Localization of G protein alpha-subunits in the human fetal adrenal gland.

The aim of the present study was to investigate the presence and localization of the main G protein alpha-subunits in the human fetal adrenal gland during the second trimester of gestation. Immunofluorescence studies conducted on sections from frozen glands obtained immediately after therapeutic abortion indicated that the alpha s subunit of the heterotrimeric Gs protein was detected in all adrenal cell types, except for endothelial cells. The other alpha-subunits had a more specific pattern of distribution. Indeed, the alpha il-2 protein was restricted to the definitive zone, whereas alpha i3 labeling was mainly expressed in the fetal zone. The alpha q protein subunit was localized in vascular endothelial cells at the periphery of the adrenal gland and in fetal cells at the center. Finally, chromaffin cells expressed alpha s, alpha q, and alpha o1, but not alpha o2 nor alpha i. Altogether, these results indicate that the human fetal adrenal gland is not only unique in its particular morphology and expression of steroidogenic enzymes, but also by the differential expression of G protein alpha-subunits. Such cell specific distribution in glands from midgestational fetuses may account for the absence or the different responses to stimuli, when compared with the adult adrenal gland.

The angiotensin AT2 receptor is present in the human fetal adrenal gland throughout the second trimester of gestation.

The aim of the present study was to characterize distribution and pharmacological properties of angiotensin II (Ang II) receptors in human fetal adrenals frozen immediately after removal. Autoradiographic studies indicate that Ang II receptors are present throughout the gland. Coincubations with DUP 753, a specific antagonist of the AT1 receptor, and with PD 123319, a specific antagonist of the AT2 receptor, reveal that Ang II receptors are mainly of the type 2. The AT1 receptors are detected after 16 weeks of gestation at the periphery of the gland. Binding of 125I-Ang II to membrane preparations is dose-dependent and saturable. Competition studies and Scatchard analysis reveal a homogenous population of high-affinity AT2 binding sites (Kd = 0.68 +/- 0.1 nmol/L). Binding capacities decrease from 1080 +/- 304 fmol/mg protein at 14 weeks to 275 +/- 55 fmol/mg protein at 21 weeks. However, when fetal adrenal cells are prepared and cultured for 6 days, the proportion of AT1 receptors increases, indicating that culture conditions induce expression of the AT1 receptor. These results differ from those obtained in adult glands, where autoradiographic studies reveal that the AT1 receptors are found mainly in zona glomerulosa and AT2 receptors mainly in the medulla. These data suggest that the AT2 receptors could be involved in the morphological or functional differentiation of the human fetal adrenal gland.

Involvement of the angiotensin II type 2 receptor in apoptosis during human fetal adrenal gland development.

The aim of this study was to establish a link between the highly expressed angiotensin II (Ang II) type 2 receptor (AT2) in human fetal adrenal cells and the proposed apoptotic activity in the center of the gland. There was an important increase in apoptotic DNA fragmentation with age in adrenal glands of fetuses from 15-20 weeks gestation. Adrenal cells showing the characteristic apoptotic internucleosomal DNA fragmentation were localized in the central portion of the fetal zone. In cells cultured for 24 h, Ang II, via the AT2 receptor, induced DNA fragmentation and cleavage of the DNA repair enzyme, poly-(ADP-ribose) polymerase. Furthermore, characteristic membrane blebbing was observed specifically on cells of the fetal zone. Immunofluorescence studies demonstrated that stimulation with Ang II or CGP 42112 (an agonist of the AT2 receptor) strongly modified the actin network, now localized exclusively along the plasma membrane, with a predominance of labeling at the base of the bleb formation. This rearrangement of actin distribution was different in cells from the definitive zone, corroborating the observation that these cells express many more Ang II type 1 receptors (AT1) than AT2 receptors. Taken together, our data indicate that the AT2 receptor is involved in the apoptotic process observed in the human fetal adrenal gland and could participate in the morphological changes occurring after birth, leading to involution of the fetal zone.

Identification of a novel secretogranin II-derived peptide (SgII(187-252)) in adult and fetal human adrenal glands using antibodies raised against the human recombinant peptide.

Molecular cloning of secretogranin II (SgII) in phylogenetically distant species has recently revealed the existence of a highly conserved 66-amino acid peptide flanked by preserved pairs of basic residues. This observation suggested that this peptide, named EM66, which had not been described to date, could be an important processing product of SgII. The aim of the present study was to investigate the possible occurrence of EM66 in the human adrenal gland. The EM66 peptide was generated in Escherichia coli, which was programmed to make a fusion protein containing the human EM66 sequence. The affinity-purified fusion protein was used to raise polyclonal antibodies in rabbits. The free EM66 peptide was obtained by cleavage of the fusion protein followed by high performance liquid chromatography purification. Immunohistochemical analysis using the EM66 antibodies revealed intense labeling of adrenochromaffin cells in the adult adrenal medulla and the fetal adrenal gland. A sensitive and specific RIA was developed and applied to the detection of EM66-like immunoreactivity in extracts of adult adrenal medulla and whole fetal adrenal gland after high performance liquid chromatographic analysis. A major immunoreactive species exhibiting the same retention time as recombinant EM66 was detected in both adult and fetal adrenal extracts. Taken together, these data demonstrate that posttranslational processing of SgII actually generates EM66 in the adrenal gland. The strong conservation of the amino acid sequence of EM66 in the vertebrate phylum and the occurrence of the mature peptide in both fetal and adult chromaffin cells suggest that EM66 could play an important physiological role in the human adrenal gland.

Localization, characterization, and second messenger coupling of pituitary adenylate cyclase-activating polypeptide receptors in the fetal human adrenal gland during the second trimester of gestation.

The distribution and pharmacological properties of pituitary adenylate cyclase-activating polypeptide (PACAP) receptors were studied in the fetal human adrenal gland during the second trimester of gestation. Autoradiographic studies, using [125I]PACAP27 as a radioligand, revealed that PACAP-binding sites are exclusively located on chromaffin cells of adrenals from fetuses 14-20 weeks old. Biochemical characterization of binding revealed the occurrence of a single class of PACAP-binding sites with a dissociation constant value of 0.32-0.74 nmol/L and a binding capacity of 0.30-0.81 pmol/mg wet tissue. PACAP27 and PACAP38 were equipotent in competing for [125I]PACAP27 binding (IC50 = 0.28-0.64 nmol/L and 0.15-0.81 nmol/L, respectively), and the Hill coefficients were close to 1. In contrast, vasoactive intestinal polypeptide was much less efficient in displacing the tracer (IC50 = 4-362 nmol/L), and the Hill coefficients were less than 0.6. PACAP38 induced a dose-dependent increase in cAMP production in fetal human adrenal cell suspension (ED50 = 0.07 +/- 0.02 nmol/L), as well as in cells maintained in culture for 5 days (5.4 +/- 1.8 nmol/L). In contrast, PACAP38 induced a modest increase in inositol phosphate formation. These data indicate that type I PACAP receptors are present in the early stages of the human medulla organization during the process of migration of chromaffin cells from the periphery to the central part of the gland. The present results suggest that PACAP could be involved in the regulation of the human adrenochromaffin cells during ontogenesis.

Occurrence and effect of PACAP in the human fetal adrenal gland.

In the study reported in this paper, we characterized PACAP in the human fetal adrenal gland and we investigated the effect of PACAP on steroid secretion from cultured fetal adrenal cells. The adrenal gland from 20-week-old fetuses contained substantial concentrations of PACAP-immunoreactive material (88.6 ng/g wet tissue). HPLC analysis of adrenal extracts revealed the presence of both PACAP27 and PACAP38, the latter being the predominant form. Incubation of cultured fetal adrenal cells with PACAP38 (10(-7) M) significantly increased cortisol and DHEAS secretion. Administration of the beta-adrenoreceptor agonist isoproterenol mimicked the stimulatory effect of PACAP on both steroid secretion whereas preincubation of fetal cells with the beta-adrenoreceptor antagonist propranolol suppressed the steroidogenic effect of PACAP. These data, together with the observation that PACAP receptors are exclusively located on chromaffin cells, suggest that, in the fetal human adrenal gland, the effect of PACAP on steroid secretion is mediated via the local release of catecholamines.

Failure of resin ionomers in the retention of multi-rooted teeth with Class III furcation involvement: a rebuttal case report.

BACKGROUND: Severe periodontal furcation invasion has long been a treatment dilemma for the clinician. Many techniques have been advocated in the treatment of multi-rooted posterior teeth ranging from conventional scaling and root planing (SRP), apically positioned flaps, root amputations, root resections, tunnel procedures, guided tissue regeneration, and restorations. The keys to success depend on the clinician's ability to access the furcation to remove local factors and create an environment that enhances the patient's own hygiene efforts. Long-term success in treating teeth with furcation invasion depends upon tooth retention and arresting the destructive processes within the furcation area. METHODS: A Class III furcation invasion in a mandibular molar was treated by surgical access for SRP along with obliterating the furcation utilizing a resin ionomer restoration. RESULTS: Initially, the patient was asymptomatic. Within 3 months of treatment, the patient presented with suppuration that was refractory to local efforts. Radiographs taken only 5 months postsurgery demonstrated advanced bone loss apical to the restoration. The tooth ultimately was extracted because mobility increased and the tooth became symptomatic. CONCLUSIONS: The clinician must consider the multi-factorial etiology of periodontal breakdown within a furcation. For this patient, the technique of sealing off the exposed furcation with restorative material appeared to have resulted in progressive bone loss and accelerate tooth loss. This single case report is presented as a rebuttal to recently published articles, which have demonstrated excellent results when treating furcations with ionomer restorations.

Ridge preservation utilizing an acellular dermal allograft and demineralized freeze-dried bone allograft: Part I. A report of 2 cases.

Alveolar ridge deformities are usually the result of trauma, periodontal disease, surgical insult, or developmental defects. Preventing ridge collapse with the extraction of maxillary anterior teeth is vital to an esthetic restorative result. Several techniques are available to prevent ridge collapse. In these case presentations, ridge preservation was achieved utilizing an acellular dermal matrix as a barrier membrane with a demineralized freeze-dried bone allograft. This report demonstrated an acceptable esthetic result with no loss of ridge height or width. Soft tissue dimensions were also preserved. The two graft materials were well accepted by the body and healing was rapid and without significant discomfort. The technique illustrated provides the surgeon with another option to prevent ridge collapse and ultimately improve esthetics.

Ridge preservation utilizing an acellular dermal allograft and demineralized freeze-dried bone allograft: Part II. Immediate endosseous implant placement.

When maxillary anterior teeth are extracted, subsequent ridge collapse can significantly compromise esthetics. Preservation of an adequate volume of bone is vital to successful implant placement. Ridge preservation achieved utilizing an acellular dermal matrix as a barrier membrane with a demineralized freeze-dried bone allograft has been previously reported. In this case presentation, guided bone regeneration was achieved around an immediate endosseous implant when this same technique was used. As in the previous case reports, this technique demonstrated an acceptable esthetic result with virtually no loss of ridge height or width. Soft tissue dimensions were also preserved. Both the hard and soft tissue grafts were well accepted by the body and healing was rapid and without significant discomfort. This surgical technique provides the clinician with an option to provide immediate implant therapy when primary closure cannot be achieved.

Retained free gingival graft rugae: a 9-year case report.

In the oral cavity, masticatory mucosa covers the hard palate and gingiva. The epithelium of masticatory mucosa is relatively thick compared to other oral tissues. This results in firmness and immobility necessary to withstand the forces of mastication. In the anterior aspect of the hard palate, long papillae within the lamina propria and thick dense collagenous tissue are found under the transverse ridges or rugae. Though palatal rugae are generally avoided during soft tissue grafting, there are few literature references detailing the consequences of transplanting tissue from the anterior palate which contains rugae. The following case report describes retained palatal rugae in a free gingival graft, which had been transplanted to an edentulous ridge 9 years earlier.

Report of a gingival "surgical cyst" developing secondarily to a subepithelial connective tissue graft.

The subepithelial connective tissue graft is a valuable technique used to cover exposed root surfaces or to increase the zone of attached gingiva. Cysts, such as the gingival cyst of the adult, are epithelial-lined cysts which may arise from heterotropic glandular tissue, a proliferating rete peg, remnants of the dental lamina, or traumatic implantation of epithelial tissue. In this paper, a case report is described of a "surgical cyst" or cystic morphogenesis of surgically implanted epithelium developing secondarily to a subepithelial connective tissue graft.

The effects of intracanal medicaments, fillers, and sealers on the attachment of human gingival fibroblasts to an exposed dentin surface free of a smear layer.

To date there has been very little research into the possible effects of endodontic therapy on regeneration of the lost periodontal attachment. The objective of this study was to examine the effects of endodontic medicaments on fibroblast attachment to dentin surfaces free of a smear layer. Pulp chambers of extracted third molars were filled with one of the following medicaments: gutta-percha with Roth's zinc oxide and eugenol-based sealer, warm gutta-percha with sealer, warm gutta-percha without sealer, calcium hydroxide, formocresol, cotton pellet, or left empty. A predetermined dentin surface area was then inoculated with human gingival fibroblasts at a concentration of 2 x 10(4) cells per ml. The cells were allowed to adhere to the dentin surface for either 4 or 24 hours, then cell attachment was quantified using a methyl-tetrazolium assay. The data were analyzed using a Kruskal-Wallis one-way analysis of variance and Dunn's multiple comparison test. It was determined that fibroblast attachment was significantly reduced when exposed to formocresol or warm gutta-percha without sealer at both the 4 and 24 hour interval (P < or = 0.05). This suggests that the use of formocresol or warm gutta-percha without sealer in a root canal may impede periodontal wound healing and regeneration.

Nasal fistula associated with dental infection: a report of a case.

Most clinicians have come across a patient with difficult symptoms to diagnose. Often confusion occurs between odontogenic and nonodontogenic causes of sinus discomfort. On many occasions, sinus pain is due to purely dental causes, whereas in other situations dental pain is reported when the sinuses are infected. Due to the intimate association between the roots of the maxillary teeth and the floor of the nasal cavity and maxillary sinuses, diagnosis may be difficult. The following is a case report of a nasal fistula that developed from an abscessed maxillary central incisor.

Radiographic osseous regeneration after initial therapy with systemic doxycycline.

Early-onset periodontal diseases are often diagnosed in the military as a result of the requirements for annual dental examinations and the youthful population served. A young soldier diagnosed with rapidly progressive periodontitis completed initial therapy of root planing with the systemic antibiotic doxycycline but was poorly compliant with additional treatment. During a subsequent mandatory dental examination, new radiographs demonstrated a significant improvement in the quantity and quality of alveolar bone, illustrating the regeneration potential of the young patient with early-onset periodontal disease.

Periodontal disease and its association with systemic disease.

Periodontal diseases are oral disorders characterized by inflammation of the supporting tissues of the teeth. Usually, periodontitis is a progressively destructive loss of bone and periodontal ligament (loss of the attachment apparatus of the teeth). Periodontitis has documented risk factors, including but not limited to specific plaque bacteria, smoking, and diabetes mellitus. Initially, the link between systemic disease and periodontal diseases was thought to be unidirectional. Currently, there is increasing evidence that the relationship between these entities may be bidirectional. Recent case-control and cross-sectional studies indicate that periodontitis may confer a 7-fold increase in risk for preterm low birth weight infants and a 2-fold increase in risk for cardiovascular disease. These early reports indicate the potential association between systemic and oral health. Additionally, these studies support the central hypothesis that periodontal disease involves both a local and a systemic host inflammatory response. This knowledge of disease interrelationships may prove vital in intervention strategies to reduce patient risks and prevent systemic disease outcomes. Based on the current evidence of the periodontal-systemic disease connection, the purpose of this report is to help establish the groundwork for closer communication between physicians and periodontists in the military health care setting.

The use of chemotherapeutic agents in localized periodontal pockets.

Gingival diseases are the most widely dispersed diseases in the United States. In some patients, periodontal disease appears in a generalized form, but more often it appears in localized areas. Furthermore, after treatment with scaling and root planing in generalized cases, the disease is often reduced to a few local areas in the patient's mouth. Because periodontitis is a bacterial infection with known pathogenic microorganisms, the local delivery of antimicrobial agents has been considered to be a possible solution for treating and controlling localized forms of periodontal disease. Three local chemotherapeutic agents are reviewed in this paper: tetracycline fiber, doxycycline gel, and chlorhexidine chip. With the advancement of local drug delivery systems, restorative dentists, periodontists, and their patients have new alternatives for the treatment of periodontal disease. Local chemotherapeutic agents offer an additional mode of therapy and should be used on a case-by-case basis, not necessarily as an initial treatment.

The immediate provisional restoration: a review of clinical techniques.

For each patient who requires removal of anterior teeth, there are a multitude of treatment considerations. Cosmetic demands, functional needs, treatment sequencing, timeliness, and affordability are some primary concerns that must be addressed on an individual basis. A patient will generally want a cosmetic and functional prosthesis at the earliest possible opportunity. Providing the most appropriate interim prosthesis for a given patient is both challenging and rewarding. The numerous clinical techniques for immediate interim tooth replacement are reviewed, and previously unreported methods are presented to assist the clinician in the selection of interim prosthesis design.

Smile enhancement via internal gingivectomies.

Periodontal plastic surgical procedures provide a wide range of techniques to improve the esthetics of the mucogingival complex. Often these procedures are prerequisites for successful restorative therapy. This article presents a simple means of enhancing a patient's smile that can be provided by simple internal gingivectomies. The technique can be provided as a stand-alone procedure or in conjunction with restorative care. The surgery is simple and predictable with virtually no postsurgical sequellae.

Early creeping attachment after frenectomy: a case report.

An abnormal labial frenutomy is capable of causing retraction of gingival margins, formation of diastema and inhibition of lip and tongue movements. When aberrant frenula are present traditional frenectomy procedures are very successful. Often mucogingival procedures are needed to correct the defects that result from harmful frenum pulls. In this case presentation, an aberrant frenum was diagnosed to be associated with an area of recession on a mandibular left central incisor. Surgery was planned as a staged approach. The first phase of care was a simple frenectomy. A follow-on procedure consisting of a connective tissue graft for root coverage was planned. After only four weeks of healing from the frenectomy, creeping attachment of 1.0 mm was appreciated and the patient was able to avoid the secondary corrective surgery.

Subgingival restorations with resin ionomer: a periodontal alternative.

The successful use and placement of subgingival resin-ionomer restorations in both anterior root and molar furcation defects are demonstrated in this article. Sustained tissue health and minimal probing depths at the surgical site demonstrate clinical success. These case reports illustrate the continued success of alternative treatment procedures for restoring subgingival mechanical root or periodontal lesions.