bluuebunny/crossref_metadata_2025 huggingface dataset:
GSK3: a key target for the development of novel treatments for type 2 diabetes mellitus and Alzheimer disease
Authors: Gao Chong , Hölscher Christian , Liu Yueze , Li Lin
Published: March 2012

As a constitutively active kinase, glycogen synthase kinase 3 (GSK3) is a kinase which regulates body metabolism by phosphorylation of glycogen synthase (GS) and other substrates. Considerable evidence suggests that GSK3 is involved in the common pathology underlying Alzheimer’s disease (AD) and type 2 diabetes mellitus (T2DM). The overexpression or overactivation of GSK3 could induce a series of pathological changes, most of which are hallmarks of AD and T2DM. Therefore, GSK3 could be a novel target to treat these two age-dependent diseases. The inhibition of this kinase can prevent the aggregation of β-amyloid (Aβ) and hyperphosphorylation of tau protein. GSK3 inhibition can also be a promising strategy to ameliorate neurodegenerative developments. Its potential association with memory formation has been shown in electrophysiological and behavioral experiments. The neuroprotective effects of novel drugs developed to treat T2DM, glucagon-like peptide 1 (GLP-1) and its long-lasting analogs, have a possible link to GSK3 modification. Recent investigations of the interaction between the phosphatidylinositol 3 kinase (PI3K) signaling pathway and the protective effect of novel GPL-1 receptor agonist geniposide on PC12 cells support this theory.
Variant Brain-Derived Neurotrophic Factor Val66Met Polymorphism Alters Vulnerability to Stress and Response to Antidepressants
Authors: Yu Hui , Wang Dong-Dong , Wang Yue , Liu Ting , Lee Francis S. , Chen Zhe-Yu
Published: March 2012

Brain-derived neurotrophic factor (BDNF) plays important roles in cell survival, neural plasticity, learning, and stress regulation. However, whether the recently found humanBDNFVal66Met (BDNFMet) polymorphism could alter stress vulnerability remains controversial. More importantly, the molecular and structural mechanisms underlying the interaction between theBDNFMetpolymorphism and stress are unclear. We found that heterozygousBDNF+/Metmice displayed hypothalamic-pituitary-adrenal axis hyperreactivity, increased depressive-like and anxiety-like behaviors, and impaired working memory compared with WT mice after 7 d restraint stress. Moreover,BDNF+/Metmice exhibited more prominent changes in BDNF levels and apical dendritic spine density in the prefrontal cortex and amygdala after stress, which correlated with the impaired working memory and elevated anxiety-like behaviors. Finally, the depressive-like behaviors inBDNF+/Metmice could be selectively rescued by acute administration of desipramine but not fluoxetine. These data indicate selective behavioral, molecular, and structural deficits resulting from the interaction between stress and the human geneticBDNFMetpolymorphism. Importantly, desipramine but not fluoxetine has antidepressant effects onBDNF+/Metmice, suggesting that specific classes of antidepressant may be a more effective treatment option for depressive symptoms in humans with this genetic variant BDNF.
Topologically Convergent and Divergent Structural Connectivity Patterns between Patients with Remitted Geriatric Depression and Amnestic Mild Cognitive Impairment
Authors: Bai Feng , Shu Ni , Yuan Yonggui , Shi Yongmei , Yu Hui , Wu Di , Wang Jinhui , Xia Mingrui , He Yong , Zhang Zhijun
Published: March 2012

Alzheimer's disease (AD) can be conceptualized as a disconnection syndrome. Both remitted geriatric depression (RGD) and amnestic mild cognitive impairment (aMCI) are associated with a high risk for developing AD. However, little is known about the similarities and differences in the topological patterns of white matter (WM) structural networks between RGD and aMCI. In this study, diffusion tensor imaging and deterministic tractography were used to map the human WM networks of 35 RGD patients, 38 aMCI patients, and 30 healthy subjects. Furthermore, graph theoretical methods were applied to investigate the alterations in the global and regional properties of the WM network in these patients. First, both the RGD and aMCI patients showed abnormal global topology in their WM networks (i.e., reduced network strength, reduced global efficiency, and increased absolute path length) compared with the controls, and there were no significant differences in these global network properties between the patient groups. Second, similar deficits of the regional and connectivity characteristics in the WM networks were primarily found in the frontal brain regions of RGD and aMCI patients compared with the controls, while a different nodal efficiency of the posterior cingulate cortex and several prefrontal brain regions were also observed between the patient groups. Together, our study provides direct evidence for the association of a great majority of convergent and a minority of divergent connectivity of WM structural networks between RGD and aMCI patients, which may lead to increasing attention in defining a population at risk of AD.
Prostaglandin E2-Mediated Attenuation of Mesocortical Dopaminergic Pathway Is Critical for Susceptibility to Repeated Social Defeat Stress in Mice
Authors: Tanaka Kohei , Furuyashiki Tomoyuki , Kitaoka Shiho , Senzai Yuta , Imoto Yuki , Segi-Nishida Eri , Deguchi Yuichi , Breyer Richard M. , Breyer Matthew D. , Narumiya Shuh
Published: March 2012

Various kinds of stress are thought to precipitate psychiatric disorders, such as major depression. Whereas studies in rodents have suggested a critical role of medial prefrontal cortex (mPFC) in stress susceptibility, the mechanism of how stress susceptibility is determined through mPFC remains unknown. Here we show a critical role of prostaglandin E2(PGE2), a bioactive lipid derived from arachidonic acid, in repeated social defeat stress in mice. Repeated social defeat increased the PGE2level in the subcortical region of the brain, and mice lacking either COX-1, a prostaglandin synthase, or EP1, a PGE receptor, were impaired in induction of social avoidance by repeated social defeat. Given the reported action of EP1 that augments GABAergic inputs to midbrain dopamine neurons, we analyzed dopaminergic response upon social defeat. Analyses of c-Fos expression of VTA dopamine neurons and dopamine turnover in mPFC showed that mesocortical dopaminergic pathway is activated upon social defeat and attenuated with repetition of social defeat in wild-type mice. EP1 deficiency abolished such repeated stress-induced attenuation of mesocortical dopaminergic pathway. Blockade of dopamine D1-like receptor during social defeat restored social avoidance in EP1-deficient mice, suggesting that disinhibited dopaminergic response during social defeat blocks induction of social avoidance. Furthermore, mPFC dopaminergic lesion by local injection of 6-hydroxydopamine, which mimicked the action of EP1 during repeated stress, facilitated induction of social avoidance upon social defeat. Taken together, our data suggest that PGE2-EP1 signaling is critical for susceptibility to repeated social defeat stress in mice through attenuation of mesocortical dopaminergic pathway.
KIF21A-Mediated Axonal Transport and Selective Endocytosis Underlie the Polarized Targeting of NCKX2
Authors: Lee Kyu-Hee , Lee Jae Sung , Lee Doyun , Seog Dae-Hyun , Lytton Jonathan , Ho Won-Kyung , Lee Suk-Ho
Published: March 2012

We have previously shown that K+-dependent Na+/Ca2+exchanger (NCKX) is a major calcium clearance mechanism at the large axon terminals of central neurons, whereas their somata display little NCKX activity. We investigated mechanisms underlying the axonal polarization of NCKX2 in rat hippocampal neurons. We identified NCKX2 as the first neuron-specific cargo molecule of kinesin family member 21A (KIF21A). The intracellular loop of NCKX2 specifically interacted with the WD-40 repeats, a putative cargo-binding domain, of KIF21A. Dominant-negative mutant or depletion of KIF21A inhibited the transport of NCKX2-GFP to axon fibers. Knockdown of KIF21A caused calcium dysregulation at axonal boutons but not at somatodendritic regions. Despite the axonal polarization of the NCKX activity, both somatodendritic and axonal regions were immunoreactive to NCKX2. The surface expression of NCKX2 revealed by live-cell immunocytochemistry, however, displayed highly polarized distribution to the axon. Inhibition of endocytosis increased the somatodendritic surface NCKX2 and thus abolished the axonal polarization of surface NCKX2. These results indicate that KIF21A-mediated axonal transport and selective somatodendritic endocytosis underlie the axonal polarized surface expression of NCKX2.
Dynamic Causal Modeling of Spatiotemporal Integration of Phonological and Semantic Processes: An Electroencephalographic Study
Authors: Yvert Gaëtan , Perrone-Bertolotti Marcela , Baciu Monica , David Olivier
Published: March 2012

Integration of phonological and lexicosemantic processes is essential for visual word recognition. Here we used dynamic causal modeling of event-related potentials, combined with group source reconstruction, to estimate how those processes translate into context-dependent modulation of effective connectivity within the temporal-frontal language network. Fifteen healthy human subjects performed a phoneme detection task in pseudo-words and a semantic categorization task in words. Cortical current densities revealed the sequential activation of temporal regions, from the occipital–temporal junction toward the anterior temporal lobe, before reaching the inferior frontal gyrus. A difference of activation between phonology and semantics was identified in the anterior temporal lobe within the 240–300 ms peristimulus time window. Dynamic causal modeling indicated this increase of activation of the anterior temporal lobe in the semantic condition as a consequence of an increase of forward connectivity from the posterior inferior temporal lobe to the anterior temporal lobe. In addition, fast activation of the inferior frontal region, which allowed a feedback control of frontal regions on the superior temporal and posterior inferior temporal cortices, was found to be likely. Our results precisely describe spatiotemporal network mechanisms occurring during integration of phonological and semantic processes. In particular, they support the hypothesis of multiple pathways within the temporal lobe for language processing, where frontal regions would exert a top-down control on temporal regions in the recruitment of the anterior temporal lobe for semantic processing.
Hepatic steatosis, GH deficiency and the effects of GH replacement: a Liverpool magnetic resonance spectroscopy study
Authors: Gardner Chris J , Irwin Andrew J , Daousi Christina , McFarlane Ian A , Joseph Franklin , Bell Jimmy D , Thomas E Louise , Adams Valerie L , Kemp Graham J , Cuthbertson Daniel J
Published: March 2012

Objective

Non-alcoholic fatty liver disease (NAFLD) is reported to be more common in patients with GH deficiency (GHD) than in the general population. We aimed to determine: i) liver fat in patients with GHD compared with age and body mass index (BMI)-matched controls; and ii) effect of 6 months of GH replacement (GHR) on liver fat.

Participants and methods

The study included 28 GHD patients and 24 controls. 12 patients were studied before and after 6 months of GHR. Anthropometry, liver enzymes and lipid profiles were measured, and body composition and intrahepatocellular lipid (IHCL) were determined by magnetic resonance imaging and spectroscopy.

Results

Age and BMI (median (inter-quartile range)) of patients and controls were 52.6 (14) vs 52.6 (12) years (P=0.9) and 27.8 (24.7, 34.7) vs 27.9 (25.1, 32.1) kg/m2(P=0.9). IGF1 was lower in the patients (11.5 vs 16.0 nmol/l,P=0.002). There was no difference in liver transaminases, lipids or IHCL between patients and controls (2.8 (1.3, 8.6) vs 5.0 (1.5, 12.7),P=0.72), despite significantly higher visceral fat in GHD patients. Thirty-two percent of patients and 50% of controls had NAFLD (defined as IHCL >5.6%), and the relationship between IHCL and BMI was the same in each group. GHR significantly reduced abdominal subcutaneous and visceral fat in all patients; however, GHR did not reduce liver fat.

Conclusions

NAFLD is equally common in patients with GHD and matched controls. GHR is associated with a hierarchical reduction in fat deposition (fat loss: visceral > subcutaneous > liver). Further studies involving GHD patients with NAFLD are required to conclude the role of GHR in treating NAFLD.
Perdas de grãos e distribuição de palha na colheita mecanizada de soja
Authors: Chioderoli Carlos Alessandro , Silva Rouverson Pereira da , Noronha Rafael Henrique de Freitas , Cassia Marcelo Tufaile , Santos Edvaldo Pereira dos
Published: March 2012

Considerando que a colheita é a etapa final de um processo produtivo e que as perdas devem ser mantidas dentro de padrões aceitáveis, as regulagens das colhedoras e as características agronômicas da cultura deverão permitir menores perdas quantitativas para que possa atingir o máximo nível de qualidade e maior sustentabilidade do sistema produtivo. Este trabalho teve como objetivo determinar as perdas quantitativas, distribuição de palha e características operacionais da colhedora por meio do controle estatístico de processo, bem como verificar a qualidade da operação de colheita. O trabalho foi realizado no município de Santa Juliana (MG), com as coordenadas geográficas de referência 19º 18'Se 47º 31'O. A área amostrada constou de 40 pontos distribuídos em malha retangular, equidistantes de 50 m, definidos sequencialmente a partir do momento de início da colheita. Em cada ponto foi determinado o teor de água dos grãos, número de vagens por planta, altura de inserção de primeira vagem, altura de plantas, produtividade, distribuição de palha e características operacionais da colhedora. A perda de grãos ocasionada pela colhedora esteve fora dos limites de controle, porém dentro dos padrões aceitáveis de perdas para cultura da soja. A qualidade da operação de colheita e as regulagens da colhedora foram dependentes da velocidade de deslocamento. A distribuição de palha esteve próxima do desejável para o sistema de semeadura direta. A utilização das cartas de controle foi eficiente na identificação dos pontos fora de controle e na avaliação da qualidade do processo de colheita.
Avaliação da incidência e fatores de risco da retenção de placenta em vacas mestiças leiteiras
Authors: Nobre M.M. , Coelho S.G. , Haddad J.P.A. , Campos E.F. , Lana A.M.Q. , Reis R.B. , Saturnino H.M.
Published: March 2012

Avaliaram-se a incidência, os fatores de risco e o impacto da retenção de placenta tanto no desempenho reprodutivo quanto no produtivo de vacas mestiças leiteiras, considerando-se: ano e época de parição, ordem de lactação, escore de condição corporal (ECC), duração da gestação, tipo de parto e número e sexo dos bezerros. Utilizaram-se primíparas e multíparas, com e sem retenção de placenta, na época de chuva e de seca, para estudar: período de serviço, número de doses de sêmen/concepção e produção de leite em até 305 dias e no pico da lactação. A incidência da retenção foi de 12,8%. Os fatores de risco da retenção de placenta foram: período de chuvas, ordem de lactação - segunda, terceira e acima da quarta -, ECC abaixo de 3,5 e acima de 4,0 - aborto, natimorto, prematuro, parto auxiliado e parto gemelar. Verificou-se aumento de 51,2 e 27,5 dias no período de serviço e aumento de 1,2 e 0,6 no número de doses de sêmen, em multíparas com retenção de placenta que pariram no período de chuva ou seca, respectivamente (P<0,05).
Landmarks in tourist wayfinding: a review
Authors: Norgate Sarah H. , Ormerod Marcus G.
Published: March 2012

Demographic trends project a significant expansion of European urban populations to 2030, leading to expanding cities being marketed as desirable tourist destinations, particularly for short city breaks. In turn, this renders the promotion of efficient, effective and satisfactory visitor wayfinding experiences as potentially lucrative to regional visitor economies, a point reflected in current UK government tourism policy. This paper reviews key outcomes from multidisciplinary research into wayfinding behaviours and acquired spatial knowledge in unfamiliar large-scale urban environments, placing emphasis on the importance of landmarks. The rationale is that understanding the relationships between wayfinding and the features of the urban built environment facilitates informed design of potential built interventions. For this purpose, those studies involving virtual urban environments are reviewed to assess the role of landmarks as aids to navigation. In addition, given the emphasis on visual access to landmarks, issues impacting on tourists who are visually impaired are addressed. Implications for interventions in urban areas for tourists are considered.
The Effects of Guided Tissue Regeneration Membrane Placement on Healthy Periodontal Sites
Authors: Stein Marc D. , Salkin Leslie M. , Freedman Arnold L.
Published: March 2012

This study investigates the effects of the placement of a bioresorbable Type I collagen barrier on clinically healthy sites. Ten human subjects, with at least one pair of matched periodontal defects included in a previous study, were investigated for the effect of guided tissue regeneration (GTR) membrane placement on adjacent healthy sites. Control sites consisted of open flap debridement, while experimental sites consisted of similar debridement procedures with placement of a collagen membrane for GTR. The membrane placement was designed to completely cover the periodontal defect, and therefore of necessity overlapped adjacent periodontally healthy sites. It is these healthy sites that are included in the present study. Standardized measurements of change in probing attachment levels were obtained at the time of surgery and 1 year later. The differences in change of clinical attachment levels (CAL) were compared utilizing the Student r‐test for paired samples. The mean loss of CAL in the control sites was 1.00±1.179 mm, and in the test sites was 0.60±1.729 mm. When comparing the difference in changes of CAL in both test and control sites, there was no statistical significance. There was, however, a wide range of changes between individual sites, which might suggest a clinically meaningful change of CAL on an individual tooth basis. The results of this study suggest that the placement of a bioresorbable collagen barrier has no significant effect on CAL in healthy areas. J Periodontol 1993; 64:57–59.
Periodontal Infection Leading to Periostitis Ossificans (“Garré's Osteomyelitis”) of the Mandible. Report of a Case
Authors: Van den Bossche Luc H. , Demeulemeester Jean D.A. , Bossuyt Michel H.
Published: March 2012

Periostitis ossificans (“Garré's osteomyelitis”) of the mandible is a rather rare pathology that occurs as a hard swelling at the mandibular angle, persists for a long period, and is mostly painful on palpation. Clinical signs of infection are rarely noted. The etiological factor is generally a carious first permanent molar with a periapical infection or a fracture of the jaw. In this case, a 10 year‐old girl showed a fixed painful swelling of the right mandibular angle. This revealed to be periostitis ossificans, although none of the classical causes were present. The symptoms were evoked by a periodontal infection: there was an osseous crater and a probing pocket depth of more than 10 mm disto‐lingually of the first right permanent molar of the mandible. This was likely the etiological factor. Extraction of the first and second permanent right molar, curettage of the corresponding alveoli, and antibiotic treatment resulted in complete healing, clinically and radiologically, after 9 months. J Periodontol 1993; 64:60‐62.
Success Rates of Osseointegration for Implants Placed Under Sterile Versus Clean Conditions
Authors: Scharf David R. , Tarnow Dennis P.
Published: March 2012

A retrospective analysis was done comparing the success rate of osseointegration at stage 2 of implants placed under “sterile” versus “clean” conditions. “Sterile” surgery took place in an operating room setting with strict sterile protocol. “Clean” surgery took place in a clinic setting with the critical factor that nothing touched the surface of the implant until it contacted the prepared bone site. A total of 273 implants in 61 cases were placed under sterile conditions with a fixture success rate of 98.9% and a case success rate of 95.1%; 113 implants were placed under clean conditions in 31 cases with a fixture and case success rate of 98.2% and 93.5%, respectively as judged clinically at stage 2. The difference in the success rates was not statistically significant. The results of this analysis indicate that implant surgery can be performed under both “sterile” and “clean” conditions to achieve the same high rate of clinical osseointegration. J Periodontol 1993; 64:954–956.
Evaluation of Ferric Oxalate as an Agent for Use During Surgery to Prevent Post‐Operative Root Hypersensitivity
Authors: Wang Hom‐Lay , Yeh Chi‐Tsai , Smith Frederic , Burgett Frederick G. , Richards Philip , Shyr Yu , O'Neal Robert
Published: March 2012

The aim of this study was to evaluate the effectiveness of a 6% ferric oxalate solution applied during periodontal surgery to prevent post‐operative tooth hypersensitivity. Twenty‐five adult patients with similar bilateral periodontal defects participated in this study. Data were collected at baseline (1 week prior to surgery) and 1, 2, 4, and 6 weeks following surgery. Sensitivity level was determined using the visual analog scale (VAS) with the following stimuli: 1) mechanical stimulation with a No. 23 dental explorer; 2) water at 50°C; 3) ice; and 4) electric pulp tester (EPT). Teeth were randomly assigned to either test (6% ferric oxalate in 0.9% saline) or control (0.9% saline) groups. Solutions were applied to the exposed root surfaces for 1 minute during surgery. Data were analyzed by repeated measures ANOVA, paired t‐test, and Pearson's correlation test. Results from this study demonstrated statistically significant reduction in the responses to thermal stimuli, especially cold, between groups treated with ferric oxalate as compared to those treated with saline. For the cold test the difference increased with time from baseline to 6 weeks. Statistically significant (P <0.05) differences in sensitivity to heat between groups were also observed, but only at 2 and 4 weeks following surgery. There were no differences at any time period between the test and control groups when tactile or EPT techniques were used. In addition, there was no correlation between sensitivity and other clinical parameters. It was concluded from this study that 6% ferric oxalate was effective in reducing post‐surgical cold sensitivity when applied during periodontal surgical procedures. J Periodontol 1993; 64:1040–1044.
Effect of a Sodium Benzoate‐Sodium Bicarbonate Compound on Dental Plaque Formation
Authors: Ozanich Debra , Winn Lori , Medina Norman A. , Wikesjö Ulf M.E. , Nygaard‐Østby Per
Published: March 2012

The objective of this study was to evaluate the effect of a sodium benzoate‐sodium bicarbonate (SBSB) compound on dental plaque formation and developing gingivitis. Eighteen subjects were given a prophylaxis and instruction in oral hygiene to establish plaque‐free conditions and gingival health for the study baseline. They were randomly divided into three groups. Each participant was instructed to rinse twice daily with either a 0.15% chlorhexidine digluconate solution, the SBSB compound, or a placebo solution for 21 days. They refrained from all other oral hygiene procedures during this period. Plaque, gingival, and stain indices were scored at baseline and at days 7, 14, and 21 during the rinsing protocol. A significant increase in plaque accumulation was observed for the SBSB compound and placebo groups in days 7 through 21. No increase in plaque accumulation was observed in the chlorhexidine group. An increase in gingival inflammation was observed in all groups, with no significant differences between groups. Significant increases in gingival bleeding occurrence compared to baseline were found in the chlorhexidine group by day 21, in the SBSB compound group by day 7, and in the placebo group by day 14. The present study did not disclose any plaque or gingivitis inhibiting effects of the SBSB compound. J Periodontol 1993; 64:1067–1070
Variation and Distribution of Periodontists: 1982–1991
Authors: Waldman H. Barry
Published: March 2012

A review of the past three ADA studies on the distribution of dentists provides specific information on the evolving numbers of periodontists at the national, regional, and state levels. Findings include: 1) a gradual increase in the ratio of periodontist‐to‐population; 2) 30% of periodontists were less than age 40 (more than almost all other specialties); and 3) an increasing percent of senior dental students anticipate applying to periodontal programs. Although government agency and dental profession association projections are available regarding major future decreases in the overall number of dentists, limited information is available for future periodontist manpower determinations. J Periodontol 1993; 64:1079–1084.
Effect of Periodontal Treatment on Gingival Overgrowth Among Cyclosporine A‐Treated Renal Transplant Recipients
Authors: Pernu Hilkka E. , Pernu L.M. Hannele , Knuuttila Matti L.E.
Published: March 2012

No data exist on any association between combined cyclosporine A (Cy A) and dihydropyridine (DHP) medication and the effect of periodontal treatment on the occurrence of gingival overgrowth (GO) among renal transplant recipients. Clinical data on 27 renal transplant recipients treated with Cy A are presented here, including determinations of serum creatinine, whole blood Cy A concentration, existence of DHP treatment, and periodontal status. GO was classified into four categories according to the clinical changes: score 0 = no GO; score 1 = mild GO; score 2 = moderate GO; and score 3 = severe GO. All participants received hygiene phase periodontal treatment and gingivectomies were performed on 10 who originally had score 2 or 3 GO and pocketing. Fourteen (14) of the recipients had no overgrown gingiva or less than at the initial examination, and none of them had GO score 2 or 3 at the time of re‐examination (group A). Thirteen (13) participants had more overgrown gingiva than initially or developed score 2 GO after gingivectomies (group B). Group B included significantly more DHP‐medicated recipients than group A (6/13 and 1/14 respectively; P <0.03). The concomitant administration of Cy A and DHP resulted in a significantly increased percentage of score 2 overgrown gingival units as compared with Cy A alone (P <0.03). It is concluded that combined treatment with Cy A and DHP is a significant risk factor for progression or recurrence of GO after periodontal treatment among susceptible patients. J Periodontol 1993; 64:1098–1100.
Guided Tissue Regeneration Using Bioresorbable and Non‐Resorbable Devices: Initial Healing and Long‐Term Results
Authors: Gottlow Jan
Published: March 2012

Studies on periodontal wound healing have resulted in the development of the treatment modality known as “guided tissue regeneration” (GTR) based on a principle of guiding the proliferation of the various periodontal tissue components during healing following periodontal surgery. The first report of a human tooth treated according to the principle of GTR was presented 10 years ago by Nyman et al. Since then numerous clinical studies and animal experiments have been performed bringing the concept of GTR to a clinical reality. We also know that the results obtained through GTR therapy can be maintained on a long‐term basis. The first generation of GTR devices has been non‐resorbable, which calls for a second surgical procedure. This is avoided when bioresorbable devices become available. This paper suggests some demands regarding safety and efficacy criteria for both non‐resorbable and bioresorbable devices. Results from recent animal experiments and clinical studies following the use of a bioresorbable device in GTR therapy are presented. J Periodontol 1993; 64:1157–1165.
Periodontal Healing in Relation to Radiographic Attachment and Endodontic Infection
Authors: Ehnevid Helge , Jansson Leif E. , Lindskog Sven F. , Blomlöf Leif B.
Published: March 2012

The aim of the present study was primarily to investigate if periodontal healing assessed by reduction in probing depth over time is significantly influenced by the initial degree of horizontal radiographic attachment loss and secondly to what degree any such relationship influenced the already established correlation between presence of a root canal infection and impaired marginal healing. The investigation was conducted as a retrospective study on 160 patients referred to a specialist periodontal clinic. The choice of variables was guided by an assumption that each variable either positively or negatively contributed to determine probing depth reduction. It was found that healing after scaling and root planing over time was significantly impaired with more advanced loss of radiographic attachment. Regardless of the extent of radiographic attachment loss, healing after scaling and root planing was also significantly impaired over time by the presence of a root canal infection. J Periodontol 1993;64:1199–1204.
Distribution of Porphyromonas gingivalis in Adult Periodontitis Patients
Authors: Kojima Takehisa , Yasui Satoshi , Ishikawa Isao
Published: March 2012

Porphyromonas gingivalis (P. gingivalis) is considered to be a pathogenic factor in adult or rapidly progressive periodontitis. The purpose of this study was to evaluate the distribution of P. gingivalis in the dentition of adult periodontitis patients using a nonradioactive DNA probe, and to compare the presence of P. gingivalis with clinical parameters. Twelve adult periodontitis patients were examined. Subgingival plaque samples were taken from 4 sites of all the remaining teeth using a paper point. At the same time, probing depth and bleeding on probing (BOP) were also recorded. Plaque samples were investigated using a whole genomic DNA probe from P. gingivalis (ATCC 33277) modified with bisulfite. The detection, percentage and amounts of P. gingivalis present were statistically compared with probing depth and BOP in each patient. P. gingivalis was detected in all patients examined. The detection percentage was 35% of all sample sites. When the probing depth was over 4 mm or BOP was positive, the detection percentage of P. gingivalis significantly increased (P < 0.01). As more P. gingivalis was identified, the percentage of sites with deep probing depth or that were BOP positive increased significantly (P < 0.01). However, P. gingivalis was also detected in clinically healthy sites, and P. gingivalis negative sites with deep probing depth or that were BOP positive existed in the same patient. These results indicate that P. gingivalis play an important role, but is not the only microorganism responsible for adult periodontitis. J Periodontol 1993;64:1231–1237.
Tetracycline Inhibition and the Cellular Source of Collagenase in Gingival Crevicular Fluid in Different Periodontal Diseases. A Review Article
Authors: Ingman Tuula , Sorsa Timo , Suomalainen Kimmo , Halinen Sirkka , Lindy Otso , Lauhio Anneli , Saari Herkko , Konttinen Yrjö T. , Golub Lome M.
Published: March 2012

Tetracyclines have recently been shown to inhibit the activity of some but not all mammalian matrix metalloproteinases believed to mediate periodontal destruction. However, the specificity of this effect, which could have significant therapeutic implications for different periodontal diseases, has not been examined in detail. Doxycycline and 4de‐dimethylaminotetracycline (CMT‐1) have been tested in vitro for their ability to inhibit human neutrophil and fibroblast interstitial collagenases and collagenase in human gingival crevicular fluid (GCF). The GCF samples were obtained from systemically healthy and insulin‐dependent diabetic adult Periodontitis patients and from localized juvenile Periodontitis (UP) patients. The concentrations of these 2 tetracyclines required to inhibit 50% of the collagenase activity (IC50) were found to be 15 to 30 μM for human neutrophil collagenase and for collagenase in GCF of systemically healthy and diabetic adult Periodontitis patients. These concentrations approximate the tetracycline levels observed in vivo during treatment with these drugs. In contrast, human fibroblast collagenase and GCF collagenase from UP patients were both relatively resistant to tetracycline inhibition; the IC50 for doxycycline and CMT‐1 for these 2 sources of collagenase were 280 and 500 μM, respectively. Based on these and other findings, we propose the following: 1) that systemic levels of tetracycline may inhibit connective tissue breakdown by inhibiting neutrophil collagenase; 2) that tetracyclines do not inhibit fibroblast‐type collagenase, which may help explain their lack of effect on normal connective tissue remodeling; 3) that tetracycline inhibition of collagenases may serve to identify the cellular origin of the enzyme; and 4) that tetracyclines can also prevent the oxidative activation of latent human procollagenases. With regards to therapy, the anti‐collagenase property of tetracyclines may be an effective adjunct in targeting tissue breakdown in systemically healthy and diabetic adult Periodontitis patients. However, in juvenile Periodontitis the anticollagenase property of tetracyclines may be less important than the antimicrobial activity of the drug because of the relative resistance of fibroblast‐type collagenase to tetracycline inhibition. J Periodontol 1993; 64:82–88.
Clinical and Laboratory Studies of Severe Periodontal Disease in an Adolescent Associated With Hypophosphatasia. A Case Report
Authors: Watanabe Hisashi , Umeda Makoto , Seki Tomoko , Ishikawa Isao
Published: March 2012

Hypophosphatasia is a congenital disease characterized by defective bone mineralization, deficiency of alkaline phosphatase (ALP) activity, increased excretion of the phosphoethanolamine (PEA) in the urine, and premature loss of the deciduous teeth. A male hypophosphatasia patient (aged 15 years 6 months) with premature exfoliation of the deciduous teeth was referred to our hospital because of severe periodontal destruction in the permanent dentition. Blood and urine tests as well as oral and periodontal examinations were performed. Serum antibody titers against 7 periodontopathic bacteria by the enzyme‐linked immunosorbent assay (ELISA), monocyte and neutrophil chemotaxis measurements, and cellular immunity tests were also performed. Low levels of ALP in serum and PEA in the urine were found. Monocyte and neutrophil chemotaxis exhibited normal values. Slightly depressed CD2+, CD3+, and CD4+ and slightly elevated activity of NK cells were found. An elevated level of serum antibody to Porphyromonas gingivalis was observed. Oral radiographic examination showed a mirror pattern of alveolar bone loss which is similar to that seen in localized juvenile periodontitis. Periodontal treatment of this patient was carried out for 4 years. The severely affected sites, the lower right and left first molars and the upper right first molar, had to be extracted. However, the other sites were well maintained. The serum IgG level against P. gingivalis was decreased after 4 years of periodontal treatment. Infection with P. gingivalis was suspected to be associated with the destruction of this patient's hypophosphatasia, but other dental abnormalities such as abnormal enamel, dentin, and cementum formation may also have contributed to the periodontal pathology. J Periodontol 1993;64:174–180.
Serum IgG and IgM Levels to Bacterial Antigens in Necrotizing Ulcerative Gingivitis
Authors: Rowland Randal W. , Mestecky Jiri , Gunsolley John C. , Cogen Ronald B.
Published: March 2012

Previous studies of the systemic antibody response in necrotizing ulcerative gingivitis (NUG) have elicited varying results. The purpose of this study was to determine the humoral response to site‐specific isolates of microbiota associated with NUG. Sera from 21 active NUG subjects and 21 age‐sex‐race matched controls were assessed for IgG and IgM antibodies to 4 clinical isolates of Prevotella intermedia and 3 clinical isolates of Treponema species. P. intermedia and Treponema strains were isolated from active and inactive sites of NUG patients and gingivitis sites of controls. P. intermedia was also isolated from noninflamed sites of the controls. IgG and IgM serum levels to these 7 bacteria were measured by ELISA. Compared to control subjects, the NUG sera exhibited significantly lower IgG and IgM levels to all 4 isolates of P. intermedia (P ≤0.001). It was also noted that sera from NUG subjects had elevated IgM levels to all 3 spirochete isolates but significantly higher only to the spirochete isolated from a gingivitis site of a control subject (P ≤0.005). The data suggest that failure to mount a substantial antibody response to P. intermedia may be associated with onset of disease activity in NUG. However, the assumed lack of “biological significance” between differences in antibody responses measured indicates the relationship is weak or nonexistent. It also appears that antibody response to spirochetes is not associated with onset of NUG. J Periodontol 1993; 64:195–201.
Clinical Furcation Diagnoses and Interradicular Bone Defects
Authors: Zappa U. , Grosso L. , Simona C. , Graf H. , Case D.
Published: March 2012

The purpose of the present study was to assess associations between clinical depth of involved furcations and their bony defect depth. Twelve patients with moderate to advanced Periodontitis in molars were recruited for clinical evaluation of furcation involvement by 6 dentists. Two groups of 3 dentists were assigned to the right or left half of the dentition. All dentists assessed the clinical depth of involvement of the furcations using the Ramfjord index (2 mm) in patients 1 through 6, and using the Hamp index (3 mm) in patients 7 through 12. Diagnoses were made with calibrated and uncalibrated Nabers 2 probes. After the clinical assessments the patients received full mouth scaling and root planing. After reevaluation the molars were surgically exposed. During surgery the depth of the bony furcation defects was assessed using horizontal probing and impressions. Clinically assessed depth of furcation involvement was then compared with the surgical measurements. A total of 1,180 clinical furcation diagnoses were available, of which 426 could be surgically evaluated using both the straight probe and the impressions. These evaluations were done in a total of 72 furcations using probe and impressions. For the Ramfjord index, 5% of the clinical degree 1, 40% of the degree 2, and 43% of the degree 3 readings were overestimations. For the Hamp index, 7% of degree 1, 24% of degree 2, and 0% of degree 3 readings were overestimations. These clinical diagnoses were overestimations. Forty‐three percent of surgical degree 3 involvements were not recognized when using the Ramfjord index, and 27% when using the Hamp Index. These results suggest that furcation diagnosis is of limited validity. J Periodontol 1993; 64:219– 227.
The Influence of Race and Gender on Periodontal Microflora
Authors: Schenkein H.A. , Burmeister J.A. , Koertge T.E. , Brooks C.N. , Best A.M. , Moore L.V.H. , Moore W.E.C.
Published: March 2012

Previous studies have demonstrated that demographic characteristics of subject populations influence both the incidence of periodontal diseases and various aspects of host responses to periodontal bacteria. In this study we analyzed the components of the subgingival microflora from individuals with adult periodontitis, early onset periodontitis, gingivitis, and periodontal health as a function of gender and race (black and white). Clinical categories were analyzed individually so that there were no differences in the clinical characteristics of the sampled sites. No significant differences were noted in the subgingival microflora between males and females. When either the first two bacterial samples from each subject or all bacterial samples taken from each subject were included in the analysis, it was found that Porphyromonas gingivalis was more significantly associated with black subjects in the adult periodontitis group. When all samples were considered in the analysis, it was found that Peptostreptococcus anaerobius was associated with black subjects in the adult periodontitis group, while Fusobacterium nucleatum was associated with white subjects in both the adult periodontitis and early onset periodontitis groups. Thus a limited number of important bacterial components of the subgingival microflora are influenced by the race and diagnosis of the subject group. J Periodontal 1993;64:292–296.
The Results of Efforts To Improve Compliance with Supportive Periodontal Treatment in a Private Practice
Authors: Wilson Thomas G. , Hale Shannon , Temple Rebecca
Published: March 2012

Patients who receive routine supportive periodontal treatment (SPT) tend to keep their teeth longer and enjoy greater periodontal health than those individuals who do not receive this therapy. Previous studies have found less than optimal compliance to suggested SPT. The study reported in this paper covered 5 years of patient data and measured the effects of efforts to improve compliance in a private periodontal practice. These efforts included attempts at simplifying compliance, maintaining records of compliance, informing patients of the consequences of noncompliance, and attempting to identify noncompliers before active periodontal therapy was initiated. The results were measured against a similar group studied in previous work within the same office published in 1984. The main finding of the present study was an increase in complete compliance from 16% in 1984 to 32% in 1991. This increase came largely at the expense of the noncompliant group. The reason for the increase in compliance is likely due to efforts to increase compliance carried out in the office. However, other factors such as change in the hygiene practice law, increased public awareness of dental needs, and economic depression may also have affected compliance. This information suggests that noncompliance can be reduced if the problem is recognized and efforts are made to increase compliance. J Periodontol 1993;64:311–314.
Oriented Cell and Fiber Attachment Systems In Vivo
Authors: Lowenguth Roxanne A. , Polson Alan M. , Caton Jack G.
Published: March 2012

This investigation was undertaken to evaluate whether an oriented cell and fiber attachment system would develop if demineralized dentin surfaces were approximated in vivo. The approximated surfaces consisted of the internal, parallel surfaces of dentin cylinders. The experimental group was demineralized on both the external and internal surfaces of the dentin cylinder with citric acid, pH 1.0, for 3 minutes, but only the external surface of the control dentin cylinder was demineralized. Specimens were implanted transcutaneously into the backs of rats with one end protruding through the surface of the skin. Three specimens in each group were available for analysis at 1 and 10 days after implantation. The groups were compared using histologic and histometric analysis and the following conclusions were made. There were marked differences in the initial cellular response between the groups, and demineralization with citric acid prior to implantation predisposed towards a greater cell attachment at 1 and 10 days. An oriented fiber attachment developed between the demineralized approximated surfaces by 10 days, but did not develop between nondemineralized approximated surfaces. The morphology of the fiber attachment system was structurally similar to a periodontal ligament, with inserting fibers perpendicular to the implant surface. The findings of this study suggest that spatial approximation of appropriate substrates facilitates development of cell and fiber orientation. Thus, to regenerate a functionally oriented attachment system in the clinical setting, it may be beneficial to provide substrates that are appropriately approximated. J Periodontol 1993; 64:330–342.
A Possible Late Onset Variation of Papillon‐Lefèvre Syndrome: Report of 3 Cases
Authors: Brown Ronald S. , Hays Granvil L. , Flaitz Catherine M. , O'Neill Peggy A. , Abramovitch Kenneth , White Robert R.
Published: March 2012

Three unusual cases of papillon‐lefévre syndrome with late onset of features and relatively mild periodontal disease are presented. These examples confirm some of the late onset of features and mild periodontal presentation of a previous case report. Bacteriologic associations, polymorphonuclear leukocyte chemotactic, phagocytic, and bactericidal activity, and therapeutics with regard to this syndrome are discussed. J Periodontol 1993;64:379–386.
Use of Bovine‐Derived Hydroxyapatite in the Treatment of Edentulous Ridge Defects: A Human Clinical and Histologic Case Report
Authors: Callan Donald P. , Rohrer Michael D.
Published: March 2012

The advent of AIDS has created patient fears regarding human tissue transfers, including bone grafts in dental surgery. In the face of these fears, alternative allograft materials are of increasing interest to clinicians. One such alternative is naturally derived xenogeneic hydroxyapatite (HA). In this study, two patients with edentulous ridge defects received bovine‐derived HA grafts in conjunction with a dental implant treatment plan. The results were evaluated histologically. Both patients showed excellent clinical results with histological confirmation of osseous formation. The outcomes suggest that further consideration of the use of bovine‐derived HA is merited as a means of remediating edentulous ridge defects. eriodontol 1993; 64:575–582.
Current Status of Lasers in Soft Tissue Dental Surgery
Authors: Pick Robert M. , Colvard Michael D.
Published: March 2012

The aims of this paper are to briefly describe laser physics, the types of lasers currently available for use on soft tissues focusing primarily on CO2 and Nd:YAG laser energies, the histological effects of lasers on oral tissues, laser safety, the clinical applications of lasers on oral soft tissues, and future directions. Of the two types of lasers currently available for dental applications, both the CO2 and Nd:YAG lasers can be used for frenectomies, ablation of lesions, incisional and excisional biopsies, gingivectomies, gingivoplasties, soft tissue tuberosity reductions, operculum removal, coagulation of graft donor sites, and certain crown lengthening procedures. The advantages of lasers include a relatively bloodless surgical and post‐surgical course, minimal swelling and scarring, coagulation, vaporization, and cutting, minimal or no suturing, reduction in surgical time, and, in a majority of cases, much less or no post‐surgical pain. CO2 lasers, compared to Nd:YAG are faster for most procedures, with less depth of tissue penetration and a well‐documented history. There have been recent reports on the use of the Nd:YAG laser for periodontal scaling, gingival curettage, and root desensitization, but further research needs to be conducted. Both the CO2 and the Nd:YAG laser have limited use in conventional flap therapy. J Periodontol 1993; 64:589–602.