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Flemming Melsen

Publications and source records attributed to Flemming Melsen.

5 recordsLinked to original sources
PubMed2006

Vascularity in thyroid neoplasms: a methodological investigation with a view to diagnostics.

The aim of the present study was to evaluate the reliability of four different methods (vascular grading, Chalkley count, microvessel density (MVD) and stereological estimation) for quantifying intratumoral microvascularity in thyroid neoplasms, by comparing the variability within and between observers. In addition, the diagnostic and prognostic potential of neovascularity expressed by the four methods was evaluated. The study had a retrospective design and involved 24 follicular adenomas (FA), 19 follicular carcinomas (FC), and 17 papillary carcinomas (PC). Chalkley count was reproducible both within and between observers. MVD was not reproducible. Within observer the reproducibility of vascular grading was substantial, between observers it was fair to moderate. Stereological estimation was a priori considered reproducible. Keeping time consumption, cost and reproducibility in mind, Chalkley count should be the preferred method for assessing microvascularity in thyroid neoplasms. The diagnostic evaluation revealed a tendency towards higher degree of vascularity in FA compared to both FC and PC for all methods. No statistically significant association was seen between vascular density and prognosis.

Adolescent↗
PubMed2004

Sentinel lymph node biopsy in breast cancer--experience with the combined use of dye and radioactive tracer at Aarhus University Hospital.

One hundred and twenty-four patients with palpable tumours underwent sentinel lymph node biopsy (SLNB) and subsequent axillary lymph node dissection. Ultrasound of the axilla was used as part of the diagnostic work-up on all patients and those with lymph node metastasis verified by fine-needle aspiration biopsy (FNAB) were not included. For identifying the SLNs, a combination of Tc-99m-labelled human albumin (Solco-ALBU-RES) and blue dye (Patent Blue V) was used. No lymphoscintigraphy was performed. The SLN was successfully identified in 122 out of 124 (98%) patients and 66 (54%) patients were found to have metastatic involvement of the axillary lymph nodes. In 52 (79%) of these patients, the SLNs were the only nodes involved, 28 (54%) had micrometastasis only. The false-negative rate was 1.5%. This method has proven valid in the staging of the axilla in patients with breast cancer. The advanced techniques of serial sectioning and immunohistochemical staining further improve the diagnostic advantage offered by the SLNB, as it increases the possibility of diagnosing micrometastatic deposits.

Adult↗
PubMed2002

Hypocalcemia and osteopathy in mice with kidney-specific megalin gene defect.

Megalin is an endocytic receptor highly expressed in the proximal tubules of the kidney. Recently, we demonstrated that this receptor is essential for the renal uptake and conversion of 25-OH vitamin D3 to 1,25-(OH)2 vitamin D3, a central step in vitamin D and bone metabolism. Unfortunately, the perinatal lethality of the conventional megalin knockout mouse model precluded the detailed analysis of the significance of megalin for calcium homeostasis and bone turnover in vivo. Here, we have generated a new mouse model with conditional inactivation of the megalin gene in the kidney by using Cre recombinase. Animals with a renal-specific receptor gene defect were viable and fertile. However, lack of receptor expression in the kidney results in plasma vitamin D deficiency, in hypocalcemia and in severe bone disease, characterized by a decrease in bone mineral content, an increase in osteoid surfaces, and a lack of mineralizing activity. These features are consistent with osteomalacia (softening of the bones) as a consequence of hypovitaminosis D and demonstrate the crucial importance of the megalin pathway for systemic calcium homeostasis and bone metabolism.

Animals↗
PubMedDate not supplied

Influence of particle size of autogenous bone grafts on the early stages of bone regeneration: a histologic and stereologic study in rabbit calvarium.

PURPOSE: The aim of this study was to investigate the influence of particle size of autogenous bone grafts on the early stages of bone regeneration. MATERIALS AND METHODS: Bicortical skull bone defects were prepared in 15 rabbits (4 in each rabbit). Two defects were filled at random with either small (0.5 to 2 mm3) or large (10 mm3) autogenous bone particles. In addition, 1 defect was left unfilled (control defect). All defects were covered bicortically by expanded polytetrafluoroethylene membranes. The animals were divided randomly into 3 groups and sacrificed after 1, 2, and 4 weeks, respectively. Histologic and stereologic evaluations were performed after the sections were blinded. RESULTS: No significant differences in total vessel surface area could be identified among the 3 groups. The total volume of newly formed bone in defects with small particles was larger and more mature compared to defects with large particles after 2 and 4 weeks. Furthermore, the resorption of small particles was more pronounced after 4 weeks, documenting a higher level of bone substitution compared to large particles. DISCUSSION: The early stages of bone regeneration were influenced by the particle site of autogenous bone grafts. CONCLUSION: The present study indicated that particles of 0.5 to 2 mm3 in size should be preferred to particles of 10 mm3 in size for bone grafting.

Analysis of Variance↗