Biomedical subjects

Ann Sandison

Publications and source records attributed to Ann Sandison.

9 recordsLinked to original sources

PubMed2006

Treatment of ligament laxity by electrothermal shrinkage or surgical plication: a morphologic and mechanical comparison.

Capsular plication or thermal shrinkage can be used to enhance surgical joint stabilization. We compared mechanical or morphologic properties of the medial collateral ligament of the rabbit knee treated by either bipolar radiofrequency electrothermal shrinkage or surgical plication. After 12 weeks, the medial collateral ligaments were procured from treated and contralateral knees to undergo viscoelastic (creep) testing, quantitative transmission electron microscopy, and immunohistochemistry. Creep strain in thermal (1.85% +/- 0.32%) and plicated (1.92% +/- 0.36%) ligaments was almost twice that of the control group (1.04% +/- 0.15%), although there was no difference between treatment modalities. The morphologic parameters of all 3 groups were significantly different (P < .001). The thermal ligaments demonstrated predominantly small fibrils, whereas the plicated group displayed an intermediate distribution of heterogeneous fibrils, suggesting a different pattern of remodeling. Viscoelastic properties are similar after thermal shrinkage or plication, though inferior to those of intact ligaments.

Animals↗

PubMed2006

Maxillary haemangioma.

Maxillary haemangioma is a rare entity. It presents with a painless, slow-growing swelling and if it involves the paranasal sinuses it may present with severe epistaxis, mimicking a malignancy. A case of haemangioma arising in the bony maxilla and causing a cosmetic problem is presented here.

Female↗

PubMed2006

Targeting rheumatoid tenosynovial angiogenesis with cytokine inhibitors.

UNLABELLED: Proliferation and invasion of the tenosynovial lining of tendons in patients with rheumatoid arthritis can result in tendon damage and rupture, leading to decreased hand function. Angiogenesis is an important process in rheumatoid joint disease; however, the role of angiogenesis in tendon disease is unknown. Our aim was to determine whether rheumatoid tenosynovial lining could produce angiogenic proteins, and if inhibition of tumor necrosis factor-alpha and interleukin-1 could decrease vascular endothelial growth factor production. Samples of encapsulating and invasive tenosynovial lining taken from the same hand and wrist synovial lining were harvested from 58 patients with rheumatoid arthritis having wrist surgery. Ex vivo samples were studied to quantify vascularity, angiogenic protein production under normoxic and hypoxic conditions, and the effect of inhibiting tumor necrosis factor-alpha and interleukin-1 on vascular endothelial growth factor production. Rheumatoid tenosynovial lining was more vascular than rheumatoid joint synovial lining and produced high levels of angiogenic factors such as vascular endothelial growth factor, interleukin-1beta, fibroblast growth factor-2, and angiopoietin-2. Hypoxia induced an increase in production of vascular endothelial growth factor by ex vivo tenosynovial lining cells. Inhibition of the cytokines interleukin-1 and tumor necrosis factor-alpha effectively reduced vascular endothelial growth factor production by tenosynovial samples. LEVEL OF EVIDENCE: Therapeutic study. Level II (Prospective comparative study). See the Guidelines for Authors for a complete description of levels of evidence.

Adult↗

PubMed2004

Time-domain fluorescence lifetime imaging applied to biological tissue.

Fluorescence lifetime imaging (FLIM) is a functional imaging methodology that can provide information, not only concerning the localisation of specific fluorophores, but also about the local fluorophore environment. It may be implemented in scanning confocal or multi-photon microscopes, or in wide-field microscopes and endoscopes. When applied to tissue autofluorescence, it reveals intrinsic excellent contrast between different types and states of tissue. This article aims to review our recent progress in developing time-domain FLIM technology for microscopy and endoscopy and applying it to biological tissue.

Animals↗

PubMed2004

Anaplastic lymphoma kinase (ALK 1) staining and molecular analysis in inflammatory myofibroblastic tumours of the bladder: a preliminary clinicopathological study of nine cases and review of the literature.

Inflammatory myofibroblastic tumours (IMFT) may arise at any anatomical site, including lung, soft tissues, retroperitoneum and bladder. Although morphologically similar, these lesions encompass a spectrum of entities with differing aetiology, ranging from reactive/regenerative proliferations to low-grade neoplasms with a risk of local recurrence, but no significant metastatic potential. Vesical IMFT usually presents as a polypoid mass with a pale firm cut surface and can be of considerable size, mimicking a malignant tumour clinically and radiologically. Its good outcome, however, warrants conservative surgical excision, emphasising the importance of identification and distinction from malignant tumours of the bladder that may require more radical surgery and/or adjuvant therapy. We conducted a preliminary retrospective, comparative immunocytochemical study of 20 bladder tumours, including nine IMFTs, five spindle cell (sarcomatoid) carcinomas, two rhabdomyosarcomas, two leiomyosarcomas and two neurofibromas. The results confirmed IMFT positivity for smooth muscle actin, desmin and cytokeratin in 78-89% cases, resulting in potential confusion with sarcomatoid carcinoma or leiomyosarcoma. In contrast, cytoplasmic anaplastic lymphoma kinase (ALK 1) staining was present in eight IMFT (89%), but was not seen in any other lesion examined. The ALK 1 staining was confirmed by fluorescence in situ hybridisation, with translocation of the ALK gene present in 15-60% tumour cells in four of six IMFT examined, but not in four cases of sarcomatoid carcinoma or three of leiomyosarcoma. In conclusion, ALK 1 staining may be of value in the distinction of vesical IMFT from morphologically similar entities, and often reflects ALK gene translocations in these lesions.

Actins↗

PubMed2004

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 degrees 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 degrees C, 55 degrees C, 65 degrees C with a control treated at 37 degrees 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.

Animals↗

PubMed2003

Studying biological tissue with fluorescence lifetime imaging: microscopy, endoscopy, and complex decay profiles.

We have applied fluorescence lifetime imaging (FLIM) to the autofluorescence of different kinds of biological tissue in vitro, including animal tissue sections and knee joints as well as human teeth, obtaining two-dimensional maps with functional contrast. We find that fluorescence decay profiles of biological tissue are well described by the stretched exponential function (StrEF), which can represent the complex nature of tissue. The StrEF yields a continuous distribution of fluorescence lifetimes, which can be extracted with an inverse Laplace transformation, and additional information is provided by the width of the distribution. Our experimental results from FLIM microscopy in combination with the StrEF analysis indicate that this technique is ready for clinical deployment, including portability that is through the use of a compact picosecond diode laser as the excitation source. The results obtained with our FLIM endoscope successfully demonstrated the viability of this modality, though they need further optimization. We expect a custom-designed endoscope with optimized illumination and detection efficiencies to provide significantly improved performance.

Animals↗

PubMed2002

Nerve fibers in lumbar spine structures and injured spinal roots express the sensory neuron-specific sodium channels SNS/PN3 and NaN/SNS2.

STUDY DESIGN: This prospective study examined the innervation of lumbar spine in tissues from patients with lower back pain and spine nerve roots from patients with traumatic brachial plexus injuries. OBJECTIVES: To demonstrate the presence of nerve fibers in lumbar spine structures and spine nerve roots, and to determine whether they express the sensory neuron-specific sodium channels SNS/PN3 and NaN/SNS2. SUMMARY OF BACKGROUND DATA: The anatomic and molecular basis of low back pain and sciatica is poorly understood. Previous studies have demonstrated sensory nerves in the facet joint capsule and prolapsed intervertebral disc, but not in the ligamentum flavum. The voltage-gated sodium channels SNS/PN3 and NaN/SNS2 are expressed by sensory neurone that mediate pain, but their presence in the lumbar spine is unknown. METHODS: Tissue samples of ligamentum flavum (n = 32), facet joint capsule (n = 20), intervertebral disc (n = 15), and spine roots (n = 8) were immunostained with specific antibodies to protein gene product 9.5 (a panneuronal marker), SNS/PN3, and NaN/SNS2. RESULTS: Protein gene product 9.5 immunoreactive nerve fibers were detected in 72% of the ligamentum flavum specimens and 70% of the facet joint capsule specimens, but in only 20% of the intervertebral disc specimens. The study detected SNS/PN3- and NaN/SNS2-positive fibers, respectively, in 28% and 3% of the ligamentum flavum specimens and 25% and 15% of the facet joint capsule specimens. Numerous SNS/PN3- and NaN/SNS2-positive fibers were found in the acutely injured spine roots, and some were still present in the dorsal roots in the chronic state. CONCLUSIONS: As the findings showed, SNS/PN3- and NaN/SNS2-immunoreactivity is present in a subset of nerve fibers in lumbar spine structures, including ligamentum flavum, and in injured spine roots. Selective SNS/PN3- and NaN/SNS2-blocking agents may provide new therapy for back pain and sciatica.

Adolescent↗

PubMedDate not supplied

Microchimerism in female bone marrow and bone decades after fetal mesenchymal stem-cell trafficking in pregnancy.

Fetal cells enter maternal blood during pregnancy and persist in women with autoimmune disease. The frequency of subsequent fetomaternal microchimerism in healthy women and its cell type is unknown. To test the hypothesis that fetal mesenchymal stem cells persist in maternal organs, we studied female bone marrow and ribs. Male cells were identified by XY fluorescence in-situ hybridisation in marrow-derived mesenchymal stem cells and in rib sections from all women with male pregnancies, but not in controls (9/9 vs 0/5, p=0.0005). We conclude that fetal stem cells transferred into maternal blood engraft in marrow, where they remain throughout life. This finding has implications for normal pregnancy, for obstetric complications that increase fetomaternal trafficking, and for graft survival after transplantation.

Aged↗