Skin-cleansing and care principles for special pediatric populations.

Good skin care has two overall goals: to support and maintain healthy stratum corneum function and to help restore barrier function perturbed by disease processes or injuries. In this article, we discuss the special attention that is required in the initial skin care of newborns, and we address what measures, beyond the basic skin care principles, are required for patients with conditions such as atopic dermatitis, acne, contact and allergic dermatitis, and diaper rash.

A lifetime of well skin care: practical recommendations for clinicians and patients.

The skin is an indicator of overall health throughout life, and the skin's lifelong care and environment are reflected with aging. The goal of skin care education by clinicians is to teach and reinforce habits that will support and maintain optimum stratum corneum barrier function throughout life and, when dermatologic conditions or injuries arise, that will aid in recovery of barrier function.

The chemistry of skin cleansers: an overview for clinicians.

Cleansers and other skin care products can be agents either of stratum corneum damage and skin barrier dysfunction or of maintaining or restoring healthy stratum corneum barrier structure and function. To guide patients toward beneficial choices most suitable for their individual skin conditions and needs, clinicians must be aware of and understand the ingredients in such skin care products and their potential effects on the stratum corneum barrier. In cleansers specifically, clinicians should be aware particularly of the benefits and potential problems associated with chemical components of surfactants, preservatives, and fragrances.

Update on the structure and function of the skin barrier: atopic dermatitis as an exemplar of clinical implications.

The healthy stratum corneum allows optimum permeability of water and provides the first line of defense against pathogenic and environmental assaults. The barrier functions of the stratum corneum are interrelated, coregulated, and interdependent. Research has demonstrated that three lipid species, which usually comprise 10% of the stratum corneum, are crucial to both its structure and its function; these must be present in sufficient quantities and in the correct proportions to provide optimum barrier function.

Understanding skin barrier differences: a demographic, cultural, and medical diversity viewpoint.

Important differences exist in the physiology of the stratum corneum barrier according to demographic, cultural, and medical factors. Understanding these differences is crucial to choosing strategies for optimum clinical management.

Tolerance of skin care regimen in healthy, full-term neonates.

Purpose: To assess the tolerance of a baby cleanser and lotion (both lightly fragranced) on healthy, full-term neonates.

Materials And Methods: Twenty-six infant-mother pairs were enrolled in a 6-week, nonrandomized, controlled-use study that took place in the routine setting of a pediatric clinic and mothers' homes. During study weeks 1 to 6, neonates were bathed by their mother with water and a test cleanser (JOHNSON'S® HEAD-TO-TOE® Baby Wash).

Prodan fluorescence mimics the GroEL folding cycle.

The non-covalent fluorescent probe 6-propionyl-2-(dimethylamino) naphthalene sulfonate (prodan) binds to hydrophobic surfaces exposed on the surface of GroEL. Under identical experimental conditions free prodan exhibits a green emission peak of intensity 390,000 cps at 520 nm. However prodan bound to GroEL, GroEL-ATP, and GroEL-ATP-GroES shows emission peaks of intensities 500,000, 540,000, and 480,000 cps at 515, 512 and 515 nm, respectively, thus mimicing the way hydrophobic surfaces on GroEL become exposed during the folding cycle.

Active rhodanese lacking nonessential sulfhydryl groups has increased hydrophobic exposure not observed in wild-type enzyme.

Mutation of all nonessential cysteine residues to serines in rhodanese turns the enzyme into a form (C3S) that is fully active but less stable than wild type (WT). bis-ANS binding studies have shown that C3S has more hydrophobic exposure than WT, although both have similar secondary structures suggesting the flexibility of its structure. Activity of C3S falls once it binds bis-ANS, and covalent binding of bis-ANS to C3S is induced by light.

Activation parameters for the spontaneous and pressure-induced phases of the dissociation of single-ring GroEL (SR1) chaperonin.

We investigated the dissociation of single-ring heptameric GroEL (SR1) by high hydrostatic pressure in the range 0.5-3.0 kbar.

Active rhodanese lacking nonessential sulfhydryl groups contains an unstable C-terminal domain and can be bound, inactivated, and reactivated by GroEL.

Mutation of all nonessential cysteine residues in rhodanese turns the enzyme into a form (C3S) that is fully active but less stable than wild type (WT). This less stable mutant allowed testing of two hypotheses; (a) the two domains of rhodanese are differentially stable, and (b) the chaperonin GroEL can bind better to less stable proteins. Reduced temperatures during expression and purification were required to limit inclusion bodies and obtain usable quantities of soluble C3S.

Dissociation of the single-ring chaperonin GroEL by high hydrostatic pressure.

We investigated the dissociation of single-ring heptameric GroEL (SR1) by high hydrostatic pressure in the range of 1-2.5 kbar. The kinetics of the dissociation of SR1 in the absence and presence of Mg2+, KCl, and nucleotides were monitored using light scattering.

The molecular chaperone DnaK is not recruited to translating ribosomes that lack trigger factor.

The molecular chaperone DnaK and trigger factor (TF), a ribosome-associated protein with folding activity, have been implicated in assisting nascent polypeptides to acquire a three-dimensional structure on Escherichia coli ribosomes. We asked whether ribosomes that lack trigger factor would recruit DnaK for synthesis and folding of nascent peptides. For these analyses, translating ribosomes with a homogeneous population of nascent peptides were isolated.

Single synonymous codon substitution eliminates pausing during chloramphenicol acetyl transferase synthesis on Escherichia coli ribosomes in vitro.

The coding sequence for chloramphenicol acetyl transferase (CAT) contains several rare codons; three of them are ATA encoding isoleucine in positions 13, 84 and 119 of the amino acid sequence. Expression of CAT on Escherichia coli ribosomes in vitro results in mostly full-length product but also distinct smaller polypeptides from less than 3 kDa to over 20 kDa. As reported earlier, the smaller polypeptides are the predominant products, if translation is initiated with fluorophore-Met-tRNA(f).

Rhodanese can partially refold in its GroEL-GroES-ADP complex and can be released to give a homogeneous product.

Molecular chaperones GroEL and GroES facilitate reactivation of denatured rhodanese which folds poorly unless the process is assisted. The present work tests the hypothesis that more extensively unfolded forms of rhodanese bind tighter than those forms that appear later in the folding pathway. The study of the interaction of different urea-induced forms of rhodanese with GroEL suggests that species preceding the domain folded form bind directly and productively to GroEL.

Conformational heterogeneity is revealed in the dissociation of the oligomeric chaperonin GroEL by high hydrostatic pressure.

We investigated the dissociation of tetradecameric GroEL by high hydrostatic pressure in the range of 1-2.5 kbar. Kinetics of the dissociation of GroEL in the absence and presence of Mg(2+) and/or KCl were monitored using light scattering.

Isolation and characterization of rhodanese intermediates during thermal inactivation and their implications for the mechanism of protein aggregation.

The initial steps of heat-induced inactivation and aggregation of the enzyme rhodanese have been studied and found to involve the early formation of modified but catalytically active conformations. These intermediates readily form active dimers or small oligomers, as evident from there being only a small increase in light scattering and an increase in fluorescence energy homotransfer from rhodanese labeled with fluorescein. These species are probably not the domain-unfolded form, as they show activity and increased protection of hydrophobic surfaces.