DiceCT Analysis of the Extreme Gouging Adaptations Within the Masticatory Apparatus of the Aye-Aye (Daubentonia madagascariensis)

Relative to all other primates, the aye-aye (Daubentonia madagascariensis) exists at the extremes of both morphology and behavior. Its specialized anatomy—which includes hypselodont incisors and highly derived manual digits—reflects a dietary niche, unique among primates, which combines tap-foraging with gouging to locate and extract wood-boring larvae. Here, we explore the impact of this extreme dietary ecology upon the masticatory musculature of this taxon with reference to a second, similarly sized but highly generalist lemuriform—the mongoose lemur (Eulemur mongoz). Using non-destructive, high-resolution diffusible iodine-based contrast-enhanced computed tomography techniques, we reconstruct the three-dimensional volumes of eight masticatory muscles, and, for the first time in strepsirrhines, isolate and visualize their constituent muscle fascicles in situ and in three dimensions. Using these data, we report muscle volumes, forces, and fascicle lengths from each muscle portion, as well as their orientation relative to two standardized anatomical planes. Our findings demonstrate the overbuilt nature of the aye-aye's masticatory apparatus, in which each muscle possesses an absolutely and relatively larger muscle volume and PCSA than its counterpart in the mongoose lemur. Likewise, for several adductor muscles, aye-ayes also possess relatively greater fascicle lengths. Finally, we note several unusual features within the lateral pterygoid of the aye-aye—the muscle most responsible for jaw protrusion—that relate to force maximization and reorientation. As this jaw motion is critical to gouging, we interpret these differences to reflect highly specific specializations that facilitate the aye-aye's extreme subsistence strategy. Anat Rec, 2019. © 2019 American Association for Anatomy Anat Rec, 303:282–294, 2020. © 2019 American Association for Anatomy     

Cerium oxide nanoparticles attenuate monocrotaline induced right ventricular hypertrophy following pulmonary arterial hypertension

Cerium oxide (CeO₂) nanoparticles have been posited to exhibit potent anti-oxidant activity which may allow for the use of these materials in biomedical applications. Herein, we investigate whether CeO₂ nanoparticle administration can diminish right ventricular (RV) hypertrophy following four weeks of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH). Male Sprague Dawley rats were randomly divided into three groups: control, MCT only (60 mg/kg), or MCT + CeO₂ nanoparticle treatment (60 mg/kg; 0.1 mg/kg). Compared to the control group, the RV weight to body weight ratio was 45% and 22% higher in the MCT and MCT + CeO₂ groups, respectively (p < 0.05). Doppler echocardiography demonstrated that CeO₂ nanoparticle treatment attenuated monocrotaline-induced changes in pulmonary flow and RV wall thickness. Paralleling these changes in cardiac function, CeO₂ nanoparticle treatment also diminished MCT-induced increases in right ventricular (RV) cardiomyocyte cross sectional area, β-myosin heavy chain, fibronectin expression, protein nitrosylation, protein carbonylation and cardiac superoxide levels. These changes with treatment were accompanied by a decrease in the ratio of Bax/Bcl2, diminished caspase-3 activation and reduction in serum inflammatory markers. Taken together, these data suggest that CeO₂ nanoparticle administration may attenuate the hypertrophic response of the heart following PAH.     

Radiation Dose Reduction during Uterine Fibroid Embolization Using an Optimized Imaging Platform

Purpose

To assess radiation dose reduction during uterine fibroid embolization (UFE) using an optimized angiographic processing and acquisition platform.

Anthropometric indicators of body composition in young adults: relation to size at birth and serial measurements of body mass index in childhood in the New Delhi birth cohort

BACKGROUND: South Asians have a muscle-thin but adipose body phenotype and high rates of obesity-related disease. Adult body composition may be predictable in early life. OBJECTIVE: Anthropometric indexes of adult body composition were examined in relation to birth size and body mass index (BMI) during childhood. DESIGN: A population-based cohort of 1526 men and women aged 26-32 y in Delhi, India, who were measured sequentially from birth until 21 y of age were followed up. Adult weight, height, skinfold thicknesses, and waist and hip circumferences were measured. BMI and indexes of adiposity (sum of skinfold thicknesses), central adiposity (waist-hip ratio), and lean mass (residual values after adjustment of BMI for skinfold thicknesses and height) were derived. RESULTS: Mean birth weight was 2851 g. As children, many subjects were underweight-for-age (>2 SDs below the National Center for Health Statistics mean; 53% at 2 y), but as adults, 47% were overweight, 11% were obese, and 51% were centrally obese (according to World Health Organization criteria). Birth weight was positively related to adult lean mass (P < 0.001) and, in women only, to adiposity (P = 0.006) but was unrelated to central adiposity. BMI from birth to age 21 y was increasingly strongly positively correlated with all outcomes. BMI and BMI gain in infancy and early childhood were correlated more strongly with adult lean mass than with adiposity or central adiposity. Higher BMI and greater BMI gain in late childhood and adolescence were associated with increased adult adiposity and central adiposity. CONCLUSIONS: Birth weight and BMI gain during infancy and early childhood predict adult lean mass more strongly than adult adiposity. Greater BMI gain in late childhood and adolescence predicts increased adult adiposity.     

Our experience with aortic root replacement using hand-sewn composite valve graft

Background The purpose of this study is to examine our experience with aortic root replacement using composite valve grafts in patients with proximal aortic disease. Methods and Results Since 1986, 16 patients underwent aortic root replacement using composite valve grafts for various indications which were Marfan's syndrome with annuloaortic ectasia (n=2), aortic regurgitation with ascending aortic aneurysm (n=3), aortic stenosis with regurgitation with poststenotic dilatation (n=9) and progressive aortic dilatation following AVR (n=2). There were 12 males and 4 females. The age range varied between 19 years and 52 years. The choice of conduit was a custom made valved graft using a monoleaflet tilting disc valve (Medtronic Hall valve=11, St Vincent's valve=3, TTK Chitra=1 and Bjork Shiley Valve=1) placed in a Dacron graft (Hemashield=13, Verisoft Cooley=3) prepared using a 4-0 polypropylene suture. The average time taken to construct a valved graft was 20 min±8 min. The coronary implantation was by isolated button technique. There was no size mismatch encountered in any patients. Postoperative bleeding necessitated a delayed sternal closure in 3 patients and re-exploration in another 2. The immediate operative mortality was 2, the cause being ventricular arrhythmia in one and cerebrovascular accident in other. Follow-up period ranged from 2 months to 16 years with a median follow-up of 12 months. One patient had an asymptomatic perigraft collection and no intervention was needed. There was no valve related complications in any of these patients. There was one late death of unknown cause. Conclusions Aortic root replacement using a custom made composite graft offers excellent long-term results, with negligible mortality rate and prosthesis related complications. Custom made grafts make this conduit easily affordable in our country and their performance is comparable to other available composite grafts.