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Biomedical subjects

L S Hansen

Publications and source records attributed to L S Hansen.

At least 91 records · Page 5Linked to original sources
PubMed1979

The histomorphologic spectrum of the gingival cyst in the adult.

Gingival cysts with clinical manifestations are relatively uncommon lesions. The present study adds thirty-three new cases to the literature and analyzes their clinical and histologic features. The mandibular cuspid and first premolar region was found to be the most common location. The epithelial lining of the cysts was of several types. The most common type was a thin, flattened lining with or without localized thickenings (buds). Other types included nonkeratinized stratified squamous epithelium, keratinized stratified squamous epithelium, and parakeratinized epithelium with palisading basal cells. Gingival cysts should be distinguished from lateral periodontal cysts on the basis of their origin in the gingiva rather than in bone. It appears that most gingival cysts with clinical manifestations are of odontogenic origin.

Adolescent↗
PubMed1977

Oral surgery program university of california, san francisco.

The two cases presented here demonstrate a successful therapeutic modality with resection followed by immediate reconstruction with bone grafts. At least one of the cases presented seems to indicate that the tumor is relatively less aggressive than the simple ameloblastoma. The histopathology of the two cases suggests that this odontogenic tumor has a wider histologic variation than originally described by Pindborg.

Adult↗
PubMed1975

Studies on oral lichen planus. III. Clinical and histologic correlations in 213 patients.

Two hundred thirteen adults in whom oral lichen planus had been diagnosed were studied in order to compare clinical and microscopic findings. In spite of considerable variabilities in both aspects, there was clinical and histologic agreement in 96 per cent. Alertness on the part of the clinician and pathologist is essential for diagnosis of atypical cases.

Adult↗
PubMedDate not supplied

Clear cell odontogenic tumor--a new histologic variant with aggressive potential.

This report delineates the clinical and laboratory findings for a previously unreported neoplasm of putative odontogenic origin. We describe the clinical, radiographic, operative, histologic, histochemical, and ultrastructural findings of the tumor in three women. All lesions were centrally located in the jaw bones, were expansile, and, except for mobile teeth and/or jaw enlargement, exhibited few symptoms. Radiographically, there was bone and tooth destruction resulting in poorly delineated margins. Microscopically, the tumors were nearly identical in that they consisted primarily of large sheets and islands of uniform vacuolated and clear cells without evidence of amyloid deposition, calcification, or glandular differentiation. One of the lesions recurred 1 1/2 years after removal without evidence of metastasis. The results, based only on these cases, suggest that this is a locally aggressive neoplasm of odontogenic origin. Casual microscopic examination of this rare neoplasm could result in misdiagnosis as a metastatic clear cell neoplasm, especially renal cell carcinoma.

Aged↗
PubMedDate not supplied

Mixed odontogenic tumors: an analysis of 23 new cases.

The ameloblastic fibroma, ameloblastic fibrodentinoma, and ameloblastic fibro-odontoma are mixed odontogenic tumors that are considered to arise from both epithelial and mesenchymal elements of the tooth germ. This article presents the clinical and histopathologic characteristics of 23 new cases. The patients' ages ranged from 3 to 19 years (median 9). Most tumors were asymptomatic and were associated with an unerupted tooth or teeth. All patients were treated with simple enucleation of the tumor. We found that histologically these lesions comprise a spectrum. Some were probably benign odontogenic tumors (neoplasms) and others were odontomas undergoing maturation (hamartomas); however, in any given case we were, on histologic grounds, unable to differentiate the two. The majority, if not all, of our cases were nonaggressive with little or no tendency to recur, whereas some reported cases have exhibited local aggressiveness and recurrence, suggestive of neoplasia. In our opinion, it is clinically important to distinguish the mixed odontogenic tumors from ameloblastoma since the mixed tumors, found mostly in children, are relatively benign when compared to ameloblastoma, which is found in all age groups (usually adults). The usually innocuous behavior of these lesions does not justify aggressive treatment initially, and simple enucleation should be appropriate in most cases.

Adolescent↗
PubMedDate not supplied

Neonatal cocaine exposure, activity, and responsivity to cocaine in a rodent model.

This study examined the effects of neonatal cocaine exposure on running wheel activity and subsequent responsivity to cocaine using a rodent model. Subjects were artificially reared from postnatal (PND) days 4-10 via an intragastric cannula. The four treatment groups included two cocaine doses (20 mg/kg/day and 40 mg/kg/day), an artificially reared control and a normally reared suckled control. Subjects were tested at either PND 21 through PND 24 (Experiment 1) or PND 60 through PND 70 (Experiment 2) for 2 consecutive days. Testing consisted of a 30-min habituation period followed by injection of either saline (Day 1) or cocaine (Day 2) and an additional 60-min test session. Neonatal treatment had little effect on baseline activity or activity following saline injection at either age. All subjects showed an activation with cocaine injections, however, the activation was more pronounced in juveniles. Again, neonatal treatment did not interact with response to cocaine. These findings suggest that neonatal cocaine exposure does not alter activity or long-term responsivity to 20 mg/kg cocaine as measured in the running wheel apparatus.

Aging↗