Evaluating the safety and efficacy of the 1,440‐nm laser in the treatment of photodamage in Asian skin

Background and Objective

As the demand for diminished procedure‐associated downtime continues to increase, nonablative fractional laser resurfacing is becoming a more popular intervention in the progression of photoaging. Patients with pigmented skin and a mild degree of photodamage may be particularly suited for a less intensive laser treatment. In this study, we have evaluated the safety and efficacy of a low energy, low density 1,440‐nm fractional laser in the treatment of multiple signs of photoaging including dyspigmentation, wrinkling, tissue laxity, enlarged pores, and skin roughness in Asians.

Study Design/Materials and Methods

Ten Chinese subjects with Fitzpatrick skin types III–V and visible signs of photodamage participated in this study. Patients received four treatments at 2‐week intervals with a 1,440‐nm diode‐based fractional laser. Photographs were taken at baseline, 2 weeks after each of the first three treatments and 4 weeks after the final treatment. Images were evaluated independently by two physicians. Clinical improvement and adverse events were analyzed. Discomfort, heat sensation and overall patient satisfaction associated with the procedure were also quantified.

Results

In this prospective single‐arm study, signs of photoaging were examined after treatment with the 1,440‐nm laser. Here we show that a series of four treatments with this device produced a mild improvement in skin texture, pigmentation, and wrinkling. Changes in pore size and skin laxity failed to reach statistical significance. Immediate after‐effects of the procedure included erythema and edema which were transient and left no permanent sequela. A significant proportion of patients reported some degree of discomfort during the procedure despite use of a topical anesthetic. One patient developed a discrete, localized area of post‐inflammatory hyperpigmentation which completely resolved by the final follow up visit.

Conclusion

The low energy, low density nonablative 1,440‐nm fractional laser produces a mild improvement in select signs of photodamage after four treatments without any long‐term adverse effects. Lasers Surg. Med. 46:375–379, 2014. © 2014 Wiley Periodicals, Inc.     

Cellular Receptors Involved in KSHV Infection

The process of Kaposi’s Sarcoma Herpes Virus’ (KSHV) entry into target cells is complex and engages several viral glycoproteins which bind to a large range of host cell surface molecules. Receptors for KSHV include heparan sulphate proteoglycans (HSPGs), several integrins and Eph receptors, cystine/glutamate antiporter (xCT) and Dendritic Cell-Specific Intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN). This diverse range of potential binding and entry sites allows KSHV to have a broad cell tropism, and entry into specific cells is dependent on the available receptor repertoire. Several molecules involved in KSHV entry have been well characterized, particularly those postulated to be associated with KSHV-associated pathologies such as Kaposi’s Sarcoma (KS). In this review, KSHV infection of specific cell types pertinent to its pathogenesis will be comprehensively summarized with a focus on the specific cell surface binding and entry receptors KSHV exploits to gain access to a variety of cell types. Gaps in the current literature regarding understanding interactions between KSHV glycoproteins and cellular receptors in virus infection are identified which will lead to the development of virus infection intervention strategies.     

Alteration of Caenorhabditis elegans gene expression by targeted transformation.

We have produced strains carrying a synthetic fusion of parts of two vitellogenin genes, vit-2 and vit-6, integrated into the Caenorhabditis elegans genome. In most of the 63 transformant strains, the plasmid sequences are integrated at random locations in the genome. However, in two strains the transgene integrated by homologous recombination into the endogenous vit-2 gene. In both cases the reciprocal exchange between the chromosome and the injected circular plasmid containing a promoter deletion led to switching of the plasmid-borne promoter and the endogenous promoter, with a reduction in vit-2 expression. Thus in nematodes, transforming DNA can integrate by homologous recombination to result in partial inactivation of the chromosomal locus. The simplicity of the event and its reasonably high frequency suggest that gene targeting by homologous recombination should be considered as a method for directed inactivation of C. elegans genes.     

Lateral diffusion of surface immunoglobulin, Thy-1 antigen, and a lipid probe in lymphocyte plasma membranes

Fluorescence photobleaching recovery was used to measure the lateral diffusion coefficient and mobile fraction of surface immunoglobulin (sIg), Thy-1 antigen, and a lipid probe in the plasma membrane of mouse lymphocytes. The lipid probe (3,3'-dioctadecylindocarbocyanine) had a mean (+/-SD) diffusion coefficient of (1.7 +/- 0.3) x 10(-8) cm(2)/sec, with essentially all of the probe mobile in the membrane. We detected little or no effect on the diffusion of this probe due to the presence of microvilli. Its diffusion was slightly restricted in capped regions. No differences in lipid probe mobility were detected between T and B cells. Fifty to 90% of the detectable sIg and Thy-1 antigen was free to move in the plane of the membrane with diffusion coefficients of approximately 3 x 10(-10) cm(2)/sec; the remainder was immobile. Crosslinking of sIg with anti-Ig antibodies (in the presence of azide to inhibit capping) completely immobilized sIg at high concentrations but failed to do so at low concentrations. Thy-1 antigen could not be immobilized with an IgG rabbit anti-mouse brain reagent without an additional layer of crosslinking antibody. In parallel labelings (in the absence of azide), capping of sIg and Thy-1 antigen was observed only under crosslinking conditions sufficient to immobilize the membrane antigen. Sodium azide, colchicine, and cytochalasin B had no measurable effect on lipid probe, sIg, or Thy-1 diffusion.     

The aging thyroid. II. An immunocytochemical analysis of the age-associated lesions

This study utilizing immunocytochemical techniques consists of two segments, 1) an analysis of the changes with age in the hormone content of normal, involuting, macro- and microfollicles, as well as calcitonin (C) cells, and 2) an analysis of the components of the lesion characteristic of lymphocytic thyroiditis. Involuting and macro- (cystic) follicles show a decline in hormone content with age, while microfollicles show a variable pattern with some showing a high and others a low content, as well as some showing an absence of hormone. There also appears to be an increase with age in hormone-containing C cell micronodules, but we were unable to demonstrate a decline in hormone content of individual C cells. Studies on the in vivo binding of immunoglobulins, as an indicator of thyroid antibody binding, showed an increase with age in IgG and IgM binding to follicular epithelium. Much stronger reactions were observed in the epithelium of microfollicles than in that of involuting or macrofollicles. There were also examples of presumptive in vivo antibody binding by C cell micronodules. We were unable to demonstrate an imbalance of helper/suppressor T cell ratio in the thyroiditis lesion, but did find that some lymphocytes contain thyroid hormones, suggesting that the latter may act as cytokines and assist in the perpetuation of the lesion. The epithelial expression of human lymphocyte antigens (HLA) was strong in microfollicles and weak or absent in involuting or macrofollicles in sections with lymphocytic thyroiditis. It was also strong in the epithelium of a microfollicular adenoma without a lymphocytic infiltrate while weak or absent in the epithelium of adjacent normal follicles.(ABSTRACT TRUNCATED AT 250 WORDS)     

Macrophage activation: dissociation of cytotoxic activity from Ia-A antigen expression.

Peritoneal macrophages were obtained from DBA/2 mice that were untreated or after the injection of bacillus Calmette-Guerin (BCG), thioglycollate broth, proteose-peptone broth, or gamma-irradiated P-815 tumor cells. These macrophages were "activated" to become cytotoxic for a fibroblast cell line (L 929) by the addition of lymphokines (LKs), lipopolysaccharide (LPS), or fibroblast interferon (IFN-beta), and the expression of I region-associated antigens (Ia-Ad) on the macrophages was examined both before and after activation. Thioglycollate-elicited macrophages became Ia-A+ when activated by LKs, but they remained Ia-A- when activated by LPS or IFN-beta. Resident macrophages and proteose-peptone-elicited macrophages remained Ia-A- when activated with LKs. Macrophages from BCG-infected mice were both Ia-A+ and cytotoxic for tumor cells without further treatment. In contrast, macrophages from mice injected with gamma-irradiated P-815 mastocytoma cells were Ia-A+ but not cytotoxic, and these macrophages could not be made cytotoxic by incubation with LKs. The cultured macrophage-like cell lines P388D1 and WEHI-3 became Ia-A+ after incubation with LKs, and this treatment amplified the cytotoxicity of both cell lines. We conclude that a number of factors are important in determining whether Ia-A expression accompanies macrophage activation and that Ia-A is irrelevant as a surface marker for macrophage activation.     

Photodynamic therapy of colorectal cancer using a new light source

PURPOSE: Photodynamic therapy (PDT) is a relatively new alternative modality for palliation of rectal cancer. Current source of light for PDT are laser systems that are expensive and not necessarily needed for PDT. We evaluated a new nonlaser light source for PDT, Versa-Light ^® .METHODS AND RESULTS: In vitro PDT—CT26 murine colon carcinoma cells were incubated with aluminum phthalocyanine (AlPcS ₄ ) for 48 hours and subjected to photoradiation using Versa-Light ^® ,and viability was assessed. There was a significant decrease in viability of treated cells compared with controls. In vivo PDT—BALB/c mice were injected either subcutaneously or intrarectally with CT26 cancer cells. IP AlPcS ₄ (2.5 mg/kg) was injected when tumors were visible. After 24 hours, mice were subjected to photoradiation. Massive tumor necrosis in response to PDT was observed. PDT also prolonged survival of treated mice. Patient treatment—A 70-year-old woman with recurrent local rectal carcinoma received intravenous Photofrin II ^® (2 mg/kg). After 48 and 96 hours, she was subjected to direct photoradiation. After the first light session, there was complete macroscopic disappearance of the tumor. Biopsies up to 10 weeks after the treatment showed no cancer cells in the treated area. Sixteen weeks later, a randomized biopsy from previous tumor site showed carcinoma cells. CONCLUSIONS: We believe that Versa-Light ^® ,is a good light source for PDT. It was effective in both in vitro and animal studies. It can also be safely used for clinical PDT.Supported by the Roni Udassin Memorial Fund of the Israel Cancer Society.