Photodynamic therapy for cosmetic uses on the skin: an update 2010.

The utilization of photodynamic therapy (PDT) in the United States has reached an all-time high with many clinicians utilizing this form of therapy for a myriad of dermatologic disorders. World-wide, PDT is now being introduced to a wider audience. The purpose of this manuscript is to review PDT, from its history to it current uses and indications, and to expand upon its proper use and after care, to minimize any potential adverse events, and to make PDT treatments useful and effective for all of our patients. Two photosensitizers are now routinely available in the US and we will review both of these sensitizers, their FDA and off-label uses, and their affects on the skin and how they have made a positive effect in dermatology.

Efficacy of lasers and PDT for the treatment of acne vulgaris.

Acne vulgaris can represent a therapeutic challenge in terms of managing ongoing symptoms and preventing scar formation. While the copious variations of available treatments address milder forms of the disease, until recently, therapies for resistant or moderate-to-severe forms were limited to systemic agents that were accompanied by potentially severe side-effects. With the addition of lasers, light sources, and aminolevulinic acid-photodynamic therapy (ALA-PDT) therapies, dermatologists may now have viable new alternatives for treating all grades of acne severity that circumvent the negative side-effects associated with many conventional options.

Purification and characterization of two manganese peroxidase isozymes from the white-rot basidiomycete Dichomitus squalens.

Two manganese peroxidase isozymes, MnP1 and MnP2, were purified from the extracellular medium of ligninolytic cultures of Dichomitus squalens. The proteins were purified to homogeneity using DEAE-Sepharose chromatography and Mono Q fast protein liquid chromatography. MnP1 and MnP2 have molecular masses of 48000 and 48900 Da, respectively, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Both isozymes are glycoproteins and each contains one iron protoporphyrin IX as a prosthetic group. The pl values of MnP1 and MnP2 are 4.15 and 3.90, respectively. N-Terminal amino-acid analysis suggests that these proteins are encoded by distinct genes. The Soret bands of the native ferric enzymes (408 nm and 406 nm, respectively) are shifted to 434 nm in the reduced enzymes and to 422 nm in the reduced-CO complexes. EPR g-values of the native enzymes are essentially identical to those for other MnPs and lignin peroxidases, and they confirm the high-spin state of the iron. The addition of 1 equivalent of H2O2 to either of the native ferric isozymes yields spectra which are characteristic of compound 1. Successive additions of 1 equivalent of ferrocyanide and 1 equivalent of H2O2 to the native enzymes yield spectra which are characteristic of compound II. Both MnP isozymes oxidize Mn2+ to Mn3+ in the presence of organic acid chelators. The MnP isozymes are produced by D. squalens only when the cells are grown in the presence of Mn.

Characterization of the gene encoding manganese peroxidase isozyme 3 from Phanerochaete chrysosporium.

The gene encoding manganese peroxidase isozyme 3 (MnP3) from the white-rot basidiomycete Phanerochaete chrysosporium was cloned and sequenced. The mnp3 gene encodes a mature protein of 357 amino acids with a 25 amino-acid signal peptide. The amino acids involved in peroxidase function, as well as those forming the MnII binding site and those involved in disulfide bond formation, are conserved in the MnP3 sequence. The mnp3 gene has six introns, indicating that the sequenced P. chrysosporium mnp genes can be divided into three subfamilies on the basis of intron-exon structure. The mnp3 gene promoter contains putative metal response elements and heat shock elements which may be involved in the regulation of mnp gene transcription by Mn, the substrate for the enzyme, and by heat shock.

Characterization of genes encoding two manganese peroxidases from the lignin-degrading fungus Dichomitus squalens(1).

Genes encoding two manganese peroxidases from the white-rot basidiomycete Dichomitus squalens were cloned and sequenced. The mnp1 and mnp2 genes encode mature proteins of 369 and 365 amino acids, respectively. The amino acids involved in peroxidase function, those forming the Mn(II) binding site, and those forming the five disulfide bonds in other Mn peroxidases are conserved in these sequences. Both predicted D. squalens proteins contain multiple acidic residues in their C-terminal sequences, which may be involved in additional metal binding. Both genes contain seven small introns, the locations of which align with each other. The promoters of both D. squalens genes contain putative AP-2 sites, which may be involved in their regulation by nutrient nitrogen. Southern blot analysis of genomic PCR fragments suggests that these sequences represent separate genes rather than allelic variants.

Preliminary crystallographic analysis of manganese peroxidase from Phanerochaete chrysosporium.

Manganese peroxidase from the white rot basidiomycete Phanerochaete chrysosporium has been crystallized in a form suitable for high-resolution X-ray structure determination. Crystals were grown from solutions containing 30% polyethylene glycol 8000, ammonium sulfate and cacodylate buffer at pH 6.5, using macroseeding techniques. A complete data set has been obtained to 2.06 A resolution. The data can be indexed in space group P1 with a = 45.96 A, b = 53.77 A, c = 84.87 A, alpha = 97.01 degrees, beta = 105.72 degrees and gamma = 90.1 degrees, with two peroxidase molecules per asymmetric unit, or in space group C2 with a = 163.23 A, b = 45.97 A, c = 53.72 A and beta = 97.16 degrees, with only one molecule in the assymetric unit. Lignin peroxidase, which shares about 57% sequence identity with manganese peroxidase, was used as a probe for molecular replacement. Unique rotation and translation solutions have been obtained in space groups P1 and C2. The structure has been partially refined in space group C2 to R = 0.22 for data between 10 and 2.06 A.

Characterization of a highly expressed lignin peroxidase-encoding gene from the basidiomycete Phanerochaete chrysosporium.

The genomic clone, LG2, encoding LiP2, the major lignin peroxidase (LiP) isozyme from Phanerochaete chrysosporium strain OGC101, was isolated and characterized. The 5'-untranslated region of LG2 contains sequences similar to CRE and XRE promoter elements. Comparison with its transcript indicates that eight introns, each less than 59 bp, interrupt the coding sequence. Comparison with genes encoding other LiP isozymes shows five related patterns of intron location, whose incidence coincides with described LiP structural subfamilies. Codon bias indices calculated for all known P. chrysosporium genes, including trpC and genes encoding LiP, MnP, and exo-cellobiohydrolase I, demonstrate that LG2 has the most biased codon usage. We conclude that subdivisions of the LiP family may be based on intron location in the encoding genes, and that ranking of isozyme production levels can be estimated by the extent of bias in codon usage in the cognate gene.

Gene replacement in the lignin-degrading basidiomycete Phanerochaete chrysosporium.

The ability to carry out gene replacements and gene targeting in the lignin-degrading basidiomycete fungus, Phanerochaete chrysosporium, would facilitate studies on the roles and regulation of various components of its lignindegrading system. A plasmid consisting of the P. chrysosporium ura3 gene (encoding orotidylate decarboxylase) interrupted with the Schizophyllum commune ade2 gene (encoding an adenine biosynthetic enzyme) was used to transform the P. chrysosporium ade2 strain to adenine prototrophy with selection on 5-fluoroorotic acid for inactivation of the ura3 gene. Stable Ade+Ura- strains were obtained at a frequency of approximately one transformant per microgram of DNA. In all of the Ade+Ura- transformants examined by Southern analysis, the chromosomal ura3 locus had been replaced by the plasmid insert.

Characterization of the mnp2 gene encoding manganese peroxidase isozyme 2 from the basidiomycete Phanerochaete chrysosporium.

The nucleotide (nt) sequence of a gene (mnp2) encoding manganese peroxidase isozyme 2 (MnP-2) from Phanerochaete chrysosporium was determined. The sequence of 3297 bp includes 1287 bp of 5'-flanking sequence and 490 bp 3' to the stop codon. Comparison of cDNA and genomic sequences indicates seven introns varying in size from 50-55 bp. The 5' upstream region of the mnp2 gene contains a TATAA element, three inverted CCAAT elements (ATTGG), six putative heat-shock elements (HSE) and three putative metal response elements (MRE) (TGCRCNC), all located within 1100-bp upstream from the start codon. The positions of the putative HSE and MRE in the promoter region of mnp2 are compared with the corresponding sequences in the mnp1 gene promoter. A Northern blot probed with a fragment specific for the mnp2 gene suggests that the transcription of mnp2 is regulated by Mn ions.

Characterization of a gene encoding a manganese peroxidase from Phanerochaete chrysosporium.

The complete nucleotide (nt) sequence of a gene (mnp-1) encoding manganese peroxidase isozyme 1 (MnP-1) (pI = 4.9) from Phanerochaete chrysosporium has been determined. The sequence of 2539 bp includes 526 bp of 5'-flanking sequence and 368 bp 3' to the poly(A) site. Comparison of cDNA and genomic sequences indicates six introns varying in size from 57-72 bp. Intron splice-junction sequences all adhere to the GT---AG rule. The positions of the introns show little similarity to the intron positions in the closely related lignin peroxidase-encoding genes. The 5' upstream region of the mnp-1 gene contains a TATAA element and three inverted CCAAT elements (ATTGG) at nt positions -81, -181, -195, and -304, respectively, relative to the start codon. In addition, the mnp-1 gene contains three putative heat-shock (HS) elements similar to the consensus C--GAA--TTC--G sequence, and two consensus metal response elements located within 500 bp upstream from the start codon. Furthermore, Northern-blot analysis demonstrates that mnp gene transcription is regulated by HS.

Lignin peroxidase from the basidiomycete Phanerochaete chrysosporium is synthesized as a preproenzyme.

The cDNA clone L18 encoding lignin peroxidase LiP2, the most highly expressed LiP isozyme from Phanerochaete chrysosporium strain OGC101, was isolated and sequenced. Comparison of the cDNA sequence with the N-terminal sequence of the mature LiP2 protein isolated from culture medium suggests that the mature protein contains 343 amino acids (aa) and is preceded by a 28-aa leader sequence. In vitro transcription followed by in vitro translation and processing by signal peptidase resulted in cleavage at a site following the Ala21 (counted from the N-terminal Met1 of the initial translation product). The resultant protein contains a 7-aa propeptide, indicating that LiP is synthesized as a preproenzyme.

Fibrel.

Fibrel is a useful product for the treatment of depressed cutaneous scars, facial lines, and wrinkles. There have been documented increases in collagen production and inflammatory response over time. Adverse reactions seem to be minimal. If a more user-friendly product can be used--no plasma, minimal inflammatory response, 30-gauge needle--Fibrel should be considered in all patients for soft tissue augmentation.

Randomized controlled trial of the tolerability, safety, and efficacy of adapalene gel 0.1% and tretinoin microsphere gel 0.1% for the treatment of acne vulgaris.

A prior meta-analysis of 5 randomized controlled trials indicates that adapalene gel 0.1% is as effective as tretinoin gel 0.025% against acne and has greater tolerability. To determine the tolerability and efficacy of adapalene gel 0.1% versus tretinoin microsphere gel 0.1% in 168 patients with acne vulgaris, we conducted a 12-week, multicenter, randomized, controlled, investigator-masked, parallel-group design study. Efficacy variables included noninflammatory, inflammatory, and total lesion counts; global grade; and global assessment of improvement in acne severity. Skin tolerability variables included erythema, desquamation (scaling), dryness, pruritus, and stinging/burning. Our results showed that the efficacy of adapalene gel 0.1% was comparable to that of tretinoin microsphere gel, and both treatments had similar onset of action. Cutaneous tolerability was noted in both groups, with scores significantly better with adapalene gel 0.1% than with tretinoin microsphere gel 0.1%, and significantly fewer treatment-related adverse events were reported with adapalene gel 0.1%.

Human bite marks. Differential diagnosis.

Human bite marks are common findings in cases of fights among children, child abuse, sexual abuse, among institutionalized persons, and in a number of homicide cases. Human bites can mimic annular or arciform dermatoses. These are reviewed from both a clinical and histologic viewpoint. An example is presented of a 2 year-old girl with several annular lesions that were clinically mistaken for a dermatophyte infection. Antifungal medications were ineffective. After several days, a dermatologist identified the lesions as human bites. Physicians and other health care workers must be able to differentiate the clinical appearance of bite marks from other dermatologic diseases at an early stage so as to initiate proper therapy and counseling and, if indicated, a search for the perpetrator.

The Fibrel mechanism of action study. A preliminary report.

BACKGROUND: Fibrel is a medical implant device that has demonstrated use in the correction of cutaneous depressions from acne scars and wrinkles. OBJECTIVE: Mechanisms of actions have been proposed that have theorized the production of new collagen over time as a result of the Fibrel implant. The present study utilized human volunteers to study the histologic response of Fibrel over time. METHODS: Fibrel was injected into tattoo sites behind the ears of human volunteers; skin biopsies were taken at various time intervals and studied histologically by a clinical pathologist. RESULTS: An overall increase over time was noted with regard to production of collagen and inflammatory response. No change in elastic tissue was found. CONCLUSIONS: Fibrel does promote new collagen synthesis and inflammatory response and thus is useful to correct cutaneous depressions via soft tissue augmentation.