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Biomedical subjects

M A Kahn

Publications and source records attributed to M A Kahn.

51 records · Page 3Linked to original sources
PubMed1992

Flow cytometer analysis of oral premalignant lesions: a pilot study and review.

In a retrospective study, we examined 34 premalignant lesions of the oral cavity by flow cytometer analysis on formalin-fixed, paraffin-embedded tissue submitted to the University of Tennessee, Memphis, Oral Pathology Laboratory. Three categories of oral epithelial dysplasia were represented (eight mild, seven moderate, nine severe), as well as five epithelial hyperplasias without dysplasia and five fibrous nodules as controls. The DNA index and total proliferative index of each case were calculated. The objective of the study was to determine the amount of epithelial dysplasia necessary in oral lesions before DNA aneuploidy or high proliferative index is detectable and thus determine if flow cytometric analysis can be a diagnostic adjunct for oral premalignant lesions. The results showed that some cases in both the control and dysplastic categories exhibited a high total proliferative index (control = 1, no dysplasia = 1, mild dysplasia = 3, moderate dysplasia = 2, severe dysplasia = 2), whereas only the dysplastic lesions had an abnormal DNA index [8 of 24 (33%)]. The results indicate that flow cytometric analysis may have some limited potential as a diagnostic adjunct in oral premalignant lesions.

Aneuploidy↗
PubMed1991

Regional odontodysplasia. Case report with etiologic and treatment considerations.

Regional odontodysplasia, a relatively rare developmental abnormality of the dental hard tissues, most often unilaterally and segmentally involves the anterior maxillary teeth of young females. Patients often have pulpal pathosis, periodontal manifestations, and irregularities of the eruption sequence of the affected teeth. The resultant reduced density of the enamel and dentin imparts a radiographic appearance of "ghosting" with correspondingly enlarged pulp chambers and canals. Etiology is uncertain; numerous local and systemic factors have been proposed. Treatment may sometimes be controversial, and timing of extractions and restorative procedures is critical. This case report illustrates the signs and symptoms of regional odontodysplasia, to aid clinicians in early recognition of the condition, to provide further evidence that a local circulatory disorder might be involved in its pathogenesis, and to illustrate treatment options that consider the patient's development and welfare.

Child, Preschool↗
PubMed1989

Ameloblastoma in young persons: a clinicopathologic analysis and etiologic investigation.

Ameloblastoma, an odontogenic tumor of ectodermal origin, has been reported to arise, on rare occasions, in a primordial or dentigerous cyst of a young person. Numerous authors have suggested differing nomenclatures for these ameloblastomas (e.g., mural, unicystic, monocystic, intracystic, cystogenic, cystic, plexiform unicystic) and have sought to describe and classify the clinical and histopathologic features. These tumors have been characterized as a distinct variant exhibiting less aggressive behavior and a lower rate of recurrence than conventional ameloblastoma. Furthermore, various etiologic factors have been proposed for these cystic ameloblastomas, including (1) nonspecific irritational factors such as extraction, caries, trauma, infection, inflammation, or tooth eruption; (2) nutritional deficit disorders, and (3) viral infection. The files of the combined accessioned cases of Emory University's and Temple University's oral pathology laboratories were searched and a review of the literature was performed. Thirty-eight cases of mandibular ameloblastoma (37 intraosseous, 1 peripheral) in persons 19-year-old and younger were found from a combined total of 311 accessioned cases of ameloblastoma (12.2%). The average age at diagnosis was 10.4 years for the 18 males and 20 females. Of the 33 cases in which race was stated, 19 (57.6%) were white and 14 (42.4%) were black. In the 28 cases in which a clinical diagnosis was offered, fifteen (53.6%) were thought to be dentigerous cysts. Ten cases from patients less than 19 years old were investigated by means of an immunohistochemical staining technique for the detection of human papilloma virus (HPV) genus-specific structural antigen in formalin-fixed, paraffin-embedded tissue. Three of the ten cases (cases 31, 37 and 38) were positive for HPV capsid antigen, whereas none of ten randomly selected ameloblastomas in adults was positive. A discussion of the clinical and histopathologic comparative findings, with emphasis on treatment results and possible HPV etiology, is included. The preliminary nature of finding HPV in the tumor cells is stressed, with recommendation for further verification and typing with the more sensitive in situ hybridization technique.

Adolescent↗
PubMed1989

Mucoepidermoid tumor: a case report involving the operculum of an erupting permanent second molar.

The mucoepidermoid tumor (carcinoma) accounts for approximately 6% to 8% of all salivary gland tumors. Although rare in children, it is the most common "malignant" salivary gland tumor, having been reported in major and minor (intraoral) salivary gland sites as well as in the maxilla and the mandible. In children, as in adults, it most often occurs in the parotid gland, but a significant percentage is found in the palate and retromolar pad area. Presently, there is no unanimity of opinion about whether to consider all mucoepidermoid tumors malignant or what the most appropriate treatment regimen is. The following is a case report of a mucoepidermoid tumor presumably arising from the reduced enamel epithelium in soft tissue overlying an erupting mandibular second molar in an 11-year-old boy. Theoretical origins of intraoral soft tissue mucoepidermoid tumors are discussed, as well as treatment philosophy. The importance of submitting, for microscopic diagnosis, all tissue removed during surgical procedure is illustrated in this case report.

Carcinoma↗
PubMed1987

Intravascular fasciitis: a case report of an intraoral location.

Nodular fasciitis is a benign reactive fibroblastic proliferation which usually arises from the superficial or deep fascia of the extremities and trunk. In 1981 a distinct variant, intravascular fasciitis (IVF), was reported which possessed the same clinical and histological features of more ordinary forms of nodular fasciitis but, in addition, had a striking involvement of associated arteries and/or veins. A case of intraoral IVF is presented and its clinical and histologic features are compared with those of IVF found elsewhere in the body. A brief discussion of etiology and differential diagnostic considerations is also included.

Adult↗
PubMed1982

Role of N-acetyltransferase phenotypes in bladder carcinogenesis: a pharmacogenetic epidemiological approach to bladder cancer.

A large excess of patients with bladder cancer who have previously been exposed to N-substituted aryl compounds as a result of the production of dyestuff intermediates have the slow phenotype of the enzyme N-acetyltransferase. Among bladder-cancer patients in general, those presenting with T3 or T4 disease or carcinoma-in-situ also show an excess of the slower subtypes. Either N-substituted aryl compounds more frequently produce tumours with this invasive potential if linked with slow acetylation or slow acetylators are more susceptible to tumour production when exposed to some N-substituted aryl compounds. It is suggested that acetylator status could be used to identify susceptible individuals in potentially hazardous occupations.

Acetylation↗
PubMedDate not supplied

Comparative pharmacokinetics of submucosal vs. intravenous flumazenil (Romazicon) in an animal model.

PURPOSE: This study was performed to determine the bioavailability and local tissue toxicological safety of flumazenil (Romazicon) when administered by oral submucosal (SM) as opposed to intravenous (i.v.) injection. METHODS: Six dogs each received SM flumazenil (0.2 mg), and their serum was collected at predetermined time intervals (0-2 h) and frozen (-70 degrees C). Seven days later, the dogs received an identical dose of i.v. flumazenil, and serum samples were again collected, as above. Comparative quantitation of flumazenil levels (i.v. vs. SM) was made using a sensitive HPLC assay (UV detection). Direct/local drug toxicity was visually scored by unbiased raters of color photographs (test and control mucosa) taken at 1, 2, and 7 days following SM flumazenil injection. An oral pathologist examined slides processed from control and treatment tissues (hematoxylin and eosin staining) taken (punch biopsy) 1 week following SM injection to compare with direct clinical scores. RESULTS: Serum flumazenil levels reached a plateau (8.5 +/- 1.5 ng/mL, mean +/- SD) within 4 min of SM drug injection and declined thereafter to -2 ng/mL by 2 h. Bioavailability of SM flumazenil was 101 +/- 14%, based upon measuring the area under the serum concentration-time curves over 1.5 h (AUC 0-1.5 h, SM vs. i.v. drug). Thus, serum drug levels following SM drug administration were broadly comparable to those obtained during the elimination phase of corresponding i.v. drug delivery. Regarding drug tissue toxicity, no evidence of direct drug toxicity was observed by unbiased raters of color photographs (test and control mucosa) taken at 1, 2, and 7 days following SM flumazenil injection. Following pathologic review, no difference was seen in the degree of inflammation between treatment and control tissue. CONCLUSION: At the quantity and concentration used, SM drug flumazenil administration appears to be both a safe and a viable alternative to bolus i.v. drug delivery and worthy of further investigation.

Administration, Oral↗