The identification of appropriate skin tear prevention guidelines for the elderly requires clinicians to focus on local risk factors such as structural alterations of the epidermis and dermis related to skin tears. The aim of this cross-sectional study is to explore the prevalence of skin tears and to explore skin properties related to skin tears in elderly Japanese patients at a long-term medical facility. After doing the prevalence study, 18 participants with skin tears and 18 without were recruited and an evaluation of their skin properties using 20-MHz ultrasonography, skin blotting and also Corneometer CM-825, Skin-pH-meterPH905, VapoMeter, Moisture Meter-D and CutometerMPA580 was undertaken. A total of 410 patients were examined, the median age was 87 years and 73·2% were women. The prevalence of skin tears was 3·9%, and 50% of skin tears occurred on the dorsal forearm. The changes in skin properties associated with skin tears included increased low-echogenic pixels (LEP) by 20-MHz ultrasonography, decreased type IV collagen and matrix metalloproteinase-2, and increased tumour necrosis factor-α by skin blotting. In conclusion, this study suggests that increased dermal LEP, including solar elastosis, may represent a risk factor for skin tears; this indicates that skin tear risk factors might not only represent chronological ageing but also photoageing.

In bacteria, 70S ribosomes (consisting of 30S and 50S subunits) dimerize to form 100S ribosomes, which were first discovered in Escherichia coli. Ribosome modulation factor (RMF) and hibernation promoting factor (HPF) mediate this dimerization in stationary phase. The 100S ribosome is translationally inactive, but it dissociates into two translationally active 70S ribosomes after transfer from starvation to fresh medium. Therefore, the 100S ribosome is called the 'hibernating ribosome'. The gene encoding RMF is found widely throughout the Gammaproteobacteria class, but is not present in any other bacteria. In this study, 100S ribosome formation in six species of Gammaproteobacteria and eight species belonging to other bacterial classes was compared. There were several marked differences between the two groups: (i) Formation of 100S ribosomes was mediated by RMF and short HPF in Gammaproteobacteria species, similar to E. coli, whereas it was mediated only by long HPF in the other bacterial species; (ii) RMF/short HPF-mediated 100S ribosome formation occurred specifically in stationary phase, whereas long HPF-mediated 100S ribosome formation occurred in all growth phases; and (iii) 100S ribosomes formed by long HPF were much more stable than those formed by RMF and short HPF.

An unnatural hydrophobic base, pyrrole-2-carbaldehyde (denoted as Pa), was developed as a specific pairing partner of 9-methylimidazo[(4,5)-b]pyridine (Q). The Q base is known to pair with 2,4-difluorotoluene (F) as an isostere of the A-T pair, and F also pairs with A efficiently in replication. In contrast, the Q-Pa pair showed specific selectivity in replication, and the five-membered-ring base Pa paired efficiently with Q but paired poorly with A. In addition, the interaction of Pa with DNA polymerases was superior, in comparison to that of F. The aldehyde group of Pa was recognized well by the Klenow fragment of Escherichia coli DNA polymerase I and the reverse transcriptase of Avian myeloblastosis virus. The structural features of the Q-Pa pair in a DNA duplex were analyzed by NMR, showing the shape complementarity of the Pa fitting with Q. The structurally unique base Pa provides valuable information for the development of unnatural base pairs toward the expansion of the genetic alphabet.

No abstract

The relationship between the prosthodontic experience of dentists and satisfaction of complete denture wearers remains unknown. To investigate whether a prosthodontist's clinical experience affects treatment satisfaction of a complete denture wearer. From April 2004 to July 2006, we conducted a randomised controlled trial at two centres, including 74 edentulous patients; of these, 32 and 30 were randomly allocated to the ED or ID group, respectively. All the patients rated their satisfaction with dentures, including general satisfaction and satisfaction of chewing ability, speaking, cleaning, stability, retention, comfort and aesthetics. These satisfaction ratings were measured by a 100-mm visual analog scale (VAS). Perceived chewing ability to foods, divided into five grades, was measured using a questionnaire. The mastication index (MI) was calculated for each grade. General satisfaction and satisfaction of speaking, stability and retention were significantly higher in the ED than in the ID group (P = 0·049, 0·003, 0·019 and 0·041, respectively). No significant difference existed between the MI of the ED (71·3 ± 18·4) and ID group (64·1 ± 16·53). However, the perceived chewing ability of grade 5 food, whose texture was the hardest among all the grades, was significantly higher in the ED group than in the ID group. Within its limitations, this study showed that a clinician's prosthodontic experience affects a complete denture wearer's satisfaction ratings.