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J M Hanifin

Publications and source records attributed to J M Hanifin.

At least 73 records · Page 4Linked to original sources
PubMed1992

Relationship between increased cyclic AMP-phosphodiesterase activity and abnormal adenylyl cyclase regulation in leukocytes from patients with atopic dermatitis.

Atopic dermatitis (AD) is characterized by a variety of abnormal physiologic and pharmacologic responses in the skin. Leukocyte abnormalities of the cyclic nucleotide system include increased cAMP phosphodiesterase (PDE) and adenylyl cyclase activities. We have evaluated the possibility that a defect of the inhibitory GTP-binding protein (Gi) might cause inadequate modulation of adenylyl cyclase activity in AD leukocytes. We carried out a series of studies assessing adenylyl cyclase and Gi subunits in monocyte membranes. Using both pertussis toxin ribosylation and direct monoclonal antibody labeling of Gi proteins, we have shown evidence for a decrease or possible absence of one of the Gi proteins in atopic monocyte membranes. A genetic defect or toxin-mediated abnormality in leukocyte membrane Gi could account for these findings. Increased cAMP degradation by PDE may be a compensatory mechanism for increased cAMP synthesis that is regulated by GTP-binding proteins. But this increased PDE activity also rendered AD leukocytes hypo-responsive to immunofunction regulatory signals mediated by cAMP.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1992

Synergistic effects of interleukin 4 and interferon-gamma on monocyte phosphodiesterase activity.

Patients with atopic dermatitis (AD) have elevated leukocyte cyclic AMP-phosphodiesterase (PDE) activity and increased in vitro IgE synthesis compared to normal (NL) subjects. Interleukin 4 (IL-4), interferon-gamma (IFN-gamma), and PDE inhibitor have been shown to regulate in vitro IgE synthesis. This study investigated whether soluble T-cell factors such as IL-4 and IFN-gamma could account for elevated PDE activity in patients with AD. Both rhIL-4 and IFN-gamma significantly increased normal monocyte PDE activity to a maximum of 188% (n = 6, p less than 0.05) and 315% above control (n = 3, p less than 0.05), respectively. At concentrations below 0.1 units/ml IL-4 and IFN-gamma had synergistic effects on activation of monocyte PDE. AD and NL T-cell culture supernatants also significantly stimulated normal monocyte PDE activity, but the stimulatory activity was not significantly greater in the AD T-cell supernatants. The effect of both cytokines and T-cell supernatants on normal monocytes was inhibited by antibodies against IL-4 and IFN-gamma, respectively. This study demonstrates that IL-4 and IFN-gamma can increase PDE activity in normal monocytes. Though the levels of IL-4 and IFN-gamma in T-cell supernatants are undetectable with an enzyme-linked immunosorbent assay (ELISA) assay, the concentration of these cytokines below the detectable level can significantly increase PDE activity of monocytes in a synergistic and dose-dependent manner. These results suggest that cytokine-mediated activation of monocytes can increase PDE activity. Furthermore, lymphokines may play an important role in modulating the cyclic nucleotide regulatory pathway.

Dermatitis, Atopic↗
PubMed1992

Secular change in the occurrence of atopic dermatitis.

Atopic dermatitis is a common disease, and population-based studies indicate that the frequency of atopic dermatitis has increased substantially during recent decades. It has been generally accepted that disease onset occurs before 7 years of age in 80-90% of the cases, and consequently the epidemiology of atopic dermatitis has been studied mostly in children on admission of first grade school. Before 1960 about 2-3% of children suffered from atopic dermatitis. In the 1960s, some 4-8% was recorded in several studies, and for those born after 1970 most researchers found that 9-12% developed atopic dermatitis during childhood. The diagnostic criteria of Hanifin and Rajka are cumbersome for population studies not designed specifically for children. In order to compare epidemiologic data from varying times and locations, a framework for questionnaire studies in atopic dermatitis is proposed.

Child↗
PubMed1991

Airway responsiveness in atopic dermatitis.

Twelve of 123 patients with atopic dermatitis (AD) were screened by questionnaire and spirometry for the absence of smoking, hay fever, and respiratory disorders. Seven of these 12 patients had a positive methacholine challenge test. None of eight patients with another skin disorder, psoriasis, screened in a similar fashion, had a positive methacholine challenge. We conclude that hyperresponsive airways are a frequent finding in patients with AD and that similar mechanisms may account for the cutaneous physiologic and pharmacologic abnormalities that have been observed in AD.

Adult↗
PubMed1991

Atopic dermatitis: new therapeutic considerations.

Atopic dermatitis is a genetically determined inflammatory condition in which the primary defect is expressed in one or more hematopoietic cells that infiltrate the skin. It is a multifactorial disease with inflammation triggered by a variety of factors. Among these, atopic dermatitis has been experimentally induced and reproduced by emotional-stress interviews and food challenges only. The inflammatory events of atopic dermatitis appear to initiated by mast cells, but eosinophils, monocytes, and T lymphocytes (predominantly CD4) also are present in lesions. The secondary effects of inflammation are a dry, brittle stratum corneum and pruritus, causing excoriation and a lichenified epidermal layer resulting from chronic rubbing. Therapeutic approaches to atopic dermatitis may be directed at several points in the evolution of the disease. Agents including emollients are needed to preserve and restore the stratum corneum barrier, and effective antipruritics are required to reduce the self-inflicted damage to the involved skin. Various other agents may be needed to antagonize mediators or cytokines and to inhibit cytokine expression and release from lesional, immune-effector cells. Likewise, new phosphodiesterase inhibitors, calcium-active agents, and antiallergic drugs may be used to reduce the quantity and pathologic functioning of inflammatory infiltrating cells in the skin.

Dermatitis, Atopic↗
PubMed1991

Atopic dermatitis in infants and children.

Atopic dermatitis is a common, chronic inflammatory skin disease triggered by a variety of irritative emotional and allergic factors. Education and simple prevention and maintenance measures such as proper moisturizing greatly reduce disease. Antibiotics and topical corticosteroids are therapeutic mainstays.

Child↗
PubMed1991

Tyrosinase gene mutations associated with type IB ("yellow") oculocutaneous albinism.

We have identified three different tyrosinase gene mutant alleles in four unrelated patients with type IB ("yellow") oculocutaneous albinism (OCA) and thus have demonstrated that type IB OCA is allelic to type IA (tyrosinase negative) OCA. In an inbred Amish kindred, type IB OCA results from homozygosity for a Pro----Leu substitution at codon 406. In the second family, type IB OCA results from compound heterozygosity for a type IA OCA allele (codon 81 Pro----Leu) and a novel type IB allele (codon 275 Val----Phe). In the third patient, type IB OCA results from compound heterozygosity for the same type IB allele (codon 275 Val----Phe) and a novel type IB OCA allele. In a fourth patient, type IB OCA results from compound heterozygosity for the codon 81 type IA OCA allele and a type IB allele that contains no identifiable abnormalities; dysfunction of this type IB allele apparently results from a mutation either well within one of the large introns or at some distance from the tyrosinase gene. In vitro expression of the Amish type IB allele in nonpigmented HeLa cells demonstrates that the Pro----Leu substitution at codon 406 greatly reduces but does not abolish tyrosinase enzymatic activity, a finding consistent with the clinical phenotype.

Albinism, Oculocutaneous↗
PubMed1990

Thymopentin therapy reduces the clinical severity of atopic dermatitis.

One hundred patients with moderate to severe atopic dermatitis were entered into a two-center, double-blind trial. Patients were randomized to receive either thymopentin (Timunox, n = 48) or placebo (n = 52), administered as daily subcutaneous injections for 6 weeks. Clinical extent of disease and severity parameters were measured at baseline and at regular time intervals during the study. Both the placebo- and thymopentin-treated groups demonstrated a progressive and statistically significant (p less than 0.001) decline in the overall severity of their disease, but reduction in the clinical severity score was higher in the thymopentin-treated group and statistically significant (p = 0.04) in comparison with the placebo-treated group after 6 weeks of treatment. Of the individual symptoms comprising the total severity score, pruritus (p = 0.02) and erythema (p = 0.04) were reduced significantly when thymopentin therapy was compared to placebo therapy. In addition, both the extent of body involvement and severity index (a combined severity/extent index) were significantly reduced after 6 weeks in the thymopentin-treated group in comparison to the placebo-treated group (p = 0.04). There were no serious adverse experiences in either treatment group. We conclude that treatment with thymopentin is safe and offers significant therapeutic promise for atopic dermatitis.

Adolescent↗
PubMed1990

Phosphodiesterase and immune dysfunction in atopic dermatitis.

Atopic dermatitis and the other atopic conditions occur as a result of direct or indirect influences from cells of hematopoietic origin. Cellular immune abnormalities have been described, but appear to be secondary to cutaneous inflammation in atopic dermatitis. Pharmacophysiologic abnormalities are numerous and may relate to defective cyclic nucleotide metabolism in circulating and infiltrating leukocytes. A consistent leukocyte abnormality is elevated cyclic AMP-phosphodiesterase. This enzyme abnormality results in reduced intracellular cyclic AMP, creating a net permissive effect upon cell function. Phosphodiesterase inhibitors have been demonstrated to reduce abnormal histamine release and IgE production by cultured leukocytes. Studies of phosphodiesterase and associated defects in atopic leukocytes may lead to delineation of basic pathogenetic mechanisms as well as providing the potential for therapeutic targeting.

Dermatitis, Atopic↗
PubMed1990

The role of antihistamines in atopic dermatitis.

Although several lines of evidence support a role for histamine in the pathogenesis of atopic dermatitis, antihistamines have generally offered only marginal therapeutic benefit. The efficacy of the classic antihistamines has been severely limited by sedative effects, demonstrating the need for improved, nonsedating agents. Multifunctional antihistamines, or third-generation "antiallergic" drugs, appear to offer a variety of advantages beyond their ability to inhibit histamine release, such as inhibition of mediator release and interference with eosinophil migration. Double-blind studies of high-dose regimens are needed to help clarify the therapeutic efficacy of these antiallergic drugs.

Basophils↗
PubMed1990

A frequent tyrosinase gene mutation in classic, tyrosinase-negative (type IA) oculocutaneous albinism.

We have identified a tyrosinase gene mutation in several patients with classic, tyrosinase-negative (type IA) oculocutaneous albinism. This mutation, which results in a proline----leucine substitution at codon 81 of the tyrosinase polypeptide (EC 1.14.18.1), was observed in 20% (6 of 30) of oculocutaneous albinism alleles from independent probands, but it was not observed in any normal individuals. This mutation thus appears to be a frequent cause of tyrosinase-negative oculocutaneous albinism.

Albinism↗
PubMed1990

Immunologic aspects of atopic dermatitis.

The immunology of atopic dermatitis is complex, multilayered, and multifaceted. In one realm are the IgE-mediated, type I hypersensitivity reactions that can be elicited in at least 80% of patients. A second realm is that associated with cell-mediated immunity and delayed-type hypersensitivity (type IV) reactions. Scattered between these immunologic paradigms are the various splinters: immune complex abnormalities, putative late-phase reactions, and cutaneous basophil hypersensitivity. The inflammatory lesion of atopic dermatitis probably is a composite of the many model reactions that investigators have glimpsed but never resolved into a reasonable concept.

Dermatitis, Atopic↗
PubMed1989

Atopic dermatitis and atopy in non-clinical populations.

A group of 523 individuals from the general population in the Denver, Colorado area responded to an advertisement for subjects with "problem skin" conditions, such as eczema, dry skin, rashes, etc. The subjects completed screening history information and were evaluated for various characteristics during an examination by a dermatologist. Of the entire population, 33% satisfied the criteria for atopic dermatitis. Another group, described as the generic atopy subset, emerged from the classification and constituted 23% of the total. Individuals in this subset typically had either a personal history of atopic disease or a limited family history. They lacked past or present evidence of flexural rash. A third group, totaling 44%, was classified as nonatopic. A relatively large percent of each of the three groups exhibited some clinical signs of dry skin (e.g., scaling, flakiness). This feature is believed to be due, at least in part, to the damaging effects of the cold, dry conditions in Denver, Colorado.

Adolescent↗
PubMed1989

Pharmacological abnormalities in atopic dermatitis.

Numerous investigations have described cutaneous and systemic physiological and pharmacological aberrations in atopic dermatitis and the atopic diathesis. Some of these studies set the stage for a focus upon cyclic nucleotide abnormalities. Elevated leukocyte cyclic AMP-phosphodiesterase accounts for low intracellular cyclic AMP levels in atopic dermatitis. The resultant permissive effect correlates with abnormal functional parameters such as increased basophil histamine release and in vitro IgE synthesis. In vitro and clinical use of phosphodiesterase inhibitors corrects abnormal parameters and may indicate future therapeutic directions.

B-Lymphocytes↗
PubMed1988

Itraconazole therapy for recalcitrant dermatophyte infections.

Five patients with recurrent Trichophyton rubrum infections had become unresponsive to topical and oral antifungal therapy. These patients were treated in an open trial of itraconazole, a new oral antifungal medication. Each patient responded promptly to therapy within 1 month and showed marked improvement at the end of 3 to 6 months of therapy. Complete clearing of toenail infections was not achieved in this limited trial and recurrences occurred in the four patients who had toenail infections. The drug was well tolerated and no adverse effects were observed. Itraconazole appears to be an effective drug for relief of clinical aspects of recalcitrant dermatophyte infections. Long-term safety and prevention of recurrence remain to be established.

Adult↗