Identifying reliable ions for the statistical differentiation of structurally similar fentanyl analogs.

Definitive identification of fentanyl analogs based on mass spectral comparison is challenging given the high degree of structural and, hence, spectral similarity. To address this, a statistical method was previously developed in which two electron-ionization (EI) mass spectra are compared using the unequal variance t-test. Normalized intensities of corresponding ions are compared, testing the null hypothesis (H ) that the difference in intensity is equal to zero.

Fluorescence of putative chromophores in Skh-1 and citrate-soluble calf skin collagens.

Background/purpose: Fluorescence of Skh-1 hairless mouse and calf skin acid-soluble type I collagens are envelopes of several bands putatively due to tyrosine (excitation/emission peak at 275/300 nm), dihydroxyphenylalanine (dopa; 280/325 nm), tyrosine aggregate (285/360 nm), dityrosine 325/400 nm), and advanced glycation end (AGE) product (370/450 nm), respectively. As these fluorophores can be markers of pathological conditions, we wish to present further evidence for or against these assignments.

Methods: We analysed intact type I mouse collagens and AGE by conventional fluorescence spectroscopy, synchronous spectroscopy, high-performance liquid chromatography (HPLC), and borate quenching.

Community-based trial of a triple-combination agent for the treatment of facial melasma.

Melasma is a common hyperpigmentation disorder that is frequently recalcitrant to treatment. An 8-week, multicenter, open-label, community-based study evaluated a new therapeutic approach that combines tretinoin 0.05%, hydroquinone 4.

Modest in vivo exposure to solar wavelengths induces a visible absorbing chromophore in Skh-1 mouse epidermis.

Background/purpose: In the previous work, we correlated epidermal hyperplasia with increased epidermal absorption in the 250-400 nm region. During a recent review of that work, the apparent formation of a chromophore, with absorption slightly longer than 400 nm, in the epidermis of irradiated animals was noted. In this study, we have extended the transmission measurement to include the 250-800 nm region.

Fluocinolone acetonide 0.01% in peanut oil: therapy for childhood atopic dermatitis, even in patients who are peanut sensitive.

Background: Fluocinolone acetonide 0.01% in a blend of refined peanut and mineral oils has been used as treatment for scalp psoriasis for several years, but only more recently for atopic dermatitis.

Objective: We sought to study the effectiveness for atopic dermatitis, potential for adrenal axis suppression, and safety of the fluocinolone acetonide 0.