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Biomedical subjects

Gerald G Krueger

Publications and source records attributed to Gerald G Krueger.

29 records · Page 2Linked to original sources
PubMed2003

Development and use of alefacept to treat psoriasis.

Activated memory T cells, expressing CD2, are key components in the pathogenesis of psoriasis. Alefacept binds to CD2, blocks co-stimulatory signaling, and selectively induces apoptosis of pathogenic T cells. Our objective is to present safety and efficacy results which lead to the new drug application (NDA) of alefacept for the treatment of psoriasis. We reviewed the key phase II and III trials in over 1300 patients and found that during treatment and follow-up of patients receiving 12 weekly intramuscular or intravenous injections of alefacept, about 1/3 will achieve a reduction in psoriasis area and severity index (PASI) of > or =75% and nearly 2/3 a reduction in PASI of > or =50%. Patients who achieved a > or =75% reduction from baseline PASI during or after a single course maintained a > or =50% reduction in PASI for a median duration of >7 months. Among patients who received 2 courses of alefacept, 40% and 71% of patients achieved a > or =75% and > or =50% reduction in PASI, respectively and duration of effect was prolonged. Adverse events in the placebo and active treatment arms did not differ. We conclude that alefacept significantly improves psoriasis and produces durable clinical improvement with a very favorable safety profile.

Alefacept↗
PubMed2003

Normal and gene-corrected dystrophic epidermolysis bullosa fibroblasts alone can produce type VII collagen at the basement membrane zone.

Type VII collagen is synthesized and secreted by both human keratinocytes and fibroblasts. Although both cell types can secrete type VII collagen, it is thought that keratinocytes account for type VII collagen at the dermal-epidermal junction (DEJ). In this study, we examined if type VII collagen secreted solely by dermal fibroblasts could be transported to the DEJ. We established organotypic, skin-equivalent cultures composed of keratinocytes from patients with recessive dystrophic epidermolysis bullosa (RDEB) and normal dermal fibroblasts. Immuno-labeling of skin equivalent sections with the anti-type VII collagen antibody revealed tight linear staining at the DEJ. RDEB fibroblasts, were gene-corrected to make type VII collagen and used to regenerate human skin on immune-deficient mice. The human skin generated by gene-corrected RDEB fibroblasts or normal human fibroblasts combined with RDEB keratinocytes restored type VII collagen expression at the DEJ in vivo. Further, intradermal injection of normal human or gene-corrected RDEB fibroblasts into mouse skin resulted in the stable expression of human type VII collagen at the mouse DEJ. These data demonstrate that human dermal fibroblasts alone are capable of producing type VII collagen at the DEJ, and it is possible to restore type VII collagen gene expression in RDEB skin in vivo by direct intradermal injection of fibroblasts.

Animals↗
PubMed2003

Tazarotene cream in the treatment of psoriasis: Two multicenter, double-blind, randomized, vehicle-controlled studies of the safety and efficacy of tazarotene creams 0.05% and 0.1% applied once daily for 12 weeks.

BACKGROUND: Tazarotene in a gel formulation is widely used in the treatment of psoriasis. OBJECTIVE: To determine the efficacy and safety of tazarotene 0.1% and 0.05% creams in the treatment of psoriasis. METHODS: A total of 1303 patients participated in 2 clinical trials. Patients applied tazarotene creams 0.1% and 0.05% or vehicle once daily to all psoriatic lesions for 12 weeks followed by a 12-week posttreatment period. RESULTS: Both creams were significantly more effective than vehicle on the basis of an overall assessment of psoriasis, a global response to treatment, and reduction in plaque elevation and scaling. Therapeutic effect was maintained during the posttreatment period. Common adverse events included signs and symptoms of skin irritation. CONCLUSION: Tazarotene creams were associated with significant reductions in the severity of the clinical signs of psoriasis and were found to be safe with acceptable tolerability. Tazarotene cream 0.1% was generally more effective, although slightly less well tolerated, than the 0.05% cream.

Administration, Topical↗
PubMed2002

Induction of dramatic hyperpigmentation in a patient with generalized lichen planus treated with re-PUVA.

BACKGROUND: Retinoids plus PUVA (re-PUVA) may be used in the treatment of lichen planus in cases that do not respond to monotherapy. Hyperpigmentation is a potential side effect of re-PUVA therapy. OBJECTIVE: A case of remarkably intense transient hyperpigmentation secondary to re-PUVA therapy is presented. METHODS AND RESULTS: An 18-year-old male with lichen planus who had been taking isotretinoin 80 mg per day for seven days developed an exaggerated hyperpigmentation following the third dose of PUVA. CONCLUSION: As the hyperpigmentary reaction did not occur until the third PUVA dose, which was near the steady state of isotretinoin, this case may illustrate a case of photosensitization secondary to isotretinoin alone or isotretinoin in combination.

Adolescent↗
PubMed2002

Doxycycline-inducible retroviral expression of green fluorescent protein in immortalized human keratinocytes.

Keratinocytes have a great potential to deliver systemically therapeutic genes, and a regulatable switch technology for transgene expression in this cell type would greatly enhance their clinical value for cutaneous gene therapy. We describe a method wherein immortalized human keratinocytes (IMKc) are transduced with high efficiency with retroviral vectors of the RetroTet-Art system, which confers stable doxycycline (Dox)-regulated green fluorescent protein (GFP) expression. In this RetroTet-Art system the TCN transactivators and TCN transrepressors are coexpressed in cells. After one round of transduction, approximately 50% of IMKc expressed GFP; after puromycin selection over 90% of cells expressed GFP. With this retroviral vector system no baseline expression of GFP was observed in the genetically modified IMKcs. Dox treatment of these transduced cells induced GFP expression in a dose- and time-dependent manner. Peak GFP expression occurred after 72 h of Dox treatment and dropped to baseline when Dox was removed. These multiply transduced cells formed differentiated epidermis in vitro and the Dox treatment did not induce evidence of toxicity in the architecture of the epidermis. Our observations demonstrate an efficient method for achieving stable Dox-regulatable transgene expression in human keratinocytes.

Cell Line↗
PubMed2002

A randomized, double-blind, placebo-controlled study of clobetasol propionate 0.05% foam in the treatment of nonscalp psoriasis.

BACKGROUND: Topical corticosteroids are the primary treatment for mild to moderate psoriasis. Foam preparations of corticosteroids offer potential cosmetic and pharmacodynamic advantages over cream and ointment vehicles. A clobetasol propionate foam product is as effective as clobetasol propionate solution in the treatment of scalp psoriasis. AIM: To evaluate the safety and efficacy of clobetasol propionate foam in the treatment of psoriasis involving sites other than the scalp. METHODS: Eighty-one subjects with mild to moderate psoriasis were randomized in a 3 : 1 ratio to receive clobetasol propionate foam vs. placebo foam treatment in this double-blind study of psoriasis involving nonscalp sites. The investigator's and subject's global assessment of the response at week 2 (or at the end of treatment) and at week 4 (follow-up) and the severity of erythema, scaling, and plaque thickness were assessed. Safety was assessed from reported adverse events. RESULTS: After 2 weeks of treatment, there was significantly greater improvement with clobetasol propionate foam compared with placebo foam in both investigator's and subject's global assessment of the response (P < 0.0005). The improvement with clobetasol propionate foam was still present at the 4-week follow-up visit. Adverse effects were generally limited to mild to moderate application site reactions. No subjects withdrew because of adverse events. CONCLUSIONS: Clobetasol propionate foam is more effective than placebo in the treatment of nonscalp psoriasis. Twice-daily applications are well tolerated, compliance exceeds 90%, cosmetic characteristics are acceptable, and the medication may eliminate the need for separate scalp and body prescriptions.

Administration, Topical↗
PubMed2002

A randomized, double-blind, placebo-controlled phase III study evaluating efficacy and tolerability of 2 courses of alefacept in patients with chronic plaque psoriasis.

BACKGROUND: In previous phase II studies, alefacept significantly improved psoriasis and was well tolerated. The clinical response to alefacept was durable. OBJECTIVE: Our purpose was to further evaluate efficacy and tolerability of alefacept in a phase III study of patients (n = 553) with chronic plaque psoriasis. METHODS: Two 12-week courses of once-weekly intravenous alefacept 7.5 mg or placebo were given in a randomized double-blind study; patients were followed up for 12 weeks after each course. RESULTS: During treatment and follow-up of course 1, a 75% or greater reduction in the Psoriasis Area Severity Index (PASI) was achieved by 28% of alefacept-treated and 8% of placebo-treated patients (P <.001). Patients who received a single course of alefacept and achieved a 75% or greater reduction from baseline PASI during or after treatment, without the use of phototherapy or systemic therapies, maintained a 50% or greater reduction in PASI for a median duration of more than 7 months. Among patients who received 2 courses of alefacept, 40% and 71% of patients achieved a 75% or greater and 50% or greater reduction in PASI, respectively, during the study period. Alefacept was well tolerated over both courses. In course 1, the incidence of transient chills was higher in the alefacept group compared with the placebo group; more than 90% of cases occurred within 24 hours after the first few doses. CONCLUSION: Alefacept significantly improved psoriasis and produced durable clinical improvements among patients who responded. A second course of alefacept increased efficacy and was equally well tolerated.

Adolescent↗
PubMed2002

Selective targeting of T cell subsets: focus on alefacept - a remittive therapy for psoriasis.

Psoriasis is an immune-mediated disease in which memory-effector (CD45RO+), skin-homing T cells play a key role in driving the disease process. Available therapies are often poorly tolerated, none are curative and most only suppress disease symptoms without attacking the underlying cause of the illness. Alefacept (Ameviv, Biogen, Inc.) is a fully human lymphocyte function associated antigen-3/immunoglobulin G1 fusion protein that targets memory-effector T cells by binding CD2 on the T cell and Fc phi receptor III IgG receptors on accessory cells, thereby preventing T cell activation and proliferation and causing selective T cell apoptosis. To date, alefacept has been studied in moderate-to-severe chronic plaque psoriasis and in a pilot study of psoriatic arthritis. In chronic plaque psoriasis, alefacept produced significant and sustained improvements in psoriasis symptoms. There was no evidence of disease rebound or worsening of psoriasis following treatment cessation. Multiple courses provided consistent efficacy, with a trend for more rapid and greater clinical improvement in subsequent courses. Alefacept reduced circulating CD4+ and CD8+ memory-effector T cells, with relatively no change in naive (CD45RA+) T cells or B cells. Alefacept also reduced IFN-phi-secreting Tcells in lesional biopsies of psoriatic skin. These reductions all correlated with the observed clinical effect. Alefacept was well-tolerated throughout these studies, with a side effect profile similar to placebo. There was no evidence of generalised immunosuppression or increased risk of infection or malignancy. Alefacept did not alter the primary or acquired immune response in psoriatic patients. Clinical data obtained to date support the use of alefacept as a safe and remittive therapy for psoriasis.

Alefacept↗
PubMed2002

Clinical features of psoriatic arthritis.

The past 5 years have seen major advances in understanding the immunology and molecular biology of psoriatic arthritis (PsA), especially the impact of cytokines such as tumor necrosis factor (TNF), which has produced striking, long-term benefits in patients with rheumatoid arthritis (RA). Because PsA is not the same disease as RA, the ability to distinguish between them is important to physicians in managing patients who have clinical features consistent with an arthropathy. The development of TNF inhibitors directed specifically at the mechanisms of skin and joint inflammation offers hope to patients who suffer from the debilitating effects of PsA.

Arthritis, Psoriatic↗
PubMedDate not supplied

The effect of hair color on the incorporation of codeine into human hair.

The influence of melanin on the binding of xenobiotics in hair will impact the interpretation of drug concentrations determined by hair testing. The purpose of this study was to determine if codeine, as a model compound of abused drugs, would be incorporated into black, brown, blond, or red hair as a function of melanin concentration. Such data would assist in the interpretation of codeine concentrations in hair and help elucidate the potential influence of hair color on incorporation of drugs. Male and female Caucasians with black (n = 6), brown (n = 12), blond (n = 8), or red hair (n = 6) and non-Caucasians with black hair (n = 12) aged 21-40 years were enrolled in the study. Each subject was administered oral codeine phosphate syrup in a dosage of 30 mg three times a day for five days. Twenty-four hours after the end of the treatment period, a 30-mg codeine dose was administered and the subject's plasma area under the concentration time curve (AUC) for codeine was determined. Codeine and melanin were measured in the first 3 cm of hair closest to the vertex region of the scalp prior to and 1, 4, 5, 6, and 7 weeks after dosing. The quantitative and qualitative melanin profiles were determined for each subject's hair to provide an objective measure of hair color. The plasma concentrations of codeine were measured to eliminate differences in the bioavailability and clearance of codeine as factors that might account for the differences in codeine hair concentrations. The subjects were asked not to cut their hair in the vertex region of the scalp or to use any form of chemical treatment on their hair, but otherwise normal hygienic measures were permitted. The mean (+/- SE) hair codeine concentrations 5 weeks after dosing were 1429 (+/- 249) pg/mg in black hair; 208 (+/- 17) pg/mg in brown hair; 99 (+/- 10) pg/mg in blond hair; and 69 (+/- 11) in red hair pg/mg. In black hair, codeine concentrations were 2564 (+/- 170) pg/mg for Asians and 865 (+/- 162) pg/mg for Caucasians. Similar concentration relationships were observed at weeks 4, 6, and 7. A strong relationship between the hair concentrations of codeine and melanin (R(2) = 0.73) was observed. Normalization of the codeine concentration with the melanin concentration reduced the hair color differences observed. These data demonstrate that the interpretation and reporting of hair test results for codeine are influenced by hair color. After this dosing protocol, the proposed federal guideline cutoff of 200 pg/mg of codeine would result in 100% of subjects with black hair and 50% of subjects with brown hair being reported as positive, and subjects with blond or red hair would be reported as negative. The incorporation of these drugs into hair should be studied carefully in humans to ensure the appropriate interpretation of drug concentrations.

Administration, Oral↗