Effect of fibroblast growth factor-1 on the expression of early growth response-1 in human periodontal ligament cells.

BACKGROUND AND OBJECTIVES: Early growth response-1 is a nuclear transcription factor implicated in regulating cell proliferation. Fibroblast growth factor-1 is the prototypic fibroblast growth factor involved in the proliferation and differentiation of various cell types. Expression of early growth response-1 induced by fibroblast growth factor-1 thus may be very important for cell growth, during both development and wound healing in oral tissue. However, little is known about the expression and kinetics of early growth response-1 in fibroblast growth factor-1-stimulated oral cells. The aim of this study was to investigate the effects of fibroblast growth factor-1 on the expression of early growth response-1 in human periodontal ligament cells. MATERIAL AND METHODS: Periodontal ligament cells were cultured in medium containing 1, 10 or 100 ng/mL of fibroblast growth factor-1 for 45 min or with 10 ng/mL of fibroblast growth factor-1 for 15, 30, 45, 60 or 120 min. The proliferation of periodontal ligament cells was evaluated by measuring 5-bromo-2'-deoxyuridine incorporation. The expression of early growth response-1 mRNA and protein, and the localization of early growth response-1 protein, were examined by western blotting, northern blotting and immunocytostaining. RESULTS: 5-Bromo-2'-deoxyuridine incorporation correlated directly with increases in fibroblast growth factor-1 concentration, and 5-bromo-2'-deoxyuridine incorporation peaked 45 min after starting treatment. Early growth response-1 protein was expressed in response to a concentration of fibroblast growth factor-1 as low as 1 ng. Peak expression of early growth response-1 mRNA was observed at 15 min and that of early growth response-1 protein at 60 min. The 140-kDa early growth response-1 protein was not detected in the nuclear fraction, and the peak expression of the 80-kDa early growth response-1 protein occurred at 60 min. Early growth response-1 localized in or around the nucleus at 30 min. CONCLUSION: These results show that a concentration of fibroblast growth factor-1 as low as 1 ng induces the expression of early growth response-1 protein, and that the 80-kDa early growth response-1 protein functions in the nucleus of periodontal ligament cells treated with fibroblast growth factor-1.

Sequencing of the primary adhesion domain of bovine von Willebrand factor.

A cDNA library, constructed from bovine heart endothelial cell poly(A)+ RNA, was screened using a BstXI fragment of human von Willebrand and factor (vWF) cDNA as a probe. This probe codes for the major adhesion domain of vWF that includes the GPIb, collagen and heparin binding domains. Of the ten positive clones obtained, a clone that spanned the region of interest was sequenced by the dideoxynucleotide method yielding a sequence of 1550 bp. This region of the bovine cDNA codes for amino acids corresponding to #262 to #777 in human vWF and encompasses the entire pro adhesion domain. Both the nucleotide sequence and the deduced amino acid sequence are 82% homologous to those of human vWF. Cysteine residues #471, 474, 509 and 695, which form intrachain bonds in human vWF, are also present in the bovine vWF sequence.

Production and characterization of a monoclonal antibody to human type III collagen.

Human type III collagen from placenta was isolated and purified for use as an immunogen. A monoclonal antibody was produced which specifically recognizes epitopes unique to type III collagen. The specificity of the antibody was determined by inhibition ELISA, an immunoblot assay, and by immunoprecipitation. Results indicated that the monoclonal antibody recognized only the alpha 1(III) polypeptide chains and did not crossreact with type I, IV, or V collagen. The monoclonal antibody was also used for immunohistochemical localization of type III collagen in tissue sections of human placenta, bovine spleen, and lymph node. In placenta, both large and small blood vessels showed pronounced staining of the tunica media, which contains largely smooth muscle cells, known to synthesize type III collagen. In contrast, the intimal areas and endothelial cells showed no staining with the antibody. In the placental villi, staining was limited to the villous core, where fine fibrillar structures showed strong staining. In lymph nodes, the capsule and pericapsular adipose cells were surrounded by a covering of type III collagen. Within the parenchyma of the node, staining was localized to a branching, reticular array of fine fibers. In the spleen, staining was pronounced in the capsule, splenic trabeculae, and white pulp, where blood vessel staining was especially prominent. The red pulp and splenic sinuses contain little or no type III collagen. The fine network-like or reticular staining pattern found in the lymph node parenchyma is consistent with the staining pattern of the protein reticulin, and suggests that type III collagen may be closely associated with reticulin in certain tissues. Since the role of type III in tissues is unclear, this reagent will be useful in providing new information in this regard.

Characterization of a fibroblast cell from the urinary bladder wall.

For the first time we report on the growth, culture, and matrix production characteristics of a cell type isolated from the lamina propria of the urinary bladder wall. A fibroblastlike cell was identified as distinct from bladder detrusor smooth muscle cells and urothelium based on morphology, growth characteristics, and immunohistochemical staining. Characterization of extracellular matrix synthesis by this cell type using 35S-methionine metabolic labeling demonstrated that these cells are capable of secreting components of the surrounding connective tissue, including several fibrillar collagens, a basement membrane collagen, and fibronectin.

Calf augmentation and correction of contour deformities.

In general, augmentation of soft tissue has been a problem for plastic surgeons because of the body's protective mechanisms against foreign material, but silicone rubber implants are the author's choice of the materials currently available. The aesthetic considerations of the shape of the calf and techniques and complications are discussed. This article is generously illustrated with case examples.

Complications in endoscopic plastic surgery.

Owing to the relatively short time endoscopic-assisted plastic surgery procedures have been done, there are few published reports of complications. The experiences of the faculty from the Endoscopy in Plastic Surgery: A consensus Multidisciplinary Symposium as well as the few published reports in the literature have been reviewed. The complications associated with endoscopic techniques are similar to those with open techniques. It is clear, however, that a subset of complications specific to endoscopic procedures exists. As endoscopic techniques and instrumentation are further developed, and as surgeons move higher up on the "learning curve", these complications should be reduced.

The role of collagen in bladder filling.

While this model is speculative, it is attractive in that it can account for the physiologic properties of the bladder. It also implies that connections must exist between the tension generating elements, i.e., the smooth muscle cells, and the other components of the bladder. In bladders that become noncompliant, it is likely that there is some interference with the ability of the collagen fibers to elastically and reversibly alter their tortuosity. This, predictably, would reduce total bladder capacity. Further studies will be required to establish the relationship between compliance changes and the passive mechanical elements of the bladder wall that comprise its structural protein matrix.

The incidence, classification, etiology, and embryology of oral clefts.

There are numerous problems encountered among individuals with a cleft lip and/or cleft palate. Addressing these problems necessitates a multidisciplinary approach, requiring a team of experts to facilitate care for these individuals. Dentists play a vital role on the team. An orthodontist, pediatric dentist, oral maxillofacial surgeon, and prosthodontist usually represent the dental members of the team. The success of this team depends on expertise within each discipline but also depends on each member having a broad base of knowledge in general about oral clefts. An understanding of other disciplines and how they approach the treatment of oral clefts is important for each team member. Also, each team representative should appreciate the need to understand the causes of oral clefts, how clefts develop in utero, how various populations are affected, and how to recognize and classify an oral cleft. It is difficult to communicate effectively within the team if we fail to recognize the importance of expanding our knowledge to include other aspects of oral clefts beyond treatment perspectives. This article provides the orthodontist with basic information as it relates to the etiology of oral clefts (ie, genetics, teratogens, and medical conditions), the demographics and incidence of oral clefts, the embryology and classification of clefts.

Roles of the lamina propria and the detrusor in tension transfer during bladder filling.

In this study, structural changes within the lamina propria and detrusor layers were analysed during development as a function of bladder filling. Second-, third- and full-term foetal bovine bladders were filled to 0%, 25%, 50%, 75% and 100% of their total capacity and snap frozen. The bladders were analysed histochemically and the relative thicknesses of the lamina propria and detrusor were measured. In all gestational stages examined, the total thickness of the bladder wall decreased during bladder filling. The lamina propria of the full-term bladder thinned at a consistently faster rate than did the detrusor. The lamina propria of second and third trimester bladders followed the same thinning pattern, except when the bladders were filled from 25% to 50% of their capacities. At these gestational stages, the detrusor thinned at a faster rate than the lamina propria. Our results demonstrate that the detrusor layer carries tension only during a specific portion of the filling cycle and only during the second and third trimesters. We conclude that the lamina propria acts as the capacitance layer, while the detrusor functions as the "limiting" or "girding" layer to prevent over-distension of the bladder wall.

The role of endoscopy and implant texture in transaxillary submuscular breast augmentation.

In 1996 the authors reported their experience with 92 consecutive patients undergoing traditional (nonendoscopic) transaxillary submuscular breast augmentation. They reported a capsular contraction rate of 1.1% using textured saline implants, as well as an implant malposition rate of 8.6%. At that time they hypothesized that "the endoscope will lessen the rate of implant malposition." To clarify the role of implant texture and to justify the use of endoscopic techniques in transaxillary submuscular breast augmentation, the authors have studied an additional 58 consecutive patients with two significant changes. First, the endoscope was used to dissect the implant pocket in each patient. Second, smooth-wall implants were substituted for the previously used textured implants. Their rate of implant malposition dropped significantly, from 8.6% to 2.0% (p = 0.10), and their capsular contraction rate remained low, at 2.0% (p = 0.63). They conclude that direct endoscopic control improves implant positioning in the transaxillary submuscular operation, and implant texture does not improve capsular contraction rates when the prosthesis is placed in the submuscular position.

Minimal expansion for correction of male pattern baldness.

Tissue expansion for correction of male pattern baldness has not gained wide acceptance by patients or surgeons because of the substantial albeit temporary deformity of the expansion. Minimal expansion is an alternative. Scalp flaps can be expanded just to the point of becoming noticeable over 4 to 6 weeks followed by scalp flap transposition and easy closure of the donor site. The temporoparietal (Juri) or superiorly based (Dardour) flaps have been used unilaterally or bilaterally. The entire restoration is completed in approximately 8 weeks, is minimally deforming during the expansion phase, and does not require the patient to alter his lifestyle significantly or to go into hiding. Hair grafts, in contrast, do not begin to grow hair until 12 weeks after transplantation, and the process usually requires four sessions over an 8- to 12-month period with the patient looking temporarily variably absurd. Tissue expansion increases scalp available for flap restorations, which appear more natural than even the most well-executed hair transplants. Minimal expansion makes the process more palatable to the patient and surgeon.

Adhesion of endothelial cells to extracellular matrix proteins.

Human and bovine endothelial cells were used in a series of studies examining cell adhesion to extracellular matrix macromolecules. Collagen types I and III, an acetic acid extract of bovine lens capsule basement membrane, laminin, and fibronectin were demonstrated to affect, in varying degrees, cell adhesion, cell growth, and "sprout cell" formation in endothelial cell cultures. All the matrix macromolecules tested promoted endothelial cell adhesion, and the adhesion to the basement membrane extract was blocked by antibodies to fibronectin. When human endothelial cells were grown on defined matrices, the level of serum required for optimum growth was decreased, while bovine endothelium grown on defined matrices did not show sprout cell formation. These data suggest that endothelial cells are able to adhere to a wide variety of connective tissue components and that extracellular matrices significantly influence cell behavior.

Localization of collagen types in regional segments of the fetal bovine aorta.

Types I, III, and IV collagens were localized immunocytochemically in muscular and small arteries of fetal bovine tissues and in different regional segments of the aorta. The distribution of these collagens was found to be unique, not only with respect to collagen type and fiber orientation but also to the specific region of the vessel being examined. Collagen types I, III, and IV often codistribute in the intimal and medial regions of blood vessels, whereas types I and III show selective association in fibers with varied morphology in the adventitial layer. Specific segments of the aorta (proximal thoracic versus distal abdominal) were examined to determine the relative distribution and morphologic presentation of the collagens. In the ascending region of the aorta proximal to the heart, the types I, III, and IV collagen colocalized in the intimal and medial layers. Types I and III collagen predominated in the relatively small adventitial layer, whereas type IV collagen was found only in association with the media of small blood vessels and capillaries in this layer. In the descending thoracic region of the aorta distal to the arch, types I and IV collagens were distributed throughout the intimal and medial layers, whereas type III collagen localization was variable depending on the antibody used for detection. The adventitia stained predominantly for type III collagen that was distinctly organized in folded arrays of fibers. These same fibers stained less intensely with antibody to type I collagen. The abdominal aorta near the common iliacs stained in a fashion similar to that of muscular arteries of the organs and tissues examined, i.e., types I and IV collagen were found in the intimal and medial layers, whereas type III collagen localized heavily to the adventitial layer, with differential staining in the intima and media depending on the antibody used. Additional staining of the adventitial region of the abdominal aorta with type I and type IV collagen antibodies was the same as in the proximal and descending regions. Since the abdominal aorta sustains decreased levels of pulsatile distension compared with the ascending thoracic aorta, type III collagen distribution and its association with other matrix components may be important in regulating the range of distensibility of the vessel wall.