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Biomedical subjects

Stanley M Shapshay

Publications and source records attributed to Stanley M Shapshay.

At least 19 recordsLinked to original sources
PubMed2006

Fiber-guided CO2 laser surgery in an animal model.

OBJECTIVE: This study tested a newly developed flexible fiber for CO(2) laser surgery. BACKGROUND DATA: The lack of a flexible delivery system with the current CO(2) laser has limited its surgical application. We conducted in vitro and in vivo studies by using the skin tissue model of animals to test a new laser fiber system. METHODS: In an in vitro study, the acute thermal effect of laser surgery using this new fiber was tested and compared on fresh porcine skin at 3.0-5.0-W laser power and at 0.3-0.5-mm spot size. In the in vivo experiments, the healing process of the skin incisions and wounds was followed microscopically in 16 rats, at post-operative days 2, 6, 12, and 21 after the laser surgery with 3.0-W power and 0.5-mm spot size. RESULTS: The results from the in vitro tissue showed limited thermal damage to neighboring tissue. In the in vivo study, there was rapid postoperative healing. CONCLUSION: Our findings indicate that this fiber system, at least with the laser parameters used in this study, appears to be an effective and feasible alternative for CO(2) laser surgery. It has great potential for development of office-based surgery under local anesthesia.

Animals↗
PubMed2005

Laser-assisted low-dose retinoic acid in oral cancer chemoprevention.

OBJECTIVES: Systemic retinoic acid (RA) treatment for chemoprevention of squamous cell carcinoma of the head and neck (HNSCC) is limited by RA's toxic side effects at therapeutic doses. The pulsed-dye laser (PDL), through a mechanism of selective vascular targeting, may allow reduction of the RA dose to one that is better tolerated when these treatments are used in combination. This study tests our hypothesis that combination therapy of PDL irradiation and low-dose systemic RA is as effective as high-dose RA therapy alone in the chemoprevention of HNSCC. STUDY DESIGN: Randomized, prospective study in a hamster model. METHODS: Dysplastic lesions were induced in the cheek pouches of 48 hamsters by painting with topical 9,10-dimethl-1,2-benzanthrancene (DMBA). The hamsters were randomly divided into four treatment groups: 1) control (no treatment); 2) PDL irradiation only; 3) 5.0 mg RA (all-trans retinoid, 5.0 mg/kg per day, intraperitoneally [IP]); and (4) PDL + 0.5 mg RA (0.5 mg/kg per day, IP). The PDL irradiation was conducted at day 0 and 15, whereas the RA treatment was continued for 27 days. Tumor burden was measured over time. RESULTS: The lesions in all of three treatment groups grow more slowly than the untreated controls. The combination treatment of PDL and RA had the greatest inhibitory effect on tumors. CONCLUSION: This study suggests that combination treatment of PDL and low-dose RA is more effective than high-dose RA alone in the chemoprevention of HNSCC in a hamster cheek-pouch model, so that it should allow greatly improved tolerance of this regimen.

Animals↗
PubMed2005

Surgical utility of a new carbon dioxide laser fiber: functional and histological study.

OBJECTIVES/HYPOTHESIS: The objective was to investigate the functional and histological properties of surgical procedures using a new carbon dioxide (CO2) laser fiber. STUDY DESIGN: In vitro and in vivo animal models. METHODS: In vitro experiments using porcine true vocal cord and arytenoid cartilage were designed to study the histological effects of using a photonic band-gap fiber assembly for CO2 laser energy delivery. Continuous and pulsed-wave settings at different wattages were tested. In vivo endoscopic surgery on canine larynges and buccal mucosa were performed to examine functional and short-term healing when performing photonic band-gap fiber assembly-assisted laser surgery. RESULTS: In vitro experiments showed consistent cutting with the photonic band-gap fiber assembly using either straight or 90 degrees bent-tip fibers. The surrounding tissue in these experiments showed little collateral thermal damage with the average range of thermal width from 14.1 to 18.8 microm in vocal cords and from 5.2 to 10.5 microm in cartilage. Similarly, thermal depth ranged from 28.0 to 350.0 microm in vocal cords and from 269.7 to 739.6 microm in cartilage. In vivo experiments demonstrated ease in maneuvering and flexibility for cutting. There was minimal blood loss, smoke plume, or carbonaceous debris. There were no postprocedural complications. Normal oral intake was noted on postprocedural day 1. There was no evidence of stridor or respiratory distress. Seven days after the procedure, re-epithelialization was complete in the buccal incisions and nearly completed in the laryngeal incisions. CONCLUSION: The photonic band-gap fiber assembly produced reliable results in cutting with functional characteristics representing an improvement over current technology. The device shows promise as an effective tool for minimally invasive procedures that are amenable to use of the CO2 laser.

Animals↗
PubMed2004

Laser assisted topical 'biofilm' chemoprevention of oral cancer.

This study examines whether a combination of laser microvascular targeting, mucosal adhesive film (MAF) and retinoic acid (RA) techniques would improve the efficacy for oral cancer chemoprevention. The cheek pouches of 48 hamsters were painted with 7,12-dimethlbenz[a]nthrancene to produce premalignant lesions. There were four groups of 12 each: (1) control; (2) pulsed dye laser (PDL) treatment; (3) topical MAF/RA patch treatment; and (4) combined treatment of PDL and MAF/RA. The treatments were conducted for 27 days. Our findings indicate that this new combined treatment is safe and effective for oral cancer chemoprevention, and warrants further study.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2004

Anatomic variants and pearls--functional endoscopic sinus surgery.

For successful endoscopic sinus surgery. a clear understanding of the anatomy is vital. Knowledge of the anatomic relationships and variations helps surgeons avoid complications. By applying anatomic knowledge with careful surgical technique, one can maximize patient safety. Basic tenets for endoscopic sinus surgery can be applied to a variety of patients with confidence.

Endoscopy↗
PubMed2004

Endoscopic treatment of laryngeal and tracheal stenosis-has mitomycin C improved the outcome?

OBJECTIVE: The management of laryngeal and tracheal stenosis remains a challenging problem despite advances in endoscopic surgical techniques. Scar formation and restenosis is the main cause of failure, and this study assesses the efficacy of two adjuvant treatments: endoscopic steroid injection and topical mitomycin C application. Study design and setting This is a retrospective cohort study comparing the efficacy of 3 endoscopic techniques: (1) carbon dioxide (CO(2)) laser incisions with bronchoscopic dilatation, (2) CO(2) laser with dilatation followed by steroid injection into the stenotic area, and (3) CO(2) laser with dilatation followed by topical application of mitomycin C. Included in the statistical analysis were 47 procedures performed by the senior investigator in a tertiary medical center between 1994 and 2001 based on their success or failure. RESULTS: The percentages of successful outcomes in the study groups were 15%, 18.2%, and 75% with the CO(2) laser, CO(2) laser with steroid injection, and CO(2) laser with mitomycin C, respectively. Statistical comparisons reveal that the differences in outcomes were statistically significant (P < 0.05) between the mitomycin group and each of the other two treatment groups, whereas there was no statistically significant difference between the laser only and laser with steroid groups. There were no complications noted with the use of adjuvant medications. CONCLUSION: These patient group results indicate a statistically significant increase, from <20% to 75%, in the success rate of endoscopic treatment of acquired upper airway stenosis when topical mitomycin C is added to the treatment regimen. No benefit has been demonstrated for using intraoperative local steroid injections as an adjunct to laser treatment. Clinical significance Mitomycin C appears to be an effective and safe adjuvant treatment in the endoscopic management of laryngeal and tracheal stenosis.

Administration, Topical↗
PubMed2004

Spectroscopic diagnosis and imaging of invisible pre-cancer.

The theme of this paper is the use of optical spectroscopy to diagnose invisible pre-cancer in patients undergoing endoscopy and similar medical procedures. We describe three techniques that provide diagnostic information and two instruments to implement them, the FastEEM for studying small regions of tissue and the LSS (light scattering spectroscopy) imaging system for wide-area surveillance. The FastEEM is an optical fiber clinical device that collects spectra of reflected light and fluorescence at multiple excitation wavelengths from the tissue, all in a fraction of a second. Quantitative information is obtained in real time, without removing the tissue and without the need for staining and fixation. Three types of spectral information are extracted intrinsic fluorescence, diffuse reflectance and elastic light scattering. Each of the three analyses is based on a biophysical model, and each provides complementary quantitative physical and chemical information about cellular/tissue structures. This information is used to make a combined spectral diagnosis, a method we call tri-modal spectroscopy (TMS). Promising clinical studies are being carried out on patients undergoing routine pre-cancer surveillance in the oral cavity, the uterine cervix and the gastrointestinal tract. The LSS imaging system provides wide-area spectroscopic images of the epithelium, typically 2 cm in each dimension, depicting the size distribution and chromatin content of the cell nuclei, which are key parameters in diagnosing pre-cancer. This instrument is in preclinical stages of development, although a laboratory prototype has been used to create diagnostic images in resected colon polyp samples. The combination of the TMS/FastEEM and LSS imaging instrument will constitute a powerful new diagnostic tool, with LSS imaging to provide wide area surveillance and the TMS probe to provide detailed information on suspect tissue sites.

Cervix Uteri↗
PubMed2004

Analysis of recurrences in 322 Tis, T1, or T2 glottic carcinomas treated by carbon dioxide laser.

An endoscopic approach to early glottic carcinoma is considered a sound treatment for both previously untreated lesions and selected recurrent lesions. Between January 1988 and December 2000, we treated 322 patients by CO2 laser at a single institution; 37 had Tis, 191 T1a, 55 T1b, and 39 T2 lesions (mean follow-up, 77 months; range, 6 to 180 months). Kaplan-Meier curves showed a 5-year overall survival rate of 88%, a determinate survival rate of 99%, a disease-free survival rate of 81%, a rate of ultimate local control with laser alone of 91%, and a laryngeal preservation rate of 97%. Univariate and multivariate analysis showed that the only factor that statistically affected endoscopic control was lateral extension of the tumor with involvement of the bottom of the ventricle (hazard risk ratio, 4.0; 95% confidence interval, 1.71 to 9.35). The 58 recurrences were classified according to their location compared with the site of the primary tumor as follows: 14 in the same area (group A), 27 in adjacent subsites with superficial spreading or multifocal distribution (group B), and 17 in adjacent sites by submucosal diffusion to the visceral spaces, cartilaginous framework, or extralaryngeal tissues (group C). For each group, we analyzed the rate of patients who underwent salvage by endoscopic or open neck procedures and the rate of laryngeal preservation. Recurrences in groups A and B were endoscopically treated in 86% and 74% of cases, respectively. By contrast, in group C no patient was endoscopically cured, and there was a low laryngeal preservation rate (47%). The pathways of spread in recurrent carcinoma are therefore the single most important factor in predicting its endoscopic curability.

Adult↗
PubMed2003

Topical inhibition of oral carcinoma cell with polymer delivered celecoxib.

Celecoxib has a potential role for oral cancer chemoprevention but its systemic side effects are a concern. Topical chemoprevention is a promising way to reduce the toxicity. This study was designed to determine whether topical application of polymer delivered celecoxib would have an inhibitory effect on human oral carcinoma cells. Seventeen nude mice were intradermally inoculated with the carcinoma cells, and then were divided into control and treatment groups. Tumor growth was measured for 15 days, at which significant difference was found between two groups (P<0.001). This study indicates a potential role of polymer film delivered celecoxib for topical inhibition of oral cancer.

Administration, Oral↗
PubMed2003

Spectroscopic detection and evaluation of morphologic and biochemical changes in early human oral carcinoma.

BACKGROUND: Understanding the development and progression of head and neck squamous cell carcinoma is key in the quest for the early diagnosis and prevention of this type of malignancy. The current study correlated early biochemical and histologic changes in oral tissue with spectral features in fluorescence, reflectance, and light scattering spectra acquired in vivo to diagnose early stages of oral malignancies. METHODS: A total of 91 tissue sites from 15 patients with varying degrees of malignancy (normal, dysplastic, and cancerous sites) and 8 healthy volunteers were analyzed with 3 spectroscopic techniques. Direct biochemical information regarding oral tissue native fluorophores was obtained with intrinsic fluorescence spectroscopy by fitting a linear combination of collagen and the reduced form of nicotinamide adenine dinucleotide (NADH) fluorescence spectra to the intrinsic tissue fluorescence spectra excited with 337 nanometer (nm) and 358-nm laser light. Diffuse reflectance spectroscopy was used to provide information regarding tissue absorption and structure, such as hemoglobin concentration and stroma density, by measuring the wavelength-dependent absorption and scattering coefficients. By subtracting the diffusely reflected component from the measured reflectance, light scattering spectroscopy (LSS) information resulting from single backscattering from epithelial cell nuclei was obtained. LSS provides information concerning the size distribution of cell nuclei. RESULTS: These optically extracted tissue parameters provide biochemical or structural information in vivo without the need for tissue excision, and can be used to diagnose tissue abnormalities. By combining the information provided by the three techniques, a method known as trimodal spectroscopy, a sensitivity and specificity of 96% and 96%, respectively, in distinguishing cancerous/dysplastic (mild, moderate, and severe) from normal tissue was achieved. In addition, the authors were able to distinguish dysplastic from cancerous tissue with a sensitivity of 64% and a specificity of 90%. CONCLUSIONS: The results of the current study demonstrated that Trimodal spectroscopy is a highly sensitive and specific technique with which to diagnose tissue abnormalities.

Carcinoma↗
PubMed2003

Topical chemoprevention of oral cancer with tretinoin "biofilm".

BACKGROUND: Oral cancer is a common malignancy. Chemoprevention is a promising treatment strategy but it produces systemic toxic effects. Topical application of chemopreventive agents is an attractive alternative that reduces toxic effects. This study is based on the hypothesis that topical application of mucosal adhesive film (MAF), as a means to deliver tretinoin, is effective and safe for oral cancer chemoprevention. SETTING: Randomized animal study conducted at the Boston University School of Medicine. DESIGN: This study uses the hamster cheek-pouch model to test efficacy and safety of the MAF/tretinoin patch for oral cancer prevention. The oral mucosa of 36 hamsters was painted with dimethylbenzanthracene to produce premalignant lesions. The 36 hamsters were divided into 3 groups of 12 hamsters each as follows: (1) control, no treatment; (2) systemic tretinoin (5.0 mg/kg per day, intraperitoneally); and (3) topically applied MAF/tretinoin patch (0.45 mg tretinoin/cm2, once daily). Treatments continued for 40 days. MAIN OUTCOME MEASURES: Tumor growth and burden were measured over time. The duration of MAF patch retention on mucosa and local tissue reaction to the treatment were also evaluated. RESULTS: The patch stayed on the mucosa for at least 5 hours with no evidence of inflammatory or other adverse reactions from the treated tissue. There was a significant difference in the tumor growth measurement between the control and systemic tretinoin groups (P<.001), and between the control and MAF patch groups (P<.001). CONCLUSIONS: This is the first study, to our knowledge, to use a polymer MAF technique for oral cancer prevention. The MAF/tretinoin patch is safe and effective for such chemoprevention in the hamster model.

Administration, Topical↗
PubMed2003

Cancer "photo-chemoprevention" with pulsed dye laser and celecoxib.

BACKGROUND AND OBJECTIVES: Our previous study demonstrated the efficacy of pulsed dye laser (PDL) in inhibiting cancer growth. This study is to determine the synergic effect of PDL and Celecoxib, when they are combined for treatment of oral cancer. STUDY DESIGN/MATERIALS AND METHODS: Fifteen mice were inoculated with oral cell carcinoma and divided into three groups of five each (30 seeding sites/group): (1) control (no treatment), (2) PDL only, and (3) treatment with combined PDL and Celecoxib (1,500 ppm). The number and volume of tumors were counted and measured for 21 days. RESULTS: The combined treatment developed tumor at the slowest rate. On day 21, the average tumor volumes were (1) 483.6 mm(3) (control), (2) 312.1 mm(3) (PDL only), and (3) 151.4 mm(3) (combined treatment). CONCLUSIONS: A synergic effect was found in the combined treatment group. This study provides the first evidence of the efficacy of a new strategy for the treatment of oral cancer, namely, cancer "photo-chemoprevention."

Animals↗
PubMed2003

The role of laser vascular targeting and retinoic acid in oral cancer inhibition.

OBJECTIVES/HYPOTHESIS: The study examines the role of the pulsed-dye laser at 585 nm, coupled with retinoic acid at therapeutic dose of 5.0 mg/kg body weight, in inhibiting chemically induced tumor growth in the hamster cheek pouch to determine whether pulsed-dye laser therapy can inhibit tumor growth and whether a combination of pulsed-dye laser and retinoic acid has a synergic effect on treatment efficacy. STUDY DESIGN: Randomized, prospective study of hamster model. METHODS: Forty-eight male golden Syrian hamsters were painted with 0.5% solution of 9,10-dimethyl-1,2-benzanthracene in acetone for 6 weeks to induce dysplasia in both sides of the cheek pouches. The hamsters were then randomly divided into four groups of 12 hamsters each as follows: (1) control group, (2) pulsed-dye laser treatment only (8.0 J/cm(2) and two pulses), (3) retinoic acid treatment only (5.0 mg/kg/d by intraperitoneal injection), and (4) combined pulsed-dye laser and retinoic acid treatment. The treatment period was 40 days. Tumors were measured throughout the study. RESULTS: The results indicated that retinoic acid and pulsed-dye laser each significantly delay tumor growth and reduce tumor volume when used alone. Tumor volumes were statistically different among the treatment groups. There was also a statistical difference in tumor volume between the retinoic acid treatment group and the combined pulsed-dye laser and retinoic acid treatment group. CONCLUSIONS: The study demonstrated the greater advantage of combining pulsed-dye laser with retinoic acid over using either retinoic acid or pulsed-dye laser alone for delay of oral cancer progression. Clinical trials are warranted to establish efficacy in humans.

Animals↗