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Biomedical subjects

H B Lampe

Publications and source records attributed to H B Lampe.

At least 19 recordsLinked to original sources
PubMed2000

Frey's syndrome and parotidectomy flaps: A retrospective cohort study.

Gustatory sweating, also known as Frey's syndrome, is a recognized phenomenon after parotidectomy. The incidence of clinically significant gustatory sweating may be dependent on the thickness of the skin flap that is elevated at the time of surgery. Dissection in the subcutaneous level or the deeper sub-superficial musculoaponeurotic system level are 2 commonly used techniques in the operation. Twenty-eight patients were prospectively evaluated for Frey's syndrome after superficial parotidectomy. Thirteen patients underwent subcutaneous and 15 patients sub-superficial musculoaponeurotic system flap elevation. The overall incidence of gustatory sweating was determined, and a comparison of the two surgical techniques was assessed subjectively by patient interview-questionnaire and objectively evaluated with starch-iodine testing.

Cohort Studies↗
PubMed1999

Role of percutaneous gastrostomy tubes in the postoperative care of patients with cancer of the oral cavity and oropharynx.

OBJECTIVE: The purpose of this study was to document the use and complications of gastrostomy tubes placed following surgery for oral cancer at our institution and to determine preoperative predictors of the procedure. METHOD: A retrospective chart review of 105 patients treated surgically for oral cancer between March 1990 and June 1995 at St. Joseph's Health Care Centre, London, Ontario was conducted. Twenty patients were studied with regard to timing, indication, and morbidity (n = 24) of the procedure. Regression analysis was performed regarding preoperative predictors of postoperative gastrostomy including tumour site and stage, and the percentage of tongue resected. Outcome measures included time from surgery to gastrostomy, length of postoperative hospital stay, time gastrostomy tube in situ, complications of gastrostomy, and the predicted risk of postoperative gastrostomy tube. RESULTS: The mean time to gastrostomy tube placement was 17.4 days, and the mean length of hospital stay in gastrostomy patients was 26.8 days. Gastrostomy was temporary in 55% of patients. No significant complications of percutaneous gastrostomy were encountered. Oropharyngeal tumour site and advanced T stage were predictive of the need for postoperative gastrostomy. CONCLUSIONS: In oral cavity and oropharyngeal cancer patients treated surgically, early postoperative percutaneous gastrostomy tube placement is indicated in those at high risk for significant postoperative dysphagia.

Administration, Cutaneous↗
PubMed1998

Nonlinear, three-dimensional finite-element model of skin biomechanics.

OBJECTIVE: The aim of this study was to expand the rigour and scope of soft-tissue finite-element modelling through the introduction of nonlinear biomechanics. The capability to simulate "tissue" movement in three-dimensional space was a priority. METHOD: A computer-based finite-element technique was used to approximate the exact solution to the governing differential equations. Common fusiform defects were "closed" in two- and three-dimensional space. Strains of approximately 17% were introduced. Skin was modelled as a nonlinear elastic anisotropic material in a laminated-composite structure undergoing large deformations and large strain. The finite-element software package for nonlinear biomechanical analysis was run on a university-based, multi-user workstation. Repeated simulations were performed. The key independent variables were the magnitude of the subcutaneous adhesion and the degree of undermining. The two dependent variables were the "closure" force and the distortion field. RESULTS: The absolute values computed for "closure" force, ranging from 4.4 N to 5.2 N, were consistent with previous animal studies. The periphery of the distortion field varied from 4.7 to 5.9 cm from the defect midline. The force of subcutaneous adhesion was varied from 2 to 20 kN/m (+900%) and led to a -19% and +16% change in the distortion field width and "closure" force, respectively. Undermining was progressively increased from 1 to 5 cm (+400%) and produced a +5% and -12% change in the width of the distortion field and the "closure" force, respectively. CONCLUSIONS: The application of nonlinear biomechanics to soft-tissue finite-element modelling has been rewarding. The results correlate well with surgical experience. With specific regard to undermining, additional insight has been gained. Undermining broad-based soft-tissue flaps has progressively limited benefits. The computational demonstration of this result, consistent with prior animal studies, has not been previously published. Future application of this technology may permit the development of more complex flaps. Animal experimentation may be reduced and/or deferred until postulated flap designs have been simulated and refined.

Biomechanical Phenomena↗
PubMed1996

Imaging and surgery in hyperparathyroidism: a 10-year review.

A 10-year review (1984-1994) of patients undergoing surgical treatment for hyperparathyroidism at St. Joseph's Health Centre in London, Ontario, is presented. The role of preoperative localization is discussed. We review our experience with the various imaging modalities and their usefulness in the surgical decision-making process. Our experiences with the surgical management of both primary and secondary hyperparathyroidism are evaluated. Controversies in parathyroid surgery, unilateral versus bilateral neck exploration for parathyroid adenomas, and autotransplantation versus total parathyroidectomy for secondary hyperparathyroidism are discussed and our approach is explained.

Adenoma↗
PubMed1996

Schwann cell differentiation of modified myoepithelial cells within adenoid cystic carcinomas and polymorphous low-grade adenocarcinomas: clinicopathologic assessment of immunohistochemical staining.

Adenoid cystic carcinomas and polymorphous low-grade adenocarcinomas have a known propensity for perineural invasion. Although modified myoepithelial cells have been shown to possess characteristics of a variety of cell types, they have not yet been found to mimic nerve tissue. Histologic evidence of Schwann cell differentiation would suggest the pathophysiologic mechanism by which these tumours exhibit neurotropism. An archival study of 41 specimens was performed to evaluate the Schwann cell staining properties of adenoid cystic and polymorphous low-grade adenocarcinomas using antibodies to S-100 protein, GFAP, neuron-specific enolase, and using a solochrome stain. Charts were reviewed to assess correlations between immunohistochemical and histochemical staining properties and various clinical parameters. The findings strongly suggest that neuronal differentiation does occur within these tumours. Furthermore, it was determined that solochrome positivity confers a significantly less favourable disease-free interval in these neoplasms. This new finding was highly statistically significant and has potential implications in the determination of prognosis for patients with these tumours.

Adenocarcinoma↗
PubMed1996

Expression of dipeptidyl aminopeptidase IV activity in thyroid tumours: a possible marker of thyroid malignancy.

The role of dipeptidyl aminopeptidase IV (DAP IV) activity staining in the investigation of a thyroid mass was explored. The study consisted of two parts: the first part involved DAP IV staining performed on various thyroid lesions sampled from operative specimens. These included frozen tissues or cytologic smears. The second part of the study, which is ongoing, prospectively examines the DAP IV activity in fine-needle aspiration (FNA) specimens from patients with a thyroid mass. Results from part 1 of the study indicated that DAP IV activity staining was a useful adjunct in distinguishing differentiated carcinoma from benign lesions, particularly the "follicular lesions." Preliminary findings of the second part of the study suggest that DAP IV staining can be applied to FNA specimens. The measure of DAP IV activity and its influence on the diagnostic accuracy of FNA remain to be seen.

Biomarkers, Tumor↗
PubMed1996

Issues in the surgical management of parathyroid disorders.

At St. Joseph's Health Centre in London, Ontario, the Departments of Otolaryngology and Endocrinology of the University of Western Ontario work closely together in the medical and surgical management of patients with parathyroid disease. Recently, a multidisciplinary Grand Rounds was held during which current issues in the management of these patients were discussed, with particular emphasis on the role of localization studies as well as the potential difficulty inherent in distinguishing parathyroid adenomas from parathyroid hyperplasia. The following is an edited transcript from the Grand Rounds.

Adenoma↗
PubMed1996

Same-day admission thyroidectomy programme: quality assurance study.

OBJECTIVE: This study was conducted to evaluate the effectiveness of a same-day admission thyroidectomy programme. DESIGN: Prospective patient surveys and a retrospective quality assurance study were conducted. METHOD: Management of the initial 58 patients having a thyroidectomy at St. Joseph's Hospital, London, Ontario, after May 1992 when a same-day admission thyroidectomy programme was initiated, was evaluated. Early in the process, staff evaluation of the programme was also surveyed. RESULTS: The average length of stay for these patients was reduced from 4.5 to 3.2 days. No operative delays, cancellations, readmissions, or increased complications resulted from the new protocol. Also, patient and staff acceptance of the new programme was high. CONCLUSION: Our success with this programme has encouraged us to apply these concepts to more complex surgical patients.

Adolescent↗
PubMed1996

Fine-needle aspiration cytology of lymphoid lesions of the salivary gland: a review of 35 cases.

OBJECTIVE: The aim of this study was to evaluate the effectiveness of fine-needle aspiration (FNA) in the diagnosis of primary lymphoid processes of the salivary gland. DESIGN: A retrospective study. METHOD: Between 1987 and 1994, 35 patients who underwent fine-needle aspiration (FNA) of the salivary gland had a diagnosis of a primary lymphoid process. Most presented with palpable parotid (28 patients) or submandibular (4 patients) gland masses which prompted a clinical diagnosis of pleomorphic adenoma. FNA was performed with immediate on-site evaluation. Flow cytometric cell-surface-marker analysis was performed in 28 of the 35 cases to determine the clonality of the B-cell proliferations. RESULTS: Sixteen cases of reactive hyperplasia and nine cases of malignant lymphoma diagnosed by FNA were confirmed by subsequent histopathologic examination. Lymphoma was confirmed in six of eight cases diagnosed as suspicious for lymphoma by FNA. Hodgkin's disease was suspected but not confirmed in one case and was diagnosed as a probable Warthin's tumour in another case. In all cases, the FNA diagnosis of either a reactive or malignant lymphoid process was unexpected and influenced the patient's further management. For patients diagnosed with an intraparotid lymph node, surgery could be deferred for a short period with the hope that the lymphadenopathy would spontaneously regress. For patients with a preoperative FNA diagnosis of lymphoma, a more limited biopsy could be performed, thereby reducing the operative risk to the patient and plans to process the tissue according to the institution's lymphoma protocol could be made. CONCLUSION: Clinically, reactive intraparotid lymph nodes and lymphomas present as parotid enlargements that are indistinguishable from pleomorphic adenomas. FNA is the only method of accurately establishing a preoperative diagnosis in these patients.

Adolescent↗
PubMed1996

Comparison of maxillectomy patients with immediate versus delayed obturator prosthesis placement.

OBJECTIVE: To compare maxillectomy patients with immediate versus delayed placement of an obturator prosthesis in terms of patient outcomes. DESIGN: Retrospective review. OUTCOME MEASURES: The outcomes of 23 maxillectomy patients seen between 1975 and 1993 at St. Joseph's Health Centre in London, Ontario, were analyzed. METHODS: For 17 patients, a prosthesis was placed immediately as part of the operative procedure, and for 6 patients, an occlusive dressing only was placed. RESULTS: In all parameters studied (length of stay, i.v. requirements, swallowing, clear fluid diet and ambulation), the prosthesis group progressed more quickly and had a more rapid return to normal function. CONCLUSION: This study demonstrates the benefits of immediate prostheses for maxillectomy patients and justifies their continued use.

Adult↗
PubMed1995

Nutritional status in head and neck cancer patients.

The nutritional status of patients with head and neck cancer has been suspected as being a significant risk factor for surgical complications and cancer recurrence. Clinical dietary assessment was performed on a mixed group of 42 previously untreated, head and neck cancer patients scheduled to receive surgery with curative intent. Cox regression analysis was performed to investigate the relationship between demographic and tumour factors and nutritional status. Nutritional status correlated only with the locoregional stage of disease. A further regression analysis was performed to determine if nutritional status is an independent risk factor for early postoperative complications or recurrence. Nutritional status was not shown to influence surgical outcomes independent of tumour stage. Further study of the relationship between nutritional status and surgical results is required before recommending preoperative hyperalimentation in head and neck cancer patients.

Aged↗
PubMed1994

The pathobiology of salivary gland. III. PCNA-localization of cycling cells induced in rat submandibular gland by low-dose x-radiation.

Application of ionizing radiation to adult rat major salivary glands tested tenets of the bicellular reserve cell hypothesis for the induction of salivary gland tumors, namely, that stem cells preferentially located to luminal cells of the intercalated duct and basal cells of the excretory duct in normal salivary glands. The effect of a single, low dose (3000 cGy) of x-radiation administered to the parotid and submandibular glands was followed with the use of immunocytochemistry and an antibody to the cell cycle-related protein proliferating cell nuclear antigen to detect the kinetics and localization of cycling cells up to 15 days postirradiation. Maximal responses occurred in acinar cells (12.6-fold increase) of submandibular glands on day 7 postirradiation. Similar but less dramatic concurrent increases in proliferating cells were evident in intercalated (3.4-fold) and striated (2.2-fold) duct cells, but little response was seen in basal or luminal cells of submandibular gland excretory ducts. A limited but maximal proliferative response again occurred on day 7 in the parotid gland. Neither in the steady state nor irradiated submandibular gland was there evidence of specific stem ("reserve") cells associated with the intercalated or excretory ducts. It appears unnecessary to invoke stem cells in a model of cellular proliferation in salivary glands. Therefore current concepts of salivary gland tumorigenesis require modification because all cell types, including acinar cells, are at risk in the carcinogenic process.

Animals↗
PubMed1994

Accuracy of fine needle aspiration in the pre-operative diagnosis of thyroid neoplasia.

The aim of this study was to determine the accuracy and clinical utility of fine needle aspiration (FNA) for the preoperative diagnosis of patients presenting with solitary thyroid nodules. Between 1987 and 1991, 317 patients with a thyroid nodule underwent FNA. Surgery was performed on 98 of the patients, and the cytologic findings were correlated with the final histologic diagnoses for these cases. Of the 98 patients operated on, satisfactory aspirates were obtained in 85 patients and classified as either malignant, suspicious for malignancy, or benign. The FNA was correct in predicting malignancy in 29 of 35 nodules (82.9%). With the benign nodules, FNA was correct in 44 of 50 nodules (88%). The overall accuracy of FNA was 85.9%. The accuracy for the combination of FNA and frozen section (FS) was 92.6%. We conclude that both FNA and FS are accurate tests that play a useful role in the pre- and intraoperative diagnostic evaluation of patients presenting with solitary thyroid nodules.

Adenoma↗
PubMed1993

DNA analysis of head and neck squamous cell carcinoma by flow cytometry.

The use of flow cytometry to measure the DNA content from tumors has evolved over the years. In squamous cell carcinoma arising in the head and neck, there has not been uniform agreement in the literature, and decisions regarding patient treatment cannot be made using this parameter. The use of proliferating cell nuclear antigen (PCNA), a newly available marker of a cell's proliferative activity (S-phase fraction) is also discussed. In a prospective series of patients, the findings of diploidy, aneuploidy, low (PCNA) positivity, and high PCNA positivity are compared to known biological parameters. Strong trends are shown demonstrating biological aggressiveness associated with aneuploidy, high PCNA fraction, and the combination of aneuploidy and high PCNA fraction. The potential use of whole-cell preparation to determine ploidy and PCNA fraction as a predictor of metastatic potential are discussed. The whole-cell preparation technique allows accurate DNA ploidy measurements and, with the use of PCNA, a measure of proliferative activity. These parameters combined with known TNM staging may 1. allow alteration in treatment and ultimately affect patient survival, and 2. allow comparison of treatment modalities between biologically similar tumors.

Aged↗
PubMed1993

Medullary thyroid carcinoma: prognostic factors.

Medullary thyroid carcinoma is an uncommon cancer of the thyroid gland. It comprises a neuroendocrine tumor of the calcitonin secreting cells. Its level of aggressiveness lies between that of well-differentiated and anaplastic thyroid malignancies. We have undertaken a retrospective study of 18 patients with medullary thyroid carcinoma to evaluate various parameters for their prognostic value. We looked at epidemiologic factors such as stage, age at onset, sex and the heredity of the disease. In addition various immunohistochemical stains were looked at including Leu-M1, calcitonin, thyroglobulin, somatostatin, carcinoembryonic antigen, neuron specific enolase and BRST-1. Finally, DNA ploidy was determined using the flow cytometer. Stage, age at onset, DNA ploidy and staining for BRST-1 were found to be significant factors in determining outcome of this disease.

Adolescent↗