Intraosseous epidermoid cyst discovered in the distal phalanx of a thumb: a case report.

Intraosseous epidermoid cyst is considered a rare benign inclusion cyst found mainly in the skull and phalanges. Once the cyst is differentiated from other similar lesions, the cyst can be treated with simple curettage, seldom requiring additional managements. We experienced this rare case that had been treated successfully without complication.

Relationship between the extent of labral lesions and the frequency of glenohumeral dislocation in shoulder instability.

PURPOSE: This study aimed to evaluate the relationship between the extent of the labral lesion and the frequency of glenohumeral dislocation in patients with shoulder instability. METHODS: Ninety-three patients, who underwent surgical treatment at our clinic for chronic anterior shoulder dislocation, were selected and divided into 3 groups (group I: only Bankart lesion; group II: Bankart and SLAP lesions; group III: circumferential-labral lesion). The pre-operative frequency of dislocation, intraoperative findings, operation time, post-operative clinical score, and range of motion 2 years after surgery were analysed and compared among the 3 groups. RESULTS: The time interval from the initial dislocation to operation was significantly shorter in group III than in groups I and II (P = 0.034 and P = 0.046, respectively). The median number of preoperative dislocations was also significantly less in group III than in groups I and II (P = 0.025 and P = 0.044, respectively). In all groups, the clinical scores (Constant, Rowe, and visual analogue scale) improved significantly post-operatively, and there were no significant differences in the scores between the different groups. All patients returned to work, and most patients returned to their preoperative sports activity levels. CONCLUSION: The extent of the labral lesion is not always related to the number of dislocations; therefore, treatment should not be based on this. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.

Comparison of the nonspecific binding of DNA-conjugated gold nanoparticles between polymeric and monomeric self-assembled monolayers.

The nonspecific binding of DNA-conjugated gold nanoparticles (AuNPs) to solid surfaces is more difficult to control than that of DNA molecules due to the more attractive interactions from the large number of DNA molecules per AuNP. This paper reports that the polymeric self-assembled monolayers (SAMs) formed on indium-tin oxide (ITO) electrodes significantly inhibit the nonspecific binding of DNA-conjugated AuNPs. The random copolymers used to prepare the polymeric SAMs consist of three functional parts: an ITO-reactive silane group, a DNA-blocking poly(ethylene glycol) (PEG) group, and an amine-reactive N-acryloxysuccinimide group. In order to compare the polymeric SAMs with various monomeric SAMs, the relative nonspecific binding of the DNA-conjugated AuNPs to the ITO electrodes modified with (3-aminopropyl)triethoxysilane (APTES), 3-aminopropylphosphonic acid, 3-phosphonopropionic acid, or 11-phosphonoundecanoic acid is examined by measuring the electrocatalytic anodic current of hydrazine caused by the nonspecifically absorbed AuNPs and by counting the AuNPs adsorbed onto modified ITO electrodes. Carboxylic-acid-terminated and amine-terminated monomeric SAMs cause high levels of nonspecific binding of DNA-conjugated AuNPs. The monomeric SAM modified with the carboxylic-acid-terminated poly(amidoamine) dendrimer shows low levels of nonspecific binding (2.0% nonspecific binding relative to APTES) due to the high surface density of the negative charge. The simply prepared polymeric SAM produces the lowest level of nonspecific binding (0.8% nonspecific binding relative to APTES), resulting from the combined effect of (i) DNA-blocking PEG and carboxylic acid groups and (ii) dense polymeric SAMs. Therefore, thin and dense polymeric SAMs may be effective in electrochemical detection and easy DNA immobilization along with low levels of nonspecific binding.

Nanocatalyst-based assay using DNA-conjugated Au nanoparticles for electrochemical DNA detection.

Compared to enzymes, Au nanocatalysts show better long-term stability and are more easily prepared. Au nanoparticles (AuNPs) are used as catalytic labels to achieve ultrasensitive DNA detection via fast catalytic reactions. In addition, magnetic beads (MBs) are employed to permit low nonspecific binding of DNA-conjugated AuNPs and to minimize the electrocatalytic current of AuNPs as well as to take advantage of easy magnetic separation. In a sandwich-type electrochemical sensor, capture-probe-conjugated MBs and an indium-tin oxide electrode modified with a partially ferrocene-modified dendrimer act as the target-binding surface and the signal-generating surface, respectively. A thiolated detection-probe-conjugated AuNP exhibits a high level of unblocked active sites and permits the easy access of p-nitrophenol and NaBH 4 to these sites. Electroactive p-aminophenol is generated at these sites and is then electrooxidized to p-quinoneimine at the electrode. The p-aminophenol redox cycling by NaBH 4 offers large signal amplification. The nonspecific binding of detection-probe-conjugated AuNPs is lowered by washing DNA-linked MB-AuNP assemblies with a formamide-containing solution, and the electrocatalytic oxidation of NaBH 4 by AuNPs is minimized because long-range electron transfer between the electrode and the AuNPs bound to MBs is not feasible. The high signal amplification and low background current enable the detection of 1 fM target DNA.