the sebaceous gland, we investigated the polymorphisms of cytochrome P-450 1A1, as being one of the most active isozymes involved in their interconversion. From the known mutations, two were investigated; an additional cleavage site for MspI in the 3'-flanking region identified as a thymine-to-cytosine transition 1,194 bp downstream of exon 7 (m1) and an adenine-to-guanine transition at position 4889 in exon 7 (m2). We studied 96 acne patients for m1 and m2 mutations by restriction fragment length polymorphism and allele-specific polymerase chain reaction, respectively, and compared the results with 408 reference individuals. No statistically significant difference was found in the distribution of m2 alleles; the frequency was 3.13 and 3.06% of the alleles, respectively (odds ratio = 1.02, confidence limits 0.41-2.52, p = 0.96). In contrast, a trend to an overrepresentation of m1 alleles in acne patients was observed; allele frequency was 8.33 in the patients and 6.99% in the control subjects, respectively (odds ratio 1.21, 95% confidence limits 0.68-2.16, p = 0.52). As the m1 mutation might define a marker for alterations on regulatory sites, the biological efficacy of natural retinoids could be greatly impaired by their rapid metabolism to inactive compounds. The resulting deficit of active natural retinoids may lead to abnormal sebocyte differentiation and hyperkeratinization of the follicular canal implicating the development of acne in some patients.     

Evaluation of antismoking advertising campaigns

BACKGROUND: Steroid acne is a folliculitis that can result from systemic or topical administration of steroid, and has been described as showing a similar clinical picture to Pityrosporum folliculitis, but there have been few reports about the incidence of Pityrosporum ovale and the effect of antimycotic drugs in steroid acne and other acneiform eruptions. Our purpose was to describe the association between steroid acne and P. ovale, and to confirm the superior efficacy of oral antifungal drugs over anti-acne drugs in the treatment of steroid acne. METHODS: The history, clinical features direct microscopy, histopathologic analysis, and therapeutic results of 125 cases with steroid acne or other acneiform eruptions were described and compared. RESULTS: Over 80% of patients with acneiform eruption receiving systemic steroid revealed significant numbers of P. ovale in the lesional follicle. Furthermore, oral antifungal drug (itraconazole) showed significantly better clinical and mycologic effects than any other group of medications used in this study. CONCLUSIONS: Steroid acne and other acneiform eruptions showing discrete follicular papules and/or pustules localized to the upper trunk and acneiform facial skin lesions associated with multiple acneiform lesions on the body in the summer period should be suspected as Pityrosporum folliculitis. In addition, oral antifungal drugs recommended for Pityrosporum folliculitis; however, it will require a larger case-control study to confirm the superiority of antifungal therapy over anti-acne treatment.     

Isotretinoin for acne vulgaris--10 years later: a safe and successful treatment

The purpose of this study was to assess the long-term benefit of isotretinoin in otherwise therapy-resistant acne. We also assessed risk factors which might influence the long-term outcome. We studied 88 patients (mean age 20.8 years), most of whom had suffered from acne for many years (mean 7.4 years). They received isotretinoin in an initial dose of 0.5 or 1.0 mg/kg/day. The dose was subsequently adjusted according to response and side-effects. Most patients only required 4 months' therapy to produce at least 85% clinical improvement. The patients were seen up to 10 years post-therapy (mean 9 years). Sixty-one patients were still virtually clear of disease. Of the others, 16% required further treatment with conventional antibiotics and 23% required a second course of isotretinoin. Of those who relapsed, 96% did so within 3 years of stopping therapy. The patients' age, sex, and duration of acne did not influence outcome. However, in patients with predominantly truncal acne, especially when severe, there was an increased incidence of relapse. Sebum excretion is known to correlate with acne severity, but the long-term degree of sebum suppression was found not to be related to relapse. The dose schedule, in particular cumulative dose, was an important factor in determining relapse rate. Those patients who received 0.5 mg/kg daily, or a cumulative dose of < 120 mg/kg, had a significantly higher relapse rate than patients receiving a larger dose. We did not elicit any long-term systemic or biochemical side-effects. We conclude that isotretinoin is a safe and effective therapy.(ABSTRACT TRUNCATED AT 250 WORDS)     

On choosing a detergent for solution NMR studies of membrane proteins

Acne is a common condition seen routinely by both primary care physicians and dermatologists. Most patients have no underlying pathology and respond to traditional treatment; others, however, require more individualized evaluation and aggressive therapy. New information regarding the pathogenesis and treatment of acne is now available. This update discusses the proper evaluation of early childhood acne, the emergence of Propionibacterium acnes resistance, and the rare but serious side effects occasionally seen with minocycline. Advances in the topical treatment of acne, the use of oral contraceptives in acne, and the use and efficacy of isotretinoin are also addressed.     

Experimental evaluation of anti-seborrheic substances

The effects of different drugs on the sebaceous gland is described by the use of an animal model. A castrated rat Wistar was made hyperseborrheic with implant of testosterone. On this model, graduated by a different anti androgen (acetate of cyproterone), anti-seborrheic effect is measured, bound or not the antiandrogenic effect of retinoids, cimetidine, spironolactone and, minoxidil. Retinoids reduced the surface of sebaceous glands but did not express an anti-androgenic effect. Cimetidine and spironolactone presented the same action. Minoxidil had no effect on this model.     

The use of retinoids in the pediatric patient

Oral retinoids are molecules derived from vitamin A that represent one of the most important steps forward in dermatologic therapeutics in the present century. The treatment of acne, severe psoriasis, and severe disorders of keratinization, prevalent diseases in children and adolescents, have radically changed since the advent of oral retinoids. Like most highly-effective medications, oral retinoids also have important untoward effects. Specialists, and in particular, dermatologists and pediatricians should be prepared to maneuver the delicate balance between therapeutic efficacy and side effects in order to give the pediatric patient the maximum benefit with the lowest possible risk.     

Safety assessment of postoperative pain management by an acute pain service

The purpose of this study was to evaluate the synthetic retinoids isotretinoin and etretinate to treat dogs with intracutaneous cornifying epitheliomas (ICE), other benign skin neoplasias, and cutaneous lymphoma. Twenty-four dogs were used. All tumors were diagnosed by histologic examination. Ten dogs with multiple (at least 5) benign skin tumors (7 with ICE, 1 each with inverted papillomas, sebaceous adenomas and epidermal cysts) were treated with isotretinoin (n = 7) and/or etretinate (n = 5). Twelve dogs with cutaneous lymphoma were treated with isotretinoin, and 2 dogs with cutaneous lymphoma were initially treated with etretinate. Successful treatment with isotretinoin was achieved in 1 dog with ICE, 1 with inverted papillomas, and 1 with epidermal cysts. Partial improvement with isotretinoin was seen in 2 dogs with ICE. Successful treatment was achieved with etretinate in 4 dogs with ICE (Norwegian Elkhound was the predominant breed with ICE). Remission was achieved in 6 of the 14 dogs with cutaneous lymphoma. Adverse effects developed in 7 of the 24 dogs, so treatment was stopped in 2 dogs.     

The effect of zinc in the form of erythromycin-zinc complex (Zineryt lotion) and zinc acetate on metallothionein expression and distribution in hamster skin

The occurrence of zinc-induced synthesis of metallothionein in skin after topical application of the anti-acne drug Zineryt lotion was investigated in hamster ears. The dinitrophenyl hapten-sandwich immunohistochemical method involving a monoclonal anti-metallothionein (MT) antibody (E9) was used to detect and localize zinc-binding MT in the 'treated' and untreated hamster skin. Atomic absorption spectrophotometry and dithizone histochemistry indicated that zinc penetrated the skin more readily, and accumulated more efficiently within the sebaceous glands, when applied to the skin surface as the organo-zinc complex, rather than as the inorganic zinc salt. MT and zinc had similar distributions in hamster skin exposed to the metal. Thus, MT immunoreactivity was especially intense in the sebaceous glands of Zineryt lotion-treated skin, with evidence of nuclear distribution in some cells. Zinc delivered to the sebaceous glands, and released from the organo-complex under the prevailing aqueous conditions, certainly induced MT synthesis; the cysteine-rich protein may protect the pilosebaceous units during the inflammatory phase of acne by scavenging generated oxyradical species.     

Pyogenic granuloma-like lesions in a patient using topical tretinoin

A 16-year-old male developed numerous pyogenic granuloma like-lesions across his neck, chest and back after 6 weeks isotretinoin therapy for cystic acne. The isotretinoin was ceased and he was commenced on oral steroids. After 6 weeks, the lesions were almost completely healed. However, due to worsening comedonal acne, the patient was commenced on topical tretinoin cream 0.05% twice daily to his chest. He was reviewed 2 weeks later and, surprisingly, 2 new pyogenic granuloma-like lesions had developed on his chest. These lesions persisted until the topical tretinoin was ceased 3 months later.     

Inhibition of ribonuclease P activity by retinoids

The effect of two naturally occurring (retinol and all-trans retinoic acid) and two synthetic (isotretinoin and acitretin) analogs of vitamin A (retinoids) on tRNA biogenesis was investigated employing the RNase P of Dictyostelium discoideum as an in vitro experimental system. RNase P is an ubiquitous and essential enzyme that endonucleolytically cleaves all tRNA precursors to produce the mature 5' end. All retinoids tested revealed a dose-dependent inhibition of RNase P activity, indicating that these compounds may have a direct effect on tRNA biogenesis. Detailed kinetic analysis showed that all retinoids behave as classical competitive inhibitors. The Ki values determined were 1475 microM for retinol, 15 microM for all-trans retinoic acid, 20 microM for isotretinoin, and 8.0 microM for acitretin. On the basis of these values acitretin is a 184, 2.5, and 1.9 times more potent inhibitor, as compared with retinol, isotretinoin, and all-trans retinoic acid, respectively. Taking into account that retinoids share no structural similarities to precursor tRNA, it is suggested that their kinetic behavior reflects allosteric interactions of these compounds with hydrophobic site(s) of D. discoideum RNase P.     

Effects of isotretinoin therapy on lipoprotein (a) serum levels

BACKGROUND: Increases in plasma concentrations of lipids, triglycerides, and liver enzymes have been reported in patients on isotretinoin therapy. Lipoprotein (a). (Lp (a)), a cholesterol-rich plasma lipoprotein, influences the clotting system and is related to premature coronary heart disease and stroke. METHODS: Blood (7 mL) was obtained from 30 patients with cystic acne before and 30 days after the initiation of oral isotretinoin (0.5 mg/kg/day). RESULTS: An increase in liver enzymes and lipids, except high density lipoprotein, was found in our patients at the end of the study. The mean Lp (a) levels (initial value, 25.91 +/- 3.17 mg/dL) were statistically reduced (p < 0.0001) at the end of treatment (14.80 +/- 2.35 mg/dL). CONCLUSIONS: It is suggested that isotretinoin could be used as an Lp (a) lowering agent in the future.     

Retinoid therapy for aging skin and acne

Primary care physicians should be familiar with the effects and appropriate uses of retinoids. Topical tretinoin (Retin-A) can reverse photoaging of the skin, although some transient, undesirable side effects usually occur. In patients with acne vulgaris, topical tretinoin and systemic isotretinoin (Accutane) are the only agents that act upon the apparent underlying causes. Recurrence is unlikely after successful results are achieved. Chronic hypervitaminosis A presents insidiously, and physicians must maintain a high index of suspicion. Complete history taking should always include questions about the patient's use of vitamin supplements.     

Dust from carpeted and smooth floors. VI. Allergens in homes compared with those in schools in Norway

This study examined 20 cases of tinea versicolor to assess the dermato-physiological, immunological and pathological status of lesion sites as compared to 20 normal control subjects. Lesion sites showed a significant decrease in sebaceous gland secretions and water content and an increase in pH value compared to normal skin. There was no significant change in involucrin, filaggrin, or number of stratum corneum cell layers. However, lesions showed weak positive staining of IL-1 alpha. A possible mechanism for these changes is that profuse sweat gland secretions predispose to fungal growth and acid mantle destruction, with the pathogens consuming amino acids and sebum as nutrients. Slight increases in IL-1 alpha levels seen in infected areas could be due to a fungus-stimulated immune reaction in the stratum corneum.     

Irreversible cataract as a possible side effect of isoretinoin

BACKGROUND: Isoretinoin, a drug used in the treatment of severe cystic acne, is known for its numerous adverse ocular side effects, among others. Generally these side effects are benign in nature and reversible on cessation of drug therapy, as for instance transient acute myopia. However, two cases of irreversible cataract possibly related to isotretinoin have been described up till now. PATIENT: We examined a 37-year-old woman with acute unilateral cataract that occurred after a treatment with isotretinoin for four months, terminated a few days previously. A clear etiological relation could not be established. CONCLUSION: The time relation, the acute onset and the absence of other factors nevertheless suggest an influence of isotretinoin therapy to the occurrence of the cataract.     

Beta-guanidinopropionic acid prevents decrease in muscle performance and reduction in mitochondrial enzymes activation under gravitation unloading in rats]

The sebum flow dynamics at the skin surface results from a multistep process starting with sebocyte proliferation, intracellular lipid synthesis, cell lysis in the sebaceous duct, storage of sebum in the follicular reservoir, discharge through the follicular opening and spreading over the stratum corneum. A handful of topical products may decrease the sebum output, most of them acting at the level of the follicular reservoir function. Among them, elubiol exhibits a clinically relevant effect on oily skin.     

In vitro and in vivo antifungal activity of amphotericin B lipid complex: are phospholipases important?

BACKGROUND: Second primary malignancies are common after bilateral retinoblastoma; their estimated incidence has been as high as 51% 50 years after diagnosis. Fifteen patients who developed sebaceous gland carcinoma after radiation therapy have been reported in the literature, five of whom were treated for bilateral retinoblastoma. METHODS: The authors conducted a retrospective chart review of patients treated for bilateral retinoblastoma at Duke University Medical Center who later developed sebaceous gland carcinoma. RESULTS: This article reports two patients who developed sebaceous gland carcinoma after radiation therapy for bilateral retinoblastoma. CONCLUSIONS: Delay in diagnosis is often associated with sebaceous gland carcinoma. Because high mortality is observed with metastatic disease, the recognition of this association is important for anyone who follows patients with a history of bilateral retinoblastoma or prior cranial radiation therapy.