Low Level Laser Effects On Pain to Palpation and Electromyographic Activity in TMD Patients: A Double-Blind, Randomized, Placebo-Controlled Study

The purpose of this study was to evaluate the effect of diode laser (GaAlAs - 780 nm) on pain to palpation and electromyographic (EMG) activity of the masseter and anterior temporalis muscles. The laser was applied on the temporalis and masseter muscles twice a week (four weeks). Forty-eight (48) patients with myofascial pain were randomly assigned between actual and placebo treatments and between the energetic doses of 25 J/cm(2) and 60 J/cm(2), and were evaluated using VAS before, immediately after the final application, and 30 days after the laser treatment. Surface electromyography was performed with maximum dental clenching before and after laser therapy. The results show there were no significant statistical differences in the EMG activity between the groups before and after laser treatment. With regard to the pain at palpation, although both groups presented a significant difference in the symptoms before and after the treatment, only the active doses showed statistically significant reductions in pain level in all the regions of the palpated muscles. However, there was no significant statistical difference between groups (experimental and placebo). In conclusion, low level laser did not promote any changes in EMG activity. The treatment did, however, lessen the pain symptoms in the experimental groups.

Effects of the domestic use of a disclosing solution on the denture biofilm: a preliminary study

To investigate the effect of the home use of a disclosing agent on the microbial composition of denture biofilm, by means of a cross-over randomized clinical trial. Two interventions were tested during 7 days each: (i) oral and denture hygiene instructions and (ii) instructions associated with the home use of a disclosing agent (1% neutral red). Eleven participants with visible biofilm deposits over their maxillary complete dentures were randomly assigned to one of the two sequences of interventions: (i) I followed by II, and (ii) II followed by I. A washout period of 7 days was established. After each intervention, samples of denture biofilm were evaluated by DNA checkerboard hybridization for the detection of Candida spp. and 17 bacterial species. Counts were low for all the tested species, and no significant difference was found between the tested interventions ( Wilcoxon test, P > 0.05). The home use of a disclosing agent does not remarkably change the composition of denture biofilm.

Ultrastructure and small-subunit ribosomal DNA sequence of Henneguya lesteri n. sp (Myxosporea), a parasite of sand whiting Sillago analis (Sillaginidae) from the coast of Queensland, Australia

Henneguya lesteri n. sp, (Myxosporea) is described from sand whiting, Sillago analis, from the southern Queensland coast of Australia. H. lesteri displays a preference for the pseudobranchs and is typically positioned along the afferent blood vessels, displacing the adjoining lamellae and disrupting their normal array, The plasmodia appeared as whitish-hyaline, elliptical cysts (mean dimensions 230 x 410 mum) attached to the oral mucosa lining of the hyoid arch on the inner surface of the operculum. Infections of the gills were also found, in which the plasmodia were spherical, averaged 240 x 240 mum in size and were located on the inner hemibranch margin. The parasites lodged in the gill filament crypts and generated a mild hyperplastic response of the branchial epithelium, In histological sections, the plasmodium wall and adjoining ectoplasm appeared as a finely granulated, weakly eosinophilic layer, Ultrastructurally, this section of the host-parasite interface contained an intricate complex of pinocytotic channels. H. lesteri is polysporic, disporoblastic and pansporoblast forming. Sporogenesis is asynchronous, with the earliest developmental stages aligned predominantly along the plasmodium periphery, and maturing sporoblasts and spores toward the center. Ultrastructural details of sporoblast and spore development are in agreement with previously described myxosporeans. The mature spore is drop-shaped, length (mean) 9.1 mum, width 4.7 mum, thickness 2.5 mum, and comprises 2 polar capsules positioned closely together, a binucleated sporoplasm and a caudal process of 12.6 mum. The polar capsules are elongated, 3.2 x 1.6 mum, with 4 turns of the polar filament. Mean length of the everted filament is 23.2 mum, Few studies have analyzed the 18S gene-of marine Myxosporea. In fact, H. lesteri is the first marine species of Henneguya to be characterized at the molecular level: we determined 1966 bp of the small-subunit (18S) rDNA, The results indicated that differences between this and the hitherto studied freshwater Henneguya species are greater than differences among the freshwater Henneguya species.

Efficiency of delivery of DNA to cells by bovine papillomavirus type-1 L1/L2 pseudovirions

To investigate the efficiency of encapsidation of plasmid by papillomavirus virus-like particles (PV VLPs), and the infectivity of the resultant PV pseudovirions, Cos-1 cells were transfected with an 8-kb plasmid incorporating a green fluorescent protein (GFP) reporter gene (pGSV), and infected with bovine PV (BPV-1) L1/L2 recombinant vaccinia virus to produce BPV1 pseudovirions. Approximately 1 in 1.5x10(4) of dense (1.35 g/ml) PV pseudovirions and 0.3 in 10(4) Of less-dense (1.29 g/ml) pseudovirions packaged an intact pGSV plasmid. The majority (>75%) of packaged plasmids contained deletions, and the deletions affected all tested genes. After exposure of Cos-1 cells to BPV-1 pseudovirions at an MOI of 40,000:1, 6% of cells expressed GFP giving a calculated efficiency of delivery of the pGSV plasmid, by pseudovirions which had packaged an intact plasmid, of approximately 5%. Plasmid delivery was not effected by purified pGSV plasmid, was blocked by antiserum against BPV-1, and was not blocked by DNase treatment of pseudovirions, confirming that delivery was mediated by DNA within the pseudovirion. We conclude that a major limitation to the use of PV pseudovirions as a gene delivery system is that intact plasmid DNA is not efficiently selected for packaging by VLPs in cell-based pseudovirions production systems.

Application of DNA microarrays to study human alcoholism

An emerging idea is that long-term alcohol abuse results in changes in gene expression in the brain and that these changes are responsible at least partly for alcohol tolerance, dependence and neurotoxicity, The overall goal of our research is to identify genes which are differentia[ly expressed in the brains of well-characterized human alcoholics as compared with non-alcoholics. This should identify as-yet-unknown alcohol-responsive genes, and may well confirm changes in the expression of genes which have been delineated in animal models of alcohol abuse. Cases were carefully selected and samples pooled on the basis of relevant criteria; differential expression was monitored by microarray hybridization. The inherent diversity of human alcoholics can be exploited to identify genes associated with specific pathological processes, as well as to assess the effects of concomitant disease, severity of brain damage, drinking behavior, and factors such as gender and smoking history. initial results show selective changes in gene expression in alcoholics; of particular importance is a coordinated reduction in genes coding for myelin components, Copyright (C) 2001 National Science Council, ROC and S. Karger AG, Basel.

DNA adducts as a biomarker of polycyclic aromatic hydrocarbon exposure in aquatic organisms: relationship to carcinogenicity

The use of DNA adduct measurement as a biomarker of exposure to polycyclic aromatic hydrocarbons (PAHs) is now well established in ecotoxicology. In particular, DNA adduct levels in aquatic organisms has been found to produce a better correlation with PAH exposure than PAH concentrations in organisms. DNA adducts levels are most commonly determined using the P-32-postlabelling assay which measures total aromatic adducts. The relationship between relative DNA adduct formation and carcinogenicity has been investigated for a number of carcinogenic and non-carcinogenic PAHs using an in vitro system. Our results demonstrate that relatively high levels of DNA adducts can be produced by some non-carcinogenic PAHs, while other non-carcinogenic compounds do not produce detectable adducts. In addition, it has been shown that all carcinogenic PAHs investigated produce DNAadducts and that a relationship exists between relative adduct formation and carcinogenic potency. An investigation of adduct levels in fish liver and crustacean hepatopancreas in Oxley Ck, Brisbane has shown that higher than expected DNA adduct levels were correlated with the presence of carcinogenic and noncarcinogenic PAHs with high relative adduct forming potential.

UV-induced hyperphosphorylation of replication protein a depends on DNA replication and expression of ATM protein

Exposure to DNA-damaging agents triggers signal transduction pathways that are thought to play a role in maintenance of genomic stability. A key protein in the cellular processes of nucleotide excision repair, DNA recombination, and DNA double-strand break repair is the single-stranded DNA binding protein, RPA. We showed previously that the p34 subunit of RPA becomes hyperphosphorylated as a delayed response (4-8 h) to UV radiation (10-30 J/m(2)). Here we show that UV-induced RPA-p34 hyperphosphorylation depends on expression of ATM, the product of the gene mutated in the human genetic disorder ataxia telangiectasia (A-T). UV-induced RPA-p34 hyperphosphorylation was not observed in A-T cells, but this response was restored by ATM expression. Furthermore, purified ATM kinase phosphorylates the p34 subunit of RPA complex in vitro at many of the same sites that are phosphorylated in vivo after UV radiation. Induction of this DNA damage response was also dependent on DNA replication; inhibition of DNA replication by aphidicolin prevented induction of RPA-p34 hyperphosphorylation by UV radiation. We postulate that this pathway is triggered by the accumulation of aberrant DNA replication intermediates, resulting from DNA replication fork blockage by UV photoproducts. Further, we suggest that RPA-p34 is hyperphosphorylated as a participant in the recombinational postreplication repair of these replication products. Successful resolution of these replication intermediates reduces the accumulation of chromosomal aberrations that would otherwise occur as a consequence of UV radiation.

ATM, a central controller of cellular responses to DNA damage

Mutations in the ATM gene lead to the genetic disorder ataxia-telangiectasia. ATM encodes a protein kinase that is mainly distributed in the nucleus of proliferating cells. Recent studies reveal that ATM regulates multiple cell cycle checkpoints by phosphorylating different targets at different stages of the cell cycle. ATM also functions in the regulation of DNA repair and apoptosis, suggesting that it is a central regulator of responses to DNA double-strand breaks.

A DNA fingerprinting procedure for ultra high-throughput genetic analysis of insects

Existing procedures for the generation of polymorphic DNA markers are not optimal for insect studies in which the organisms are often tiny and background molecular Information is often non-existent. We have used a new high throughput DNA marker generation protocol called randomly amplified DNA fingerprints (RAF) to analyse the genetic variability In three separate strains of the stored grain pest, Rhyzopertha dominica. This protocol is quick, robust and reliable even though it requires minimal sample preparation, minute amounts of DNA and no prior molecular analysis of the organism. Arbitrarily selected oligonucleotide primers routinely produced similar to 50 scoreable polymorphic DNA markers, between individuals of three Independent field isolates of R. dominica. Multivariate cluster analysis using forty-nine arbitrarily selected polymorphisms generated from a single primer reliably separated individuals into three clades corresponding to their geographical origin. The resulting clades were quite distinct, with an average genetic difference of 37.5 +/- 6.0% between clades and of 21.0 +/- 7.1% between individuals within clades. As a prelude to future gene mapping efforts, we have also assessed the performance of RAF under conditions commonly used in gene mapping. In this analysis, fingerprints from pooled DNA samples accurately and reproducibly reflected RAF profiles obtained from Individual DNA samples that had been combined to create the bulked samples.

Coupling between replication and packaging of flavivirus RNA: Evidence derived from the use of DNA-based full-length cDNA clones of kunjin virus

In order to study whether flavivirus RNA packaging is dependent on RNA replication, we generated two DNA-based Kunjin virus constructs, pKUN1 and pKUN1dGDD, allowing continuous production of replicating (wild-type) and nonreplicating (with a deletion of the NS5 gene RNA-polymerase motif GDD) full-length Kunjin virus RNAs, respectively, via nuclear transcription by cellular RNA polymerase II. As expected, transfection of pKUN1 plasmid DNA into BHK cells resulted in the recovery of secreted infectious Kunjin virions. Transfection of pKUN1dGDD DNA into BHK cells, however, did not result in the recovery of any secreted virus particles containing encapsidated dGDD RNA, despite an apparent accumulation of this RNA in cells demonstrated by Northern blot analysis and its efficient translation demonstrated by detection of correctly processed labeled structural proteins (at least prM and E) both in cells and in the culture fluid using coimmunoprecipitation analysis with anti-E antibodies. In contrast, when dGDD RNA was produced even in much smaller amounts in PKUN1dGDD DNA-transfected repBHK cells (where it was replicated via complementation), it was packaged into secreted virus particles, Thus, packaging of defective Kunjin virus RNA could occur only when it was replicated. Our results with genome-length Kunjin virus RNA and the results with poliovirus replicon RNA (C, I. Nugent et al,, J, Virol, 73:427-435, 1999), both demonstrating the necessity for the RNA to be replicated before it can be packaged, strongly suggest the existence of a common mechanism for minimizing amplification and transmission of defective RNAs among the quasispecies in positive-strand RNA viruses, This mechanism may thus help alleviate the high-copy error rate of RNA-dependent RNA polymerases.

Randomized controlled trial of two cigarette quit programmes in coronary care patients after acute myocardial infarction

Background: Tobacco cessation after acute myocardial infarction (AMI) substantially improves outcome but how effective individual programmes are needs to be established. To date, few studies have examined this factor. Aims: To assess the outcome of two smoking cessation programmes after AMI. Methods: One hundred and ninety-eight current smokers admitted to coronary care with an AMI participated in a randomized controlled study comparing two outpatient tobacco interventions, the Stanford Heart Attack Staying Free (SF) programme and a Usual Care (UC) programme. Results: Log-rank analyses revealed that patients in the SF programme were retained longer (P < 0.001) and had higher cotinine validated abstinence rates (P < 0.001) compared with patients in the UC programme. Twelve months after intervention, 39% of the SF programme compared with 2% of the UC programme demonstrated cotinine validated tobacco cessation, representing a significant reduced relapse rate in the SF programme (chi (2), P < 0.001). Conclusions: The SF smoking cessation programme initiated in hospital can significantly reduce smoking rates at 12 months after myocardial infarction. Although superior to the UC quit programme, Australian outcomes were lower than the American programme originators' published outcomes.

A cost-minimization analysis of the societal costs of realtime teledermatology compared with conventional care: results from a randomized controlled trial in New Zealand

A randomized controlled trial was carried out to measure the societal costs of realtime teledermatology compared with those of conventional hospital care in New Zealand. Two rural health centres were linked to a specialist hospital via ISDN at 128 kbit/s. Over 10 months, 203 patients were referred for a specialist dermatological consultation and 26 were followed up, giving a total of 229 consultations. Fifty-four per cent were randomized to the teledermatology consultation and 46% to the conventional hospital consultation. A cost-minimization analysis was used to calculate the total costs of both types of dermatological consultation. The total cost of the 123 teledermatology consultations was NZ$34,346 and the total cost of the 106 conventional hospital consultations was NZ$30,081. The average societal cost of the teledermatology consultation was therefore NZ$279.23 compared with NZ$283.79 for the conventional hospital consultation. The marginal cost of seeing an additional patient was NZ$135 via teledermatology and NZ$284 via conventional hospital appointment. From a societal viewpoint, and assuming an equal outcome, teledermatology was a more cost-efficient use of resources than conventional hospital care.