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Biomedical subjects

L S Hansen

Publications and source records attributed to L S Hansen.

At least 55 records · Page 3Linked to original sources
PubMed1984

The influence of the hair cycle on the thickness of mouse skin.

The data on mouse skin thickness reported here was prompted by the need to know the true position of basal cells of the epidermis and hair follicles as these are important "cells at risk" for a variety of skin reactions including carcinogenesis following exposure to radiation. There is little reliable data in the literature and most previous reports have ignored the shrinkage of skin that occurs because of its natural elasticity. The values determined for mouse flank skin in telogen--the resting phase of the hair cycle for the different skin layers--are epidermis 10 micron, corium 250 micron, adipose layer 150 micron, and hair follicle depth 150 micron. Three days after chemical depilation which triggers the hair follicles into active cycle (anagen) the epidermis doubles in thickness, remains at this value for 7 days, and then gradually returns to telogen values by day 18. The corium and adipose layers also increase significantly to reach approximately 390 micron and approximately 260 micron, respectively, by day 10 and then return to control values from day 15 onward. The change in hair follicles depths are more dramatic with active follicle basal cells reaching approximately 450-550 micron into the adipose layer between days 7 and 15. One important finding is that chemical depilation does not affect the telogen thickness of skin-the teleogen values for the epidermis and dermis immediately prior to and immediately after depilation were similar to those 23 days later at the beginning of the next telogen phase.

Animals↗
PubMed1984

Histopathologic spectrum of oral Kaposi's sarcoma.

There has been a striking increase in the incidence of oral Kaposi's sarcoma in association with acquired immunodeficiency syndrome (AIDS). Oral lesions are seen in approximately 50% of AIDS patients with Kaposi's sarcoma. Lesions may appear as a flat or raised pigmented area, often resembling a benign vascular lesion, and are commonly found on the palate. Useful histopathologic criteria for the recognition and diagnosis of oral Kaposi's sarcoma include (1) atypical vascular channels (especially in early lesions), (2) a prominent spindle cell component in later lesions, (3) extravasated red blood cells, (4) hemosiderin, (5) the presence of eosinophilic bodies, (6) chronic inflammatory cells in early lesions, and (7) mitotic figures in tumor-stage lesions.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Second primary tumor associated with salivary gland cancer.

That patients with salivary gland cancer are at increased risk of second primary tumors has been suggested in several studies. This report presents the case of a 53-year-old woman with an epithelial-myoepithelial carcinoma of intercalated duct origin occurring in the parotid gland synchronously with a follicular cell carcinoma of the thyroid gland. This is believed to be the first report of such an association.

Adenocarcinoma↗
PubMed1984

Changes in the DNA labelling index after beta irradiation of the mouse epidermis.

This study looked at the changes in the interfollicular DNA labelling index (LI) with time after strontium-90/yttrium-90 beta irradiation of approximately 100 mm2 of mouse flank skin, after a dose of 100 Gy which produces transitory moist desquamation. Within 24 hr of such a dose the LI of the irradiated area was essentially zero (0.07 +/- 0.03%), whilst those of the side area and of the control area were 15.0 +/- 2.6% and 21.4 +/- 2.7%, respectively. The LI of the side and the control areas then fell within 3-5 days to approximately 4% and approximately 2% respectively, whilst that of the irradiated area rose rapidly to a peak value of 30.2 +/- 1.7% at 10 days post-irradiation. There was a 20% reduction in the diameter of the area with detectable radiation damage within 5 days, and this is primarily due to cell proliferation and migration from the unirradiated margins of the field. In contrast, between days 10 and 20 the major source of repopulation is probably derived from local migration and proliferation of surviving hair follicle basal cells within the irradiated field.

Animals↗
PubMed1984

A methodologic study of histologic classification and grading of malignancy in oral squamous cell carcinoma.

A multifactorial grading system was devised for the histologic classification and grading of malignancy in carcinoma of tongue and floor of mouth. The system is presented with all morphologic variables defined and illustrated. Statistical analysis of the classification of 52 cases of squamous cell carcinoma revealed that the reproducibility of the system by two independent observers was good for all morphologic variables. Mean total malignancy, tumor cell population, and tumor-host relationship scores showed statistically significant correlations with mean ratings for all the different morphologic parameters, with certain specified exceptions. Reasons for the exceptions and lack of correlation of the histotechnical and theoretical errors of previous grading systems are explored.

Biopsy↗
PubMed1984

Encysted parasitic larvae in the mouth.

Oral appearances of intestinal parasitic disease are rare. One such appearance is the presence in oral tissues of encysted or encapsulated larvae of organisms from the classes Cestoidea and Nematoda. Cestode larvae form cyst-like lesions that are often clinically diagnosed as mucoceles. In these lesions, the cyst cavity is lined by fibrous tissue with inflammatory cells, and contains fluid and the larval stage of a parasite. The diagnosis of these parasitic cysts is more frequently made in younger persons. The cysts may be treated by simple excision, but care must be taken that the cyst does not rupture, as in some parasites this may result in new cyst formation. Nematode infection in the oral cavity, the most common of which appears to be trichinosis, is rarely reported. Patients with oral or maxillofacial (or both) parasitic disease must undergo a thorough medical investigation to exclude possible life-threatening involvement in other parts of the body.

Adult↗
PubMed1984

Nonstochastic effects of different energy beta emitters on the mouse skin.

The effect of irradiating varying areas of mouse skin from 860 down to 0.8 mm2 with different energy beta emitters was studied to clarify protection problems of localized doses to the skin. Both 90Sr and 170Tm sources show area effects for dose-response curves. The 90Sr doses that produced moist desquamation in 50% of irradiated fields (MD-50 doses) were 22, 42, 70, and 1000 Gy for 400-, 95-, 20-, and 0.8-mm2 sources. The MD-50 doses for 170Tm were 50, 54, 90, and 170 Gy for 860-, 64-, 20-, and 3.1-mm2 sources. Thus for the larger 170Tm sources there is much less area effect. There was no significant difference in effect between the different energy 90Sr and 170Tm sources for moist desquamation. A simple hypothesis based upon the repopulation of epithelial cells from the edges of the irradiated field and/or from surviving follicle basal cells can explain these area and energy effects in the mouse and in parallel pig skin experiments. The doses needed for 50% of the mice to show ulceration after 64-, 20-, and 3.1-mm2 170Tm sources were 260, 550, and 8300 Gy, respectively, while those for 90-, 20-, and 0.8-mm2 90Sr sources were 150, 210, and 3100 Gy. Thus there is a definite area and energy effect for these sources for this deep dermal damage. The steep rise in dose needed to produce given skin reactions for the smallest area (0.8 mm2) should reassure those faced with assessing the hazard of sub-millimeter-sized particles in/on human skin.

Animals↗
PubMed1983

The differential diagnosis of pyostomatitis vegetans and its relation to bowel disease.

Pyostomatitis vegetans is a rare oral disorder that is usually associated with bowel and/or skin disease. The clinical appearance is of soft hyperplastic folds of mucosa characterized by small miliary abscesses with superficial erosions. Upon analysis of the clinical, histologic, and immunofluorescent findings, cases of pyostomatitis vegetans may be classified as the oral manifestation of either pyoderma vegetans of Hallopeau, pemphigus vegetans of Hallopeau, or pemphigus vegetans of Neumann, although the exact definitions and even the existence of these diseases as separate entities are still a matter of controversy.

Adult↗
PubMed1983

Minor salivary gland calculi. A clinical and histopathological study of 49 cases.

The clinical and histopathological characteristics of 49 previously unpublished cases of sialolithiasis of minor salivary glands are presented. The lesions are usually solitary, small, submucosal nodules, which are hard or firm and freely movable in the surrounding tissue and on rare occasions may be multiple. They are most often seen in the buccal mucosa and the upper lip of patients in the 5th, 6th or 7th decade, but are rarely found in the lower lip and palate. The authors found that clinicians usually failed to include calculi in the differential diagnosis and further, they concluded that minor salivary gland calculi are more common than generally believed. In contrast to other studies of calculi in major and minor salivary glands, the periphery of the stones was found to be less frequently lamellated and mineralized. The authors also confirmed the finding of mucous cell metaplasia of ductal epithelium and commented on its possible role in the pathogenesis of sialolithiasis.

Adolescent↗
PubMed1983

Bilateral ureteral obstruction as a complication to a perforated appendix. Report of a case.

A 44-year-old man developed anuria 8 days after an operation for a perforated appendix. An intravenous pyelography showed delayed excretion on both sides with hydronephrosis, a right dilated ureter and no contrast passing to the bladder. On neither sides a ureter-catheter could be passed through the obstructions from below. By surgical intervention no ureter-catheter could be passed through the obstructions from above, and both ureters were drained with a T-tube. The benign obstruction was caused by a periappendicular abscess with inflammation and oedema of the ureteral and periureteral tissues. The condition was normalized within 7 days.

Adult↗
PubMed1982

Neutralizing antibody to herpes simplex virus type 1 in patients with oral cancer.

Neutralizing antibody to Herpes simplex virus type 1 (HSV-1), type 2, and measles virus was measured in the serum of patients with oral cancer, patients with oral leukoplakia, and in control subjects who were smokers and nonsmokers. Significantly higher titers to HSV-1 were found in controls who smoked than in controls who did not smoke. Patients with untreated oral cancer had HSV-1 neutralizing titers similar to those of the controls who smoked, but those with later stage tumors had higher titers than those with earlier stage tumors. In patients who were tumor free after treatment for oral cancer, higher antibody titers to HSV-1 were associated with longer survival times. No association was found between clinical status and antibody to measles virus. The data are consistent with a role for both HSV-1 and smoking in the pathogenesis of oral cancer.

Antibodies, Viral↗
PubMed1982

Comparison of the osteoblastoma in gnathic and extragnathic sites.

A comparative analysis of extragnathic and gnathic osteoblastomas showed that the lesion was similar clinical, radiologic, and histologic features in these two sites. Osteoblastomas in both areas most commonly present as painful swellings and appear radiographically as lucent or sclerotic lesions, depending on the degree of calcification. The typical histologic appearance is of a highly vascularized stroma with osteoblasts and abundant trabeculae of osteoid and immature bone in various degrees of calcification. These lesions are most often treated conservatively by curettage or local excision. The results of this comparison indicate that oral and maxillofacial surgeons can draw on the wider experience of other types of surgeons when treating this rare lesion.

Adolescent↗
PubMed1982

Variations in keratinizing odontogenic cysts and tumors.

Classification of keratinizing odontogenic cysts and tumors is not entirely satisfactory to the clinician and pathologist because many individual cases do not fit precisely into a particular category. This report describes the nature of some of these marginal lesions in order that similar cases may be diagnosed and treated correctly. Eight selected cases are described histologically, and their clinical behavior is discussed. It is concluded that the histopathologic appearance of the odontogenic epithelium in odontogenic cysts and tumors varies to a large extent and gives rise to a variety of keratinizing lesions. It is further concluded that some varieties are unique and, for the present, treatment of the rare lesions depends more on observed clinical behavior, with morphology having a lesser role in prognosis. It is important that clinicians as well as pathologists be aware of the wide variation of these keratinizing lesions so that the patient will receive optimum treatment.

Adult↗