Teriparatide improves microarchitectural characteristics of peri-implant bone in orchiectomized rats.

This study evaluated the peri-implant bone repair in orchiectomized rats receiving intermittently PTH 1-34. The treatment returned the bone quality and quantity of the animals to normal in the computerized microtomography, laser confocal microscopy, and histological analysis. The PTH 1-34 promoted marked bone formation with increased volume, improved quality, and greater bone turnover. INTRODUCTION: Osteoporosis can be a problem in implant osseointegration. So this study aimed to evaluate the quantity and quality of peri-implant bone repair in orchiectomized Wistar rats receiving intermittently administered PTH 1-34. METHODS: Animals (n = 24) were divided into 3 groups: healthy control (SHAM), orchiectomized (ORQ), and orchiectomized and treated with 0.5 µg/kg/day PTH 1-34 (TERI), and each received an implant in the right and left tibial metaphysis, which was allowed to repair for 60 days. The resultant bone formation was evaluated through computerized microtomography (micro-CT) to compare the percent bone volume (BV/TV), trabecular thickness (Tb.Th), trabecular number and separation (Tb.N, Tb.Sp), and bone implant contact (BIC) through the intersection surface (i.S) between groups. Laser confocal microscopy was used to evaluate fluorochrome areas for mineral apposition rate (MAR) and neoformed bone area (NBA). In addition, histological evaluation of calcified tissues with Stevenel blue and alizarin red staining was performed. RESULTS: Treatment with PTH 1-34 returned the bone quality and quantity of the osteoporotic animal to normal, as the TERI group presented statistically significant higher values for BV/TV, Tb.Th, and BIC parameters compared with ORQ (p < 0.05), but when compared with SHAM (p > 0.05), no statistical difference was noted. In addition, in the bone turnover analysis (MAR, NBA) for TERI, the highest results are presented, followed by SHAM, and then ORQ (TERI × ORQ: p < 0.05). CONCLUSIONS: Intermittent treatment with PTH 1-34 on orchiectomized animals promoted marked bone formation with increased volume, improved quality, and greater bone turnover in the peri-implant space, returning the bone quality and quantity to the present standard in healthy animals.

Exploring the mechanism of PPARγ phosphorylation mediated by CDK5.

Peroxisome proliferator-activated receptor gamma (PPARγ) is a nuclear receptor with a key role in metabolic processes and is target of CDK5 kinase phosphorylation at S245 (S273 in PPARγ isoform 2), thereby inducing insulin resistance. A remarkable effort has been addressed to find PPARγ ligands that inhibit S245 phosphorylation, but the poor understanding in this field challenges the design of such ligands. Here, through computational and biophysical methods, we explored an experimentally validated model of PPARγ-CDK5 complex, and we presented K261, K263 or K265, which are conserved in mammals, as important anchor residues for this interaction. In addition, we observed, from structural data analysis, that PPARγ ligands that inhibit S245 phosphorylation are not in direct contact with these residues; but induce structural modifications in PPARγ:CDK5/p25 interface. In summary, our PPARγ and CDK5/p25 interaction analyses open new possibilities for the rational design of novel inhibitors that impair S245 phosphorylation.

Gene expression of thyroid-specific transcription factors may help diagnose thyroid lesions but are not determinants of tumor progression.

PURPOSE: The role of thyroid-specific transcription factors in thyroid malignancy is still poorly understood, so we investigate thyroid-specific transcription factors gene expression both in benign and in malignant thyroid nodules, aiming to study a possible clinical utility of these molecules. METHODS: We quantified TTF-1, FOXE1 and PAX8 mRNA levels, relating their expression to diagnostic and prognostic features of thyroid tumors. RNA was extracted from 4 normal thyroid tissues, 101 malignant [99 papillary thyroid carcinomas (PTC) and 2 anaplastic thyroid carcinomas] and 99 benign thyroid lesion tissues [49 goiter and 50 follicular adenomas (FA)]. RESULTS: Levels of mRNA of both FOXE1 (P < 0.0001) and PAX8 (P < 0.0001) genes, but not TTF-1 (P = 0.7056), were higher in benign than in malignant thyroid lesions. FOXE1 was able to identify malignant nodules with 75.8 % sensitivity, 76.1 % specificity, 75.8 % positive predictive value, 76.1 % negative predictive value and 75.9 % accuracy. PAX8 was able to identify malignancy with 60.6 % sensitivity, 81.1 % specificity, 76.9 % positive predictive value, 66.4 % negative predictive value and 70.6 % accuracy. Both FOXE1 and PAX8 gene expression patterns were also able to differentiate FA from the follicular variant of PTC-FVPTC. However, the investigated gene expression was neither associated with any clinical feature of tumor aggressiveness nor associated with recurrence or survival. CONCLUSIONS: We suggest that FOXE1 and PAX8 gene expression patterns may help to diagnose thyroid nodules, identifying malignancy and characterizing follicular-patterned thyroid lesions, but are not determinants of thyroid tumor progression.

The two membrane isoforms of human IgE assemble into functionally distinct B cell antigen receptors.

The human C epsilon gene expresses two membrane IgE heavy chain mRNAs which differ in the sequence that encodes their extracellular membrane-proximal domain. In the long IgE isoform (mLIgE), this domain contains a stretch of 52 amino acids which are absent in the short variant (mSIgE). We have now generated B cell transfectoma cell lines that express these two isoforms and show that both types of mIgE form functional B cell antigen receptors (BCR). Both receptors associate with the Ig-alpha/Ig-beta heterodimer, as well as with protein kinases that are capable of phosphorylating this complex. Upon their cross-linking, both receptors can activate protein tyrosine kinases that phosphorylate the same substrate proteins. Both IgE receptors also associate with two novel proteins that do not bind to mIgM. Apart from these similarities, the two IgE-BCRs show several differences of which some are analogous to the differences between the IgM- and IgD-BCRs. First, the mSIgE is transported to the cell surface at a higher rate than the mLIgE. Second, the two IgE-BCRs associate with differently glycosylated Ig-alpha proteins, the mLIgE associates with the completely glycosylated form, whereas the mSIgE associates with an Ig-alpha glycoform that is partially sensitive to endoglycosidase H. Third, the kinetics of protein tyrosine phosphorylation induced by receptor cross-linking is significantly different for the two IgE-BCRs. Finally, cross-linking of the mSIgE-BCR leads to growth inhibition of the B cell transfectoma, whereas signaling through the mLIgE-BCR does not affect the cellular proliferation. These data show that the two human membrane IgE isoforms assemble into functionally distinct antigen receptors which can induce different cellular responses.

Deficiency in CD22, a B cell-specific inhibitory receptor, is sufficient to predispose to development of high affinity autoantibodies.

CD22 is a B cell-specific transmembrane glycoprotein that acts to dampen signals generated through the B cell antigen receptor (BCR): B cells from CD22-deficient mice give increased Ca2+ fluxes on BCR ligation. Here we show that this B cell hyperresponsiveness correlates with the development of autoantibodies. After the age of eight months, CD22-deficient mice developed high titers of serum IgG directed against double-stranded DNA; these antibodies were of multiclonal origin, somatically mutated, and high affinity. Increased titers of antibodies to cardiolipin and myeloperoxidase were also noted. The results demonstrate that a single gene defect exclusive to B lymphocytes is, without additional contrivance, sufficient to trigger autoantibody development in a large proportion of aging animals. Thus, CD22 might have evolved specifically to regulate B cell triggering thresholds for the avoidance of autoimmunity.

The relaxation induced by uroguanylin and the expression of natriuretic peptide receptors in human corpora cavernosa.

INTRODUCTION: Receptors for natriuretic peptides have been demonstrated as potential targets for the treatment of male erectile dysfunction. AIM: This study investigates the relaxant effects of the atrial natriuretic peptide (ANP) and uroguanylin (UGN), and expression of natriuretic peptide receptors on strips of human corpora cavernosa (HCC). MAIN OUTCOME MEASURES: Quantitative analysis of natriuretic receptor expression and relaxation of precontracted strips were used to assess the membrane-bound guanylate cyclase-cyclic guanosine monophosphate (cGMP) pathway in HCC strips. METHODS: HCC was obtained from a cadaver donor at the time of collection of organs for transplantation (14-47 years) and strips were mounted in organ baths for isometric studies. RESULTS: ANP and UGN both induced concentration-dependent relaxation on HCC strips with a maximal response attained at 300 nM, corresponding to 45.4±4.0% and 49±4.8%, respectively. The relaxation is not affected by 30 µM 1H-[1,2,4]oxaolodiazolo[4,3-a]quinoxalin-1-one (ODQ) (a soluble guanylate cyclase inhibitor), but it is significantly blocked by 10 µM isatin, a nonspecific particulate guanylate cyclase (pGC) inhibitor. UGN was unable to potentiate electrical field stimulation (EFS) or acetylcholine-induced relaxations. The potential role of pGC activation and cGMP generation in this effect is reinforced by the potentiation of this effect by phosphodiesterase-5 inhibitor vardenafil (55.0±7.5-UGN vs. 98.6±1.4%-UGN+vardenafil; P<0.05). The relaxant effect was also partially (37.6%) blocked by the combination iberitoxin-apamin but was insensitive to glybenclamide. The expression of guanylate cyclase receptors (GC-A, GC-B, GC-C) and the expression of the natriuretic peptide "clearance" receptor (NPR-C) were confirmed by real-time polymerase chain reaction. The exposure of HCC strips to ANP (1 µM) and UGN (10 µM) significantly increased cGMP, but not cyclic adenosine monophosphate (cAMP) levels. CONCLUSIONS: UGN relaxes HCC strips by a guanylate cyclase and K(ca)-channel-dependent mechanism. These findings obtained in HCC reveal that the natriuretic peptide receptors are potential targets for the development of new drugs for the treatment of erectile dysfunction.

Structural characterization of SnO nanoparticles synthesized by the hydrothermal and microwave routes.

SnO particles were synthesized by an alkali-assisted hydrothermal and microwave methods. The aqueous-based reactions were carried out at pH ~ 8, under inert atmosphere (Ar). The reactions were taken under different times, and a full XRD structural analysis was made to evaluate the conversion from the Sn6O4(OH)4 intermediate to SnO particles. Williamson-Hall analysis showed that the size and strain of the SnO particles were time and route treatment dependent. Microwave heating yielded a single tetragonal SnO phase after 1 h of thermal treatment, and TEM images revealed spherical-shaped SnO nanoparticles with an average size of 9(1) nm. While by the hydrothermal treatment single SnO phase was obtained only after 4 hours, yielding non-uniform and elongated particles with sub-micrometric size. A dissolution-recrystallization process was taken into account as the mechanism for SnO particles formation, in which hydroxylated complexes, Sn2(OH)6-2, then condense to form the oxide. The time-shorting reaction provided by the microwave-assisted synthesis may be attributed to better heat distribution.

Infestation of the cupped oysters Crassostrea angulata, C. gigas and their first-generation hybrids by the copepod Myicola ostreae: differences in susceptibility and host response.

SUMMARY: We studied the prevalence and intensity of the parasitic copepod Myicola ostreae in 2 closely related oysters Crassostrea angulata and C. gigas and their F1 hybrids. The effects on host and host reaction were also analysed to better understand host-parasite relationships between copepods and bivalve molluscs. Full reciprocal crosses were carried out between C. angulata and C. gigas and the progenies were reared in the wild in Ria Formosa Lagoon (Portugal), allowing natural infestation by M. ostreae. Prevalence and intensity were significantly higher in C. angulata than in C. gigas. The parasite level of F1 hybrids was similar to C. angulata and significantly higher than in C. gigas. The results of our study support a hypothesis of dominantly inherited susceptibility to M. ostreae infestation. Moreover, copepods were observed on the gill surface of C. gigas engulfed by a capsule-like structure. Histological analyses revealed that the copepods were surrounded by a massive agglomerate of haemocyte-like cells encircled by a thin layer of fibroblast-like cells. This encapsulation response was not observed in C. angulata or in F1 hybrids. These results suggest that the differential susceptibility to M. ostreae between C. angulata and C. gigas may be ascribed to host defence factors.

The mutations and potential targets of the forkhead transcription factor FOXL2.

Mutations of FOXL2, a gene encoding a forkhead transcription factor, have been shown to cause the blepharophimosis-ptosis-epicanthus inversus syndrome (BPES). This genetic disorder is characterized by eyelid and mild craniofacial abnormalities that can appear associated with premature ovarian failure. FOXL2 is one of the earliest ovarian markers and it offers, along with its targets, an excellent model to study ovarian development and function in normal and pathological conditions. In this review we summarize recent data concerning FOXL2, its mutations and its potential targets. Indeed, many mutations have been described in the coding sequence of FOXL2. Among them, polyalanine expansions and premature nonsense mutations have been shown to induce protein aggregation. In the context of the ovary, FOXL2 has been suggested to be involved in the regulation of cholesterol and steroid metabolism, apoptosis, reactive oxygen species detoxification and inflammation processes. The elucidation of the impact of FOXL2 mutations on its function will allow a better understanding of the pathogenic mechanisms underlying the BPES phenotype.

Bioactivity and Toxicity of Senna cana and Senna pendula Extracts.

This work investigated the content of total polyphenolic compounds and flavonoids as well as their toxicity and larvicidal and acetylcholinesterase inhibitory activities. The antioxidant activities of two medicinal Senna species extracts (Senna cana and Senna pendula) were also investigated. The ethanol extract of the leaves of S. cana and the ethanol extract of the branches of S. pendula presented the best performance in the DPPH/FRAP and ABTS/ORAC assays, respectively. For the inhibition of acetylcholinesterase, the hexane extract of the flowers of S. pendula presented the lowest IC50 value among the ethanol extracts of the leaves of S. cana and showed the best performance in some assays. The hexane extract of the leaves of S. pendula and the hexane extract of the branches of S. cana were moderate to Artemia salina Leach. In the quantification of phenols and flavonoids, the ethanol extract of the leaves of S. cana presented the best results. The ethanol extracts of the leaves of S. cana were found to be rich in antioxidants, phenolic compounds, and flavonoids. These results indicate the antioxidant potential of the extracts of Senna species and can be responsible for some of the therapeutic uses of these plants.

IgM-producing chronic lymphocytic leukemia cells undergo immunoglobulin isotype-switching without acquiring somatic mutations.

The malignant B cells in chronic lymphocytic leukemia (CLL) typically express low-density membrane IgM or IgM/IgD. In vitro experiments have shown that the CLL cells can be induced to differentiate into cells that secrete immunoglobulin (Ig) and can occasionally undergo heavy (H) chain class switching. We now show that the CLL cells also undergo isotype-switching in vivo, since gamma and/or alpha H chain transcripts with identical FW3/CDR3/FW4 regions as the mu CLL transcripts were detected in all of the 13 investigated patients with IgM+ CLL. In most cases switching had occurred to alpha1 and gamma3, but CLL transcripts corresponding to the other gamma chain isotypes were also detected. In one case both the productively and nonproductively rearranged allele were found to undergo H chain class switching. CLL gamma transcripts were also present in surface IgG+ sorted B cells, demonstrating that a small subset of the CLL cells express membrane IgG. In addition, transcripts encoding secretary gamma2 and gamma3 H chains were detected in two cases, which suggests that some serum IgG could be produced by the leukemic clone. Analysis of sorted PBL showed that isotype-switching occurs in CLL cells that express the CD5 antigen. Finally, nucleotide sequence analysis showed that the mu, alpha, and gamma CLL transcripts are identical, demonstrating that the CLL cells do not accumulate somatic mutations in their variable region genes after the H chain class switching. These data provide in vivo evidence that isotype-switching is a frequent phenomenon in CLL, and indicate that a subset of the CLL lymphocytes progress to later stages of B cell differentiation.

The accuracy of seven mathematical functions in modeling dairy cattle lactation curves based on test-day records from varying sample schemes.

Daily milk yield over the course of the lactation follows a curvilinear pattern, so a suitable function is required to model this curve. In this study, 7 functions (Wood, Wilmink, Ali and Schaeffer, cubic splines, and 3 Legendre polynomials) were used to model the lactation curve at the phenotypic level, using both daily observations and data from commonly used recording schemes. The number of observations per lactation varied from 4 to 11. Several criteria based on the analysis of the real error were used to compare models. The performance of models showed few discrepancies in the comparison criteria when daily or 4-weekly (with first test at days in milk 8) data by lactation were used. The performance of the Wood, Wilmink, and Ali and Schaeffer models were highly affected by the reduction of the sample dimension. The results of this work support the idea that the performance of these models depends on the sample properties but also shows considerable variation within the sampling groups.

[Lymphatic filariasis in Belém, Pará State, North of Brazil and the perspective of elimination]. / Filariose linfática em Belém, Estado do Pará, Norte do Brasil e a perspectiva de eliminação.

The objective was to characterize the epidemiological situation of lymphatic filariasis in Belém, state of Pará. Hemoscopic data was analyzed from 1951 through 2003. Information for the period from 1951 to 1994 was collected from reports available from the National Health Foundation. Data from 1995 to 2003 was obtained through surveys carried out in 62 city sectors, within the eight administrative districts of the city. An appreciable drop in the microfilaraemic rates was observed over the years. The percentages of parasitized individuals in the decades of 1950, 1960, 1970, 1980 and 1990, were respectively: 8.2%, 2.6%, 0.7%, 0.16% and 0.02%. In 2001, a single microfilaraemic case was diagnosed, interrupting a series of two years without registering positive cases in the city. In 2002 and 2003, hemoscopic and entomological surveys were performed simultaneously revealing no microfilariae positive individuals, nor infected mosquitoes. To maintain this trend, surveillance measures must be conducted in order to detect and promptly treat patients, to prevent the risk of resurgence of a focus apparently now controlled.

Multiple transcripts of the murine immunoglobulin epsilon membrane locus are generated by alternative splicing and differential usage of two polyadenylation sites.

The human C epsilon gene produces a number of alternatively spliced heavy chain transcripts of which some encode functional IgE isoforms. We now show that differentially processed epsilon mRNA variants also exist in the mouse and are generated by differential polyadenylation and alternative splicing of primary epsilon chain transcripts. The two poly(A) sites of the mouse membrane transcripts were identified in the present study by RACE-PCR analysis. The first poly(A) site is located 743 nt downstream from the beginning of the second membrane exon (M2) and contains the same non-consensus AGTAAA signal sequence as the single poly(A) site of the human membrane transcripts. The second poly(A) site is located almost 500nt further downstream and is characterized by an AAGAAA hexamer. This poly(A) site contains a (G+T) rich element downstream to the site of cleavage and polyadenylation and is preferentially utilized by the membrane epsilon transcripts. Additional diversity of epsilon transcripts is generated by alternative splicing between the last constant region exon (CH4) and the two membrane exons (M1 and M2). The alternatively spliced transcripts include two variants that skip the first membrane exon and encode epsilon heavy chains that lack the transmembrane domain. The third variant is generated by splicing to an internal site in M2 and codes for a membrane isoform that is 10 amino acids shorter in the cytoplasmic domain than the classical membrane IgE. Although little amino-acid sequence homology exists between the murine epsilon chain isoforms and their human counterparts, the pattern of splicing is rather conserved between the two species.

Efficacy of a simple dosage scheme to convert from shorter-acting erythropoiesis-stimulating agent to continuous erythropoietin receptor activator in kidney transplantation patients.

INTRODUCTION: Anemia after kidney transplantation (KT) has a negative impact on graft and patient survival. Anemia management includes iron supplements and erythropoiesis-stimulating agents (ESAs). Most ESAs require short frequency of administration and conversion to ESAs with longer half-life are complex. OBJECTIVE: This study was performed to assess the efficacy of continuous erythropoietin receptor activator (CERA) in hemoglobin (Hb) maintenance after conversion from shorter-acting ESAs with a simple conversion scheme in kidney transplant recipients. METHOD: This is an open-label, prospective, single-arm, single-center, 12-month follow-up study including 77 anemic KT patients with stable renal function. Baseline and monthly measurements of Hb, iron, and creatinine were performed. The conversion scheme from darbepoetin alfa or epoetin was as follows: <30 µg or 5000 IU/week was switched to 75 µg/mo; between 30-50 or 5000-8000 was switched to 100 µg/mo; >50 µg or 8000 IU was changed to 150 µg/month of CERA. Dose adjustments were performed to maintain Hb levels between 10 g/dL and 12 g/dL. RESULTS: The mean age was 57 ± 19 years. The mean time of conversion after KT was 61 ± 49 months. Before conversion, 62.9% of patients were administered epoetin and 37.1% with darbepoetin alfa. Baseline Hb is noted at 10.6 ± 1.3 g/dL. Thirteen percent of patients started receiving CERA at doses of 50 µg/mo, 66% at 75 µg/mo, 13% at 100 µg/mo, and 8% at 150 µg/mo. During the first month, 21% required dose adjustment (6% were increased, 15% were decreased). The final Hb was 11.2 ± 0.8 g/dL. Iron and creatinine levels remained stable during the follow-up examination. CONCLUSION: We propose a simple scheme of conversion from short-acting ESAs to a once-monthly dose of CERA that provides sustained Hb levels within the recommended target with small dose adjustments and low CERA doses.

Prediction of a common beta-propeller catalytic domain for fructosyltransferases of different origin and substrate specificity.

The three-dimensional (3D) structure of fructan biosynthetic enzymes is still unknown. Here, we have explored folding similarities between reported microbial and plant enzymes that catalyze transfructosylation reactions. A sequence-structure compatibility search using TOPITS, SDP, 3D-PSSM, and SAM-T98 programs identified a beta-propeller fold with scores above the confidence threshold that indicate a structurally conserved catalytic domain in fructosyltransferases (FTFs) of diverse origin and substrate specificity. The predicted fold appeared related to that of neuraminidase and sialidase, of glycoside hydrolase families 33 and 34, respectively. The most reliable structural model was obtained using the crystal structure of neuraminidase (Protein Data Bank file: 5nn9) as template, and it is consistent with the location of previously identified functional residues of bacterial levansucrases (Batista et al., 1999; Song & Jacques, 1999). The sequence-sequence analysis presented here reinforces the recent inclusion of fungal and plant FTFs into glycoside hydrolase family 32, and suggests a modified sequence pattern H-x (2)-[PTV]-x (4)-[LIVMA]-[NSCAYG]-[DE]-P-[NDSC][GA]3 for this family.

Management of soft tissue ridge deformities with acellular dermal matrix. Clinical approach and outcome after 6 months of treatment.

BACKGROUND: Soft tissue ridge defects often hamper ideally shaped artificial crowns and are basically treated using autogenous soft tissue grafts or alloplastic materials. These approaches present disadvantages such as the necessity of creating additional surgical fields to harvest the graft and the requirement of primary closure, which may reduce ridge height. This investigation evaluated the use of acellular dermal matrix (ADM) in the treatment of soft tissue ridge defects. METHODS: Eight patients, non-smokers with non-contributory medical history, provided 18 sites corresponding to missing teeth in the anterior maxillary arch. The ideal horizontal gain (desired gain) was waxed up in study casts, which served as templates for construction of modified acrylic stents with orthodontic wires. These stents served as references for ideal horizontal gain and also as fixed reference points for further evaluation. The distance from the orthodontic wire to the buccal plate of the defect also represented its baseline horizontal component. Vertical variations were evaluated with another stent and, in this case, no desired gain was considered. After raising partial-thickness flaps, the ADM material was rehydrated and folded to fill the defect and reproduce the desired gain. Flaps were sutured with no tension, and part of the material was intentionally left exposed to avoid pressure on the incision line and prevent height loss. Patients used local and systemic antimicrobials, and the sutures were removed at 7 days. RESULTS: Evaluations were carried out at 30 days, and 3 and 6 months, and all sites healed uneventfully. Neither infection nor significant pain was reported by the patients, and the material was covered by tissue at about 21 days. Mean horizontal gain of 1.72 +/- 0.59 mm (58.5%) at 6 months and mean shrinkage of 1.22 +/- 0.46 mm (41.4%) were observed. There was a mean improvement in vertical gain of only 0.61 +/- 0. 77 mm, although 66. 7% of the treated sites showed a 1 to 2 mm gain. Clinically, the total gain in the subjects was very effective and matched the receptor tissues nicely. CONCLUSIONS: ADM may be a suitable material for the treatment of soft tissue ridge deformities due to its biocompatibility, color matching, and horizontal gain. Additional controlled, comparative trials are necessary to establish its advantages and potential compared to autogenous soft tissue techniques.

Use of bovine-derived anorganic bone associated with guided tissue regeneration in intrabony defects. Six-month evaluation at re-entry.

BACKGROUND: Different filling materials have been associated with guided tissue regeneration (GTR) in order to improve its regenerative potential and predictability. Anorganic bovine bone (ABB) has demonstrated biocompatibility and osteoconductive properties; however, there are limited data regarding its performance in the treatment of intrabony defects. This investigation aimed to evaluate the clinical outcome of the association of anorganic bovine bone with cellulose membranes in intrabony defects after 6 months. METHODS: Twenty-six paired intrabony defects were selected from 11 non-smoking patients with no relevant medical history. The defects were similar regarding the number of bony walls and defect depth, and presented pocket depths > or = 6 mm. Four weeks after completion of basic therapy, probing depth (PD), clinical attachment level (CAL), and gingival margin position (GP) were recorded (baseline values). The defects were then surgically accessed and debrided, and the intrabony component measured to the nearest millimeter with periodontal probes and customized acrylic stents (distance from the stent to the base of the defect and from the stent to the alveolar crest). Each intrabony defect was randomly assigned to receive the membrane alone (control, C) or the membrane with anorganic bovine bone (test, T). The patients were re-evaluated after 6 months, and re-entry procedures were performed. RESULTS: Significant (P <0.01) improvement in all variables was observed: mean pocket reduction of 4.61+/-1.60 mm (C) and 4.46+/-1.50 mm (T) and clinical attachment gain of 2.85+/-1.46 mm (C) and 3.15+/-1.40 mm (T); the difference between groups was not significant (P >0.05). Nevertheless, gingival recession in the control group (1.84+/-0.89 mm) was significantly (P <0.05) more pronounced than that observed in the test group (1.30+/-0.48 mm). Bone measurements indicated a significant resolution of the defects (P <0.01). A mean defect resolution of 2.76+/-0.72 mm (C) and 2.69+/-1.03 mm (T) and crestal resorption of 1.07+/-0.64 mm (C) and 1.30+/-0.85 mm (T) were detected (P >0.05). Stepwise multiple regression analysis indicated that for both groups, the baseline depth of the defects and the alveolar crest resorption accounted for 82% of the variability of bone fill observed in the control group (F = 23.65, P <0.001) and 89% in the test group (F = 41.32, P <0.001). CONCLUSIONS: ABB may be used in conjunction with GTR in the treatment of intrabony defects. Its use, however, did not result in a better outcome than the use of membranes alone. Studies employing more patients would be of interest in order to determine the advantages and indications of the tested approaches on a more predictable basis.

Managing soft tissue fenestrations in bone grafting surgery with an acellular dermal matrix: a case report.

The success of bone grafting procedures depends largely on the management and integrity of the gingival flaps. Soft tissues aid in the protection of the bone graft, participate in the revascularization of the newly formed hard tissues, and play an important role in the esthetic outcome of the reconstructive phase. Acellular dermal matrix (ADM) is a material obtained from human skin and used in plastic and reconstructive surgery as an allograft. It acts as a bioactive substrate for cell attachment and proliferation. The outcome of the use of ADM as a dressing material to treat flap fenestrations in bone grafting surgery is presented.