At least 50% of people will develop cancer at some point during their lifetime and half these will end in fatality. Improving patients’ prognosis relies on early and accurate diagnosis and treatment. Current diagnostic methods are based on histopathological analysis and are time-consuming, expensive and require biopsy. Raman spectroscopy can measure subtle biochemical changes and provides a rapid, non-destructive and objective technique that can be used in vivo for identifying pathological changes in tissue samples. This study investigates both a standard Raman spectrometer system and also a Raman needle probe for their use as diagnostic techniques and clinical tools. Oesophageal, femoral and head and neck lymph nodes were analysed in this study. Metastatic lymph nodes from the three areas could be identified from the non-cancer lymph nodes with a sensitivity of 71% and specificity of 89%. Lymphoma was identified from non-cancer lymph nodes with a sensitivity of 64% and specificity of 86%. It was observed that oesophageal nodes often contained carbon particles, clinically diagnosed as anthracosis. These nodes were much harder to study than the femoral or head and neck, due to strong Raman signal detected from the carbon particles. Lymph nodes are embedded in adipose tissue and as a consequence, very strong lipid peaks were frequently observed in spectra. Spectral differences were exhibited in the measurements of the lymph nodes from the three different anatomical regions. A comparison of the point measurements and mapped data showed no difference in classification. Therefore, indicating that just a few measurements can be sufficient enough sampling to represent a specimen, and demonstrates the practicability of Raman use in vivo for rapid analysis. The Raman needle probe feasibility study showed its potential for in vivo use for real-time diagnosis and as a surgical tool to support biopsy. A sensitivity and specificity of 80% and 79% for the identification of non-cancer head and neck lymph nodes from non-cancer provides similar accuracies to the standard Raman approach, therefore supports its viability for use as a diagnostic tool.

In addition to leukocytes, secondary lymphoid organs are populated by non-hematopoietic stromal cells. This diverse group of cells supports lymphocyte migration and homing, facilitates antigen delivery, and promotes T cell survival. However, there is relatively little known about the specific molecules governing the roles that these cells play in regulating dendritic cell (DC) motility and lymph node architecture. Here, we examine the interaction between two molecules, CLEC-2 and podoplanin (PDPN), that are critical for DC migration and maintaining structural integrity of lymph nodes. Together, these studies identify novel functions of lymph node stromal cells and a unique function for PDPN in the immune system. In response detecting an potentially harmful antigen, DCs in peripheral tissues mature and travel to downstream lymph nodes by following chemokine gradients secreted by lymphatic endothelial cells (LECs) and fibroblastic reticular cells (FRCs) present in the lymph node paracortex. We discovered that, in addition to chemokines, DC migration requires CLEC-2 on DCs, as engagement of CLEC-2 with PDPN, which is expressed by LECs and FRCs, incites DC motility and is required for DC entry into the lymphatics, efficient arrival in the lymph node, and migration along the FRC network within the lymph node. Next, we examined the effect of this interaction with respect to the stromal cell. Through a combination approaches, we discovered that PDPN is a master regulator of contractility in FRCs. The fact that FRCs are contractile cells was previously reported, but our study is the first to identify a function for this contractility: upon blockade of PDPN-mediated contractility, lymph nodes became enlarged, the FRC network became more sparse, and there were increased numbers of lymphocytes in the lymph node. Importantly, during an immune response, these changes resulted in more proliferation of antigen-specific T cells and impaired contraction of the lymph node upon resolution of inflammation. Finally, we found that CLEC-2 binding PDPN recapitulated the effect of PDPN deletion. Thus, during an immune response, CLEC-2+ DCs would use PDPN to efficiently migrate to the lymph node and simultaneously cause FRCs to relax and prepare the lymph node for expansion.

Lymph nodes (LNs) are dynamic organs responsible for providing a supportive and centralized environment for the generation of immune response. Utilizing a highly organized network of non-hematopoietic stromal cells, the LN serves as the context in which the immune system collects and presents antigen, promotes innate and adaptive immune interaction, and generates protective cell-mediated and humoral immunity. In this way, proper organization and function of the LN environment is a critical component of effective immunity, and understanding its complexity has direct impact on the ability to generate and modulate primary immune response to specific antigens. To this end, the LN architecture, underlying stromal networks, and environmental and cellular responses to influenza vaccination were investigated. Using novel approaches to conduit imaging, details of the collagen network that comprises the LN scaffolding have been integrated into current understandings of LN architecture. The cellular compartment responsible for the maintenance of that scaffolding, fibroblastic reticular cells (FRCs), have been studied using an induced diptheria toxin receptor model. By specifically ablating the FRC population in mice, their role in the maintenance of T cell homeostasis has been confirmed in vivo. More surprisingly, a disruption of the FRC network resulted in a loss of B cell follicle structure within LNs, and a reduction in humoral immunity to influenza vaccination. These findings led to the identification of a new subset of FRCs which reside in B cell follicles, and serve as a critical source of the B cell survival factor BAFF. Turning towards the hematopoietic response to influenza vaccination, a highly unexpected lymph node resident dendritic cell (LNDC) response has been identified following vaccine antigen deposition within specialized sites in the LN medulla. Rapid migration of LNDCs into these sites optimizes exposure of the population to viral antigen, and de novo synthesis of a CXCL10 chemokine gradient by activated LNDCs ensures efficient antigen specific \(CD4^+\) T cell response, and protective humoral immunity - independent of migratory dendritic cell status. Altogether, these studies highlight a highly dynamic, responsive LN environment with direct influence on primary immune response - the understanding of which has broad implications in vaccine biology.

No description available.

Breast cancer is the second leading cause of cancer-related death in women in the United States. Complications that lead to mortality of cancer patients are associated with tumor metastasis. Specifically, lymphatic metastasis in breast cancer patients strongly correlates with poor patient survival and this process is facilitated by the formation of new tumor lymphatic vessels termed lymphangiogenesis. Previously, our lab reported that lymphangiogenesis was promoted by a distinct subset of bone marrow (BM)-derived myeloid cells that co-express lymphatic-specific markers designated as myeloid-derived endothelial cell progenitors (M-LECPs). Furthermore, our lab has generated M-LECP in vitro from a mouse macrophage cell line (RAW264.7) by LPS stimulation. Taken together, these data suggest that chronically inflamed sites drive M-LECP differentiation and that these cells can contribute to the formation of new lymphatic vessels and promote lymph node metastasis. Evidence supporting this hypothesis was indicated by high levels of circulating M-LECP in peripheral blood of breast cancer patients but undetectable levels in healthy donors, cancer-free donors. Additionally, the generation of M-LECP was prompted through TLR4-signaling pathway, and de novo expression of VEGFR-3 and VEGF-C. This co-expression produces an autocrine loop essential for pro-lymphatic reprogramming in both primary human monocytes and the immature monocytic cell line, THP-1. Taken together, these data indicate the major regulatory role of TLR4 in inflammation-driven lymphangiogenesis involves the recruitment and differentiation of M-LECP, a process that may promote lymphatic metastasis.

Thesis (MTech (Nursing))--Cape Peninsula University of Technology, 2011. / To determine the incidence, risk factors and the treatment of lymphedema after breast cancer treatment at the oncology unit of KATH, Kumasi, Ghana from 01 January 2005 to 31 December 2008. Descriptive retrospective survey was used. Using a data capture sheet, data was collected from the medical records of the breast cancer patients. Breast cancer and lymphedema-related variables were collected. Data was analyzed as descriptive statistics. Chi-square test was applied to determine whether or not two variables are independent variables. Among 313 patients treated for breast cancer between 2005 and 2008, 31 (9.9%) developed lymphedema after treatment. A chi-square test showed that axillary lymph node dissection was statistically a significant risk factor of lymphedema (Chi-square test value=7.055, P value=0.008). Radiation and late stage of breast cancer diagnosis may have contributed in development of lymphedema despite having P value> 0.05. Age, body mass index (BMI) and hypertension were also not associated with lymphedema.

Thoracic duct (TD) ligation has long been the treatment of choice for canine idiopathic chylothorax. Clear identification of all the TD branches at the surgical site is critical to facilitate complete ligation, and this can be difficult due to the highly variable nature of the TD system in number, location and patency of TD branches. Failure to ligate all of the TD branches may result in persistent flow of chyle into the pleural cavity through any missed ducts, and this is the single most common cause of failure with TD ligation. Performing direct positive contrast lymphography with a water soluble contrast medium, administered through a surgically implanted mesenteric lymphatic vessel catheter has been the conventional method used to identify TD branches. This procedure involves invasive surgery to both implant and remove the mesenteric lymphatic catheter, which increases patient risk and discomfort, as well as the diagnostic time and cost. Ultrasound (US) guided percutaneous administration of contrast medium into either a popliteal or mesenteric lymph node (LN) have been proposed as alternatives to mesenteric lymphatic vessel catheterisation, however their comparability with the conventional approach has not been assessed. Computed tomographic (CT) lymphography of the caudal canine TD was performed in seven beagles with contrast medium administered through a mesenteric lymphatic catheter, and by US guided percutaneous injection into a popliteal LN. Images of the TD system were collected using both helical and sequential CT modalities for each contrast medium administration technique. It was found that percutaneous popliteal lymphography had a total diagnostic procedure time just 46% of that found with mesenteric lymphatic vessel administration, and resulted in a time saving of 52 minutes. It also incurred only 29% of the total costs, and patients were assessed to have significantly less discomfort compared to mesenteric lymphatic vessel lymphography. There was no significant difference in the number of TD branches identified by the two contrast medium administration techniques (P = 0.256). However administration of contrast medium into a mesenteric lymphatic vessel did result in the largest TD branch having a significantly greater widest diameter (P < 0.001), cross-sectional area (P < 0.001) and mean Hounsfield unit (HU) value (P < 0.001) than popliteal administration. The significant difference in TD size and contrast medium concentration may help to explain the trend for popliteal administration of contrast medium to detect slightly fewer TD branches (CR = 0.830), however this study could not confirm this trend nor its possible causes. There was no significant difference in the number of TD branches identified by the two CT modalities (P = 0.417). However helical CT did result in the largest TD branch having a significantly greater widest diameter (P < 0.001), cross-sectional area (P < 0.001) and higher mean HU value (P < 0.001). It should be noted however that in this study sequential CT was consistently performed after the helical CT was completed, which could explain the differences seen between the two CT modalities in TD branch size and contrast medium concentration. Despite helical CT having the apparent advantage of a larger TD branch which contained a higher concentration of contrast medium, it was actually found that there was a trend for helical CT to detect slightly fewer TD branches (CR = 0.876). This is possibly due to the positive pressure breath hold that was used to minimise thoracic respiratory movement for the helical CT; while the sequential CT was performed during normal respiration and was therefore not subject to abnormally elevated intrapleural pressure. This study could not confirm the slight superiority of sequential CT in detecting TD branches nor the possible reasons for this apparent difference. / Dissertation (MMedVet)--University of Pretoria, 2010. / Companion Animal Clinical Studies / unrestricted

No description available.

In dogs with large primary tumors, regional lymph node involvement or evidence of distant metastasis can have worse prognoses and significantly decreased survival. Lymph node size alone has been shown to be insufficient as a predictor for the accurate clinical staging of some canine neoplasia, including oral malignant melanoma. However, regional lymph nodes of the oral cavity, such as the medial retropharyngeal lymph nodes, are difficult to access for routine sampling. Diffusion weighted magnetic resonance imaging (DWI) has demonstrated the ability to differentiate metastatic from inflammatory/benign lymph nodes in clinical studies with human cancer patients through the calculation of quantitative values of diffusion termed apparent diffusion coefficients (ADC). The objective of this exploratory study was to evaluate DWI and ADC as potential future methods for detecting malignant lymph nodes in dogs with naturally occurring disease. We hypothesized that DWI would identify significantly different ADC values between benign and metastatic lymph nodes in a group of canine patients with head or neck disease. Our results demonstrated that two of four observers identified a significant difference between the mean ADC values of the benign and metastatic lymph nodes. When data from all four observers were pooled, the difference between the mean ADC values of the benign and metastatic lymph nodes approached but did not reach significance (P-value: 0.0566). Therefore, our hypothesis was not supported. However, DWI does show promise in its ability to differentiate benign from metastatic lymph nodes, and further studies with increased patient numbers are warranted / Master of Science

Made available in DSpace on 2016-03-22T17:26:57Z (GMT). No. of bitstreams: 1 Neivo.pdf: 343535 bytes, checksum: e65c41380c8ceabe9bc780ffcc1c99f1 (MD5) Previous issue date: 2005-02-14 / Objective: The objective of this study is to describe the reproducibility of the sentinel lymph node technique in patients with prostate cancer and verify if there is improved accuracy over modified lymphadenectomy. Material and methods: Twenty-three patients with biopsy proven prostate cancer were enrolled in this study. Lymphoscintigraphy was performed after the transrectal administration of 99mTc-Sulphur Colloid guided by ultrasound, with one injection in each prostate lobe. Images were obtained 15 and 180 minutes after injection. Sentinel lymph node was harvested during surgery using a gamma probe, followed by extended lymphadenectomy. Results: The mean age of the patients in this study was 66 years old. An average of 3.36 sentinel lymph nodes was found for each patient. Radioactive lymph nodes were identified by the gamma probe in 21 out of 23 patients. In one of the patients there was no radiopharmaceutical migration from the injection site and in another the sentinel lymph node was visualized by lymphoscintigraphy but was not found during surgery. Three patients had lymph node metastasis; in one of these patients the sentinel lymph node was the only positive node and was found outside the modified lymphadenectomy region (dissection of the lymph nodes from the obturator fossa and the external iliac). Conclusion: Sentinel lymph node biopsy in prostate cancer adds important information to the staging of patients, not always attained through the lymphadenectomy restricted to the obturator fossa and external iliac. Such information is essencial for the choice of the best treatment to be applied. / n