Faculty Bibliography

Cellular response to inflammatory mediators is central to the regulation of new scar tissue formation. Fibroblasts derived from normal dermis and from 14-day old skin wound granulation tissue were compared with regard to production of non-collagenous extracellular matrix and response to interleukin-1 (IL-1). Following a serum-free 48 hour labeling with [3H]-glucosamine, the cellular, pericellular and medium fractions from the two cell types were collected, precipitated with cetylpyridinium chloride (CPC), and analyzed by cellulose acetate electrophoresis. In addition, susceptibility of precipitates to the polysaccharidases Streptomyces hyaluronidase and chondroitinase ABC was determined. Labeled conditioned medium from both cell types contained dermatan sulfate (DS) and hyaluronate (HA), although the relative amounts of these glycosaminoglycans (GAGs) were different. Medium from normal dermal fibroblasts contained more DS than HA, while 14-day granulation tissue culture medium contained a proportionately larger amount of HA. The amount of HA in the medium fraction of normal dermal fibroblasts was increased approximately 10-fold in the presence of 5 U/ml IL-1, while HA in the medium of wound-derived fibroblasts was quantitatively unaffected by addition of the mediator. Pericellular GAG consisted of heparan sulfate (HS) and chondroitin sulfate (CS), with no observable differences between the two cell types and no effect of IL-1 on this profile for either cell type. Conditioned medium from both cell types contained IL-1 activity (measured by thymocyte proliferation assay), with medium from 14-day granulation tissue fibroblasts containing 10-fold higher activity than normal dermal fibroblast medium

The objective of this work was to identify and compare hyaluronidase activities of normal dermal and dermal wound granulation tissue fibroblasts. Direct evidence of the fibroblast as a source of tissue hyaluronidase was obtained. Fourth passage rabbit dermal fibroblasts were harvested on culture days 4, 8, 14, 18, and 22. Hyaluronidase activity and [35S]-sulfate- or [3H]-glucosamine-labeled glycosaminoglycans (GAGs) were monitored. Hyaluronidase assays were performed on medium and cellular fractions at the designated intervals. Enzyme activity of cellular fractions for both normal dermal and 14-day post-wound granulation tissue fibroblasts increased progressively through culture day 8. Thereafter (days 14-22), an eight-fold drop in cellular activity was coupled with cell death and emergence of hyaluronidase activity in medium fractions. Marked increases in degradation of secreted matrix components were concurrent with lysis-induced release of hyaluronidase. In this culture system, hyaluronidase activity was confined exclusively to cellular fractions and was released into the medium only under non-physiological conditions conducive to cellular death and lysis. Accordingly, this work suggests that previously reported skin wound hyaluronidases may be of fibroblastic origin and that susceptible GAGs are not degraded extracellularly, but, rather, must be internalized as a prerequisite to depolymerization

Spectral analyses were performed on sounds recorded from TMJ's that had previously been classified into different intracapsular categories, in an attempt to determine whether the inherent properties of these sounds were unique for each different disorder. A total of 55 joints was studied: 32 were diagnosed as displaced disc with reduction [DDR], 10 were diagnosed as displaced disc without reduction [DDN], and 13 were diagnosed as degenerative joint disease [DJD]. The spectral analysis for each recorded joint sound was performed using a Fast Fourier transform routine, the results of which were plotted as a frequency vs. amplitude envelope. These analyses showed that different intracapsular TMJ disorders were characterized by sounds whose energy distribution patterns, while showing certain across-group differences, usually shared significant common spectral properties. The joint-propagated noises associated with DDR, DDN, and DJD were each characterized by a spectral envelope whose primary band of energy was centered around a peak at approximately 1 kHz, and which dropped off from that point to background levels. These patterns presumably reflect the resonance characteristics of the disordered joint as defined by the mass and stiffness of its articulating surfaces. Based on the findings of this study, it would appear that comparisons of the spectral envelopes of joint-propagated sounds would have only limited application in the differential diagnosis of intracapsular TMJ disorders

This paper describes the results of a clinical study that recorded and analyzed sounds emitted from the temporomandibular joint (TMJ) during simple function as a means for differentially diagnosing disorders of the joint. The technique is based on the principle that each different disorder of the TMJ produces a different effect on the mechanical relationship between the articulating surfaces of the joint, and that these mechanical effects can be determined by analyzing joint sounds in relation to joint movement. A total of 79 patients (101 joints) were studied; 32 (46 joints) were diagnosed as having extracapsular disorders, (primarily MPD), 27 (32 joints) were diagnosed as having a displaced disc with reduction, nine (10 joints) were diagnosed as having a displaced disc without reduction, and 11 (13 joints) were diagnosed as degenerative disease (osteoarthritis/arthrosis). In addition, 25 adults (50 joints) with normal TMJs were included as controls. The results of this study demonstrated that each specific disease of the TMJ is characterized by a unique relationship between the sounds propagated by the joint and the movement of the joint. Essentially, an extracapsular disease was characterized by acoustic quiescence during natural (as opposed to maximal) jaw movement, an internal derangement by a usually symmetrical short duration click/reciprocal click, or random click complex, depending on the subcategory of the disorder, and a degenerative disease by a long duration noise during either or both jaw opening and closing. The data further suggest that the technique serves to reflect the mechanical events (and abnormalities) that are involved in function of the diseased joint and has potential for use as a clinical diagnostic tool