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Biomedical subjects

T A Luger

Publications and source records attributed to T A Luger.

At least 37 records · Page 2Linked to original sources

[Pruritus in childhood. A diagnostic and therapeutic challenge].

From the clinician's point of view, pruritus in children is quite frequent. It mainly occurs along with dermatoses but rarely with systemic diseases such as renal and liver failure or with genetic disorders. Mostly, it appears in the setting of atopic dermatitis (AD). Other frequent differential diagnoses comprise e.g. scabies, impetigo, varicella, tinea, urticaria, mastocytosis and psoriasis. In children, pruritus is most often associated with severe scratching leading to artefacts. This group of patients requires a therapeutical regimen of its own. The use of topical and systemic treatments depends on the underlying aetiology of pruritus and the stage and status of the skin. The physician has to consider that topically applied drugs may cause intoxication due to the different body volume/body surface proportion, especially in newborns and infants. The dosages of systemic drugs need to be adapted in children and UV phototherapy should be performed with caution due to possible longterm photo damage of the skin. Physicians feel more insecurity treating pruritus in children, especially when systemic treatments are taken into consideration. We want to highlight the major aetiologies of pruritus in children and point out the cornerstones of antipruritic therapy in this challenging group of patients in recognition of our own clinical experiences and the current literature.

Adolescent↗

[Antipruritic therapy with the oral opioid receptor antagonist naltrexone. Open, non-placebo controlled administration in 133 patients].

BACKGROUND AND OBJECTIVES: The perception of pruritus is modified by endogenous and exogenous opioids via central opiate receptors and can be suppressed with opioid receptor antagonists. The aim of this investigation was to describe the efficacy and safety of naltrexone, an orally active opiate antagonist, in the treatment of severe, otherwise intractable pruritus of varying origins. PATIENTS: A total of 133 patients with pruritus caused by inflammatory skin diseases (asteatotic dermatitis, atopic dermatitis, prurigo, and psoriasis vulgaris), liver- and renal diseases, cutaneous lymphoma, as well as with pruritus of unknown origin were treated with naltrexone (Nemexin) 50 to 150 mg daily. RESULTS: A therapeutic response was achieved in 86 of the 133 (64.6%) patients. Naltrexone was most effective in prurigo nodularis, cutaneous lymphoma and pruritus of unknown origin. Tachyphylaxis occurred in 13% of the patients, but appeared late, and could be counterbalanced by raising the dosage. Adverse drug effects were restricted to the first two weeks of treatment and included mainly neurological (dizziness, headache, fatigue) and gastrointestinal (nausea, vomiting, diarrhea) symptoms. CONCLUSIONS: The oral opiate antagonists may well be an effective, well-tolerated therapy for intractable pruritus in many diseases.

Administration, Oral↗

Long-term safety and tolerability of pimecrolimus cream 1% and topical corticosteroids in adults with moderate to severe atopic dermatitis.

OBJECTIVE: This randomized, double-blind, multi-centre study compared the long-term safety and tolerability of pimecrolimus cream 1% and topical corticosteroids (TCS) in 658 adults with moderate-severe atopic dermatitis (AD). METHODS: Patients applied either pimecrolimus or TCS (i.e. 0.1% triamcinolone acetonide cream and/or 1% hydrocortisone acetate cream) twice daily to all affected areas until complete clearance or for up to 1 year. The study was approved by the institutional review board or ethics committee at each centre. RESULTS: A majority of patients treated with either pimecrolimus or TCS used the drug on a continuous basis over 1 year. In patients who had >30% of the body surface involved by AD, the incidence rate of all skin infections was significantly lower in the pimecrolimus group than in the TCS group (95% CI of the treatment difference: -25.3% to -3.4%). The most frequent application site reaction was burning (25.9% of patients on pimecrolimus and 10.9% on TCS), which was transient and mild-moderate in most cases. Three TCS-treated patients reported skin striae. There were no treatment-related serious or clinically significant systemic adverse events. Efficacy was better in patients on continuous TCS therapy, although patients completing the study were similarly well-controlled in both groups. About 42% of the pimecrolimus-treated patients were maintained for 1 year without TCS. CONCLUSION: Pimecrolimus demonstrated a favourable safety profile when used to treat adult patients with moderate-severe AD for up to 1 year. A significant proportion of patients could be maintained without TCS for a year.

Administration, Cutaneous↗

Pimecrolimus -- an anti-inflammatory drug targeting the skin.

Pimecrolimus is the most recent member of calcineurin inhibitors available for the therapy for inflammatory skin diseases. It targets T-cells and mast cells and inhibits the production and release of cytokines and other inflammatory mediators, as well as the expression of signals essential for the activation of inflammatory T-lymphocytes. Pimecrolimus has a cell-selective mode of action. In contrast to corticosteroids, it does not affect, e.g., Langerhans'cells/dendritic cells (LC/DC), as demonstrated in vitro with human monocyte-derived DC and in vivo with epidermal LC in mice, nor human primary fibroblasts. As shown in vitro with human skin and by comparison of clinical pharmacokinetic data from patients with atopic dermatitis, pimecrolimus permeates less through skin than tacrolimus and much less than corticosteroids. It, thus, has a lower potential for transcutaneous resorption after topical administration, resulting in a lower risk of systemic effects. Pimecrolimus has high anti-inflammatory activity in animal models of skin inflammation, including a model reflecting neurogenic inflammation, but a more favourable balance of anti-inflammatory vs. immunosuppressive activity than tacrolimus. Pimecrolimus does not affect sensitization in a murine model of allergic contact dermatitis and has a lower potency in various models of immunosuppression after systemic administration, compared to tacrolimus. In conclusion, the results of preclinical studies show that pimecrolimus has a selective pharmacological profile, suited for effective and safe treatment for inflammatory skin diseases.

Animals↗

[Squamous epithelial carcinomas of the face with neurotropic growth].

BACKGROUND AND OBJECTIVE: Invasion of squamous cell carcinoma of the head and neck into cutaneous nerves is rare and can easily be missed. Perineural outgrowth into cerebral nerves may result in severe pain or neurological disturbances. In addition, these carcinomas more often recur or metastasize and therefore are associated with a poor prognosis. PATIENTS/METHODS: We report on two patients with squamous cell carcinoma of the dorsum of the nose and lower lip exhibiting neurotropic growth. RESULTS: Histology showed pleomorphic keratinocytes growing deep into the subcutaneous tissue and bone, respectively. The presence of few pleomorphic keratinocytes could be only confirmed by immunohistochemistry, though indicated by a perineural lymphocytic infiltrate. In both patients, several re-excisions were necessary to achieve cure. CONCLUSIONS: In neurotropic squamous cell carcinoma a consequent radical micrographic surgery as well as neurological and radiological investigations are mandatory. We also review the literature.

Aged↗

[Antipruritic effects of pimecrolimus and tacrolimus].

The development of topical calcineurin inhibitors resulted in a significant improvement in the treatment of inflammatory skin diseases such as atopic dermatitis. In addition, an excellent amelioration of pruritus could be observed. Other itchy dermatoses such as chronic irritative hand dermatitis, rosacea, graft-versus-host-disease, renal pruritus, lichen sclerosus, prurigo simplex, prurigo nodularis, scrotal eczema, and inverse psoriasis also have been treated successfully with pimecrolimus and tacrolimus. The antipruritic effect currently is believed to be related to the inhibition of inflammatory cytokines. Furthermore, recent investigations indicate a release of neuropeptides from sensory nerve fibers and degranulation of mast cells mediated by pimecrolimus and tacrolimus. Similar effects have been observed during capsaicin treatment. These findings may provide a possible explanation for initially observed calcineurin inhibitors related side-effects such as burning and pruritus. Moreover, the antipruritic potency may be related to a direct effect on nerve fibers leading to suppression of itch mediated by unknown mechanisms.

Administration, Topical↗

Alpha-melanocyte stimulating hormone prevents lipopolysaccharide-induced vasculitis by down-regulating endothelial cell adhesion molecule expression.

The neuroendocrine hormone alpha-melanocyte stimulating hormone (MSH) has profound antiinflammatory and immunomodulating properties. Here we have examined the possibility that alpha-MSH may interfere with the expression and function of cell adhesion molecules (CAMs) expressed by human dermal microvascular endothelial cells (HDMECs) in response to lipopolysaccharide (LPS) or TNFalpha in vitro and in vivo. In HDMEC, alpha-MSH (10(-8)/10(-12) M) profoundly reduced the mRNA and protein expression of E-selectin, vascular CAM (VCAM)-1, and intercellular CAM (ICAM)-1 induced by LPS or TNFalpha as determined by semiquantitative RT-PCR, ELISA, and fluorescence-activated cell sorter analysis. In addition, alpha-MSH significantly impaired the LPS-induced ICAM-1 and VCAM-1-mediated adhesion of lymphocytes to HDMEC monolayer in a functional adhesion assay. Likewise, alpha-MSH effectively inhibited the transcription factor nuclear factor-kappaB activation in HDMEC, which is required for CAM gene expression. Importantly in vivo, in murine LPS-induced cutaneous vasculitis (local Shwartzman reaction), a single ip injection of alpha-MSH significantly suppressed the deleterious vascular damage and hemorrhage by inhibiting the sustained expression of vascular E-selectin and VCAM-1. This persistent expression has been implicated in the dysregulation of diapedesis and activation of leukocytes, which subsequently leads to hemorrhagic vascular damage. Our findings indicate that alpha-MSH may have an important therapeutical potential for the treatment of vasculitis, sepsis, and inflammatory diseases.

Animals↗

Hydroxyethyl starch does not cross the blood-brain or the placental barrier but the perineurium of peripheral nerves in infused animals.

Therapy with hydroxyethyl starch (HES) is associated with a high incidence of persistent pruritus due to HES storage in cutaneous nerves. Up to now it has been unknown if HES also accumulates in the extracutaneous peripheral or central nervous system. To study this, five rats including one pregnant one were infused with a single dose (34-150 mg) of HES (70/200/450 kDa molecular weight) conjugated with fluorescein isothiocyanate (FITC). In addition, four sheep were infused with a cumulative dosage of 30 g, 120 g, and 420 g HES (200 kDa), respectively. After 7-13 days, biopsies from the adult rats, four fetal rats and sheep were taken from various organs. The specimens were analyzed by light, electron, and confocal laser scanning microscopy. Typical HES storage vacuoles were found in macrophages of the skin, liver, spleen, lung, and kidney. HES storage in healthy animals was not associated with signs of either inflammation or apoptosis contrary to a previously described animal hemorrhagic shock model. Beyond that, fetus biopsies did not show any storage phenomenon, confirming that HES does not cross the placental barrier. Deposits of HES could be detected in Schwann cells of cutaneous nerve fibers as well as in perineural and endoneural cells of sciatic nerve in one rat (HES 450 kDa) and three of four sheep. No HES storage was found in the central nervous system. Our findings clearly demonstrate that storage of HES is detectable only in small peripheral nerves, suggesting a cutaneous origin of the HES-induced pruritus.

Animals↗

[Persistent inflammatory reaction at the injection site of Il-2 with lymphoma-like inflammatory infiltrates].

Interleukin-2 (Il-2) is widely used for treatment of carcinomas, leukemia, and melanoma. Adverse drug effects of Il-2 include various systemic and generalized cutaneous drug reactions. In the following we report on a persistent inflammatory reaction at the injection site of Il-2. A patient received chemoimmuno-therapy for treatment of metastasizing melanoma, including subcutaneous application of recombinant interleukin-2 (Proleukin((R))). Within a few days reddish nodules developed at the injection sites that persisted after cessation of Il-2 injections for two years until final lethal outcome. Histologic examination revealed a lobular panniculitis expressing atypical lymphocytes and multinucleated histiocytes.

Aged↗

Mycophenolate mofetil and leflunomide: promising compounds for the treatment of skin diseases.

In the past decade, there has been enormous progress in the understanding of the pathomechanisms of immune-mediated diseases, which has led to major advances in immunotherapeutic strategies. As a consequence, the armamentarium of specific and nonspecific immune-modulating and immunosuppressive drugs for the treatment of skin diseases has been widely extended. Among the nonspecific immunomodulators, mycophenolate mofetil and leflunomide show promising effects in a variety of autoimmune and inflammatory skin disorders. Both compounds inhibit a key enzyme in nucleotide biosynthesis, a step that is pivotal for the production of cytotoxic T cells and antibody formation. They do not act in the nucleus, which may explain their advantageous side-effect profile.

Administration, Oral↗

Overexpression of CD40 ligand in murine epidermis results in chronic skin inflammation and systemic autoimmunity.

CD40-CD40 ligand (L) interactions play a pivotal role in immune-mediated inflammatory responses via the activation of antigen-presenting cells (APCs). To investigate the effects of continuous activation of resident tissue APCs, in this case the Langerhans cells (LCs) of the skin, CD40L expression was targeted to the basal keratinocytes of the epidermis of mice using the keratin-14 promoter. Approximately 80% of the transgenic (Tg) mice spontaneously developed dermatitis on the ears, face, tail, and/or paws. Compared with littermates, Tgs had a >90% decrease in epidermal LCs yet increased numbers within the dermis suggestive of enhanced emigration of CD40-activated LCs. Tgs also displayed massive regional lymphadenopathy with increased numbers of dendritic cells and B cells. Moreover, a decrease in IgM and an increase in IgG1/IgG2a/IgG2b/IgE serum concentrations was detectable. Screening for autoantibodies revealed the presence of antinuclear antibodies and anti-dsDNA antibodies implicative of systemic autoimmunity. Accordingly, renal Ig deposits, proteinuria, and lung fibrosis were observed. Adoptive transfer of T cells from Tgs to nonTg recipients evoked the development of skin lesions similar to those found in the Tgs. Dermatitis also developed in B cell-deficient CD40L Tg mice. These findings suggest that in situ activation of LCs by CD40L in the skin not only leads to chronic inflammatory dermatitis but also to systemic mixed-connective-tissue-like autoimmune disorders, possibly by breaking immune tolerance against the skin.

Animals↗

Failure of alpha-melanocyte stimulating hormone to attenuate cerebral complications in experimental pneumococcal meningitis.

Alpha-melanocyte-stimulating hormone (alpha-MSH) is an endogenous neuroimmunomodulatory peptide that can inhibit a broad range of inflammatory mediators known to be involved in the pathophysiology of bacterial meningitis. We evaluated the effect of alpha-MSH in a rat model of pneumococcal meningitis. Rats were intracisternally infected with Streptococcus pneumoniae and treatment was started 6 h after infection. Both systemic and intracisternal alpha-MSH failed to influence blood-brain barrier disruption, increased intracranial pressure, brain cytokine concentrations (IL-1beta, IL-6, TNF-alpha, MIP-2, and IL-10), CSF bacterial titers, and clinical parameters of disease severity (weight loss, body temperature, and blood pressure), although the treatment strongly increased the CNS concentrations of alpha-MSH. However, systemic but not intracisternal alpha-MSH slightly reduced the CNS leukocyte accumulation, indicating that leukocyte extravasation is inhibited by alpha-MSH from the blood side. Our results show that alpha-MSH reduces the CNS leukocyte accumulation by its systemic action, but does not attenuate meningitis-associated intracranial complications.

Animals↗

Neutral endopeptidase terminates substance P-induced inflammation in allergic contact dermatitis.

Sensory nerve-derived neuropeptides such as substance P demonstrate a number of proinflammatory bioactivities, but less is known about their role in inflammatory skin disease. The cell surface metalloprotease neutral endopeptidase (NEP) is the principal proteolytic substance P-degrading enzyme. This study tests the hypothesis that the absence of NEP results in dysregulated inflammatory skin responses. The effector phase of allergic contact dermatitis (ACD) responses was examined in NEP(-/-) knockout and NEP(+/+) wild-type mice and compared with the irritant contact dermatitis response in these animals. NEP was found to be normally immunolocalized in epidermal keratinocytes and dermal blood vessels. The ACD ear swelling response was 2.5-fold higher in animals lacking NEP and was accompanied by a significant increase in plasma extravasation and infiltration of inflammatory leukocytes. The augmented ACD response in NEP(-/-) animals was abrogated by either administration of a neurokinin receptor 1 antagonist or by repeated pretreatment with topical capsaicin. Similar to NEP(-/-) mice, the acute inhibition of NEP in NEP(+/+) animals resulted in an augmented ACD response. In contrast to the ACD responses, little differences were observed in the irritant contact dermatitis response of NEP(-/-) compared with NEP(+/+) animals after epicutaneous application of the skin irritants croton oil or SDS. Thus, these results indicate that NEP and cutaneous neuropeptides have a significant role in the pathogenesis of ACD.

Administration, Cutaneous↗

[Cyclic neutropenia. Detection of a mutation in the gene for neutrophil elastase (ELA2)].

BACKGROUND AND OBJECTIVE: Cyclic neutropenia is a rare congenital hematopoietic disease which occurs sporadically or as an autosomal dominantly inherited disorder. Recently, the locus for cyclic neutropenia was mapped to chromosome 19p13.3. Autosomal dominant and sporadic cyclic neutropenia are now attributable to mutations of the ELA2 gene encoding neutrophil elastase. PATIENTS/METHODS: Based on a case report we review the clinical picture and diagnostic criteria of cyclic neutropenia and report about the recent molecular biological findings and current treatment options. RESULTS: Serial blood cell counts revealed the characteristic oscillations of the circulating neutrophils with 21-day periodicity from near normal to extremely low levels. The neutrophil nadir lasted 3-5 days. The neutropenia was associated with fever, malaise, painful oral aphthous ulcers and lymphadenopathy. Mutational analysis of the patient's genomic DNA revealed a single base-pair transition (nt 4716, G-->A) in intron 4 of ELA2. Since the initiation of therapy with subcutaneous recombinant human granulocyte-stimulating colony factor (rHuG-CSF) 24 months ago, the patient has been free of symptoms. CONCLUSIONS: Despite the typical medical history with onset of the symptoms in early infancy the diagnosis of cyclic neutropenia was not established until the age of 9 years. A common reason for the delayed diagnosis of cyclic neutropenia may be unawareness of the rare but distinctive disorder and the practice of obtaining screening blood counts without leukocyte differentials. Patients with cyclic neutropenia should be enrolled to the Severe Chronic Neutropenia International Registry (SCNIR).

Base Pairing↗

[Cytokines: current status and prospects in the treatment of skin tumors].

Various therapeutic options using cytokines have been described in the treatment of melanoma, T cell lymphoma, B cell lymphoma, squamous cell carcinoma, basal cell carcinoma and Merkel cell carcinoma. The treatment regimens include cytokine substitution, cytokine induction, cytokine transfection and therapeutic cytokine constructs. In the adjuvant treatment of melanomas, IFN-alpha has become well established. Statistical evaluations of different adjuvant trials show that a significant prolongation of recurrence-free intervals can be achieved. IL-2 has a role in the therapy of advanced melanomas as well as in vaccination strategies. Further possible therapeutic immune modulations, which have been evaluated in experimental approaches and pilot studies, include treatment with IL-4, IL-7 and GM-CSF. Treatment with IL-12 promises to open new perspectives. A well established regimen in the treatment of T cell lymphoma stages Ia-IIb is the combination of PUVA and IFN-alpha. In vitro data also indicate an important (patho)physiological role for IL-12, so that this agent has been tested in phase I studies. IL-2, IFN-gamma, and the fused cytokine-toxin molecules DAB389IL-2 offer further therapeutic alternatives. B cell lymphomas are treated with antibody-IL-2 fusion proteins. Advanced or inoperable squamous cell carcinoma and basal cell carcinoma may be treated with local IFN-alpha injections. IFN-alpha or TNF-alpha may be considered for the treatment of recurrent or advanced Merkel cell carcinoma. In dermatological oncology cytokine treatment focuses on melanome an T cell lymphome. Cytokine application is mainly an integral part of multimodal regimens.

Animals↗

Differential storage of hydroxyethyl starch (HES) in the skin: an immunoelectron-microscopical long-term study.

Hydroxyethyl starch (HES) is widely used as a plasma substitute. Serious side effects occur only rarely, whereas a high incidence of severe pruritus has been reported. Moreover, tissue storage of HES has been demonstrated in various organs. The aim of the current study has been to examine precisely the intracellular uptake and long-term storage of HES in the skin. Skin biopsies from 119 patients who received HES of various preparations and cumulative dosage were obtained 30 min to 130 months after infusion therapy. The samples were analysed by ultrastructural and immunoelectron microscopy with HES-specific monoclonal and polyclonal antibodies. A characteristic vacuolisation of perivascular histiocytes was a regular finding in all skin biopsies as early as 1 day after a single infusion of 30 g. Immunoreactivity for HES was demonstrable within the vacuoles. Generally, the size and number of vacuoles in the histiocytes increased concomitantly with the cumulative dosage. Following administration of higher HES dosages, vacuoles were demonstrable in endothelial cells of blood and lymphatic vessels, basal keratinocytes, epithelia of sweat glands and in small peripheral nerves, the last mentioned being associated with pruritus. A subsequent reduction of the vacuoles in size and number could be demonstrated within 52 months. In nerves, HES deposits persisted no longer than 17 months paralleling the cessation of pruritus. Biopsies taken after 94 months exhibited no HES deposits in the skin. The condensation and final dissolution of the vacuoles may either indicate the release and subsequent redistribution of HES into the circulation or lysosomal degradation.

Adolescent↗