Bioluminescence-Activated Photodynamic Therapy for Luciferase Transfected, Grade 4 Astrocytoma cells in vitro

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. Hence the search for endogenous sources such as bioluminescence that can generate light at cancer cells. This requires a substrate (a luciferin) and an enabling enzyme (a luciferase), neither seen in mammalian cells. METHODS: Preliminary studies confirmed that U87 cells (derived from a human grade 4 astrocytoma) could be killed by conventional PDT using the photosensitisers hypericin or mTHPC. U87 cells were then transfected with firefly and other luciferases and light generating cell lines (U87-luc, U87-hRluc, U87-CBG68luc) identified using the appropriate substrate. Reagent doses and conditions were optimized and U87-luc cells incubated with hypericin or mTHPC with d-luciferin added to initiate bioluminescence activated PDT (bPDT). Cell survival was assessed by MTT assay, haemocytometry and growth assay. Control groups included U87-luc cells with no added active reagents, substrate only, photosensitiser only and non-transfected U87 cells. Results were expressed as a percentage of surviving cells compared with untreated U87-luc controls. RESULTS: There was no bPDT effect on non-transfected cells. The mean survival of treated transfected cells was 36%, (P<0.001) using hypericin and 35% (P<0.001) using mTHPC, compared with untreated U87-luc cells. bPDT effects were suppressed by the anti-oxidant, lycopene. CONCLUSIONS: bPDT can kill Grade 4 astrocytoma cells transfected with luciferase in vitro. This justifies progression to in vivo studies

Severe Pelvic Endometriosis Involving the Rectum with Near Complete Bowel Obstruction: A Case Report

Endometriosis is a common gynecological disease among reproductive-age women that can result in chronic pain, severely decreased quality of life, and infertility. We present a case of a 44-year-old female with a known history of endometriosis who presented with constipation, decreased appetite, iron deficiency anemia, and unintentional weight loss for 6 months. Investigation with colonoscopy discovered a partially-obstructing mass in her proximal rectum and no evidence of malignancy on biopsy. The mass was subsequently removed during a combined robotic-assisted total hysterectomy with bilateral salpingo-ophorectomy and low anterior resection with reanastomosis. Surgical pathology determined that the mass was consistent with endometriosis and no malignancy was identified. This case calls attention to a unique manifestation of endometriosis and highlights the importance of maintaining a broad differential diagnosis while utilizing a multidisciplinary team in the management of a rectal mass in reproductive-age women

Survival following Treatment of Aortoesophageal Fistula with Dual Esophageal and Aortic Intervention

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. Emergency gastroscopy revealed an arterial bleeding point in the proximal esophagus. A self-expanding metal esophageal stent was placed to achieve initial partial haemostasis. CT angiography confirmed an aortoesophageal fistula. An endoluminal stent device was thus inserted within the thoracic aorta stabilising the bleeding point. The patient subsequently made an uneventful recovery and was discharged on long-term antibiotics for palliative care. He survived for 2 months at home before dying of disseminated malignancy. The successful use of esophageal stenting as a means of achieving haemostasis, allowing time for endovascular intervention, is as yet a relatively unexplored area of management of this rare condition

Safety Study of Photodynamic Therapy Using Talaporfin Sodium in the Pancreas and Surrounding Tissues in the Syrian Golden Hamster

Aim. To assess the safety of photodynamic therapy (PDT) using talaporfin sodium on the pancreas and surrounding organs in normal hamsters. Methods. Fluorescence microscopy documented talaporfin levels in liver, duodenum, and pancreas up to 24 hours after photosensitisation. Lesion size in liver 3 days after PDT (50 J, 5 mg/kg, variable drug-light interval (DLI)) was documented to optimise the DLI. Using optimum DLI, pancreas and surrounding organs were treated with laser fibre touching the surface and animals were killed at 3 or 21 days. Results. Peak fluorescence was seen in duodenum and pancreas at 15 mins (second lower peak at 2 hours). Liver fluorescence was consistently high (peak 1 hour) until after 4 hours. Optimum DLI was seen at 15 minutes. The pancreas was relatively resistant to direct PDT injury (small lesions at high doses) but surrounding stomach, duodenum, and liver were more susceptible with evidence of adhesions and full thickness damage (localised peritonitis and duodenal perforation at highest doses). Conclusion. The safety profile is similar to PDT with longer acting photosensitisers. The pancreas appears safe to treat, but care is required to avoid high light doses to the intestinal tract, particularly the duodenum

A Partially Supervised Bayesian Image Classification Model with Applications in Diagnosis of Sentinel Lymph Node Metastases in Breast Cancer

A method has been developed for the analysis of images of sentinel lymph nodes generated by a spectral scanning device. The aim is to classify the nodes, excised during surgery for breast cancer, as normal or metastatic. The data from one node constitute spectra at 86 wavelengths for each pixel of a 20*20 grid. For the analysis, the spectra are reduced to scores on two factors, one derived externally from a linear discriminant analysis using spectra taken manually from known normal and metastatic tissue, and one derived from the node under investigation to capture variability orthogonal to the external factor. Then a three-group mixture model (normal, metastatic, non-nodal background) using multivariate t distributions is fitted to the scores, with external data being used to specify informative prior distributions for the parameters of the three distributions. A Markov random field prior imposes smoothness on the image generated by the model. Finally, the node is classified as metastatic if any one pixel in this smoothed image is classified as metastatic. The model parameters were tuned on a training set of nodes, and then the tuned model was tested on a separate validation set of nodes, achieving satisfactory sensitivity and specificity. The aim in developing the analysis was to allow flexibility in the way each node is modelled whilst still using external information. The Bayesian framework employed is ideal for this.Comment: 31 pages, 7 figure

Resource competition drives an invasion-replacement event among shrew species on an island

Invasive mammals are responsible for the majority of native species extinctions on islands. While most of these extinction events will be due to novel interactions between species (e.g. exotic predators and naive prey), it is more unusual to find incidences where a newly invasive species causes the decline/extinction of a native species on an island when they normally coexist elsewhere in their overlapping mainland ranges. We investigated if resource competition between two insectivorous small mammals was playing a significant role in the rapid replacement of the native pygmy shrew Sorex minutus in the presence of the recently invading greater white-toothed shrew Crocidura russula on the island of Ireland. We used DNA metabarcoding of gut contents from >300 individuals of both species to determine each species' diet and measured the body size (weight and length) during different stages of the invasion in Ireland (before, during and after the species come into contact with one another) and on a French island where both species have long coexisted (acting as a natural ‘control’ site). Dietary composition, niche width and overlap and body size were compared in these different stages. The body size of the invasive C. russula and composition of its diet changes between when it first invades an area and after it becomes established. During the initial stages of the invasion, individual shrews are larger and consume larger sized invertebrate prey species. During later stages of the invasion, C. russula switches to consuming smaller prey taxa that are more essential for the native species. As a result, the level of interspecific dietary overlap increases from between 11% and 14% when they first come into contact with each other to between 39% and 46% after the invasion. Here we show that an invasive species can quickly alter its dietary niche in a new environment, ultimately causing the replacement of a native species. In addition, the invasive shrew could also be potentially exhausting local resources of larger invertebrate species. These subsequent changes in terrestrial invertebrate communities could have severe impacts further downstream on ecosystem functioning and services

Diagnosis of breast cancer using elastic-scattering spectroscopy: preliminary clinical results

We report on the first stages of a clinical study designed to test elastic-scattering spectroscopy, mediated by fiberoptic probes, for three specific clinical applications in breast-tissue diagnosis: (1) a transdermal-needle (interstitial) measurement for instant diagnosis with minimal invasiveness similar to fine-needle aspiration but with sensitivity to a larger tissue volume, (2) a hand-held diagnostic probe for use in assessing tumor/resection margins during open surgery, and (3) use of the same probe for real-time assessment of the `sentinel' node during surgery to determine the presence or absence of tumor (metastatic). Preliminary results from in vivo measurements on 31 women are encouraging. Optical spectra were measured on 72 histology sites in breast tissue, and 54 histology sites in sentinel nodes. Two different artificial intelligence methods of spectral classification were studied. Artificial neural networks yielded sensitivities of 69% and 58%, and specificities of 85% and 93%, for breast tissue and sentinel nodes, respectively. Hierarchical cluster analysis yielded sensitivities of 67% and 91%, and specificities of 79% and 77%, for breast tissue and sentinel nodes, respectively. These values are expected to improve as the data sets continue to grow and more sophisticated data preprocessing is employed. The study will enroll up to 400 patients over the next two years

Clinical assessment of a low-cost, hand-held, smartphone-attached intraoral imaging probe for 5-aminolevulinic acid photodynamic therapy monitoring and guidance

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. AIM: Our study aimed to use a hand-held smartphone-coupled intraoral imaging device, previously investigated for autofluorescence (auto-FL) diagnostics adapted here for treatment guidance and monitoring photodynamic therapy (PDT) using 5-aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) fluorescence (FL). APPROACH: A total of 12 patients with 14 buccal mucosal lesions having moderately/well-differentiated micro-invasive OSCC lesions (1.65 at the time of treatment were associated with successful outcomes. CONCLUSION: These results indicate the utility of a low-cost, handheld intraoral imaging probe for image-guided PDT and treatment monitoring while also laying the groundwork for an integrated approach, combining cancer screening and treatment with the same hardware