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Biomedical subjects

J L Freeman

Publications and source records attributed to J L Freeman.

At least 91 records · Page 5Linked to original sources
PubMed1994

Laryngeal verrucous carcinoma: a clinicopathologic study and detection of human papillomavirus using polymerase chain reaction.

Laryngeal verrucous carcinoma (LVC) is a rare, well-differentiated variant of squamous carcinoma with a low malignant potential. Human papillomavirus (HPV)-16 DNA has been identified in a small number of LVC and an etiologic relationship has been suggested. A correlative clinical and molecular pathological study was performed in order to determine the prevalence and typing of HPV DNA in LVC. Possible associations between patient and tumor subsets, and the presence of HPV DNA were also investigated. Formalin-fixed, paraffin-embedded tissue samples from 29 patients with LVC were examined by polymerase chain reaction (PCR) using DNA primers specific for HPV types 6b/11, 16, and 18. Overall, HPV DNA was detected in 13 (45%) of the cases. Of these, HPV-16 DNA, HPV-18 DNA, and both HPV-16 DNA and HPV-18 DNA were detected in 4 (14% overall; 31% of positive cases), 4, and 5 (17% overall; 38% of positive cases), respectively. HPV-6b/11 DNA was not detected in any LVCs. In 16 cases, no HPV DNA was detected. There was a trend toward HPV DNA detection in higher stage tumors. HPV DNA detection was unrelated to patient age, tumor site, or radiotherapeutic responsiveness. The detection of HPV DNA in 45% of LVCs suggests an association between the presence of HPV-16 DNA and HPV-18 DNA, and some LVCs.

Blotting, Southern↗
PubMed1994

Ultrasonography and ultrasound-guided fine-needle aspiration biopsy of head and neck lesions: a surgical perspective.

A head and neck ultrasound-guided fine-needle aspiration clinic was set up to determine the role of ultrasound and ultrasound-guided fine-needle aspiration in the evaluation of patients with lesions in this region. One hundred ninety-five lesions were biopsied by ultrasound-guided fine-needle aspiration in 203 patients. Ultrasound detected 2 or more lesions in 14 (48%) of 29 patients with a clinically solitary thyroid nodule. Three (8.8%) of 34 lesions thought to be within the parotid gland were determined to be external. A pronounced learning curve was evident in the technique of ultrasound-guided fine-needle aspiration, particularly for nonpalpable disease. Adequacy of sampling for each 3-month period was 71%, 89%, and 94%, respectively. Seventy-four percent of central aspirations were satisfactory compared to 54% of peripheral aspirations. Ultrasound-guided fine-needle aspiration did not alter the clinical staging of metastatic neck disease in 8 patients having 10 neck dissections but proved useful in detecting nodal recurrence in 3 irradiated necks that did not proceed to surgery. The smallest node to harbor malignancy had 4-mm maximal axial diameter. We conclude that ultrasound and ultrasound-guided fine-needle aspiration are valuable adjuncts to the clinical examination.

Biopsy, Needle↗
PubMed1994

Epstein-Barr virus and nasopharyngeal carcinoma: bringing molecular genetics strategies to head and neck oncology.

In this article, we consider the tools of molecular genetics and strategies that have, or likely will have, an impact in otolaryngology, either as diagnostic tools or as strategies, with more far-reaching applications in tumour therapy, relapse monitoring, and ultimately, approaches to tumour prevention. Nasopharyngeal carcinoma (NPC) is closely associated with Epstein-Barr virus (EBV). Detection of the virus following gene amplification by the polymerase chain reaction (PCR) can provide a diagnostic tumour marker, both in primary and metastatic sites. NPC can be considered as a model disease on which molecular genetics is and likely will be of considerable impact. NPC is characterized by the presence of a genetically stable, viral agent of proven oncogenicity. The presence of attractive experimental systems for the study of EBV-associated tumours and their accessibility may combined with new molecular approaches towards diagnostic and, eventually, therapeutic improvements in the treatment of this clinically ominous malignancy.

Biomarkers, Tumor↗
PubMed1994

Use of tissue expansion in head and neck reconstruction.

Esthetic reconstruction of facial defects requires the use of skin with similar characteristics to that of the deficient site. Local and regional skin are the most suitable, but the amount available may be insufficient for both reconstruction and primary closure of the donor site. We describe three illustrative cases in which tissue expansion of local and regional skin allowed satisfactory reconstruction and donor site closure that would otherwise not have been possible.

Adult↗
PubMed1994

The nasal glabellar flap.

Reconstruction of nasal defects presents a challenging problem for the surgeon. This is due to the complexity of the nasal surface lines and the diversity of the colour, texture, and appearance of its lining skin. Furthermore, there is a limited availability of mobile, adjacent skin. Defects of nasal cover after cancer-ablative procedures have been rehabilitated with numerous reconstructive modalities including free skin grafting and local flaps. Each technique differs according to the depth and size of the defect, the quality of the donor site, and the skills of the surgeon. The nasal glabellar rotation flap, initially described by Gillies and later modified by Reiger, has evolved into a choice flap for nasal defects of cover since it provides local skin with an exact colour, thickness, and contour match for the nasal skin. It is a safe flap, the donor site morbidity being minimal and especially suited for dorsal and lateral nasal resurfacing. The technique of the flap development is presented.

Humans↗
PubMed1993

Estimating the variance of standardized rates of recurrent events, with application to hospitalizations among the elderly in New England.

Usual approaches for estimating the variance of a standardized rate may not be applicable to rates of recurrent events. Where individuals are prone to repeated health events, Greenwood and Yule (J R Stat Soc [A], 1920;83:255-79) advocated use of the negative binomial distribution to account for departures from the assumption of randomness of recurrent events required by the Poisson distribution. In this paper, the authors implemented the negative binomial distribution in the computation of annual hospitalization rates within certain hospital market areas. Data used were from 1,549,915 New England residents aged 65 years or more who were enrolled in Medicare between October 1, 1988, and September 30, 1989, and who had 458,593 hospital admissions during that year. New England was partitioned into 170 hospital market areas ranging in population size from 162 to 70,821 elderly Medicare enrollees. The negative binomial distribution demonstrated substantially better fits than the Poisson distribution to the numbers of hospitalizations within hospital market areas. Estimated standard errors for indirectly standardized rates based on the negative binomial distribution were 25-51 percent higher than estimated standard errors that assumed an underlying Poisson distribution. Using regression analysis to smooth overdispersion parameters across hospital market areas produced similar results. The approach described in this paper may be useful in estimation of confidence intervals for standardized rates of recurrent events when these events do not recur randomly.

Age Factors↗
PubMed1993

Nonpalpable occult and metastatic papillary thyroid carcinoma.

The results of palpation, ultrasound, and detailed pathology were compared in 50 patients undergoing total thyroidectomy. Of the 211 nodules recognized by pathology, palpation detected 24% and ultrasound detected 43%. There were 14 patients with palpable papillary carcinomas, and 12 of these 14 had metastatic foci in other portions of the gland. Metastatic foci would have been left in 10 patients if only a lobectomy had been performed and would have been left in 6 patients if only a subtotal thyroidectomy (as defined in this report) had been performed. Of the 33 patients with benign palpable nodules, 5 had occult papillary carcinomas. In 2 of those 5 patients, the occult carcinomas would not have been removed if a less-than-total thyroidectomy had been performed. The significance of these occult and metastatic papillary carcinomas is discussed.

Carcinoma, Papillary↗
PubMed1993

CT of congenital and acquired abnormalities of the spleen.

Computed tomography (CT) is an excellent imaging modality for demonstrating the size, shape, and position of the spleen, as well as for depicting intrasplenic pathologic features. However, it has limited value in the diagnosis of splenic involvement by lymphoma. Greater accuracy in diagnosing splenic lymphoma may be obtained by demonstrating adenopathy in the splenic hilum or by showing focal splenic defects, in addition to splenomegaly. In discussing the normal anatomy of the spleen, congenital variations (eg, accessory spleen, polysplenia, asplenia, and wandering spleen), and acquired abnormalities such as those resulting from trauma, infection, infarction, cysts, and neoplasms, this article provides evidence that CT is valuable in showing a wide variety of splenic variations and abnormalities while simultaneously allowing evaluation of the remaining intraabdominal structures. The cases presented demonstrate both the value and limitations of CT in the examination of patients with congenital and acquired abnormalities of the spleen.

Humans↗
PubMed1993

Pre-operative localization of 25 consecutive parathyroid adenomas: a prospective imaging/surgical correlative study.

The successful diagnosis and surgical treatment of primary hyperparathyroidism due to parathyroid adenoma benefits significantly, in our experience, from a process of pre-operative imaging localization of the parathyroid adenoma. This prospective study evaluates a window of 25 consecutive patients who underwent pre-operative imaging localization prior to successful unilateral parathyroidectomy for parathyroid adenoma. All parathyroid adenomas were successfully localized by imaging, and subsequently documented photographically in surgical correlation, and pathologically confirmed. All patients were cured biochemically. Ultrasound accurately localized 92% of adenomas (100% in the neck and extrathyroidal) while radionuclide subtraction scanning identified 60% of a smaller subset. Both DSA and CT were successful in the two cases utilized, and MRI demonstrated four of five adenomas. The high yield of these pre-operative localization studies should make them an important consideration in the routine evaluation of patients undergoing surgery for possible parathyroid adenoma. Their usefulness in directing a conservative unilateral operation may result in time and cost savings, as well as reduced surgical exposure.

Adenoma↗
PubMed1993

The significance of false-positive nodes in patients with oral cancer.

The significance of palpable non-metastatic (false-positive) lymph nodes in the neck of patients with head and neck cancer is not quite clear. These nodes may be the result of inflammation, which usually accompanies the primary tumor, or they may reflect an immunological response of the patient to the tumor. The present study was undertaken to elucidate this problem by comparing the survival rate of patients with false-positive necks to the rates of patients with true-negative, false-negative, or true-positive necks. The records of 138 patients with primary squamous cell carcinoma of the oral cavity who were treated surgically between 1980 and 1987 at the University of Toronto were reviewed. There were 53 patients with true-negative necks, 18 with false-negative necks, 35 false-positive necks, and the remaining 32 patients had true-positive necks. T-stage was the single variable with a significant impact on survival. Nodal status did not influence survival in patients with large primary tumors. In patients with T1 or T2 cancers, occult nodes did not, but palpable nodes did have a detrimental impact on survival. The presence of false-positive nodes did not have a beneficial effect on survival in this study. Possible explanations for this observation are discussed.

Adult↗
PubMed1993

Metastasizing neuroendocrine tumor of unknown origin found in cervical lymph nodes: a case report.

Neuroendocrine tumors are a diverse category of tumors that have been known to produce biologically active amines and ectopic hormones of various types. Numerous metastasizing primary lesions have been identified, however, the head and neck region is not a common site for them. Even less common than these are head and neck metastatic sites without an identifiable primary lesion. We report a case of a metastatic neuroendocrine tumor, where the primary site eluded detection despite an extensive battery of investigations.

Adult↗
PubMed1993

A monomorphic adenoma of the minor salivary glands presenting at the base of the tongue: a case report and review of the literature.

A case of a monomorphic adenoma of the minor salivary glands situated at the base of the tongue in a 49-year-old female is reported. The patient had a prolonged clinical course of eight years' duration. The histopathologic, immunohistologic and ultra-structural findings are described. A review of the literature concerning minor salivary gland tumors and their location in the oral cavity is presented. This is the first case, to our knowledge, of a monomorphic adenoma presenting at the base of the tongue. The difficulties in its diagnosis are discussed specifically in regard to its location.

Adenoma↗
PubMed1992

Diagnosis of nasopharyngeal carcinoma by DNA amplification of tissue obtained by fine-needle aspiration.

BACKGROUND: In nasopharyngeal carcinoma the primary lesion is often difficult to find. Metastatic lesions occur frequently but are difficult to distinguish from other head and neck tumors. The viral genome of the Epstein-Barr virus (EBV) can be identified in the cells of this carcinoma. METHODS: We used the polymerase chain reaction (PCR) to test for the presence of EBV genomes in 15 samples of metastatic squamous-cell carcinoma of the neck obtained by fine-needle aspiration and in 26 samples obtained by biopsy of lymph nodes. For controls we used disease-free lymph nodes from 10 patients with various head and neck tumors, tonsillar tissue from 46 subjects, blood from 59 EBV-seropositive blood donors, and mononuclear cells from 8 patients with fatal lymphoproliferative lesions. RESULTS: Of the 41 malignant lesions examined, only the nine nasopharyngeal carcinomas (one primary lesion and eight metastases) contained EBV genomes. None of the 20 nodes with other types of cancer, the 10 disease-free nodes, or any of the 105 normal control samples contained detectable EBV. In two patients with suspected metastases from occult primary tumors, the presence of EBV was predictive of nasopharyngeal carcinoma; in both cases overt nasopharyngeal carcinoma developed within one year. CONCLUSIONS: In patients with suspected nasopharyngeal carcinoma, fine-needle aspiration can provide tissue for diagnosis by DNA amplification of EBV genomes. The presence of EBV in metastases from an occult primary tumor is predictive of the development of overt nasopharyngeal carcinoma.

Base Sequence↗
PubMed1992

Detection of occult nasopharyngeal primary tumours by means of in situ hybridization.

Detection of nasopharyngeal carcinoma primaries in patients presenting with neck node metastases may sometimes demand considerable efforts. By using the 'in situ hybridization' technique, we manage to identify the Epstein-Barr virus in neck metastases secondary to nasopharyngeal carcinomas. We propose that such identification in neck node metastases where the primary lesion is unknown indicates a nasopharyngeal primary.

DNA, Viral↗