Embryonic Stem Cell Sphere: A Controlled Method for Production of Mouse Embryonic Stem Cell Aggregates for Differentiation

Objectives

Embryonic stem cells (ESCs) are of significant interest as a renewable source of nonproliferating cells. Differentiation of ESCs is initiated by the formation of embryoid bodies (EBs). Standard methods of EB formation are limited in their production capacity, in any variations in EB size and formation of EBs through frequent passages. Here we have reported the utility of a microencapsulation technique for overcoming these limitations by mass production of mouse ESCs in alginate beads called ESC spheres.

Methods

The mouse ESCs were encapsulated in 1.2% alginate solution and cocultured on a feeder layer. The cells were evaluated by flow cytometry, in vitro differentiation, immunofluorescence, and reverse transcriptase polymerase chain reaction (RT-PCR).

Results

Analysis of encapsulated ESC spheres by flow cytometry showed similar percentages of Oct-4 and stage-specific embryonic antigen-1 (SSEA-1) expression in comparison with routine culture of ESCs. Moreover, the ESC spheres maintained a pluripotency potential which was comparable with ESCs cultured on feeder cells directly, as demonstrated by immunofluorescence and RT-PCR.

Conclusions

The results demonstrated that alginate encapsulation as a simple bioreactor, provides a scalable system for mass undifferentiated ESC sphere production with similar sizes and without the need for frequent passages for differentiation and clinical and pharmaceutical applications.

The diagnostic value of the native fluorescence visualization device for early detection of premalignant/malignant lesions of the oral cavity

PURPOSE

The present study aimed to determine the diagnostic value of a native fluorescence visualization device in the identification of oral malignant/dysplastic lesions.

METHODS

This study involved 45 patients who had oral lesions that were suspected to be malignant, potentially malignant, or benign. The patients visited the Oral Medicine Department of the Mashhad Dental School. The sensitivity, specificity, positive and negative predictive values, and likelihood ratio of this device were determined.

RESULTS

The histopathological assessment of samples showed 9 cases of oral squamous cell carcinoma and 12 lesions with dysplasia. Ten samples of dysplastic lesions and all malignant lesions appeared dark or red/orange when examined with the native fluorescence visualization device. In 90% of the dysplastic/malignant lesions, the label-free fluorescence results were positive. The sensitivity, specificity, and positive and negative predictive values of this device were 90%, 15%, 40%, and 71%, respectively.

CONCLUSIONS

The native fluorescence visualization device can be used in specialized centers as an adjunctive device to increase the sensitivity of a clinical examination, but is not capable of distinguishing benign lesions from malignant and dysplastic ones due to its low specificity.

Extranodal NK/T Cell Lymphoma with Destruction of the Uvulae: A Case Report

INTRODUCTION

Extranodal Natural Killer (NK)/T-cell lymphoma (NKTCL) nasal type is a rare but well-known disease with poor prognosis. NKTCL is more prevalent in Asia and comprises about 7-10% of all non-Hodgkin lymphoma cases in this region. The characteristic clinical pattern of NKTCL is the destruction of the midline structures of the mid-face.

CASE REPORT

The present study examines a case of NKTCL in a 23-year-old man with a destructive ulcer of the palate and uvulae. Based on immunohistochemical results, after three months of delay, the definitive diagnosis was revealed to be Extranodal NK/T cell lymphoma. Following the third cycle of chemotherapy, the patient died due to sepsis and infection.

CONCLUSION

It is very common to misdiagnose NKTCL with other clinical conditions such as necrotizing stomatitis, deep fungal ulcers, Wegener's Granulomatosis disease, etc. Delay in diagnosis can worsen the course of the disease and its prognosis.

Herpes Zoster Induced Alveolar Bone Necrosis in Immunocompromised Patients; Two Case Reports

INTRODUCTION

Herpes zoster Infection (HZI) is a viral disease with painful skin rashes and blisters in a limited area on one side of the body, often in a strip. Osteonecrosis with spontaneous exfoliation of teeth in association with HZI of the mandibular nerve is a rare phenomenon. In this report, such an unusual complication of HZI is presented.

CASE REPORT

The clinical course of a 53-year-old woman and a 54-year-old man with HZI associated with alveolar bone necrosis and tooth exfoliation were reviewed in order to develop a patient profile for this rare combination of physical findings.

CONCLUSION

In immunocompromised patients, the clinicians should consider HZI as a possible cause of tooth mobility, exfoliation, and alveolar osteonecrosis, which needs early intervention to prevent secondary complications.

Ab initio and DFT studies on the structures, binding energies and nature of bonds in X2Y3 metal clusters (X+ = Li+, Na+ and K+; ${\rm Y}_{3}^{2-} = {\rm Zn}_{3}^{2-}, {\rm Cd}_{3}^{2-}$ and ${\rm Hg}_{3}^{2-}$)

A comprehensive theoretical study on the structure and stability of linear and triangular isomers of anionic clusters of zinc, cadmium and mercury [Formula: see text] and their binding with one and two alkali metal cations ( X + = Li +, Na +, K +) has been investigated at the density functional (BP86 and B3LYP) and ab initio (MP2, MP4 and coupled cluster single and double (CCSD)) methods. The results showed that in all cases, the triangular geometry with D3h symmetry is more stable than linear one. The calculated values of interaction energies (IE) between [Formula: see text] anions and two X+ cations, Wiberg bond indices (WBI) and the electron densities at bond critical points (BCP), ρ(BCP), for Y–X bonds show that among all complexes investigated here at all levels of theory Zn 3 Li 2 and Hg 3 K 2 have the largest and the smallest values of IE, WBI and ρ(BCP), respectively. The natural charges of the atoms and WBI involved in the bonding as well as the global value of the charge transfer ΔQ from [Formula: see text] to X+ cation in X2Y3 clusters, evaluated through natural population analysis, confirmed that covalent contribution in Y–X bond formation increases from K + to Li +. Also the energy decomposition analyses (EDA) were used to detect the nature of interaction in the complexes. The results confirmed that the contribution of electrostatic interactions in present complexes is almost more than 70%.