Bending properties of stainless steel dynamic compression plates and limited contact dynamic compression plates

The equivalent bending stiffness and bending strength of the stainless steel DCP and stainless steel LC-DCP were compared. Three plates, of each size, were tested destructively in ‘four point bending’. All of the LC-DCP were significantly less stiff and less strong than the comparable size DCP, with the exception of the 4.5 mm narrow LC-DCP which was significantly stronger and more stiff than the 4.5 mm narrow DCP (p <.01). The design advantages of the LC-DCP are ease and versatility of plate application and improved cortical blood flow which one assumes promotes fracture healing. Also, the lower recorded stiffness of the LC-DCP may be advantageous in that it decreases the stress protection of the plated bone. Since optimal strength and stiffness of bone plates are currently unknown, the clinical relevance of the decreased strength and stiffness of the LC-DCP has yet to be determined.

Stainless steel LC-DCP and DCP of various sizes were tested in four point bending to ascertain equivalent bending stiffness and bending strength of each type of plate. The LC-DCP were consistently less stiff and strong than their DCP counterparts (p <.01) with the exception of the 4.5 mm Narrow LC-DCP which was stronger and more stiff than the 4.5 mm Narrow DCP. In general, as plate size increased. the difference between the two plate designs decreased. If it can be shown that there is not any detrimental effect on fracture healing, the design features of the LC-DCP make it a desirable choice for most fracture applications.

The relationship between lip-closing force and dental arch morphology in patient with Angle Class I malocclusion

Dental arch morphology and tooth position are affected by lip-closing force (LCF). This study aimed to quantitatively evaluate the relationships between the horizontal or vertical balance of the LCF generated during maximum voluntary pursing-like movements and dental arch length (DAL) or width (DAW) or the lingual inclination of the upper or lower 1st molars (LIUM, LILM) in patients with Angle Class I malocclusion. Sixteen subjects with Angle Class I malocclusion (median age: 23·4 ± 5·9 years) who had never undergone orthodontic treatment were randomly selected. LCF was measured in eight directions during maximum voluntary pursing-like lip-closing movements. Dental arch models were scanned and analysed to obtain DAW, DAL, LIUM and LILM measurements. Mandibular deviation was measured on posteroanterior cephalograms. A significant negative correlation was detected between maxillary DAL and upper LCF. Maxillary DAL, DAW and the DAL/DAW ratio displayed significant negative correlations with total LCF and upper LCF. However, no significant correlations were detected between any mandibular dental arch morphological parameter and LCF. The difference in the LIUM between the deviation and non-deviation sides exhibited a significant positive correlation with the difference in upper LCF between the deviation and non-deviation sides and was significantly negatively correlated with the difference in lower LCF between the deviation and non-deviation sides. These results suggest that upper LCF is related to maxillary DAL, and the horizontal balance of the LCF of the upper and lower lips is related to the LIUM during pursing-like lip-closing movements in patients with Angle Class I malocclusion.

Note: Application of CR-39 plastic nuclear track detectors for quality assurance of mixed oxide fuel pellets

A CR-39 plastic nuclear track detector was used for quality assurance of mixed oxide fuel pellets for next-generation nuclear power plants. Plutonium (Pu) spot sizes and concentrations in the pellets are significant parameters for safe use in the plants. We developed an automatic Pu detection system based on dense α-radiation tracks in the CR-39 detectors. This system would greatly improve image processing time and measurement accuracy, and will be a powerful tool for rapid pellet quality assurance screening.

Operational test of micro-oven for 48Ca beam

In order to supply a high-intensity and stable (48)Ca beam from the RIKEN 18-GHz electron cyclotron resonance ion source, we are conducting operational tests of a micro-oven. A mixture of CaO and Al powders is placed into the crucible of the micro-oven and heated to produce metallic calcium by a reductive reaction. The successful production of a calcium beam was confirmed. In addition, we reduced the material consumption rate by using a so-called "hot liner," and we enhanced the beam intensity by applying a negative voltage bias to the micro-oven, the effect of which is similar to the effect of a "biased disk."

Genetic analysis of novel avian A(H7N9) influenza viruses isolated from patients in China, February to April 2013

Novel influenza viruses of the H7N9 subtype have infected 33 and killed nine people in China as of 10 April 2013. Their haemagglutinin (HA) and neuraminidase genes probably originated from Eurasian avian influenza viruses; the remaining genes are closely related to avian H9N2 influenza viruses. Several characteristic amino acid changes in HA and the PB2 RNA polymerase subunit probably facilitate binding to human-type receptors and efficient replication in mammals, respectively, highlighting the pandemic potential of the novel viruses.

Genetic analysis of novel avian A(H7N9) influenza viruses isolated from patients in China, February to April 2013

Novel influenza viruses of the H7N9 subtype have infected 33 and killed nine people in China as of 10 April 2013. Their haemagglutinin (HA) and neuraminidase genes probably originated from Eurasian avian influenza viruses; the remaining genes are closely related to avian H9N2 influenza viruses. Several characteristic amino acid changes in HA and the PB2 RNA polymerase subunit probably facilitate binding to human-type receptors and efficient replication in mammals, respectively, highlighting the pandemic potential of the novel viruses.

Development-dependent expression of calreticulin in the brain and other tissues of the Japanese monkey, Macaca fuscata

BACKGROUND

Calreticulin (CRT) is a molecular chaperone localized to endoplasmic reticulum lumen. The protein is involved in the correct folding of glycoproteins and its cellular level changes depending on various physiologic conditions.

METHODS

To clarify the Crt level in various tissues of the Japanese monkey during postnatal development, an enzyme-linked immunosorbent assay system that we have established was applied.

RESULTS AND CONCLUSIONS

Calreticulin is distributed ubiquitously in various tissues. Its level in the heart, lung, liver, spleen, and kidney was high in newborns and decreased in juveniles and adults. In various cerebral areas, Crt was present in the gray matter but scarcely found in the white matter. The Crt levels in the cerebral areas were low in newborns and increased in juveniles and adults. These distribution and developmental changes in Crt might be correlated with the quality control of glycoproteins that are synthesized in respective tissues.

Molecular cloning and gene expression of endoplasmic reticulum stress proteins in Japanese monkey, Macaca fuscata

BACKGROUND

Immunoglobulin heavy-chain binding protein (BiP), calreticulin (Crt), and protein disulfide isomerase (PDI), are major resident endoplasmic reticulum (ER) stress proteins which are involved in diverse roles relating to successful folding, assembly, intracellular localization, and degradation of other proteins.

METHODS

In this study, we molecular cloned cDNAs for BiP, Crt, and PDI from Japanese monkey (Macaca fuscata), and analyzed tissue-specific expression of respective genes.

RESULTS AND CONCLUSIONS

The lengths of protein-coding regions of these cDNAs for BiP, Crt and PDI are 1965, 1254, and 1533 bp, respectively. Each protein has a signal peptide and a KDEL motif in N- and C-terminal parts respectively, showing its intracellular localization to be the lumen of the ER. These stress proteins are highly conserved, showing that their similarities among mammals are more than 90% in the level of amino acid. The expression of the genes for stress proteins differed among the monkey tissues examined. BiP and PDI gene expression was predominant in secretory tissues such as liver and kidney, and brain tissues. But Crt gene expressed rather ubiquitously in a variety of tissues.

Effect of vascularity on canine distracted tibial callus consolidation

In the consolidation period of distraction osteogenesis, mineralization occurs before corticalization. We hypothesized that the increased rate of bone mineral density correlates to the density of vascularity in the callus. We unilaterally lengthened the tibia in eight adult beagles. After a waiting period of 7 days, tibiae were lengthened for 30 days. After a consolidation period of an additional 60 days, all animals were euthanized. Just before euthanasia, blood vessels were perfused with 50% w/v barium sulfate solution, and soft radiographs of the distracted callus and the control tibiae were taken. Bone mineral density of the regenerated bones was measured preoperatively by quantitative computed tomography on Days 37, 68, and 98. Increases of the percent bone mineral density (from Day 37 to Day 98 and from Day 68 to Day 98) correlated with the blood vessel volume density ratios on Day 98. Our results suggest that preservation of the higher density of blood vessels in the consolidation period could lead to the better mineralization of the distracted callus.

Cleavage activity of the sapovirus 3C-like protease in Escherichia coli

We recently determined the ORF1 cleavage map of Mc10, a human sapovirus (SaV) strain, as follows: NH2-p11-p28-p35(NTPase)-p32-p14(VPg)-p70(Pro-Pol)-p60(VP1)-COOH. This cleavage was dependent on the viral encoded 3C-like protease. To identify the cleavage site of SaV ORF1, putative p70 (Pro-Pol) and p14-p70 (VPg-Pro-Pol) were expressed as N-terminal GST and C-terminal 6 x His-tag fusion proteins in Escherichia coli, and the expressed products were analyzed by SDS-PAGE and Western blotting. Our results indicated that the efficient proteolytic cleavage occurred between p14 (VPg) and p70 (Pro-Pol), and N-terminal amino acid sequencing revealed that the cleavage site was between E(1055) and A(1056). In contrast, the p70 (Pro-Pol) was not further cleaved. We also found that SaV protease cleaved the Q/G site within the rhinovirus 3C protease recognition site. Site-directed mutagenesis in a conserved GDCG motif of the protease completely abolished these proteolytic activities. This is the first report to identify the cleavage site of the SaV ORF1 polyprotein.

Visual results and complications of temporal incision phacoemulsification performed with the non-dominant left hand by junior ophthalmologists

AIMS

To assess the results of temporal incision phacoemulsification and aspiration performed with dominant and non-dominant hand of ophthalmology trainees.

METHODS

Retrospective analysis were made of 203 surgeries with dominant hand and 207 with non-dominant by five trainees at two institutions. Trainees sat at the patient's head, manipulating instruments with the dominant right hand for the right eye, and the non-dominant left hand for the left eye.

RESULTS

Vitreous loss occurred in 12 (5.9%) of 203 dominant operated eyes and seven (3.4%) of 207 non-dominant operated eyes. The rate of endothelial cell loss was 6.1% (9.8%) in dominant and 7.4% (12.4%) in non-dominant. Mean ultrasound time were 1.81 (0.70) minutes in dominant and 1.78 (0.78) minutes in non-dominant. One trainee showed statistically significant excesses in incidence of vitreous loss in dominant operated eyes (8.7%, p=0.0270), and one showed statistically significant prolongation of the operation in nondominant operated eyes (26.3 minutes, p=0.0315). In all other trainees, all parameters had no difference in both sides.

CONCLUSIONS

Ophthalmology trainees could successfully learn the technique with both hands. The authors consider that the skill of the non-dominant hand may be knowledge based and that surgeons avoid mistakes by mental efforts.

Yersinia pseudotuberculosis infection in breeding monkeys: detection and analysis of strain diversity by PCR

In the last three decades, several monkeys reared in outdoor/indoor-outdoor breeding colonies and cages of the Primate Research Institute, Kyoto University, died of yersiniosis caused by Yersinia pseudotuberculosis, necessitating introduction of a method to detect the bacteria rapidly and thus allow preventive measures to be undertaken. A rapid nested polymerase chain reaction (PCR) method for identification of Y. pseudotuberculosis in fecal samples and a random amplified polymorphic DNA (RAPD)-PCR approach for distinguishing between bacterial strains were therefore developed. Yersinia pseudotuberculosis isolates from monkey specimens were found to be classifiable into several types. To determine the source of infection, hundreds of fecal samples of wild rats, pigeons, and sparrows were collected from around the breeding colonies and cages, and subjected to PCR analyses. Yersinia pseudotuberculosis was detected in 1.7% of the fecal samples of wild rats. The DNA fingerprints of the bacteria revealed by RAPD-PCR were the same as that of one strain isolated from macaques, suggesting the wild rat to be a possible source of infection.

Novel mutations in the a3 subunit of vacuolar H(+)-adenosine triphosphatase in a Japanese patient with infantile malignant osteopetrosis

A case of infantile malignant osteopetrosis is described. The patient died from respiratory hemorrhage at 7 months of age despite treatment that included high doses of active vitamin D and administration of interferon-gamma. A postmortem examination revealed the presence of many osteoclasts in the bone, which lacked ruffled borders. This observation was consistent with the histology of bone reported in Atp6i-knockout mice, which lack the gene encoding the a3 subunit of vacuolar-type H(+)-adenosine triphosphatase (ATPase). Sequence analysis of the TCIRG1 gene encoding the a3 subunit revealed two novel mutations: a deletion/insertion mutation in exon 9 and a T-to-C transition at the splice donor site of intron 19. The former mutation caused a frame shift and premature stop codon. The latter was associated with abnormal splicing, which was confirmed by sequencing the products amplified by reverse transcription-polymerase chain reaction (RT-PCR), using total RNA from the liver specimen as template. Although several mutations in the TCIRG1 gene in infantile malignant osteopetrosis have been reported in other populations, this is the first case of a Japanese patient with a mutation identified in this gene. These results support the important role of the subunit in the function of the proton pump.

Pepsinogens, progastricsins, and prochymosins: structure, function, evolution, and development

Five types of zymogens of pepsins, gastric digestive proteinases, are known: pepsinogens A, B, and F, progastricsin, and prochymosin. The amino acid and/or nucleotide sequences of more than 50 pepsinogens other than pepsinogen B have been determined to date. Phylogenetic analyses based on these sequences indicate that progastricsin diverged first followed by prochymosin, and that pepsinogens A and F are most closely related. Tertiary structures, clarified by X-ray crystallography, are commonly bilobal with a large active-site cleft between the lobes. Two aspartates in the center of the cleft, Asp32 and Asp215, function as catalytic residues, and thus pepsinogens are classified as aspartic proteinases. Conversion of pepsinogens to pepsins proceeds autocatalytically at acidic pH by two different pathways, a one-step pathway to release the intact activation segment directly, and a stepwise pathway through a pseudo-pepsin(s). The active-site cleft is large enough to accommodate at least seven residues of a substrate, thus forming S4 through S'3 subsites. Hydrophobic and aromatic amino acids are preferred at the P1 and P'1 positions. Interactions at additional subsites are important in some cases, for example with cleavage of kappa-casein by chymosin. Two potent naturally occurring inhibitors are known: pepstatin, a pentapeptide from Streptomyces, and a unique proteinous inhibitor from Ascaris. Pepsinogen genes comprise nine exons and may be multiple, especially for pepsinogen A. The latter and progastricsin predominate in adult animals, while pepsinogen F and prochymosin are the main forms in the fetus/infant. The switching of gene expression from fetal/infant to adult-type pepsinogens during postnatal development is noteworthy, being regulated by several factors, including steroid hormones.

Cross-sectional survey on risk factors for insomnia in Japanese female hospital nurses working rapidly rotating shift systems

A cross-sectional survey was carried out for the purpose of examining the association of work stress with insomnia among nurses working rotating shift systems. A self-administered questionnaire on sleep and mental health was distributed to 875 nurses at five hospitals in Japan. Out of the data from 785 (89.7%) respondents, those from 555 women engaged in rapidly and irregularly rotating shift systems as full-time nurses were examined. The prevalence of insomnia (29.2%) was three to four times higher than that in the general population. Among the insomniacs, 23% were current users of medically prescribed hypnotics. Multiple logistic analysis revealed that being 24 or less years old, working three or less night shifts per month, having six or less non-working days per month, receiving less support from colleagues and superiors, and taking care of severely ill patients were independent risk factors for insomnia. The number of hours of a night shift was found not associated with insomnia, taking the above variables into account. These results suggest that at least three factors, i.e., 1) young nurses not adapted to shiftwork, 2) the nurses requiring to remedy sleep deficits on non-working days, and 3) the work stress partly characteristic of nurses, have an adverse influence on their sleep.