Peripheral dentinogenic ghost cell tumor—report of two cases and review of the literature

Oral and Maxillofacial Surgery - Peripheral dentinogenic ghost cell tumor (DGCT) is a rare and non-aggressive benign odontogenic tumor. They usually affect the elderly and are predominantly located...     

Dietary fatty acids and the time elapsed from their intake are related to their composition in rat submandibular gland and salivary flow rates

Clinical Oral Investigations - The aim of this study was to analyze the influence of dietary fatty acids (FAs) and the time elapsed from their intake on FA tissue profile of rat submandibular gland...     

Radiochemotherapy-induced changes of tumour vascularity and blood supply estimated by dynamic contrast-enhanced CT and fractal analysis in malignant head and neck tumours

Objective:

To investigate radiochemotherapy (RChT)-induced changes of transfer coefficient (K^trans) and relative tumour blood volume (rTBV) estimated by dynamic contrast-enhanced CT (DCE-CT) and fractal analysis in head and neck tumours (HNTs).

Methods:

DCE-CT was performed in 15 patients with inoperable HNTs before RChT, and after 2 and 5 weeks. The dynamics of K^trans and rTBV as well as lacunarity, slope of log(lacunarity) vs log(box size), and fractal dimension were compared with tumour behaviour during RChT and in the 24-month follow-up.

Results:

In 11 patients, an increase of K^trans and/or rTBV after 20 Gy followed by a decrease of both parameters after 50 Gy was noted. Except for one local recurrence, no tumour residue was found during the follow-up. In three patients with partial tumour reduction during RChT, a decrease of K^trans accompanied by an increase in rTBV between 20 and 50 Gy was detected. In one patient with continuous elevation of both parameters, tumour progressed after RChT. Pre-treatment difference in intratumoral heterogeneity with its decline under RChT for the responders vs non-responders was observed.

Conclusion:

Initial growth of K^trans and/or rTBV followed by further reduction of both parameters along with the decline of the slope of log(lacunarity) vs log(box size) was associated with positive radiochemotherapeutic response. Increase of K^trans and/or rTBV under RChT indicated a poor outcome.

Advances in knowledge:

The modification of K^trans and rTBV as measured by DCE-CT may be applied for the assessment of tumour sensitivity to chose RChT regimen and, consequently, to reveal clinical impact allowing individualization of RChT strategy in patients with HNT.Combined radiochemotherapy (RChT) plays an important role in the management of malignant head and neck tumours (HNTs) and has been considered as the standard treatment for clinically non-operable cases.¹ Experimental observations indicate that RChT, besides direct cytotoxic effect, exerts its influence also on tumorangiogenesis.^2–4 Folkman and Camphausen⁵ suggested that endothelial cells may represent the principal targets for irradiation. Some studies reported the upregulation of angiogenic pathways and activation of different growth factors during radiotherapy as a kind of tumour response to radiation stress.^2,3,6,7 By affecting endothelial cells in the tumour''s vascular bed, chemotherapeutic agents indirectly modify neovascularization and blood supply, thus modulating tumour radiosensitivity.^4,8,9At the same time, malignant tumours display substantial internal heterogeneity in cellular morphology, vascularization and metabolism.^10–12 Intrinsic pattern of microenvironment and blood supply is among factors that are influencing the efficacy of RChT in every individual tumour.^13–15Therefore, implementation of advanced imaging techniques into clinical routine may provide morphological and functional information that may help characterizing tumour biology. Tumours with certain biological features, potentially resistant to standard treatment regimens, could then be treated with other measures, improving the chances of success.¹⁶Dynamic contrast-enhanced CT (DCE-CT) is an evolving functional imaging method assessing vascularity and blood supply in normal organs or in tumour tissue.¹⁷This work aimed to clarify the clinical relevance of DCE-CT in patients with HNT. We hypothesized that transfer coefficient (K^trans) and relative tumour blood volume (rTBV) as well as their intratumoral heterogeneity are additional functional parameters associated with RChT outcome. To prove this, the dynamics of K^trans and rTBV as well as lacunarity, slope of log(lacunarity) vs log(box size), and fractal dimension was estimated by DCE-CT and fractal analysis. The influence of tumour shape and size on lacunarity parameters thereby was reduced by modification of the gliding box counting method.     

Intercostal nerve transfer to the biceps motor branch in complete traumatic brachial plexus injuries

The purpose of this report is to critically evaluate our results of two intercostal nerve transfers directly to the biceps motor branch in complete traumatic brachial plexus injuries. From January 2007 to November 2012, 19 patients were submitted to this type of surgery, but only 15 of them had a follow‐up for ≥2 years and were included in this report. The mean interval from trauma to surgery was 6.88 months (ranging from 3 to 9 months). Two intercostals nerves were dissected and transferred directly to the biceps motor branch. The mean follow‐up was 38.06 months (ranging from 24 to 62 months). Ten patients (66.6%) recovered an elbow flexion strength ≥M3. Four of them (26.66%) recovered a stronger elbow flexion ≥M4. One patient (6.25%) recovered an M2 elbow flexion and four patients (26.66%) did not regain any movement. We concluded that two intercostal nerve transfers to the biceps motor branch is a procedure with moderate results regarding elbow flexion recovery, but it is still one of the few options available in complete brachial plexus injuries, especially in five roots avulsion scenario. © 2015 Wiley Periodicals, Inc. Microsurgery 35:428–431, 2015.     

Method to quantify accuracy of position feedback signals of a three-dimensional two-photon laser-scanning microscope

Two-photon laser-scanning microscopy enables to record neuronal network activity in three-dimensional space while maintaining single-cellular resolution. One of the proposed approaches combines galvanometric x-y scanning with piezo-driven objective movements and employs hardware feedback signals for position monitoring. However, readily applicable methods to quantify the accuracy of those feedback signals are currently lacking. Here we provide techniques based on contact-free laser reflection and laser triangulation for the quantification of positioning accuracy of each spatial axis. We found that the lateral feedback signals are sufficiently accurate (defined as <2.5 µm) for a wide range of scan trajectories and frequencies. We further show that axial positioning accuracy does not only depend on objective acceleration and mass but also its geometry. We conclude that the introduced methods allow a reliable quantification of position feedback signals in a cost-efficient, easy-to-install manner and should be applicable for a wide range of two-photon laser scanning microscopes.OCIS codes: (180.6900) Three-dimensional microscopy, (180.4315) Nonlinear microscopy, (170.0180) Microscopy, (170.2520) Fluorescence microscopy, (180.2520) Fluorescence microscopy     

Pain and Bloody Ear Discharge in a Returning Traveler

Cochliomyia hominivorax, the New World screwworm, was a serious livestock pest in the southern United States until the 1960s, when it was successfully eradicated by the release of sterile male flies. It remains endemic in parts of the Caribbean and South America, and there is concern that climate change may extend its geographic distribution. Cochliomyia hominivorax is voracious and can cause extensive damage to soft tissue and bone. We describe the case of a 26-year-old traveler who presented with otalgia and bloody otorrhea after returning from a vacation in the Dominican Republic, where exposure to screwworm flies most likely occurred during a nap on the beach. The causative agent was recognized by its characteristic larval anatomy, which includes pigmented dorsal tracheal trunks and posterior spiracles with an open peritreme.A 26-year-old female presented with a 2-day history of otalgia and bloody otorrhea after returning from a week of vacation in the Dominican Republic, where she stayed in a beachside resort with screened windows, swam in the ocean, hiked near an estuary, and sunbathed on the beach. She admitted to falling asleep on the beach one evening after drinking alcohol. The next day she had right ear discomfort with the sensation of movement, and removed a fly from her ear. One day later during the flight home, she had acute onset of ear pain, which she initially attributed to pressure changes associated with her flight, until she began noting discharge from the ear. The discharge was initially clear but became bloody within 1–2 hours. She sought medical care the next day, when an otoscopic examination revealed multiple motile larvae (Figure 1, Panel A). She was immediately referred to an otolaryngologist who performed excision and debridement of her external auditory canal with atticotomy.Open in a separate windowFigure 1.Panel A: Excised tissue displaying multiple motile larvae that were removed from the external auditory canal of a returning traveler vacationing in the Dominican Republic with auricular myiasis. Panel B: The characteristic pigmented dorsal tracheal trunks (white open arrow) and posterior spiracles with an open peritreme (gray closed arrow and inset) of Cochliomyia hominivorax.Intraoperative findings revealed soft tissue larval infiltration extending to the temporal bone and tympanic membrane perforation without middle ear involvement. The patient tolerated the debridement well and was prescribed amoxicillin-clavulanic acid for potential secondary soft-tissue infection. She subsequently underwent tympanoplasty with a split-thickness skin graft. The removed larvae were preliminarily identified as Cochliomyia hominivorax by the University of Washington Microbiology Laboratory on the basis of characteristic anatomic findings. Definitive identification was confirmed by the U.S. Department of Agriculture Screwworm Research Unit.Cochliomyia hominivorax (“human eater”), the New World screwworm, has smooth larvae with pigmented dorsal tracheal trunks (white open arrow) and posterior spiracles with an open peritreme (gray closed arrow, and inset) (Figure 1, Panel B).¹ The larvae feed on the living tissue of warm-blooded mammals using sharp hook-like mandibles (Supplemental Video). Spines found in concentric rings along the larvae resemble a screw and aid in anchoring the larvae within tissue, hence the name “screwworm.”² A female adult can lay hundreds of eggs at one time, often within existing open wounds.³ The voracious larvae emerge within 24 hours and can cause extensive soft tissue damage, and in some cases, destruction of bone. After 5–7 days the pupae mature and attempt to leave the wound to eventually burrow into the ground to pupate.² Adult flies can live for 2–3 weeks. Female flies are attracted to the scent of normal secretions of the orifices of mammals, with case reports describing infestation of the ears, eyes, nose, mouth, vagina, and rectum,⁴ and are able to fly great distances (∼50 km/week) to find a suitable host in which to deposit their eggs.² The scent of tissue infested with C. hominivorax can attract additional adult female flies that deposit their eggs within the same site. Individuals who are immobile, developmentally delayed, mentally ill, or alcoholic are at a higher risk of infestation.³ Orbital myiasis can be particularly devastating, requiring extensive debridement and sometimes enucleation.⁴ Several case reports have described secondary myiasis of ulcerative cutaneous malignancies.⁵ Auricular myiasis, as observed in our patient, is extremely rare and primarily occurs in children.³ Treatment of New World screwworm infestation consists of debridement, antibiotics if evidence of secondary infection is present, and adjunctive ivermectin in severe cases.⁴Cochliomyia hominivorax was formerly endemic in the southern United States where it was responsible for a serious economic burden caused by livestock destruction, until the 1960s when it became the first pest to be successfully eradicated by the release of sterile male flies.⁶ The New World screwworm remains endemic in parts of the Caribbean and South America, and there is concern that climate change may extend its geographic distribution.⁷ Since the New World screwworm has been eradicated from the United States for decades, clinicians may be unaware of this potentially devastating infestation resulting from foreign travel to endemic areas. As a result of the risk for significant tissue destruction, particularly if diagnosis is delayed, it is important for clinicians to be able to promptly recognize and appropriately treat this form of myiasis.