L. Shapira - Academia.edu (original) (raw)
Papers by L. Shapira
Journal of Clinical Periodontology
Background: In Europe cardiovascular disease (CVD) is responsible for 3.9 million deaths (45% of ... more Background: In Europe cardiovascular disease (CVD) is responsible for 3.9 million deaths (45% of deaths), being ischaemic heart disease, stroke, hypertension (leading to heart failure) the major cause of these CVD related deaths. Periodontitis is also a chronic non-communicable disease (NCD) with a high prevalence, being severe periodontitis, affecting 11.2% of the world's population, the sixth most common human disease.
Journal of craniofacial genetics and developmental biology, 1987
The present study describes the detailed changes in mineral concentration in developing human ena... more The present study describes the detailed changes in mineral concentration in developing human enamel across the different stages of development from early formation to maturation. The results indicate a stage in the development of deciduous human incisor enamel in which the tissue becomes porous because of a loss of matrix protein, which is subsequently replaced by mineral during the maturation process, with the enamel finally becoming fully mineralized and hard. The importance of this stage with regard to enamel susceptibility to metabolic influences is discussed.
Refuʾat ha-peh ṿeha-shinayim (1993), 2001
The present article describes the preliminary results of a short-term follow up retrospective stu... more The present article describes the preliminary results of a short-term follow up retrospective study of 104 external hex, screw-type MIS implants with rough surface that were consecutively implanted in 34 patients. The implants were followed up between 1 to 3 years. 49 implants were placed in the maxilla and 55 in the mandible. Bone regenerative procedures were carried out simultaneously in the time of implant placement in 21 of the implants. A total of 6 implants failed (5.7%) during the observation period, all in the first year after implant placement. Two implants failed in the same diabetic patient, and one in a heavy smoker. Two of the failed implants were placed together with bone regenerative procedures, and another one was with no initial stability at the time of implant placement. This short-term follow up report has shown that the success rate of MIS screw-type implants with rough surface is similar to the success rate reported for other implant systems. However, long-term ...
ASDC journal of dentistry for children
The present study describes the prevalence of alveolar bone loss (ABL) in children in relation to... more The present study describes the prevalence of alveolar bone loss (ABL) in children in relation to caries, contact and space loss. In addition, the microbial composition of the subgingival plaque of 20 sites, from 5 children, is presented. Bite-wing radiographs from 500 children were examined. ABL was evident in: 99 sites from 60 children; > 1 site in 27 children; the maxilla only in 34 children; the mandible only in 17 children; both arches in 9 children; 37 sites with no caries; 4.9 percent of all sites with proximal caries; 15.8 percent of all sites with contact loss; and 20.5 percent of all sites with mesial drift. Anaerobic bacteria were cultured from all 20 sites. No significant differences in the percentages of colony forming units of Actinobacillus actinomycetemcomitans and black pigmented Bacteroides were found among sites with/without bone loss, with/without caries or probing depths smaller/equal or larger than 2.5 mm.
Infection and immunity, 1998
Porphyromonas gingivalis is one of the pathogens associated with periodontal diseases, and its li... more Porphyromonas gingivalis is one of the pathogens associated with periodontal diseases, and its lipopolysaccharide (LPS) has been suggested as a possible virulence factor, acting by stimulation of host cells to secrete proinflammatory mediators. However, recent studies have shown that P. gingivalis LPS inhibited some components of the inflammatory response. The present study was designed to test the hypothesis that there are strain-dependent variations in the ability of P. gingivalis LPS to elicit the host inflammatory response. By using LPS preparations from two strains of P. gingivalis, W50 and A7346, the responses of mouse macrophages and human monocytes were evaluated by measuring the secretion of nitric oxide (NO) and tumor necrosis factor alpha (TNF-alpha). Both direct and indirect (priming) effects were investigated. LPS from Salmonella typhosa was used as a reference LPS. P. gingivalis A7436 LPS induced lower secreted levels of NO from the tested cells than S. typhosa LPS but...
Oral Microbiology and Immunology, 1994
Journal of Periodontology, 2002
Background: Several studies have suggested that peripheral inflammation may be involved in the et... more Background: Several studies have suggested that peripheral inflammation may be involved in the etiology of multiple sclerosis (MS), a demyelinating disease of the central nervous system (CNS). T-cells activated in the periphery enter the CNS, leading to demyelination and axonal loss. We hypothesized that peripheral infection by Porphyromonas gingivalis can affect pathological processes in the CNS and aggravate MS. Methods: Glial cells derived from rat brains were cultured and stimulated with P. gingivalis or P. gingivalis lipopolysaccharide (LPS). Secretion of nitric oxide (NO) and prostaglandin E 2 (PGE 2) was determined. In addition, we examined the proliferation of lymphocytes harvested from P. gingivalis-immunized mice in response to stimulation by echephalitogenic proteins. The effect of peripheral inflammation induced by P. gingivalis on the clinical course of the disease was tested in experimental autoimmune encephalomyelitis (EAE), a mouse model used for the study of MS. Results: P. gingivalis LPS and heat-killed bacteria induced secretion of the proinflammatory mediators NO and PGE 2 by CNS glial cells. Lymphocytes derived from P. gingivalis-immunized mice proliferated in the presence of the echephalitogenic protein myelin basic protein. Injection of P. gingivalis into subcutaneous chambers in mice, followed by EAE induction led to aggravation of the disease. Conclusions: The present study provides evidence that infection with a periodontal pathogen, such as P. gingivalis, may play a role in the pathogenesis of CNS inflammatory disorders such as MS.
Journal of Periodontology, 1993
In this paper, we review the relevant aspects of host responses in periodontal diseases as we und... more In this paper, we review the relevant aspects of host responses in periodontal diseases as we understand them today. Discussion will focus on neutrophil function, lymphocytes and the immune response, macrophage function, cytokines and complement, fibroblasts and growth factors, and regeneration. Recent literature and concepts will be presented with an emphasis on future directions and application to treatment regimens.
Journal of Periodontology, 1994
HLA proteins are genetically determined, and account in part for individual immune response. Seve... more HLA proteins are genetically determined, and account in part for individual immune response. Several studies have been performed seeking an association between HLA antigens and various forms of periodontitis with no conclusive results. The aim of the present study was to determine the frequency of HLA antigens of patients suffering from the localized (LJP) and the generalized (SGP) forms of early-onset periodontitis (EOP). Twenty-six EOP patients from the same ethnic group were studied in comparison to 113 race-matched controls. The EOP group included 11 LJP and 15 SGP patients. HLA-A9 and B15 antigens were found to be significantly elevated in the patient group. These differences were found to be due to the high frequency of A9 and B15 antigens in the SGP patients, with the LJP patient group showing no significant difference from the control group. The results are in agreement with previous studies in which A9 and B15 were found to be associated with EOP. However, previous studies did not differentiate between the localized and the generalized form of EOP. These results support the hypothesis that the generalized and the localized forms of EOP are under different genetic control.
Journal of Periodontology, 1994
Pathogenic bacteria constitute the primary extrinsic agent in the etiology of early onset Periodo... more Pathogenic bacteria constitute the primary extrinsic agent in the etiology of early onset Periodontitis. However, the risk of developing periodontal disease is not equal for all individuals, suggesting host factors are involved in determining an individual's disease susceptibility. In this report, a case of an otherwise healthy female, who exhibited prepubertal Periodontitis (PPP) at age 10, juvenile Periodontitis (JP) at age 13, and rapidly progressive Periodontitis (RPP) at age 29 years, is presented. Microbial, immunological, and genetic features of the case are presented. PPP, JP, and RPP are considered distinct disease entities, albeit with similar pathology and pathogenesis, yet all were manifest sequentially in the same individual. This report presents the idea that certain individuals are predisposed to early-onset periodontal diseases and the early identification of risk factors is important in the management of these individuals.
Journal of Periodontal Research, 1994
Journal of Clinical Periodontology, 1997
This study presents the dinical findings and the distribution of prepubertal periodontitis in an ... more This study presents the dinical findings and the distribution of prepubertal periodontitis in an extended family with high prevalence of this entity. The expression of surface markers and adhesion molecules on peripheral lymphocytes were also studied. Approximately 50% of the children in this family suffered from prepubertal periodontitis. All the affected children were otherwise healthy. 2 identical twins were similarly, but not identically, affected. Detailed laboratory tests and analysis of lymphocyte surface marker expression, including CD18. were all within the normal levels. Both localized and generalized forms of prepubertal periodontitis were found. The high prevalence of prepubertal periodontitis in the 2 branches of this family, and the fact that identical twins were similarly affected, suggest a strong genetic predisposition for prepubertal periodontitis. The family pedigree is consistent with an autosomal-dominant mode of transmission. The coexistence of locahzed and generalized forms of the disease in sibs suggests the same genetic etiology for both entities with variability in disease expression. This variability in disease expression is further supported by the fact that 2 identical twins were not identically affected.
Endocrinology, 1999
We have previously shown that the stimulatory effect of TRH on ␣-MSH secretion from the frog pars... more We have previously shown that the stimulatory effect of TRH on ␣-MSH secretion from the frog pars intermedia is associated with Ca 2ϩ influx through voltage-dependent Ca 2ϩ channels, activation of a phospholipase C and mobilization of intracellular Ca 2ϩ stores. The aim of the present study was to investigate the contribution of protein kinase C (PKC), adenylyl cyclase (AC), Ca 2ϩ /calmodulindependent protein kinase II (CAM KII), phospholipase A 2 , and protein tyrosine kinase (PTK) in TRH-induced ␣-MSH release. Incubation of frog neurointermediate lobes (NILs) with phorbol 12-myristate-13-acetate (24 h), which causes desensitization of PKC, or with the PKC inhibitor NPC-15437, reduced by approximately 50% of the effect of TRH on ␣-MSH release. In most melanotrope cells, TRH induces a sustained and biphasic increase in cytosolic Ca 2ϩ concentration ([Ca 2ϩ ] i). Preincubation with phorbol 12-myristate-13-acetate or NPC-15437 suppressed the plateau phase of the Ca 2ϩ response. Incubation of NILs with TRH (10 Ϫ6 M; 20 min) had no effect on cAMP production. In addition, the AC inhibitor SQ 22,536 did not affect the secretory response of NILs to TRH. These data indicate that the phospholipase C/PKC pathway, but not the AC/protein kinase A pathway, is involved in TRH-induced ␣-MSH release. The calmodulin inhibitor W-7 and the CAM KII inhibitor KN-93 did not significantly reduce the response to TRH. Similarly, the phospholipase A 2 inhibitors quinacrine and 7-7Ј-DEA did not impair the effect of TRH on ␣-MSH secretion. The PTK inhibitors ST638 and Tyr-A23 had no effect on TRH-induced [Ca 2ϩ ] i increase but inhibited in a dose-dependent manner TRH-evoked ␣-MSH release (ED 50 ϭ 1.22 ϫ 10 Ϫ5 M and ED 50 ϭ 1.47 ϫ 10 Ϫ5 M, respectively). Taken together, these data indicate that, in frog melanotrope cells, PKC and PTK are involved in TRH-induced ␣-MSH secretion. Activation of PKC is responsible for the sustained phase of the increase in [Ca 2ϩ ] i , whereas activation of PTK does not affect Ca 2ϩ mobilization.
Clinical Implant Dentistry and Related Research, 2013
Implantoplasty is one of the options in treating peri-implantitis. The efficacy of the dental bur... more Implantoplasty is one of the options in treating peri-implantitis. The efficacy of the dental bur used can reduce the time needed for the procedure and, as a consequence, minimize the risk of overheating that can negatively affect the remaining bone surrounding the implant. The aim of this study was to evaluate the efficacy of three dental burs in removing implant substance (titanium) and to determine the amount of heat generated by each bur. Four burs with different surface properties (diamond, diamond - Premium Line, carbide, and smooth bur - control [Strauss Co., Raanana, Israel]) were attached to a high-speed handpiece and applied to a titanium implant for a total of 60 seconds after cooling by water spray. Variations in temperature were recorded every 5 seconds, and the amount of implant substance removed (reduction in weight of the implant) was evaluated. The diamond Premium Line bur removed 59.24 mg; carbide, 29.39 mg; diamond, 11.35 mg; and smooth bur (control) 0.19 mg, statistically significant. Only minimum thermal changes (∼1.5°C) were recorded for all four burs. There are considerable differences in efficiency of different burs working on titanium. Selecting the proper bur can reduce working time. Under proper cooling conditions, implantoplasty does not generate excess temperature increases that can damage soft tissue or bone surrounding the treated implant.
Archives of Oral Biology, 1999
Extracellular polysaccharides (PS) synthesized by oral bacteria constitute one of their major vir... more Extracellular polysaccharides (PS) synthesized by oral bacteria constitute one of their major virulence factors. The PS, synthesized from sucrose, facilitate adhesion and colonization by bacteria to tooth surfaces. The study was designed to test the eect of in situ production of extracellular PS by Streptococcus mutans on the bactericidal activity of human neutrophils. These eects were tested on bacteria pre-exposed to sucrose (PS-positive Strep. mutans) and compared to bacteria not exposed to sucrose (PS-negative Strep. mutans). The interactions between neutrophils and Strep. mutans were tested in suspension and on bacteria in an experimental model of dental plaque. Viability of Strep. mutans was measured by [ 3 H]-thymidine incorporation into the bacteria. Degranulation of neutrophils was evaluated by the release of lysozyme, and the production of reactive oxygen products was measured by chemiluminescence. When neutrophils were incubated with suspended bacteria, the viability of PS-negative Strep. mutans was 20% of that of bacteria not incubated with neutrophils (control), while the viability of PS-positive Strep. mutans was 40% of the control. In the experimental dental-plaque model, 50% of the PS-negative Strep. mutans were killed by neutrophils while the viability of PS-positive Strep. mutans was not dierent than of the control. Degranulation of neutrophils was not aected by the presence of extracellular PS of Strep. mutans. Arti®cial stimulation of neutrophils with phorbol myristate acetate also did not enhance the bactericidal eect of neutrophils on PS-positive Strep. mutans. However, PS-positive Strep. mutans elicited oxygen-reactive products from neutrophils, 2-fold less than with PS-negative Strep. mutans. The results indicate that in situ production of bacterial extracellular polysaccharides might be a major virulence factor of Strep. mutans, enabling PS-positive Strep. mutans in the dental-plaque bio®lm to evade killing by human neutrophils.
Imaging and Printing in a Web 2.0 World IV, 2013
ABSTRACT Recommender systems seek to predict the interest a user would find in an item, person or... more ABSTRACT Recommender systems seek to predict the interest a user would find in an item, person or social element they had not yet considered, based upon the properties of the item, the user's past experience and similar users. However, recommended items are often presented to the user with no context and no ability to influence the results. We present a novel visualization technique for recommender systems in which, a user can see the items recommended for him, and understand why they were recommended. Focusing on a user, we render a planar visualization listing a set of recommended items. The items are organized such that similar items reside nearby on the screen, centered around realtime generated categories. We use a combination of iconography, text and tag clouds, with maximal use of screen real estate, and keep items from overlapping to produce our results. We apply our visualization to expert relevance maps in the enterprise and a book recommendation system for consumers. The latter is based on Shelfari, a social network for reading and books.
Journal of Clinical Periodontology, 2015
Periodontitis is a ubiquitous and irreversible inflammatory condition and represents a significan... more Periodontitis is a ubiquitous and irreversible inflammatory condition and represents a significant public health burden. Severe periodontitis affects over 11% of adults, is a major case of tooth loss impacting negatively upon speech, nutrition, quality of life and self-esteem and has systemic inflammatory consequences. Periodontitis is treatable and treatment leads to reduced rates of tooth loss and improved quality of life. However, successful treatment necessitates behaviour change in patients to address lifestyle risk factors (e.g. smoking) and, most importantly, to attain and sustain high standards of daily plaque removal, life-long. Whilst mechanical plaque removal remains the bedrock of successful periodontal disease management, in high risk patients it appears that the critical threshold for plaque accumulation to trigger periodontitis is low, and such patients may benefit from adjunctive agents for primary prevention of periodontitis. The aims of this working group were to systematically review the evidence for primary prevention of periodontitis by preventing gingivitis via four approaches: 1) the efficacy of mechanical self-administered plaque control regimes; 2) the efficacy of self-administered interdental mechanical plaque control; 3) the efficacy of adjunctive chemical plaque control; 4) anti-inflammatory (sole or adjunctive) approaches. Two meta-reviews (mechanical plaque removal) and two traditional systematic reviews (chemical plaque control/anti-inflammatory agents) formed the basis of this consensus. Data support the belief that professionally administered plaque control significantly improves gingival inflammation and lowers plaque scores, with some evidence that re-enforcement of oral hygiene provides further benefit. Re-chargeable power tooth brushes provide small but statistically significant additional reductions in gingival inflammation and plaque levels. Flossing cannot be recommended other than for sites of gingival and periodontal health, where interdental brushes (IDBs) will not pass through the interproximal area without trauma. Otherwise, IDBs are the device of choice for interproximal plaque removal. Use of local or systemic anti-inflammatory agents in the management of gingivitis has no robust evidence base. We support the almost universal recommendations that all people should brush their teeth twice a day for at least 2 minutes with fluoridated dentifrice. Expert opinion is that for periodontitis patients 2 minutes is likely to be insufficient, especially when considering the need for additional use of interdental cleaning devices. In patients with gingivitis once daily interdental cleaning is recommended and the adjunctive use of chemical plaque control agents offers advantages in this group. This article is protected by copyright. All rights reserved.
The Wilson Journal of Ornithology, 2007
Abstract Examination of 193 whole pellets and a number of partial pellets of a pair of Barn Owls ... more Abstract Examination of 193 whole pellets and a number of partial pellets of a pair of Barn Owls (Tyto alba) in Neve Shiret, a neighborhood of Tel Aviv, Israel during the 2005 and 2006 breeding seasons revealed a total of 711 prey specimens. Six species of small mammals comprised 99.3% of the diet with a frequency of occurrence of 100% in pellets. Levant voles (Microtus socialis guentheri)(48.1%) and house mice (Mus musculus)(32.9%) were the most common prey species. The Barn Owl pair hunted in croplands adjacent to an urban ...
Oral Diseases, 2003
Individual susceptibility to periodontal breakdown involves an interplay of genes, periodontal pa... more Individual susceptibility to periodontal breakdown involves an interplay of genes, periodontal pathogens and other modulating factors. Anti-infective treatment, which includes oral hygiene measures, mechanical debridement, pharmacologic intervention and surgery, has been shown to be effective in arresting the progression of periodontal disease. Nevertheless, due to the chronic nature of the disease, susceptible individuals who are not maintained in a supervised recall program subsequent to the active treatment phase, show signs of recurrent destruction. Supportive periodontal therapy (SPT) is an integral part of periodontal treatment for patients with history of periodontitis, and is needed to prevent recurrence of disease in susceptible individuals. To prevent re-infection with periodontal pathogens, SPT includes elimination of dental plaque and bacteria from the oral cavity, thereby preventing the recurrence of pathogens into the gingival area. For individuals at risk of developing periodontitis, SPT should combine self-performed and professional anti-infective therapy, using mechanical and pharmacological means. The existing evidence suggests that the adjunctive use of antimicrobial pharmacologic therapy during SPT may enhance the results of mechanical debridement. The use of antimicrobials varies between patients, and is dependent on risk assessment and longitudinal monitoring of the clinical status of the periodontium.
Journal of Clinical Periodontology
Background: In Europe cardiovascular disease (CVD) is responsible for 3.9 million deaths (45% of ... more Background: In Europe cardiovascular disease (CVD) is responsible for 3.9 million deaths (45% of deaths), being ischaemic heart disease, stroke, hypertension (leading to heart failure) the major cause of these CVD related deaths. Periodontitis is also a chronic non-communicable disease (NCD) with a high prevalence, being severe periodontitis, affecting 11.2% of the world's population, the sixth most common human disease.
Journal of craniofacial genetics and developmental biology, 1987
The present study describes the detailed changes in mineral concentration in developing human ena... more The present study describes the detailed changes in mineral concentration in developing human enamel across the different stages of development from early formation to maturation. The results indicate a stage in the development of deciduous human incisor enamel in which the tissue becomes porous because of a loss of matrix protein, which is subsequently replaced by mineral during the maturation process, with the enamel finally becoming fully mineralized and hard. The importance of this stage with regard to enamel susceptibility to metabolic influences is discussed.
Refuʾat ha-peh ṿeha-shinayim (1993), 2001
The present article describes the preliminary results of a short-term follow up retrospective stu... more The present article describes the preliminary results of a short-term follow up retrospective study of 104 external hex, screw-type MIS implants with rough surface that were consecutively implanted in 34 patients. The implants were followed up between 1 to 3 years. 49 implants were placed in the maxilla and 55 in the mandible. Bone regenerative procedures were carried out simultaneously in the time of implant placement in 21 of the implants. A total of 6 implants failed (5.7%) during the observation period, all in the first year after implant placement. Two implants failed in the same diabetic patient, and one in a heavy smoker. Two of the failed implants were placed together with bone regenerative procedures, and another one was with no initial stability at the time of implant placement. This short-term follow up report has shown that the success rate of MIS screw-type implants with rough surface is similar to the success rate reported for other implant systems. However, long-term ...
ASDC journal of dentistry for children
The present study describes the prevalence of alveolar bone loss (ABL) in children in relation to... more The present study describes the prevalence of alveolar bone loss (ABL) in children in relation to caries, contact and space loss. In addition, the microbial composition of the subgingival plaque of 20 sites, from 5 children, is presented. Bite-wing radiographs from 500 children were examined. ABL was evident in: 99 sites from 60 children; > 1 site in 27 children; the maxilla only in 34 children; the mandible only in 17 children; both arches in 9 children; 37 sites with no caries; 4.9 percent of all sites with proximal caries; 15.8 percent of all sites with contact loss; and 20.5 percent of all sites with mesial drift. Anaerobic bacteria were cultured from all 20 sites. No significant differences in the percentages of colony forming units of Actinobacillus actinomycetemcomitans and black pigmented Bacteroides were found among sites with/without bone loss, with/without caries or probing depths smaller/equal or larger than 2.5 mm.
Infection and immunity, 1998
Porphyromonas gingivalis is one of the pathogens associated with periodontal diseases, and its li... more Porphyromonas gingivalis is one of the pathogens associated with periodontal diseases, and its lipopolysaccharide (LPS) has been suggested as a possible virulence factor, acting by stimulation of host cells to secrete proinflammatory mediators. However, recent studies have shown that P. gingivalis LPS inhibited some components of the inflammatory response. The present study was designed to test the hypothesis that there are strain-dependent variations in the ability of P. gingivalis LPS to elicit the host inflammatory response. By using LPS preparations from two strains of P. gingivalis, W50 and A7346, the responses of mouse macrophages and human monocytes were evaluated by measuring the secretion of nitric oxide (NO) and tumor necrosis factor alpha (TNF-alpha). Both direct and indirect (priming) effects were investigated. LPS from Salmonella typhosa was used as a reference LPS. P. gingivalis A7436 LPS induced lower secreted levels of NO from the tested cells than S. typhosa LPS but...
Oral Microbiology and Immunology, 1994
Journal of Periodontology, 2002
Background: Several studies have suggested that peripheral inflammation may be involved in the et... more Background: Several studies have suggested that peripheral inflammation may be involved in the etiology of multiple sclerosis (MS), a demyelinating disease of the central nervous system (CNS). T-cells activated in the periphery enter the CNS, leading to demyelination and axonal loss. We hypothesized that peripheral infection by Porphyromonas gingivalis can affect pathological processes in the CNS and aggravate MS. Methods: Glial cells derived from rat brains were cultured and stimulated with P. gingivalis or P. gingivalis lipopolysaccharide (LPS). Secretion of nitric oxide (NO) and prostaglandin E 2 (PGE 2) was determined. In addition, we examined the proliferation of lymphocytes harvested from P. gingivalis-immunized mice in response to stimulation by echephalitogenic proteins. The effect of peripheral inflammation induced by P. gingivalis on the clinical course of the disease was tested in experimental autoimmune encephalomyelitis (EAE), a mouse model used for the study of MS. Results: P. gingivalis LPS and heat-killed bacteria induced secretion of the proinflammatory mediators NO and PGE 2 by CNS glial cells. Lymphocytes derived from P. gingivalis-immunized mice proliferated in the presence of the echephalitogenic protein myelin basic protein. Injection of P. gingivalis into subcutaneous chambers in mice, followed by EAE induction led to aggravation of the disease. Conclusions: The present study provides evidence that infection with a periodontal pathogen, such as P. gingivalis, may play a role in the pathogenesis of CNS inflammatory disorders such as MS.
Journal of Periodontology, 1993
In this paper, we review the relevant aspects of host responses in periodontal diseases as we und... more In this paper, we review the relevant aspects of host responses in periodontal diseases as we understand them today. Discussion will focus on neutrophil function, lymphocytes and the immune response, macrophage function, cytokines and complement, fibroblasts and growth factors, and regeneration. Recent literature and concepts will be presented with an emphasis on future directions and application to treatment regimens.
Journal of Periodontology, 1994
HLA proteins are genetically determined, and account in part for individual immune response. Seve... more HLA proteins are genetically determined, and account in part for individual immune response. Several studies have been performed seeking an association between HLA antigens and various forms of periodontitis with no conclusive results. The aim of the present study was to determine the frequency of HLA antigens of patients suffering from the localized (LJP) and the generalized (SGP) forms of early-onset periodontitis (EOP). Twenty-six EOP patients from the same ethnic group were studied in comparison to 113 race-matched controls. The EOP group included 11 LJP and 15 SGP patients. HLA-A9 and B15 antigens were found to be significantly elevated in the patient group. These differences were found to be due to the high frequency of A9 and B15 antigens in the SGP patients, with the LJP patient group showing no significant difference from the control group. The results are in agreement with previous studies in which A9 and B15 were found to be associated with EOP. However, previous studies did not differentiate between the localized and the generalized form of EOP. These results support the hypothesis that the generalized and the localized forms of EOP are under different genetic control.
Journal of Periodontology, 1994
Pathogenic bacteria constitute the primary extrinsic agent in the etiology of early onset Periodo... more Pathogenic bacteria constitute the primary extrinsic agent in the etiology of early onset Periodontitis. However, the risk of developing periodontal disease is not equal for all individuals, suggesting host factors are involved in determining an individual's disease susceptibility. In this report, a case of an otherwise healthy female, who exhibited prepubertal Periodontitis (PPP) at age 10, juvenile Periodontitis (JP) at age 13, and rapidly progressive Periodontitis (RPP) at age 29 years, is presented. Microbial, immunological, and genetic features of the case are presented. PPP, JP, and RPP are considered distinct disease entities, albeit with similar pathology and pathogenesis, yet all were manifest sequentially in the same individual. This report presents the idea that certain individuals are predisposed to early-onset periodontal diseases and the early identification of risk factors is important in the management of these individuals.
Journal of Periodontal Research, 1994
Journal of Clinical Periodontology, 1997
This study presents the dinical findings and the distribution of prepubertal periodontitis in an ... more This study presents the dinical findings and the distribution of prepubertal periodontitis in an extended family with high prevalence of this entity. The expression of surface markers and adhesion molecules on peripheral lymphocytes were also studied. Approximately 50% of the children in this family suffered from prepubertal periodontitis. All the affected children were otherwise healthy. 2 identical twins were similarly, but not identically, affected. Detailed laboratory tests and analysis of lymphocyte surface marker expression, including CD18. were all within the normal levels. Both localized and generalized forms of prepubertal periodontitis were found. The high prevalence of prepubertal periodontitis in the 2 branches of this family, and the fact that identical twins were similarly affected, suggest a strong genetic predisposition for prepubertal periodontitis. The family pedigree is consistent with an autosomal-dominant mode of transmission. The coexistence of locahzed and generalized forms of the disease in sibs suggests the same genetic etiology for both entities with variability in disease expression. This variability in disease expression is further supported by the fact that 2 identical twins were not identically affected.
Endocrinology, 1999
We have previously shown that the stimulatory effect of TRH on ␣-MSH secretion from the frog pars... more We have previously shown that the stimulatory effect of TRH on ␣-MSH secretion from the frog pars intermedia is associated with Ca 2ϩ influx through voltage-dependent Ca 2ϩ channels, activation of a phospholipase C and mobilization of intracellular Ca 2ϩ stores. The aim of the present study was to investigate the contribution of protein kinase C (PKC), adenylyl cyclase (AC), Ca 2ϩ /calmodulindependent protein kinase II (CAM KII), phospholipase A 2 , and protein tyrosine kinase (PTK) in TRH-induced ␣-MSH release. Incubation of frog neurointermediate lobes (NILs) with phorbol 12-myristate-13-acetate (24 h), which causes desensitization of PKC, or with the PKC inhibitor NPC-15437, reduced by approximately 50% of the effect of TRH on ␣-MSH release. In most melanotrope cells, TRH induces a sustained and biphasic increase in cytosolic Ca 2ϩ concentration ([Ca 2ϩ ] i). Preincubation with phorbol 12-myristate-13-acetate or NPC-15437 suppressed the plateau phase of the Ca 2ϩ response. Incubation of NILs with TRH (10 Ϫ6 M; 20 min) had no effect on cAMP production. In addition, the AC inhibitor SQ 22,536 did not affect the secretory response of NILs to TRH. These data indicate that the phospholipase C/PKC pathway, but not the AC/protein kinase A pathway, is involved in TRH-induced ␣-MSH release. The calmodulin inhibitor W-7 and the CAM KII inhibitor KN-93 did not significantly reduce the response to TRH. Similarly, the phospholipase A 2 inhibitors quinacrine and 7-7Ј-DEA did not impair the effect of TRH on ␣-MSH secretion. The PTK inhibitors ST638 and Tyr-A23 had no effect on TRH-induced [Ca 2ϩ ] i increase but inhibited in a dose-dependent manner TRH-evoked ␣-MSH release (ED 50 ϭ 1.22 ϫ 10 Ϫ5 M and ED 50 ϭ 1.47 ϫ 10 Ϫ5 M, respectively). Taken together, these data indicate that, in frog melanotrope cells, PKC and PTK are involved in TRH-induced ␣-MSH secretion. Activation of PKC is responsible for the sustained phase of the increase in [Ca 2ϩ ] i , whereas activation of PTK does not affect Ca 2ϩ mobilization.
Clinical Implant Dentistry and Related Research, 2013
Implantoplasty is one of the options in treating peri-implantitis. The efficacy of the dental bur... more Implantoplasty is one of the options in treating peri-implantitis. The efficacy of the dental bur used can reduce the time needed for the procedure and, as a consequence, minimize the risk of overheating that can negatively affect the remaining bone surrounding the implant. The aim of this study was to evaluate the efficacy of three dental burs in removing implant substance (titanium) and to determine the amount of heat generated by each bur. Four burs with different surface properties (diamond, diamond - Premium Line, carbide, and smooth bur - control [Strauss Co., Raanana, Israel]) were attached to a high-speed handpiece and applied to a titanium implant for a total of 60 seconds after cooling by water spray. Variations in temperature were recorded every 5 seconds, and the amount of implant substance removed (reduction in weight of the implant) was evaluated. The diamond Premium Line bur removed 59.24 mg; carbide, 29.39 mg; diamond, 11.35 mg; and smooth bur (control) 0.19 mg, statistically significant. Only minimum thermal changes (∼1.5°C) were recorded for all four burs. There are considerable differences in efficiency of different burs working on titanium. Selecting the proper bur can reduce working time. Under proper cooling conditions, implantoplasty does not generate excess temperature increases that can damage soft tissue or bone surrounding the treated implant.
Archives of Oral Biology, 1999
Extracellular polysaccharides (PS) synthesized by oral bacteria constitute one of their major vir... more Extracellular polysaccharides (PS) synthesized by oral bacteria constitute one of their major virulence factors. The PS, synthesized from sucrose, facilitate adhesion and colonization by bacteria to tooth surfaces. The study was designed to test the eect of in situ production of extracellular PS by Streptococcus mutans on the bactericidal activity of human neutrophils. These eects were tested on bacteria pre-exposed to sucrose (PS-positive Strep. mutans) and compared to bacteria not exposed to sucrose (PS-negative Strep. mutans). The interactions between neutrophils and Strep. mutans were tested in suspension and on bacteria in an experimental model of dental plaque. Viability of Strep. mutans was measured by [ 3 H]-thymidine incorporation into the bacteria. Degranulation of neutrophils was evaluated by the release of lysozyme, and the production of reactive oxygen products was measured by chemiluminescence. When neutrophils were incubated with suspended bacteria, the viability of PS-negative Strep. mutans was 20% of that of bacteria not incubated with neutrophils (control), while the viability of PS-positive Strep. mutans was 40% of the control. In the experimental dental-plaque model, 50% of the PS-negative Strep. mutans were killed by neutrophils while the viability of PS-positive Strep. mutans was not dierent than of the control. Degranulation of neutrophils was not aected by the presence of extracellular PS of Strep. mutans. Arti®cial stimulation of neutrophils with phorbol myristate acetate also did not enhance the bactericidal eect of neutrophils on PS-positive Strep. mutans. However, PS-positive Strep. mutans elicited oxygen-reactive products from neutrophils, 2-fold less than with PS-negative Strep. mutans. The results indicate that in situ production of bacterial extracellular polysaccharides might be a major virulence factor of Strep. mutans, enabling PS-positive Strep. mutans in the dental-plaque bio®lm to evade killing by human neutrophils.
Imaging and Printing in a Web 2.0 World IV, 2013
ABSTRACT Recommender systems seek to predict the interest a user would find in an item, person or... more ABSTRACT Recommender systems seek to predict the interest a user would find in an item, person or social element they had not yet considered, based upon the properties of the item, the user's past experience and similar users. However, recommended items are often presented to the user with no context and no ability to influence the results. We present a novel visualization technique for recommender systems in which, a user can see the items recommended for him, and understand why they were recommended. Focusing on a user, we render a planar visualization listing a set of recommended items. The items are organized such that similar items reside nearby on the screen, centered around realtime generated categories. We use a combination of iconography, text and tag clouds, with maximal use of screen real estate, and keep items from overlapping to produce our results. We apply our visualization to expert relevance maps in the enterprise and a book recommendation system for consumers. The latter is based on Shelfari, a social network for reading and books.
Journal of Clinical Periodontology, 2015
Periodontitis is a ubiquitous and irreversible inflammatory condition and represents a significan... more Periodontitis is a ubiquitous and irreversible inflammatory condition and represents a significant public health burden. Severe periodontitis affects over 11% of adults, is a major case of tooth loss impacting negatively upon speech, nutrition, quality of life and self-esteem and has systemic inflammatory consequences. Periodontitis is treatable and treatment leads to reduced rates of tooth loss and improved quality of life. However, successful treatment necessitates behaviour change in patients to address lifestyle risk factors (e.g. smoking) and, most importantly, to attain and sustain high standards of daily plaque removal, life-long. Whilst mechanical plaque removal remains the bedrock of successful periodontal disease management, in high risk patients it appears that the critical threshold for plaque accumulation to trigger periodontitis is low, and such patients may benefit from adjunctive agents for primary prevention of periodontitis. The aims of this working group were to systematically review the evidence for primary prevention of periodontitis by preventing gingivitis via four approaches: 1) the efficacy of mechanical self-administered plaque control regimes; 2) the efficacy of self-administered interdental mechanical plaque control; 3) the efficacy of adjunctive chemical plaque control; 4) anti-inflammatory (sole or adjunctive) approaches. Two meta-reviews (mechanical plaque removal) and two traditional systematic reviews (chemical plaque control/anti-inflammatory agents) formed the basis of this consensus. Data support the belief that professionally administered plaque control significantly improves gingival inflammation and lowers plaque scores, with some evidence that re-enforcement of oral hygiene provides further benefit. Re-chargeable power tooth brushes provide small but statistically significant additional reductions in gingival inflammation and plaque levels. Flossing cannot be recommended other than for sites of gingival and periodontal health, where interdental brushes (IDBs) will not pass through the interproximal area without trauma. Otherwise, IDBs are the device of choice for interproximal plaque removal. Use of local or systemic anti-inflammatory agents in the management of gingivitis has no robust evidence base. We support the almost universal recommendations that all people should brush their teeth twice a day for at least 2 minutes with fluoridated dentifrice. Expert opinion is that for periodontitis patients 2 minutes is likely to be insufficient, especially when considering the need for additional use of interdental cleaning devices. In patients with gingivitis once daily interdental cleaning is recommended and the adjunctive use of chemical plaque control agents offers advantages in this group. This article is protected by copyright. All rights reserved.
The Wilson Journal of Ornithology, 2007
Abstract Examination of 193 whole pellets and a number of partial pellets of a pair of Barn Owls ... more Abstract Examination of 193 whole pellets and a number of partial pellets of a pair of Barn Owls (Tyto alba) in Neve Shiret, a neighborhood of Tel Aviv, Israel during the 2005 and 2006 breeding seasons revealed a total of 711 prey specimens. Six species of small mammals comprised 99.3% of the diet with a frequency of occurrence of 100% in pellets. Levant voles (Microtus socialis guentheri)(48.1%) and house mice (Mus musculus)(32.9%) were the most common prey species. The Barn Owl pair hunted in croplands adjacent to an urban ...
Oral Diseases, 2003
Individual susceptibility to periodontal breakdown involves an interplay of genes, periodontal pa... more Individual susceptibility to periodontal breakdown involves an interplay of genes, periodontal pathogens and other modulating factors. Anti-infective treatment, which includes oral hygiene measures, mechanical debridement, pharmacologic intervention and surgery, has been shown to be effective in arresting the progression of periodontal disease. Nevertheless, due to the chronic nature of the disease, susceptible individuals who are not maintained in a supervised recall program subsequent to the active treatment phase, show signs of recurrent destruction. Supportive periodontal therapy (SPT) is an integral part of periodontal treatment for patients with history of periodontitis, and is needed to prevent recurrence of disease in susceptible individuals. To prevent re-infection with periodontal pathogens, SPT includes elimination of dental plaque and bacteria from the oral cavity, thereby preventing the recurrence of pathogens into the gingival area. For individuals at risk of developing periodontitis, SPT should combine self-performed and professional anti-infective therapy, using mechanical and pharmacological means. The existing evidence suggests that the adjunctive use of antimicrobial pharmacologic therapy during SPT may enhance the results of mechanical debridement. The use of antimicrobials varies between patients, and is dependent on risk assessment and longitudinal monitoring of the clinical status of the periodontium.