Q开关Nd:YAG激光治疗太田痣的疗效及影响因素分析

目的:观察Q开关Nd:YAG激光对1012例太田痣疗效并探讨与疗效相关的影响因素。方法:用Q开关Nd:YAC激光(1064nm波长)对1012例大田痣进行治疗。通过回顾性总结治疗效果,分析影响疗效的相关因素。结果:Q开关Nd:YAG激光治疗1012例太田痣,痊愈496(4.34％)例,痊愈率与治疗次数有关,x~2=460.850,P<0.005,即随治疗次数增加,痊愈率增高;男性患者痊愈率明显高于女性,x~2=5.670,P<0.025,平均治愈次数也少于女性;各年龄组疗效无显著性差异,皮损部位与疗效有关,额、颞部皮损疗效相对较好。其他因素如治疗光斑、能量密度、治疗间隔时间等也与疗效有关。结论:Q开关Nd:YAG激光治疗太田痣效果好,影响疗效的相关因素主要有治疗次数、患者性别、皮损部位。光斑、能量密度、治疗间隔时间、皮损颜色、患者皮肤类型、全身状况等与疗效也有一定关系。     

Possibility of using laser spectroscopy for the intraoperative detection of nonfluorescing brain tumors and the boundaries of brain tumor infiltrates. Technical note

The response of nonfluorescing infiltrating tumors that had been exposed to 5-aminolevulinic acid and irradiated using a laser at a wavelength of 405 nm was analyzed intraoperatively using spectroscopy. Histological analyses demonstrated that neoplastic cells were present in the tissue region that displayed a peak at 636 nm, whereas no neoplastic cells were present in the region that exhibited only the excitation light peak. The authors conclude that the intraoperative use of laser spectroscopy can allow the diagnosis of infiltrating tumor and the detection of boundaries of the infiltrate when standard fluorescence techniques fail.     

Laser autofluorescent spectroscopy in the diagnostics of tumor masses in the abdominal cavity

Laser autofluorescent spectroscopy was fulfilled to 93 patients during laparoscopy. A device of the authors' construction was used for the excitation of autofluorescence and the method of performing laser autofluorescent spectroscopy during laparoscopy is described. Parallel morphological investigations of the affected tissues showed high sensitivity (93.6%) and specificity (98.6%) of the method.     

Long-term histologic effects of inferior turbinate laser surgery.

OBJECTIVE: In this study we sought to define the histologic changes produced by laser treatment of inferior turbinates. Study Design: Eight inferior turbinates with prior laser treatment (mean, 26.8 months) were analyzed by light microscopy after turbinectomy for relief of refractory nasal obstruction. Histologic findings were compared with those of a group of 8 hypertrophic inferior turbinates that had no previous laser surgery. RESULTS: Laser-treated areas of the inferior turbinates demonstrated a histologically bland appearance, with marked diminution of seromucinous glands and relative preponderance of connective tissue matrix. Prominence of venous sinusoids was also significantly reduced in the laser-treated areas. Surface epithelium including goblet cells was reconstituted over the areas of laser application. CONCLUSION: Clinical laser surgery of the inferior turbinate produces striking long-term histologic changes. SIGNIFICANCE: The data suggest a differential response of turbinate histologic components to application of laser energy, with the glandular component being particularly sensitive. Further correlative study is needed to clarify the clinical significance of laser-induced histologic changes in inferior turbinates.     

Estimation of possibilities of conventional and nontraditional methods of diagnosis of the thyroid gland diseases

There were analyzed 445 hospital history charts of patients, who were operated on for the thyroid gland pathology. The trustworthiness of complex of conventional and nontraditional methods of treatment was estimated. The plasma of 100 patients with diseases of thyroid gland was investigated, using laser correlation spectroscopy. In 228 patients the titer of autoantibodies to normal tissue of thyroid gland in the blood serum was determined. Application of laser correlation spectroscopy and determination of the autoantibodies titer to normal tissue of thyroid gland have permitted to obtain additional information, permitting to improve the quality of diagnosis and differential diagnosis of the thyroid gland diseases. These methods are recommended to be included in complex of the screening investigations.     

Towards the intra-operative use of Raman spectroscopy in breast cancer—overcoming the effects of theatre lighting

The ability to use Raman spectroscopy to assess tissue in the operative theatre setting could be advantageous for both patients and clinicians. In this study, a method of overcoming the deleterious effects of theatre lighting on the Raman spectra is demonstrated. The effectiveness of this technique is highlighted both within the theatre setting and using human lymph node tissue. The portable MiniRam II Raman spectroscopy device that incorporated a 785-nm laser was used in all experiments. This is an important step towards the use of Raman spectroscopy as a means of analysing sentinel lymph nodes in patients who have been newly diagnosed with breast cancer.     

Fluorescence spectroscopy guidance of laser ablation of atherosclerotic plague

Laser-induced fluorescence (LIF) spectroscopy can only be used for laser angioplasty guidance if high-power laser ablation does not significantly alter the pattern of tissue fluorescence. Although the spectra of normal and atherosclerotic arteries differ, the change in fluorescence spectra following laser angioplasty has not been well studied. Therefore, the purpose of this study was to assess whether laser-induced fluorescence spectroscopy could guide selective laser ablation of atherosclerotic plaque and, if so, to develop a quantitative LIF score that could be used to control a "smart" laser angioplasty system. Baseline LIF spectroscopy of 50 normal and 50 atherosclerotic human aortic specimens was performed using an optical fiber coupled to a He-Cd laser and optical multichannel analyzer. LIF was then serially recorded during erbium:YAG laser ablation of 27 atherosclerotic specimens. Laser ablation was terminated when the arterial LIF spectrum visually appeared normal. Histologic analysis revealed a mean initial plaque thickness of 1,228 +/- 54 microns and mean residual plaque thickness of 198 +/- 27 microns. Ablation of the media occurred in only three specimens. A discriminant function was derived to discriminate atherosclerotic from normal tissue for computer guidance of laser angioplasty. The LIF score, derived from stepwise multivariate linear regression analysis of the LIF spectra, correctly classified 93% of aortic specimens. The spectra obtained from the atherosclerotic specimens subjected to fluorescence-guided laser revealed a change in score from "atherosclerotic" to "normal" following plaque ablation. Seven atherosclerotic specimens were subjected to laser angioplasty with on-line computer control using the LIF score. Mean initial plaque thickness was 1,014 +/- 86 microns, and mean residual plaque thickness was 78 +/- 29 microns. There was no evidence of ablation of the media. Therefore, LIF guidance of laser ablation resulted in minimal residual plaque without arterial perforation. These findings support the feasibility of an LIF-guided laser angioplasty system for selective atherosclerotic plaque ablation.     

Spectroscopic characterization of cardiovascular tissue

We present results of a series of laser spectroscopic measurements on in vitro samples of cardiovascular tissue. These include laser Raman scattering, Fourier transform infrared, plasma emission and fluorescence, and electron paramagnetic resonance spectroscopy. The results of these spectroscopic measurements are discussed in terms of their implications for the field of laser angioplasty.     

Comparison of Near-Infrared Spectroscopy and Laser Doppler Flowmetry for Detecting Decreased Hepatic Inflow in the Porcine Liver

Hepatic artery and portal vein thrombosis are devastating complications of partial liver transplantation. Early detection of inflow complications is important, as re-reconstruction can salvage the graft. Near-infrared spectroscopy or laser Doppler flowmetry can be used to detect tissue oxygenation or microcirculation on the liver surface. The aim of this study was to examine which of these two methods better detects changes in hepatic inflow. Sangen-strain pigs (n = 5) were used. The tips of the near-infrared spectroscopy and laser Doppler flowmetry probes were placed separately on the surface of the right liver. Inflow to the liver was controlled during the following seven conditions: control (not clamped), half- and totally clamped portal vein, half- and totally clamped hepatic artery, and half- and totally clamped portal vein and artery. Tissue blood flow was calculated using laser Doppler flowmetry. Oxyhemoglobin, deoxyhemoglobin, and the tissue oxygenation index were measured and calculated using a near-infrared spectroscopy system. The tissue blood flow and oxygenation index could not be used to differentiate between the half-clamped portal vein, half-clamped hepatic artery, and totally clamped portal vein conditions. The oxyhemoglobin minus deoxyhemoglobin value was significantly decreased after half or total clamping of the portal vein or hepatic artery (p <. 001 for each condition). The findings of the present study indicate that near-infrared spectroscopy was more sensitive than Doppler flowmetry for detecting changes in hepatic tissue inflow from the liver surface.     

Discrimination of normal and atherosclerotic aorta by laser-induced fluorescence

Precise targeting of laser energy to atherosclerotic plaque is crucial for the safe performance of laser angioplasty. The present study was designed to evaluate whether laser-induced fluorescence could distinguish atherosclerotic from normal aorta. Segments of human aorta obtained at necropsy were classified grossly and histologically as normal aorta (n = 7), thin yellow fatty plaque (n = 5), and thick white atheromatous plaque (n = 9), and analyzed by laser-induced fluorescence spectroscopy using a pulsed nitrogen laser. Fluorescence spectra were recorded over a wavelength range from 385 to 725 nm. Normal specimens had maximal fluorescence intensity at 514 nm. A prominent fluorescence peak at 448 nm was present in specimens characterized as white atheromatous plaque and at 538 nm in specimens characterized as yellow fatty plaque. The ratios of fluorescence intensity at 448 nm/514 nm and at 538 nm/514 nm correctly classified all specimens according to their gross and histologic type (p < .001). Thus, a “smart” laser angioplasty catheter system might incorporate low-power laser radiation for arterial fluorescence spectroscopy to guide delivery of high-power laser radiation for plaque ablation.     

Effect of the 585 nm Flashlamp-Pumped Pulsed Dye Laser for the Treatment of Keloids

BACKGROUND: Due to its potential effects on skin microcirculation and collagen metabolism, the 585 nm flashlamp-pumped pulsed dye laser has been proposed for treating abnormal scars. Indeed, one of the main problems with keloidal scars is their disfiguring erythematous color. OBJECTIVE: To assess the efficacy of the 585 nm pulsed dye laser on the appearance of keloids. METHODS: Eleven patients with skin phototypes II-IV and keloids were treated with the 585 nm pulsed dye laser. After one to three treatment sessions, clinical assessments of the scars were performed in combination with remittance spectroscopy measurements of the redness and melanin pigmentation. A group of nine keloids covered by silicone gel sheeting served as controls. Data were compared statistically. RESULTS: During laser treatments, a discrete decrease in redness of the scars was clinically reported. However, this improvement was not confirmed by the objective spectrophotometric data. No side effects, especially hyperpigmentation, were disclosed. The keloids redness was not improved in the control group. CONCLUSION: The 585 nm pulsed dye laser yields only minimal effects, if any, on the erythema of keloids. Similarly silicone gel sheeting does not modify the keloids redness.     

Laser medicine in America: An overview

Laser medicine, as differentiated from laser surgery, has made tremendous progress in recent years. Laser diagnosis includes various laser techniques such as spectroscopy, Doppler velocimetry. and cytofluorometry, including cell sorter systems for current htbridima technology. In addition, there is laser induced fluorescence for cancer detection and treatment. Laser immunobiology includes laser nephelometry. Laser acoustical microscopy and laser transillumination for cancer diagnosis are also a part of current laser medicine, which offers much for cancer research, diagnosis, and treatment.     

Using the laser-induced fluorescence spectroscopy in the differentiation between normal and neoplastichuman breast tissue

This article reports results of the in vitro study for potential evaluation of the laser-induced fluorescence spectroscopy in the differentiation between normal and neoplastic human breast tissue. A coumarine dye laser pumped by nitrogen laser generated an excitation light centered at 458 nm. In order to collect the fluorescence signal was used an optical fiber catheter coupled to a spectrometer and CCD detector. Fluorescence spectra were recorded from normal and neoplastic (benign and malignant) human breast tissue, adding up 94 different areas. The discrimination between normal and neoplasm groups reach a sensitivity and specificity of 100%.     

Controlled synthesis, characterization, and application of iron oxide nanoparticles for oral delivery of insulin

Impurity-free, controlled synthesis of iron oxide nanoparticle, in ultrapure water and chitosan, using laser ablation technique and its application for type II diabetes management through oral delivery of insulin-loaded iron oxide–chitosan nanocomposite is presented. The purity of the nanoparticle is monitored by laser-induced breakdown spectroscopy technique. The synthesized iron oxide nanoparticle was characterized by UV/Vis absorption spectroscopy, and morphological study was performed by scanning electron microscope. The intensity of absorption peak and wavelength corresponding to peak of the nanoparticle prepared in water and chitosan is dependent on the laser energy used for ablation purpose. Red shift in the absorption peak wavelength was observed by increasing laser energy. In addition to red shift, an increase in intensity of absorption peak was also seen when ablating laser energy was increased. The appearance of a weak peak around 295 nm was observed in iron oxide–chitosan nanocomposite. The spherical shape of the nanoparticle synthesized at the lower laser energy has gradually changed to triangular and irregular shaped structures as ablating laser energy was increased. The spherical nanoparticles loaded with insulin were used for oral delivery for diabetic management. The iron oxide–chitosan nanocomposite loaded with insulin has resulted in reduction in blood glucose level in mild diabetic, subdiabetic, and severely diabetic rats; more than 51 % reduction in blood glucose level, compared to the control group, has been achieved in the present work.     

肝硬化程度与吲哚氰绿排泄试验的相关性评价

目的 研究肝硬化程度与吲哚氰绿排泄试验的相关性。方法 分别测定了３８例肝硬化患者和１４例正常个体的吲哚氰绿排泄试验消失率（ＫＩＣＧ）、总胆汁酸盐（ＴＢＡ）、单胺氧化酶（ＭＡＯ）、白蛋白（ＡＬＢ）,并用相关分析的方法分析了诸因素与肝硬化程度的相关关系。结果 ＫＩＣＧ与肝硬化程度高度相关,其次分别为ＴＢＡ,ＭＡＯ、ＡＬＢ。结论 ＫＩＣＧ能准确反映肝硬化程度,对指导治疗有较高的辅助诊断价值。     

In vivo study of age-related changes in the optical properties of the skin

The optical properties of the skin (absorption coefficient, scattering coefficient, refractive index) may serve to characterize the skin and are important for correct light dosimetry in many optical diagnostic procedures and laser treatments especially photodynamic therapy and laser therapy. We determined in vivo the optical properties of tissues near the wrist, elbow and knee in subjects of different ages using diffuse reflectance spectroscopy, having in view the establishment of laser system types for the laser treatment of posttraumatic lesions in subjects of different ages. Diffuse reflection of light from biological tissue is due to the variation in refractive index of tissular and cellular components and the surrounding medium and depends on the wavelength of the incident optical radiation. The diffuse reflectance spectrum of the tissues tested showed two maxima localized at λ_M1 ≈ 610 nm and λ_M2 ≈ 675 nm. Laser systems which emit radiation at these wavelengths are not efficient for the treatment of joints, regardless of the subject’s age. The deep tissues have a strong absorption in the range 630–700 nm, which indicates that for treating posttraumatic lesions we can use laser systems such as the He–Ne laser, the GaAlAs laser, and the InGaAlAs laser. Using Kramers-Kronig analysis of the diffuse reflectance spectra, the optical parameters n(ω) and k(ω) were determined. The age-dependent changes in these optical parameters of tissue must be taken into consideration and the use of laser treatments or optical diagnosis methods must be based on a knowledge of these properties and of the optical radiation parameters.     

Combined FT-Raman and SEM studies of the effects of Er:YAG laser irradiation on dentin

OBJECTIVE: This study evaluated the molecular and morphological changes on dentin elements after Er:YAG laser irradiation. BACKGROUND DATA: Spectroscopy studies reporting the effects of Er:YAG laser irradiation as an alternative to acid etching are needed to better understand the laser's effects. METHODS: The occlusal one-third of the crown of six human third molars was removed. The dentin surface was schematically divided into areas corresponding to four surface treatment groups: control (group C): 37% phosphoric acid etching; group I: Er:YAG laser 80 mJ; group II: Er:YAG laser 120 mJ; and group III: Er:YAG laser 180 mJ. The analysis was performed by scanning electron microscopy (SEM) and Fourier transform Raman spectroscopy (FT-Raman) before and after the treatments. Raman data were submitted to ANOVA and Bonferroni tests. RESULTS: The SEM photomicrographs revealed open dentin tubules in the control group. The molars from groups I, II, and III showed partially open dentin tubules. SEM images showed that the laser-irradiated dentin surface was not favorable to the diffusion of monomers. A significant reduction of the spectra relative intensity was observed in group III specimens. CONCLUSIONS: Er:YAG laser irradiation with 180 mJ could produce chemical changes in proteins, phosphate, and carbonate in dentin.     

Laser light scattering spectroscopy: a new method to measure tracheobronchial mucociliary activity.

Laser light scattering spectroscopy is based on the evaluation of the frequency shift of coherent light scattered by moving particles. This makes it particularly suitable for use in light guiding systems. In this study laser light scattering spectroscopy was assessed for its ability to provide information on the motility of respiratory cilia. In vitro and in vivo measurements were undertaken with animal tracheal mucosa. The intensity fluctuations of laser light scattered from moving cilia were analysed in terms of their autocorrelation functions to provide information on the frequency and synchrony of beating cilia. In vitro measurements were performed on fresh bovine trachea to estimate a safe laser power level for mucosal exposure and to test the method by defining the temperature dependence of the ciliary beat frequency. Power densities not exceeding 0.3 kW/cm2 were found to be the upper limit for long term exposure of the mucosa in vitro. Ciliary beat frequency showed a pronounced temperature dependence, ranging from 5.8 to 28.3 Hz over the temperature range 20-43.5 degrees C. A maximum frequency was found at 41.5 degrees C. In vivo measurements of ciliary activity were performed in six pigs by means of optical fibres for light transmission combined with fibreoptic bronchoscopy. A ciliary beat frequency of 5 Hz was obtained; heart and breathing frequencies could be separated and identified. These results suggest that laser light scattering spectroscopy might provide a convenient method of studying the mucociliary system of the lower airways.     

Research and development of additional aids for dermatologic and plastic surgery

Increasing numbers of accessories continue to be found to make laser surgery more effective for dermatologic and plastic surgery. Argon laser surgery aids are available to increase the dilatation of the superficial vessels and to localize increasing numbers of red cell masses. Laser probes for intravascular thrombogenesis and thrombolysis have now been adapted for intradermal and deep dermal tissues and for cardiology. Studies on laser effects on platelets and heat transmission and thromboembolic phenomena are lacking. Investigative studies are developing for laser fiber optic probes for laser-induced fluorescence, not only for oncology, but also for studies of metabolism of tissues and also for spectroscopy. The use of different wavelengths and shorter pulses, more flexible fiber-optics transmission for all laser systems, combinations of laser systems into a single operating probe, as well as the increased use of lasers for diagnosis and treatment will all stimulate the development of new aids for laser surgery. Cooperative programs developed jointly by dermatologic and plastic surgeons will make for great progress in skin and soft-tissue laser surgery.     

Optical nerve identification in head and neck surgery after Er:YAG laser ablation

Facial nerve function may be hampered by iatrogenic damage during head and neck laser surgery procedures. Optical techniques can serve as a basis for feedback-controlled tissue-specific laser surgery on the jaw bone and the parotid gland. In order to preserve nerve tissue during laser surgery, the alteration of optical tissue properties through laser-tissue interactions have to be taken into account. It was the aim of this study to evaluate the viability of optical tissue differentiation through diffuse reflectance spectroscopy after exposure to laser light as a basis for a feedback system for tissue-specific laser surgery. Spectra of diffuse reflectance (wavelength, 350–650 nm) of nerves, salivary glands, and cortical and cancellous bone of the midfacial region (ex vivo domestic pig heads) were acquired before/after Er:YAG laser (wavelength, 2.94 μm) ablation (each 16,800 spectra). Principal component analysis was computed followed by quadratic discriminant analysis. The tissue classification performance as well as area under the curve (AUC) sensitivity and specificity for tissue differentiation was assessed before and after laser-tissue exposure. A high classification performance was observed before laser ablation (total error, 7.74 %). Nerve tissue was differentiated from bone and salivary glands with results greater than 0.96 in AUC, sensitivity and specificity. After laser exposure, a total classification error of 18.61 % was observed. The differentiation of nerve tissue was reduced with an AUC of >0.94, sensitivity of >0.95, and specificity >0.87. Er:YAG laser ablation only slightly reduces the differentiation performance through diffuse reflectance in the investigated tissue types. The results show the general viability of diffuse reflectance spectroscopy in identifying neural structures in the vicinity of salivary glands and bone as a basis for nerve preservation during feedback-controlled laser surgery.