Post-acute response of 9L gliosarcoma to Photofrin™-mediated PDT in athymic nude mice

The objective of this study is to measure the chronic responses of 9L glioma and normal brain to photodynamic therapy (PDT). Tumor size, proliferation activity of glioma cells, and vascular endothelial growth factor (VEGF) expression in both the tumor area and the brain adjacent to tumor (BAT) were observed 7 days after clinically relevant doses of PDT treatment. 9L Gliosarcoma cells were implanted into the brain of 20 athymic nude mice. Fifteen mice were injected intraperitoneally with Photofrin™ at a dose of 2 mg/kg on day 6 after tumor implantation and were treated with laser at different optical doses of 40 J/cm² (n = 5), 80 J/cm² (n = 5), and 120 J/cm² (n = 5) at 24 h after Photofrin injection, respectively. The remaining five tumor-bearing mice served as a tumor-only control. All animals were killed 14 days after tumor implantation. Hematoxylin and eosin and immunostaining were performed to assess tumor volume, VEGF expression in the tumor and the BAT, as well as Ki67 expression in the tumor area. The tumor volume of the mice receiving 80 or 120 J/cm² group was significantly smaller than the control group (p < 0.01). VEGF immunoreactivity in the BAT was significantly increased in the 120 J/cm² PDT-treated mice (p < 0.001), compared with the immunoreactivity seen in untreated mice and those receiving Photofrin and lower optical doses. No significant differences were detected in the proliferation of glioma cells and VEGF expression in the tumor area between these groups. These data indicate that PDT can shrink tumor, especially at the high light dose, and that PDT induces expression of VEGF in the BAT, which is associated with tumor recurrence. Therefore, PDT combined with anti-angiogenic agents may be an effective treatment strategy for glioma.     

Cell kinetic analysis of human tumor xenografts using anti-bromodeoxyuridine monoclonal antibody

The cell kinetics of human tumor xenografts serially transplanted into nude mice was examined using bromodeoxyuridine (BrdU) and anti-BrdU monoclonal antibody. After various doses of BrdU were given intraperitoneally into tumor bearing nude mice, the tumors were resected and stained immunohistochemically, using the anti-BrdU monoclonal antibody. The number of stained cells was demonstrated as the labeling index (LI). The optimal condition for BrdU staining was assumed to be 300mg of BrdU per kg followed by an incubation period of one hour. Since the LI by BrdU closely correlated with that in autoradiography by³H-TdR, this method is more useful and safer than the conventional autoradiographic study for investigating clinical cell kinetic analysis, as there is no need to use potentially hazardous radioactive compounds and the period of assay is shorter.     

Antisense inhibition of vascular endothelial growth factor in human head and neck squamous cell carcinoma

BACKGROUND: Vascular endothelial growth factor (VEGF) is a potent paracrine angiogenic factor involved in angiogenesis. We determined whether antisense VEGF transfection can suppress angiogenic activity of a human squamous cell carcinoma of the head and neck (SCCHN) cell line. METHODS: Human SCCHN cell lines were screened for VEGF secretion by ELISA. The highest VEGF secreting cell line was transfected with an antisense VEGF vector. Endothelial cell migration assays were performed using the conditioned medium from the transfected clones. Tumorigenicity assays of the transfectants in nude mice were also performed. RESULTS: Antisense VEGF expression exhibited a 20-fold inhibition of VEGF secretion. The addition of conditioned medium from the antisense clones resulted in 50% reduction of endothelial migration. There was no effect on in vivo tumorigenicity. CONCLUSIONS: Antisense VEGF transfection effectively down-regulated VEGF secretion from SCCHN cells that had high VEGF secretion. Targeting VEGF expression may be useful for suppressing angiogenesis in head and neck cancer.     

小剂量阿司匹林协同干扰素-α抑制肝细胞肝癌生长转移的实验研究

目的 探讨小剂量阿司匹林协同干扰素-α(IFN-α)抑制肝细胞癌(hepatocellular carcinoma,HCC)生长转移的作用及机制.方法 培养具有肺转移潜能的人MHCC97L肝癌细胞.将MHCC97L肝癌组织块种植于BALB/c nu/nu雄性裸鼠肝脏,建立人肝癌裸鼠原位模型.以不同剂量组合的阿司匹林和IFN-α作用于荷瘤裸鼠,测量肿瘤体积,计算肺转移灶数目及肺转移率.用MTT及明胶酶谱实验检测阿司匹林对MHCC97L细胞增殖及金属蛋白酶2(matrix metalloproteinases 2,MMP-2)活性的影响.用Western Blot及ELISA检测细胞及血清MMP-2及血管内皮生长因子(vascular endothelial growth factor,VEGF)蛋白水平.结果 对照组肿瘤体积为(3.12±0.85)cm3,肺转移率为66.7％.大剂量阿司匹林[45 mg/(kg· d)]治疗组肿瘤体积为(1.89±0.88)cm3 (P＞0.05),肺转移率为58.3％ (P＞0.05).而大剂量IFN-α[1.5×107/(kg·d)]治疗组、大剂量IFN-α+大剂量阿司匹林治疗组、小剂量IFN-α [7.5×106/(kg·d)]+小剂量阿司匹林15 mg/(kg· d)]治疗组肿瘤体积分别为(0.69±0.40)cm3、(0.55±0.31)cm3、(0.40±0.43)cm3,均显著低于对照组(P＜0.05),肺转移率均为0(P＜0.05).2 mmol/L阿司匹林对MHCC97L细胞增殖无显著影响(P＞0.05),但可抑制其MMP-2的活性及VEGF的水平.小剂量IFN-α+小剂量阿司匹林治疗组裸鼠血清MMP-2及VEGF显著降低(P＜0.05).结论 小剂量阿司匹林可协同IFN-α抑制HCC生长转移,抑制MMP-2和VEGF的活性和表达是其重要作用机制之一.     

Tolerance of small bowel anastomoses in rabbits to photodynamic therapy with dihematoporphyrin ethers and 630 nm red light

Photodynamic therapy (PDT) is being evaluated in experimental clinical trials in patients with peritoneal malignancies. Some patients require partial small bowel resection with re-anastomosis prior to PDT because of bulky tumor or focal involvement of the small bowel by tumor. To assess the safety of PDT in this setting, the tolerance of small bowel anastomoses in New Zealand white rabbits to PDT with dihematoporphyrin ethers (DHE) and 630 nm light was studied. With conventional DHE doses of 1.5–2.5 mg/kg given 24 hours prior to surgery and light doses of 0–20 J/cm² of 630 nm light, no adverse effects were seen on the healing of small bowel anastomoses. Higher photosensitizer doses of 10 mg/kg and 20 mg/kg in conjunction with 20 J/cm², however, induced failure and breakdown of fresh anastomoses in 2/3 and 4/4 animals, respectively. © 1993 Wiley-Liss, Inc.     

RhoC基因对肝癌细胞促血管生长因子表达的影响

目的:观察RhoC基因对肝癌HepG2细胞表达促血管生长因子（VEGF，bFGF）的影响。 方法:将pcDNA3.1-RhoC重组质粒和空载体pcDNA3.1转染HepG2细胞，用RT-PCR及免疫组化检测HepG2细胞的RhoC mRNA及RhoC蛋白表达情况;RT-PCR及免疫组化检测HepG2细胞VEGF和bFGFmRNA及蛋白的表达。将转染pcDNA3.1-RhoC重组质粒和空载体pcDNA3.1的HepG2细胞接种裸鼠，观察肿瘤的成瘤率。结果:与转染空载体pcDNA3.1的HepG2细胞相比，转染pcDNA3.1-RhoC重组质粒的细胞表达RhoC mRNA及RhoC 蛋白增强，其表达VEGF和bFGFmRNA及蛋白明显增强（P＜0.01）;重组质粒转染组成瘤率高于空载体组。结论:RhoC表达可促进HepG2细胞表达血管内皮生成因子。RhoC可促进肝癌细胞分泌促血管生长因子，可能是促进肝癌侵袭、转移的机制之一。     

Photochemotherapy of experimental colonic tumours with intra-tumorally applied methylene blue

Introduction: Phototoxicity of intra-tumoral injected methylene blue (MB⁺) was studied in 48 experimental colonic tumours in comparison with photosan-3, Zn-phthalocyanine and tetrasulphanated ClAl-phthalocyanine. Methods: In mice, xenotransplanted subcutaneous tumours about 1 cm in diameter were treated photodynamically twice, with different sensitisers. The irradiation was performed at the sensitiser-specific wavelength, and a densitiy of 100 mW/cm² and a dose of 100 J/cm². Results: Light alone without sensitiser did not induce any effect in mice tumours. Surprisingly, Al-phthalocyanine could only be used for intratumoral injections because of toxic effects after intravenous applications in nude mice. Using MB⁺ (1%), 75% of the tumours were destroyed by a single photodynamic treatment (PDT). In addition, toxicity of MB⁺ was most intense when compared with Zn-phthalocyanine and photosan-3. However, after the second PDT, there was no statistically significant difference among these sensitisers. Dark toxicity of MB⁺ (1%) could be well demonstrated by sufficient sensitiser incorporation without irradiation, which led to a stationary tumour volume up to 3 weeks after injection. Conclusion: Intra-tumoral MB⁺ PDT is a potential treatment for inducing necrosis in vivo. With regard to tumour tissue, the selectivity of MB⁺ is high and depends on a precise local injection of the dye. Received: 25 May 1998     

Photodynamic therapy inhibits transforming growth factor β activity associated with vascular smooth muscle cell injury

Purpose: The multifunctional cytokine, transforming growth factor β1 (TGF-β), plays an important role in the development of injury-associated intimal hyperplasia (IH). Strategies to suppress local TGF-β activity may have a clinical potential to prevent restenosis caused by IH. Photodynamic therapy (PDT) involves the local generation of cytotoxic free radicals by light activation of photosensitizer dyes and has been shown to inhibit experimental IH. This study investigated whether PDT-generated free radicals can affect TGF-β activity in a biologic system using vascular smooth muscle cells (SMCs).Methods: The release and activation of TGF-β by injured SMCs in culture was compared between mechanical injury and PDT. Mechanical injury was induced with a rubber policeman, and PDT was performed with the photosensitizer chloroaluminum sulfonated phthalocyanine (5 μg/ml) and 675 nm laser light at subtherapeutic 10 J/cm² and the in vivo therapeutic dose of 100 J/cm². Cell viability was assessed by the tetrazolium salt conversion assay, and active and total (active + latent) TGF-β was determined by enzyme-linked immunosorbent assay in the conditioned media of SMCs 24 hours after treatment. Functional TGF-β activity was assessed by inhibition of endothelial cell mitogenesis.Results: Both forms of injury severely reduced (p < 0.0005) SMC viability to less than 15%. In untreated SMC conditioned media, only 14.5% of the total TGF-β was active (27.7 ± 8.7 pg per 1 × 10⁵ cells). However, after mechanical injury and PDT with 10 J/cm², there was a significant increase (p < 0.02) in active TGF-β (60.1 ± 10.1 pg and 48.6 ± 21.0 pg, respectively), despite a total reduction of approximately 50%. In contrast to this result, PDT with 100 J/cm² did not result in increased levels of active TGF-β (8.1 ± 3.5 pg), despite having similar levels of total TGF-β. Consequently, the conditioned media of SMCs that had 100 J/cm² PDT did not inhibit endothelial cell mitogenesis as compared with the conditioned media of SMCs with mechanical injury and 10 J/cm² PDT (p < 0.0002).Conclusions: This report describes two novel findings: (1) injury to SMCs in vitro induces the conversion of biologically latent TGF-β to active TGF-β; and (2) the therapeutic PDT dose interferes with this injury activation process. This study substantiates the concept of local cytokine inhibition by PDT in a biologic system and provides new insights into the mechanisms of PDT-mediated inhibition of experimental IH. (J Vasc Surg 1997;25:1033-43.)     

In vitro and in vivo effects of photodynamic therapy on murine malignant melanoma

Background: The role of photodynamic therapy (PDT) in the treatment of malignant melanoma is not well defined, nor is it known whether the dark melanoma cells absorb the light used in PDT. Methods: In vitro studies: 2×10⁵ B16 murine melanoma cells were incubated with aluminum phthalocyanine (AlpcS₄, 2.5 mg/kg) and were then subjected to photoradiation (50, 100 or 200 J/cm²). Viability was then assessed.In vivo studies: Histology: C57/B1 mice received 2×10⁵ B16 cells subcutaneously and were randomized into study (PDT) and three control groups. AlpcS₄ 2.5 mg/kg was injected intraperitoneally and the mice were exposed to light (100 J/cm²). After 24 hours they were sacrificed and underwent autopsies. Survival: 40 mice were randomized into PDT (40 J/cm²) and control groups and were monitored for 50 days. Tumor growth: 40 mice were randomized into one control and three treatment groups (PDT on day 3, 6, or 12 after injection with B16 cells), and were monitored for 50 days. Temperature: Tumor temperatures before and at the end of PDT were recorded. Results: In vitro studies: PDT caused a decrease in cell viability to 15.5±0.7%, 11.5±2.1%, and 1.5±0.7% (at 50, 100, and 200 J/cm², respectively;P<.001). A significant reduction in thymidine incorporation was noted at all energy levels.In vivo studies: Histology: PDT caused massive tumor necrosis. Survival: PDT prolonged the survival of mice (41±13.4 days) compared to controls (15.8±3.8 days,P<.001). Tumor growth: 31 days after injection with B16 cells, the tumor size was 2.6±0.3 cm in the control group and 1.6±0.2, 0.9±0.3, and 1.0±0.4 cm in the PDT groups (days 3, 6 and 12, respectively;P<.01). Temperature: PDT increased skin temperature to 42.8°C±1.3°C, 45.3°C±3.5°C, and 51.7°C±2.7°C at 40, 60, and 100 J/cm², respectively (P<.01). Conclusions: Photodynamic therapy was found to have significant effects in experimental melanoma in mice. The role of PDT in human melanoma remains to be studied.Presented at the 50th Annual Cancer Symposium of The Society of Surgical Oncology, Chicago, Illinois, March 20–23, 1997.     

Competency-based student self-assessment on a surgery rotation

INTRODUCTION: Vascular endothelial growth factor (VEGF) is an angiogenic factor that increases vascular permeability. VEGF stimulates capillary formation and has mitogenic effects on vascular endothelial cells. The development of malignant ascites causes significant morbidity. We hypothesized that increased levels of VEGF play a role in the development of malignant ascites in patients with pancreatic cancer. METHODS: Athymic mice underwent orthotopic implantation of human pancreatic ductal adenocarcinoma tumors (250,000 cells) into the body of the pancreas. Tumors were allowed to grow for 12 weeks, at which time ascites develops in 50% of mice. Paracentesis was performed on mice with noticeable ascites. Saline lavage was performed in mice with equivalent pancreatic tumor masses without ascites and served as control. Both ascites and tumor masses were harvested for VEGF protein quantitation by ELISA. RESULTS: VEGF protein levels were elevated in malignant ascites by 15-fold compared to control mice with equivalent tumors (N = 6, P < 0.001, t test). VEGF levels were slightly higher in the primary tumor masses harvested from mice without ascites. Mice with ascites also had metastatic nodules throughout the abdominal cavity. CONCLUSIONS: We are reporting for the first time that VEGF levels are increased in the ascites of nude mice with orthotopically transplanted human pancreatic cancers. VEGF increases vascular permeability and allows for extrapancreatic seeding of tumors. Irrespective of primary tumor size, intraperitoneal VEGF levels are increased when ascites and extrapancreatic nodules are present, while a paradoxical decrease is observed in VEGF levels of primary tumors.     

Photodynamic therapy of vein grafts: Suppression of intimal hyperplasia of the vein graft but not the anastomosis

Purpose: There is no clinically useful therapy for the suppression of vein bypass graft intimal hyperplasia (IH). Photodynamic therapy (PDT), a technique that uses light to activate otherwise biologically inert photosensitizers to produce cytotoxic effects, has been demonstrated to successfully inhibit experimental IH in balloon-injured arteries. The purpose of this study was to investigate the efficacy of PDT as a method to reduce vein graft IH.Methods: Reversed external jugular vein bypass grafts of the common carotid artery were performed in 28 male Sprague-Dawley rats. The animals received either chloroaluminum sulfonated phthalocyanine (2.5 mg/kg intravenously) 24 hours before the ex vivo irradiation of the vein grafts (VG) with 100 joule/cm² at 675 nm (PDT VG) or saline solution as control (CON VG). Preharvest bromodeoxyuridine was administered to label proliferating cells. All vein grafts were perfusion fixed within 96 hours for a pilot study or at 2 and 4 weeks for the main study. Histology, immunohistochemistry, and morphometric analysis were performed.Results: There was no acute thrombus formation in the hypocellular PDT VG with occasional platelets but no leukocytes adherent to the luminal surface. Intimal areas of the PDT VG were 18% at 2 weeks and 53% at 4 weeks of the CON VGs (p < 0.05). Medial areas and percent of stenoses were also significantly less in PDT than in CON VG. However, intimal hyperplasia noted in the longitudinal sections within 2 mm of the anastomoses did not demonstrate a difference between PDT and CON VG. Intimal hyperplasia of both PDT and CON VG consisted of smooth muscle cells, verified by immunohistochemistry. Bromodeoxyuridine-labeled cells were more abundant in 2-week than in 4-week specimens, were found most frequently in the intimal areas of the CON VG body, and were equivalent in the anastomoses of PDT VG and CON VG.Conclusions: These data suggest that PDT of vein grafts suppresses the development of IH in the body of the vein graft but does not affect IH adjacent to the anastomoses. The artery may be the source of proliferating smooth muscle cells that contribute to the anastomotic vein graft IH. (J VASC SURG 1995;21:882-90.)     

槐耳清膏抑制肝癌切除术后复发瘤的生长及机制

目的 探讨槐耳清膏对原位移植瘤手术切除后复发肿瘤的作用及其机制.方法 人高转移肝癌HCC-LM3原位移植瘤建立后14 d,手术切除原位瘤,分别使用槐耳清膏和生理盐水灌胃28 d后,比较肝脏复发肿瘤的大小和肺转移率,免疫组织化学检测肿瘤微血管密度,实时荧光定量聚合酶链反应(PCR)检测肿瘤里血管生成因子表达的变化,酶联免疫吸附试验(ELISA)检测血清血管生成因子的表达.结果 槐耳清膏可显著延缓移植瘤手术切除后复发肿瘤生长、抑制肺转移,降低肿瘤MVD,降低血管生成因子的表达.结论 槐耳清膏显著抑制人肝癌HCC-LM3原位移植瘤手术切除后复发肿瘤的生长以及肺转移,抗血管生成作用可能是其主要机制.     

Biostimulatory effect of low-level laser therapy on keratinocytes in vitro

Epithelial cells play an important role in reparative events. Therefore, therapies that can stimulate the proliferation and metabolism of these cells could accelerate the healing process. To evaluate the effects of low-level laser therapy (LLLT), human keratinocytes were irradiated with an InGaAsP diode laser prototype (LASERTable; 780?±?3 nm; 40 mW) using 0.5, 1.5, 3, 5, and 7 J/cm² energy doses. Irradiations were done every 24 h totaling three applications. Evaluation of cell metabolism (MTT assay) showed that LLLT with all energy doses promoted an increase of cell metabolism, being more effective for 0.5, 1.5, and 3 J/cm². The highest cell counts (Trypan blue assay) were observed with 0.5, 3, and 5 J/cm². No statistically significant difference for total protein (TP) production was observed and cell morphology analysis by scanning electron microscopy revealed that LLLT did not promote morphological alterations on the keratinocytes. Real-time polymerase chain reaction (qPCR) revealed that LLLT also promoted an increase of type I collagen (Col-I) and vascular endothelial growth factor (VEGF) gene expression, especially for 1.5 J/cm², but no change on fibroblast growth factor-2 (FGF-2) expression was observed. LLLT at energy doses ranging from 0.5 to 3 J/cm² promoted the most significant biostimulatory effects on cultured keratinocytes.     

Photodynamic therapy of C3H tumours in mice: Effect of drug/light dose fractionation and misonidazole

C3H mammary carcinomas transplanted to the feet of mice were treated with haematoporphyrin derivative (HPD) or Photofrin II(PII) and laser light at 630 nm. While fluence rates lower than 100 mW cm⁻² gave minimal hyperthermic effects, a slight but significant growth delay was observed in unsensitized tumours exposed to a fluence rate of 150 mW cm⁻² which induced tumour temperatures in the range 40–50°C. Different modes of fractionation of the light fluence and of the HPD dose were tested but were found to give poorer rather than better results than the application of a single light exposure 24 h after intraperitoneal injection of HPD. Different PII doses were applied together with different light fluences, keeping the product of the drug dose and light fluence constant. In the dose range 6.25–50 mg/kg body weight the resulting effect on tumours was constant, allowing for a slight effect of hyperthermia at the highest light fluences, and possibly a photodegradation of PII. Misonidazole given before photodynamic treatment (PDT) slightly reduced the effect of PDT on the tumour growth. When given after PDT, however, misonidazole improved the therapeutic results significantly.     

Interstitial photodynamic therapy in the Dunning R3327-AT6 prostatic carcinoma

Interstitial photodynamic therapy (PDT) could be an alternative radical treatment for prostate cancer. The ability to predict the depth of necrosis is necessary for light treatment planning using multiple optical fibres. The extent of PDT necrosis was studied in subcutaneously implanted R3327-AT6 Dunning prostate tumours which had similar optical characteristics to human prostate. Tumour-bearing subjects were given 20 mg kg^–1 Haematoporphyrin esters (HPE) and irradiated 24 h later with 630 nm laser light. Five subjects per group were treated with increasing light doses (50–450 J cm^–1) delivered interstitially via a single 2 cm long cylindrical diffuser. After 450 J cm^–1 of irradiation, 4.3±0.8 cm³ [standard error of the mean (s.e.m.)] of tumour tissue was necrosed to a depth of 10.5±0.8 mm around the diffuser. There was an approximately linear correlation between the volume of PDT necrosis around the fibre and prescribed light dose. The mean threshold light dose for PDT effect was 18±2 J cm^–2. In this tumour with a mean photosensitizer concentration of 16±1.5g g^–1, low light doses produced tumour necrosis. PDT using multiple diffusers could destroy a relatively large tumour volume and the diffusion theory model reliably predicted the depth of necrosis.     

Toluidine blue-mediated photoinactivation of periodontal pathogens from supragingival plaques

This study aimed to assess the effect of toluidine blue (TB)-mediated photodynamic inactivation of periodontal pathogens (PP) from periodontopathic patients. Photodynamic therapy (PDT) was carried out using TB and 635 nm laser light irradiation. The bactericidal effect was evaluated, and important PDT parameters including light intensity, energy dose, and TB concentration were determined. Our findings suggest that TB-mediated lethal photosensitization of PP in vivo is possible. However, to obtain ideal bactericidal effect, higher doses of light and photosensitizer should be required in treatment in vivo than their planktonic counterparts. The best therapeutic effect was observed in treatment by 1 mg/ml TB combined with 12 J/cm² at 159 mW/cm² light irradiation. Moreover, because of the considerable interindividual differences of bacterial populations, TB-mediated PDT might not be equally effective among periodontopathic patients, and further studies on improvement of this therapeutic modality is needed.     

Effect of photodynamic therapy on urinary bladder function: an experimental study with rats

Photodynamic therapy (PDT) produces localized necrosis with light after prior administration of a photosensitizing drug. The problems with laser light dosimetry and complications relating to bladder function appear to be important limiting factors of PDT in urology. Photodynamic therapy on urinary bladder with normal epithelium of rats was performed using an argon ion laser as an energy source, with aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) photosensitizer. Four hours after ALA intravenous administration, the bladders were intravesically radiated with light doses 20, 40, or 80 J/cm². Animals in the control group did not receive ALA and were radiated with 20 J/cm² light dose. Three weeks prior to PDT, the bladder capacity and pressure changes during filling cystometry were assessed. Cystometrics were repeated 1, 3, 7, or 21 days after laser therapy. The light dose 20 J/cm² and 40 J/cm² together with the used ALA dose caused no reduction in bladder capacity, whereas 80 J/cm² light dose produced up to 50% reduction in the capacity at 3 weeks postoperatively. In control group without ALA, the animals did not regain more than 34% of the capacity of their control values at 3 weeks. The light dose of 20 J/cm² and 40 J/cm² with ALA induced functional changes that subsided after day 1. Our results indicate that with proper dosing of photosensitizing drug and light energy, the functional impairment of urinary bladder may be reduced as transient. These findings support the use of PDT as safe therapy of superficial bladder cancer. Received: 10 April 2000 / Accepted: 16 November 2000     

Intrapleural photodynamic therapy: Results of a phase I trial

Background: The management of pleural neoplasms, specifically mesothelioma, remains difficult. We performed a phase I trial in 54 patients with isolated hemithorax pleural malignancy to determine (a) the feasibility of intraoperative, intrapleural photodynamic therapy after debulking surgery; (b) the influence of light dose/sensitizer interval on postoperative morbidity in order to define the photodynamic therapy (PDT) maximal tolerated dose (MTD); and (c) whether first order dosimetry could be applied to this complex geometry. Methods: Cohorts of three patients were given escalating intraoperative light doses of 15–35 J/cm² 48 h after i.v. delivery of 2.0 mg/kg Photofrin II (Quadra Logic Technologies, Vancouver, British Columbia, Canada), and then escalating light doses of 30–32.5 J/cm² after a 24-h sensitizer/operation interval. Twelve patients could not be debulked to the prerequisite 5 mm residual tumor thickness. The remaining 42 patients underwent 19 modified pleuropneumonectomies, five lobectomy-pleurectomies, and 18 pleurectomies. Intrapleural PDT was delivered using 630 nm light from two argon pump-dye lasers, and real-time and cumulative light doses were monitored using seven uniquely designed, computer-interfaced photodiodes. Results: There was one 30-day mortality from intraoperative hemorrhage. In the 48-h sensitizer/operation group (n=33), possible PDT-related complications included an empyema with late hemorrhage in one of three patients at 17.5 J/cm² and a bronchopleural fistula at 35 J/cm². At each of these light doses, three additional patients were treated without complication. Two patients subjected to 24-h sensitizer dosing and 32.5 J/cm² developed esophageal perforations after pleuropneumonectomy at identical sites. The MTD was declared as 30 J/cm² light with a 24-h dosing interval when none of the six patients (three original, three repeat) at that level developed toxicity. Conclusions: These data demonstrate that resection and intrapleural PDT can be performed safely with currently available sensitizers and lasers. Phase II and III trials are now warranted at this MTD in a homogeneous population of patients with pleural malignancies.The results of this study were presented at the 46th Annual Cancer Symposium of the Society of Surgical Oncology, Los Angeles, March 18–21, 1993.Work of the US government. Not subject to copyright in the United States.     

Synergistically therapeutic effects of VEGF165 and angiopoietin-1 on ischemic rat myocardium

PURPOSE: The aim of this study was to determine whether the combination of 2 angiogenic growth factor, vascular endothelial growth factor 165(VEGF165) and angiopoietin-1 (Ang1), could increase angiogenesis and cardiomyocyte(CM) proliferation in an infarcted myocardium. METHODS: Myocardial ischemia was induced in rats by ligation of the left anterior descending (LAD) coronary artery. Replication-deficient adenoviruses encoding VEGF165 (Ad-VEGF165), Ang1 (Ad-Ang1) or enhanced green fluorescence protein (Ad-EGFP) was injected into the ischemic myocardium immediately. Bromodexyuridine (BrdU) was administered intraperitoneally 1 week after ligation. One week later, the hearts were harvested and sectioned for hematoxylin-eosin (HE) and immunohistochemistry to evaluate densities of capillary, arteriole and double labelled BrdU(+) CM. M-mode echocardiography was used to evaluate the cardiac function. RESULTS: Ang1 significantly increased collateral vessel formation. Both VEGF165 and Ang1 significantly increased densities of capillary and arteriole, as well as the number of double labelled BrdU(+) CM, and improved cardiac function. CONCLUSION: Our results suggest that the combination of VEGF165 and Ang1 can increase both myocardial angiogenesis and CM proliferation following myocardial ischemia in rats, leading to improved cardiac function.