Biomedical subjects

J L Kasperbauer

Publications and source records attributed to J L Kasperbauer.

5 recordsLinked to original sources

PubMed1992

Early mucosal changes in experimental sinusitis.

Normal mucociliary flow is a significant defense mechanism in the prevention of acute sinusitis. We have undertaken a study to examine the early sinus mucosal and mucociliary changes that occur in response to acute infection. Twenty rabbits were evaluated for 5 days after an obstructed maxillary sinus was inoculated with either Streptococcus pneumoniae, Hemophilus influenzae, Pseudomonas aeruginosa, or a sterile saline solution. Data collected included measurements of sinus mucosal ciliary beat frequency, quantitation of ciliated cell losses, and electron microscopic observations. Results demonstrate statistically significant (p < 0.05) changes in mucosal ciliary beat frequency that were either excitatory or inhibitory, depending both on the length of the infection and the specific organism. No changes in ciliary beat frequency were observed in the control animals (p > 0.55). Control animals likewise demonstrated no loss of ciliated cells from mucosal epithelium; however, dramatic losses of ciliated cells from the sinus mucosa of the experimental groups were observed. These losses occurred at different rates, depending on the infecting organism, but all infected groups demonstrated a > 86% decrease in the number of viable ciliated cells from the sinus mucosa after sinusitis of 5 days duration. We conclude that a significant loss of ciliated cells from sinus mucosa and a corresponding disruption of normal mucociliary flow occurs early after exposure to pathogenic organisms and is a significant predisposing factor in the development of acute sinusitis.

Animals↗

PubMed1992

Biological characteristics of primary cultures of human gallbladder epithelial cells.

Epithelial cells of the gallbladder have potential to represent an important model for studies of ductal epithelial in normal and pathological states. We therefore initiated studies to establish human gallbladder epithelial cells (GBEC) in culture. GBEC were isolated by trypsinization of small tissue fragments from human gallbladders obtained at cholecystectomy; cells were plated on tissue culture dishes and grown in defined MCDB 153 medium containing added growth factors. In this medium, GBEC showed a plating efficiency of approximately 1%; those GBEC that attached formed colonies and proliferated, as demonstrated by autoradiographic analysis of [3H]thymidine incorporation into DNA. Cultured GBEC expressed two markers found on GBEC in situ, i.e., gamma-glutamyl transpeptidase and cytokeratin 19. By using various attachment substrates, with and without added serum, increased plating efficiency and better growth were achieved. When type IV collagen was used as substrate and 10% fetal bovine serum was added to MCDB 153, passage of GBEC was possible, and cells proliferated through five to six population doublings. GBEC in culture under all conditions eventually enlarged, showed vacuolization, and demonstrated irreversible growth arrest. Nonetheless, the culture conditions described here allow for preparation of large quantities of highly enriched human GBEC.

Cell Division↗

PubMed1990

Proliferation and differentiation characteristics of normal human squamous mucosal cells of the upper aerodigestive tract.

Normal human squamous mucosal cells of the soft palate, buccal surface, epiglottis, hypopharynx, floor of the mouth, and tongue were cultured in vitro in serum-free medium. In medium MCDB 153 containing epidermal growth factor, insulin, bovine pituitary extract, and 0.1 or 2.0 mmol/L Ca++, squamous mucosal cells double every 24 hours. These cells then can be induced to arrest their proliferation reversibly by treatment with transforming growth factor-beta or ethionine, and they can irreversibly growth-arrest during senescence or when cultured in growth factor-deficient medium containing 2 mmol/L Ca++. The latter medium also induces differentiation, as does culture of cells in serum-containing medium. Serum-containing medium furthermore promotes extensive cell stratification and the formation of multilayered squamous mucosal tissue specimens that can be removed intact by Dispase treatment. These specimens represent potential autogenous mucosal grafts that can be used in patients who require reconstructive surgery of the oral cavity and oropharynx. Normal human squamous mucosal cells therefore closely resemble keratinocytes derived from the epidermis in the mechanisms that regulate proliferation and differentiation. This model cell system should facilitate future studies on upper aerodigestive tract squamous mucosal cell physiology and pathophysiology.

Calcium↗

PubMed1988

Human squamous carcinoma cells express complex defects in the control of proliferation and differentiation.

Four human squamous carcinoma cell (SCC) lines (SCC-9, SCC-13, SCC-15, and SCC-25) were studied to characterize their relative ability to control proliferation and differentiation. These experiments were based on previous data that established that in normal human keratinocytes three distinct and sequential steps are involved in the integrated control of proliferation and differentiation: 1) reversible growth-arrest at a predifferentiation state, 2) irreversible loss of proliferative potential, and 3) terminal differentiation. The current results show that SCC can show changes in the culture conditions required to undergo reversible growth-arrest and SCC can express partial or complete defects in their ability to irreversibly growth-arrest or terminally differentiate. For example, SCC-9 and SCC-25 cannot irreversibly growth-arrest or terminally differentiate, SCC-13 can irreversibly growth-arrest but cannot terminally differentiate, and SCC-15 can irreversibly growth-arrest and terminally differentiate to a moderate extent. These results therefore extend previous data by establishing that the malignant transformation of human epithelial cells does not simply result from defects in the control of terminal differentiation but rather from a combination of complex defects in the regulation of proliferation and differentiation.

Calcium↗

PubMed1987

Nasal valve physiology. Implications in nasal surgery.

Knowledge of the structure and function of the nasal valve region is required by all who operate on the nose. This article defines and classifies nasal valve region abnormalities; discusses principles, goals, and details of surgery in this area; and considers strategies to avoid or minimize complications, especially in cosmetic rhinoplasty.

Cartilage↗