A non-laser light source for photodynamic therapy: in vitro effects on normal and malignant cells

AIM

Photodynamic therapy (PDT) involves the use of photosensitizing drugs combined with light to treat tumors. Laser systems, the current source of light for PDT, have several inherent drawbacks: the spectrum is essentially monochromatic which may be problematic for second generation photosensitizers, the systems are bulky and nearly impossible to move between hospital locations and require complicated electrical and cooling installations, the cost of a typical system is enormous, and its maintenance and operation require highly trained personnel. We now introduce a new non-laser light system, Versa-Light, which appears to work as effectively and has none of the above drawbacks.

METHODS

A series of in vitro studies were performed using various murine and human normal and cancer cells which underwent PDT using aluminum phthalocyanine (AlPcS4) as a photosensitizer and Versa-Light as the light source.

RESULTS

PDT of cancer cells at light energy levels of 50, 100 and 200 j/cm2 significantly decreased cell viability. PDT also decreased cell viability of normal murine splenocytes and normal human lymphocytes, but to a lesser extent. The observed significant hyperthermia was light dose-dependent.

CONCLUSIONS

We believe that Versa-Light can replace laser systems as an enhanced light source for PDT. Further in vitro and pre-clinical studies are in progress.

[Stapled hemorrhoidectomy--early experience in 30 patients]

INTRODUCTION

We report the early results of 30 patients treated by stapled hemorrhoidectomy.

PATIENTS AND METHODS

Thirty patients with symptomatic grade 2-4 hemorrhoids were treated by stapled hemorrhoidectomy. The procedure was performed with a 33 mm diameter automatic hemorrhoidal circular stapler. The patients were prospectively evaluated for immediate and functional recovery, postoperative pain and subjective success of the treatment.

RESULTS

The median age of the patients was 46.2 years, and the median duration of the symptoms was 27 months. The main symptom was bleeding (in 96% of the patients). The average operative time was 22 minutes. The operation was performed with spinal (63.3%) or general (36.7%) anesthesia. There was no mortality, urinary retention, incontinence, fecal urgency or persistent pain. One patient, who was under anticoagulant treatment, had postoperative bleeding, which required transfusion of 3 units of blood, and another patient was operated on because of perforation of the sigmoid colon. Most patients (twenty eight) had complete functional recovery and returned to their usual daily activities within 10.4 days. Postoperative pain and subjective success were evaluated by a 1 to 10 scale. The average pain score decreased from 5.8 on the first postoperative day to 2.4 on the 7th postoperative day. The average satisfactory score was 9.2.

CONCLUSION

Stapled hemorrhoidectomy is an alternative to conventional surgical hemorrhoidectomy. The procedure seems to be associated with less postoperative pain and early recovery with a high satisfaction rate among patients.

Detection of hepatocyte growth factor/scatter factor receptor (c-Met) and MUC1 from the axillary fluid drainage in patients after breast cancer surgery

BACKGROUND

Drains are inserted in the dissected axilla of most patients during surgery for breast cancer.

OBJECTIVE

To evaluate the presence and prognostic value of MUC1 and Met-hepatocyte growth factor/scatter factor in the axillary drainage of these patients.

METHODS

The study group included 40 consecutive patients with invasive ductal carcinoma of the breast who were suitable for breast-conserving treatment; 20 malignant melanoma patients found to have negative axillary sentinel lymph node served as the control group. The output of the drains, which had been placed in the axilla during operation, was collected, and the presence of MUC1, Met-HGF/SF and beta-actin were assessed in the lymphatic fluid by reverse transcription-polymerase chain reaction assays. The data were compared to the pathologic features of the tumor and the axillary lymph nodes, and to the estrogen and progesterone receptors status.

RESULTS

RT-PCR assays of the axillary lymphatic drainage were positive for MUC1 and Met-HGF/SF in 15 (37.5%) and 26 (65%) of the patients, respectively. Patients in whom MUC1 and Met-HGF/SF were not found in the axillary fluid had smaller tumors and less capillary and lymphatic invasion, compared to patients with positive assays (P < 0.0 for all these comparisons). The lymph nodes were negative for metastases in all patients with negative assays (P < 0.001). The presence of MUC1 and Met-HGF/SF showed negative correlations with the estrogen and progesterone receptors (P < 0.05).

CONCLUSION

MUC1 and Met-HGF/SF can be detected in the axillary fluids of patients with breast cancer. The expression of both tumor markers in the axillary drainage is strongly associated with unfavorable tumor features and can be used as a prognostic factor.

Hypericin activated by an incoherent light source has photodynamic effects on esophageal cancer cells

BACKGROUND AND AIMS

Photodynamic therapy (PDT) is a new treatment modality for early esophageal neoplasia. With two absorption maxima in the visible light range (550 and 588 nm) hypericin is a very promising photosensitizer for PDT with incoherent light sources. We studied the effects of photosensitizing hypericin in both primary cell cultures and cell lines (squamous: Kyse-140 and adenocarcinoma: OE-33) of human esophageal cancer using an incoherent white light source.

MATERIALS AND METHODS

Esophageal cancer cells were preincubated (4-24 h) with hypericin (10 nM-1 micro M) and then irradiated with a light energy dose of 30 J/cm(2).

RESULTS

Hypericin showed strong phototoxic effects and induced apoptosis in a dose-dependent fashion. The IC(50) value of hypericin phototoxicity was approximately 30 nM in both squamous and adenocarcinoma cells. In the concentrations used nonphotoactivated hypericin showed no toxic or apoptotic potency. The phototoxicity of hypericin was compared to that of delta-aminolevulinic acid (5-ALA), which is already being used for photodynamic therapy of gastrointestinal cancer. 5-ALA produced similar phototoxic effects but at a much higher dose (IC(50) 182+/-8 micro M in Kyse-140 and 308+/-40 micro M in OE-33 cells). Moreover, 5-ALA did not induce apoptosis to a relevant extent.

CONCLUSION

Hypericin is a very promising new photosensitizer for innovative photodynamic therapy of esophageal cancer. Both the well known clinical safety of hypericin and the lower costs of broad band light sources argue in favor of clinical trials.

Portal vein air embolization after blunt abdominal trauma: a case report and review of the literature

Gas in the portal vein is a rare and often fatal condition in surgical patients. However, the presence of gas in the mesenteric and portal veins in association with abdominal trauma is a transient incidental finding that resolves spontaneously. We describe a young patient with Crohn's disease who suffered air embolism of the portal veins secondary to blunt abdominal trauma. The condition was clinically benign and resolved spontaneously. The pathogenesis is discussed and a review of the literature is provided.

Isolated rib fractures in elderly patients: mortality and morbidity

OBJECTIVES

To describe the management, morbidity and mortality seen with isolated rib fractures in elderly patients and assess the need for hospitalization.

DESIGN

A case series.

SETTING

A tertiary care centre in Tel Aviv.

METHODS

Hospital records of 77 elderly patients (age 65 yr and older) admitted with isolated rib fractures were reviewed over a 9-year period.

MAIN OUTCOME MEASURES

Demographic, medical and hospitalization data, blood hemoglobin and oxygen saturation levels.

RESULTS

The number of fractured ribs was found to correlate with the morbidity (p = 0.027) and mortality (p = 0.006). There were no significant differences in these rates with respect to comorbidity except for diabetes (higher morbidity) and congestive heart failure (higher mortality). Twenty-eight patients (36%) had pulmonary complications and 1 had cardiac complications. Pulmonary complications were fatal in 6 patients (7.8%). Multivariate analysis of the factors related to morbidity demonstrated that only oxygen saturation (p = 0.0009) and diabetes (p = 0.03) correlated significantly.

CONCLUSIONS

In spite of significant morbidity and mortality in elderly patients with isolated rib fractures, prediction of the prognosis for these patients is presently not possible. Admission for observation and treatment is therefore justified and beneficial.

Immunoguided lymph node dissection in colorectal cancer: a new challenge?

Knowledge of lymphatic involvement in patients with colorectal cancer is important in surgery and in the postoperative decision-making process. Fifty-eight patients with recurrent colorectal cancer underwent operation with the RIGS/(Radioimmunoguided Surgery) technology. Preoperatively, patients were injected with 1 mg monoclonal antibody (MoAb) CC49 (anti-TAG-72-tumor-associated glycoprotein) labeled with 2 mCi of iodine 125. Traditional surgical exploration was followed by survey with a gamma-detecting probe. Localization of MoAb on tumor was noted in 54/58 patients (93%). Traditional exploration identified 117 suspected tumor sites. With RIGS, 177 suspected tumor sites were detected. In 17 of the 58 patients (27.5%), at least one occult tumor site identified by RIGS was confirmed by pathology with hematoxylin & eosin (H & E) staining. This finding resulted in 16 major changes in surgical plan. RIGS performance varied between lymphatic and non-lymphatic tissue, with a positive predictive value (PPV) of 95.6% and negative predictive value (NPV) of 90% in non-lymphoid tissue compared to PPV of 40% and NPV of 100% in lymphoid tissue. In patients with tumors that localize, no RIGS activity in lymph nodes signifies no tumor, while decisions based on RIGS activity in lymph nodes requires H & E confirmation. Using this guideline, additional information acquired by RIGS can help the surgeon in making an informed decision during surgery and in planning postoperative therapy.

Benefits of radioimmunoguided surgery for pelvic recurrence

AIM

Surgery for recurrent rectal cancer is usually traumatic and of questionable curative value. The use of radioimmunoguided surgery (RIGS) in enhancing the surgeon's assessment of the extent of disease in these patients was investigated.

METHODS

Twenty-one patients diagnosed with recurrent pelvic cancer were operated using the RIGS(O)system. Preoperative assessment included CTs of chest, abdomen and pelvis as well as colonoscopy. Patients were injected with CC49, a monoclonal antibody (MoAb) labelled with 125I. Surgical exploration was followed by survey with the gamma-detecting probe.

RESULTS

Surgical exploration identified eight intra-colorectal recurrences, nine extra-colonic pelvic recurrences and five extra-pelvic lymph node metastases. RIGS exploration confirmed all intra-colonic recurrences except for one (patient with no MoAb localization), identified 13 pelvic recurrences and 10 lymph node metastases. There were seven patients with occult findings (33%), resulting in a modified surgical procedure. Surgery included five abdomino-perineal resections, six low anterior resections, seven excisions of presacral tumour, eight total abdominal hysterectomy and bilateral salpingo-oophorectomy, one pelvic exenteration and one post-exenteration. There were no operative deaths. Eight patients had minor complications, and one patient had a major complication with reoperation due to urinary leak. The mean follow-up was 18 months. Ten patients died of disease.

CONCLUSION

Although not curative, RIGS can help the surgeon in the decision-making process through better disease staging.

Identification of lymph node metastases in recurrent colorectal cancer

Lymph node metastases are an important prognostic prediction factor in patients with recurrent colorectal cancer, particularly those with liver metastasis. Fifty-six patients with recurrent colorectal cancer were operated by us using the RIGS (radioimmunoguided surgery) technology. Patients were injected with 1 mg monoclonal antibody (MoAb) CC49 labeled with 2 mCi 125I. In surgery, traditional exploration was followed by survey with a gamma-detecting probe. Sixty of 151 patients enrolled in the Neo2-14 Phase III study for recurrent colorectal cancer were diagnosed with liver metastases based on preoperative CT. In 17/56 patients (30%), RIGS identified at least one tumor site confirmed by pathology (H&E). This resulted in 16 major changes in surgical plan. RIGS performance varied between lymphatic and non-lymphatic tissue, with positive predictive value (PPV) of 100% and negative predictive value (NPV) of 94% for non-lymphoid tissue, compared to PPV of 46.5% and NPV of 100% for the lymphoid tissue. Thirty-five out of 60 patients were considered resectable after traditional evaluation. RIGS identified occult tumor in 10 of these patients (28.5%). 7/10 occult patients expired (70%), while only 7/25 of the non-occult patients expired (28%) (P = 0.046). In localizing patients, no RIGS activity in lymph nodes signifies no tumor, while H&E confirmation is needed for decisions based on RIGS activity in the lymph nodes. RIGS provides important staging information, identifying patients for whom surgery may be done with curative intent.

Effects of intravenous gamma immunoglobulins treatment on severe peritonitis in rats

BACKGROUND

Generalized purulent peritonitis is characterized by an early exposure of the immune system to a large number of bacterial antigens. The hypothesis that intravenous IgG treatment may improve the outcome of severe experimental peritonitis was studied.

METHODS

Peritonitis was induced in rats by cecal ligation and perforation. Continuous intravenous fluid infusion, broad-spectrum antibiotics, and twenty-four hours treated forty rats after the induction of the disease they were re-operated and the perforated cecum was excised. Twenty of these animals received in addition specific rat IgG in two intravenous infusions (0.4 gr./kg), two and twenty four hours after the induction of peritonitis.

RESULTS

Elevated WBC counts and mild metabolic acidosis was found one day after the induction of peritonitis. IgG treatment was associated with lower WBC counts in the following days and with higher pH than in the control group (p < 0.05 for both parameters). All peritoneal cultures and 90% of blood cultures were positive 24 hours after the initial operation. These rates decreased in the following days and in the IgG treatment rats the peritoneal cavity and blood were sterile earlier than in the control animals (p < 0.05). Serum IgG was depleted in the control animals within 48 hours after the induction of peritonitis, while in the IgG treated animals its levels were remarkably elevated. IgG administration significantly improved the survival, which was 70% in the IgG treatment rats as compared to 40% in the control rats.

CONCLUSION

These results indicate that intravenous IgG has beneficial effects on severe experimental peritonitis.

[Photodynamic therapy of nasal basal cell carcinoma]

Photodynamic therapy (PDT) is a noninvasive modality used topically for several skin cancers. We evaluated the effects of PDT on basal cell carcinoma (BCC) of the nose, using aminolevulinic acid (ALA) as a photosensitizer and a non-laser light source (Versa-Light). The advantages of this light source are synergistic, hyperthermia and fewer side effects. A paste of 20% ALA was applied topically to biopsy-proven BCC of the nose. Lesions were covered with occlusive light-shielding dressing and after 18 hours they were submitted to 10 minutes of exposure to the light. Initial evaluation was made after 21 days and every 3 months thereafter. Patients who did not respond after 2 treatments were referred for surgery. Mean follow-up in 31 patients was 19 months (range 6-36). There were no significant side-effects. There was complete response in 24/27 (88.9%), in whom there was recurrence in 2/27 (7.4%).

Radioimmunoguided surgery for recurrent colorectal cancer manifested by isolated CEA elevation

BACKGROUND

Carcinoembryonic antigen (CEA) is a sensitive marker for detecting recurrent colorectal carcinoma. An asymptomatic rise of CEA can precede by several months the detection of recurrent cancer by standard imaging modalities. Yet, surgeons are hesitant to operate solely on the basis of an observed increase in CEA. We investigated the ability of radioimmunoguided surgery to enhance the surgeon's capability of detecting intraabdominal disease in these patients.

METHODS

Nineteen patients who underwent radioimmunoguided surgery for suspected tumor recurrence based solely on elevated CEA were included in the study. They underwent colonoscopy and CT of the abdomen and chest, all of which were negative. They then underwent scintigraphy scan with an anti-CEA monoclonal antibody (MoAb) labeled with (99m)Tc or Indium I-111. All patients were injected with the CC49 MoAb (an anti-TAG-72 tumor-associated glycoprotein) labeled with (125)I three weeks before surgery. During surgery, traditional exploration was followed by survey with a gamma-detecting probe.

RESULTS

Traditional surgical exploration identified 26 recurrent tumors: 7 hepatic, 8 pelvic, 6 retroperitoneal, 3 colonic, 1 splenic, and 1 anastomotic. Radioimmunoguided surgical exploration confirmed all recurrent tumors and identified additional tumor sites in seven patients that resulted in changing the surgical plan. CEA scans correlated with intraabdominal findings in seven patients. Abdominal pathology did not correlate completely with the scans in three patients, and CEA scan results were undetermined in two patients.

CONCLUSION

Patients with elevated CEA and no other findings should be operated upon without delay, and radioimmunoguided surgery should be used to enhance the surgeon's knowledge of the extent of disease.

Return visits to the emergency room after minor trauma from motor vehicle accidents

Most patients with minor trauma following motor vehicle accidents (MVAs) are discharged from the emergency room (ER) of a trauma centre after evaluation and observation. Some return with similar or additional symptoms. This study aimed to determine which patients returned, if any injuries had been missed, and what should be the policy of medical management. We reviewed the records of 8836 patients with minor trauma following MVAs who were examined in an inner city trauma centre during 1997. When the group of patients who returned to the emergency room (n = 160) was compared with the whole post-MVA minor trauma group, the former was found to have more males (75.6% vs. 55.9%), younger age (36.31 years vs. 39.72 years), more motorcyclists than drivers, passengers and pedestrians ( p < 0.002, for the three variables), and had more multi-site injures. During the return visits the patients stayed longer in the emergency room, were examined by more consultants and had repeated radiological evaluations and tests, compared with the initial visit. However, in none of the patients was the initial diagnosis revised nor were additional injuries found and consequently the initial management was not changed in any of them. It is concluded that the initial thorough evaluation by the primary traumatologist is adequate for MVA patients with minor trauma. These patients do not require any follow up in specialized clinics, and are best managed in the community by their general practitioners.

The effects of somatostatin and octreotide on experimental and human acute pancreatitis

The role of somatostatin and octreotide for AP has been studied for two decades, yet the data still remain inconclusive. The inconsistencies of the results of experimental studies and clinical trials may stem from the fact that the optimal therapeutic modality has not been determined. Furthermore, although they are similar in structure and physiologic activities, the mechanisms of action and effects of somatostatin and octreotide in AP may be different. Because the data are sparse, most reports, primarily those in the English literature, on the efficacy of somatostatin and octreotide in the management of AP were reviewed. Included are both nonrandomized and prospective, double-blind, clinical trials and studies on the effects of these agents on various experimental models of the disease. The results of the studies on somatostatin and octreotide are presented and discussed separately, with specific reference to the experimental and treatment details. The main focus of the review is the effect of subcutaneous and intravenous administration of octreotide. Analysis of the data suggests that somatostatin could not be recommended for AP and that the efficacy of subcutaneous administration of octreotide is also questionable. Theoretically, intravenous octreotide may be more appropriate for this condition, but recent results with this therapeutic method are limited and contradictory. Studies that would delineate the optimal therapeutical modality and the patient population most likely to respond to the treatment are prerequisite for large-scale clinical trials on the effects of octreotide on human pancreatitis.

Photodynamic therapy of murine colon cancer and melanoma using systemic aminolevulinic acid as a photosensitizer

BACKGROUND

Side effects of conventional photosensitizers, such as hematoporphyrins, are a limiting factor in the use of photodynamic therapy (PDT). We evaluated the effect of PDT on mice colon carcinoma and melanoma using systemic 5-aminolevulinic acid (ALA).

METHODS

IN VITRO STUDIES

CT26 colon carcinoma and B16 melanoma cells were incubated with ALA for 48 h. Subsequently, cells were subjected to photoradiation at 40, 60 and 100 J/cm2 and viability was assessed. In vivo studies: Balb/C mice were injected subcutaneously with 2x10(5) CT26 colon cancer cells and C57/Bl mice were injected subcutaneously with 2x10(5) melanoma cells. ALA 60 mg/kg was injected intra-peritoneally when tumors were visible. After 24 h mice were subjected to photoradiation (100 J/cm2).

RESULTS

IN VITRO STUDIES

There was a significant decrease in the viability of treated cells as compared with non-treated tumor cells and with treated splenocytes (p<0.001). In vivo studies: PDT induced necrosis of both tumors. PDT also significantly prolonged the survival of the treated mice (p<0.05).

CONCLUSIONS

Photodynamic therapy using systemic ALA as a photosensitizer was effective in treating mice colon cancer and melanoma in both in-vitro and in-vivo studies. Further pre-clinical and clinical studies are being conducted now.

[Photodynamic therapy for dysphagia due to esophageal carcinoma]

Surgery is the mainstay in the treatment of esophageal carcinoma and is effective for palliation of dysphagia. Patients unfit for surgery are difficult therapeutic problems. We evaluated photodynamic therapy for palliation of dysphagia in this condition. Patients were given 5-aminolevulinic acid, 60 mg/kg, orally and 24 hour later gastroscopy was performed during which red light illumination (100 j/cm2 for 600 seconds) was administered. This was repeated 48 hours later. The degree of dysphagia was recorded before and 14 days after treatment. 8 patients with an advanced non-resectable tumor, or who were unfit for surgery, were thus treated. 4 had squamous cell carcinoma of the mid-esophagus and 4 had adenocarcinoma of the lower esophagus. There was mild, self-limited photosensitivity in all. Liver and renal function tests and blood count were not affected by the treatment. Dysphagia was improved in all except 1 patient. A patient with early stage disease continued to eat a normal diet. We believe that photodynamic therapy with systemic aminolevulinic acid as a photosensitizer and a non-laser light source is feasible and safe in advanced esophageal cancer. It is an effective modality for relief of dysphagia in that condition.

Effect of photodynamic therapy on normal fibroblasts and colon anastomotic healing in mice

Photodynamic therapy as an adjuvant modality to surgical resection of colon cancer is feasible provided that it does not affect healing of the anastomosis. The aim of this study was to evaluate the effects of photodynamic therapy on the viability of normal fibroblasts and on the healing process of colonic anastomosis in mice. Both in vitro and in vivo methods were employed. For in vitro study, 2 x 10(to the fifth power); human fibroblasts were incubated in triplicate with 5-aminolevulinic acid (2.5 microg/well) for 48 hours. Cells then underwent photoradiation at light doses of 50, 100, and 200 joules/cm(2) using a nonlaser light source. Viability was assessed by methylene blue dye exclusion. For in vivo studies, 60 mice were randomized into study and control groups and underwent laparotomy involving colonic anastomosis. The anastomosis underwent photodynamic therapy using 5-aminolevulinic acid (60 mg/kg) as a photosensitizer and a nonlaser light (40 joules/cm(2)). On postoperative days 1, 4, 7, 14, and 21, six mice were killed and subjected to bursting pressure and histologic examinations. Results of in vitro study showed pretreatment cell viability to be 96% to 99% in both groups. Photodynamic therapy caused no significant change in fibroblast viability at all light doses. Results of in vivo studies showed that the mean bursting pressure of both groups dropped to a low peak on day 4. Subsequently there was a gradual increase in bursting pressure along the examined time points (P <0. 001). There was no difference in bursting pressure between the two groups for all time points examined. It was concluded that photodynamic therapy has no effect on viability of normal human fibroblasts and no adverse effects on healing of colonic anastomosis.

Photodynamic therapy of cancer of the esophagus using systemic aminolevulinic acid and a non laser light source: a phase I/II study

BACKGROUND

Surgery is the mainstay for the treatment of carcinoma of the esophagus and is also considered to be effective for palliation of dysphagia. Patients who are unfit for surgery represent a difficult therapeutic problem. The goal of the present study was to evaluate the effects of photodynamic therapy by using systemic administration of 5-aminolevulinic acid and a non laser light source on carcinoma of the esophagus.

METHODS

Patients were given 60 mg/kg 5-aminolevulinic acid orally. Twenty-four hours later gastroscopy was performed. After initial localization of the tumor with the use of white light, the light source was switched to the red light band at 100 J/cm2 for 600 seconds. Gastroscopy was repeated at 48 hours and 7 days after the treatment. The degree of dysphagia was recorded before and 14 days after treatment.

RESULTS

Five patients with advanced nonresectable tumors or who were unfit for surgery were treated. Two patients had squamous cell carcinoma of the mid-esophagus and three had adenocarcinoma of the distal esophagus. Mild self-limiting photosensitivity was noted in all patients. Liver and renal function tests as well as hemoglobin level and white blood cell count were not affected by the treatment. Improvement of dysphagia was observed in four patients who had pretreatment dysphagia. The patient with the early stage of disease continued to eat a normal diet.

CONCLUSIONS

Photodynamic therapy with systemic aminolevulinic acid as a photosensitizer and a non laser light source is feasible and safe in advanced-stage esophageal cancer. It can be an effective modality for the relief of dysphagia in these patients.

Continuous intravenous octreotide treatment for acute experimental pancreatitis

BACKGROUND

The efficacy of octreotide, the synthetic analogue of the hormone somatostatin, for the treatment of acute pancreatitis is controversial. Octreotide has been commonly administered in subcutaneous bolus injections; however, continuous intravenous infusion may be advantageous for acute conditions.

METHODS

Acute experimental pancreatitis was induced in rats by intraparenchymal injections of 1 ml 10% sodium taurocholate, and octreotide (1 microg/kg/h, dissolved in physiological solution, intravenously was started 4 h later and continuously infused for 48 h. Physiological solution infusions, in identical volumes, were used in the controls. The following parameters were examined: mortality; macroscopic and histological damage; hematocrit; plasma pH; acid-base balance; serum glucose; calcium, and amylase.

RESULTS

Octreotide treatment had a striking effect on mortality: 8.3 versus 91.6% in the treatment and control groups, respectively (p < 0.001). Octreotide also ameliorated pancreatic edema and intestinal dilatation, and had significant beneficial effects on histopathological damage and the biochemical alterations which are associated with acute pancreatitis.

CONCLUSIONS

Continuous intravenous octreotide infusion is a potentially efficacious therapeutic method for acute pancreatitis.

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 x 10(5) 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 x 10(5) 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 degrees C +/- 1.3 degrees C, 45.3 degrees C +/- 3.5 degrees C, and 51.7 degrees C +/- 2.7 degrees 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.