Bimodal Approach: A Key to Manage a Case of Traumatic Superior Orbital Fissure Syndrome.

An unusual complication associated with maxillofacial trauma is the superior orbital fissure syndrome (SOFS). Trauma-related SOFS often presents within 48 h of injury, but presentation can be delayed by several days. This article sums up the particulars of the syndrome and treatments done in the literature and discusses our experience of managing this complex case.

Co-existence of oral intra-muscular lipoma and lobular capillary hemangioma: A rare case report.

INTRODUCTION: Intramuscular lipoma are benign mesenchymal soft tissue neoplasm of mature adipocytes that arises within the muscle. Oral intramuscular lipoma are more commonly seen on tongue. Lobular capillary hemangioma (LCH) on the other hand are common benign vascular neoplasms which are often confused with pyogenic granuloma. PRESENTATION OF CASE: In this paper we present a rare case of co-existence of oral intramuscular lipoma with LCH. A 65 year old male complains of swelling on the left chin region from past 4-5 years. On complete intraoral examination another mass was noted on ventral surface of tongue. After performing USG and FNAC of the swelling in the chin region, an excisional biopsy was done and was sent for histopathological examination which showed thin connective tissue septa separating lobules of mature adipocytes. Histopathological examination of tongue mass revealed a benign tumor composed of blood vessels comprising of small capillary sized vascular channels. After a follow-up of 1 year patient showed no signs of recurrence. DISCUSSION: According to the literature recurrences are seen in case of intramuscular lipoma due to difficulty in total excision of the lesion. Immunohistochemistry plays a crucial role in distinguishing LCH from pyogenic granuloma. Intraoral LCH should be properly excised after understanding the vascularity of the lesion. CONCLUSION: In literature, the co-existence of intraoral lipoma with other lesions have been encountered hence for a surgeon a complete examination of oral cavity plays a crucial role to rule out such co-existence.

Evaluation of Blob Theory for the Diffusion of DNA in Nanochannels.

We have measured the diffusivity of λ-DNA molecules in approximately square nanochannels with effective sizes ranging from 117 nm to 260 nm at moderate ionic strength. The experimental results do not agree with the non-draining scaling predicted by blob theory. Rather, the data are consistent with the predictions of previous simulations of the Kirkwood diffusivity of a discrete wormlike chain model, without the need for any fitting parameters.

Experimental evidence of weak excluded volume effects for nanochannel confined DNA.

We present experimental demonstration that weak excluded volume effects arise in DNA nanochannel confinement. In particular, by performing measurements of the variance in chain extension as a function of nanochannel dimension for effective channel size ranging from 305 nm to 453 nm, we show that the scaling of the variance in extension with channel size rejects the de Gennes scaling δ2X ~ D1/3 in favor of δ2X ~ D0 using uncertainty at the 95% confidence level. We also show how simulations and confinement spectroscopy can be combined to reduce molecular weight dispersity effects arising from shearing, photocleavage, and nonuniform staining of DNA.

Distribution of distances between DNA barcode labels in nanochannels close to the persistence length.

We obtained experimental extension data for barcoded E. coli genomic DNA molecules confined in nanochannels from 40 nm to 51 nm in width. The resulting data set consists of 1 627 779 measurements of the distance between fluorescent probes on 25 407 individual molecules. The probability density for the extension between labels is negatively skewed, and the magnitude of the skewness is relatively insensitive to the distance between labels. The two Odijk theories for DNA confinement bracket the mean extension and its variance, consistent with the scaling arguments underlying the theories. We also find that a harmonic approximation to the free energy, obtained directly from the probability density for the distance between barcode labels, leads to substantial quantitative error in the variance of the extension data. These results suggest that a theory for DNA confinement in such channels must account for the anharmonic nature of the free energy as a function of chain extension.

Mixed confinement regimes during equilibrium confinement spectroscopy of DNA.

We have used a combination of fluorescence microscopy experiments and Pruned Enriched Rosenbluth Method simulations of a discrete wormlike chain model to measure the mean extension and the variance in the mean extension of λ-DNA in 100 nm deep nanochannels with widths ranging from 100 nm to 1000 nm in discrete 100 nm steps. The mean extension is only weakly affected by the channel aspect ratio. In contrast, the fluctuations of the chain extension qualitatively differ between rectangular channels and square channels with the same cross-sectional area, owing to the "mixing" of different confinement regimes in the rectangular channels. The agreement between experiment and simulation is very good, using the extension due to intercalation as the only adjustable parameter.

Hydrodynamics of DNA confined in nanoslits and nanochannels.

Modeling the dynamics of a confined, semi exible polymer is a challenging problem, owing to the complicated interplay between the configurations of the chain, which are strongly affected by the length scale for the confinement relative to the persistence length of the chain, and the polymer-wall hydrodynamic interactions. At the same time, understanding these dynamics are crucial to the advancement of emerging genomic technologies that use confinement to stretch out DNA and "read" a genomic signature. In this mini-review, we begin by considering what is known experimentally and theoretically about the friction of a wormlike chain such as DNA confined in a slit or a channel. We then discuss how to estimate the friction coefficient of such a chain, either with dynamic simulations or via Monte Carlo sampling and the Kirk-wood pre-averaging approximation. We then review our recent work on computing the diffusivity of DNA in nanoslits and nanochannels, and conclude with some promising avenues for future work and caveats about our approach.