Abdominal wall fibromatosis associated with previous laparoscopic hernia repair.

CASES: Two cases of desmoid-type fibromatosis developing after laparoscopic hernia repair are described: one in a young male 3 years after laparoscopic umbilical hernia repair and the other in a young female 1 year after laparoscopic incisional hernia repair. FINDINGS: The male patient presented with a slowly enlarging non-tender firm abdominal wall mass; the female patient had similar findings. Excision biopsy in the male and core biopsy in the female were consistent with fibromatosis. TREATMENT: The young male patient underwent resection of the fibromatosis, and the female patient has been managed conservatively. RELEVANCE TO CURRENT KNOWLEDGE: These are the first documented cases of fibromatosis developing after laparoscopic hernia surgery. Whilst the safety of hernia meshes has been assessed in animal studies, it may be that more detailed study of intraperitoneal placement of these meshes is required.

Probing microbubble targeting with atomic force microscopy.

Microbubble science is expanding beyond ultrasound imaging applications to biological targeting and drug/gene delivery. The characteristics of molecular targeting should be tested by a measurement system that can assess targeting efficacy and strength. Atomic force microscopy (AFM) is capable of piconewton force resolution, and is reported to measure the strength of single hydrogen bonds. An in-house targeted microbubble modified using the biotin-avidin chemistry and the CD31 antibody was used to probe cultures of Sk-Hep1 hepatic endothelial cells. We report that the targeted microbubbles provide a single distribution of adhesion forces with a median of 93pN. This interaction is assigned to the CD31 antibody-antigen unbinding event. Information on the distances between the interaction forces was obtained and could be important for future microbubble fabrication. In conclusion, the capability of single microbubbles to target cell lines was shown to be feasible with AFM.

Is the biology of breast cancer changing? A study of hormone receptor status 1984-1986 and 1996-1997.

Using archived tumours, those from 1984-1986 and 1996-1997 underwent immunohistochemistry for hormone receptors and grade analysis. A significant shift towards more ER-positive and low-grade disease was found; this appears to reflect screening practices, but could still influence survival.

Phthalocyanine-mediated photodynamic therapy induces cell death and a G0/G1 cell cycle arrest in cervical cancer cells.

We have developed a series of novel photosensitizers which have potential for anticancer photodynamic therapy (PDT). Photosensitizers include zinc phthalocyanine tetra-sulphonic acid and a family of derivatives with amino acid substituents of varying alkyl chain length and degree of branching. Subcellular localization of these photosensitizers at the phototoxic IC(50) concentration in human cervical carcinoma cells (SiHa Cells) was similar to that of the lysosomal dye Lucifer Yellow. Subsequent nuclear relocalization was observed following irradiation with 665nm laser light. The PDT response was characterized using the Sulforhodamine B cytotoxicity assay. Flow cytometry was used for both DNA cell cycle and dual Annexin V-FITC/propidium iodide analysis. Phototoxicity of the derivatives was of the same order of magnitude as for tetrasulphonated phthalocyanine but with an overall trend of increased phototoxicity with increasing amino acid chain length. Our results demonstrate cell death, inhibition of cell growth, and G(0)/G(1) cell cycle arrest during the phthalocyanine PDT-mediated response.

Effects of water-borne 4-nonylphenol and 17beta-estradiol exposures during parr-smolt transformation on growth and plasma IGF-I of Atlantic salmon (Salmo salar L.).

4-Nonylphenol (4-NP) is an endocrine disrupting substance (EDS) capable of mimicking the action of 17beta-estradiol (E2). It has been hypothesized that 4-NP in a pesticide formulation is linked to historical declines in Canadian Atlantic salmon (Salmo salar L.) populations, with effects being related to exposure during parr-smolt transformation (PST). To test this hypothesis, Atlantic salmon smolts were exposed to pulse-doses of water-borne 4-NP (20 ug/l), sustained doses of water-borne E2 (100 ng/l) (positive control), or ethanol vehicle (negative control) in mid-May during the final stages of PST. Individually tagged smolts were then sampled at three times (June, July and October) to monitor subsequent growth in sea water and plasma insulin-like growth factor I (IGF-I) concentrations. Smolt weights and plasma IGF-I concentrations were both affected by E2 and 4-NP. The effects of E2 and 4-NP on mean smolt weights were most prominent in July and October [E2 (*98.1 +/- 2.8, *242.3 +/- 10.6 g), 4-NP (*102.1 +/- 3.1, 255.7 +/- 9.5 g), controls (112.5 +/- 2.8, 282.3 +/- 8.8 g)] (P < 0.05), while their effects on mean plasma IGF-I concentrations were most prominent in June and October [E2 (15.0 +/- 1.9, 28.4 +/- 1.8 ng/ml), 4-NP (*14.8 +/- 1.9, *21.6 +/- 1.7 ng/ml), controls (20.0 +/- 1.1, 31.1 +/- 2.0 ng/ml)] (P < 0.05). Additionally, results suggest that the mechanisms of action of E2 and 4-NP involve disruption in the GH/IGF-I axis, and that they may be different from each other. The effects of E2 and 4-NP on growth and plasma IGF-I concentrations observed in this study are ecologically significant because they evoke concerns for successful growth and survival of wild salmon smolts exposed to low levels of estrogenic substances that may occur from current discharges into rivers supporting sea-run salmon stocks.

Comparison of high- vs low-dose 5-aminolevulinic acid for photodynamic therapy of Barrett's esophagus.

BACKGROUND: Barrett's esophagus is the major risk factor for esophageal adenocarcinoma, the incidence of which is increasing rapidly in the Western world. Aminolevulinic acid for photodynamic therapy (ALA-PDT) is effective in the treatment of Barrett's esophagus, but controversy exists regarding optimum ALA dosage. The aim of this study was to establish the optimum dosage regime for ALA-PDT for Barrett's esophagus. METHODS: Twenty-five patients with Barrett's esophagus were randomized to receive 30 (low-dose) or 60 (high-dose) mg/kg oral ALA at 4 or 6 h or 30 mg/kg in two fractions 4 and 6 h before PDT. PDT was standardized using red (635 nm) light. Biopsy specimens were taken for protoporphyrin IX (PpIX) quantification. Endoscopy was repeated 4 weeks later. RESULTS: All patients showed a macroscopic response, with squamous re-epithelialization. This response was greatest in the 30 mg/kg and fractionated ALA groups. There was no significant difference in response between dosing 4 or 6 h prior to PDT. Tissue levels of PpIX were similar for all dosage groups and were not predictive of clinical response. Side effects were more common with the higher dose of ALA. CONCLUSION: Low-dose ALA-PDT appears to be a safe protocol for the ablation of Barrett's esophagus.

The role of light in the treatment of non-melanoma skin cancer using methyl aminolevulinate.

Photodynamic therapy (PDT) is a developing approach to the treatment of cancer and other diseases that involves the use of light to activate photosensitizer molecules. The light energy absorbed by the photosensitizer is transferred to molecular oxygen, which is converted into the highly reactive and cytotoxic species, singlet oxygen. Topical agents such as aminolevulinic acid (ALA) or methyl aminolaevulinate (MAL) may be used for PDT of non-melanoma skin cancers (NMSC) because, in vivo, these agents stimulate the production of porphyrins which act as powerful photosensitisers. This brief review focuses on the use of light to activate MAL, which is now an approved drug (Metvix for certain NMSCs in the European Union. Porphyrins produced by the action of MAL can be activated using red light, which is also capable of deeply penetrating the skin. A number of light sources are available for treatment of NMSC using MAL, including very convenient non-laser sources such as non-coherent filtered lamps and, more recently, sources containing arrays of light-emitting diodes (LEDs). The Aktilite lamp, specifically designed for use with Metvix cream, has an emission spectrum that closely matches the red light absorption profile of PpIX.

Photodynamic therapy effect of m-THPC (Foscan) in vivo: correlation with pharmacokinetics.

m-Tetra(hydroxyphenyl)chlorin (m-THPC, Foscan, Temoporfin) has an unusually high photodynamic efficacy which cannot be explained by its photochemical properties alone. In vivo interactions are therefore of critical importance in determining this high potency. The pharmacokinetics of m-THPC in a rat tumour model was determined using (14)C m-THPC in an LSBD(1) fibrosarcoma implanted into BDIX rats. The photodynamic therapy (PDT) efficacy was determined at different drug administrations to light intervals and correlated with the tumour and plasma pharmacokinetic data. The plasma pharmacokinetics of m-THPC can be interpreted by compartmental analysis as having three half-lives of 0.46, 6.91 and 82.5 h, with a small initial volume of distribution, suggesting retention in the vascular compartment. Tissues of the reticuloendothelial system showed high accumulation of m-THPC, particularly the liver. PDT efficacy of m-THPC over the same time course seemed to exhibit two peaks of activity (2 and 24 h), in terms of tumour growth delay with the peak at 24 h postinjection correlating to the maximum tumour concentration. Investigation on tumour cells isolated from m-THPC-treated tumours suggested that the peak PDT activity at 2 h represents an effect on the vasculature while the peak at 24 h shows a more direct response. These results indicate that the in vivo PDT effect of m-THPC occurs via several mechanisms.

Porphyrin accumulation induced by 5-aminolaevulinic acid esters in tumour cells growing in vitro and in vivo.

The ability of 5-aminolaevulinic acid and some of its esterified derivatives to induce porphyrin accumulation has been examined in CaNT murine mammary carcinoma cells growing in culture and as tumours in vivo. Topical or intravenous administration of 5-aminolaevulinic acid-esters to mice bearing subcutaneous tumours produced lower porphyrin levels in the tumour than an equimolar dose of 5-aminolaevulinic acid. Reducing the dose of intravenous hexyl- or benzyl-ALA and topical hexyl-5-aminolaevulinic acid resulted in a dose-dependent reduction in porphyrin accumulation. A number of normal tissues accumulated higher concentrations of porphyrins than tumour tissue following intravenous administration of 5-aminolaevulinic acid-esters. Esterase activity in these normal tissues was greater than that in tumour tissue. In contrast to the situation in vivo, all of the 5-aminolaevulinic acid-esters examined were at least as effective as 5-aminolaevulinic acid when applied to cloned CaNT cells in vitro, with the drug concentration required for maximum porphyrin accumulation varying with ester chain-length. Tumour cells growing in culture released esterase activity into the medium. These findings suggest that the efficacy of 5-aminolaevulinic esters may vary depending on the esterase activity of the target tissue, and suggest caution when interpreting the findings of in vitro studies using these and similar prodrugs.

The advantages of aminolevulinic acid photodynamic therapy in dermatology.

Photodynamic therapy (PDT) is being increasingly employed in the detection and treatment of malignant and non-malignant disease. This local technique uses a photosensitizing drug activated by light to generate cell death via the production of reactive oxygen species. This review describes the fundamental processes behind PDT, focussing on the use of 5-aminolevulinic acid (ALA). ALA itself is not a photosensitizing drug, but administration of exogenous ALA induces the build-up of the natural endogenous photosensitizer protoporphyrin IX (PpIX). This form of PDT has proved promising for the treatment of a number of dermatological indications. An overview of these current and potential applications of ALA-based PDT is presented, with emphasis on the advantages of the technique that make it especially suitable for skin conditions and the problem areas on which future research should be focussed.

Guidelines for topical photodynamic therapy: report of a workshop of the British Photodermatology Group.

Topical photodynamic therapy (PDT) is effective in the treatment of certain non-melanoma skin cancers and is under evaluation in other dermatoses. Its development has been enhanced by a low rate of adverse events and good cosmesis. 5-Aminolaevulinic acid (ALA) is the main agent used, converted within cells into the photosensitizer protoporphyrin IX, with surface illumination then triggering the photodynamic reaction. Despite the relative simplicity of the technique, accurate dosimetry in PDT is complicated by multiple variables in drug formulation, delivery and duration of application, in addition to light-specific parameters. Several non-coherent and coherent light sources are effective in PDT. Optimal disease-specific irradiance, wavelength and total dose characteristics have yet to be established, and are compounded by difficulties comparing light sources. The carcinogenic risk of ALA-PDT appears to be low. Current evidence indicates topical PDT to be effective in actinic keratoses on the face and scalp, Bowen's disease and superficial basal cell carcinomas (BCCs). PDT may prove advantageous where size, site or number of lesions limits the efficacy and/or acceptability of conventional therapies. Topical ALA-PDT alone is a relatively poor option for both nodular BCCs and squamous cell carcinomas. Experience of the modality in other skin diseases remains limited; areas where there is potential benefit include viral warts, acne, psoriasis and cutaneous T-cell lymphoma. A recent British Photodermatology Group workshop considered published evidence on topical PDT in order to establish guidelines to promote the efficacy and safety of this increasingly practised treatment modality.

Field-deployable sniffer for 2,4-dinitrotoluene detection.

A field-deployable instrument has been developed to detect low-level 2,4-dinitrotoluene (2,4-DNT) vapors. The system is based on previously developed artificial nose technology and employs an array of sensory materials attached to the distal tips of an optical fiber bundle. Both semiselective and nonspecific, cross-reactive sensors were employed. Each sensor within the array responds differentially to vapor exposure so the array's fluorescence response patterns are unique for each analyte. The instrument is computationally "trained" to discriminate target response patterns from nontarget and background environments. This detection system has been applied to detect 2,4-DNT, an analyte commonly detected on the soil surface above buried 2,4,6-trinitrotoluene (TNT) land mines, in spiked soil and aqueous and ground samples. The system has been characterized and demonstrated the ability to detect 120 ppb 2,4-DNT vapor in blind (unknown) humidified samples during a supervised field test.

5-Aminolaevulinic acid methyl ester transport on amino acid carriers in a human colon adenocarcinoma cell line.

The transport mechanisms of 5-aminolevulinic acid methyl ester (5-ALA-ME) have been studied in a human adenocarcinoma cell line (WiDr) by means of 14[C]-labeled 5-ALA-ME. The transport was found to be partly Na+ dependent, while the extracellular Cl- concentration did not affect the uptake. The transport of 5-ALA-ME into WiDr cells was dependent on the incubation temperature and was found to be completely blocked by the inhibitors of energy metabolism, 2-deoxyglucose and sodium azide. WiDr cells were treated with 10 mM of 14 different amino acids and the substrate specificity of the 5-ALA-ME transporter(s) was analyzed by treating the cells with 23 microM or 1 mM 14[C]-labeled 5-ALA-ME. The transport of 5-ALA-ME was found to be inhibited to the highest extent, i.e. about 60%, by the nonpolar amino acids L-alanine, L-methionine, L-tryptophan and glycine. The uptake of 5-ALA-ME followed an exponential decay with increasing concentration of glycine, reaching a maximum inhibition of uptake of 5-ALA-ME of 55%. Sarcosine, a specific inhibitor of system Gly, did not significantly inhibit 5-ALA-ME transport. In contrast to transport of 5-ALA, 5-ALA-ME does not seem to be taken up by system BETA transporters. In conclusion, the cellular uptake of 5-ALA-ME into WiDr cells seems to be due to active transport mechanisms, involving transporters of nonpolar amino acids.

Investigation of cross-resistance to a range of photosensitizers, hyperthermia and UV light in two radiation-induced fibrosarcoma cell strains resistant to photodynamic therapy in vitro.

Two distinct photodynamic therapy-resistant variants of the murine radiation-induced fibrosarcoma (RIF) cell line have been isolated. One strain displayed relative resistance over the parental RIF-1 strain to treatment with the porphyrin-based compound, polyhaematoporphyrin (PHP), whereas the other strain displayed relative resistance over the RIF-1 strain to treatment using the cationic zinc (II) pyridinium-substituted phthalocyanine (PPC). The PHP-resistant strain did not display cross-resistance to PPC-mediated treatment, and vice versa. In both PDT-resistant strains, the increased resistance could not be attributed to altered cellular growth rate, antioxidant capacity or intracellular sensitizer localization. The PHP-resistant strain displayed resistance to treatment with both short (1 h) and extended (16 h) sensitizer incubation periods, which may indicate that in this strain, the resistance has arisen through an alteration in a membrane component. Conversely, the PPC-resistant strain only displayed increased resistance over the parental cells to treatment involving the short drug incubation, which is likely to reflect the existence of a threshold effect caused by the alteration of an individual cellular target. Each resistant strain has been compared to the parental strain in terms of cellular sensitivity to treatment with a range of other photosensitizers, hyperthermia, UV light and the anticancer agent cis-diamminedichloroplatinum. The PHP-resistant strain exhibited crossresistance to photosensitization treatment using exogenously added protoporphyrin IX, and also to treatment with the anionic phthalocyanine sensitizers, zinc (II) tetrasulfonated phthalocyanine and zinc (II) tetraglycine-substituted phthalocyanine. The PPC-resistant strain did not display cross-resistance to any of the treatment strategies employed in this investigation. The results of this investigation indicate that there are at least two distinct mechanisms of PDT resistance in RIF cells, and that the mechanism of PHP resistance may, to some extent depend, upon the physical nature of the sensitizer molecule.

Decreased efficiency of trypsinization of cells following photodynamic therapy: evaluation of a role for tissue transglutaminase.

Identifying the cellular responses to photodynamic therapy (PDT) is important if the mechanisms of cellular damage are to be fully understood. The relationship between sensitizer, fluence rate and the removal of cells by trypsinization was studied using the RIF-1 cell line. Following treatment of RIF-1 cells with pyridinium zinc (II) phthalocyanine (PPC), or polyhaematoporphyrin at 10 mW cm-2 (3 J cm-2), there was a significant number of cells that were not removed by trypsin incubation compared to controls. Decreasing the fluence rate from 10 to 2.5 mW cm-2 resulted in a two-fold increase in the number of cells attached to the substratum when PPC used as sensitizer; however, with 5,10,15,20 meso-tetra(hydroxyphenyl) chlorine (m-THPC) there was no resistance to trypsinization following treatment at either fluence rate. The results indicate that resistance of cells to trypsinization following PDT is likely to be both sensitizer and fluence rate dependent. Increased activity of the enzyme tissue-transglutaminase (tTGase) was observed following PPC-PDT, but not following m-THPC-PDT. Similar results were obtained using HT29 human colonic carcinoma and ECV304 human umbilical vein endothelial cell lines. Hamster fibrosarcoma cell (Met B) clones transfected with human tTGase also exhibited resistance to trypsinization following PPC-mediated photosensitization; however, a similar degree of resistance was observed in PDT-treated control Met B cells suggesting that tTGase activity alone was not involved in this process.

Routine double treatments of superficial basal cell carcinomas using aminolaevulinic acid-based photodynamic therapy.

BACKGROUND: Superficial basal cell carcinomas of the skin (sBCC) often respond poorly to single-treatment aminolaevulinic acid-based photodynamic therapy (ALA-PDT), with a number of reports indicating a relapse rate of 50% or more. OBJECTIVES: To determine whether a second treatment at seven days can improve the response. METHODS: Twenty-six lesions were treated twice with ALA-PDT, with an interval of 7 days between the two treatment sessions. RESULTS: We observed a complete response rate of 100% 1 month after treatment. Only one lesion relapsed (16 months post-PDT), a relapse rate of 4% (median follow up 27 months; range 15-45 months). Cosmetic results were excellent. CONCLUSIONS: We consider routine double treatments with ALA-PDT to be an effective approach to the management of sBCC, particularly those located in anatomically difficult, or cosmetically sensitive, sites.

Overexpression of cyclin D1 occurs frequently in human pancreatic endocrine tumors.

The molecular pathogenesis of human pancreatic endocrine tumors (PETs) is poorly understood. Three independent animal models have pointed to the pivotal role of the G1/S cell cycle transition in pancreatic endocrine cell proliferation. We thus hypothesized that the cell cycle regulator cyclin D1 may contribute to the pathogenesis of human PETs. Overexpression of cyclin D1 was identified in 43% of cases, and no correlation was observed with clinical phenotype. The novel observation of frequent overexpression of cyclin D1 suggests that this established oncogene may be implicated in the pathogenesis of human PETs. The absence of detectable alterations in cyclin D1 genomic structure suggests that the mechanism for its oncogenic activation in PETs may be transcriptional or posttranscriptional.

Effect of photodynamic therapy on recurrent pituitary adenomas: clinical phase I/II trial--an early report.

Pituitary adenomas, although histologically benign, are not always curable by surgery alone, principally because of dural infiltration, as well as their peculiar anatomical location. Radiotherapy has been employed as an adjuvant therapy to address residual disease with favourable results. This approach is, however, not without side effects, and it cannot be repeated. We are therefore investigating the effectiveness of photodynamic therapy (PDT) on recurrent pituitary adenomas in humans. This study details the protocol applied to 12 patients with recurrent pituitary adenomas, which involved systemic administration of photosensitizer (Photofrin) followed, after a period of 24-48 h, by intraoperative illumination of the tumour bed using 630 nm laser light. The primary end points were visual, endocrine and radiological improvement. The incidence of side effects was also monitored. The longest follow-up is 2 years. Most patients suffering from visual acuity or field defects have shown improvement when followed for 12 months or more. Three patients showed complete recovery of their visual fields. All those who presented with functional adenomas have shown reduction in their hormone levels. Tumour volume, relative to the preoperative size, was 122, 87, 66, 60 and 46% at 4 days, and 3, 6, 18 and 24 months, respectively. One patient developed severe skin photosensitization due to early exposure to direct sunlight and three others displayed minor skin reactions. There was no treatment-related mortality or morbidity. One patient (operated transcranially) developed hemiparesis postoperatively, which recovered completely. We think this is unrelated to the treatment. This prospective study demonstrates that PDT may be safely applied to the pituitary fossa by the trans-sphenoidal route and indicates the need for a randomized, controlled trial in order to establish its therapeutic potential.

Vitamin D receptor as a candidate tumor-suppressor gene in severe hyperparathyroidism of uremia.

Most chronic renal failure patients with severe refractory hyperparathyroidism harbor at least one monoclonal parathyroid tumor, but the specific acquired genetic defects that confer this clonal selective advantage remain poorly understood. Somatic inactivation of the vitamin D receptor (VDR) gene could contribute to clonal outgrowth, because a parathyroid cell containing this lesion would have an impaired response to the antiproliferative influence of 1,25-dihydroxyvitamin D3. Furthermore, diminished expression of VDR protein has been described in uremia-associated parathyroid tumors. Therefore, to assess VDR gene inactivation's potential pathogenetic role in this disease, we rigorously analyzed the VDR gene in 59 parathyroid tumors surgically resected from uremic patients. First, Southern blotting and/or PCR analyses of 29 tumor samples from 14 genetically informative patients revealed no allelic losses at the VDR locus. Next, direct DNA sequencing of all VDR splice junctions, associated intronic sequences, and virtually the entire VDR-coding region for all 59 tumors revealed no acquired mutations. Last, 37 tumor DNA samples were subjected to comparative genomic hybridization, and no chromosomal losses in the VDR region (12cen-q12) were observed. These observations suggest that inactivating defects within the VDR gene do not commonly contribute to the primary pathogenesis of severe refractory hyperparathyroidism in uremia.

Constitutive death of platelets leading to scavenger receptor-mediated phagocytosis. A caspase-independent cell clearance program.

Apoptosis is a physiological program for the deletion of cells in which caspases govern events leading to safe clearance by phagocytes. However, a growing weight of evidence now suggests that not all forms of programmed cell death are caspase-dependent. We now report a complete and constitutive but caspase-independent program for the specific phagocytic clearance of intact effete platelets, anucleated blood cells of critical importance in health and disease. Platelets aged in vitro not only exhibited increased expression of proapoptotic Bak and Bax but also evidenced constitutive diminution of function such as decreased aggregation to ADP, which was accelerated by culture in the absence of plasma. This abrogation of cell function in plasma-deprived platelets was associated with morphological and biochemical features similar to those of granulocyte apoptosis, that is, cytoplasmic condensation, plasma membrane changes including exposure of phosphatidylserine and the granule protein P-selectin, and recognition by phagocyte scavenger receptors. However, and in contrast with constitutive death of other inflammatory blood cells by apoptosis, these events were not affected by caspase inhibitors, nor was there evidence of caspase-3 activation either by hydrolysis of analog peptide substrates or Western blot analysis, serving to emphasize that neither programmed cell death nor clearance by phagocytes need involve caspases.