High Plaque Levels after Thorough Toothbrushing: What Impedes Efficacy?

OBJECTIVES: Previous studies have shown high levels of dental plaque after toothbrushing and poor toothbrushing performance. There is a lack of evidence about what oral hygiene behavior predicts persistent plaque. The present cross-sectional study thus relates toothbrushing behavior to oral cleanliness after brushing and to gingivitis. METHODS: All young adults from a central town in Germany who turned 18 y old in the year prior to the examination were invited to participate in the study. They were asked to clean their teeth to their best abilities while being filmed. Videos were analyzed regarding brushing movements (vertical, circular, horizontal, modified Bass technique) and evenness of distribution of brushing time across vestibular (labial/buccal) and palatinal (lingual/palatinal) surfaces. Dental status, gingival bleeding, and oral cleanliness after oral hygiene were assessed. RESULTS: Ninety-eight young adults participated in the study. Gingival margins showed persistent plaque at 69.48% ± 12.31% sites (mean ± SD) after participants brushed to their best abilities. Regression analyses with the brushing movements and evenness of distribution of brushing time as predictors explained 15.2% (adjusted R2 = 0.152, P = 0.001) of the variance in marginal plaque and 19.4% (adjusted R2 = 0.194, P < 0.001) of the variance in bleeding. Evenness of distribution of brushing time was the most important behavioral predictor. CONCLUSION: Even when asked to perform optimal oral hygiene, young German adults distributed their brushing time across surfaces unevenly. Compared with brushing movements, this factor turned out to be of more significance when explaining the variance of plaque and bleeding. KNOWLEDGE TRANSFER STATEMENT: Results of this study can help clinicians and patients understand the meaning of specific behavioral aspects of toothbrushing for oral cleanliness and oral health.

Crystal and molecular structure of r(CGCGAAUUAGCG): an RNA duplex containing two G(anti).A(anti) base pairs.

BACKGROUND: Non-Watson-Crick base pair associations contribute significantly to the stabilization of RNA tertiary structure. The conformation adopted by such pairs appears to be a function of both the sequence and the secondary structure of the RNA molecule. G.A mispairs adopt G(anti).A(anti) configurations in some circumstances, such as the ends of helical regions of rRNAs, but in other circumstances probably adopt an unusual configuration in which the inter-base hydrogen bonds involve functional groups from other bases. We investigated the structure of G.A pairs in a synthetic RNA dodecamer, r(CGCGAAUUAGCG), which forms a duplex containing two such mismatches. RESULTS: The structure of the RNA duplex was determined by single crystal X-ray diffraction techniques to a resolution in the range 7.0-1.8A, and found to be an A-type helical structure with 10 Watson-Crick pairs and two G.A mispairs. The mispairs adopt the G(anti).A(anti) conformation, held together by two obvious hydrogen bonds. Unlike analogous base pairs seen in a DNA duplex, they do not exhibit a high propeller twist and may therefore be further stabilized by weak, reverse, three-center hydrogen bonds. CONCLUSIONS: G(anti).A(anti) mispairs are held together by two hydrogen of guanine and the N6 and N1 of adenine. If the mispairs do not exhibit high propeller twist they may be further stabilized by inter-base reverse three-centre hydrogen bonds. These interactions, and other hydrogen bonds seen in our study, may be important in modelling the structure of RNA molecules and their interactions with other molecules.

Using linkers to investigate the spatial separation of the conserved nucleotides A9 and G12 in the hammerhead ribozyme.

Two series of hammerhead-derived ribozymes, or 'minizymes', in which helix II has been replaced by linkers of non-nucleotidic moieties, have been synthesised by solid-phase methods. In the first series, the minizymes had linkers containing one, two, three, four or five repeated units of phosphopropanediol, so that the number of atoms in the chain connecting the 3'O of the conserved A9 to the 5'O of the conserved G12 varied from 7 to 31. In the second, more-limited series, the minizymes contained linkers of either tetra- or hexa-ethyleneglycol. The rates at which these minizymes cleaved their cognate 13-nucleotide substrate were determined at 30 degrees C, and compared with the rates of cleavage by an analogous series of minizymes containing from two to six repeated units of thymine deoxyribonucleotide in place of helix II. In all three series, the cleavage rates increased with increasing linker length, with a plateau being reached at the longer lengths tested. Relative cleavage rates within the phosphopropanediol and the thymidine series depended strongly on linker length, but maximal activity was achieved in both series with 25 atoms in the chain joining A9 and G12. The lengths of linkers required to achieve maximal activity of the minizymes are considerably greater than the linkers of 13 atoms which are sufficient to stabilise the ends of double-helices of DNA or RNA.

Analysis of atropine, its degradation products and related substances of natural origin by means of reversed-phase high-performance liquid chromatography.

Chromatographic separation and quantification methods of tropa alkaloids were often described. In order to separate atropine from its degradation products ion-pair chromatography (IPC) has been frequently applied. Beside long equilibration times IPC often suffers from poor robustness. The aim of this study was to develop robust and simple HPLC methods for both stability testing of atropine solutions and limitation of related substances in atropine from plant material. Using a hydrophilic embedded RP18 column and a gradient elution gave baseline separation of all components.

Analytical oxidation of reserpine.

Electrochemical (anodic) oxidation of reserpine in an acidic medium results in the formation of 3,4-dehydroreserpine instead of the reported 10-hydroxy-reserpine. Electrochemical and chemical oxidation by sodium nitrite lead quantitatively to the same product; few by-products or consecutive products are formed if protected from light. The validity of the conditions of the spectrophotometric assay of the European Pharmacopoeia were confirmed by following the reaction using HPLC with a photodiode-array detector.

The llama industry in the United States.

This chapter provides an overview of the llama in the United States. It covers the animal and its history, the people who own llamas, and the business that is developing around them and describes the industry's needs from the veterinary profession in terms of health care.

The role of the physical therapist in hospice care.

The role of the physical therapist in hospice care is different from the role the therapist plays when a member of a rehabilitation team. This article will address the need for a fundamental role change and offer suggestions for ways physical therapists can contribute to the care of the hospice patient. In working with hospice patients, therapists must, for the most part, change from a controlling role to one of listener and problem-solver. In this manner, therapists can: Assist the patient to maintain functional abilities for as long as possible; Reduce the burden of care for the caregivers; Assist in pain control. Physical therapists can provide hospice nurses with valuable assistance in caring for hospice patients.

Two-year follow-up study of elderly residents in S. Paulo, Brazil: methodology and preliminary results.

INTRODUCTION: Previous cross-sectional studies have shown a high prevalence of chronic disease and disability among the elderly. Given Brazil's rapid aging process and the obvious consequences of the growing number of old people with chronic diseases and associated disabilities for the provision of health services, a need was felt for a study that would overcome the limitations of cross-sectional data and shed some light on the main factors determining whether a person will live longer and free of disabling diseases, the so-called successful aging. The methodology of the first follow-up study of elderly residents in Brazil is presented. METHOD: The profile of the initial cohort is compared with previous cross-sectional data and an in-depth analysis of nonresponse is carried out in order to assess the validity of future longitudinal analysis. The EPIDOSO ('Epidemiologia do Idoso') Study conducted a two-year follow-up of 1,667 elderly people (65+), living in S. Paulo. The study consisted of two waves, each consisting of household, clinical, and biochemical surveys. RESULTS AND CONCLUSIONS: In general, the initial cohort showed a similar profile to previous cross-sectional samples in S. Paulo. There was a majority of women, mostly widows, living in multigenerational households, and a high prevalence of chronic illnesses, psychiatric disturbances, and physical disabilities. Despite all the difficulties inherent in follow-up studies, there was a fairly low rate of nonresponse to the household survey after two years, which did not actually affect the representation of the cohort at the final household assessment, making unbiased longitudinal analysis possible. Concerning the clinical and blood sampling surveys, the respondents tended to be younger and less disabled than the nonrespondents, limiting the use of the clinical and laboratory data to longitudinal analysis aimed at a healthier cohort. It is worth mentioning that gender, education, family support, and socioeconomic status were not important determinants of nonresponse, as is often the case.

[Analytical data and preparation of important 3-hydroxy-5-phenyl-1,4-benzodiazepin-2-one derivatives (author's transl)]. / Analytik und Synthese wichtiger 3-Hydroxy-5-phenyl-1,4-benzodiazepin-2-on-Derivate.

The article describes analytical data (TLC, IR, MS) of 7-chloro-1-methyl-1,3-hydroxy-5-phenyl-2H-1,4-benzodiazepin-2-one (3-hydroxydiazepam) and 7-cyclopropyl-methyl-1,3-dihydro-3-hydroxy-5-phenyl-2H-1,4-benzodiazpin-2-one (3-hydroxy-prazepam). Analytical properties of important derivatives (N-oxides, 3-acetoxy compounds, re-arrangement products) are also reported. Besides preparation methods are given for the synthesis of these substances, considering in particular preparation as solution-reactions as well as reaction on the TLC-plate.

[Studies on the detection of clonazepam and its main metabolites considering in particular thin-layer chromatography discrimination of nitrazepam and its major metabolic products (author's transl)]. / Untersuchungen zum Nachweis von Clonazepam und seinen Hauptmetaboliten unter besonderer Berücksichtigung der dünnschichtchromatographischen Unterscheidung von Nitrazepam und dessen wichtigsten Stoffwechselprodukten

The article describes analytical methods concerning screening tests for clonazepam and nitrazepam and the 7-amino derivatives. Further a detailed method is reported for the separation and identificatin of the benzodiazepine pair de. The method described permits a sharp separation and the nitro compounds with TiCl3 on the plate and forming the 7-acetamido derivatives by subsequent separation in the second dimension with ethyl acetate/acetic anhydride. The method described permits a sharp separation and highly sensitive detection by diazotization and coupling with Bratton-Marshall reagent. Amounts as low as 0.02 microng per spot can be detected. Besides preparation methods are reported for 7-aminoclonazepam, 7-acetaminoclonazepam, 2-amino-2'-chloro-5-nitrobenzophenone and 2,5-diamino-2'-chlorobenzophenone. Also spectral data (UV, IR, MS) and a literature review are given.

[Analytical data of flunitrazepam (rohypnol), a new benzodiazepine-derivative, in special consideration of its metabolites (author's transl)]. / Zur Analytik von Flunitrazepam (Rohypnol), einem neuen Benzodiazepinderivat, unter besonderer Berücksichtigung der Metaboliten.

The article describes analytical data (TLC, GLC, IR, UV and MS) of flunitrazepam, 7-amino-flunitrazepam, desmethylflunitrazepam, 3-hydroxyflunitrazepam, 7-amino-desmethyl-flunitrazepam and many other benzodiazepine-derivatives, especially aminobenzophenones. Also extraction from biological specimen is reported.

[Screening and detection of tetrazepam and its major metabolites]. / Screening und Nachweis von Tetrazepam und seinen Hauptmetaboliten.

The paper describes a screening procedure for 7-Chloro-1,3-dihydro-1-methyl-5-(cyclohexene-1-yl)-2H-1,4-benzodiazepine -2-one (Tetrazepam, Musaril) and other important analytical data (TLC, GLC, UV-, IR-, and mass spectra).

[Studies on the analysis of nifedipine considering in particular transformation products formed by light exposition (author's transl)]. / Untersuchungen zur Analytik von Nifedipin unter besonderer Berücksichtigung der bei Lichtexposition entstehenden Umwandlungsprodukte.

Under the influence of light (VIS and UV) on thin-layer plates and in liquid solutions, 1,4-dihydro-2,6-dimethyl-4-(0-nitro-phenyl)-pyridine-3,5-carboxylic acid dimethylester (nifedipine, Adalat) is converted to the nitroso compound 4-(2-'nitrosophenyl)-2,6-dimethyl-3,5-dicarbomethoxy-pyridine. The article also describes TLC-, GLC-, UV-, IR- and MS-data of nifedipine, the nitroso and the nitro derivative.

[Analytical methods for stability testing of metronidazole infusion solutions]. / Analytische Methoden für die Stabilitätsprüfung von Metronidazol-Infusionslösungen.

UV-spectroscopy, thin layer- and high pressure liquid-chromatography as well as voltammetry (polarography) are suggested and compared as methods for use in stability testing of solutions of metronidazol. If some conditions are fulfilled UV-spectroscopy is the method of highest precision. TLC/HPTLC has advantages compared to HPLC, for more polar degradation products are visible at the starting point, whereas in HPLC these substances may be irreversibly adsorbed on the columne. Combination of HPLC and voltammetric (polarographic) techniques may lead to the optimal solution of this analytical problem with respect to best accuracy and precision (reproducibility) as compared in this paper.

Neutral and anionic cyclodextrins in capillary zone electrophoresis: enantiomeric separation of ephedrine and related compounds.

Two methods for the enantiomeric separation of chiral ephedrine alkaloids (ephedrine, methylephedrine, methylpseudoephedrine and norephedrine) by capillary zone electrophoresis in uncoated capillaries were developed. Both methods were optimized to more than 100,000 theoretical plate numbers. The first method used a neutral cyclodextrin (CD) derivative: heptakis (2,6-di-O-methyl)-beta-cyclodextrin at an acidic pH of 2.5 (20 mM phosphate buffer) at an 18 mM concentration. The second used a newly developed acidic CD derivative, the tetrakis[6-O-(4-sulfobutyl)]-beta-cyclodextrin sodium salt. The benefits of this new reagent for the chiral separation are a wide range of basic pH available for the enantiomeric resolution. It is also useful for other cases, e.g. preventing adsorption without additives.

[Hand disinfection as the central factor in prevention of puerperal mastitis. Clinical study and results of a survey]. / Die Händedesinfektion als zentraler Faktor in der Prophylaxe der puerperalen Mastitis. Klinische Untersuchung und Umfrageergebnis.

The incidence of puerperal mastitis was evaluated in the course of two 12-month periods with and without additional hand disinfection at the bedside. Disinfection was available throughout both periods for all patients, mounted at the door of each room. Without additional disinfection at the bedside, 32 patients developed mastitis. With reference to the birth rate of 1095 during this period, the incidence of mastitis was 2.9%. When additional bedside disinfection was available, mastitis dropped to 8 cases per 12 months (1212 births = 0.66%) (p less than 0.001). A telephone survey, at 55 obstetrical units revealed that 41.8% of maternity clinics do not provide hand disinfectants at the bedside. These results indicate to the breast-feeding mother, that in the pathogenesis of puerperal mastitis, the essential recommendation emphasises, that puerperal women practise strict hygiene in maternity.