Protective effect of intense pulsed light on fibroblast injury induced by UVA Ⅰ

Objective To study the protective effects of intense pulse light (IPL) on the injury of normal human skin fibroblasts (FB) induced by ultraviolet A (UVA Ⅰ ) in vitro and to explore its possible mechanism. Methods The human skin fibroblasts were isolated and cultured, and then irradiated by UVA Ⅰ (9 J/cm2) and IPL (15 J/cm2), respectively. The proliferative ability of the cells were detected by CCK-8. Cell cycle was detected by flow cytometry, and cylin D1 and CDK2 protein expression levels were detected by Western blot. Results Different doses of UVA Ⅰ irradiation caused certain damages of cultured fibroblasts. With the increasing of of UVA Ⅰ dose, cell proliferation was decreased. Cells went to death at the exposure to 11 J/cm2 UVA Ⅰ , while the proliferative activity did not change much at 7 J/cm2 UVA Ⅰ . Cells were treated with UVA Ⅰ for other 2 days, then with IPL irradiation for other 2days, showing clear stimulating to the cell proliferation as compared with the cells that received UVA Ⅰ treatment only. Flow cytometry results showed that an increase of cell proliferating index, and cell cycle protein cyclin D1 and CDK2 expression levels were also upregulated after IPL irradiation.Conclusion UVA Ⅰ irradiation may cause cell damage as showed by cell growth index, cyclin D1 and CDK2 expression, and this injury could be protected partly by IPL treatment. The intense pulsed light may regulate the expression of cyclin proteins that may promote normal fibroblast proliferation, which could be one of the mechanisms of IPL skin rejuvenation.     

Protective effect of intense pulsed light on fibroblast injury induced by UVA Ⅰ

Objective To study the protective effects of intense pulse light (IPL) on the injury of normal human skin fibroblasts (FB) induced by ultraviolet A (UVA Ⅰ ) in vitro and to explore its possible mechanism. Methods The human skin fibroblasts were isolated and cultured, and then irradiated by UVA Ⅰ (9 J/cm2) and IPL (15 J/cm2), respectively. The proliferative ability of the cells were detected by CCK-8. Cell cycle was detected by flow cytometry, and cylin D1 and CDK2 protein expression levels were detected by Western blot. Results Different doses of UVA Ⅰ irradiation caused certain damages of cultured fibroblasts. With the increasing of of UVA Ⅰ dose, cell proliferation was decreased. Cells went to death at the exposure to 11 J/cm2 UVA Ⅰ , while the proliferative activity did not change much at 7 J/cm2 UVA Ⅰ . Cells were treated with UVA Ⅰ for other 2 days, then with IPL irradiation for other 2days, showing clear stimulating to the cell proliferation as compared with the cells that received UVA Ⅰ treatment only. Flow cytometry results showed that an increase of cell proliferating index, and cell cycle protein cyclin D1 and CDK2 expression levels were also upregulated after IPL irradiation.Conclusion UVA Ⅰ irradiation may cause cell damage as showed by cell growth index, cyclin D1 and CDK2 expression, and this injury could be protected partly by IPL treatment. The intense pulsed light may regulate the expression of cyclin proteins that may promote normal fibroblast proliferation, which could be one of the mechanisms of IPL skin rejuvenation.     

Critical parameters in the cytotoxicity of photodynamic therapy using a pulsed laser

. Photodynamic therapy (PDT) using a pulsed laser is becoming popular, but its cytotoxic effect is still not clear. We therefore studied the cytotoxicity of PDT using a pulsed laser by changing its irradiation parameters and compared the degrees of cytotoxicity with those of PDT using continuous-wave (CW) light sources. Mice renal cell carcinoma cells were incubated with PAD-S31, a water-soluble photosensitiser of which the excitation peak is 670 nm, and were then irradiated with either a tungsten lamp, a CW diode laser, or a nanosecond pulsed Nd:YAG laser-based optical parametric oscillator system. When the PAD-S31 concentration and total light dose were constant (12 μg/ml and 40 J/cm², respectively), the CW laser caused fluence rate-dependent decrease in cellular proliferation until the fluence rate reached 90 mW/cm², at which point inhibition of cellular proliferation was more than 80%. The cytotoxicity then became almost saturated at fluence rates of>90 mW/cm². On the other hand, inhibition of cellular proliferation in samples irradiated with the pulsed laser reached 80% even at the fluence rate of 15 mW/cm², and, interestingly, the cytotoxicity paradoxically decreased with increase in the fluence rate. Moreover, the cytotoxicity in the PDT using the pulsed laser depended on the repetition rate. The inhibition of cellular proliferation by PDT using 30-Hz irradiation was greater than that by PDT using 5-Hz irradiation when the same fluence rates were used. These results suggest that the efficacy of PDT using a pulsed laser depends considerably on fluence rate and repetition rate. Paper received 4 March 2002; accepted after revision 24 May 2002. Correspondence to: Yuji Morimoto, MD, PhD, Department of Medical Engineering, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan. Tel: +81-42-995-1596; Fax: +81-42-996-5199; e-mail: moyan@interlink.or.jp     

Er:YAG laser modification of root canal dentine: influence of pulse duration,repetitive irradiation and water spray

. The aim of this study was to determine the effects of varying parameters of Er:YAG laser irradiation with and without water spray cooling on root canal dentine in vitro. After horizontally removing tooth crowns from extracted human teeth, roots were axially sectioned into thin slices, exposing the root canal surface. An Er:YAG laser delivered 10–30 J/cm² into a 0.4-mm diameter laser spot on the root canal surface. Single pulses of different lengths (80–280 μs) were applied with and without water spray cooling/irrigation, and sequences of three pulses at a repetition rate of 30 Hz were applied at selected pulse parameters. The irradiated samples were investigated using both confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). At most irradiation conditions, the root canal dentine surface was ablated. Three-dimensional images from CLSM revealed that the cavity walls were not smooth. Depths of the cavities revealed significant differences between the cavities. No debris was observed at the surface of cavities at any irradiation condition. Strong melting and recrystallisation, or unusually flat surfaces with open dentinal tubules were obtained with sequences of three pulses without water cooling. CLSM is an effective tool for investigation of laser effects on root canal dentine. By varying the irradiation conditions, the Er:YAG laser can induce different modifications of root canal surface, which may be very interesting for root canal preparation. Paper received 23 November 2001; accepted after revision 3 January 2002.     

顺铂联合加热对体外血液中肝肿瘤细胞的杀灭作用及对红细胞的影响

Objective To investigate the effectiveness of cis-diamminedichloroplatinum (DDP) combined with hyperthennia in killing liver tumor cells and its influence on erythrocytes in vitro. Methods Cultured liver tumor cells (2 ml) were mixed with erythrocyte suspension (10 ml) and then the mixture was separated into 6 centrifuge tubes with 2 ml in each one. The centrifuge tubes were randomly divided into A-F groups and the experiment was repeated for 30 times. Normal saline 2 ml was added in A and D groups. DDP 2 ml (200 μg/ml) was added in B and E groups. DDP 2 ml (400 μg/ml) was added in C and F groups. The cells were then incubated in warm bath of 37 ℃ for 30 min in A, B and C groups and in warm bath of 42 ℃ for 30 min in the other three groups.After hyperthermic treatment, tumor cells were isolated from erythrocytes using density gradient centrifugation, the inhibition rate of tumor cells was determined by MTT method and the clone formation of tumor cells was checked.The erythrocyte osmotic fragility and content of 2,3-diphosphoglyceric acid in erythrocytes were measured. Results The inhibition rate of tumor cells was gradually increased, while the rate of tumor cell clone formation decreased with the increase in the temperature and DDP concentrations ( P < 0.01) . The rate of tumor cell clone formation was more than 98% and no clone formation was tested in group F. There was no significant difference in the content of 2,3-diphosphoglyceric acid in erythrocytes between before and after hyperthermic treatment in group F ( P >0.05 ) . The rate of hemolysis of erythrocytes was less than 1 % in the 0.68 % sodium chloride solution in group F.Conclusion DDP 200 μg/ml combined with hyperthermic treatment with temperature of 42 ℃ for 30 min can make the liver tumor cells lose the capability of proliferation, however, it exerts slight effect on erythrocyte membrane and no influence on the oxygen-carrying capacity of erythrocytes.     

顺铂联合加热对体外血液中肝肿瘤细胞的杀灭作用及对红细胞的影响

Objective To investigate the effectiveness of cis-diamminedichloroplatinum (DDP) combined with hyperthennia in killing liver tumor cells and its influence on erythrocytes in vitro. Methods Cultured liver tumor cells (2 ml) were mixed with erythrocyte suspension (10 ml) and then the mixture was separated into 6 centrifuge tubes with 2 ml in each one. The centrifuge tubes were randomly divided into A-F groups and the experiment was repeated for 30 times. Normal saline 2 ml was added in A and D groups. DDP 2 ml (200 μg/ml) was added in B and E groups. DDP 2 ml (400 μg/ml) was added in C and F groups. The cells were then incubated in warm bath of 37 ℃ for 30 min in A, B and C groups and in warm bath of 42 ℃ for 30 min in the other three groups.After hyperthermic treatment, tumor cells were isolated from erythrocytes using density gradient centrifugation, the inhibition rate of tumor cells was determined by MTT method and the clone formation of tumor cells was checked.The erythrocyte osmotic fragility and content of 2,3-diphosphoglyceric acid in erythrocytes were measured. Results The inhibition rate of tumor cells was gradually increased, while the rate of tumor cell clone formation decreased with the increase in the temperature and DDP concentrations ( P < 0.01) . The rate of tumor cell clone formation was more than 98% and no clone formation was tested in group F. There was no significant difference in the content of 2,3-diphosphoglyceric acid in erythrocytes between before and after hyperthermic treatment in group F ( P >0.05 ) . The rate of hemolysis of erythrocytes was less than 1 % in the 0.68 % sodium chloride solution in group F.Conclusion DDP 200 μg/ml combined with hyperthermic treatment with temperature of 42 ℃ for 30 min can make the liver tumor cells lose the capability of proliferation, however, it exerts slight effect on erythrocyte membrane and no influence on the oxygen-carrying capacity of erythrocytes.     

Er:YAG laser ablation of cerebellar and cerebral tissue

. With the availability of suitable fibres, the Er:YAG laser has become an indispensable tool for invasive neurosurgical applications as a source of precise ablation. The aim of this study was to investigate the ablative effects of the Er:YAG laser on brain tissue. The response of neuronal tissue to 2.94 μm Er:YAG laser irradiation was investigated on excised rat brain specimens. Ablation craters were created in cerebral and cerebellar tissues using 0.3, 0.5 and 1.0 J single pulses of 150 μs duration. The corresponding average irradiances were 37.7 J/cm², 62.9 J/cm² and 125.8 J/cm², respectively. Craters were checked qualitatively, crater dimensions were measured and compared, and volume of ablated tissue was estimated. Laser-induced crater dimensions were found to be significantly different at different energy levels applied. Moreover, dimensions of craters on cerebral and cerebellar tissues were significantly different in terms of dimensions. We observed that with the Er:YAG laser ablation craters were created with practically no thermal damage to adjacent tissues. The differences observed in the response of cerebral and cerebellar cortical tissues were dependent on the anatomical and chemical differences. Paper received 3 August 1999; accepted after revision 26 June 2000.     

泌尿系统原发性原始神经外胚层瘤临床病理分析

目的 探讨泌尿系统原发性原始神经外胚层瘤(primitive neuroectodermal tumor,PNET)的临床病理特征、免疫学表型、治疗方法及预后.方法 回顾性分析3例泌尿系统原发性PNET患者资料.3例均为男性,年龄分别为29、32和75岁.2例原发于肾脏,1例原发于膀胱.2例肾肿瘤大小分别为7.7 cm×6.2 cm和12.6 cm×9.4 cm,影像学检查提示肿瘤边界尚清,内部回声欠均匀.膀胱肿瘤大小为10.0 cm×10.0 cm,影像学检查提示膀胱壁不规则增厚,其内密度不均匀.2例肾肿瘤行肿瘤根治术,膀胱肿瘤行血块取出术及肿瘤活检术.结果 光镜下,瘤细胞为形态一致的小圆形或卵圆形,被纤维结缔组织分隔成实性片状或巢状,并形成假菊形团或Homer-Wright菊形团,核分裂象多见.免疫组化标记:3例肿瘤CD99、突触素和波形蛋白均为阳性.1例肾肿瘤Ki67阳性率＜5%,另1例80%阳性.3例病理诊断均为PNET.例1肾肿瘤患者未行化疗,于术后14个月复发死亡;例2肾肿瘤及例3膀胱肿瘤患者术后予以化疗,分别于术后4、6个月死亡.结论泌尿系统原发性PNET是一种少见的高度恶性软组织肿瘤,诊断主要依据病理形态学特征及免疫组化标记.目前治疗方法主要是手术加放、化疗.

Abstract：

Objective To explore the clinico-pathological features, immunophenotype, treatment and prognosis of urologic primary primitive neuroectodermal tumor (PNET). Methods The clinical data of 3 patients with urologic PNET were analyzed retrospectively. All patients were male, aged 29, 32 and 75 years respectively. Two of the lesions were located in the kidney, and the third was located in the bladder. The sizes of renal tumors were 7.7 cm×6.2 cm and 12.6 cm×9.4 cm respectively. Imaging examinations revealed a well-defined mass with inhomogeneous echo inside. The size of bladder tumor was 10.0 cm×10.0 cm. CT scan demonstrated irregular thickening of the bladder wall, and the density of the wall was inhomogeneous. In the 2 cases of renal PNET radical surgery was performed, while an emergency palliative surgery to remove a blood clot and biopsy were performed in the bladder PNET case. Results In light microscope, the tumors were characterized by uniform small round or oval cells and nest-like or dense sheet structures surrounded by sparse fibrovascular stroma. Homer-Wright rosettes or pseudorosettes were observed, as well as mitoses. Immunohistochemical study revealed that all cases showed positive staining for CD99, synaptophysin and vimentin. One of the renal tumor cells showed positive for CD56, and the other renal tumor and urocystic tumor cells were focally positive for chromogranin A. Additionally, in 1 of the cases of renal tumor there was a high positive rate of 80% for Ki67 staining while the other case showed less than 5%. All 3 cases were eventually diagnosed as PNET. The first renal tumor case was not treated with radiotherapy and chemotherapy postoperatively, and the patient died of recurrence 14 months after surgery. Both the second renal tumor case and the bladder tumor case underwent chemotherapy postoperatively, and they died 4 and 6 months after surgery respectively. Conclusions The urologic primary PNET is a very rare, highly malignant soft tissue tumor, and the diagnosis must be based on pathologic findings and immunohistochemical phenotypes. The multimodal treatment for urologic primary PNET consists of surgery, chemotherapy and radiotherapy.     

胰腺实性假乳头状瘤的诊治(附4例)

Objective To discuss the management of solid-pseudopapillary tumor of the pancreas. Methods Four patients of solid-pseudopapillary tumor of the pancreas (SPT) were diagnosed by pathology. One patient was underwent magnetic resonance and two enhanced computer tomography scan. The mass was located in tuberculum (1 case), neck (1 case), and body-tail (2 cases) of pancreases respectively. Four cases were underwent duodenopancreatectomy, local resection of mass, resection of body-tail of pancreases respectively. The maximal diameter of tumor ranged from 5 cm to 16cm, averaged 10.3cm. The blood regular test and biochemistry were normal, and the tumor markers including AFP,CA19-9,CA125,CEA also were normal. The specimens were examined by pathology and immunohistochemistry. Results Four cases all were diagnosed solid-pseudopapillary tumor of the pancreas by pathology. At histologic analysis, the tumor was composed of uniform polygonal cells with moderate to abundant amphophilic cytoplasm and arranged in solid nests with areas of degeneration characterized by separation of the cells into pseudopapillary aggregates with intervening accumulation of mucopolysaccharide rich ground substance. The expressions of Vimentin, α-ACT, α-AAT were positive, and CgA negative. Four cases were followed up for six months and norecurred. Conclusions SPT of pancreases was a kind of tumor of low potential malignancy, and the magnetic resonance and computer tomography were often to be used. The effective therapy was thoroughly resection, and the prognosis in most patients is excellent.     

胰腺实性假乳头状瘤的诊治(附4例)

Objective To discuss the management of solid-pseudopapillary tumor of the pancreas. Methods Four patients of solid-pseudopapillary tumor of the pancreas (SPT) were diagnosed by pathology. One patient was underwent magnetic resonance and two enhanced computer tomography scan. The mass was located in tuberculum (1 case), neck (1 case), and body-tail (2 cases) of pancreases respectively. Four cases were underwent duodenopancreatectomy, local resection of mass, resection of body-tail of pancreases respectively. The maximal diameter of tumor ranged from 5 cm to 16cm, averaged 10.3cm. The blood regular test and biochemistry were normal, and the tumor markers including AFP,CA19-9,CA125,CEA also were normal. The specimens were examined by pathology and immunohistochemistry. Results Four cases all were diagnosed solid-pseudopapillary tumor of the pancreas by pathology. At histologic analysis, the tumor was composed of uniform polygonal cells with moderate to abundant amphophilic cytoplasm and arranged in solid nests with areas of degeneration characterized by separation of the cells into pseudopapillary aggregates with intervening accumulation of mucopolysaccharide rich ground substance. The expressions of Vimentin, α-ACT, α-AAT were positive, and CgA negative. Four cases were followed up for six months and norecurred. Conclusions SPT of pancreases was a kind of tumor of low potential malignancy, and the magnetic resonance and computer tomography were often to be used. The effective therapy was thoroughly resection, and the prognosis in most patients is excellent.     

Photodynamic therapy for the treatment of induced mammary tumor in rats

The objective of this work was to evaluate photodynamic therapy (PDT) by using a hematoporphyrin derivative as a photosensitizer and light-emitting diodes (LEDs) as light source in induced mammary tumors of Sprague–Dawley (SD) rats. Twenty SD rats with mammary tumors induced by DMBA were used. Animals were divided into four groups: control (G1), PDT only (G2), surgical removal of tumor (G3), and submitted to PDT immediately after surgical removal of tumor (G4). Tumors were measured over 6 weeks. Lesions and surgical were LEDs lighted up (200 J/cm² dose). The light distribution in vivo study used two additional animals without mammary tumors. In the control group, the average growth of tumor diameter was approximately 0.40 cm/week. While for PDT group, a growth of less than 0.15 cm/week was observed, suggesting significant delay in tumor growth. Therefore, only partial irradiation of the tumors occurred with a reduction in development, but without elimination. Animals in G4 had no tumor recurrence during the 12 weeks, after chemical induction, when compared with G3 animals that showed 60 % recurrence rate after 12 weeks of chemical induction. PDT used in the experimental model of mammary tumor as a single therapy was effective in reducing tumor development, so the surgery associated with PDT is a safe and efficient destruction of residual tumor, preventing recurrence of the tumor.     

Photodynamic therapy of superficial bladder tumors

Photodynamic therapy (PDT), using hematoporphyrin derivative (HPD) and the red light (wavelength 630 nm) of an argon-dye laser as the source of excitation energy was performed on 46 patients with superficial bladder tumors. Two methods of laser irradiation, (1) focal PDT using a 400 micron quartz fiber through a cystourethroscope in 22 patients with superficial bladder tumors and (2) whole bladder wall total PDT using a motor-driven laser light scattering device in 24 patients with multifocal carcinoma in situ and/or dysplasia of bladder mucosa associated with multicentric concurrent superficial tumors, were used. The patients in (2) had been referred for total cystectomy, and 19 of these 24 patients had a history of several transurethral resections, hyperthermia and/or instillation therapy. HPD 2-4 mg/kg was i.v. injected 48 to 72 hours before PDT. Judging from the results of 60 protrusions treated by focal PDT, the light power should be 200 mW/cm2 for 5-10 minutes or more and the total light energy should be 100 J/cm2 or more in tumors up to 2 cm in size. With focal PDT, 4 of the 22 patients had no recurrence with the mean tumor free time of 20.8 months. In 6 of the 24 patients treated with total PDT using 10, 20 or 30 J/cm2 of light energy, there was no recurrence with a mean tumor-free time of 7.5 months and there was no significant relationship between the recurrence rate and total light energy used.     

Photodynamic therapy using pheophorbide a and Nd:YAG laser.

The authors describe a new photodynamic therapy (PDT) method for malignant brain tumors. Pheophorbide a (Ph-a), the photosensitizer, has low toxicity, causes no skin sensitization and is activated with an acoustic Q switched neodymium yttrium-argon-garnet (Nd:YAG) laser which achieves deep tissue penetration. The Ph-a distribution in Fisher 344 (F344) rats bearing rat T9 glioma at 24 hours after intravenous injection was very low in the normal brain tissue, but significantly higher in the T9 glioma giving a tumor to normal brain tissue concentration ratio of 7.5:1. The in vitro survival rate of T9 glioma cells pretreated with Ph-a was 68.8 +/- 5.4% after laser irradiation for 20 minutes, significantly lower than in the control groups. This indicates that Ph-a was activated with the acoustic Q switched Nd:YAG laser causing the photodynamic effect. The survival rate after Ph-a pretreatment and laser irradiation in a waterbath at 44.0 degrees C was further reduced to 15.8 +/- 3.3%. In vivo PDT studies using T9 glioma cells inoculated into the dorsal region of F344 rats showed tumor eradication in four of six rats. The combination of PDT and laser hyperthermia produced tumor eradication in all six rats. The combination of PDT and hyperthermia is a promising method for tumor treatment.     

Intraoperative phototherapy (PDT) and surgical resection in a mouse neuroblastoma model

This study evaluates the effect of intraoperative photodynamic therapy (PDT) using the multiline argon laser (488-514 nm) or the argon-dye laser (630 nm) combined with surgical resection compared with surgical resection alone in reducing the incidence of C1300 neuroblastoma recurrence in mice. In the control groups, surgical resection alone resulted in 86% +/- 12% tumor recurrence. Surgical resection and intraoperative lasing without photosensitizer resulted in 75% +/- 27% tumor recurrence with the argon-dye laser and 55% +/- 18% recurrence with the multiline argon laser. In the treatment groups, surgical resection and intraoperative PDT at 630 nm resulted in 56% +/- 19% tumor recurrence whereas surgical resection and intraoperative PDT at 488-514 nm resulted in 21% +/- 7% tumor recurrence. The cause for the decrease in local recurrence in the control group using the multiline argon laser is unknown, but could it be due in part to hyperthermic effects. Intraoperative PDT was an effective adjunct to surgical resection in preventing local recurrence in this tumor model.     

Endovascular photodynamic therapy using mono-L-aspartyl-chlorin e6 to inhibit Intimal hyperplasia in balloon-injured rabbit arteries

BACKGROUND AND OBJECTIVE: Intimal hyperplasia (IH) leading to restenosis is a major complication of arterial revascularization. The purpose of this study was to investigate the effect of photodynamic therapy (PDT) using mono-L-aspartyl chlorin e6 (NPe6) as a photosensitizer and intraluminal radial irradiation for inhibition of IH experimentally. STUDY DESIGN/MATERIALS AND METHODS: Study of laser transmission through the blood indicated that exclusion of blood is a prerequisite for intraluminal PDT. For homogeneous radial laser irradiation to the vessel wall, we used a newly developed cylindrical diffusing balloon laser fiber. Injuries were induced by pulling a balloon catheter through the right iliac artery of rabbits. One and 6 hours after the NPe6 injection (5mg/kg i.v.), drug distribution was examined by fluorescence microscopy. Nineteen rabbits received NPe6 at the time of injuries and PDT was performed with 664-nm laser at 30 and 10 J/cm(2) (20, 30, 40 mW/cm(2)) 1 hour after the injuries. The arteries were harvested at 2 days. In a second group of rabbits, PDT was given at 30 mW/cm(2) (30 J/cm(2)). Two weeks after treatment, the arteries were removed and examined histologically. RESULTS: NPe6 was found to be distributed selectively in the injured media. Endovascular NPe6-PDT showed complete depletion of smooth muscle cells even with 10 J/cm(2) at 2 days. IH was significantly inhibited at 14 days after PDT. CONCLUSIONS: Endovascular PDT of injured artery using NPe6 can prevent IH in this model of arterial wall injury and may become clinically useful for the prophylaxis of IH.     

Implications of a pre-existing tumor hypoxic fraction on photodynamic therapy.

The presence of oxygen in tissue is a requirement for photodynamic therapy (PDT)-induced destruction of solid tumors, otherwise no cell death occurs. Since many tumors have been shown to have significant populations of hypoxic cells, it is of clinical interest to determine if pre-existing tumor hypoxia limits phototherapy. This question was examined using RIF tumors where tumor response to PDT of completely oxygenated tumors was compared to tumors with an induced hypoxic fraction. Tumor hypoxia was induced by using vasoactive drugs (epinephrine, chlorpromazine, or isoproterenol), given 30 min prior to PDT, or by a surgical method. PDT consisted of 5 mg/kg Photofrin II ip 24 hr prior to treatment and 135 J/cm2 630-nm light. The administration of the various vasoactive agents induced hypoxic fractions of 2.2 to 10%. The surgical method induced hypoxic fractions of 35%. Tumor response and cure in animals given vasoactive agents did not differ from controls, suggesting that low levels of pre-existing tumor hypoxia do not limit photodynamic therapy in this tumor model. Animals with tumors made hypoxic by a surgical method showed significantly reduced tumor response to PDT. Only 14% of these animals had tumors which became flat and necrotic by the day following PDT, compared to nearly 100% for animals given vasoactive drugs or controls. Furthermore, no tumor cure was observed in animals treated by this method. The higher level of tumor hypoxia in these animals likely represents one point where large proportions of PDT-resistant cells can survive after treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Enhanced cell death in NR-S1 tumor by photodynamic therapy: possible involvement of Fas and Fas ligand system

BACKGROUND AND OBJECTIVES: To investigate the effect of photodynamic therapy (PDT) on cell death in malignant tumor tissue, the frequency of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive cells and the possible involvement of Fas and Fas ligand system were evaluated. STUDY DESIGN/MATERIALS AND METHODS: NR-S1 tumor-bearing C3H/HeNCrj mice were treated by PDT with Photofrin(R) (12 mg/kg body weight) and Nd:YAG dye laser (630 nm, 10 Hz, 150 J/cm(2)). Paraffin-embedded tissue sections from the excised tumor tissues at 6, 12, 24, 48 hours after PDT were analyzed by TUNEL for the occurrence of apoptosis and by immunohistochemistry for Fas and Fas ligand (FasL) expression. TUNEL-positive cells as well as Fas- or FasL-positive cells were counted and expressed as a percentage of positive cells per total cells. RESULTS: Based on the percent area of tumor necrotic foci, the most effective conditions for PDT were first determined. Under these conditions, PDT increased the number of TUNEL-positive tumor cells at 12 hours after irradiation. In parallel with the increase in TUNEL-positive cells, Fas-positive tumor cells were also found in the same area where many TUNEL-positive tumor cells were found. The expression of Fas ligand was found in the tumor cells surrounding TUNEL-positive cells on serial sections. A significant increase in FasL-positive lymphocytes was observed at 12 hours, whereas the infiltration of such lymphocytes into the area where TUNEL-positive tumor cells were observed was rare. CONCLUSION: The possible role of Fas/FasL system in the cell death induced by PDT with Photofrin(R) and Nd:YAG dye laser was suggested. Moreover, the role of infiltrated lymphocytes seemed not to be so much in this model.     

癌光啉对人肝癌细胞HepG2的光动力作用及机制

目的:探讨光敏剂癌光啉(PsD-007)对肝癌细胞HepG2的体外光动力效应及其机制。方法:将HepG2细胞分为3个光动力处理组,分别以10,20,30μg/mL PsD-007孵育细胞,期间均用630 nm波长的可见光照射(光照能量为6.0 J/cm2,时间2.0 min);同时设3个对照组,分别为空白对照,单纯光照组和暗毒组(30μg/mL PsD-007,未光照)。各组细胞于实验24 h后用MTT法检测存活率,并用凋亡试剂盒结合荧光显微镜观察凋亡情况。应用Real-time PCR和Western blot方法检测20,30μg/mL PsD-007 2个光动力处理组和3个对照组细胞caspase-3,caspase-8和p53的基因、蛋白表达水平。结果:与空白对照组比较,3个光动力处理组HepG2细胞存活率均明显降低,且呈浓度依赖性(P<0.05),而单纯光照组和暗毒组细胞存活率均无明显改变(P>0.05)。荧光显微镜观察结果显示,各光动力处理组坏死或晚期的凋亡细胞较3个对照组显著增多。Real-time PCR和Western blot结果显示,2个光动力处理组细胞caspase-3,caspase-8和p53基因、蛋白表达水平较3个对照组明显上调。结论:PsD-007在体外对HepG2细胞具有光动力杀伤作用,其机制可能与调控caspase蛋白酶和p53的表达从而诱导细胞凋亡和坏死有关。     

Photodynamic activity of lutetium-texaphyrin in a mouse tumor system.

BACKGROUND AND OBJECTIVE: New photosensitizers proposed for photodynamic therapy (PDT) treatment of tumors need to be evaluated in animal models to determine the parameters needed for treatment. They also need to be compared with existing photosensitizers for efficacy. We examined the PDT response to lutetium-texaphyrin (PCI-0123) in a mouse mammary adenocarcinoma model and compared it with the PDT response seen when using Photofrin. STUDY DESIGN/MATERIALS AND METHODS: DBA/2 mice with SMT-F tumors were used to explore PCI-0123 toxicity, laser light dose, and drug dose effects on PDT response and to determine the most effective time for light application. The PDT response of PCI-0123-treated tumors was compared with that of Photofrin-treated tumors. RESULTS: Treatment of tumors with 150 J/cm2 of 740 nm laser light 5-6 hr after PCI-0123 administration (40 mg/kg) resulted in a 100% response rate and a 55% cure rate. Tumors treated with 150 J/cm2 of 630 nm laser light 24 hr after Photofrin administration (10 mg/kg) resulted in a 67% response rate and a 16% cure rate. CONCLUSION: PCI-0123 was found to be a more effective photosensitizer than Photofrin.     

Scanning laser system for photodynamic therapy of choroidal neovascularization

BACKGROUND AND OBJECTIVES: In order to improve selectivity of photodynamic therapy (PDT) to choroidal neovascularization (CNV) associated with age-related macular degeneration, a laser scanning technique was applied to perform focal laser irradiation to the retina, and the occlusion effects of a new device to the choriocapillaris were evaluated in primate eyes. STUDY DESIGN/MATERIALS AND METHODS: The device contains lasers for fundus observation of 785 nm and for PDT of 670 nm, matching the absorption peak of a photosensitizer, ATX-S10(Na). The laser irradiated the shape on the retina specified before treatment and shut off automatically when the predetermined treatment was achieved. The occlusion of the choriocapillaris after PDT was documented by fluorescein and indocyanine green angiography and histology. RESULTS: The area designated for PDT was easily drawn on the touch-screen monitor, and occlusion of the choriocapillaris was achieved precisely in the area pre-selected for treatment with 5 J/cm(2) or more of radiance following administration of 8 mg/kg ATX-S10(Na). CONCLUSIONS: This device is useful for irradiating CNV of any shape, sparing the surrounding retina. Since our previous studies suggested that selective occlusion of CNV would decrease not only the functional disturbance caused by PDT, but also the recurrence of CNV, the present device may allow more effective PDT than the slit-lamp system presently used.