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Biomedical subjects

R Rox Anderson

Publications and source records attributed to R Rox Anderson.

44 records · Page 3Linked to original sources
PubMed2002

In vivo confocal imaging of pigmented eccrine poroma.

BACKGROUND: Near-infrared reflectance confocal microscopy (CM) imaging is a noninvasive technique that can be utilized to evaluate histologic features of cutaneous lesions in vivo. OBJECTIVE: A case of pigmented eccrine poroma was examined with CM. METHODS: Confocal images were taken to define the features of the lesion and correlated with transverse hematoxylin-eosin (HE)-stained sections. RESULTS: In CM imaging, a well-demarcated homogeneous nest consisting of small uniform cells was seen. The nest contained nonrefractile dark spaces that may represent cuticuli. Many dendritic melanocytes containing melanin were intermingled with the tumor cells, and numerous melanophages were present in the upper dermis. A marked prominence of surrounding vessels was also demonstrated. CONCLUSIONS: CM could well demonstrate the features of a pigmented eccrine poroma, as correlated with transverse HE-stained sections. However, high reflectance signals from melanin had to be carefully considered before a definitive diagnosis could be made.

Acrospiroma↗
PubMed2002

585-nm pulsed dye laser treatment of glottal papillomatosis.

Treatment of recurrent respiratory papillomatosis of the glottis is often challenging. The surgeon and patient must cooperatively balance decisions regarding airway safety, effects of multiple general anesthesias, employment disturbance, and vocal dysfunction. A pilot study was done in 41 adult cases (23 patients; 78 vocal folds) without complication to evaluate the effectiveness of a 585-nm pulsed dye laser (PDL; 450-micros pulse width; fluence of 38 to 255 J/cm2; 1- to 2-mm spot size) in the treatment of this disorder. Thirty-seven of the 41 cases (90%) were bilateral disease. Twenty-six of the 41 cases (63%; including 20 cases with involvement of the anterior commissure) were treated by bilateral photocoagulation of the lesions' microcirculation without microflap resection of tissue. Clinical observation revealed that irradiated but unresected disease involuted without development of an anterior commissure web. In the initial 13 of the 41 cases (32%), PDL treatment was followed by cold instrument microflap resection. The PDL enhanced the epithelial excision by improving hemostasis and by creating an optimal dissection plane between the basement membrane and the underlying superficial lamina propria. The PDL at 585 nm was less effective in the management of exophytic lesions because of its limited depth of penetration (approximately 2 mm). In this initial trial, the PDL was a relatively safe and efficacious treatment for glottal recurrent respiratory papillomatosis. Since the lesions involute without complete resection of the diseased epithelium, the anterior commissure can be treated to minimize the number of procedures. To study patterns of recurrence will require longer follow-up.

Female↗
PubMed2001

Laser-beam-triggered microcavitation: a novel method for selective cell destruction.

We describe a new method of cell destruction that may have potential for use in antitumor therapy. Cells are loaded by phagocytosis with microparticles (<1 microm) and irradiated with short laser pulses. Absorption of laser energy by the microparticles causes localized vaporization of the fluid surrounding the microparticles, leading to the generation of transient vapor bubbles (microcavitation) around the microparticles. Using cultures of bovine aortic endothelial cells, we demonstrate that induction of intralysosomal microcavitation is an efficient, rapid and selective method of cell killing that is dependent on the number of microparticles, the number of laser pulses, and the fluence of the laser pulses. Cell killing by microcavitation is a very selective process that is restricted to cells containing microparticles, leaving other cells unaffected. Intracytoplasmic release of lysosomal hydrolases is, in part, responsible for cell death, because the protease inhibitors E64d and TLCK diminished cell killing. Using the broad-specificity caspase inhibitor Z-VAD-fmk, we determined that lysosomal hydrolases could induce apoptosis in a caspase-independent manner. We also examined the possibility of microcavitation-induced delayed effects in the cells that survived the treatment. Using flow cytometry, we determined that there was no delayed cell death between 1 and 4 days after microcavitation. Moreover, we did not observe changes in the cell cycle, in expression of the proteins BCL2, HSP70 and HSP27, or in PARP degradation. In conclusion, microcavitation induces rapid and specific cells death (limited only to cells containing microparticles), without producing delayed effects among the surviving cells.

Animals↗
PubMedDate not supplied

Visible light treatment of photoaging.

Recently, a number of new devices have been developed specifically to improve the visible signs of aging in a noninvasive way. These include visible or near-infrared lasers, intense pulsed light sources (IPL), light-emitting diode (LED), and radiofrequency devices. This paper reviews the use of visible light sources and examines the attributes of specific systems for noninvasive skin rejuvenation.

Aged↗
PubMedDate not supplied

Treatment of melanocytic nevi.

Pigmented nevi are a heterogeneous group of lesions that range from uniquely curable with laser treatment, to partially responsive, to unresponsive or dangerous. This article presents laser and IPL treatment strategies from a clinical perspective for nevi organized by their typical responsiveness. A rationale for surgical excision, laser, and/or medical therapy in individual patients is also presented. Despite significant recent progress, it is clear that much understanding are still lacking about optimal laser treatment for pigmented lesions.

Adult↗
PubMedDate not supplied

Treating vascular lesions.

The treatment of acquired vascular lesions is one of the most commonly requested and performed cutaneous laser procedures. Furthermore, every year, 40,000 children are born in the United States each with congenital vascular lesions and malformations. Laser treatment of vascular lesion is based on the principle of selective photothermolysis, conceived in the 1980s. A variety of different lasers and light sources have since been used in the treatment of vascular lesions: lasers with wavelengths between green and yellow, near infrared lasers, and broadband light sources. Despite limitations, this remains the treatment of choice today. This publication addresses acquired and congenital vascular lesions as different entities and proposes a separation of vascular lesions into those that can easily be treated from those where clearance is difficult. Different treatment modalities and the various endpoints of individual vascular lesions will be discussed.

Adolescent↗
PubMedDate not supplied

Combining multispectral polarized light imaging and confocal microscopy for localization of nonmelanoma skin cancer.

Multispectral polarized light imaging (MSPLI) enables rapid inspection of a superficial tissue layer over large surfaces, but does not provide information on cellular microstructure. Confocal microscopy (CM) allows imaging within turbid media with resolution comparable to that of histology, but suffers from a small field of view. In practice, pathologists use microscopes at low and high power to view tumor margins and cell features, respectively. Therefore, we study the combination of CM and MSPLI for demarcation of nonmelanoma skin cancers. Freshly excised thick skin samples with nonmelanoma cancers are rapidly stained with either toluidine or methylene blue dyes, rinsed in acetic acid, and imaged using MSPLI and CM. MSPLI is performed at 630, 660, and 750 nm. The same specimens are imaged by reflectance CM at 630, 660, and 830 nm. Results indicate that CM and MSPLI images are in good correlation with histopathology. Cytological features are identified by CM, and tumor margins are delineated by MSPLI. A combination of MSPLI and CM appears to be complementary. This combined in situ technique has potential to guide cancer surgery more rapidly and at lower cost than conventional histopathology.

Basal Cell Carcinoma↗