bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gene Expression Analysis of the Function of the Male-Specific Lethal Complex in Drosophila
Authors: Pal Bhadra Manika , Bhadra Utpal , Kundu Joydeep , Birchler James A 
Published: February 2005

Abstract
Dosage compensation refers to the equal expression of X-linked genes despite the difference in copy number between the two sexes. The male-specific lethal (MSL) complex is concentrated on the X chromosome in males. A gene expression assay for embryos was developed to examine the function of this complex. In mutant male embryos without either the MSL complex or MOF histone acetylase, dosage compensation is retained but autosomal expression is increased. Dosage compensation is lost in the double-mutant embryos. In embryos in which the MSL complex and MOF are targeted to the X chromosomes in females, the results are consistent with previous surveys showing that in general the X expression remains unchanged, but autosomal expression is reduced. Mutations in the ISWI chromatin-remodeling component cause increases specifically of X-linked genes in males. Thus, the function of the MSL complex in conjunction with ISWI is postulated to override the effect on gene expression of high histone acetylation on the male X. The basic determinant of dosage compensation is suggested to be an inverse dosage effect produced by an imbalance of transcription factors on the X vs. the autosomes. The sequestration of the MSL complex to the male X may have evolved to counteract a similar effect on the autosomes and to prevent an overexpression of the X chromosome in males that would otherwise occur due to the high levels of histone acetylation.
Identification and Characterization of Regions of the Rice Genome Associated With Broad-Spectrum, Quantitative Disease Resistance
Authors: Wisser Randall J , Sun Qi , Hulbert Scot H , Kresovich Stephen , Nelson Rebecca J 
Published: February 2005

AbstractMuch research has been devoted to understanding the biology of plant-pathogen interactions. The extensive genetic analysis of disease resistance in rice, coupled with the sequenced genome and genomic resources, provides the opportunity to seek convergent evidence implicating specific chromosomal segments and genes in the control of resistance. Published data on quantitative and qualitative disease resistance in rice were synthesized to evaluate the distributions of and associations among resistance loci. Quantitative trait loci (QTL) for resistance to multiple diseases and qualitative resistance loci (R genes) were clustered in the rice genome. R genes and their analogs of the nucleotide binding site–leucine-rich repeat class and genes identified on the basis of differential representation in disease-related EST libraries were significantly associated with QTL. Chromosomal segments associated with broad-spectrum quantitative disease resistance (BS-QDR) were identified. These segments contained numerous positional candidate genes identified on the basis of a range of criteria, and groups of genes belonging to two defense-associated biochemical pathways were found to underlie one BS-QDR region. Genetic dissection of disease QTL confidence intervals is needed to reduce the number of positional candidate genes for further functional analysis. This study provides a framework for future investigations of disease resistance in rice and related crop species.
Mutation Rate Variation at Human Dinucleotide Microsatellites
Authors: Xu Hongyan , Chakraborty Ranajit , Fu Yun-Xin 
Published: February 2005

Abstract
Mutation is the ultimate source of genetic variation, and mutation rate is thus an important parameter governing the extent of genetic variation. Microsatellites are highly informative genetic markers that have been widely used in genetic studies. While previous studies showed that the mutation rate differs in di-, tri-, and tetranucleotide repeats, how mutation rate distributes within each class of repeat is poorly understood. This study first revealed the pattern of the mutation rate variation within the dinucleotide repeats. Two data sets were used. The first is the allele frequency data from 115 microsatellites with dinucleotide repeats distributed along the human genome in 10 worldwide populations. The second data set is much larger, consisting of the allele frequency of 5252 dinucleotide repeats from the Genome Database. Mutation rate for each locus is estimated through a new homozygosity-based estimator, which has been shown to be unbiased and highly efficient and is reasonably robust against deviations from the single-step model. The mutation rates among loci can be approximated well by a gamma distribution and its shape parameter can be accurately estimated with this approach. This result provides the basic guidelines for analyzing the large-scale genomic data from microsatellite loci.
A 6‐Month Comparative Clinical Study of a Conventional and a New Surgical Approach for Root Coverage With Acellular Dermal Matrix
Authors: Barros Raquel R.M. , Novaes Arthur B. , Grisi Márcio F.M. , Souza Sérgio L.S. , Taba Mário , Palioto Daniela B. 
Published: February 2005

Background: The acellular dermal matrix graft (ADMG) has become widely used in periodontal surgeries as a substitute for the subepithelial connective tissue graft (SCTG). These grafts exhibit different healing processes due to their distinct cellular and vascular structures. Therefore the surgical technique primarily developed for the autograft may not be adequate for the allograft. This study compared the clinical results of two surgical techniques–the “conventional” and a modified procedure–for the treatment of localized gingival recessions with the ADMG.Methods: A total of 32 bilateral Miller Class I or II gingival recessions were selected and randomly assigned to test and control groups. The control group received the SCTG and the test group the modified surgical technique. Probing depth (PD), relative clinical attachment level (RCAL), gingival recession (GR), and width of keratinized tissue (KT) were measured 2 weeks prior to surgery and 6 months post‐surgery.Results: Both procedures improved all the evaluated parameters after 6 months. Comparisons between the groups by Mann‐Whitney rank sum test revealed no statistically significant differences in terms of CAL gain, PD reduction, and increase in KT from baseline to 6‐month evaluation. However, there was a statistically significant greater reduction of GR favoring the modified technique (P = 0.002). The percentage of root coverage was 79% for the test group and 63.9% for the control group.Conclusion: We conclude that the modified technique is more suitable for root coverage procedures with the ADMG since it had statistically significant better clinical results compared to the traditional technique. J Periodontol 2004;75:1350‐1356.
Enamel Matrix Derivative and Guided Tissue Regeneration in the Treatment of Dehiscence‐Type Defects: A Histomorphometric Study in Dogs
Authors: Sallum Enilson A. , Pimentel Suzana P. , Saldanha Juliana B. , Nogueira‐Filho Getúlio R. , Casati Marcio Z. , Nociti Francisco H. , Sallum Antonio Wilson 
Published: February 2005

Background: The goal of this investigation was to histologically and histometrically evaluate the healing process of dehiscencetype defects treated by enamel matrix derivative (EMD) and/or guided tissue regeneration (GTR).Methods: Seven mongrel dogs were used. Buccal osseous dehiscences were surgically created on the mesial roots of the mandibular third and fourth premolars. The defects were exposed to plaque accumulation for 3 months. After this period, the defects were randomly assigned to one of the treatments: open flap debridement (OFD), enamel matrix derivative (EMD), GTR with bioabsorbable membrane (GTR), and the combination of both procedures (EMD + GTR). After 4 months of healing, the dogs were sacrificed and the blocks were processed. The histometric parameters evaluated included gingival recession, epithelial length, connective tissue adaptation, new cementum, and new bone.Results: A superior length of new cementum was observed in the sites treated by EMD (3.7 mm) and EMD + GTR (3.8 mm) in comparison with OFD (2.4 mm) (P <0.05). No statistically significant differences were found in the remaining histometric parameters.Conclusions: Within the limits of this study, it can be concluded that EMD alone or in combination with GTR barriers may effectively promote new cementum formation. The combination of both therapies may not provide additional benefits. J Periodontol 2004;75: 1357‐1363.
The Relationship Between Porphyromonas gingivalis Infection and Local and Systemic Factors in Children
Authors: Bimstein Enrique , Sapir Shabetai , Houri‐Haddad Yael , Dibart Serge , Van Dyke Thomas E. , Shapira Lior 
Published: February 2005

Background:Porphyromonas gingivalis (P. gingivalis) is a major pathogen related to periodontitis. There are few reports on the prevalence and effect of P. gingivalis in children. The purpose of the present study was to describe in children the level of DNA‐P. gingivalis in subgingival plaque and the IgG serum reactivity to P. gingivalis (IgG‐Pg), and examine their relationship to demographic, systemic, and oral variables.Methods: Thirty‐four children, aged 1.83 to 13.42 years, were included in the study; 16 with no systemic disease and 18 with systemic conditions. The demographic data for caries incidence, plaque and gingival indices, probing depth, and alveolar bone height were recorded. The IgG‐Pg and DNA‐Pg levels were determined by enzyme‐linked immunosorbent assay and DNA‐DNA hybridization, respectively. The relationships between the IgG‐Pg and DNA‐Pg values to the demographics, oral parameters, and systemic conditions were examined.Results: IgG‐Pg was evident in 53% of the children and DNAPg in 47%. IgG‐Pg values significantly correlated positively with age, plaque index, and bone height. DNA‐Pg values had statistically significant positive correlations with age. IgG‐Pg and DNAPg values correlated with probing depth among children with systemic diseases. Neither the IgG‐Pg nor the DNA‐Pg values had a significant correlation to systemic conditions. Multiple regression analyses indicated that only age remained significantly related to IgG‐Pg and DNA‐Pg values.Conclusions:P. gingivalis can be found in significant levels in the plaque of young children and elicits an immune reaction that increases with age and may be related to incipient signs of periodontal disease. Plaque DNA‐Pg and serum IgG‐Pg levels correlate significantly. J Periodontol 2004;75:1371‐1376.
Localized Gingival Recessions Treated With the Original Envelope Technique: A Report of 50 Consecutive Patients
Authors: Vergara Jaime A. , Caffesse Raul G. 
Published: February 2005

Background: The surgical techniques used to treat gingival recession have changed considerably in the last 50 years. The envelope technique described nearly 20 years ago still offers an excellent alternative for the problem of recession. The purpose of this retrospective study is to show the results of 115 recession sites treated in 50 patients using the envelope technique.Methods: One hundred‐fifteen consecutive procedures were performed in 50 patients in a private practice in the last 5 years using the envelope technique. Briefly, the teeth are scaled, a split thickness flap is performed around the recession, a subepithelial connective tissue graft is harvested from the palate and placed over the recession, and sutured with 6‐0 silk. Four cases representing different types of recession will be reviewed and all cases will be analyzed.Results: In general, this surgical method provided excellent root coverage and an increased amount of keratinized gingiva. The complete root coverage mean was 85%, 65%, and 16% for recession Class I, II, and IV, respectively.Conclusion: The cases support the use of the envelope technique to treat different types of single and multiple recessions. J Periodontol 2004;75:1397‐1403.
Submental Cutaneous Sinus Tract as a Result of Progressive Peri‐Implantitis: A Case Report
Authors: Nkenke Emeka , Amann Kerstin , Reich Sven , Neukam Friedrich W. , Frankenberger Roland 
Published: February 2005

Background: The aim of the present case report was to define diagnosis and treatment options of a submental cutaneous sinus tract as a result of a progressive periimplantitis around mandibular dental implants in a patient with a history of oral squamous cell carcinoma.Methods: Before the removal of the submental fistula, a panoramic radiograph and a computed tomography of the head and neck were assessed to identify the implants responsible for the cutaneous sinus tract and to exclude the presence of a tumor recurrence and lymph node metastases. The involved implants were removed, as there was a communication along them between the oral cavity and the cutaneous sinus tract resulting from progressive peri‐implantitis. A histological examination of the excised fistula was carried out.Results: The histological examination excluded a recurrence of the oral squamous cell carcinoma. The fistula completely consisted of granulation tissue without epithelialization. After affected implants were removed, the wound healing was uneventful.Conclusions: A panoramic radiograph is mandatory to identify the involved implants. Computed tomography, and excision of the fistula and a histological examination should be performed only in patients with a history of oral squamous cell carcinoma. Since the cutaneous sinus tract showed no epithelialization, it healed spontaneously after the removal of the responsible implants. Because of the large bony defect caused by progressive peri‐implantitis leading to a communication of the oral cavity with the cutaneous sinus tract, more conservative treatment options with preservation of the implants could not be adopted in the present case. J Periodontol 2004;75:1417‐1423.
Effect of Enamel Matrix Derivative on Collagen Guided Tissue Regeneration‐Based Root Coverage Procedure
Authors: Trabulsi Manal , Oh Tae‐Ju , Eber Robert , Weber Daniel , Wang Hom‐Lay 
Published: February 2005

Background: Enamel matrix derivative (EMD) has been shown to promote periodontal wound healing and/or regeneration when applied to tooth root surfaces in soft tissue dehiscence models. In addition, guided tissue regeneration (GTR)‐based root coverage using collagen membrane (GTRC) has shown promising results. However, limited information is available regarding how EMD may influence GTRC outcome.Methods: Twenty‐six patients with Miller's Class I or II gingival recession defects of 2.5 mm were recruited for the study. Subjects were randomly assigned to receive either EMD + collagen (EMDC; test group) or collagen membrane (GTRC; control group). Clinical parameters, including plaque index (PI), gingival index (GI), relative clinical attachment levels (RCAL) to the stent, recession depth (RD), recession width (RW), probing depth (PD), gingival tissue thickness (GTT), and width of keratinized gingiva (KG) were assessed at baseline, and 3 and 6 months after surgery. A repeated measure of analysis of variance (ANOVA) was used to determine differences between treatment groups and time effect.Results: Both treatments (GTRC and EMDC) resulted in a statistically significant decrease in RD and RW between baseline and 6 months (P <0.05). However, no difference was noted between treatment groups. The percent of root coverage after 6 months was 75% for GTRC and 63% for EMDC. Complete 100% root coverage was achieved in five patients in the GTRC group, compared to only one patient in the EMDC group. There was a statistically significant gain (P <0.05) in the clinical attachment level (CAL) between baseline and 6 months in both groups, as reflected on the RCAL data. No other significant differences were noted on other clinical parameters (PD, GTT, KG, GI, and PI).Conclusions: GTR‐based root coverage utilizing collagen membrane, with or without enamel matrix derivative, can be successfully used in obtaining gingival recession coverage. The application of EMD during GTRC procedures did not add additional benefit to the final clinical outcome. J Periodontol 2004;75:1446‐1457.
Aggressive Periodontitis With Supernumerary Teeth: A Retrospective Study
Authors: Açikgöz Gökhan , Açikgöz Aydan , Keskiner İlker , Türk Tamer , Otan Feyza 
Published: February 2005

Background: There are four key studies in the periodontology literature reporting the correlation between supernumerary teeth and aggressive periodontitis. The aim of this study is to detect such a relationship.Methods: Patients with supernumerary teeth were identified retrospectively from their orthopantomographs and were invited to the periodontology department for intraoral examination. They were then evaluated for aggressive periodontitis. The number of existing teeth, age, family histories, attachment loss, probing depths, and bleeding on probing scores were recorded.Results: Of the 5,850 subjects randomly observed among 48,000 patients, only 174 exhibited supernumerary teeth. Of these 174 subjects, only three patients were diagnosed with aggressive periodontitis. One of the patients was also suffering from Fanconi's anemia.Conclusions: Despite the similarities (aggressive periodontitis accompanied by supernumerary teeth) in the previous reports, we do not agree with the earlier results. We rather suggest that this association might be a random occurrence, rather than a biological one, although this observation should be further investigated using genetic testing. J Periodontol 2004;75:1458‐1460.
Effect of Subantimicrobial Dose Doxycycline as an Effective Adjunct to Scaling and Root Planing
Authors: Lee Ji‐Young , Lee Yong‐Moo , Shin Seung‐Yun , Seol Yang‐Jo , Ku Young , Rhyu In‐Chul , Chung Chong‐Pyoung , Han Soo‐Boo 
Published: February 2005

Background: This study evaluated the efficacy and safety of a subantimicrobial dose of doxycycline (SDD) in conjunction with scaling and root planing (SRP).Methods: The study was a 9‐month, double masked, randomized, placebo‐controlled, parallel‐group trial. A total of 41 patients with moderate chronic periodontitis who received SRP were randomly allocated to receive either a doxycycline hyclate or a placebo 2 weeks after SRP. Clinical attachment level (CAL), the probing depth (PD), gingival crevicular fluid (GCF) levels, and matrix metalloproteinase (MMP)‐8 and ‐13 levels were measured throughout the study. The effect of SDD in conjunction with SRP on the dynamics of the periodontal microflora was also assessed using dark‐field microscopic and culture analysis. Information on adverse events was collected throughout the study.Results: During the treatment period, per‐patient reductions in PD and CAL were demonstrated for both treatment groups, with a significantly greater reduction for the SDD group. The mean value of per‐patient change in the GCF was much greater for the SDD group. Microbial analysis showed there were a general tendency for cocci, non‐motile rods, and aerobes to increase with increasing treatment duration and a general decreasing tendency for spirochetes, motile rods, and anaerobes and black pigmented bacteria in both treatment groups, but no significant difference between the groups. The MMP‐8 and ‐13 levels of the SDD group gradually reduced with time, and the mean perpatient average was significantly higher than in the placebo group. The adverse events in the SDD group were similar to those in the placebo group.Conclusion: This study suggests that a submicrobial dose of doxycycline as an adjunct therapy with SRP might be safe and effective in the long‐term management of chronic periodontitis. J Periodontol 2004;75:1500‐1508.
Enhancement of Bone Formation by Bone Morphogenetic Protein‐2 During Alveolar Distraction: An Experimental Study in Sheep
Authors: Rachmiel Adi , Aizenbud Dror , Peled Micha 
Published: February 2005

Background: The purpose of this study was to perform alveolar ridge augmentation by distraction osteogenesis (DO) and to enhance bone regeneration through the use of recombinant human bone morphogenetic protein‐2 (rhBMP‐2), followed by implant placement.Methods: Alveolar segmental osteotomy was performed in the mandible of 10 sheep followed by placement of 1.5 mm alveolar distraction devices. The study group was injected on the fifth day of distraction with a single dose of 10 µg rhBMP‐2. Only distraction was performed in the control group.Results: A mean alveolar augmentation of 12 mm was achieved. After 12 weeks of consolidation, the distraction devices were removed and biopsies were taken for histological and immunohistochemical characterization and morphometry of the newly formed bone. Titanium threaded cylindrical implants were then placed in the newly augmented bone. Radiological evaluation showed lifting of the transport segment and integration of the implants within both the transport segment and the regenerated bone. The histological study demonstrated that the association of DO and BMP resulted in increased trabecular bone size and volume (32.2% ± 0.95% versus 18.6% ± 0.71%; P <1 × 10–17 after 24 days of lengthening and 63.8% ± 1.89% versus 42.5% ± 1.33%; P <1 × 10–15 after 12 weeks of consolidation) and increased numbers of proliferating cell nuclear antigen stained cells (0.7 ± 0.04 versus 0.47 ± 0.04; P <1 × 10–10) compared with the DO only group.Conclusions: Alveolar distraction augments atrophic alveolar ridge and creates new bone that permits implant placement. rhBMP‐2 enhances bone quality and may shorten the consolidation period of distraction allowing for earlier implant placement.J Periodontol 2004;75:1524‐1531.
Gene Expression Profiles of Periodontal Ligament Cells Treated With Enamel Matrix Proteins In Vitro: Analysis Using cDNA Arrays
Authors: Parkar Mohamed H. , Tonetti Maurizio 
Published: February 2005

Background: A number of procedures have been used to achieve periodontal regeneration. Recently, enamel matrix derivative (EMD) has been the subject of significant basic and clinical investigations. The precise molecular events involved in EMD modulation of periodontal wound healing are not completely understood; however, cDNA microarray technology may enable rapid and accurate examination of EMD‐mediated changes in gene expression in periodontal ligament (PDL) cells in vitro. The present study was undertaken to explore the selective effects of EMD on the activities of 268 cytokine, growth factor, and receptor genes in PDL.Methods: PDL cells were cultured in the absence and presence of EMD at a concentration of 100 µg/ml for 4 days. RNA was extracted and used to generate labeled cDNA probes. These were hybridized to cDNA arrays comprising 268 genes and exposed to x‐ray films. Autoradiographs were digitized and analyzed.Results: Forty‐six percent (125 of 268) of the tested genes were found to be expressed by the PDL cells. Of these 125 genes, 38 were differentially expressed by PDL cells which had been cultured in the presence of EMD. Among the 38, 12 were found to be downregulated, notably mostly inflammatory genes, whereas 26 genes demonstrated upregulation, many of these coding for growth factors and growth factor receptors.Conclusions: The present study has shown that EMD downregulates the expression of genes involved in the early inflammatory phases of wound healing while simultaneously upregulating genes encoding growth and repair‐promoting molecules. This may partly explain the apparent efficacy of EMD application in periodontal regeneration. J Periodontol 2004;75:1539‐1546.