A Water-Based Biocoating to Increase the Infection Resistance and Osteoconductivity of Titanium Surfaces.

As the population ages, the number of patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA) continues to increase. Infections after primary arthroplasty are rare but have high rates of morbidity and mortality, as well as enormous financial implications for healthcare systems. Numerous methods including the use of superhydrophobic coatings, the incorporation of antibacterial agents, and the application of topographical treatments have been developed to reduce bacterial attachment to medical devices. However, most of these methods require complex manufacturing processes. Thus, the main purpose of this study was to apply biocoatings to titanium (Ti) surfaces to increase their infection resistance and osteoconductivity via simple processes, without organic reagents. We modified titanium surfaces with a combination of aminomalononitrile (AMN) and an antibiotic-loaded mesoporous bioactive glass (MBG) and evaluated both the antibacterial effects of the coating layer and its effect on osteoblast proliferation and differentiation. The properties of the modified surface, such as the hydrophilicity, roughness, and surface morphology, were characterized via contact angle measurements, atomic force microscopy, and scanning electron microscopy. The cell proliferation reagent WST-1 assay and the alkaline phosphatase (ALP) assay were used to determine the degrees of adhesion and differentiation, respectively, of the MG-63 osteoblast-like cells on the surface. Antimicrobial activity was evaluated by examining the survival rate and inhibition zone of Escherichia coli (E. coli). The AMN coating layer reduced the water contact angle (WCA) of the titanium surface from 87° ± 2.5° to 53° ± 2.3° and this change was retained even after immersion in deionized water for five weeks, demonstrating the stability of the AMN coating. Compared with nontreated titanium and polydopamine (PDA) coating layers, the AMN surface coating increased MG-63 cell attachment, spreading, and early ALP expression; reduced E. coli adhesion; and increased the percentage of dead bacteria. In addition, the AMN coating served as an adhesion layer for the subsequent deposition of MBG-containing antibiotic nanoparticles. The synergistic effects of the AMN layer and antibiotics released from the MBG resulted in an obvious E. coli inhibition zone that was not observed in the nontreated titanium group.

A rare case of pancreatic macrocystic serous cystadenoma in an adolescent: a case report and literature review.

While serous cystadenomas of the pancreas usually consist of small cysts, one rare variant has been reported to be composed of macrocysts. Herein, we present the case of the youngest patient with macrocystic serous cystadenoma (MSC) to be reported in the literature. The patient was a 17-year-old girl who presented with the major symptoms of a palpable abdominal mass accompanied by epigastric pain and vomiting for several months. A potential malignancy could not be excluded on the basis of imaging studies, which showed a large macrocystic pancreatic tumor that was 7 cm in diameter. Owing to the patient's symptoms, after diagnosing the mass as a pancreatic cystic tumor with potential malignancy and large tumor size, surgical intervention was arranged. Pathological analysis of the biopsy sample suggested MSC. By reviewing the literature, we found several unique characters of MSCs that cause them to be frequently misdiagnosed as potential malignancies. Additionally, the age of MSC occurrence was found to be lower than of general serous cystadenomas. The potential of MSC should be kept in mind by clinicians when diagnosing young people with pancreatic macrocystic lesions.

Clinical and radiologic outcomes of the modified phemister procedure with coracoclavicular ligament augmentation using mersilene tape versus hook plate fixation for acute acromioclavicular joint dislocation.

BACKGROUND: The clinical superiority of surgical treatment for acromioclavicular (AC) joint dislocation remains controversial. The aim of this study was to compare the clinical and radiological outcomes of the modified Phemister procedure with CC ligament augmentation using Mersilene tape to those of hook plate fixation for acute AC joint dislocation. METHODS: In this study, patients who received modified Phemister surgery with CC ligament augmentation using Mersilene tape (PM group) or hook plate fixation (HK group) for acute unstable AC joint dislocation with a minimum 5-year follow-up period were retrospectively reviewed. The clinical outcomes were evaluated according to blood loss during surgery, surgical duration, visual analogue scale (VAS), Constant-Murley score (CMS), University of California at Los Angeles (UCLA) shoulder rating scale, and the occurrence of complications. Radiological outcomes were assessed from radiographs according to multiple parameters, including CC distance maintenance, acromion osteolysis, and the presence of distal clavicle osteolysis. RESULTS: A total of 35 patients completed follow-up for more than 5 years and were analyzed in this study (mean = 74.08 months). There were 18 patients in the PM group and 17 in the HK group. The PM group exhibited similar improvement in functional outcome to the HK group. Regarding radiological outcomes, the HK group had a superior performance in terms of CC distance maintenance, of statistical significance (CCDR: 94.29 ± 7.01% versus 111.00 ± 7.69%, p < 0.001) after a one-year follow-up period. However, there were 4 cases of acromion osteolysis and 2 cases of distal clavicle osteolysis in the HK group. CONCLUSION: Hook plate fixation was found to be superior to the modified Phemister technique with CC ligament augmentation using Mersilene tape in terms of CC distance maintenance, but there was no significant difference in the functional outcome after 5 years of follow-up. Both surgical methods are reliable options for the treatment of acute AC joint dislocation. Modified Phemister surgery with CC ligament augmentation using Mersilene tape is a relatively lower-cost option for acute AC joint dislocation without the need of a second surgery for implant removal.

Treatment of sirolimus in the pathological femoral fracture related to blue rubber bleb nevus syndrome: A case report.

RATIONALE: Blue rubber bleb nevus syndrome (BRBNS) is a rare condition with characteristic vascular malformations of the skin, most frequently lesions of the gastrointestinal tract and central nervous system, and less often, the musculoskeletal system. We report a 5-year case of BRBNS complicated with pathological femoral fracture that was successfully treated with sirolimus. PATIENT CONCERNS: We report the case of a 1-week-old girl with a diagnosis of BRBNS who had multiple venous malformations over her body. She also presented with right lower-limb swelling and complicated with a pathological femoral fracture. DIAGNOSES: BRBNS with the complication of pathological femoral fracture. INTERVENTIONS: Treatment with low-dose sirolimus as an antiangiogenic agent was administered, combined with hip spica protection. OUTCOMES: The vascular lesion was reduced after about 6 months and the fracture site had healed around 2.5 years after initiation of sirolimus therapy. There were no drug adverse effects at the 5-year follow-up point. The patient showed excellent spirit and no obvious sequelae were found. LESSONS: To the best of our knowledge, this is the first report of the successful use of sirolimus in a patient with a pathological femoral fracture related to BRBNS complications.

Measurement of Electrical Discharge Machining Oil Quality by Analyzing Variations in the Equivalent Relative Permittivity of the Capacitive Sensor.

In this study, a concentration monitoring system was successfully developed. A sensor was immersed in electrical discharge machining oil, and the capacitance of the sensor changed as a function of the impurity concentration. Thus, DC voltage variations were produced via a conversion circuit. Carbon black and iron particles with different concentrations were successfully characterized. The capacitance increments were positively correlated with the particle concentration. The linear fitting results based on the impurity concentration were used to express the degree of influence of particles with different weight percentage concentrations on the increase in the overall capacitance value. An equivalent medium theory model was then developed according to the electrical characteristics of the impurities to predict different particle volume percentages.

Design and Synthesis of Benzimidazole-Chalcone Derivatives as Potential Anticancer Agents.

Numerous reports have shown that conjugated benzimidazole derivatives possess various kinds of biological activities, including anticancer properties. In this report, we designed and synthesized 24 new molecules comprising a benzimidazole ring, arene, and alkyl chain-bearing cyclic moieties. The results showed that the N-substituted benzimidazole derivatives bearing an alkyl chain and a nitrogen-containing 5- or 6-membered ring enhanced the cytotoxic effects on human breast adenocarcinoma (MCF-7) and human ovarian carcinoma (OVCAR-3) cell lines. Among the 24 synthesized compounds, (2E)-1-(1-(3-morpholinopropyl)-1H-benzimidazol-2 -yl)-3-phenyl-2-propen-1-one) (23a) reduced the proliferation of MCF-7 and OVCAR-3 cell lines demonstrating superior outcomes to those of cisplatin.

Daptomycin treatment in patients with resistant staphylococcal periprosthetic joint infection.

BACKGROUND: Resistant staphylococcal organisms remain a serious problem in the treatment of periprosthetic joint infection (PJI). Higher failure rates have been reported when vancomycin was used. The purpose of this study was to assess the clinical dosage, effect, and safety of daptomycin in patients with resistant staphylococcal PJI. METHODS: We retrospectively enrolled patients with hip or knee PJI who were treated with daptomycin in our institution (n = 16) from January 2013 to December 2014 with a minimum follow-up of 2 years. The patients received daptomycin when glycopeptide could not be used due to multiple resistance, any adverse reaction, chronic kidney disease stage 3 or worse, and previous treatment failure with glycopeptide or empirical therapy. RESULTS: These patients received daptomycin at a median dose of 8.3 mg∕kg per day for a median duration of 14 days. The overall treatment success rate was 87.5% (14 of 16 cases) after a median follow-up period of 27 months. In the subgroups of acute and chronic PJI, the success rate was 80% and 91%, respectively. One patient developed asymptomatic transient serum aspartate transaminase (AST) elevation. No severe side effects such as myositis, acute renal failure due to rhabdomyolysis or eosinophilic pneumonia were found in our series. CONCLUSION: Relatively high daptomycin doses combined with adequate surgical intervention were effective in treating resistant staphylococcal PJI. Daptomycin is an option worthy of consideration in PJI patients for whom glycopeptide treatment is unsuitable. Further prospective randomized comparative study is needed in the future.

Nanoscale, catalytically enhanced local oxidation of silicon-containing layers by 'burrowing' Ge quantum dots.

A new phenomenon of highly localized, nanoscale oxidation of silicon-containing layers has been observed. The localized oxidation enhancement observed in both Si and Si(3)N(4) layers appears to be catalyzed by the migration of Ge quantum dots (QDs). The sizes, morphology, and distribution of the Ge QDs are influenced by the oxidation of the Si-bearing layers. A two-step mechanism of dissolution of Si within the Ge QDs prior to oxidation is proposed.

Crystal structure of Bacillus subtilis guanine deaminase: the first domain-swapped structure in the cytidine deaminase superfamily.

Guanine deaminase, a key enzyme in the nucleotide metabolism, catalyzes the hydrolytic deamination of guanine into xanthine. The crystal structure of the 156-residue guanine deaminase from Bacillus subtilis has been solved at 1.17-A resolution. Unexpectedly, the C-terminal segment is swapped to form an intersubunit active site and an intertwined dimer with an extensive interface of 3900 A(2) per monomer. The essential zinc ion is ligated by a water molecule together with His(53), Cys(83), and Cys(86). A transition state analog was modeled into the active site cavity based on the tightly bound imidazole and water molecules, allowing identification of the conserved deamination mechanism and specific substrate recognition by Asp(114) and Tyr(156'). The closed conformation also reveals that substrate binding seals the active site entrance, which is controlled by the C-terminal tail. Therefore, the domain swapping has not only facilitated the dimerization but has also ensured specific substrate recognition. Finally, a detailed structural comparison of the cytidine deaminase superfamily illustrates the functional versatility of the divergent active sites found in the guanine, cytosine, and cytidine deaminases and suggests putative specific substrate-interacting residues for other members such as dCMP deaminases.

Crystallization and preliminary crystallographic analysis of Bacillus subtilis guanine deaminase.

Guanine deaminase, a key enzyme in nucleotide metabolism, catalyzes the hydrolytic deamination of guanine to xanthine. The first guanine deaminase crystal from Bacillus subtilis was grown in the absence or presence of the inhibitor hypoxanthine in 30% polyethylene glycol 4000, 0.2 M ammonium acetate and 0.1 M sodium citrate pH 6.5. The crystals belong to space group C222(1), with unit-cell parameters a = 84.91, b = 90.90, c = 80.19 angstroms, with one dimer per asymmetric unit. The crystals diffract X-rays to beyond 1.2 angstroms resolution and an initial atomic model has been built based on selenomethionyl multiwavelength anomalous data at 2 angstroms resolution. Unexpectedly, this is the first domain-swapped structure in the cytidine deaminase superfamily.