Biomedical subjects
R L Moy
Publications and source records attributed to R L Moy.
Comparison of the effect of various chemical peeling agents in a mini-pig model.
BACKGROUND: With the advent of newer chemical peels, there is now a wide range of peeling agents that can be applied on specific patients. OBJECTIVE: The purpose of this study was to closely examine the more common chemical peeling agents at different concentrations. METHODS: The study methods were carried out by thoroughly cleansing the skin surface with acetone. Different concentrations of the chemical peels were applied on different skin areas (2 x 2 cm each) and left on the skin for 15 minutes: phenol-Bakers, 25%, 50%, 75%, 88%; trichloroacetic acid, 25%, 50%, 75%; glycolic acid, 50%, 70%; and pyruvic acid, 50%, 100%. Serial biopsies were taken from each peeling site at 1, 7, and 21 days post-peel. Biopsies were then evaluated for epidermal changes, inflammation, and collagen deposition. RESULTS: The results show that Bakers phenol peel caused the most inflammation and nonspecific reaction, and in addition, a proportionate amount of new collagen deposition. Plus, increasing concentrations of phenol and TCA caused increasing amount of epidermal sloughing and inflammation after 1 day post-peel. The extent of reaction from the phenol and TCA was directly proportional to the collagen deposition at 21 days. CONCLUSIONS: The glycolic acid and pyruvic acid caused minimal nonspecific reaction. However, the collagen deposition caused by the glycolic acid and pyruvic acid was disproportionately increased suggesting a direct stimulatory effect by the two agents.
Glycolic acid modulation of collagen production in human skin fibroblast cultures in vitro.
BACKGROUND: Glycolic acid has been used extensively for the treatment of photoaging and wrinkles. Suggestions have been made that glycolic acid may have specific dermal effects, although biochemical studies are limited. OBJECTIVE: This study's purpose was to examine the effect of glycolic acid on the radioactively labeled collagen production in human skin fibroblasts in culture. METHODS: Normal dermal fibroblasts were grown to semi-confluence and incubated in the presence of glycolic acid for 24 hours. Radioactive proline was added to the cultures. Using a specific amino acid assay, the amount of radioactive hydroxyproline was measured and was used as an accurate index of collagen production. RESULTS: Results show that glycolic acid caused an elevated collage production in the fibroblasts. CONCLUSION: These results demonstrate a specific stimulatory effect by the glycolic acid and could explain some of the positive benefits from the clinical use of glycolic acid.
Clinical improvement of photoaged skin with 50% glycolic acid. A double-blind vehicle-controlled study.
BACKGROUND: Although there is increasing interest in the use of glycolic acid in the treatment of photoaged skin, to our knowledge, no controlled study has been done to assess the efficacy or the mode of this agent. OBJECTIVE: The purpose of this study was to determine whether 50% glycolic acid can improve photoaged skin and to study the histological basis for this improvement. METHODS: Forty-one volunteers were recruited into this double-blind vehicle-controlled study. Glycolic acid (50%) or vehicle was applied topically for 5 minutes to one side of the face, forearms, and hands, once weekly for 4 weeks. Punch biopsies were taken at pretherapy and at 5 weeks for histologic study. RESULTS: Significant improvement noted included decrease in rough texture and fine wrinkling, fewer solar keratoses, and a slight lightening of solar lentigines. Histology showed thinning of the stratum corneum, granular layer enhancement, and epidermal thickening. Some specimens showed an increase in collagen thickness in the dermis. CONCLUSION: The results of this study demonstrate that the application of 50% glycolic acid peels improves mild photoaging of the skin.
Comparison of room temperature and warmed local anesthetic solution for tumescent liposuction. A randomized double-blind study.
BACKGROUND: The tumescent technique of local anesthesia has been accepted as the standard of care for liposuction surgery. Large volumes of a dilute solution of lidocaine, epinephrine, sodium bicarbonate, and triamcinolone are infused into the subcutaneous fat. The technique eliminates the need for general anesthesia and provides greater safety and improved esthetic results. OBJECTIVE: A study was designed to evaluate the benefit of warming of the local anesthetic to 40 degrees C prior to infiltration and thus to determine whether warming provides improved patient comfort. METHODS: A double-blind randomized cross-over study was performed in 16 patients undergoing outpatient tumescent liposuction. Pain scores were determined using a visual analog pain scale. RESULTS: The mean pain score was significantly lower for areas treated with the 40 degrees C warmed solution. CONCLUSION: Warming of local anesthetic solution for tumescent liposuction significantly reduces pain as perceived by the patient and is recommended in all tumescent liposuction surgery.
IL-10 production in cutaneous basal and squamous cell carcinomas. A mechanism for evading the local T cell immune response.
Cytokines play a vital role in the host immune response by regulating the development and function of immunocompetent cells. To explore the possibility that tumors may alter the host response via release of immunomodulatory cytokines, we studied two different skin cancers, basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) as models. By RT-PCR, we found that the type 2 cytokines, IL-4 and IL-10, were strongly expressed in BCC compared with matched PBMC. Furthermore, IL-10 was more strongly expressed in SCC compared with benign growths. To identify the cell types responsible for production of these cytokines, tumor and tumor-infiltrating lymphocyte (TIL) cell lines were derived from BCC and SCC biopsy specimens. IL-2 and IFN-gamma mRNAs were expressed in TIL, while IL-10 mRNA were strongly expressed in BCC lines. In addition, IL-10 was detected in culture supernatants from BCC and SCC cell lines by ELISA and in tissue sections by immunohistology. TIL lines derived from these tumors demonstrated proliferative activity to autologous tumor cells in the presence of APCs, dependent on the addition of low concentrations of rIL-2 or neutralizing anti-IL-10 mAb in the culture medium. Furthermore, treatment of BCC with intralesional IFN-alpha induced tumor regression with concomitant up-regulation of IL-2 and down-regulation of IL-10 mRNA expression in lesions. These data suggest that tumor production of the cytokine, IL-10, may provide a mechanism for evading the local T cell-mediated immune response.
Surgical pearl: manual dermabrasion.
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Flaps and grafts for facial reconstruction.
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Selective accumulation of T cells according to T-cell receptor V beta gene usage in skin cancer.
To investigate whether specific T-cell populations are overrepresented in tumor-infiltrating lymphocytes (TIL) in skin cancer, we determined the T-cell receptor (TCR) diversity in biopsy specimens of basal cell carcinoma and squamous cell carcinoma. Immunostaining of tissue sections indicated that the majority of T cells expressed alpha beta TCRs. To assess diversity of the TCR beta chain, RNA was isolated directly from the tumor specimens and peripheral blood mononuclear cells (PBMC) from the same patient, cDNA was synthesized, and variable (V) beta chain gene usage was determined by the polymerase chain reaction (PCR). In each basal cell (n = 11) and squamous cell (n = 7) carcinoma studied, several V beta families were overrepresented in TIL versus PBMC, in that they accounted for greater than 5% of the repertoire in TIL and were at least 2% higher in TIL than in PBMC. The predominant V beta gene segments overrepresented in TIL generally differed from individual to individual. Simultaneous comparison of the V beta repertoire of TIL to that of uninvolved skin and PBMC from the same individual revealed preferential expression of V beta families within the TIL in three of five basal cell and four of four squamous cell carcinomas. Again, the predominant V beta s differed from individual to individual. Comparison of the TCR repertoire in uninvolved skin versus PBMC did indicate that some V beta families were overexpressed in the resident T-cell compartment in skin, although the overrepresented families were not constant from individual to individual. These data indicate the selective concentration of T cells bearing specific alpha beta TCRs in the local immune response to basal cell and squamous cell carcinomas.
Reconstruction of the nose utilizing a bilobed flap.
BACKGROUND: Defects of the distal nose are particularly challenging to reconstruct because of this area's unique texture, lack of elasticity, and possible distortion of the alar rim. The bilobed flap has been criticized for having a high incidence of "trapdooring," flap necrosis, dog ears, and prominent suture lines. METHODS: Patients who underwent bilobed flap repairs of the distal nose (n = 171) were reviewed for complications and cosmetic results. The modifications from the traditional design include minimizing the angle of transposition between lobes, thinning of the flap, basing the pedicle on the lateral aspect of the nose, and creating the lobes of the flap to be of equal diameter to the defect. RESULTS: There was a 3% incidence of infection, 7% incidence of partial flap necrosis, and 5% incidence of "trapdooring" and contour distortion. Color match and contour were excellent for all other patients. CONCLUSIONS: The modified bilobed flap is an excellent choice for reconstruction of defects of the lower nose because of the good skin match and low incidence of complications.
Decrease in skin-closing tension intraoperatively with suture tension adjustment reel, balloon expansion, and undermining.
BACKGROUND: The biomechanical and viscoelastic properties of the skin enable it to be significantly stretched within a relatively short period of time. This property, called mechanical creep, is exploited in various surgical maneuvers for intraoperative closure of large surgical defects. The recently introduced Miami Suture Tension Adjustment Reel (S.T.A.R.) device permits both the precise sutured attachment of a linear cycled load to approximate the edges of widened surgical defects, and the easy measurement of wound edge tension across the defects. OBJECTIVE: It was our purpose to compare the relative effects of linear load cycling with the S.T.A.R. device, spherical load cycling with balloon expander, and surgical undermining on the closing tension of surgical defects. METHOD: Surgical wounds were created on the flanks of six pigs and these defects were closed by various methods of repair. The combination of undermining and the S.T.A.R. device ws also evaluated. RESULTS: The average total decreases in skin closing tension were: undermining, 17.8 +/- 0.5%; balloon, 28.5 +/- 1.6%; S.T.A.R. device, 36.6 +/- 4.8%. CONCLUSION: Our data showed that all three techniques were effective in lowering the tension required to approximate surgically created defects, with the S.T.A.R. device proving to be most effective. Undermining and the S.T.A.R. device also worked synergistically to decrease skin-closing tension.
Photodynamic therapy for the treatment of squamous cell carcinoma using benzoporphyrin derivative.
BACKGROUND: Photodynamic therapy (PDT) involves laser light excitation of a tumor-localizing photosensitizer to destroy neoplasms. Benzoporphyrin derivative (BPD) is a new photosensitizer with several favorable characteristics. OBJECTIVE: Studies were designed to: 1) assess the efficacy of BPD-mediated PDT in treating in vivo squamous cell carcinomas (SCC); 2) obtain dosimetry data for BPD and laser parameters; and 3) establish clinical and histologic correlates of BPD-induced tumor regression. METHODS: Human SCC was implanted into nude mice. One group received BPD followed by laser light of 150 J/cm2 from an argon-pumped dye laser at 690 nm. Three control groups included laser energy alone, BPD alone, and no treatment. RESULTS: At day 21 posttreatment only PDT-treated tumors showed a statistically significant decrease in tumor volume and complete cure rate. Clinical resolution (scar) correlated perfectly with histologic resolution (scar). CONCLUSION: Human SCC in a nude mouse model responds to BPD-mediated PDT.
Verruca vulgaris and radiation exposure are associated with squamous cell carcinoma of the finger.
BACKGROUND: Factors associated with the development of squamous cell carcinoma (SCC) of the finger are verruca vulgaris, radiation exposure, burns, and arsenic ingestion. OBJECTIVES: We wish to further document the relationship between human papillomavirus (HPV) and roentgen exposure to squamous cell carcinoma of the finger. METHODS: A retrospective study of 32 cases of digital squamous cell carcinoma seen at UCLA Medical Center was performed. RESULTS: Ten patients (31%) had histories of verrucae at the site of the carcinoma. Eight patients (25%) had histories of x-ray therapy to the hand. CONCLUSION: Our study further supports the association of verruca vulgaris and radiation exposure in the development of squamous cell carcinoma of the finger.
Expression of CD45 isoforms in fresh and IL-2-cultured tumor-infiltrating lymphocytes from basal cell carcinoma.
Immunohistochemistry and flow cytometry analyses were performed to characterize the specific T cell subpopulations infiltrating basal cell carcinomas (BCC) and to determine their phenotypic response to in vitro expansion with IL-2. Tumor-infiltrating lymphocytes (TIL) within BCC predominantly expressed the CD45RO (activated or "memory") phenotype (65 +/- 3%) and the percentage of TIL expressing CD45RO consistently increased when cultured in vitro with IL-2 (85 +/- 5%). In comparison, fresh normal peripheral blood lymphocytes predominantly expressed the CD45RA (naive) phenotype (79 +/- 4%), but shifted to the expression of CD45RO following in vitro expansion in IL-2 (86 +/- 6%). To determine whether IL-2 alone, in the absence of antigen or mitogen, can promote naive lymphocytes to convert from the expression of the CD45RA isoform to the CD45RO isoform, we cultured purified CD45RA+ lymphocytes in IL-2. After three weeks in culture, 90% of the lymphocytes expressed exclusively CD45RO. We conclude that tumor-infiltrating lymphocytes from BCC predominantly express CD45RO and that this expression may represent specific antigen stimulation and/or in situ activation by cytokines.
Microcystic adnexal carcinoma: in vitro growth characteristics and effect on stromal collagen production.
BACKGROUND: Microcystic adnexal carcinoma (MAC) is a locally aggressive cutaneous neoplasm, which is characterized by follicular and sweat gland differentiation and a stroma of dense collagen. METHODS: MAC cells were studied and characterized in vitro through phase microscopy and proliferation assays. Additionally, to delineate a possible role of soluble mediators in bringing about the dense stromal collagen seen in association with these tumors, the effect of conditioned media derived from the tumor cells on the level of collagen production by normal fibroblasts was examined. RESULTS: A significant morphologic difference between the MAC cells and normal keratinocytes was not noted. Proliferation assays demonstrated a significantly slower rate of growth of the MAC cells in comparison to controls. Media conditioned by MAC cells did not induce an increase in collagen synthesis by cultured fibroblasts, but rather, there appeared to be an inhibitory effect on the level of collagen synthesis. CONCLUSIONS: The increased stromal collagen seen in MAC histologically is not the result of growth factors or cytokines produced by the MAC cells.
Glycolic acid peels for the treatment of wrinkles and photoaging.
BACKGROUND: Glycolic acid is an alpha hydroxyacid that is useful as a chemical peeling agent. OBJECTIVE: To discuss the techniques using glycolic acid to remove actinic keratoses, fine wrinkles, lentigines, melasma, and seborrheic keratoses. METHOD: Applied in a carefully timed manner, the depth of penetration can be titrated by the timed duration of application of acid on the skin. Chemical peels are left on the skin for 3 to 7 minutes for most patients. For ideal results, the chemical peel can be repeated 3 to 4 times. RESULT: Glycolic acid can easily be used to peel skin of all skin types with minimal risk. CONCLUSION: We have found glycolic acid can be an ideal adjunct to other cosmetic modalities such as soft tissue augmentation.
The immunogenicity of bovine collagen implants.
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Wound care after office procedures.
A knowledge of wound healing physiology and how it is influenced by wound dressings is valuable information for all dermatologists. Such knowledge enables the dermatologist to give authoritative advice on postoperative wound care and more importantly, to use wound dressings as a complement to good planning and surgical technique in order to optimize the conditions for rapid healing following office surgical procedures.