Laser-induced thermal stress and the heat shock response in neural cells

Background The Ho: YAG laser is used extensively in orthopedic surgery. It offers a minimally invasive method of ablating tissue with precision. Previous studies have explored the effects of laser use on temperature during experimental foraminoplasty. To date, there has been limited work on the effects of thermal stress on cells in this context. Material and methods Cells were exposed either to heated medium or the Ho: YAG laser in the high-power mode. Heated medium was used as a stressor by (I) exposing groups of cells to a constant temperature of 45°C for varying lengths of time: 5, 10, 15 and 20 min, and (II) exposing cells for a fixed length of time (5 min) to varying temperatures: 45°C, 55°C, 65°C with a control treated at 37°C. A third group was subjected to direct laser treatment. The effects of the treatments were assessed using trypan blue staining as a measure of viability and immunocytochemistry was used to measure changes in heat shock protein (HSP) expression. Results There was a negative correlation between cell viability and HSP expression, and between cell viability and the severity of the treatment. Interpretation Our findings suggest a possible role for the Ho: YAG laser in spinal foraminoplasty based on the high level of cell viability in the treatment regimen that most closely mirrored the clinical application of the laser

Collagen-induced arthritis in C57BL/6 mice is associated with a robust and sustained T-cell response to type II collagen

Many genetically modified mouse strains are now available on a C57BL/6 (H-2b) background, a strain that is relatively resistant to collagen-induced arthritis. To facilitate the molecular understanding of autoimmune arthritis, we characterised the induction of arthritis in C57BL/6 mice and then validated the disease as a relevant pre-clinical model for rheumatoid arthritis

Ethical and technical considerations for the creation of cell lines in the head & neck and tissue harvesting for research and drug development (Part I): Techniques of tissue harvesting and propagation

BACKGROUND: Although much has been published for the development of cell lines, these were lab based and developed for scientific technical staff. OBJECTIVE OF REVIEW: We present a simple and successful protocol for the development of cell lines and tissue harvesting for the clinical scientist. We also discuss the ethical implications of tissue retention and present a generic consent form. CONCLUSION: The advantages of hospital-based cell line creation are numerous. We can be more certain that cell lines are developed from the particular tissues of interest and accurate anatomical and appropriate clinico-pathological control tissues are also harvested. We can also be certain of less cell line cross contamination

Serial step sections at narrow intervals with immunohistochemistry are required for accurate histological assessment of sentinel lymph node biopsy in oral squamous cell carcinoma

Background: Sentinel lymph node (SLN) biopsy is an accurate staging modality in early oral squamous cell carcinoma (OSCC), but its accuracy relies on labor-intensive histopathology protocols. We sought to determine whether serial step sections with immunohistochemistry (SSSIHC) at narrow intervals of the entire SLN are required to accurately exclude metastasis. Methods: Consecutive SLN biopsies over a 13-year period were retrospectively evaluated. If the index section was negative for carcinoma, the entire SLN was subjected to SSSIHC at 150 μm intervals. The first section level and total number of section levels to contain carcinoma were recorded. Results: One hundred and eighteen SLN+ from 90 patients were included. SSSIHC upstaged the nodal status in 19.5% of patients. Metastasis was identified in 16.7% and 10.2% beyond section levels 4 and 6, respectively. Among SLNs requiring SSSIHC, 47.5% contained carcinoma in a single section level. Conclusion: SSSIHC of the entire SLN at 150 μm intervals are required to identify occult metastasis in OSCC

Rheumatoid nodule of the thyrohyoid membrane: a case report

BACKGROUND: Rheumatoid nodules are common extra-articular findings occurring in 20% of rheumatoid arthritis patients. They develop most commonly subcutaneously in pressure areas (elbows and finger joints) and may occasionally affect internal organs including pleura, lungs, meninges, larynx, and in other connective tissues elsewhere in the body CASE PRESENTATION: We present the case of a 62-year-old male who presented with a midline neck mass. Clinically it moved on swallowing and tongue protrusion-suggesting attachment to the thyrohyoid membrane. Ultrasound examination revealed a cystic lesion in the absence of cervical lymphadenopathy in a non-smoker. The neck was explored and histological examination of the excised lesion which was attached to the thyrohyoid membrane revealed a rheumatoid nodule. CONCLUSION: A rheumatoid nodule of the thyrohyoid membrane is very rare. The triple diagnostic scheme of clinical examination supplemented with ultrasound and guided fine needle aspiration for neck lumps remains valid in most cases. If excision is indicated we feel it should be performed in such a manner that the scar tract could easily be encompassed in a neck dissection excision should definitive histological examination be adverse. We suggest that when dealing with patients with established rheumatoid arthritis one should consider a rheumatoid nodule as a differential diagnosis for any swelling on the patient whether it be subcutaneous or deep

The stylomastoid artery as an anatomical landmark to the facial nerve during parotid surgery: a clinico-anatomic study

BACKGROUND: The identification of the facial nerve can be difficult in a bloody operative field or by an incision that limits exposure; hence anatomical landmarks and adequate operative exposure can aid such identification and preservation. In this clinico-anatomic study, we examined the stylomastoid artery (SMA) and its relation to the facial nerve trunk; the origin of the artery was identified on cadavers and its nature was confirmed histologically. METHODS: The clinical component of the study included prospective reviewing of 100 consecutive routine parotidectomies; while, the anatomical component of the study involved dissecting 50 cadaveric hemifaces. RESULTS: We could consistently identify a supplying vessel, stylomastoid artery, which tends to vary less in position than the facial nerve. Following this vessel, a few millimetres inferiorly and medially, we have gone on to identify the facial nerve trunk, which it supplies, with relative ease. The origin of the stylomastoid artery, in our study, was either from the occipital artery or the posterior auricular artery. CONCLUSION: This anatomical aid, the stylomastoid artery, when supplemented by the other more commonly known anatomical landmarks and intra-operative facial nerve monitoring further reduces the risk of iatrogenic facial nerve damage and operative time

MYC regulates fatty acid metabolism through a multigenic program in claudin-low triple negative breast cancer

Background: Recent studies have suggested that fatty acid oxidation (FAO) is a key metabolic pathway for the growth of triple negative breast cancers (TNBCs), particularly those that have high expression of MYC. However, the underlying mechanism by which MYC promotes FAO remains poorly understood. Methods: We used a combination of metabolomics, transcriptomics, bioinformatics, and microscopy to elucidate a potential mechanism by which MYC regulates FAO in TNBC. Results: We propose that MYC induces a multigenic program that involves changes in intracellular calcium signalling and fatty acid metabolism. We determined key roles for fatty acid transporters (CD36), lipases (LPL), and kinases (PDGFRB, CAMKK2, and AMPK) that each contribute to promoting FAO in human mammary epithelial cells that express oncogenic levels of MYC. Bioinformatic analysis further showed that this multigenic program is highly expressed and predicts poor survival in the claudin-low molecular subtype of TNBC, but not other subtypes of TNBCs, suggesting that efforts to target FAO in the clinic may best serve claudin-low TNBC patients. Conclusion: We identified critical pieces of the FAO machinery that have the potential to be targeted for improved treatment of patients with TNBC, especially the claudin-low molecular subtype

Head & neck optical diagnostics: vision of the future of surgery

Review paper and Proceedings of the Inaugural Meeting of the Head and Neck Optical Diagnostics Society (HNODS) on March 14th 2009 at University College London