Publications by authors named "Bown S"

Background: Grade 4 astrocytomas are usually incurable due to their diffusely infiltrative nature. Photodynamic therapy (PDT) is a promising therapeutic option, but external light delivery is impractical when cancer cells infiltrate unknown areas of normal brain. Hence the search for endogenous sources to generate light at cancer cells.

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Significance: India has one of the highest rates of oral squamous cell carcinoma (OSCC) in the world, with an incidence of 15 per 100,000 and more than 70,000 deaths per year. The problem is exacerbated by a lack of medical infrastructure and routine screening, especially in rural areas. New technologies for oral cancer detection and timely treatment at the point of care are urgently needed.

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Background: . Grade 4 astrocytoma is incurable due to the diffusely infiltrative nature of the disease. Photodynamic therapy (PDT) is a promising therapeutic option, but external light delivery is not feasible when cancer cells infiltrate unknown areas of normal brain.

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Background: Morbidity and mortality due to oral cancer in India are exacerbated by a lack of access to effective treatments amongst medically underserved populations. We developed a user-friendly low-cost, portable fibre-coupled LED system for photodynamic therapy (PDT) of early oral lesions, using a smartphone fluorescence imaging device for treatment guidance, and 3D printed fibreoptic attachments for ergonomic intraoral light delivery.

Methods: 30 patients with TNM buccal mucosal cancer were recruited from the JN Medical College clinics, Aligarh, and rural screening camps.

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Significance: India has one of the highest rates of oral cancer incidence in the world, accounting for 30% of reported cancers. In rural areas, a lack of adequate medical infrastructure contributes to unchecked disease progression and dismal mortality rates. Photodynamic therapy (PDT) has emerged as an effective modality with potential for treating early stage disease in resource-limited settings, while photosensitizer fluorescence can be leveraged for treatment guidance.

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Photodynamic therapy (PDT) is a technique for producing localized necrosis with light after prior administration of a photosensitizing agent. This study investigates the nature, safety, and efficacy of PDT for image-guided treatment of primary breast cancer. We performed a phase I/IIa dose escalation study in 12 female patients with a new diagnosis of invasive ductal breast cancer and scheduled to undergo mastectomy as a first treatment.

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Sentinel lymph node biopsy is a standard diagnosis procedure to determine whether breast cancer has spread to the lymph glands in the armpit (the axillary nodes). The metastatic status of the sentinel node (the first node in the axillary chain that drains the affected breast) is the determining factor in surgery between conservative lumpectomy and more radical mastectomy including axillary node excision. The traditional assessment of the node requires sample preparation and pathologist interpretation.

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Photodynamic therapy (PDT) is already being used in the treatment of many cancers. This review examines its components and the new developments in our understanding of its immunological effects as well as pre-clinical and clinical studies, which have investigated its potential use in the treatment of breast cancer.

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Objective: Photodynamic therapy (PDT) and radiofrequency ablation (RFA) are effective non-surgical options for the treatment of Barrett's esophagus (BE) associated neoplasia. Development of subsquamous intestinal metaplasia after successful PDT and/or RFA is a recognized phenomenon; however, the occurrence of neoplasia arising from buried glands is a rare complication.

Methods: This is a prospective case series of patients treated with PDT and/or RFA from 1999 to 2014 at University College London Hospital for neoplasia associated with BE, whose outcomes were analyzed retrospectively.

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The goal of this study was to determine dominant factors affecting treatment response in pancreatic cancer photodynamic therapy (PDT), based on clinically available information in the VERTPAC-01 trial. This trial investigated the safety and efficacy of verteporfin PDT in 15 patients with locally advanced pancreatic adenocarcinoma. CT scans before and after contrast enhancement from the 15 patients in the VERTPAC-01 trial were used to determine venous-phase blood contrast enhancement and this was correlated with necrotic volume determined from post-treatment CT scans, along with estimation of optical absorption in the pancreas for use in light modeling of the PDT treatment.

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Background: Patients with pancreatic cancer have a poor prognosis apart from the few suitable for surgery. Photodynamic therapy (PDT) produces localised tissue necrosis but previous studies using the photosensitiser meso-tetrahydroxyphenylchlorin (mTHPC) caused prolonged skin photosensitivity. This study assessed a shorter acting photosensitiser, verteporfin.

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Background: Anal Intraepithelial Neoplasia (AIN), a pre-cursor of anal squamous carcinoma, is increasingly detected in individuals with impaired immune function. However, choices for effective, low morbidity treatment are limited. Photodynamic Therapy (PDT) is promising as it is known to ablate more proximal gastrointestinal mucosa with safe healing, without damage to underlying muscle.

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Photodynamic therapy for photochemists.

Philos Trans A Math Phys Eng Sci

July 2013

Photodynamic therapy (PDT) is an evolving technique for localized control of diseased tissue with light after prior administration of a photosensitizing agent and in the presence of oxygen. The biological effect is quite different from surgery, radiotherapy and chemotherapy. With no temperature change during treatment, connective tissues like collagen are largely unaffected, so maintaining the mechanical integrity of hollow organs.

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This study investigated the photophysical and photobiological properties of a new amphiphilic chlorin photosensitiser, disulfonated tetraphenylchlorin (TPCS(2a)), for photochemical internalisation (PCI). The absorption and fluorescence spectra of TPCS(2a) were examined in a range of solvents together with fluorescence lifetime measurements. The fluorescence lifetime of TPCS(2a) was found to be 8.

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Although photodynamic therapy (PDT) has been used successfully to treat an assortment of different types of cancer, it has yet to reach the level of mainstream medicine on either side of the Atlantic. Unsubstantiated claims of PDT's efficacy in the past may be part of the reason for this. However, perhaps the main obstacle to PDT's endorsement by conventional medicine is the limited number of high-quality randomized controlled trials (RCTs) comparing it with relevant comparators for all meaningful outcomes, including effectiveness, safety, adverse events, quality of life, survival, and cost.

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Photofrin photodynamic therapy (PDT) is a licenced treatment for Barrett's oesophagus (BE) with high-grade dysplasia (HGD) but causes strictures and photosensitivity and complete reversal of dysplasia (CR-HGD) by 50 % at 5 years. 5-Aminolaevulinic acid (ALA) is an alternative treatment with non-randomised data suggesting 85 % CR-HGD and a low risk of side effects. We aimed to compare efficacy and side effect profile between the drugs.

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Emerging evidence has documented comorbidity between posttraumatic stress disorder (PTSD) and obsessive-compulsive disorder (OCD) among individuals with a history of traumatic events. There is growing recognition of the importance of disgust in each of these conditions independently. No study, however, has examined the potential role of disgust in these conditions following traumatic event exposure.

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Since the first report of the use of photodynamic therapy (PDT) for prostate cancer in 1990 it has been investigated as a primary and a salvage treatment, using either whole gland or focal approaches. Since 1990 advances in the transperineal approach to the prostate, coupled with photosensitizers which have a short drug-light interval and minimal skin phototoxicity, have resulted in major advances in the field. This review will look at the work done to date, and the ongoing studies which help to define the place of PDT as a useful treatment modality for organ-confined prostate cancer.

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Pegylated liposomal nanocarriers have been developed with the aim of achieving improved uptake of the clinical PDT photosensitiser, m-THPC, into target tissues through increased circulation time and bioavailability. This study investigates the biodistribution and PDT efficacy of m-THPC in its standard formulation (Foscan®) compared to m-THPC incorporated in liposomes with different degrees of pegylation (FosPEG 2% and FosPEG 8%), following i.v.

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Photochemical internalisation (PCI) is a site-specific technique for improving cellular delivery of macromolecular drugs. In this study, a cell penetrating peptide, containing the core HIV-1 Tat 48-57 sequence, conjugated with a porphyrin photosensitiser has been shown to be effective for PCI. Herein we report an investigation of the photophysical and photobiological properties of a water soluble bioconjugate of the cationic Tat peptide with a hydrophobic tetraphenylporphyrin derivative.

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Endoscopic radiofrequency ablation (RFA) is an effective treatment for high-grade dysplasia in Barrett's esophagus in ablation-naïve patients, but no studies have evaluated its use in patients in whom ablative therapy has previously failed. We describe 14 patients with residual high-grade dysplasia following aminolevulinic acid or Photofrin (porfimer sodium) photodynamic therapy (PDT). An overall complete reversal of dysplasia was achieved in 86 % with a combination of RFA and rescue endoscopic mucosal resection.

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Aortoesophageal fistulas are a rare but commonly fatal complication of esophageal cancer. Reports of successfully managed cases are few, with high mortality and morbidity usually resulting from failure to control the initial massive haemodynamic insult. We report the case of a 47-year-old Caucasian man with recently diagnosed advanced esophageal cancer who suffered an episode of massive haematemesis.

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