The influence of photodynamic therapy on the wound healing process in rats

In photodynamic therapy (PDT), photosensitisers (PS) are used along with lasers for the treatment of tumors. The combined effect of photosensitisers and lasers on the wound healing process is studied using delta-aminolevulinic acid (ALA) (5 mg/kg) and hematoporphyrin derivative (HPD) (5 mg/kg) as photosensitisers in the open excision wounds of rats. The lasers used were He-Ne laser (3 J/cm2) and Nd:YAG laser (30 J/cm2). This study is important for understanding the healing process involved after PDT. Open excision wounds treated with He-Ne lasers in animals that received ALA as photosensitiser showed complete wound closure at the earliest by 13 +/- 1 days, and with results obtained for HPD and the combination of lasers with complete closing by 14 +/- 1 days. However, the control group of animals that received ALS or HPD with no laser treatment showed wound healing on the twentieth and eighteenth days with a deviation of one day and two days, respectively. ALA with the combination of Nd:YAG and He-Ne lasers and HPD with He-Ne laser alone does not show quicker wound healing effects. Histopathological results also gave similar results. Tensile strength measurements do not vary significantly from control group to the test group. ALA along with He-Ne laser of HPD along with the combination of He-Ne and low power Nd-YAG lasers are found to be ideal methods for quickening the wound healing process in rat.     

Nd:YAG激光治疗儿童后发障的临床观察

目的探讨Nd:YAG激光治疗儿童后发障的时机、效果及并发症。方法用Nd:YAG激光对65例87眼儿童后发障患者进行治疗。结果术后视力提高1行者7眼,占8%;提高2行者20眼,占22.9%;提高3行及以上者54眼,占62%;术后视力未提高者6眼,占6.8%。结论Nd:YAG激光治疗儿童后发障是一种安全有效的方法,并应尽早进行。     

激光泪道成形术治疗泪道阻塞的临床观察

目的 观察激光泪道成形术治疗泪道阻塞的效果及复发病例再次激光联合插管治疗的效果。方法 采用Nd：YAG激光泪道成形术治疗泪道阻塞102例。132眼。对复发病例。再次行激光联合插管治疗。结果 113眼一次治愈，有效9眼。术后10眼复发，再次行激光联合插管治疗，7眼治愈，3眼未愈。本组总治愈率90．9％，有效率97．7％。结论 Nd：YAG激光泪道成形术治疗泪道阻塞操作简单，安全有效，复发病例联合插管治疗可以提高治愈率。     

Endoscopic laser surgery for subglottic stenosis in Wegener's granulomatosis

PURPOSE: Wegener's granulomatosis (WG) is a rare multisystem inflammatory disease, which infrequently involves the subglottic area and trachea. Treatment usually involves the use of immunosuppressive agents with corticosteroids. Some patients, however, continue to have symptoms of airway obstruction after clinical remission following the standard therapeutic regimen. OBJECTIVE: To investigate laser treatment for subglottic stenosis in five patients suffering from WG. MATERIALS AND METHODS: We endoscopically treated 5 patients with subglottic stenosis due to WG and airway obstruction by Nd:YAG and CO2 lasers. One of the patients had preoperative tracheostomy and after treatment was decannulated and could not breathe without dyspnea. Another patient required stenting of the subglottic area. RESULTS: All five patients were able to breathe without dyspnea after the treatment. Three patients were treated with an Nd:YAG laser but needed repeated laser treatment every four to six months, whenever they complained of dyspnea. The other two patients were treated with a CO2 laser; one of these patients had preoperative tracheostomy and was treated twice by CO2 laser and decannulated, with no further difficulty in breathing. The follow-up period was 1-5 years. CONCLUSIONS: Nd:YAG and CO2 lasers are recommended in the treatment of subglottic stenosis (SS) due to WG, particularly when the stenosis is in continuity or close proximity to the vocal cords.     

宫腔镜下Nd:YAG激光治疗子宫内疾病78例分析

目的 :评价宫腔镜对子宫内疾病的诊断价值和采用Nd :YAG激光治疗子宫内疾病的效果。方法 :对 78例子宫内疾病 (包括子宫内粘连、子宫粘膜下肌瘤、子宫纵隔、子宫粘膜息肉、宫颈息肉及宫颈管囊肿 )采用宫腔镜进行诊断 ,并用Nd :YAG激光进行治疗。结果 :宫腔镜诊断子宫内疾病的准确率高于超声诊断及放射诊断。采用Nd :YAG激光治疗的一次性成功率为 97.43 %。手术时间为 2 0 5 5分钟 ,平均 3 5 .7± 18.5分钟。无明显并发症。术后 1 3个月随访 2例病人有残留的粘连带及纵隔组织而进行二次手术。其余患者均恢复正常。 8例患者 (有生育要求者 )在一年内妊娠。结论 :对于子宫内疾病宫腔镜有较高的临床价值 ,采用Nd :YAG激光治疗具有更简便、安全、疗效确切等优点 ,具有广泛的应用前景     

Overexposure analysis of pulsed distributed feedback laser source

The goal of this study is to assess the risk of overexposure, when DFB dye laser is used for medical treatment in pulsed mode operation. Results of experimental study showing an unexpected rise of energy in pulses of distributed feedback dye laser (DFDL) output due to temperature phase gratings in dye cell during passively Q switched and mode-locked operation is reported. This unintended increase in the number of pulses, pulse duration, per pulse energy may cause side effects, when used for selective photothermolysis. To probe this phenomenon the most commonly used Rh6G dye was excited with 10-20 pulses of second harmonic of a passively Q switched and mode-locked Nd:yttrium-aluminum-garnet(YAG) laser. The outputs of DFDL and Nd:YAG laser were recorded by an Imacon-675 streak camera. The peak of DFDL output pulses was found delayed proportionally from the peak of the Nd:YAG pulses by more than an interpulse period of excitation laser. A computer program was used to simulate the experimentally measured results to estimate the thermal decay constants and energy retained by medium. The delay between peaks of Nd:YAG (input) and DFDL (output) pulses was found to vary from 10 to 14 ns for various cavity lengths. It was interesting to note that for smaller inter-pulse periods the effect of gradual gain buildup satisfied the threshold conditions for some of the pulses that otherwise cannot lase. This may lead to unintended increase in energy fluence causing overexposure-induced bio effects.     

Human malignant mesothelial cells: Variability of ultrastructural features in established and nude mice transplanted cell lines

The aim of this study was to determine, by transmission electron microscopy, the differentiation features of 21 human malignant mesothelioma cell lines (HMCLs) established from 13 specimens of 12 confirmed human malignant mesotheliomas, and of tumours induced in nude mice injected with 16 HMCLs. Fifty per cent of HMCLs showed typical mesothelial differentiation (long and slender microvilli, desmosomes, perinuclear intermediate filaments); 29 per cent did not show differentiation; and the remainder were poorly differentiated. Three human tumour specimens gave several different HMCLs; the cell lines obtained from a given tumour exhibited variable mesothelial differentiation. Eleven HMCLs were compared with the native tumour. Four were similar to the tumour and seven were less well differentiated, in most cases in relation to their microvilli. With six HMCLs, tumours induced in nude mice were less well differentiated than the corresponding cell lines, whereas with four HMCLs, tumours were equally or better differentiated. However, in most nude mice tumours, typical mesothelial microvilli were present. These results show that cell lines established from malignant mesothelioma may exhibit dedifferentiated features. However, while the variability in ultrastructural differentiation may result from the culture microenvironment, it could also be related to the state of differentiation, of the native tumour sample and to tumour cell heterogeneity.     

Protective effect of Picroliv, the active constituent of Picrorhiza kurroa, against chemical carcinogenesis in mice.

Cancer chemoprevention of chemically induced tumours by Picroliv, an iridoid glycoside mixture purified from Picrorhiza kurroa, was studied on 20-methylcholanthrene (20-MC)-induced sarcoma model and 7,12-dimethylbenz[a]anthracene (DMBA)-initiated papilloma formation in BALB/c mice. Administration of Picroliv (100 and 200 mg/kg, p.o) inhibited the sarcoma development by 47 and 53% as estimated on day 200 after 20-MC administration. Control animals started dying of tumour burden 76 days after 20-MC administration and all animals were dead by day 170, while 60 and 66% of the animals survived in the Picroliv treated group, 100 and 200 mg/kg, respectively. Picroliv exhibited anti-tumour-promoting activity on a two-stage carcinogenesis test on mouse skin using DMBA as an initiator and croton oil as a promoter. Topical application of Picroliv (1 and 5 mg/mouse) 30 minutes prior to that of croton oil application resulted in a 50 and 60% reduction in the number of animals that developed papillomas, and 48 and 64% reduction in the number of papillomas per mouse. There was also a delay in the onset of first skin tumour in the group of animals treated with Picroliv. Oral administration of Picroliv (150 mg/kg, p.o.) prior to DMBA application delayed the onset of papillomas and the percent of mice (60%) with tumours indicates that Picroliv inhibited the tumour initiation induced by DMBA. Picroliv administration was also found to increase the life span of transplanted Dalton's Lymphoma Ascites (DLA) and Ehrlich Ascites Carcinoma (EAC) harboring mice and reduced the volume of transplanted solid tumours.     

强脉冲光联合Nd:YAG激光治疗黄褐斑疗效观察

目的:探讨强脉冲光联合Nd:YAG激光治疗黄褐斑的疗效。方法:60例患者按治疗方法不同分成3组:强脉冲光组、Nd:YAG激光组、联合组（强脉冲光联合Nd:YAG激光组）,每组20例患者,观察3组患者疗效和副作用。结果:3组之间疗效两两比较采用Mann-Whitney秩和检验,强脉冲光组和激光组疗效无显著差异,而联合组疗效显著好于强脉冲光组（Z=7.123, P=0.024）和激光组（Z=6.024, P=0.030）。3组患者治疗后均无出现色素沉着加重、色素脱失病等不良反应。强脉冲光组和激光组的满意度无显著差异,而联合组的满意度显著好于强脉冲光组（Z=7.361, P=0.029）和激光组（Z=6.831, P=0.027）。结论:强脉冲光联合Nd:YAG激光治疗黄褐斑是一种安全有效的治疗方法,值得临床推广。     

氦-氖激光对小鼠巨噬细胞、淋巴细胞和中性粒细胞内 非特异性酯酶影响的图像分析研究

目的探讨氦-氖(He-Ne)激光照射对机体免疫功能的影响。方法将小鼠随机分成4组,Ⅰ组为对照组,Ⅱ～ⅣV组为He-Ne激光照射的不同时间组,采用a-茶酚醋酸酯法显示非特异性酯酶,并用图像分析系统对小鼠腹腔巨噬细胞、淋巴细胞和中性粒细胞内非特异性酯酶作定量分析。结果各照射组的三种免疫细胞内非特异性酯酶的各项指标均较对照组差异有非常显著性(P＜0.01),各照射组之间比较,差异也均有非常显著性(P＜0.01)。结论He-Ne激光可激活三种免疫细胞,增强机体免疫力。     

Three-dimensional topographic scanning electron microscope and Raman spectroscopic analyses of the irradiation effect on teeth by Nd:YAG, Er: YAG, and CO(2) lasers

A three-dimensional analyzer installed in a scanning electron microscope was used to evaluate the morphology and surface roughness using noncontact profilometry. Observations were carried out on the enamel and dentin surface irradiated by three different lasers: Nd:YAG (wavelength 1.06 microm), Er:YAG (2.94 microm), and CO(2) (10.6 microm). Spectroscopic analysis was done by Raman spectroscopy for nonirradiated and laser-irradiated surfaces. The lasers were applied perpendicularly to vertically sectioned and polished human extracted caries-free molars. The tooth was sectioned at each cavity for cross-section analysis after laser irradiation. Irradiation by Nd:YAG and CO(2) lasers of the enamel surface showed an opaque white color, different from dentin where the surface turned black. The Er:YAG laser induced no changes in color of the dentin. Numerous cracks associated with thermal stress were observed in the CO(2) laser-irradiated dentin. Noncontact surface profile analysis of Er:YAG laser-irradiated enamel and dentin showed the deepest cavities, and direct cross-sectional observations of them showed similar cavity outlines. The CO(2) laser-irradiated dentin had the least surface roughness. Raman spectroscopic analysis showed that fluorescence from the laser-irradiated tooth was generally greater than from nonirradiated teeth. Bands in dentin attributed to organic collagen matrix were lost after Nd:YAG and CO(2) laser irradiation, and a broad peak due to amorphous carbon appeared. The Er:YAG laser-irradiated dentin showed no sign of a carbon band and had more suitable results for dental ablation. Noncontact surface profile analysis was effective to evaluate the structural change in the tooth in the microarea of study after laser irradiation.     

Electron histochemical characteristics of laser necrosis

Linear or dot-shaped lesions were inflicted on rat liver with Nd:YAG laser, and fine structural alterations of hepatocytes were studied in the specimens processed for an endoplasmic reticulum (ER) marker glucose-6-phosphatase (GP). 5-7 s after irradiation a severe cell damage and GP inhibition occurred near the lesions, with less injured cells located laterally. 24 hr later the zone of the necrosis increased markedly. An autolytic decomposition in the newly formed necrotic area was much more pronounced as compared to the area of the initial necrosis. Phagocytic resorption of the intensively irradiated tissue was retarded this explaining some clinical observations on the long-term healing after Nd:YAG laser surgery. Based on our observations the so-called contact regimen of the irradiation is recommended due to the small size of the initial necrosis produced with this method. The various patterns of cell injuries including some changes in ER and enzyme GP as its marker are described in detail.     

Busulfan and chloramphenicol induced T cell lymphoma: cell surface characteristics and functional properties.

We report the immunological studies on three transplantable lymphoma lines that developed when CAF1 mice were injected with busulfan and chloramphenicol. The lymphoma cells displayed Thy-1.2, brain associated antigen, and H-2d alloantigen. They were negative for surface IgM and Ia antigens. Expression of T cell differentiation antigens differed among the three lines. The 508 tumour line displayed only Thy-1.2: 408 tumour line displayed Thy-1.2, Lyt-2.2 and TL; and 808 tumour line was positive for Thy-1.2, Lyt-1.2, Lyt-2.2 and TL antigens. We established in vitro culture lines from 508 and 808 lymphoma cells. The lymphoma cells did not respond to mitogens and antigens. The splenic cells from mice bearing 508 or 808 had decreased phytohaemagglutinin (PHA), concanavalin A (Con A) and mixed leucocyte responses (MLR). When mitomycin-C treated lymphoma cells from the tumour bearing mice were cocultured with normal splenic mononuclear cells, the 808 lymphoma cells suppressed the mitogenic responses of the normal cells more profoundly than 508 lymphoma cells. Adherent cells from both tumours suppressed the Con A responses of normal spleen cells. Cells from in vitro 508 or 808 cell lines had no effect on mitogenic responses of normal cells. Plasma from tumour bearing mice, but not the supernatants taken from cultures of these lymphoma cells, suppressed the mitogenic responses of normal lymphocytes. Spleen cells from normal CAF1 mice responded in mixed leucocyte tumour reactions (MLTR) when cocultured with lymphoma cells. Mice immunized with mitomycin-C treated tumour cells had greater response. Responder cells taken from mice with established 508 or 808 tumors had suppressed MLTR responses. Although prior immunization with tumor antigen increased the MLTR response, injection of live tumour cells into immunized mice resulted in a more rapid tumour growth and suppression of MLTR response.     

红外线、He-Ne激光照射对CAG大鼠胃酸的影响

目的:探讨红外线、He-Ne激光对慢性萎缩性胃炎(CAG)大鼠胃酸的影响.方法:将63只成年雄性Wistar大鼠随机分成正常组、模型组,红外线组及各激光照射组.应用2%水杨酸钠和30%酒精的混合溶液灌胃8周,刺激大鼠胃粘膜,并结合劳累、饥饱失常等多因素方法建立大鼠CAG模型,照射组在建模完成后,分别给予红外线、不同剂量的He-Ne激光照射,每日一次.照射20天后,观察各组大鼠胃酸的变化.结果:红外线组及3.36 J/cm2的He-Ne激光组与模型组比较,胃酸分泌明显增多.结论:红外线及3.36J/cm2的He-Ne激光照射能够促进CAG大鼠的胃酸分泌,对大鼠CAG有较好的治疗作用.     

Immediate cutaneous hypersensitivity after treatment of tattoo with Nd:YAG laser: a case report and review of the literature.

BACKGROUND: To our knowledge this is the first reported case of an immediate cutaneous reaction to Q-switched neodymium:yttrium-aluminum-garnet (Nd:YAG) laser tattoo removal. A 26-year-old female presented with two 6-year-old tattoos placed at different times. These were of different colors and had remained entirely asymptomatic since placement. There was a Mardi Gras mask on her thigh and a Tasmanian devil on her chest. With laser treatment of the Tasmanian devil, she experienced no untoward effects. However, with treatment of the Mardi Gras mask tattoo, she developed an extensive urticarial and indurated reaction 30 minutes posttreatment. The identical reaction occurred twice with subsequent laser treatments. Dermatology consulted allergy to provide prophylaxis against possible systemic reaction with subsequent Nd:YAG laser therapy. The patient was treated with 3 days of prednisone, cetirizine, and ranitidine before subsequent laser treatments. Prophylactic treatment suppressed all subsequent reactions to laser therapy. RESULTS: Delayed hypersensitivity to tattoo pigments occurring days to weeks after placement is well documented. There are no previous reports of immediate hypersensitivity during placement or laser removal. However, there are two previous reports of local and systemic delayed reactions after laser therapy. CONCLUSIONS: As far as we know, this is the first case report of immediate hypersensitivity after Nd:YAG laser treatment of a tattoo. Prophylactic treatment with steroids and antihistamines prevented reactions with subsequent laser treatments. Reactions after laser removal are rare, but may increase as popularity of skin art increases with the need for subsequent removal.     

影响激光间质热毁损肝脏区域形状因素的实验观察与讨论

根据“激光汽化兼热杀癌肿瘤理论模型”给出的方法。采用Nd：YAG激光裸光纤插入离体猪肝做间质内热毁损实验。观察影响激光热毁损区域形状的因索,刈沿光纤削开切面上热毁损区域的长径、短径和平均直径作统计学相关分析。     

Nd：YAG泪道激光成形术治疗泪道阻塞的体会

目的 探讨应用泪道激光治疗泪道阻塞的方法及疗效。方法 应用Nd：YAG泪道激光仪按泪道探通方法连续击射阻塞部位。用抗生素和丝裂霉素C混合液冲洗畅通后植入义管，每周冲洗一次，1月后拔管。结果共治疗53例60眼，随访1～3月。治愈57眼占95％，好转2眼占3．33％，无效1眼仍有溢脓，1月后行泪囊鼻腔吻合术治愈。结论 激光泪道成形术治疗泪总管、鼻泪管阻塞及泪囊炎，方法简单、疗效满意。     

Nd：YAG激光泪道成形术和鼻泪管支架术治疗慢性泪囊炎的疗效对比

目的比较Nd：YAG激光泪道成形术和鼻泪管支架术治疗慢性泪囊炎的临床效果。方法 93例（102眼）慢性泪囊炎患者随机分成两组,一组应用Nd：YAG激光泪道成形术治疗,另一组应用鼻泪管支架术治疗,比较两组的治疗效果。结果应用Nd：YAG激光泪道成形术治疗57眼,有效39眼（68.42%）;鼻泪管支架术治疗45眼,有效40眼（88.89%）,两组疗效差异有统计学意义（χ2=6.03,P〈0.01）。结论鼻泪管支架术相对于同样微创的Nd：YAG激光泪道成形术治疗慢性泪囊炎疗效更加稳定,手术成功率更高,不失为微创治疗慢性泪囊炎的首选术式。     

Long-Pulsed Nd:YAG Laser Treatment of Warts: Report on a Series of 369 Cases

Various treatment methods have been adopted in the management of warts; however, there is still no consensus on first-line treatment. This study was designed to evaluate the efficacy of long-pulsed Nd:YAG laser in the treatment of warts. Over the course of 1 yr, 369 patients with recalcitrant or untreated warts were exposed to a long-pulsed Nd:YAG laser. The following parameters were used: spot size, 5 mm; pulse duration, 20 msec; and fluence, 200 J/cm². No concomitant topical treatment was used. In all, 21 patients were lost during follow up; hence, the data for 348 patients were evaluated. The clearance rate was 96% (336 of the 348 treated warts were eradicated). The clearance rate of verruca vulgaris after the first treatment was very high (72.6%), whereas the clearance rate of deep palmopantar warts after the first treatment was low (44.1%). During a median follow-up period of 2.24 months (range, 2-10 months), 11 relapses were seen (recurrence rate, 3.27%). In conclusion, long-pulsed Nd:YAG laser is safe and effective for the removal or reduction of warts and is less dependent on patient compliance than are other treatment options.     

Metastatic capacity of Burkitt's lymphoma cell lines in nude mice.

Burkitt's lymphoma (BL) cell lines estimated in a previous study as having a high, low and no tumourigenicity (7) were intravenously (i.v.) injected into preirradiated (480 rad) nude mice. BL cell lines with a high tumourigenic potential produced metastatic tumours in the brain, spinal cord, bone marrow, stomach and kidney, but did not disseminate into the lung, liver, ovary and spleen. The survival time of the tumour bearing animals ranged from 2 to 10 weeks. The majority of mice i.v. injected with highly tumourigenic BL cell lines showed paresis or paralysis of the hind legs. This was associated with the presence of neoplastic nodules either in the brain and/or in the spinal cord. In animals with metastasis to the stomach and kidney progressive cachexia was observed. The described experimental model of metastatic BL tumours in nude mice can effectively be used for the in vivo study of new therapeutic molecules such as monoclonal antibodies coupled or not to substances, toxic to tumour cells. This model can also be useful for the identification and analysis of homing properties of BL cells and their implication in BL pathogenesis.