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Notes: Abstract The discrimination of species of the copepod genus, Calanus (Copepoda; Calanoida), is problematical-especially in regions of sympatry. Although the species of Calanus exhibit exceptional morphological similarity, they are quite distinct in genetic character. The DNA base sequences of the mitochondrial large subunit (16S) ribosomal RNA (rRNA) gene unambiguously discriminated C. finmarchicus (Gunnerus 1765), C. glacialis (Jaschnov 1955), C. marshallae (Frost 1974), C. helgolandicus (Claus 1863), C. pacificus (Brodsky 1948), C. sinicus (Brodsky 1965), and C. hyperboreus (Kroyer 1838). Sequence differences among Calanus species for this gene portion range from 7.3% (between C. glacialis and C. marshallae) to 23.9% (between C. glacialis and C. sinicus). Differences among conspecific individuals were approximately 1 to 2%. [These sequence data were determined between April and November 1993; the sequenced domain is similar to that published previously in Bucklin et al. (1992) but are derived from analysis of additional individuals.] Statistical analysis of the sequence data using a variety of tree-building algorithms separated the taxa into one group of species corresponding to the C. finmarchicus group (C. finmarchicus, C. marshallae, and C. glacialis) and another ungrouped set of species corresponding to the C. helgolandicus group (C. helgolandicus, C. pacificus, and C. sinicus). The C. helgolandicus group may be older than the C. finmarchicus group, making the tree topology less reliable in this area. Calanus hyperboreus was an outlier; Nannocalanus minor (Claus 1863) was the outgroup. Similar analysis of Metridia species confirmed that M. lucens (Boeck 1864) and M. pacifica (Brodsky 1948) are distinct species; M. longa (Lubbock 1854) was still more divergent. These sequence data will allow the design of simple, molecular tools for taxonomic identifications. Diagnostic characters, assayed by rapid molecular protocols, will enable biological oceanographers to answer important questions about the distribution and abundance of all life stages (as well as patterns of reproduction) of morphologically similar species, such as those of Calanus.

Notes: Abstract In the absence of reliable morphological characters, or in conjunction with morphology-based identifications, meiofaunal turbellarians may also be identified using the nucleotide sequence of a portion of the large subunit of the ribosomal RNA (26/28S rRNA). A 284 base pair-long region of the 26/28S rRNA has been identified by isolating genomic DNA from ten species of turbellarians belonging to four orders, namely, the Proseriata, Macrostomida, Prolecithophora and Acoela. The proseriates had been collected from localities in Europe and Israel and were preserved in ethanol. The remaining turbellarians were isolated from intertidal sediment samples collected from two sites on the Maine and New Hampshire coast, USA in 1992. Amplification of the genomic DNA was carried out using two primers designed to match the nucleotide sequence of a portion of the 26/28S rDNA gene of the terrestrial nematode,Caenorhabditis elegans (Maupas 1900). This area consists of a highly variable, about 150 base pair-long region, called the D3 expansion segment, followed by a very conserved stretch of sequence. When folded into its secondary structure, the conserved region will form stem structures that correspond to helices 15 to 18 of theC. elegans structural model. The sequence alignment program PILEUP was used to perform a cluster analysis (unweighted pair group method using arthmetic averages, UPGMA) on the sequences. This analysis revealed that the helices allow for the classification of the turbellarians at the level of families and above, whereas if the D3 expansion segment itself was included in the analysis, intrageneric and intraspecific groupings could be established.

Notes: Abstract The physical uniformity of the deep sea suggests a lack of absolute barriers to faunal dispersal, and thus genetic homogeneity in broadly distributed species is expected. The deep-sea amphipod Eurythenes gryllus Lichtenstein (Crustacea: Lysianassoidea) is considered a panoceanic, cold-water stenotherm, with a vertical depth distribution from 184 to 6500 m. We surveyed mtDNA sequence diversity in E. gryllus to assess genetic diversity and population structure in different oceans and across traditionally defined bathyal and abyssal zones. DNA sequences (437 nucleotides length) from the mitochondrial large-subunit ribosomal RNA gene (16S rRNA) of 95 individuals, collected between 1982 and 1990 from 14 locations in the central North Pacific (including multiple samples on the slope of a seamount), castern and western North Atlantic, and the Arctic Ocean, were obtained. Our analysis of DNA sequence diversity indicates (1) genetic homogeneity among sites within the same depth zone at the scale of ocean basins; and (2) genetically divergent, cryptic taxa distributed at different depths, with the greatest diversity in the bathyal zone. These observations suggest that ecological and physical conditions are important isolating mechanisms that may lead to speciation in this group.

Notes: The isolation of seven tri-, and 133 di-nucleotide microsatellite markers from a tilapia, Oreochromis niloticus, is described. An efficient methodology for isolating large numbers of such markers and their potential applications in applied aquaculture and evolutionary genetics are discussed.

Notes: Objectives: For various clinical applications, polyhexamethylene biguanide (PHMB) has been used for many years as an antiseptic in medicine. Little is known, however, of its antibacterial activity in the oral cavity and its ability to inhibit plaque formation. In this study, a 0.04% PHMB mouthrinse (A) was compared with a negative control placebo rinse (10% ethanol, flavour) (B) and 2 positive control chlorhexidine rinses, one of which was a 0.12% aqueous solution (C) and the other a commercially available mouthrinse (Skinsept® mucosa) diluted to a chlorhexidine concentration of 0.12% (D).Material and Methods: The study was a double-blind, randomised 4-replicate 4×4 Latin square cross-over design. Plaque regrowth was assessed with the Turesky et al. modification of the Quigley and Hein plaque index. The in vivo antibacterial effect was assessed by taking bacterial counts from the tooth surface (smears from the lingual surface of 16) and mucosa (smears from the buccal mucosa) 4 h after the 1st rinse with the preparations on day 1 and prior to the clinical examination on day 5. 16 volunteers participated, and on day 1 of each study period were rendered plaque-free, ceased toothcleaning, and rinsed 2× daily with the allocated mouthrinse. On day 5, plaque was scored and smears were collected according to the protocol. Washout periods were 9 days. Data were analysed using ANOVA with Tukey HSD adjustment for multiple comparisons (significance level α=0.05).Results: Mouthrinses A, C, and D were significantly more effective in inhibiting plaque than the placebo (B). Mouthrinse C was significantly better than mouthrinses A and D, while mouthrinses D and A were equally effective in inhibiting plaque. Bacterial count reductions on the tooth surface with mouthrinse C were significantly greater compared to mouthrinse A and the placebo (B). The reduction of bacterial counts on the mucosa with C was significantly greater than with A and B after 4 h and significantly greater than with A, B and D after 5 days. Mouthrinse A reduced bacteria on the mucosa significantly more effectively than the placebo (B) after 4 h and 5 days, while mouthrinse D was more effective than the placebo (B) after 4 h.Conclusion: The results indicate that a 0.04% PHMB mouthwash inhibits plaque regrowth and reduces oral bacterial counts, and may be used in preventive applications in the oral cavity.

Notes: Background: In this study, risk determinants were determined for periodontal disease in the representative population sample (n=3146) of the Study of Health in Pomerania.Methods: After examining the net random sample (response 69%) and exclusion of edentulous cases and those with missing values, 2595 subjects remained. Using a multivariate, fully adjusted logistic regression, different definitions of “periodontally diseased/healthy” were examined as the dependent variable (extent of attachment loss (AL〈inlineGraphic alt="geqslant R: gt-or-equal, slanted" extraInfo="nonStandardEntity" href="urn:x-wiley:03036979:JCPE629:ges" location="ges.gif"/〉4 mm, combined AL and tooth loss). The independent variables used were sociodemographic factors (age, gender, income, education), medical factors (systemic diseases, drugs), behavioral factors (regular dental checkup, smoking), and oral factors (presence of supragingival calculus and plaque).Results: The following risk determinants were found for AL: male gender, presence of supragingival plaque and calculus, smoking, low educational level. For the combination of AL and tooth loss, risk determinants were female gender, supragingival plaque, smoking, and low educational level. Consumption of antiallergic medications and regular dental checkups proved to be protective. Smoking was the most influential risk determinant. These parameters explained approximately 43–55% of the variation.Conclusion: These results concur with those of the literature. In order to explain disease status further, host-response and microbiological factors must also be examined.

Notes: Aim: Benchmarking is a means of setting goals or targets. On an oral health level, it denotes retaining more teeth and/or improving the quality of life. The goal of this pilot investigation was to assess whether the data generated by a population-based study (SHIP 0) can be used as a benchmark data set to characterize different practice profiles.Material and Methods: The data collected in the population-based study SHIP (n=4310) in eastern Germany were used to generate nomograms of tooth loss, attachment loss, and probing depth. The nomograms included twelve 5-year age strata (20–79 years) presented as quartiles, and additional percentiles of the dental parameters for each age group. Cross-sectional data from a conventional dental office (n=186) and from a periodontology unit (n=130, Greifswald) in the study region as well as longitudinal data set of a another periodontology unit (n=135, Kiel) were utilized in order to verify whether the given practice profile was accurately reflected by the nomogram.Results: In terms of tooth loss, the data from the conventional dental office agree with the median from the nomogram. For attachment loss and probing depth, some age groups yielded slight but not uniform deviations from the median. Cross-sectional data from the periodontology unit Greifswald showed attachment loss higher than the median in younger but not in older age groups. The probing depth was uniformly less than the median and tended toward the 25th percentile with increasing age. The longitudinal data of the Unit of Periodontology in Kiel showed a pronounced trend towards higher percentiles of residual teeth, meaning that the patients retained more teeth.Conclusion: The profile of the Pomeranian dental office does not deviate noticeably from the population-based nomograms. The higher attachment loss of the Unit of Periodontology in Greifswald in younger age strata clearly reflects their selection because of periodontal disease; the combination of higher attachment loss and decreased probing depth may reflect the success of the treatment. The tendency of attachment loss towards the median with increasing age may indicate that the Unit of Periodontology in Greifswald does not fulfill its function as a special care unit in the older subjects. The longitudinal data set of the Unit of Periodontology in Kiel impressively reflects the potential of population-based data sets as a means for benchmarking. Thus, nomograms can help to determine the practice profile, potentially yielding benefits for the dentist, health insurance company, or – as in the case of the special care unit – public health research.

Notes: Background/aims: In a dummy-head trial, we assessed how effectively untrained operators were able to learn scaling with curettes and power-driven instruments.Methods: Two untrained operator groups (n = 11 each) received six 2-h lessons during a 10-week period following a training program. Subgingival scaling was performed with curettes (GRA) and a power-driven system (PP). At 6 test days each subject had to instrument 10 test teeth. The percentage of debrided area was assessed with an image analysis program. Learning success was measured as a percentage of debrided root area and scaling time. Furthermore, the effectivity was related to difficulty in anatomical situations and access to root surfaces. Statistical analysis was carried out with SPSS.Results: At baseline, effectivity was 63.1% (GRA) vs. 52.3% (PP). Between weeks 9 and 11, operators reached a plateau for group GRA at 84.7% and group PP at 81.3%. Scaling time did not differ between the two groups. Debridement of teeth with complex root shapes that were hard to access was less effective with the power-driven system.Conclusion: Independent of the instrument used, untrained operators were only able to debride root surfaces at low levels of efficacy. With systematical training, effective scaling with the power- driven system was as easy to learn as with hand instruments. On root surfaces with complicated shape and anatomy or difficult accessibility, the power-driven system works significantly less effectively.