bluuebunny/crossref_metadata_2025 huggingface dataset:
Bone Marrow Stromal Cells of Young and Adult Rats Respond Similarly to Platelet‐Released Supernatant and Bone Morphogenetic Protein‐6 In Vitro
Authors: Cei Silvia , Kandler Barbara , Fügl Alexander , Gabriele Mario , Hollinger Jeffrey O. , Watzek Georg , Gruber Reinhard
Published: April 2006

Background: Age‐related changes in periodontal bone regeneration, osseointegration of dental implants, and graft consolidation are increasingly considered in treatment planning. This study was intended to show whether aging is associated with a diminished responsiveness of osteoprogenitor cells to growth and differentiation factors.

Methods: We compared the capacity of bone marrow stromal cells harvested from young and adult rats to proliferate, migrate, and differentiate into the osteogenic lineage following exposure to platelet‐released supernatant (PRS) or bone morphogenetic protein‐6 (BMP‐6). Bone marrow stromal cells were isolated from 12 young rats aged 6 weeks and 12 adult rats aged 9 months. Proliferation was assessed by 3[H]thymidine incorporation, migration was evaluated with the Boyden chamber assay, and osteogenic differentiation was deduced from alkaline phosphatase activity.

Results: Irrespective of the donor age, bone marrow stromal cells showed increased mitogenic activity and chemotactic motility when exposed to PRS. Adult bone marrow stromal cells had higher alkaline phosphatase activities at baseline and upon incubation with BMP‐6 than cells obtained from young animals. There was no difference between the two groups in the slope of the alkaline phosphatase activity curve following stimulation with BMP‐6.

Conclusions: The data demonstrate that, irrespective of their age, bone marrow stromal cells respond similarly to PRS and BMP‐6 under in vitro conditions. These findings suggest that osteoprogenitor cells within the bone marrow of adult rats retain their juvenile potential to respond to growth and differentiation factors, which are released naturally or are applied therapeutically at sites of bone regeneration.
Langerhans' Cell Histiocytosis in a 5‐Year‐Old Girl: Evidence of Periodontal Pathogens
Authors: Torrungruang Kitti , Sittisomwong Sapatporn , Rojanasomsith Kaesarin , Asvanit Pornpun , Korkongwisarut Dusadee , Vipismakul Vichitra
Published: April 2006

Background: Langerhans' cell histiocytosis (LCH) is a rare disorder characterized by Langerhans' cell proliferation in various organs or tissues. When periodontal tissue is involved, clinical manifestations can vary from gingival recession and pocket formation to severe alveolar bone loss. This case report describes periodontal pathogens found in the pockets of involved primary teeth.

Methods: A 5‐year‐old girl with LCH presented with loose teeth. Intraoral examination and radiographs revealed deep pockets and severe bone loss around all primary molars. Bacterial samples were obtained from saliva and subgingival plaque and analyzed for the presence of five periodontopathic bacteria using a polymerase chain reaction (PCR) method. Due to severe periodontal destruction, all primary molars were extracted, and a gingival biopsy was taken from tooth T to confirm the diagnosis of LCH.

Results: The biopsy specimen revealed the histologic features of LCH. The patient was diagnosed as having periodontitis as a manifestation of LCH. PCR results of subgingival plaque from LCH‐affected molars indicated the presence of Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, and Prevotella intermedia. However, Actinobacillus actinomycetemcomitans was absent from these teeth. No tested bacteria were found in the non‐affected anterior teeth.

Conclusions: The bacteria commonly associated with periodontal disease were detected in subgingival plaque samples from this LCH patient. More microbiological data are required to understand the role of these bacteria in LCH‐associated periodontal destruction.
Are Dental Plaque, Poor Oral Hygiene, and Periodontal Disease Associated With Helicobacter pylori Infection?
Authors: Anand Pradeep S. , Nandakumar K. , Shenoy K.T.
Published: April 2006

Background: The microorganism Helicobacter pylori has been closely linked to chronic gastritis, peptic ulcer, gastric cancer, and mucosa‐associated lymphoid tissue (MALT) lymphoma. Despite the current treatment regimens that lead to successful management of H. pylori‐positive chronic gastritis, the reinfection rate is high. It has been suggested that one of the possible mechanisms of reinfection is the recolonization from dental plaque. The purpose of this study was to determine whether dental plaque, poor oral hygiene, and periodontal disease were risk factors for H. pylori infection.

Methods: Among the 134 patients, 65 patients who had a positive H. pylori serology or positive rapid urease test or histologic evidence for the presence of H. pylori in antral biopsy specimens were categorized as cases. The remaining 69 patients who were negative for H. pylori serology, the rapid urease test, and histology were controls.

Results: It was found that the association of periodontal disease and poor oral hygiene with H. pylori infection was not significant. There was a higher prevalence of H. pylori in the dental plaque of patients with gastric H. pylori infection than in controls, but both groups had a surprisingly high positive urease test for H. pylori in plaque (89% and 71%, respectively).

Conclusions: H. pylori in dental plaque is seldom eliminated by H. pylori‐eradication therapy, and this may act as a source for future reinfection. Hence, eradication of H. pylori from the dental plaque should be made an important part of comprehensive management of H. pylori‐associated gastric diseases.
Effects of Selective Cyclooxygenase‐2 Inhibitor and Omega‐3 Fatty Acid on Serum Interleukin‐1β, Osteocalcin, and C‐Reactive Protein Levels in Rats
Authors: Vardar‐Şengül Saynur , Buduneli Nurcan , Buduneli Eralp , Baylas Haluk , Atilla Gül , Lappin David , Kinane Denis F.
Published: April 2006

Background: The aim of this study was to evaluate the effects of selective cyclooxygenase‐2 inhibitor, celecoxib, and omega‐3 fatty acid on serum levels of interleukin 1‐beta (IL‐1β), osteocalcin (OC), and C‐reactive protein (CRP) in experimental periodontitis.

Methods: Experimental periodontitis in rats was induced by repeated injection of purified lipopolysaccharide (LPS) derived from Escherichia coli endotoxin. Forty‐seven adult male Sprague‐Dawley rats were divided into five study groups as follows: saline control, LPS, LPS + celecoxib, LPS + omega‐3 fatty acid, and LPS + celecoxib + omega‐3 fatty acid. Celecoxib and omega‐3 fatty acid were given alone or in combination during 14 days of the experimental study period. At the end of the 2‐week protocol, serum samples were obtained, and the rats were sacrificed. Serum samples were analyzed for IL‐1β, OC, and CRP concentrations by enzyme‐linked immunosorbent assay. Defleshed jaws were analyzed morphometrically for alveolar bone loss. Data were evaluated statistically by non‐parametric tests.

Results: According to the morphometric measurements, the LPS and drug treatment groups showed significantly higher bone loss than the saline control group (P <0.05). Omega‐3 fatty acid, both alone and in combination with celecoxib, revealed significantly higher IL‐1β levels than LPS and celecoxib groups (P <0.05). Individual and combined administration of celecoxib and omega‐3 fatty acid significantly increased OC levels compared to the LPS group (P <0.05). There were no significant differences in serum CRP levels.

Conclusions: Celecoxib and/or omega‐3 fatty acid administration does not significantly influence circulating levels of CRP. The significantly increased serum OC level observed after individual and combination administration suggests that celecoxib and omega‐3 fatty acid may influence bone remodeling and thereby inhibit the progression of alveolar bone resorption. However, the failure to observe any significant inhibition of bone loss in celecoxib‐ and/or omega‐3 fatty acid‐treated rats compared to the LPS group suggests that their therapeutic effect may be reduced by other factors, such as increases in serum IL‐1β promoting osteoclast activity.
Enamel Matrix Derivative and Systemic Antibiotics as Adjuncts to Non‐Surgical Periodontal Treatment: Biologic Response
Authors: Giannopoulou C. , Andersen E. , Brochut P. , Plagnat D. , Mombelli A.
Published: April 2006

Background: Short‐term clinical observations suggest an anti‐inflammatory effect of enamel matrix derivative (EMD). The purpose of this study was to evaluate the anti‐inflammatory capacity of EMD, used as an adjunct to non‐surgical periodontal treatment of deep lesions in chronic periodontitis patients, by monitoring inflammatory markers in gingival crevicular fluid (GCF).

Methods: Sixteen subjects were randomly assigned to treatment with EMD or placebo in contralateral dentition areas. Half of the subjects received 250 mg metronidazole and 375 mg amoxicillin three times a day for 7 days; the other half received a placebo. GCF samples were collected from one interproximal lesion in each of the contralateral quadrants before treatment and after 10 days and 2, 6, and 12 months. Total protein content was determined according to the Bradford method. Myeloid‐related protein (MRP) 8/14 and interleukin (IL)‐1β were analyzed quantitatively by enzyme‐linked immunosorbent assay (ELISA), and elastase activity was determined using a low molecular weight fluorogenic substrate.

Results: No significant differences were observed between sites treated with or without EMD for any biochemical parameter. Two months after treatment, subjects treated with antibiotics exhibited less clinical signs of inflammation. Furthermore, these subjects had lower MRP 8/14 levels only at day 10 compared to those receiving the placebo. For total protein, IL‐1β, and elastase, no statistically significant differences were noted for subjects with or without antibiotic therapy at any time point.

Conclusions: Improved healing of the soft tissues has been noted clinically in non‐surgically treated sites in subjects treated with antibiotics. The expression of inflammatory mediators in GCF corroborated this finding only in part. EMD did not seem to further affect the expression of inflammatory mediators.
Influence of the Interimplant Distance on Crestal Bone Resorption and Bone Density: A Histomorphometric Study in Dogs
Authors: Papalexiou Vula , Novaes Arthur B. , Ribeiro Ricardo F. , Muglia Valdir , Oliveira Rafael R.
Published: April 2006

Background: The position of gingival soft tissues depends on the position and health of the underlying alveolar bone. The aim of this study was to evaluate the influence of different interimplant distances on crestal bone resorption after prosthetic restoration with a 5‐mm distance between the contact point and the bone crest.

Methods: The mandibular bilateral premolars of six dogs were extracted and, after 12 weeks, each dog received eight implants, totaling 48 implants in the experiment. Two pairs, one in each hemiarch, were separated by 2 mm (group 1) and two by 3 mm (group 2). After 12 weeks, the implants received temporary acrylic prostheses. After 4 more weeks, metallic crowns substituted the temporary prostheses. After 4 more weeks, the animals were sacrificed, and their hemimandibles were removed, dissected, and processed.

Results: For groups 1 and 2, respectively, the mean of interimplant bone resorption (IIBR) analyzed histologically was 2.03 and 1.98 mm (P ≥0.05), and the mean of the distal extension bone resorption was 2.04 and 1.92 mm for groups 1 and 2, respectively (P ≥0.05). The crestal bone resorption between the implants was 0.13 mm (P ≥0.05) for both groups. The mean of IIBD for groups 1 and 2 was 79% and 80%, respectively. When the IIBD was compared to the distal extension bone density for group 1 (79% and 64%) and group 2 (80% and 62%), statistically significant differences were obtained for both groups (P ≤0.05).

Conclusions: The distances of 2 and 3 mm between implants do not result in statistically significant differences in crestal bone resorption around implant surfaces in dogs. The bone density is enhanced when loading is present at the interimplant area.
Oral Post‐Surgical Complications Following the Administration of Bisphosphonates Given for Osteopenia Related to Malignancy
Authors: Soileau Kristi M.
Published: April 2006

Background: This case report seeks to illustrate the clinical consequences of the administration of bisphosphonate therapy to prevent osteopenia secondary to malignancy in one patient.

Methods: A 69‐year‐old white female with a history of breast cancer with metastasis presented with pain in the upper left quadrant and periodontal pocketing of at least 6 mm in each of the four quadrants of the oral cavity. One week following surgery on the lower right region, lingual bone exposure was noted, and several attempts at achieving healing over the course of 15 months proved unsuccessful.

Results: Upon referral to a surgeon at the Louisiana State University Medical Center, New Orleans, Louisiana, a potential causative factor was finally identified. The drug zoledronic acid, a bisphosphonate given for prevention of osteoclastic activity of bone metastasis, secondary to breast cancer, was identified as the possible cause of inhibition of healing, most likely from regional vascular insufficiency. The drug was immediately discontinued. The patient is healing very slowly with the aid of hyperbaric therapy; she has been unable to achieve smoking cessation, which is deterring thorough healing of the exposed bony area on the lower right lingual side.

Conclusions: Physicians and dentists alike must become increasingly aware of impaired oral healing following the use of bisphosphonates given for malignancy‐related osteopenia. A dental exam should be performed before bisphosphonate therapy, as recommended for radiation therapy related to malignancy.
Effect of Cigarette Smoke Inhalation and Estrogen Deficiency on Bone Healing Around Titanium Implants: A Histometric Study in Rats
Authors: Carvalho Marcelo Diniz , Benatti Bruno Braga , César‐Neto João Batista , Nociti Francisco Humberto , da Rocha Nogueira Filho Getúlio , Casati Marcio Zaffalon , Sallum Enilson Antonio
Published: April 2006

Background: It has been shown that cigarette smoke inhalation (CSI) and estrogen deficiency (OVX) may affect bone quality around titanium implants; however, their association has not been evaluated. Therefore, this study aimed to verify the effects of CSI associated with OVX on bone healing around titanium implants.

Methods: The tibia surface of 45 female Wistar rats was surgically exposed, and screw‐shaped titanium implants were placed. The animals were randomly assigned to OVX (ovariectomized rats; n = 15), SHAM (sham‐operated rats; n = 15), and CSI + OVX (4 months of intermittent cigarette smoke inhalation, starting 2 months before implant placement in ovariectomized rats; n = 15). The implants were placed at the time of OVX or SHAM surgery. After 60 days, the animals were sacrificed and undecalcified sections obtained. The percentages of mineralized tissue (bone density [BD]) in a 500‐μm‐wide zone lateral to the implant, bone filling (BF) within the limits of the threads, and bone‐to‐implant contact (BIC) were measured in cortical (zone A) and cancellous (zone B) bone.

Results: In zone A, the CSI + OVX group showed a significant difference regarding BIC and BD (P <0.05) compared to the other groups. In zone B, data analysis showed that the CSI + OVX group presented the lowest percentage of BD and BIC, followed by the OVX and SHAM groups, respectively (P <0.05).

Conclusion: Within the limits of the present study, it can be concluded that cigarette smoke inhalation amplified the deleterious effects of estrogen deficiency, affecting both preexisting and newly formed bone in the cortical and cancellous bone around titanium implants.
Periodontal Disease in Patients From the Original Kostmann Family With Severe Congenital Neutropenia
Authors: Carlsson Göran , Wahlin Ylva‐Britt , Johansson Anders , Olsson Anders , Eriksson Torbjörn , Claesson Rolf , Hänström Lennart , Henter Jan‐Inge
Published: April 2006

Background: Patients with Kostmann syndrome (severe congenital neutropenia [SCN]) typically normalize their absolute neutrophil count (ANC) upon granulocyte colony‐stimulating factor (G‐CSF) therapy. However, although they no longer experience life‐threatening bacterial infections, they frequently still have recurrent gingivitis and even severe periodontitis, often starting in early childhood.

Methods: We studied the periodontal disease in the four surviving patients belonging to the family originally described by Kostmann. Their odontological records, x‐rays, color photos, bacterial cultures, serum antibodies to oral bacteria, and histopathological examinations were reviewed. The data were also correlated to previous investigations on their antibacterial peptides and molecular biology.

Results: Three patients had periodontal disease, despite normal ANC and professional dental care, and had neutrophils deficient in antibacterial peptides. One of these patients also had a heterozygous mutation in the neutrophil elastase gene, had severe periodontal disease and overgrowth of the periodontal pathogen Actinobacillus actinomycetemcomitans in the dental flora, and 15 permanent teeth had been extracted by the age of 27. One bone marrow–transplanted patient had no periodontal disease.

Conclusions: Normalized ANC levels are not sufficient to maintain normal oral health in SCN patients, and because neutrophils are important for first‐line defense and innate immunity, the deficiency of the antibacterial peptide LL‐37 probably explains their chronic periodontal disease. Professional dental care is still important for SCN patients, despite treatment with G‐CSF and normal ANC levels. Whether antibacterial peptides play a role in the pathogenesis of periodontitis in other patients remains to be elucidated.
Surgical or Non‐Surgical Periodontal Treatment: Factors Affecting Patient Decision Making
Authors: Patel Amit M. , Richards Philip S. , Wang Hom‐Lay , Inglehart Marita R.
Published: April 2006

Background: This study explored which factors affected patients' decisions to pursue either surgical or non‐surgical periodontal treatment.

Methods: Data were collected from 74 patients at a regularly scheduled periodontal appointment, at which each patient was told that periodontal treatment was needed, and 2 weeks following the actual treatment. The surveys assessed the patients' decisions and potential determinants of these decisions. The dental anxiety scale‐revised, the state‐trait anxiety inventory, and the Iowa dental control index were used to measure psychosocial factors.

Results: Patients who decided to have surgery did not differ from patients who decided against surgery in sociodemographic variables such as gender, age, education, and socioeconomic status, nor in their desire for control over the treatment decision. However, they had less dental fear and less general anxiety than the non‐surgery patients. Although the two patient groups did not differ in their responses concerning how well the dentists had informed them about the procedure, they differed in the degree of trust and rapport with their dentists.

Conclusions: The less dentally fearful and anxious patients were in general and the more they trusted their provider and felt they had good rapport, the more likely they were to accept surgical periodontal treatment. These results stress the importance of good patient‐provider communication.
Modulation of Phagocytosis, Chemotaxis, and Adhesion of Neutrophils by Areca Nut Extracts
Authors: Hung Shan‐Ling , Lee Ya‐Yun , Liu Tsung‐Yun , Peng Ji‐Lung , Cheng Yi‐Yun , Chen Yen‐Ting
Published: April 2006

Background: A higher prevalence of periodontal diseases among areca chewers than non‐areca chewers has been demonstrated. Neutrophils, representing the first line of the host defense mechanism against microbial infection, play important roles in maintaining periodontal health. This study determined the possible effects of areca nut on phagocytosis, chemotaxis, and adhesion of human neutrophils.

Methods: Aqueous extracts of ripe areca nut without husk (rANE) and fresh and tender areca nut with husk (tANE) were examined for their effects on neutrophil phagocytosis using flow cytometry and confocal laser scanning microscopy. The effects of rANE and tANE on chemotaxis and adhesion of neutrophils to human aortic endothelial cells were examined using fluorescence‐labeled neutrophils.

Results: Both rANE and tANE inhibited the phagocytic activity of neutrophils in a dose‐dependent manner. The levels of internalized fluorescent bacteria in neutrophils decreased after ANE treatment. However, exposure of neutrophils to rANE and tANE stimulated the chemotaxis activity of neutrophils to N‐formyl‐Met‐Leu‐Phe (fMLP) and enhanced adhesion of neutrophils to human aortic endothelial cells in a dose‐dependent manner. Moreover, treatment of neutrophils with rANE was more effective than incubation with tANE.

Conclusions: Components of areca nut inhibited phagocytosis activity of neutrophils but enhanced chemotaxis and adhesion of neutrophils. Alterations in functions of neutrophils may lead to signs of clinical diseases associated with areca chewing. The components in ANEs that are responsible for these observations remain to be elucidated.
Fabrication of Cultured Oral Gingiva by Tissue Engineering Techniques Without Materials of Animal Origin
Authors: Yamada Kazuto , Yamaura Junji , Katoh Masakazu , Hata Ken‐ichiro , Okuda Kazuhiro , Yoshie Hiromasa
Published: April 2006

Background: Cultured gingival substitute has been found to be a useful graft material for treatment of gingival recession. However, such substitutes include xenograft derivative materials that involve concomitant risk of viral contamination. To eliminate this risk, we designed new gingival substitutes made of recombinant human collagen types I and III sponges and cultured these substitutes in animal‐free media (HFDM‐1).

Methods: Gingival fibroblasts were seeded onto sponges of type I or III recombinant collagen. These sponges were cultured in Dulbecco's modified Eagle's medium (DMEM) with 10% fetal bovine serum (FBS), HFDM‐1 with 2% human serum (HS), or HFDM‐1. Fibroblast proliferation in these samples was compared using the cell‐counting kit assay. Vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) released into the cultured media were examined by enzyme‐linked immunosorbent assay.

Results: The fibroblasts proliferated significantly in all six combinations of collagen and medium types. The fibroblast growth rate after 9 days of culture was equal between HFDM‐1 with 2% HS and DMEM with 10% FBS. The type III collagen sponge showed a higher fibroblast growth rate than the type I sponge. VEGF concentrations in HFDM‐1 with 2% HS were higher than those in other media. The highest HGF levels were detected in DMEM with 10% FBS.

Conclusions: The new cultured gingival substitute containing no animal‐derived materials produced good cell proliferation and VEGF release. The results suggested that the substitute may provide a new tool for the treatment of gingival recession.
prtH in Tannerella forsythensis Is Not Associated With Periodontitis
Authors: van der Reijden Wil A. , Bosch‐Tijhof Caroline J. , Strooker Hans , van Winkelhoff Arie Jan
Published: April 2006

Background: It has been suggested that prtH in Tannerella forsythensis encodes for a cystein proteinase that is associated with its pathogenic potential and can discriminate between periodontal health and disease. The aim of this investigation was to further establish this potentially important observation.

Methods: A group of 33 consecutive adult patients with periodontitis (mean age: 47.6 ± 10.1 years) harboring T. forsythensis was selected to investigate the presence of prtH by polymerase chain reaction (PCR). The T. forsythensis strains were isolated by anaerobic culture techniques. To investigate the association of this gene with periodontitis, a group of 14 age‐matched subjects (mean age: 56.4 ± 6.9 years) without any signs of periodontal disease (probing depths <3 mm and no radiographic attachment loss) was tested for comparison. Pure isolates and crude subgingival plaque samples were used as a template for the PCR.

Results: In the group of 33 T. forsythensis‐positive patients, we found two T. forsythensis isolates to be prtH negative. Despite repeated analyses, testing of the whole subgingival plaque samples revealed only 17 of 33 samples to be prtH positive. The T. forsythensis isolates from the 14 periodontally healthy subjects were all prtH positive. The odds ratio of the presence of prtH in T. forsythensis in periodontitis patients versus healthy controls is 1.06 (P >0.05).

Conclusions: On the basis of our data, we conclude that the presence of prtH in T. forsythensis is not discriminative for patients with T. forsythensis‐associated periodontitis compared to healthy carriers of T. forsythensis. In addition, the use of whole subgingival plaque samples to test for the prevalence of prtH in bacteria appeared unreliable. Culture of the microorganism is an important condition to receive a sufficient amount of template DNA to detect the specific locus of the genome.
Gingival Crevicular Fluid Leptin Levels in Periodontitis Patients With Long‐Term and Heavy Smoking
Authors: Bozkurt F. Yeşim , Yetkin Ay Z. , Sütçü R. , Delibaş N. , Demirel R.
Published: April 2006

Background: The aim of the present study was to evaluate gingival crevicular fluid (GCF) leptin levels and the influence of long‐term and heavy smoking on GCF leptin levels in patients with chronic periodontitis.

Methods: In this study, 143 individuals were divided into three groups: non‐smokers (NS), smokers (S), and control (C). Three subgroups of NS and S were grouped as follows: a) probing depth (PD) ≤3 mm; b) PD = 4 to 5 mm; and c) PD >5 mm. For each patient, PD, gingival index (GI), plaque index (PI), gingival bleeding time index (GBTI), and clinical attachment level (CAL) values were recorded. The GCF leptin levels obtained from sampling sites were determined by using enzyme‐linked immunosorbent assay kits.

Results: The GCF leptin levels were found significantly lower in the a and b subgroups in the S group than those in the NS group (P <0.05). The inflammatory markers GI and GBTI showed significant correlations with leptin in NS (P <0.05).

Conclusions: Our results suggest that higher leptin GCF levels in healthy sites in periodontitis patients may play a protective role in periodontal disease. Further studies are needed to determine the cellular origin of the leptin in the gingiva and the effect of plasma leptin levels on GCF leptin concentrations.
Gingival Crevicular Fluid Matrix Metalloproteinase‐25 and ‐26 Levels in Periodontal Disease
Authors: Emingil Gülnur , Kuula Heidi , Sorsa Timo , Atilla Gül
Published: April 2006

Background: Tissue destruction associated with the progression of periodontal disease is caused by a cascade of host and microbial proteolytic enzymes. Host‐derived matrix metalloproteinases (MMPs) play an important role in the degradation of the extracellular matrix. Leukolysin/membrane‐type 6 (MT‐6)/MMP‐25, the latest member of the MT‐MMP subgroup of the MMP family, is primarily expressed by neutrophils and involved in extracellular matrix turnover. Matrilysin‐2/MMP‐26 (endometase), a novel member of the matrilysin subgroup of the MMP family, can degrade the extracellular matrix, α1‐antitrypsin, and activate pro‐MMP‐9. Our study aimed to examine the levels, molecular forms, and degrees of activation of MMP‐25 and MMP‐26 in gingival crevicular fluid (GCF) from patients with different periodontal diseases.

Methods: A total of 105 subjects, 35 with generalized aggressive periodontitis (GAgP), 29 with chronic periodontitis (CP), 20 with gingivitis, and 21 periodontally healthy subjects, were included in this study. Periodontal status was evaluated by measuring probing depth, clinical attachment loss, presence of bleeding on probing, and plaque. GCF MMP‐25 and MMP‐26 levels were analyzed by computer‐quantitated Western immunoblotting using specific antibodies.

Results: The 57‐kDa soluble pro‐MMP‐25 and 45‐ to 47‐kDa active form of MMP‐25 were detected by Western immunoblots in CP and GAgP GCF, and lesser levels of these soluble MMP‐25 immunoreactive bands were detected in gingivitis GCF. An enhanced and similar degree of MMP‐25 activation was found in GAgP, CP, and gingivitis groups. There were no detectable MMP‐25 immunoreactivities in the healthy subjects' GCF. GAgP and CP groups had elevated GCF MMP‐26 levels and degrees of activation compared to the gingivitis and healthy groups (P <0.008). The gingivitis group had higher GCF MMP‐26 levels and degree of activation compared to the healthy group (P <0.008).

Conclusions: The present study demonstrated the presence of soluble or shed forms of MMP‐25 and MMP‐26 in GCF of patients with different periodontal diseases. Increased levels and activation of MMP‐25 and MMP‐26 in GCF are associated with an enhanced severity of periodontal inflammation, suggesting that these novel MMPs can participate in the progression of periodontal diseases. They may prove to be diagnostically useful and could be targets of medication in the future.
Lasers in Periodontics: A Review of the Literature
Authors: Cobb Charles M.
Published: April 2006

Background: Despite the large number of publications, there is still controversy among clinicians regarding the application of dental lasers to the treatment of chronic periodontitis. The purpose of this review is to analyze the peer‐reviewed research literature to determine the state of the science concerning the application of lasers to common oral soft tissue problems, root surface detoxification, and the treatment of chronic periodontitis.

Methods: A comprehensive computer‐based search combined the following databases into one search: Medline, Current Contents, and the Cumulated Index of Nursing and Allied Health. This search also used key words. In addition, hand searches were done for several journals not cataloged in the databases, and the reference lists from published articles were checked. All articles were considered individually to eliminate non‐peer‐reviewed articles, those dealing with commercial laser technology, and those considered by the author to be purely opinion articles, leaving 278 possible articles.

Results: There is a considerable conflict in results for both laboratory studies and clinical trials, even when using the same laser wavelength. A meaningful comparison between various clinical studies or between laser and conventional therapy is difficult at best and likely impossible at the present. Reasons for this dilemma are several, such as different laser wavelengths; wide variations in laser parameters; insufficient reporting of parameters that, in turn, does not allow calculation of energy density; differences in experimental design, lack of proper controls, and differences in severity of disease and treatment protocols; and measurement of different clinical endpoints.

Conclusions: Based on this review of the literature, there is a great need to develop an evidence‐based approach to the use of lasers for the treatment of chronic periodontitis. Simply put, there is insufficient evidence to suggest that any specific wavelength of laser is superior to the traditional modalities of therapy. Current evidence does suggest that use of the Nd:YAG or Er:YAG wavelengths for treatment of chronic periodontitis may be equivalent to scaling and root planing (SRP) with respect to reduction in probing depth and subgingival bacterial populations. However, if gain in clinical attachment level is considered the gold standard for non‐surgical periodontal therapy, then the evidence supporting laser‐mediated periodontal treatment over traditional therapy is minimal at best. Lastly, there is limited evidence suggesting that lasers used in an adjunctive capacity to SRP may provide some additional benefit.
Convergence analysis of blind image deconvolution via dispersion minimization
Authors: Vural C. , Sethares W. A.
Published: April 2006

A new non‐linear adaptive filter called blind image deconvolution via dispersion minimization has recently been proposed for restoring noisy blurred images blindly. This is essentially a two‐dimensional version of the constant modulus algorithm that is well known in the field of blind equalization. The two‐dimensional extension has been shown capable of reconstructing noisy blurred images using partial a priori information about the true image and the point spread function in a variety of situations by means of simulations. This paper analyses the behaviour of the algorithm by investigating the static properties of the cost function and the dynamic convergence of the parameter estimates. The theoretical results are supported with computer simulations. Copyright © 2006 John Wiley & Sons, Ltd.
High Strength Nanocrystalline Ni‐Co Alloy with Enhanced Tensile Ductility
Authors: Gu C. , Lian J. , Jiang Z.
Published: April 2006

Nanocrystalline Ni‐1.7%Co alloy exhibited high ultimate tensile strength of about 1600 MPa and enhanced ductility of 8‐9.6% over a wide strain rate range of 1.04 × 10–6–1.04 s–1 revealed by tensile tests at room temperature. The typical tradeoff characteristic between yield stress and elongation to failure would make this Ni‐1.7%Co alloy for potential use in different applications.
Intermetallics in Magnesium Alloys
Authors: Hort N. , Huang Y. , Kainer K. U.
Published: April 2006

Intermetallic phases can be found in almost every magnesium alloy. These intermetallic compounds play a very important role in optimizing the microstructure and mechanical properties. The present paper reviews the effects of intermetallics in magnesium alloys mainly based on their stabilities: dissolvable intermetallics at low temperatures and thermal stable intermetallics at elevated temperatures. The effects of intermetallics are discussed in the age hardenable and creep resistant magnesium alloys, separately. Finally, the further investigations are remarked on the intermetallics, including their precipitation processes, crystal structures and crystallographic orientation relations with magnesium matrix. The aim is to supply useful information in developing new wrought and creep‐resistant magnesium alloys which will be used in the powertrain at elevated temperatures.
Robust iterative learning control design for batch processes with uncertain perturbations and initialization
Authors: Shi Jia , Gao Furong , Wu Tie‐Jun
Published: April 2006

A robust iterative learning control (ILC) scheme for batch processes with uncertain perturbations and initial conditions is developed. The proposed ILC design is transformed into a robust control design of a 2‐D Fornasini–Marchsini model with uncertain parameter perturbations. The concepts of robust stabilities and convergences along batch and time axes are introduced. The proposed design leads to nature integration of an output feedback control and a feedforward ILC to guarantee the robust convergence along both the time and the cycle directions. This design framework also allows easy enhancement of the feedback and/or feedforward controls of the system by extending the learning information along the time and/or the cycle directions. The proposed analysis and design are formulated as matrix inequality conditions that can be solved by an algorithm based on linear matrix inequality. Application to control injection packing pressure shows the proposed ILC scheme and its design are effective. © 2006 American Institute of Chemical Engineers AIChE J, 2006
Hypersensitivity pneumonitis due to metal working fluids: Sporadic or under reported?
Authors: Gupta Amit , Rosenman Kenneth D.
Published: April 2006

Background

Occupational exposure to metal working fluids (MWF) is common with over 1.2 million workers in the United States involved in machine finishing, machine tooling, and other metalworking operations. MWF is a known cause of hypersensitivity pneumonitis (HP). Recent reports of outbreaks of hypersensitivity HP secondary to exposure to MWF are reported.

Design

Cases were identified through the Occupational Disease surveillance system in the State of Michigan and from referrals for evaluation to the Division of Occupational and Environmental Medicine at Michigan State University (MSU). Each patient underwent a clinical examination including an occupational history, lung function studies, radiographic imaging, and in some cases lung biopsies. Following the diagnosis of definite HP, an industrial hygiene investigation was carried out, which included a plant walk‐through, and review of the “Injury and Illness” log. Air monitoring and microbial sampling results were reviewed.

Results

As part of Michigan's mandatory surveillance system for occupational illnesses, seven cases of suspected HP were identified in 2003–2004 from three facilities manufacturing automobile parts in Michigan. Each plant used semi‐synthetic MWFs, and conducted a MWF management program including biocide additions. Two facilities had recently changed the MWF before the cases arose. Growth of mycobacteria was found in these two MWFs. Breathing zone samples for particulates of two employees in plant A (two cases) ranged from 0.48 to 0.56 mg/m3. In plant B (four cases), two employees' sampling results ranged from 0.10 to 0.14 mg/m3. No air sampling data were available from plant C.

Conclusion

Hypersensitivity pneumonitis due to exposure to MWFs is under‐recognized by health care providers, and current surveillance systems are inadequate to provide a true estimate of its occurrence. HP arose from environments with exposures well below the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) for MWF, and in one case from exposures well below the National Institute of Occupational Safety and Health (NIOSH) recommended exposure limit (REL). The sporadic nature of reports of HP in relationship to MWF probably represents a combination of workplace changes that cause the disease and inadequate recognition and reporting of the disease when it does occur. Physician awareness of HP secondary to MWF and an effective medical surveillance program are necessary to better understanding the epidemiology and prevention of this disease. Am. J. Ind. Med. 2006. © 2006 Wiley‐Liss, Inc.
Parental exposure to lead and small for gestational age births
Authors: Chen Pau‐Chung , Pan I‐Jen , Wang Jung‐Der
Published: April 2006

Background

Previous studies about the effect of lead exposure on adverse birth outcomes are still inconsistent and few studies estimate the relationship between parental lead exposure and small for gestational age (SGA) infants. An occupational cohort study to assess whether parental lead exposure would be related to decreased birth weight and shortened gestational ages of their offspring was conducted. Whether higher lead exposure doses would increase risks of low birth weight (LBW), preterm delivery, and SGA births was also investigated.

Methods

A Program to Reduce Exposure by Surveillance System—Blood Lead Levels (Press‐BLLS) was established in Taiwan in July 1993. The names of workers exposed to lead was collected from this occupational blood‐lead notification database. The birth outcomes of their offspring were determined by linking to the Taiwan birth registration database from 1993 to 1997. Only singleton births whose parental blood‐lead concentrations were tested during pregnancy or prior to conception, or within a 1‐year span before these two periods were included.

Results

Among 1,611 eligible births, 72 births were LBW, 74 were preterm deliveries, and 135 were SGA. Maternal blood‐lead concentrations (PbBs) equal to or more than 20 µg/dl had a higher risk of mothering a SGA child (risk ratio (RR) = 2.15; 95% confidence interval (CI), 1.15–3.83).

Conclusions

Additional evidence of the effects of lead on adverse birth outcomes, especially for SGA births is reported. Maternal exposure to lead plays a more important role in the adverse effect on birth outcome than does paternal exposure. Am. J. Ind. Med. 2006. © 2006 Wiley‐Liss, Inc.
Risk of lung cancer from exposure to dusts and fibers in Leningrad Province, Russia
Authors: Baccarelli Andrea , Khmelnitskii Oleg , Tretiakova Maria , Gorbanev Sergey , Lomtev Alexei , Klimkina Irina , Tchibissov Vladimir , Averkina Olga , Rice Carol , Dosemeci Mustafa
Published: April 2006

Background

Exposures to several dusts and fibers (DFs) have been established or suggested as etiologic factors for lung cancer.

Methods

To investigate lung cancer risk in relation to exposure to DFs, we identified 540 pathologically‐diagnosed lung cancer cases and 582 controls from the 1993–1998 autopsy records of the 88 hospitals of Leningrad Province, Russia. Lifetime job‐specific exposure measurements were available for 15 organic, 15 man‐made and 28 natural‐inorganic agents.

Results

In male workers, increased risks were found for linen dust (OR = 3.68, 95% CI 1.00–13.6, adjusted for age, smoking and residence), and unspecified DFs (OR = 1.44, 95% CI 1.07–1.94). Small non‐significant excess risks were observed for quartz dust (OR = 1.27; 95% CI 0.83–1.93) and man‐made vitreous fibers (MMVFs) (OR = 1.82, 95% CI 0.88–3.75). In female subjects, risks were non‐significantly associated with paper dust (OR = 1.77, 95% CI 0.74–4.20), and unspecified DFs (OR = 1.52, 95% CI 0.77–3.03).

Conclusions

The study showed increased lung cancer risk for selected categories of DFs. Am. J. Ind. Med. 2006. Published 2006 Wiley‐Liss, Inc.
Synthesis of Non‐Nucleosides: 7‐ and 1,3‐Substituents of New Pyrrolo[2,3‐d]pyrimidin‐4‐ones on Antiviral Activity
Authors: Hilmy Khalid Mohammed Hassan
Published: April 2006

A series of non‐nucleosides 9–47 were synthesized. Compounds 1–4 were reacted with formic acid (85%) to afford compounds 5‐8. Then, the latter compounds were reacted with alkyl halides a–f (2‐bromopropane, 2‐bromobutane, benzyl bromide, benzyl chloromethyl ether, chloromethyl ethyl ether, phenacyl bromide) in the presence of NaH in dry DMF to give the desired compounds 9–47, which were evaluated for activity against herpes simplex virus type‐II (HSV‐II).
In Vitro and in Vivo Antimalarial Activity of Derivatives of 1,10‐Phenanthroline Framework
Authors: Yapi Ange‐Désiré , Valentin Alexis , Chezal Jean‐Michel , Chavignon Olivier , Chaillot Bernard , Gerhardt Roseline , Teulade Jean‐Claude , Blache Yves
Published: April 2006

A series of trisubstituted 1,10‐phenanthrolines was prepared. These compounds exhibited mild to high biological activities in vitro both toward chloroquino‐resistant FcB1‐Columbia and FcM29‐Cameron strains and Nigerian chloroquino‐sensitive strain of Plasmodium falciparum. Cytotoxicity of the most active compounds was estimated showing that one compound (10) exhibited a selective activity against malaria parasite (selectivity indexes of 52 and 144). Antiplasmodial activity of this derivative was optimized by N‐10 alkylation and the phenanthrolinium salt (15) submitted to an in vivo study using mices infected by P. vinckei petteri showing an ED50 of 7.86 mg/kg/day.
Now that i think about it, i'm in the mood for laughs: decisions focused on mood
Authors: Caruso Eugene M. , Shafir Eldar
Published: April 2006

Four studies examined the impact that thinking about mood can have on people's choices. In Study 1, participants who were asked to suppose they were in good, bad, or neutral moods were more likely to choose a silly comedic movie over an otherwise more attractive drama, compared to others who had not thought about mood. Similar patterns were observed when people introspected about how they felt before making a hypothetical choice (Study 2) or an actual choice (Study 3). In Study 4, participants who pursued mood‐relevant information chose to see a comedic play more often than those who had not focused on such information. Thinking about their own mood appears to increase decision makers' concern with the hedonic consequences of decisions, thereby promoting mood regulatory activities and altering preference, possibly in favor of suboptimal outcomes. Copyright © 2006 John Wiley & Sons, Ltd.
The effect of time on pleasure with chosen outcomes
Authors: Ritov Ilana
Published: April 2006

Emotional reactions, such as regret and disappointment, are associated with the comparison of an obtained outcome with what might have been. Past research revealed that these counterfactual comparisons affect one's pleasure with the outcome, at least in the short term. However, whether such effects are transient or long lasting is unknown. The present research explores the time course of outcome evaluation, by eliciting ratings of pleasure with a specific real choice at two points in time. In three experimental studies, pleasure with a small gift immediately following the gift's selection was compared to pleasure with the gift 4 to 8 weeks later. The results indicate that satisfaction with a chosen outcome, unlike satisfaction with a randomly assigned one, decreases in the long term. These findings are compatible with the assumption that under some conditions the impact of forgone options on the evaluation of decision outcomes does not diminish, and may even increase with time. A fourth study, a survey of people's retrospective evaluation of their choice of undergraduate major, yielded compatible results. Copyright © 2006 John Wiley & Sons, Ltd.
Clomiphene and hypospadias on a detailed level: Signal or chance?
Authors: Meijer Willemijn M. , de Jong‐Van den Berg Lolkje T.W. , van den Berg Marjan D. , Verheij Joke B.G.M. , de Walle Hermien E.K.
Published: April 2006

BACKGROUND

Clomiphene, a drug used to induce ovulation, is chemically related to diethylstilbestrol (DES). DES is associated with vaginal cancer and infertility among daughters and with hypospadias among second‐generation male offspring. Because clomiphene has a long half‐life and metabolites have been found in feces up to 6 weeks after administration, fetal exposure is possible if the mother took this drug prior to becoming pregnant.

METHODS

Case‐control analyses were performed to investigate the association between clomiphene exposure and hypospadias. Cases were all male subjects registered in the European Concerted Action on Congenital Anomalies and Twins (EUROCAT) Northern Netherlands registry for congenital anomalies with nonsyndromal hypospadias. Controls were all male children born without hypospadias, including those with chromosomal and monogenic defects. Logistic regression analyses were performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Of 392 cases, 7 (1.8%) were exposed to clomiphene compared with 64 of 4538 controls (1.4%). For penoscrotal hypospadias, we found that the OR was significantly increased (6.08; 95% CI, 1.40–26.33); for the mild and moderate forms of hypospadias, the ORs were not increased.

CONCLUSIONS

Because penoscrotal hypospadias is rare, the effect is diluted when all forms of hypospadias are studied as a group. Therefore, our study stresses the importance of studying birth defects on as detailed a level as possible. Other studies should be conducted to confirm our findings. Birth Defects Research (Part A), 2006. © 2006 Wiley‐Liss, Inc.