STEM and HRTEM studies of accumulated deposits on human tooth surface

Abstract

The aim of this study was to clarify the fine structure of accumulated deposits on the surface of teeth that are considered to affect the gloss of teeth.

The study was carried out using, as specimens, human incisor teeth having gloss, which were extracted from teenage donors and those incapable of showing gloss even by brushing which were extracted from donors in their 50s. Thin longitudinal sections of tooth enamel with accumulated deposits on the surface were prepared by focused ion beam (FIB) milling, and the fine structure was analyzed using a scanning transmission electron microscope (STEM) and a high resolution transmission electron microscope (HRTEM).

By FIB, thin longitudinal sections could be prepared from tooth enamel together with organic and inorganic substances accumulated on the surface without artifacts. The accumulated deposits on the surface of teeth having gloss were composed of organic substances. However, it was first revealed by STEM observation that the accumulated solid deposits on the surface of teeth having no gloss had a complicated structure wherein inorganic and organic substances coexisted.

It is suggested that the organic substances contain proteins derived from saliva. The inorganic substances were spherical and needle-like hydroxyapatites (HAs). It is considered that amino acids constituting the proteins affected the nucleus formation and the crystal formation of HA. It is considered that the unevenness of the accumulated deposits existing on the surface of tooth enamel having no gloss causes the decrease in gloss of teeth due to diffuse reflection of light.

from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2k2vpU6
via IFTTT

Skin regeneration stimulation: The role of PCL-platelet gel nanofibrous scaffold

Abstract

Skin is the largest organ of the human body. Thus far, tissue engineering of skin has developed rapidly and has used many types of growth factors and nanofibrous scaffolds. In this study, we differentiated neonate keratinocytes for epithelialization on the polycaprolactone-Platelet gel (PCL-PG) scaffold. Fabricated PCL nanofibers prepared by electrospinning technology and coated by platelet gel. Subsequently, the structure of the scaffold was evaluated by SEM, FTIR-ATR, contact angle and tensile test assays. After seeding the neonate keratinocytes on neat PCL and PCL-PG scaffolds, the epidermal maturation was tested by detecting cytokeratin 10 and loricrin determinants by immunocytochemistry; moreover, keratinocyte genes such as keratin 14, keratin 10, and Involucrin were investigated by real-time PCR. The results of MTT assay indicated an increase in cell viability and cell proliferation of neonate keratinocytes on PCL-PG nanofiber scaffolds compared with PCL. RT-PCR and immunocytochemical analysis showed better cell differentiation on the PCL-PG scaffolds than neat PCL. Furthermore, SEM microscopy images demonstrated that neo-keratinocytes enhance adhesion and proliferation on PCL-PG nanofiber scaffolds. We found that PG increases biocompatibility and wettability of scaffold, cell adhesion, and expression of keratinocyte markers. Overall, this procedure is recommended to be employed in skin tissue engineering and wounds healing.

from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2klQUNs
via IFTTT

Eyelid Eccrine Cyst: An Exceptional Lesion Among Dominant Apocrine Cysts.

A 71-year-old woman developed a small bluish lesion beneath the cilia of the left lower eyelid. Excision and microscopic examination disclosed a cyst with an intimately associated eccrine sweat gland. Immunohistochemistry demonstrated that the cyst's epithelium was strongly CK5/6+, CK14+, CK7 weakly positive, and gross cystic disease fluid protein-15 and smooth muscle actin negative. This is the first immunohistochemically proven eccrine cyst of the eyelid skin. Apocrine cysts develop only at the eyelid margin where the glands of Moll are located. They immunostain positively for cytoplasmic gross cystic disease fluid protein-15 in the adlumenal cells and smooth muscle actin in an outer myoepithelial (abluminal) layer. (C) 2017 by The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc., All rights reserved.

from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2kuYnZR
via IFTTT

The Use of Integra(R) Dermal Regeneration Template for the Orbital Exenteration Socket: A Novel Technique.

Purpose: Integra(R) dermal regeneration template is a bilayer membrane system that acts as a scaffold for regenerating dermal skin cells. It is used for wound reconstruction following burns, extensive injuries, and a large tumor excision in multiple parts of the body. The dermal layer is made of porous matrix of bovine tendon collagen and glycosaminoglycan. The epidermal layer is made of polysiloxane layer. In this study, the authors evaluated the use of Integra(R) dermal regeneration template for the immediate reconstruction of the orbital exenteration socket. Methods: Five patients who underwent exenteration and immediate reconstruction of the socket with Integra(R) dermal regeneration template were included in this study. Demographic and clinical features, healing time, complications, and follow-up time were recorded. Results: The study included 4 male patients and 1 female patient with a mean age of 74 years (range, 49-87 years). The primary diagnoses were orbital extension of conjunctival melanoma in 2 patients, squamous cell carcinoma in 1 patient, and uveal melanoma in 1 patient, and aggressive orbital Wegener granulomatosis in 1 patient. There was no postoperative infection, necrosis, hematoma, or fluid accumulation in any patients. The mean postoperative follow-up period was 20 months (range, 11-42 months). The sockets were completely granulated by 4 weeks, and epithelized, getting ready for the prosthesis in 8 weeks. Conclusions: Integra(R) dermal regeneration template can be used for the immediate reconstruction of the socket following exenteration. It is easy to use, and provides a short healing time without any need for any additional reconstructive procedures. (C) 2017 by The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc., All rights reserved.

from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2k5XUkh
via IFTTT

Chronic Eyelid Edema Following Periocular Hyaluronic Acid Filler Treatment.

A 54-year-old woman received multiple injections of hyaluronic acid filler to the brow region to address volume loss over a 21-month period. She then developed significant pitting edema of both upper eyelids, which persisted for 6 years. Hyaluronidase (Hyalase) was injected into the subcutaneous brows and resulted in complete resolution of the edema within 2 days. This confirms that the hyaluronic acid injected into the brows was responsible for this patient's chronic eyelid edema. This case illustrates an unusual long-term complication of periocular hyaluronic acid filler. (C) 2017 by The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc., All rights reserved.

from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2kuRxne
via IFTTT

Primary Orbital Chondromyxoid Fibroma: A Rare Case.

A 56-year-old male with history of chronic sinusitis was found to have a 3 cm left orbital lesion on CT. Subsequent MRI demonstrated a multilobulated enhancing soft tissue lesion at the superotemporal region of the left orbit. Initial biopsy was reported as a low-grade sarcoma. On further evaluation, a consensus was made that the lesion was likely a benign mixed mesenchymal type tumor but should nonetheless be surgically removed. Left lateral orbitotomy was performed which revealed a tumor originating in the lateral orbital bone with segments eroding through the wall of the orbit. Intraoperative frozen sections revealed myoepitheliod tissue with locally aggressive features and the tumor was completely removed. The final histopathologic analysis of the tissue was consistent with a chondromyxoid fibroma. Chondomyxoid fibroma is a rare entity in the orbital bones and is more commonly seen in long bones. (C) 2017 by The American Society of Ophthalmic Plastic and Reconstructive Surgery, Inc., All rights reserved.

from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2k5UnCF
via IFTTT

Stick or twist? Career decision-making during contractual uncertainty for NHS junior doctors

Objectives

To examine the extent, and nature, of impact on junior doctors' career decisions, of a proposed new contract and the uncertainty surrounding it.

Design

Mixed methods. Online survey exploring: doctors' future training intentions; their preferred specialty training (ST) programmes; whether they intended to proceed immediately to ST; and other plans. Linked qualitative interviews to explore more fully how and why decisions were affected.

Setting

Doctors (F2s) in second year of Foundation School (FS) Programmes in England.

Participants

Invitations sent by FSs. Open to all F2s November 2015–February 2016. All FSs represented. Survey completed by 816 F2s. Sample characteristics broadly similar to national F2 cohort.

Main outcome measures

Proportions of doctors intending to proceed to ST posts in the UK, to defer or to exit UK medicine. Proportion of doctors indicating changes in training and career plans as a result of the contract and/or resulting uncertainty. Distribution of changes across training programmes. Explanations of these intentions from interviews and free text comments.

Results

Among the responding junior doctors, 20% indicated that issues related to the contract had prompted them to switch specialty and a further 20% had become uncertain about switching specialty. Switching specialty choice was more prevalent among those now choosing a community-based, rather than hospital-based specialty. 30% selecting general practice had switched choice because of the new contract. Interview data suggests that doctors felt they had become less valued or appreciated in the National Health Service and in society more broadly.

Conclusions

Doctors reported that contract-related issues have affected their career plans. The most notable effect is a move away from acute to community-based specialities, with the former perceived as more negatively affected by the proposed changes. It is concerning that young doctors feel undervalued, and this requires further investigation.

from #AlexandrosSfakianakis via Alexandros G.Sfakianakis on Inoreader http://ift.tt/2k2HJns
via IFTTT