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Biomedical subjects

J J Leyden

Publications and source records attributed to J J Leyden.

At least 19 recordsLinked to original sources
PubMed1992

Effects of topical ammonium lactate on cutaneous atrophy from a potent topical corticosteroid.

BACKGROUND: Topical corticosteroids produce atrophic changes in skin, including thinning of the epidermis and decrease in dermal ground substance. We observed that 12% ammonium lactate produced an increase in the thickness of epidermis and increased amounts of dermal glycosaminoglycans. OBJECTIVE: Our purpose was to determine whether 12% ammonium lactate could minimize cutaneous atrophy produced by a potent topical corticosteroid. METHODS: Clobetasol propionate, 12% ammonium lactate, and both agents were repetitively applied under occlusive patches as well as in open patches on the forearms of human volunteers for 3 to 4 weeks. Biopsy specimens were analyzed for thickness of the epidermis and dermal glycosaminoglycans by image analysis. RESULTS: Twelve percent ammonium lactate produced a significant sparing of atrophy in both the epidermis and dermis without any influence on the bioavailability or antiinflammatory properties of the corticosteroid. CONCLUSION: Twelve percent ammonium lactate may be useful in mitigating the adverse effects of corticosteroid on skin.

Administration, Topical↗
PubMed1992

Handwashing practices and resistance and density of bacterial hand flora on two pediatric units in Lima, Peru.

The handwashing practices and bacterial hand flora of 62 pediatric staff members of a teaching hospital in Lima, Peru, were studied. Handwashing followed patient contact 29.3% of the time (204/697 contacts). Mean duration was 14.5 seconds, and significant differences in practices were found by unit (rehydration or neonatal intensive care), type of staff member (nurses or physicians), and type and duration of patient contact. Mean count of colony-forming units was log10 5.87 +/- 0.41, with significant differences in density of flora found between patient care and kitchen staffs. There was no significant effect of handwashing on counts of colony-forming units. Significant differences were also found by unit and by staff position with regard to species isolated and antimicrobial resistance of isolates. A more efficacious and cost-effective form of hand hygiene and a more prudent use of antimicrobial agents are indicated.

Colony Count, Microbial↗
PubMed1992

Antibiotic resistance patterns in coagulase-negative staphylococci after treatment with topical erythromycin, benzoyl peroxide, and combination therapy.

Antibiotic resistance of the resident cutaneous bacterial flora is a well recognized consequence of systemic antibiotic therapy. In this study, we followed the development of antibiotic resistance of coagulase-negative staphylococci (CNS), the most numerous aerobic bacteria found on the skin surface, during treatment with three topical antimicrobial agents used to treat acne vulgaris. Groups of 20 subjects received either topical erythromycin, benzoyl peroxide or a combination of the two for 16 weeks. After 12 weeks of treatment with erythromycin, the aerobic flora was dominated by S. epidermidis which was completely resistant to erythromycin. In addition there was an increase in resistance to clindamycin and tetracycline. Treatment with benzoyl peroxide and the combination of erythromycin and benzoyl peroxide resulted in a significant reduction in the number of aerobic bacteria without any change in the resistance pattern to erythromycin or other antibiotics.

Acne Vulgaris↗
PubMed1992

Review of mupirocin ointment in the treatment of impetigo.

The introduction of mupirocin ointment gives the pediatrician a reliable topical alternative to oral antibiotic therapy for group A streptococcal and staphylococcal impetigo. It is as effective as oral antibiotics and is associated with fewer adverse effects. In superficial skin infections that are not widespread, mupirocin ointment offers several advantages. It is highly active against the most frequent skin pathogens, even those resistant to other antibiotics, and the topical route of administration allows delivery of high drug concentrations to the site of infection.

Administration, Topical↗
PubMed1991

Skin replica analysis of photodamaged skin after therapy with tretinoin emollient cream.

Computerized image analysis of silicone replicas, a reproducible, objective technique for measuring skin topography, was used in addition to clinical measures in two multicenter, double-blind, randomized, controlled studies of tretinoin emollient cream, a new formulation for treating photodamaged skin. Previously, the skin replica technique had been successfully used in a pilot study of tretinoin 0.05% cream by one investigator. In the present studies, subjects treated for 24 weeks with tretinoin emollient 0.05% cream consistently showed more improvement in skin topography than did vehicle-treated patients. A 0.01% concentration of tretinoin emollient cream also improved skin topography to a greater extent than the vehicle, while the lowest concentration tested (0.001%) showed little difference from vehicle. These results, reflecting a smoothening of the skin surface in tretinoin emollient cream-treated subjects, were consistent with clinical data showing greater improvement in fine wrinkling and roughness after tretinoin emollient cream therapy than after vehicle therapy. Findings from these multicenter studies confirm the value of the skin replica technique and help establish the efficacy of tretinoin emollient 0.05% cream for photodamaged skin.

Adult↗
PubMed1991

Computerized image analysis of full-hand touch plates: a method for quantification of surface bacteria on hands and the effect of antimicrobial agents.

A method is described for quantification of the bacterial flora on the hand surface. Computer-assisted image analysis of bacterial growth of large full-hand touch plates provides a quantifiable measure of the bacterial flora on the hand surface. Image analysis pixel intensity values showed a significant correlation (P less than 0.0001) with colony forming unit values determined by the glove juice method. Image analysis of impressions from hands treated with various antimicrobial agents in detergent bases showed that 4% chlorhexidine gluconate produces a 96% reduction after a 30 s washing and 98% reduction after a 3 min washing while 7.5% povidone-iodine and 1% triclosan produce a 77% and 70% reduction after 3 min respectively, and 70% isopropanol produces a 98% reduction after a 30 s wash.

Adult↗
PubMed1991

Indigenous multiresistant bacteria from flowers in hospital and nonhospital environments.

The microbial flora of 60 vase water samples from cut flowers obtained from several environments, including a hospital, were examined in this study. Forty-one different bacterial species were identified, including 12 species of Pseudomonas. The mean total aerobic bacterial count per 500 ml of vase water was 4.5 x 10(8) organisms, and high levels of antibiotic resistance were found. To ascertain the origin of the bacteria found on the flowers as well as their growth patterns, natural cut flowers were compared with sterilized cut flowers in tap water over time. Although the density of organisms was similar, the flora in vase water of sterilized flowers consisted almost entirely of aerobic spore formers while mixed flora of gram-negative bacteria, staphylococci, aerobic spore formers, and fungi were isolated from natural flowers. Our results indicate that the multiply-resistant microbial flora found in vase water is indigenous to flowers, rather than originating from the environment in which they are placed, and that such water is a reservoir of large numbers of multiresistant organisms.

Bacteria↗
PubMed1991

Acne: current concepts of pathogenesis and approach to rational treatment.

Acne is a skin disorder of the sebaceous follicles that commonly occurs in adolescence and young adulthood. The pathogenesis involves abnormal follicular hyperkeratosis and obstruction of the follicle, stimulation of sebaceous gland secretion by androgens, and proliferation of Propionibacterium acnes, which promotes inflammation. Treatment regimens should be designed based upon an understanding of the multifactorial basis of pathogenesis. Both topical and systemic agents may be employed to normalize keratinization, decrease sebaceous gland activity, decrease the follicular P. acnes population, and minimize inflammation.

Acne Vulgaris↗
PubMed1990

Mupirocin: a new topical antibiotic.

One hundred fifty-three strains of Staphylococcus aureus recovered from infected eczema frequently demonstrated resistance to multiple antibiotics. Penicillin and ampicillin resistance was extremely frequent (88%), methicillin resistance was found in nearly 14% of strains, and erythromycin and tetracycline resistance was present in 16%. S. aureus strains were uniformly sensitive to vancomycin, mupirocin, and cephalosporins. Experimental infections in human volunteers showed topical therapy with 2% mupirocin was more effective than oral erythromycin in suppression of both S. aureus and Streptococcus pyogenes.

Administration, Topical↗
PubMed1990

Clinical features of ageing skin.

Ageing of the skin involves the intrinsic process of senescence and extrinsic damage induced by chronic exposure to UV radiation. A recent consensus forum of the American Academy of Dermatology concluded that the majority of undesirable clinical features associated with 'skin ageing' are the result of damage to skin due to UV radiation (photoageing). Clinically photoageing is characterized by coarseness, wrinkling, mottled pigmentation, laxity, telangiectasia, and premalignant and malignant neoplasms. The role of genetics, hormones and diet needs to be clarified. Appropriate lifelong use of sunscreens may minimize many of the changes associated with photoageing.

Adult↗
PubMed1990

Tretinoin therapy in photoageing: historical perspective.

Tretinoin was shown in the late 1960s to be useful for the treatment of disorders associated with abnormal epithelial differentiation; however, because of irritation, retinoids were only slowly accepted. In the 1970s, evidence accumulated to show that topical tretinoin could modulate many of the abnormalities in the epidermis and dermis associated with photoageing. It has been shown in hairless mice that tretinoin can reverse dermal elastosis with the formation of new collagen and this has led to clinical trials being carried out in man. Randomized, controlled trials have shown that topical tretinoin is effective in the treatment of photoaged skin.

Administration, Topical↗
PubMed1979

Contact dermatitis to neomycin sulfate.

The prevalence of contact allergic dermatitis and nonallergic irritant reactions to neomycin sulfate was determined in a large group of young adults who had a noteworthy exposure to topical antibiotics. Only two subjects (0.09%) had contact allergy proved by closed patch testing, while 20 (0.9%) had nonallergic irritant reactions to 20% neomycin sulfate and 17 (0.78%) had nonallergic reactions to one of the hydrophilic ointment bases. In a separate population of 653 children referred for diagnostic patch testing, only one subject had contact allergy to neomycin. All three subjects who had reactions had a history of repeated use of neomycin on chronically damaged skin. These results support the conclusion that intermittent use of neomycin on minor cuts and wounds is not associated with an excessive rate of sensitization.

Adolescent↗
PubMed1979

Congenital herpes simplex virus infections. Report of three cases and review of the literature.

Three infants with congenital herpes simplex virus infection were examined and treated. One demonstrated findings of individual vesicles on an erythematous base; another had pustules. The children were treated with vidarabine intravenously. Two of the three survived. The literature suggests a potential increase in the occurrence of this infection in neonates. Since the dermatologist is often asked to aid in the diagnosis of this entity and early recognition is vital, it is important to be familiar with the possible causes of vesicopustular lesions, as well as the epidemiology, clinical manifestations, pathogenesis, and current forms of treatment of congenital herpes simplex virus infections.

Diseases in Twins↗
PubMed1979

Updated in vivo methods for evaluating topical antimicrobial agents on human skin.

Updated and expanded in vivo quantitative testing procedures to determine the efficacy of topical antimicrobial agents are presented. The occlusion test measures the ability of an agent to prevent the expansion of the resident microflora which occurs when an impermeable dressing is applied to the forearm. Measurements are made at 24 and 48 hr. The expanded flora test measures the ability of an agent to suppress a dense population of micro-organisms produced by expansion of the resident flora of the forearm by prior application of an impermeable occlusive dressing. Measurements are made at 6, 24 and 48 hr or after 10 min in the case for agents designed for immediate degerming. The persistence test measures the ability of an agent to establish a reservoir in skin and exert an antimicrobial effect up to 3 days after the last application of the test material. The ecological shift test determines any major alteration in cutaneous microbial ecology following several applications of the material under occlusive dressings. The serum inactivation test determines whether the presence of serum proteins interferes with antimicrobial activity.

Adult↗
PubMed1979

Characteristic gamma-lactone odor production of the genus Pityrosporum.

Mass spectrometric-gas chromatographic analysis of culture headspaces revealed that members of the genous Pityrosporum produce volatile gamma-lactones during growth on lipid-containing media. Representative members of other yeast genera found on humans failed to produce these compounds. Addition of lecithin, oleic acids, triolein, or human sebum to the culture media stimulated gamma-lactone production by Pityrosporum species. All yeasts tested produced isopentanol and phenylethanol. Production of gamma-lactones may serve as a valuable characteristic in the identification of organisms of the genus Pityrosporum.

Culture Media↗