Experimental approaches to assess the effect of composition of abrasives in the cause of dental microwear.

Dental microwear is used to investigate feeding ecology. Animals ingest geological material in addition to food. The full effect of geological abrasives on tooth wear is unknown. To evaluate mineralogical abrasives as tooth wear agents, rats were fed food manufactured with quartz silt, diatomaceous earth, and calcium carbonate. Rats were assigned to treatments and fed for 15 days. Molars were scanned with a Sensofar Plu Neox confocal microscope and evaluated using ISO-25178-2 parameters and traditional microwear variables using light microscopy. Using a pellet-diet as the control, all treatments had influence on microwear and discriminant function analyses indicated that unique surface textures had been produced. ISO variables with high discriminatory values were correlated to scratch and pit frequencies, but more ISO parameters identified changes associated with numbers of scratches than changes associated with pits. The microwear changes associated with the abrasive inclusions were co-dependent on the type of diet that the abrasives had been added to. The abrasives had less effect with pellets but produced more modified and more differentiated microwear when added to the transgenic dough. Although abrasives produce distinctive surface textures, some knowledge of the properties of food with the abrasives is needed to identify the abrasive agent.

Regional variation in the density of Meissner's corpuscles in human fingers.

Manual therapies in medicine rely on a physician's ability to sense and respond to tactile cues from their hands to inform them of symptoms within the patient. Sensory cues through skin may not be equally sensitive among all people, and little is known about the variation in distribution of sensory corpuscles in the human hand. Variation of corpuscle numbers studied in living people are limited to less invasive techniques, limiting their accuracy. Body-donor studies that thoroughly sample the distribution throughout the hand are extremely rare, usually only including a small number of sites around the hand and only a small number of individuals. Does the distribution of Meissner's corpuscles vary greater between individuals, between fingers, along the finger, or at specialized regions of the fingers themselves (pads, over interphalangeal joints, tips)? We tested whether there were significant differences between finger regions (fingertips vs. pads, vs. interphalangeal joints), or from proximal to distal, or between digits, or between individuals by histologically sampling human body-donors to science. There were significant differences in the quantity of Meissner's corpuscles between finger regions, from proximal to distal regions along digits, between individuals, but not between digits. Specifically, fingertips demonstrated higher counts of Meissner's corpuscles than pads and interphalangeal joints, more distally located regions (i.e. tips and distal pads) demonstrated higher Meissner's corpuscles than more proximal regions, and most individuals demonstrated significantly different average amounts of total Meissner's corpuscles from each other. Our results suggest that variability exists in the amounts and distribution of Meissner's corpuscles both between and within fingers of human subjects.

Surface metrology of bone surface attachments of knee ligaments.

OBJECTIVES: Textural differences between entheses reflect biomechanical activities of the musculoskeletal system. Methods used to measure these surfaces have limitations. Here, the surface metrology of roughness of articular and entheseal surfaces of the knee are investigated with an optical profiler. METHODS: Osteological specimens of six femora and seven tibiae were prepared from cadavers. Measurements were obtained to surrogate body mass. Specimens were molded with polyvinylsiloxane and casts prepared with resin, which were scanned using a white light optical profiler. Scans were processed by a computer program. Each scan produced 32 variables, categorized into 6 groups for each location. RESULTS: The distribution of data was mostly normal. Analysis of variance (ANOVA) identified Ssk significant (p-value .002); post hoc Tukey testing indicated significance between femoral PCL and tibial ACL entheses groups (p-value .007), and between tibial ACL and tibial entheses groups (p-value .002) suggesting the ability to differentiate anterior and posterior cruciate ligament entheses. Sku was found significant with a t test between articular and entheseal surfaces. Correlation coefficients were significant between surface metrology parameters and measurements related to body mass. CONCLUSIONS: This study distinguished differences between entheses of the anterior and posterior cruciate ligaments, with the Ssk parameter most useful. Differences in articular and entheseal surfaces were found with the Sku parameter most useful. Correlations indicated a relationship between body mass and surface metrology parameters. Finally, these findings suggest this method can be used for further investigation of spondyloarthropathies.

A long-forgotten 'dinosaur' bone from a museum cabinet, uncovered to be a Japan's iconic extinct mammal, Paleoparadoxia (Desmostylia, Mammalia).

Here, we report a new 'discovery' of a desmostylian fossil in the geological collection at a national university in Japan. This fossil was unearthed over 60 years ago and donated to the university. Owing to the original hand-written note kept with the fossil in combination with interview investigation, we were able to reach two equally possible fossil sites in the town of Tsuchiyu Onsen, Fukushima. Through the interviews, we learned that the fossil was discovered during construction of a debris flow barrier and that it was recognized as a 'dinosaur' bone among the locals and displayed in the Village Hall before/until the town experienced a fire disaster in 1954. As scientific findings, the fossil was identified to be a right femur of Paleoparadoxia (Desmostylia), which shows well-preserved muscle scars on the surface. The age was estimated to be 15.9 Ma or younger in zircon-dating. This study shows an excellent case that historical and scientific significances could be extracted from long-forgotten uncatalogued specimens as long as the original information is retained with the specimens.

Peripheral Arteries May Be Reliable Indicators of Coronary Vascular Disease.

Atherosclerosis is a stronger predictor for ischemic cardiovascular events than traditional risk factors such as race, age, sex, history, and metabolic profile. Previous research had primarily used ultrasound; however, we performed a study using histopathology to more accurately grade atherosclerosis development using the American Heart Association's grading scale. We cross-sectioned 13 different arteries from 48 cadavers and placed them into three separate groups based on anatomic location: central arteries, peripheral arteries, and carotid arteries. The central artery group included arteries that are non-palpable and commonly lead to ischemic diseases when occluded. The peripheral artery group included arteries that are accessible to palpation. The carotid artery group included branches of the carotid artery. We investigated whether a centrally located atherosclerotic vessel was associated with atherosclerosis of a specific peripheral artery. We hypothesized a correlation between carotid, peripheral and central arteries that may point to specific arteries that are more effective to analyze clinically when assessing cardiovascular risk. We observed a correlation between pathology in the left coronary artery and bifurcation of the carotid artery (r = 0.37 P ≤ 0.016), two arteries known to be implicated in ischemic stroke and ischemic heart disease. Importantly, our study demonstrates that the radial artery, a peripheral vessel, exhibited a positive correlation between both the pathologic left coronary (r = 0.33 P ≤ 0.041) and bifurcation of the carotid arteries (r = 0.34 P ≤ 0.025). Therefore, we propose investigating the radial artery as a clinically accessible location to monitor with ultrasound when assessing a patient's risk for ischemic cardiovascular disease. Anat Rec, 300:1230-1239, 2017. © 2017 Wiley Periodicals, Inc.

Regional quantitative histological variations in human oral mucosa.

Oral mucosa demonstrates regional variations that reflect contact with food during mastication. Though known qualitatively, our aim was to quantitatively assess regions to establish a measurable baseline from which one could compare in pathological and comparative studies, in which the abrasiveness of diets may differ. We assessed variations in the epithelial-connective tissue junction (rete ridges counts), collagen organization within the lamina propria, and elastin composition of the lamina propria of 15 regions of the labial (buccal) gingiva, lingual gingiva, vestibule, and palate. All characteristics varied more between regions within the same individual than between individuals. Lingual gingiva had high rete ridges counts, high level of collagen organization, and moderate elastin composition compared to other regions. The labial gingiva had few rete ridges, high collagen organization, and low elastin. The vestibule had the fewest average of rete ridges, least organized collagen, and high elastin. The hard palate had the highest average of rete ridges, high collagen organization, and the lowest elastin content. The soft palate conversely had the smallest average of rete ridges, moderate collagen organization, and the highest elastin composition. Our results indicate that comparison of these quantitative histological differences is warranted only for collagen organization and elastin composition. Differences in rete ridges counts were not statistically significant. Most histological characteristics observed were not significantly different between dentulous and edentulous cadavers, and the group containing all individuals. An exception was the level of collagen fiber organization within the lamina propria, which was higher in most regions when teeth were present.

A histological investigation into the correlation of central retinal artery atherosclerosis with the systemic circulation.

Current research suggests that retinal arterial changes such as arteriovenous nicking and arterial narrowing are pathologically distinct from atherosclerosis. Other studies have found a positive correlation between retinal changes and systemic atherosclerosis. However, limited recent histopathologic evidence assessing atherosclerosis in the central retinal artery exists. We investigated atherosclerosis in the central retinal artery and how it correlates to atherosclerosis in the carotid and coronary arteries. Twenty-two cadavers (12 males, 10 females) were dissected, obtaining one orbit, one carotid artery, and one coronary artery from each. The specimens were sectioned and stained for histologic analysis by light microscopy using hematoxylin and eosin, Verhoeff's elastic, and Gomori's trichrome stains. The degree of atherosclerosis was graded from absent, or I (least severe) to VIII (most severe) based on the current American Heart Association guidelines. Atherosclerotic changes were present in the central retinal, coronary, and carotid arteries. A positive correlation was found between the central retinal artery and the carotid artery (r = 0.23, P = 0.15), the central retinal artery and the coronary artery (r = 0.31, P = 0.08), and the carotid artery and the coronary artery (r = 0.45, P = 0.02). The presence of low-grade atherosclerosis in the central retinal artery is prevalent in a population of advanced vascular disease. However, central retinal artery atherosclerotic lesion severity is poorly correlated with disease severity in the carotid and coronary arteries.

Osteological associations with unique tooth development in manatees (Trichechidae, Sirenia): a detailed look at modern Trichechus and a review of the fossil record.

Modern manatees have a unique type of tooth development, continually forming identical new molars in the posterior end of each quadrant of their mouths, and then progressively moving teeth anteriorly, only to reabsorb roots and spit out worn crowns. This process is not only developmentally complex, but requires space in the oral cavity that imposes its own limitations on other uses of that space. To gain a clearer understanding of the anatomical constraints on the evolution of this unique developmental process, we identified the specialized craniodental features in modern Trichechus that permit this specialization using visual observation and CT. Furthermore, to better understand the evolution of these traits, we review the fossil record of trichechids for these traits, including CT analysis of the skull of Miosiren kocki, a possible early member of the family from the Early Miocene of Belgium.

Decompression syndrome and the evolution of deep diving physiology in the Cetacea.

Whales repetitively dive deep to feed and should be susceptible to decompression syndrome, though they are not known to suffer the associated pathologies. Avascular osteonecrosis has been recognized as an indicator of diving habits of extinct marine amniotes. Vertebrae of 331 individual modern and 996 fossil whales were subjected to macroscopic and radiographic examination. Avascular osteonecrosis was found in the Oligocene basal odontocetes (Xenorophoidea) and in geologically younger mysticetes, such as Aglaocetus [a sister taxon to Balaenopteridae + (Balaenidae + Eschrichtiidae) clade]. These are considered as early "experiments" in repetitive deep diving, indicating that they independently converged on their similar specialized diving physiologies.