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Biomedical subjects

C N Bertolami

Publications and source records attributed to C N Bertolami.

At least 37 records · Page 2Linked to original sources
PubMed1988

Distinctive fibroblastic subpopulations in skin and oral mucosa demonstrated by differences in glycosaminoglycan content.

The glycosaminoglycan (GAG) content of rabbit skin, oral mucosa, and cultured [3H]-glucosamine-labeled dermal and submucosal fibroblasts was compared. Skin contained predominantly dermatan sulfate (DS) and a small amount of hyaluronic acid (HA), whereas mucosa contained primarily keratan sulfate (KS) and smaller quantities of HA and DS. Culture medium from dermal and submucosal fibroblasts contained GAGs co-electrophoresing with DS, HA, and chondroitin sulfate (CS), although the relative proportions of these GAG differed. CS isolated from dermal and mucosal fibroblast culture medium co-electrophoresed with chondroitin 4-sulfate (C4-S) on cellulose acetate, whereas dermal medium CS was resistant to digestion by chondroitinase ABC, and mucosal medium CS was chondroitinase ABC-susceptible. The pericellular matrix of dermal fibroblasts contained primarily DS and C4-S/C6-S, as confirmed by chondroitinase ABC digestion; the corresponding fraction of mucosal fibroblasts contained HS and a GAG co-electrophoresing with a C6-S standard, yet resistant to digestion by chondroitinase ABC. Thus the GAG content of dermal and mucosal fibroblasts differed both qualitatively in terms of the type of GAG secreted into the culture medium and pericellular matrix, and quantitatively, in terms of the relative proportions of these GAGs in both fractions. These differences support the concept of distinctive fibroblastic subpopulations in skin and mucosal tissue, inasmuch as the cells were subjected to identical culturing conditions.

Animals↗
PubMed1988

Healing of cutaneous and mucosal wounds grafted with collagen-glycosaminoglycan/silastic bilayer membranes: a preliminary report.

This report describes the healing of cutaneous wounds in experimental animals grafted with collagen-glycosaminoglycan (GAG) matrix/Silastic (Dow Corning Corp., Midland, MI) bilayers; assesses the feasibility of using collagen-GAG matrix as a vehicle for delivering culture-selected, autogenous fibroblasts to cutaneous wound sites; and evaluates the use of collagen-GAG/Silastic bilayers as mucosal substitutes. Cutaneous and mucosal wounds in New Zealand white rabbits were grafted with either acellular collagen-GAG/Silastic membrane or collagen-GAG/Silastic membrane previously seeded with cultured autogenous fibroblasts. Over 63 days, wound sites were analyzed at intervals based on wound contraction and histology. Cutaneous wound successfully incorporated grafted collagen-GAG matrix and were significantly inhibited in their rate and extent of wound contraction. Seeding membrane matrices with autogenous, cultured fibroblasts before grafting caused a marked increase in cellularity that persisted throughout the postgraft period. In mucosa, matrices were exteriorized rather than incorporated. This work suggests that collagen-GAG/Silastic bilayer may have value as a dermal substitute and, more significantly, may be appropriate as a vehicle for delivering culture-selected fibroblasts to cutaneous wound sites.

Animals↗
PubMed1988

Interleukin-1-induced changes in extracellular glycosaminoglycan composition of cutaneous scar-derived fibroblasts in culture.

Fibroblast cultures established from explants of mature scar and skin tissue were analyzed with regard to extracellular glycosaminoglycan (GAG) composition and response to interleukin-1 (IL-1). Following a serum-free 48 hour label with [3H]glucosamine, pericellular and medium GAGs were isolated by precipitation with cetylpyridinium chloride (CPC) and analyzed by cellulose acetate electrophoresis. In addition, susceptibility of the precipitates to Streptomyces hyaluronidase, chondroitinase ABC and heparitinase was determined. Labeled conditioned medium from the scar-derived cells contained both dermatan sulfate (DS) and hyaluronate (HA), as compared to medium from the control (skin-derived) cells which contained predominantly DS. IL-1 induced the appearance of chondroitin 4-sulfate (C4-S) in the medium of the scar cells with no concurrent effect on either DS or HA, and increased the amount of HA in the medium fraction of normal skin cells. The pericellular fraction of the scar-derived cells contained chondroitin 6-sulfate (C6-S) and DS; addition of IL-1 resulted in a shift from DS to heparan sulfate (HS), and the emergence of a pericellular GAG profile similar to that of normal dermal fibroblasts.

Animals↗
PubMed1988

The acoustical characteristics of the normal temporomandibular joint.

Both clinical and empirical evidence suggests that the "normal" temporomandibular joint produces noise during function. The purpose of this study was to determine the conditions under which these noises might arise. Joint sounds and mandibular movements were recorded simultaneously from 200 adults who had no previous history or present symptoms of TMJ pain or dysfunction. The joint sounds were recorded bilaterally by means of two separate miniature vibration transducers mounted on a common headband, and incisal point mandibular movements were measured by a magnetometer tracking system. Recordings were made while each subject opened and closed the mouth, first in a natural and comfortable manner, and then to maximum displacement. Two types of measurements were made: the appearance, onset, and duration of joint-propagated sounds in relation to relative mandibular position; and the spectral properties of the detected sounds. The results of this study showed that for natural opening and closing movements of the mandible, the "normal" TMJ was silent for all age groups. However, for the maximum displacement condition, detectable sounds appeared at the points of maximum displacement in both the opening and closing phases of the cycle in over 80 percent of the subjects. However, these sounds were, as a class, substantially longer than, and spectrally distinct from, abnormal joint sounds, suggesting that they arise from a distinct physical substrate.

Adolescent↗
PubMed1987

The acoustical characteristics of the normal and abnormal temporomandibular joint.

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.

Acoustics↗
PubMed1987

Modulation of fibroblast growth and glycosaminoglycan synthesis by interleukin-1.

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.

Animals↗
PubMed1987

The spectral properties of temporomandibular joint sounds.

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.

Adolescent↗
PubMed1987

Hyaluronidase activity of rabbit skin wound granulation tissue fibroblasts.

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.

Animals↗
PubMed1986

Photodensitometric evaluation of osseous repair following Le Fort I osteotomy.

This study evaluated photodensitometry as a noninvasive method for quantitating bone mineral content (BMC) and osseous repair after Le Fort I osteotomy. Le Fort I osteotomies were performed on 6 Macaca fasicularis monkeys; maxillas were either advanced (Group I, n = 3) or impacted and advanced (Group II, n = 3). Postoperative, standardized lateral cephalometric films were taken at weekly intervals up to 25 weeks and osteotomy site repair was studied using photodensitometry. Segment stability was also evaluated and correlated with measured densities. In both experimental groups, clinical stability occurred at about the same time (45.7 and 48.7 days postoperatively) despite large differences in the size of the initial surgical defects. The net rate (slope) of osteotomy site remineralization was significantly different (Group II greater than Group I), but the relative difference in film absorbance between the osteotomy site and adjacent bone at the time of clinical stability was the same. This difference can be extrapolated from early postoperative films and may constitute a useful parameter for predicting when clinical stability will be achieved.

Animals↗
PubMed1986

Separation and properties of rabbit buccal mucosal wound hyaluronidase.

This study establishes the existence of a mammalian buccal mucosal wound hyaluronidase (hyaluronate 4-glycohydrolase; EC 3.2.1.35) having properties distinct from those of the endogenous lysosomal hyaluronidase of normal (uninjured) buccal mucosa. A time-dependent change in hyaluronidase activity was measured, with the highest specific activity occurring on post-wound day 4 (7.7 +/- 1.3 units/mg protein), followed by consecutive decreases until activity was no longer discernible by day 21. Mucosal wound hyaluronidase closely resembled a previously described integumentary wound endoglycosidase in terms of a high pH optimum (5.0-6.0), distinct (but non-exclusive) substrate preference for hyaluronic acid, and ability to generate saturated depolymerization products by an endoglycosidic hydrolysis.

Animals↗
PubMed1985

Identification and characterization of rabbit buccal mucosal hyaluronidase.

This study establishes the existence of a mammalian buccal mucosal hyaluronidase having properties typical of a lysosomal enzyme. Mucosal hyaluronidase exhibited a distinct substrate preference for hyaluronic acid, generated saturated de-polymerization products by endoglycosidic hydrolysis, and possessed a pH optimum of 3.5 and an isoelectric point of 5.9.

Animals↗
PubMed1983

Alterations in purine salvage and hypoxanthine levels in granulation tissue during skin wound repair.

We report the levels of hypoxanthine in rabbit skin granulation tissue, harvested at different postwound intervals and from various locations within the wounds. The effect of full-thickness autogenous skin grafts on hypoxanthine levels has also been examined. The levels of inosine, xanthine, adenosine 5'-monophosphate, and inosine 5'-monophosphate are reported as well. The correlation between the level of these compounds and the healing process suggests they may be useful indicators of the extent of tissue damage.

Animals↗
PubMed1982

Chin trauma: a clue to associated mandibular and cervical spine injury.

Chin trauma, mandibular fracture, and cervical spine injury are often progressive components of a single injury pattern. Knowledge of a commonly occurring sequence of damage in patients who have sustained minor head trauma helps to minimize diagnostic omissions and provides a rational basis for deciding how extensive the patient's evaluation should be. Chin laceration associated with underlying skeletal damage has been described previously, but its diagnostic significance seldom has been appreciated. This report describes representative patients with fractures of the cervical spine and of the mandible secondary to chin trauma and suggests a protocol for efficient diagnosis.

Adult↗
PubMed1982

Quantitation of experimental postsurgical edema.

Many oral surgical procedures are followed by varying degrees of edema. Although numerous methods of minimizing swelling have been advocated, no technique has gained complete acceptance. A major problem has been the inability to document the efficacy of suggested treatments convincingly. The present study quantitates edema by measuring differences in percentage of water content between operated and unoperated tissues over a period of one week. Percentage difference in water content peaked by 48 to 72 hours and was followed by gradual resolution. By use of this model system, a steroid-induced, dose-dependent suppression of postsurgical swelling was confirmed.

Animals↗
PubMed1982

Identification, characterization, and partial purification of mammalian skin wound hyaluronidase.

A recently described mammalian wound hyaluronidase is successfully characterized and partially purified in the current study. Peak enzyme activity occurred on postwound day 7, pH optimum 4.5. Both crude and purified wound enzyme exhibited endoglycosidic activity against hyaluronate and chondroitin-4-sulfate but not against chondroitin-6-sulfate or dermatan sulfate. A 5.3-fold increase in activity was obtained by the DEAE-Sephadex purification technique described. Polyacrylamide gel electrophoresis yielded a single major band near the gel's midrange and one minor band of lesser electrophoretic mobility. These enzyme characteristics support a biochemical analogy between tissue repair in skin and numerous developmental systems and may also provide a simple means for enzymatic differentiation among chondroitin sulfate isomers.

Animals↗
PubMed1981

The role of CT scan in diagnosis of TMJ ankylosis: report of case.

Computed tomography was found to be useful in identifying complete, unilateral, fibro-osseous ankylosis of the temporomandibular joint in a case of mandibular hypomobility. The scan had increased sensitivity and reliability in studying hard and soft tissues of the TMJ and gave the patient less radiation exposure than conventional tomography or arthrotomography. The current report incorporates the CT scan into a radiographic protocol for the diagnosis of mandibular hypomobility and identifies situations in which conventional tomography can be omitted.

Adult↗