Epidermoid Cyst of Orbit Requiring Cranialization of Frontal Sinus.

How often do intracranial epidermoid cysts occur?Is a coronary incision necessary?What are the steps of the procedure, difficulties encountered, and process for circumventing those difficulties?What is the follow-up protocol and outcome?

Dimerization of ER-resident molecular chaperones mediated by ERp29.

The lectin chaperones calnexin (CNX) and calreticulin (CRT) localized in the endoplasmic reticulum play important roles in glycoprotein quality control. Although the interaction between these lectin chaperones and ERp57 is well known, it has been recently reported that endoplasmic reticulum protein 29 (ERp29), a member of PDI family, interacts with CNX and CRT. The biochemical function of ERp29 is unclear because it exhibits no ERp57-like redox activity. In this study, we addressed the possibility that ER chaperones CNX and CRT are connected via ERp29, based on our observation that ERp29 exists as a dimer. As a result, we showed that CNX dimerizes through ERp29. These results endorse the hypothesis that ERp29 serves as a bridge that links two molecules of CNX. Also, we showed that similar complexes such as CNX-CRT were formed via ERp29.

An analytical study of neocartilage from microtia and otoplasty surgical remnants: A possible application for BMP7 in microtia development and regeneration.

To investigate auricular reconstruction by tissue engineering means, this study compared cartilage regenerated from human chondrocytes obtained from either microtia or normal (conchal) tissues discarded from otoplasties. Isolated cells were expanded in vitro, seeded onto nanopolyglycolic acid (nanoPGA) sheets with or without addition of bone morphogenetic protein-7 (BMP7), and implanted in nude mice for 10 weeks. On specimen harvest, cartilage development was assessed by gross morphology, histology, and RT-qPCR and microarray analyses. Neocartilages from normal and microtia surgical tissues were found equivalent in their dimensions, qualitative degree of proteoglycan and elastic fiber staining, and quantitative gene expression levels of types II and III collagen, elastin, and SOX5. Microarray analysis, applied for the first time for normal and microtia neocartilage comparison, yielded no genes that were statistically significantly different in expression between these two sample groups. These results support use of microtia tissue as a cell source for normal auricular reconstruction. Comparison of normal and microtia cells, each seeded on nanoPGA and supplemented with BMP7 in a slow-release hydrogel, showed statistically significant differences in certain genes identified by microarray analysis. Such differences were also noted in several analyses comparing counterpart seeded cells without BMP7. Summary data suggest a possible application for BMP7 in microtia cartilage regeneration and encourage further studies to elucidate whether such genotypic differences translate to phenotypic characteristics of the human microtic ear. The present work advances understanding relevant to the potential clinical use of microtia surgical remnants as a suitable cell source for tissue engineering of the pinna.

An automated microliter-scale high-throughput screening system (MSHTS) for real-time monitoring of protein aggregation using quantum-dot nanoprobes.

Protein aggregation is the principal component of numerous protein misfolding pathologies termed proteinopathies, such as Alzheimer's disease, Parkinson's disease, prion disease, and AA amyloidosis with unmet treatment needs. Protein aggregation inhibitors have great potential for the prevention and treatment of proteinopathies. Here we report the development of an automated real-time microliter-scale high throughput screening (MSHTS) system for amyloid aggregation inhibitors using quantum-dot nanoprobes. Screening 504 crude extracts and 134 low molecular weight aromatic compounds revealed the relationship of amyloid-ß (Aß) aggregation inhibitory activities of plant extracts using a plant-based classification. Within the eudicots, rosids, Geraniales and Myrtales showed higher activity. Screening low molecular weight aromatic compounds demonstrated that the structure of tropolone endows it with potential Aß aggregation inhibitory activity. The activity of the most active tropolone derivative was higher than that of rosmarinic acid. MSHTS also identified three chaperone molecules as tau aggregation inhibitors. These results demonstrate that our automated MSHTS system is a novel and robust tool that can be adapted to a wide range of compounds and aggregation-prone polypeptides.

PDI family protein ERp29 recognizes P-domain of molecular chaperone calnexin.

Endoplasmic reticulum (ER) resident lectin chaperone calnexin (CNX) and calreticulin (CRT) assist folding of nascent glycoproteins. Their association with ERp57, a member of PDI family proteins (PDIs) which promote disulfide bond formation of unfolded proteins, has been well documented. Recent studies have provided evidence that other PDIs may also interact with CNX and CRT. Accordingly, it seems possible that the ER provides a repertoire of CNX/CRT-PDI complexes, in order to facilitate refolding of various glycoproteins. In this study, we examined the ability of PDIs to interact with CNX. Among them ERp29 was shown to interact with CNX, similarly to ERp57. Judging from the dissociation constant, its ability to interact with CNX was similar to that of ERp57. Results of further analyses by using a CNX mutant imply that ERp29 and ERp57 recognize the same domain of CNX, whereas the mode of interaction with CNX might be somewhat different between them.

Long-Term Comparison between Human Normal Conchal and Microtia Chondrocytes Regenerated by Tissue Engineering on Nanofiber Polyglycolic Acid Scaffolds.

BACKGROUND: Previous regeneration studies of auricle-shaped cartilage by tissue engineering leave unresolved whether the chondrocyte phenotype from human auricular chondrocytes seeded onto polymeric scaffolds is retained over the long term and whether microtia remnants may be a viable cell source for auricular reconstruction. METHODS: Chondrocytes were isolated from human ears, either normal conchal ear or microtia cartilage remnants, expanded in vitro, and seeded onto nanoscale-diameter polyglycolic acid sheets. These tissue-engineered constructs were implanted into athymic mice for up to 40 weeks. At harvest times of 5, 10, 20, and 40 weeks, samples were documented by gross morphology, histology, and reverse transcription-quantitative polymerase chain reaction analysis. RESULTS: Neocartilages generated from the two types of surgical tissues were similar in appearance of their extracellular matrices and positive staining for elastin and proteoglycans. In the 5- to 40-week time interval, there was an increasing trend in gene expression for type II collagen, elastin, and sex determining region Y box 5, important to normal cartilage phenotype, and a decreasing trend in gene expression for type III collagen, a fibroblast and dedifferentiation marker. Over 40 weeks of implantation, the original nanoscale-diameter polyglycolic acid scaffold dimensions (1 cm × 1 cm × 80 µm) were generally maintained in tissue-engineered cartilage length and width, and thickness was statistically significantly increased. CONCLUSIONS: Auricular cartilage can be regenerated over the long term (40 weeks) from surgical remnants by tissue-engineering techniques incorporating nanoscale-diameter polyglycolic acid scaffolds. Based on the present assays, microtia neocartilage very closely resembles tissue-engineered cartilage regenerated from chondrocytes isolated from normal conchal cartilage.

Long-term result of a biodegradable osteo-inductive copolymer for the treatment of orbital blowout fracture.

PURPOSE: We have recently reconstructed the orbital wall using a bioabsorbable osteo-inductive copolymer as a support material for the bone defects in patients with orbital blowout fracture. The purpose of this study was to investigate a 2-year follow-up after implantation. MATERIAL AND METHODS: In order to investigate the efficacy and safety of the bioabsorbable osteo-inductive copolymer HA-P(LA/CL), hydroxyapatite-poly(l-lactide-ε-caprolactone), we measured CT density of the implanted copolymers in 7 patients at such time points as 1 week, 6 months and 2 years after surgery along with the long-term outcomes with regard to postoperative complications. RESULTS: Five patients in whom the intraoperative maximum width of the bone defect was less than 15 mm demonstrated the fracture types of either linear or trap-door. All patients treated with HA-P(LA/CL) copolymer indicated good bone formation with high CT density (>500) at 2 years postoperatively. In contrast, 2 patients in whom the intraoperative maximum width of the bone defect was more than 16 mm demonstrated a punched-out type fracture. Postoperative CT of the HA-P(LA/CL) copolymer showed low density (28.0 and 173.4) at 2 years postoperatively, indicative of limited bone formation. None of the cases demonstrated significant postoperative complications such as diplopia, enophthalmos, infection and extrusion of the implant material. CONCLUSION: The results of this study demonstrate that surgical treatment of orbital blowout fractures using bioabsorbable osteo-inductive copolymer was useful in linear and trap-door fractures.

Is it truly necessary to add epicanthoplasty for correction of the epiblepharon?

BACKGROUND: There are many modified variations of the original Hotz procedure for the repair of the epiblepharon. No matter which procedure is used, there must be some factors that may cause recurrence. One of possible causes of these unsatisfactory results can be due to the presence of epicanthal folds (EFs) among the oriental population. It is important to determine whether patients should be repaired with the simple epiblepharon or if it should be combined with epicanthoplasty especially for actively growing children. METHODS: All the patients were between 4 and 7 years old and had both epiblepharon and EF. The EFs were classified in 3 types, and all patients were operated on with the modified Hotz procedure. A "good" outcome was defined to be no contact between the eyelash and eyeball, and a "fair" outcome was defined to be several eyelashes contact with the eyeball, without any annoying symptoms. A "poor" outcome was defined to be most of the eyelids still in contact with the eyeball, and these patients persistently complain of irritation or keratitis. RESULTS: The study included 46 lower eyelids of 23 patients (14 females, 9 males; mean age, 5.7 years) who underwent operation. Thirty-five eyelids (76.1%) were assessed to have a "good" outcome, 9 eyelids (19.6%) were assessed to have a "fair" outcome, and 2 eyelids (4.3%) were assessed to have a "poor" outcome. CONCLUSIONS: We firmly believe that epicanthoplasty is not necessarily performed routinely for all epiblepharon unless there is any specific reason to justify the combined procedure.

Mycolyltransferase from Mycobacterium leprae excludes mycolate-containing glycolipid substrates.

Trehalose dimycolate (TDM) is a major surface-exposed mycolyl glycolipid that contributes to the hydrophobic cell wall architecture of mycobacteria. Nevertheless, because of its potent adjuvant functions, pathogenic mycobacteria appear to have evolved an evasive maneuver to down-regulate TDM expression within the host. We have shown previously that Mycobacterium tuberculosis (M.tb) and Mycobacterium avium (M.av), replace TDM with glucose monomycolate (GMM) by borrowing host-derived glucose as an alternative substrate for the FbpA mycolyltransferase. Mycobacterium leprae (M.le), the causative microorganism of human leprosy, is also known to down-regulate TDM expression in infected tissues, but the function of its mycolyltransferases has been poorly analysed. We found that, unlike M.tb and M.av FbpA enzymes, M.av FbpA was unexpectedly inefficient in transferring alpha-branched mycolates, resulting in impaired production of both TDM and GMM. Molecular modelling and mutational analysis indicated that a bulky side chain of leucine at position 130 of M.le FbpA obstructed the intramolecular tunnel that was proposed to accommodate the alpha-branch portion of the substrates. Notably, even after a highly reductive evolution, M.le FbpA remained functional in terms of transferring unbranched acyl chains, suggesting a role that is distinct from that as a mycolyltransferase.

Mycolyltransferase-mediated glycolipid exchange in Mycobacteria.

Trehalose dimycolate (TDM), also known as cord factor, is a major surface glycolipid of the cell wall of mycobacteria. Because of its potent biological functions in models of infection, adjuvancy, and immunotherapy, it is important to determine how its biosynthesis is regulated. Here we show that glucose, a host-derived product that is not readily available in the environment, causes Mycobacterium avium to down-regulate TDM expression while up-regulating production of another major glycolipid with immunological roles in T cell activation, glucose monomycolate (GMM). In vitro, the mechanism of reciprocal regulation of TDM and GMM involves competitive substrate selection by antigen 85A. The switch from TDM to GMM biosynthesis occurs near the physiological concentration of glucose present in mammalian hosts. We further demonstrate that GMM is produced in vivo by mycobacteria growing in mouse lung. These results establish an enzymatic pathway for GMM production. More generally, these observations provide a specific enzymatic mechanism for dynamic alterations of cell wall glycolipid remodeling in response to the transition from noncellular to cellular growth environments, including factors that are monitored by the host immune system.