What do Brazilian paediatric dentists know about bruxism in children? Cross-sectional study.

PURPOSE: Little is known about the knowledge of paediatric dentists on bruxism in children. The aim of this cross-sectional study was to assess the knowledge of paediatric dentists on the concept, associated factors of bruxism and management of sleep bruxism (SB) in children'. METHODS: An electronic questionnaire was sent to paediatric dentists in the state of Goiás, Brazil. Information was collected on (1) characteristics of the participants; (2) the concept of bruxism; (3) diagnosis; (4) associated factors; (5) strategies for the management of SB; and (6) updated knowledge on bruxism in children. The data were analysed descriptively. RESULTS: Fifty-seven paediatric dentists participated (10.7% of the total number of professionals). A high level of agreement was found with statements on the concepts of SB (94.7%) and awake bruxism (96.5%). The main strategy for the diagnosis was the combination of a parental report and a clinical examination (79.0%). Most participants indicated that bruxism is associated with anxiety/stress (96.5%), screen use (93%), airway obstruction (91.2%), and sleep apnoea (91.2%). In suspected cases of bruxism, the dentists would send the child for assessment by other health care providers (87.7%). The management options frequently indicated were the use of an occlusal splint, aromatherapy, and homeopathy. More than 70% of them considered themselves to be updated on the issue and sought information through scientific articles and discussions with colleagues. CONCLUSION: Paediatric dentists have knowledge on the concept of bruxism and associated factors. However, further information is needed on the management of this condition in children.

Exploring the Impact of External Facilitation Using Evidence-Based Implementation Strategies for Increasing Motivational Interviewing Capacity Among Outpatient Substance Use Disorder (SUD) Treatment Providers.

The large majority of individuals who access substance use disorders (SUD) treatment do not receive evidence-based care. Little attention has been paid to the notion that the scale-up of evidence-based practices (EBPs) has been limited in large part due to a weakness in the "distribution system" for bringing new innovations to the attention of practitioners and into practice settings. This study explores the impact of the Training and Practice Implementation Institute (TPII; funded by the New York City Department of Health and Mental Hygiene), an intensive technical assistance initiative that offers external facilitation to outpatient SUD treatment providers via the incorporation of multiple evidence-based implementation strategies to enhance the practice of motivational interviewing (MI). Findings from this study show that staff completed a large majority (86%) of required training/technical assistance (TTA) activities across the 9-month implementation period, demonstrating a high level of engagement among staff and the feasibility of externally facilitated intensive TTA delivered to community-based organizations for the purpose of enhancing implementation of MI for SUDs. Results also show statistically significant improvements in the delivery of MI's technical components among staff, though did not reveal corresponding improvements in the delivery of MI's relational components. An understanding of the potential return on investment associated with externally facilitated TA, offers organizations an opportunity to inform the allocation of limited resources to areas where they will have the greatest impact and ultimately improve the quality and efficacy of services.

[Algorithm for securing an unexpected difficult airway : User analysis on a simulator]. / Algorithmus zur Sicherung des unerwartet schwierigen Atemwegs : Eine Anwenderanalyse am Simulator.

BACKGROUND: Critical incidents in difficult airway management are still a main contributory factor for perioperative morbidity and mortality. Many national associations have developed algorithms for management of these time critical events. For implementation of these algorithms the provision of technical requirements and procedure-related training are essential. Severe airway incidents are rare events and clinical experience of the individual operators is limited; therefore, simulation is an adequate instrument for training and evaluating difficult airway algorithms. OBJECTIVE: The aim of this observational study was to evaluate the application of the institutional difficult airway algorithm among anesthetists. MATERIAL AND METHODS: After ethics committee approval, anesthetists were observed while treating a "cannot intubate" (CI) and a "cannot intubate, cannot ventilate" (CICV) situation in the institutional simulation center. As leader of a supportive team the participants had to deal with an unexpected difficult airway after induction of anesthesia in a patient simulator. The following data were recorded: sequence of the applied airway instruments, time to ventilation after establishing a secured airway using any instrument in the CI situation and time to ventilation via cricothyrotomy in the CICV situation. Conformity to the algorithm was defined by the sequence of the applied instruments. Analysis comprised conformity to the algorithm, non-parametric tests for time to ventilation and differences between junior and senior anesthetists. RESULTS: Out of 50 participants 45 were analyzed in the CI situation. In this situation 93% of the participants acted in conformity with the algorithm. In 62% the airway was secured by flexible intubation endoscopy, in 38% with another device. Data from 46 participants were analyzed in the CICV situation. In this situation 91% acted in conformity with the algorithm. The last device used prior to the decision for cricothyrotomy was flexible intubation endoscopy in 39%, a laryngeal mask in 22% and other instruments in 39%. Of the 50 participants 38 had already been institutionally trained in difficult airway management during the previous 2 years. For cricothyrotomy the participants needed a median time of 63 s and there was no difference between junior and senior anesthetists (p = 0.46). The cricothyrotomy was performed faster using a surgical approach than a transtracheal puncture approach using a Melker emergency cricothyrotomy set (52 s vs. 73 s, p = 0.014). CONCLUSION: The conformity to the algorithm of over 90% indicates a good training level of the participants concerning the difficult airway algorithm. In the observed sample flexible intubation endoscopy tended to be of high significance even in the unanticipated difficult airway. Cricothyrotomy was performed faster surgically than by the use of the transtracheal puncture approach, while no differences between junior and senior anesthetists were observed. For the successful management of an unexpected difficult airway, specific training of these special and rare events is crucial. A standardized provision of special airway instruments stored in a special trolley and frequent application of this trolley in the clinical routine is recommended.

Anthrax vaccine. Model of a response to the biologic warfare threat.

Anthrax vaccine is being administered to all 2.4 million active duty, reserve, and National Guard troops, as prophylaxis against biologic warfare. The vaccine's effectiveness in this setting may be limited. This article discusses unresolved issues of safety, with an emphasis on the need for careful surveillance of vaccines used by the military, which has sidestepped the commercial process. Also considered are ethical issues related to the development and use of military biologics, as the United States Army advances its Joint Vaccine Acquisition Program, a plan to produce more than ten vaccines specifically for biologic warfare threat, and to administer them to all military servicemembers.

The fission yeast UVDR DNA repair pathway is inducible.

In addition to nucleotide excision repair (NER), the fission yeast Schizosaccharomyces pombe possesses a UV damage endonuclease (UVDE) for the excision of cyclobutane pyrimidine dimers and 6-4 pyrimidine pyrimidones. We have previously described UVDE as part of an alternative excision repair pathway, UVDR, for UV damage repair. The existence of two excision repair processes has long been postulated to exist in S.pombe, as NER-deficient mutants are still proficient in the excision of UV photoproducts. UVDE recognizes the phosphodiester bond immediately 5'of the UV photoproducts as the initiating event in this process. We show here that UVDE activity is inducible at both the level of uve1+ mRNA and UVDE enzyme activity. Further, we show that UVDE activity is regulated by the product of the rad12 gene.

A human homolog of the Schizosaccharomyces pombe rad9+ checkpoint control gene.

The product of the Schizosaccharomyces pombe rad9+ gene is required for cell cycle arrest at the G2 checkpoints in response to incompletely replicated or damaged DNA. We have identified a human cDNA from an infant brain library that is a structural homolog of S. pombe rad9+, by searching the dBest data base for sequences similar to the fission yeast gene. The human gene encodes a 391-amino acid long, 42,520-Da protein that is approximately 25% identical and 52% similar to the yeast protein. The human and yeast gene products demonstrate partial conservation of function, as the human cDNA can rescue to different degrees the sensitivity of S. pombe rad9::ura4+ cells to the DNA synthesis inhibitor hydroxyurea and gamma rays, as well as the associated checkpoint controls. These results suggest an underlying conservation of the molecular mechanisms of S and G2 checkpoint control pathways in most if not all eukaryotes. Fluorescence in situ hybridization using a fragment of the corresponding human genome as a probe, in conjunction with PCR reactions employing DNA from human X rodent somatic cell hybrids, has localized the gene to human chromosome 11q13.1-13.2. This region contains a number of tumor suppressor loci, and based on the biology of checkpoint control genes, HRAD9 should be considered a strong candidate for one of them.

Family practice in Saudi Arabia: chronic morbidity and quality of care.

Over a one-year period, 2990 patients attended a primary health care practice in urban Riyadh, Saudi Arabia. Of these, 33.5% had chronic disorders. Clinically significant obesity (BMI > 29.9 Kg/m2) was present in 24.5% of those with chronic disorders. Musculoskeletal disorders, diabetes mellitus (DM), digestive disorders and cardiovascular disease accounted for 38%, 36%, 24% and 22% of encounters respectively. Uncontrolled DM was encountered in 7.1% while uncontrolled systolic hypertension was present in 28.8% of patients with these disorders. A significant proportion (42%) of patients with bronchial asthma required emergency management. Symptomatic relief was obtained in 57% of patients with irritable bowel and 87% of patients with osteoarthritis of the knees. The results point to a trend of morbidity similar to that encountered in developed nations with affluence and sedentary life style. There is a need to focus on obesity, life style measures that reduce weight would be expected to positively influence diabetes, hypertension and osteoarthritis of the knees. Monitoring of outcome measures would help identify areas of improvement and preventive measures.

Precise sequence assignment of replication origin in the control region of chick mitochondrial DNA relative to 5' and 3' D-loop ends, secondary structure, DNA synthesis, and protein binding.

The data reported identify for the first time the sequence of an avian mitochondrial heavy-strand replication origin, OH, located only about 12 nucleotides (nt) downstream from the conserved sequence block CSB-1, as well as the sequence of premature synthesis arrest of the 781 (+/-1) nt D-loop strand, only 6-7 nt downstream from a TAS-like (termination-associated) element. Both sites are associated with putative cruciform secondary structures. A major sequence-specific DNA-binding/cleavage site of a potential regulatory protein, the approximately 36-kDa aMDP1 (shown previously to stimulate mtDNA synthesis), is located about 90 nt upstream of OH. Correlated in vivo analysis of avian genome-length mtDNA replication provides missing evidence on the functional equivalence of D-loop origin with nascent initiation, and on the direction, asymmetry and temporal aspects of a full round of replication. The importance of the results to understanding the regulation of linked replication/transcription and the unusual sequence evolution of avian mtDNA is

A new chick mitochondrial DNA-binding protein exhibits sequence-specific interaction near heavy-strand replication origin: cleavage activity, stimulation of mtDNA synthesis, and enhancement in transformed fibroblasts.

We have identified a new, double-strand-dependent, mtDNA-binding protein in chick embryo fibroblast (CEF) mitochondria (and inner-membrane-matrix preparations) which demonstrates both an exclusive specific affinity for the displacement loop (D-loop) control region of chick mtDNA and intramitochondrial levels that reflect corresponding changes in mtDNA replication activity both in vivo and in vitro. This approximately 36 kDa protein (designated aMDP1, avian mitochondrial DNA-binding protein 1) was identified by elution and renaturation following SDS-polyacrylamide gel electrophoresis and by direct isolation from specific mtDNA-protein complexes excised from mobility shift gels. Analysis of the entire 16.7-kb mt genome determined that a MDP1 mediates cleavage of chick mtDNA in vitro at three H- and two L-strand sequence-specific target sites located within a 90-bp A + T-rich genomic tract, theoretically capable of forming stable secondary structures, approximately 200 bases upstream from the H-strand origin (OH) of replication. Furthermore, gel-isolated aMDP1 relaxes supercoiled mtDNA, and exogenous addition of the protein, in a permeabilized in vitro system, preferentially stimulates the synthesis of H-strand sequences which hybridize to OH-containing fragments. Oncogenic transformation of CEF by Rous sarcoma viruses results in a threefold elevated level of aMDP1, directly correlating with a similarly increased level of mtDNA replication in vivo. Heterologous chick-human cross-competition experiments showed that aMDP1 also selectively interacts with human (HeLa) D-loop region mtDNA, possibly reflective of an evolutionary importance for aMDP1 interaction in the region. Functionally, we hypothesize that aMDP1 may operate in conjunction with other mtDNA-binding proteins, important in replication and transcription, by potentiating duplex unwinding either prior to or during an initial stage of H-strand synthesis. Together, these results suggest that aMDP1 is a good potential candidate for a nucleus-encoded regulatory protein which communicates with the mt genome during the replication process.

Analysis of methylglyoxal bis(guanylhydrazone)-induced alterations of hamster tumor mitochondria by correlated studies of selective rhodamine binding, ultrastructural damage, DNA replication, and reversibility.

Because of the renewed importance of methylglyoxal bis(guanylhydrazone) (MGBG) in recent clinical trials for a variety of cancers, and because the antiproliferative activity of MGBG cannot be accounted for exclusively by the known inhibition by the drug of polyamine biosynthesis, but is thought to involve an alternative action in which the mitochondria are implicated, we have investigated several new aspects of the nature and reversibility of this mitochondrial damage. Using Rous sarcoma hamster tumor cells as a model, treatment of monolayer cultures during exponential growth with 10, 25, and 50 microM MGBG (up to 48 hr) resulted in dose-dependent (reversible) growth inhibition and selective ultrastructural damage to the mitochondria (e.g., extreme swelling, loss of cristae and matrix components, and dense inclusions) in up to 96% of cells, while nuclei appeared normal, corroborating and extending findings by others in mouse, rat, and human cells. Mitochondria in 3 to 5% of cells failed to swell, even at highest drug dosage, but were of unusual structure. After removal of MGBG, damaged mitochondria in 90 to 95% of cells recovered near-normal ultrastructure within 1 to 2 days; in some cells, mitochondrial recovery from severe damage could be monitored following a lag period of up to 5 days. The potential-dependent, supravital fluorescent probe rhodamine 123 (RH 123) selectively and relatively uniformly stained the grossly enlarged mitochondria, strikingly delineating residual organelle membranes. Quantitative assays of the uptake and retention of RH 123/10(6) cells demonstrated the maintenance of mitochondrial membrane potential in both control and MGBG-treated cell populations. These data also support the concept of mitochondrial fusion in MGBG-treated cells. The fate of mitochondrial DNA (mtDNA) both during (24 to 48 hr) and following (7 hr to 7 days) MGBG treatment was monitored by ultrastructural, electron autoradiographic, pulse-labeling, gradient centrifugation, restriction cleavage, and electrophoretic methods. MGBG treatment (50 microM; 7 and 16 hr) selectively inhibited mtDNA replication (73% at 16 hr) prior to significant inhibition of nuclear DNA synthesis (19% at 16 hr); the drug induced structural alterations, without substantial degradation, of the closed circular (major form) of mtDNA, and cessation of D-loop strand (7S) initiation within the replication origin. Upon return to drug-free medium, mtDNA resumed replicative activity, and mtDNA fibrils appeared to be associated with regenerating cristae, as assessed by electron microscopy. The combined results demonstrate mitochondria to be a selective target of MGBG action, and define structu

The effect of retroviral transformation on DNA replication and DNA polymerase-gamma activity in chick embryo fibroblast mitochondria.

The effect of transformation by oncogenic Rous sarcoma viruses on the replication of mitochondrial DNA (mtDNA) in chick embryo fibroblasts (CEF) was investigated, extending our previous report of a three- to five-fold increase in the rate of mtDNA replication, which is strictly linked to the expression of the transformed state, is mitochondria-specific, and is not attributable to virus production per se or different growth rates between normal and transformed CEF. In this paper, in vivo pulse-label and pulse-chase analysis shows an increased specific activity in all the replicative and topological forms of transformed cell mtDNA I, labeled within a 10-min pulse, 30-min chase period, reflecting about the same proportion of total label incorporated into D-loop strands (approximately 9S) relative to full-length closed circular forms (approximately 37S) of mtDNA from both cell types. In contrast to the concomitant changes observed in many other systems with elevated DNA synthesis, neither the estimated intramitochondrial pool size of the labeled DNA precursor (dTTP), nor the total level of the mtDNA-replicating enzyme (mt gamma-polymerase) is increased in the transformed cells. Notably, however, in both cell types the mitochondrial dTTP pools relative to the mtDNA complement are significantly larger than whole-cell pools relative to the nuclear DNA complement, confirming recent reports in HeLa cells. The solubilized mt gamma-polymerases from normal and transformed CEF, respectively, are both precipitated by 50% ammonium sulfate, inhibited by N-ethylmaleimide, have similar sedimentation coefficients, and exhibit optimal activity when poly(rA) . d(pT)10 is used as the template-primer. On the other hand, the transformed cell enzyme demonstrates an altered response to thiol compounds, a decreased tendency to aggregate during sedimentation, and is significantly less tightly attached to the mitochondria than the normal cell enzyme. We conclude that, as a result of transformation, an increased fraction of mtDNA molecules replicate at a given time, and that this increased replication rate in vivo is correlated with the expression of several altered endogenous properties, which possibly include a modified intramitochondrial structural attachment of the mt gamma-polymerase in situ. This experimental system may be well suitable for use in the identification of regulatory factors which function during the replication of the mitochondrial genome in vivo.

Restriction map of Chinese hamster mitochondrial DNA containing replication coordinates: comparison with Syrian hamster mitochondrial genome.

A precise physical map, containing the structurally and operationally defined D-loop origin, terminal region, and direction of heavy-strand replication, has been constructed for mitochondrial DNA (mtDNA) from ovary (CHO-KI) and lung cells of Chinese hamster (Cricetulus griseus, 2 N = 22), and compared with our previously established genome coordinates for mtDNA from Syrian hamster (Mesocricetus auratus, 2 N = 44). All four HpaI sites in Cricetulus are conserved in Mesocricetus (8 sites). Extensive variation exists for hexanucleotides cleaved by EcoRI, HindIII, PstI, KpnI and BamHI. Sequence divergence between Chinese and Syrian hamster mtDNAs, as reflected from analysis of the mapped recognition sites for these six endonucleases, is estimated as 5-9% base substitutions. mtDNAs from both hamster and several other mammalian species contain a commonly conserved HpaI site in the region of light strand initiation.

Restriction endonuclease analysis of mitochondrial DNA from virus-transformed, tumor and control cells of human, hamster and avian origin. Sequence conservation and intraspecific variation.

This study compares over 70 recognition sites for restriction endonucleases on mtDNAs from various control versus malignant cells, derived from Syrian hamster, chick embryo, viper and human cells, exhibiting a wide spectrum of cellular transformation and tumor histories. Agents for transformation in vitro and in vivo include Rous sarcoma viruses, simian virus 40, polyoma virus and adenovirus. The results show a striking intraspecific sequence homogeneity of different mtDNAs regardless of tissue origin and oncogenic history. mtDNA from human biopsy specimens of tumor versus pathologically normal areas yielded indistinguishable restriction cleavage patterns reflecting either the "wild-type' form (with seven restriction endonucleases) or, in one individual, a variant pattern detected with HpaI. The precise position of the HpaI variant site was determined on the physical map of human mtDNA. Additional cleavage sites in the previously reported restriction map of Syrian hamster mtDNA are also presented. It is concluded that (1) mtDNA sequence in higher animal cells are highly conserved in malignant transformation; (2) no evidence for integration of viral sequences in mtDNA is apparent; (3) variant patterns in mtDNA are likely to be intraspecific polymorphisms that pre-exist neoplastic transformation. The possibility is discussed that altered regulatory interaction with the mitochondrial genome, rather than evident changes in mtDNA primary structure, determine anomalous mitochondrial functions in malignant transformation.

A covalently bound photoisomerizable agonist: comparison with reversibly bound agonists at Electrophorus electroplaques.

After disulphide bonds are reduced with dithiothreitol, trans-3- (alpha-bromomethyl)-3'-[alpha- (trimethylammonium)methyl]azobenzene (trans-QBr) alkylates a sulfhydryl group on receptors. The membrane conductance induced by this "tethered agonist" shares many properties with that induced by reversible agonists. Equilibrium conductance increases as the membrane potential is made more negative; the voltage sensitivity resembles that seen with 50 [mu]M carbachol. Voltage- jump relaxations follow an exponential time-course; the rate constants are about twice as large as those seen with 50 muM carbachol and have the same voltage and temperature sensitivity. With reversible agonists, the rate of channel opening increases with the frequency of agonist-receptor collisions: with tethered trans-Qbr, this rate depends only on intramolecular events. In comparison to the conductance induced by reversible agonists, the QBr-induced conductance is at least 10-fold less sensitive to competitive blockade by tubocurarine and roughly as sensitive to "open-channel blockade" bu QX-222. Light-flash experiments with tethered QBr resemble those with the reversible photoisomerizable agonist, 3,3',bis-[alpha-(trimethylammonium)methyl]azobenzene (Bis-Q): the conductance is increased by cis {arrow} trans photoisomerizations and decreased by trans {arrow} cis photoisomerizations. As with Bis-Q, ligh-flash relaxations have the same rate constant as voltage-jump relaxations. Receptors with tethered trans isomer. By comparing the agonist-induced conductance with the cis/tans ratio, we conclude that each channel's activation is determined by the configuration of a single tethered QBr molecule. The QBr-induced conductance shows slow decreases (time constant, several hundred milliseconds), which can be partially reversed by flashes. The similarities suggest that the same rate-limiting step governs the opening and closing of channels for both reversible and tethered agonists. Therefore, this step is probably not the initial encounter between agonist and receptor molecules.