Influence of a triclosan toothpaste on periodontopathic bacteria and periodontitis progression in cardiovascular patients: a randomized controlled trial.

BACKGROUND AND OBJECTIVE: Triclosan/copolymer toothpaste is effective in controlling plaque and gingivitis and in slowing the progression of periodontitis. This study describes its influence on microbiological and clinical outcomes, over a 5-year period, in patients with established cardiovascular disease (CVD). MATERIAL AND METHODS: Four-hundred and thirty-eight patients were recruited from the Cardiovascular Unit at The Prince Charles Hospital, Brisbane, Australia, and randomized to triclosan or placebo groups. Six sites per tooth were examined annually for probing pocket depth and loss of attachment. These outcomes were analysed, using generalized linear modelling, in 381 patients who had measurements from consecutive examinations. Concurrent load of the periodontal pathogens Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Tannerella forsythia and Porphyromonas gingivalis was determined, using quantitative real-time PCR, in 437 patients with baseline plaque samples. Group comparisons were expressed as geometric means. The chi-square test was used to test for differences between the two groups of patients with regard to the proportion of patients with different numbers of bacterial species. RESULTS: There was no difference in general health or periodontal status between the groups at baseline. There was a significant reduction in the number of interproximal sites showing loss of attachment between examinations, by 21% on average (p < 0.01), in the triclosan group compared with the placebo group. The prevalence of patients with F. nucleatum and A. actinomycetemcomitans was high and remained relatively constant throughout the 5 years of the study. In contrast, the prevalence of T. forsythia and P. gingivalis showed more variability; however, there was no significant difference between the groups, at any time point, in the prevalence of any organism. A significant difference in the geometric means for P. gingivalis (p = 0.01) was seen at years 1 and 4, and for F. nucleatum (p = 0.01) and in the total bacterial load (p = 0.03) at year 2; however, these differences were not statistically significant following a Bonferroni correction for multiple comparisons. There was no difference between the groups in the geometric means for each organism at year 5. CONCLUSION: Within the limitations of the study, these data suggest that the use of triclosan/copolymer toothpaste significantly slowed the progression of periodontitis in patients with CVD but that it had little influence on key subgingival periodontopathic bacteria in these patients over the 5 years of the study.

Radio-sensitizing effect of MEK inhibition in glioblastoma in vitro and in vivo.

INTRODUCTION: Glioblastoma (GBM) is an incurable cancer type. New therapeutic options are investigated, including targeting the mitogen-activated protein kinase (MAPK) pathway using MEK inhibitors as radio-sensitizers. In this study, we investigated whether MEK inhibition via PD0325901 leads to radio-sensitization in experimental in vitro and in vivo models of GBM. MATERIALS AND METHODS: In vitro, GBM8 multicellular spheroids were irradiated with 3 fractions of 2 Gy, during 5 consecutive days of incubation with either PD0325901 or MEK-162. In vivo, we combined PD0325901 with radiotherapy in the GBM8 orthotopic mouse model, tumor growth was measured weekly by bioluminescence imaging and overall survival and toxicity were assessed. RESULTS: Regrowth and viability of spheroids monitored until day 18, showed that both MEK inhibitors had an in vitro radio-sensitizing effect. In vivo, PD0325901 concentrations were relatively constant throughout multiple brain areas and temporal PD0325901-related adverse events such as dermatitis were observed in 4 out of 14 mice (29%). Mice that were treated with radiation alone or combined with PD0325901 had significantly better survival compared to vehicle (both P < 0.005), however, no significant interaction between PD0325901 MEK inhibition and irradiation was observed. CONCLUSION: The difference between the radiotherapy-enhancing effect of PD0325901 in vitro and in vivo urges further pharmacodynamic/pharmacokinetic investigation of PD0325901 and possibly other candidate MEK inhibitors.

Progression of periodontal disease and interleukin-10 gene polymorphism.

BACKGROUND AND OBJECTIVE: Interleukin-10 is a key immunoregulatory cytokine that may be of significance in the immunopathogenesis of chronic inflammatory diseases such as periodontal disease. Molecular genetic studies have defined a number of haplotypes that may be associated with differing levels of interleukin-10 secretion. The present study investigated the possible association between interleukin-10 gene polymorphism and periodontal disease progression. MATERIAL AND METHODS: Genomic DNA was obtained from 252 adults who were part of a prospective longitudinal study on the progression of periodontal disease in a general adult Australian population. Single nucleotide polymorphisms at positions -592 and -1082 in the interleukin-10 promoter were analysed using an induced heteroduplex methodology and used to determine interleukin-10 promoter haplotypes in individual samples. Periodontitis progression was assessed by measuring probing depths and relative attachment levels at regular intervals over a 5-year period. A generalized linear model was used to analyse the data, with age, gender, smoking status, interleukin-1 genotype and Porphyromonas gingivalis included as possible confounders. RESULTS: There was a significant (p approximately 0.02) main effect of interleukin-10 haplotypes, with individuals having either the ATA/ACC or the ACC/ACC genotype experiencing around 20% fewer probing depths of >or= 4 mm compared to individuals with other genotypes. Age and smoking had significant (p < 0.001) additional effects. CONCLUSION: These data suggest that the interleukin-10 genotype contributes to the progression of periodontal disease.

A 5-year longitudinal study of Tannerella forsythia prtH genotype: association with loss of attachment.

BACKGROUND: Tannerella forsythia (previously T. forsythensis) in subgingival plaque has been recognized as a defined periodontal pathogen, but its mere presence may be insufficient for disease initiation and/or progression. The organism may produce a cysteine protease, encoded by the prtH gene, which may play a role in the transition from commensal organism to opportunistic pathogen. This study aimed to relate changes in the level of T. forsythia prtH genotype over a 5-year period to a concomitant loss of attachment. METHODS: Real-time polymerase chain reaction was used to quantify the level of the prtH gene in plaque samples from subjects with and without attachment loss (> or =2 mm in at least two sites) over a 5-year period. Clinical measures and subgingival plaque samples were obtained at yearly intervals. RESULTS: Baseline levels of the prtH genotype were significantly lower in the subjects without loss of attachment compared to those who lost attachment over 1, 2, 4, or 5 years. In the subjects with loss of attachment, the higher prtH levels at baseline were not maintained until the end of the observation period. CONCLUSION: Higher levels of the prtH genotype were associated significantly with future attachment loss.

Basic helix-loop-helix transcription factor profiling of lung tumors shows aberrant expression of the proneural gene atonal homolog 1 (ATOH1, HATH1, MATH1) in neuroendocrine tumors.

Microarray-based expression profiling studies of lung adenocarcinomas have defined neuroendocrine subclasses with poor prognosis. As neuroendocrine development is regulated by members of the achaete-scute and atonal classes of basic helix-loop-helix (bHLH) transcription factors, we analyzed lung tumors for expression of these factors. Out of 13 bHLH genes tested, 4 genes, i.e., achaete-scute complex-like 1 (ASCL1, HASH1, Mash1), atonal homolog 1 (ATOH1, HATH1, MATH1), NEUROD4 (ATH-3, Atoh3, MATH-3) and neurogenic differentiation factor 1 (NEUROD1, NEUROD, BETA2), showed differential expression among lung tumors and absent or low expression in normal lung. As expected, tumors that have high levels of ASCL1 also express neuroendocrine markers, and we found that this is accompanied by increased levels of NEUROD1. In addition, we found ATOH1 expression in 9 (16%) out of 56 analyzed adenocarcinomas and these tumors showed neuroendocrine features as shown by dopa decarboxylase mRNA expression and immunostaining for neuroendocrine markers. ATOH1 expression as well as NEUROD4 was observed in small cell lung carcinoma (SCLC), a known neuroendocrine tumor. Since ATOH1 is not known to be involved in normal lung development, our results suggest that aberrant activation of ATOH1 leads to a neuroendocrine phenotype similar to what is observed for ASCL1 activation during normal neuroendocrine development and in lung malignancies. Our preliminary data indicate that patients with ATOH1-expressing adenocarcinomas might have a worse prognosis.

Identification and characterization of a novel luciferase-like protein in the human female reproductive tract.

A novel cDNA was cloned from human endometrium, matching a human gene with the interim name KIAA1463. An mRNA identified by 5'-rapid amplification of cDNA ends was found to be 3349 nt in length. PCR analysis also identified another transcript of 6626 nt, with an open reading frame encoding a 900 amino acid protein. A fold recognition program identified similarity to firefly luciferase containing an AMP-binding motif; hence, we refer to the predicted protein as the AMP binding/luciferase-like protein (ALLP). ALLP mRNA and protein were expressed throughout the female reproductive tract with the highest levels found in the ovary and uterus. In situ hybridization and immunohistochemistry showed predominant localization of the ALLP mRNA/protein in endometrial glandular epithelium and within the theca and granulosa cells in the ovary. In the endometrium expression of ALLP, mRNA and protein were higher during d 16-21 of the secretory phase of the cycle. Western blot analysis showed decreased expression of ALLP in the postmenopausal endometrium, and hormone replacement therapy increased the expression of ALLP. Endometrial adenocarcinoma cell lines expressed more ALLP, compared with cultured primary endometrial cells or normal endometrial tissue. The ubiquitous expression of ALLP in reproductive and nonreproductive tissues suggests that this protein, which is probably regulated by ovarian steroids, plays an important metabolic role and may be involved in such processes as implantation and tumorigenesis.

Role of the mitochondrial DnaJ homologue, Mdj1p, in the prevention of heat-induced protein aggregation.

The role of the mitochondrial Hsp70 system in the prevention of heat-induced protein aggregation was studied in isolated mitochondria from Saccharomyces cerevisiae. Firefly luciferase was employed as a thermolabile tester protein. After shift to 40 degrees Celsius transient increase of mt-Hsp70/luciferase complex was observed, which required functional Mdj1p and Mge1p, the mitochondrial homologues of DnaJ and GrpE. The kinetics of luciferase aggregation, however, were not influenced by mutations in either mt-Hsp70 or Mge1p. Only the absence of Mdj1p led to enhanced protein aggregation. Thus, a central role in the transient protection against heat stress is attributed to this mitochondrial DnaJ homologue.

Myocardial uptake of thallium-201 augmented with bicarbonate: concise communication.

Sodium bicarbonate was used to enhance the myocardial concentration of Tl-201 in rabbits and dogs. Organ distribution studies in rabbits and in vivo imaging in dogs showed a 1.5-2 fold increase in myocardial Tl-201 concentration in bicarbonate-treated animals as compared with matched controls. Image improvement was noted, with threefold enhancement of myocardium-to-liver ratios. The results suggest that a similar improvement may be possible for clinical myocardial imaging.

Licensing criteria for nuclear medicine.

The use of radioactive materials in medicine is one of the most highly regulated areas the physician has to deal with. There are three basic types of licenses for use of radioactive material defined in the Code of Federal Regulations (CFR), chapter 10, part 35. These are the general license, which is mainly applicable to small volume in vitro work; the specific license, which is used in most medical facilities; and the broad license, which is suited for larger research-oriented practices. Licensing requires proof of competence of the user and of adequate provision for protection of public health. Materials used in medicine are grouped for convenience into three diagnostic categories and two therapeutic categories. A sixth group, for sealed implants, is not generally applicable in nuclear medicine. Training and experience of users may be documented in a number of ways, including board certification in nuclear medicine. Therapeutic applications require additional proof of direct personal experience. The radiation safety officer is a pivotal individual in the licensing procedure, being directly responsible for carrying out the highly detailed requirements for protection of personnel and patients. A radiation safety program based on the "as low as reasonably achievable" (ALARA) concept requires personal monitoring, inventory control, detection and control of contamination, and strict adherence to licensing rules. Training of personnel and proper maintenance of equipment and facilities are also vital parts of the licensing process. The requirements of licensing and for renewal are clearly spelled out by the various regulatory agencies and require meticulous record keeping with documentation that all prescribed procedures have been followed and duly recorded.

Transportation issues in nuclear medicine and the release of radioactivity into the environment.

Large volumes of radioactive materials are shipped daily over the nation's highways, by air, and by other transportation modes for a variety of purposes. These shipments include those intended for nuclear medicine applications. Shipments are governed by the Federal Department of Transportation, the Nuclear Regulatory Commission, and, for international shipments, the International Atomic Energy Agency. Knowledge of the regulations of these agencies is essential for maintenance of a viable radiation safety program. The use of radioactive materials is invariably accompanied by the potential for release of radioactivity into the environment. This potential is addressed in the recommendations and regulations of several voluntary and governmental agencies. Recently, new concepts have been introduced into these recommendations and regulations that use the concepts of "annual limit of intake," "committed effective dose equivalent," and "derived air concentrations." These concepts improve the applicability of present standards for the release of radioactive materials into the environment and for the protection of individuals from these materials.

The Human Achaete Scute Homolog 2 gene contains two promotors, generating overlapping transcripts and encoding two proteins with different nuclear localization.

Placental development involves control by the basic helix-loop-helix transcription factor Mash2. Transcript analysis of the Human Achaete Scute Homolog 2 (HASH2) mRNA revealed the presence of two overlapping transcripts in first trimester placentae. The two transcripts (2.6 and 1.5 kb) are generated by two promotors which are separated by 1.1 kb, generating transcripts 1 and 2, respectively. Surprisingly, in transcript 1 which shows a broad expression, a second potential coding region, tentatively called Human Achaete Scute Associated Protein (HASAP) was present. Transcript 2 contains the HASH2 encoding region only. Analysis of protein expression from both transcripts by transfection studies with eGFP fusion proteins, revealed that both coding regions are translated from their endogenous translation initiation site and showed that both proteins are transported to the nucleus. HASH2 is distributed throughout the nucleus but the HASAP protein is transported into nuclear compartments, the nucleoli. In addition, the HASAP protein lacks the bHLH domain and bears no homology to known proteins. Moreover, allele-specific RT-PCR showed the human gene not to be subject to imprinting, possibly reflecting the biallelic expression of one of both transcripts. Our data indicate a species-specific difference between mouse and human expression of the Achaete Scute Homolog 2 and suggests a dual function of the human homologue.

Computer processed 99mTc-DTPA studies of renal allotransplants.

In order to refine the diagnostic possibilities of the radionuclide renal study in transplanted patients and to compensate for the nonspecificity of the 131I-hippuran study in some situation, 99mTc-DTPA WAS USED SIMULTANEOUSLY FOR IMAGING AND TIME-ACTIVITY CURVES. For these curves to be significant, appropriate background subtraction had to be made with a simple computer-processing method. The results obtained have shown that it is possible to distinguish marked acute tubular necrosis from milder degrees, thus affording a prognostic index in the immediate postoperative period, when the hippuran data are often nonspecific. Further, the diagnosis and follow-up of acute rejection episodes can be improved by the DTPA processed curves. Although these curves when examined individually do not show a specific pattern for rejection, they may reveal striking evolutionary changes when compared to the previous studies, even when the hippuran curves are unchanged. The physiologic basis for the differences between the two time-activity curves may be related to the differential handling of the two radiopharmaceuticals by the kidney.

Ante-dependence modeling in a longitudinal study of periodontal disease: the effect of age, gender, and smoking status.

BACKGROUND: It is generally accepted that periodontal disease progresses by a series of bursts that are interspersed by periods of stability or even gain of attachment. In order to analyze longitudinal data on a patient's disease experience, it is necessary to use models which accommodate serial dependence. Ante-dependence between the results of a series of periodontal examinations over time can be modeled using a Markov chain. This model describes temporal changes in patients' levels of disease in terms of transition probabilities, which allow for both regression and progression of the disease. The aim of the present study was to demonstrate the use of a Markov chain model to analyze data from a longitudinal study investigating the progression of periodontal disease in an adult population. METHODS: The study population consisted of 504 volunteers; however, only 456 were included in the analysis because the remaining 48 subjects did not give consecutive data. Subjects were examined at baseline, 6 months, and 1, 2, and 3 years. Probing depths (PD) were recorded using an automated probe. Disease was defined as four or more sites with PD > or = 4 mm. Markov chain modeling was used to determine the effect of age, gender, and smoking on the natural progression and regression (healing) of periodontal disease. RESULTS: Smoking and increasing age had no effect on the progression of disease in this population, but did have a significant effect (P values < or = 0.05) in reducing the regression of disease; i.e., their effect on disease appears to be inhibition of the natural healing process. Gender had no significant effects. CONCLUSIONS: These results demonstrate how ante-dependence modeling of longitudinal data can reveal effects that may not be immediately apparent from the data, with smoking and increasing age being seen to inhibit the healing process rather than promote disease progression.

Effect of increased community and professional awareness of plaque control on the management of inflammatory periodontal diseases.

Data from CPITN studies indicate that severe periodontitis affects approximately 10 per cent of most populations. These data have remained static for a number of years. Of interest, however, is that despite the dramatic increase in the use of oral hygiene aids, efforts by the dental profession in oral hygiene instruction, and the associated general improvement in oral hygiene levels in the community, the incidence of severe chronic inflammatory periodontal disease has remained largely unaffected. The effects of changing oral hygiene may be reflected in slight shifts in the mild and moderate classifications of periodontal disease but the prevalence of advanced disease in presumably susceptible subjects has remained relatively unchanged. The ramifications of relatively non-specific plaque control measures in the management of advanced disease in susceptible subjects are still unclear and it may not be until the adoption of a more specific approach to the control of specific pathogens which inhabit the subgingival biofilm that major changes in the general incidence of the severe inflammatory periodontal diseases will be seen.

Appropriate dental care for employees at the workplace.

The data from a dental health survey of an Australian employee group in Brisbane were used to test the value of dental health programmes at the workplace as a means of improving general dental health. The amount and complexity of treatment needs were investigated. Although both dental caries and periodontal disease were widespread, few of the employees had major treatment needs, most requiring minimal, simple dental care. Because of the minor treatment needs of a relatively static group of employees, the viability of a dental practice at work with emphasis on restorative dental care was questioned. Given the disease levels, the treatment needs indicated that a system based on prevention and maintenance care would be more appropriate.

A preventive dental care programme at the workplace.

Employees from an industrial group in Brisbane were examined at the workplace and found to have generally low levels of dental disease. At the same time, the Australian Bureau of Statistics suggests that less than 45 per cent of Australians attend a dentist annually. This low attendance for regular dental care reduces the effectiveness of any preventive dental service. A pilot scheme of preventive dental care was provided for employees at the workplace in Brisbane. The aim of the programme was to provide regular health counselling and reinforcement of oral health activities, general dental information, regular prophylaxis, scaling and cleaning, and referrals for restorative care. The preventive programme was appropriate given the disease levels. The services were effective in improving the periodontal status and restorative care which resulted from referrals. As well, the preventive dental care programme proved to be readily acceptable to both employees and management.

An improved mouthguard material.

A modified mouthguard material which reduces transmitted forces is described. Tests showed that the inclusion of air cells in a 4 mm thick polyvinyl-acetate-polyethylene (EVA) copolymer reduced the effects of impacts of less than 10 kN when compared with a material of the same EVA composition and thickness. The EVA copolymer with air-inclusions is suitable for the construction of stock mouth-formed and vacuum-formed mouthguards. The improved elastic properties of the modified mouthguard material reduced transmitted forces by 32 per cent when compared with traditional EVA mouthguard polymers of the same thickness.

The effect on energy absorption of hard inserts in laminated EVA mouthguards.

One of the suggestions for using laminated mouthguards is the inclusion of hard inserts to improve mouthguard performance. However, there is a paucity of published material on the use of such inserts and this study was designed to investigate this theory. Hard layers of ethylene vinyl acetate (EVA) were included in laminated mouthguard sheets which were then subject to repeated impacts with an impact rig. Hard inserts resulted in reduced energy absorption when compared with a control sheet of the same material and approximate thickness but without the hard inserts. Additionally, the further the hard inserts were located from the impact surface, the least reduction there was on energy absorption.

Forces transmitted through EVA mouthguard materials of different types and thickness.

Previous studies into sporting mouthguards have been mainly attitudinal or epidemiological. The aim of the present study was to build an impact rig to measure the impact absorbed by mouthguard materials of various thicknesses. The acceleration of the pendulum of the rig was measured and used to calculate the force transmitted to the materials. Impact tests were also performed on three commercially available mouthguard materials. Tests showed that the force transmitted through mouthguard materials was inversely related to the material thickness. Mouthguard construction techniques with ethylene vinyl acetate (EVA) plastics should be monitored to avoid occlusal thinning especially on the incisal edges. Thinning results in reduction in the protection offered by the mouthguard.