Common Avian Infection Plagued the Tyrant Dinosaurs

Background

Tyrannosaurus rex and other tyrannosaurid fossils often display multiple, smooth-edged full-thickness erosive lesions on the mandible, either unilaterally or bilaterally. The cause of these lesions in the Tyrannosaurus rex specimen FMNH PR2081 (known informally by the name ‘Sue’) has previously been attributed to actinomycosis, a bacterial bone infection, or bite wounds from other tyrannosaurids.

Methodology/Principal Findings

We conducted an extensive survey of tyrannosaurid specimens and identified ten individuals with full-thickness erosive lesions. These lesions were described, measured and photographed for comparison with one another. We also conducted an extensive survey of related archosaurs for similar lesions. We show here that these lesions are consistent with those caused by an avian parasitic infection called trichomonosis, which causes similar abnormalities on the mandible of modern birds, in particular raptors.

Conclusions/Significance

This finding represents the first evidence for the ancient evolutionary origin of an avian transmissible disease in non-avian theropod dinosaurs. It also provides a valuable insight into the palaeobiology of these now extinct animals. Based on the frequency with which these lesions occur, we hypothesize that tyrannosaurids were commonly infected by a Trichomonas gallinae-like protozoan. For tyrannosaurid populations, the only non-avian dinosaur group that show trichomonosis-type lesions, it is likely that the disease became endemic and spread as a result of antagonistic intraspecific behavior, consumption of prey infected by a Trichomonas gallinae-like protozoan and possibly even cannibalism. The severity of trichomonosis-related lesions in specimens such as Tyrannosaurus rex FMNH PR2081 and Tyrannosaurus rex MOR 980, strongly suggests that these animals died as a direct result of this disease, mostly likely through starvation.     

Intra-guild competition and its implications for one of the biggest terrestrial predators, Tyrannosaurus rex

Identifying tradeoffs between hunting and scavenging in an ecological context is important for understanding predatory guilds. In the past century, the feeding strategy of one of the largest and best-known terrestrial carnivores, Tyrannosaurus rex, has been the subject of much debate: was it an active predator or an obligate scavenger? Here we look at the feasibility of an adult T. rex being an obligate scavenger in the environmental conditions of Late Cretaceous North America, given the size distributions of sympatric herbivorous dinosaurs and likely competition with more abundant small-bodied theropods. We predict that nearly 50 per cent of herbivores would have been within a 55–85 kg range, and calculate based on expected encounter rates that carcasses from these individuals would have been quickly consumed by smaller theropods. Larger carcasses would have been very rare and heavily competed for, making them an unreliable food source. The potential carcass search rates of smaller theropods are predicted to be 14–60 times that of an adult T. rex. Our results suggest that T. rex and other extremely large carnivorous dinosaurs would have been unable to compete as obligate scavengers and would have primarily hunted large vertebrate prey, similar to many large mammalian carnivores in modern-day ecosystems.     

Wood exposure and smoking: association with cancer of the nasal cavity and paranasal sinuses in British Columbia.

A case-control study of 121 men seen for cancer of the nasal cavity or paranasal sinuses in British Columbia between 1939 and 1977 showed increased relative risks associated with occupations involving exposure to wood (2.5) and with smoking (4.9). The occupations involved were chiefly forestry and carpentry. Both risk factors appeared to be associated with the principal sites within the nasal cavity paranasal sinuses and with most histologic subtypes of cancer.     

Cannibalism in Tyrannosaurus rex

Background

Tyrannosaurus rex was one of the largest terrestrial carnivores of all time, and consequently its ecology and diet have been the focus of much discussion. However, there is little direct evidence of diet or feeding habits in this species.

Methodology/Principal Findings

Examination of museum collections has revealed four specimens of Tyrannosaurus rex that bear tooth marks made by large, carnivorous dinosaurs. Because Tyrannosaurus is the only large carnivore known from the Late Maastrichtian of western North America, we infer that Tyrannosaurus made these tooth marks.

Conclusions/Significance

The marks are interpreted as feeding traces and these fossils therefore record instances of cannibalism. Given that this behavior has a low preservation potential, cannibalism seems to have been a surprisingly common behavior in Tyrannosaurus, and this behavior may have been relatively common in carnivorous dinosaurs.     

Ontogeny of the Middle-Ear Air-Sinus System in Alligator mississippiensis (Archosauria: Crocodylia)

Modern crocodylians, including Alligator mississippiensis, have a greatly elaborated system of pneumatic sinuses invading the cranium. These sinuses invade nearly all the bones of the chondrocranium and several bony elements of the splanchnocranium, but patterns of postnatal paratympanic sinus development are poorly understood and documented. Much of crocodylomorph—indeed archosaurian—evolution is characterized by the evolution of various paratympanic air sinuses, the homologies of which are poorly understood due in large part to the fact that individual sinuses tend to become confluent in adults, obscuring underlying patterns. This study seeks to explore the ontogeny of these sinuses primarily to clarify the anatomical relations of the individual sinuses before they become confluent and thus to provide the foundation for later studies testing hypotheses of homology across extant and extinct Archosauria. Ontogeny was assessed using computed tomography in a sample of 13 specimens covering an almost 19-fold increase in head size. The paratympanic sinus system comprises two major inflations of evaginated pharyngeal epithelium: the pharyngotympanic sinus, which communicates with the pharynx via the lateral (true) Eustachian tubes and forms the cavum tympanicum proprium, and the median pharyngeal sinus, which communicates with the pharynx via the median pharyngeal tube. Each of these primary inflations gives rise to a number of secondary inflations that further invade the bones of the skull. The primary sinuses and secondary diverticula are well developed in perinatal individuals of Alligator, but during ontogeny the number and relative volumes of the secondary diverticula are reduced. In addition to describing the morphological ontogeny of this sinus system, we provide some preliminary exploratory analyses of sinus function and allometry, rejecting the hypothesis that changes in the volume of the paratympanic sinuses are simply an allometric function of braincase volume, but instead support the hypothesis that these changes may be a function of the acoustic properties of the middle ear.     

Acoustic rhinometry in humans: accuracy of nasal passage area estimates, and ability to quantify paranasal sinus volume and ostium size.

A comprehensive study that compared acoustic rhinometry (AR) data to computed tomography (CT) data was performed to evaluate the accuracy of AR measurements in estimating nasal passage area and to assess its ability of quantifying paranasal sinus volume and ostium size in live humans. Twenty nasal passages of 10 healthy adults were examined by using AR and CT. Actual cross-sectional areas of the nasal cavity, sinus ostia sizes, and maxillary and frontal sinus volumes were determined from CT sections perpendicular to the curved acoustic axis of the nasal passage. Nasal cavity volume (from nostril to choana) calculated from the AR-derived area-distance curve was compared with that from the CT-derived area-distance curve. AR measurements were also done on pipe models that featured a side branch (Helmholtz resonator of constant volume but two different neck diameters) simulating a paranasal sinus. In the anterior nasal cavity, there was good agreement between the cross-sectional areas determined by AR and CT. However, posterior to the sinus ostia, AR overestimated cross-sectional area. The difference between AR nasal volume and CT nasal volume was much smaller than the combined volume of the maxillary and frontal sinuses. The results suggest that AR measurements of the healthy adult nasal cavity are reasonably accurate to the level of the paranasal sinus ostia. Beyond this point, AR overestimates cross-sectional area and provides no quantitative data for sinus volume or ostium size. The effects of paranasal sinuses and acoustic resonances in the nasal cavity are not accounted for in the present AR algorithms.     

Occult Renal Cell Carcinoma Manifesting as Nasal Mass and Epistaxis

Metastasis of renal cell carcinoma (RCC) to the nasal cavity and paranasal sinuses is rare, with fewer than 50 cases described in the literature. Nasal metastasis as the initial presentation of RCC is even rarer. Metastases to the nasal cavity usually represent advanced disease with poor outcome. The authors report a case of metastatic RCC presenting with right nasal cavity mass and epistaxis, followed by a brief review of the relevant literature.Key words: Renal cell carcinoma, Nasal metastasis, EpistaxisRenal cell carcinoma (RCC) accounts for approximately 85% of primary renal tumors, and represents approximately 3% of all adult malignancies.¹ Usual sites of metastasis include lungs (75%), regional lymph nodes (65%), bone (40%), liver (40%), and brain (5%).² Metastasis to the nasal cavity is an extremely rare occurrence, with fewer than 50 cases reported,^3,4 although RCC is the most common infraclavicular primary tumor that metastasizes to the nasal cavity and paranasal sinuses.⁵ We describe a case of occult clear-cell RCC that presented with epistaxis due to nasal cavity metastasis.     

Development of the paratympanic pneumatic system of Japanese quail

Avian heads are characterized as having two extensive air-filled systems lined with epithelia; the paranasal and paratympanic sinuses. Many diverticula derived from the paratympanic sinus system are known to reticulate with each other to form a single merged pneumatic space within the adult braincase. However, the development of these complex branching and reticulating epithelia has not been examined in detail. In this study, we describe the comprehensive developmental pattern of the paratympanic sinus and its associated soft tissues in a model bird, Japanese quail (Coturnix japonica). The data are derived from three-dimensional reconstructions based on histological sections and soft tissue enhanced micro-CT data. Those data provide the foundation of the complex hierarchical developmental pattern of the paratympanic sinus system. Moreover, associations with other tissues help establish key morphologies that identify each pneumatic entity. This study clarifies the developmental relationships of the ventral portions of the paratympanic sinus system, the siphoneal diverticulum and marginal sinus, based on the ligaments associated with the Eustachian tube. In addition, detailed histological pneumatic morphologies reveal hitherto unknown epithelial diversity, which may be indicative of equally complex developmental processes. We use the pneumatization of the quadrate as an example to support a close relationship with vascular growth and pneumatic epithelia invasion into ossified bone. We confirm pneumatic diverticula never enter into cartilages, possibly due to the absence of vasculature in these tissues. Lastly, we use the concept of a morphogenetic tree as a tool to help present the complex developmental pattern of the paratympanic sinus system and apply it toward inferring pneumatic morphologies in a nonavian theropod braincase.     

Low nitric oxide concentrations in exhaled gas and nasal airways of mammals without paranasal sinuses

To investigatewhether relevant levels of nasal nitric oxide (NO) are produced in theabsence of paranasal sinuses, we studied 17 healthy baboons, mammalswithout any paranasal sinuses. The animals were anesthetized withketamine hydrochloride and breathed spontaneously. While the baboonsbreathed through a face mask (mouths closed) connected to a respirator,NO concentrations in exhaled gas were sampled from the expiratory limband analyzed by chemiluminescence. While the animals were breathingambient air, nasal gas was sampled via a thin plastic tube and analyzed for NO concentrations by chemiluminescence. Mean NO concentration inthe exhaled gas was 1.00 ± 0.59 parts/billion, and NO release was4.28 ± 2.72 nl/min. A NO concentration of 4.79 ± 2.08 parts/billion was found in the nasal gas (NO release: 7.18 ± 3.13 nl/min). An age-dependent increase in nasal NO levelswas not observed. Exhaled and nasal NO concentrations in baboons weremarkedly lower than in mammals with paranasal sinuses, suggesting thatparanasal sinuses might be an anatomic requirement for production ofrelevant nasal NO levels.

     

Focus: Rare Disease: Sinonasal Glomangiopericytoma: Review of Imaging Appearance and Clinical Management Update for a Rare Sinonasal Neoplasm

Introduction: Glomangiopericytoma (GPC) is a rare tumor in the nasal cavity or paranasal sinuses with low malignant potential. Initially deemed a hemangiopericytoma, in 2005 it was classified as a distinct entity by the World Health Organization (WHO). Case Presentation: A male patient in his early 60s presented with new-onset right arm and leg weakness/numbness, who was incidentally found to have a left ethmoid sinus mass with extension in the olfactory fossa. On CT and MRI, the mass enhanced with well-defined borders and eroded the bone, but without dural enhancement. The mass was surgically excised, and pathology confirmed the diagnosis of glomangiopericytoma by microscopic appearance and staining. Discussion: Glomangiopericytoma has less than 0.5% incidence of all neoplasms of the sinonasal cavity, making it rare. Most diagnosed patients are in their 6th or 7th decade of age, with a slight female predominance. Treatment is complete surgical excision, with excellent prognosis, although there is up to 17% local recurrence. Despite the non-specific appearance on CT and MRI, imaging can help provide differential diagnosis, tumor extent, size, and reassuring non-aggressive characteristics of the tumor prior to surgery. GPC tumors are relatively resistant to radiation and chemotherapy. Conclusion: It is important to recognize glomangiopericytoma in the differential of masses of the nasal cavities or paranasal sinuses, as they rarely warrant aggressive treatment beyond local excision. Each reported case of glomangiopericytoma helps to build guidance for imaging and treatment since GPC is rare and not well-represented in the medical literature.     

Olfactory and vomeronasal systems of caecilians (Amphibia: Gymnophiona)

The morphology of both the main nasal cavity and the vomeronasal organ differs among species representing six families of caecilians. The main nasal cavity is either divided or undivided. The vomeronasal organ differs in position (mediolateral, lateral), size (large vomeronasal organ in the aquatic species), and shape (mediolateral extension, vomeronasal organ with a lateral rostral projection). The great amount of respiratory epithelium of the main nasal cavity, the large vomeronasal organ, and its extensive innervation in typhlonectids may reflect both phylogeny and habitat adaptation, for these taxa are secondarily aquatic or semiaquatic and have several concomitant morphological and physiological modifications. The vomeronasal organ is associated with the caecilian tentacle as the tentacular ducts open into it. This association is further evidence for the involvement of the caecilian tentacle in vomeronasal chemoperception and may represent the mechanism by which these animals smell though the main nasal cavity is closed during burrowing or swimming. Labelings of primary olfactory and vomeronasal projections by means of horseradish peroxidase reaction reveal that the pattern of vomeronasal projections is similar in Ichthyophis kohtaoensis, Dermophis mexicanus, and Typhlonectes natans, even though T. natans possess stronger vomeronasal projections relative to olfactory projections than I. kohtaoensis and D. mexicanus. However, there are differences with respect to the patterns of olfactory projections. The olfactory projection of I. kohtaoensis is characterized by many displaced glomeruli. T. natans has the smallest olfactory projection. The nervus terminalis is associated with the olfactory system as shown by selective labelings of olfactory projections. Six characters potentially useful for phylogenetic analysis emerge from this study of comparative morphology. The characters were subjected to analysis using PAUP to see (1) if any resolution occurred and (2) if any groups were distinguished, whether they corresponded to phylogenetic arrangements based on other morphological characters. The characters are too few to produce nested dichotomous sets for all cases, but they do support the two typhlonectid genera examined and Dermophis and Gymnopis as sister taxa discrete from other groups, and they show that species within genera cluster together.     

Optimization of magnetophoretic-guided drug delivery to the olfactory region in a human nose model

Magnetophoretic-guided delivery has been shown to be able to improve the olfactory doses. However, due to the complex nasal structure and quick decay of magnetic intensity, precise control of particle motion in the human nose remains a challenge. In this study, an optimization model was developed for magnetophoretic olfactory delivery systems. The performance of the model was evaluated using a baseline device design in an MRI-based human nose geometry. Three key components of the delivery system were examined, which included the particle release position, the front magnet to minimize nasal valve depositions, and the top magnet to attract particles into the olfactory region. Results show that the magnetophoretic olfactory delivery device can be significantly improved by optimizing the product and operational parameters. The olfactory delivery efficiency was increased by 1.5-fold compared to the baseline design. The top magnet height and strength were shown to be the most influential factor in olfactory delivery, followed by the drug release position and the front magnet strength. The optimization framework developed in this study can be easily adapted for the optimization of intranasal drug delivery to other regions such as paranasal sinuses.     

The mechanism of olfactory organ ventilation in Periophthalmus barbarus (Gobiidae, Oxudercinae)

Periophthalmus barbarus Linnaeus, 1766 has many adaptations for amphibious life as a consequence of tidal zone occupation. One of them is the ability to keep a little amount of water and air in mouth while on land or in hypoxic water, correlated with closing a gill lid for gas exchange improvement. It causes that mechanisms of olfactory organ ventilation described in other species of actinopterygians (compression of accessory nasal sac(s) by the skull and jaw elements while mouth and gill lid moving) are not in operation. There is a specific mechanism of olfactory organ ventilation independent on jaw and skull elements movements. Compression of accessory nasal sacs is possible by a0 contraction and it is a movement effect on bones combined by ligaments. This process can be observed on P. barbarus as lifting the rostral part of the head.     

Intranasal Volume Changes Caused by the Endoscopic Endonasal Transsphenoidal Approach and Their Effects on Nasal Functions

Objective

We evaluated postoperative changes in nasal cavity volume and their effects on nasal function and symptoms after endoscopic endonasal transsphenoidal approach for antero-central skull base surgery.

Study Design

Retrospective chart review at a tertiary referral center.

Methods

We studied 92 patients who underwent binostril, four-hand, endoscopic endonasal transsphenoidal approach surgery using the bilateral modified nasoseptal rescue flap technique. Pre- and postoperative paranasal computed tomography and the Mimics^® program were used to assess nasal cavity volume changes at three sections. We also performed several pre- and postoperative tests, including the Connecticut Chemosensory Clinical Research Center test, Cross-Cultural Smell Identification Test, Nasal Obstruction Symptoms Evaluation, and Sino-Nasal Outcome Test-20. In addition, a visual analog scale was used to record subjective symptoms. We compared these data with the pre- and postoperative nasal cavity volumes.

Results

Three-dimensional, objective increases in nasal passage volumes were evident between the inferior and middle turbinates (p<0.001) and between the superior turbinate and choana (p = 0.006) postoperatively. However, these did not correlate with subjectively assessed symptoms (NOSE, SNOT-20 and VAS; all nasal cavity areas; p≥0.05) or olfactory dysfunction (CCCRC and CCSIT test; all nasal cavity areas; p≥0.05).

Conclusion

Skull base tumor surgery via an endoscopic endonasal transsphenoidal approach altered the patients’ nasal anatomy, but the changes in nasal cavity volumes did not affect nasal function or symptoms. These results will help surgeons to appropriately expose the surgical field during an endoscopic endonasal transsphenoidal approach.     

Intravascular microstructures in trabecular bone tissues of Tyrannosaurus rex

Histological analyses of trabecular tissue from the limb bones of a Tyrannosaurus rex revealed the presence of small (average 25 μm) round microstructures in the vascular channels of the bone. These bony tissues otherwise evidenced minimal diagenetic change, and no secondary mineral deposition was observed in the vessel channels. While we have published analyses of the bony tissues of this specimen, we have not published data obtained on these small intravascular microstructures. Several characteristics link these microstructures to endogenous biological components, although their origin is not confirmed, and several hypotheses are considered. A discussion of the meaning of the term ‘organic preservation’ and a suggestion of criteria that should be met to be described as such is included.     

Vital statistics,absolute abundance and preservation rate of Tyrannosaurus rex

I present a simulation model on vital statistics, absolute abundance (N, total number of individuals that ever lived) and preservation rate (p, minimum number of fossils known divided by N) of Tyrannosaurus rex. It is based on a published age-structured population model that assumes a reptile or bird-like reproduction for T. rex to estimate its age-specific survival rates. My model applies input variables and equations from a recently published model on N and p. This model yielded 2.5 billion T. rex individuals (N) and one fossil per 80 million individuals (p). The average N values calculated by my model were at minimum 27.6% and p values at maximum 361.5% that of a previous model and uncertainties in all output variables were always larger in my model. The equation on output variable ‘population density’ introduced the largest uncertainty to N and p. The output variable ‘generation time’ differed the most between models, but for N and p, the huge size of the input area modelled and geological longevity minimized this difference. Unlike my model, the generation time as well as life expectancies, gross reproduction rates, and reproductive values of individuals calculated from the previous model all strongly contradicted our current understanding of the biology of T. rex and of other theropods. Their values also disagreed with those of large extant reptiles, birds and mammals. All of these shortcomings of the previous model favour the assessment of individual and population characteristics of T. rex and of other extinct species using my model.     

Effects of paranasal sinus ostia and volume on acoustic rhinometry measurements: a model study.

We used pipe models to investigate the effects of paranasal sinus ostium size and paranasal sinus volume on the area-distance curves derived by acoustic rhinometry (AR). Each model had a Helmholtz resonator or a short neck as a side branch that simulated the paranasal sinus and sinus ostium. The AR-derived cross-sectional areas posterior to the ostium were significantly overestimated. Sinus volume affected the AR measurements only when the sinus was connected via a relatively large ostium. The experimental area-distance curve posterior to the side branch showed pronounced oscillations in association with low-frequency acoustic resonances in this distal part of the pipe. The experimental results are discussed in terms of theoretically calculated "sound-power reflection coefficients" for the pipe models used. The results indicate that the effects of paranasal sinuses and low-frequency acoustic resonances in the posterior part of the nasal cavity are not accounted for in the current AR algorithms. AR does not provide reliable information about sinus ostium size, sinus volume, or cross-sectional area in the distal parts of nasal cavity.     

Downsized Dinosaurs: The Evolutionary Transition to Modern Birds

Living birds are the most diverse land vertebrates and the heirs of a rich chapter in the evolution of life. The origin of modern birds from animals similar to Tyrannosaurus rex is among the most remarkable examples of an evolutionary transition. A wealth of recently discovered fossils has finally settled the century-old controversy about the origin of birds and it has made the evolutionary saga toward modern birds one of the best documented transitions in the history of life. This paper reviews the evidence in support of the origin of birds from meat-eating dinosaurs, and it highlights the array of fossils that connect these fearsome animals with those that fly all around us.     

Lethal destructive sinusopathy due to amphotericin B-resistant Aspergillus flavus: A case report

BackgroundThe prevalence of pulmonary aspergillosis and the importance of its early diagnosis are recognized. However, non-pulmonary involvement, including the sinuses region, is not frequently reported, and an infection in this area can affect all paranasal sinuses (pansinusopathy), being a rare pathology that affects immunocompromised hosts. Recent studies have highlighted the occurrence of Aspergillus flavus resistant to antifungal therapy. Therefore, a nasal sinus infection by resistant Aspergillus strains in immunocompromised patients may be linked to a high risk of lethality.Case reportWe are reporting a resistant A. flavus infection in an allogeneic hematopoietic stem cell transplant recipient with episodes of febrile neutropenia, and prolonged use of various antibacterial drugs and antifungal prophylaxis. The patient underwent brain magnetic resonance, which showed the presence of pansinusopathy, and presented necrosis in the left nasal region. Direct microscopic examination of a sample taken from the nasal mucosa revealed the presence of septate hyphae and conidiophores resembling those of A. flavus, that species being the identification achieved with MALDI-TOF MS. Antifungigram was performed by microdilution in broth (EUCAST-E.DEF. 9.3.2) and E-test, and resistance to amphotericin B was shown in both tests. The patient died after septic shock and hemorrhage.ConclusionsInvasive fungal infections due to amphotericin-B resistant A. flavus may lead to the death of the patient due to an ineffective therapeutic management. Therefore, antifungal susceptibility testing are of utmost importance for administering the proper treatment.