Impact of control measures including decolonization and hand hygiene for orthopaedic surgical site infection caused by MRSA at a Japanese tertiary-care hospital.

BACKGROUND: Meticillin-resistant Staphylococcus aureus (MRSA) is the most common pathogen in orthopaedic surgical site infections (SSIs). However, few studies have investigated the transmission process of orthopaedic MRSA SSI. AIM: To investigate the transmission process of orthopaedic MRSA SSI using epidemiological and molecular analyses and to determine a method to prevent MRSA SSI in nosocomial orthopaedic surgery. METHODS: Active MRSA surveillance, preoperative decolonization and contact precautions for MRSA-positive cases was performed at our institution. Changes in epidemic strains were evaluated and the possibility of transmission from patients in an orthopaedic ward of a Japanese tertiary-care hospital was assessed by genotyping stored MRSA strains. In addition, data on the prevalence of MRSA SSI, MRSA colonization, and use of an alcohol antiseptic agent (mL/patient-days) during 2005-2022 were retrospectively assessed. FINDINGS: SCCmec type II strain in the SSI group decreased over time, associated with fewer outbreaks. Even during a period of high infection rates, no cases of transmission-induced SSI from nasal MRSA carriers were identified. The infection rate correlated negatively with the use of an alcohol antiseptic agent (r = -0.82; P < 0.0001). Two cases among five nasal carriers developed MRSA SSI caused by strains different from those related to nasal colonization. CONCLUSION: The infection control measures for transmission from the hospital reservoirs including strict adherence to hand hygiene and decolonization of carriers is likely to be important for the prevention of orthopaedic MRSA SSI. However, the need for contact precautions for decolonized nasal carriers might be low.

Development of a novel animal model of rotator cuff tear arthropathy replicating clinical features of progressive osteoarthritis with subchondral bone collapse.

Objective: To establish an animal model of modified cuff tear arthropathy (mCTA) in order to better replicate the pathophysiology associated with rotator cuff tear-induced humeral head collapse. Design: mCTA was induced by transection of the rotator cuff, the long head of the biceps brachii (LHB), and superior half of the joint capsule in the right shoulder of 12-week-old rats; the left shoulder underwent sham surgery. The severity of CTA was quantitated using the Murine Shoulder Arthritis Score (MSAS). The trabecular bone of the humeral head and metaphysis was analyzed using bone histomorphometry. The expression of proinflammatory cytokines and catabolic enzymes was evaluated immunohistochemically. Results: In the mCTA model, the MSAS increased starting from 2 weeks after induction, and there was notable subchondral bone collapse with fibrous cells at 4 weeks. The mCTA cartilage exhibited positive staining for TNF-α, IL-1ß/6, MMP-3/13, and ADAMTS5. The trabecular bone volume was reduced not only in the subchondral bone but also in the metaphysis of the humeri, and bone resorption was enhanced in these areas. In the collapsed subchondral bone, both bone formation and resorption were increased. The fibrous cells showed expression of TNF-α, IL-6, and MMP-13, along with specific markers of mesenchymal stem cells. Furthermore, the fibrous cells showed osteoblastic characteristics (RUNX2-positive) and expressed RANKL. Conclusions: The LHB and the capsuloligamentous complex are critical stabilizers of the glenohumeral joint, serving to prevent the advancement of CTA following massive rotator cuff tears. Fibrous cells appear to play a role in the humeral head bone resorption.

Prospective predictors of exacerbation status in severe asthma over a 3-year follow-up.

BACKGROUND: A predisposition to exacerbations is being recognized as a distinct phenotype with "previous exacerbations" representing the strongest clinical factor associated with future exacerbation. Thus, to identify additional novel biomarkers associated with asthma exacerbations, "past exacerbation status" must be included as a confounding factor. OBJECTIVE: This study aimed to characterize the clinical and biomarker features associated with asthma exacerbations in severe asthma. METHODS: We evaluated clinical parameters from 105 severe asthmatics yearly for 3 years, as well as their exacerbation status. We classified the subjects into 3 groups: (i) consistent non-exacerbators (CNE, subjects who did not experience any exacerbation over the 3-year period); (ii) consistent frequent exacerbators (CFE, subjects with frequent exacerbation, defined as those who had 2 or more exacerbations within 1 year, throughout the 3-year period); and (iii) intermittent exacerbators (IE). We conducted multivariate analysis for comparisons among the groups for multiple factors, including several Th2-related biomarkers, in addition to the "past exacerbation status." RESULTS: Thirty-nine subjects were classified as CNE, 15 as CFE, and 51 as IE. Frequent exacerbations in the previous year predicted exacerbations for the following year (P < .001). Among the several Th2-related biomarkers, only FeNO was associated with exacerbation status. When we analysed the data after the second visit, the impact of FeNO on predicting future exacerbation remained significant, even after considering the exacerbation status during the first year (P < .05). CONCLUSIONS AND CLINICAL RELEVANCE: Measurement of FeNO has a significant potential to predict future asthma exacerbation, which is independent of the "past exacerbation history."

Do screws and screw holes affect osteolysis in cementless cups using highly crosslinked polyethylene? A 7 to 10-year follow-up case-control study.

BACKGROUND: The use of screws and the presence of screw holes may cause acetabular osteolysis and implant loosening in cementless total hip arthroplasty (THA) using conventional polyethylene. In contrast, this issue is not fully understood using highly crosslinked polyethylene (HXLPE), particularly in large comparative study. Therefore, we performed a case-control study to assess the influence of screw usage and screw holes on: (1) implant fixation and osteolysis and (2) polyethylene steady-state wear rate, using cases with HXLPE liners followed up for 7-10 years postoperatively. HYPOTHESIS: The screw usage and screw holes adversely affect the implant fixation and incidence of wear-related osteolysis in THA with HXLPE. PATIENTS AND METHODS: We reviewed 209 primary cementless THAs performed with 26-mm cobalt-chromium heads on HXLPE liners. To compare the effects of the use of screws and the presence of screw holes, the following groups were established: (1) with-screw (n=140); (2) without-screw (n=69); (3) no-hole (n=27) and (4) group in which a cup with screw holes, but no screw was used (n=42). Two adjunct groups (no-hole cups excluded) were established to compare the differences in the two types of HXLPE: (5) remelted group (n=100) and (6) annealed group (n=82). Implant stability and osteolysis were evaluated by plain radiography and computed tomography. The wear rate from 1 year to the final evaluation was measured using plain X-rays and PolyWare Digital software. RESULTS: All cups and stems achieved bony fixation. On CT-scan, no acetabular osteolysis was found, but there were 3 cases with a small area of femoral osteolysis. The mean steady-state wear rate of each group was (1) 0.031±0.022, (2) 0.033±0.035, (3) 0.031±0.024, (4) 0.029±0.018, (5) 0.030±0.018 and (6) 0.034±0.023mm/year, respectively. A comparison of the effects of screw usage or screw holes found no significant between-group differences in the implant stability, prevalence of osteolysis [no acetabular osteolysis and 3/209 at femoral side (1.4%)] and steady-state wear rate. DISCUSSION: This study suggests that there are no adverse effects on the results of THA with HXLPE from the use of cups with screw holes and the use of screws for cup fixation. LEVEL OF EVIDENCE: Level III retrospective case-control study.

Screening for musculoskeletal problems in Japanese schoolchildren: a cross-sectional study nested in a cohort.

OBJECTIVES: To clarify the frequency of musculoskeletal problems in public elementary and junior high school children and to determine the advantages and problems of musculoskeletal examinations. STUDY DESIGN: School-based cross-sectional study nested in a cohort. METHODS: We examined 41,376 public elementary and junior high school children (aged 6-15 years) in Miyazaki, Japan, from 2008 to 2014. Participation was voluntary. Participants received an in-school primary musculoskeletal examination (clinical examination with check items and a questionnaire) and a secondary examination at an orthopaedic outpatient clinic as indicated. Estimated prevalence rates for musculoskeletal problems were calculated from the results of both examinations. RESULTS: The total estimated prevalence of musculoskeletal problems was 8.6%. Prevalence by school grade ranged from 3.2% to 13.7%. Estimated prevalence rates increased as grade increased and were higher in junior high school students than in elementary school students. The secondary examination identified musculoskeletal problems on the back (65.4%), knee (8.1%), ankle or feet (7.3%) and elbow (5.4%). Of those referred for a secondary examination, 44.4% had not reported musculoskeletal complaints on the initial questionnaire. Overall, 69.8% of problems diagnosed in the secondary examination were previously undiagnosed. CONCLUSIONS: School-based musculoskeletal examination enables early detection of abnormal growth and disorders of the locomotive organs and is expected to support children's musculoskeletal growth and development. We recommend musculoskeletal examinations as part of school check-ups in Japan. Our findings suggest musculoskeletal examinations should be conducted for students in higher elementary school grades and for all junior high school students. Evaluation should include both direct clinical examination and questionnaires.

Preventing E-cadherin aberrant N-glycosylation at Asn-554 improves its critical function in gastric cancer.

E-cadherin is a central molecule in the process of gastric carcinogenesis and its posttranslational modifications by N-glycosylation have been described to induce a deleterious effect on cell adhesion associated with tumor cell invasion. However, the role that site-specific glycosylation of E-cadherin has in its defective function in gastric cancer cells needs to be determined. Using transgenic mice models and human clinical samples, we demonstrated that N-acetylglucosaminyltransferase V (GnT-V)-mediated glycosylation causes an abnormal pattern of E-cadherin expression in the gastric mucosa. In vitro models further indicated that, among the four potential N-glycosylation sites of E-cadherin, Asn-554 is the key site that is selectively modified with ß1,6 GlcNAc-branched N-glycans catalyzed by GnT-V. This aberrant glycan modification on this specific asparagine site of E-cadherin was demonstrated to affect its critical functions in gastric cancer cells by affecting E-cadherin cellular localization, cis-dimer formation, molecular assembly and stability of the adherens junctions and cell-cell aggregation, which was further observed in human gastric carcinomas. Interestingly, manipulating this site-specific glycosylation, by preventing Asn-554 from receiving the deleterious branched structures, either by a mutation or by silencing GnT-V, resulted in a protective effect on E-cadherin, precluding its functional dysregulation and contributing to tumor suppression.

Circulating soluble receptor for advanced glycation end products is inversely correlated to oxidized low-density lipoproteins in asymptomatic subjects.

OBJECTIVE: There is growing evidence that circulating soluble receptor for advanced glycation end products (sRAGE) exerts antiatherogenic effects as a decoy receptor that abolishes RAGE signalling. A previous study reported that oxidized low-density lipoprotein (oxLDL) can be one of the RAGE ligands. The present cross-sectional study investigated the clinical association between sRAGE and oxLDL in humans. METHODS: Serum levels of the conventional atherosclerotic risk factors, sRAGE and malondialdehyde-modified low-density lipoprotein (MDA-LDL) were analysed in asymptomatic subjects; MDA-LDL was measured as a biomarker of oxLDL. RESULTS: Mean serum levels of sRAGE and MDA-LDL were 1101 ng/l and 57.6 IU/l, respectively, in 33 subjects of mean age 65 years. Simple linear regression analysis showed a significant inverse correlation between sRAGE and MDA-LDL. Stepwise multiple linear regression analysis confirmed MDA-LDL to be independently, significantly and inversely correlated with sRAGE. CONCLUSIONS: An independent, significant and inverse correlation was shown to exist between circulating levels of sRAGE and oxLDL (MDA-LDL), which suggests that part of the antiatherosclerotic effects of sRAGE may be related to oxLDL quenching.

Sorption and desorption of 17ß-estradiol to natural sediment.

The sorption and desorption of 17ß-estradiol (E2) to various natural sediment were investigated. First, the quantitative solvent-water partition indices were measured. Significant differences were found between the n-octanol-water partition coefficient (K(OW)) and the n-hexane-water partition coefficient (K(HW)) of E2. The value of K(HW) (Log K(HW) = 0.07) is lower than those of two to four ring polyaromatic hydrocarbons (PAHs), while the value of K(OW) (Log K(OW) = 3.99) and that of organic matter-water partition coefficient (K(OC)) onto humic acid (Log K(OC) = 4.30) were similar to those of the PAHs. Five natural sediments of various characteristics and origins were selected for sorption and desorption experiments. Linear isotherms were obtained for sorption and desorption. The equilibrium partitioning coefficients of E2 were well-correlated with their values of weight fraction of organic carbon in sediments (f(OC)). Results suggest that E2 is sorbed mainly onto the organic portion of sediments and that its sorption coefficient can be estimated from K(OW) and f(OC), as in the case of non-polar PAHs. However, because of its polarity, the sorption mechanism of E2 onto sediments cannot be explained solely by the hydrophobic interaction.

Correlation between ischaemia-modified albumin and intermediate-density lipoprotein in haemodialysis patients with end-stage renal disease.

This study investigated the association between ischaemia-modified albumin (IMA), a biomarker of cardiac ischaemia, and increases in the levels of intermediate-density lipoprotein (IDL), an atherogenic particle that can cause oxidative stress, in haemodialysis patients with end-stage renal disease (ESRD). Fasting levels of serum IMA and lipids/lipoproteins were analysed in 15 patients and 15 healthy control subjects. There was a close positive correlation between IMA and IDL levels in ESRD patients but no significant correlation between IMA and lipids/lipoproteins in control subjects. This suggests a possible link between the characteristic dyslipoproteinaemia found in ESRD and levels of IMA and, if confirmed in studies with larger sample sizes, may lead to further studies on the potential of the relationship between IMA and IDL as a biomarker in haemodialysis patients with ESRD.

The association between circulating secreted protein acidic and rich in cysteine (SPARC) and glycosylated haemoglobin (HbA(1c)) during lifestyle-modified weight reduction intervention in obese male subjects.

The physiological role and clinical relevance of circulating secreted protein acidic and rich in cysteine (SPARC, or osteonectin) is still poorly understood. This study investigated the correlation between circulating SPARC and metabolic variables, including glucose and glycosylated haemoglobin (HbA(1c)), during a diet and exercise modified weight reduction intervention programme. Changes in plasma SPARC levels and several metabolic variables were analysed in asymptomatically obese, nondiabetic, male subjects before and after weight reduction intervention. Body mass index and blood pressure, serum cholesterol and HbA(1c) levels were all significantly reduced after weight reduction intervention. Multiple regression analysis demonstrated that changes in SPARC levels were significantly and positively correlated with HbA(1c). The relationship between SPARC and HbA(1c) may merit further investigation with regard to its association with postprandial or long-term glucose variation in obese male subjects.

Defect of glucosyltransferases reduces platelet aggregation activity of Streptococcus mutans: analysis of clinical strains isolated from oral cavities.

OBJECTIVE: Streptococcus mutans is a major pathogen of dental caries and occasionally isolated from the blood of patients with infective endocarditis, though the association of its cell-surface glucosyltransferases (GTFB, GTFC, and GTFD) with pathogenicity for infective endocarditis remains to be elucidated. In this study, we investigated the contribution of S. mutans GTFs to platelet aggregation and analysed GTF expression profiles in a large number of clinical oral isolates. DESIGN: The platelet aggregation properties of GTF-defective isogenic mutant strains constructed from S. mutans reference strain MT8148 were evaluated using whole blood and platelet-rich plasma (PRP) taken from mice, as well as human PRP. In addition, GTF expression profiles for 396 S. mutans strains isolated from the oral cavities of 396 subjects were analysed by western blotting using antisera specific for each GTF. RESULTS: The platelet aggregation activities of the GTF-defective isogenic mutants were significantly lower than that of MT8148 when added to a large number of cells. Western blotting revealed no strains without GTF expression, though six strains had alterations of GTFB and GTFC as compared to MT8148. PCR analyses indicated that the gtfB-gtfC region length was approximately 4.5 kb shorter in those strains as compared to MT8148. These were designated as "GTFBC-fusion" strains and they demonstrated lower levels of platelet aggregation. CONCLUSIONS: Our findings indicate that GTFs are associated with platelet aggregation. Although the clinical detection frequency of S. mutans strains with altered expressions is extremely low, GTFBC-fusion strains have activities similar to GTF-defective mutant strains.

Molecular characterization of Streptococcus mutans strains containing the cnm gene encoding a collagen-binding adhesin.

OBJECTIVE: Streptococcus mutans, known to be a major pathogen of dental caries, is also considered to cause infective endocarditis. Its 120-kDa Cnm protein binds to type I collagen, which may be a potential virulence factor. In this study, we characterized S. mutans clinical strains focusing on the cnm gene encoding Cnm. DESIGN: A total of 528 S. mutans strains isolated from Japanese, Finnish, and Thai subjects were investigated. Using molecular techniques, the distribution frequency of cnm-positive strains and location of the inserted cnm were analyzed. Furthermore, isogenic mutant strains were constructed by inactivation of the cnm gene, then their biological properties of collagen-binding and glucan-binding were evaluated. Southern hybridization of the genes encoding glucan-binding proteins was also performed. RESULTS: The distribution frequency of cnm-positive strains from Thai subjects was 12%, similar to that previously reported for Japanese and Finnish subjects. Furthermore, the location of insertion of cnm was the same in all cnm-positive clinical isolates. As for the cnm-inactivated mutant strains constructed from 28 clinical isolates, their collagen-binding activity was negligible. In addition, glucan-binding activity in the cnm-positive clinical isolates was significantly reduced and corresponded to a lack of gbpA encoding glucan-binding protein A. CONCLUSIONS: Our results indicate that strains with cnm genes, the most crucial factor for the collagen-binding property of S. mutans, are detectable at similar frequencies over several different geographic locations. In addition, the common properties of these strains are a high level of collagen-binding activity and tendency for a low level of glucan-binding activity.

Measurement of branching fractions, isospin, and CP-violating asymmetries for exclusive b-->dgamma modes.

We report new measurements of the decays B+-->rho+gamma, B0-->rho0gamma, and B0-->omegagamma using a data sample of 657x10(6) B meson pairs accumulated with the Belle detector at the KEKB e+e- collider. We measure branching fractions B(B+-->rho+gamma)=(8.7_-2.7-1.1;+2.9+0.9)x10(-7), B(B0-->rho0gamma)=(7.8_-1.6-1.0;+1.7+0.9)x10(-7), and B(B0-->omegagamma)=(4.0_-1.7;+1.9+/-1.3)x10(-7). We also report the isospin asymmetry Delta(rhogamma)=-0.48_-0.19-0.09;+0.21+0.08 and the first measurement of the direct CP-violating asymmetry ACP(B+-->rho+gamma)=-0.11+/-0.32+/-0.09, where the first and second errors are statistical and systematic, respectively.

Hole localization in the one-dimensional doped Anderson-Hubbard model.

We study an interplay of disorder and correlation in the one-dimensional hole-doped Hubbard-model with disorder (Anderson-Hubbard model) by using the density-matrix renormalization group method. Concentrating on the doped-hole-density profile, we find in a large U/t regime that the clean system exhibits a simple fluidlike behavior whereas finite disorders create locally Mott regions which expand their area with increasing the disorder strength contrary to the conventional sense. We propose that such an anomalous Mott phase formation assisted by disorder is easily observable in atomic Fermi gases by setting up the box-shape trap.

Protein antigen in serotype k Streptococcus mutans clinical isolates.

Streptococcus mutans, a major pathogen of dental caries and infective endocarditis, is classified into serotypes c, e, f, and k, with serotype k strains recently reported to be frequently detected in persons with infective endocarditis. Thus, we hypothesized that common properties associated with infective endocarditis are present in those strains. Fifty-six oral S. mutans strains, including 11 serotype k strains, were analyzed. Western blotting analysis revealed expression of the 3 types of glucosyltransferases in all strains, while expression of the approximately 190-kDa cell-surface protein (PA) was absent in 12 strains, among which the prevalence of serotype k (7/12) was significantly high. Furthermore, cellular hydrophobicity and phagocytosis susceptibility were lower in the group of serotype k strains. These results indicate that the absence of PA expression, low cellular hydrophobicity, and phagocytosis susceptibility are common bacterial properties associated with serotype k strains, which may be associated with virulence for infective endocarditis.

Time-dependent CP-violating asymmetry in B0-->rho0gamma decays.

We report the first measurement of CP-violation parameters in B0-->rho0gamma decays based on a data sample of 657x10(6)BB pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. We obtain the time-dependent and direct CP-violating parameters, Srho0gamma=-0.83+/-0.65(stat)+/-0.18(syst) and Arho0gamma=-0.44+/-0.49(stat)+/-0.14(syst), respectively.

A new three-dimensional automatic bodymarker system for transvaginal ultrasonography.

OBJECTIVE: To evaluate the accuracy and usefulness of a newly developed three-dimensional automatic bodymarker system for transvaginal ultrasonography. METHODS: A bodymarker system which utilizes an electromagnetic field to specify the probe position was developed. Software was written which enabled the positional information of the probe and the ultrasound image to be simultaneously displayed on a personal computer. The bodymarker was displayed as a three-dimensional graphic model. The differences between the estimated and the actual position--i.e. the error--for both position (x, y and z) and angles (azimuth, elevation and roll) of the probe were measured. The movement of the probe was then evaluated in healthy female volunteers and the comparative time required for ultrasound examination was determined. RESULTS: Both the position and the angles of the probe were accurately shown in the computer display. The errors were 1.0 mm and 0.7 degrees (median) for position and angle, respectively. The system was also shown to work well in healthy female volunteers. Calibration of the new system required only 5.0 seconds, compared with an average of 7.6 seconds for the conventional bodymarker. CONCLUSION: The newly developed three-dimensional automatic transvaginal bodymarker system provides an accurate indication of probe position and its tilting angle. It works well in healthy female volunteers and speeds up the examination time. It may be clinically useful for transvaginal ultrasound examination.

[Penetrating chest trauma in which thoracoscopy was helpful; report of a case].

A 32-year-old builder suffered from a chest trauma in a construction area. A ratchet penetrated his right chest wall posterolaterally, and he was transferred to our hospital. A chest X-ray and a computed tomography (CT) revealed that the tip of the instrument remained in the thoracic cavity and there were no other obvious damages including pneumothorax, hemothorax, and liver damage. We thought the simple removal of the instrument from his body was dangerous so he was transferred to the operating room and his chest was opened under general anesthesia. However, it was difficult to confirm the inside of penetrating point from the thoracotomy wound; therefore we used a thoracoscope. The thoracoscopy disclosed a penetration in the lung and a contusion on the diaphragm. The application of thoracoscopy in the operation of thoracic trauma is very promising in exploration of the thoracic cavity, especially in the area which is out of vision from the open thoracotomy.

Increased expression of humanin peptide in diffuse-type pigmented villonodular synovitis: implication of its mitochondrial abnormality.

OBJECTIVES: To define the pathogenesis of pigmented villonodular synovitis (PVNS), by searching for highly expressed genes in primary synovial cells from patients with PVNS. METHODS: A combination of subtraction cloning and Southern colony hybridisation was used to detect highly expressed genes in PVNS in comparison with rheumatoid synovial cells. Northern hybridisation was performed to confirm the differential expression of the humanin gene in PVNS. Expression of the humanin peptide was analysed by western blotting and immunohistochemistry. Electron microscopic immunohistochemistry was performed to investigate the distribution of this peptide within the cell. RESULTS: 68 highly expressed genes were identified in PVNS. Humanin genes were strongly expressed in diffuse-type PVNS, but were barely detected in nodular-type PVNS, rheumatoid arthritis, or osteoarthritis. Humanin peptide was identified in synovium from diffuse-type PVNS, and most of the positive cells were distributed in the deep layer of the synovial tissue. Double staining with anti-humanin and anti-heat shock protein 60 showed that humanin was expressed mainly in mitochondria. Electron microscopy disclosed immunolocalisation of this peptide, predominantly around dense iron deposits within the siderosome. CONCLUSIONS: Increased expression of the humanin peptide in mitochondria and siderosomes is characteristic of synovial cells from diffuse-type PVNS. Humanin is an anti-apoptotic peptide which is encoded in the mitochondrial genome. Present findings suggest that mitochondrial dysfunction may be the principal factor in pathogenesis of diffuse-type PVNS and that humanin peptide may play a part in the neoplastic process in this form of PVNS.